WO2012161012A1 - Color-conversion substrate, lighting device, and color display device - Google Patents

Abstract

A color-conversion substrate (101) provided with the following: a transparent substrate (1) that has a principal surface (1a); a plurality of phosphor layers (3) that are arranged on the aforementioned principal surface (1a) and each have side surfaces; a first low-refractive-index layer (9) that is interposed between the principal surface (1a) and the phosphor layers (3) and has a lower index of refraction than the phosphor layers (3); reflective films (6) that are formed on at least the sides of the phosphor layers (3) in order to reflect light exiting the side surfaces of said phosphor layers (3); and a second low-refractive-index layer (10) that has a lower index of refraction than the phosphor layers (3) and covers the parts of the phosphor layers (3) not covered by the reflective films (6) on the surfaces of said phosphor layers (3) on the opposite side from the transparent substrate (1).

Description

Color conversion substrate, illumination device, and color display device

The present invention relates to a color conversion substrate, a lighting device, and a color display device.

As one form of a conventional color display device that is not a self-luminous type, there is a configuration including a backlight that emits white light and an optical shutter. For example, a liquid crystal display device, which is a type of display device, includes, as a backlight, a device that combines a light source such as an LED (Light Emitting Diode) or a cold cathode tube, a light guide plate, and an optical sheet. On the other hand, the liquid crystal display device includes a liquid crystal panel as an optical shutter. The liquid crystal panel includes two substrates and a liquid crystal layer sealed between the two substrates. Usually, a TFT element is provided on one surface of two substrates, and a color filter (CF) is provided on the other surface. The white light of the backlight is emitted as light of a desired color by passing through one of the three primary colors of red, green, and blue provided as a color filter, but is incident by passing through the color filter. Since light components other than the color of the filter are absorbed, the amount of light is reduced to about 1/3.

On the other hand, Japanese Patent Laid-Open No. 2000-131683 (Patent Document 1) proposes a display device including a backlight that emits blue light, a liquid crystal panel, and a phosphor substrate. The phosphor substrate herein includes a phosphor that absorbs blue light and emits red light, and a phosphor that absorbs blue light and emits green light. Blue light is displayed by light transmitted through the blue color filter, but since the light source light is originally blue, there is almost no loss of light in the blue color filter. As described above, in the display device described in Patent Document 1, there is no loss of light amount due to absorption by the color filter, and light utilization efficiency is improved.

As a first method for forming a phosphor layer having a desired pattern on a phosphor substrate, a method in which a phosphor is supplied and arranged only in a necessary region can be considered. As a second method, a method may be considered in which a phosphor layer is formed so as to cover the entire surface of the substrate, and only the phosphor layer in a necessary region is left and the others are removed.

The first method includes an inkjet method and various printing methods. The second method includes a photolithography method. In the second method, the phosphor is applied to the entire substrate. On the other hand, the first ink jet method applies a phosphor only to a necessary region. Therefore, compared with the second method, the ink jet method of the first method has an advantage that the amount of phosphor to be used can be reduced. Among the first methods, the inkjet method is preferable because the inkjet method can form a pattern with higher accuracy than the printing method.

In order to reduce crosstalk, it is desirable to make the distance between the optical shutter and the color filter as short as possible. Therefore, the phosphor constituting the color filter needs to be disposed on the surface of the phosphor substrate on the side of the optical shutter, that is, the side on which light that has passed through the optical shutter enters. “Crosstalk” here means that light that has passed through the optical shutter of one pixel enters a phosphor region other than the phosphor region of the color that correctly corresponds to that pixel. Since display quality deteriorates when crosstalk occurs, it is desirable that the crosstalk be as little or as little as possible. Here, the “pixel” refers to a monochrome pixel. For example, when one element of color display in an image is expressed by a combination of three different colors of single color display, it means an area for displaying one of the three colors.

Another example of a liquid crystal display device using a blue light source is described in Japanese Unexamined Patent Application Publication No. 2009-244383 (Patent Document 2). The liquid crystal display device includes a color filter having a phosphor that emits red fluorescence when excited by blue light, and a phosphor that emits green fluorescence when excited by blue light, and further scatters at least blue light. A light scattering film is provided.

Japanese Patent Application Laid-Open No. 2010-66437 (Patent) discloses a configuration in which a phosphor is used for a front plate of a liquid crystal display device, and a reflector is provided on the side of the phosphor of the front plate for the purpose of improving light extraction efficiency from the phosphor. Reference 3). The configuration described in Patent Document 3 is shown in FIG. On one surface of the transparent substrate 1, a red phosphor layer 3r, a green phosphor layer 3g, and a diffusion layer 3b are formed. An optical shutter 42 is arranged so as to overlap this surface.

JP 2000-131683 A JP 2009-244383 A JP 2010-66437 A

FIG. 26 shows a situation where blue light 4b is incident as backlight from below in the structure shown in FIG. When the blue light 4b is incident, the red phosphor layer 3r and the green phosphor layer 3g are excited and emit light, and the red light 5r and the green light 5g are emitted upward from the transparent substrate 1, respectively. In the diffusion layer 3 b, the incident blue light 4 b is scattered, and the blue light 5 b is emitted by being incident on the upper side from the transparent substrate 1.

As described in paragraph 0029 of Patent Document 3, if the refractive index of the phosphor is 1.5, the light emitted from the phosphor and transmitted through the front glass substrate according to Snell's law is If the incident angle to the interface between the glass substrate and the outside air is larger than a certain level when exiting from the inside toward the outside on the viewing side, it will be reflected at the interface and exit to the outside on the viewing side as shown in FIG. I can't. As a result, the light use efficiency decreases.

