JP2012128211A - Light source device and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device and a liquid crystal display device using the same, which are made more compact and thinner and in which generation of display defects due to position deviations of optical sheets is reliably suppressed.SOLUTION: On a light guide plate 71 of a plane emission radiation panel 7 disposed on the back side of a liquid crystal display panel 4, an optical sheet laminate 76 composed of three optical sheets successively stacked, which are a light diffusion sheet 761, a first prism sheet 762 and a second prism sheet 763, is disposed on a front surface 711 facing the liquid crystal display panel 4, and the end parts on the light source side of the light diffusion sheet 761 in the lowest layer of the optical sheet laminate 76 and the first prism sheet 763 in the middle layer are fixed by an extension part 751 of a first double-sided adhesive shading sheet 75 for attaching an FPC 74 for the light source, on which an LED 72 is directly installed, to the front surface 711 of the light guide plate 71.

Description

  The present invention relates to a light source device in which a reduction in size and thickness is promoted without degrading display quality and a liquid crystal display device using the same.

  In recent years, mobile electronic devices such as mobile phones and personal digital assistants (PDAs) have become widespread, and the demand for smaller and thinner devices has been increasing. Therefore, the demand for a small and thin liquid crystal display device that is frequently used as a display monitor for mobile devices is extremely severe.

  In the case of a liquid crystal display device having a backlight, in order to promote thinning, a light source is disposed on the end face of the light guide plate as a backlight, and light that is emitted from the light source, enters the light guide plate, and propagates in one of the main light sources. A side-light type surface emitting irradiation panel that emits in a planar shape from a surface is preferably used.

  The above-described liquid crystal display device has a configuration in which irradiation light emitted in a planar shape from the surface emitting irradiation panel is irradiated over a wide area that sufficiently covers the entire effective display area of the liquid crystal display panel. In general, an optical sheet is provided as a light control member on the light emitting surface of the surface emitting irradiation panel in order to make the luminance distribution of the emitted irradiation light uniform and efficiently irradiate the effective display area. In this case, usually, a light control member is configured by laminating a plurality of optical sheets such as a light diffusion sheet and a prism sheet.

  In order to further reduce the thickness, the driver chip is directly mounted on the glass substrate of the liquid crystal display panel by the COG (Chip On Glass) method, and a flexible wiring board is used as a wiring member for inputting a drive control signal to the driver chip. The flexible wiring board is folded back to the back side of the liquid crystal display device and electrically connected to the external drive control circuit board.

JP 2007-121709 A

  In the above-described liquid crystal display device, the plurality of optical sheets constituting the light control member are not bonded to each other, but are merely placed so as to be freely slidable. This is to avoid problems such as bending or wrinkling when each optical sheet expands or contracts due to a change in environmental temperature or the like.

  Therefore, when the liquid crystal display panel is lifted by the bending elastic force of the folded flexible wiring board or the liquid crystal display device is vibrated by an external force, the position of each optical sheet with respect to the liquid crystal display panel is shifted, and display defects such as uneven brightness are caused. cause.

  An object of the present invention is to provide a light source device and a liquid crystal display device using the light source device in which the occurrence of display defects due to the displacement of the optical sheet is reliably prevented.

