JP4438539B2 - Display device and planar light source device - Google Patents

Description

The present invention relates to a transmissive display device and a planar light source device used for the display device . More specifically, the present invention relates to a light emitter and light from the light emitter is incident on the light incident surface, and light is emitted from the light exit surface. A light guide plate that emits light, a reflective sheet that is disposed on the back side of the light emitter and the light guide plate, and has an end that covers the light emitter, and a display device and a planar light source including a casing that holds them Relates to the device.

Compared to other display devices, liquid crystal display devices have features such as thinness, light weight, and low power consumption, and are widely used as display devices for personal computers, mobile terminals such as mobile phones, and car navigation terminals. ing. In the case of a liquid crystal display device, since the liquid crystal panel that reproduces image information for each pixel does not emit light, a light source device is separately required. Usually, a liquid crystal display device is a backlight device that emits light from the back side of the liquid crystal panel. It has a light source device called.

In such a display device, since it is necessary to irradiate light uniformly to a display area such as an image, the display apparatus has a light emitting surface having a shape corresponding to the display area, and the light emission characteristics within the light emitting surface are uniform. There is a need for an excellent planar light source device. Further, in order to reduce the thickness and weight of the entire device, it is required to reduce the thickness and weight of the light source device. For this reason, the light source device of this type usually employs a sidelight system in which linear light emitters are arranged in the side surface direction of the light guide plate.

An example of a conventional planar light source device is described in Patent Document 1. As shown in FIG. 1 of the publication, the planar light source device adopting the sidelight method described in Patent Document 1 makes a projection on the light guide plate side provided on the front housing abut on the reflection sheet. Thus, there has been proposed a structure that avoids a gap between the reflection sheet and the light guide plate and improves display performance.

JP 20003-346535 A (page 5-16, FIG. 1)

In the assembly of the planar light source device, first, the reflection sheet 5 is accommodated in the rear casing 7, and then the light emitter 3 and the wiring 4 are accommodated. The reflection sheet 5 is bent and housed in the rear case 7, but when the bending process is not sufficient or when the repulsive force against bending of the reflection sheet 5 is strong, Since the bent portion is in an open state, it is necessary to assemble while holding the reflective sheet. Here, when the front housing 6 is provided with a protrusion for suppressing the floating of the end of the reflection sheet 5 that is bent in a U shape and eliminating the gap with the light guide plate, the rear housing 7 When the folded portion of the encapsulated reflection sheet 5 is in an open state, when assembling while holding the reflection sheet with the front housing 6, the movement of the reflection sheet is restricted by the projection of the front housing, There is a problem that it is not easy to place the reflective sheet in a regular position and assemble the front case.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a planar light source device that is easy to assemble while providing good display performance, and has a high work efficiency. An object is to provide a light source device. In particular, the front case is provided with a protrusion for suppressing the float between the reflection sheet and the light guide plate, and the assembly work in the planar light source device using a material having a strong repulsive force against the bending process is efficiently performed on the reflection sheet. An object of the present invention is to provide a planar light source device that can be used.

The display device according to the present invention has a housing formed by combining a box-shaped front housing having an opening on the top surface and an open back surface and a back housing having an open top surface, and is housed inside the housing. A light guide plate having a light exit surface that receives light from the light emitter and emits light toward the opening of the front housing, and a back surface that faces the light exit surface of the light guide plate and covers the periphery of the light emitter And a reflection sheet having one end reaching the light exit surface of the light guide plate and a display panel mounted on the upper surface of the front case. The front case has a front surface for contacting one end of the reflection sheet to the light guide plate. A reflective sheet abutting portion that protrudes in the back direction formed on the upper surface of the housing, and a display panel mounting portion that is formed in the area from the reflective sheet abutting portion to the side surface of the front housing on the upper surface of the front housing And the top of the reflective sheet abutting part formed on a part of the reflective sheet abutting part Display device characterized by comprising an extending portion which extends to a side surface of Luo front cabinet, a.
The planar light source device according to the present invention includes a case formed by combining a box-shaped front case having an opening on the upper surface and an open rear surface and a rear case having an open upper surface, and the case. A light guide plate having a light exit surface that receives light from the light emitter housed in the interior and exits toward the opening of the front housing, and a light emitter provided on the back surface facing the light exit surface of the light guide plate. A reflection sheet that has one end that reaches the light exit surface of the light guide plate, and a reflection sheet contact portion that is convex in the rear direction on the upper surface of the front housing. In the planar light source device, a separate member is disposed on the housing so as to extend from the top of the reflection sheet contact portion to the side surface of the front housing.

