JP2012084301A - Light source module and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source module, along with an electronic apparatus, in which the occurrence of luminance unevenness is suppressed.SOLUTION: The backlight module includes LEDs, a light guide plate 21, positioning pins 51 for positioning the light guide plate 21 and a light diffusion part 61. The light diffusion part 61 is scattered and provided in a rectangular range of light diffusion part formation 60 on a backside 23, and makes light propagating inside the light guide plate 21 diffused. Notches 31 with the positioning pins 51 arranged therein are formed at the light guide plate 21. The light diffusion part 61 is provided in the range of light diffusion part formation 60 on the backside 23 so as to generate a correction region 71 and a peripheral region 72. The correction region 71 includes a position 73 nearest to the notch 31, and the peripheral region 72 includes a position 74 nearest to an end surface 25p most and adjoins to the correction region 71. A ratio of the light diffusion part 61 occupying per unit area is sparse in the correction region 71, and a ratio is dense in the peripheral region 72.

Description

  The present invention generally relates to a light source module and an electronic device, and more particularly to a light source module using a light guide plate and an electronic device including the light source module.

  Regarding a conventional light source module, for example, Japanese Patent Application Laid-Open No. 2002-287138 aims to avoid an increase in manufacturing cost by easily optimizing the distance between a light guide plate and a light source during manufacturing. A liquid crystal display device is disclosed (Patent Document 1). The liquid crystal display device disclosed in Patent Document 1 includes an LED, a light guide plate that allows light from the LED to enter from the side surface and emits light to the liquid crystal display element, and a case that attaches the LED and the light guide plate to a fixed state. .

  Japanese Patent Application Laid-Open No. 2004-184493 discloses an electro-optical device intended to have high light emission luminance even when the mounting position of the light source on the circuit board is shifted (patent). Reference 2). The electro-optical device disclosed in Patent Document 2 includes a light guide plate, a light source that emits light to the electro-optical panel via the light guide plate, and a circuit board on which the light source is mounted.

  Japanese Patent Application Laid-Open No. 2008-84811 discloses a backlight unit for suppressing wobbling of an optical sheet and suppressing wrinkling of the optical sheet (Patent Document 3). The backlight unit disclosed in Patent Document 3 includes a light source, a light guide that guides light from the light source, an optical sheet that is stacked on the light guide, and a housing that houses these.

  Japanese Patent Application Laid-Open No. 2008-243402 prevents damage to members caused by external thermal shocks, enables thinning and narrowing of the frame, improves reliability, and suppresses manufacturing costs. A planar light source device for the purpose is disclosed (Patent Document 4). The planar light source device disclosed in Patent Document 4 includes a light guide plate for emitting light incident from a light source toward a liquid crystal panel.

JP 2002-287138 A JP 2004-184493 A JP 2008-84811 A JP 2008-243402 A

  As disclosed in the above-mentioned patent documents, a light source module including a light guide plate is used in an image display device such as a liquid crystal display device. The light guide plate is disposed so as to overlap with the image display panel for displaying an image, and irradiates the image display panel with light from the light source while propagating the light in a plane. On the other hand, in order to irradiate light to an appropriate range of the image display panel, the light source module needs a means for positioning the light guide plate. As such means, there is a positioning pin. Correspondingly, a notch for arranging the pin is formed in the light guide plate.

  However, when such a positioning mechanism is adopted for the light guide plate, a phenomenon occurs in which light propagating inside the light guide plate is reflected by the notch part or the pin arranged in the notch part. In this case, unintended reflected light is emitted from the light guide plate in the vicinity of the notch, which causes uneven brightness in the light source module.

  Accordingly, an object of the present invention is to provide a light source module and an electronic device in which the occurrence of luminance unevenness is suppressed.

  A light source module according to the present invention includes a light source that emits light, a light guide plate, a positioning member for positioning the light guide plate, and a light diffusion portion. The light guide plate has a first surface, a second surface disposed behind the first surface, and an end surface connected to the first surface and the second surface. The light guide plate propagates the light from the light source incident through the end face and emits the light to the first surface. The light diffusing unit is provided dispersed in a rectangular range on the second surface, and diffuses light propagating through the light guide plate. The light guide plate is formed with a notch in which the positioning member is disposed. The notch is notched from the end surface and extends from the second surface toward the first surface. The light diffusion portion is provided so that the first region and the second region are generated within the above range on the second surface. The first region includes a position closest to the notch. The second region includes a position closest to the end surface and is adjacent to the first region. In the first region, the ratio of the light diffusion portion per unit area is sparse, and in the second region, the ratio of the light diffusion portion per unit area is dense.

  According to the light source module configured as described above, the diffusion of light is suppressed in the first region in which the ratio of the light diffusion portion per unit area is sparse compared to the second region in which the ratio is dense. It is done. For this reason, although the light reflected by the notch or the positioning member is generated around the notch, the first region including the position closest to the notch and the second region adjacent to the first region The difference in the amount of light emitted from the first surface can be suppressed. Thereby, it is possible to prevent luminance unevenness from occurring in the light irradiated from the light source module.

  Further preferably, in the first region, the ratio of the light diffusion portion per unit area becomes zero. According to the light source module configured as described above, the light diffusion effect by the light diffusion portion is not exhibited in the first region. For this reason, it can prevent more effectively that a brightness nonuniformity arises in the light irradiated from a light source module.

  Preferably, in the first region, the ratio of the light diffusion portion per unit area increases as the distance from the position closest to the cutout portion increases. According to the light source module configured as described above, it is possible to suppress a significant change in luminance between the first region and the second region.

  Preferably, the light guide plate is disposed as an end surface facing the light source, and is connected to the first end surface on which light from the light source is incident, and extends from the first end surface along the light emission direction of the light from the light source. And a second end surface. The notch is formed so as to be notched from the second end surface. According to the light source module configured as described above, the light source module enters the first end surface, and is cut off due to reflection of light by the notch portion formed in the second end surface or the positioning member disposed in the notch portion. It is possible to prevent a phenomenon in which the brightness around the notch is locally increased.

  Preferably, the light guide plate includes a first notch portion disposed relatively close to the first end surface and a second notch portion disposed relatively far from the first end surface as the notch portions. And are formed. The light diffusing portion is provided in a range on the second surface such that a first region is generated corresponding to each of the first cutout portion and the second cutout portion. The area of the first region corresponding to the first notch is larger than the area of the first region corresponding to the second notch.

  According to the light source module configured as described above, in the vicinity of the first notch portion disposed near the first end surface on which light from the light source enters, the second notch disposed far from the first end surface. Compared with the periphery of the part, the influence of the reflected light by the notch part or the positioning member becomes large. For this reason, the occurrence of uneven brightness can be effectively prevented by setting the area of the first region corresponding to the first cutout portion larger.

  Preferably, the light diffusing portion includes a plurality of protrusions that protrude from the second surface in a hemispherical shape and are formed of a transparent resin. According to the light source module configured as described above, it is possible to prevent occurrence of luminance unevenness by changing the ratio of the plurality of protrusions occupying per unit area between the first region and the second region. .

