JP2003043220A - Inside surface diffusion semitransmissive reflection plate and inside surface diffusion semitransmissive color liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inside surface diffusion semitransmissive reflection plate used for an inside surface diffusion semitransmissive color liquid crystal display device having excellent color reproducibility of a color filter and the inside surface diffusion semitransmissive color liquid crystal display device with the foregoing characteristics. SOLUTION: The inside surface diffusion semitransmissive reflection plate comprises a diffusion film having fine protrusions and recessions on its surface and formed on one surface of a glass plate and, at the same time, having light guide paths formed on the diffusion film so as to make light from a backlight serving as a light source incident from the other surface off the glass plate opposite to the surface on which the diffusion film is formed pass therethrough, further having a metal film formed on the diffusion film with the fine protrusions and recessions on the surface and with the light guide paths formed thereon and having light guide paths subsequently formed on the metal film with etching corresponding to the light guide paths formed on the diffusion film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner surface diffusion semi-transmission type reflection plate used for an inner surface diffusion semi-transmission type color liquid crystal display device having excellent color reproducibility of a color filter, and an inner surface diffusion semi-transmission type reflection plate having the above characteristics. The present invention relates to a color liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, light that uses a backlight as a light source together with outside light has been used, and has a high reflection efficiency over a wide angle both in bright and dark areas and has a wide viewing angle in any direction. Type color liquid crystal display devices are receiving attention. For example, JP-A-200
In 0-19507, the surface of a transparent plate, such as a glass plate, through which light is transmitted is made uniform and fine by sandblasting, and a metal film such as aluminum is formed thereon as a reflective film by a vacuum deposition method or the like. , An inner surface diffusion semi-transmissive reflection plate in which a light guide path through which light passes through the reflection film at regular intervals is formed by etching is disclosed, and transparent protection is provided on the reflection film of the inner surface diffusion semi-transmission type reflection plate. An inner surface diffusion semi-transmissive color liquid crystal which is formed by forming a film to prevent oxidation of the reflection film, flattening the surface, and forming a color filter layer and a transparent electrode layer on the surface to form one substrate for liquid crystal display. A display device is disclosed. According to this inner surface diffusion semi-transmissive type color liquid crystal display device, light incident from the outside is diffusely reflected by the surface of the reflection film to be uniformly diffused, and light from the backlight as a light source passes through the light guide path to the front side. Since it is radiated to the outside, it is possible to efficiently use the light from the outside and the light from the light source, and it has a high reflection efficiency over a wide angle both in bright and dark places, and has a wide viewing angle in any direction. The effect is obtained.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The inner surface diffusion transflective color liquid crystal display device described in Japanese Patent Application Laid-Open No. 000-19507 has the above-mentioned excellent characteristics, but it is not always satisfactory in the color reproducibility of the color filter. Therefore, the present invention provides an inner diffusion semi-transmissive reflective plate used in an inner diffusion semi-transmissive color liquid crystal display having excellent color reproducibility of a color filter and an inner diffusion semi-transmissive color liquid crystal display having the above characteristics. The purpose is to do.

[0004]

