WO2012147650A1 - Led module, backlight unit, and liquid crystal display device - Google Patents

Abstract

Provided is an LED module (6) which comprises a box-shaped package (60) the top surface of which is open, and a plurality of LED elements (61) constituting light-emitting elements disposed on a bottom surface (601) within the package (60), wherein a plurality of inclined surfaces (603, 604) having different angles of inclination are formed in a row in one direction on the bottom surface (601), and at least one of the LED elements (61) is attached to each of the plurality of inclined surfaces (603, 604).

Description

LED module, backlight unit, and liquid crystal display device

The present invention relates to an edge light type backlight unit that emits part of planar light having different luminance, and relates to an LED module provided in the backlight unit and a liquid crystal display device including the backlight unit. It is.

In electronic appliances such as information home appliances, notebook PCs, mobile phones and game machines, liquid crystal display devices are often used as display devices. The liquid crystal display device includes a liquid crystal panel unit and a backlight unit disposed on the back surface of the liquid crystal panel unit, and the liquid crystal panel unit transmits the degree of transmittance (transmittance) of planar light from the backlight unit. ) For each pixel, and an image is displayed in the image display area in front of the liquid crystal panel unit.

There are two types of backlight units. One is a light guide plate method (edge light method) that includes a light guide plate and receives light from the light receiving surface on the side surface of the light guide plate, and the other is a direct type method in which a light source is arranged on the back surface of the liquid crystal panel unit. is there. In recent years, there has been an increasing demand for thinning display devices in the electronic devices, and an edge light type backlight unit effective for thinning is often used (JP-A-9-160035, etc.). reference).

In the backlight unit, a light emitting diode (LED) is often used for the light source unit. The LED itself is smaller and has a longer life than a fluorescent lamp (such as a cold-cathode tube) that has been conventionally used, and the drive circuit can be simplified, and the backlight unit can be further reduced in size and thickness. It becomes.

Here, a conventional backlight unit will be described with reference to the drawings. FIG. 14 is an exploded perspective view of a conventional edge light type backlight unit.

As shown in FIG. 14, the backlight unit 91 includes a light guide plate 92 and a light source unit 93 arranged to face the light receiving surface 922 of the light guide plate 92. The light source unit 93 includes a substrate 930 arranged along the light receiving surface 922 and LED modules 96 arranged on the substrate 930 at equal intervals. The backlight unit 91 is used as a backlight for the liquid crystal display device.

In the backlight unit, the brightness of the planar light is determined so that the image displayed on the liquid crystal display device has a certain level of brightness, and the number of LED modules 96 is determined based on the brightness of the planar light. For example, in the backlight unit 91 shown in FIG. 14, five LED modules 96 are required to emit planar light having a necessary luminance. Therefore, five LED modules 96 are arranged on the substrate 930 of the light source unit 93. The LED modules 96 are arranged side by side at equal intervals in order to allow light to enter the light guide plate 92 evenly.

The LED used in the conventional backlight unit will be described with reference to the drawings. FIG. 15 is a schematic view of an LED module used in a conventional backlight unit. As shown in FIG. 15, the LED module 96 includes a box-shaped package 960 having an open upper surface, an LED chip 961 disposed at the bottom of the package 960, and a sealing portion 962 for sealing the LED chip 961. It is the composition provided with. The light emitted from the LED chip 96 has a strong directivity, and in the LED module 96 having this configuration, the light emitted from the LED chip 961 is irradiated in a direction perpendicular to the bottom of the package 960 and is not so wide. I don't get it.

Since the LED module 96 is a light source in which light does not easily spread, the portion of the light guide plate 92 that faces the LED module 96 is a bright region (B in the figure), and the light from the LED module 96 is incident on the side of the bright region B. It becomes a dark region (D in the figure). The light emitted from the LED module 96 has strong directivity and the traveling direction of the light is orthogonal to the light receiving surface 922, so that it is not diffused even if it is reflected by the surface opposite to the light receiving surface 922. Bright regions B and dark regions D appear alternately inside the light guide plate 92. As a result, a brightness difference between light and dark is generated in the light emitted from the light guide plate 92, and further, variation in luminance (luminance unevenness) occurs in the planar light emitted from the backlight unit 91. As a result, the display quality of the image displayed on the liquid crystal display device is degraded.