  Preferably, a light-shielding sheet that blocks light from the light source is provided on the surface of the light guide plate that forms the notch. According to the light source module configured as described above, the light shielding sheet suppresses the progress of light from the inside of the light guide plate to the positioning member. Thereby, the occurrence of uneven brightness can be effectively prevented.

  Preferably, a light shielding sheet for blocking the progress of light from the light source is provided at a position on the first surface surrounding the notch. According to the light source module configured as described above, the light shielding sheet prevents the reflected light from the cutout portion or the positioning member from being emitted from the first surface around the cutout portion. Thereby, the occurrence of uneven brightness can be effectively prevented.

  An electronic apparatus according to the present invention includes any one of the light source modules described above. According to the electronic device configured in this way, light with uniform luminance is extracted from the light source module, so that the quality of the electronic device can be improved.

  As described above, according to the present invention, it is possible to provide a light source module and an electronic apparatus in which the occurrence of luminance unevenness is suppressed.

It is a disassembled perspective view which shows the liquid crystal display device provided with the backlight module in Embodiment 1 of this invention. It is a top view which shows the component of the backlight module in FIG. It is sectional drawing of the liquid crystal display device corresponding to the position along the III-III line | wire in FIG. It is sectional drawing which expands and shows the range enclosed by the dashed-two dotted line IV in FIG. FIG. 3 is an enlarged plan view showing a range surrounded by a two-dot chain line V in FIG. 2. It is a top view which shows the backlight module for a comparison. 6 is a graph showing the luminance at each position in the longitudinal direction of the light guide plate in the backlight module shown in FIG. 5. It is a top view which shows the 1st modification of the backlight unit in FIG. It is a top view which shows the 2nd modification of the backlight unit in FIG. It is a top view which shows the 3rd modification of the backlight unit in FIG. It is sectional drawing which shows the backlight module in Embodiment 2 of this invention. 12 is a graph showing luminance at a specific position in the backlight module shown in FIG. It is sectional drawing which shows the backlight module in Embodiment 3 of this invention. It is sectional drawing which shows the backlight module in Embodiment 4 of this invention. It is sectional drawing which shows the modification of the backlight module shown in FIG. It is sectional drawing which shows the backlight module in Embodiment 5 of this invention. It is sectional drawing which shows one form of the backlight module in Embodiment 6 of this invention. 18 is a graph showing luminance at a specific position in the backlight module shown in FIG. It is sectional drawing which shows another form of the backlight module in Embodiment 6 of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment 1)
[Description of overall structure of liquid crystal display device]
1 is an exploded perspective view showing a liquid crystal display device including a backlight module according to Embodiment 1 of the present invention. First, the overall structure of the liquid crystal display device 100 will be described with reference to FIG. 1. The liquid crystal display device 100 includes a bezel 120, a liquid crystal display panel 110, a backlight module 10, and a control unit 160.

  The liquid crystal display panel 110 is disposed so as to overlap the backlight module 10. The liquid crystal display panel 110 includes an active matrix substrate, a color filter, a counter substrate, and liquid crystal sealed between the active matrix substrate and the counter substrate. A plurality of TFT (Thin Film Transistor) elements are formed on the active matrix substrate. The liquid crystal display panel 110 receives light emitted from the backlight module 10 and displays an image in the display range.

  When viewed from the stacking direction of the liquid crystal display panel 110 and the backlight module 10, the liquid crystal display panel 110 has a rectangular shape having a pair of relatively long long sides and a pair of relatively short short sides. In the installed state of the liquid crystal display device 100, the liquid crystal display panel 110 is positioned such that its long side extends in the horizontal direction and its short side extends in the vertical direction.

  The bezel 120 is provided so as to cover the periphery of the liquid crystal display panel 110. The bezel 120 has a frame shape, and a window portion that allows the display range of the liquid crystal display panel 110 to be visible is formed inside the frame shape.

  FIG. 2 is a plan view showing components of the backlight module in FIG. 1 and 2, the backlight module 10 includes a light guide plate 21, LED (Light Emitting Diode) units 41 and 42, a laminated sheet group 130, a reflective sheet 150, and a backlight chassis 142 (see FIG. 1). 3).

  The light guide plate 21 is formed of a material that can transmit light emitted from the LED units 41 and 42. The light guide plate 21 is made of a transparent resin such as acrylic resin, polystyrene resin, methacrylic resin, or polycarbonate resin. The light guide plate 21 may be made of glass.

  The light guide plate 21 has a rectangular parallelepiped flat plate shape as a whole. When viewed from the stacking direction of the liquid crystal display panel 110 and the backlight module 10, the light guide plate 21 has a shape corresponding to the liquid crystal display panel 110, that is, a rectangular shape having a pair of long sides and a pair of short sides. The direction in which the pair of long sides extends is referred to as the longitudinal direction of the light guide plate 21, and the direction in which the pair of short sides extends is referred to as the short direction of the light guide plate 21.

  The light guide plate 21 has a main surface 22 and a back surface 23. The main surface 22 and the back surface 23 have a rectangular plan view. The back surface 23 is disposed on the back side of the main surface 22. The main surface 22 and the back surface 23 are arranged in parallel at a distance. The main surface 22 and the back surface 23 are side surfaces having the widest area among the plurality of side surfaces of the light guide plate 21. The light guide plate 21 is disposed so that the main surface 22 faces the liquid crystal display panel 110.

  The light guide plate 21 further has an end face 25. The end surface 25 is connected to the main surface 22 and the back surface 23. The end surface 25 is disposed at a right angle with respect to the main surface 22 and the back surface 23. The end surface 25 extends along the four sides of the main surface 22 and the back surface 23.

  The light guide plate 21 has an end surface 25p, an end surface 25q, an end surface 25r, and an end surface 25s as end surfaces 25. The end face 25p and the end face 25q are arranged in parallel with a distance therebetween. The end surface 25p and the end surface 25q extend in the longitudinal direction of the light guide plate 21. In the installed state of the liquid crystal display device 100, the end surface 25p is disposed below the main surface 22 and the back surface 23, and the end surface 25q is disposed above the main surface 22 and the back surface 23. The end surface 25r and the end surface 25s are arranged in parallel at a distance, and are orthogonal to the end surface 25p and the end surface 25q. The end surface 25r and the end surface 25s extend in the short direction of the light guide plate 21. In the installed state of the liquid crystal display device 100, the end face 25 r and the end face 25 s are arranged on the sides of the main surface 22 and the back surface 23.

  In the backlight module 10 according to the present embodiment, the case where the light guide plate 21 is configured by a single flat plate will be described. However, the light guide plate 21 is not limited to such a structure, and the light guide plate 21 is shorter than the light guide plate 21. You may be comprised from the some division board arranged along a direction. A plurality of grooves may be formed in the light guide plate 21 so as to be recessed from the main surface 22.

  The LED unit 41 and the LED unit 42 are arranged at a distance from each other. The LED unit 41 is disposed adjacent to the end surface 25 r of the light guide plate 21, and the LED unit 42 is disposed adjacent to the end surface 25 s of the light guide plate 21.