According to the display device and the planar light source device of the present invention, the upper surface of the reflective sheet is smoothly placed on the light guide plate without being restricted from moving such as being caught by a corner formed at the contact portion of the front housing. Therefore, the assembly can be easily performed.

Embodiments of a planar light source device and a display device including the device according to the present invention will be described below with reference to the drawings. In addition, what attached | subjected the same code | symbol in each figure has shown the substantially same component.
Embodiment 1.
Hereinafter, the planar light source device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view of a planar light source device according to Embodiment 1 of the present invention, FIG. 2 is a partial cross-sectional view taken along line AA in FIG. 1, and FIG. 4 and 4 are exploded perspective views.

1-4, 1 is a light guide plate, 2 is an optical sheet, 3 is a light emitter, 4 is a wiring, 5 is a reflection sheet, 6 is a front case, and 7 is a back case. The front housing 6 has a substantially box shape in which an opening 12 is provided on the front surface and the back surface is open, and the back housing 7 is a box shape in which the top surface is open. The light guide plate 1, the optical sheet 2, the light emitter 3, the wiring 4, and the reflection sheet 5 are housed in a casing formed by combining the front casing 6 and the rear casing 7 by means such as fitting, and thus a planar light source device. The display device is configured by fixing and attaching a display panel (not shown) with a double-sided tape 11 attached to the upper surface 61 of the front housing.

The light guide plate 1 is made of a transparent member such as acrylic resin, polycarbonate, or glass having a predetermined refractive index, and is formed as a flat plate or a substantially rectangular plate-like body. The light guide plate 1 has a function of having at least one side surface as a light incident surface and an upper surface (opening 12 side) as a light exit surface. On the back surface of the light guide plate 1 facing the light exit surface, a diffusion pattern is formed as light diffusing means for diffusing light propagating through the light guide plate 1. For example, the diffusion pattern is formed by printing a fine shape or a fine pattern such as a linear notch or dot-shaped unevenness provided on the back surface of the light guide plate 1, and diffusely reflects light propagating in the light guide plate 1. Let In the process of propagating through the light guide plate 1, the light incident from the light incident surface is diffused by the diffusion pattern and is emitted from the light exit surface as scattered light. By adjusting the diffusion pattern, the light emitted from the light exit surface can be made uniform or adjusted to a desired luminance distribution.

Optical sheet 2 is a diffusion sheet in which diffused particles are applied to a resin material having translucency, or a fine uneven shape is formed on the surface thereof to give diffusibility, or a lens sheet provided with prism rows Various sheet members such as are used. These various sheet members are used in a plural number or a plurality of types as required. By disposing such an optical sheet 2 on the light exit surface side of the light guide plate 1, the light distribution characteristics of the light emitted from the light guide plate 1 can be adjusted, and a desired luminance distribution can be obtained.

The light emitter 3 is disposed along the light incident surface on the side surface side of the light guide plate 1, and generally uses a linear light source such as a CCFL (Cold Cathode Fluoresent Lamp) to enter the light incident surface of the light guide plate 1. To supply light. The light emitter 3 may be provided on one side of the surface light source device according to the luminance required for the surface light source device, and may be provided on two sides when higher luminance is required. It may be provided so as to surround the periphery. Moreover, the light emitter 3 may use a point light source typified by an LED (Light Emitting Diode), or may use a light source in which the point light sources are arranged in a line.

As an example of the case where the light emitters 3 are arranged in a form surrounding the light guide plate 1, the corner holders 32 of elastic bodies (for example, rubber) are provided at the respective corner portions, and the light emitters 3 are formed in a U shape. The light emitting unit 33 is configured by connecting the discharge electrode portions 30 and 31 and the wiring 4 serving as a power supply line for supplying power to both ends of the U-shaped light emitting body 3.

The reflection sheet 5 emits light deviating from the light guide path of light emitted from the light emitter 3 (the original path emitted from the opening 12 of the front housing 6 via the light guide plate 1 and the optical sheet 2). Reflecting to the light guide path, the brightness of the planar light source device is improved and stray light is prevented to make the brightness of the light exit surface of the light guide plate 1 uniform. The reflection sheet 5 is composed of a plate-like or sheet-like member on which a highly reflective material such as silver or aluminum is deposited, or a sheet-like member made of a white resin and having a high surface reflectance. It is placed adjacent to and covers the entire back surface.

