JP2017199526A - Planar light source device and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technique capable of suppressing a collision sound between a light guide plate and a peripheral member and a flapping sound, and also making a frame of a display device narrower.SOLUTION: A planar light source device 100 comprises: a spot light source 9; a light guide plate 1 having an emission surface 1a for emitting light from the spot light source 9, a plurality of side faces 1c, 1d, 1e, and 1f connected to the emission surface 1a, and a recessed part 13 formed inside a corner part 1g formed of contiguous first, second side faces, and opened over the first, second side faces; an elastic body 7 arranged at the recessed part 13, and having front end parts 7c, 7d projecting from an opening 14 of the recessed part 13 toward the first, second side faces respectively; and an intermediate frame 6 and a rear frame 2 accommodating the spot light source 9, light guide plate 1 and elastic body 7.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a planar light source device and a display device including the same.

  2. Description of the Related Art In recent years, liquid crystal display devices (LCDs) have been widely used for various applications due to advantages such as light weight and thinness. The liquid crystal display device includes a liquid crystal display panel. In the liquid crystal display panel, a glass substrate on which wirings and electrodes are formed and a counter substrate are arranged in parallel, and liquid crystal is sandwiched between the substrates. Polarizers are attached to the surfaces of both substrates. The display area of the liquid crystal display panel is composed of a large number of pixels, and a signal corresponding to the display image is input to each pixel to display an image. This display image is visually recognized by an observer when light is irradiated by a planar light source device installed on the back surface of the liquid crystal display panel.

  As described above, the liquid crystal display device is a so-called light receiving type display device including a liquid crystal display panel in which light transmittance is controlled for each pixel and a planar light source device, and various applications using this characteristic. Is used. Liquid crystal display devices are used, for example, as displays for personal computers, devices used in industrial applications, and in-vehicle display devices. As a liquid crystal display device, a device capable of displaying under a wide temperature range and strong vibration conditions is demanded particularly for in-vehicle use.

  However, in the planar light source device in the conventional liquid crystal display device, it is necessary to provide a gap (hereinafter referred to as “clearance”) between the light guide plate and the mold frame in order to absorb the temperature expansion and contraction of the light guide plate. When an impact is applied, the light guide plate moves in the mold frame, which causes a collision sound due to rattling.

  A light guide plate of a general planar light source device is provided with a plurality of protrusions (hereinafter referred to as “light guide plate ears”) on the side surface of the light guide plate, and the light guide plate ears are sandwiched between frames or the like. Was fixed to the frame. Or, fix the light guide plate to the frame by fixing the light guide plate to the frame using adhesive tape, etc., or providing elastic parts between the light guide plate and the frame and pressing and holding the light guide plate in one direction Was.

  For example, Patent Document 1 discloses a pressing member that is provided with a convex or concave rib portion on a side end surface of a light guide plate of a backlight unit, and that can be elastically deformed on a frame facing the convex or concave rib portion. A technique for providing and holding a light guide plate by a pressing member is disclosed. This suppresses the occurrence of problems such as light source damage due to movement of the light guide plate, wear of the light guide plate, abnormal noise in an environment with severe vibration, and luminance change.

  Patent Documents 2 to 4 disclose techniques for holding the light guide plate with the outer shape of the light guide plate without providing the light guide plate ears. Specifically, a technique for holding a light guide plate by sandwiching a light source holding elastic member between two corners of the light guide plate, a metal spring or a resin elastic member provided on two side surfaces of the light guide plate, This is a technique for holding, and a technique for pressing and holding the light guide plate on one side of the frame by bending the reflection sheet to form an elastic member.

JP 2008-78010 A JP 2009-76357 A JP 2008-27736 A JP 2009-158233 A

  However, in the technique described in Patent Document 1, since it is necessary to provide a light guide plate ear on the side surface of the light guide plate, there is a problem that the frame area of the display device is enlarged and it is difficult to narrow the display device. there were.

  Further, in the techniques described in Patent Documents 2 and 3, when there is a side of the light guide plate where the elastic member is not disposed, the elastic member is disposed in an environment where vibration and impact are intensely applied, such as higher-order resonance frequency vibration. In some cases, the light guide plate flutters in the frame on the side where it is not performed, and fluttering propagates to the frame and the fluttering sound cannot be sufficiently suppressed.