A part of the light reflected at the interface between the glass substrate and the outside air trying to be emitted from the inside of the glass substrate toward the outside on the viewing side may enter the other phosphor and excite the other phosphor. . When other phosphors emit light by such excitation, display quality is deteriorated.

Also, light that travels toward the light source rather than the viewer side among the light emitted by excitation of the phosphor does not contribute to the viewer.

In the configuration described in Patent Document 3, since it is necessary to ensure a large area occupied by the inclined surface in a plan view, the opening that can enter the phosphor and the diffusion layer is reduced, and the whole As a result, the light utilization efficiency is reduced.

Therefore, an object of the present invention is to provide a color conversion substrate, an illumination device, and a color display device that can improve the light use efficiency.

In order to achieve the above object, a color conversion substrate according to the present invention includes a transparent substrate having a main surface, a plurality of phosphor layers disposed on the main surface and having side surfaces, and the main surface and the phosphor layer. Between the first low refractive index layer having a refractive index smaller than the refractive index of the phosphor layer and at least one of the phosphor layers for reflecting light emitted from the side surface of the phosphor layer. The reflective film formed on the side and the area of the phosphor layer opposite to the transparent substrate that covers a region not covered with the reflective film, have a refractive index smaller than the refractive index of the phosphor layer A second low refractive index layer.

According to the present invention, since the structure in which each of the plurality of phosphor layers is sandwiched between the first and second low refractive index layers is provided, the light use efficiency can be improved.

It is sectional drawing of the color conversion board | substrate in Embodiment 1 based on this invention. It is a top view of the color conversion board | substrate in Embodiment 1 based on this invention. It is explanatory drawing of the state into which the blue light injects into the color conversion board | substrate in Embodiment 1 based on this invention. In Embodiment 1 based on this invention, it is the 1st explanatory drawing about the relationship between the angle of a reflecting film, and an opening part. In Embodiment 1 based on this invention, it is the 2nd explanatory drawing about the relationship between the angle of a reflecting film, and an opening part. It is sectional drawing of the color conversion board | substrate in Embodiment 2 based on this invention. It is a schematic diagram of the illuminating device in Embodiment 3 based on this invention. It is a top view of the illuminating device in Embodiment 3 based on this invention. It is a conceptual diagram of the illuminating device in Embodiment 3 based on this invention. It is a conceptual diagram of the 1st modification of the illuminating device in Embodiment 3 based on this invention. It is a conceptual diagram of the 2nd modification of the illuminating device in Embodiment 3 based on this invention. It is a conceptual diagram of the 3rd modification of the illuminating device in Embodiment 3 based on this invention. It is explanatory drawing of the color display apparatus in Embodiment 4 based on this invention. It is a conceptual diagram of the color display apparatus in Embodiment 5 based on this invention. It is a conceptual diagram of the 1st modification of the color display apparatus in Embodiment 5 based on this invention. It is a conceptual diagram of the 2nd modification of the color display apparatus in Embodiment 5 based on this invention. It is a conceptual diagram of the 3rd modification of the color display apparatus in Embodiment 5 based on this invention. It is a conceptual diagram of the 4th modification of the color display apparatus in Embodiment 5 based on this invention. It is the elements on larger scale of the color display apparatus shown in FIG. It is a conceptual diagram of the 5th modification of the color display apparatus in Embodiment 5 based on this invention. It is sectional drawing of the 1st example of an optical shutter. It is sectional drawing of the 2nd example of an optical shutter. It is sectional drawing of the 1st example of a self-luminous display apparatus. It is sectional drawing of the 2nd example of a self-luminous display apparatus. It is sectional drawing of the structure based on a prior art. It is explanatory drawing of the course of the light in the structure based on a prior art.

(Embodiment 1)
With reference to FIG. 1 and FIG. 2, the color conversion board | substrate in Embodiment 1 based on this invention is demonstrated. As shown in FIG. 1, the color conversion substrate 101 includes a transparent substrate 1 having a main surface 1a, a plurality of phosphor layers 3 disposed on the main surface 1a and having side surfaces, and a main surface 1a and phosphor layers 3 respectively. In order to reflect the light emitted from the side surface of the phosphor layer 3 and the first low-refractive index layer 9 having a refractive index smaller than that of the phosphor layer 3, The reflective film 6 formed at least on the side and the area of the phosphor layer 3 opposite to the transparent substrate 1 that covers the region not covered with the reflective film 6 and has a refractive index smaller than the refractive index of the phosphor layer 3 A second low-refractive index layer 10.

The phosphor layer 3 preferably includes a red phosphor layer 3r and a green phosphor layer 3g. The red phosphor layer 3r is formed of a phosphor material that absorbs at least blue light and emits red light. The green phosphor layer 3g is formed of a phosphor material that absorbs at least blue light and emits green light. In addition to the plurality of phosphor layers 3, a diffusion layer 3b is formed on the main surface 1a. The first low refractive index layer 9 and the second low refractive index layer 10 can be formed of resin.

The upper side in FIG. 1 is the viewer side. As shown in FIG. 1, the color conversion substrate 101 can be used by making blue light 4b as backlight light incident from the opposite side to the viewing side. However, in contrast to that shown in FIG. 1, a usage method in which backlight light is incident from the transparent substrate 1 side and viewed from the opposite side of the transparent substrate 1 is also possible.

When the color conversion substrate 101 is viewed from a direction perpendicular to the main surface 1a of the transparent substrate 1, that is, from above in FIG. 1, it is as shown in FIG. In FIG. 2, the phosphor layer 3 and the like are seen through the transparent substrate 1.

FIG. 3 shows a situation when the blue light 4b is incident as the backlight light on the color conversion substrate 101 in the present embodiment. The upper side in FIG. 3 is the viewing side. Blue light 4b is irradiated from a backlight (not shown) disposed below.

