JP6638439B2 - Surface light source device, display device, and electronic device - Google Patents

Description

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

  In recent years, electronic devices have been reduced in size and thickness. There is a need for a liquid crystal display device mounted on such an electronic device to have a narrower frame and a thinner thickness in order to obtain a larger display area with the same area. As a backlight of a display panel, for example, an LED (Light Emitting Diode) package emitting white light is used as a light source, and a side light type (also called an edge light type) surface light source using a light guide plate (also called a light guide) is used. The device is used. In connection with the above technology, there has been proposed a liquid crystal display device in which a liquid crystal panel is disposed on an upper surface of a frame via a cushion tape to prevent deformation of the liquid crystal panel (see Patent Document 1).

JP 2012-198434 A

  FIG. 11 is a partial sectional view of a conventional liquid crystal display device. An LCD (Liquid Crystal Display) 102 is arranged on a backlight (surface light source device) 101, and a touch panel 103 is arranged on the LCD 102. The panel including the LCDs 102 and 103 is called a display panel. The touch panel 103 is a panel formed by integrally forming a transparent conductive film as a touch sensor on a cover glass. The backlight 101 includes a light guide plate 110, a light source 111, a flexible printed circuit board 112, a frame 113, a reflection sheet 114, an FPC fixing tape 115, a diffusion sheet 116, a prism sheet 117, and a light-shielding double-sided tape 118.

  In order to prevent the end of the LCD 102 from being damaged by the collision of the end of the LCD 102 with the cover glass of the touch panel 103, a cushion material 120 is arranged on the end of the LCD 102. With the demand for a thinner liquid crystal display device, the LCD 102 is becoming thinner. As the thickness of the LCD 102 decreases, the strength of the LCD 102 decreases. For example, an external force may be applied to the backlight 101 to push up the end portion of the light guide plate 110 or the light source 111, thereby applying a stress from the backlight 101 side to the LCD 102 side. When the strength of the LCD 102 decreases, the LCD 102 may be damaged by stress from the backlight 101 side to the LCD 102 side.

  In view of such a situation, an object of the present invention is to provide a technique for reducing stress from the surface light source device side to the display panel side.

In the present invention, the following means are employed in order to solve the above problems. That is, the present invention has a light incident surface on which light enters, and a light guide plate that emits light incident from the light incident surface from the light exit surface, and faces the light incident surface of the light guide plate. The arranged light source, a light shielding member arranged on the light exit surface side of the light guide plate, and covering a part of the light guide plate and at least a part of the light source, and a buffer member arranged in contact with the light shield member, It is a surface light source device characterized by having. According to the present invention, an external force is applied to the surface light source device, the ends of the light guide plate and the light source are pushed up, and stress is applied from the surface light source device side to the display panel side arranged on the surface light source device. Even if it is, the stress from the surface light source device side to the display panel side can be reduced.

  Further, the surface light source device according to the present invention may have the following features. A wiring board disposed on the light source, wherein the buffer member is disposed between the light blocking member and the wiring board. According to the present invention, the stress from the surface light source device side to the display panel side can be reduced by disposing the buffer member between the light shielding member and the wiring board.

  Further, the surface light source device according to the present invention may have the following features. A light-shielding member, wherein the first surface of the light-shielding member is in contact with the wiring substrate, and the buffer member is arranged on a second surface of the light-shielding member opposite to the first surface. That you are. According to the present invention, the first surface of the light shielding member comes into contact with the wiring board arranged on the light source, and the buffer member is arranged on the second surface of the light shielding member. Stress can be reduced.

  Further, the surface light source device according to the present invention may have the following features. The buffer member has a notch portion that is recessed in a direction perpendicular to the longitudinal direction of the buffer member when viewed from the normal direction of the light exit surface of the light guide plate. According to the present invention, the amount of expansion and contraction of the buffer member due to a temperature change is reduced, and the durability of the buffer member can be improved. Further, according to the present invention, even if the cushioning member expands and contracts due to a temperature change, the shape of the concave portion of the cushioning member changes, thereby suppressing the overall dimensional change of the cushioning member and preventing the cushioning member from peeling off. Be deterred.