The end portion 34 of the reflecting sheet on the light emitting body 3 side arranged along the light incident surface of the light guide plate 1 has a substantially U-shaped cross section. The reflection sheet 5 has a bottom surface 51 that faces the inner bottom surface 71 of the rear housing 7, a side surface 52 that faces the inner wall 72, and an upper surface 53 that reaches the light exit surface of the light guide plate 1, and has a substantially U-shaped cross section. It is bent like this. The reflective sheet 5 has a bent portion 341 for forming the bottom surface 51 and the side surface 52 and a bent portion 342 for forming the upper surface 53 in order to form the U-shaped end portion 34. Further, the upper surface 53 of the reflection sheet 5 is partially overlapped with the light exit surface of the light guide plate 1, and the reflection sheet 5 is brought into contact with the light guide plate 1 by the reflection sheet contact portion 20 provided in the front housing 6. The gap between the light guide plate 1 and the reflection sheet 5 is eliminated to prevent light from leaking. In this way, by forming the substantially U-shaped end portion 34 in the reflecting sheet 5, it covers the periphery of the light emitting body 3 and reflects and guides the light traveling from the light emitting body 3 toward the inner wall 72 of the rear housing 7. Light can enter the light plate 1. When the U-shaped light emitter unit 33 is used for the light emitter 3, the U-shaped end portion 35 (folded) with respect to the light incident surface of each light guide plate 1 on which the light emitter 3 is disposed is provided on the reflection sheet 5. Part 351, 352) and a U-shaped end part 36 (folded parts: 361, 362) are further formed in the same manner as the U-shaped end part 34.

The end portion 37 on the wiring 4 side of the reflection sheet 5 is raised by being bent into a substantially L-shaped cross section, and is disposed adjacent to the side surface on the wiring 4 side of the light guide plate 1. The end portion 37 is formed so as to reflect light traveling from the light-emitting body 3 toward the inner wall 72 on the wiring 4 side of the rear housing 7 and return to the light guide plate 1 again.

As described above, the reflection sheet 5 reflects the light emitted from the back surface of the light guide plate 1 and returns the light into the light guide plate 1 again to emit light from the light exit surface. Moreover, since it covers the periphery of the light emitter 3 and is disposed adjacent to the side surface on the wiring 4 side, it reflects light traveling toward the inner wall 72 of the rear housing 7 and efficiently enters the light incident surface of the light guide plate 1. Make the light come from. As such a reflection sheet 5, it is desirable to use a member having a reflectance of 90% or more from the viewpoint of emitting light to the light guide plate 1 side without attenuating light from the light emitter 3.

Both the front housing 6 and the back housing 7 are part of a housing of a planar light source device obtained by pressing a metal plate such as aluminum or iron or molding a resin material. A generally box-shaped thin casing can be obtained by combining the above means. The front housing 6 has an opening 12 on the top surface 61 and has a substantially box shape with the back surface open, and the back housing 7 has a substantially box shape with the top surface 61 open. 7 is covered and combined by means such as fitting. The upper surface 61 of the front housing 6 is provided with a reflective sheet contact portion 20 that protrudes toward the back surface of the front housing 6, and the top portion 201 of the reflective sheet contact portion 20 contacts the upper surface 53 of the reflective sheet 5. . As shown in FIG. 1, the reflection sheet contact portion 20 formed on the front housing 6 is formed in the entire area where the upper surface 53 of the reflection sheet 5 is overlapped, so that a gap between the reflection sheet 5 and the light guide plate 1 is formed. This prevents light leakage. Further, as shown in FIGS. 1 and 2, an extending portion that extends from the top portion 201 of the reflection sheet contact portion 20 to the side surface 62 of the front housing 6 is formed in a part of the reflection sheet contact portion 20. The extending portion 21 is formed so as to reach the side surface 62 of the front housing 6 from the top portion 201 of the reflection sheet contact portion 20 substantially parallel to the upper surface 61 of the front housing 6.

