JP2012059607A - Light source module and electronic apparatus with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source module in which luminous unevenness on an irradiation surface is suppressed and moreover reduction of the efficiency of using light is suppressed, and to provide an electronic apparatus with the same.SOLUTION: The light source module includes an LED 105 and a light guide 131 which has an incident surface 132 which is located so as to face the LED 105 and to which the light from the LED 105 enters and a light emitting face 120 neighboring the incident surface 132 and makes the light incident from the incident surface 132 propagated inward and discharged from the light emitting face 120. Furthermore, there are provided a reflection sheet 112 located along a main surface opposing the light emitting face 120 of the light guide 131 and a light shield 210 which extends inward of the light guide 131 along the main surface 121 of the light guide 131 from a position of a prescribed distance from the LED 105 within a range where the reflection sheet 112 is not positioned in a facing direction of the LED 105 and the incident surface 132 of the light guide 131, and which is not fixed to the reflection sheet 112 and the light guide 131.

Description

  The present invention relates to a light source module and an electronic apparatus including the light source module.

  In order to use light emitted from a point light source or a line light source as light emitted in a planar shape from an irradiation surface, there is a light source module using a light guide. In this light source module, the light source is arranged so as to face the incident surface which is the side surface of the block-shaped light guide. The light incident from the incident surface is propagated through the light guide, and then emitted from the emission surface toward the irradiation surface to be irradiated in a planar shape from the irradiation surface.

  Patent Documents 1 to 3 are prior art documents that disclose a light source module provided with a light-shielding portion in order to reduce unevenness in luminance of light irradiated in a planar shape from an irradiation surface.

  In the planar light source device described in Patent Document 1, light from between the light source and the light guide is obtained by applying a light-shielding tape to all or part of the edge on the light exit surface side of the light guide. Luminance unevenness of light irradiated from the irradiation surface due to leakage is suppressed.

  In the backlight edge luminance dimming means described in Patent Document 2, a light absorbing measure is applied to the reflecting surface of the reflective material arranged on the back side of the edge light panel to control the amount of light reflected on the reflecting surface. Thus, luminance unevenness of light irradiated from the irradiation surface is suppressed.

  In the surface light source device described in Patent Document 3, a gap shielding member including an adhesive layer, a reinforcing plate, and a light shielding layer is sequentially projected from the substrate side on the surface facing the emission surface of the flexible printed circuit board. Yes. The gap shielding member is in contact with the emission surface and closes the gap between the flexible printed circuit board and the emission surface. With this configuration, light leaking from the gap between the flexible printed circuit board or the light shielding member and the light guide that covers the gap between the light guide and the light source causes the edge of the flexible printed circuit board or the light shielding member near the light source. It prevents the eyeball-like high brightness area from occurring.

JP 2004-71167 A Japanese Patent No. 3004555 JP 2008-77852 A

  As described above, the light source module is provided with the light shielding portion to suppress the luminance unevenness at the edge of the irradiation surface. However, in order to effectively suppress the luminance unevenness, the positional relationship between the light source and the light shielding portion is is important. Specifically, it is necessary to provide a light-shielding part in the middle of the path where the light emitted from the light source reaches the edge of the irradiation surface of the light source module.

  However, since the light shielding part is formed of a member that absorbs light, if a light shielding part that is larger than necessary is provided, light that is to be effectively irradiated from the irradiation surface of the light source module is also shielded. The light utilization efficiency of the module is reduced.

  The light guide and the reflection sheet constituting the light source module are thermally expanded by heat generated during use of the light source module. In particular, in a large-sized light source module, the size of the light guide and the reflection sheet is large, so that the dimensional change due to thermal expansion is large.

  In the planar light source device described in Patent Document 1, since the light guide is provided with a light shielding portion, the positional relationship between the light source and the light shielding portion is shifted due to thermal expansion of the light guide. As a result, luminance unevenness cannot be effectively suppressed by the light shielding portion, and if a large light shielding portion is provided in consideration of positional deviation, the light use efficiency of the planar light source device is reduced.

  In the backlight edge luminance dimming means described in Patent Document 2, since the light shielding portion is provided on the reflection sheet, the positional relationship between the light source and the light shielding portion is shifted due to thermal expansion of the reflection sheet. As a result, luminance unevenness cannot be effectively suppressed by the light shielding portion, and if a large light shielding portion is provided in consideration of positional deviation, the light use efficiency of the backlight is reduced.

  In the surface light source device described in Patent Document 3, a light shielding portion is provided on the light exit surface side of the light guide. In this case, since the light that is emitted from the emission surface of the light guide and is to be effectively emitted from the irradiation surface of the light source module is also blocked, the light use efficiency of the surface light source device is reduced.

  The present invention has been made in view of the above-described problems, and provides a light source module and an electronic apparatus including the light source module that suppresses a reduction in light utilization efficiency while suppressing luminance unevenness on an irradiation surface. Objective.