Each of the plurality of phosphor layers 3 is excited by the incidence of blue light 4b. Nondirectional light emission occurs at each point inside the phosphor layer 3. When omnidirectional light emission occurs, the light 11e1 traveling at a small incident angle with respect to the interface 61 between the first low refractive index layer 9 and the phosphor layer 3 is reflected in the first low refractive index layer 9 and the transparent substrate 1. Is transmitted to the viewing side. The light 11e2 traveling sideways is reflected by the reflective film 6. As a result, when it proceeds with a sufficiently small incident angle toward the viewing side, the light passes through the first low refractive index layer 9 and the transparent substrate 1 and exits to the viewing side.

The light 11e3 that has traveled at a large incident angle with respect to the interface 61 due to omnidirectional light emission by excitation of the phosphor layer 3 is reflected by the interface 61 and returns to the inside of the phosphor layer 3. The same applies to light that has traveled at a large incident angle with respect to the interface 61 after having been reflected by the reflective film 6 or the like one or more times without exiting the phosphor layer 3. If the incident angle is smaller than a certain level, it can enter the first low refractive index layer 9, but if the incident angle is larger than a certain level, it cannot enter the first low refractive index layer 9 and is reflected by the interface 61. Return to the inside of the phosphor layer 3.

Of the light traveling toward the opposite side to the viewing side by non-directional light emission by excitation of the phosphor layer 3, the incident angle with respect to the interface 62 between the second low refractive index layer 10 and the phosphor layer 3 is large. The advanced 11e4 is reflected by the interface 62 and returns to the inside of the phosphor layer 3. The same applies to light that has traveled at a large incident angle with respect to the interface 62 after having been reflected by the reflective film 6 or the like one or more times without exiting the phosphor layer 3.

The light can enter the first low refractive index layer 9 side beyond the interface 61 between the first low refractive index layer 9 and the phosphor layer 3 only when the incident angle with respect to the interface 61 is small to some extent. Therefore, the incident angle of such light is sufficiently small even at the interface 63 between the transparent substrate 1 and the outside air. Therefore, it can be emitted to the viewing side without being reflected by the interface 63. Even though the light has entered the inside of the first low refractive index layer 9, it is possible to avoid a situation in which the light is reflected at the interface 63 and cannot be emitted to the viewer side and lost.

The color conversion substrate 101 according to the present embodiment has a structure in which the upper and lower sides of each phosphor layer 3 are sandwiched between the first and second low refractive index layers 9 and 10, thus improving the light utilization efficiency. Can be made.

Even in the diffusion layer 3b provided separately from the phosphor layer 3, the blue light 4b is scattered with omnidirectionality, but the first and second low refractive index layers above and below the diffusion layer 3b. By adopting a structure sandwiched between 9 and 10, the same effect can be obtained with respect to the light scattered inside the diffusion layer 3 b by the reflective film 6 and the first and second low refractive index layers 9 and 10. However, it is not essential for the present invention to have a structure in which the upper and lower sides of the diffusion layer 3b are sandwiched between the first and second low refractive index layers 9 and 10.

The reflective film 6 directly covers the side surface of the phosphor layer 3. By adopting this configuration, the number of types of members can be reduced, so that the manufacturing process can be reduced.

The second refractive index layer 10 can be replaced by an air layer. It can be said that the air layer has a refractive index of 1. The transparent substrate 1 is generally a glass substrate, and the refractive index of the glass substrate is 1.52. It can be said that the phosphor layer 3 has a refractive index of 1.49 to 1.59. The first low refractive index layer 9 preferably has a refractive index of 1.20 or more and 1.40 or less. The second low refractive index layer 10 preferably has a refractive index of 1.20 or more and 1.40 or less. By adopting this configuration, the first and second low-refractive index layers 9 and 10 are members having a refractive index sufficiently lower than that of the phosphor layer 3, so that the light to be emitted from the phosphor layer 3 is severe. It is possible to reflect light other than light having a sufficiently small incident angle after sorting under conditions.

It is preferable that the plurality of phosphor layers 3 have no scattering characteristics. By adopting this configuration, the phosphor layer 3 can efficiently emit light emitted by itself to the outside.

The plurality of phosphor layers 3 are preferably transparent. Such a phosphor layer 3 can be formed of, for example, an organic phosphor or a nanophosphor. If the fluorescent substance layer 3 is a transparent body, it can radiate | emit the light which emitted light itself outside efficiently.

As shown in FIG. 1, it is preferable that the reflective film 6 has a slope facing the transparent substrate 1 side when viewed from the center of the phosphor layer 3. By adopting this configuration, the light reflected by the reflective film 6 travels to the transparent substrate 1 side, and the light is easily emitted from the transparent substrate 1 side. The characteristics change depending on the angle of the inclined surface of the reflective film 6 with respect to the main surface 1 a of the transparent substrate 1. As shown in FIG. 4, if the angle θ between the inclined surface of the reflective film 6 and the main surface 1a is small, the probability that the light traveling in the phosphor layer 3 can be emitted to the viewer side with only a small number of reflections increases. On the other hand, as shown in FIG. 5, if the angle formed by the inclined surface of the reflective film 6 and the main surface 1a is large, the light traveling in the phosphor layer 3 has a high probability that it cannot be emitted to the viewer side unless it is reflected many times. However, since the phosphor layer 3 of each pixel can have a large opening 24 for receiving light, the light utilization efficiency can be further increased.