  The display device according to the present invention includes the surface light source device according to the present invention and a first polarizing plate, a first glass plate, a second glass plate, and a second polarizing plate that are sequentially arranged from the light exit surface side of the light guide plate. A light-shielding member having a frame shape covering an outer peripheral portion of the light-emitting surface of the light guide plate, wherein the first polarizing plate is disposed inside a frame portion of the light-shielding member. It is characterized by. According to the present invention, by arranging the first polarizing plate inside the frame portion of the light-shielding member, the light-shielding member does not intervene between the light guide plate and the display panel, whereby the thickness of the display device can be reduced. it can.

  The display device according to the present invention includes the surface light source device according to the present invention and a first polarizing plate, a first glass plate, a second glass plate, and a second polarizing plate that are sequentially arranged from the light exit surface side of the light guide plate. Wherein the buffer member is disposed between the light blocking member and the display panel. According to the present invention, the stress from the surface light source device side to the display panel side can be reduced by disposing the buffer member between the light shielding member and the display panel.

  Further, the display device according to the present invention may have the following features. The light blocking member contacts the buffer member and the first polarizing plate, and a height of a position of a contact surface between the light blocking member and the buffer member, and a position of a contact surface between the light blocking member and the first polarizing plate. That the height is the same. According to the present invention, the height of the position of the contact surface between the light-shielding member and the buffer member is made equal to the height of the position of the contact surface between the light-shielding member and the first polarizing plate, so that the light-shielding member is in a flat state. can do. When the light shielding member is in a flat state, the adhesion between the light shielding member and the buffer member can be improved, and the adhesion between the light shielding member and the first polarizing plate can be improved.

  Further, the display device according to the present invention may have the following features. An end of the buffer member and an end of the second glass plate overlap in a plan view as viewed from a normal direction of the light exit surface of the light guide plate. According to the present invention, the first glass plate and the second glass plate are overlapped with each other by overlapping the end portion of the buffer member and the end portion of the second glass plate in a plan view seen from the normal direction of the light exit surface of the light guide plate. The stress applied to the contact portion with the end of the glass plate can be further reduced.

Further, an electronic device according to the present invention includes the display device according to the present invention. Since such an electronic device includes the surface light source device and the display device according to the present invention, it is possible to provide an electronic device in which stress from the surface light source device side to the display panel side is reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which reduces the stress from a surface light source device side to a display panel side can be provided.

FIG. 1 is a perspective view illustrating the configuration of the liquid crystal display device according to the first embodiment. FIG. 2 is a partial cross-sectional view of the liquid crystal display device according to the first embodiment. FIG. 3 is a configuration diagram of the light-shielding double-sided tape and the cushion material according to the first embodiment. FIG. 4 is a plan view of the cushion material according to the first embodiment. FIG. 5 is a partial cross-sectional view of the liquid crystal display device according to the first embodiment. FIG. 6 is a partial cross-sectional view of the liquid crystal display device according to the first embodiment. FIG. 7 is a partial cross-sectional view of the liquid crystal display device according to the second embodiment. FIG. 8 is a configuration diagram of a light-shielding double-sided tape and a cushion material according to the second embodiment. FIG. 9 is a partial cross-sectional view of the liquid crystal display device according to the second embodiment. FIG. 10 is a partial cross-sectional view of the liquid crystal display device according to the second embodiment. FIG. 11 is a partial sectional view of a conventional liquid crystal display device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiment described below shows an example of practicing the present invention, and does not limit the present invention to a specific configuration described below.

  In the following embodiments, the “display device” is described as a liquid crystal display device, and the “surface light source device” is described as a backlight of the liquid crystal display device. The “surface light source device” may be used for applications other than a backlight, such as a front light disposed on the front of a display device such as a display panel or electronic paper.

[Embodiment 1]
The liquid crystal display device according to the first embodiment will be described with reference to FIGS.
(Configuration of liquid crystal display device)
FIG. 1 is a perspective view illustrating the configuration of the liquid crystal display device according to the first embodiment. As shown in FIG. 1, the liquid crystal display device includes a surface light source device 1 arranged as a backlight, and a display panel 2 receiving light emitted from the surface light source device 1. The display panel 2 is a display panel that displays an image by applying a voltage to liquid crystal enclosed between glass plates to increase or decrease the light transmittance. Hereinafter, in the surface light source device 1, the display panel 2 side may be referred to as an upper surface side, and the opposite surface side may be referred to as a lower surface side.