Therefore, measures like the backlight unit shown in FIG. 16 are taken. FIG. 16 is a schematic view of an improved edge light type backlight unit. In the backlight unit 91B shown in FIG. 16, the dark space D is reduced by narrowing the mounting interval of the LED modules 96, thereby suppressing the luminance difference of light incident on the light guide plate 92 and being emitted from the backlight unit 91B. The brightness unevenness of the planar light is suppressed.

Japanese Patent Application Laid-Open No. 11-265610 discloses a method in which an LED chip is sealed with a light-transmitting resin, and a light emitting surface (light-emitting surface) of the sealing resin is formed in a concave lens shape. There has been proposed a backlight unit configured to spread light emitted from a resin.

JP-A-11-265610

However, if the mounting interval of the LED modules 96 is reduced, the number of the LED modules 96 to be mounted increases, and the circuit for supplying power to the LED modules 96 formed on the substrate 930 becomes complicated, and the structure of the backlight unit becomes complicated. Become. This increases the time and labor required for manufacturing and increases the manufacturing cost. Moreover, since the number of LED modules 96 mounted increases, power consumption (energy consumption) increases.

On the other hand, in the backlight unit described in Japanese Patent Laid-Open No. 11-265610, the light exit surface of the resin that seals the LED chip is formed in a concave lens shape, so that the number of LEDs can be reduced without increasing the number of LEDs. The occurrence of uneven brightness can be suppressed. However, since the sealing resin is formed in a complicated concave lens shape, it takes time and effort to seal the LED chip, and the manufacturing cost increases. Further, in order to form the concave lens shape, the length of the sealing resin is required to some extent, and it is often difficult to reduce the size of the light source unit and hence the backlight unit.

Accordingly, an object of the present invention is to provide a backlight unit of an edge light system, which can reduce energy consumption with a simple configuration and emits planar light having a uniform luminance distribution. To do.

Another object of the present invention is to provide an LED module used in this backlight unit and having a wide-angle light irradiation range and a liquid crystal display device using this backlight unit.

In order to achieve the above object, the present invention includes a box-shaped package having an open top surface and a plurality of LED elements that are light emitting elements disposed on a bottom surface inside the package, and the bottom surface has different slopes. Provided is an LED module in which a plurality of inclined surfaces are arranged in one direction and at least one LED element is attached to each of the plurality of inclined surfaces.

According to this configuration, since the LED elements are arranged on the inclined surfaces having different inclinations, it is possible to emit light from each LED element in different directions. For this reason, even if the light emitted from the LED element has high directivity, the light emitted from the LED module can be light diffusing at a wide angle.

In the above configuration, a plurality of inclined surfaces may be arranged so that the bottom surface is higher in the center than in the periphery. According to this configuration, since the light emitted from the LED elements arranged on the inclined surfaces is emitted in the opposite direction, the light spreading direction can be one direction. That is, light can be irradiated in a wide range in one direction of the irradiation target, and light leaking in a direction intersecting (orthogonal) with it can be suppressed.

In the above configuration, the bottom surface may include a reflecting wall body extending in a direction intersecting with a direction in which the plurality of inclined surfaces are arranged in the center. According to this structure, it can suppress that the area | region where a brightness | luminance becomes high in the front of an LED module is formed.

In the above configuration, the reflection wall body may have a tip protruding outside the package.

In the above configuration, a transparent sealing portion that seals the LED element may be provided while closing the opening of the package.

In the above-described configuration, a transparent high refractive part that is disposed adjacent to the sealing part and has a refractive index higher than that of the sealing part may be provided on the opening side of the package.

A backlight having the light source unit in which the LED modules are mounted side by side, and a light guide plate that receives light from the light source unit on the light receiving surface and emits the light from the light emitting surface as planar light. Mention a unit.

A liquid crystal display device having a liquid crystal panel unit disposed on the front surface of the backlight unit can be cited as one using the backlight unit having the above-described configuration.

