JP3180147B2 - Light guide plate for liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate for use in a liquid crystal display or the like, and more particularly to a light guide plate for a liquid crystal display which exhibits high brightness and uniform brightness over the entire surface of the light guide plate.

[0002]

2. Description of the Related Art The characteristics required of a light guide plate for a liquid crystal display used in a liquid crystal display or the like are such that the light utilization rate of a light source is increased to increase the luminance of light transmitted to the front of the light guide plate, and furthermore, the transmitted light Exhibit uniform brightness over the entire surface of the plate.

FIG. 14 shows an example of a conventional light guide plate. A light guide plate 20 is provided on one side of a transparent plate along a straight tube light source (CFL) 22 provided on one side of the light guide plate 20 as shown in FIG. A plurality of reflection grooves 21 having a triangular cross section as shown are formed at predetermined intervals, and light 23 emitted from the light source 22 strikes the inclined surfaces 21a of the respective reflection grooves 21 and is reflected and transmitted to the transmission surface side.

In such a conventional light guide plate 20,
In order to increase the reflection efficiency, the angle of the reflection groove is set to 45 °, or the width of the plate is reduced in a tapered shape as the distance from the light source 22 increases, so that the frequency of reflection on the far side of the light source 22 is increased, and the entire surface of the plate surface is increased. To obtain uniform brightness.

[0005]

However, in order to obtain a light guide plate with higher brightness, even if the light guide plate is devised to have a tapered width, the effect is limited.
There has been a tendency to cope by changing the groove depth and the groove pitch.

In such a light guide plate, it is very difficult to clearly grasp the characteristics of light, and even if the groove depth and groove pitch are theoretically adjusted, a light guide plate having high luminance and uniform luminance can be obtained. Accomplishing it was a cruel difficulty.

[0007] In the light guide plate, as the area of the plate surface increases, the brightness tends to become uneven. As described above, it is very difficult to deal with such luminance unevenness by adjusting the groove depth or groove pitch of the reflection groove.

The present invention has been made in view of the above circumstances, and a liquid crystal display capable of exhibiting high brightness and uniform brightness over the entire surface of a light guide plate by increasing the light utilization rate of a light source. It is an object to provide a light guide plate for use.

[0009]

In order to solve the above-mentioned problems, a light guide plate for a liquid crystal display according to the first aspect of the present invention is provided on one side.
On the opposite side of the one side of the light guide plate provided with a plurality of reflection grooves
A plurality of fine expansion
A diffuse reflection groove is provided, and
In the light guide plate subjected to the strike processing, the diffuse reflection groove
Has a shallower groove depth than the single-sided reflection groove and has a groove pitch.
It is characterized in that the hook is formed narrow .

Further , a light guide for a liquid crystal display according to claim 2 of the present invention.
2. The plate according to claim 1, wherein the light guide plate is on a side of the light guide plate.
The thickness gradually increases as you move away from the light source
It is characterized by being formed thin .

The light guide for a liquid crystal display according to claim 3 of the present invention.
The plate is provided on a side of the light guide plate according to claim 1.
Extending above the light source and extending the outer edge of the light guide plate
Is formed to adjust the light transmittance on the inner surface of the extension.
And a transmission adjustment unit that diffuses light.
Sign .

Further, according to a fourth aspect of the present invention, there is provided a liquid crystal display
The light plate is provided on a side of the light guide plate according to claim 1.
Extending the outer edge of the light guide plate above the illuminated light source
Part is formed, and a light transmittance is provided on the transmission surface side of the extension part.
There is a transmission adjustment unit that adjusts and diffuses light.
It is characterized by the following .

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

According to the present invention, in a light guide plate provided with a plurality of reflection grooves on one surface, incident light from a light source provided on the side of the light guide plate is reflected by the reflection grooves on one surface and is reflected. In some cases, uneven brightness or a phenomenon of low brightness may occur on the transmission surface on the side opposite to the one surface provided with. According to the present invention, the partial luminance unevenness or low luminance can be eliminated by performing diffusion processing on the transmission surface side with respect to the portion where the luminance unevenness or low luminance of the transmission surface has occurred.

