JP2000275445A - Light guide and electro-optic device therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-optic device with a structure resisting cracking even when a board is thinned, particularly to allow a light guide having a structure for supporting various electro-optic panels to resist deformation even when impacted. SOLUTION: A rib-like reinforcing part 31c shaped like a bracing is formed on the back face 31b of a light conducting part 31. The reinforcing part 31c is formed in such a manner that a pair of straight lines interconnecting the opposite corners of panel support 30 cross each other to increase the rigidity of the panel support 30 against curving and twisting. The reinforcing part 31c is secured to the back face 31b near the corners of the panel support 30. A slit 31d is formed between the reinforcing part 31c and the back face 31b except at the peripheral edge of the back face 31b and a reflective film 35 is inserted into the slit 31d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide and an electro-optical device having the same.

[0002]

2. Description of the Related Art Generally, an electro-optical device is constituted by bonding a pair of substrates made of glass or the like via a sealant, and sealing liquid crystal in an inner region of the sealant sandwiched between the pair of substrates. Liquid crystal panel is provided. The liquid crystal panel is mounted and fixed on a panel support, usually made of synthetic resin, for mounting and mounting the liquid crystal panel on various devices.
For example, it is configured to be installed on a circuit board or the like.

Conventionally, for example, in a relatively small-sized electro-optical device, a plate-like support portion on which a liquid crystal panel is mounted on a front surface is provided as a panel support, and an outer periphery or an end face of the liquid crystal panel is positioned outside the support portion. And a frame-shaped part for covering and protecting the edge of the liquid crystal panel. In this case, when the liquid crystal panel is illuminated by a backlight, the plate-shaped support portion often has a light guide function as a light guide (light guide plate).

FIG. 1 is an exploded perspective view showing a configuration example of a conventional electro-optical device. The liquid crystal panel 10 includes substrates 11 and 12
Are bonded via a sealing agent (not shown), and a liquid crystal is injected between them. The substrate 11 includes an overhang region 11 a that extends outside the substrate 12.
On the surface of a, a wiring pattern 11b drawn out of the liquid crystal sealed area is formed. This wiring pattern 11b
Are conductively connected to electrodes formed on the respective opposing surfaces of the substrates 11 and 12. A panel terminal 11c is formed at an end of the wiring pattern 11b, and the panel terminal 11c is conductively connected to a flexible wiring board (not shown) or the like. A polarizing film 15 is adhered on the outer surfaces of the substrates 11 and 12, respectively.

The liquid crystal panel 10 is mounted on a panel support 20 integrally formed of a transparent resin such as polycarbonate or acrylic. The panel support 20 has a plate-shaped light guide 21 disposed behind the liquid crystal panel 10 and a frame 22 protruding to the front side in a region outside the light guide 21. The light guide section 21 includes a plurality of semi-cylindrical cutouts 21a along one side of the panel support 20.
Light emitted from a light source such as a light emitting diode (not shown) is introduced into the light guide section 21 from the concave portion 21a.
The light guide unit 21 has a light guide function of emitting light from the front surface (the upper surface in the figure) while propagating the light that has been introduced and incident on the plate surface. In this case, the light guide 2
The back surface (the lower surface in the drawing) of the light guide portion 1 is inclined so that the light guide portion 1 becomes thinner from the side where the concave portion 21a is formed to the opposite side. Then, a white reflective film 25 made of polyethylene terephthalate or the like is stuck on the inclined back surface. The reflection film 25 is used for the light guide 2.
1 has a function of scattering. The introduced light is gradually emitted to the front side by the reflection surface formed by the reflection film 25 attached on the inclined back surface. The light source may be mounted on a circuit board on which the panel support 20 is installed, or the light source may be mounted on a flexible wiring board which is conductively connected to the panel terminal portion 11c of the liquid crystal panel 10. The flexible printed circuit board is folded back to the back side of the panel support 20 so that the recess 2
You may set so that a light source may be arrange | positioned in the position facing 1a.

