TWI693457B - Surface light source device, display device and electronic device - Google Patents

Abstract

The surface light source device, the display device, and the electronic device of the present invention suppress the peeling of the wiring board from the light guide plate and the frame. The surface light source device includes: a holding portion having a bottom plate, a side wall standing on the bottom plate, and a top plate disposed on the side wall and facing the bottom plate; the light source is disposed between the bottom plate and the top plate and has a light-emitting surface that emits light; The side surface has a light incident surface opposite to the light emitting surface and light is incident, and the light incident from the light incident surface is emitted from the light exit surface; the frame houses the light source and the light guide plate; the wiring board is disposed between the top plate and the light source and is fixed at The light guide plate and the frame; and the light-shielding tape are fixed to the opposite surface of the top plate and the opposite surface of the bottom plate.

Description

Surface light source device, display device and electronic device

The invention relates to a surface light source device, a display device and an electronic device.

In recent years, the miniaturization and thinning of electronic devices have continued to develop. For a liquid crystal display device mounted in such an electronic device, there is a demand for narrowing and thinning for obtaining a larger display area with the same area. In the backlight of a display device, for example, a side light type (side light) that uses a light emitting diode (LED) that emits white light as a light source and uses a light guide plate (also referred to as a light guide) type) (also called edge light) surface light source device.

FIG. 12 is a schematic cross-sectional view of the conventional surface light source device 100. The surface light source device 100 includes a light guide plate 101, a light source 102 arranged adjacent to the light guide plate 101, and a reflection sheet 103 arranged below the light guide plate 101 and the light source 102. In addition, the surface light source device 100 includes a housing 104 that houses the light guide plate 101, the light source 102, and the reflection sheet 103. The frame 104 includes a bezel (metal frame) 105 and a resin frame 106. The light source 102 is mounted on a flexible printed circuit board (hereinafter also referred to as "FPC (Flexible Printed Circuit)") 107. The FPC 107 is fixed to the light guide plate 101 and the resin frame 106 by the double-sided adhesive tape 108. Double-sided adhesive tape 108 is excellent in mass productivity and thin. Therefore, it is used to fix component parts.

The present invention provides a cover member with a substantially cross-sectional shape covering a rod-shaped light source and a light guide plate, and by the strong elastic force of the cover member to firmly support the light guide plate, thereby maintaining the light guide plate and the rod-shaped light source Adhesive surface light-emitting device (see Patent Document 1).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-39570

Due to the narrower frame of the display, the attachment area of the double-sided adhesive tape 108 is reduced, and the thickness of the paste of the double-sided adhesive tape 108 gradually becomes thinner due to the thinner electronic device. Therefore, the adhesive force of the double-sided adhesive tape 108 decreases, and the double-sided adhesive tape 108 gradually becomes unable to withstand external stress. As an example of external stress, there is a bending stress of the main FPC provided in the liquid crystal display mounted on the surface light source device 100. 13 is a cross-sectional view of the conventional surface light source device 100 and the liquid crystal display 111. The liquid crystal display 111 includes an upper glass 112 and a lower glass 113. In FIG. 13, the liquid crystal display 111 is fixed to the FPC 107 using the light-shielding double-sided tape 114, and the surface light source device 100 is connected to the liquid crystal display 111 using the main FPC 115. The main FPC 115 is bent 180 degrees and attached to the back of the frame 104. Since the main FPC 115 has a large resilience, the FPC 107 is stretched toward the liquid crystal display 111 side to apply stress to the double-sided adhesive tape 108. In addition, by dropping the electronic device including the surface light source device 100 and the liquid crystal display 111, the electronic device Impact is applied, and stress is applied to the double-sided adhesive tape 108.

Due to the decrease in the adhesive force of the double-sided adhesive tape 108 and the stress applied to the double-sided adhesive tape 108, there is a possibility that the FPC 107 may peel off from the resin frame 106 or the FPC 107 may peel off from the light guide plate 101. In addition, by thin-wall molding, ripples are generated on the surface of the resin frame 106, whereby the possibility of the FPC 107 peeling from the resin frame 106 becomes high. As shown in FIG. 14, when the FPC 107 is peeled from the resin frame 106, there is a possibility that light leaks to the outside of the surface light source device 100. As shown in FIG. 15, when the FPC 107 is peeled off from the light guide plate 101, the position of the light source 102 is shifted, and there is a possibility that the brightness of the light emitted from the light guide plate 101 decreases or the brightness distribution of the light is destroyed. As a result, uneven bright spots (hot spots) are generated in the screen of the liquid crystal display 111.

In view of this situation, an object of the present invention is to suppress the peeling of the wiring board from the light guide plate and the frame.