  Each LED unit of the LED units 41 and 42 includes a plurality of LEDs 46 and a circuit board 47. The LED 46 is a light source that emits light. The plurality of LEDs 46 are mounted on the circuit board 47. The plurality of LEDs 46 are arranged in a plane in which the light guide plate 21 extends in a flat plate shape. The plurality of LEDs 46 are arranged at intervals along the short direction of the light guide plate 21. The plurality of LEDs 46 constituting the LED unit 41 are arranged to face the end surface 25r of the light guide plate 21. The plurality of LEDs 46 constituting the LED unit 42 are disposed to face the end face 25 s of the light guide plate 21. The end face 25p and the end face 25q of the light guide plate 21 extend along the light emission direction of the light from the LED 46.

  In the present embodiment, the plurality of LEDs 46 are arranged at positions adjacent to the end face 25r and the end face 25s of the light guide plate 21, but the present invention is not limited to this structure, and any of the positions adjacent to the end face 25r and the end face 25s is used. A plurality of LEDs 46 may be arranged on either side. Further, a plurality of LEDs 46 may be arranged at positions adjacent to the end face 25p and / or the end face 25q of the light guide plate 21.

  Further, the light source is not limited to the example in which the LED is used, and a fluorescent tube such as a cold cathode tube and a hot cathode or other light sources can be adopted.

  The reflection sheet 150 is disposed so as to overlap the light guide plate 21. The reflection sheet 150 is disposed so as to face the back surface 23. The reflection sheet 150 is disposed between the light guide plate 21 and a chassis 140 described later.

  The reflection sheet 150 has a characteristic capable of reflecting the light emitted from the LED 46. The reflection sheet 150 is formed from a sheet-like member having high reflectivity, and is formed from, for example, a white polyester film typified by a white polyethylene terephthalate film. The reflection sheet 150 has a function of reflecting the light leaked from the back surface 23 of the light guide plate 21 and returning it to the inside of the light guide plate 21, and increases the light use efficiency.

  The laminated sheet group 130 is disposed so as to overlap the light guide plate 21. The laminated sheet group 130 is disposed so as to face the main surface 22. The laminated sheet group 130 is disposed between the liquid crystal display panel 110 and the light guide plate 21.

  The laminated sheet group 130 has a function of suppressing luminance unevenness of light emitted from the light guide plate 21 and condensing the light from the light guide plate 21 and irradiating the light toward the liquid crystal display panel 110. In order to exhibit such a function, the laminated sheet group 130 includes a diffusion sheet and a plurality of prism sheets.

  The liquid crystal display panel 110 and the LED units 41 and 42 are electrically connected to the control unit 160. The control unit 160 is a part for controlling the entire liquid crystal display device 100. For example, the control of the driving of the TFT elements provided in the liquid crystal display panel 110 and the driving of the LEDs 46 provided in the LED units 41 and 42 are performed. Control and so on.

  3 is a cross-sectional view of the liquid crystal display device corresponding to the position along the line III-III in FIG. With reference to FIGS. 1 to 3, the backlight chassis 142 is provided as a mounting base to which the light guide plate 21 is attached. In the present embodiment, the backlight chassis 142 includes a chassis 140 and a p-chassis 141.

  The chassis 140 has a saucer shape opened in one direction. On the chassis 140, the reflection sheet 150, the light guide plate 21, and the laminated sheet group 130 are stacked in the order given. The p-chassis 141 is provided so as to cover the periphery of the laminated sheet group 130. Further, a bezel 120 is provided so as to cover the P-chassis 141. The liquid crystal display panel 110 is sandwiched between the P-chassis 141 and the bezel 120 via the buffer material 112 and the buffer material 114. The bezel 120 and the chassis 140 are fixed to each other by fixing means (not shown), whereby each component of the liquid crystal display device 100 is sandwiched between the bezel 120 and the chassis 140.

  As shown in FIGS. 2 and 3, the liquid crystal display panel 110 displays an image in the display range 115. The display range 115 is formed inside the bezel 120. The display range 115 has a rectangular shape.

  FIG. 4 is an enlarged cross-sectional view of a range surrounded by a two-dot chain line IV in FIG. With reference to FIGS. 2 to 4, the backlight module 10 further includes a light diffusion portion 61. The light diffusing unit 61 has a function of diffusing light propagating through the light guide plate 21. The light diffusing unit 61 is provided on the back surface 23 of the light guide plate 21.

  The structure of the light diffusion part 61 will be described more specifically. The light diffusion part 61 is formed as a dot pattern dispersed on the back surface 23. The light diffusion part 61 is composed of a plurality of protrusions 61j. The protrusion 61j is formed so as to protrude from the back surface 23 in a hemispherical shape. The protrusion 61j has a circular shape when the back surface 23 is viewed in plan. The plurality of protrusions 61j are provided on the back surface 23 at intervals. The protrusion 61j is made of a material that can transmit light emitted from the LED 46. The protrusion 61j is made of a transparent resin. The protrusion 61j may be formed of the same material as that of the light guide plate 21.

  The light diffusing portion 61 is formed by printing the resin for forming the protruding portion 61j on the back surface 23. As a method for printing the light diffusion portion 61, an ink jet printing method or a silk printing method is used.

  In the present embodiment, the case where the light diffusing portion 61 is composed of a plurality of protrusions 61j has been described. However, the present invention is not limited to this. You may form by giving a shape, you may form by printing of the ink containing the microbead which has a diffusibility, and you may form by giving the back surface 23 a blast process.

  The light diffusion part 61 is formed within the range of the light diffusion part formation range 60 defined on the back surface 23. The light diffusion portion forming range 60 has a rectangular shape. The light diffusion part formation range 60 is defined in association with the display range 115. On the back surface 23, an outer peripheral range 65 is further defined. The outer peripheral range 65 has a shape that circulates in a strip shape on the outer periphery of the light diffusion portion forming range 60. A cutout portion 31 and a cutout portion 32 described later are formed in the outer peripheral range 65. The light diffusion portion 61 is not formed in the outer peripheral range 65.

  As shown in FIG. 2, the light diffusing unit 61 has the end of the light diffusing unit forming range 60 and the end of the display range 115 in the short direction of the light guide plate 21, and the display range in the longitudinal direction of the light guide plate 21. 115 is provided so that the end of 115 is included in the light diffusion portion formation range 60. The light diffusing portion forming range 60 and the display range 115 are not limited to such a relationship. For example, the light diffusing portion 61 is configured such that the end of the light diffusing portion forming range 60 is included in the display range 115 in the longitudinal direction of the light guide plate 21. May be formed.

  The backlight module 10 described above displays an image in the display range 115 by irradiating the liquid crystal display panel 110 with light.

  The mechanism will be described. Light emitted from the LED 46 of the LED unit 41 and the LED unit 42 enters the light guide plate 21 through the end face 25r and the end face 25s, respectively. That is, the end surface 25r and the end surface 25s function as an incident surface on which light from the LED 46 is incident on the light guide plate 21. The light propagates in a planar manner while repeating total reflection inside the light guide plate 21.