(Embodiment 2)
With reference to FIG. 6, a color conversion substrate according to the second embodiment of the present invention will be described. As shown in FIG. 6, the color conversion substrate 102 in the present embodiment includes a transparent partition wall 2 formed on the main surface 1a so as to have a side surface. The side surface of the transparent partition 2 is in contact with the side surface of the phosphor layer 3. The reflective film 6 covers the side surface of the transparent barrier rib 2 opposite to the surface in contact with the phosphor layer 3 and the surface opposite to the transparent substrate 1. Other configurations are the same as those of the color conversion substrate 101 described in the first embodiment.

The transparent barrier rib 2 may be provided not only in contact with the side surface of the phosphor layer 3, but also in contact with the side surface of the diffusion layer 3b as shown in FIG.

Also in the present embodiment, the light traveling in the lateral direction inside the phosphor layer 3 is transmitted through the transparent partition wall 2 and reflected by the reflective film 6, so that the same effect as in the first embodiment can be obtained. Can do. Furthermore, in this embodiment, since a part of the space surrounded by the reflective film 6 is occupied by the transparent partition wall 2, the volume of the space to be filled with the phosphor material in order to form the phosphor layer 3 is increased. It can be kept small. Therefore, the usage amount of the phosphor material can be reduced. If the amount of phosphor material used can be reduced, the cost will be reduced.

Further, when the phosphor layer 3 is formed, it is possible to employ a method in which the transparent barrier ribs 2 are formed first and the concave portions surrounded by the transparent barrier ribs 2 are filled with the phosphor material. Conveniently, the body material can be easily placed in the correct location. The phosphor material can be filled, for example, by inkjet. If the transparent barrier ribs 2 are formed in advance, the phosphor materials of the adjacent pixels are physically separated, so that the phosphor materials of the adjacent pixels can be prevented from being undesirably mixed.

The transparent barrier rib 2 is preferably formed of a material having a refractive index equal to or higher than that of the phosphor layer 3.

So far, each embodiment has been described on the assumption that the backlight light is the blue light 4b. However, the backlight light is not limited to the blue light but may be light of other colors.

The backlight light may be white light, for example. When the backlight light is white light, the plurality of phosphor layers 3 emit red light by absorbing and exciting white light, and emitting green light by absorbing and exciting white light. It is preferable to use a combination of three types of phosphor layers and phosphor layers that emit blue light when excited by absorbing white light.

Further, the backlight light may be a specific type of light having no color. For example, the backlight light may be ultraviolet light. When the backlight light is ultraviolet light, the plurality of phosphor layers 3 emits red light by absorbing and exciting ultraviolet light, and emits green light by absorbing and exciting ultraviolet light. It is preferable to use a combination of three types of phosphor layers and phosphor layers that emit blue light when excited by absorbing ultraviolet light.

The generalization of this idea is as follows.
The color conversion substrate includes, as one of the plurality of phosphor layers 3, a second wavelength region phosphor layer that absorbs at least light in the first wavelength region and emits light in the second wavelength region. It is preferable that the other one of the body layers 3 includes a third wavelength region phosphor layer that absorbs at least light in the first wavelength region and emits light in the third wavelength region. By adopting this configuration, it is possible to emit at least two kinds of light in the second wavelength range and the third wavelength range by irradiating the light in the first wavelength range, using the received light in the first wavelength range as a trigger. The color conversion substrate can be made. By adopting this configuration, it is possible to emit at least two kinds of light in the second wavelength range and the third wavelength range by irradiating the light in the first wavelength range, using the received light in the first wavelength range as a trigger. The color conversion substrate can be obtained.

Furthermore, it is preferable that a diffusion layer or a transparent layer for scattering or transmitting light in the first wavelength region is disposed on the main surface 1a. Actually, in each of the above-described embodiments, the color conversion substrates 101 and 102 include the diffusion layer 3 b in addition to the plurality of phosphor layers 3. In this way, if a portion that scatters or transmits light in the first wavelength range is provided as it is, any light in the first to third wavelength ranges can be emitted, and a color that allows more diverse displays. It becomes a conversion board.

Light with different wavelength ranges can be light of different colors. Specifically, it is preferable that the light in the first wavelength range is blue light, the light in the second wavelength range is red light, and the light in the third wavelength range is green light. The example of the color conversion board shown in the above embodiments corresponds to this. By adopting this configuration, as long as a blue light source is prepared, the plurality of phosphor layers 3 can emit either red or green light, and color conversion capable of color display is possible. It can be a substrate.

Furthermore, in this configuration, it is preferable that a diffusion layer 3b or a transparent layer for scattering or transmitting blue light is disposed on the main surface 1a. By adopting this structure, the plurality of phosphor layers 3 can emit any one of the three primary colors of red, green, and blue as long as they are irradiated with blue light, and color display is possible. A color conversion substrate can be obtained. In the illustrated example, the configuration includes the diffusion layer 3b. However, the configuration is not limited to the diffusion layer 3b. Instead of scattering the blue light as the light in the first wavelength region as in the diffusion layer 3b, a portion that transmits blue light as it is may be provided.

(Embodiment 3)
With reference to FIGS. 7 to 9, a lighting apparatus according to Embodiment 3 based on the present invention will be described.

The lighting device in this embodiment includes the color conversion substrate having the configuration described in each of the above embodiments. In the color conversion substrate described in each of the above embodiments, as one of the plurality of phosphor layers 3, a second wavelength region phosphor layer that absorbs at least light in the first wavelength region and emits light in the second wavelength region. A third wavelength region phosphor layer that absorbs at least the light in the first wavelength region and emits light in the third wavelength region as another one of the plurality of phosphor layers 3, and Assume a color conversion substrate in which the light in the first wavelength region is blue light, the light in the second wavelength region is red light, and the light in the third wavelength region is green light. In this embodiment, for example, an illumination device using the color conversion substrate 101 is assumed. As shown in FIG. 7, the illumination device 701 according to the present embodiment includes a color conversion board 101 and a blue light source 43b disposed on the color conversion board 101 so as to emit light toward the color conversion board 101. .