  In the technique described in Patent Document 4, since the reflective sheet is bent and sandwiched between the light guide plate and the frame member, the light guide plate is weakly fixed, and the material of the reflective sheet is resin, so that the creep phenomenon occurs with low stress. Arise. This creep phenomenon is accelerated in a high temperature environment, and there is a problem that the holding force of the light guide plate gradually decreases due to a change with time. Therefore, there is a problem that it is difficult to obtain an effect of suppressing fluttering sound in an environment where vibration and impact are applied.

  In addition, a technology for adhering and fixing the light guide plate to the frame using adhesive tape etc. is also conceivable, but it is displayed in an environment where the operating temperature range is wide and vibration and impact are applied, such as for automotive, marine, or construction machinery applications. In the case of using the device, in addition to the fact that the physical properties of the adhesive material change greatly, there is a problem in that the fixing force of the adhesive material decreases due to the expansion and contraction of the peripheral members, leading to the peeling of the adhesive material. It was. Therefore, there is a problem that it is difficult to obtain an effect of suppressing fluttering sound in an environment where vibration and impact are applied.

  Therefore, the present invention provides a technique capable of suppressing the collision sound and flapping sound between the light guide plate and the peripheral member even under an environment where vibration and impact are applied, and achieving a narrow frame of the display device. Objective.

  The planar light source device according to the present invention is formed by a light source, an emission surface for emitting light from the light source, a plurality of side surfaces connected to the emission surface, and the first and second side surfaces adjacent to each other. A light guide plate provided inside the corner portion and having a recess opening over the first and second side surfaces, and disposed in the recess, and a tip portion from the opening of the recess is the first and first And an elastic body that protrudes to the side surfaces of the two, and a frame that houses the light source, the light guide plate, and the elastic body.

  According to the present invention, the planar light source device includes a light source, an emission surface that emits light from the light source, a plurality of side surfaces that are connected to the emission surface, and an angle formed by the adjacent first and second side surfaces. A light guide plate provided inside the portion and having a recess opening over the first and second side surfaces, and disposed in the recess, and the leading end portion from the opening of the recess is on the first and second side surfaces And an elastic body projecting from the light source, a light source, a light guide plate, and a frame for housing the elastic body.

  Therefore, even in an environment where vibrations and impacts are applied, the elastic body can buffer the vibrations and shocks in the four directions, so that the collision sound between the light guide plate and the peripheral member can be suppressed. Moreover, since the front-end | tip part of an elastic body absorbs an impact, since a light-guide plate flutters within a frame and it suppresses that fluttering propagates to a flame | frame, it can suppress that fluttering sound arises.

  Furthermore, since the elastic body is arranged in a state in which the tip portion protrudes from the opening of the recess to the first and second side surfaces, it is not necessary to provide a light guide plate ear on the side surface of the light guide plate, and the frame of the display device Expansion of the area can be suppressed. Thereby, it is possible to narrow the frame of the display device.

It is a disassembled perspective view of the display apparatus which concerns on embodiment. It is a disassembled perspective view of the planar light source device according to the embodiment. It is a front view of a display apparatus. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a disassembled perspective view of a light-guide plate unit. It is a perspective view of a light-guide plate unit. It is a front view of a light-guide plate unit. It is the front view and principal part enlarged view of a light-guide plate unit. It is the perspective view and principal part enlarged view of a light-guide plate. It is the perspective view and principal part enlarged view of a light-guide plate unit. It is a perspective view of an elastic body. It is a perspective view of the elastic body in the modification of embodiment.

<Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a liquid crystal display device 101 according to the embodiment, and FIG. 2 is an exploded perspective view of a planar light source device 100 according to the embodiment. FIG. 3 is a front view of the liquid crystal display device 101. 4 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 5 is a cross-sectional view taken along line BB in FIG.

  As shown in FIG. 1, the liquid crystal display device 101 according to the present embodiment includes a display panel 3 and a planar light source device 100. The display panel 3 is disposed on the emission surface side of the planar light source device 100. The display panel 3 is configured such that a glass substrate on which wirings and electrodes are formed and a counter substrate are arranged in parallel, and liquid crystal is sandwiched between the two substrates. Polarizers are attached to the surfaces of both substrates.

