KR20060086494A - Display - Google Patents

Abstract

The present display device is configured to perform display by dimming a predetermined display surface, and interposing between the light source 12 emitting light L1 having a first wavelength and the light source and the display surface, and entering the light source. A fluorescent plate 22 is provided which converts at least a part of the light of the first wavelength in to the light L2 of the second wavelength longer than the first wavelength and emits the light toward the display surface.

Display device, display surface, light source, wavelength, fluorescent plate

Description

Display device

1 is a perspective view showing a collective display lamp to which a first embodiment of a display device according to the present invention is applied.

Fig. 2 is an exploded perspective view of a unit display lamp constituting the collective display lamp of Fig. 1.

3 is a schematic cross-sectional view of the unit display lamp of FIG. 2.

4 is a schematic diagram showing optical characteristics of a fluorescent plate of the unit display lamp of FIG. 2.

Fig. 5 is a perspective view showing an illuminated push button switch to which a second embodiment of a display device according to the present invention is applied.

6 is a partial perspective exploded view of FIG. 5.

7 is a schematic cross-sectional view showing a third embodiment of a display device according to the present invention.

Fig. 8 is a schematic cross-sectional view showing the configuration of a fluorescent plate in a fifth embodiment of a display device according to the present invention.

9 is a schematic cross-sectional view showing an improved example of the display device of FIG. 8.

Fig. 10 is a schematic cross-sectional view showing the configuration of a fluorescent plate in a sixth embodiment of a display device according to the present invention.

11 is a graph showing a spectrum of light in a blue LED light-emitting device and block light in the experimental examples of the first to sixth embodiments.

Fig. 12 is a graph showing the spectrum of fluorescence emitted from the green fluorescent plate when light from a blue LED light-emitting element is incident on the green fluorescent plate in the experimental examples of the first to sixth embodiments.

13 is a graph showing the spectrum of fluorescence emitted from the orange fluorescent plate when light from a blue LED light emitting device is incident on an orange fluorescent plate in the experimental examples of the first to sixth embodiments.

14 is a graph showing the spectrum of fluorescence emitted from the red fluorescent plate when light from a blue LED light emitting element is incident on a red fluorescent plate in the experimental examples of the first to sixth embodiments.

15 is a graph showing the spectrum of light from green LED light emitting devices and block light in the experimental examples of the first to sixth embodiments.

Fig. 16 is a graph showing the spectrum of fluorescence emitted from the green fluorescent plate when light from a green LED light-emitting device is incident on a green fluorescent plate in the experimental examples of the first to sixth embodiments.

Fig. 17 is a graph showing the spectrum of fluorescence emitted from the orange fluorescent plate when light from the green LED light emitting device is incident on the orange fluorescent plate in the experimental examples of the first to sixth embodiments.

18 is a graph showing the spectrum of fluorescence emitted from the red fluorescent plate when light from a green LED light emitting element is incident on a red fluorescent plate in the experimental examples of the first to sixth embodiments.

Fig. 19 is a cross-sectional view showing a configuration of a unit display lamp to which a seventh embodiment of a display device according to the present invention is applied.

20 is a plan view of an LED unit constituting the unit display lamp of FIG. 19.

21 is a side view of the LED unit of FIG. 20.

22 is a plan view of a prism sheet constituting the unit display lamp of FIG. 19.

23 is a cross-sectional view of the prism sheet of FIG. 22.

24 is a perspective view showing a prism installed in the prism sheet of FIG. 22.

25 is a cross-sectional view showing a unit display lamp to which an eighth embodiment of a display device according to the present invention is applied.

26 is a cross-sectional view showing a unit display lamp to which a ninth embodiment of the display device according to the present invention is applied.

Fig. 27 is a plan view of an LED unit constituting the unit display lamp of Fig. 26;

Fig. 28 is a circuit diagram showing the electrical configuration of the LED unit of Fig. 27;

29 is a cross-sectional view of a portion of the unit display lamp of FIG. 26 on which a variable resistor is provided.

FIG. 30 is a partial bottom view of FIG. 29.

Fig. 31 is a block diagram showing the electrical configuration of an LED unit provided in a unit display lamp to which a tenth embodiment of a display device according to the present invention is applied.

Fig. 32 is an exploded perspective view of a unit display lamp to which a twelfth embodiment of the display device according to the present invention is applied.

33 is a schematic cross-sectional view of the unit display lamp of FIG. 32.

34 is a plan view of a light source provided in the unit display lamp of FIG. 32.

FIG. 35 is a diagram showing the structure of the unit display lamp of FIG. 32 centering on a light source and a power supply circuit thereof.

FIG. 36 is a schematic diagram showing optical characteristics of a fluorescent plate provided in the unit display lamp of FIG. 32 with respect to light having a first wavelength.

37 is a schematic diagram showing optical characteristics of light having a wavelength different from the first wavelength of the fluorescent plate provided in the unit display lamp of FIG. 32.

FIG. 38 is a schematic diagram showing optical characteristics when both light of a first wavelength and light of a separate wavelength are incident on a fluorescent plate provided in the unit display lamp of FIG. 32.

39 is a diagram showing a modified example of a power supply circuit for a light source in the unit display lamp of FIG. 32;

Fig. 40 is a perspective view showing an illuminated push button switch to which a thirteenth embodiment of a display device according to the present invention is applied.

41 is a partial perspective exploded view of FIG. 40.

42 is a schematic cross-sectional view showing a fourteenth embodiment of a display device according to the present invention.

43 is a schematic diagram showing the optical characteristics of the fluorescent plate laminate of FIG. 42 with respect to light having a wavelength different from that of the first wavelength.

FIG. 44 is a schematic diagram showing the optical characteristics of the fluorescent plate laminate of FIG. 42 when both light of a first wavelength and light of a separate wavelength are incident.

Fig. 45 is a graph showing the spectrum of fluorescence emitted from the yellow fluorescent plate when light of various wavelengths is incident on the yellow fluorescent plate in the experimental examples of the twelfth to fourteenth embodiments.

Fig. 46 is a graph showing the spectrum of fluorescence emitted from the green fluorescent plate when light of various wavelengths is incident on the green fluorescent plate in the experimental examples of the twelfth to fourteenth embodiments.

Fig. 47 is an exploded perspective view of a unit display lamp to which a fifteenth embodiment of the display device according to the present invention is applied.

48 is a schematic cross-sectional view of the unit display lamp of FIG. 47.

49 is a schematic diagram showing optical characteristics of a fluorescent plate provided in the display device of FIG. 47.

Fig. 50 is a partial perspective exploded view of an illuminated push button switch to which a sixteenth embodiment of a display device according to the present invention is applied.

51 is a schematic cross-sectional view showing a seventeenth embodiment of a display device according to the present invention.

Fig. 52 is a diagram showing how light of a first wavelength is converted into light of a second wavelength by the wavelength conversion plate of the seventeenth embodiment.

Fig. 53 is a cross-sectional view showing the configuration of a filter in the eighteenth embodiment of the display device according to the present invention.

Fig. 54 is a cross-sectional view showing the configuration of a fluorescent plate and a filter in the nineteenth embodiment of the display device according to the present invention.

55 is a graph showing a spectrum of light emitted by a blue LED light-emitting device in the experimental examples of the 15th to 19th embodiments.

Fig. 56 is a graph showing a spectrum of fluorescence (light of a second wavelength) obtained from light (light of a first wavelength) from a blue LED light-emitting element in an experimental example of the 15th to 19th embodiments.

Fig. 57 is a graph showing a spectrum of fluorescence (light of a second wavelength) obtained from light (light of a first wavelength) from a blue LED light-emitting device in an experimental example of the 15th to 19th embodiments.

Fig. 58 is a longitudinal sectional view of a display to which an LED sphere according to a twentieth embodiment of the present invention is applied.

Fig. 59 is an enlarged longitudinal sectional view of an LED sphere according to a twentieth embodiment of the present invention.

60 is a cross-sectional view taken along line III-III in FIG. 59.

61 is a diagram for explaining the effects of the twentieth embodiment.

Fig. 62 is an enlarged longitudinal sectional view of an LED sphere according to a twenty-first embodiment of the present invention.

63 is a diagram for explaining the effects of the twenty-first embodiment.

Fig. 64 is an enlarged longitudinal sectional view of an LED sphere according to a twenty-third embodiment of the present invention.

Fig. 65 is a split perspective view of a unit display lamp to which a 24th embodiment of the display device according to the present invention is applied.

66 is a schematic cross-sectional view of the unit display lamp of FIG. 65.

67 is a partial cross-sectional view of a wavelength conversion member provided in the unit display lamp of FIG. 65.

68 is a schematic diagram showing as an example the optical characteristics of the wavelength conversion member of FIG. 67;

69 is a schematic diagram showing as an example the optical characteristics of the wavelength converting member of FIG. 67.

FIG. 70 is a schematic diagram showing as an example the optical characteristics of the wavelength converting member of FIG. 67; FIG.

71 is a side view of another wavelength conversion member provided in the unit display lamp of FIG. 65.

72 is a schematic cross-sectional view of a display device according to the related art of the present invention.

Fig. 73 is a partial cross-sectional view of a diffusion plate provided in the display device of Fig. 72;

74 is a graph showing a spectrum of light emitted by a blue LED light emitting device in each experimental example of the 24th embodiment.

75 is a diagram showing chromaticity coordinates of the color of display light obtained in each experimental example of the twenty-fourth embodiment.

76 is a graph showing light transmission characteristics of a filter layer provided in each of the wavelength conversion members A, B, and C according to the first experimental example of the 24th embodiment.

Fig. 77 is a diagram showing a spectrum of display light generated from light having a blue wavelength by the wavelength conversion members A, B, and C according to the first experimental example of the twenty-fourth embodiment.

78 is a graph showing the optical characteristics of the wavelength converting member D according to the second experimental example of the twenty-fourth embodiment.

79 is a graph showing light transmission characteristics of a filter layer provided in the wavelength conversion member E according to the third experimental example of the 24th embodiment.

80 is a graph showing light transmission characteristics of a filter layer provided in the wavelength conversion member F according to the third experimental example of the 24th embodiment.

FIG. 81 is a diagram showing a spectrum of display light generated from light having a blue wavelength by each of the wavelength conversion members E and F according to the third experimental example of the 24th embodiment.

82 is a graph showing optical characteristics of a filter layer used in the display device of FIG. 72 according to the related art of the present invention.

The present invention is a display device that guides light from a light source to a predetermined display surface, such as an industrial indicator (especially for industrial use), and provides optical display over the entire display surface. A display device (LED) consisting of a lighting device that illuminates the entire surface, a light emitting device body formed by mounting a light emitting diode element (LED) in a flat shape, and a dome-shaped cap member mounted thereon. Gu) is about.

In order to safely operate systems in factories, etc., it is necessary for workers to operate, control, manage, and operate their machinery while monitoring the condition of machines and facilities at all times. For this reason, an indicator indicating the status of the system is installed on the control panel or the like in the factory. Such indicators have a light-transmitting plate (signal plate) on which characters or symbols such as "on", "off", "operating", and "abnormal", and a picture pattern are displayed. And, the system's Depending on the operating state, optical display is performed on the entire display surface by lighting the light source installed behind their name plate, and the operator can visually recognize it. A single-piece indicator that displays a message, a collective indicator that displays multiple information, and a push-button switch with an indicator that adds operation functions for systems such as operation and stop, etc. There is this.

That is, the indicator light is a device that communicates the state of the system to an operator on a plate surface such as a control panel, and is at an important position as a man-machine interface for the operator to safely operate the system.

By the way, there is a request to display color classification in such an indicator light. Even so, usually, since a plurality of indicators are installed on one control panel, etc., information (characters, symbols, picture patterns, etc.) is not displayed in a single color. This is because the visibility of the indicator light can be improved by displaying.

However, in the light sources currently usable for an indicator light, the color type of light emitted by the light source is limited, and color classification display is also limited.

In addition, in such indicators, the shape of the luminous body of the light source (a dot shape in the case of an LED light-emitting device, and a filament shape or a spherical outline of a light bulb in the case of an incandescent light bulb) are not recognized from the outside, so that the operator It is necessary to make it easy to recognize the content of the display of the back (that is, the content of characters, etc.).

In addition, it is also possible to use a halogen lamp as a light source in order to obtain an indicator of pure color matching, but in this case, there is a problem that the amount of heat generated is large and the life of the light source is shortened, and thus it cannot be applied to actual use in the current state.

In addition, if the color of the indicator at the time of lighting (the color of the display light) and the color of the indicator at the time of extinguishing (the exterior color) are different, there is a problem that the color of the indicator at the time of lighting cannot be distinguished from the state at the time of turning off. In this way, if the color of the indicator light at the time of lighting is not distinguished, it is difficult to know which color of the indicator is turned off when each indicator is turned off, especially when a plurality of different types of color indicators are provided on the control panel, etc. It is difficult to intuitively recognize what it means in color information.

In addition, in the art, a conventional incandescent light bulb is used as a light source, and the display color obtained by transmitting light from this light source to a milky white plate is referred to as "white", but the color temperature of the incandescent light bulb can be said to be white. No, it is far from pure white obtained when red, green, and blue LED light-emitting elements are integrated as a light source or a halogen lamp is used, and the above request is not satisfied.

The present invention is intended to overcome the above-described problems in a conventional display device, and an object of the present invention is to provide a display device capable of performing optical display in an arbitrary color.

Another object of the present invention is to provide a display device capable of achieving high brightness and high diffusivity of a display in a high dimension.

Another object of the present invention is to provide a display device and a lighting device capable of preventing fluctuations in the amount of light on a display surface or a light-transmitting surface.

In addition, another object of the present invention is to improve productivity and reduce cost, while at the same time obtaining an arbitrary color display light by a single color light source, and from the color of the display surface when the light source is turned off. A display device capable of easily recognizing the color of a display surface (display light) when a light source is on is provided.

In addition, an object of the present invention is to provide a display device (LED sphere) capable of emitting light of a minute color other than white, which is difficult to emit light with a single LED light emitting device.

The present invention is a display device that displays by dimming a predetermined display surface, comprising: a light source emitting light of a first wavelength, and the first light source interposed between the light source and the display surface and incident thereon. A fluorescent plate is provided for converting at least a part of light of a wavelength into light L2 of a second wavelength having a wavelength longer than that of the first wavelength and emitting toward the display surface.

According to the present invention, at least a part of the light of the first wavelength from the light source incident on the fluorescent plate interposed between the light source and the display surface is converted into light of a second wavelength longer than the first wavelength to be converted to the display surface. Since it emits toward the direction, it is possible to easily change the color of the light of the second wavelength or the ratio of the light of the second wavelength emitted from the fluorescent plate to the light of the first wavelength transmitted through the fluorescent plate by simply changing the type of the fluorescent plate to be used. As a result, it is possible to easily obtain display lights of various colors for dimming the display surface from light of a single first wavelength. As a result, since the light source needs to be equipped with one type of light source that emits light of the first wavelength, for example, productivity is improved and lower cost compared to changing the combination of types of LED light emitting devices used according to the color of the display light. I can plan anger.

In addition, the display device according to the present invention further includes a filter interposed between the fluorescent plate and the display surface to transmit at least some of the light emitted from the fluorescent plate toward the display surface, and when the light source is turned on, the The color of the light transmitted through the filter to dim the display surface and the external color of the filter that substantially defines the color of the display surface when the light source is turned off are substantially identical or approximated.

According to the present invention, since the color of light that passes through the filter and dims the display surface when the light source is turned on and the external color of the filter that defines the color of the display surface when the light source is turned off are substantially identical or approximated, the light source is The color of the display surface when the light source is on (i.e., the color of the display light that dims the display surface) can be easily recognized intuitively from the color of the display surface when it is turned off, and surface illumination is achieved. The meaning of the display device can be intuitively understood more intuitively than the color of the display surface when the display device is turned off.

In addition, by installing a filter, only light having a desired color component (wavelength component) can be extracted from the components of light emitted from the fluorescent plate, and the color of light emitted from the fluorescent plate can be easily converted or corrected. As a result, display lights of various colors can be easily obtained by changing the combination of the fluorescent plate and the filter.

Further, in the display device according to the present invention, the fluorescent plate and the filter are integrated as a wavelength conversion member including a phosphor layer functioning as the fluorescent plate and a filter layer functioning as the filter.

According to the present invention, since the fluorescent plate and the filter are integrated as a wavelength converting member having a phosphor layer and a filter layer, the number of parts can be reduced, and the assembly process can be simplified and the cost can be reduced.