According to the present invention, it is possible to provide an edge light type backlight unit that can reduce energy consumption and emits planar light with a uniform luminance distribution with a simple configuration.

It is a disassembled perspective view of an example of the backlight unit concerning this invention. It is sectional drawing of the backlight unit shown in FIG. It is a front view of the LED module with which the light source unit shown in FIG. 1 is equipped. FIG. 4 is a cross-sectional view taken along the line IV-IV of the LED module shown in FIG. 3. It is the figure which expanded the light source unit of the backlight unit concerning this invention. It is sectional drawing of the other example of the LED module concerning this invention. It is a front view of the LED module used for the backlight unit concerning this invention. It is VIII-VIII arrow sectional drawing of the LED module shown in FIG. It is the schematic of the other example of the backlight unit concerning this invention. It is sectional drawing of the LED module used for the backlight unit concerning this invention. It is the schematic of the other example of the backlight unit concerning this invention. It is a disassembled perspective view of the liquid crystal display device concerning this invention. It is sectional drawing of the liquid crystal display device shown in FIG. It is an exploded perspective view of an example of a conventional edge light type backlight unit. It is the schematic of the LED module used for the conventional backlight unit. It is the schematic of the other example of the backlight unit of the conventional edge light system.

Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is an exploded perspective view of an example of a backlight unit according to the present invention, and FIG. 2 is a cross-sectional view of the backlight unit shown in FIG. In the backlight unit 1 shown in FIG. 1, the upper side of the drawing is the front side, that is, the observer side, and the lower side is the back side. Further, in the following description, the description is based on the front and back surfaces in the state of FIG.

The backlight unit 1 is an illumination device that emits planar light. The backlight unit 1 includes a flat light guide plate 2, a light source unit 3 that emits light toward a light receiving surface 22 formed on a side surface of the light guide plate 2, and an optical sheet that is disposed in the vicinity of the light guide plate 2. 4 is provided. The backlight unit 1 includes a backlight chassis 10, and at least the light guide plate 2, the light source unit 3, and the optical sheet 4 are disposed inside the backlight chassis 10.

As shown in FIGS. 1 and 2, the backlight chassis 10 is a box member whose front side (liquid crystal panel unit side) is open, and has a bottom 100 that is rectangular in plan view, and a side wall that protrudes from four sides of the bottom 100. 101. As shown in FIG. 1, the backlight unit 1 is arranged from the bottom surface 100 in the order of the reflection sheet 11, the light guide plate 2, and the optical sheet 4. Moreover, the light source unit 3 is attached to the inner peripheral side of the side wall 101 as shown in FIG. Moreover, it is arrange | positioned so that the front surface of the backlight chassis 10 may be covered, and the front case 102 which presses the edge part of the optical sheet 4 is provided (refer FIG. 2).

The light guide plate 2 is formed by forming a transparent resin such as polymethyl methacrylate (PMMA) or polycarbonate into a flat plate shape. In addition, it is not limited to these resin, The thing which can be formed in a transparent flat plate shape can be employ | adopted widely.

As shown in FIG. 1, the light guide plate 2 is a flat plate member having a rectangular shape in plan view. The main surface on the front side is configured as a light exit surface 21. Further, one side surface of the lateral direction and the side surfaces at both ends is configured as a light receiving surface 22 that receives light from the light source unit 3.

The light source unit 3 includes a plurality of LED modules 6 arranged in a straight line. In the light source unit 3, the LED modules 6 are arranged at equal intervals. However, the luminance of the central portion of the planar light is changed according to the visual characteristics of the human eye. The arrangement may be such that the outer space is wide so that the brightness of the edge portion is high and low. The light emitted from the LED module 6 is arranged to enter the light receiving surface 22. Details of the light source unit 3 will be described later.

As an optical sheet member, the optical sheet 4 aligns the direction of the light emitted from the light exit surface 21 with the diffusion sheet members 41 and 42 that diffuse the light emitted from the light exit surface 21 of the light guide plate 2. And a prism sheet member 43 that changes the direction of the incident light so as to face the liquid crystal panel unit 5. An optical sheet member having optical characteristics other than these may be used.