  The display area of the display panel 3 is composed of a large number of pixels, and a signal corresponding to the display image is added to each pixel to display an image. Here, the liquid crystal display device 101 corresponds to a display device, and the display panel 3 corresponds to a display unit.

<Configuration of planar light source device>
Next, the planar light source device 100 will be described. As shown in FIG. 2, the planar light source device 100 includes a planar light guide plate 1, an optical sheet 4, a reflective sheet 5, an elastic body 7, a point light source 9 that is a light source, a circuit board 10, a rear frame 2, And an intermediate frame 6. The light guide plate 1, the optical sheet 4, the reflection sheet 5, the elastic body 7, the point light source 9, and the circuit board 10 are accommodated in the rear frame 2, and the intermediate frame 6 is covered from the opposite side of the rear frame 2. . Here, the rear frame 2 and the intermediate frame 6 correspond to frames.

  As in Patent Document 1, in the technique of holding the light guide plate by pressing the light guide plate ear with a pressing member, when the shape of the light guide plate ear is convex, the size of the light guide plate increases and the liquid crystal display device There is a problem that it is difficult to narrow the frame. On the contrary, when the shape of the light guide plate ear is concave, the light propagating in the light guide plate is reflected at the tip of the concave portion, and brightness unevenness such as bright lines, bright portions, and dark portions is present in the vicinity of the light guide plate ear. Will be visually recognized. Therefore, it is necessary to provide the recess with a sufficient distance from the LCD display range, and there is a problem that it is difficult to narrow the frame of the liquid crystal display device.

  As shown in FIG. 2, the light guide plate 1 is disposed on a rear frame 2 having an opening 2a. The light guide plate 1 emits light in the direction of the opening 6a of the intermediate frame 6, and that direction is defined as the emission direction. The light guide plate 1 includes an output surface 1 a of the light guide plate 1 that emits light from the point light source 9, an anti-output surface 1 b that is a surface opposite to the output surface 1 a of the light guide plate 1, and an output surface of the light guide plate 1. A plurality of side surfaces connected to 1a are provided. More specifically, the plurality of side surfaces are formed substantially perpendicular to the emission surface 1a and the opposite emission surface 1b of the light guide plate 1, and are connected to the emission surface 1a and the opposite emission surface 1b of the light guide plate 1. The light guide plate 1 has a substantially rectangular flat plate shape in plan view, and is provided with a pair of side surfaces 1c and 1d facing each other and a pair of side surfaces 1e and 1f as a plurality of side surfaces. .

  The point light source 9 is disposed on the side surface 1 f of the light guide plate 1 while being mounted on the circuit board 10. In addition, optical sheets 4 such as a lens sheet and a diffusion sheet that diffuses light are disposed on the light exit surface 1 a side of the light guide plate 1. In addition, a reflection sheet 5 is disposed on the light exit surface 1 b side of the light guide plate 1. The light guide plate 1 and the optical sheets 4 are sandwiched between the rear frame 2 and the intermediate frame 6 facing the rear frame 2.

  Inside the corner 1g (see FIG. 10) formed by the side surfaces 1c, 1d, 1e, and 1f of the light guide plate 1, recesses 13 (see FIG. 6) in which the elastic bodies 7 can be placed are respectively provided. The elastic body 7 is integrated into the recess 13 of the light guide plate 1 and integrated with the light guide plate 1. Details of the elastic body 7 and the recess 13 will be described later.

  As shown in FIGS. 1, 3, 4, and 5, the display panel 3 is held by the intermediate frame 6 and is sandwiched between the front frame 8 and the planar light source device 100. As shown in FIGS. 4 and 5, a clearance 12 for absorbing temperature expansion and contraction of the light guide plate 1 is provided between the light guide plate 1 and the rear frame 2.

<Light guide plate>
The light guide plate 1 is a flat plate having a substantially rectangular shape and a constant thickness in plan view, but a wedge-shaped light guide plate may be used. Further, it may be a circular shape such as a circle or an ellipse, or a shape other than a substantially rectangular shape such as a polygon. The light guide plate 1 is configured using a material such as transparent acrylic resin, polycarbonate resin, or glass. Further, a light scattering portion (not shown) is formed on the side opposite to the light emitting surface 1b of the light guide plate 1 to disturb the light propagation direction and guide the light in the direction of emitting light from the light emitting surface 1a of the light guide plate 1. Has been. The light scattering portion functions as a means for reflecting light toward the inside of the light guide plate 1. As a means for reflecting, there are a method of dot printing on the anti-emission surface 1b, a method of roughening the anti-emission surface 1b to form a textured surface, or a method of forming a minute spherical surface or unevenness.