In addition, one display device of the present invention is a surface-dimmed display device that performs display by dimming a predetermined display surface, and (a) a first luminous body that emits light of a first wavelength, and a separate display device different from the first wavelength. A light source having a second luminous body emitting light of a wavelength, (b) an incident surface receiving light from the light source and an emission surface facing the display surface, and a part of the light of the first wavelength is more than the first wavelength. It is equipped with a fluorescent plate that converts into light of a long second wavelength.

Further, it is characterized in that the color of light emitted from the emission surface can be changed by changing the lighting state of the first and second luminous bodies.

As the fluorescent plate, one that substantially transmits light of the separate wavelength may be used.

On the other hand, the other display device of the present invention is a surface-dimmed display device that displays by dimming a predetermined display surface, (a) a first light-emitting body emitting light of a first wavelength, and a separate wavelength different from the first wavelength. A light source including a first light-emitting body emitting light of, (b) an incident surface receiving light from the light source and an emission surface facing the display surface side, and a part of the light of the first wavelength is less than the first wavelength. And a phosphor (wavelength converting member) formed by stacking a plurality of fluorescent plates that convert light of a plurality of long wavelengths.

And, by changing the lighting state of the first luminous body and the second luminous body, it is characterized in that the color of the light emitted from the exit surface can be changed.

Also in this configuration, the phosphor may be used to substantially transmit light of the separate wavelength.

In the one and the other display devices of the present invention, it is preferable to further provide a light diffusion member for diffusing the light on an optical path of light traveling from the light source toward the display surface, and the light diffusion member is a hologram diffusion plate. You can do it.

In addition, it is also possible to incorporate a light diffusing member into the fluorescent plate instead.

As a particularly characteristic application state of the present invention, the first luminous body is a semiconductor light emitting device emitting blue light as light of the first wavelength, and the fluorescent plate is a part of the blue light emitted from the semiconductor light emitting device. It has a fluorescence characteristic of absorbing and emitting yellow light as light of the second wavelength, and the color of light for optical display when only the first luminous body is turned on may be made to be substantially white.

In addition, when only the first luminous body of the light sources emit light, light of a first chromatic color is emitted from the emission surface. When the light is emitted and both of the first and second light-emitting bodies are turned on, the light of a third chromatic color is emitted by the additive color mixing of the first chromatic light and the second chromatic light. It can also be done so that it is emitted from the cotton.

In addition, when one of the first and second luminous bodies is turned on, and when both of the first and second luminous bodies are turned on, the luminance of the first luminous body and the second luminous body By further providing the luminance variable part for changing the luminance, it is possible to prevent a situation in which the luminance of the display light changes greatly according to the switching of the lighting state.

Further, in the display device according to the present invention, the light source has a first luminous body emitting light of the first wavelength and a second luminous body emitting light of a wavelength different from the first wavelength, and the second light source The color of the light emitted from the fluorescent plate may be changed by making light emitted by the first and second luminous bodies incident on the fluorescent plate and changing the lighting states of the first luminous body and the second luminous body.

Other objects and features of the present invention will become apparent from the following description.

<First Example>

Fig. 1 is a perspective view showing a set of indicator lights to which a first embodiment of a display device (surface dimming display device) according to the present invention is applied. When this collective display lamp 1 is actually installed and used, the upper side of Fig. 1 is set toward the operator side, but for convenience of illustration, the display side is shown facing up.

This collective indicator 1 is configured by attaching a plurality of unit indicators 10a, 10b, ..., 10i to the inside of the housing 2. These unit indicators 10a, 10b, ..., 10i differ in their size and display color, but the basic configuration is the same, and each unit indicator 10a, 10b, ..., 10i is the present invention. It corresponds to the first embodiment of the surface dimming display device according to the first embodiment. In addition, in the following, the configuration of the unit display lamp 10a will be described, and the description of other configurations will be omitted.

2 is an exploded perspective view of the unit display lamp 10a. In addition, FIG. 3 is a schematic cross-sectional view of the unit display lamp 10a of FIG. 2. In the unit display lamp 10a, a plurality of light sources 12 (LED light emitting devices) are arranged in a matrix form inside a case 11 made of resin having a window W. Each light source 12 is mounted on the main surface of the printed circuit board and accommodated in the case 11, and its light emitting portion is exposed toward the upper surface side of the case 11. The LED light-emitting elements constituting these light sources 12 emit light having a wavelength (first wavelength) assigned to the unit display lamp 10a.

Meanwhile, a frame 13 is disposed around the upper surface of the window W. The frame 13 is fitted into the housing 2 of FIG. 1 through the case 11 and is joined together. The composite plate 20 is fitted to the frame 13. This composite plate 20 is from the light source 12 side,

(1) a holographic diffusion plate 21 having a holographic surface 21a,

(2) a fluorescent plate (22),

(3) Name plate made of transparent resin (23),

(4) a transparent resinous cover plate (24),

It has a structure that overlaps four. Characters or symbols to be displayed are written on the name plate 23.

Among these, the fluorescent plate 22 is provided in accordance with the main features of the present invention. The fluorescent plate 22 receives the light of the first wavelength from the light source 12 and transmits a part of the incident light as it is toward the display surface side (the upper side of the drawing), and at the same time transmits the light of the first wavelength to the rest of the light of the first wavelength. Accordingly, light having a second wavelength longer than the first wavelength is emitted, and light having the second wavelength is emitted to the display surface side. Fig. 4 schematically shows this optical phenomenon.

4 is a schematic diagram showing the optical properties of the fluorescent plate 22. The fluorescent plate 22 is formed by molding a fluorescent material (color conversion paint) having a fluorescent property described later as a transparent resin material into a mixed sheet form or a plate form, and reference numeral FM in the drawing denotes a fluorescent material. When this fluorescent material FM is excited by light L1 of a first wavelength indicated by a solid line in the figure and returns to the ground state, light L2 of a second wavelength longer than the first wavelength ( It has a fluorescence characteristic of emitting a broken line). In addition, this fluorescence characteristic will be described with reference to a specific example in the next experimental example of the sixth embodiment.

As a whole of the fluorescent plate 22 having such fluorescent characteristics, when the light L1 of the first wavelength from the light source 12 enters the incident surface 22a through the hologram diffusion plate 21, as shown in the figure. Likewise, a part of the incident light L1 is emitted from the emission surface 22b to the display surface as it is, and the remainder of the incident light L1 is absorbed by the fluorescent material FM and has a second wavelength longer than the first wavelength (fluorescent light) ( L2) is emitted to emit light from the emission surface 22b.

Next, it returns to FIG. 2 and the description continues. The light of the first and second wavelengths emitted from the fluorescent plate 22 as described above is guided to the display surface through the name plate 23 and the cover plate 24, thereby performing optical display.

As described above, according to the indicator (surface dimming display) 10a according to the present embodiment, the color (display color) of light for optical display on the display surface side is a combination of the first and second wavelengths, that is, the light source 12 Since it is defined by a combination of the types of the fluorescent plate 22 and, by adjusting this combination, it is possible to optically display in an arbitrary color. In addition, the combination of the light source 12 and the fluorescent plate 22 will be described with reference to a specific example in the following experimental example of the sixth embodiment.

In addition, as shown in FIG. 4, the incident surface 22a and the emission surface 22b of the fluorescent plate 22 face each other, and the fluorescent plate 22 is further so that the incident surface 22a faces the light source 12. Since it is arranged, the following effects are obtained.

In other words, as a comparative example, when optical display is performed by directly guiding light from a light source to the display surface side through a name plate, etc., the operator observing from the display surface is positioned in the deeper part of the light-emitting surface. It feels like doing. On the other hand, when the fluorescent plate 22 is interposed, light of the second wavelength is emitted from the fluorescent plate 22, so that the light of the second wavelength gives the operator the feeling that the light emitting surface is floating close to the display surface. As a result, the visibility can be improved compared to the comparative example.

Further, in the present embodiment, a hologram diffusion plate 21 is provided to diffuse the light from the light source 12 at a predetermined diffusion angle, and then the diffused light is incident on the fluorescent plate 22. This hologram diffusion plate 21 is provided with a diffusion surface (hologram surface) 21a using a diffraction phenomenon of light on one side of a transparent member, and diffusion can be performed without attenuation of light. For this reason, in the unit display lamp 10a, it is possible to prevent the shape of the light source 12 from being recognized from the outside without providing an element such as a milky white name plate that substantially absorbs or attenuates light. I can. That is, according to the present embodiment, "higher brightness of display" and "higher light diffusion" can be achieved at the same time.

By the way, as described above, one of the most desired colors as a display color from the prior art is "pure white". In this regard, in the indicator 10a according to the present embodiment, in order to obtain "pure white", an LED light emitting device that emits blue light is used as the light source 12, and the blue light emitted from the light source 12 is used. A fluorescent plate 22 having a fluorescence characteristic of emitting yellow light (light of a second wavelength) by a part of light (light of the first wavelength) may be provided.

In this case, for example, it is not necessary to use a light source packaged with LED light emitting devices emitting red, green and blue light, and a single LED light emitting device can be used as a light source, so a white indicator (surface-illuminated display device) Can be provided inexpensively. In addition, since the light source 12 has a small amount of heat, when a halogen lamp is used as a light source, it is possible to extend the life of the indicator lamp without causing any problems related to heat generation of the light source.

In addition, since white optical display is possible as described above, a filter that transmits only a specific wavelength component to an appropriate position (e.g., the surface of the name plate 23) on the emission surface 22b (Fig. 4) side of the fluorescent plate 22 By installing, it is possible to change the display color of the indicator light 10a to a color corresponding to the filter. As a result, in the indicator light 10a provided with the light source 12 of the blue LED light-emitting element and the fluorescent plate 22 having a fluorescent characteristic that emits yellow light by a part of the blue light from the light source 12, By further disposing a filter in the vicinity of the emission surface 22b of the fluorescent plate 22, the color of light for optical display can be changed from white to a color substantially defined by the filter. Therefore, by appropriately changing the filter, the display color of the indicator lamp 10a can be changed to any color.

<Second Example>

Fig. 5 is a perspective view showing an illuminated push button switch to which a second embodiment of a display device (surface-illuminated display device) according to the present invention is applied, and Fig. 6 is a partial perspective exploded view of Fig. 5. Among them, FIG. 5 shows as an example a case where the illuminated pushbutton switch 40 is installed on a panel 70 such as a control panel. The illuminated push button switch 40 is of a separate type, and its components are roughly divided into an operation unit 60 and a contact unit 50. The operation unit 60 is inserted into the mounting hole 71 from the front side (operation side) of the panel 70. The contact unit 50 is connected to the central portion 62 of the operation unit 60 from the rear side of the panel 70.

Further, the contact unit 50 has a built-in switch contact, and at the same time, the LED unit light source 54 is mounted. This LED unit light source 54 has a substantially cylindrical shape, and a plurality of LED light emitting elements 54L are arranged at the top of the LED unit light source 54. In addition, a ring 55 used when installing the operation unit 60 on the panel 70 is provided separately, and a lock lever for fixing the connection after connecting the operation unit 60 and the contact unit 50 (lock lever) (53) is provided. This contact unit 50 is electrically connected to a necessary device through a terminal 52.

On the other hand, the operation unit 60 is composed of a main body 61 and a push unit 80 of the operation unit. An insertion groove 62a is provided in the central portion 62 of the operation portion main body 61 so as to be fitted with the shelf portion 51a formed in the inner wall of the mounting hole 51H. Then, the center portion 62 of the operation unit 60 is inserted into the mounting hole 51H of the contact unit 50 while the shelf portion 51a is engaged with the insertion groove 62a.

When the insertion is complete and the lock lever 53 is rotated, the protrusion (not shown) of the lock lever 53 disposed in the shelf portion 51a rotates, thereby making it orthogonal to the insertion groove 62a. The protrusion is inserted into the installed fixing groove 62b so that the operation unit 60 and the contact unit 50 are connected and fixed. Further, a male threaded surface 62s is formed in the central portion 62, and the operation unit main body 61 is mounted on the panel 70 by engaging with the female threaded surface 55S of the ring 55. As shown in FIG.

A rectangular input port 63 is formed in the upper part of the operation part main body 61, and the push part 80 is accommodated in the input port 63. The details of the push unit 80 will be described later, but the push unit 80 opens and closes (on, off) the contact point in the contact unit 50 by manually pressing down the push unit 80 after assembly. The LED unit light source 54 is turned on or off in response to opening and closing of this contact point. Alternatively, as another configuration, the LED unit light source 54 may be turned on or off in response to a signal from an external device (controller, etc.) to which the illuminated pushbutton switch 40 is connected.

The operation surface 80S of the push unit 80 is light-transmitting, and characters or the like displayed inside the operation surface 80S are dimmed by light from the LED unit light source 54 to be recognized from the outside.

The disassembled state of the push unit 80 is shown in FIG. 6. In the figure, the lower part of the push part 80 is made of an empty base body 81 having a perforated hole W1, on which,

(1) holographic diffusion plate (82),

(2) a fluorescent plate 83 having the same fluorescent characteristics as the fluorescent plate 22 in the first embodiment,

(3) Colorless and transparent name plate formed of a resin such as acrylic (84)

They are stacked in this order. And, as a member defining the operation surface 80S of FIG. 5, a colorless and transparent front plate 85 made of, for example, an atrium is provided. In addition, necessary characters and the like are written on the name plate 84.

The LED unit light source 54 is inserted to face the diffusion plate 82 through the hole W1. Accordingly, when the LED unit light source 54 is turned on, the light of the first wavelength from the LED light emitting element 54L enters the incident surface 83a of the fluorescent plate 83 through the hologram diffusion plate 82. In addition, a part of the incident light proceeds to the display surface as it is (the upper side of the drawing), while the remainder of the incident light is converted to light of a second wavelength longer than the first wavelength by a fluorescent material (not shown) of the fluorescent plate 83. As a result, light of the first and second wavelengths is emitted from the emission surface. The outgoing light of these first and second wavelengths sequentially passes through the name plate 84 and the front plate 85 to perform surface-dimmed display in display colors defined by the first and second wavelengths on the display surface side.

Thus, in the second embodiment, as in the first embodiment, the color of light for optical display on the display surface side depends on the combination of the first and second wavelengths, that is, the combination of the types of the LED unit light source 54 and the fluorescent plate 83. Therefore, it is possible to optically display in any color by adjusting this combination.

Further, as shown in Fig. 6, the fluorescent plate 83 is arranged so that the incident surface 83a and the emission surface of the fluorescent plate 83 face each other, and the incident surface 83a faces the LED unit light source 54. Therefore, as in the first embodiment, visibility can be improved by giving the operator a visual effect such that the light emitting surface is raised toward the display surface.

In addition, by providing the hologram diffusion plate 82, it is possible to simultaneously achieve “high brightness of the display” and “high diffusivity of light” as in the first embodiment.

In addition, a fluorescent plate having a fluorescent characteristic that emits yellow light by a part of blue light emitted from the LED unit light source 54 as the fluorescent plate 83 while using a blue LED light emitting device as the LED light emitting device 54L. By using, as in the first embodiment, the display color of the indicator light of the illuminated push button switch can be set to white with a small amount of heat.

In addition, in the illuminated pushbutton switch capable of optical display of white, the color of light for optical display is changed from white to a color substantially defined by the filter by additionally placing a filter in the vicinity of the emission surface of the fluorescent plate 83. I can. Therefore, by appropriately changing the filter, the display color of the indicator light of the illuminated push button switch can be changed to any color.

<Third Example>

7 is a schematic cross-sectional view showing a third embodiment of a display device (surface dimming display device) according to the present invention. The major difference between the surface-illuminated display device of this embodiment and the embodiment shown in Fig. 4 is that in the first embodiment, a single fluorescent plate 22 is provided to emit light of a second wavelength. In the third embodiment, a phosphor (wavelength converting member) 90 formed by stacking two fluorescent plates 91 and 92 is provided to emit light having a third wavelength as well as a second wavelength. In addition, other basic configurations are the same.

In this phosphor 90

(1) A second wavelength longer than the first wavelength due to the remainder of the incident light L1 while transmitting a part of the light L1 of the first wavelength from the light source 12 as it is to the exit surface side (the upper side of the drawing). A fluorescent plate 91 that emits light of light L2 toward the exit surface side,

(2) A part of the light L1 and the light L2 from the fluorescent plate 91 are transmitted to the exit surface as it is, while the light L3 of a third wavelength longer than the first wavelength due to the remainder of the light L1 A fluorescent plate 92 that emits light toward the emission surface side,

It is composed of stacked ones.