The liquid crystal display device of the present invention includes a liquid crystal display panel in which an effective display area on which an image is displayed is set, and a surface that is disposed on the rear side of the liquid crystal display panel and emits light in a planar shape toward the liquid crystal display panel A light emitting irradiation panel, and the surface emitting irradiation panel has a thickness between a front surface and a rear surface, and guides light incident from an end surface to be emitted in a planar shape from the front surface facing the liquid crystal display panel. An optical plate; a light source disposed opposite to the end surface of the light guide plate; an optical sheet placed on the front surface of the light guide plate; a flexible wiring board on which the light source is mounted; and guiding the flexible wiring board. And a sheet-like first fixing member that fixes the light source side end of the optical sheet to the front surface of the light guide plate, while fixing the light plate to the light source side end of the light plate. To do.
In the liquid crystal display device, preferably, the light guide plate includes a light incident portion including the end face, a light introduction portion whose thickness gradually decreases as the distance from the light incidence portion, and a tip of the light introduction portion. The subsequent light emitting portion has a constant thickness, and light is emitted in a planar shape from the front surface of the light emitting portion.
In the liquid crystal display device, preferably, the optical sheet is disposed so as to cover the front surface of the light guide plate from the light emitting portion to the light introducing portion of the light guide plate, and the first fixing member is the guide member. It arrange | positions so that the edge part of the said optical sheet mounted in the front surface of the said light introduction part of an optical plate and the said flexible wiring board may overlap.
In the liquid crystal display device, preferably, the optical sheet overlaps the light emitting portion and the light diffusing sheet and the first prism sheet arranged so as to overlap from the light emitting portion to the light introducing portion of the light guide plate. The second prism sheet arranged in this manner is laminated on the front side of the light guide plate, and each end of the first prism sheet and the light diffusion sheet that overlaps the light introducing part is the first fixed sheet. The member sheet is fixed to the front surface of the light guide plate.
In the liquid crystal display device, preferably, the liquid crystal display device further includes a sheet-like second fixing member provided with an opening in a portion overlapping the effective display area, and the second fixing sheet allows the second prism sheet to be formed. Is fixed to the liquid crystal display panel.
In the liquid crystal display device, preferably, both the first fixing member and the second fixing member have light shielding properties.
In the liquid crystal display device, preferably, the flexible wiring board is disposed so as to overlap from the light incident portion of the light guide plate to the light introduction portion, and the light introduction portion of the light guide plate of the flexible wiring substrate. The first overlapping member sheet is fixed to each end of the first prism sheet and the light diffusing sheet that overlaps the light introducing portion.
In the liquid crystal display device, it is preferable that the flexible wiring board includes an area where the light guide plate overlaps with the light introducing portion is sandwiched between the liquid crystal display panel and the light guide plate. Between the liquid crystal display panel and the light guide plate, each end of the sheet and the light diffusing sheet that is overlapped with the light introducing portion is pressed toward the light guide plate. .

The light source device of the present invention has a thickness between the front surface and the rear surface, and is disposed so as to face the end surface of the light guide plate, and a light guide plate that emits light incident from the end surface in a planar shape from the front surface. A light source, an optical sheet placed on the front surface of the light guide plate, a flexible wiring substrate on which the light source is mounted, and the flexible wiring substrate fixed to the front surface of the light source side end of the light guide plate. And a sheet-like first fixing member that fixes an end portion of the optical sheet on the light source side to the front surface of the light guide plate.
In the light source device, preferably, the light guide plate continues to a light incident portion including the end surface, a light introduction portion whose thickness gradually decreases as the distance from the light incidence portion increases, and a tip of the light introduction portion. A light emitting part that emits light in a planar shape from a front surface, and the flexible wiring board is disposed so as to overlap from the light incident part to the light introducing part of the light guide plate, A region of the flexible wiring board that overlaps the light introducing portion of the light guide plate is attached to each end of the first prism sheet and the light diffusion sheet that overlaps the light introducing portion. It is fixed by a member sheet.

  According to the light source device of the present invention and the liquid crystal display device using the same, it is possible to reliably prevent the occurrence of display defects due to the positional deviation of the optical sheet.

It is a disassembled perspective view of the liquid crystal display device as one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 of the liquid crystal display device as one embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a liquid crystal display device as another embodiment of the present invention.

FIG. 1 is an exploded perspective view of a liquid crystal display device as an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. In FIG. 1, the storage case 1 and the cover case 2 are not shown.
As shown in FIG. 2, the casing in the liquid crystal display device of the present embodiment has a cover case 2 in which a bottom plate is removed in a storage case 1 in a shape in which a top plate of a box having a flat outer shape is removed. It is fitted. Both of these cases 1 and 2 are formed by processing a metal plate. A display window 22 for observing the display is formed in the top plate 21 of the cover case 2.

  A frame case 3 is disposed in the casing. The frame case 3 of the present embodiment is formed by resin molding using a resin material, for example, by an injection method or the like. Inside, a front chamber 3a serving as a storage chamber for a liquid crystal display panel in a flat rectangular parallelepiped space is formed on the front side. The rear chamber 3b serving as a storage chamber for the surface emitting irradiation panel is disposed on the rear side, and these are formed in two layers. And the shelf part 32 is protrudingly provided by the three side walls 31b-31d except the side wall 31a in the four side walls 31a-31d (refer FIG. 1) of the frame case 3. As shown in FIG. That is, the internal space of the frame case 3 is divided into the front chamber 3 a and the rear chamber 3 b by the shelf surface 321. Therefore, the front chamber 3a is wider than the rear chamber 3b by the area of the shelf surface 321.