<Reflection sheet>
The reflection sheet 5 is made of polyethylene, polyethylene terephthalate mixed with barium sulfate or titanium oxide, resin formed with fine bubbles, silver on a metal plate, or metal It is comprised using the material which apply | coated the coating material containing a titanium oxide to a board. The reflectance of the reflection sheet 5 is desirably 90% or more in order to suppress reflection loss on the reflection surface, and the reflection sheet 5 may be configured using a material that performs specular reflection. By disposing the reflection sheet 5, the light emitted from the light guide plate 1 can be directed again to the light guide plate 1 and incident on the light guide plate 1, so that the light use efficiency can be improved.

<Optical sheets>
The optical sheets 4 are disposed on the light exit surface 1a side of the light guide plate 1 and can be configured by combining a lens sheet, a diffusion sheet, and the like. Alternatively, the optical sheets 4 may be configured using a structure in which a lens sheet is sandwiched between diffusion sheets. Further, in order to improve luminance, the optical sheets 4 may be configured by using a plurality of lens sheets in which prism directions are optimally combined. Furthermore, when improving the diffusibility of a diffusion sheet, you may comprise the optical sheets 4 using two or more diffusion sheets. Further, only one diffusion sheet may be used or not used. Further, a protective sheet, a viewing angle control sheet, or a polarization reflection sheet may be used as the optical sheets 4. That is, the optical sheets 4 are configured in combination according to required luminance and light distribution characteristics.

<Rear frame, intermediate frame>
The rear frame 2 is provided with a circuit board 10 on which a point light source 9 for emitting light is mounted. Further, when a point light source is used as the light source, the rear frame 2 can further improve the heat dissipation of the point light source by using a metal material such as aluminum as the material. Thereby, the loss of light can be suppressed and the light use efficiency of the planar light source device 100 can be improved. In the present embodiment, the rear frame 2 is configured using a metal material. The intermediate frame 6 is configured using a resin material or a metal material, and engages with the rear frame 2 to sandwich the optical member. Here, the optical members are the light guide plate 1, the optical sheets 4, the reflection sheet 5, and the point light source 9.

<Surface light source device>
The planar light source device 100 is configured by sandwiching the light guide plate 1, the reflection sheet 5, the optical sheets 4, and the point light source 9 between the rear frame 2 and the intermediate frame 6.

<Display panel>
The liquid crystal display device 101 is configured by disposing the display panel 3 on the planar light source device 100. As the display panel 3, a liquid crystal display panel using the birefringence of a liquid crystal material or a display panel on which characters or pictures are printed on a transparent plate is used. A liquid crystal display panel includes a color filter substrate on which a color filter, a light shielding layer, a counter-current, and the like are formed, and a thin transistor (hereinafter referred to as “TFT”) serving as a switching element on the substrate. And a TFT substrate on which pixel electrodes and the like are formed so as to face each other. The liquid crystal display panel includes a spacer for maintaining a distance between both substrates, a sealing material for bonding the color filter substrate and the TFT substrate, a liquid crystal material sandwiched between the color filter substrate and the TFT substrate, and a liquid crystal It is comprised by the orientation film | membrane which orientates, and a polarizing plate. The liquid crystal display panel controls the orientation of the liquid crystal layer by turning on or off the voltage by the switching element, and modulates the light incident on the liquid crystal display panel in accordance with the video signal for display.

<Front frame>
The front frame 8 includes an opening 8a for visually recognizing the exit surface 1a of the light guide plate 1 of the display panel 3 from the outside, and the front frame 8 is configured using a metal material such as SUS or aluminum. . By configuring the front frame 8 using a metal material, the rigidity of the liquid crystal display device 101 is improved.

<Light guide plate, elastic body, light guide plate unit>
Next, the light guide plate 1, the elastic body 7, and the light guide plate unit will be described. FIG. 6 is an exploded perspective view of the light guide plate unit. FIG. 7 is a perspective view of the light guide plate unit. FIG. 8 is a front view of the light guide plate unit. FIG. 9 is a front view and a main part enlarged view of the light guide plate unit. FIG. 10 is a perspective view and an enlarged view of a main part of the light guide plate 1. FIG. 11 is a perspective view and an enlarged view of a main part of the light guide plate unit.