An inner surface diffusion semi-transmissive reflection plate of the present invention made on the basis of the above points, as described in claim 1, has fine irregularities on one surface of a glass plate. With the diffusion film having, the light guide path is formed in the diffusion film so that light having a light source through a backlight incident from the surface opposite to the surface of the glass plate on which the diffusion film is formed passes. Further, after the metal film is formed on the diffusion film having the fine unevenness on the surface and the light guide path is formed, the metal film is etched to correspond to the light guide path formed on the diffusion film. Is also characterized in that a light guide path is formed. The inner surface diffusion semi-transmissive reflection plate according to claim 2 is the inner surface diffusion semi-transmission type reflection plate according to claim 1, which has fine irregularities on its surface by exposure and development by a photolithography method and has a light guide path. It is characterized in that the formed diffusion film is formed. The inner surface diffusion semi-transmissive reflection plate according to claim 3 is the inner surface diffusion semi-transmission type reflection plate according to claim 1 or 2, wherein the fine irregularities are formed in a random pattern having periodicity. Is characterized by. Further, the inner surface diffusion transflective color liquid crystal display device of the present invention is as described in claim 4,
An inner surface diffusion semi-transmissive reflection plate according to any one of claims 1 to 3 is provided. An inner surface diffusion semi-transmission type color liquid crystal display device according to claim 5 is the inner surface diffusion semi-transmission type color liquid crystal display device according to claim 4, wherein the inner surface diffusion semi-transmission type liquid crystal display device according to any one of claims 1 to 3 is used. A color filter layer is directly formed on the reflection plate, and a transparent electrode layer and an alignment film are formed on the color filter layer via a flattening film to form one substrate for a liquid crystal display, and via the liquid crystal layer. An inner surface diffusion semi-transmission type color liquid crystal display device having a color liquid crystal display mechanism by disposing the other substrate for liquid crystal display so as to face the substrate, the liquid crystal display device being formed on the diffusion film and the metal film. The color filter layer is formed so that a single color filter material is filled in the light guide path. An inner surface diffusion semi-transmissive color liquid crystal display device according to a sixth aspect is the inner surface diffusion transflective color liquid crystal display device according to the fifth aspect, wherein a black matrix is formed on the metal film. And

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The inner surface diffusion transflective type reflection plate of the present invention comprises a glass plate having a diffusion film having fine irregularities formed on one surface of the glass plate and the diffusion film formed thereon. A light guide path is formed in the diffusion film so that light from a light source of a backlight incident from a surface opposite to the surface of the plate passes through the light guide path. After the metal film is formed on the diffusion film, the light guide path is also formed on the metal film by etching corresponding to the light guide path formed on the diffusion film. The metal film which is the reflection film in the inner surface diffusion semi-transmissive reflection plate of the present invention is formed on the diffusion film having fine irregularities on its surface. Since the fine irregularities on the surface of the diffusion film can be easily and freely formed by using a photolithography method or the like, in the inner surface diffusion transflective reflector of the present invention, the fine irregularities on the surface of the metal film are It has an advantage that it can be easily and freely formed corresponding to the fine irregularities. JP 20
In the inner surface diffusion transflective color liquid crystal display device described in Japanese Patent Application Laid-Open No. 00-19507, a transparent protective film is formed on a reflective film formed on a glass plate whose surface is a uniform and fine rough surface. Since the surface thereof is flattened and the color filter layer is formed thereon, the light guide path formed in the reflection film is filled with the protective film material, and the individual color filters, red (R) and green ( G) and blue (B) are formed on the protective film. On the other hand, in the inner surface diffusion semi-transmission type color liquid crystal display device provided with the inner surface diffusion semi-transmission type reflection plate of the present invention, the color filter layer is directly formed on the metal film which is the reflection film, and the diffusion film Since the single color filter material is filled in the light guide formed in the metal film, the thickness of the color filter is increased, and in particular, the metal film is formed. Further, it is effective in improving the color reproducibility of the color filter when the light incident from the surface opposite to the surface of the glass plate passes through the light guide path.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The inner diffusion / semitransmissive reflection plate of the present invention and the inner diffusion / semitransmission type color liquid crystal display device provided with this reflection plate will now be specifically described with reference to the accompanying drawings. The present invention is not limited to the following description.

FIG. 1 shows an embodiment of the inner surface diffusion transflective type reflection plate of the present invention. The inner surface diffusion semi-transmissive reflection plate A is manufactured, for example, as shown in FIG.