  A liquid crystal display panel 4 is accommodated and held in the front chamber 3a. Before the liquid crystal display panel 4 forms a pair of rectangles, the rear glass substrates 41 and 42 are joined together with a frame-shaped sealing material (not shown) while maintaining a predetermined gap, and the front and rear glass substrates are surrounded by the frame-shaped sealing material. The liquid crystal is sealed between the opposing surfaces 41 and 42 (hereinafter referred to as inner surfaces). A pair of front and rear polarizing plates 43 and 44 are attached to the outer surfaces of the front and rear glass substrates 41 and 42, respectively.

  Of the front and rear glass substrates 41 and 42, the rear glass substrate 42 is formed with a protruding edge portion 421 by projecting one short side edge outward from the corresponding end surface of the front glass substrate 41. On the surface of the protruding edge 421 (extension surface of the electrode formation surface), although not shown, lead wires that are conductively connected to the electrodes of both substrates 41 and 42, their connection terminals, and drive signal input Wiring and the like are arranged, and a driver chip 5 as a liquid crystal driving circuit element is directly mounted by a COG (Chip On Glass) method. The external size of the liquid crystal display panel 4, that is, the area of the rear glass substrate 41, is set to an area that is slightly smaller than the area of the front chamber 3a (can be accommodated while keeping a slight gap over the entire circumference).

  A flexible wiring board for supplying drive control signals (hereinafter referred to as a main FPC (Flexible Printed Circuit Board)) 6 is electrically connected to the connection terminal row of the drive signal input wiring formed at the tip of the protruding edge 421. It is joined. The main FPC 6 is pulled out of the case from a notch 31e provided on the side wall 31a of the frame case 3, and is folded back to the back side of the rear chamber 3b.

  In the rear chamber 3b of the frame case 3, a surface emitting irradiation panel 7 as a backlight is installed. The surface emitting irradiation panel 7 of the present embodiment is a backlight panel that emits planar irradiation light by a sidelight method, and includes a transparent light guide plate 71 that has a rectangular shape that roughly corresponds to the liquid crystal display panel 4 to be irradiated. The light guide plate 71 has a thickness between the front surface 711 and the rear surface 712, and emits light incident from the end surface in a planar shape from the front surface 711 facing the liquid crystal display panel 4. A plurality of LEDs 72 as light sources are arranged on one end side of the light guide plate 71, and a light reflection sheet 73 is provided on the rear surface 712 opposite to the front surface 711 facing the liquid crystal display panel 4 of the light guide plate 71. is set up. The LED 72 is disposed opposite to the end surface of the light guide plate 71 on the light source side. Although not shown, the back surface 712 has minute irregularities.

  The light guide plate 71 is molded into a substantially transparent rectangular plate using a resin material such as polycarbonate. The light guide plate 71 includes a thick portion 71a on the side where the light source is disposed, a diaphragm portion 71b whose thickness gradually decreases and a remaining thin portion 71c having a large area. The thick portion 71a is disposed with the light source. The light entrance part, the thin part 71c serve as a light exit part that emits light in a planar shape, and the aperture part 71b serves as a light introduction part that guides the incident light to the light exit part 71c.

  As shown in FIG. 1, the thick light incident portion 71 a is formed with a recess 713 for accommodating the LED 72 as a light source. In the present embodiment, the two LEDs 72 are installed in a state of being accommodated in two recesses 713 that are equally recessed on the light source side end face of the light guide plate 71.

  The two LEDs 72 are directly mounted on a power supply FPC 74 by a COF (Chip On Film) method, and this FPC (hereinafter referred to as “light source FPC”) 74 is mounted on the front surface 711 of the light guide plate light incident portion 71a. It is accommodated and held in each corresponding recess 714. The light source FPC 74 is conductively connected to a predetermined portion of the main FPC 6 joined to the liquid crystal display panel 4 described above.

  Here, the light source FPC 74 is attached to the front surface of the light incident portion 71 a via the first double-sided pressure-sensitive adhesive sheet 75. The first double-sided adhesive light-shielding sheet 75 has black organic or inorganic dyes or pigments such as carbon black, acetylene black, lamp black, bone on both sides of a flexible base made of polyethylene terephthalate (Poly-Eethylene Trephthalate) or the like. A paint containing a black colorant composed of black, graphite, aniline black, cyanine black, etc. is printed and applied to form a black layer, and a bar coat, Mayer bar coat, It can be obtained by applying an acrylic pressure-sensitive adhesive by an appropriate means such as reverse coating, gravure coating or die coating to form a pressure-sensitive adhesive layer.