  At this time, as shown in FIG. 4, a part of the light traveling toward the back surface 23 enters the protrusion 61 j constituting the light diffusion portion 61. The light incident on the protrusion 61j is reflected in multiple directions by the outer peripheral surface 62 of the protrusion 61j, whereby the light traveling from the back surface 23 toward the main surface 22 is diffused. As a result, light that does not satisfy the total reflection condition on the main surface 22 is generated, and the light is emitted through the main surface 22. At this time, the main surface 22 functions as an emission surface that emits light from the inside of the light guide plate 21. The light further transmitted through the outer peripheral surface 62 of the protrusion 61j is reflected by the reflection sheet 150 and returned to the inside of the light guide plate 21.

  The light emitted from the light guide plate 21 is irradiated with the liquid crystal display panel 110 after being optically corrected by the laminated sheet group 130.

  As described above, in order to irradiate light to an appropriate range of the liquid crystal display panel 110, it is necessary to provide means for positioning the light guide plate 21 in the backlight module 10. Hereinafter, the positioning structure of the light guide plate 21 will be described.

  With reference to FIGS. 1 to 3, the backlight module 10 further includes positioning pins 51 for positioning the light guide plate 21. The positioning pin 51 is fixed to the chassis 140. The positioning pins 51 have a pin shape extending in the stacking direction of the liquid crystal display panel 110 and the backlight module 10. The positioning pin 51 is provided corresponding to each position where a notch 31 and a notch 32 described later are formed.

  The light guide plate 21 is formed with a notch 31 and a notch 32 where the positioning pins 51 are arranged. The notch 31 and the notch 32 are formed by notching from the end face 25. The cutout portion 31 and the cutout portion 32 are formed so that the end face 25 extending linearly along the longitudinal direction or the short side direction of the light guide plate 21 is discontinuous. The notch 31 and the notch 32 extend from the back surface 23 toward the main surface 22. The notch 31 and the notch 32 are formed so as to penetrate the light guide plate 21 between the main surface 22 and the back surface 23.

  In the present embodiment, notches 31a, 31b, 31c, 31d, 31e, 31f are formed as the notches 31. The notches 31a, 31b, 31c, 31d, and 31e are formed by notching from the end face 25p. The cutout portion 31f is formed by cutting out from the end face 25q.

  The notch 31 c is disposed at the center of the end face 25 p in the longitudinal direction of the light guide plate 21. The cutout portion 31 b and the cutout portion 31 d are disposed on both sides of the cutout portion 31 c in the longitudinal direction of the light guide plate 21. The notch 31a is disposed on the opposite side of the notch 31c with respect to the notch 31b, and the notch 31e is disposed on the opposite side of the notch 31c with respect to the notch 31d. The notch 31 f is disposed at the center of the end face 25 q in the longitudinal direction of the light guide plate 21.

  Further, in the present embodiment, the notches 32 a and 32 b are formed as the notches 32. The cutout portion 32a is formed by cutting out from the end face 25r. The cutout portion 32b is formed by cutting out from the end face 25s.

  The notch 32 a is arranged at the center of the end surface 25 r in the short direction of the light guide plate 21. The notch 32 b is disposed at the center of the end face 25 s in the short direction of the light guide plate 21.

  Positioning pins 51 are arranged in the cutout portion 31 and the cutout portion 32 in a state where the reflection sheet 150, the light guide plate 21, and the laminated sheet group 130 are stacked on the chassis 140. As a result, the position of the light guide plate 21 in the planar direction is restrained by the positioning pins 51.

  The position where the notch is formed in the light guide plate 21 is not limited to the position described above. For example, only the notch 31 of the notch 31 and the notch 32 may be formed. Of the cutout portions 31, only the cutout portion 31c and the cutout portion 31f may be formed. Further, in addition to the notch 31 and / or the notch 32, the notch may be formed at the four corners of the light guide plate 21.

[Description of detailed structure of light diffusing section]
Next, the structure of the light diffusing unit 61 provided in the backlight module 10 in the present embodiment will be described in detail.

  FIG. 5 is an enlarged plan view showing a range surrounded by a two-dot chain line V in FIG. Referring to FIG. 5, in the present embodiment, the light diffusing portion 61 includes a correction region 71 in which the ratio of the light diffusing portion 61 occupying per unit area is sparse in the light diffusing portion forming range 60, and per unit area. And the peripheral region 72 where the ratio of the light diffusion portion 61 occupying is dense.

  The correction region 71 is formed so as to include a position 73 closest to the notch 31 (the notch 31c in the position shown in the drawing) within the range of the light diffusion portion formation range 60.

  The peripheral area 72 is formed adjacent to the correction area 71. The peripheral region 72 is a position closest to the end face 25 in which the notch 31 is formed (the end face 25p in which the notch 31c is formed in the position shown in the drawing) within the range of the light diffusion part formation range 60. 74 is included. The correction area 71 is surrounded by a peripheral area 72 and an outer peripheral area 65. The boundary between the correction area 71 and the peripheral area 72 extends in an arc shape. The correction area 71 has a shape surrounded by an arc and a straight line connecting both ends of the arc. The correction region 71 has a shape that protrudes inward from the end side of the light diffusion portion forming range 60 that is close to the cutout portion 31.

  In the present embodiment, the light diffusion portion 61 is not formed in the correction region 71. That is, when the light diffusing unit 61 is printed on the back surface 23, the correction area 71 is deleted (trimmed) from the print area.

  FIG. 6 is a plan view showing a backlight module for comparison. In the figure, the backlight module in the range shown in FIG. 5 is shown. Referring to FIG. 6, in the backlight module in this comparative example, correction region 71 where light diffusing portion 61 is not printed is not provided in light diffusing portion forming range 60.

  The light propagating through the light guide plate 21 reaches the vicinity of the notch 31 while repeating total reflection between the main surface 22 and the back surface 23. In this case, as indicated by arrows 201 and 202 in the drawing, when light is reflected by the surface of the light guide plate 21 forming the notch 31 or the positioning pin 51, the main surface 22 is formed around the notch 31. A phenomenon occurs in which the luminance of light emitted from the light increases. The occurrence of such a phenomenon becomes prominent in the vicinity of the outer edge of the display range 115 where an image is displayed, and is reduced as the distance from the outer edge of the display range 115 approaches the inner side.

  Referring to FIG. 5, in contrast, in backlight module 10 according to the present embodiment, light diffusing portion 61 is not formed in correction region 71 including position 73 closest to notch portion 31. With such a configuration, the light diffusing effect by the light diffusing unit 61 is not exhibited in the correction region 71, so that the light total reflection condition on the main surface 22 is hardly broken. Thereby, it is possible to suppress a difference in the amount of light emitted from the main surface 22 between the correction region 71 and the peripheral region 72, and to prevent luminance unevenness around the notch 31.

  In FIG. 5, only the positions where the notches 31c are provided are shown, but the light diffusion portions correspond to the notches 31 of the notches 31a, 31b, 31d, 31e, and 31f. A correction area 71 is provided in the formation range 60.

  Further, a correction region 71 may be provided in the light diffusion portion formation range 60 corresponding to the cutout portion 32 cut out from the end side 25r and the end side 25s of the light guide plate 21. Even in such a case, for example, light from the LED unit 42 that has entered through the end 25s travels into the notch 32a that is cut out from the end 25r. be able to.