  The light source module according to the present invention has a light source, an incident surface that faces the light source and is incident with light from the light source, and an output surface adjacent to the incident surface, and the light incident from the incident surface is inward. And a light guide that is propagated to and emitted from the exit surface. In addition, the light source module is within a range in which the reflection sheet is positioned along the main surface facing the light exit surface of the light guide and the reflection sheet is not positioned in the facing direction of the light source and the light entrance surface. The light source includes a light shielding portion that extends from the light source at a predetermined distance along the main surface of the light guide toward the inside of the light guide and is not fixed to the reflection sheet and the light guide.

  In one aspect of the present invention, the light source module has at least a part along the main surface of the light guide body in a range where the reflection sheet is not positioned in the facing direction of the light source and the incident surface of the light guide body. The other reflective sheet located in is further provided. The other reflection sheet has a gap between the reflection sheet and the reflection sheet in the facing direction of the light source and the incident surface of the light guide. The light shielding part is fixed on another reflection sheet.

  In one embodiment of the present invention, the light source module includes a reflector that surrounds the light source and reflects light on the inner surface. The reflector has an extending portion that extends along the end of the main surface of the light guide. The other reflection sheet is fixed to the extending portion of the reflector.

  In one embodiment of the present invention, the light source module includes a reflector that surrounds the light source and reflects light on the inner surface. The reflector has an extending portion that extends along the end of the main surface of the light guide. The light shielding part is fixed to the extension part of the reflector.

  ADVANTAGE OF THE INVENTION According to this invention, in a light source module and an electronic device provided with the same, the reduction of light utilization efficiency can be suppressed, suppressing the brightness nonuniformity of an irradiation surface.

It is a disassembled perspective view explaining schematic structure of the liquid crystal display device which concerns on Embodiment 1 of this invention. It is a top view which shows arrangement | positioning with the light-guide plate and light source group in the liquid crystal display device which concerns on the same embodiment. It is the figure seen from the III-III line arrow direction of FIG. It is a side view of the light guide of the embodiment. It is the figure seen from the VV line arrow direction of FIG. FIG. 6 is a plan view of the main surface in the vicinity of the portion shown in FIG. 5. It is the figure seen from the VII-VII line arrow direction of FIG. It is a top view of the main surface of the vicinity of the part shown in FIG. It is the figure seen from the IX-IX line arrow direction of FIG. FIG. 10 is a plan view of the main surface in the vicinity of the portion shown in FIG. 9. FIG. 2 is a partial cross-sectional view of the liquid crystal display device according to the same embodiment. It is a perspective view which shows the structure of the reflector which concerns on the same embodiment. It is a perspective view which shows the external appearance of the extension reflector in the same embodiment. It is a figure which shows an example of the optical path of the light irradiated from the irradiation part of the embodiment. It is a top view which shows the structure of the backlight module which concerns on the same embodiment. It is a figure which shows the positional relationship of a light source and a light-shielding part. It is a figure which shows the change of the brightness | luminance of the display area in a liquid crystal display panel by the distance between a light source and the light shielding part in Experimental example 1. FIG. It is a figure which shows the change of the brightness | luminance of the display area in a liquid crystal display panel by the length in which the light-shielding part is provided in Experimental example 2. FIG. It is a figure which shows an example of the optical path of the light irradiated from the irradiation part in the liquid crystal display device which concerns on Embodiment 2 of this invention. It is a figure which shows an example of the optical path of the light irradiated from the irradiation part in the liquid crystal display device which concerns on Embodiment 3 of this invention.

  Hereinafter, a light source module according to Embodiment 1 of the present invention and an electronic apparatus including the light source module will be described with reference to the drawings. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. In the description of the embodiments, for the sake of convenience of explanation, upper, lower, left, and right expressions are used. However, these expressions are based on the drawings and do not limit the configuration of the invention.

  In the following embodiments, a liquid crystal display device will be described as an electronic device, and a backlight module of the liquid crystal display device will be described as a light source module. However, the electronic device and the light source module are not limited thereto, and include, for example, an indoor lighting device as the electronic device, and a light emitting unit that emits light that is part of the lighting device on the surface as the light source module.

Embodiment 1
FIG. 1 is an exploded perspective view illustrating a schematic configuration of a liquid crystal display device according to Embodiment 1 of the present invention. FIG. 2 is a plan view showing the arrangement of the light guide plate and the light source group in the liquid crystal display device according to the present embodiment. FIG. 3 is a view as seen from the direction of arrows III-III in FIG.

  As shown in FIG. 1, the liquid crystal display device 1 according to the first embodiment of the present invention includes a bezel 100, a chassis 101, a reflection sheet 110, a light guide plate 130, a laminated sheet group 150, a liquid crystal display panel 170, and light source groups 103 and 104. , A control unit 160 and a light shielding unit 210 (not shown). Between the bezel 100 and the chassis 101, a reflective sheet 110, a light guide plate 130, a laminated sheet group 150, and a liquid crystal display panel 170 are arranged in this order from the bottom. Further, light source groups 103 and 104 are arranged on the side of the light guide plate 130. The light source groups 103 and 104 and the liquid crystal display panel 170 are connected to the control unit 160. Further, a light shielding unit 210 (not shown) is disposed on the side of the reflection sheet 110.

  The backlight module that is a light source module includes a reflection sheet 110, a light guide plate 130, a laminated sheet group 150, a light source group 103 and a light source group 104, and a light shielding unit 210.