For this reason, when the light L1 of the first wavelength from the light source 12 is given to the incident surface 90a of the phosphor 90, a part of the light L1 of the first wavelength in the fluorescent plate 91 is unchanged. At the same time as it transmits to the side 92, the remainder of the incident light L1 is absorbed by the fluorescent material FM1, and light L2 of a second wavelength longer than the first wavelength is emitted from each of the fluorescent materials FM1, and the fluorescent plate 92 Proceed to the) side. And, in the fluorescent plate 92 receiving the first and second wavelengths of light (L1, L2), a part of the first wavelength of light (L1) and the second wavelength of light (L2) are At the same time, the light of the first wavelength L1 is absorbed by the fluorescent material FM2 while the light is emitted from the emission surface 90b to the display side (the upper side of the drawing), and the first wavelength is absorbed by the fluorescent material FM2. Light L3 of a third wavelength longer than that is emitted and is emitted from the exit surface 90b to the display surface side. In this way, optical display is performed on the entire display surface by the light of the first to third wavelengths (L1 to L3).

In addition, a part of the light L2 of the second wavelength is absorbed by the fluorescent material FM2, and light (not shown) of a fourth wavelength longer than the second wavelength is emitted from the fluorescent material FM2, and the exit surface It is emitted toward the display surface at (90b).

As described above, according to the third embodiment, the display color on the display surface side is defined by light of the first to third wavelengths (L1 to L3). Therefore, the display color is defined by light of two wavelengths (L1, L2). Compared to the first embodiment, it is possible to control the display color more precisely.

In addition, in the third embodiment, the phosphor 90 is arranged so that the incident surface 90a and the exit surface 90b of the phosphor 90 face each other, and the incident surface 90a faces the light source 12. Therefore, as in the first and second embodiments, a visual effect such as that the light emitting surface of the indicator (surface dimming display device) floats toward the display surface can be provided to the operator, thereby improving visibility.

Further, in the above embodiment, the phosphor 90 is formed by stacking two fluorescent plates 91 and 92, but the phosphor 90 may be formed by stacking three or more fluorescent plates. In addition, the order of lamination of the fluorescent plate is arbitrary.

<Fourth Example>

By the way, in the first to third embodiments, the fluorescent plates 22, 83, 91, 92 are formed by molding the fluorescent material (FM) as a transparent resin material into a mixed sheet form or a plate form. Most of the fluorescence (lights generated by the fluorescent plates 22, 83, 91, and 92, respectively) from the fluorescent plate travels inside the fluorescent plate according to the law of total reflection and is guided to its cross section, so that it is emitted in a concentrated state. For this reason, the amount of fluorescence emitted from the emission surface to the display surface side tends to decrease. In this regard, by forming a fluorescent plate by mixing a diffusion material in addition to the fluorescent material (FM), fluorescence can be diffused inside the fluorescent plate, and fluorescence emitted from the fluorescent plate is prevented from concentrating on the cross section of the fluorescent plate. It can be emitted from the side.

<Fifth Example>

When a diffusion material is mixed in the fluorescent plate as in the fourth embodiment, light is absorbed by the light diffusion material, resulting in loss, which is a hindrance to the high brightness of the display. Therefore, as shown in FIG. 8, a fluorescent material (FM) is thinly applied to the other side of the hologram diffusion plate 21 (the surface on which the hologram surface 21a is provided), and this coating film is used as the fluorescent plate 101. I can. According to the fluorescent plate 101 thus formed, the fluorescence generated in the fluorescent plate 101 can be efficiently emitted to the display surface side without mixing the light diffusion material.

In addition, in order to protect the film-shaped fluorescent plate 101 formed in this way, as shown in FIG. 9, a transparent plate 102 is disposed on the fluorescent plate 101, and the transparent plate 102 and the hologram diffusion plate 21 are The fluorescent plate 101 may be inserted.

<Sixth Example>

Fig. 10 is a schematic cross-sectional view showing a sixth embodiment of a display device (surface dimming display device) according to the present invention. The difference between this apparatus and the apparatus of the first embodiment shown in Fig. 3 is that the fluorescent plate 111 having the functions of the fluorescent plate 22 and the name plate 23 of the first embodiment is provided. That is, the fluorescent plate 111 is a transparent resin material formed of a fluorescent material and a diffusion material in the form of a mixed sheet or plate, and at the same time, characters or symbols to be displayed on the surface thereof are written. In addition, other configurations are the same as in the first embodiment.

<Modification of the first to sixth embodiments>

In addition, in the first embodiment, the hologram diffusion plate 21 is disposed between the light source 12 and the fluorescent plate 22, and in the second embodiment, the hologram diffusion plate 82 is connected to the LED unit light source 54 and the fluorescent plate 83. ), and in the sixth embodiment, the hologram diffusion plate 21 is disposed between the light source 12 and the fluorescent plate 11, respectively, but the placement position of the hologram diffusion plate is not limited to this, and the light source It can be arranged at any position as long as it is on the optical path of light traveling toward the display surface. However, when visibility is considered, it is preferable to place a gram diffusion plate on the side of the light source with respect to the fluorescent plate. Even so, in the case of such arrangement, the light passing through the hologram diffuser plate as described above is diffused at a predetermined diffusion angle and proceeds in various directions, which increases the probability of hitting the fluorescent material by entering the fluorescent plate. It is because it emits light from the whole, and visibility can be improved.

In addition, in the above embodiment, a hologram diffusion plate is used as a diffusion member for diffusing light traveling from the light source toward the display surface on the optical path, but a conventionally known light diffusion plate may be used instead of the hologram diffusion plate. do.

In addition, in the above embodiment, a light diffusion means such as a hologram diffusion plate is provided, but the light diffusion member does not have any influence on the display color, so the light diffusion member is not an essential component for controlling the display color. It is preferable that it is provided in order to make it easier for the operator or the like to recognize the contents of the display such as characters.

<Experimental examples of the first to sixth embodiments>

Next, as a fluorescent plate, three types of a green fluorescent plate, an orange fluorescent plate and a red fluorescent plate were prepared, and light from a blue LED light emitting element (light having a spectrum indicated by a dashed-dotted line in Fig. 11) was incident on the incident surface of each fluorescent plate. At the same time, it was investigated how the incident light was converted into fluorescence having a spectrum by receiving the fluorescence emitted from the surface orthogonal to the incident surface.

Fig. 12 is a graph showing a spectrum of fluorescence emitted from the green fluorescent plate (dashed-dotted line) when light from a blue LED light-emitting device is incident on a green fluorescent plate. Fig. 13 is a graph showing a spectrum of fluorescence emitted from the orange fluorescent plate (dashed-dotted line) when light from a blue LED light-emitting device is incident on an orange fluorescent plate. 14 is a graph showing a spectrum of fluorescence emitted from the red fluorescent plate (dashed-dotted line) when light from a blue LED light-emitting device is incident on a red fluorescent plate.

For reference, when block light (ultraviolet light source) having a spectrum indicated by a solid line in FIG. 11 is incident on a green fluorescent plate, an orange fluorescent plate, and a red fluorescent plate, the spectrum of fluorescence emitted from each fluorescent plate is shown in FIGS. 12 to 14, respectively. Is shown by a solid line.

As shown in Figs. 12 to 14, by injecting light of the first wavelength from the blue LED light emitting device onto the fluorescent plate, light (fluorescent light) having a second wavelength longer than the first wavelength can be emitted from the fluorescent plate. Accordingly, as described in the above embodiment, light of the first wavelength and the second wavelength is guided toward the display surface, and optical display is achieved with a display color determined by the combination of the first and second wavelengths over the entire display surface. Can be done.

Even when light from a red LED light-emitting element (light having a spectrum indicated by a dashed-dotted line in Fig. 15) is incident on the fluorescent plate, the same results as above are obtained. Fig. 16 is a graph showing a spectrum of fluorescence emitted from the green fluorescent plate when light from a red LED light-emitting device is incident on a green fluorescent plate (one-dot chain line). Fig. 17 is a graph showing a spectrum of fluorescence emitted from the orange fluorescent plate (dashed-dotted line) when light from a green LED light-emitting device is incident on an orange fluorescent plate. Fig. 18 is a graph showing a spectrum of fluorescence emitted from the red fluorescent plate (dashed-dotted line) when light from a green LED light-emitting device is incident on a red fluorescent plate.

In addition, for reference, spectrums of fluorescence emitted from each fluorescent plate when block light having a spectrum indicated by a solid line in FIG. 15 is incident on a green fluorescent plate, an orange fluorescent plate, and a red fluorescent plate are shown by solid lines in FIGS. 16 to 18, respectively.

Next, a blue LED light-emitting element is provided as the light source 12 constituting the indicator (surface-illuminated display device) shown in Fig. 4, while a yellow fluorescent plate is provided as the fluorescent plate 22. It was tested whether it was optically displayed.

Table 1 is a table showing the display colors in this combination.

x y Light source(12) Blue LED 0.133 0.149 Fluorescent plate(22) Yellow fluorescent plate 0.287 0.323

In the same table and the following Tables 2 to 4, the columns "x" and "y" represent the x and y components of the chromaticity coordinates when expressed using the color expression according to the CIEXYZ color system. In addition, the values in the "x" and "y" columns of each table represent the luminous color for the light source 12, and the colors of the light emitted from the fluorescent plates for the fluorescent plates 22, 91 and 92 as x and y components, respectively. It is divided and expressed.

As can be seen from Table 1, the light emitted from the fluorescent plate 22 is the display color on the display surface side, the x component is 0.287, and the y component is 0.323.

Table 2 is a table showing the display colors when a blue LED light-emitting element is used as the light source 12 constituting the indicator (surface-illuminated display device) shown in Fig. 4 and a green fluorescent plate is used as the fluorescent plate 22. .

x y Light source(12) Blue LED 0.133 0.149 Fluorescent plate(22) Green fluorescent plate 0.409 0.555

As can be seen from the table, the light emitted from the fluorescent plate 22 is the display color on the display surface side, the x component is 0.409 and the y component is 0.555.

Next, a blue LED light-emitting element is provided as the light source 12 constituting the indicator (surface-illuminated display device) shown in Fig. 7, while a yellow fluorescent plate and a red fluorescent plate are provided as fluorescent plates 91 and 92, respectively, and this combination. In which display color the entire display surface was optically displayed was tested.

Table 3 is a table showing the display colors in this combination.

x y Light source(12) Blue LED 0.133 0.149 Fluorescent plate(91) Yellow fluorescent plate 0.287 0.323 Fluorescent plate(92) Red fluorescent plate 0.428 0.223

As can be seen from the table, the light emitted from the fluorescent plate 92 is the display color on the display surface side, and the x component is 0.428 and the y component is 0.223.

Next, a blue LED light-emitting element is provided as the light source 12 constituting the indicator (surface-illuminated display device) shown in Fig. 7, while a green fluorescent plate and an orange fluorescent plate are provided as the fluorescent plates 91 and 92, respectively, and the display surface is It was tested in which display color the whole was optically displayed.

Table 4 is a table showing the display colors in this combination.

x y Light source(12) Blue LED 0.133 0.149 Fluorescent plate(91) Green fluorescent plate 0.200 0.631 Fluorescent plate(92) Orange fluorescent plate 0.445 0.517

As can be seen from the table, the light emitted from the fluorescent plate 92 is the display color on the display surface side, and the x component is 0.445 and the y component is 0.517.

As the above experimental results show, by combining the type of light source and the type of fluorescent plate, the display color on the display surface side can be controlled with a high degree of freedom.

<Seventh Example>

19 is a cross-sectional view showing a seventh embodiment of a display device (surface dimming display device) according to the present invention. The major difference between the surface-illuminated display device (unit indicator) 10a according to this embodiment from the first embodiment shown in Figs. 2 and 3 is that the prism sheet 213 described later is used as a light diffusing member. This is a point that further improves the light dispersion efficiency.

The LED unit 212 is installed in the case 211 of the unit indicator 10a, and in the opening 211a of the case 211, in order from the LED unit 212 side,

① Prism sheet 213 (sheet member),

② fluorescent plate 214,

③ diffusion plate 215,

④ Name plate (216),

⑤ cover plate (217),

Are being inserted in a stacked state. Then, the surface on the outer surface side of the cover plate 217 serves as the display surface 218. Here, the prism sheet 213, the fluorescent plate 214, the diffusion plate 215, the name plate 216, and the cover plate 217 have a quadrangular plate shape of the same size, and the prism sheet 213 and the fluorescent plate ( 214 is intended to cover the entire surface of the display surface 218.

A step portion 211b protruding inward is provided on the sidewall of the opening 211a of the case 211. The step portion 211b regulates the amount of the prism sheet 213, the fluorescent plate 214, the diffusion plate 215, the name plate 216, and the cover plate 217 inserted into the opening 211b. .

20 is a plan view of the LED unit 212, and FIG. 21 is a side view thereof.

On the upper surface of the LED unit 212, in order to efficiently guide the light emitted by the LED light-emitting element 212a (light source) to the display surface 218 side, a mesh-shaped cross-linking portion 212b is provided. Two LED light-emitting elements 212a are provided in each of four LED installation areas surrounded by the bridging portion 212b. The inclined surface of the bridge portion 212b surrounding the four LED mounting regions is a reflective surface so as to efficiently guide the light from the LED light-emitting element 212a to the display surface 218 side. Each LED light-emitting device 212a is configured to emit light of a first wavelength (here, light of a blue wavelength). Further, power is supplied to each of the LED light emitting elements 212a through a terminal 212C at the bottom of the LED unit 212.

Fig. 22 is a plan view of a prism sheet 213, which is a characteristic point of the present invention, and Fig. 23 is a cross-sectional view. The prism sheet 213 is a rectangular plate-shaped member having a thickness of about 1 mm made of a transparent resin such as acrylic. The incidence surface 213a of this prism sheet 213 toward the LED unit 212 side is a flat surface, and a plurality of minute prisms 213c are provided on the exit surface 213b toward the display surface 218 side. Is formed.

Each prism 213c provided in the prism sheet 213 has a shape of a corner cube in which the angle of a rectangular parallelepiped is cut so that the bottom surface becomes a regular triangle, as shown in FIG. 24. For this reason, the three surfaces of the upper surface of the prism 213c are the prism surfaces 219 of a right-angled isosceles triangle. The size S of the prism 213c is preferably several hundred microns or less, and more preferably several tens of microns or less.

Such a prism 213c is set to the same size, and the prism surface 219 is directed toward the display surface 218 so that the bottom surfaces of an equilateral triangle of the adjacent prism 213c are in close contact (i.e., adjacent prism ( 213c) They are arranged in an orderly manner so that they share and touch the three sides of the bottom surface forming an equilateral triangle. As a result, the exit surface 213b of the prism sheet 213 is covered by a plurality of prisms 213c without gaps.

Next, the optical characteristics of the prism sheet 213 will be described. When the light L emitted from the LED light emitting device 212a enters the center C of the adjacent six prisms 213b through the incident surface 213a as shown in FIG. 22, the incident light ( L) is dispersed in six directions by the action of refraction or the like in the prism sheet 213 to emit light. For this reason, when the LED light-emitting element 212a is viewed from the emission surface 213b side through the prism sheet 213, one LED light-emitting element 212a is seen as six.

Returning to FIG. 19 and continuing the description, the fluorescent plate 214 is formed by mixing a fluorescent material that receives light of a first wavelength in the substrate and emits light (fluorescence) of a second wavelength longer than the first wavelength. Here, a fluorescent material that receives light of a blue wavelength (first wavelength) and emits light of a yellow wavelength (second wavelength) is mixed.

The fluorescent plate 214 has an incident surface that receives light from the LED unit 212 and an exit surface that faces toward the display surface 218. When the blue wavelength light from the LED unit 212 enters the fluorescent plate 214 through the incident surface, part of the incident light passes through the fluorescent plate 214 as it is, and the remaining light is yellow wavelength light by the fluorescent material. It is converted into and emitted from the fluorescent plate 214. That is, from the emission surface of the fluorescent plate 214, white light consisting of blue wavelength light and yellow wavelength light is emitted, and this white light is used as display light.

The diffusion plate 215 is obtained by mixing an inorganic or organic material for diffusing light into a substrate made of the resin. For this reason, the light incident on the diffusion plate 215 is diffused and emitted. Further, on the name plate 216 made of a transparent resin, characters or symbols to be displayed are written by printing or engraving. In addition, although the diffusion plate 215 is used here, instead of using the diffusion plate 215, a diffusion material for diffusing light is mixed in the above-described fluorescent plate 214, so that the fluorescent plate 214 has a function of diffusing light. You can do it.

The light emitted from the LED light emitting element 212a of the LED unit 212 enters the prism sheet 213, is dispersed by the prism sheet 213, and enters the fluorescent plate 214. Since the prism sheet 213 has an effect of dispersing incident light in 6 directions as described above, even a small number of LED light emitting devices 212a irradiate light to the fluorescent plate 214 with a plurality of LED light emitting devices 212a. The same effect as existing is obtained, and by this, the amount of light incident on the fluorescent plate 214 is made uniform on the incidence surface. Here, since eight LED light-emitting elements 212a are used, the same effect as irradiating light to the fluorescent plate 214 with 48 LED light-emitting elements is obtained.

