WO2012067002A1 - Backlight device and liquid crystal display device provided with backlight device - Google Patents

Abstract

The backlight device (40) is provided with a plurality of point light sources (80), a flexible circuit board (30) on which the light sources are arranged, a light guide plate (50), and a chassis (70) for housing the light sources, light guide plate, and the circuit board. Housing sections (76) capable of housing the light sources are formed at positions on an inner side of the chassis so as to face the light incident surface (52) of the light guide plate when the light guide plate is housed. A plurality of first slits (34) and second slits (37) are formed respectively on the flexible circuit board. The flexible circuit board is configured so as to be deformable by the presence of the first slits and the second slits, so that the plurality of point light sources are allowed to be housed inside the housing sections while brought into close contact with the light incident surface of the light guide plate.

Description

Backlight device and liquid crystal display device including the backlight device

The present invention relates to a backlight device having a light source for irradiating a liquid crystal display panel and a liquid crystal display device including the backlight device. Specifically, the present invention relates to an edge light type backlight device including a light guide plate.
This application claims priority based on Japanese Patent Application No. 2010-257191 filed on Nov. 17, 2010, the entire contents of which are incorporated herein by reference. .

In recent years, liquid crystal display devices used as image display devices (displays) such as televisions and personal computers have been made thinner. In order to realize such a thinning, for example, an edge light in which a light guide plate is disposed on the back side of the liquid crystal display panel and a light source (for example, a light emitting diode element) is disposed at an end portion of the light guide plate (that is, the edge of the liquid crystal display panel). A type of backlight device is employed.
In such an edge light type backlight device, as one form of arranging light sources, for example, a plurality of point light sources mounted on a flexible printed circuit board (FPC) are accommodated in predetermined accommodating portions in the backlight chassis. There is something.

By the way, when the point light source is mounted and electrically connected to a predetermined position on the FPC, the light source may not be mounted accurately, and the mounting position of the light source may be displaced. For this reason, the accommodating part is made larger than the light source in consideration of the deviation of the mounting position of the light source. However, if the accommodating portion is formed larger than the light source, the light source that is not accurately mounted on the FPC among the light sources accommodated in the accommodating portion, and the end portion of the light guide plate (that is, the light incident on which light from the light source is incident). There may be a space between the surface. Since the light from the light source is a three-dimensional radiation light having a predetermined solid angle, the light passes through the space and is reflected on the light incident surface of the light guide plate, and the light is efficiently guided from the light source. There is a possibility that it cannot be transmitted into the optical plate. In order to cope with such a problem, Patent Document 1 is cited as a prior art. Patent Document 1 describes a technique for filling a light source having a refractive index higher than that of air between a light source and a light guide plate to efficiently transmit light from the light source into the light guide plate.

Japanese Patent Application Publication No. 2004-241237

However, in the technique described in Patent Document 1, although transmission of light into the light guide plate can be improved by a resin or the like, since the substance is disposed between the light source and the light guide plate, It can be difficult to make the best use of the light. In addition, in the case where a housing portion that is substantially the same size as the light source is formed, if a light source that is not accurately mounted on the FPC is housed in the housing portion, stress is applied to the connection portion between the FPC and the light source, causing a problem. There is a fear.
Therefore, the present invention has been created to solve the above-described conventional problems, and the object thereof is to accurately arrange a point light source at a predetermined position in the accommodating portion and efficiently emit light from the light source. It is an object of the present invention to provide a backlight device with excellent light efficiency that can be transmitted into a light guide plate.

In order to achieve the above object, the present invention provides a backlight device having the following configuration. That is, the backlight device of the present invention includes a plurality of point light sources, a flexible wiring board on which the plurality of point light sources are arranged, a light incident surface on which light from the point light sources is incident, and incident light. A light guide plate having a light exit surface for emitting light, and a chassis for housing the plurality of point light sources and the light guide plate. An accommodating portion capable of accommodating the point light source is formed at a position facing the light incident surface of the light guide plate when the light guide plate is accommodated inside the chassis. In the flexible wiring board, in a state where the point light source is arranged in the housing portion, a first slit extending from a side close to the light incident surface of the light guide plate toward a side facing the side, A plurality of second slits extending from the opposing sides toward the side close to the light incident surface are formed. Here, the flexible wiring board accommodates the plurality of point light sources in the accommodating portion while being in close contact with the light incident surface of the light guide plate due to the presence of the first slit and the second slit. It is configured to be deformable to allow.