  As shown in FIGS. 1 and 2, in the present embodiment, the light guide plate 130 includes a plurality of light guides 131 having a substantially rectangular parallelepiped shape. Specifically, a plurality of light guides 131 are arranged at intervals in the lateral direction of the light guide 131, whereby a substantially flat light guide plate 130 is configured. However, the light guide plate 130 may be composed of one flat light guide.

  On one side of the light guide plate 130 in the longitudinal direction, a light source group 103 in which a plurality of LEDs (Light Emitting Diodes) 105, which are light sources, are mounted on the circuit board 106 at an interval is disposed. On the other side of the light guide plate 130 in the longitudinal direction, a light source group 104 in which a plurality of LEDs 107 serving as light sources are mounted on the circuit board 108 at intervals is disposed.

  Each of the plurality of light guides 131 is positioned so as to face the LED 105 and the incident surface 132 on which the light from the LED 105 enters, and the incident surface 133 positioned so as to face the LED 107 and on which the light from the LED 107 enters. And have. Each of the plurality of light guides 131 has an exit surface 120 adjacent to the entrance surfaces 132 and 133.

  As shown in FIG. 3, each of the plurality of light guides 131 has a main surface 121 that faces the emission surface 120. Each of the plurality of light guides 131 includes a side surface 134 adjacent to the emission surface 120 and the main surface 121, and a side surface 135 facing the side surface 134. The main surface 121 is formed with a light diffusion portion to be described later.

  The plurality of light guides 131 respectively reflect the light incident from the incident surfaces 132 and 133 between the emission surface 120 and the main surface 121 and between the side surfaces 134 and 135 while reflecting the light from the light guides 131. The light is propagated inward and mainly emitted from the emission surface 120.

Hereinafter, the above components will be described in detail.
As a light source, it is not restricted to the example which employ | adopted LED, A fluorescent tube and another light source can be employ | adopted.

  The laminated sheet group 150 includes a diffusion sheet and a prism sheet. The laminated sheet group 150 has a function of suppressing luminance unevenness of light emitted from the light guide plate 130 and condensing light emitted from the light guide plate 130 toward the liquid crystal display panel 170.

  The liquid crystal display panel 170 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 thin film transistor (TFT) elements are formed on the active matrix substrate. The liquid crystal display panel 170 displays an image using light that passes through the laminated sheet group 150 and enters the liquid crystal display panel 170.

  The controller 160 switches ON / OFF of each TFT element of the liquid crystal display panel 170 based on the image data to be displayed. In addition, the control unit 160 applies a video signal to the liquid crystal display panel 170, and sequentially turns off each of the plurality of LEDs 105 and 107 in synchronization with the application timing. Thereby, in the liquid crystal display panel 170, since the light emission period and the non-light emission period can be provided in one frame, image display and black display can be performed alternately.

  The bezel 100 has a window portion that allows the display area of the liquid crystal display panel 170 to be visually recognized.

Hereinafter, the light guide of this embodiment will be described in detail.
FIG. 4 is a side view of the light guide according to the present embodiment. FIG. 5 is a view as seen from the direction of arrows VV in FIG. FIG. 6 is a plan view of the main surface in the vicinity of the portion shown in FIG. 7 is a view as seen from the direction of the arrow VII-VII in FIG. FIG. 8 is a plan view of the main surface in the vicinity of the portion shown in FIG. 9 is a view as seen from the direction of arrows IX-IX in FIG. FIG. 10 is a plan view of the main surface in the vicinity of the portion shown in FIG.

  As shown in FIGS. 3, 5, 7, and 9, when the light guide 131 is viewed in a cross section perpendicular to the longitudinal direction, the light guide 131 is formed at the center portion in the short side direction (width direction). Part 136 and projecting parts 137 and 138 formed so as to project from both side surfaces of main part 136. The cross-sectional shape of the light guide 131 in the cross section perpendicular to the longitudinal direction of the light guide 131 is an inverted T-shape. A plurality of grooves 124 are formed on the exit surface 120 of the light guide 131.

  The length of the light guide 131 of this embodiment is, for example, 1358.5 mm. The thickness of the main part 136 is 4 mm, for example. The thickness of the overhang portions 137 and 138 is, for example, 1 mm. The overhang amounts of the overhang portions 137 and 138 are, for example, 2 mm. The width of the light guide 131 in the direction from the side surface 134 side to the side surface 135 side (short direction) is, for example, about 40 mm or more and about 100 mm. The pitch of the groove part 124 is 1.0 mm, and the depth of the groove part 124 is 0.2 mm or more and 0.3 mm.

  As shown in FIGS. 6, 8, and 10, a plurality of light diffusion portions 125 are formed on the main surface 121 at intervals. In the present embodiment, the light diffusion portion 125 is formed in a dot shape.

  The dot diameter of the light diffusion portion 125 is formed so as to increase from the incident surface 132 side toward the central portion in the longitudinal direction of the light guide 131. Similarly, the dot diameter of the light diffusion portion 125 is formed so as to increase from the incident surface 133 side toward the central portion in the longitudinal direction of the light guide 131. The light diffusing unit 125 is disposed so as to be symmetric with respect to a virtual axis that passes through the center of the light guide 131 in the width direction and extends in the longitudinal direction of the light guide 131.