That is, first, as shown in FIG.
The diffusion film 11 is formed on the glass plate 2 which is a transparent substrate. The surface of the diffusion film 11 is made finely uneven, and a light guide path is provided so that light from the backlight, which is incident from the surface opposite to the surface of the glass plate 2 on which it is formed, passes through the diffusion film 11. 11a is formed. The diffusion film 11 can be easily formed by exposure / development by a photolithography method, for example. Specifically, after coating the resin on the glass plate 2 by a coating method such as a spin coating method, the temperature is 80 ° C. to 120 ° C. using a heating device such as a heating furnace.
Pre-baking is performed by heating for 1 minute or more in the temperature range of 1 to form a resin layer. Next, according to a conventional method, a predetermined fine pattern (the surface of the diffusion film 11 is made finely uneven and the light guide path 1 is formed).
1a) is exposed using a photomask on which a pattern for forming 1a) is drawn with high accuracy, and then developed using a predetermined developing solution to remove resin other than the pattern portion, and finally, , About 240 ° C using a heating device such as a heating furnace
The resin layer is baked by performing post-baking by heating for 60 minutes or more. By the above operation, the pattern on the photomask is accurately transferred to the resin layer, and the diffusion film 11 having the fine unevenness on its surface and the light guide path 11a is formed.
As long as the light guide path 11a can function as a light guide path and can increase the film thickness of the color filter by being filled with a single color filter material, the bottom part of the light guide path 11a is not always required. It does not have to be formed to reach the glass plate 2. However, when the bottom portion of the light guide path 11a does not reach the glass plate 2, the constituent resin of the diffusion film 11 is not covered by the light guide path 11a.
It should not diminish its function as a light guide. Therefore, from this viewpoint, the diffusion film 1
It is desirable that the constituent resin 1 is a resin of a transparent material such as an acrylic resin that allows light having a backlight as a light source to pass therethrough. By forming the fine irregularities in a random pattern having a periodicity, light incident from the outside can be diffused more uniformly on the surface. Further, the formation of the diffusion film 11 having fine irregularities on the surface thereof and the light guide path 11a formed thereon can be easily performed by the exposure and development by the photolithography method as described above. The method is not limited to this method. For example, JP-A-11-
As described in Japanese Patent No. 52110, after forming fine irregularities on the surface of a resin layer using a transfer mold, exposure / development is performed by a photolithography method to form a light guide path 11a to form a diffusion film 11. It may be formed.

The thickness of the diffusion film 11 is 1 μm to 3 μm at the maximum (convex portion of the uneven portion) and 0 at the minimum (recessed portion of the uneven portion).
It is desirable that the height difference is set to μm to 2 μm, and the maximum value of the height difference is set to 2.5 μm or less from the viewpoint of preventing a decrease in reflectance. From the same viewpoint, it is desirable that the pitch of fine irregularities (distance between adjacent convex portions) be 15 μm to 25 μm. The pattern for forming the light guide path 11a is not particularly limited, but the size of the formed light guide path 11a may be smaller than the size of each color filter formed later. Desirably, it is desirable that the pattern is such that at least one light guide path 11a is present in the area of each color filter. In this case, it is desirable that the aperture ratio of the opening formed as the light guide path 11a in the area of each color filter is 10% to 30%. Aperture ratio is 10
If it is less than%, the transmittance may decrease, while
This is because if the aperture ratio exceeds 30%, the reflectance may decrease.

Subsequently, as shown in FIG. 2B, a metal film 12 serving as a reflection film is provided on the diffusion film 11 having fine irregularities on its surface and having a light guide path 11a formed thereon. It is formed corresponding to the fine unevenness of. The metal film 12 is
Made of aluminum, silver, etc., with a film thickness of 0.1 μm to 1
It is preferably μm. Such a metal film 12 is
For example, it can be easily formed by a vacuum vapor deposition method, a sputtering method, or the like.