Further, in the liquid crystal display device A shown in FIG. 1, the prism sheet member 43 is sandwiched between the two diffusion sheet members 41 and 42, but the present invention is not limited to this. The diffusion sheet members 41 and 42 and the prism sheet member 43 have a shape and a size that cover the light exit surface 21.

In the light guide plate 2, the light incident from the light receiving surface 22 is repeatedly reflected inside the light guide plate 2 and finally emitted from the light exit surface 21 as planar light. It is preferable that all light incident from the light receiving surface 22 is emitted from the light emitting surface 21. However, actually, there is also light that exits from the main surface opposite to the light exit surface 21. Therefore, a reflection sheet 11 is disposed between the bottom surface 100 of the backlight chassis 10 and the light guide plate 2 to reflect the light emitted from the surface opposite to the light exit surface 21 and return it to the light guide plate 2. .

As shown in FIG. 1, the light source unit 3 has a long substrate 30 and five LED modules 6 mounted on the upper surface of the substrate 30 side by side at equal intervals. A wiring circuit that supplies power to each of the five LED modules 6 is formed on the upper surface of the substrate 30. The wiring circuit may be configured to supply power common to the LED modules 6, or may be configured to supply different power for each LED module 6.

As shown in FIGS. 1 and 2, the light source unit 3 has a substrate 30 protruding from the long side of the bottom surface 100 of the backlight chassis 10 and a LED module 6 inside the backlight unit 2, that is, a light guide. It is attached to the backlight chassis 10 by being fixed so as to face the light receiving surface 22 of the optical plate 2. Therefore, the board | substrate 30 is a rectangular board member of the substantially the same magnitude | size and shape as the side wall part 101 to which it is attached. Further, the LED modules 6 are arranged on the substrate 30 such that when the substrate 30 is attached to the side wall portion 101, the light emitted from the LED modules 6 enters from the light receiving surface 22 of the light guide plate 2.

Next, details of the LED module 6 will be described with reference to the drawings. 3 is a front view of the LED module provided in the light source unit shown in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line IV-IV of the LED module shown in FIG. As shown in FIGS. 3 and 4, the LED module 6 includes a package 60 that is an integrally molded body of resin, two LED chips 61 (LED elements) arranged inside the package 60, and the LED chip 61. And a sealing portion 62 for sealing.

Note that the LED chip 61 may include a light emitting element that emits light of wavelengths of red (R), green (G), and blue (B) to produce white light. In addition, the LED chip 61 that emits light of blue (B) wavelength and the sealing unit 62 that includes a portion that emits yellow light when blue (B) wavelength light is incident on at least a part thereof are combined. , A pseudo-white type that emits white light by mixing light of blue (B) and yellow wavelengths, and an LED chip 61 that emits light of blue (B) wavelength, and at least partially blue (B) Blue (B), red (R), and green (G) wavelengths combined with a sealing portion 62 having a portion that emits red (R) and green (G) light when light having a wavelength of It is possible to adopt a high color rendering type that emits white light by mixing the light.

As shown in FIGS. 3 and 4, the package 60 has a box shape having an opening at the top, and includes a bottom surface portion 601 having a rectangular shape when viewed from the front, and a side wall portion 602 protruding from the edge of the bottom surface portion 601. ing. The bottom surface portion 601 and the side wall portion 602 of the package 60 are configured to easily reflect the light emitted from the LED chip 61. As a configuration that easily reflects light, the package 60 may be formed of a white resin, a white printing is performed on a region irradiated with light from the LED chip 61, or a metal film is formed. You may do. The thing of the structure which reflects the light radiate | emitted from LED chip 61 can be employ | adopted widely.

Further, the bottom surface portion 601 of the package 60 has a shape in which a first inclined surface 603 and a second inclined surface 604 that are inclined to the opposite side are continuous. In other words, as shown in FIGS. 3 and 4, the first inclined surface 603 and the second inclined surface 604 are arranged side by side in one direction and are inclined to the opposite sides. That is, the bottom surface portion 601 has a triangular cross-section with a raised central portion in the left-right direction. One LED chip 61 is mounted on each of the first inclined surface 603 and the second inclined surface 604.

