JP2003279965A - Liquid crystal display - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a liquid crystal display device with improved reflection luminance without lowering color reproducibility in a transflective liquid crystal full color display. SOLUTION: A color filter is provided with a regular-shaped non-colored portion 2 formed corresponding to each of a plurality of types of colored portions, and the non-colored portion is formed on a convex portion, that is, a reflection portion formed on the other substrate. The areas of the non-colored portions are changed depending on the color of the color filter to improve the color reproducibility.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using a color filter formed by coloring a transparent organic film with a dye.

[0002]

2. Description of the Related Art A color filter in which a transparent organic film is colored with a dye is used in various fields because it is relatively inexpensive and has excellent optical characteristics. In particular, so-called dyeing, in which an organic film such as gelatin, casein, glue, etc. is formed on a transparent substrate such as glass in a pattern of line stripes or squares, and dyed regularly into three primary colors of red, green and blue with dyes. Modal color filter
It is often used as a color separation filter of a color image pickup device together with an interference filter. In recent years, this dyeing method color filter has been put into practical use and is becoming widespread as an application as a liquid crystal display device in combination with it along with the progress of liquid crystal displays.

Since this dyeing method color filter forms a pattern by photolithography, it has a higher pattern forming accuracy and a higher saturation than those of other color filters proposed for liquid crystal display devices. Since it is dyed directly with an organic dye, it also has superior optical characteristics compared to other types of color filters.

However, a liquid crystal display device produced by using this dyeing method color filter uses a polarizing plate, separates white light with a color filter, and controls light using a liquid crystal as a shutter. As a result, the brightness of outside light or white light behind can not be fully utilized, and the screen display is dark.

At present, in order to solve the above problem, the dyed color filter is provided with a regular non-colored portion formed corresponding to each colored portion, and the area of the non-colored portion is 10 times the area of the colored portion. By forming a liquid crystal display device using a color filter of 50% to 50%, brightness can be ensured without sacrificing display definition. Therefore, it is not necessary to make the dyeing lighter, and it is possible to obtain a liquid crystal display device which is excellent in light resistance of the colored portion and is uniform and bright.

[0006]

However, in the semi-transmissive liquid crystal display device having the characteristics of both the reflective portion and the transmissive portion, light passes through the color filter only once in the transmissive portion, whereas in the reflective portion. Since the light passes through twice, there is a problem that the reflection brightness is inevitably lower than the transmission brightness. Therefore, if the color filter provided with the non-colored portion is designed to face the transmission portion, there is a problem that the color reproducibility in transmission is deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a liquid crystal display device having an improved reflection brightness without lowering the color reproducibility.

[0008]

According to the present invention, a color filter is provided with a regular shaped non-colored portion formed corresponding to each of the plurality of types of colored portions, and the non-colored portion is provided on the other substrate. The projections, that is, the reflection portions thus formed are made to face each other, and the area of the non-colored portion is changed depending on the color of the color filter to improve the color reproducibility.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) A sectional structure of a liquid crystal display device of the present invention will be described with reference to the drawings. In FIG. 1, 1 and 4 are transparent glass substrates, and 2 and 8 are color layers formed by coloring an organic film such as gelatin, casein, and glue with a dye. 3 is a liquid crystal layer sandwiched between glass substrates.

The color layer pattern of each color formed by coloring an organic film such as gelatin formed on a glass substrate with a dye is substantially matched with the shape of the transparent pixel electrode. This shape is not as simple as a quadrangle or a triangle, but it is so small that it is regularly arranged, so it cannot be seen individually by the human eye. Each color pattern is incorporated so as to exactly match the shape of the transparent pixel electrode. In this case, the liquid crystal 3 is colored only in the portion that functions as a shutter, which is efficient.

By arranging the non-colored portion of the color filter so as to coincide with the convex portion of the reflecting plate formed on the other side, conventionally, the reflected light passes through the color layer twice, so that the reflected luminance is significantly lowered. However, by forming the non-colored portion as described above, like the transmitted light, the light passes through the color layer only once, and the reflected luminance can be increased without lowering the transmitted luminance.

(Second Embodiment) The positional deviation between the non-colored portion and the convex portion will be described. When the convex portion, that is, the portion where the reflective electrode is formed and the non-colored portion are deviated from each other, white light is directly emitted since the light passes through the color layer only once in transmission. Therefore, color reproducibility may deteriorate.
As a result of actually producing a sample in which the amount of deviation between the non-colored portion and the convex portion was large and measuring the color reproducibility in the reflection and transmission states, it was confirmed that the sample with the deviation deteriorates. It is considered that this demonstrates that the area of the non-colored portion on the transmissive portion becomes large and the color reproducibility in the transmissive state is deteriorated. Therefore, the non-colored area must be smaller than the convex area of the reflective region.

In the actual process, it is necessary to take into consideration the bonding accuracy of the glass substrate, the forming accuracy of the convex portion, that is, the reflective electrode, and the positional accuracy of the non-colored portion in the color filter, and the glass substrate is installed on the convex portion. It is considered appropriate to design the area of the non-colored portion to be 10% to 80% of the area of the convex electrode.

[0014]

As described above, according to the present invention, it is possible to manufacture a liquid crystal display device having a high reflection brightness without deteriorating the color reproducibility in the reflection state, and therefore the industrial value is great.

[Brief description of drawings]

FIG. 1 is a diagram showing a cross-sectional structure of a liquid crystal display device of the present invention.

FIG. 2 is a diagram showing a cross-sectional structure of a conventional liquid crystal display device.

[Explanation of symbols]

1 glass substrate 2 Colored layer having non-colored portion 3 Liquid crystal layer 4 glass substrates 5 reflector 6 reflected light 7 transmitted light 8 colored layers

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Motoaki Aoki             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yoshikazu Sakurai             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Seiji Nishiyama             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Yoshihiro Konishi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 2H048 BB02 BB07 BB08 BB10 BB42                 2H091 FA02Y FA14Y FC05 LA17

Claims (4)

[Claims] 1. A liquid crystal is sandwiched between a pair of substrates, a reflective region and a transmissive region are formed in a pixel region arranged in a matrix on one substrate of the pair of substrates, and the other substrate is formed. A color filter composed of a plurality of types of colored portions obtained by dyeing an organic substance film with a dye is formed on the upper side, and the plurality of types of colored portions of the color filter are arranged corresponding to the plurality of transparent pixel electrodes. In the liquid crystal display device, the reflective region is formed by forming a reflective film on a plurality of convex portions that are spaced apart from each other, and the transmissive region is
A liquid crystal display device, wherein the liquid crystal display device is formed by a substantially flat bottom portion other than the convex portion. 2. The liquid crystal display device according to claim 1, wherein a non-colored portion of the color filter is arranged on the other substrate so as to face the reflection region on the other substrate. A liquid crystal display device characterized in that 3. The liquid crystal display device according to claim 2, wherein the area of the non-colored portion of the color filter on the other substrate is different for each color of the colored portion of the color filter. Liquid crystal display device. 4. The liquid crystal display device according to claim 2, wherein the non-colored portion of the color filter is formed so as to face the flat portion on the convex portion of the reflection region, and the non-colored portion of the color filter is formed. A liquid crystal display device, wherein an area of a colored portion is smaller than an area of a convex portion of the reflective region.