[0006] The frame-like portion 22 has a planar L-shaped L-frame portion 22a protruding above the light guide portion 21 and a planar I-shaped I-frame portion 22b.
Are provided in pairs. These L frame portions 22
The liquid crystal panel 10 is mounted on the panel support 20 in a state where the liquid crystal panel 10 is substantially positioned by the a and the I frame portion 22b.
A light scattering plate 23 is provided on the front surface of the light guide 21 as necessary.
Is affixed. Further, a pair of double-sided adhesive tapes 24 are attached to both sides of the front surface of the light guide 21, and the liquid crystal panel 10 is attached to the panel support 20 by the double-sided adhesive tape 24.

[0007]

In recent years, various devices incorporating a liquid crystal panel have been reduced in size and weight, and liquid crystal display devices have also been required to be thinner and lighter. One way to address this is to:
Attempts have been made to reduce the thickness of a substrate constituting a liquid crystal panel as compared with the related art. For example, conventionally, a glass substrate having a thickness of about 0.7 to 1.2 mm has been used, but in order to meet the above demand for thinning, the glass substrate has been further thinned, and 0.4 to 0.5
mm or less.

However, when the glass substrate is formed thin as described above, when the panel support is deformed due to an impact or the like when attached to and fixed to the panel support, stress is applied to the liquid crystal panel due to the deformation, and the substrate is cracked. there's a possibility that. In particular, when the support surface of the panel support is deformed in a direction in which it is curved or twisted, stress is easily applied to the substrate of the liquid crystal panel, and the substrate is easily broken. Furthermore, since the substrate of the liquid crystal panel is formed in a rectangular shape, cracks may occur near four corners of the substrate when an impact or the like is applied.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a structure of an electro-optical device which is less likely to crack even if the substrate is made thinner. An object of the present invention is to provide a light guide having a structure that does not easily deform even when subjected to an impact or the like.

[0010]

In order to solve the above-mentioned problems, a light guide according to the present invention has a structure in which an electro-optical panel can be integrally supported on a front surface, and light is introduced from a side end. A light guide having a plate-shaped light guide configured to emit light from the front surface facing the electro-optic panel toward the electro-optic panel, wherein the light guide has a plate of the light guide. A reinforcing portion having a thickness increased from the thickness is provided on the back side of the light guide portion.

According to the present invention, while the electro-optical panel is supported on the front surface of the light guide, light can be emitted from the front surface of the guide to illuminate the electro-optical panel. Since the light guide is reinforced by providing the unit integrally, the light guide is less likely to be deformed when subjected to external stress such as impact, so that the electro-optical panel supported on the front surface is damaged. Can be reduced.

In the present invention, it is preferable that the reinforcing portion is formed in a rib shape on the back surface.

According to the present invention, since the reinforcing portion is formed in the shape of a rib on the back surface, the curvature and torsion of the plate surface of the light guide can be reduced.

In this case, it is preferable that the reinforcing portion has a strut-like plane pattern on the back surface.

According to the present invention, the degree of reinforcement can be increased as a whole by providing the rib-shaped reinforcing portion having the strut-like plane pattern, and in particular, the curvature and torsion of the plate surface of the light guide. Can be reduced.

[0016] In the above invention, it is preferable that the reinforcing portion is formed so as to cover substantially the entire back surface.

According to the present invention, since the reinforcing portion is configured to substantially entirely cover the back surface, the reinforcing area of the reinforcing portion is increased, so that the rigidity of the light guide can be further increased.

In each of the above inventions, it is preferable that the reinforcing portion is formed so as to gradually increase in thickness from a peripheral portion of the back surface toward a central portion.

According to the present invention, the rigidity of the reinforcing portion itself can be increased by forming the reinforcing portion so as to gradually increase in thickness from the peripheral portion of the rear surface toward the center portion, so that the light can be increased. The amount of deformation of the guide can be further reduced.