  Next, an example performed to confirm the functions and effects achieved by the backlight module 10 in FIG. 5 will be described.

  FIG. 7 is a graph showing the luminance at each position in the longitudinal direction of the light guide plate in the backlight module shown in FIG. Referring to FIG. 7, positions A, B, C, D, and E shown on the horizontal axis correspond to the positions where notches 31a, 31b, 31c, 31d, and 31e are formed in light guide plate 21 in FIG. To do.

  In this embodiment, the luminance is measured in the vicinity of the outer edge of the display range 115 where the image is displayed, and how the luminance changes in the longitudinal direction of the light guide plate 21 is shown in FIG. As shown in FIG. 5, when the length a between the side edge 25p and the outer edge of the light diffusion portion formation range 60 is set to b, the depth of the notch 32 is set to b, and the width of the correction region 71 is set to c. In addition, a = 9.5 mm, b = 6.8 mm, and c = 33 mm. Furthermore, when the depth of the correction area 71 is h, in the correction area 71 provided corresponding to the notches 31a and 31e, h = 10 mm and provided corresponding to the notches 31b, 31c and 31d. In the correction area 71, h = 8 mm. Furthermore, in this example, the luminance was also measured for the backlight module for comparison shown in FIG. 6, and the result is shown in FIG.

  In the backlight module for comparison, the luminance suddenly increased at each position where the notches 31a, 31b, 31c, 31d, and 31e were formed. On the other hand, the brightness can be smoothly changed around the notch 31 by providing the correction region 71 in which the light diffusion part 61 is not formed corresponding to the notch 31.

  Referring to FIG. 2, cutout portions 31a and 31e as first cutout portions are arranged close to end surfaces 25r and 25s functioning as incident surfaces. Compared with the notches 31a and 31e, the notches 31b, 31c and 31d as the second notches are arranged farther from the end faces 25r and 25s. In this case, in the cutout portions 31a and 31e, the effect of the reflected light from the cutout portion 31 and the positioning pin 51 becomes large, and the phenomenon that the brightness is locally increased becomes remarkable.

  On the other hand, in the above embodiment, by providing a difference in the depth h of the correction area 71, the area of the correction area 71 provided corresponding to the notches 31a and 31e is reduced to the notches 31b, 31c and 31d. Is set to be larger than the area of the correction region 71 provided corresponding to. With such a configuration, since the area where the light diffusion portion 61 is not formed is large around the notches 31a and 31e, it is possible to effectively prevent occurrence of luminance unevenness.

  FIG. 8 is a plan view showing a first modification of the backlight unit in FIG. Referring to FIG. 8, in the present modification, the number of protrusions 61 j formed per unit area of back surface 23 is set to be large in correction region 71 and small in peripheral region 72. Even with such a configuration, since the light diffusion effect by the light diffusing unit 61 is suppressed in the correction region 71, it is possible to prevent the occurrence of luminance unevenness.

  Further, by providing a difference in the size of each protrusion 61j or by providing a difference in the number and size of the protrusions 61j, the light diffusion portion 61 occupying per unit area in the correction region 71 The ratio may be sparse, and the ratio of the light diffusing portion 61 occupying per unit area in the peripheral region 72 may be dense.

  FIG. 9 is a plan view showing a second modification of the backlight unit in FIG. Referring to FIG. 9, in the present modification, in the correction region 71, the proportion of the light diffusing portion 61 occupying per unit area increases as the distance from the position 73 closest to the notch 31 increases. . In the example shown in the figure, the change in the ratio of the light diffusion portion 61 per unit area is manipulated by the number of protrusions 61 j formed per unit area of the back surface 23.

  According to such a configuration, the luminance does not change abruptly between the inside and outside of the correction area 71. For this reason, it can be avoided that the boundary between the correction region 71 and the peripheral region 72 appears as a line on the display screen of the liquid crystal display panel 110.

  FIG. 10 is a plan view showing a third modification of the backlight unit in FIG. Referring to FIG. 10, the shape of correction region 71 is not limited to a shape including an arc, and may be, for example, a rectangular shape as shown in FIG. 10 (A) or as shown in FIG. 10 (B). As such, it may be triangular. The shape of the correction region 71 is appropriately selected in consideration of the location of the positioning pin 51, the distance from the LED 46, the cutout shape of the cutout portion 31, and the like.

  The structure of the backlight module 10 according to the first embodiment of the present invention described above will be described together. The backlight module 10 as the light source module in the present embodiment includes an LED 46 as a light source that emits light, and a light guide. An optical plate 21, positioning pins 51 as positioning members for positioning the light guide plate 21, and a light diffusion portion 61 are provided. The light guide plate 21 has a main surface 22 as a first surface, a back surface 23 as a second surface disposed on the back side of the main surface 22, and an end surface 25 connected to the main surface 22 and the back surface 23. The light guide plate 21 causes the light from the LED 46 incident through the end face 25 r and the end face 25 s to propagate inside and be emitted to the main surface 22. The light diffusing portions 61 are provided dispersed in the light diffusing portion forming range 60 as a rectangular range on the back surface 23, and diffuse the light propagating through the light guide plate 21.

  The light guide plate 21 is formed with a notch 31 in which the positioning pin 51 is disposed. Cutout portion 31 is cut out from end surface 25p and end surface 25q, and extends from back surface 23 toward main surface 22. The light diffusion portion 61 is provided so that a correction region 71 as a first region and a peripheral region 72 as a second region are generated in a light diffusion portion formation range 60 on the back surface 23. The correction area 71 includes a position 73 that is closest to the notch 31. The peripheral area 72 includes a position 74 closest to the end face 25p and the end face 25q, and is adjacent to the correction area 71. In the correction region 71, the ratio of the light diffusion portion 61 occupying per unit area is sparse, and in the peripheral region 72, the ratio of the light diffusion portion 61 occupying per unit area is dense.

  A liquid crystal display device 100 as an image display device according to the present invention is disposed on the side facing the backlight module 10 and the main surface 22 and displays an image by receiving light emitted from the main surface 22. As a liquid crystal display panel 110.

  According to the backlight module 10 and the liquid crystal display device 100 according to Embodiment 1 of the present invention configured as described above, the correction region 71 in which the arrangement density of the light diffusion portions 61 is sparse in the light diffusion portion formation range 60. By providing this, it is possible to prevent luminance unevenness from occurring around the notch 31. Thereby, the display performance of the liquid crystal display device 100 can be improved.

  Note that in this embodiment, a liquid crystal display device is illustrated as a representative example of an electronic device, and a backlight module included in the liquid crystal display device is illustrated as a representative example of a light source module. In addition, examples of the electronic apparatus to which the present invention is applied include lighting fixtures, projectors, projectors, advertising lights, and the like, and examples of the light source module to which the present invention is applied include light source modules included therein.

(Embodiment 2)
The backlight module and the liquid crystal display device including the backlight module according to the present embodiment have the basic structure described in the item [Description of overall structure of liquid crystal display device] in the first embodiment. Furthermore, in the backlight module according to the present embodiment, the positioning pin 51 disposed in the notch 31 has a characteristic structure.