When the illumination device 701 is viewed from a direction perpendicular to the main surface 1a of the transparent substrate 1, that is, from above in FIG. 7, it is as shown in FIG. In FIG. 8, the phosphor layer 3 and the like are seen through the transparent substrate 1.

FIG. 9 shows a more detailed display of the blue light source 43b in FIG. The blue light source 43 b includes a blue LED 431 b and a light guide plate 432.

In the illumination device 701 in this embodiment, since the blue light 4b is supplied from the blue light source 43b to the color conversion substrate 101, the color conversion substrate 101 has three types of red light, green light, and blue light. Light is emitted. Since the three primary colors of light are emitted all at once, the whole becomes white light, and the lighting device 701 can be used in the same manner as conventional white light illumination.

In the color conversion substrate 101 provided in the lighting device 701 in the present embodiment, the phosphor layer 3 is configured to be sandwiched between the first low refractive index layer 9 and the second low refractive index layer 10, so that the light Therefore, it is possible to provide a lighting device with high light utilization efficiency.

Note that the color conversion substrate 102 may be used instead of the color conversion substrate 101.
The configuration of the blue light source 43b is not limited to that illustrated in FIG. 9, and may be another configuration. For example, as shown in FIG. 10, the blue light source 43b may be a blue LED 433b arranged in a planar manner without a light guide plate. In that case, as shown in FIG. 10, it is preferable to dispose a diffusion plate 436 between the blue LED 433 b and the color conversion substrate 101.

For example, as shown in FIG. 11, the blue light source 43b may include an organic EL panel 434b. The organic EL panel 434b emits blue light.

Alternatively, for example, as shown in FIG. 12, the blue light source 43b may include an inorganic EL panel 435b. The inorganic EL panel 435b emits blue light.

The lighting device includes the color conversion substrate 102 described in Embodiment 2 and a light source that is disposed on the color conversion substrate 102 and emits light in the first wavelength range toward the color conversion substrate 102. May be. In the color conversion substrate 102 provided in this illumination device, the phosphor layer 3 is sandwiched between the first low refractive index layer 9 and the second low refractive index layer 10, so that the light use efficiency is high. Therefore, it is possible to provide a lighting device with high light use efficiency.

(Embodiment 4)
With reference to FIG. 13, a color display device according to Embodiment 4 of the present invention will be described. The color display device in this embodiment includes the color conversion substrate having the configuration described in any of the above embodiments. A color conversion substrate similar to that assumed as the color conversion substrate included in the lighting device in Embodiment 3 is assumed. In the present embodiment, for example, a color display device using the color conversion substrate 101 is assumed.

As shown in FIG. 13, a color display device 711 according to the present embodiment is arranged so as to overlap the color conversion substrate 101 and the color conversion substrate 101, and emits blue light 4 b toward the color conversion substrate 101. 44. The self-luminous display device 44 may be an organic EL display panel or an inorganic EL display panel. The self-luminous display device 44 includes a substrate 442. On the main surface of the substrate 442, EL elements 441r, 441g, and 441b are arranged corresponding to each pixel. Also on the main surface 1a of the color conversion substrate, since the phosphor layer 3 or the diffusion layer 3b is arranged corresponding to each pixel, the EL element is arranged in a state of being positioned corresponding to each of these layers. It can be said that.

The EL elements 441r, 441g, and 441b are organic EL elements or inorganic EL elements. The EL elements 441r, 441g, and 441b may all emit blue light. The EL elements 441r, 441g, and 441b may emit only blue light. The EL elements 441r, 441g, and 441b can be individually turned on / off by a switching element such as a TFT (Thin Film Transistor) provided for each pixel. The EL elements 441r, 441g, and 441b emit a desired amount of blue light respectively corresponding to red, green, and blue of the final display content by being operated by the switching elements.

In FIG. 13, the EL elements 441 r, 441 g, and 441 b that are formed in layers protruding individually on the main surface of the substrate 442 of the self-luminous display device 44 are displayed as if exposed. The structure of the self-luminous display device 44 shown in FIG. Actually, the EL elements 441r, 441g, and 441b are not limited to such a structure. The EL elements 441r, 441g, 441b may be covered with other transparent members. An example of a more specific structure will be described later.

In the present embodiment, the blue light 4b is merely irradiated from the self-luminous display device 44 to the color conversion substrate 101. However, the color conversion substrate 101 receives the received blue light 4b in a different color for each pixel. Can be converted to The phosphor layer 3r absorbs the blue light 4b incident from the EL element 441r and emits red light. That is, red light 5r is emitted from the phosphor layer 3r. The phosphor layer 3g absorbs the blue light 4b incident from the EL element 441g and emits green light. That is, 5 g of green light is emitted from the phosphor layer 3g. The phosphor layer 3b scatters the blue light 4b incident from the EL element 441b and emits it as blue light 5b.

In this way, since each of red, green, and blue light can be appropriately emitted for each pixel, color display is possible. In the color conversion substrate 101 provided in the color display device 711 in the present embodiment, the phosphor layer 3 is configured to be sandwiched between the first low refractive index layer 9 and the second low refractive index layer 10. Since the light use efficiency is high, a color display device with high light use efficiency can be obtained.

(Embodiment 5)
With reference to FIGS. 14 to 17, a color display device according to Embodiment 5 of the present invention will be described. The color display device in this embodiment includes the color conversion substrate having the configuration described in any of the above embodiments. A color conversion substrate similar to that assumed as the color conversion substrate included in the lighting device in Embodiment 3 is assumed. Therefore, in the present embodiment, for example, a color display device using the color conversion substrate 101 is assumed.