In the LED module 6, with the LED chip 61 mounted on each of the first inclined surface 603 and the second inclined surface 604, the concave portion surrounded by the bottom surface portion 601 and the side wall portion 602 is sealed with the sealing portion 62. is doing. The sealing portion 62 is a transparent resin and is filled in the package 60 and solidified. By forming the sealing portion 62, it is possible to suppress foreign matters such as moisture, dust, and dust from adhering to the LED chip 61, and to suppress deterioration of the LED chip 61.

The light emitted from the LED chip 61 is highly directional light. However, since the LED chip 61 is a point light source, the light emitted from the LED chip 61 is diffuse light although the angle is small. In the LED module 6, diffused light is emitted from the LED chips 61 disposed on the first inclined surface 603 and the second inclined surface 604 that are inclined in opposite directions. Thereby, the light which spreads widely in the left-right direction is emitted from the LED module 6.

Details of the light source unit 3 provided in the backlight unit 1 according to the present invention will be described with reference to the drawings. FIG. 5 is an enlarged view of the light source unit of the backlight unit according to the present invention. In addition, the ellipse shown in FIG. 5 schematically shows the light emitted from the LED chip.

The light emitted from the LED module 6 is diffused at a large angle as the LED chips 61 disposed on the first inclined surface 603 and the second inclined surface 604 emit light. And the LED module 6 which can irradiate light in such a wide angle is mounted in the board | substrate 30 at equal intervals, and the light source unit 3 is comprised.

The light emitted from the LED module 6 is irradiated at a wide angle toward the light receiving surface 22 of the light guide plate 2, and the light emitted from the LED module 6 enters the light guide plate 2 at an angle that is not perpendicular. Thereby, the light emitted from the LED module 6 is repeatedly reflected on the side surface of the light guide plate 2, and spreads over the entire area inside the light guide plate 2. Thereby, it is possible to suppress the formation of clear bright regions and dark regions inside the light guide plate 2. Thereby, generation | occurrence | production of the brightness nonuniformity of the planar light radiate | emitted from the backlight unit 1 can be suppressed.

The light source unit 3 including the LED module 6 emits light that does not spread so much in the front-rear direction, that is, in the thickness direction of the light guide plate 2. Thereby, it is difficult for light to leak in the front direction from the gap between the light source unit 3 and the light guide plate 2. As a result, luminance unevenness due to leaked light hardly occurs.

In the LED module 6 according to the present embodiment, the first inclined surface 603 and the second inclined surface 604 are inclined surfaces having different directions but the same inclination angle. However, the present invention is not limited to this, and different inclinations are possible. The structure which has an angle | corner may be sufficient.

(Modification of the first embodiment)
A modification of the LED module used in the backlight unit according to the present invention will be described with reference to the drawings. FIG. 6 is a cross-sectional view of another example of the LED module according to the present invention. The LED module 6 used in the backlight unit 1 described above has a bottom surface provided with a first inclined surface 403 and a second inclined surface 604. However, in the LED module 6A shown in FIG. 6, the first inclined surface 603 is the first inclined surface 603. The auxiliary inclined surface 605 and the second auxiliary inclined surface 606 are combined. Further, the second inclined surface 604 is configured by combining the third auxiliary inclined surface 607 and the fourth auxiliary inclined surface 608.

The LED chip 61 is attached to each of the first auxiliary inclined surface 605, the second auxiliary inclined surface 606, the third auxiliary inclined surface 607, and the fourth auxiliary inclined surface 608. The LED module 6A having this configuration can emit light at a wider angle than the LED module 6A described above. Thereby, the number of LED modules mounted on the substrate 30 of the light source unit 3 can be reduced.