In the present invention, the following means are adopted to solve the above problems. That is, the present invention is a surface light source device including the following components, the surface light source device including: a holding portion having a bottom plate, a side wall standing on the bottom plate, and a top plate provided on the side wall and facing the bottom plate; There is a light-emitting surface that emits light; the light guide plate has a light-incident surface on the side opposite to the light-emitting surface and light is incident, and the light incident from the light-incident surface is emitted from the light-emitting surface; the frame body houses the light source and the guide The light board; the wiring board, which is arranged between the top board and the light source, and is fixed to the light guide plate and the frame body;

In the surface light source device of the present invention, the wiring board disposed between the bottom plate and the top plate is fixed to the light guide plate and the frame, and the light-shielding tape is fixed to the top plate. When the light-shielding tape is stretched, the top plate is stretched, and since the top plate is not fixed to the wiring board, the wiring board is not stretched. Therefore, even when the light-shielding tape is stretched, the wiring substrate is not stretched, so the peeling of the wiring substrate from the light guide plate is suppressed, and the peeling of the wiring substrate from the frame is suppressed.

In the surface light source device of the present invention, the frame body may have a protruding portion protruding in a direction away from the light guide plate, and the protruding portion is fitted into the through hole provided in the bottom plate. In the surface light source device of the present invention, the protruding portion can be accommodated in the through hole. In the surface light source device of the present invention, the front end of the top plate and the front end of the bottom plate can be bent by hemming. The surface light source device of the present invention may include a buffer member disposed between the top plate and the wiring board. In the surface light source device of the present invention, the wiring board can be fixed to the light guide plate and the frame body with an adhesive tape. The display device of the present invention may include the surface light source device of the present invention and a display panel that receives light emitted from the surface light source device, and the display panel is fixed to the light-shielding tape. The electronic device of the present invention may also include the display device of the present invention.

According to the present invention, peeling of the wiring board from the light guide plate and the frame can be suppressed.

1.100: Surface light source device

2: display panel

10, 101: light guide plate

10A: incident surface

10B: Light emitting surface

11, 102: light source

12, 107: FPC

13, 103: reflection sheet

14, 104: frame

15, 16, 108: Double-sided adhesive tape

17: Holding Department

18, 114: shading double-sided tape

19: diffuser

20: 珜鏡片

21, 105: border

22, 106: resin frame

23: Underside

31: bottom plate

32, 44: side wall

33: top plate

34: through hole

35: front end of the bottom plate

36: front end of the top plate

37, 46: L bend

38: Hole for positioning

41, 47, 48: protrusion

42: inclined surface

43: Lower surface

45: Tablet

51: buffer member

52: spacer

71: upper side glass

72: Lower glass

73, 115: Main FPC

74: Driver IC

111: LCD display

112: on glass

113: Lower glass

L1, L2, L3, L4: length

T1: height

W1, W2: width

FIG. 1 is a cross-sectional view showing an example of a surface light source device.

2 is a perspective view illustrating an example of the liquid crystal display device of the first embodiment.

3 is a cross-sectional view showing an example of the surface light source device of the first embodiment.

FIG. 4A is a schematic diagram of a protrusion.

Fig. 4B is a schematic diagram of a protrusion.

5A is a schematic view of the surface light source device of the first embodiment.

5B is a schematic view of the surface light source device of the first embodiment.

5C is a schematic view of the surface light source device of the first embodiment.

5D is a schematic view of the surface light source device of the first embodiment.

6 is a cross-sectional view showing an example of the surface light source device of the first embodiment.

7 is a cross-sectional view showing an example of the surface light source device of the first embodiment.

8A is a perspective view of the holding portion of the first embodiment.

8B is a cross-sectional view of the holding portion of the first embodiment.

8C is a cross-sectional view of the holding portion of the first embodiment.

9A is an explanatory diagram of a method of attaching the holding portion to the surface light source device.

9B is an explanatory diagram of a method of attaching the holding portion to the surface light source device.

9C is an explanatory diagram of a method of attaching the holding portion to the surface light source device.

10 is a cross-sectional view of the liquid crystal display device of the first embodiment.

11 is a cross-sectional view showing an example of the surface light source device of the second embodiment.

12 is a schematic cross-sectional view of a conventional surface light source device.

13 is a cross-sectional view of a conventional surface light source device and liquid crystal display.

14 is a cross-sectional view of a conventional surface light source device.

15 is a cross-sectional view of a conventional surface light source device.

Hereinafter, embodiments of the present invention will be described based on the drawings. In addition, the embodiment described below shows an example of implementing the present invention, and does not limit the present invention to the specific configuration described below.

<application example>

FIG. 1 is a cross-sectional view showing an example of the surface light source device 1. The surface light source device 1 includes a light guide plate 10, a light source 11, an FPC 12, a reflective sheet 13, a frame 14, a double-sided adhesive tape 15, a double-sided adhesive tape 16, a holding portion 17, and a light-shielding double-sided adhesive tape 18. The light guide plate 10 has a light incident surface 10A on the side where light enters, and light incident from the light incident surface 10A is emitted from the light exit surface 10B. The light source 11 has a light emitting surface that emits light. The light source 11 is mounted on the FPC 12. The light incident surface 10A of the light guide plate 10 faces the light emitting surface of the light source 11.