The backlight device provided by the present invention includes a flexible wiring board in which a plurality of first slits and second slits are formed, and a plurality of points are formed due to the presence of the first slit and the second slit. The flexible wiring board is deformed so that the light source is housed in the housing portion in close contact with the light incident surface of the light guide plate. The deformation referred to here is a deformation that varies the opening width of the first slit and the opening width of the second slit, and the relative positional relationship between the first slit and the second slit.
According to such a configuration, the flexible wiring board can be deformed to adjust the opening width of the first slit, the opening width of the second slit, and the relative positions thereof, so that the point light source is provided on the flexible wiring board. Even if it is not mounted correctly, the chassis with the point light source in close contact with the light incident surface of the light guide plate without applying excessive stress to the connection part between the point light source and the flexible wiring board It can be accommodated in an accommodating portion formed inside. Thus, since the point light source and the light incident surface of the light guide plate are in close contact, light from the point light source can be efficiently transmitted from the light incident surface of the light guide plate into the light guide plate.
Here, it is preferable that the outer peripheral edge of the inner wall of the housing portion is chamfered to form a chamfered portion. Since the chamfered portion is formed on the outer peripheral edge of the inner wall of the housing portion as described above, the point light source can be easily housed in the housing portion when the backlight device disclosed herein is manufactured.

In one preferable aspect of the backlight device disclosed herein, the vertex of the first slit is provided on the side opposite to the vertex of the second slit, and the second slit is provided. Is provided on the side closer to the light incident surface than the vertex of the first slit.
According to such a configuration, since the opening width of the slit can be changed more flexibly, the point light source is incident on the light guide plate without applying excessive stress to the connection portion between the flexible wiring board and the point light source. The point light source can be accommodated in the accommodating portion in contact with the surface.

In another preferred aspect of the backlight device disclosed herein, at least a portion of the chassis that constitutes the housing portion is formed of an elastic resin material. In the chassis, the inner wall facing the light incident surface of the light guide plate in the housing portion is formed to be a convex surface protruding toward the light incident surface.
According to such a configuration, since the point light source has a force to push out from the convex surface of the housing portion toward the light guide plate in a state where the point light source is housed in the housing portion, the point light source and the light guide plate (that is, The close contact state with the light incident surface is further increased.

In another preferable aspect of the backlight device disclosed herein, the storage unit includes the point light source and the light incident surface of the light guide plate in a state where the point light source is stored in the storage unit. It is formed so as to be in contact with the inner wall of the housing portion facing the light incident surface.
According to such a configuration, one surface of the point light source contacts the light incident surface of the light guide plate, and the other surface of the point light source facing the surface contacts the inner wall of the housing portion. Even if it is not fixed to the chassis, the point light source does not leave the light incident surface of the light guide plate in a state where the point light source is accommodated in the accommodating portion.

In another preferred embodiment of the backlight device disclosed herein, the point light source is a light emitting diode element.
In addition, according to the present invention, a liquid crystal display device including any one of the backlight devices disclosed herein is provided. Since the liquid crystal display device includes the backlight device, it can be a liquid crystal display device with excellent light efficiency that can efficiently transmit light from the light source into the light guide plate.

FIG. 1 is an exploded perspective view schematically showing the structure of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the structure of the liquid crystal display device according to one embodiment of the present invention. FIG. 3 is a plan view schematically showing a backlight device according to an embodiment of the present invention. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a plan view schematically showing a flexible wiring board according to an embodiment of the present invention. FIG. 6 is a plan view schematically showing main parts of the backlight device according to the embodiment of the present invention. FIG. 7 is a plan view schematically showing a housing part of a backlight device according to another embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing a housing portion of a backlight device according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in the present specification and drawings and the common general technical knowledge in the field.