  FIG. 2 is a partial cross-sectional view of the liquid crystal display device according to the first embodiment. The surface light source device 1 includes a light guide plate 10, a light source 11, a flexible printed circuit board (hereinafter also referred to as "FPC") 12, a frame 13, a reflection sheet 14, an FPC fixing tape 15, a diffusion sheet 16, a prism sheet 17, and light-shielding double sides. A tape 18 and a cushion material 19 are provided. The display panel 2 includes a liquid crystal display (hereinafter, also referred to as “LCD”) 20, a touch panel 21, a cushion material 22, and an optical adhesive sheet 23.

The light guide plate 10 has a substantially flat shape and is formed of a light-transmitting material such as a polycarbonate resin or a polymethyl methacrylate resin. The light guide plate 10 includes a light guide plate main body 10A and a light introducing portion 10B.
And a light introducing section 10B is integrally formed at an end of the light guide plate main body 10A. The light guide plate 10 (light introduction part 10B) has a light incident surface 10C on which light is incident. The light guide plate 10 has a light incident surface 10C on the side, and the light incident surface 10C is a part of a side surface of the light guide plate 10. The light guide plate 10 has a light exit surface for emitting light incident from the light entrance surface 10 </ b> C, and the light exit surface of the light guide plate 10 faces the display panel 2. Further, the light exit surface of the light guide plate 10 may be the upper surface of the light guide plate 10, and the surface opposite to the light exit surface of the light guide plate 10 (the opposite surface) may be the lower surface of the light guide plate 10.

  The light guide plate main body 10A has a smaller thickness than the light introduction part 10B, and is continuous with the light introduction part 10B. The light introducing portion 10B has a tapered shape in which an inclined surface that is inclined from the vicinity of the light incident surface 10C toward the light guide plate main body 10A is formed. The thickness of the end face of the light introducing portion 10B, that is, the light incident surface 10C of the light guide plate 10 is equal to or greater than the height of the light exit window of the light source 11. As a result, the light emitted from the light source 11 efficiently enters the light guide plate main body 10A from the light incident surface 10C of the light guide plate 10, and the light use efficiency of the light guide plate 10 is improved. However, the shape of the light guide plate 10 is not limited to the shape of the light guide plate 10 shown in FIG. 2, and the light guide plate 10 may have a flat plate shape without the light introducing portion 10B.

  The light source 11 emits white light from the fluorescent part. The light source 11 is, for example, an LED package, but a light source other than the LED package may be used. The light source 11 is formed by sealing an LED chip as a light emitting element with a translucent resin (resin layer) containing a phosphor. The light source 11 is driven by being supplied with power from the FPC 12. Note that an LED light source other than white may be used as the light source 11. The light source 11 is arranged to face the light incident surface 10 </ b> C of the light guide plate 10. The FPC 12 is configured such that wiring is provided by a conductive foil on a base material that is a flexible insulating film, and a coverlay or resin (photosensitive resin) that is a protective insulating film is adhered to the surface. Wiring board. A plurality of light sources 11 are mounted on the FPC 12 at regular intervals in a line. The FPC 12 is arranged on the light source 11.

  The frame 13 is a frame-shaped member having an opening and having four sides. The frame 13 is formed of a polycarbonate resin containing titanium oxide or a polycarbonate resin not containing titanium oxide. The light guide plate 10 is fitted into the frame 13, and the inner peripheral surface of the frame 13 surrounds the side surface forming the outer peripheral surface of the light guide plate 10. The frame 13 has a high reflectance, and reflects light so that light in the light guide plate 10 does not leak from the outer peripheral surface of the light guide plate 10.

  The reflection sheet 14 is arranged so as to be in contact with the lower surface of the light guide plate 10. The reflection sheet 14 is a high-reflection film having a multilayer structure or a smooth sheet made of a high-reflectance white resin sheet or a metal foil, so that light in the light guide plate 10 does not leak from the lower surface of the light guide plate 10. Reflects light. The FPC fixing tape 15 is disposed on the lower surface of the FPC 12, fixes the light guide plate 10 and the FPC 12, and fixes the FPC 12 and the frame 13. The lower surface of the FPC 12 faces the light exit surface of the light guide plate 10.