  Among the plurality of light diffusing portions 125, the dot diameter of the light diffusing portion 125 at the portion facing the emission surface 120 is larger than the dot diameter of the light diffusing portion 125 at the portion facing the protruding portions 137 and 138. Is formed. In addition, the dot diameter of one light-diffusion part 125 is 0.3 mm or more and 1.5 mm or less, for example.

  The light diffusion part 125 is formed, for example, by dispersing light scattering particles in a polymer and then printing the polymer on the main surface 121. A phosphor may be used as the light scattering particles. Further, the light diffusing portion 125 may be configured by forming a fine uneven shape such as a prism on the main surface 121. Furthermore, the light diffusing unit 125 may be configured by performing blasting on the main surface 121.

  By forming the light diffusion portion 125 on the main surface 121, the optical path of the light propagating through the light guide 131 can be changed. Specifically, the light propagating through the light guide 131 enters the light diffusion portion 125 of the main surface 121, so that the light is diffused and the direction of traveling through the light guide 131 is changed. As a result, at least part of the light diffused by the light diffusing unit 125 is emitted from the emission surface 120 to the outside without being totally reflected by the emission surface 120.

  Light entering the light guide 131 from the incident surface 132 and the incident surface 133 is diffused and the luminance is attenuated as the distance from the incident surface 132 and the incident surface 133 increases. Therefore, as described above, as the distance from the incident surface 132 and the incident surface 133 is increased, the dot density of the light diffusion portion 125 is increased to increase the arrangement density, thereby varying the luminance of the light emitted from the emission surface 120. It is possible to suppress the occurrence.

Hereinafter, the reflection sheet of this embodiment will be described in detail.
FIG. 11 is a partial cross-sectional view of the liquid crystal display device according to the present embodiment. In the following description, the configuration on the one LED 105 side will be described, but the configuration on the other LED 107 side is the same.

  As shown in FIG. 11, in this embodiment, the reflection sheet 110 includes a reflection sheet 112 that is a main body, and the reflection sheet 112 is a reflection sheet 113 that is another reflection sheet. The reflection sheet 112 is located along the main surface 121 facing the emission surface 120 of the light guide 131. However, the reflection sheet 112 is not located in the vicinity of the incident surface 132 in the facing direction of the LED 105 and the incident surface 132 of the light guide 131.

  The reflection sheet 113 is positioned so that at least a part of the reflection sheet 113 is along the main surface 121 of the light guide 131 within a range where the reflection sheet 112 is not positioned in the facing direction of the LED 105 and the incident surface 132 of the light guide 131. is doing. In addition, the reflective sheet 113 has a gap between the reflective sheet 112 and the reflective sheet 112 in the facing direction of the LED 105 and the incident surface 132 of the light guide 131. The gaps are formed at intervals such that the reflective sheet 112 does not contact the reflective sheet 113 when the reflective sheet 112 is thermally expanded.

  Further, the reflection sheet 113 is formed thinner than the thickness of the reflection sheet 112. Specifically, the reflection sheet 113 is formed so that the sum of the thickness of the light shielding unit 210 (to be described later) and the thickness of the reflection sheet 113 is the same as or thinner than the thickness of the reflection sheet 112.

  The reflection sheets 112 and 113 are made of polyester, for example. For example, it is made of foamed PET (Polyethylene Terephthalate) and has light reflection characteristics. The reflection sheets 112 and 113 have a function of reflecting light leaking from the main surface 121 of the light guide 131 and returning it to the light guide 131.

  Hereinafter, the light shielding part 210 of the present embodiment will be described in detail. In the following description, the configuration on the one LED 105 side will be described, but the configuration on the other LED 107 side is the same.

  As shown in FIG. 11, in the present embodiment, a light shielding unit 210 made of a light shielding sheet is provided between the main surface 121 of the light guide 131 and the reflection sheet 113. In the present embodiment, a light-shielding sheet on which a black pattern that absorbs light is formed is used as the light-shielding part 210, but the light-shielding part 210 is not limited to this, and for example, a black color is formed on the reflective surface of the reflective sheet 113. A pattern may be formed.

The light shielding unit 210 is placed on the main surface 121 of the light guide 131 from a position at a predetermined distance from the LED 105 within a range where the reflection sheet 112 is not located in the facing direction between the LED 105 and the incident surface 132 of the light guide 131. Along the inward direction of the light guide 131. Specifically, as shown in FIG. 11, the light shielding unit 210 is long inward from the position of the distance L ₁ from the LED 105 in the facing direction of the LED 105 and the incident surface 132 of the light guide 131. It is formed so as to extend in the range of L _2.

  The light shielding unit 210 is fixed on the reflection sheet 113. Specifically, the light shielding sheet is bonded to the reflection surface of the reflection sheet 113 with an adhesive. The light shielding part 210 and the main surface 121 of the light guide 131 are in contact with each other or there is a slight gap therebetween, and the light shielding part 210 is not fixed to the light guide 131. Further, the light shielding unit 210 is not fixed to the reflection sheet 112.