Hereinafter, an active matrix type (TFT type) liquid crystal display device 100 including a liquid crystal display panel 10 as a display panel according to a preferred embodiment (first embodiment) of the present invention with reference to FIGS. Will be described as an example.
In addition, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show the same effect | action, and the overlapping description may be abbreviate | omitted or simplified. In addition, the dimensional relationship (length, width, thickness, etc.) in each drawing does not necessarily accurately reflect the actual dimensional relationship. In the following description, “front side” or “front side” means a side facing the viewer (viewer) in the liquid crystal display device 100 (that is, the liquid crystal display panel 10 side), and “back side” or “back side”. Means the side of the liquid crystal display device 100 that does not face the viewer (that is, the backlight device 40 side).

First, the overall configuration of the liquid crystal display device 100 will be described. As shown in FIG. 1, the liquid crystal display device 100 includes a liquid crystal display panel 10 and a backlight device 40 that is an external light source disposed on the back side of the liquid crystal display panel 10. The liquid crystal display panel 10 and the backlight device 40 are integrally held by being assembled by a bezel (frame body) 20 or the like.

As shown in FIG. 1, the liquid crystal display panel 10 generally has a rectangular shape as a whole, and has a display area 10 </ b> A that is an area where a pixel is formed at the center and displays an image. Yes. As shown in FIG. 2, the liquid crystal display panel 10 has a sandwich structure composed of a pair of transparent glass substrates 11 and 12 facing each other and a liquid crystal layer 13 sealed therebetween. . Of the pair of substrates 11 and 12, the front side is the color filter substrate (CF substrate) 12, and the back side is the array substrate 11. A sealing material 17 is provided on the periphery of the CF substrate 12 and the array substrate 11 so as to surround the display area described above, and seals the liquid crystal layer 13. The liquid crystal layer 13 is made of a liquid crystal material containing liquid crystal molecules. In such a liquid crystal material, the alignment of liquid crystal molecules is manipulated with the application of an electric field between the array substrate 11 and the CF substrate 12, and the optical characteristics change. An alignment film (not shown) for determining the alignment direction of the liquid crystal molecules is formed on the opposite surfaces (inner side) of the substrates 11 and 12, respectively. The polarizing plates 18 and 19 are attached, respectively.

In the liquid crystal display panel 10 disclosed herein, pixels (not shown) for displaying an image are arranged on the front side (side facing the liquid crystal layer 13) of the array substrate 11, and each pixel (sub pixel) is arranged. A plurality of source wirings and gate wirings (not shown) for driving (1) are formed in a lattice pattern. In each lattice region surrounded by the wiring, a (sub) pixel electrode and a thin film transistor (TFT) as a switching element are provided. The pixel electrode is typically made of ITO (indium tin oxide), which is a transparent conductive material. A voltage corresponding to an image is supplied to these pixel electrodes through the source wiring and the thin film transistor at a predetermined timing.
On the other hand, the CF substrate 12 has one color filter (not shown) of R (red), G (green), B (blue), and Y (yellow) for one pixel electrode of the array substrate 11. ) Are facing each other. Further, the CF substrate 12 is provided with a black matrix for partitioning the color filters of the respective colors, and a counter electrode (transparent electrode) uniformly formed on the surfaces of the color filters and the black matrix.

