JPH0711603B2 - Color liquid crystal display element - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color liquid crystal display device for displaying pictures and characters, and more specifically, to increase the transmittance of natural light or light emitted by a back light. The present invention relates to a color liquid crystal display device having improved screen brightness and high contrast.

[Conventional technology]

Generally, a conventional color liquid crystal display device has a glass or plastic upper substrate (2) with red,
Green and blue (hereinafter referred to as RGB) pixels (a) (b) (c)
Forming a color filter (3) in which are arranged, and indium tin oxide (Indium Tin Oxide) or tin oxide is sputtered or vacuum-deposited on the entire surface to form a film, which is photo-etched. The upper transparent electrode (4) is formed by removing the coating on unnecessary parts, and further, Pi, (polyimide isoindoloquinazoline), PiQ (polyimide isoindoloquinazolinedione), PVA (polyvinyl acetate) An insulating material is applied to form an upper alignment film (5)
Is formed. On the other hand, on the lower substrate (9), the lower transparent electrode (8) is formed similarly to the upper transparent electrode (4), and the lower alignment film (6) is formed.

Then, the peripheral portions of the upper and lower substrates (2) and (9) are adhered with an adhesive to form a space portion having a predetermined space between the upper and lower substrates (2) and (9). , Liquid crystal is enclosed inside the space, and upper and lower polarizing plates (1) are placed outside.
A liquid crystal display element was constructed by attaching each of (10).

Such a general color liquid crystal display device includes RGB pixels (a), (b) and (c) and upper and lower transparent electrodes (4),
The pixel of the transparent electrode generated by superimposing (8) and (1) is made to correspond to 1: 1 and the back light (11) of white light is emitted from the back side of the color filter (3) to RGB of the color filter (3).
Transparent electrodes (4) and (8) above and below that convert to hue
The light quantity of each pixel is controlled by changing the arrangement of the liquid crystal (6) caused by turning the voltage on and off. Further, the back light (11) of the white light source may use a fluorescent lamp housed inside or may use external light such as natural light.

In the color filter of the prior art, the pixel arrangement is, as shown in FIGS. 4A, 4B, 4C, and 4D, stripe type, mosaic type, triangle, and square, respectively. It has a type of pixel array,
In the figure, a, b, and c represent RGB pixels of each color filter, and the hatched d portion represents a unit color pixel. Of these, the mosaic type shown in FIG. 4B was often used for the color filter.

[Problems to be solved by the invention]

However, such a conventional color filter is
Even if the arrangement of B pixels (a), (b), and (c) is different, since all the pixels are directly and densely arranged in a flat plate shape, the amount of light emitted from the back light (11) is attenuated, and the screen is Since it appears dark, in order to increase the brightness of the color filter and obtain a clear pixel display, the power consumption of the light source increases and it is not suitable for portable devices.

Therefore, the present invention has been devised as follows in order to solve such a drawback.

[Means for solving problems]

That is, liquid crystal is sealed between two substrates having transparent electrodes, and the peripheral portions of the substrates are adhesively fixed, and at least one substrate has red, green, and blue (RGB) pixels. In a color liquid crystal display device having no conductive layer or electrode between a pixel and a substrate, each pixel of the color filter is formed with a transmission hole through which a part of the light emitted from the back light can pass. Between them, a black band that can prevent excessive leakage of light is formed to increase the light transmittance of the color filter, improve the brightness of the screen, and prevent a decrease in contrast, resulting in clear image quality. We provide color liquid crystal display devices.

[Examples] Examples of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a plan view showing a color filter used in a color liquid crystal display device according to the present invention. As shown in the drawing, RGB pixels are provided with several transmission holes of 10 to 50 μm (diameter). , A black band of 1 to 50 μm (width) is formed between the RGB pixels or between the unit color pixels.