In addition, the light incident on the prism sheet 213 is refracted in the prism sheet 213 and dispersed in multiple directions, and is emitted from the prism sheet 213 at an angle in a direction extending toward the end. For this reason, the light from the LED light emitting element 212a is also incident on the peripheral portion of the fluorescent plate 214 which is a shade of the blocking portion 211b provided in the opening 211a of the case 211.

When light having a blue wavelength is incident on the fluorescent plate 214 in this way, white light used as display light is emitted from the fluorescent plate 214 as described above. This white display light is incident on the diffusion plate 215 and is diffused by the diffusion plate 215 to become more uniform, and the front surface of the display surface 218 on the outer surface of the cover plate 217 through the name plate 216 Is emitted with a uniform amount of light and a uniform color, thereby performing flat display on the display surface 218. At this time, the information written on the name plate 216 is displayed on the display surface 218 by white display light.

As described above, according to the present embodiment, since the light emitted by the LED light emitting device 212a is dispersed by the prism sheet 213 to enter the fluorescent plate 214, the opening 211a of the case 211 Light from the LED light-emitting element 212a can also be incident on the peripheral portion 214a of the fluorescent plate 214 in the shade of the step portion 211b, and the number of LED light-emitting elements 212a is installed on the fluorescent plate 214 And it is possible to remove the fluctuation in the amount of light that is small compared to the area of the display surface 218 but caused by the influence of the reflection light of the bridge part 212b of the LED unit 212, and the fluorescent plate 214 is used as the LED light emitting device 212a. A uniform amount of light can be irradiated on the entire surface of the device. As a result, it is possible to prevent fluctuations in the amount of light and color fluctuations in the white display light on the display surface 218, so that good display can be performed.

In addition, since the white display light emitted from the fluorescent plate 214 is made more uniform by the diffusion plate 215, a more highly uniform display light can be obtained.

In addition, since the prism sheet 213 is a resin molded product, it is suitable for mass production and can be manufactured at an inexpensive price.

In addition, in the present embodiment, a fluorescent material in which a fluorescent material that emits yellow wavelength light by receiving blue wavelength light is mixed with the substrate is used, but as in the first embodiment described above, the LED light emitting device The combination of the light of the first wavelength emitted from 212a and the light of the second wavelength emitted from the fluorescent plate 214 may be controlled to obtain display light of various colors.

In addition, a filter for blocking the blue wavelength light emitted by the LED light emitting device 212a and transmitting the light plate emitted by the fluorescent material in the fluorescent plate 214 is interposed between the fluorescent plate 214 and the display surface 218. It may be provided so that only the light emitted by the fluorescent plate 214 is used as the display light, whereby the color of the light emitted by the fluorescent plate 214 can be extracted purely as the color of the display light.

In addition, in the present embodiment, the collective indicator 1 of FIG. 1 described above is composed of a plurality of unit indicators 10a, 10b....10i, but the entire collective indicator 1 is constituted by a single indicator. At the same time, the LED unit 212 may be formed in the form of a one board, and the display surface portion thereof may be divided as shown in FIG. 1 to provide a name plate or the like.

<Eighth Example>

25 is a cross-sectional view of an indicator light 10a to which a second embodiment of the display device of the present invention is applied. This indicator 10a is a configuration in which the fluorescent plate 214 is removed from the indicator 10a according to the seventh embodiment described above, and the same reference numerals are attached to portions corresponding to the indicator 10a of FIG. Is omitted.

Even in the indicator 10a of this embodiment, since the light from the LED unit 212 is guided to the display surface 218 side through the prism sheet 213, the light from the LED unit 212 is reduced to a uniform amount of light. The same effects as those of the seventh embodiment can be obtained, such as the ability to emit light from the entire surface of the display surface 218 and to perform good display without fluctuation.

<Ninth Example>

26 is a cross-sectional view of an indicator 10a to which the ninth embodiment of the display device of the present invention is applied, and FIG. 27 is a plan view of an LED unit 241 provided in the indicator 10a. This indicator 10a is described above, except that the LED unit 241 having three types of LED light emitting elements 242, 243, 244 emitting light of red, green, and blue wavelengths is used. It has the same configuration as the indicator light 10a of the eighth embodiment, and portions corresponding to each other are denoted by the same reference numerals, and the description thereof is omitted.

In the LED unit 241 of the present embodiment, as shown in FIG. 27, three types of LED light-emitting elements ( 242, 243, 244) are excreted in the form of a matrix, three at a time.

28 is a circuit diagram of the LED unit 241, three types of LED light emitting elements 242, 243, 244 are connected in parallel to the DC power supply 245, and at the same time, each type of LED light emitting elements 242, Between the 243, 244 and the DC power supply 245, variable resistors 246, 247, 248 (current control unit) and protection resistors 249, 250, 251 are provided in series. Therefore, by changing the resistance values of the variable resistors 246, 247, 248, the values of the currents supplied to each type of LED light emitting devices 242, 243, 244 can be independently adjusted.

In addition, in the example shown in Fig. 28, only one LED light emitting element 242, 243, 244 of each type is connected to each variable resistor 246, 247, 248, but a plurality of LED light emitting elements 242, 243 , 244) may be connected in series. In addition, components other than the DC power supply 245 in the circuit configuration of FIG. 28 are provided in the LED unit 241, and the DC power supply 245 is installed outside the indicator 10a.

29 is a cross-sectional view of a portion of the indicator light 10a in which variable resistors 246, 247, and 248 are installed, and FIG. 30 is a bottom view thereof. Variable resistors (246, 247, 248) and protection resistors (249, 250, 251) are provided in the case 252 of the LED unit 241 of the substrate 253 for installation of the LED light emitting elements (242, 243, 244). Excreted on the back side.

Further, the variable resistors 246, 247, 248 are provided with rotation shafts 246a, 247a, 248a for changing the resistance value, and accordingly, the indicator 10a and the case 211 of the LED unit 241 The through holes 211c and 252a are provided on the bottom surface of the 252 so that the rotation shafts 246a, 247a, 248a can be externally adjusted by a minus driver or the like. Further, the variable resistors 246, 247, 248 may be provided outside the indicator lamp 10a to connect electric wires.

In the indicator 10a configured as described above, the light obtained by overlapping the light emitted by the red, green, and blue LED light emitting elements 242, 243, 244 is used as the display light. Therefore, by changing the resistance value of the variable resistors 246, 247, 248, the value of the current supplied to each type of LED light emitting device 242, 243, 244 is adjusted, and each type of LED light emitting device 242, By adjusting the amount of light emitted by the 243 and 244, it is possible to convert the color of the display light into an arbitrary color such as white.

The light emitted from each of the LED light emitting devices 242, 243, 244 enters the prism sheet 213 and is sufficiently dispersed in the prism sheet 213 to be uniform. After incident on 215 and diffused by the diffusion plate 215 to be further uniform, the light is emitted from the front surface of the display surface 218 of the cover plate 217 through the name plate 216.

As described above, according to the present embodiment, the effect of obtaining display light of an arbitrary color is obtained simply by adjusting the resistance values of the variable resistors 246, 247, 248, The same effects as those of the seventh embodiment are obtained, such as the occurrence of fluctuations can be prevented and good display can be performed.

In addition, in the case of overlapping light from multiple types of light sources emitting light of different colors to obtain light of a desired color, it is necessary to increase the distance between the display surface 218 and the light source in order to obtain light of a uniform color. Therefore, there is a problem that the light becomes dark because of this, but in this embodiment, the light from the LED light emitting devices 242, 243, 244 is efficiently dispersed and uniformized by the prism sheet 213, so that the LED light emitting device ( The distance between 242, 243, 244 and the display surface 218 can be reduced, and sufficient brightness can be obtained even with a small number of LED light emitting devices 242, 243, 244.

In addition, since the current value is controlled by the variable resistors 246, 247, 248 and the amount of light emitted by each type of LED light emitting device 242, 243, 244 is adjusted, the desired color of display light is obtained. Can be easily adjusted.

In addition, since the resistance value of the variable resistors 246, 247, 248 can be adjusted from the outside of the device, it is easy to adjust the resistance value, and since the resistance value can be adjusted while viewing the display state, it is easy to finely adjust the color tone of the display light. .

<Tenth Example>

31 is a block diagram of an LED unit provided in an indicator light to which the tenth embodiment of the display device of the present invention is applied. This indicator is a current controller that changes the current value of the current supplied to each type of LED light-emitting elements 242, 243, 244 in response to a command from the control unit 26, as an alternative to the variable resistors 246, 247, 248 ( It has the same configuration as the indicator light 10a of the ninth embodiment, except that 262, 263, and 264 are provided, and the corresponding parts are denoted by the same reference numerals, and the description thereof is omitted.

For example, in the control unit 261, data corresponding to the current value of the current to be supplied to each type of LED light emitting device 242, 243, 244 when generating the display light of each type of a plurality of colors of the display light to be configured Together, the color of the display light generated by the control unit 261 is determined from among a plurality of colors by inputting a command corresponding to the desired color to the control unit 261 from the outside.

When the color of the display light is determined to be a predetermined color, the controller 261 transmits to each type of LED light emitting device 242, 243, 244 through the current controllers 262, 263, 264 based on the previously registered data. The current value of the supplied current is adjusted, whereby the ratio of the amount of light emitted by the LED light emitting elements 242, 243, 244 of each type is adjusted, and display light of a predetermined color is obtained.

Also in this embodiment, the same effect as in the ninth embodiment is obtained, such as that a display light of an arbitrary color is obtained while preventing light amount fluctuation or color fluctuation, and at the same time, it is necessary to specifically adjust the variable resistors 246, 247, 248. Without it, the effect of automatically obtaining display light of a desired color is obtained.

In addition, it is possible to change the color of the display light continuously or stepwise, and the degree of freedom of the display method can be expanded.

<Modification of the 7th to 10th embodiments>

In addition, in the seventh to tenth embodiments described above, the prism sheet 213c formed on the exit surface 213b of the prism sheet 213 is in the shape of a corner cube, but the space above the exit surface 213b is If it can be covered without, it is not limited to a corner cube, and it may be a general triangular weight, or other vertebral shape such as a square weight or a hexagonal weight.

In addition, in the seventh to tenth embodiments described above, the name plate 216 is disposed toward the display surface 218 of the diffusion plate 215, but may be disposed toward the LED units 212 and 241 of the diffusion plate 215. do.

In addition, although the name plate 216 is used in the seventh to tenth embodiments described above, information may be transmitted by removing the name plate 216 and turning the indicator light 10a on, off, or blinking. .

In addition, in the seventh to tenth embodiments described above, the prism 213c of the exit surface 213b of the prism sheet 213 is exposed on the surface, but the prism 213c is made of a transparent resin having a lower refractive index than the prism sheet 213. ) May be covered.

In addition, in the seventh to tenth embodiments described above, a case in which the display device of the present invention is applied to an indicator light has been described, but the pressure control unit may be applied to an illuminated push button switch that lights according to the on and off states. do.

<Eleventh Example>

Further, as an eleventh embodiment according to the present invention, it is considered that the indicator lamps 10a of the seventh to tenth embodiments described above are used as a lighting device. In this lighting device, illumination is performed using light irradiated in a plane from the front of the display surface 218 (transmission surface), and good illumination can be performed by unchanged light irradiated from the display surface 218. . Also, in this case, the name plate 216 is removed.

<Principle of the invention according to the twelfth to fourteenth embodiments>

In the present invention, attention is paid to the wavelength conversion function of the fluorescent plate. In general, a fluorescent plate has a characteristic of converting a part of light of a wavelength shorter than its inherent fluorescent wavelength (light of the first wavelength) into light of a fluorescent wavelength (light of the second wavelength), while , When light having a wavelength longer than the fluorescent wavelength enters, there is a property that the incident light is transmitted as it is without performing substantial wavelength conversion for it.

Therefore, if light of a shorter wavelength and light of a longer wavelength than that of the fluorescent plate are selectively incident on the fluorescent plate, when light of a short wavelength is incident on the fluorescent plate, additive color mixed light of the light of the short wavelength and the light of the fluorescent wavelength When a light of a long wavelength is incident on a fluorescent plate, the light of the long wavelength itself becomes a display light. In addition, when both short-wavelength light and long-wavelength light are incident on a fluorescent plate, a mixed color of short-wavelength light, fluorescent-wavelength light, and long-wavelength light becomes a display color.

For this reason, it is possible to switch the display colors among a plurality of colors by switching them between each other.

Here, it is important that the color corresponding to the false-color mixing of the light of the short wavelength and the light of the fluorescent wavelength is not the luminous color of the luminous body itself. Accordingly, a color in which the luminous body itself cannot emit light can be included among a plurality of colors switchable with each other.

Particularly, if blue light is used as the light of the first wavelength and yellow phosphor is used as the phosphor, yellow light is obtained as light of the second wavelength, and substantially pure white is obtained as additive color mixture thereof. This white light is different from that produced by using the three primary colors of “blue”, “red” and “green”, and the color fluctuation from pure white does not occur due to the lapse of time of the luminous body of a specific color. Even if deterioration occurs over time, only the luminance decreases. Therefore, it is of special significance to include pure white as one of a plurality of switchable display colors in the present invention.

In addition, it is also possible to extend the above-described principle to selectively or simultaneously cause a plurality of lights shorter than the fluorescent wavelength and having different wavelengths to be incident on the fluorescent plate.

In this case, among the plurality of switchable colors, a plurality of colors other than a color that can be generated only by the light-emitting body may be included.

<Twelfth Example>

Fig. 32 is an exploded perspective view of a unit display lamp 10a to which a twelfth embodiment of the display device (surface dimming display device) according to the present invention is applied. Further, Fig. 33 is a schematic cross-sectional view of the unit display lamp 10a of Fig. 32. In the unit display lamp 10a, a plurality of light sources 312 (four LED units in the illustrated example) are arranged in a matrix form inside a case 311 made of resin having a window W. Further, each light source 312 is mounted on the main surface of the printed circuit board and accommodated in the case 311 of FIG. 32, and the light emitting portion thereof is exposed toward the upper surface of the case 311.

Each of the above light sources 312 is arranged in a matrix form alternately with a plurality of types of luminous bodies (S1, S2) having different luminous colors (a plurality of types of LED light emitting devices in this embodiment) as shown in a plan view in FIG. 34 It is composed of. The first luminous body S1 in one of the typical examples is a blue LED that generates light of a blue wavelength as a first wavelength. In addition, the second luminous body S2 may be a red LED that generates light of a red wavelength as light of a separate wavelength different from the first wavelength.

FIG. 35 is a schematic diagram including an A-A cross section of the light source 312 (LED unit) in FIG. 34. Electric power from the power supply PW is supplied in parallel to the switches SW1 and SW2. Of these, each of the first luminous bodies S1 among the two types of luminous bodies S1 and S2 constituting the light source 312 is electrically connected to the first switch SW1. In addition, each of the second light-emitting bodies S2 is electrically connected to the second switch SW2.

Therefore, if only the first switch SW1 is turned ON, the plurality of first luminous bodies S1 are turned on so that the light L1 of the first wavelength (refer to FIG. 33) is emitted from the light source 312 and the second When only the switch SW2 is turned ON, the plurality of second light emitters S2 are turned on and light L0 of different wavelengths is emitted from the light source 12. When both the first and second switches SW1 and SW2 are turned on, the mixed light of the first wavelength light L1 and the separate wavelength light L0 is emitted from the light source 312. When both the first and second switches SW1 and SW2 are turned off, substantially no light is emitted from the light source 312. Fig. 33 shows this situation, and only the light of the first wavelength (L1), the light of the separate wavelength (L0), or the mixed light of the light of the first wavelength (L1) and the light of the separate wavelength (L0) ( It schematically shows that L1+L0) is selectively emitted from the light source 312.

Meanwhile, a frame 313 is disposed around the upper surface of the window W in FIG. 32. The frame 313 is fitted into the housing 2 of FIG. 1 through the case 311, and the composite plate 320 is fitted to the frame 313. This composite plate 320, from the light source 312 side,

(1) a holographic diffusion plate 321 having a holographic surface 321a,

(2) Fluorescent plate 322,

(3) Name plate made of transparent resin (323),

(4) a transparent resin cover plate 324,

It has a structure that overlaps four. Characters or symbols to be displayed are written on the name plate 323.

Among these, the fluorescent plate 322 has the same configuration as the fluorescent plate 22 according to the first embodiment described above, and when the light L1 of the first wavelength from the first luminous body S1 in the light source 312 is received. A part of the incident light is transmitted as it is toward the display surface side (upper side of the figure), and the remainder of the second wavelength light L2, which is longer than the first wavelength, is emitted to emit light of the second wavelength ( L2) is emitted toward the display surface (see Fig. 36).