In each of the above inventions, it is preferable that a reflection layer is interposed between the light guide portion and the reinforcing portion on the back surface so as to be integrally formed.

According to the present invention, the reflection layer is disposed on the back surface of the light guide section, and the reinforcing section is provided with the reflection layer interposed therebetween. Since it is separated from the light guide portion, it is possible to prevent the optical characteristics of the light guide portion from being affected by the reinforcing portion.

In the present invention, it is preferable that a slit is formed between the rear surface of the light guide and the reinforcing portion so that the reflection layer can be inserted and removed.

According to the present invention, since the slit is formed between the back surface of the light guide portion and the reinforcing portion, the reflection layer can be put in and out between the back surface and the reinforcing portion. Since the assembly becomes easy and the reflection layer can be removed after the assembly, the handling in the manufacturing process becomes easy.

Further, a liquid crystal display device of the present invention includes the light guide described in each of the above inventions, and a liquid crystal panel which is the electro-optical panel mounted and supported so as to face the front surface of the light guide. It is a thing.

[0025]

Next, embodiments of a light guide according to the present invention and an electro-optical device having the same will be described in detail. FIG. 2 shows a panel support 3 according to the present embodiment.
FIG. 3 is a perspective view showing a back surface 31b of the light guide unit 31 of FIG.
FIG. 4 is a rear view showing a rear surface 31b of the light guide unit 31 in the present embodiment, and FIG. 4 is a panel support 3 in the present embodiment.
It is sectional drawing which shows the state cut | disconnected along the straight line which connects between 0 corner parts (state cut | disconnected in the extension direction of the reinforcement part 31c mentioned later).

The panel support 30 is exactly the same as the panel support 20 shown in FIG. 1 in terms of the structure on the front side, and includes a light guide section 31 having a recess 31a and an L frame section 32a.
Frame part 32 provided with the I-frame part 32b and the reflection film 3
5 is a light guide section 21, a frame section 22, a reflection film 2 respectively.
5, the description is omitted. Further, the liquid crystal panel 10 is also exactly the same as that shown in FIG. 1, and is attached to the front side of the panel support 30 in the same manner as that shown in FIG.

On the back surface 31b of the light guide 31, there is formed a reinforcing portion 31c having a thickness of a convex rib formed in a strut shape (a plane X shape). The reinforcing portion 31c is configured to have a shape in which a pair of straight lines connecting opposed corners of the panel support 30 having a rectangular shape in a plan view intersect. Reinforcing part 31
c is fixed to the back surface 31b near the corner of the panel support 30. That is, the thickness of the reinforcing portion 31c is further added to the rear side of the plate-shaped light guide portion 31 in addition to the plate thickness of the light guide portion 31 to be reinforced. Therefore, the rigidity of the panel support 30 against bending and torsion of the plate surface is increased.

On the other hand, between the reinforcing portion 31c and the back surface 31b, a slit 31d is formed in a portion excluding the peripheral portion of the back surface 31b.
Are formed, and the reflection film 35 is inserted into the slit 31d. Here, the reflective film 35 may be simply inserted into the inside of the slit 31d, or may be stuck to the back surface 35.

There are various methods for forming the panel support 30 having the above-mentioned reinforcing portion 31c.
b, the reinforcing portion 31c is integrated (formed integrally with the frame-shaped portion 32), and the above-mentioned slit 3 into which the reflective film 35 can be inserted from the outside between the back surface 31b and the reinforcing portion 31c.
1d, and a reflection film 35 is formed in the slit 31d.
Is inserted while sliding from below in FIG. In this case, as shown by the arrow in FIG.
Can be taken in and out, so that there is an advantage that the reflection film 35 can be removed as necessary due to a product defect or the like.