Hereinafter, the structure of the irradiation part in the liquid crystal display device 1 of this embodiment is demonstrated.
FIG. 12 is a perspective view showing the structure of the reflector according to this embodiment. FIG. 13 is a perspective view showing the appearance of the extension reflector in the present embodiment. In the following description, the configuration on the one LED 105 side will be described, but the configuration on the other LED 107 side is the same.

  As shown in FIGS. 11 and 12, in the liquid crystal display device 1 according to the present embodiment, a reflector 180 is disposed so as to surround the LED 105 that is a light source mounted on the circuit board 106. In other words, the reflector 180 has an opening 181 in which the LED 105 is disposed.

  The reflector 180 has an extending part 182 that extends in a flat plate shape from a part of one opening end 187 of the opening part 181 in the depth direction of the opening part 181. In addition, the reflector 180 is formed so as to reflect light on the inner surface of the opening 181 that receives light from the LED 105 and the inner surface 183 of the extending portion 182.

  As shown in FIGS. 11 and 13, the extended reflector 190 is partially in contact with the outer surface 186 opposite to the outer surface 185 of the reflector 180, and the other part is in contact with the exit surface 120 of the light guide 131. Assembled. The extension reflector 190 is formed so as to reflect light on the surface 191 facing the light guide 131.

  In this embodiment, the reflector 180 and the extension reflector 190 are manufactured by molding using a polycarbonate resin having high light reflectivity as a material. However, the materials of the reflector 180 and the extension reflector 190 are not limited thereto. Any material having light reflectivity and a predetermined strength may be used.

  As shown in FIG. 11, the irradiation unit 200 including the LED 105, the circuit board 106, the reflector 180, and the extension reflector 190 is disposed on the chassis 101. Specifically, the irradiation unit 200 is arranged on the chassis 101 so that the extending part 182 of the reflector 180 is along the upper surface of the chassis 101.

  The light guide 131 is disposed so that the incident surface 132 of the light guide 131 faces the LED 105. Specifically, a part of the light guide 131 is an extension part of the reflector 180 with a part 111 of the end part of the reflection sheet 112 arranged along the main surface 121 of the light guide 131 interposed therebetween. 182. In other words, the reflector 180 has an extending part 182 that extends along the end of the main surface 121 of the light guide 131.

  The light guide 131 is fastened and fixed to the chassis 101 by a connecting member (not shown). As a result, a part 111 of the end portion of the reflection sheet 112 is sandwiched between the extending portion 182 of the reflector 180 included in the irradiation unit 200 and the light guide 131.

  A P-chassis 109 is disposed so as to cover the irradiation unit 200 from above. The bezel 100 is disposed so as to cover the P-chassis 109 from above. The end portion of the liquid crystal display panel 170 is sandwiched between the P-chassis 109 and the bezel 100 via the buffer portion 211 and the buffer portion 212.

  The bezel 100 and the chassis 101 are fixed to each other by a fixing member (not shown), so that the components located between the bezel 100 and the chassis 101 are sandwiched. As a result, a part of the end part of the light guide 131 and a part 111 of the end part of the reflection sheet 112 are sandwiched between the extension part 182 and the extension reflector 190 of the reflector 180 of the irradiation part 200.

  With the above configuration, as shown in FIGS. 11 and 12, at the position between the opening end 187 of the reflector 180 and the incident surface 132 of the light guide 131, the upper portion is extended by the extension reflector 190 and the lower portion is reflected by the reflector 180. The extended portion 182 can be covered without a gap.

  As a result, the light emitted obliquely upward from the LED 105 and reaching the surface 191 of the extension reflector 190 is reflected and incident on the light guide 131 from the incident surface 132 of the light guide 131. Further, light that is emitted obliquely downward from the LED 105 and reaches the inner surface 183 of the extending portion 182 of the reflector 180 is reflected and incident on the light guide 131 from the incident surface 132 of the light guide 131.

  In this way, by providing the extending portion 182 and the extended reflector 190 of the reflector 180, the light emitted from the LED 105 is guided between the opening end 187 of the reflector 180 and the incident surface 132 of the light guide 131. Light leaking outside without entering the light body 131 can be reduced.

  Hereinafter, the function of the light shielding unit 210 in the liquid crystal display device 1 according to the present embodiment will be described.

  FIG. 14 is a diagram illustrating an example of an optical path of light emitted from the irradiation unit of the present embodiment. FIG. 14 shows a cross section at a position where the bottom of the groove 124 appears on the emission surface 120 of the light guide 131.

  As shown in FIG. 14, in the liquid crystal display device 1 of the present embodiment, the reflection sheet 113 is fixed on the inner surface 183 of the extending portion 182 of the reflector 180. Specifically, the reflection sheet 113 is bonded to the extending portion 182 of the reflector 180 with an adhesive. The reflection sheet 113 has higher light reflectivity than the inner surface 183 of the reflector 180. As described above, the light shielding unit 210 is fixed on the reflection sheet 113.