The FPC 12 is a wiring board that supplies power to the light source 11. The reflection sheet 13 is arranged to be in contact with the lower surface of the light guide plate 10, and reflects the light so that the light in the light guide plate 10 does not leak from the lower surface of the surface light source device 1. The frame 14 includes a frame (metal frame) 21 and a resin frame 22. The frame 14 is an example of a frame. The frame 21 has a bottom and a side plate portion standing on the bottom. The bottom of the bezel 21 is disposed on the side opposite to the light exit surface 10B of the light guide plate 10. The side plate portion of the bezel 21 is the outer periphery of the bottom of the bezel 21 and is arranged to face the light incident surface 10A of the light guide plate 10. A resin frame 22 is arranged at a corner formed by the bottom of the bezel 21 and the side plate portion. The side plate portion of the bezel 21 is the outer periphery of the bottom of the bezel 21 and can be arranged so as to surround the side surface of the light guide plate 10.

The double-sided adhesive tape 15 adheres the light guide plate 10 and the FPC 12, thereby fixing the FPC 12 to the light guide plate 10. Double-sided adhesive tape 16 adheres FPC 12 to resin frame 22 By this, the FPC 12 is fixed to the resin frame 22. The holding portion 17 includes a bottom plate 31, a side wall 32 standing on the bottom plate 31, and a top plate 33 provided on the side wall 32 and facing the bottom plate 31. The holding portion 17 has elasticity. The light source 11 and the FPC 12 are arranged between the bottom plate 31 and the top plate 33. The FPC 12 is arranged between the light source 11 and the top plate 33. The light-shielding double-sided tape 18 is fixed to the surface of the top plate 33 opposite to the surface facing the bottom plate 31. The surface of the top plate 33 facing the bottom plate 31 is the inner surface of the top plate 33, and the surface of the top plate 33 opposite to the surface facing the bottom plate 31 is the outer surface of the top plate 33. The light-shielding double-sided tape 18 is an example of a light-shielding tape.

The light-shielding double-sided tape 18 is fixed to the top plate 33. When the light-shielding double-sided tape 18 is stretched toward the normal direction side of the light exit surface 10B of the light guide plate 10, the top plate 33 is stretched toward the normal direction side of the light exit surface 10B of the light guide plate 10. The top plate 33 is in contact with the FPC 12, but the top plate 33 is not fixed to the FPC 12. Therefore, even when the light-shielding double-sided tape 18 is stretched toward the normal direction side of the light exit surface 10B of the light guide plate 10, the FPC 12 is not stretched. Therefore, even when the light-shielding double-sided tape 18 is stretched toward the normal direction side of the light exit surface 10B of the light guide plate 10, no stress is applied to the double-sided adhesive tape 15 and the double-sided adhesive tape 16. According to the surface light source device 1, the FPC 12 is suppressed from peeling off from the light guide plate 10, and the FPC 12 is suppressed from peeling off from the resin frame 22.

In the following embodiments, the "surface light source device" will be described as the backlight unit of the liquid crystal display device. Furthermore, the “surface light source device” can also be used for applications other than backlight units such as front lights arranged on the front surface of a display device formed of a display panel or electronic paper.

<First embodiment>

(Configuration of liquid crystal display device)

2 is a perspective view illustrating an example of the liquid crystal display device of the first embodiment. As shown in FIG. 2, the liquid crystal display device includes a surface light source device 1 arranged as a backlight, and a display panel (liquid crystal display) 2 that receives light emitted from the surface light source device 1. The display panel 2 displays an image by applying a voltage to the liquid crystal sandwiched and sealed in the glass plate to increase or decrease the transmittance of light. Hereinafter, the description will be made with the display panel 2 side of the surface light source device 1 as the upper surface side and the opposite surface side as the lower surface side.

(Configuration of surface light source device)

3 is a cross-sectional view showing an example of the surface light source device 1 of the first embodiment. FIG. 3 shows a part of the surface light source device 1 of the first embodiment. The surface light source device 1 includes a light guide plate 10, a light source 11, an FPC 12, a reflective sheet 13, a frame 14, a double-sided adhesive tape 15, a double-sided adhesive tape 16, a holding portion 17, a light-shielding double-sided tape 18, and a diffusion sheet 19. One or two slices of lozenge 20.

The light guide plate 10 has a substantially flat plate shape, and is formed of a light-transmitting material such as polycarbonate resin or polymethyl methacrylate resin. The light guide plate 10 has a light incident surface 10A on the side where light enters, and the light incident from the light incident surface 10A is emitted from the light exit surface 10B. The light guide plate 10 may include a light guide plate body and a light introduction part having a height higher than that of the light guide plate body. The light emitted from the light source 11 efficiently enters the light guide plate body from the light introduction portion, and the light utilization efficiency of the light guide plate 10 is improved. Since the light guide plate body is thinner than the light introduction portion, the thickness reduction of the surface light source device 1 is improved, and the thickness reduction of the liquid crystal display device including the surface light source device 1 is improved. However, the light guide plate 10 may have a flat plate shape without a light introduction part.

The light source 11 has a light emitting surface that emits light. The light source 11 is mounted on the FPC 12. The light incident surface 10A of the light guide plate 10 faces the light emitting surface of the light source 11. The plurality of light sources 11 can be mounted on the FPC 12 in a row at regular intervals. The light source 11 is, for example, an LED package, but a light source other than the LED package can also be used. The light source 11 can be formed by sealing a LED chip as a light-emitting element with a light-transmitting resin (resin layer) containing phosphor. Alternatively, instead of arranging phosphor on the LED chip, a phosphor layer may be disposed on the light exit surface 10B of the light guide plate 10, or a phosphor layer may be disposed on the reflective sheet 13. The light source 11 is driven and turned on by receiving power from the FPC 12. In addition, as the light source 11, LED light sources other than white can also be used.

