JPS6217204B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a liquid crystal display device comprising a material in which a dye is added to a nematic liquid crystal with positive dielectric anisotropy, that is, a guest-host type liquid crystal display device. The design is made interesting by adding shading patterns to the background color.

[Prior art]

A conventional guest-host type liquid crystal display device will be explained with reference to FIG. FIG. 1 is a cross-sectional view, in which 1 is a transparent electrode substrate, 2 is a nematic liquid crystal, and 3 is a dye molecule, which absorbs light of a specific wavelength when vibrating in the direction of its long axis, and has the property of changing color. 4 is a polarizing plate, 5
is its polarization direction and produces linearly polarized light that oscillates in that direction. This direction is the same as the long axis direction of the liquid crystal molecules or dye molecules that are in contact with the lower substrate surface. In such a display device, natural light is observed by the polarizing plate 4 as linearly polarized light that vibrates in the long axis direction of dye molecules or liquid crystal molecules. Therefore, in the absence of an electric field, the entire area appears colored. When an electric field is applied, the long axes of the dye molecules and liquid crystal molecules become almost perpendicular to the substrate surface, and the vibration direction of the incident light becomes almost perpendicular to the long axis of the dye molecules, resulting in absorption of light of a specific wavelength. Almost no light is produced and white light is observed. Therefore, a white pattern is displayed on a colored background. In these conventional devices, the alignment direction and inclination of liquid crystal molecules and dye molecules on the substrate surface are almost uniform over the entire surface, and although color is produced, there is a problem in that designability is poor.

〔the purpose〕

The present invention overcomes the above problems, and provides a liquid crystal display device in which a density pattern is formed in the background color of a display pattern by performing multiple types of molecular orientation treatments on a substrate. With the goal.

〔Example〕

FIG. 2 is a cross-sectional view of an embodiment of the present invention, in which 6 is the transparent electrode substrate surface, 7 is the substrate surface portion that is not subjected to alignment treatment, and 8 is the substrate surface where molecules are tilted at an angle of 15° to 20°. part. This can be done by performing so-called oblique deposition, in which a material such as SiO is deposited obliquely to the substrate surface. 9 is the part of the substrate surface where the inclination of molecules on the substrate surface is approximately 0 degrees. This can be done by rubbing the surface of the substrate with gauze or the like, or by the above-mentioned oblique evaporation method. 10 is a liquid crystal molecule, and 11 is a dye molecule. 12 is the polarization direction of the polarizing plate, which is parallel to the plane of the paper. The direction of the molecules in the portion 7 is completely random, and in the portion 8 they are parallel to the plane of the paper but tilted with respect to the substrate surface. 9 are parallel to each other. Therefore, the absorption of specific wavelengths decreases in the order of 9, 8, and 7.
Part 9 is most strongly colored, followed by parts 8 and 7. Although the above description has been made on the substrate surface on the polarizing device side, it may be performed on the substrate surface on the opposite side, and it is more effective if it is performed on both substrate surfaces. The decolorization of the parts to which the electric field is applied is almost uniform in each of the above parts.

FIG. 3 shows an example of an image display when the three types of molecular orientation shown in FIG. 2 are performed on the same substrate. In this case, the character display electrode section 13 is transparent when a voltage is applied, and the character shape is clearly displayed. On the other hand, in the background part of the characters, for example, there is a region 14 where the liquid crystal molecules are parallel to the substrate surface, a region 15 where the molecules are tilted at an angle of 15° to 20° with respect to the substrate surface, and a region 15 where the molecules are oriented in completely random directions. Area 16
and are formed sequentially. By doing so, even if the colors are displayed using the same dye, a dark color area 14, a medium density area 15, and a low density area 16 can be obtained.

〔effect〕

As described above, the present invention provides a liquid crystal display device having a nematic liquid crystal doped with a dye between a pair of substrates, a liquid crystal driving electrode formed on the substrate, and a polarizing device provided on one side of the substrate. On one of the same substrates, there is a first region in which the orientation direction of all liquid crystal molecules and dye molecules is parallel to the substrate plane, and a second region in which all liquid crystal molecules and dye molecule axes are uniformly inclined to the substrate plane.
and a third region in which liquid crystal molecules and dye molecule axes are randomly oriented with respect to the plane of the substrate, and the first, second, and third regions are continuous within one liquid crystal display region. Since the liquid crystal drive electrode in the liquid crystal display area is formed across the first, second, and third areas, a voltage is applied to the liquid crystal drive electrode to display characters, etc. Even when displayed, a pattern of light and shade of color is continuously formed in the liquid crystal display area, which has the effect of making it possible to display a display rich in design.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional guest-host type liquid crystal display device. 1...Transparent electrode substrate, 2...Liquid crystal molecules, 3...
Dye molecule, 4...Polarizing plate, 5...Polarization direction. FIG. 2 is a sectional view of the liquid crystal display device of the present invention. FIG. 3 is a plan view of the liquid crystal display device of the present invention. 6...Substrate surface, 7,8,9...Molecular arrangement structure, 10...Liquid crystal molecules, 11...Dye molecules, 12
...Polarization direction.

Claims (1)

[Claims] 1. In a liquid crystal display device that has a nematic liquid crystal with a dye added between a pair of substrates, a liquid crystal driving electrode is formed on the substrate, and a polarization device is provided on one side of the substrate, at least one of the same substrates On the top, a first region in which the orientation direction of all liquid crystal molecules and dye molecules is parallel to the substrate plane, a second region in which all liquid crystal molecules and dye molecule axes are uniformly inclined to the substrate plane, and liquid crystal molecules, a third region in which dye molecular axes are randomly oriented with respect to the plane of the substrate; the first, second, and third regions are continuously formed within one liquid crystal display region; A liquid crystal display device characterized in that the liquid crystal drive electrode in the liquid crystal display area is formed across the first, second, and third areas.