  As shown in FIGS. 6, 9 and 10, the four corners 1 g of the light guide plate 1 are respectively formed with recesses 13 which are recessed inward. The opening 14 of the recess 13 is integrally formed across the ends of two adjacent side surfaces that form the corner 1g. One elastic body 7 is arranged in each of the four recesses 13. That is, the elastic body 7 is disposed in the recesses 13 in all the corners 1 g of the light guide plate 1. As shown in FIGS. 7, 8, 9, and 11, the elastic body 7 is integrated into the concave portion 13 of the light guide plate 1 and integrated with the light guide plate 1. In the present specification, this structure is referred to as a “light guide unit”.

  The recess 13 will be described in detail. Hereinafter, although the recessed part 13 corresponding to the corner | angular part 1g formed by two adjacent side surfaces 1c and 1e is demonstrated, since it is the same also about the recessed part 13 corresponding to the other three corner | angular parts 1g, description is abbreviate | omitted. Here, the side surface 1c is the first side surface, and the side surface 1e is the second side surface. As shown in FIG. 10, the recessed part 13 provided in the light-guide plate 1 is formed inside the corner | angular part 1g formed by two adjacent side surfaces 1c and 1e. The recess 13 is appropriately formed in a shape corresponding to the shape of the elastic body 7 described later. In addition, the elastic body 7 is configured such that the tip portion protrudes from the opening 14 of the recess 13 toward the side surfaces 1 c and 1 e in a state where the elastic body 7 is disposed in the recess 13 of the light guide plate 1. Further, as described above, the elastic body 7 is disposed at all four corners 1g formed by two adjacent side surfaces. That is, the distal end portion of the elastic body 7 is disposed on all sides where the light guide plate 1 faces the intermediate frame 6.

<Elastic body>
Next, the elastic body 7 will be described in detail. FIG. 12 is a perspective view of the elastic body 7. As shown in FIGS. 10 and 11, the recess 13 is formed to have substantially the same dimensions as the elastic body 7. Since the center part of the opening 14 in the recessed part 13 is formed narrower than the edge part on the side surface side, the elastic body 7 is difficult to come off from the corner part 1g side.

  When the elastic body 7 is incorporated into the light guide plate 1, the elastic body 7 is inserted from the opening 14 of the light guide plate 1 and pressed and elastically deformed, so that the elastic body 7 is disposed and fixed in the concave portion 13 of the light guide plate 1. The elastic body 7 is deformed when a load is applied, and has an elasticity that returns to its original state when the load is removed. The elastic body 7 is not easily detached once incorporated into the light guide plate 1, but the recess 13 of the light guide plate 1. To constitute a light guide plate unit. Next, the light guide plate unit is arranged in the rear frame 2 on which the reflection sheet 5 is arranged, so that the light guide plate unit can be fixed and held.

  As shown in FIG. 12, the elastic body 7 is formed using a silicone rubber or a fluorine rubber that does not contain a sulfide that is a sulfur component or a plasticizer that is a chlorine component. The sulfur component or chlorine component contained in a general rubber material shifts to metal or resin, for example, a significant decrease in the luminance life of the LED due to blackening discoloration of the silver reflector, a decrease in physical properties of the resin member, and a crack phenomenon Therefore, the use of the elastic body 7 should be avoided.

  The stress generated in the elastic body 7 is expressed by the following formula, and the stress can be adjusted by changing the material properties such as the elastic modulus and the shape of the elastic body 7. Depending on the size and weight of the light guide plate, the elastic modulus of the material of the elastic body 7, that is, the hardness, or the cross-sectional shape can be freely selected as appropriate.

σ = Eε
Here, σ is stress, E is elastic modulus, and ε is strain.