In the LED module 6A shown in FIG. 6, the first inclined surface 603 and the second inclined surface 604 are formed in a protruding shape, that is, the abutting portions of the auxiliary inclined surfaces constituting the respective inclined surfaces protrude outward. However, the present invention is not limited thereto, and may be a concave shape recessed inward. Further, the number of auxiliary inclined surfaces is not limited to two, and may not be the same on the left and right.

(Second Embodiment)
Another example of the backlight unit according to the present invention will be described with reference to the drawings. 7 is a front view of an LED module used in the backlight unit according to the present invention, and FIG. 8 is a cross-sectional view of the LED module shown in FIG. The LED module 7 shown in FIGS. 7 and 8 has the same configuration as the LED module 6 shown in the first embodiment, except that it includes a reflective wall 705 that protrudes from the central portion of the bottom surface 70. Detailed description of substantially the same parts is omitted.

7 and 8, the LED module 7 includes a package 70, an LED chip 71, and a sealing portion 72. The bottom surface of the package 70 includes a first inclined surface 703 and a second inclined surface 704 that are inclined in opposite directions, and includes a reflection wall body 705 disposed between the first inclined surface 703 and the second inclined surface 704. ing. The reflection wall body 705 is formed integrally with the bottom surface portion 701.

The reflection wall body 705 will be described in detail. As shown in FIG. 8, the reflecting wall body 705 is formed higher than the side wall portion 702. That is, the reflection wall body 705 is formed so as to protrude from the package 70. The reflection wall body 705 is a ridge extending in a direction intersecting with the arrangement direction of the first inclined surface 703 and the second inclined surface 704. The reflecting wall body 705 can be a white one that easily reflects light, but is not limited thereto, and can be a thin film made of metal or the like. Furthermore, by forming fine irregularities on the surface of the reflecting wall 705, irregular reflection can be achieved, and the light diffusion effect can be enhanced.

As shown in FIG. 8, among the light emitted from the LED chip 71 arranged on the first inclined surface 703, the light spread and irradiated on the second inclined surface 704 side is reflected by the reflecting wall body 705, It proceeds to the outside on the first inclined surface 703 side (left side in the figure). Of the light emitted from the LED chip 71 arranged on the second inclined surface 704, the light spread and irradiated on the first inclined surface 703 side is reflected by the reflecting wall body 705 and is on the second inclined surface 704 side. Proceed to the outside (right side in the figure).

From the above, the light emitted from the LED chip 71 arranged on the first inclined surface 703 and the light emitted from the LED chip 71 arranged on the second inclined surface 704 are on the front of the LED module 7. Leakage can be suppressed. Thereby, it can suppress that the area | region brighter than the periphery is formed in the front surface of the reflective wall body 705 of the LED module 7, ie, the center part of the LED module 7. FIG.

Also, a backlight unit including such an LED module 7 will be described. FIG. 9 is a schematic view of another example of a backlight unit according to the present invention. The backlight unit 1B shown in FIG. 9 has the same configuration as the backlight unit 1 shown in the first embodiment except that the LED module 7 provided in the light source unit 3 is different. The same reference numerals are given and detailed descriptions of the same parts are omitted.

As shown in FIG. 9, each light emitted from the LED chip 71 of the LED module 7 is irradiated outward. Thereby, since the light output from the LED module 7 is incident on the light guide plate 2 from the light receiving surface 22, the directivity of the light emitted from the LED chip 71 forms an angle other than perpendicular to the side surface. Light incident from 22 is appropriately diffused. Thereby, it can suppress that a brightness nonuniformity generate | occur | produces in the planar light radiate | emitted from the backlight unit 1B.

In the LED module 7, the tip of the reflecting wall body 705 protrudes to the outside of the package 70. However, depending on the shape of the package 70 and the diffusion angle of light emitted from the LED chip 71, the shape may not be projected. is there. Moreover, although the reflective surface is planar, it is not limited to this, A concave curved surface or a convex curved surface may be sufficient. The thing of the structure which can reflect the light radiate | emitted from LED chip 71 can be employ | adopted widely.