Here, the array substrate 11 is formed so as to be larger (in area) than the CF substrate 12. When the two substrates 11 and 12 are superposed, at least one of the four sides constituting the rectangular periphery of the array substrate 11 slightly protrudes from the CF substrate 12. As shown in FIG. 1, a panel flexible wiring board (panel FPC) 90 is disposed at the protruding peripheral edge portion. The panel FPC 90 is mounted with a liquid crystal display panel driving IC chip (driver IC chip) (not shown) for driving the liquid crystal display panel 10. In the panel FPC 90 having such a configuration, one end of the panel FPC 90 is fixed to the protruding peripheral portion, so that the panel FPC 90 is connected to an electrode (the pixel electrode, the counter electrode, or the like) in the liquid crystal display panel 10. Connected. The other end of the panel FPC 90 is attached to a printed circuit board 95 in which a controller for controlling the driver IC (chip) and other electronic components are incorporated. The printed circuit board 95 is disposed on the side surface portion of the backlight device 40 (strictly, the side surface portion on the outer peripheral side of the frame 25) by being folded to the backlight device 40 side. It may be configured to be disposed on the back side of the backlight device 40.

As shown in FIG. 1 to FIG. 4, the backlight device 40 according to this embodiment disposed on the back side (back side) of the liquid crystal display panel 10 roughly includes a point light source 80 and the point light source. A light guide plate 50 that converts light from the light source 80 into planar light, a reflection sheet 60, and a chassis (also referred to as a backlight chassis or a case) 70 that accommodates these are provided. FIG. 1 shows a portion of the light source flexible wiring board 30 described later, taken along a broken line, for easy understanding of the arrangement state of the point light sources 80.
As shown in FIG. 1, the chassis 70 includes a rectangular (typically rectangular) bottom portion 72 and a frame-like side wall portion 74 formed so as to surround the bottom portion 72. The box shape is open toward the front side. As shown in FIGS. 1 and 3, a plurality of accommodating portions 76 that can accommodate the point light sources 80 are formed in a part of the side wall portion 74 of the chassis 70. More specifically, as shown in FIGS. 3 and 4, the light incident plate 52 faces the light incident surface 52 from the light incident surface 52 of the light guide plate 50 in a state in which the light guide plate 50 is disposed in (the opening portion of) the chassis 70. The accommodating portion 76 is formed so that the length to the inner wall 78 in the accommodating portion 76 is substantially the same as the length of the point light source 80 in the depth direction (the direction of the arrow X in FIGS. 3 and 4). Yes. The length of the accommodating portion 76 in the width direction (the direction of the arrow Y in FIG. 3) is formed larger than the length of the point light source 80 in the width direction in consideration of the positional deviation of the point light source 80. Further, as shown in FIG. 4, a recess 79 is formed in the vicinity of the inner wall 78 of the housing portion 76 and at a position away from the light incident surface 52 of the light guide plate 50. The light source FPC 30 described later is accommodated in the recess 79 (for example, the light source FPC 30 and the chassis 70 are fixed to each other with a double-sided tape), thereby reducing bending stress generated due to the deformation of the light source FPC 30. Can do.

The light guide plate 50 is formed by injection molding or the like into a rectangular flat plate with a size covering the display area 10A of the liquid crystal display panel 10. As shown in FIG. 4, the light guide plate 50 has a light incident surface 52 on which light from the point light source 80 is incident and a light emitting surface 54 that emits the incident light toward the liquid crystal display panel 10. . The material which comprises the light-guide plate 50 will not be restrict | limited especially if it is a material which has translucency and is excellent in a moldability. For example, an acrylic resin, a polycarbonate resin, etc. are mentioned. On the bottom surface of the light guide plate 50 (the surface on the back side and facing the reflection sheet 60), a dot pattern (not shown) is formed that scatters light and increases the light use efficiency. Such a dot pattern is formed by printing using an ink or the like that forms a reflection pattern or a diffusion pattern.
Further, as shown in FIGS. 1 and 4, in the vicinity of one of the light incident surfaces 52 of the light guide plate 50, a plurality of point light sources 80 are in the accommodating portion 76 so as to contact the light incident surface 52. It is housed and arranged. As the point light source 80, for example, a light emitting diode element (LED element) or the like can be used. The point light source 80 is covered with a reflector (reflective film) except for a portion in contact with the light incident surface 52 so that light from the light source 80 is efficiently incident on the light guide plate 50 (for example, in the accommodating portion 76). Preferably, the side walls are covered with a reflector. The point light source 80 is not limited to being disposed in the vicinity of one light incident surface 52 of the light guide plate 50 as described above, and may be disposed in the vicinity of the light incident surfaces 52 facing each other.