  A diffusion sheet 16 and one or two prism sheets 17 are arranged on the light guide plate 10. The diffusion sheet 16 is disposed on the light exit surface of the light guide plate 10. The diffusion sheet 16 is a translucent resin film, and diffuses the light emitted from the light exit surface of the light guide plate 10 to expand the directivity of the light. The prism sheet 17 is arranged on the upper surface of the diffusion sheet 16. The upper surface of the diffusion sheet 16 faces the display panel 2. The prism sheet 17 is a transparent resin film having a triangular prism-shaped fine pattern formed on the upper surface, condenses the light diffused by the diffusion sheet 16, and has a luminance when the surface light source device 1 is viewed from the upper surface side. To rise. The diffusion sheet 16 and the prism sheet 17 are examples of an optical sheet.

The light-shielding double-sided tape 18 is a black adhesive tape in which both upper and lower surfaces are adhesive surfaces, and is an example of a light-shielding member. The light-shielding double-sided tape 18 is disposed above the light guide plate 10 and on the light exit surface side of the light guide plate 10, and covers a part of the light guide plate 10 and at least a part of the light source 11. That is, the light-shielding double-sided tape 18 covers a part of the light exit surface of the light guide plate 10 and covers the upper surface of the light source 11. The upper surface of the light source 11 faces the display panel 2. The light-shielding double-sided tape 18 has a frame shape that covers the outer peripheral portion of the light output surface of the light guide plate 10 in a plan view when viewed from the normal direction of the light output surface of the light guide plate 10. The frame shape may be a closed loop shape, and may be, for example, a rectangular shape, a substantially elliptical shape, or any other shape. The frame portion of the light-shielding double-sided tape 18 is adhered along the upper end of the frame 13 to suppress light from leaking from the surface light source device 1.

  The cushion member 19 is a sheet-like cushioning member. The cushion material 19 is arranged in contact with the light-shielding double-sided tape 18. The cushion 19 is disposed between the FPC 12 and the light-shielding double-sided tape 18, and the cushion 19 is in contact with the upper surface of the FPC 12 and the lower surface of the light-shielding double-sided tape 18. The upper surface of the FPC 12 and the upper surface of the light-shielding double-sided tape 18 face the display panel 2. The lower surface of the light-shielding double-sided tape 18 is a surface opposite to the upper surface of the light-shielding double-sided tape 18 and faces the light exit surface of the light guide plate 10.

  FIG. 3 is a configuration diagram of the light-shielding double-sided tape 18 and the cushion member 19 according to the first embodiment. The light-shielding double-sided tape 18 uses, for example, a PET (polyethylene terephthalate) material as a base material 31, and adhesive materials 32 and 33 are formed on both surfaces of the base material 31, respectively. For the cushioning material 19, for example, an acrylic material or a urethane material is used as the base material 34, and an adhesive 35 is formed on one surface of the base material 34. Since the adhesives 32 and 33 are formed on both sides of the base 31 of the light-shielding double-sided tape 18, the adhesive 35 is formed on one side of the base 34 of the cushioning material 19. Therefore, the light-shielding double-sided tape 18 and the cushion 19 are adhered by the adhesive 32 of the light-shielding double-sided tape 18, and the FPC 12 and the cushion 19 are adhered by the adhesive 35 of the cushion 19.

  The LCD 20 is disposed above the light guide plate 10 and on the light exit surface side of the light guide plate 10. The LCD 20 includes a lower polarizing plate (first polarizing plate) 24A, a lower glass plate (first glass plate) 25A, an upper glass plate (second glass plate) 25B, and an upper polarizing plate (first polarizing plate) 25A, which are arranged in this order from the light exit surface side of the light guide plate 10. It has a polarizing plate (second polarizing plate) 24B. Liquid crystal (not shown) is sealed between the lower glass plate 25A and the upper glass plate 25B. Further, transparent electrodes (not shown) are formed on the lower glass plate 25A and the upper glass plate 25B. The lower polarizing plate 24A and the upper polarizing plate 24B are arranged so as to sandwich the lower glass plate 25A and the upper glass plate 25B.