The FPC 12 is a wiring board that supplies power to the light source 11. The FPC 12 is formed by using conductor foil to provide wiring on a substrate that is a flexible insulating film, and bonding a cover layer or resin (photosensitive resin) that is an insulating film for protection to the surface. The reflection sheet 13 is arranged to be in contact with the lower surface of the light guide plate 10, and reflects the light so that the light in the light guide plate 10 does not leak from the lower surface of the surface light source device 1. The lower surface of the light guide plate 10 is opposite to the light exit surface 10B of the light guide plate 10.

The frame 14 accommodates the light guide plate 10, the light source 11, the FPC 12, the reflection sheet 13, the double-sided adhesive tape 15, the double-sided adhesive tape 16, the diffusion sheet 19, and the prism sheet 20. The frame 14 includes a frame 21 and a resin frame 22. The frame 21 has a bottom and a side plate portion standing on the bottom. The bottom of the frame 21 is disposed on the opposite side of the light exit surface 10B of the light guide plate 10. The side plate portion of the bezel 21 is arranged so as to surround the side surface of the light guide plate 10. A resin frame 22 is arranged at a corner formed by the bottom of the bezel 21 and the side plate portion. Make As the base material of the resin frame 22, for example, polycarbonate resin can be used. The side plate portion of the bezel 21 and the resin frame 22 surround the light incident surface 10A of the light guide plate 10. The side plate portion of the frame 21 and the resin frame 22 may surround the other side surface other than the light incident surface 10A of the light guide plate 10. The end of the side plate portion of the bezel 21 is bent by folding.

The upper and lower surfaces of the double-sided adhesive tape 15 and the double-sided adhesive tape 16 are adhesive surfaces. The double-sided adhesive tape 15 is disposed between the light guide plate 10 and the FPC 12, and the double-sided adhesive tape 15 adheres the light guide plate 10 and the FPC 12 to fix the FPC 12 to the light guide plate 10. The double-sided adhesive tape 16 is disposed between the FPC 12 and the resin frame 22, and the FPC 12 and the resin frame 22 are adhered by the double-sided adhesive tape 16 to fix the FPC 12 to the resin frame 22.

The holding portion 17 includes a flat bottom plate 31, a flat side wall 32 standing on the bottom plate 31, and a flat top plate 33 provided on the side wall 32 and facing the bottom plate 31. The holding portion 17 has elasticity. The holding portion 17 has a substantially U-shape when viewed in section. The holding portion 17 may not be limited to a substantially U-shape in a cross-sectional view, but may have another shape. The material of the holding portion 17 is, for example, metal such as stainless steel (SUS) or phosphor bronze, or resin such as liquid crystal polymer. The thicknesses of the bottom plate 31, the side walls 32, and the top plate 33 are, for example, greater than or equal to 0.05 mm and less than or equal to 0.1 mm, but are not limited to this range. The light source 11 and the FPC 12 are arranged between the bottom plate 31 and the top plate 33. The FPC 12 is arranged between the light source 11 and the top plate 33. The top plate 33 covers the FPC 12. The light-shielding double-sided tape 18 is fixed to the surface of the top plate 33 opposite to the surface facing the bottom plate 31. The surface of the top plate 33 facing the bottom plate 31 is the inner surface of the top plate 33, and the surface of the top plate 33 opposite to the surface facing the bottom plate 31 is the outer surface of the top plate 33.

The diffusion sheet 19 is provided on the light exit surface 10B of the light guide plate 10. One or two prism sheets 20 are provided on the diffusion sheet 19. In the example shown in FIG. 3, two prism sheets 20 are provided on the diffusion sheet 19. The diffusion sheet 19 is a translucent resin film, and diffuses the light emitted from the light exit surface 10B of the light guide plate 10 to expand the directivity of the light. The prism sheet 20 is a transparent resin film in which a fine pattern of a triangular prism is formed on the upper surface, and the light diffused by the diffusion sheet 19 is collected to increase the brightness when the surface light source device 1 is viewed from the upper surface side.

The bottom of the bezel 21 has a protrusion 41 that protrudes away from the light guide plate 10. 4A and 4B are schematic diagrams of the protrusion 41. FIG. 4A is a view of the protrusion 41 viewed from the side. FIG. 4B is a view of the protrusion 41 viewed from the direction of the arrow in FIG. 4A. The protrusion 41 has an inclined surface 42 inclined with respect to the bottom surface 23 of the frame 21. In addition, the protruding portion 41 has a lower surface 43 having a step difference from the bottom surface 23 of the bezel 21. As shown in FIG. 4B, the protruding portion 41 includes a side wall 44 erected on the frame 21 and a flat plate 45 provided on the side wall 44. The side wall 44 is orthogonal to the bottom of the frame 21, and the flat plate 45 is parallel to the bottom of the frame 21.