Next, the light source flexible wiring board 30 (light source FPC) will be described. FIG. 5 is a plan view schematically showing the light source flexible wiring board 30 according to the present embodiment.
As shown in FIGS. 3 and 5, the light source FPC 30 is formed in a band shape, and a plurality of the point light sources 80 are arranged at predetermined intervals in a portion close to the light incident surface 52 of the light guide plate 50. (Implemented) In the light source FPC 30, a side (side on the side where the point light source 80 is arranged) 33 close to the light incident surface 52 of the light guide plate 50 is changed to a side (opposite side) 36 facing the side 33. A first slit 34 that extends toward the side 33 (typically extending in a direction perpendicular to the adjacent side 33), and extends from the opposite side 36 toward the side 33 adjacent to the light incident surface 52 (typically opposite). A plurality of second slits 37 extending in a direction perpendicular to the side 36 are formed. The first slit 34 is formed at a substantially central portion between the point light source 80 and the point light source 80 from the proximity side 33 toward the opposing side 36, and the second slit 37 is a point of the opposing side 36. It is formed in such a length that it does not reach the point light source 80 from the portion facing the position where the light source 80 is disposed toward the proximity side 33. Furthermore, as shown in FIG. 5, the vertex 35 of the first slit is provided on the opposite side 36 side of the vertex 38 of the second slit, and the vertex 38 of the second slit is the vertex of the first slit. It is preferably formed so as to be provided on the side closer to the side 33 (side closer to the light incident surface 52 of the light guide plate 50) than 35. That is, it is preferable to form the first slit 34 and the second slit 37 so that a line connecting the vertex 35 of the first slit and the vertex 38 of the second slit has a zigzag shape. The first slit 34 and the second slit 37 may be V-shaped or U-shaped.

Next, an example of a state in which the point light source 80 is accommodated in the accommodating portion 76 in the backlight device 40 according to the present embodiment will be described.
A plurality of point light sources 80 are arranged in the light source FPC 30 of the present embodiment, but one point light source 80A of the point light sources 80 is a predetermined point on the light source FPC 30 as shown in FIG. It is arranged at a position shifted from the arrangement position. That is, the point light source 80 </ b> A is not disposed along the adjacent side 33, but is displaced (tilted) by a predetermined angle with respect to the adjacent side 33. However, since the plurality of first slits 34 and the second slits 37 are formed in the light source FPC 30 according to the present embodiment, the first light source FPC 30 is deformed as shown in FIG. Among the slits 34, the slit width of the first slit 34 </ b> A is narrowed to widen the slit width of the first slit 34 </ b> B, thereby moving the relative position of the point light source 80 </ b> A and the light incident surface 52 of the light guide plate 50. The point light source 80 </ b> A can be accommodated in the accommodating portion 76 in a state of being in close contact with each other. At this time, among the second slits, the slit widths of the second slits 37A and 37C are widened to narrow the slit width of the second slit 37B. The first slits 34A, 34B and the second slits 37A, 37B, 37C change the relative positional relationship, whereby the light source FPC 30 is connected at the connection portion (arrangement portion) between the point light source 80A and the light source FPC 30. It is possible to prevent an excessive stress accompanying deformation from being applied.
Therefore, the backlight device 40 according to the present embodiment has a plurality of first slits 34 and second slits 37 even when the point light source 80 is not accurately arranged on the light source FPC 30. Therefore, the point light source 80 and the light incident surface 52 of the light guide plate 50 are brought into close contact with each other without applying excessive stress to the connection portion between the point light source 80 and the light source FPC 30. In this state, the point light source 80 can be accommodated in the accommodating portion 76. Thereby, the backlight device 40 with excellent light efficiency that can efficiently transmit the light from the point light source 80 into the light guide plate 50 is realized.