As shown in FIG. 14, the color display device 712 according to the present embodiment includes a color conversion substrate 101, a blue light source 43 b disposed on the color conversion substrate 101 so as to emit light toward the color conversion substrate 101, and a color An optical shutter 42 is provided between the conversion substrate 101 and the blue light source 43b. The optical shutter 42 is positioned so as to correspond to the color conversion substrate 101. “Positioned so as to correspond” means that, for example, when the optical shutter 42 includes a plurality of pixels, each of the plurality of phosphor layers 3 in the color conversion substrate 101 corresponds to the plurality of pixels of the optical shutter 42. It means that the optical shutter 42 is positioned so as to correspond to one of them. Further, when the color conversion substrate 101 includes a diffusion layer or a transparent layer for scattering or transmitting blue light in addition to the plurality of phosphor layers 3, the diffusion layer or the transparent layer is also a plurality of pixels of the optical shutter 42. Means one of the above. The blue light source 43 b includes a blue LED 431 b and a light guide plate 432.

The configuration of the blue light source 43b is not limited to that illustrated in FIG. 14, but may be other configurations. For example, as shown in FIG. 15, the blue light source 43b may be a blue LED 433b arranged in a plane without having a light guide plate. In that case, as shown in FIG. 15, it is preferable to dispose a diffusion plate 436 between the blue LED 433 b and the color conversion substrate 101.

For example, as shown in FIG. 16, the blue light source 43b may include an organic EL panel 434b. The organic EL panel 434b emits blue light.

Alternatively, as shown in FIG. 17, for example, the blue light source 43b may include an inorganic EL panel 435b. The inorganic EL panel 435b emits blue light.

The optical shutter 42 may be any device that can control whether or not to transmit light for each pixel by some principle. The optical shutter 42 may be, for example, a liquid crystal display panel or a transmissive MEMS panel. Still other things may be used. Details will be described later.

The operation and effect of the color display device 712 in this embodiment will be described. It is controlled whether or not the blue light 4b emitted from the blue light source 43b is transmitted through each pixel by the optical shutter 42 or how much light is transmitted. Therefore, after passing through the optical shutter 42, each pixel is transmitted. It proceeds as blue light 4b with a light amount set for each. Thus, a predetermined amount of blue light 4b is incident on each of the plurality of phosphor layers 3 and the diffusion layer 3b. When the blue light 4b is incident on any of the plurality of phosphor layers 3r and 3g, the phosphor layer is excited by the blue light 4b to emit light, and red light or green light is emitted to the viewing side. When the blue light 4b is incident on the diffusion layer 3b, the incident blue light 4b is scattered and emitted to the viewing side. In this way, only light that has been correctly processed in each pixel is emitted, so that color display can be performed. In the color conversion substrate 101 provided in the color display device 712 in the present embodiment, the phosphor layer 3 is configured to be sandwiched between the first low refractive index layer 9 and the second low refractive index layer 10. Since the light utilization efficiency is high, a color display device with high light utilization efficiency can be obtained.

In the examples shown in FIGS. 14 to 17, the optical shutter 42 is disposed between the color conversion substrate 101 and the blue light source 43b. However, other arrangements are conceivable.

For example, a color display device 713 illustrated in FIG. 18 includes a color conversion substrate 101, a blue light source 43b disposed on the color conversion substrate 101 so as to emit light toward the color conversion substrate 101, and a blue light source of the color conversion substrate 43b. And an optical shutter 42 disposed on the side opposite to 43b. Assuming that the side where the user viewing the display content is located is called “front side” and the side far from the user is called “rear side”, in the example shown in FIG. 18, it can be said that the optical shutter 42 is located on the foremost side. .

In each configuration of the color display devices 712 and 713 shown in FIGS. 14 and 18, the color conversion substrate 101 has a surface opposite to the surface on which the transparent substrate 1 is located facing the optical shutter 42 side. It is preferable to arrange | position. For example, FIG. 19 shows a partially enlarged view when this condition is satisfied in the color display device 712 shown in FIG. With this arrangement, the distance in the thickness direction between the color conversion layer inside the color conversion substrate 101 and the structure for controlling the light transmission of each pixel inside the optical shutter 42 becomes small. The transmission / reception of light for each pixel to / from the shutter 42 is more reliably performed in a correct correspondence relationship.

In FIG. 19, the uneven surface of the color conversion substrate 101 is in direct contact with the optical shutter 42. However, as shown in FIG. 20, the planarization film covers the phosphor layer 3 and the diffusion layer 3 b of the color conversion substrate. 23 may be provided. If the surface on which the planarizing film 23 is provided is overlapped with the optical shutter 42, the surface becomes more stable.

The planarizing film 23 is not necessarily provided as a hard film before being overlapped with the optical shutter 42, and may serve as an adhesive for bonding to the optical shutter 42. The planarizing film 23 may be a transparent resin.