  FIG. 11 is a cross-sectional view showing a backlight module according to Embodiment 2 of the present invention. In the figure, a positioning pin 51 disposed in the notch 31 is shown.

  Referring to FIG. 11, positioning pin 51 has a cylindrical shape. The positioning pin 51 has a circular cross-sectional shape when cut by a plane orthogonal to the stacking direction of the liquid crystal display panel 110 and the backlight module. The positioning pin 51 has a multilayer structure including an inner peripheral layer and an outer peripheral layer in its cross section. That is, the positioning pin 51 has a main body 53 provided as an inner peripheral layer and a covering portion 54 provided as an outer peripheral layer.

  The main body 53 has a cylindrical shape. The main body 53 is formed in a solid shape. The covering portion 54 is provided so as to cover the surface of the main body portion 53. The covering portion 54 is provided so as to cover at least the outer peripheral surface of the main body portion 53 having a columnar shape. The covering portion 54 is provided so as to be exposed to the outside.

  The main body 53 has a first reflectance with respect to the light emitted from the LED 46. The first reflectance is a value obtained by the ratio of the energy of the reflected light to the energy of the incident light (the energy of the reflected light / the energy of the incident light) when the light is incident on the surface of the main body 53 at a right angle. . The covering portion 54 has a second reflectance with respect to the light emitted from the LED 46. The second reflectance is a value obtained by the ratio of the energy of the reflected light to the energy of the incident light (the energy of the reflected light / the energy of the incident light) when the light is incident on the surface of the covering portion 54 at a right angle. .

  The second reflectance is smaller than the first reflectance. That is, when light of the same energy is incident on the main body 53 and the cover 54, the energy of the reflected light from the cover 54 becomes smaller than the energy of the reflected light from the main body 53.

  The main body 53 is made of metal. The main body 53 is made of, for example, stainless steel, aluminum, or iron. The covering portion 54 is formed from a resin using an epoxy resin, a silicone resin, a polyimide resin, or the like. The covering portion 54 may be formed of a coating film having a color that efficiently absorbs light, such as black or gray. The covering portion 54 may be formed by a plating layer for the metal main body portion 53. For example, the covering portion 54 may be formed from a plating layer by black chrome plating. Furthermore, when the main body 53 is formed from aluminum, the covering 54 may be formed from a plating layer by black alumite treatment.

  In addition, the cross-sectional shape of the positioning pin 51 is not limited to a circle, and may be changed as appropriate, such as a quadrangle, a triangle, or an ellipse.

  When the positioning pin 51 is made of metal, the surface thereof has a high reflectance due to the metallic luster. For this reason, the light propagating through the light guide plate 21 and transmitted through the notch 31 is reflected by the positioning pins 51, causing a phenomenon in which the brightness increases around the notch 31. On the other hand, in the present embodiment, since the coating portion 54 having a low reflectance is disposed on the surface of the positioning pin 51, the light transmitted through the cutout portion 31 is reflected by the positioning pin 51 and again the light guide plate 21. Can be controlled. Thereby, luminance unevenness around the notch 31 can be prevented. On the other hand, the metal main body 53 contributes to increasing the rigidity of the positioning pin 51. Thereby, the light guide plate 21 can be positioned with high reliability using the positioning pins 51.

  FIG. 12 is a graph showing the luminance at a specific position in the backlight module shown in FIG. Referring to FIG. 12, a position E represented on the horizontal axis corresponds to a position where notch portion 31e is formed in light guide plate 21 in FIG.

  In this example, using the backlight module in FIG. 11, the luminance was measured in the same manner as in the example whose result was shown in FIG. 7 of the first embodiment. The main body 53 was formed from stainless steel, and the covering 54 was formed from a plated layer by black chrome treatment. As a result of the measurement, it was confirmed that the luminance peak value was reduced by about 30% around the notch 31e.

  The structure of the backlight module according to Embodiment 2 of the present invention described above will be described together. The backlight module as the light source module in the present embodiment includes the LED 46 as a light source that emits light, and the light guide plate 21. And positioning pins 51 as positioning members for positioning the light guide plate 21. The light guide plate 21 has a main surface 22 as a first surface, a back surface 23 as a second surface disposed on the back side of the main surface 22, and an end surface 25 connected to the main surface 22 and the back surface 23. The light guide plate 21 causes the light from the LED 46 incident through the end face 25 r and the end face 25 s to propagate inside and be emitted to the main surface 22.

  The light guide plate 21 is formed with a notch 31 in which the positioning pin 51 is disposed. Cutout portion 31 is cut out from end surface 25p and end surface 25q, and extends from back surface 23 toward main surface 22. The positioning pin 51 is provided so as to cover the main body 53 having a first reflectance with respect to the light from the LED 46, and is smaller than the first reflectance with respect to the light from the LED 46. And a covering portion 54 having a reflectance of 2.

  According to the backlight module and the liquid crystal display device including the backlight module according to the second embodiment of the present invention configured as described above, the low-reflectance coating portion 54 is disposed on the surface of the positioning pin 51. Further, it is possible to prevent uneven brightness from occurring around the notch 31. Thereby, the display performance of a liquid crystal display device can be improved.

(Embodiment 3)
The backlight module and the liquid crystal display device including the backlight module according to the present embodiment have the basic structure described in the item [Description of overall structure of liquid crystal display device] in the first embodiment. Furthermore, in the backlight module according to the present embodiment, the positioning pin 51 disposed in the notch 31 has a characteristic structure.

  FIG. 13 is a cross-sectional view showing a backlight module according to Embodiment 3 of the present invention. In the figure, a positioning pin 51 disposed in the notch 31 is shown.

  Referring to FIG. 13, in the present embodiment, positioning pin 51 is formed of resin. The positioning pin 51 is made of a resin that can transmit light emitted from the LED 46. The positioning pin 51 is made of, for example, an epoxy resin, a silicone resin, or a polyimide resin. Further, the positioning pin 51 may be formed of a resin having a color that efficiently absorbs light, such as black or gray.

  In the present embodiment, by forming the positioning pin 51 from resin, it is possible to suppress the light transmitted through the notch 31 from being reflected by the positioning pin 51 and heading again toward the light guide plate 21. Thereby, luminance unevenness around the notch 31 can be prevented.

  The structure of the backlight module according to Embodiment 3 of the present invention described above will be described together. The backlight module as the light source module in the present embodiment includes the LED 46 as a light source that emits light, and the light guide plate 21. And positioning pins 51 as positioning members for positioning the light guide plate 21. The light guide plate 21 has a main surface 22 as a first surface, a back surface 23 as a second surface disposed on the back side of the main surface 22, and an end surface 25 connected to the main surface 22 and the back surface 23. The light guide plate 21 causes the light from the LED 46 incident through the end face 25 r and the end face 25 s to propagate inside and be emitted to the main surface 22.

  The light guide plate 21 is formed with a notch 31 in which the positioning pin 51 is disposed. Cutout portion 31 is cut out from end surface 25p and end surface 25q, and extends from back surface 23 toward main surface 22. The positioning pin 51 is made of resin.