In the backlight device 40 as described above, a plurality of sheet-like optical sheets 48 are laminated and disposed on the front side of the light guide plate 50 in the opening portion of the chassis 70 so as to cover the opening portion. . The configuration of the optical sheet 48 includes, for example, a diffusion plate, a diffusion sheet, a lens sheet, and a brightness enhancement sheet in order from the backlight device 40 side to the liquid crystal display panel 10 side. It is not limited to. Further, a substantially frame-like frame 25 is provided on the chassis 70 to hold the optical sheet 48 between the chassis 70. Note that an inverter circuit board (not shown) for mounting an inverter circuit and an inverter transformer (not shown) as a booster circuit for supplying power to each point light source 80 are provided on the back side of the chassis 70.

As described above, the optical sheet 48 is disposed on the front side of the backlight device 40. The frame 25 having an opening corresponding to the display area 10 </ b> A of the liquid crystal display panel 10 is mounted on the front side of the optical sheet 48 so as to sandwich the optical sheet 48 with the backlight device 40. A liquid crystal display panel 10 is placed on the front surface of the frame 25. Further, the liquid crystal display device 100 is constructed by mounting the bezel 20 on the front side of the liquid crystal display panel 10.

Next, a second embodiment will be described with reference to FIG. FIG. 7 is a plan view schematically showing the accommodating portion 176 of the backlight device 140 according to this embodiment. In FIG. 7, the light source FPC 30 and the point light source 80 are not shown in a simplified manner.
As shown in FIG. 7, a plurality of accommodating portions 176 that can accommodate the point light sources 80 (see FIG. 1) are formed in a part of the side wall portion 174 of the chassis 170. More specifically, in a state where the light guide plate 50 is disposed in the chassis 170, the inner wall 178 in the housing portion 176 that faces the light incident surface 52 of the light guide plate 50 becomes a convex surface that protrudes toward the light incident surface 52. It is formed as follows. The accommodating portion 176 is formed so that the length from the light incident surface 52 to the central portion of the convex surface of the inner wall 178 is shorter than the length of the point light source 80 in the depth direction (the direction of arrow X in FIG. 7). . In addition, as shown in FIG. 7, a space portion 179 is formed by partially removing the side wall portion 174 in the rear portion of the inner wall 178 (that is, the direction away from the light irradiation surface 52 of the side wall portion 174).
The chassis 170 according to this embodiment is formed from a resin material having elasticity. Examples of the resin material include polycarbonate. When the point light source 80 is accommodated in the accommodating portion 176, the repulsive force that the inner wall 178 (convex surface) displaced in the direction away from the light incident surface 52 (that is, the direction of narrowing the space portion 179) tries to return to the original shape. Therefore, the point light source 80 is pressed against the light incident surface 52 of the light guide plate 50 by the repulsive force. Thereby, the close contact state between the point light source 80 and the light incident surface 52 (light guide plate 50) is further increased, and the light from the point light source 80 can be efficiently transmitted into the light guide plate 50. A backlight device 140 is realized.
Note that the above-described effects are realized by a repulsive force in a portion constituting the housing portion 176 (which can include the peripheral portion of the housing portion 176), and the entire chassis 170 including the other portions is elastic. The resin material may not be formed.

Next, a third embodiment will be described with reference to FIG. It is sectional drawing which shows typically the accommodating part 276 of the backlight apparatus 240 which concerns on this embodiment.
A plurality of accommodating portions 276 that can accommodate the point light sources 80 are formed in a part of the side wall portion 274 of the chassis 270 according to the present embodiment. As shown in FIG. 8, chamfering (corner cutting) is performed on the outer peripheral edge of the inner wall 278 of the housing portion 276 to form a chamfered portion 279. The chamfered portion 279 is formed at least on the inner wall 278 in the accommodating portion 276 facing the light incident surface 52 of the light guide plate 50, and is preferably formed on the inner wall in the accommodating portion 276 orthogonal to the light incident surface 52. . By forming the chamfered portion 279 on the outer peripheral edge of the inner wall 278 in the accommodating portion 276 in this manner, the point light source 80 is accommodated in the accommodating portion 276 after the light guide plate 50 is disposed in the chassis 270. Since the light source 80 can be accommodated in the accommodating portion 276 so as to slide on the chamfered portion 279, the backlight device 240 can be easily assembled.