(Third embodiment)
Still another example of the backlight unit according to the present invention will be described with reference to the drawings. FIG. 10 is a cross-sectional view of an LED module used in the backlight unit according to the present invention. The LED module 8 shown in FIG. 10 has the same configuration as that of the LED module 7 shown in the second embodiment except that the LED module 8 includes the high refraction part 83, and a detailed description of substantially the same part is omitted. .

As shown in FIG. 10, the LED module 8 has a high refraction part 83 disposed on the light emitting side. The high refraction part 83 is formed of a transparent material and is formed so as to cover the front side of the package 80. The high refraction part 83 is formed of a material having a higher refractive index than that of the sealing part 82.

As shown in FIG. 10, the high refraction part 83 is formed to have a surface connecting the side surface of the package 80 to the tip of the reflection wall body 805. That is, the high refraction part 83 has a mountain shape that rises from the front end of the side wall toward the reflection wall body 805.

By providing such a high refraction part 83, when the light emitted from the LED chip 81 arranged on the first inclined surface 803 enters the high refraction part 83 from the sealing part 82, the LED chip 81. Refracts to the outside. And the light which goes outside the LED module 8 is further emitted to the outside (wide angle) when it is emitted from the high refraction part 83 to the outside. Further, the light directed toward the inside of the LED module 8 has a smaller incident angle on the surface of the reflecting wall body 805 than the case where the high refraction part 83 is not provided, and the light reflected by the reflecting wall body 805 is the LED module 8. Toward the outside. Further, when the light is emitted from the high refraction part 83 to the outside, it is refracted to the outside and further to the outside.

From the above, the light emitted from the LED chip 81 arranged on the first inclined surface 803 and the light emitted from the LED chip 81 arranged on the second inclined surface 804 are on the front of the LED module 8. Leakage can be suppressed. Thereby, the irradiation angle of the light emitted from the LED module 8 shell is further increased with respect to the LED module 7 of the second embodiment, and the front surface of the reflection wall body 805, that is, the central portion of the LED module 8 from the periphery. It is possible to suppress the formation of a bright region.

Also, a backlight unit including such an LED module 8 will be described. FIG. 11 is a schematic view of another example of a backlight unit according to the present invention. The backlight unit 1C shown in FIG. 11 has the same configuration as the backlight unit 1 shown in the first embodiment except that the LED module 8 provided in the light source unit 3 is different. The same reference numerals are given and detailed descriptions of the same parts are omitted.

As shown in FIG. 11, the light emitted from the LED chip 81 of the LED module 8 is irradiated outward. As a result, the light output from the LED module 8 is incident on the light guide plate 2 from the light receiving surface 22, and the directivity of the light emitted from the LED chip 81 forms an angle other than perpendicular to the side surface. Light incident from 22 is appropriately diffused. Thereby, it is possible to suppress the occurrence of luminance unevenness in the planar light emitted from the backlight unit 1C.

In addition, although the outer surface part of the high refractive part 83 has shown what is a plane, you may form in the convex curve shape swelled outside. By forming in this way, light can be irradiated at a wider angle. In addition, the shape of the curved surface is preferably determined based on the light irradiation angle and / or the luminance distribution.

In each of the above-described embodiments, the LED module is described as an example having a rectangular package as viewed from the front, but is not limited to this, and is not limited to a square shape, a circular shape, an elliptical shape, or the like. It may be a shape. Moreover, although shapes other than these may be sufficient, it is preferable that it is a line symmetrical shape.

(Fourth embodiment)
A liquid crystal display device including a backlight unit according to the present invention will be described with reference to the drawings. 12 is an exploded perspective view of the liquid crystal display device according to the present invention, and FIG. 13 is a cross-sectional view of the liquid crystal display device shown in FIG. In addition, in the liquid crystal display device according to the present invention, any of the backlight units 1, 1B, and 1C described in the above-described embodiments can be adopted, but in the liquid crystal display device A of the present embodiment, The backlight unit 1 is used as a representative.

As shown in FIG. 12, in the liquid crystal display device A according to the present invention, a liquid crystal panel unit 5 is disposed on the front side of the backlight unit 1. Further, as shown in FIG. 13, the liquid crystal panel unit 5 is disposed on the front surface of the front case 102 of the backlight unit 1, and a bezel Bz, which is a frame-shaped member, covers the front side of the liquid crystal panel unit 5. It has been.