  The shape of the elastic body 7 will be described. As shown in FIG. 9 and FIG. 12, the elastic body 7 has two side surfaces 1 c and 1 e adjacent to each other, more specifically, in a plan view so that the tip end portions 7 c and 7 d protrude from the opening 14 of the recess 13. It is formed in an L shape. As shown in FIG. 12, specifically, the elastic body 7 has a shape corresponding to the concave portion 13 formed in the light guide plate 1, and includes two columnar columnar portions 7 a and 7 b. The cross-sectional shapes of the two columnar portions 7a and 7b are elliptical or rectangular, and the base end portions are connected so that the two columnar portions 7a and 7b form an angle of approximately 90 °. It has become. Moreover, the front-end | tip parts 7c and 7d of the elastic body 7 are formed in planar shape. Furthermore, the connection part 7e to which the two columnar parts 7a and 7b are connected is formed with a protruding part 7f protruding from the connection part 7e. The protruding portion 7 f protrudes from the central portion of the opening 14 in the concave portion 13.

  As described above, the planar light source device 100 according to the embodiment includes the point light source 9, the emission surface 1a that emits light from the point light source 9, and the plurality of side surfaces 1c and 1d that are connected to the emission surface 1a. , 1e, 1f, and a light guide plate 1 having a recess 13 provided inside the corner 1g formed by the adjacent first and second side surfaces and opening over the first and second side surfaces, An elastic body 7 which is disposed in the concave portion 13 and whose tip portions 7c and 7d protrude from the opening 14 of the concave portion 13 to the first and second side surfaces, respectively, the point light source 9, the light guide plate 1 and the elastic body 7 The intermediate frame 6 and the rear frame 2 are provided.

  Therefore, even under an environment in which vibration and impact are applied, the elastic body 7 can buffer the vibration and impact in four directions, thereby suppressing the collision sound between the light guide plate 1 and the peripheral member. In addition, the light guide plate 1 flutters inside the intermediate frame 6 and the rear frame 2 by the tip portions 7 c and 7 d of the elastic body 7 absorbing the shock, and the flickering propagates to the intermediate frame 6 and the rear frame 2. Therefore, it is possible to suppress the occurrence of flapping noise.

  Furthermore, since the elastic body 7 is arranged in a state in which the end portions 7c and 7d protrude from the opening 14 of the recess 13 to the first and second side surfaces, it is necessary to provide a light guide plate ear on the side surface of the light guide plate 1. The expansion of the frame area of the liquid crystal display device 101 can be suppressed. Thereby, the frame of the liquid crystal display device 101 can be narrowed. Further, since the elastic body 7 is held by being elastically deformed in the recess 13, an area for fixing with the double-sided adhesive tape or the cushion adhesive tape is not necessary in the light guide plate 1, and the frame area of the liquid crystal display device 101 is not required. Expansion can be suppressed.

  Since the elastic body 7 is disposed in the recesses 13 in all the corners 1g of the light guide plate 1, the vibration and shock buffering performance of the elastic body 7 can be further improved.

  The elastic body 7 includes two columnar portions 7a and 7b to which the base end portions are connected and is formed in an L shape in a plan view, so that the elastic body 7 is difficult to move in the recess 13. Thereby, holding and fixing of the elastic body 7 are further strengthened.

  Since the front end portions 7c and 7d of the elastic body 7 are formed in a flat shape, the contact area between the front end portions 7c and 7d protruding from the opening 14 and the rear frame 2 through the reflection sheet 5 is increased, and the light guide plate 1 Can be held in a stable state.

  Since the elastic body 7 includes the protrusion 7f protruding from the connection portion 7e to which the two columnar portions 7a and 7b are connected, the protrusion 7f further protrudes from the opening 14 so that the elastic body 7 has four directions. The shock absorbing performance of vibration and impact can be further improved.

  Since the elastic body 7 is formed using silicone rubber or fluororubber that does not contain a sulfur component or a chlorine component, it has a small compression set, a wide use temperature range, and a high weather resistance. Moreover, since it does not peel off like fixation with a double-sided adhesive tape or a cushion adhesive tape, positioning of the light-guide plate 1 and holding | maintenance and fixation of the elastic body 7 are possible for a long time. As described above, the positioning of the light guide plate 1 and the holding and fixing of the elastic body 7 can be performed for a long period of time, and the light guide plate 1, and thus the planar light source device 100 and the liquid crystal display device 101 can be used for a long period of time.