  In the first embodiment, a cushion member 19 is disposed above the end of the light guide plate 10 and between the FPC 12 and the light-shielding double-sided tape 18. Further, a cushion member 19 is disposed above the light source 11 and between the FPC 12 and the light-shielding double-sided tape 18. Therefore, even when an external force is applied to the surface light source device 1 and the end portion of the light guide plate 10 and the light source 11 are pushed up toward the display panel 2, the surface light source device 1 moves to the display panel 2 side. The generated stress is absorbed by the cushion material 19. As a result, the stress applied to the lower glass 25A of the LCD 20 is reduced, and the damage to the lower glass 25A of the LCD 20 is suppressed.

4A and 4B are plan views of the cushion material 19 according to the first embodiment, and show a state where the cushion material 19 is arranged on the FPC 12. FIG. As shown in FIG. 4A, a cushioning material 19 may be arranged on the FPC 12 so as to cover the FPC 12. Further, in consideration of the influence of the expansion and contraction of the cushion material 19 due to the temperature change, as shown in FIG. 4B, the cushion material 19 is viewed from above in the normal direction of the light exit surface of the light guide plate 10. , The cushion member 19 may have a cutout portion 19A that is recessed in a direction orthogonal to the longitudinal direction. Therefore, the outer portion of the cushion material 19 has a concave portion. At least one notch portion 19 </ b> A may be provided for the cushion material 19, or a plurality of notch portions 1 may be provided for the cushion material 19.
9A may be provided. As shown in FIG. 4B, the dimension of the linear portion in the outer portion of the cushion material 19 is small. Therefore, the amount of expansion and contraction of the cushion material 19 due to a temperature change is reduced, and the durability of the cushion material 19 is improved. Further, even if the cushion material 19 expands and contracts due to a temperature change, the shape of each concave portion of the cushion material 19 is deformed, so that the overall dimensional change of the cushion material 19 is suppressed, and peeling of the cushion material 19 is suppressed. Is done.

  The touch panel 21 detects, for example, a contact operation by a user. The touch panel 21 is a panel integrally formed by forming a transparent conductive film as a touch sensor on a cover glass. As the touch panel 21, for example, a resistance film type panel, a capacitance type panel, an optical detection type panel, or the like is used. Further, a cover glass may be used instead of the touch panel 21. In this case, an LCD 20 incorporating a touch panel is used.

  The cushion material 22 is a sheet-like cushioning member in which an acrylic material or a urethane material is used as a base material and an adhesive is formed on both surfaces of the base material. The cushion member 22 is disposed between the LCD 20 and the touch panel 21. More specifically, the cushion member 22 is disposed between the lower glass plate 25A and the touch panel 21, and is in contact with the upper surface of the lower glass plate 25A and the lower surface of the touch panel 21. By arranging the cushion material 22 between the lower glass plate 25A and the touch panel 21, a collision between the end of the lower glass plate 25A and the end of the touch panel 21 is suppressed. An IC (Integrated Circuit) not shown is arranged on the upper surface of the lower glass plate 25A. The IC controls the display panel 2 and the like. The cushion material 22 may surround the IC, or the cushion material 22 may be arranged so as to avoid the area where the IC is arranged. An optical adhesive sheet 23 is arranged between the LCD 20 and the touch panel 21. The optical adhesive sheet 23 fixes the LCD 20 and the touch panel 21.

  The structure is not limited to the example of the structure of the liquid crystal display device shown in FIG. 2, and the light-shielding double-sided tape 18 may not be arranged between the prism sheet 17 and the LCD 20, as shown in FIG. Since the light-shielding double-sided tape 18 has a frame shape, the lower polarizing plate 24A is arranged inside the frame portion of the light-shielding double-sided tape 18. Therefore, the frame portion of the light-shielding double-sided tape 18 surrounds the side surface of the lower polarizing plate 24A. In this case, the upper part of the prism sheet 17 may be in contact with the lower surface of the lower polarizing plate 24A, or the upper part of the prism sheet 17 may be in non-contact with the lower surface of the lower polarizing plate 24A. In the structural example of the liquid crystal display device shown in FIG. 5, the upper part of the prism sheet 17 is in contact with the lower surface of the lower polarizing plate 24A. The upper surface of the light-shielding double-sided tape 18 is in contact with the lower surface of the lower glass plate 25A. The lower surface of the lower glass plate 25A faces the light exit surface of the light guide plate 10. According to the structural example of the liquid crystal display device shown in FIG. 5, by disposing the lower polarizing plate 24 </ b> A inside the frame portion of the light-shielding double-sided tape 18, the light-shielding double-sided tape 18 is interposed between the prism sheet 17 and the LCD 20. Therefore, the height of the liquid crystal display device is reduced, and the thickness of the liquid crystal display device can be reduced. Further, the light-shielding double-sided tape 18 is arranged between the cushion material 19 and the LCD 20 and is not arranged between the prism sheet 17 and the LCD 20, so that the light-shielding double-sided tape 18 can be made flat (flat). it can.