As a whole of the fluorescent plate 322 having such fluorescent characteristics, when light L1 of the first wavelength from the light source 312 enters the incident surface 322a through the hologram diffusion plate 321, as shown in FIG. Likewise, a part of the incident light L1 is emitted from the emission surface 322b to the display surface as it is, and the remainder is absorbed by the fluorescent material FM and has a second wavelength longer than the first wavelength (fluorescent light) L2. ) Is emitted from the emission surface (322b).

On the other hand, this fluorescent plate 322 does not have a substantial wavelength conversion function for light having a wavelength longer than its inherent fluorescent wavelength. Therefore, if a wavelength longer than the first wavelength and longer than the intrinsic fluorescence wavelength (second wavelength) of the fluorescent plate 322 is selected as the separate wavelength, only the light L0 of the separate wavelength is shown in FIG. Similarly, when incident from the light source 312, light L0 of this separate wavelength substantially passes through the fluorescent plate 322 as it is. Therefore, in this case, the color does not change according to the change of the wavelength.

In addition, as shown in FIG. 38, when the light L1 of the first wavelength and the light L0 of a separate wavelength are incident on the fluorescent plate 322 from the light source 312, the light L1 of the first wavelength is A part of the light is converted into light L2 of the second wavelength, and light L0 of a separate wavelength passes through the fluorescent plate 322 as it is. Accordingly, from the fluorescent plate 322, mixed light in which the light L1 of the first wavelength and the light L2 of the second wavelength are mixed with the separate light L0 is emitted.

As described above, the state of the light emitted from the fluorescent plate 322 is different depending on the state of the light emitted from the light source 312, but as shown in FIG. 32, the light incident on the fluorescent plate 322 is referred to as "input light (Lin)". In addition, the light emitted from the fluorescent plate 322 is referred to as “output light (Lout)”. In addition, light that is actually recognized on the display surface is referred to as “display light (Ld)”.

Next, it returns to Fig. 32 and the description continues. As described above, the output light Lin emitted from the fluorescent plate 322 is guided to the display surface side through the name plate 323 and the cover plate 324, and becomes the display light Ld, whereby optical display is performed. As in this embodiment, when a color filter is not used and the name plate 323 or the cover plate 324 is not colored, the display light Ld has substantially the same wavelength component as the output light Lout. Have (color).

Thus, according to the indicator (surface-illuminated display) 10a according to this embodiment, the color (display color) of the display light Ld for optical display on the display surface side,

(1) a color corresponding to the combination of the first and second wavelengths,

(2) Colors corresponding to the above separate wavelengths,

(3) a color corresponding to a combination of the first and second wavelengths and a mixture of the separate wavelengths,

It can be switched to 3 types.

Of these, the color of the combination of the first and second wavelengths is defined by the combination of the type of the first luminous body (S1) and the fluorescent plate 322, and therefore, it can be optically displayed in any color by adjusting this combination. have.

In particular, in the indicator light according to this embodiment, by using the selective wavelength conversion function of the fluorescent plate 322, the display color by the second luminous body S2 is not substantially affected, and can be realized only with the first luminous body S1. The great advantage is that it is possible to create colors that cannot be obtained. The combination of the first luminous body S1 and the fluorescent plate 322 using such a selective wavelength conversion function will be described with reference to a specific example in the following experimental examples.

Further, in this embodiment, a hologram diffusion plate 321 is provided and light from the light source 312 is diffused at a predetermined diffusion angle, and then the diffused light is incident on the fluorescent plate 322. This hologram diffusion plate 321 is provided with a diffusion surface (hologram surface) 321a using a diffraction phenomenon of light on one surface of a transparent member, and diffusion can be performed without attenuation of light. For this reason, in the unit indicator 10a, the shape of the light source 312 itself can be prevented from being recognized from the outside without providing an element such as a milky white sign plate that substantially absorbs or attenuates light. I can. That is, according to this embodiment, "higher brightness of display" and "uniform light diffusion" can be achieved at the same time.

However, one of the most desired colors for display colors from the related art is "pure white", but in order to obtain "pure white" in the indicator 10a according to this embodiment, a blue light is emitted as the first luminous body. A fluorescent plate 322 having a fluorescent property of emitting yellow light (light of a second wavelength) by a part of blue light (light of a first wavelength) emitted from the first luminous body while using an LED light emitting element. ). In this case, it is not necessary to use a light source packaged in one LED light emitting device emitting red, green, and blue light to obtain white.

In addition, since the amount of heat generated by the light source 312 is small, the life of the indicator that displays white optically can be increased without causing problems related to heat generation of the light source, which is a problem when a halogen lamp is used as a light source. can do. In addition, even if the first luminous body S1 deteriorates over time, its luminance only decreases, and the color of the display light Ld does not fluctuate from pure white.

In particular, when switching the display color between a plurality of colors, there is a possibility that if the purity of the display color is lost, the color cannot be distinguished from other display colors, but such a problem is also solved in this invention. .

When white is used as the mixed light of the light of the first wavelength and the light of the second wavelength, as the light of the separate wavelength, for example, red light can be used. In this case, by changing the lighting state of the first luminous body S1 and the second luminous body S2, it is possible to switch the display to three colors of pure white, red, and pink.

Here, by appropriately changing the ratio of the number of the first luminous bodies S1 and the second luminous bodies S2 included in the light source 312, various pink colors from a relatively dark pink color to a relatively light pink color can be expressed.

Although three types of colors can be switched by the first and second luminous bodies S1 and S2, it is not always necessary to switch colors using all three colors. For example, only switching between two colors of the first display color by lighting only the first luminous body S1 and the second display color by lighting only the second luminous body S2 may be used.

Further, only switching of the first display color by lighting of only the first luminous body S1 and the third display color by lighting of both the first luminous body S1 and the second luminous body S2 may be used. Further, only switching of the second display color by lighting of only the second luminous body S1 and the third display color by lighting of both the first luminous body S1 and the second luminous body S2 may be used.

By the way, when only the first luminous body S1 or only the second luminous body S2 is turned on, and when both the first luminous body S1 and the second luminous body S2 are turned on, the amount of heat generated by the light source 12 as a whole ( Luminance) is different. When the difference in the amount of heat generated is reduced, as shown in FIG. 39, power is paralleled to both the first and second luminous bodies S1 and S2 through the switch SWa from the power supply PWa of a relatively low voltage. A second circuit that selectively supplies power to only one of the first luminous body S1 and the second luminous body S2 through a switch SWb in the first circuit part provided as an alternative and a relatively high voltage power supply PWb You may prepare a part. These circuits function as a luminance variable part that changes the luminance of the first luminous body S1 and the second luminous body S2 according to the different lighting states. In addition, in Fig. 39, the supply voltage is lowered when both are turned on, but whether to increase the luminance of individual luminous bodies in either the case of lighting one or the case of lighting both is appropriately taken in consideration of the visual effect of the display color. You just have to decide.

However, this invention is applicable not only to switching of display colors in a plurality of colors including white, but also to switching of display colors among plural types of chromatic colors. That is, the combination of the first luminous body S1 and the fluorescent plate 22 is selected so that the mixed light of the first wavelength and the second wavelength becomes the first chromatic color. In addition, the light of a separate wavelength emitted by the second luminous body S2 is used as the second chromatic light. If so, when both of the first luminous body (S1) and the second luminous body (S2) are turned on, the third colored light is displayed as a display color due to the additive color mixing of the first colored light and the second colored light. Can be obtained as Specific examples of switching between these chromatic colors will also be described later, but such a configuration is applicable not only to this twelfth embodiment, but also to the thirteenth and fourteenth embodiments below.

<Thirteenth Example>

Fig. 40 is a perspective view showing a lighted push button switch to which a thirteenth embodiment of a display device (surface-illuminated display device) according to the present invention is applied, and Fig. 41 is a partial perspective exploded view of Fig. 40; The lighted push button switch according to this embodiment and the lighted push button switch of the second embodiment described above have only different configurations of the LED unit light source 54 and the other configurations are substantially the same, so that the corresponding parts are denoted with the same reference numerals. The explanation is omitted.

In this embodiment, the luminous body group 54P disposed at the top of the LED unit light source 54 is the first luminous body (LED light-emitting device of the first wavelength) (S1) and the second luminous body (LED light emission of separate wavelengths). Elements) (S2) are alternately disposed and configured.

The LED unit light source 54 is inserted to face the diffusion plate 82 through the hole W1. Therefore, when only the first light-emitting body S1 of the LED unit light source 54 is lit, the light of the first wavelength from the LED light-emitting device 54P passes through the hologram diffusion plate 82 and the incident surface 83a of the fluorescent plate 83 ). In addition, a part of the incident light proceeds as it is to the display surface side (upper side in the drawing), while the rest of the incident light is incident on the fluorescent material (not shown) of the fluorescent plate 83 and becomes light with a second wavelength longer than the first wavelength. The wavelength is converted and light of the first and second wavelengths is emitted from the emission surface. The outgoing light of these first and second wavelengths sequentially transmits the name plate 84 and the front plate 85 to perform surface-dimmed display with the display colors defined by the first and second wavelengths on the display surface side.

In addition, when only the second luminous body S2 is turned on, the light of the above separate wavelength is used as display light to perform surface-dimmed display on the display surface side. In addition, when both of the first luminous body S1 and the second luminous body S2 are turned on, a mixture of light of the first wavelength, light of the second wavelength, and light of the different wavelengths is emitted from the display surface side.

In this way, in the thirteenth embodiment, as in the twelfth embodiment, by using the selective wavelength conversion function of the fluorescent plate 83, the first luminous body S1 is not substantially affected by the display color of the second luminous body S2. ), it is possible to create colors that cannot be realized.

In addition, by providing the hologram diffusion plate 82, as in the twelfth embodiment, “higher brightness of the display” and “uniform diffusion of light” can be achieved at the same time as compared to the case of using a conventionally known light diffusion plate.

In particular, a fluorescent plate having a fluorescent characteristic that emits yellow light by using a blue LED light-emitting device as the first luminous body (S1) and at the same time as the fluorescent plate 83 by part of the blue light emitted from the first luminous body (S1). If is used, the display color of the indicator light of the illuminated push button switch can be set to white with a small amount of heat, as in the twelfth embodiment.

<14th Example>

Fig. 42 is a schematic cross-sectional view showing a fourteenth embodiment of a display device (surface dimming display device) according to the present invention. The surface-dimmed display device according to this embodiment differs greatly from the twelfth embodiment shown in FIG. 36. In the twelfth embodiment, a single fluorescent plate 322 is provided to emit light having a second wavelength. In this fourteenth embodiment, a phosphor 390 (wavelength converting member) formed by stacking two fluorescent plates 391 and 392 is provided to emit light having a third wavelength as well as a second wavelength. In addition, other basic configurations are the same.

In this phosphor 390,

(1) A part of the light L1 of the first wavelength from the light source 312 is transmitted as it is to the emission surface side (the upper side of the drawing), while the remainder of the incident light L1 is longer than the light of the first wavelength. A fluorescent plate 391 that emits light of two wavelengths L2 toward the emission surface,

(2) A part of the light L1 and the light L2 from the fluorescent plate 391 are transmitted directly to the exit surface side, while the light L3 of a third wavelength longer than the first wavelength due to the remainder of the light L1 A fluorescent plate 392 emitting light toward the emission surface side,

Are stacked.

For this reason, when the light L1 of the first wavelength from the light source 312 is given to the incident surface 390a of the phosphor 390, first, a part of the light L1 of the first wavelength from the fluorescent plate 391 is transferred to the fluorescent plate as it is. At the same time as it transmits to the (392) side, the remainder of the incident light L1 is absorbed by the fluorescent material FM1, and light L2 of a second wavelength longer than the first wavelength is emitted from each fluorescent material FM1 to emit light. Proceed to the (392) side. In addition, in the fluorescent plate 392 receiving the first and second wavelengths of light (L1, L2), a part of the first wavelength of light (L1) and the second wavelength of light (L2) are emitted from the phosphor 390 as it is. At the same time, the light L1 of the first wavelength is absorbed by the fluorescent material FM2, and the remainder of the light L1 of the first wavelength is absorbed by the fluorescent material FM2 and is higher than the first wavelength in each of the fluorescent materials FM2. Light L3 of a long third wavelength is emitted and is emitted from the emission surface 90b toward the display surface. In this way, optical display is performed on the entire display surface by the light of the first to third wavelengths L1 to L3.

In addition, a part of the light L2 of the second wavelength is absorbed by the fluorescent material FM2, and light (not shown) of a fourth wavelength longer than the second wavelength is emitted from the fluorescent material FM2 to emit light, and the exit surface ( It is emitted from 90b) toward the display surface.

As described above, according to the fourteenth embodiment, when the first luminous body S1 in the light source 312 is emitted, the display color on the display surface is defined by light of the first to third wavelengths (L1 to L3). Therefore, it is possible to control the display color more precisely compared to the twelfth embodiment in which the display color is defined by the two wavelengths of light (L1, L2).

On the other hand, when only the second luminous body S2 is turned on, the display color is the color of the separate wavelength that the second luminous body S2 emits light (Fig. 43), and the first luminous body S1 and the second luminous body When (S2) is simultaneously lit, the display color becomes a mixed color of the light of the first to third wavelengths (L1 to L3) and the color of the separate wavelength (FIG. 44).

Further, in this embodiment, the phosphor 390 is formed by stacking two fluorescent plates 391 and 392, but the phosphor 390 may be formed by stacking three or more fluorescent plates.

In addition, the order of lamination of the fluorescent plate is arbitrary.

<Modification of Examples 12 to 14>

In the twelfth embodiment, the hologram diffuser 321 is provided between the light source 312 and the fluorescent plate 322, and in the thirteenth embodiment, the hologram diffuser plate 382 is provided with the LED unit light source 54 and the fluorescent plate 83. Although they are respectively arranged between, the arrangement position of the hologram diffusion plate is not limited to this, and can be arranged at any position as long as it is on the optical path of light traveling from the light source to the display surface side. However, when visibility is considered, it is preferable to place a hologram diffusion plate toward the light source side with respect to the fluorescent plate. Even so, in the case of such arrangement, as described above, the light passing through the hologram diffusion plate is diffused at a predetermined diffusion angle and is diffused light traveling in various directions, which increases the probability of hitting the fluorescent material by entering the fluorescent plate. It is because it emits light from the whole, and visibility can be improved.

Further, in the above, a hologram diffusion plate is used as a light diffusion member for diffusing light traveling from the light source to the display surface on the optical path, but instead of the hologram diffusion plate, a conventionally known light diffusion plate or the above-described seventh light diffusion plate is used. The prism sheet 213 used in the example may be used.

In addition, in the above embodiment, a light diffusion member such as a hologram diffusion plate is provided, but the light diffusion member does not have any effect on the display color, so the light diffusion member is not an essential component for controlling the display color, but the operator It is preferable to provide the lamps in order to make it easier to recognize the displayed contents of characters or the like.

In addition, the color of light for optical display may be changed by additionally arranging a filter in the vicinity of the emission surface of the fluorescent plate. For example, in an indicator light or illuminated push button switch that enables optical display of pure white as one of the display colors, if a filter is additionally disposed in the vicinity of the emission surface of the fluorescent plates 322, 83, the light spectrum emitted from the fluorescent plate is , It is possible to change the display color by the light spectrum extracted from the filter.

In this case, the display color corresponding to the above separate wavelength also changes according to the color of the filter. For example, if red light is used as the light of the above separate wavelength and a yellow filter is used as the filter, it is possible to switch to three colors of yellow, a mixed color of yellow and red, and a mixed color of yellow and pink. It is possible.

As the first luminous body S1 and the second luminous body S2, a light-emitting body that is shorter than the fluorescent wavelength of the fluorescent plate and generates two light having different wavelengths, respectively, may be used. For example, when a yellow fluorescent plate is used, a blue light-emitting body and a green light-emitting body having a wavelength shorter than that of yellow can be used. No matter which luminous body is turned on, a partial wavelength of the light is converted by the fluorescent plate to obtain a display color different from the luminous color of the luminous body itself.

The number of light-emitting bodies coupled to the light source is not limited to two types, but may be three or more types. In this case, one or more types of light emitters are used as light emitters that generate light that is wavelength-converted with a fluorescent plate.

In addition, in the twelfth to fourteenth embodiments, a configuration in which a second luminous body S2 for emitting light of the separate wavelength is added to the light sources of the first, second and third embodiments described above is shown. The second luminous body S2 may be added to the light sources of the fourth to sixth embodiments.