Further, the light guide plate provided with a plurality of reflection grooves on one side may have uneven brightness on the entire surface or low brightness on the entire surface. In this case, by performing diffusion processing on the entire transmission surface of the light guide plate, it is possible to eliminate uneven brightness on the entire surface of the light guide plate and improve the brightness over the entire surface.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view of a light guide plate according to the present invention, showing an example in which a diffuse reflection groove is partially formed on a transmission surface. FIG. 2 is a schematic sectional view of a light guide plate according to the present invention, showing an example in which a sandblasting process is partially applied to a transmission surface.
FIG. 3 is a schematic sectional view of a light guide plate according to the present invention, showing an example in which a diffuse reflection groove is formed on the entire transmission surface. FIG. 4 is a schematic cross-sectional view of a light guide plate according to the present invention, showing an example in which sand blasting is applied to the entire transmission surface. FIGS. 5A to 5K are plan views showing various patterns of the reflection groove provided on one surface of the light guide plate according to the present invention. Fig. 6 (a) through
(c) is a partial cross-sectional view showing various examples of the cross-sectional shape of the reflection groove provided on one surface of the light guide plate in the present invention. FIG.
FIG. 7A is a partial plan view illustrating an example of a reflection groove provided on one surface of the light guide plate according to the present invention, and FIG. 7B is a partial cross-sectional view along the line AA in FIG. . FIG. 8A is a partial plan view showing an example of a reflection groove provided on one surface of the light guide plate in the present invention, and FIG. 8B is a partial cross-sectional view taken along line BB of FIG. 8A. It is. FIG. 9A is a partial plan view showing an example of a reflection groove provided on one surface of the light guide plate according to the present invention, and FIG. 9B is a partial cross-sectional view taken along line CC of FIG. 9A. It is. FIGS. 10 (a) to 10 (i) show various embodiments in which the light-transmitting surface of the light guide plate according to the present invention is partially diffused. FIG. 11 is a partial cross-sectional view showing a state in which a transmission adjusting unit is provided on the inner surface of an extension provided on the outer edge of the light guide plate according to the present invention. FIG. 12 is a partial cross-sectional view showing a state in which a transmission adjusting unit is provided on the surface of an extension provided on the outer edge of the light guide plate according to the present invention. FIGS. 13 (a) and (b) show FIG.
FIG. 13 is a plan view illustrating an enlargement effect of the light guide plate having the transmission adjusting unit in FIG. 12.

The light guide plate 1 for a liquid crystal display according to the present invention is shown in FIG.
As shown in FIG. 4 to FIG. 4, a light-transmitting plate made of plastic or the like is provided, a plurality of reflection grooves 3 are provided on one surface 2 of the plate, and a diffusion process 5 is formed on a transmission surface 4 opposite to the one surface 2. Is applied. This diffusion process 5
Can be carried out by applying the diffuse reflection groove 6, the sand blast processing 7, or the sand blast processing 7 to the diffusion reflection groove 6, as described later.

Further, as described above, the light guide plate 1 having the various reflection grooves 3 provided on the one surface 2 is formed such that its thickness gradually decreases as the distance from the light source 8 provided on the side of the light guide plate 1 increases. The tapered shape is preferable in order to increase the utilization rate of light from the light source 8.

The planar shape of the reflecting groove 3 provided on one surface 2 of the light guide plate 1, that is, the pattern of the reflecting groove 3 is shown in FIG.
As shown in (k) to (k), various things can be considered depending on the shape of the light source 8 installed on the side of the light guide plate 1 and the like. As the light source 8, a normal electrode tube (LED) is used, which includes a straight tube, an L-shaped tube, a U-shaped tube, or a quadrangular tube (hereinafter, referred to as a tube) surrounding the entire outer periphery of the light guide plate 1. Called "quadrilateral pipe").

FIGS. 5A to 5K show various patterns of the reflection groove 3 provided on one surface 2 of the light guide plate 1 according to the present invention. The light guide plate 1 has a planar shape composed of a rectangle of long side: short side = 4: 3.

FIG. 5 (a) shows that a straight tube type light source 8 is provided on the long side of the light guide plate 1, and a plurality of reflection grooves 3 are provided along the long side of the light guide plate 1. ing.

Further, as shown in FIG.
(A) The straight tube type light source 8 may be provided on both opposing sides of the light guide plate 1.

As the light source 8, an L-shaped tube as shown in FIG. 5C, a U-shaped tube as shown in FIG. A quadrilateral tube as shown in (e) may be used. The quadrilateral tube shown in FIG. 5E can be substituted by disposing two L-shaped tubes opposite to the light guide plate 1 as shown in FIG. 5H.