Even in the configuration in which the optical shutter 42 is at the foremost side as in the color display device 713 shown in FIG. 18, the side where the transparent substrate 1 is present can be obtained by inverting the front and back of the color conversion substrate without changing the position of the optical shutter. You may arrange | position so that the surface on the opposite side to this surface may face the optical shutter 42 side. In this case, the optical shutter 42 and the color conversion substrate are arranged in this order from the front side, and the plurality of phosphor layers 3 are located on the front side of the transparent substrate 1 inside the color conversion substrate. This is preferable because the transmission / reception of light for each pixel between the color conversion substrate and the optical shutter 42 can be performed in a correct correspondence. However, in this case, simply by reversing the front and back using the color conversion substrate 101, the inclined surface of the reflective film 6 that surrounds the phosphor layer 3 is not spread to the front side but to the rear side, A correction is required. It is necessary to form the inclined surface of the reflective film 6 so as to spread to the front side. For this purpose, when the phosphor layer 3 and the reflective film 6 are formed on the main surface 1a of the transparent substrate 1, a partition wall is formed in advance between the phosphor layers 3 and then the reflective film 6 is formed. Thus, the direction of the inclined surface of the reflective film 6 may be changed. In that case, it is conceivable to form the phosphor layer 3 by forming the reflective film 6 so as to cover the slopes of the partition walls and then filling the recess material surrounded by the partition walls with a phosphor material.

The configuration in which the color conversion board is disposed on the foremost side as illustrated in FIG. 14 and the configuration in which the optical shutter 42 is disposed on the foremost side as illustrated in FIG. 18 have different advantages. is there.

In the configuration in which the color conversion substrate 101 is disposed on the foremost side as in the color display device 712 illustrated in FIG. 14, light emitted from the color display device toward the user is caused by phosphor emission or scattering on the color conversion substrate 101. Since the light is generated, it is emitted at a wide angle, and as a result, the viewing angle characteristics are excellent. For example, when the optical shutter 42 is a liquid crystal display panel, the viewing angle may be limited. However, the problem of the viewing angle is solved by passing through the color conversion substrate 101, and viewing from a wide viewing angle is possible. You can display as you can.

In the configuration in which the optical shutter 42 is arranged on the foremost side as in the color display device 713 shown in FIG. 18, external light entering from the front side enters the phosphor layer or the diffusion layer of the color conversion substrate 101 and is undesired. Can be prevented by the optical shutter 42. In pixels that should not be displayed, the optical shutter 42 is in a state of blocking light, so that external light does not reach the color conversion substrate 101 in such pixels. Therefore, undesired light emission can be eliminated and display quality can be improved.

Two typical examples of structures that can be employed as the optical shutter 42 are shown.
A liquid crystal display panel can be considered as a first example of the optical shutter 42. In this case, as shown in FIG. 21, the optical shutter 42 has a structure in which a liquid crystal layer 503 is sandwiched between a glass substrate 501 and a glass substrate 502. A source bus line 506 is formed on the surface of the glass substrate 501 on the liquid crystal layer 503 side, and an insulating layer 507 is formed so as to cover the source bus line 506. Further, pixel electrodes 504 are arranged on the surface of the insulating layer 507 so as to correspond to the respective pixels. A counter electrode 505 is formed on the surface of the glass substrate 502 on the liquid crystal layer 503 side. Polarizing plates 508 and 509 are attached to the outer surfaces of the glass substrates 501 and 502, respectively. When a voltage is applied between the pixel electrode 504 and the counter electrode 505, the molecular orientation of the liquid crystal layer 503 in the pixel changes. Depending on the combination of the change in the polarization state by the liquid crystal layer 503 and the polarizing plates 508 and 509, the optical shutter 42 switches whether to transmit light in the pixel.

As a second example of the optical shutter 42, a transmissive MEMS panel can be considered. The transmissive MEMS panel is a panel that can open and close an opening as each pixel by mechanically moving a member by an electric signal for each arranged pixel. When the optical shutter 42 is a transmissive MEMS panel, the optical shutter 42 has a structure in which a glass substrate 501 and a glass substrate 502 face each other as shown in FIG. A source bus line 506 is formed on the surface of the glass substrate 501 on the glass substrate 502 side, and an insulating layer 507 is formed so as to cover the source bus line 506. Further, an electrostatic actuator 510 and a shutter member 511 are arranged on the surface of the insulating layer 507 so as to correspond to each pixel. A light shielding layer 512 is formed on the surface of the glass substrate 502 on the glass substrate 501 side so as to separate each pixel. The shutter member 511 can be displaced by the action of the electrostatic actuator 510, and as a result, the first state positioned so as to block the opening of the light shielding layer 512 for each pixel and the opening of the light shielding layer 512 are opened. Can be switched to the second state. In the first state, light in the pixel is blocked by the shutter member 511 and is not transmitted. In the second state, light in the pixel is transmitted. In this way, the optical shutter 42 is configured to switch whether to transmit light in the pixel. In the transmissive MEMS panel, if the degree of displacement of the shutter member 511 is controlled in multiple stages, the amount of light to be transmitted can be controlled in multiple stages.

The optical shutter 42 is not limited to these types. When the optical shutter 42 is a liquid crystal display panel, it is not limited to the structure shown in FIG. When the optical shutter 42 is a transmissive MEMS panel, the structure is not limited to that shown in FIG.

Two typical examples of structures that can be employed as the self-luminous display device 44 are shown.
As a first example of the self-luminous display device 44, an organic EL display panel can be considered. In this case, as shown in FIG. 23, the self-luminous display device 44 has a structure in which an organic EL layer 513 is sandwiched between a glass substrate 501 and a glass substrate 502. The organic EL layer 513 is a layer in which a hole transport layer, a light emitting layer, and an electron transport layer are laminated in this order. A cathode electrode 514 is formed on the surface of the glass substrate 501 on the organic EL layer 513 side. A transparent electrode 515 is formed on the surface of the glass substrate 502 on the organic EL layer 513 side so as to correspond to each pixel. When a voltage is applied between the cathode electrode 514 and the transparent electrode 515, a portion corresponding to the pixel in the organic EL layer 513 emits light.