As shown in FIG. 3, the bottom plate 31 has a through hole 34, and the protruding portion 41 of the frame 21 is fitted into the through hole 34 of the bottom plate 31. The number of through holes 34 may be one or a plurality. The number of protrusions 41 may be one or plural. When the protrusion 41 of the bezel 21 is inserted into the through hole 34 of the bottom plate 31, a part of the protrusion 41 of the bezel 21 protrudes from the through hole 34 of the bottom plate 31. As a result, the protruding portion 41 of the frame 21 is fitted into the through hole 34 of the bottom plate 31. When the protrusion 41 of the frame 21 is inserted into the through hole 34 of the bottom plate 31, the side wall 44 of the protrusion 41 and the through hole of the bottom plate 31 The outer peripheral portion of 34 is in contact, so the protrusion 41 is not on the bottom plate 31. The outer peripheral portion of the through-hole 34 of the bottom plate 31 abuts the protruding portion 41 of the frame 21 to restrict the horizontal movement of the bottom plate 31. Thereby, the positional deviation of the holding portion 17 is suppressed, and the holding portion 17 is suppressed from being detached from the surface light source device 1.

5A to 5D are schematic views of the surface light source device 1 of the first embodiment. 5A is a view of a part of the surface light source device 1 viewed from the upper surface side, and shows a state where the holding portion 17 is removed from the surface light source device 1. 5B is a view of a part of the surface light source device 1 viewed from the lower surface side, and shows a state where the holding portion 17 is removed from the surface light source device 1. 5C is a view of a part of the surface light source device 1 viewed from the upper surface side, and shows a state where the holding portion 17 is attached to the surface light source device 1. 5D is a diagram of a part of the surface light source device 1 viewed from the lower surface side, and shows a state where the holding portion 17 is attached to the surface light source device 1. In the examples shown in FIGS. 5C and 5D, the width of the top plate 33 of the holding portion 17 is larger than the width of the bottom plate 31 of the holding portion 17. However, it is not limited to the examples shown in FIGS. 5C and 5D. The width of the top plate 33 of the holding portion 17 may be the same as the width of the bottom plate 31 of the holding portion 17 or may be smaller than the width of the bottom plate 31 of the holding portion 17.

As shown in FIG. 6, the front end (end portion) 35 of the bottom plate 31 and the front end (end portion) 36 of the top plate 33 can be bent by hemming. 6 is a cross-sectional view showing an example of the surface light source device 1 of the first embodiment. FIG. 6 shows a part of the surface light source device 1 of the first embodiment. The surface light source device 1 shown in FIG. 6 includes a buffer member 51 between the FPC 12 and the top plate 33 of the holding portion 17. The cushioning member 51 is, for example, a base material having cushioning properties such as a sponge member, a rubber member, or a resin member. buffer The member 51 may have a belt shape. By bending the front end 35 of the bottom plate 31 and the front end 36 of the top plate 33 by folding, the strength of the bottom plate 31 and the top plate 33 is improved. In the example of FIG. 6, the front end 35 of the bottom plate 31 is bent toward the outer surface side of the bottom plate 31. The surface of the bottom plate 31 facing the top plate 33 is the inner surface of the bottom plate 31, and the surface of the bottom plate 31 opposite to the surface facing the top plate 33 is the outer surface of the bottom plate 31. In the example of FIG. 6, the front end 36 of the top plate 33 is bent toward the inner surface side of the top plate 33. Not limited to the example of FIG. 6, the front end 36 of the top plate 33 may be bent toward the outer surface side of the top plate 33. When the front end 36 of the top plate 33 is bent toward the outer surface side of the top plate 33, the buffer member 51 may be fixed to the outer surface of the top plate 33 via an adhesive or a double-sided adhesive tape.

Since the front end 36 of the top plate 33 is bent toward the inner surface side of the top plate 33, a space is formed between the FPC 12 and the top plate 33. A buffer member 51 is arranged in the space formed between the FPC 12 and the top plate 33. Since the buffer member 51 is arranged between the FPC 12 and the top plate 33, when a force is applied to the surface light source device 1 from the outside, the stress applied to the light source 11 or the FPC 12 can be reduced. In addition, it is not limited to the example of FIG. 6, and the cover layer is equal to the FPC 12 to form the convex portion, thereby filling the space between the FPC 12 and the top plate 33. In addition, without bending the front end 35 of the bottom plate 31 and the front end 36 of the top plate 33, the buffer member 51 may be disposed between the FPC 12 and the top plate 33.