In addition to the above-described method, after attaching the reflective film 35 on the back surface 31b, the reinforcing portion 31 is attached to the back surface 31b.
b, the four ends of the reinforcing portion 31
May be welded or adhered to the surface of the corner. In this case, the reflection film 35 may be sandwiched between the reinforcing portion 31c and the back surface 31b. Furthermore,
After attaching or arranging the reflective film 35 on the back surface 31b, the reinforcing portion 31c may be entirely welded or bonded including the surface of the reflective film 35.
In the method described in this paragraph, the slit 31d is not always necessary.

In the illustrated example, the convex ribs 31c are formed in an X shape in plan view, but the convex ribs may be formed integrally on the back surface 31b, and the planar pattern is arbitrary. The cross-sectional shape of the above-mentioned convex rib 31c is semicircular, but this cross-sectional shape is also arbitrary, and the cross-sectional shape is rectangular,
The cross section may be triangular. Furthermore, if there is no problem in the illumination unevenness of the back lighting, a reinforcing portion may be integrally formed on the back surface of the light guide portion, and the reflection film 35 may be adhered on the surface of the reinforcing portion as needed.

In the present embodiment, the rigidity of the panel support 30 is improved by the reinforcing portion 31c integrated with the panel support 30, so that the panel support 30 is not easily deformed even when an external stress such as an impact is applied. . Therefore, stress is less likely to be applied to the liquid crystal panel 10 supported by the panel support 30, so that damage to the liquid crystal panel 10 can be reduced. In particular, since the reinforcing portions 31c are formed in the rectangular panel support 30 in the form of struts, the rigidity of the panel support 30 against bending and twisting of the plate shape can be increased. The application of stress can be prevented. This torsional stress is particularly likely to damage the vicinity of the corners of the substrates 11 and 12 of the liquid crystal panel 10.

FIG. 5 shows a panel support 30 'according to a modification of the above-described embodiment. FIG. 6 shows a state in which the panel support 30' is cut along a straight line connecting the corners of the liquid crystal display device according to this modification (extending direction of the reinforcing portion). FIG.
In this example, as in the above-described embodiment, a reinforcing portion 31 ′ having a brace shape in plan view is formed. However, as shown in FIG. 6, the reinforcing portion 31'c is formed to be gradually thicker from the peripheral portion of the back surface 31'b toward the central portion. That is, the light guide section 3 is provided on the back side of the plate-shaped light guide section 31 '.
The thickness of the reinforcing portion 31'c is further added to the thickness of the reinforcing portion 31'c so as to be reinforced. Therefore, the rigidity of the reinforcing portion 31'c itself is improved, the effect of reinforcing the panel support 30 'is high, and the deformation of the panel support 30' can be further reduced.

FIG. 7 is a rear view of a panel support showing another modification of the above embodiment, and FIG. 8 is a longitudinal sectional view of this modification. The reinforcing portion does not need to be formed in the shape of a rib as described above, and may be integrated with the panel support 30 on the back surface 31b. For example, the reinforcing portion is configured to entirely cover the back surface 31b. May be.
FIG. 7 is a rear view showing the structure of the panel support 40 showing an example having such a reinforcing portion. In this modification, the panel support 40 includes a light guide section 41 and a frame section 42, and the reflective film 4 is provided on a flat back surface 41 b of the light guide section 41.
5, and a reinforcing portion 41c configured to cover substantially the entire back surface 41b from above is adhered by a double-sided adhesive tape or the like. Reinforcing part 41c and back 41b
May be performed only on the peripheral edge of the reflective film 45 so as to avoid the reflective film 45, but it is more preferable that the adhesive is also bonded on the reflective film 45 in order to enhance the reinforcing effect. The reinforcing portion 41c has a flat pyramid shape formed so that the thickness gradually increases from the peripheral portion of the back surface 41b toward the central portion. That is, the thickness of the reinforcing portion 41c is further added to the rear side of the plate-shaped light guide portion 41, which is larger than the plate thickness of the light guide portion 41, and the light guide portion 41 is reinforced.

