LIQUID CRYSTAL DISPLAY PANEL

Abstract

A liquid crystal display panel includes an array substrate, a counter-substrate, a liquid crystal layer which is held between the array substrate and the counter-substrate and contains liquid crystal molecules whose alignment state is to be transitioned to a bend alignment for enabling a display operation, a retardation plate which is disposed at least on the counter-substrate, and a polarizer which is disposed on the retardation plate. The array substrate and counter-substrate include a pair of electrodes which are covered with alignment films, respectively, and are opposed to each other to define a rectangular display area, and the polarizer has an absorption axis which is substantially parallel or substantially perpendicular to each of the sides of the display area.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

FIG. 1 shows the circuit configuration of a liquid crystal display device according to an embodiment of the present invention;

FIG. 2 schematically shows a general appearance of a liquid crystal display panel shown in FIG. 1;

FIG. 3 shows a cross-sectional structure of the liquid crystal display panel shown in FIG. 1 and FIG. 2;

FIG. 4 shows the arrangement of absorption axes of upper and lower polarizers shown in FIG. 3;

FIG. 5 shows non-uniformity in display occurring in the vicinity of corners of a display area shown in FIG. 1;

FIG. 6 shows a luminance distribution characteristic which is obtained at a time of white display by the setting of absorption axes shown in FIG. 4;

FIG. 7 is a view for explaining the impression of brightness obtained when the liquid crystal display panel shown in FIG. 1, which is mounted on a vehicle, is viewed from an upper left side and an upper right side;

FIG. 8 schematically illustrates a method of fabricating a glass plate shown in FIG. 2;

FIG. 9 is a conceptual view showing a non-uniform state of transmissive light in a case where absorption axes of polarizers are disposed at 45° with respect to the sides of a glass plate, and the glass plate is disposed between the polarizers;

FIG. 10 is a conceptual view showing a non-uniform state of transmissive light in a case where absorption axes of polarizers are disposed substantially parallel or perpendicular to the sides of a glass plate, and the glass plate is disposed between the polarizers;

FIG. 11 shows the alignment state of liquid crystal molecules which is transitioned from a splay alignment to a bend alignment in order to execute a display operation in an OCB mode liquid crystal display panel;

FIG. 12 shows a relationship between rubbing directions of alignment films and absorption axes of polarizers, which is adopted in a conventional OCB mode liquid crystal display panel;

FIG. 13 shows a luminance distribution characteristic which is obtained at a time of white display in the liquid crystal display panel, which has been described with reference to FIG. 12;

FIG. 14 shows non-uniformity in display occurring at a time of black display in a case where the liquid crystal display panel, which has been described with reference to FIG. 12, is left in a high-temperature environment for a long time;

FIG. 15 shows non-uniformity in display occurring at a time of white display in a case where the liquid crystal display panel, which has been described with reference to FIG. 12, is left in a high-temperature environment for a long time;

FIG. 16 shows a distribution of stress occurring in a polarizer in a case where the liquid crystal display panel, which has been described with reference to FIG. 12, is left in a high-temperature environment for a long time; and

FIG. 17 shows a distribution of retardation occurring due to the distribution of stress shown in FIG. 16.

Claims

1. A liquid crystal display panel comprising: first and second electrode substrates;a liquid crystal layer which is held between said first and second electrode substrates and contains liquid crystal molecules whose alignment state is capable of transitioning to a bend alignment for enabling a display operation;a retardation plate disposed at least on said first electrode substrate; anda polarizer disposed on the retardation plate,wherein said first and second electrode substrates include a pair of electrodes which are covered with alignment films, and are opposed to each other to define a rectangular display area, and said polarizer has an absorption axis substantially parallel or substantially perpendicular to each of the sides of said display area.

2. The liquid crystal display panel according to claim 1, wherein said polarizer is of a rectangular shape having four sides which are parallel to the four sides of said display area.

3. The liquid crystal display panel according to claim 1, wherein said first electrode substrate is of a rectangular shape having four sides which are parallel to the four sides of said display area.

4. The liquid crystal display panel according to claim 1, wherein said first electrode substrate is set by the display operation to have a temperature distribution inclined in a direction which is parallel to any one of the four sides of said display area.

5. The liquid crystal display panel according to claim 1, wherein said display area has a luminance distribution characteristic that said display area looks dark in white display when said display area is viewed from one of an upper right side and an upper left side.

6. The liquid crystal display panel according to claim 1, wherein said display area has a size of 9 inches or more in each of diagonal directions.

7. The liquid crystal display panel according to claim 1, wherein said display area has a size of 15 inches or more in each of diagonal directions.

8. The liquid crystal display panel according to claim 1, wherein said retardation plate includes a stress-relaxing adhesive layer which attaches said polarizer to said first electrode substrate.