JPH05188365A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide the liquid crystal display device which makes color display by spectrally splitting the transmitted light from the rear surface, of which surface of color filters is flat and which is not deformed and deteriorated in properties by a high temp. and UV rays. CONSTITUTION:A tungsten layer 21 for preventing the static charge of a glass substrate is first formed in (b) on the glass substrate 20 in the process for production of the color filters of this liquid crystal display device. A resist 22 is applied on the tungsten layer 21 in (c) and is subjected to exposing by using a photomask 23 in (d); thereafter, the tungsten layer 21 is subjected to boring. The stage (e) is the state in which the resist is removed after the boring of the tungsten layer 21. A coloring material 24 of metallic atoms or metallic ions, etc., is applied in (f). The coloring material 24 is diffused into the substrate by thermal diffusion in (g), by which a diffused layer 24' is formed. The tungsten layer 21 is thereafter removed. The stages (b) to (g) are repeated three times in total by changing the metallic ions to be applied, by which three colors of patterns are formed.

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,
In particular, it relates to a liquid crystal display device for color display.

[0002]

2. Description of the Related Art Liquid crystal display devices having characteristics of thinness, light weight and low power consumption have been used in a wide variety of fields including electronics, but colorization of the liquid crystal display was a natural request. This colorization is performed by dispersing the transmitted light from the back surface in a backlight type liquid crystal display device that transmits light from the back surface for display. A color filter is usually used for the spectroscopy. A cross-sectional view of a conventional liquid crystal display device for color display is shown in FIG. Here, the liquid crystal layer is shown enlarged. The liquid crystal display device 10 is a glass substrate.
A liquid crystal 13 is sealed between 11 and 12, and polarizing plates 14 and 15 are provided outside the glass substrates 11 and 12, respectively. 16 is a liquid crystal
This is a seal for enclosing 13 in the container. On the glass substrates 11 and 12 (on the liquid crystal 13 side), ITO (In Tin Oxi
Although a transparent electrode formed by de) or the like is provided, it is omitted here. Reference numeral 17 is a color filter for separating the transmitted light from the glass substrate 12 side, that is, the rear surface side of the liquid crystal display device 10.

The color filter 17 is formed by arranging RGB colors, which are the three primary colors of light, at a pitch of about 0.1 mm. As a method of manufacturing the color filter 17, there are a dyeing method, a pigment dispersion method, a printing method, a vapor deposition method, and the like, and each is formed by laminating a coloring material on the glass substrate 11 (the liquid crystal 13 side). The dyeing method is a method in which a dyeable photosensitive film is processed using a photomask and dyed. The pigment dispersion method is a method of processing a colored photosensitive film using a photomask. Further, the printing method is a method of printing a pigment ink on a glass substrate, and the vapor deposition method is a method of vapor-depositing a multilayer interference film, which also uses a photomask. In any method, the above steps are repeated three times to form a pattern of three colors.

[0004]

However, the color filter formed by the above method is vulnerable to high temperature and ultraviolet rays as a material. In assembling the liquid crystal display device, when the ITO film is attached, the work is performed at a high temperature.
Further, the liquid crystal display device is often arranged in a place where it is easily exposed to ultraviolet rays. Under such a high temperature and an ultraviolet ray, the color filter is deformed or deteriorated to cause a problem such as a change in color development. In addition, if unevenness occurs on the color filter surface due to pattern shift during manufacturing, the liquid crystal layer 13
Thickness changes and the contrast deteriorates. Further, due to the temperature cycle that occurs when the power is turned on / off, the degree of adhesion of the color filter to the glass substrate is reduced, causing color shift due to peeling and the like, which also leads to a reduction in image quality. . The present invention is
It is an object of the present invention to solve the above problems and provide a liquid crystal display device in which a color filter has a flat surface and is not deformed or altered by high temperature or ultraviolet rays.

[0005]

In order to achieve the above object, a liquid crystal display device of the present invention is a liquid crystal display device which disperses transmitted light from the back surface to perform color display, and is a glass substrate on the front surface side. A coloring material required for spectroscopy is diffused inside.

[0006]

In this case, since the coloring material is directly injected into the glass substrate to form the color filter, the surface is always flat, and there is a possibility that the surface may be deteriorated at high temperature or under ultraviolet light. Absent.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.
explain. FIG. 1 shows a manufacturing process of a color filter in the liquid crystal display device of the present invention. The process proceeds from (a) to (g) in FIG. Through these steps (a) to (g), the glass substrate 20 on the front surface side (corresponding to the glass substrate 11 in FIG. 2)
After the color filter is formed on the substrate, the glass substrate 20 is turned upside down so that the color filter is on the liquid crystal 13 side to assemble the liquid crystal display device. On the glass substrate 20, a tungsten layer 21 having a high melting point is formed as shown in (b). The tungsten layer 21 also has a role of preventing the glass substrate 20 from being charged. A resist 22 is applied on the tungsten layer 21 in (c), and a photomask is applied in (d).
After performing exposure using 23, the tungsten layer 21 is perforated. (E) is a state in which the resist has been removed after the holes in the tungsten layer 21 have been drilled. In (f), a coloring material 24 such as metal atoms or metal ions as shown in Table 1 is applied. In (g), by heat diffusion with a furnace,
The coloring material 24 is diffused inside the glass substrate to form a diffusion layer 24 '. Then, the tungsten layer 21 is removed. The diffusion at this time is limited to the surface of the glass substrate 20. (B)
The steps (g) to (g) are repeated three times in total by changing the metal ion to be applied to form a pattern of three colors.

In the color filter of the liquid crystal display device of the present invention, the coloring material is diffused inside the glass substrate, but the manufacturing method is not limited to that shown in FIG. That is, metal ions may be injected instead of coating, and if a conductive glass substrate is used, a tungsten layer for antistatic is unnecessary,
It is also possible to mask only the resist 22.

The present invention is not limited to liquid crystal color display,
It can be applied to color display such as EL (electroluminescence) and plasma, and also to a CCD filter.

[0010]

[Table 1]

[0011]

As described above, according to the present invention,
Since the color filter is formed by diffusing the coloring material inside the glass substrate, the surface can be made smooth. Further, since the material is glass, it can be used at a considerably high temperature (glass melting temperature) and is resistant to ultraviolet rays. Since the coloring material is protected inside the glass substrate, there is almost no secular change, and there is an advantage that a finer pattern can be formed.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a liquid crystal display device embodying the present invention.

FIG. 2 is a sectional view of a conventional liquid crystal display device.

[Explanation of symbols] 10 Liquid crystal display device 11 Glass substrate 12 Glass substrate 13 Liquid crystal 14 Polarizing plate 15 Polarizing plate 16 Seal 17 Color filter 20 Glass substrate 21 Tungsten 22 Resist 23 Photomask 24 Coloring material 24 'Diffusion layer

Claims (1)

[Claims] 1. A liquid crystal display device for performing color display by dispersing transmitted light from the back surface, wherein a coloring material required for the light dispersion is diffused inside a glass substrate on the front surface side. apparatus.