As shown in FIG. 7, a part of the bottom of the frame 21 may be L-shaped, and a part of the bottom plate 31 of the holding portion 17 may be L-shaped. 7 is a cross-sectional view showing an example of the surface light source device 1 of the first embodiment. FIG. 7 shows a part of the surface light source device 1 of the first embodiment. In the example of FIG. 7, the penetration of the bottom plate 31 Around the hole 34, an L-curved portion 37 is provided on the front end 35 side of the bottom plate 31. In the example of FIG. 7, an L-curved portion 46 is provided at the bottom of the frame 21 so as to be adjacent to the protrusion 41 of the frame 21. The L-curved portion 46 of the frame 21 is inserted into the through hole 34 of the bottom plate 31, and a part of the L-curved portion 46 of the frame 21 protrudes from the through hole 34 of the bottom plate 31. When the protruding portion 41 and the L-curved portion 46 of the bezel 21 are inserted into the through-hole 34 of the bottom plate 31, part of the protruding portion 41 and the L-curved portion 46 of the bezel 21 protrude from the through-hole 34 of the bottom plate 31. As a result, the protruding portion 41 of the frame 21 is fitted into the through hole 34 of the bottom plate 31. The L-curved portion 37 of the bottom plate 31 abuts the L-curved portion 46 of the frame 21 to restrict the horizontal movement of the bottom plate 31. Thereby, the positional deviation of the holding portion 17 is suppressed, and the holding portion 17 is suppressed from being detached from the surface light source device 1. Since the L-curved portion 37 of the bottom plate 31 is in surface contact with the L-curved portion 46 of the frame 21, the fitting of the protruding portion 41 of the frame 21 and the through-hole 34 of the bottom plate 31 becomes firm. In addition, the L-curved portion 46 of the bezel 21 closes the hole surrounded by the side wall 44 of the protruding portion 41 and the flat plate 45. It is not limited to the example of FIG. 7, and the L-curved portion 46 at the bottom of the frame 21 may be omitted. In this case, since the L-curved portion 37 of the bottom plate 31 is in line contact with the protruding portion 41 of the frame 21, the fitting of the protruding portion 41 of the frame 21 and the through-hole 34 of the bottom plate 31 becomes firm. It is not limited to the example of FIG. 7, and the L-curved portion 37 of the bottom plate 31 may be omitted. In this case, since the outer peripheral portion of the through-hole 34 of the bottom plate 31 is in line contact with the L-curved portion 46 of the frame 21, the fitting of the protrusion 41 of the frame 21 and the through-hole 34 of the bottom plate 31 becomes firm.

In the surface light source device 1 of the first embodiment, a resin frame may be erected on the outer periphery of the bottom of the frame 21 and the resin frame abuts on the width side of the top plate 33 Towards both ends. In addition, a metal frame may be erected on the outer periphery of the bottom of the frame 21, and the metal frame abuts on both ends in the width direction of the top plate 33. The both ends of the top plate 33 in the width direction abut the resin frame or the metal frame to restrict the movement of the top plate 33 in the width direction. Thereby, the positional deviation of the holding portion 17 is suppressed, and the holding portion 17 is suppressed from being detached from the surface light source device 1.

8A is a perspective view of the holding portion 17 of the first embodiment. In the example of FIG. 8A, the bottom plate 31 of the holding portion 17 has a plurality of through holes 34. As shown in FIG. 8A, the bottom plate 31 may have positioning holes 38. In addition, the bezel 21 may have a positioning protrusion. The holding portion 17 can be positioned relative to the frame 21 using the positioning protrusions of the frame 21 and the positioning holes 38 of the bottom plate 31. The width W1 of the bottom plate 31 is, for example, 50 mm or more and 60 mm or less, but it is not limited to this range. The width W2 of the top plate 33 is, for example, 70 mm or more and 80 mm or less, but it is not limited to this range.

8B and 8C are cross-sectional views of the holding portion 17 of the first embodiment. In the example of FIG. 8B, the front end 35 of the bottom plate 31 and the front end 36 of the top plate 33 of the holding portion 17 are bent by hemming. In the example of FIG. 8C, the front end 35 of the bottom plate 31 and the front end 36 of the top plate 33 of the holding portion 17 are bent by bending, and around the through-hole 34 of the bottom plate 31 of the holding portion 17, on the bottom plate 31 The L-curved portion 37 is provided on the front end 35 side. The length L1 of the bottom plate 31 is, for example, 4 mm or more and 5 mm or less, but it is not limited to this range. The length L2 of the top plate 33 is, for example, 2 mm or more and 3 mm or less, but it is not limited to this range. The length L3 of the bent portion of the front end 35 of the bottom plate 31 is, for example, 0.5 mm or less, but not Limited to this value. The length L4 of the bent portion of the front end 36 of the top plate 33 is, for example, 0.5 mm or less, but it is not limited to this value. The height T1 of the side wall 32 shown in FIGS. 8B and 8C is, for example, 0.8 mm or more and 1 mm or less, but it is not limited to this range. The inner angle of the bottom plate 31 and the side wall 32 is, for example, 90°, but it is not limited to this value. The inner angle of the side wall 32 and the top plate 33 is less than 90°, for example, 85°, but it is not limited to this value.

9A to 9C, a method of attaching the holding portion 17 to the surface light source device 1 will be described. First, as shown in FIG. 9A, the top plate 33 is raised in the vertical direction of the top plate 33, thereby increasing the inner angle of the side wall 32 and the top plate 33 and expanding the opening of the holding portion 17. Next, as shown in FIG. 9B, with the top plate 33 raised, the surface light source device 1 is arranged so as to face the opening of the holding portion 17, and then the surface light source device 1 is slid in the parallel direction to make the surface light source The device 1 enters between the bottom plate 31 and the top plate 33. When the raised state of the top plate 33 is released, the inner angle of the side wall 32 and the top plate 33 becomes smaller due to the restoring force of the holding portion 17, and the opening of the holding portion 17 becomes narrower. As shown in FIG. 9C, the surface light source device 1 enters between the bottom plate 31 and the top plate 33, and the protrusion 41 of the frame 21 is fitted into the through hole 34 of the bottom plate 31.