  And the 1st double-sided adhesive light-shielding sheet 75 of this embodiment is formed wider than FPC74 for light sources, and the other side is attached in the state where one long side was aligned with the end surface of the light-guide plate light incident part 71a. Is extended from the light source FPC 74 to such an extent that it can cover substantially the entire front surface of the light introducing portion 71b. An end of an optical sheet, which will be described later, is fixed to the front surface 711 by the extending portion 751.

  Since the first double-sided pressure-sensitive adhesive sheet 75 has light-shielding properties in addition to adhesiveness, the first double-sided adhesive light-shielding sheet 75 does not enter the light guide plate 71 even when emitted from the LED 72 and blocks stray light from traveling toward the liquid crystal display panel 4 side. Thus, it is possible to prevent the display quality of the liquid crystal display panel 4 from being deteriorated due to such stray light.

  On the front surface 711 of the light guide plate 71, an optical sheet laminate 76 as a light control member is installed. The optical sheet laminate 76 is formed by superimposing and stacking the light diffusion sheet 761, the first prism sheet 762, and the second prism sheet 763 on the light guide plate front surface 711 in this order. The light diffusion sheet 761 is provided in order to make the luminance distribution of the planar emitted light uniform, and the first and second prism sheets 762 and 763 are luminance enhancing lens sheets, and the two prism sheets 762 and 763 are provided. It is provided to adjust the traveling direction of the planar emitted light by the cooperative action and to increase the luminance in the front direction.

  The lengths of the three optical sheets 761, 762, and 763 are the longest in the light diffusion sheet 761 in the lowermost layer and become shorter as it goes up. These three optical sheets 761, 762, and 763 have one short side aligned with the corresponding short side of the light guide plate front surface 711, and the other short side is the light diffusion of the lowest layer. The other shorter side of the sheet 761 and the intermediate first prism sheet 762 extends to the area covering the light introducing portion 71b, and the other shorter side of the uppermost second prism sheet 763 is connected to the light introducing portion 71b. It is extended and extended to the boundary part of the light emission part 71c.

  Then, each end portion extended to the light introducing portion 71b of the light diffusion sheet 761 in the lowermost layer and the first prism sheet 762 in the intermediate layer is fixed by the extension portion 751 of the first double-sided adhesive light shielding sheet 75 described above. Has been. Specifically, the end portion of the light diffusion sheet 761 is pressed and fixed on the light guide plate front surface 711 and the end portion of the first prism sheet 762 is pressed and fixed on the light diffusion sheet 761 by the extending portion 751.

  A light case 77 is fitted and mounted at a predetermined position in the frame case rear chamber 3b. The light case 77 is a case formed by sheet metal processing of an open top surface in which not only the top plate but also the side plate at the corner portion is removed. The light case FPC 74 in which the light reflection sheet 73 and the LED 72 are mounted in the light case 77. The light guide plate 71 and the optical sheet laminate 76 to which are attached are stacked and disposed, and the entire surface emission irradiation panel 7 is held in a predetermined position in the rear chamber 3b.

  In the surface emitting irradiation panel 7 configured as described above, the light emitted from the LEDs 72 enters the light guide plate 71 from its opposite end surface (light incident end surface), and this incident light is light of the light guide plate 71. While the inner surface reflection is repeatedly propagated in the emission part 71c, the light emission part 71c is reflected toward the front surface 711 by the rear surface 712 on which minute irregularities are formed, and the edge of the front surface 711 in the light emission part 71c is excluded. Light is emitted in a planar shape from the effective light emitting region Di.

  A rectangular frame-shaped second double-sided pressure-sensitive adhesive sheet 8 is interposed between the liquid crystal display panel 4 and the surface emitting irradiation panel 7. The second double-sided pressure-sensitive adhesive sheet 8 bonds the rear polarizing plate 44 of the liquid crystal display panel 4 and the uppermost second prism sheet 763 in the optical sheet laminate 76. Thereby, the arrangement of the second prism sheet 763 with respect to the liquid crystal display panel 4 is fixed.