  As shown in FIGS. 9 and 14, in the liquid crystal display device 1 of the present embodiment, since the groove portion 124 is formed on the emission surface 120 of the light guide 131, the surface of the extension reflector 190 that faces the light guide 131. A gap is generated between 191 and the exit surface 120 of the light guide 131.

  The light 220 emitted from the LED 105 and reaching this gap is reflected by the surface 191 of the extension reflector 190 and enters the light guide 131. Since the light 220 is not incident on the light guide 131 from the incident surface 132 of the light guide 131, the light 220 is incident on the main surface 121 of the light guide 131 at an angle less than the critical angle. As a result, the light 220 leaks from the main surface 121 of the light guide 131 to the outside of the light guide 131.

  If the light blocking portion 210 is not provided, the light 220 leaking from the main surface 121 of the light guide 131 is reflected by the reflection sheet 110 and returned into the light guide 131. Since the light 220 is incident on the emission surface 120 of the light guide 131 at an angle less than the critical angle, the light 220 is emitted from the emission surface 120 of the light guide 131 toward the edge of the display area of the liquid crystal display panel 170. . As a result, uneven brightness of the display screen occurs.

In the liquid crystal display device 1 of the present embodiment, the light shielding unit 210 is provided in the assumed reachable range of the light 220. Specifically, as shown in FIG. 14, in the facing direction of the LED 105 and the incident surface 132 of the light guide 131, a range of a length L ₂ from the position of the distance L ₁ from the LED 105 to the inside of the light guide. It is formed so as to extend.

  FIG. 15 is a plan view showing the configuration of the backlight module according to this embodiment. In FIG. 15, for simplicity, the laminated sheet group 150 is not shown.

As shown in FIG. 15, the light-shielding portion 210 has a length L _{2 in} a direction opposite to the LED 107 and the incident surface 133 of the light guide 131 from the position of the distance L ₁ from the LED 107 to the inside of the light guide. It is formed so as to extend.

  In the liquid crystal display device 1 of the present embodiment, the light shielding unit 210 is not fixed to the reflection sheet 112 and the light guide 131 as described above. Therefore, even when the reflective sheet 112 and the light guide 131 are thermally expanded and the relative positions of the LEDs 105 and 107 are changed, the relative positional relationship between the light shielding unit 210 and the LEDs 105 and 107 is not affected. . The reflective sheet 113 is smaller in size than the reflective sheet 112, and is less affected by the thermal expansion of the reflective sheet 113 itself. Further, since the reflection sheet 113 and the reflection sheet 112 are formed with a gap between each other, even when the reflection sheet 112 is thermally expanded, the reflection sheet 113 is not in contact with the reflection sheet 112. In addition, no deviation occurs in the position of the reflection sheet 113. Furthermore, the reflector 180 to which the reflection sheet 113 is fixed hardly expands thermally, and the influence on the position of the reflection sheet 113 is small.

  As described above, the light shielding unit 210 according to the present embodiment is provided at a predetermined distance from the LEDs 105 and 107 with a predetermined length, and the position thereof is stably maintained during use of the liquid crystal display device 1. Therefore, luminance unevenness in the display area of the liquid crystal display panel 170 can be efficiently suppressed. Furthermore, since the light shielding unit 210 does not absorb light more than necessary, the reduction of the light use efficiency of the liquid crystal display device 1 is suppressed.

  In the present embodiment, the reflection sheet 113 is fixed to the extending portion 182 of the reflector 180. For example, the reflector 180 does not have the extending portion 182 and the reflection sheet 113 is fixed on the chassis 101. Also good. That is, it is only necessary that the light shielding unit 210 be provided at a predetermined distance from the light source over a predetermined length without being affected by thermal expansion of the light guide 131 and the reflection sheet 112.

Experimental Example Hereinafter, experimental results verifying the relationship between the positional relationship between the light source and the light-shielding portion and the luminance of the display area in the liquid crystal display panel are shown. In Experimental Example 1, an experiment was performed to confirm the change in luminance unevenness of the display area due to the distance from the light source at the position where the light shielding unit 210 is provided. In Experimental Example 2, an experiment was performed to confirm the change in luminance unevenness of the display area due to the length of the light shielding unit 210 provided.

FIG. 16 is a diagram illustrating a positional relationship between the light source and the light shielding unit. FIG. 17 is a diagram illustrating a change in luminance of the display region in the liquid crystal display panel according to the distance between the light source and the light shielding unit in Experimental Example 1. FIG. 18 is a diagram illustrating a change in luminance of the display area in the liquid crystal display panel according to the length of the light shielding portion in Experimental Example 2. 17 and 18, the vertical axis represents the luminance (cm / m ² ) of the display area in the liquid crystal display panel, and the horizontal axis represents the position of the display area in the liquid crystal display panel. In this experiment, the light shielding unit 210 is provided only on the LED 105 side and not on the LED 107 side.

As shown in FIG. 16, the light-shielding part 210 is provided with a length L ₂ from the position of L ₁ from the LED 105. Note that the distance L ₁ between the light shielding unit 210 and the LED 105 is an optimum distance for suppressing luminance unevenness in the display region in the liquid crystal display panel of the liquid crystal display device 1 of the present embodiment.