As shown in FIG. 6, when viewed in a plan view from the normal direction of the light exit surface of the light guide plate 10, the end of the lower glass plate 25 </ b> A and the end of the upper glass plate 25 </ b> B are not aligned. In the above, stress is likely to be applied to a portion where the end of the upper glass plate 25B is in contact. The portion of the lower glass plate 25A where the end of the upper glass plate 25B is in contact is the portion surrounded by the thick line in FIG. As shown in FIG. 6, the end of the cushion material 19 and the end of the upper glass 25B may be overlapped in a plan view as viewed from the normal direction of the light exit surface of the light guide plate 10. Thereby, the stress applied to the portion of the lower glass plate 25A where the end of the upper glass plate 25B is in contact is further reduced, and the damage of the LCD 20 is suppressed. In the structure example of the liquid crystal display device shown in FIG. 5, similarly to the structure example of the liquid crystal display device shown in FIG. 6, the end of the cushion material 19 is viewed in a plan view from the normal direction of the light exit surface of the light guide plate 10. And the end of the upper glass 25B may be overlapped.

[Embodiment 2]
The liquid crystal display device according to the second embodiment will be described with reference to FIGS. FIG. 7 is a partial cross-sectional view of the liquid crystal display device according to the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted. In the second embodiment, as shown in FIG. 7, the cushioning material 19 is disposed between the light-shielding double-sided tape 18 and the LCD 20, and the cushioning material 19 contacts the upper surface of the light-shielding double-sided tape 18 and the lower surface of the lower glass 25A. ing. As shown in FIG. 7, the lower surface of the light-shielding double-sided tape 18 contacts the FPC 12, and the cushioning material 19 is disposed on the upper surface of the light-shielding double-sided tape 18. The lower surface of the light-shielding double-sided tape 18 faces the light exit surface of the light guide plate 10. The lower surface of the light-shielding double-sided tape 18 corresponds to the first surface of the light-shielding double-sided tape 18. The upper surface of the light-shielding double-sided tape 18 faces the display panel 2. The upper surface of the light-shielding double-sided tape 18 corresponds to a second surface opposite to the first surface of the light-shielding double-sided tape 18. As in the first embodiment, the cushion member 19 may have one or a plurality of notched portions 19A.

  FIG. 8 is a configuration diagram of the light-shielding double-sided tape 18 and the cushion material 19 according to the second embodiment. In the second embodiment, the light-shielding double-sided tape 18 and the cushioning material 19 are adhered by the adhesive 33 of the light-shielding double-sided tape 18, and the cushioning material 19 and the lower glass 25 </ b> A are adhered by the adhesive 35 of the cushioning material 19. .

  In the second embodiment, the cushioning material 19 is disposed above the end of the light guide plate 10 and between the light-shielding double-sided tape 18 and the LCD 20. A cushion member 19 is disposed above the light source 11 and between the light-shielding double-sided tape 18 and the LCD 20. Therefore, even when an external force is applied to the surface light source device 1 and the end portion of the light guide plate 10 and the light source 11 are pushed up toward the display panel 2, the surface light source device 1 moves to the display panel 2 side. The generated stress is absorbed by the cushion material 19. As a result, stress applied to the LCD 20 is reduced, and damage to the LCD 20 is suppressed.