As shown in FIG. 5F, an L-shaped tube is used as the light source 8, and a plurality of reflection grooves 3 are juxtaposed in a direction sandwiched between two sides of the L-shaped tube of the light source 8. The light guide plate 1, that is, the light guide plate 1 in which the inclined reflection grooves 3 are juxtaposed, may be used.

Further, as shown in FIG.
The inclination direction of the reflection groove 3 of the light guide plate 1 shown in FIG.
Reflection grooves 3 in a direction parallel to the corners of the L-shaped tube 3
May be juxtaposed.

Further, as shown in FIG.
(F) Or two L-shaped tubes may be arranged on the side of the light guide plate 1 having the inclined reflection groove 3 shown in FIG.

For the light guide plate 1 having the inclined reflecting groove 3 shown in FIG. 5 (f) or 5 (g), in addition to the above-mentioned L-shaped tube, a straight tube, a U-shaped tube, and four sides A mold tube or the like may be used.

Further, as shown in FIG. 5 (i), an L-shaped tube is used as the light source 8, and a light guide plate in which the reflecting grooves 3 are juxtaposed in parallel to the long side and the short side of the L-shaped tube. It may be 1. In the light guide plate 1, as described above, two L-shaped tubes may be used as the light source 8, or a straight tube, a U-shaped tube, a quadrilateral tube, or the like may be used.

The reflection groove 3 shown in FIGS. 5A to 5I has a triangular cross section as shown in FIG. 6A, a trapezoid as shown in FIG. 6B or a circle as shown in FIG. 6C. The shape may be an arc shape, and the planar shape may be a straight shape or an arc shape.

The reflection groove 3 shown in FIGS. 5 (j) to 5 (k)
A plurality of concave shapes are formed on one surface of the light guide plate 1.
The shape of the reflecting groove 3 is a pyramid shown in FIGS. 7 (a) and (b), a truncated pyramid shown in FIGS. 8 (a) and (b), or FIGS. 9 (a) and 9 (b). The shape may be a hemisphere as shown.
As shown in FIG. 5 (j), a plurality of these reflecting grooves 3 are formed in a grid pattern along the long side and the short side of the light guide plate 1, or as shown in FIG. The reflection groove 3 having the shape shown in FIG. 7, FIG. 8, or FIG. 9 may be formed in each section as a rectangular section.

Each of the reflection grooves 3 shown in FIGS. 5A to 5K is formed such that the groove pitch becomes narrower as the distance from the light source 8 increases, so that the amount of light weakened as the distance from the light source 8 decreases. In addition, the reflection efficiency may be improved by increasing the density of the reflection groove 3.

Similarly, by increasing the depth of the reflection groove 3 as the distance from the light source 8 increases, the reflection efficiency of each reflection groove 3 may be increased, and the amount of light weakening as the distance from the light source 8 decreases may be compensated. .

Further, by applying sandblasting 7 or fine metal particles to such a reflection groove 3, the light incident on the reflection groove 3 is scattered in a complicated manner. The luminance may be averaged over the entire plate surface.

The flat surface 2a (see FIGS. 6 (a) to 6 (c)) other than the reflection groove 3 on the one surface 2 is preferably mirror-finished by a cutting tool or the like. This allows
In the light guide plate 1, diffuse reflection light is generated only in the inclined surface of the reflection groove 3 in the reflection groove 3, and the diffusion light in the reflection groove 3 is more effectively diffused in the reflection groove 3 without interference from others. Be demonstrated.

According to the present invention, a diffusion process 5 is performed on the transmission surface 4 on the opposite side of the one surface 2 of the light guide plate 1 provided with the reflection groove 3 as described above. This diffusion processing 5
The reflection groove 3 provided on the one surface 2 causes uneven brightness in the light guide plate 1 or the entire surface thereof, or diffuses the light reflected from the reflection groove 3 by applying the light guide plate 1 when the brightness of the light guide plate 1 is low. Thus, uneven brightness is eliminated, and the brightness is improved.

Therefore, as shown in FIG. 1 and FIG. 2, when luminance unevenness occurs in the portion of the light guide plate 1, a diffusion process 5 is applied to the portion, and as shown in FIG. 1
In the case where uneven brightness occurs on the entire surface of the light guide plate 1 or when it is necessary to improve the brightness of the entire surface of the light guide plate 1, the diffusion process 5 can be performed on the entire surface of the light guide plate 1.