  The opening 81 of the second double-sided adhesive light-shielding sheet 8 is formed to have a size that includes the effective display area Dd of the liquid crystal display panel 4 on the inner side with a very small interval, that is, one size larger than the effective display area Dd. ing. The entire opening 81 is included in the effective light emitting region Di of the surface emitting irradiation panel 7. As a result, among the light emitted from the effective light emitting area Di of the light guide plate light emitting portion 71c, only the emitted light suitable for the uniformed display is displayed while the luminance is enhanced through the optical sheet laminate 76. Light emitted to the liquid crystal display panel 4 as light to be performed and emitted light from the edge of the effective light emitting area Di that is not suitable for display due to a decrease in luminance is absorbed by the second double-sided adhesive light-shielding sheet 8 and Not irradiated.

  Here, even if the position of the liquid crystal display panel 4 with respect to the surface emission irradiation panel 7 is slightly shifted due to the resilience of the main FPC 6 or the like, the second prism sheet 763 is post-polarized by the second double-sided adhesive light-shielding sheet 8 as described above. Since the second prism sheet 763 is not displaced with respect to the liquid crystal display panel 4 because it is affixed to the plate 44, the liquid crystal display panel 4 is always stably and efficiently irradiated with suitable planar emission light. be able to. The second double-sided PSA sheet 8 is formed in a rectangular frame shape, but the material is the same as that of the first double-sided PSA sheet 75.

  A rectangular frame spacer 9 is disposed between the liquid crystal display panel 4 and the surface emitting irradiation panel 7. The outer shape of the rectangular frame spacer 9 is substantially equal to the rear glass substrate 42 of the liquid crystal display panel 4, and the size of the rectangular opening 91 is slightly larger than the outer shape of the rear polarizing plate 44, that is, the rear polarizing plate 44. Is set to a size that includes a small gap around the entire circumference.

  Of the four frame sides 92a to 92d (see FIG. 1) of the rectangular frame-shaped spacer 9, the three frame sides 92b to 92d excluding the wide frame side 92a corresponding to the protruding edge 421 are frame It is placed on the shelf surface 321 of the case 3. Therefore, the wide frame side 92 a is configured to be interposed between the light source FPC 74 and the rear glass substrate 42. This prevents the light source FPC 74 from floating. That is, the light source FPC 74 is folded in the same manner in order to be electrically connected to the main FPC 6 folded back on the back side of the surface emitting irradiation panel 7, and is in a state of being biased in the direction of lifting by the elastic force. However, since the frame side 92a is interposed between the rear glass substrate 42, the light source FPC 74 is peeled off from or together with the first double-sided adhesive light-shielding sheet 75, and the occurrence of a malfunction is reliably prevented. As a result, misalignment of the LED 72 with respect to the light incident surface of the light guide plate 71 is prevented, generation of useless and harmful light that does not enter the light guide plate 71, such as stray light, is avoided, and utilization efficiency of the LED emitted light is improved. To do.

  Here, the material of the rectangular frame-shaped spacer 9 may be a rigid body such as metal or hard plastic, or may be an elastic body such as various elastomers. In order to stably maintain a state where the prism sheet 762 is placed without any gap, an elastic body is preferable. Further, it is preferably an opaque body that does not substantially transmit light, thereby preventing stray light or leakage light from entering the liquid crystal display panel as a light shielding member, thereby contributing to an improvement in display quality of the liquid crystal display panel 4.

  The rectangular frame spacer 9 may be formed of the same material as the first double-sided adhesive light-shielding sheet 75, that is, a double-sided adhesive light-shielding sheet. Thereby, in addition to the expected effect mentioned above, the effect that the liquid crystal display panel 4 is securely fixed by the frame case 3 is also added.

  Returning to FIG. 2, on the rear surface of the light case 77, a drive control circuit board 10 for controlling the drive of the entire liquid crystal display device of the present embodiment is installed. The main FPC 6 to which the FPC 75 is electrically connected is conductively joined.

  As described above, the liquid crystal display device of the present embodiment includes the light diffusion sheet 761 in the lowermost layer of the optical sheet laminate 7 placed on the light emitting surface of the surface emitting irradiation panel 7 and the first prism sheet in the intermediate layer. When the liquid crystal display device vibrates due to an external force, each light source side end portion 762 is fixed by the extension portion 751 of the first double-sided pressure-sensitive adhesive sheet 75 that attaches the light source FPC 74 to the light guide plate front surface 711. Further, it is possible to prevent the occurrence of the problem that the positions of the first prism sheet 762 and the light diffusion sheet 761 with respect to the liquid crystal display panel 4 are shifted.