  As shown in FIG. 9, in plan view when viewed from the normal direction of the light exit surface of the light guide plate 10, since the end of the lower glass plate 25A and the end of the upper glass plate 25B are not aligned, the lower glass plate 25A Stress is likely to be applied to a contact portion between the upper glass plate 25B and the end of the upper glass plate 25B. The contact portion between the lower glass plate 25A and the end portion of the upper glass plate 25B is a boundary portion between the lower glass plate 25A and the end portion of the upper glass plate 25B, and is a portion surrounded by a thick line in FIG. As shown in FIG. 9, the end of the cushion material 19 and the end of the upper glass 25 </ b> B may be overlapped in a plan view as viewed from the normal direction of the light exit surface of the light guide plate 10. Thereby, the stress applied to the contact portion between the lower glass plate 25A and the end of the upper glass plate 25B is further reduced, and the damage of the LCD 20 is suppressed.

  The structure is not limited to the example of the structure of the liquid crystal display device shown in FIG. 9. As shown in FIG. 10, the height of the position of the contact surface between the light-shielding double-sided tape 18 and the cushion material 19, and the light-shielding double-sided tape 18 and the lower polarizing plate 24 </ b> A May be matched with the height of the position of the contact surface. The light-shielding double-sided tape 18 contacts the cushioning material 19 and the lower polarizing plate 24A, and the thickness of the cushioning material 19 matches the thickness of the lower polarizing plate 24A. The height of the position can be matched with the height of the position of the contact surface between the light-shielding double-sided tape 18 and the lower polarizing plate 24A. The height of the position of the contact surface between the light-shielding double-sided tape 18 and the cushioning material 19 and the height of the position of the contact surface between the light-shielding double-sided tape 18 and the lower polarizing plate 24A are made to be in a flat state. (Flat). When the light-shielding double-sided tape 18 is in a flat state, the adhesion between the light-shielding double-sided tape 18 and the cushion material 19 is improved, and the adhesion between the light-shielding double-sided tape 18 and the lower polarizing plate 24A is improved.

  Depending on the dimensional tolerance of the cushioning material 19 and the dimensional tolerance of the lower polarizing plate 24A, the thickness of the cushioning material 19 and the thickness of the lower polarizing plate 24A may substantially match, or the thickness of the cushioning material 19 and the thickness of the lower polarizing plate 24A may be different. May be approximate. Therefore, the agreement between the thickness of the cushion member 19 and the thickness of the lower polarizing plate 24A includes that the thickness of the cushion member 19 substantially matches or approximates the thickness of the lower polarizing plate 24A. Therefore, to match the height of the position of the contact surface between the light-shielding double-sided tape 18 and the cushioning material 19 with the height of the position of the contact surface between the light-shielding double-sided tape 18 and the lower polarizing plate 24A is required. The height of the position of the contact surface with the material 19 and the height of the position of the contact surface between the light-shielding double-sided tape 18 and the lower polarizing plate 24A are substantially matched or approximated.

  The light-shielding double-sided tape 18 and the cushioning material 19 are adhered by the adhesive 33 of the light-shielding double-sided tape 18, and the light-shielding double-sided tape 18 and the lower polarizing plate 24A are adhered. The cushion material 19 and the lower glass 25A are adhered by the adhesive material 35 of the cushion material 19. As shown in FIG. 10, two prism sheets 17 may be arranged on the diffusion sheet 16, and the light-shielding double-sided tape 18 may be arranged between the two prism sheets 17 and the LCD 20. Further, one prism sheet 17 may be arranged on the diffusion sheet 16, and the light-shielding double-sided tape 18 may be arranged between one prism sheet 17 and the LCD 20. The upper part of the prism sheet 17 and the lower surface of the light-shielding double-sided tape 18 may be in contact, or the upper part of the prism sheet 17 and the lower surface of the light-shielding double-sided tape 18 may not be in contact.

