JPS6125135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the orientation of a crystalline polymer substance when the substrate is used as a substrate for a liquid crystal display panel.

An object of the present invention is to improve the appearance of a liquid crystal display panel using a crystalline polymer material as a substrate.

A plate of crystalline polymer material, especially a plate made by stretching, has directionality. There are two types of directionality; the first is related to optical rotation. When linearly polarized light is incident on the plate, the degree of optical rotation differs depending on the polarization direction of the linearly polarized light. Second, the transmittance of linearly polarized light incident on the plate from an oblique direction differs depending on the projection direction of the incident light. Due to the above-mentioned orientation, it has conventionally been difficult to use a plate of crystalline polymer material, especially a plate made by stretching, as a substrate for a liquid crystal display panel.

In contrast, the present invention shows a method for using the plate as a substrate for a liquid crystal display panel and still obtaining excellent appearance characteristics. First, regarding the direction of optical rotation, when linearly polarized light enters the plate, the direction with the least optical rotation is the polarization direction, orientation direction, or polarization direction and orientation direction of the polarizing plate used for the liquid crystal display panel. It is to make them coincide or at right angles to both of them. Next, regarding the directionality of linearly polarized light incident obliquely, it is possible to make the direction in which the obliquely incident light with the highest transmittance is projected onto the substrate parallel to the direction in which the liquid crystal display panel is most frequently used. be. The best appearance characteristics can be obtained by using the two directional methods mentioned above simultaneously.

The present invention will be explained below with reference to the figures.

FIG. 1 shows a polyester substrate biaxially stretched in the AA' and BB' directions. In this case, the direction with the least optical rotation for linearly polarized light is the angle α with respect to AA′, and the direction in which the incident light with the highest transmittance for obliquely incident light is projected onto the substrate is also It is an angle α with respect to AA′ (the direction of the angle α with respect to AA′ is the direction of CC′). In FIG. 2, the substrate shown in FIG. 1 was used as a liquid crystal display panel substrate. This is an example of the present invention, and shows relationships between various directions. 1
is the upper panel substrate, 2 is the lower panel substrate, 3 is the upper polarizing plate, 4 is the lower polarizing plate, and 5 is the upper panel substrate orientation direction.
Perpendicular to the CC′ direction, 6 is the lower panel board orientation direction.
Parallel to the CC' direction, 7 is the polarization direction of the upper polarizer parallel to the CC' direction, and 8 is the polarization direction of the lower polarizer perpendicular to the CC' direction. The direction in which the panel is most frequently used is indicated by arrow 9, which is in front of the panel (6 o'clock direction on a clock) and parallel to the CC' direction. As described above, the electric field of the panel can be applied by using the orientation of the crystalline polymer material in good combination with the orientation of other parts of the liquid crystal display panel, the orientation treatment direction, and the panel display direction. It is possible to obtain a liquid crystal display panel with high transmittance for the portions that are not covered.

Although the above example referred to polyester,
The present invention is also effective for other crystalline polymer substances.

Further, although the above example describes a liquid crystal display panel having two polarizing plates, the present invention can also be applied to a case where there is one polarizing plate or less.

As described above, in the present invention, a liquid crystal is sealed within a pair of substrates, each of the pair of substrates is made of a biaxially stretched crystalline polymer material, and a pair of polarizing plates are mounted above and below the substrates. In the liquid crystal display panel, each of the substrates has an optical characteristic axis that is deviated by a certain angle from the two axes, and the optical characteristic axis has the least optical rotation with respect to linearly polarized light and This is the direction in which the transmittance of light is highest, and the direction in which the liquid crystal display panel is used most frequently coincides with the direction of the optical axis, so the liquid crystal display panel is easy to see without coloring, improves visibility, and has no variations. This has the effect that it can be provided at low cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the directionality of a polyester plate, and FIG. 2 is an example of the present invention in which the directionality is successfully utilized in a liquid crystal display panel. AA', BB'... Direction of biaxial stretching, CC'... Directionality generated in the polyester plate as a result of biaxial stretching, 1
...Upper panel board, 2...Lower panel board, 3...
Upper polarizing plate, 4... Lower polarizing plate, 5... Upper panel orientation direction, 6... Lower panel alignment direction, 7... Upper polarizing plate polarization direction, 8... Lower polarizing plate polarization direction, 9... Panel Frequently used direction.

Claims (1)

[Claims] 1. A liquid crystal display in which a liquid crystal is enclosed within a pair of substrates, each of the pair of substrates is made of biaxially stretched crystalline polymer material, and a pair of polarizing plates are placed above and below the substrates. In the panel, each of the substrates has an optical characteristic axis that is offset by a certain angle from the two axes, and the optical characteristic axis has the least optical rotation for linearly polarized light and the highest transmittance of incident light. A liquid crystal display panel characterized in that the direction in which the liquid crystal display panel is frequently used coincides with the direction of the optical axis.