  Further, since the first prism sheet 762 and the light diffusion sheet 761 are only fixed to the respective end portions on the light source side in the length direction, the sheets 761 and 762 themselves are caused by a change in environmental temperature or the like. Even if they are thermally expanded or contracted by cooling, their dimensional changes in the length direction are allowed freely, and there is no possibility of bending or wrinkling.

  Further, since the uppermost second prism sheet 763 is adhered to the rear polarizing plate 44 of the liquid crystal display panel 4 by the rectangular frame-shaped second double-sided pressure-sensitive adhesive sheet 8, the main FPC 6 in which the liquid crystal display panel 4 is folded back. The surface of the second prism sheet 763 is not displaced with respect to the liquid crystal display panel 4 even when it is lifted by the elastic force of the liquid crystal or vibrated by an external force. The liquid crystal display panel 4 can be irradiated.

  As a result of the various effects described above, in the liquid crystal display device of the present embodiment, reduction in size and thickness is promoted, and planar emission light suitable for display is always stable over the entire effective display area Dd of the liquid crystal display panel 4. Therefore, good display quality without display defects such as luminance unevenness is stably secured.

  Moreover, since the rectangular frame-shaped spacer 9 with light-shielding property is interposed between the liquid crystal display panel 4 and the surface emitting irradiation panel 7, the first double-sided adhesive light-shielding sheet 75 and the second double-sided adhesive light-shielding sheet 8. The triple light shielding effect combined with the light shielding effect reliably blocks the stray light and leakage light from being irradiated on the liquid crystal display panel, and the display quality of the liquid crystal display panel 4 becomes more stable and advanced.

  Next, another embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component same as the said embodiment, and the description is abbreviate | omitted.

  In the liquid crystal display device of the present embodiment, the light emitting portion side end of the light source FPC 74 ′ on which the LED 72 is mounted overlaps the light diffusion side 761 in the optical sheet laminate 7 and the light source side end of the first prism sheet 762. The embodiment and the configuration are that the light emitting part side end of the light source FPC 74 ′ is extended to a position overlapping the light incident part 71a and the light introducing part 71b of the light guide plate 71 while extending to the position. Is different. Accordingly, one (front side) adhesive surface of the first double-sided adhesive light-shielding sheet 75 is adhered to the light source FPC 20 over the entire surface. Other configurations are the same as those in the above embodiment. In this case, the FPC 6 is sandwiched between the light guide plate 71 and a region of the light guide plate 71 that overlaps the light introducing portion 71 b between the liquid crystal display panel 4 and the spacer 9 disposed on the rear side of the liquid crystal display panel 4. In the first prism sheet 762 and the light diffusing sheet 761, the liquid crystal display is brought into close contact with the respective end portions of the first prism sheet 762 and the light diffusing sheet 761 which are overlapped with the light introducing portion 71 b and pressed toward the light guide plate 71 side. It is interposed between the panel 4 and the light guide plate 71.

  With the above-described configuration, the light source side end portions of the light diffusion sheet 761 and the first prism sheet 762 can be more firmly fixed by the first double-sided adhesive light-shielding sheet 75.

  In addition, this invention is not limited to said embodiment etc., Of course, various deformation | transformation are possible in the technical scope of this invention.

  For example, in the above embodiment, three optical sheets are superimposed and placed on the light exit surface of the light guide plate. However, the present invention is not limited to this, and when one, two, or four or more optical sheets are stacked. However, the present invention is effectively applied. In this case, at least one optical sheet may be fixed by a double-sided adhesive light-shielding sheet for attaching the light source FPC to the front surface of the light guide plate.

  Further, the light guide plate may be a flat plate having a constant thickness, in which case the double-sided pressure-sensitive adhesive sheet is in a mode in which the extending portion runs on the light source side end of the optical sheet, but the optical sheet is securely fixed. Is done.

  In addition, the double-sided pressure-sensitive adhesive sheet may not have light shielding properties.