The diffusion processing 5 is performed by forming the diffusion / reflection groove 6 as shown in FIG. 1 or FIG. 3, applying the sand blast processing 7 as shown in FIG. It can be carried out by a method of performing sandblasting 7 after forming 6.

The above-mentioned diffuse reflection groove 6 is provided on one side 2 of the reflection groove 3.
Similarly to the above, the shape is not particularly limited. However, it is preferable that the groove is shallower than the reflecting groove 3 on one side and the groove pitch is narrow and fine and tight. The reason is that when the diffuse reflection groove 6 of the transmission surface 4 has a reflectance equal to or higher than that of the one-side reflection groove 3, the diffuse reflection groove 6 may rather promote uneven brightness, and the diffuse reflection groove 6 This is because, in order to further exhibit the diffusion effect of (1), it is desirable to finely diffuse the reflected light generated by the reflection groove 3 on one side.

Therefore, as the diffusion processing 5, the diffusion / reflection groove 6 which is very fine and tightly formed, or the fine and dense diffusion / reflection groove 6 is formed and then subjected to sandblasting 7 or sandblasting 7 It is preferable to perform only the processing.

FIGS. 10A to 10I show various light guide plates 1 formed according to the present invention. In these figures, a dotted portion shows a diffusion process 5 applied to the transmission surface 4, and on the background thereof, a reflection groove 3 of one side 2 as shown in FIGS. 3 shows a state seen through the transmission surface 4 side. As shown in these figures, the diffusion process 5 is partially applied to the transmissive surface 4 by the above-described method with respect to the partial brightness unevenness or the partial brightness reduction.

As shown in FIG. 10 (d) or 10 (h), it is also possible to apply a diffusion process 5 to a portion of the light guide plate 1 away from the center or the side edge of the transmission surface 4. In particular, in the case of the light guide plate 1 having a large area, a light quantity shortage easily occurs in a central portion or the like. In such a case, the light guide plate 1 is suitable for eliminating the insufficient light quantity and partial uneven brightness.

The reflection groove 3 on one side 2 shown in FIG.
5 (i), the reflected light from the two reflection grooves 3, 3 is concentrated at the intersection of the reflection groove 3 along the long side of the L-shaped tube 8 and the reflection groove 3 along the short side in FIG. May be too strong. Such a long side reflection groove 3 and a short side reflection groove 3
By performing the diffusion processing 5 on the transmission surface 4 side along the intersection with the above, the reflected light that is too strong can be diffused and uniform brightness can be obtained.

FIG. 11 shows an extended portion formed by providing a light source 8 on the side of a light guide plate 1 having a plurality of reflection grooves 3 formed on one surface 2 and extending the outer edge of the light guide plate 1 above the light source 8. 9 shows a partial cross-sectional state of the light guide plate 1 on which 9 is formed. Also in this light guide plate 1, the reflection groove 3 on one surface 2 is subjected to sandblasting, the flat surface 2 a is mirror-finished,
The fact that the thickness of the light guide plate 1 is gradually reduced as the distance from the light source 8 increases can be applied as described above. The same applies to the light guide plate 1 shown in FIG.

In the light guide plate 1 shown in FIG. 11, in order to solve the problem of uneven brightness occurring at the end of the light guide plate 1 near the light source 8 or the problem that the shape of the light source 8 is projected on the end of the light guide plate 1, In addition to performing the above-described diffusion processing 5 on the transmission surface 4, it is preferable to provide a transmission adjustment unit 10 that adjusts the light transmittance and diffuses the light on the inner surface of the extension unit 9. As the diffusion processing 5 shown in FIG. 11, a fine and tight diffusion reflection groove 6 is provided. In addition, by performing the above sand blast processing 7 or performing the sand blast processing 7 on the diffusion reflection groove 6. Is achieved.

The above-mentioned transmission adjusting section 10 forms a white plastic by mixing a transparent plastic with titanium for generating a white agent and fine particles such as gold as a light diffusing agent, and forms a white plastic. In addition to adjusting the light transmittance, the light diffusing agent can exhibit light diffusivity.

However, the light transmittance of the transmission adjusting unit 10 is determined not only by the white density based on the titanium content but also by the thickness of the transmission adjusting unit 10. The thickness of the transmission adjusting section 10 can be determined by considering the supporting strength of the extension section 9 and the like, and the white density may be determined so as to obtain a desired transmittance correspondingly.

