JPH0350250B2 - - 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 an electroless state, the entire area appears colored. When electrolysis is applied, the long axis of the dye molecules and liquid crystal molecules becomes 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 white 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, the design 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 continuously shifting the polarization direction and the liquid crystal molecule axis direction. It is aimed at something.

〔Example〕

FIG. 2 shows an embodiment of the present invention, and shows the relationship among the substrate surface portion 13 on the polarizer side, the polarization direction 14 of the polarizer, and the long axis directions 15 of crystal molecules and dye molecules. In this case, the polarization direction 14 and the long axis direction of the molecules deviate from each other toward the ends. Therefore, the coloring is strongest in the center and becomes weaker towards the edges. As the arrangement method in this embodiment, oblique evaporation can be used, and the smaller the distance between the point evaporation source and the substrate, the more effective it is. That is, the polarization direction 14 and the molecule long axis direction 15 deviate to a greater extent in a region away from the center. In this embodiment, the substrate surface on the polarizing device side has been described, but the substrate surface on the opposite side may be arranged uniformly or the arrangement direction may be changed continuously. However, even if the polarizer side is uniformly arranged and the arrangement direction is continuously changed on the opposite side, there is no effect. This is because the linearly polarized light on the polarizer side is
This is because the light rotates toward the opposite substrate according to the rotation of the liquid crystal molecules, so that the linearly polarized light is almost parallel to the direction of the dye molecules in all parts, and the colored state is almost the same.

FIG. 3 shows an embodiment of a liquid crystal display device using a substrate subjected to the alignment process shown in FIG. Here, the character display electrode 16 is transparent when a voltage is applied, and the shape of the character is clearly displayed.

On the other hand, in the character background area, since the polarization direction 14 and the long axis direction 15 of liquid crystal molecules almost match in the central region 17, a high density color is reproduced, and in the region 18 off the center, the polarized light Since the direction 14 and the long axis direction 15 of the liquid crystal molecules are continuously shifted from each other, colors of medium to low density are reproduced and displayed.

According to the present invention, it is possible to create a shading pattern even in a liquid crystal display type wristwatch, which is inferior in design, just like the shading pattern on the dial of an analog display wristwatch, and the effect is extremely large.

〔effect〕

As described above, in the present invention, a nematic liquid crystal containing a dye is added between a pair of substrates, a liquid crystal driving electrode is formed on the substrate, and a polarizing plate is arranged on the back surface of one of the substrates. In a liquid crystal display device, the substrate on the side where the polarizing plate is arranged has a region in which the molecular axis of the liquid crystal is aligned in the same direction as the polarizing axis of the polarizing plate, and a region on the substrate on the side where the polarizing plate is arranged. Since the liquid crystal molecular axes are aligned in a direction that is continuously shifted from the direction of the polarization axis of This creates a color shading pattern on the background of the characters, which has the effect of making the display rich in design.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional guest-host type liquid crystal display device. FIG. 2 is a diagram showing an example of the relationship between the polarization axis of the polarizing plate of the present invention and the liquid crystal molecule axis. FIG. 3 is a diagram showing an embodiment of the liquid crystal display device of the present invention. 3...Dye molecule, 4...Polarizing plate, 5...Polarization direction, 6...Substrate surface, 13...Substrate surface, 14...
...Polarization direction, 15...Molecular alignment direction.

Claims (1)

[Claims] 1. In a liquid crystal display device in which a nematic liquid crystal containing a dye is added between a pair of substrates, a liquid crystal driving electrode is formed on the substrate, and a polarizing plate is disposed on the back surface of one of the substrates. On the substrate on the side where the polarizing plate is arranged, there is a region in which the molecular axis of the liquid crystal is aligned in the same direction as the polarizing axis of the polarizing plate, and a region in which the molecular axis of the liquid crystal is aligned in the same direction as the polarizing axis of the polarizing plate. A liquid crystal display device comprising a region in which the molecular axes of the liquid crystal are aligned in a direction continuously shifted from the other direction.