<Experimental Examples of Examples 12 to 14>

Of the first and second luminous bodies S1 and S2 of the light source 312, when only the first luminous body S1 is turned on, the first luminous body S1 emits light of the first wavelength and the light having the first wavelength The type of color of the display light obtained by the combination of light of the second wavelength emitted by the fluorescent plate 322 is the same as in the first to sixth embodiments described above, and thus is omitted here.

Here, a case where a plurality of types of display colors is obtained by turning on and off the first and second luminous bodies S1 and S2 provided in the light source 312 will be described. In addition, here, it is assumed that a case where a plurality of types of display colors contain pure white and a case where all of the display colors are chromatic is described, and Figs. 45 and 46 show the spectrum of the display light obtained in each case.

However, among the wavelength conversion units (TW, TG) used in these measurements, the wavelength conversion unit (TW) of FIG. 45 is the same yellow fluorescent plate 322Y as the yellow fluorescent plate 22 shown in Table 1 above, and milky white diffusion. It is constituted by a plate 321D and a transparent cover plate 324. In addition, the wavelength conversion unit TG of FIG. 46 includes a green fluorescent plate 322G identical to the green fluorescent plate shown in Table 2, a milky white diffusion plate 321D, and a transparent cover plate 324. These wavelength conversion units (TW, TG) are not completely identical to the structure of Fig. 32, but the wavelength conversion unit (TW, TW, TW, TW, TW) for the color conversion function by the combination of the blue light-emitting body S1 and the fluorescent plates 322Y, 322G. It is fully understandable by the measurement result by TG).

First, refer to FIG. 45. This graph shows each of the three cases in which a blue LED light-emitting element 312B is used as a light source, a red LED light-emitting element 312R is used, and a red-brown LED light-emitting element 312A is used. It shows the color spectrum. Among them, the blue LED light emitting device 312B has the same emission spectrum as the blue LED light emitting devices shown in Tables 1 and 2 above.

As can be seen from FIG. 45, when the blue LED light emitting device 312B is emitted, most of the spectrum is obtained in a wide range from 400 nm to 650 nm, and a display color close to pure white is obtained. That is, the fluorescent plate 322Y has a yellow fluorescent color, but its spectral distribution range is quite wide, and when mixed with blue light, it can be seen that it is in a state close to pure white.

On the other hand, when the reddish-brown LED light-emitting element 312A is emitted, a spectrum with a peak around 60 nm is obtained, and the display color is substantially the same as the input light. In addition, when the red LED light-emitting element 312R is emitted, a spectrum with a peak around 650 nm is obtained, and the display color is substantially the same as the input light.

Therefore, when the blue LED light emitting device 312B is used as the first luminous body S1 and the reddish brown LED light emitting device 312A is used as the second luminous body S2, pure white, reddish brown, whiteish reddish brown, 3 You can change the display color by type. In addition, when the blue LED light emitting device 312B is used as the first luminous body (S1) and the red LED light emitting device 312R is used as the second luminous body (S2), pure white, red, whiteish red (i.e., pink) is used. ) The display color can be changed in 3 types.

Next, reference is made to FIG. 46. This graph shows the display color spectrum of the green fluorescent plate 322G in the case where the three types of light-emitting bodies similar to those of Fig. 45 are respectively lit. When the blue LED light emitting element 312B is emitted, it becomes a pure green display color with a peak around 510 nm. This green is more pure green than the green produced by the green LED light-emitting device. On the other hand, when the reddish-brown LED light-emitting element 312A is emitted, a spectrum with a peak around 600 nm is obtained, and the display color is substantially the same as the input light. In addition, when the red LED light-emitting element 312R is emitted, a spectrum with a peak around 650 nm is obtained, and the red display color is substantially the same as the input light.

Therefore, when the blue LED light emitting device 312B is used as the first luminous body S1 and the reddish brown LED light emitting device 312A is used as the second luminous body S2, pure green, reddish brown, green and reddish brown additive colors are mixed. The display color can be changed in three types. In addition, when the blue LED light emitting device 312B is used as the first luminous body S1 and the red LED light emitting device 312R is used as the second luminous body S2, pure green, red, red and green additive colors are mixed ( In general, the display color can be changed to three chromatic colors of yellow area to orange area).

In this way, a part of the light of the first wavelength of the fluorescent plate is converted into light of the second wavelength of a longer wavelength than that of the light, while the optical property of substantially transmitting the light with a wavelength longer than that of its intrinsic fluorescent color is used. This makes it possible to switch the display color among a plurality of colors.

In addition, if a plurality of types of light sources capable of emitting a plurality of lights shorter than the fluorescent wavelength are disposed as a light source and selectively emit light, the display color between a plurality of colors that cannot be realized by the LED light emitting device itself. Conversion becomes possible.

For example, a light source having two types of LED light-emitting elements: an LED light-emitting element generating ultraviolet light and an LED light-emitting element generating blue light, and at the same time, the light when selectively emitting them is a yellow fluorescent plate. It emits through. When only the LED light emitting element that generates ultraviolet light is turned on, a part of the ultraviolet light generated by it is converted into yellow light by the fluorescent plate, but the remaining part passes through the fluorescent plate as it is. As is well known, since ultraviolet light cannot be visually recognized, when only the LED light-emitting device that generates ultraviolet light is turned on, the color that can be observed from the outside becomes yellow.

On the other hand, when only the blue LED light emitting element is turned on, a part of it is converted into yellow light by the fluorescent plate, and the remainder of the blue light passes through the fluorescent plate as blue light as it is. For this reason, in this case, when observed from the outside, it becomes the display color of white.

Therefore, in this example, the display colors can be switched to yellow and blue by selectively lighting the two types of LED light-emitting elements.

<Fifteenth Example>

Fig. 47 is an exploded perspective view of a unit display lamp 10a to which a fifteenth embodiment of a display device (surface dimming display device) according to the present invention is applied. In addition, FIG. 48 is a schematic cross-sectional view of the unit display lamp 10a of FIG. 47. In the unit display lamp 10a, a plurality of light sources 412 (LED light emitting devices) are arranged in a matrix form inside a case 411 made of a resin having a window W. Each light source 412 is mounted on the main surface of the printed circuit board and accommodated in the case 411, and its light emitting portion is exposed toward the upper surface side of the case 411. The LED light-emitting elements constituting these light sources 412 emit light of any one wavelength (first wavelength) of wavelengths from the ultraviolet region to blue, in this case, light of a blue wavelength.

Meanwhile, a frame 413 is disposed around the upper surface of the window W. The frame 413 is fitted into the housing 2 of FIG. 1 through the case 411, and the composite plate 420 is fitted to the frame 413. This composite plate 420 is from the light source 412 side,

(1) Fluorescent plate 421 (wavelength converting member),

(2) Name plate made of transparent resin (422),

(3) filter 423,

(4) Milky white diffusion plate 424 (light diffusion member),

(5) Cover plate made of transparent resin (425),

It has a structure in which five are stacked. Characters or symbols to be displayed are written on the name plate 422.

Among these, the fluorescent plate 421 and the filter 423 are provided according to the main features of the present invention. The fluorescent plate 421 has an incidence surface 421a that receives light from the light source 412 and an emission surface 421b facing the display surface side (the upper side of the drawing). Further, the fluorescent plate 421 emits light of a second wavelength longer than the first wavelength by the light of the first wavelength incident through the incident surface 421a, and the light of the second wavelength is emitted from the exit surface 421b. do. The filter 423 removes the light of the first wavelength transmitted through the fluorescent plate 421 among the light emitted from the emission surface 421b of the fluorescent plate 421 and substantially transmits only the light of the second wavelength. Fig. 49 schematically shows this optical phenomenon.

49 is a schematic diagram showing optical characteristics of the fluorescent plate 421 and the filter 423. This fluorescent plate 421 has the same configuration as the fluorescent plate 22 according to the above-described first embodiment, and corresponding portions are denoted by the same reference numerals, and descriptions thereof are omitted. The filter 423 is for removing the light L1 of the first wavelength transmitted through the fluorescent plate 421 and transmitting only the light L2 of the second wavelength as display light to the display surface side.

The light L1 of the first wavelength incident on the filter 423 is sufficiently attenuated while reaching the surface 423a on the display side of the filter 423 and does not pass through the filter 423, compared to the second wavelength. The light L2 is transmitted through the filter 423 without attenuation in general, so that the light consisting of the light L2 of the second wavelength is emitted from the surface 423a of the filter 423. .

Next, it returns to FIG. 47 and the description continues. When light of the first wavelength emitted by the light source 412 is incident on the fluorescent plate 421, the fluorescent plate 421 emits light of the second wavelength by receiving the light of the first wavelength. The light of the first wavelength transmitted through the fluorescent plate 421 together with the light of the second wavelength is incident on the filter 423 through the name plate 422, and the light of the first and second wavelengths by the filter 423 Among them, the light of the first wavelength is removed, and only the light of the second wavelength is substantially emitted from the surface 423a of the filter 423. Then, the light of the second wavelength transmitted through the filter 423 is guided to the display surface side through the milky diffusion plate 424 and the cover plate 425 to perform optical display.

As described above, according to the indicator (surface dimming display) 10a according to this embodiment, light for optical display on the display surface side is substantially composed of only light of the second wavelength, and light of the first wavelength is included. Therefore, the color of the second wavelength light emitted by the fluorescent plate 421 can be extracted purely as the color of the display light. As a result, it is possible to obtain a color of light with high saturation compared to a method of obtaining light of a desired color by overlapping a plurality of types of light having different wavelengths, for example.

In addition, a plurality of types of fluorescent plates 421 that receive light of a first wavelength, in this case, light of blue, and emit light of a second wavelength of various colors (for example, light of red, yellow, orange, green, etc.), and the fluorescent plate According to the type of 421, a plurality of types of filters 423 are prepared, and among them, the fluorescent plate 421 and the filter 423 to be used are selected according to the color of the desired display light, so that the light source 412 emits light. From the light of the first wavelength, in this case, blue light, light of a variety of colors that cannot be obtained by a single type of LED light-emitting device can be obtained. As a result, since the light for display of a desired color is obtained from light of the first wavelength (blue light) only by exchanging the fluorescent plate 421 and the filter 423, for example, an LED used in accordance with the color of the display light Compared to changing the combination of types of light-emitting elements, it is possible to improve productivity and reduce cost. In addition, the combination of the fluorescent plate 421 and the filter 423 will be described with reference to a specific example in the following experimental examples.

Further, in this embodiment, light from the filter 423 is diffused to the milky diffusion plate 424 and then emitted to the display surface side through the cover plate 425, thereby changing the amount of light on the display surface. This is supposed to be alleviated.

In addition, in this embodiment, since the light of the first wavelength has a shorter wavelength having any one of the wavelengths from the ultraviolet region to the blue, in this case, it is blue light, so it can produce light of a variety of colors than the light of the first wavelength. I can.

Further, in this embodiment, the milky diffusion plate 424 is used as the diffusion plate, but the holographic diffusion plate 21 described above may be used instead of the milky diffusion plate 424 or in addition to the milky diffusion plate. Further, in this embodiment, the milky white diffusion plate 424 is provided on the display surface side of the fluorescent plate 421, the name plate 422, and the filter 423, but is not limited thereto, and the cover plate ( The diffusion plate 424 may be provided at either position on the optical path leading to 425.

<16th embodiment>

Fig. 50 is a partial perspective view showing an illuminated push button switch to which a sixteenth embodiment of a display device (surface-illuminated display device) according to the present invention is applied. The illuminated push button switch according to the present embodiment is a combination of the illuminated push button switch according to the second embodiment shown in Figs. 5 and 6 and that is fitted to the front of the push unit 80. The configuration of the plate is only different, other configurations are the same, and the same reference numerals are used for corresponding parts, and descriptions thereof are omitted.

As shown in Fig. 50, the lower portion of the push portion 80 is made of a hollow body 81 having a perforated hole W1, on which

(1) a fluorescent plate 482 having the same fluorescent characteristics as the fluorescent plate 421 in the fifteenth embodiment,

(2) a colorless and transparent name plate 483 formed of a resin such as acrylic,

(3) filter 484,

(4) Holographic diffusion plate (485)

A composite plate laminated in this order is provided. In addition, a colorless and transparent front plate 85 made of, for example, acrylic is provided as a member defining the operation surface 80S of FIG. 50. In addition, required characters and the like are written on the name plate 483.

The LED unit light source 54 is inserted to face the fluorescent plate 482 through the hole W1. Accordingly, when the LED unit light source 54 is turned on, the light of the first wavelength from the LED light emitting element 54L enters the incident surface 482a of the fluorescent plate 482. Then, the incident light is wavelength-converted into light of a second wavelength longer than the first wavelength by a fluorescent material (not shown) of the fluorescent plate 482 and is emitted from the emission surface, and thereafter, the name plate 483 and the filter 484 And the diffuser plate 485 is sequentially transmitted to perform a surface dimming display in a display color defined by the second wavelength from the display surface side. Here, the filter 484 has the same optical characteristics as the filter 423 of the fifteenth embodiment, which transmits only light of the second wavelength, and transmits the fluorescent plate 482 without wavelength conversion. The light of the wavelength is removed by the filter 484, and substantially only the light of the second wavelength is emitted from the emission surface of the filter 484.

As described above, in the sixteenth embodiment as well, the above-described problems such as improvement in productivity and reduction in cost are possible while obtaining a display light of a color with an arbitrary high saturation from the light source light of a single color (light of the first wavelength). The same effect as in Example 15 can be obtained.

<17th Example>

Fig. 51 is a schematic cross-sectional view showing a seventeenth embodiment of the display device (surface dimming display device) of the present invention. In this surface dimming display device, a wavelength converting plate 491 (a wavelength converting member) is used in place of the fluorescent plates 421 and 482 and filters 423 and 484 of the fifteenth and sixteenth embodiments described above, and a light source 492 ), an LED light-emitting device that emits light of a blue wavelength (first wavelength) is used, as in each of the above embodiments.

The wavelength conversion plate 491 includes a substrate 493 and a fluorescent material FMa having the same fluorescence characteristics as the fluorescent material FM of the fifteenth embodiment incorporated into the substrate 493. The substrate 493 of the wavelength conversion plate 491 is colored in a predetermined color by mixing a pigment in a transparent resin such as acrylic. In addition, light of a predetermined color (light of the second wavelength) among the light incident on the substrate 493 is transmitted without attenuation, but light other than the predetermined color is attenuated in the substrate 493, and most It is designed not to pass through the substrate 493. Further, since a fluorescent material FMa is mixed in the substrate 493, when the light L1 of the first wavelength is incident on the wavelength conversion plate 491 from the incident surface 491a, the fluorescent material FMa is the first The light L1 of the wavelength is received, light L2 of the second wavelength longer than the first wavelength is emitted, and substantially only the light L2 of this second wavelength is emitted from the exit surface 491b.

52 shows a pattern in which light of a first wavelength is converted into light of a second wavelength. In the figure, the horizontal axis represents the propagation direction of the light, and the vertical axis represents the intensity of light. As shown in the figure, the light of the first wavelength incident on the wavelength conversion plate 491 is attenuated by the substrate 493 and converted into light of the second wavelength by the fluorescent material FMa, while the substrate ( 493) Proceed with the proposal. As a result, the intensity of the incident light having the first wavelength reaches approximately zero when it reaches the exit surface 491b. In contrast, the intensity of light of the second wavelength increases from the incident surface 491a side to the exit surface 491b side. As a result, substantially only light of the second wavelength is emitted from the emission surface 491b.

In the seventeenth embodiment as well, the fifteenth above, in which light for display of an arbitrary color having higher saturation than light of a single color light source (light of the first wavelength) is obtained, and productivity is improved and cost can be reduced. The same effect as in the embodiment is exhibited, and since light of the first wavelength can be converted into light of the second wavelength with a single wavelength conversion plate 491, the effect of reducing the number of parts and reducing the cost is achieved. You can get it.

<Eighteenth Example>

Fig. 53 is a cross-sectional view of a filter used in the display device (surface dimming display device) of the eighteenth embodiment of the present invention. In this surface dimming display device, instead of using the fluorescent plates 421 and 482 as in the fifteenth and sixteenth embodiments, a fluorescent material FMb is coated on the incident surface 501a of the filter 501, and the light source In the (not shown), an LED light emitting device that emits light of a blue wavelength (first wavelength) is used as in each of the above embodiments.

The fluorescent material FMb has the same fluorescence characteristics as the above-described fluorescent materials FM and FMa, and emits light of a second wavelength longer than the first wavelength by receiving light of a first wavelength from a light source. The filter 501 is configured to transmit substantially only light of the second wavelength. As a result, the light of the first wavelength transmitted through the fluorescent material FMb applied to the incident surface 501a is sufficiently attenuated while traveling inside the filter 501, and is almost emitted from the exit surface 501b of the filter 501. Does not happen. On the other hand, since the light of the second wavelength emitted by the fluorescent material FMb is hardly attenuated and passes through the filter 501, only the light of the second wavelength is substantially emitted from the exit surface 501b.