When the light guide plate 1 is formed, the transmission adjusting portion 10 is formed on the inner surface of the extension portion 9 in a shape in which the transmission adjusting portion 10 is removed, and the transmission adjusting portion 10 is formed there. Alternatively, the transmission adjusting section 10 may be directly adhered to the inner surface of the extension section 9.

Since such a transmission adjusting section 10 is formed on the inner surface of the extension section 9 of the light guide plate 1 on the light source 8 side, light incident on the extension section 9 from the light source 8 is first transmitted by the transmission adjustment section 10. The light transmittance is adjusted and simultaneously diffused.
Of the light, the light transmitted above the extension 9 has its brightness weakened by the transmittance adjustment of the transmission adjuster 10, and further diffuses the light by the diffusion processing 5, so that the light is transmitted as in the conventional case. And the shape of the light source 8 is not projected above the extension 9.

A part of the diffused light generated by the transmission adjusting section 10 reaches the transparent section 1a of the light guide plate 1, and
The light is also diffused by the diffusion processing 5 provided on the transmission surface 4a and is also reflected in the direction of the reflection groove 3, and the overall light guide plate 1 is improved in brightness and uniformized by such a diffuse reflection action of various lights. can do.

The light guide plate 1 shown in FIG. 12 is provided on the transmission surface 4 side of the extension 9 in FIG.
Numeral 0 is provided along the surface of the extension portion 9, and the transmission adjusting portion 10 is formed so as to be inclined toward the surface toward the inside of the light guide plate 1. Then, the diffusion processing 5 as described above is performed including the surface of the transmission adjusting unit 10.

As the diffusion processing 5 shown in FIG. 12, a sand blast processing 7 is provided. In addition, the above-mentioned fine and dense diffusion reflection groove 6 or the sand blast processing 7 is formed on the diffusion reflection groove 6. It is realized by applying.

In the case of the light guide plate 1 shown in FIG. 12, the transmitted light from the light source 8 is transmitted in a relaxed state by the light transmittance of the transmission adjusting unit 10, and the light is transmitted by the diffusing agent in the transmission adjusting unit 10. Since diffusion occurs, the diffused light also enters the inside of the light guide plate 1 to improve the light use efficiency, thereby contributing to the improvement of the luminance of the entire plate surface and averaging.

Further, the transmission adjusting section 10 is formed in a portion extending from the upper surface of the extension section 9 to the inside of the light guide plate 1,
Since the transmission adjusting portion 10 is formed so as to be inclined toward the upper surface as it reaches the inside of the light guide plate 1, a portion where the thickness of the transmission adjusting portion 10 is gradually reduced is formed. The transmittance of incident light from the light source 8 can be adjusted by adjusting the thickness of the transmission adjusting unit 10 as described above.

In the light guide plate shown in FIGS. 11 and 12, when the straight tube type light source 8 is provided on one side of the light guide plate 1 as shown in FIGS. Adjustment unit 10
As shown by a dotted line in FIG. 13 (b), the extension 9 has a width t and is formed in a strip shape on one side of the light guide plate 1, and the width t and one side of the light guide plate 1 are defined. Is multiplied by the effective area of the light guide plate 1, so that an L-shaped tube, a U-shaped tube, two L-shaped tubes are provided diagonally, and so on. As the usage of the light source 8 increases, the area of the extension 9 increases, and the effective area of the light guide plate 1 increases.

[0062]

As described above, according to the light guide plate for a liquid crystal display of the present invention, in a light guide plate provided with a plurality of reflection grooves on one surface, the luminance of the transmission surface on the opposite side provided with the reflection grooves is provided. By performing a diffusion process on the transmission surface side of the portion where unevenness or low brightness has occurred, the partial brightness unevenness or low brightness is eliminated, and high brightness and uniform brightness are obtained over the entire surface of the light guide plate. Can be obtained.

When the light guide plate provided with a plurality of reflection grooves on one side is uneven in brightness or has low brightness, it is necessary to perform a diffusion process on the entire light transmitting surface of the light guide plate. Thereby, the brightness unevenness on the entire surface of the light guide plate is eliminated, or a light guide plate with high brightness over the entire surface can be obtained.