  According to the backlight module and the liquid crystal display device including the backlight module according to Embodiment 3 of the present invention configured as described above, the positioning pins 51 are formed from resin, so that the periphery of the notch 31 is formed. It is possible to prevent luminance unevenness from occurring. Thereby, the display performance of a liquid crystal display device can be improved.

(Embodiment 4)
The backlight module and the liquid crystal display device including the backlight module according to the present embodiment have the basic structure described in the item [Description of overall structure of liquid crystal display device] in the first embodiment. Furthermore, in the backlight module according to the present embodiment, the groove depth of the notch 31 and the size of the positioning pin 51 have a characteristic relationship.

  FIG. 14 is a cross-sectional view showing a backlight module according to Embodiment 4 of the present invention. In the figure, a notch 31 and a positioning pin 51 arranged in the notch 31 are shown.

  Referring to FIG. 14, the cutout portion 31 has a rectangular cross-sectional shape having a bottom portion 36 and a side wall portion 37. The bottom portion 36 is disposed at the bottom portion of the groove that forms the cutout portion 31. The side wall part 37 is formed so as to continue from the end face 25 to the bottom part 36. In the figure, the notch 31 disposed at the lower part of the light guide plate 21 is shown, so that the positioning pin 51 is in contact with the bottom 36. A minute gap is formed between the positioning pin 51 and the side wall portion 37.

  In the backlight module according to the present embodiment, the positioning pin 51 is arranged in the cutout portion 31 in a form protruding from the end face 25 (the end face 25p in the range shown in the drawing). That is, when the diameter of the positioning pin 51 is D and the groove depth of the cutout portion 31 (the length between the end face 25 and the bottom portion 36) is H, the cutout portion 31 has a relationship of H <D. It is formed to satisfy.

  The diameter of the positioning pin 51 is determined in consideration of the rigidity required for the positioning pin 51 and the like. In the present embodiment, the notch 31 is formed so that the groove depth is smaller than the diameter of the positioning pin 51. Thus, since the length of the side wall part 37 can be made small by making the notch part 31 low-profile, it can suppress that light permeate | transmits the side wall part 37 and is reflected by the positioning pin 51. FIG. On the other hand, the light traveling inside the side wall portion 37 has a shallow incident angle with respect to the bottom portion 36, and most of the light is reflected by the bottom portion 36. Since the light reflected by the bottom part 36 travels away from the notch 31, the probability that this light is emitted from the periphery of the notch 31 is low. For the above reason, luminance unevenness around the notch 31 can be prevented.

  Further, the notch 31 is preferably formed so as to satisfy the relationship of H> D / 2. In this case, since the side wall portions 37 are arranged on both sides of the large diameter portion of the positioning pin 51, the positioning accuracy of the light guide plate 21 by the positioning pin 51 can be improved.

  FIG. 15 is a cross-sectional view showing a modification of the backlight module shown in FIG. Referring to FIG. 15, the cross-sectional shape of positioning pin 51 is not limited to a circle, and may be, for example, a rectangular shape as shown in FIG. 15A or as shown in FIG. A triangular shape may be used. The shape of the notch 31 is appropriately changed according to the shape of the positioning pin 51.

  The structure of the backlight module according to Embodiment 4 of the present invention described above will be described together. The backlight module as the light source module in the present embodiment includes the LED 46 as a light source that emits light, and the light guide plate 21. And positioning pins 51 as positioning members for positioning the light guide plate 21. The light guide plate 21 has a main surface 22 as a first surface, a back surface 23 as a second surface disposed on the back side of the main surface 22, and an end surface 25 connected to the main surface 22 and the back surface 23. The light guide plate 21 causes the light from the LED 46 incident through the end face 25 r and the end face 25 s to propagate inside and be emitted to the main surface 22. The light guide plate 21 is formed with a notch 31 cut out from the end surface 25p and the end surface 25q and extending from the back surface 23 toward the main surface 22. In the notch 31, the positioning pin 51 is arranged so as to protrude from the end face 25p and the end face 25q.

  According to the backlight module and the liquid crystal display device including the backlight module according to the fourth embodiment of the present invention configured as described above, by reducing the height of the notch 31 in relation to the positioning pin 51, Further, it is possible to prevent uneven brightness from occurring around the notch 31. Thereby, the display performance of a liquid crystal display device can be improved.

(Embodiment 5)
The backlight module and the liquid crystal display device including the backlight module according to the present embodiment have the basic structure described in the item [Description of overall structure of liquid crystal display device] in the first embodiment. Furthermore, in the backlight module according to the present embodiment, the notch 31 has a characteristic structure.

  FIG. 16 is a cross-sectional view showing a backlight module according to Embodiment 5 of the present invention. In the drawing, in the longitudinal direction of the light guide plate 21, a range from the position where the LED unit 41 is arranged to the position where the notch 31b is formed is shown.

  Referring to FIG. 16, in the present embodiment, cutout portion 31 b has a shape that is stretched in the longitudinal direction of light guide plate 21. That is, when the back surface 23 is viewed from the front, the notch 31b is formed so as to reach the end surface 25r from the position where the positioning pin 51 is disposed.

  The cutout portion 31b has a shape in which a cross section when opened by a plane parallel to the back surface 23 is opened to the end surface 25r. The cutout portion 31 b has a bottom portion 28. The bottom portion 28 is continuous with the end surface 25r. The bottom portion 28 extends in a direction parallel to the end face 25p. The bottom portion 28 extends from the end surface 25r in a direction away from the end surface 25r. The bottom portion 28 extends along the emission direction of light from the LEDs 46 constituting the LED unit 41.

  According to such a configuration, the light emitted from the LED 46 has a relationship in which the total reflection condition is not easily broken with respect to the bottom portion 28 extending in the emission direction. The amount of light traveling toward 51 can be suppressed. Thereby, luminance unevenness around the notch 31 can be prevented.

  Although only the notch 31b is shown in FIG. 16, the notch 31d in FIG. 2 is also formed so as to be open to the end face 25s.

  The structure of the backlight module in the fifth embodiment of the present invention described above will be described together. The backlight module as the light source module in the present embodiment includes the LED 46 as a light source that emits light, and the light guide plate 21. And positioning pins 51 as positioning members for positioning the light guide plate 21. The light guide plate 21 has a main surface 22 as a first surface, a back surface 23 as a second surface disposed on the back side of the main surface 22, and an end surface 25 connected to the main surface 22 and the back surface 23. The light guide plate 21 causes the light from the LED 46 incident through the end face 25 r and the end face 25 s to propagate inside and be emitted to the main surface 22. The light guide plate 21 is disposed as an end face 25 so as to face the LED 46, and is connected to the end face 25 r and the end face 25 s as the first end face to which the light from the LED 46 is incident, and the end face 25 r and the end face 25 s, and the light from the LED 46 It has the end surface 25p and the end surface 25q as a 2nd end surface extended along the radiation | emission direction.

  The light guide plate 21 is formed with a notch 31 in which the positioning pin 51 is disposed. Cutout portion 31 is cut out from end surface 25p and end surface 25q, and extends from back surface 23 toward main surface 22. When the back surface 23 is viewed from the front, the notch 31 is formed so as to reach the end surface 25r and the end surface 25s from the position where the positioning pin 51 is disposed.