Hereinafter, a method for manufacturing a planar light source device according to the present invention will be described with reference to FIGS.
First, the reflection sheet 5 is accommodated in the rear housing 7. On the reflection sheet 5, bent portions 341, 351, 361, 342, 352, 362 for forming substantially U-shaped end portions 34, 35, 36 for housing the light emitter 3 are formed in advance. The reflection sheet 5 on which the bent portion is formed is stored in the rear housing 7 and the light emitting unit 33 is stored. At this time, the light emitter 3 is stored inside the U-shaped end portions 34, 35, and 36 of the reflection sheet 5, and the discharge electrode portions 30 and 31 and the wiring 4 are stored outside the end portion 37 of the reflection sheet 5. The Thereafter, the light guide plate 1 and the optical sheet 2 (the diffusion sheet 2C, the prism sheet 2B, and the polarization separation sheet 2A) are sequentially stored. These constituent members are stored so as to be completely contained in the back housing 7.

Next, the front housing 6 is put on the rear housing 7. While the upper surface 53 of the reflection sheet 5 is pressed by the reflection sheet abutting portion 20 of the front case 6, the front case 6 is put on and is incorporated into the rear case 7. At this time, as described above, when there is a corner portion 22 formed in the reflection sheet contact portion 20 as shown in FIG. 6, the reflection sheet 5 is caught by the corner portion 22, and the reflection sheet 5 is moved by the front housing 6. By being pressed down, it has been deformed and incorporated, causing problems such as being unable to fit in a proper position. In the present invention, as shown in FIG. 5, the extension portion 21 extending from the top portion 201 of the reflection sheet abutting portion 20 to the side surface 62 of the front housing 6 is formed. Since the upper surface 53 of the reflection sheet 5 is smoothly guided to a predetermined position on the light guide plate 1 without being caught by the corner portion 22 and being restricted in movement, it can be easily assembled. Further, if the extended portion 21 is formed in the entire area of the front housing 6 where the reflective sheet contact portion 20 is formed, the area for applying the double-sided tape for mounting the display panel cannot be secured. By forming it in a part of the contact part 20, a double-sided tape affixing area for mounting the display panel on the front housing 6 is sufficiently secured, and the adhesive strength is not lowered.

As described above, the planar light source device according to the present invention includes the reflection portion that extends from the top portion 201 of the reflection sheet contact portion 20 formed on the front housing 6 to the side surface 62 of the front housing 6. Since it is formed in a part of the contact portion, the upper surface 53 of the reflection sheet 5 is smoothly guided to a predetermined position on the light guide plate 1 without being restricted by movement such as being caught by the corner portion 22 of the front housing 6. Therefore, assembly can be performed easily.

The extending portion 21 formed on the front housing 6 is formed so as to extend from the top portion 201 of the contact portion to the side surface 62 of the front housing 6 substantially in parallel with the upper surface 61 of the front housing 6. As a modification of the present invention, as shown in FIG. 7, an extension part extending from the top part 201 to the side face 62 of the front housing 6 may be formed, and the extension part 23 having a substantially inclined section is formed. You may form in a part of reflection sheet contact part. With such a configuration, the front casing 6 has the extending portion 23 of the reflecting sheet abutting portion 20 that has a substantially inclined section extending from the top portion 201 of the reflecting sheet abutting portion to the side surface 62 of the front casing. Since the reflection sheet 5 is smoothly guided to a predetermined position on the light guide plate 1, it can be easily assembled.

Embodiment 2. FIG.
FIG. 8 is a diagram showing another embodiment of the planar light source device according to the present invention. In the first embodiment, the extending portion extending from the top 201 of the reflective sheet contact portion 20 to the side surface 62 of the front case 6 is formed in a part of the reflective sheet contact portion 20 in the front case 6. As shown in FIG. 8, the separate member 24 may be disposed so as to extend from the top portion 201 of the reflection sheet contact portion 20 formed on the front housing 6 to the side surface 62 of the front housing 6. The separate member 24 covers the corner portion 22 formed on the reflective sheet contact portion 20 formed on the front housing 6 and prevents the reflective sheet 5 from being caught so that the reflective sheet contact portion 20 of the reflective sheet contact portion 20 is prevented. It arrange | positions so that it may extend from the top part 201 to the side surface 62 of the front housing | casing 6. FIG. Other configurations are the same as those of the first embodiment.

The material of the separate member 24 may be a metal or other material in addition to a resin material. The attachment of the separate member 24 to the front housing 6 uses means such as fitting provided between the front housing 6 and the separate member 24 in addition to the double-sided adhesive tape.