As described above, according to the present invention, according to the reflection performance of the reflection groove formed on one side, the portion having uneven brightness, the portion having low brightness, or the entire surface is diffused toward the transmission surface side. Since the treatment is performed, a light guide plate having high luminance and uniform luminance can be easily obtained by flexibly responding to the reflection characteristic of the reflection groove on one side.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a light guide plate according to the present invention, showing an example in which a diffuse reflection groove is partially formed on a transmission surface.

FIG. 2 is a schematic sectional view of a light guide plate according to the present invention, showing an example in which a sandblasting process is partially applied to a transmission surface.

FIG. 3 is a schematic sectional view of a light guide plate according to the present invention, showing an example in which a diffuse reflection groove is formed on the entire transmission surface.

FIG. 4 is a schematic cross-sectional view of a light guide plate according to the present invention, showing an example in which a sandblasting process is applied to the entire transmission surface.

5 (a) to 5 (k) are plan views showing various patterns of a reflection groove provided on one surface of the light guide plate according to the present invention.

FIGS. 6A to 6C are partial cross-sectional views showing various examples of the cross-sectional shape of a reflection groove provided on one surface of the light guide plate according to the present invention.

FIG. 7A is a partial plan view showing an example of a reflection groove provided on one surface of the light guide plate according to the present invention, and FIG.
FIG. 7 is a partial cross-sectional view taken along the line AA of FIG.

FIG. 8A is a partial plan view showing an example of a reflection groove provided on one surface of a light guide plate according to the present invention, and FIG.
FIG. 9 is a partial sectional view taken along line BB of FIG.

FIG. 9A is a partial plan view showing an example of a reflection groove provided on one surface of the light guide plate according to the present invention, and FIG.
FIG. 10 is a partial sectional view taken along the line CC of FIG.

FIGS. 10 (a) to 10 (i) show various forms in which a partial diffusion process is performed on a transmission surface of a light guide plate according to the present invention.

FIG. 11 is a partial cross-sectional view showing a state in which a transmission adjusting unit is provided on the inner surface of an extension provided outside the light guide plate according to the present invention.

FIG. 12 is a partial cross-sectional view showing a state in which a transmission adjusting unit is provided on the surface of an extension provided on the outer edge of the light guide plate according to the present invention.

FIGS. 13 (a) and 13 (b) are plan views showing the enlargement effect of the light guide plate having the transmission adjusting unit of FIG. 11 or FIG.

FIG. 14 is a plan view showing a conventional light guide plate.

FIG. 15 is a partial cross-sectional view taken along line DD of FIG. 14;

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 ... Light guide plate 2 ... One surface of a light guide plate 3 ... Reflection groove 4 ... Transmissive surface of a light guide plate 5 ... Diffusion processing 6 ... Diffuse reflection groove 7 ... Sandblasting 8 ... Light source 9 ... Extension part 10 ... Transmission adjustment part

Continuation of the front page (56) References JP-A-62-223022 (JP, A) JP-A-6-230378 (JP, A) JP-A-6-342159 (JP, A) JP-A-6-148408 (JP JP-A-7-301713 (JP, A) JP-A 52-120797 (JP, U) JP-A 59-9383 (JP, U) JP-A 62-161223 (JP, U) JP-A 62-161223 63-14204 (JP, U) WO 92/4648 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/00 311 F21V 8/00 601 G02F 1/13357

Claims (4)

(57) [Claims] 1. A light guide plate provided with a plurality of reflection grooves on one side.
Diffusion treatment on a part or the whole of the transmission surface on the opposite side of the one surface
And a plurality of fine diffuse reflection grooves are provided.
Light guide plate with sandblasted reflection groove
The diffusion reflection groove has a groove depth greater than that of the single-sided reflection groove.
Shallow and the groove pitch is narrow.
The liquid crystal display light guide plate for that. 2. A light guide plate for a liquid crystal display according to claim 1, wherein said light guide plate is formed to have a gradually decreasing thickness as it goes away from a light source provided on a side of said light guide plate. 3. An extension formed by extending an outer edge of the light guide plate above a light source provided on a side of the light guide plate,
2. A light guide plate for a liquid crystal display according to claim 1, wherein a transmission adjusting portion for adjusting light transmittance and diffusing light is provided on an inner surface of said extension portion. 4. An extended portion formed by extending an outer edge of the light guide plate above a light source provided on a side of the light guide plate,
2. The light guide plate for a liquid crystal display according to claim 1, wherein a transmission adjusting portion for adjusting light transmittance and diffusing light is provided on the transmission surface side of the extension portion.