10 is a cross-sectional view of the liquid crystal display device of the first embodiment. The liquid crystal display device includes: a surface light source device 1 and a display panel 2. The display panel 2 has an upper glass 71 and a lower glass 72. In addition, the display panel 2 includes a lower polarizing plate and an upper polarizing plate (not shown). The display panel 2 is fixed to the light-shielding double-sided tape 18. The surface light source device 1 and the display panel 2 are connected by the main FPC 73. The main FPC 73 is fixed to the surface light source device 1 and the display panel 2 by a double-sided adhesive tape. Set in the main FPC 73 Driver Integrated Circuit (IC) 74. The driver IC 74 controls the display panel 2. The main FPC 73 is bent 180 degrees and attached to the protrusion 41 of the bezel 21. In the example of FIG. 10, the driver IC 74 is arranged between the bezel 21 and the main FPC 73 and in the plane direction of the holding portion 17. It is not limited to the example of FIG. 10, and the driver IC 74 may be provided on the display panel 2.

The main FPC 73 has high resilience, so the display panel 2 is stretched in the normal direction of the light exit surface 10B of the light guide plate 10. Therefore, the light-shielding double-sided tape 18 is stretched toward the display panel 2 side. The light-shielding double-sided tape 18 is attached to the top plate 33, and the top plate 33 is fixed to the light-shielding double-sided tape 18. When the light-shielding double-sided tape 18 is stretched toward the display panel 2 side, the top plate 33 is stretched toward the display panel 2 side. The top plate 33 is in contact with the FPC 12, but the top plate 33 is not fixed to the FPC 12. Therefore, even when the light-shielding double-sided tape 18 is stretched toward the display panel 2 side, no stress is applied to the double-sided adhesive tape 15 and the double-sided adhesive tape 16. According to the surface light source device 1 of the first embodiment, peeling of the FPC 12 from the light guide plate 10 is suppressed, and peeling of the FPC 12 from the resin frame 22 is suppressed. Since the top plate 33 covers the FPC 12, when a force is applied to the surface light source device 1 from the outside, the stress applied to the light source 11 or the FPC 12 can be reduced. By reducing the stress applied to the light source 11, the positional deviation of the light source 11 is suppressed, thereby suppressing the decrease in the brightness of the light emitted from the light guide plate 10 and the uneven distribution of the brightness of the light. By reducing the stress applied to the FPC 12, the peeling of the FPC 12 from the light guide plate 10 is suppressed, and the peeling of the FPC 12 from the resin frame 22 is suppressed. By suppressing the separation of the FPC 12 from the light guide plate 10 and the positional deviation of the light source 11, the decrease in the brightness of the light emitted from the light guide plate 10 and the uneven distribution of the brightness of the light are suppressed. By suppressing the peeling of the FPC 12 from the resin frame 22, to Light leakage to the outside of the surface light source device 1 is suppressed.

<Second Embodiment>

The second embodiment will be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same symbols as in the first embodiment, and their descriptions are omitted. 11 is a cross-sectional view showing an example of the surface light source device 1 of the second embodiment. FIG. 11 shows a part of the surface light source device 1 of the second embodiment. The surface light source device 1 includes a light guide plate 10, a light source 11, an FPC 12, a reflective sheet 13, a frame 14, a double-sided adhesive tape 15, a double-sided adhesive tape 16, a holding portion 17, a light-shielding double-sided tape 18, and a diffusion sheet 19. One piece or two pieces of lozenges 20 and spacers 52.

The bottom of the bezel 21 has a protrusion 47 that protrudes away from the light guide plate 10. The bottom plate 31 has a through hole 34, and the protruding portion 47 of the frame 21 is fitted into the through hole 34 of the bottom plate 31. The number of through holes 34 may be one or a plurality. The number of protrusions 47 may be one or more. When the protruding portion 47 of the bezel 21 is inserted into the through hole 34 of the bottom plate 31, the protruding portion 47 of the bezel 21 does not protrude from the through hole 34 of the bottom plate 31, but is accommodated in the through hole 34 of the bottom plate 31. As a result, the protruding portion 47 of the frame 21 is fitted into the through hole 34 of the bottom plate 31. The outer peripheral portion of the through-hole 34 of the bottom plate 31 abuts the protruding portion 47 of the frame 21 to restrict the horizontal movement of the holding portion 17. Thereby, the positional deviation of the holding portion 17 is suppressed, and the holding portion 17 is suppressed from being detached from the surface light source device 1.

When the protruding portion 47 of the bezel 21 is accommodated in the through hole 34 of the bottom plate 31, there is no step difference between the bottom plate 31 and the protruding portion 47 of the bezel 21. That is, the outer surface of the bottom plate 31 and the top surface of the protruding portion 47 of the frame 21 may be located on the same surface. Since there is no step difference between the bottom plate 31 and the protruding portion 47 of the bezel 21, when force is applied to the surface light source device 1 from the outside, the stress generated in the surface light source device 1 can be dispersed to reduce the application to the double-sided adhesive tape 15. Stress of double-sided adhesive tape 16. The outer surface of the bottom plate 31 is the surface of the bottom plate 31 opposite to the facing surface of the top plate 33. In addition, when the protruding portion 47 of the frame 21 is accommodated in the through hole 34 of the bottom plate 31, the protruding portion 47 of the frame 21 is more recessed than the bottom plate 31, whereby the protruding portion 47 of the bottom plate 31 and the frame 21 There is a step difference.