As shown in FIG. 1A, in the mosaic type color filter (30), RGB pixels (a) and (b)
Three circular transmission holes (31) are formed in each of (c), and a black band (32) is formed between unit color pixels (d) composed of three RGB pixels. Where RG
The size of each B pixel is 140 μm × 160 μm, the diameter of the transmission hole (31) is 30 μm, and the width of the black band (32) is 10 μm.

On the other hand, as shown in FIG. 1B, in the mosaic type color filter (30), the RGB pixel (a)
Four rectangular transmission holes (33) are punched in (b) and (c) to form a black band (34) between each pixel (a), (b) and (c). Here, the size of the transmission hole (33) is 20 μm × 30
The width of the black band (34) is 5 μm.

A laser machining, an electric discharge machining, a photolithography method or the like is used to form the transmission holes (31) (33), and a photolithography method is used to form the black bands (32) (34).
A printing method or the like is used. The material of the black belts (32) (34) is
Graphite for coating, black pigment, carbon black for black color, or the like is used.

Further, as a method for producing a color filter, a screen, an offset printing method, a dyeing method, a vacuum deposition method, a photolithography method by forming a multicolor polarizing film, a polymer electrodeposition method using a cation-anion, etc. are used. There is. The color filter according to the present invention uses a photolithographic method by dyeing, which has excellent light transmittance and color consistency and is capable of forming a precise pattern. The manufacturing process will be described below with reference to FIG.

As shown in the drawing, a black strip (34) is formed on the glass substrate (40) by photolithography using a photoresist.
Are selectively formed (see FIG. 2A). A gelatin or a glue layer (41) such as casein is applied thereon by a spinner or a roller. (See FIG. 2B) Then, the entire surface of the glue layer (41) is coated with a photoresist (42), and a red dye is attached using a photomask (43). Irradiate the part with light (44) (second
(See FIG. (C)). Then, the photoresist at the exposed portion irradiated with light is removed by a developing solution, and a red dye (45) is added to the exposed glue layer (41a) to dye the exposed R layer (a) with a red dye. Form. ((D) of FIG. 2
reference). Further, a color filter in which RGB pixels (a) (b) (c) are formed by changing the color of the dye to green or blue while sequentially repeating the steps shown in (C) and (D) of FIG. Is manufactured (see FIG. 2 (E)).

In the color filter manufacturing process according to the present invention, the transmission holes may be formed on the completed color filter by using the laser machining discharge method as described above. In the step shown in (B), it may be formed by partially masking the transmission hole forming portion of the color filter, or by forming a glue layer excluding the transmission hole portion using a photoresist and dyeing. it can.

〔The invention's effect〕

As described above, in the color liquid crystal display device according to the present invention, a transparent hole is formed in the pixel of the color filter to allow a part of the light emitted from the back light to pass therethrough, thereby increasing the amount of light and providing a liquid crystal display. The screen of the device can be brightened, and by forming a black band between color pixels to prevent excessive light leakage, the pixel contrast is improved and a clear image screen is obtained. effective.

[Brief description of drawings]

1 (A) and 1 (B) are plan views of a color filter used in a color liquid crystal display device according to the present invention, and FIGS. 2 (A) to 2 (E) show a manufacturing process of the color filter according to the present invention. FIG. 3 is a sectional view of a general color liquid crystal display device, and FIGS. 4A to 4D are plan views of color filters used in conventional color liquid crystal display devices. In the figure, 30 …… color filter, 31,33 …… transmission hole, 32,34 ……
Black band, a, b, c ... Red, green, blue (RGB) pixel, d ... Unit color pixel.

Claims (1)

[Claims] 1. A liquid crystal is sealed between two substrates on which transparent electrodes are formed, and the peripheral portion of the substrates is adhesively fixed, and at least one of the substrates has red, green, and blue (RGB) pixels. In a color liquid crystal display device having a conductive layer or an electrode between the pixel and the substrate, a plurality of light transmitting holes are formed in the pixel of the color filter, and the red, green, blue (RGB) ) A color liquid crystal display device characterized by being formed by forming a black band between each pixel or between unit color pixels.