  Further, since the light guide plate 1 is positioned at a predetermined position by elastic deformation of the elastic body 7, a change in the distance between the point light source 9 and the light guide plate 1 can be reduced. Thereby, the luminance change of the light emitted from the planar light source device 100 is reduced. In addition, since the light guide plate 1 is positioned at a predetermined position by elastic deformation of the elastic body 7, the disassembly and assembling property of the light guide plate 1 is improved unlike the fixing method using a double-sided adhesive tape or a cushion adhesive tape, etc. Easy.

  Further, the cross-sectional shape of the elastic body 7 is an elliptical shape or a rectangular shape, and can be appropriately selected according to the shape of the concave portion 13 of the light guide plate 1. Moreover, the elastic body 7 should just be a shape from which the front-end | tip parts 7c and 7d protrude from two adjacent side surfaces of the light-guide plate 1, and can select a shape suitably freely according to the shape of the recessed part 13 of the light-guide plate 1. FIG. it can. That is, the two columnar portions 7a and 7b may be connected to form an angle larger than 90 °.

  The elastic body 7 can be easily removed from the liquid crystal display device 101 by inserting a tool into the elastic body 7 disposed in the recess 13 of the light guide plate 1, and the light guide plate 1 can be removed from the rear frame 2. Easy.

  Also, the spring force of the elastic body 7, in other words, the spring constant can be adjusted by adjusting the physical properties of the elastic body 7, but the spring force can also be adjusted by changing the size and shape of the curved surfaces of the tip portions 7c and 7d. Is possible. For example, as shown in FIG. 13, the tip portions 7g and 7h may be formed in a curved surface shape. FIG. 13 is a perspective view of an elastic body 7A according to a modification of the embodiment. The elastic body 7A does not include the protruding portion 7f as shown in FIG. 12, but the connecting portion 7e may be provided with the protruding portion 7f.

  Since the tip portions 7g and 7h of the elastic body 7A are formed in a curved surface, the buffer performance of the tip portions 7g and 7h of the elastic body 7A can be improved as compared with the case of FIG.

  Further, in the liquid crystal display device 101, the color of the elastic body 7 is not particularly specified. In order to suppress luminance unevenness due to reflection of light from the elastic body 7 in the light guide plate 1, the elastic body 7 is preferably black or colorless and transparent. When the elastic body 7 is made black, it absorbs light, so that luminance unevenness caused by reflection can be suppressed. Moreover, when the elastic body 7 is made colorless and transparent, since light is transmitted, luminance unevenness caused by reflection can be suppressed. In addition, the type or arrangement position of the point light source 9 and the light guide plate 1 can be appropriately selected.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

  DESCRIPTION OF SYMBOLS 1 Light-guide plate, 1a Output surface, 1c, 1d, 1e, 1f Side surface, 1g Corner | angular part, 2 Rear frame, 3 Display panel, 6 Intermediate | middle frame, 7, 7A Elastic body, 7a, 7b Column-shaped part, 7c, 7d Tip Part, 7f protrusion part, 7g, 7h tip part, 9 point light source, 13 recessed part, 14 opening, 100 planar light source device, 101 liquid crystal display device.

Claims (8)

A light source;
Provided on the inside of a corner formed by an exit surface that emits light from the light source, a plurality of side surfaces connected to the exit surface, and the adjacent first and second side surfaces, and the first and first sides. A light guide plate having a recess opening over two side surfaces;
An elastic body that is disposed in the recess and has a tip protruding from the opening of the recess toward the first and second side surfaces;
A frame that houses the light source, the light guide plate, and the elastic body;
A planar light source device.   The planar light source device according to claim 1, wherein the elastic body is disposed in the concave portion in all the corner portions of the light guide plate.   The planar light source device according to claim 1, wherein the elastic body includes two columnar portions to which base ends are connected, and is formed in an L shape in a plan view.   The planar light source device according to any one of claims 1 to 3, wherein the tip portion of the elastic body is formed in a planar shape.   The planar light source device according to any one of claims 1 to 3, wherein the tip portion of the elastic body is formed in a curved surface shape.   The planar light source device according to claim 3, wherein the elastic body includes a protrusion that protrudes from a connection portion to which the two columnar portions are connected.   The planar light source device according to any one of claims 1 to 6, wherein the elastic body is formed using silicone rubber or fluorine rubber that does not contain a sulfur component or a chlorine component. A planar light source device according to any one of claims 1 to 7,
A display unit disposed on the exit surface side of the planar light source device;
A display device comprising:

Images