Even in the surface-dimmed display device of this eighteenth embodiment, the fifteenth above, such as the ability to improve productivity and low cost, while obtaining the display light of an arbitrary color with high saturation from the single color light source light (light of the first wavelength). It exhibits the same effect as the embodiment, and can convert light of the first wavelength into light of the second wavelength with one filter 501 coated with a fluorescent material (FMb), thus reducing the size and reduction of the number of parts by reducing the number of parts. The effect of being excellent in cost reduction can be achieved.

<19th embodiment>

54 is a cross-sectional view of a fluorescent plate and a filter used in a display device (surface dimming display device) according to the nineteenth embodiment of the present invention. In this surface dimming display device, a fluorescent plate 511 having the same fluorescent characteristics as the fluorescent plates 421 and 482 and a filter 512 having the same characteristics as the above-described filters 423 and 484 are stacked together. As in each of the above embodiments, an LED light emitting device that emits light of a blue wavelength (first wavelength) is used as a light source (not shown).

The filter 512 is located on the emission surface side of the fluorescent plate 511, receives light of the first wavelength from the light source, and substantially only light of the second wavelength longer than the first wavelength emitted by the fluorescent plate 511 is substantially filter 512 It is supposed to be emitted from the exit side of ).

In the surface-dimmed display device of the nineteenth embodiment, the above mentioned above, such as improving productivity and reducing cost, while obtaining light for display of an arbitrary color with higher saturation than light of a single color light source (light of the first wavelength) is obtained. The same effects as those of the fifteenth embodiment are exhibited, and since the fluorescent plate and the filter are integrated into one, the number of parts can be reduced, and the assembly process can be simplified.

<Experimental examples of the 15th to 19th embodiments>

In each of the experimental examples shown below, five types of fluorescent plates and filters were prepared, and light of the first wavelength was actually incident on each fluorescent plate and filter, and as a result, the light of the first wavelength was converted into light (light of the second wavelength). It was investigated.

In addition, in each of the experimental examples, an LED light emitting device that emits blue wavelength light is used as a light source. The blue wavelength light emitted by the LED light-emitting element has a spectrum indicated by a solid line in Fig. 55, and the color of the light has a chromaticity coordinate of x = 0.131 and y = 0.120 in the CIEXYZ color system. And, in each experimental example, a composite having the same configuration as the composite plate 420 of the fifteenth embodiment, comprising a fluorescent plate, a name plate made of transparent resin, a filter, a milky diffusion plate, and a cover plate to emit light from the light source. It was guided to the plate and irradiated with light of the second wavelength emitted from the cover plate. In Figs. 55 to 57, the vertical axis represents the intensity of light, and the horizontal axis represents the wavelength of light.

In the first experimental example, a sample (A) was used as a fluorescent plate, and a red filter was used as a filter. As a result, red light having the spectrum indicated by the solid line in Fig. 56 and the values of the x and y components of the chromaticity coordinates x = 0.692 and y = 0.280 was obtained.

In the second experimental example, a sample (B) was used as a fluorescent plate, and a yellow filter was used as a filter. As a result, with the spectrum indicated by the dashed-dotted line in Fig. 56, the values of the x component and the y component of the chromaticity coordinates x = 0.476, y = 0.516 yellow light was obtained.

In the third experimental example, a sample (C) was used for a fluorescent plate, and a red filter was used as a filter. As a result, with the spectrum indicated by the dashed-dotted line in Fig. 56, red light with x = 0.386 and y = 0.133 values of the x and y components of the chromaticity coordinates was obtained.

In the fourth experimental example, a sample (D) was used for a fluorescent plate, and a yellow filter was used as a filter. As a result, with the spectrum shown by the solid line in Fig. 57, yellow light with x = 0.473 and y = 0.491 values of the x component and y component of the chromaticity coordinate was obtained.

In the fifth experimental example, a sample (E) was used for a fluorescent plate and a green filter was used as a filter. As a result, green light having the spectrum indicated by the dashed-dotted line in Fig. 57 and the values of the x and y components of the chromaticity coordinates x = 0.131 and y = 0.630 was obtained.

As the above experimental results show, various colors of light can be obtained from the blue light of the light source by changing the type of the fluorescent plate and filter to be used.

<Twenty Example>

58 is a longitudinal sectional view showing an example in which a display device (LED sphere) according to the twentieth embodiment of the present invention is applied to a display, FIG. 59 is an enlarged longitudinal sectional view of the LED sphere, and FIG. 60 is a line III-III in FIG. 59 Fig. 61 is a cross-sectional view for explaining the effect of this embodiment.

As shown in FIG. 58, the display device 601 is provided with the lens 602 in a rough shell shape, and the LED bulb 603 arrange|positioned in the inside. As shown in Figs. 59 and 60, a plurality of light emitting diode elements 604 are mounted in a flat shape on the light emitter body 603a of the LED sphere 603, and each light emitting diode element 604 is a transparent mold resin 605 ). Further, the number of light emitting diode elements 604 may be one.

A cap member (first dome-shaped cap member) 606 made of resin formed in a dome shape (hemispheric shell shape) is mounted on the upper part of the light emitter body 603a of the LED bulb 603 (FIG. 58 And Figure 59). It is preferable that the center of the bone marrow of the cap member 606 is disposed on the mounting surface of the light emitting diode element 604.

A fluorescent material is mixed inside the cap member 606. This fluorescent material has a fluorescence characteristic of emitting light of a wavelength different from that of incident light when it is excited by incident light and returns to a ground state. The cap member 606 is formed by mixing a fluorescent material having such fluorescent properties with a transparent resin material in a dome shape.

Next, the operation and effect of the first embodiment of the present invention will be described with reference to Fig. 61.

Light L1 from the light emitting diode element 604 enters the dome-shaped cap member 606. Then, the fluorescent material 7 inside the dome-shaped cap member 606 is excited, and a unique fluorescent light L2 is emitted to the fluorescent material. On the other hand, a part of the light L1 incident on the dome-shaped cap member 606 passes through the dome-shaped cap member 606.

As a result, the light emitted from the dome-shaped cap member 606 is mixed with the transmitted light (L1) transmitted through the dome-shaped cap member 606 and the fluorescence (L2) emitted from the fluorescent material 607 to add false colors. It becomes a mixed color light.

For example, a light emitting diode element 604 that emits light of a blue wavelength (light of a first wavelength) is used, and a fluorescent material 607 is excited by light of a blue wavelength, so that the fluorescence of a yellow wavelength is longer than that of the blue wavelength. In the case of using one emitting (light of the second wavelength), the light emitted from the dome-shaped cap member 606 becomes white light, which is a mixed color of blue light and yellow light.

Alternatively, if a light emitting diode element 604 that emits blue wavelength light is used, and a fluorescent material 7 that emits red wavelength fluorescence with a wavelength longer than the blue wavelength excited by light of blue wavelength is used, dome shape The light exiting the cap member 6 becomes light of a painted color, which is a mixed color of blue light and red light.

In this way, it is possible to emit white light or other color light, which is difficult to emit light in a single light-emitting diode element.

In addition, in this case, since the LED sphere 603 according to the present embodiment is configured by simply attaching the dome-shaped cap member 606, which is easily molded, to the upper portion of the conventionally used LED sphere, the increase in cost is also minimal.

<Twenty-first Example>

Fig. 62 is an enlarged longitudinal sectional view of a display device (LED sphere) according to the twenty-first embodiment of the present invention, and Fig. 63 is a view for explaining the operation and effect thereof. In addition, in these drawings, portions denoted by the same reference numerals as those in the twentieth embodiment indicate the same or the same portions as those in the twentieth embodiment.

As shown in Fig. 62, in the upper part of the light emitter body 603a of the LED sphere 603, the outer periphery of the first dome-shaped cap member 606 is similarly formed in a dome-shaped resin cap member (second A dome-shaped cap member) 608 is attached. It is preferable that the center of curvature of the cap member 608 is similarly disposed on the mounting surface of the light emitting diode element 604.

A diffusion material is mixed inside the cap member 608. As this diffusion material, for example, ceramic powder is used, but the application of this embodiment is not limited to this, and any material other than ceramic powder may be used as long as it has a property of diffusing light, and an organic material may be used. The cap member 608 is formed by mixing such a diffusion material with a transparent resin material in a dome shape.

Next, effects of the twenty-first embodiment of the present invention will be described with reference to FIG. 63. FIG.

After the light L emitted from the light emitting diode element 604 passes through the dome-shaped cap member 606, it becomes light of a predetermined mixed color, for example, white light, and enters the dome-shaped cap member 608.

Light incident into the dome-shaped cap member 608 is incident on particles of a plurality of diffusion materials 609 mixed into the cap member 608, and is diffused in various directions by the surfaces of these particles.

As a result, the entire dome-shaped cap member 608 becomes a light emitting surface, and the light emitting surface of the LED sphere 603 is formed in a three-dimensional dome shape. Thereby, it is possible to confirm the lighting state of the LED sphere 603 from all directions, and the visibility of the LED sphere 603 can be improved.

<The 22nd Example>

In the twenty-first embodiment, it has been shown that the dome-shaped cap member 608 containing the diffusion material is mounted around the outer periphery of the dome-shaped cap member 606 containing the fluorescent material, but the application of the present invention is not limited to this.

In the LED sphere 603 shown in Fig. 59, a dome-shaped cap member 606 containing a fluorescent material and a diffusion material may be used.

In this case, the light emitted from the light emitting diode element 604 and incident on the dome-shaped cap member 606 is diffused in various directions by the diffusion material inside the dome-shaped cap member 606, and a part of the light is diffused in various directions. It is emitted from the dome-shaped cap member 606, and the remaining light excites the fluorescent material to emit fluorescence.

As a result, the entire dome-shaped cap member 606 becomes a light emitting surface of mixed color light of emission light and fluorescent color, for example, white light, and the light emitting surface of the LED sphere 603 is formed in a three-dimensional dome shape. Thereby, as in the case of the twenty-first embodiment, it is possible to check the lighting state of the LED sphere 603 in all directions, and the visibility of the LED 603 can be improved.

In addition, in this case, since the dome-shaped cap member to be attached to the light emitter body 603a is one, assembly is facilitated, and it is possible to contribute to overall miniaturization.

<23rd Example>

64 is an enlarged longitudinal sectional view of a display device (LED bulb) according to a twenty-third embodiment of the present invention. In addition, in the drawing, portions denoted with the same reference numerals as in the twenty-first embodiment represent the same or the same portions as those in the twenty-first embodiment.

In the twenty-third embodiment, the point in which the third dome-shaped cap member (ie, color filter) 610 containing the dye is mounted instead of the dome-shaped cap member 608 into which the diffusion material shown in FIG. 62 is inserted. It is different from the embodiment.

For example, a light emitting diode device 604 that emits light of a blue wavelength (light of a first wavelength) is used, and a fluorescent material 607 in the dome-shaped cap member 606 is excited by light of a blue wavelength to produce a blue wavelength. In the case of using a fluorescent light having a longer wavelength than that of a red wavelength (light of the second wavelength), the light emitted from the dome-shaped cap member 606 becomes pink light, which is a mixed color of blue light and red light.

In this case, if a red one is used as the dome-shaped cap member 610, a component of blue light in the pink light is absorbed by the dome-shaped cap member 610, and the dome-shaped cap member 610, that is, the LED sphere 603, is red. Only Kwangman of will be emitted.

In addition to the above example, it is possible to emit light of all colors by combining the fluorescent material 607 inside the dome-shaped cap member 606 and the dye inside the dome-shaped cap member 610 in various ways. It is done.

<24th embodiment>

Fig. 65 is an exploded perspective view of a unit indicator 10a to which a 24th embodiment of a display device (surface dimming display device) according to the present invention is applied. Further, Fig. 66 is a schematic cross-sectional view of the unit display lamp 10a of Fig. 65. In this unit indicator 10a, a plurality of light sources 712 (LED light emitting devices) are arranged in a matrix form inside a case 711 made of a resin having a window W. Each light source 712 is mounted on the main surface of the printed circuit board and accommodated in the case 711, and its light emitting portion is exposed toward the upper surface side of the case 11. The LED light-emitting elements constituting these light sources 712 emit light having one wavelength (first wavelength) of wavelengths from the ultraviolet region to blue, in this case, light having a blue wavelength.

Meanwhile, a frame 713 is disposed around the upper surface of the window W. The frame 713 is fitted into the housing 2 of FIG. 1 through the case 711, and the composite plate 720 is fitted to the frame 713. This composite plate 720 is from the light source 712 side

(1) a diffusion plate (light diffusion member) 721,

(2) wavelength conversion member 722,

(3) Name plate made of transparent resin (723),

(4) a cover plate made of transparent resin (724),

It has a structure that overlaps four. Information to be displayed (letters, symbols, picture patterns, etc.) is written on the name plate 723.

Among these, the wavelength conversion member 722 is provided according to the main features of the present invention. The wavelength converting member 722 is disposed between the cover plate 724 serving as a display surface and the light source 712, and receives the light from the light source 712 on the side of the incident surface 722a and the display surface (upper side of the drawing). It is a plate-shaped or sheet-shaped member having an exit surface (722b) facing toward.

67 is a partial cross-sectional view of the wavelength conversion member 722. As shown in FIG. 67, the wavelength conversion member 722 has a two-layer structure in which the phosphor layer 731 and the filter layer 732 are integrated. In addition, the wavelength conversion member 722 is disposed so that the phosphor layer 731 is located on the incident surface 722a side, and the filter layer 732 is located on the emission surface 722b side.

The phosphor layer 731 is adapted to convert at least a part of the first wavelength incident through the incident surface 722a into light having a first wavelength longer than the first wavelength, and then emit light. Therefore, in a general case, among the light of the first wavelength emitted by the phosphor layer 731 and the light of the first wavelength incident on the phosphor layer 731, the light incident from the phosphor layer 731 to the filter layer 732 The remaining light that has not been converted into light of the second wavelength by the layer 732 is included. In addition, when substantially all of the light of the first wavelength incident on the phosphor layer 731 is converted to light of the second wavelength, the light of the first wavelength is the light incident from the phosphor layer 731 to the filter layer 732 not included.

The light transmission characteristic of the filter layer 732 is set so that at least a part of the light incident from the phosphor layer 731 is transmitted toward the display surface as display light. In addition, the external color of the filter layer 732 is largely dependent on whether the light of any one wavelength component of incident light (visible light) from outside such as white light is best transmitted. In general, the color of the wavelength component that transmits the best The color is substantially the same or approximate, but here the external color of the filter layer 732 is set to substantially match or approximate the color of the display light that passes through the filter layer 732 and dims the display surface when the light source 712 is turned on. have.

As a result, when the light source 712 is turned off, when light from the outside, which is white light, enters the filter layer 732 through the cover plate 724 and the name plate 723 constituting the display surface, the filter layer ( The reflected light from 732 is emitted from the display surface so that the external color of the filter layer 732 is substantially recognized as the color of the display surface by the naked eye.

That is, the filter layer 732 plays the following two roles. The first role is to convert the color of the light emitted from the phosphor layer 731 toward the display surface (in general, a color mixture of the color of the light of the first wavelength and the color of the light of the second wavelength) to a desired color (display color), or It is to correct. The second role is to substantially match or approximate the color of the display surface when the light source 712 is on (the color of the display light) and the color of the display surface when the light source 712 is off. Accordingly, the light transmission characteristic of the filter layer 732 that substantially defines the color of the display light or the color of the display surface when the light source 712 is turned off needs to be set so that the filter layer 732 performs these two roles.

68 is a schematic cross-sectional view showing optical characteristics of the phosphor layer 731 and the filter layer 732 of the wavelength conversion member 722 as an example. Further, in the example shown in FIG. 68, the light transmission characteristic of the filter layer 732 is substantially transmitted so that only light of the second wavelength emitted by the phosphor layer 731 is transmitted, that is, light of a wavelength component other than the second wavelength is substantially It is set so that it is not transmitted through. Accordingly, the external color of the filter layer 732 is inevitably the same color as the color of light of the second wavelength.

The fluorescent member 733 constituting the phosphor layer 731 is formed of a transparent resin material and is formed in a plate shape or a sheet shape in which a fluorescent material (color conversion paint) having fluorescent properties described below is mixed, and the reference numerals in the drawing FM represents a fluorescent material.