  In the second embodiment, the light-shielding double-sided tape 18 may not be disposed between the prism sheet 17 and the LCD 20 as in the structure example of the liquid crystal display device shown in FIG. Therefore, similarly to the first embodiment, in the second embodiment, the lower polarizing plate 24A can be disposed inside the frame portion of the light-shielding double-sided tape 18. In this case, one or a plurality of prism sheets 17 may be arranged on the diffusion sheet 16. By disposing the lower polarizing plate 24A inside the frame portion of the light-shielding double-sided tape 18, the light-shielding double-sided tape 18 does not intervene between the prism sheet 17 and the LCD 20, so that the height of the liquid crystal display device is reduced, The thickness of the display device can be reduced. Further, the light-shielding double-sided tape 18 is arranged between the cushion material 19 and the LCD 20 and is not arranged between the prism sheet 17 and the LCD 20, so that the light-shielding double-sided tape 18 can be made flat (flat). it can.

  Further, such a display device can be mounted on various electronic devices. Examples of an electronic device including such a display device include a smartphone, a digital camera, a tablet terminal, an electronic book, a wearable device, a car navigation device, an electronic dictionary, and an electronic billboard. Such an electronic device can be reduced in size and thickness and can be expected to provide excellent quality display.

Reference Signs List 1 surface light source device 2 display panel 10 light guide plate 11 light source 12 FPC
13 Frame 14 Reflective sheet 15 FPC fixing tape 16 Diffusion sheet 17 Prism sheet 18 Light-shielding double-sided tape 19, 22 Cushion material 20 LCD
21 Touch Panel 23 Optical Adhesive Sheet 24A Lower Polarizer 24B Upper Polarizer 25A Lower Glass Plate 25B Upper Glass Plate 31, 34 Base Material 32, 33, 35 Adhesive

Claims (9)

A light guide plate that has a light incident surface on which light is incident on a side and emits light incident from the light incident surface from a light exit surface,
A light source disposed opposite to the light incident surface of the light guide plate,
A light-blocking member that is disposed on the light exit surface side of the light guide plate and covers at least a part of the light guide plate and at least a part of the light source.
A buffer member arranged in contact with the light shielding member,
Equipped with a,
The buffer member, said in a plan view as viewed from the normal direction of the light output surface of the light guide plate, the cushioning surface light source device according to claim Rukoto which have a longitudinal cutout portion recessed in the orthogonal direction of the member. Comprising a wiring board arranged on the light source,
The surface light source device according to claim 1, wherein the buffer member is disposed between the light blocking member and the wiring board. Comprising a wiring board arranged on the light source,
A first surface of the light blocking member contacts the wiring board,
The surface light source device according to claim 1, wherein the buffer member is disposed on a second surface of the light blocking member opposite to the first surface. A surface light source device according to any one of claims 1 to 3 ,
A display panel having a first polarizing plate, a first glass plate, a second glass plate, and a second polarizing plate arranged in order from the light exit surface side of the light guide plate;
With
The light blocking member has a frame shape that covers an outer peripheral portion of the light exit surface of the light guide plate,
The display device, wherein the first polarizing plate is disposed inside a frame portion of the light shielding member. A surface light source device according to claim 3,
A display panel having a first polarizing plate, a first glass plate, a second glass plate, and a second polarizing plate arranged in order from the light exit surface side of the light guide plate;
With
The display device, wherein the buffer member is disposed between the light blocking member and the display panel. The light blocking member contacts the buffer member and the first polarizing plate,
6. The display according to claim 5 , wherein a height of a position of a contact surface between the light shielding member and the buffer member coincides with a height of a position of a contact surface between the light shielding member and the first polarizing plate. apparatus.   A light guide plate that has a light incident surface on which light is incident on the side and emits light incident from the light incident surface from a light exit surface, and a light source arranged to face the light incident surface of the light guide plate, A light-shielding member arranged on the light-emitting surface side of the light guide plate, covering a part of the light guide plate and at least a part of the light source, and a surface light source device including a buffer member arranged in contact with the light-shielding member; ,
  A display panel having a first polarizing plate, a first glass plate, a second glass plate, and a second polarizing plate arranged in order from the light exit surface side of the light guide plate;
  With
  The light blocking member has a frame shape that covers an outer peripheral portion of the light exit surface of the light guide plate,
  The display device, wherein the first polarizing plate is disposed inside a frame portion of the light shielding member. In a plan view as viewed from the normal direction of the light exiting surface of the light guide plate, claim 4, wherein the end portion and the end portion of the second glass plate of the cushioning member is characterized in that the overlap 7 The display device according to claim 1. An electronic apparatus comprising the display device according to claim 4 .

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