Finally, as shown in FIG. 2C, from the surface opposite to the surface of the glass plate 2 on which the metal film 12 is formed, corresponding to the light guide path 11a formed on the diffusion film 11. A light guide path is formed in the metal film 12 by etching so that light from the incident backlight as a light source may pass through. Complete the manufacturing of. The metal film may be etched by a conventional method such as photolithography.

Since the inner surface diffusion semi-transmissive reflection plate A manufactured as described above has fine irregularities on the surface of the metal film 12, the light incident from the outside is diffusely reflected on the surface of the reflection film and diffused uniformly. Can be made. In addition, the diffusion film 11 and the metal film 12 are arranged so that light from a backlight as a light source passes through.
Since the light guide path 13 is formed in the
3 can be made to pass and it can be made to radiate to the front side. Therefore, it becomes possible to efficiently use the external light and the light from the light source.

FIG. 3 shows an embodiment of a color filter layer formed on the inner surface diffusion semi-transmissive reflection plate A. Three types of color filters, namely red (R) 18R
And a green (G) 18G and a blue (B) 18B color filter layer are directly formed on the metal film 12 having fine irregularities on the surface thereof, and are also formed on the diffusion film 11 and the metal film 12. 13 is filled with a single color filter material. Therefore, the thickness of the color filter is increased, and in particular, the color of the color filter when the light incident from the surface opposite to the surface of the glass plate on which the metal film 12 is formed passes through the light guide path 13. Effective for improving reproducibility. It is to be noted that the boundary portions of the color filters adjacent to each other are positioned on the metal film 12,
In order to prevent light leakage and ensure the contrast, it is desirable to form the black matrix 22 in the relevant portion. The black matrix may be formed by a conventional method either before or after forming the color filter layer.

FIG. 4 shows an embodiment of an internal diffusion semi-transmissive color liquid crystal display device including an internal diffusion semi-transmissive reflection plate A. This inner surface diffusion semi-transmissive color liquid crystal display device B has color filter layers (18R, 18G, 1) on the inner surface diffusion semi-transmissive reflection plate A in the manner as shown in FIG.
8B) is directly formed, and the transparent electrode layer 20 made of ITO and the alignment film 21 are formed on the color filter layer through the planarizing film 19 to form one substrate for the liquid crystal display.
Then, the other substrate for liquid crystal display is arranged so as to face the substrate with the liquid crystal layer 4 sealed by the sealant 3 interposed therebetween. This substrate comprises a polarizing plate 6 which is sequentially provided on the upper surface side of the glass substrate 1 and retardation plates 7 and 8, and ITO is formed on the lower surface side of the glass substrate 1.
A transparent electrode layer 15 made of a material, a flattening film 16, and an alignment film 17 are laminated. Inner surface diffusion semi-transmissive reflector A
By arranging a backlight 30 such as a lamp on the back side of the above, an inner surface diffusion transflective color liquid crystal display device B is formed. The backlight 30 consumes less power than that used in a transmissive color liquid crystal display device, and is preferably one that can uniformly illuminate the inner surface diffusion semi-transmissive reflection plate A. The transparent electrode layer 20 may be omitted by providing the metal film 12 with an electrode function to form a reflective electrode plate.

FIG. 5 is an enlarged cross-sectional view showing light diffusion and light transmission of the inner surface diffusion semi-transmissive reflection plate A. Light incident from the outside is diffusely reflected by the fine irregularities on the surface of the metal film 12 formed corresponding to the fine irregularities on the surface of the diffusion film 11 and diffused uniformly. Further, the light incident from the outside is also diffusedly reflected at the corner portions of the light guide path 13 formed on the diffusion film 11 and the metal film 12.
Then, the light whose light source is the backlight 30 arranged on the back side of the inner surface diffusion semi-transmissive reflection plate A passes through the light guide path 13 and is radiated to the front side. At this time, since the light guide path 13 is filled with a single color filter material to increase the film thickness of the color filter, the color reproducibility of the color filter is improved.