DESCRIPTION OF SYMBOLS 1 Storage case 2 Cover case 3 Frame case 3a Front chamber 3b Rear chamber 4 Liquid crystal display panel 41, 42 Front, rear glass substrate 43, 44 Front, rear polarizing plate 5 Driver chip 6 Main FPC
7 Surface emitting irradiation panel (light source device)
71 Light guide plate 72 LED
73 Light reflection sheet 74, 74 'FPC for light source
75 First Double-sided Adhesive Shading Sheet (First Fixing Member)
76 Optical sheet laminate 761 Light diffusion sheet 762 First prism sheet 763 Second prism sheet 8 Second double-sided adhesive light-shielding sheet (second fixing member)
81 Opening 9 Frame-shaped spacer 91 Opening 10 Drive control circuit board

Claims (10)

A liquid crystal display panel with an effective display area on which an image is displayed; and
A surface emitting irradiation panel disposed on the rear side of the liquid crystal display panel and emitting light in a plane toward the liquid crystal display panel;
The surface emitting irradiation panel is:
A light guide plate having a thickness between the front surface and the rear surface, and emitting light incident from the end surface in a planar shape from the front surface opposed to the liquid crystal display panel;
A light source disposed opposite to the end face of the light guide plate;
An optical sheet placed on the front surface of the light guide plate;
A flexible wiring board on which the light source is mounted;
A sheet-like first fixing member that fixes the flexible wiring board to the front surface of the light source side end portion of the light guide plate and fixes the light source side end portion of the optical sheet to the front surface of the light guide plate; A liquid crystal display device comprising:   The light guide plate includes a light incident portion having the end face, a light introduction portion whose thickness gradually decreases as the distance from the light incidence portion, and a light emission portion having a constant thickness following the tip of the light introduction portion The liquid crystal display device according to claim 1, wherein light is emitted in a planar shape from a front surface of the light emitting portion. The optical sheet is arranged so as to cover the front surface of the light guide plate from the light emitting portion of the light guide plate to the light introducing portion,
The first fixing member is disposed so as to overlap an end portion of the optical sheet placed on a front surface of the light introducing portion of the light guide plate and the flexible wiring board. A liquid crystal display device according to 1.   The optical sheet includes a light diffusion sheet and a first prism sheet that are arranged so as to overlap from the light emitting part to the light introducing part of the light guide plate, and a second prism sheet that is arranged so as to overlap the light emitting part. Are stacked on the front side of the light guide plate, and each end of the first prism sheet and the light diffusion sheet that overlaps the light introducing portion is formed by the first fixing member sheet on the front surface of the light guide plate. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is fixed to the liquid crystal display device. The liquid crystal display device further includes a sheet-like second fixing member provided with an opening in a portion overlapping the effective display area,
The liquid crystal display device according to claim 4, wherein the second prism sheet is fixed to the liquid crystal display panel by the second fixing member.   6. The liquid crystal display device according to claim 5, wherein both the first fixing member and the second fixing member have light shielding properties. The flexible wiring board is disposed so as to overlap from the light incident part of the light guide plate to the light introducing part,
A region of the flexible wiring board that overlaps the light introduction portion of the light guide plate is located at each end of the first prism sheet and the light diffusion sheet that overlaps the light introduction portion. The liquid crystal display device according to claim 4, wherein the liquid crystal display device is fixed by a fixing member sheet.   In the flexible wiring board, an area of the light guide plate that overlaps the light introducing portion is sandwiched between the liquid crystal display panel and the light guide plate, so that the first prism sheet and the light diffusion sheet are included. 8. The liquid crystal display panel and the light guide plate are interposed in a state where each end portion overlapping the light introducing portion is pressed toward the light guide plate side. The liquid crystal display device described. A light guide plate having a thickness between the front surface and the rear surface, and emitting light incident from the end surface in a planar shape from the front surface;
A light source disposed opposite to the end face of the light guide plate;
An optical sheet placed on the front surface of the light guide plate;
A flexible wiring board on which the light source is mounted;
A sheet-like first fixing member that fixes the flexible wiring board to the front surface of the light source side end portion of the light guide plate and fixes the light source side end portion of the optical sheet to the front surface of the light guide plate. A light source device comprising: The light guide plate includes a light incident portion having the end surface, a light introduction portion that gradually decreases in thickness as the distance from the light incidence portion increases, and a constant thickness from the front end of the light introduction portion. A light emitting part for emitting light in a planar shape,
The flexible wiring board is disposed so as to overlap from the light incident part of the light guide plate to the light introducing part,
A region of the flexible wiring board that overlaps the light introduction portion of the light guide plate is located at each end of the first prism sheet and the light diffusion sheet that overlaps the light introduction portion. The light source device according to claim 9, wherein the light source device is fixed by a fixing member sheet.

Images