As a second example of the self-luminous display device 44, an inorganic EL display panel can be considered. In this case, as shown in FIG. 24, the self-luminous display device 44 includes an insulating layer 516, a light emitting layer 517, and an insulating layer 518 stacked in this order from the bottom and sandwiched between the glass substrate 501 and the glass substrate 502. It has a rare structure. A back electrode 519 is formed on the surface of the glass substrate 501 on the light emitting layer 517 side. The back electrode 519 can be formed as an Al or ITO film. A transparent electrode 515 is formed on the surface of the glass substrate 502 on the light emitting layer 517 side so as to correspond to each pixel. When a voltage is applied between the back electrode 519 and the transparent electrode 515, a portion of the light emitting layer 517 corresponding to the pixel emits light.

The self-luminous display device 44 is not limited to these types. When the self-luminous display device 44 is an organic EL display panel, it is not limited to the structure shown in FIG. When the self-luminous display device 44 is an inorganic EL display panel, it is not limited to the structure shown in FIG.

It should be noted that the above-described embodiment disclosed herein is illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The present invention can be used for a color conversion substrate, a lighting device, and a color display device.

1 transparent substrate, 1a main surface, 2 transparent barrier ribs, 3 phosphor layer, 3r red phosphor layer, 3g green phosphor layer, 3b diffusion layer, 4b blue light, 6 reflective film, 9 first low refractive index layer, 10 Second low refractive index layer, 11e1, 11e2, 11e3, 11e4 light, 23 flattening film, 24 openings, 42 light shutter, 43b blue light source, 44 self-luminous display device, 61, 62, 63 interface, 101, 102 color Conversion substrate, 431b, 433b, blue LED, 432, light guide plate, 434b, organic EL panel (as blue light source), 435b, inorganic EL panel (as blue light source), 436 diffusion plate, 441r, 441g, 441b, EL element, 442 substrate, 501, 502 glass substrate, 503 liquid crystal layer, 504 pixel electrode, 505 counter electrode, 506 saw Bus line, 507, 516, 518 insulating layer, 508, 509 polarizing plate, 510 electrostatic actuator, 511 shutter member, 512 light shielding layer, 513 organic EL layer, 514 cathode electrode, 515 transparent electrode, 517 light emitting layer, 519 back electrode 701, lighting device, 711, 712, 713 color display device.

Claims (17)

A transparent substrate (1) having a main surface (1a);
A plurality of phosphor layers (3) disposed on the main surface and each having a side surface;
A first low refractive index layer (9) interposed between the main surface and the phosphor layer and having a refractive index smaller than the refractive index of the phosphor layer;
A reflective film (6) formed on at least the side of the phosphor layer in order to reflect light emitted from the side surface of the phosphor layer;
A second low-refractive index layer (10) that covers a region of the phosphor layer opposite to the transparent substrate and that is not covered by the reflective film and has a refractive index smaller than the refractive index of the phosphor layer; A color conversion board comprising: The color conversion substrate according to claim 1, wherein the reflective film directly covers a side surface of the phosphor layer. A transparent partition wall (2) formed on the main surface so as to have a side surface;
The side surface of the transparent partition wall is in contact with the side surface of the phosphor layer,
2. The color conversion substrate according to claim 1, wherein the reflective film covers a side surface of the transparent partition opposite to a surface in contact with the phosphor layer and a surface opposite to the transparent substrate. The color conversion substrate according to any one of claims 1 to 3, wherein the reflective film has an inclined surface facing the transparent substrate side when viewed from the center of the phosphor layer. The first low refractive index layer has a refractive index of 1.20 to 1.40, and the second low refractive index layer has a refractive index of 1.20 to 1.40. 5. The color conversion board according to any one of 4 above. The color conversion substrate according to claim 1, wherein the plurality of phosphor layers do not have scattering characteristics. The color conversion substrate according to any one of claims 1 to 5, wherein the plurality of phosphor layers are transparent. One of the plurality of phosphor layers includes a second wavelength region phosphor layer that absorbs at least light in the first wavelength region and emits light in the second wavelength region, and includes one of the plurality of phosphor layers The color conversion substrate according to any one of claims 1 to 7, further comprising a third wavelength range phosphor layer that absorbs at least light in the first wavelength range and emits light in the third wavelength range. The color conversion substrate according to claim 8, wherein a diffusion layer (3b) or a transparent layer for scattering or transmitting light in the first wavelength region is disposed on the main surface. The color conversion substrate according to claim 8, wherein the light in the first wavelength range is blue light, the light in the second wavelength range is red light, and the light in the third wavelength range is green light. The color conversion substrate according to claim 10, wherein a diffusion layer (3b) or a transparent layer for scattering or transmitting blue light is disposed on the main surface. An illumination device comprising: the color conversion substrate according to claim 10 or 11; and a blue light source (43b) disposed on the color conversion substrate so as to emit light toward the color conversion substrate. A color display device comprising: the color conversion substrate according to claim 10 or 11; and a self-luminous display device (44) disposed on the color conversion substrate and emitting blue light toward the color conversion substrate. The color conversion board according to claim 10 or 11, a blue light source (43b) disposed on the color conversion board so as to emit light toward the color conversion board, the color conversion board, and the blue light source, An optical shutter (42) disposed between
The color display device, wherein the optical shutter is positioned so as to correspond to the color conversion substrate. The color conversion board according to claim 10 or 11, a blue light source (43b) disposed on the color conversion board so as to emit light toward the color conversion board, and the blue light source of the color conversion board And a light shutter (42) disposed on the opposite side. The color display device according to claim 14 or 15, wherein the color conversion substrate is disposed such that a surface opposite to a surface on which the transparent substrate is present faces the optical shutter side. An illumination device comprising: the color conversion board according to claim 8 or 9; and a light source that is disposed on the color conversion board and emits light in the first wavelength range toward the color conversion board.

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