In Experimental Example 1, the length L ₂ of the light shielding portion 210 was 10 mm. In the experimental example 1, the case of arranging the light-shielding portion 210 from the LED 105 at a distance L _1, the case of arranging the light-shielding portion 210 at a distance L ₁ + 4.5 mm from the LED 105, the distance the light shielding portion 210 from LED 105 An experiment was conducted under four conditions when the lens was placed at a position of L ₁ -1.0 mm and when the light shielding portion 210 was not provided.

17, a case of arranging the light-shielding portion 210 from the LED 105 at a distance L ₁ solid lines, chain lines turn a case where the light-shielding portion 210 is disposed at a distance L ₁ + 4.5 mm from the LED 105, the light shielding portion 210 LED 105 the two-dot chain line a when placed at a distance L ₁ -1.0 mm from and shows a case without the light blocking portion 210 in dotted lines. In FIG. 17, the right display area end is on the LED 105 side, and the left display area end is on the LED 107 side.

As shown in FIG. 17, when the light shielding portion 210 is not provided, luminance unevenness with extremely high luminance occurs at the end of the display area. When the light shielding part 210 is arranged at a distance L ₁ +4.5 mm from the LED 105, the degree of luminance unevenness is smaller than when the light shielding part 210 is not provided, but the luminance unevenness is at the end of the display area. Has occurred.

When the light shielding unit 210 is disposed at a distance L ₁ from the LED 105, luminance unevenness does not occur at the end of the display area. When the light shielding unit 210 is disposed at a distance L ₁ -1.0 mm from the LED 105, luminance unevenness does not occur in the display area, but the luminance of the display area in the liquid crystal display panel is reduced as a whole.

In Experimental Example 2, the light shielding unit 210 was disposed at a distance L ₁ from the LED 105. In Experimental Example 2, there are three conditions when the length of the light shielding portion 210 is L ₂ = 10 mm, when the length of the light shielding portion 210 is L ₂ = 6 mm, and when the light shielding portion 210 is not provided. The experiment was conducted.

In FIG. 18, the case where the length of the light-shielding portion 210 is L ₂ = 10 mm, the solid line, the case where the length of the light-shielding portion 210 is L ₂ = 6 mm, and the case where the light-shielding portion 210 is not provided. Shown with dotted lines. In FIG. 18, the right display area end is on the LED 105 side, and the left display area end is on the LED 107 side.

As shown in FIG. 18, when the light shielding portion 210 is not provided, luminance unevenness with extremely high luminance occurs at the end of the display area. When the length of the light-shielding portion 210 is L ₂ = 6 mm, the degree of luminance unevenness is smaller than when the light-shielding portion 210 is not provided, but luminance unevenness occurs at the edge of the display area. Yes. When the length of the light shielding part 210 is set to L ₂ = 10 mm, luminance unevenness does not occur at the edge of the display area.

  From Experimental Example 1 and Experimental Example 2 described above, it can be seen that luminance unevenness in the display area can be effectively suppressed by providing the light shielding unit 210 with a predetermined length from a predetermined distance from the light source. In other words, if a deviation occurs in the relative positional relationship between the position of the light shielding unit 210 and the position of the light source, luminance unevenness in the display area cannot be suppressed. Further, if the length of the light shielding portion 210 provided is too short, the luminance unevenness cannot be sufficiently suppressed, and if the length of the light shielding portion 210 provided is too long, the luminance of the entire display area is reduced, and the light of the liquid crystal display device is reduced. The utilization efficiency of is reduced.

Hereinafter, a liquid crystal display device according to Embodiment 2 of the present invention will be described.
Embodiment 2
The liquid crystal display device according to the present embodiment is different from the liquid crystal display device 1 according to the first embodiment only in the arrangement of the light shielding unit 210 and the reflection sheet 113, and therefore, the description of the other configurations will not be repeated.

  FIG. 19 is a diagram illustrating an example of an optical path of light emitted from the irradiation unit in the liquid crystal display device according to Embodiment 2 of the present invention. FIG. 19 shows a cross section at a position where the bottom of the groove 124 appears on the emission surface 120 of the light guide 131.

  As shown in FIG. 19, in the liquid crystal display device of this embodiment, the light shielding portion 210 is fixed to the inner surface 183 of the extending portion 182 of the reflector 180. Specifically, the light shielding sheet is bonded to the extending portion 182 of the reflector 180 with an adhesive. The reflection sheet 113 is fixed to the inner surface 183 of the extending part 182 of the reflector 180 so as to be adjacent to the light shielding part 210. Specifically, the reflection sheet 113 is bonded to the extending portion 182 of the reflector 180 with an adhesive.

The positional relationship of the light shielding unit 210 with respect to the LED 105 is the same as that of the liquid crystal display device 1 of the first embodiment, and is provided with a length L ₂ from the position of L ₁ from the LED 105. Even in such a case, the light 220 can be shielded, and the luminance unevenness of the display area of the liquid crystal display panel 170 can be reduced.