As mentioned above, although the specific example of this invention was demonstrated in detail, referring drawings, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, it can be suitably used as a backlight device used in a small portable game machine, a notebook computer, a mobile phone, or the like.

According to the present invention, even when the point light source is not accurately arranged (mounted) on the light source FPC, the point light source is accurately arranged at a predetermined position in the housing portion formed in the chassis. Thus, it can be brought into close contact with the light incident surface of the light guide plate. Therefore, it is possible to provide a backlight device with excellent light efficiency that can efficiently transmit light from a point light source into the light guide plate.

10 Liquid crystal display panel 10A Display area 11 Array substrate 12 Color filter substrate (CF substrate)
13 Liquid crystal layer 17 Sealing material 18, 19 Polarizing plate 20 Bezel 25 Frame 30 Light source flexible wiring board (FPC for light source)
33 Proximal sides 34, 34A, 34B First slit 35 First slit vertex 36 Opposite sides 37, 37A, 37B, 37C Second slit 38 Second slit vertex 40 Backlight device 48 Optical sheet 50 Light guide plate 52 Light entrance surface 54 Light exit surface 60 Reflective sheet 70 Chassis 72 Bottom surface portion 74 Side wall portion 76 Housing portion 78 Inner wall 79 Recess 80, 80A Point light source 90 Flexible printed circuit board for panel (FPC for panel)
95 Printed circuit board 100 Liquid crystal display device 140 Backlight device 170 Chassis 174 Side wall portion 176 Housing portion 178 Inner wall 179 Space portion 240 Backlight device 270 Chassis 274 Side wall portion 276 Housing portion 278 Inner wall 279 Chamfered portion

Claims (7)

A backlight device,
A plurality of point light sources;
A flexible wiring board on which the plurality of point light sources are arranged;
A light guide plate having a light incident surface on which light from the point light source is incident and a light emitting surface from which the incident light is emitted; and
A chassis that houses the plurality of point light sources and the light guide plate;
An accommodating portion capable of accommodating the point light source is formed at a position facing the light incident surface of the light guide plate when the light guide plate is accommodated inside the chassis,
The flexible wiring board, in a state where the point light source is arranged in the housing portion, a first slit extending from a side close to the light incident surface of the light guide plate toward a side facing the side, A plurality of second slits extending from the opposing sides to the side close to the light incident surface are formed, respectively.
Here, the flexible wiring board accommodates the plurality of point light sources in the accommodating portion in close contact with the light incident surface of the light guide plate due to the presence of the first slit and the second slit. A backlight device configured to be deformable to allow. The apex of the first slit is provided on the side opposite to the apex of the second slit, and the apex of the second slit is the light more than the apex of the first slit. The backlight device according to claim 1, wherein the backlight device is provided on a side close to the incident surface. Of the chassis, at least a portion constituting the housing portion is formed of a resin material having elasticity,
The backlight according to claim 1, wherein an inner wall facing the light incident surface of the light guide plate in the housing portion is formed to be a convex surface projecting toward the light incident surface. apparatus. The accommodating portion is formed so that the point light source contacts the light incident surface of the light guide plate and the inner wall of the accommodating portion facing the light incident surface in a state where the point light source is accommodated in the accommodating portion. The backlight device according to any one of claims 1 to 3, wherein the backlight device is provided. The backlight device according to any one of claims 1 to 4, wherein a chamfered portion is formed by chamfering the outer peripheral edge of the inner wall of the housing portion. The backlight device according to any one of claims 1 to 5, wherein the point light source is a light emitting diode element. A liquid crystal display device comprising the backlight device according to any one of claims 1 to 6.

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