As described above, in the second embodiment, the separate member 24 is provided so as to extend from the top portion 201 of the reflection sheet contact portion 20 to the side surface 62 of the front housing 6. Since the upper surface 53 of the reflection sheet 5 is smoothly guided to a predetermined position on the light guide plate 1 without restricting movement such as being caught, assembly can be easily performed. Further, since the separate member 24 does not reduce the area where the double-sided tape is applied to mount the display panel of the front housing 6, the adhesive strength between the display panel and the front housing 6 does not decrease.

Note that, as a modification of the second embodiment, since the corner 22 formed on the front housing 6 may be covered, the side 62 of the front housing 6 from the top 201 of the reflective sheet abutting portion 20 may be used. You may stick a tape (not shown) so that it may reach | attain. With such a configuration, the reflection sheet 5 can be smoothly guided to a predetermined position of the light guide plate 1 with a simple operation.

Embodiment 3.
FIG. 9 is a diagram showing another embodiment of the planar light source device according to the present invention. In the first and second embodiments, the extending portion 21 extending from the top portion 201 of the reflecting sheet contact portion 20 to the side surface 62 of the front housing 6 and the separate member 24 are formed. A part 533 may be further provided. As shown in FIG. 9, by forming a bent portion 533 that is convex on the upper surface 53 of the reflective sheet 5, the angle at which the tip 534 of the upper surface 53 of the reflective sheet 5 contacts the front housing 6 becomes shallow. It is possible to further prevent the sheet 5 from being caught by the corner 22 of the front housing. Other configurations are the same as those in the first and second embodiments.

As a modification of the third embodiment, the distal end portion 534 may be bent toward the rear housing 7 without providing the bent portion 533.

In the above embodiment, an example of a planar light source device using a metal casing has been described. However, the present invention is not limited to such a planar light source device, but a casing made of other materials, for example, a resin casing. The present invention can also be applied to a planar light source device using a body. Moreover, although the example of the planar light source device using a U-shape as the light emitter 3 has been described, the present invention is not limited to such a planar light source device, and other shapes such as an L-shape and a linear shape are used. The present invention can also be applied to a planar light source device using the light emitter 3.

It is a top view of the planar light source device concerning Embodiment 1 of this invention. It is sectional drawing of the planar light source device concerning Embodiment 1 of this invention. It is a principal part enlarged view of the planar light source device concerning Embodiment 1 of this invention. 1 is an exploded perspective view of a surface light source device according to Embodiment 1 of the present invention. It is sectional drawing of the planar light source device concerning Embodiment 1 of this invention. It is sectional drawing of the conventional planar light source device. It is sectional drawing of the planar light source device concerning Embodiment 1 of this invention. It is sectional drawing of the planar light source device concerning Embodiment 2 of this invention. It is sectional drawing of the planar light source device concerning Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light guide plate, 2 Optical sheet, 3 Light-emitting body, 5 Reflective sheet, 6 Front housing | casing, 7 Back housing | casing, 20 Contact part, 21 Extension part, 22 Corner | angular part, 201 Top part of contact part

Claims (2)

Has an opening on the upper surface, a housing that forms form in combination the back housing front housing and the upper surface of the box-shaped rear is opened is opened,
A light guide plate having a light exit surface that receives light from a light emitter stored in the housing and emits light toward an opening of the front housing;
A reflection sheet provided on the back surface facing the light exit surface of the light guide plate, covering the periphery of the light emitter and having one end reaching the light exit surface of the light guide plate;
A display panel mounted on the upper surface of the front housing,
The front housing has a reflection sheet contact portion that is convex in the back direction formed on the upper surface of the front housing in order to bring one end of the reflection sheet into contact with the light guide plate ,
On the upper surface of the front housing, a display panel mounting portion formed in a region from the reflective sheet contact portion to the side surface of the front housing;
A display device, comprising: an extension portion that extends from a top portion of the reflection sheet contact portion formed in a part of the reflection sheet contact portion to a side surface of the front housing. A housing formed by combining a box-shaped front housing having an opening on the upper surface and the rear surface being opened and a rear housing having an upper surface opened;
A light guide plate having a light exit surface that receives light from a light emitter stored in the housing and emits light toward an opening of the front housing;
A reflection sheet provided on the back surface facing the light exit surface of the light guide plate, covering the periphery of the light emitter and having one end reaching the light exit surface of the light guide plate;
A planar light source device having a reflective sheet contact portion that is convex in the back direction on the upper surface of the front housing in order to bring one end of the reflective sheet into contact with the light guide plate,
The planar light source device, wherein another member is disposed on the front casing so as to extend from the top of the reflection sheet contact portion to a side surface of the front casing.

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