LIQUID CRYSTAL DISPLAY DEVICE

Abstract

In order to suppress noise in display, which would occur due to variations of inclination directions of liquid crystal molecules, and to improve display quality, a first structure in a shape having a discontinuous portion is provided to a first electrode, and a second structure is provided to a second electrode so as to face the discontinuous portion of the first structure. When a voltage is applied to the first and second electrodes to generate an electric field in a liquid crystal layer, the first structure controls the inclination directions of the liquid crystal molecules, and the second structure controls the inclination directions of the liquid crystal molecules existing in the discontinuous portion of the first structure. In the discontinuous portion of the first structure, the amount of light passing through the liquid crystal layer increases, and the liquid crystal molecules are aligned more vertically. Hence, light leakage is reduced.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a liquid crystal display device of a first embodiment;

FIG. 2 is a circuit diagram on an array substrate in the liquid crystal display device of FIG. 1;

FIG. 3 is a cross-sectional view of the array substrate in the liquid crystal display device of FIG. 1;

FIG. 4 is a cross-sectional view of the liquid crystal display device of FIG. 1;

FIG. 5 is a plan view of one pixel disposed on the liquid crystal display device of FIG. 1;

FIG. 6 is a cross-sectional view taken along the line A-A of FIG. 5;

FIG. 7 is a cross-sectional view taken along the line B-B of FIG. 5;

FIG. 8 is a cross-sectional view taken along the line C-C of FIG. 5;

FIG. 9 is a cross-sectional view taken along the line A-A of FIG. 5 at the time of displaying an image;

FIG. 10 is a cross-sectional view taken along the line B-B of FIG. 5 at the time of displaying an image;

FIG. 11 is a cross-sectional view taken along the line C-C of FIG. 5 at the time of displaying an image;

FIG. 12 is a plan view of one pixel at the time of displaying an image;

FIG. 13 is a plan view of one pixel disposed on a liquid crystal display device of a second embodiment;

FIG. 14 is a cross-sectional view taken along the line A-A of FIG. 13 at the time of displaying an image;

FIG. 15 is a cross-sectional view taken along the line B-B of FIG. 13 at the time of displaying an image;

FIG. 16 is a cross-sectional view taken along the line C-C of FIG. 13 at the time of displaying an image;

FIG. 17A is a plan view of one pixel disposed on a liquid crystal display device of a first comparative example;

FIG. 17B is a cross-sectional view taken along the line I-I of FIG. 17A;

FIG. 18A is a plan view of one pixel disposed on a liquid crystal display device of a second comparative example;

FIG. 18B is a cross-sectional view taken along the line I-I of FIG. 17A;

FIG. 19 shows results of comparing noise in display of the embodiments with that of the comparative examples;

FIG. 20 shows results of comparing a display quality of the embodiments with that of the comparative examples;

FIG. 21 is a plan view of one pixel disposed on a liquid crystal display device of a third embodiment;

FIG. 22 is a cross-sectional view taken along the line I-I of FIG. 21;

FIG. 23 is a cross-sectional view taken along the line I-I of FIG. 21 at the time of displaying an image;

FIG. 24 is a plan view of one pixel disposed on a liquid crystal display device of a third comparative example;

FIG. 25 is a cross-sectional view taken along the line I-I of FIG. 24;

FIG. 26 is a cross-sectional view taken along the line I-I of FIG. 24 at the time of displaying an image;

FIG. 27 is a cross-sectional view of an array substrate in a liquid crystal display device of a fourth embodiment;

FIG. 28 is a plan view of one pixel disposed on the liquid crystal display device;

FIG. 29 is a plan view of one pixel disposed on a liquid crystal display device of a first modified example; and

FIG. 30 is a plan view of one pixel disposed on a liquid crystal display device of a second modified example.

Claims

1. A liquid crystal display device comprising: first and second substrates which are disposed so as to face each other with a gap interposed in between;a first electrode disposed on the first substrate;a second electrode disposed on the second substrate in a way that the second electrode faces the first electrode;a liquid crystal layer which is held in the gap between the substrates, and which is formed of liquid crystal molecules having a negative dielectric anisotropy;a first structure which is provided to the first electrode in a shape including a discontinuous portion therein, and which is configured to control inclination directions of the liquid crystal molecules; anda second structure provided to the second electrode so as to face the discontinuous portion of the discontinuously-provided first structure.

2. The liquid crystal display device according to claim 1, wherein the first structure is a projection provided to the first electrode in a shape including a discontinuous portion therein, andthe second structure is a slit which is formed by partially removing the second electrode, and which faces a discontinuous portion of the projection.

3. The liquid crystal display device according to claim 1, wherein the first structure is a slit formed by partially removing the first electrode in a shape including a discontinuous portion therein, andthe second structure is a slit which is formed by partially removing the second electrode, and which faces a discontinuous portion of the slit of the first structure.

4. The liquid crystal display device according to claim 1, wherein the first structure is a projection provided to the first electrode in a shape including a discontinuous portion therein, andthe second structure is a projection provided to the second electrode so as to face the discontinuous portion of the projection.

5. The liquid crystal display device according to claim 2, wherein all the portions in the projection on the first electrode extend in one direction, andthe slit of the second electrode extends in a direction perpendicular to the direction in which all the portions of the projection extend.

6. The liquid crystal display device according to claim 3, wherein all the portions in the slit of the first electrode extend in one direction, andthe slit of the second electrode extends in a direction perpendicular to the direction in which all the portions of the slit of the first electrode extend.

7. The liquid crystal display device according to claim 1, further comprising a stepped portion which is provided to at least one of the first and second substrates, and which is configured to adjust a thickness of the liquid crystal layer, wherein the second electrode is formed of a reflective electrode and a transmissive electrode, the reflective electrode disposed in a first region where the stepped portion makes the liquid crystal layer thinner than a second region, and the transmissive electrode disposed in the second region where the liquid crystal layer is thicker, andthe second structure straddles a boundary between the two regions.

8. The liquid crystal display device according to claim 1, further comprising a stepped portion which is provided to at least one of the first and second substrates, and which is configured to adjust a thickness of the liquid crystal layer, wherein the second electrode is formed of a reflective electrode and a transmissive electrode, the reflective electrode disposed in a first region where the stepped portion makes the liquid crystal layer thinner than a second region, and the transmissive electrode disposed in the second region where the liquid crystal layer is thicker, andthe second structure is along a boundary between the two regions.