The liquid crystal panel unit 5 includes a liquid crystal panel 51 in which liquid crystal is sealed, and a polarizing plate 52 attached to the front surface (observer side) and the back surface (backlight unit 1 side) of the liquid crystal panel 51. The liquid crystal panel 51 includes an array substrate, a counter substrate disposed to face the array substrate, and liquid crystal filled between the array substrate and the counter substrate.

The array substrate is provided with a source wiring and a gate wiring orthogonal to each other, a switching element (for example, a thin film transistor) connected to the source wiring and the gate wiring, a pixel electrode connected to the switching element, an alignment film, and the like. The counter substrate is provided with a color filter in which colored portions of red, green, and blue (RGB) are arranged in a predetermined arrangement, a common electrode, an alignment film, and the like.

A voltage is applied between the array substrate and the counter substrate in each pixel of the liquid crystal panel 51 by driving the switching elements of the array substrate with a drive signal. By changing the voltage between the array substrate and the counter substrate, the degree of light transmission in each pixel is changed. As a result, an image is displayed in the image display area on the viewer side of the liquid crystal panel 51.

By using the backlight unit according to the present invention, the occurrence of uneven brightness of the planar light incident on the liquid crystal panel unit 5 is suppressed, so that uneven brightness of an image displayed on the liquid crystal display device can be suppressed. .

In the above-described embodiment, the liquid crystal display device is described as an image display device using the backlight unit of the present invention. However, the present invention is not limited to this, and the backlight unit according to the present invention is a transmissive type. It can be widely used in image display devices.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this content. The embodiments of the present invention can be variously modified without departing from the spirit of the invention.

The backlight unit and the liquid crystal display device according to the present invention can be used as a display unit of an electronic device such as an information appliance, a notebook PC, a mobile phone, or a game device.

DESCRIPTION OF SYMBOLS 1 Backlight unit 2 Light-guide plate 21 Light-emitting surface 22 Light-receiving surface 3 Light source unit 30 Board | substrate 4 Optical sheet 5 Liquid crystal panel unit 6 LED module 60 Package 601 Bottom surface part 602 Side wall part 603 1st inclined surface 604 2nd inclined surface 61 LED chip 62 Sealing portion 7 LED module 70 Package 701 Bottom surface portion 702 Side wall portion 703 First inclined surface 704 Second inclined surface 705 Reflecting wall body 71 LED chip 72 Sealing portion 8 LED module 80 Package 801 Bottom surface portion 802 Side wall portion 803 First inclined surface Surface 804 Second inclined surface 805 Reflecting wall body 81 LED chip 82 Sealing portion 83 High refractive portion

Claims (8)

A box-shaped package with an open top;
A plurality of LED elements that are light emitting elements disposed on the bottom surface inside the package;
The bottom surface is formed by arranging a plurality of inclined surfaces having different inclinations in one direction,
An LED module, wherein at least one LED element is attached to each of the plurality of inclined surfaces. The LED module according to claim 1, wherein the bottom surface has a plurality of inclined surfaces arranged so that the center is higher than the periphery. 3. The LED module according to claim 1, wherein the bottom surface includes a reflecting wall body extending in a direction intersecting with a direction in which the plurality of inclined surfaces are arranged at a center. The LED module according to claim 3, wherein a tip of the reflecting wall body protrudes outside the package. The LED module according to any one of claims 1 to 4, further comprising a transparent sealing portion that seals the LED element while closing the opening of the package. The LED module according to claim 5, further comprising a transparent high-refractive portion disposed adjacent to the sealing portion on the opening side of the package and having a refractive index higher than that of the sealing portion. A light source unit in which the LED modules according to any one of claims 1 to 6 are mounted side by side on a substrate;
A backlight unit having a light guide plate that receives light from a light source surface on a light receiving surface and emits the light from the light emitting surface as planar light. The backlight unit according to claim 7,
A liquid crystal display device having a liquid crystal panel unit disposed in front of the backlight unit.

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