Also in this modification, since the reinforcing portion 41c is gradually thickened from the peripheral portion toward the central portion, the rigidity of the reinforcing portion 41c is increased, so that the reinforcement of the panel support 40 is enhanced. The effect can be enhanced. When the reinforcing portion 41c is configured to cover almost the entirety on the back surface 41b, it is preferable that the reinforcing portion 41c be formed gradually thicker from the peripheral portion toward the center portion as described above. The external surface shape is arbitrary, and may be, for example, a stepped pyramid shape, a convex lens shape, or the like.

It should be noted that the light guide and the electro-optical device using the same according to the present invention are not limited to the illustrated examples described above, and that various changes can be made without departing from the gist of the present invention. Of course. For example, in the above embodiment, the case has been described where the panel support having a light guiding function as a light guide constitutes a part of a backlight for illuminating the liquid crystal panel from behind. Can also be applied to those that have a light guiding function as a front light that illuminates from the front side,
Further, the present invention can be applied to an electro-optical device using various electro-optical panels other than the liquid crystal panel.

[0037]

As described above, according to the present invention,
While the electro-optic panel is supported on the front of the light guide, light can be emitted from the front of the guide and illuminate the electro-optic panel, but the reinforcing part is integrally provided on the back. Accordingly, the light guide is reinforced, so that the light guide is less likely to be deformed when subjected to an external stress such as an impact, and damage to the electro-optical panel supported on the front surface can be reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a structure of a liquid crystal display device.

FIG. 2 is a perspective view showing the structure of the back side of the panel support in the embodiment of the liquid crystal display device according to the present invention.

FIG. 3 is a rear view of the panel support of the embodiment.

FIG. 4 is a cross-sectional view showing a state where the embodiment shown in FIG. 2 is cut along a straight line connecting between corners of the panel support.

FIG. 5 is a perspective view of a panel support according to a modification of the embodiment.

FIG. 6 is a cross-sectional view showing a state in which the modification shown in FIG. 5 is cut along a straight line connecting between corners of the panel support.

FIG. 7 is a rear view of a panel support according to a further modification of the embodiment.

8 is a cross-sectional view showing a state in which the modification shown in FIG. 7 is cut.

[Explanation of symbols]

 Reference Signs List 10 Liquid crystal panel 11, 12 Substrate 20, 30, 30 ', 40 Panel support 21, 31, 31', 41 Light guide 31b, 31'b, 41b Back 31c, 31'c, 41c Reinforcement 22, 32, 32 ', 42 Frame 25, 35, 35', 45 Reflective film

Claims (8)

[Claims] 1. An electro-optical panel is configured to be integrally supported on a front surface thereof, and light is introduced from a side end portion to transmit light from the front surface facing the electro-optical panel toward the electro-optical panel. A light guide having a plate-like light guide portion configured to emit light, wherein the light guide is provided with a reinforcing portion having a thickness increased from a plate thickness of the light guide portion on a back side of the light guide portion. A light guide characterized by being used. 2. The light guide according to claim 1, wherein the reinforcing portion is formed in a rib shape on the back surface. 3. The light guide according to claim 2, wherein the reinforcing portion has a strut-like plane pattern on the back surface. 4. The light guide according to claim 1, wherein the reinforcing portion is formed so as to cover substantially the entire back surface. 5. The method according to claim 1, wherein:
The light guide according to claim, wherein the reinforcing portion is formed so as to gradually increase in thickness from a peripheral portion of the rear surface toward a central portion. 6. Any one of claims 1 to 5
The light guide according to claim, wherein a reflection layer is interposed between the light guide portion and the reinforcing portion on the back surface of the light guide portion to be integrally formed. 7. The light guide according to claim 6, wherein a slit is formed between the rear surface of the light guide portion and the reinforcing portion so that the reflection layer can be inserted and removed. 8. One of claims 1 to 7
An electro-optical device comprising: the light guide according to any one of the preceding items, and the electro-optical panel mounted and supported so as to face the front surface of the light guide.