[0016]

According to the present invention, an inner surface diffusion semi-transmission type reflection plate used in an inner surface diffusion semi-transmission type color liquid crystal display device excellent in color reproducibility of a color filter, and an inner surface diffusion semi-transmission type liquid crystal having the above characteristics. It is possible to provide a color liquid crystal display device.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an internal diffusion semi-transmissive reflection plate of the present invention.

FIG. 2 is a diagram showing one manufacturing process of the inner surface diffusion semi-transmissive reflection plate shown in FIG.

FIG. 3 is a view showing an embodiment of a color filter layer formed on an inner surface diffusion semi-transmission type reflection plate of the present invention.

FIG. 4 is a diagram showing an embodiment of an internal diffusion semi-transmissive color liquid crystal display device including an internal diffusion semi-transmissive reflection plate of the present invention.

FIG. 5 is an enlarged cross-sectional view showing light diffusion and light transmission of the inner surface diffusion semi-transmission type reflection plate of the present invention.

[Explanation of symbols]

A Inner surface diffuse transflective reflector B Inner surface diffusion transflective color liquid crystal display device 1, 2 glass substrate 4 liquid crystal 11 Diffusion film 12 metal film 13 Light guide path 18R, 18G, 18B color filter layer 22 Black Matrix

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1333 500 G02F 1/1333 500 1/1335 500 1/1335 500 505 505 520 520 1/13357 1 / 13357 (72) Inventor Teru Koyama 145th, Shikatakida, Takasaka-cho, Iwaki City, Fukushima Prefecture 1 Andean Intec Co., Ltd. (72) 145th, Hiromi Kikuchi, 145, Shikatakita, Takasaka-cho, Iwaki City, Fukushima Prefecture F Terms (reference) 2H042 AA09 AA15 AA26 AA32 BA04 BA12 BA13 BA15 BA20 DA02 DA04 DA11 DB00 DC08 DD10 DE04 2H048 BA02 BA11 BB02 BB14 BB15 BB28 BB44 2H090 JA03 JA06 JA19 JB02 LA10 LA15 LA16 2H091 FAZ FA31Z FA16Z FA16Z FA16 FA FAZ

Claims (6)

[Claims] 1. A diffusion film having fine irregularities on its surface is formed on one surface of a glass plate, and a backlight incident from a surface opposite to the surface of the glass plate on which the diffusion film is formed is provided. A light guide path is formed in the diffusion film so that light as a light source passes, and further, a metal film is formed on the diffusion film having the fine unevenness on its surface and the light guide path formed, An inner surface diffusion semi-transmissive reflection plate characterized in that a light guide path is also formed in the metal film by etching so as to correspond to the light guide path formed in the diffusion film. 2. The inner diffusion semi-transmission according to claim 1, wherein the diffusion film having fine irregularities on its surface and having a light guide path is formed by exposure / development by a photolithography method. Type reflector. 3. The fine irregularities are formed in a random pattern having periodicity.
Alternatively, the inner surface diffusion semi-transmission type reflection plate described in 2. 4. An inner surface diffusion semi-transmission type color liquid crystal display device comprising the inner surface diffusion semi-transmission type reflection plate according to any one of claims 1 to 3. 5. A color filter layer is directly formed on the inner surface diffusion semi-transmissive reflection plate according to claim 1, and a transparent electrode layer is formed on the color filter layer via a planarizing film. And an alignment film are formed to serve as one substrate for liquid crystal display, and the other substrate for liquid crystal display is arranged so as to face the substrate via the liquid crystal layer, thereby providing an inner diffusion half having a color liquid crystal display mechanism. A transmissive color liquid crystal display device, wherein the color filter layer is formed so that a single color filter material is filled in a light guide formed in the diffusion film and the metal film. The inner surface diffusion transflective color liquid crystal display device according to claim 4. 6. The inner surface diffusion transflective color liquid crystal display device according to claim 5, wherein a black matrix is formed on the metal film.