  In addition, the light shielding unit 210 of the present embodiment is provided at a predetermined distance from the LEDs 105 and 107 at a predetermined length, and the position thereof is stably maintained during use of the liquid crystal display device 1. Therefore, luminance unevenness in the display area of the liquid crystal display panel 170 can be efficiently suppressed. Furthermore, since the light shielding unit 210 does not absorb light more than necessary, the reduction of the light use efficiency of the liquid crystal display device 1 is suppressed.

  In the present embodiment, the light shielding part 210 is fixed to the extending part 182 of the reflector 180. For example, the reflector 180 does not have the extending part 182 and the light shielding part 210 is fixed on the chassis 101. Also good. That is, it is only necessary that the light shielding unit 210 be provided at a predetermined distance from the light source over a predetermined length without being affected by thermal expansion of the light guide 131 and the reflection sheet 112.

Hereinafter, a liquid crystal display device according to Embodiment 3 of the present invention will be described.
Embodiment 3
The liquid crystal display device according to the present embodiment is different from the liquid crystal display device 1 according to the second embodiment only in that the reflective sheet 113 is not provided. Therefore, the description of other configurations will not be repeated.

  FIG. 20 is a diagram illustrating an example of an optical path of light emitted from the irradiation unit in the liquid crystal display device according to Embodiment 3 of the present invention. Note that FIG. 20 illustrates a cross section at a position where the bottom of the groove 124 appears on the emission surface 120 of the light guide 131.

  As shown in FIG. 20, in the liquid crystal display device of the present embodiment, the light shielding part 210 is fixed to the inner surface 183 of the extending part 182 of the reflector 180. Specifically, the light shielding sheet is bonded to the extending portion 182 of the reflector 180 with an adhesive.

The positional relationship of the light shielding unit 210 with respect to the LED 105 is the same as that of the liquid crystal display device 1 of the first embodiment, and is provided with a length L ₂ from the position of L ₁ from the LED 105. Even in such a case, the light 220 can be shielded, and the luminance unevenness of the display area of the liquid crystal display panel 170 can be reduced.

  In addition, the light shielding unit 210 of the present embodiment is provided at a predetermined distance from the LEDs 105 and 107 at a predetermined length, and the position thereof is stably maintained during use of the liquid crystal display device 1. Therefore, luminance unevenness in the display area of the liquid crystal display panel 170 can be efficiently suppressed. Furthermore, since the light shielding unit 210 does not absorb light more than necessary, the reduction of the light use efficiency of the liquid crystal display device 1 is suppressed.

  In the present embodiment, the light shielding part 210 is fixed to the extending part 182 of the reflector 180. For example, the reflector 180 does not have the extending part 182 and the light shielding part 210 is fixed on the chassis 101. Also good. That is, it is only necessary that the light shielding unit 210 be provided at a predetermined distance from the light source over a predetermined length without being affected by thermal expansion of the light guide 131 and the reflection sheet 112.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It does not become a basis of limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the scope of claims. Further, all modifications within the meaning and scope equivalent to the scope of the claims are included.

  DESCRIPTION OF SYMBOLS 1 Liquid crystal display device, 100 Bezel, 101,109 Chassis, 103,104 Light source group, 106,108 Circuit board, 110,112,113 Reflective sheet, 111 A part of reflective sheet, 120 Output surface, 121 Main surface, 124 Groove , 125 Light diffusion part, 130 Light guide plate, 131 Light guide, 132, 133 Incident surface, 134, 135 Side surface, 136 Main part, 137, 138 Overhang part, 150 Laminated sheet group, 160 Control part, 170 Liquid crystal display panel , 180 reflector, 181 opening, 182 extending portion, 183 inner surface, 185, 186 outer surface, 187 opening end, 190 extending reflector, 191 surface, 200 irradiation portion, 210 light shielding portion, 211, 212 buffer portion, 220 light.

Claims (5)

A light source;
An exit surface that is positioned so as to face the light source and on which light from the light source is incident and an exit surface that is adjacent to the entrance surface, the light incident from the entrance surface is propagated inwardly and the exit surface A light guide to be emitted from,
A reflective sheet positioned along a main surface facing the exit surface of the light guide;
In a direction in which the light source and the light incident surface of the light guide face each other, the reflection sheet is within a range where the light source is not located, and the light source is moved along a main surface of the light guide from a predetermined distance. A light source module comprising: a light shielding portion that extends inward of the light guide and is not fixed to the reflection sheet and the light guide. Other reflections located at least partially along the main surface of the light guide within a range where the reflection sheet is not located in the facing direction of the light source and the incident surface of the light guide. A seat further,
The other reflection sheet has a gap between the light source and the light incident surface of the light guide and the reflection sheet.
The light source module according to claim 1, wherein the light shielding unit is fixed on the other reflection sheet. A reflector surrounding the light source and reflecting light on the inner surface;
The reflector has an extending portion that extends along an end portion of the main surface of the light guide,
The light source module according to claim 2, wherein the other reflection sheet is fixed to the extension portion of the reflector. A reflector surrounding the light source and reflecting light on the inner surface;
The reflector has an extending portion that extends along an end portion of the main surface of the light guide,
The light source module according to claim 1, wherein the light shielding portion is fixed to the extending portion of the reflector.   The electronic device provided with the light source module in any one of Claim 1 to 4.

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