The bottom of the bezel 21 has a protrusion 48 that protrudes away from the light guide plate 10. The protruding portion 48 is arranged closer to the center of the bezel 21 than the protruding portion 47. The protrusion 48 is arranged in the normal direction of the lower surface of the light guide plate 10 and below the light guide plate 10. There can be no step difference between the bottom plate 31 and the protrusion 48 of the frame 21. That is, the outer surface of the bottom plate 31 may be on the same plane as the top surface of the protruding portion 48 of the frame 21. Since there is no step difference between the bottom plate 31 and the protruding portion 48 of the bezel 21, when force is applied to the surface light source device 1 from the outside, the stress generated in the surface light source device 1 can be dispersed to reduce the application to the double-sided adhesive tape 15. Stress of double-sided adhesive tape 16. A space is formed inside the protrusion 48, and a spacer 52 is provided in the space inside the protrusion 48. Therefore, the spacer 52 is arranged between the light guide plate 10 and the protruding portion 48. When the reflection sheet 13 is arranged on the lower surface side of the light guide plate 10, the reflection sheet 13 and the spacer 52 are arranged between the light guide plate 10 and the protruding portion 48. The spacer 52 is a base material such as polyethylene terephthalate (PET) or a thermally conductive member such as graphite sheet. When the spacer 52 is a heat conduction member, the heat generated by the light source 11 can be diffused in the horizontal direction of the surface light source device 1, thereby improving the surface area The heat dissipation of the light source device 1.

In the surface light source device 1 of the second embodiment, a resin frame may be erected on the outer periphery of the bottom of the frame 21, and the resin frame abuts on both ends in the width direction of the top plate 33. In addition, a metal frame may be erected on the outer periphery of the bottom of the frame 21, and the metal frame abuts on both ends in the width direction of the top plate 33. The both ends of the top plate 33 in the width direction abut the resin frame or the metal frame to restrict the movement of the top plate 33 in the width direction. Thereby, the positional deviation of the holding portion 17 is suppressed, and the holding portion 17 is suppressed from being detached from the surface light source device 1.

According to the surface light source device 1 of the second embodiment, peeling of the FPC 12 from the light guide plate 10 is suppressed, and peeling of the FPC 12 from the resin frame 22 is suppressed. Since the top plate 33 covers the FPC 12, when a force is applied to the surface light source device 1 from the outside, the stress applied to the light source 11 or the FPC 12 can be reduced.

Furthermore, such a display device can be mounted on various electronic devices. Examples of electronic devices equipped with such display devices include smartphones, digital cameras, tablet terminals, e-books, wearable devices, navigation devices, electronic dictionaries, and electronic advertising boards. It is expected that such an electronic device can provide an excellent quality display on the basis of miniaturization and thinning.

1‧‧‧Surface light source device

10‧‧‧Light guide plate

10A‧‧‧Into the light

10B‧‧‧Glossy

11‧‧‧Light source

12‧‧‧FPC

13‧‧‧Reflective film

14‧‧‧frame

15, 16‧‧‧ Double-sided adhesive tape

17‧‧‧Maintaining Department

18‧‧‧Double-sided tape

21‧‧‧Border

22‧‧‧Resin frame

31‧‧‧Bottom plate

32‧‧‧Side wall

33‧‧‧Top plate

Claims (7)

A surface light source device, comprising: a holding part, a bottom plate, a side wall standing on the bottom plate, and a top plate provided on the side wall and facing the bottom plate; a light source is arranged between the bottom plate and the top plate , With a light-emitting surface that emits light; a light guide plate that has a light-incident surface on the side facing the light-emitting surface and where light is incident, and light that is incident from the light-incident surface is emitted from the light-emitting surface; a frame that houses the A light source and the light guide plate; a wiring board, disposed between the top plate and the light source, and fixed to the light guide plate and the frame; and a light-shielding tape, fixed to the top plate and the bottom plate The opposite surface of the opposing surface, wherein the frame body has a protruding portion protruding in a direction away from the light guide plate, and the protruding portion is fitted into a through hole provided in the bottom plate. The surface light source device according to item 1 of the patent application, wherein the protruding portion is accommodated in the through hole. The surface light source device according to the first or second patent application scope, wherein the front end of the top plate and the front end of the bottom plate are bent by hemming. The surface light source device as described in item 1 or item 2 of the patent application scope includes: A buffer member disposed between the top plate and the wiring board. The surface light source device according to claim 1 or claim 2, wherein the wiring board is fixed to the light guide plate and the frame by an adhesive tape. A display device comprising: the surface light source device according to any one of claims 1 to 5; and a display panel that receives light emitted from the surface light source device, and the display panel is It is fixed to the shading tape. An electronic device including the display device described in item 6 of the patent application scope.

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