  According to the backlight module and the liquid crystal display device including the backlight module according to the fifth embodiment of the present invention configured as described above, the notch 31b and the notch 31d are arranged so that the LEDs 46 face each other. By making the shape open to the end face 25r and the end face 25s, it is possible to prevent uneven brightness from occurring around the notch 31. Thereby, the display performance of a liquid crystal display device can be improved.

(Embodiment 6)
The backlight module and the liquid crystal display device including the backlight module according to the present embodiment have the basic structure described in the item [Description of overall structure of liquid crystal display device] in the first embodiment. Further, in the backlight module in the present embodiment, light shielding sheets 81 and 82 are further provided.

  FIG. 17 is a cross-sectional view showing one form of a backlight module according to Embodiment 6 of the present invention. In the figure, a notch 31 and a positioning pin 51 arranged in the notch 31 are shown.

  With reference to FIG. 17, light propagating through the light guide plate 21 is emitted to the notch 31, and the light shielding sheet 81 capable of blocking the light from the LED 46 on the light path toward the positioning pin 51. Is provided. More specifically, a light shielding sheet 81 is provided on the surface of the light guide plate 21 that forms the notch 31. The light shielding sheet 81 is formed of a sheet-like member or a coating film having a color that efficiently absorbs light, such as black or gray.

  FIG. 18 is a graph showing the luminance at a specific position in the backlight module shown in FIG. Referring to FIG. 18, position A represented on the horizontal axis corresponds to the position where notch portion 31 a is formed in light guide plate 21 in FIG. 2.

  In this example, using the backlight module in FIG. 17, the luminance was measured in the same manner as in the example whose result was shown in FIG. 7 of the first embodiment. As the light shielding sheet 81, a black light shielding tape was used, and this light shielding tape was bonded to the surface of the light guide plate 21 forming the cutout portion 31. As a result of the measurement, it was confirmed that the luminance peak value was reduced by about 60% around the notch 31a.

  FIG. 19 is a cross-sectional view showing another form of the backlight module according to Embodiment 6 of the present invention. In the figure, a notch 31 and a positioning pin 51 arranged in the notch 31 are shown.

  Referring to FIG. 19, a light shielding sheet 82 capable of blocking the progress of light from the LED 46 is provided at a position surrounding the notch 31 on the main surface 22. The light shielding sheet 82 is formed of a sheet-like member or a coating film similar to the light shielding sheet 81 described above. The light shielding sheet 82 is preferably disposed in a region outside the display region 115.

  In the present embodiment, the amount of light leaking from the periphery of the notch 31 can be reduced by arranging the light shielding sheet 81 or the light shielding sheet 82. Thereby, luminance unevenness around the notch 31 can be prevented. In particular, when luminance unevenness occurs in the outer peripheral range 65 around the light diffusion portion formation range 60 (see FIG. 2) in comparison with the backlight module 10 in Embodiment 1, the light shielding sheet 81 or the light shielding sheet. The arrangement of 82 is effective.

  According to the backlight module and the liquid crystal display device including the backlight module according to Embodiment 6 of the present invention configured as described above, the arrangement of the light shielding sheet 81 or the light shielding sheet 82 causes the periphery of the notch 31. It is possible to prevent luminance unevenness from occurring. Thereby, the display performance of a liquid crystal display device can be improved.

  In addition, the brightness | luminance nonuniformity in the periphery of the notch part 31 can be prevented effectively by combining suitably the structure of the backlight module demonstrated in the above Embodiments 1-6. For example, a backlight module may be configured by combining the structure of the light diffusing unit 61 described in the first embodiment and the structure of the positioning pin 51 described in the second and third embodiments. The backlight module may be configured by combining the structure of the positioning pin 51 described in the second and third embodiments and the structure of reducing the height of the notch 31 described in the fourth embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. 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 is typically applied to a liquid crystal display device having a backlight module.

  10 Backlight module, 21 Light guide plate, 22 Main surface, 23 Back surface, 25, 25p, 25q, 25r, 25s End surface, 28 Bottom, 31, 31a, 31b, 31c, 31d, 31e, 31f, 32, 32a, 32b Notch part, 36 bottom part, 37 side wall part, 41, 42 LED unit, 46 light source, 47 circuit board, 51 positioning pin, 53 body part, 54 covering part, 60 light diffusion part forming range, 61 light diffusion part, 61j protrusion part 62, outer peripheral surface, 65 outer edge range, 71 correction region, 72 peripheral region, 73, 74 position, 81, 82 light shielding sheet, 100 liquid crystal display device, 110 liquid crystal display panel, 112, 114 cushioning material, 115 display range, 120 bezel , 130 laminated sheet group, 140 chassis, 141 p-chassis, 142 backlight Yashi, 150 reflective sheet, 160 controller.

Claims (9)

A light source that emits light;
Light from the light source having a first surface, a second surface disposed on the back side of the first surface, and an end surface connected to the first surface and the second surface, and incident through the end surface A light guide plate that propagates inside and emits it to the first surface;
A positioning member for positioning the light guide plate;
A light diffusing section that is provided dispersed in a rectangular range on the second surface and diffuses light propagating through the light guide plate;
The light guide plate is notched from the end surface, extends from the second surface toward the first surface, and is formed with a notch portion where the positioning member is disposed.
The light diffusing portion includes a position closest to the cutout portion within the range, and a position closest to the end surface, and a first region in which a ratio of the light diffusing portion per unit area is sparse And a second region adjacent to the first region and having a dense proportion of the light diffusing portion per unit area.   2. The light source module according to claim 1, wherein in the first region, a ratio of the light diffusion portion per unit area is zero.   2. The light source module according to claim 1, wherein in the first region, the ratio of the light diffusion portion per unit area increases as the distance from the position closest to the cutout portion increases. The light guide plate is disposed as the end face so as to face the light source, is connected to the first end face on which light from the light source is incident, and extends from the first end face, along the emission direction of light from the light source. A second end surface extending,
4. The light source module according to claim 1, wherein the cutout portion is formed so as to be cut out from the second end surface. 5. The light guide plate includes a first cutout portion disposed relatively close to the first end surface and a second cutout portion disposed relatively far from the first end surface as the cutout portion. And formed,
The light diffusion portion is provided in the range such that the first region is generated corresponding to each of the first cutout portion and the second cutout portion,
The light source module according to claim 4, wherein an area of the first region corresponding to the first notch is larger than an area of the first region corresponding to the second notch.   6. The light source module according to claim 1, wherein the light diffusing portion includes a plurality of protruding portions that are hemispherically protruded from the second surface and are formed of a transparent resin.   7. The light source module according to claim 1, wherein a light shielding sheet that blocks the progress of light from the light source is provided on a surface of the light guide plate that forms the notch. 8.   8. The light source module according to claim 1, wherein a light shielding sheet that blocks the progress of light from the light source is provided at a position surrounding the notch on the first surface. 9.   An electronic device comprising the light source module according to claim 1.

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