The fluorescent material FM is excited by the light L1 of the first wavelength indicated by the solid line in the drawing, and then returns to the ground state, the second wavelength of the predetermined display color is longer than the first wavelength. It has a fluorescence characteristic of emitting light L2 (dashed line in the drawing). For this reason, when the light L1 of the first wavelength from the light source 712 is incident on the incident surface 722a of the phosphor layer 731, the incident light L1 is absorbed by the fluorescent material FM and is higher than the first wavelength. Light (fluorescent light) L2 of a long second wavelength is emitted, and light L2 of the second wavelength is emitted from the phosphor layer 731 to the filter layer 732.

The light L1 of the first wavelength incident on the filter layer 732 is sufficiently attenuated until it reaches the surface of the display surface side of the filter layer 732 and does not pass through the filter layer 732. In contrast, the light L2 of the second wavelength passes through the filter layer 732 without substantially attenuation. As a result, on the surface of the filter layer 732 on the display surface side, light consisting of substantially only the light L2 of the second wavelength is emitted toward the display surface side.

In addition, the filter layer 732 also has a function of correcting the color of the second wavelength light L2 emitted by the phosphor layer 731, and the second wavelength light passes through the filter layer 732 The intensity of each wavelength component of the wavelength light is corrected so that light with a color closer to the desired display color is obtained.

Further, in this case, the light transmission characteristic of the filter layer 732 is set to transmit substantially only light of the second wavelength, but, for example, as shown in FIG. 69, substantially all of the light of the second wavelength is transmitted, and You may set it so that a part of light of 1 wavelength may be transmitted. Alternatively, as shown in FIG. 70, the light transmission characteristics of the filter layer 732 may be set so as to transmit substantially all of the light of the first wavelength and to transmit a part of the light of the second wavelength, and various changes are considered.

However, in either case, the filter layer 732 needs to transmit at least a portion of the light emitted from the phosphor layer 731, and at the same time, its appearance color substantially matches the color of the display light, which is the transmitted light of the filter layer 732. Or you need to approximate. In addition, a specific configuration example of the wavelength conversion member 722 will be described in detail in the following experimental examples.

Here, a method of forming the filter layer 732 will be described.

As a first method, an ink 734 (filter material) (refer to Fig. 67) or a paint (filter material) having a predetermined light transmission characteristic and an appearance color substantially identical or close to the display color is applied to the phosphor layer 731 There is a method of forming the filter layer 732 by applying screen printing or spraying on the surface of one surface of the fluorescent member 733 in the form of a plate or a sheet constituting a sheet. In this method, there is an advantage that the filter layer 732 can be easily formed by a simple method of screen printing or spraying. In addition, the filter layer 732 according to this embodiment is formed by screen printing.

As a second method, a filter layer by thermally transferring a thermal transfer film having a predetermined light transmission characteristic and an external color substantially matching or approximating the display color to one surface of the fluorescent member 733 constituting the phosphor layer 731. There is a way to form (732). In this method, there is an advantage that the filter layer 732 can be easily formed by a simple method called thermal transfer, and as a thermal transfer film capable of constituting the filter layer 732, a thermal transfer film of sufficient color can be obtained. , There is an advantage that the filter layer 732 having a desired external color and light transmittance can be easily formed.

As a third method, a predetermined coloring material having impregnation property is impregnated on one surface of the fluorescent member 733 constituting the phosphor layer 731, and one surface layer of the fluorescent member 733 is There is a method of forming the filter layer 732 by coloring so as to have a light transmission characteristic and to have an external color that is substantially coincident or close to the display color. According to this method, when the filter layer 732 is formed by coating or the like, the filter layer 732 may be peeled off due to contact with other members, but the fluorescent member 733 constituting the phosphor layer 731 Since the filter layer 732 is formed by impregnating a predetermined coloring material on one surface and partially coloring the fluorescent member 733 itself, there is an advantage that the filter layer 732 does not come off.

As a fourth method, as shown in FIG. 71, a plate-shaped or sheet-shaped fluorescent member 733 constituting the phosphor layer 731, and a plate-shaped or sheet-shaped filter member constituting the filter layer 732 ( There is a method of forming the wavelength conversion member 722 by bonding the 735 with a transparent adhesive material or by applying ultrasonic vibration to weld contact surfaces of each other.

As a fifth method, there is a method of integrally forming the wavelength conversion member 722 having the phosphor layer 731 and the filter layer 732 by two-layer molding (double molding). As a specific two-layer molding method, a resin plate constituting either of the phosphor layer 731 or the filter layer 732 is prepared first, and the phosphor layer 731 or the resin plate prepared first is mounted in a mold. There is a method of manufacturing the wavelength conversion member 722 by pouring a resin material for constituting the other side of the filter layer 732 into a mold.

Next, it returns to FIG. 65 and the description continues. When the light source 712 is turned on and the light emitted from the phosphor layer 731 of the wavelength conversion member 722 passes through the filter layer 732 to generate display light having a predetermined display color, the display light is sent to the name plate ( Through 723, it is guided to the display surface constituted by the cover plate 724, the entire surface of the display surface is dimmed with a predetermined display color, and a predetermined optical display (information display) is performed. That is, the indicator 10a lights up in a predetermined display color.

As described above, according to the indicator (surface-illuminated display) 10a according to this embodiment, the color of the display light transmitted through the filter layer 732 to dim the display surface when the light source 712 is turned on, and the light source 712 ), the external color of the filter layer 732, which defines the color of the display surface when turned off, is substantially matched or approximated, so that the light source 712 lights up in the color of the display surface when the light source 712 is turned off. The color of the display surface (i.e., the color of the display light that dims the display surface) can be easily recognized intuitively, and the meaning of the indicator 10a can be intuitively recognized from the color of the display surface when the indicator is turned off. It can be easily understood.

In addition, at least a part of the light of the first wavelength from the light source 712 to which the phosphor layer 731 interposed between the light source 712 and the display surface is incident is converted into light of a second wavelength that is longer than the first wavelength. The light emitted from the phosphor layer 731 is passed through the filter layer 732 so that the display surface is dimmed by the light (display light) that has passed through the filter layer 732. By changing the type of the fluorescent member 733 constituting the phosphor layer 731 or the filter material (ink 734, etc.) forming the filter layer 732, it is easy to display light having various colors from light of the first wavelength. You can get it. As a result, since the light source 712 may be provided with one type of light source 712 (here, a blue LED light emitting device) that emits light of the first wavelength, for example, the type of LED light emitting device used according to the color of the display light. Compared to changing the combination of, the productivity can be improved and the cost can be reduced. In addition, a specific configuration example of the wavelength conversion member 722 will be described in detail in the following experimental examples.

In addition, since the phosphor layer 731 and the filter layer 732 are integrally provided in the wavelength conversion member 722, the number of parts can be reduced, and the assembly process can be simplified and the cost can be reduced.

In addition, in this embodiment, since the light from the light source 712 is diffused to the diffusion plate 721 and then incident on the wavelength conversion member 722, fluctuations in the amount of light or color fluctuations on the display surface are reduced. Has been.

In addition, in this embodiment, since the light of the first wavelength is light of a shorter wavelength having any one of the wavelengths from the ultraviolet region to blue, in this case, it is blue light, so it can produce light of a variety of colors than the light of the first wavelength. I can.

In addition, in this embodiment, the name plate 723 is inserted into the composite plate 720 and the information written on the name plate 723 is displayed according to the lighting of the light source 712, but the name plate 723 is used. Instead, predetermined information may be displayed only by turning on or off the display surface.

In addition, in the present embodiment, a wavelength conversion member 722 integrally provided with a phosphor layer 731 and a filter layer 31 is used, but a fluorescent plate having the same function as the phosphor layer 731 and the same as the filter layer 732 are used. A filter member (filter) having a function may be separately formed, and may be inserted into the composite plate 720 while being separated.

In addition, the following are considered as related technologies of the present invention.

72 is a schematic cross-sectional view of a display device (surface dimming display device) according to the related art of the present invention. This surface-illuminated display device is also the same unit indicator as the unit indicator 10a of the twenty-fourth embodiment, and portions corresponding to the unit indicator 10a are denoted by the same reference numerals and a description thereof will be omitted.

In this unit indicator light, the wavelength converting member 722 is not used, and the light emitted by the light source 712 (light of the first wavelength) is guided substantially as it is to the display surface to perform optical display. A characteristic point of this unit display lamp is that, as shown in FIG. 73, a filter layer 736 is formed on the surface of the diffusion plate 721 (here, the milky white diffusion plate) on the display surface side.

The filter layer 736 is provided for the same purpose as the filter layer 732 described above, and among the light emitted by the light source 712, light having a wavelength component of a predetermined display color used as display light (e.g., pure blue It is designed to transmit only the wavelength component light). For this reason, the filter layer 736 inevitably has an external color that substantially matches or approximates the display color.

Accordingly, the light of the first wavelength that is dimmed by the light source 712 passes through the filter layer 736 of the diffusion plate 721 so that the color of the light is corrected to a predetermined display color and is emitted toward the display surface. In addition, when the light source 712 is turned off, the color of the filter layer 36 having substantially the same color as the display color is visually recognized through the cover plate 24 and the name plate 23, and the light source 712 is turned off. Even in the city, the display color when this unit indicator light is on can be recognized by the naked eye.

<Experimental example of Example 24>

Here, a blue LED light emitting element is used for the light source 712, and in the blue wavelength light (light of the first wavelength) emitted by the blue LED light emitting element, six kinds of wavelength converting members 722 (wavelength converting member A , B, C, D, E, F) to generate red display light, green display light, and white display light (slightly reddish white, slightly yellowish white) Explain. Here, the graph of FIG. 74 shows a spectrum of blue wavelength light emitted by the light source 712.

In addition, in the first experimental example, the wavelength converting member (A, B, C) is used to generate red display light, and in the second experimental example, the wavelength converting member (D) is used to generate green display light, In the third experimental example, a white-based display light is generated by using the wavelength conversion members E and F. Also, Fig. 75 is a diagram showing chromaticity coordinates of the color of display light obtained in each experimental example.

First, as a first experimental example, a case of generating red light from blue wavelength light will be described. In FIG. 76, each graph represented by a chain line, a double-dot chain line, and a single-dot chain line is the light transmission of the red ink 734 having a red external color used for the filter layer 732 of the wavelength conversion members A, B, and C. It represents a characteristic. In addition, the same fluorescent member 733 is used for the phosphor layer 731 of each of the wavelength conversion members A, B, and C. In addition, the measurement of the light transmission characteristics is a screen-printed ink 734 for wavelength conversion members (A, B, C) on a transparent acrylic plate, irradiating light from a halogen lamp, and measuring the transmittance of each wavelength component of the light. I did it. The method of measuring this light transmission characteristic is the same in other experimental examples below.

The graph shown by the solid line in FIG. 77 shows that when the fluorescent member 733 used as the phosphor layer 731 of the wavelength conversion member (A, B, C) is irradiated with light of the blue wavelength of the light source 712, the fluorescence The spectrum of light emitted from the member 733 is shown. In this graph, as the light emitted from the fluorescent member 733, in addition to the red wavelength light emitted by the fluorescent member 733 by the blue wavelength light from the light source 712, the fluorescent member 733 is not converted. It can be seen that the blue wavelength light that has transmitted through is also quite contained. The point Rin on the chromaticity diagram in FIG. 75 represents the color of light emitted from the fluorescent member 733 here.

In Fig. 77, each graph represented by a chain line, a two-dot chain line, and a single-dot chain line is generated when each wavelength conversion member (A, B, C) according to the present experimental example is irradiated with light of the blue wavelength of the light source 712. It shows the spectrum of the red light that becomes. From these graphs, it can be seen that the blue wavelength light transmitted through the phosphor layer 731 by the filter layer 732 of each wavelength conversion member (A, B, C) is removed or significantly suppressed. From this, when the wavelength conversion member (A) is used, a purely red display light is obtained, and when the wavelength conversion member (B, C) is used, the red wavelength light is mixed with the blue wavelength light, as a result. It can be seen that a slightly pinkish red display light is obtained. Further, the color of the display light generated by the wavelength conversion member A is indicated by a point Rout on the chromaticity diagram of FIG. 75.

Next, as a second experimental example, a case of generating green light from blue wavelength light will be described. In FIG. 78, the graph indicated by the dashed line shows the light transmission characteristics of the green ink 734 having a green external color used for the filter layer 732 of the wavelength conversion member D. The graph shown by the dashed-dotted line in the figure shows that when the light of the blue wavelength of the light source 712 is irradiated to the fluorescent member 733 used as the phosphor layer 731 of the wavelength conversion member D, the fluorescent member 733 It shows the spectrum of light emitted from. In addition, the graph indicated by the solid line in the figure shows the spectrum of green wavelength light generated when the wavelength conversion member D according to the present experiment is irradiated with the blue wavelength light of the light source 712. In addition, the color of the light emitted from the fluorescent member 733 and the color of the display light generated by the wavelength conversion member D are indicated by points Gin and Gout on the chromaticity diagram of FIG. 75, respectively. .

As can be seen from these graphs, in this experimental example, since the wavelength conversion characteristic of the fluorescent member 733 constituting the phosphor layer 731 is good, the light of the blue wavelength incident on the phosphor layer 731 is substantially completely Light of blue wavelength is hardly included in the light converted to green wavelength light and incident on the filter layer 732 from the phosphor layer 731, but pure green among the light components included in the light emitted from the phosphor layer 731 The long wavelength component (yellow component) whose wavelength is longer than that of the filter layer 732 is removed by the filter layer 732 to correct the color of the light, so that the display light of a color closer to the desired display color (here, pure green with high saturation) is obtained. .

Next, as a third experimental example, a case in which light of a white color system is generated from light of a blue wavelength will be described. The graph of FIG. 79 shows the light transmission characteristics of the filter layer 732 (ink 734) of the wavelength conversion member E for generating reddish white light, and the graph of FIG. 80 is It shows the light transmission characteristics of the filter layer 732 (ink 734) of the wavelength conversion member F for generating light. In addition, the same fluorescent member 733 is used for the phosphor layer 731 of the wavelength conversion members E and F.

The graph shown by the solid line in FIG. 81 shows that when the fluorescent member 733 used as the phosphor layer 731 of the wavelength conversion members E and F is irradiated with light of a blue wavelength from the light source 712, the fluorescent member 733 ) Shows the spectrum of light emitted from. The graphs shown by the two-dot chain line and the one-dot chain line in the drawing are reddish white light generated when the wavelength conversion members E and F according to the present experiment are irradiated with light of the blue wavelength of the light source 712, Each of the spectrums of yellowish white light is shown. In addition, the color of the light emitted from the fluorescent member 733 of each wavelength conversion member (E, F), and the color of the display light generated by each wavelength conversion member (E, F) is the dot on the chromaticity diagram of FIG. And Wout1 and Wout2) respectively.

As can be seen from these graphs, the phosphor layer 731 of the wavelength conversion member (E, F) receives blue wavelength light and emits light in an approximately yellow wavelength region, and the phosphor layer 731 The color of light emitted from is white, which is an additive color mixture of the color of light in the blue wavelength and the color of light in the approximately yellow wavelength range. Then, the white light is converted into reddish white light or yellowish white light by the filter layer 732 of each of the wavelength conversion members E and F.

In addition, in this experimental example, a light red or light yellow filter layer 732 was formed to convert white light emitted from the phosphor layer 731 into reddish white light or yellowish white light. A filter layer 732 having a white external color may be attached to the phosphor layer 731 according to the present experimental example, so that the color of the display surface at the time of light-off becomes white.

Next, a specific example of the filter layer 736 used in the surface dimming display device according to the related art of the present invention shown in FIGS. 72 and 73 is shown. In FIG. 82, a graph indicated by a dashed line shows the light transmission characteristics of blue ink having an external color of blue used for the filter layer 736. In the figure, a graph showing a dashed-dotted line represents a spectrum of blue wavelength light emitted by the light source 712. In addition, in the figure, a graph indicated by a solid line shows the spectrum of transmitted light when the transparent acrylic plate on which the filter layer 736 is formed is irradiated with light of a blue wavelength from the light source 712.

As can be seen from these graphs, among the components of light included in the light emitted by the light source 712, the peripheral components of the desired wavelength component (here, the pure blue wavelength component) are suppressed by the filter layer 736, It is corrected so that the color of the light emitted by 712 becomes closer to the desired display color.

Although each experimental example of the present invention has been described above, the scope of the present invention is not limited to the above embodiments, but is defined by the appended claims.

Claims (1)

A display device for dimming a predetermined display surface to perform display. Light sources 12, 54, 212a, 312, 412 and 712 which emit light L1 of a first wavelength, Interposed between the light source and the display surface, at least a portion of the light of the first wavelength in the incident light source is converted into light L2 of a second wavelength having a longer wavelength than the first wavelength to display the display surface. And a fluorescent plate (22, 214, 322, 421, 731) for emitting toward the light emitting device.

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