Substrate for liquid crystal display and liquid crystal display utilizing the same

• US 20050253988A1
• Filed: 06/29/2005
• Published: 11/17/2005
• Est. Priority Date: 10/02/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Fujitsu Display Technologies Corporation (Fujitsu Limited)
• Inventors: Shibasaki, Masakazu, Sasaki, Takahiro, Hanaoka, Kazutaka, Kataoka, Shingo, Nakanishi, Yohei, Inoue, Yuichi, Koike, Yoshio, Nakamura, Kimiaki
• Granted Patent: US 7,372,533 B2
• Time in Patent Office: Days
• US Class Current: 349/139
• CPC Class Codes: G02F 1/133753 with different alignment orientations or pretilt angles on a same surface, e.g. for grey scale or improved viewing angle
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line

Abstract

It is an object of the invention to provide a substrate for a liquid crystal display having optical transmittance improved without reducing the speed of a response to a tone change and a liquid crystal display utilizing the same. There is provided a drain bus line formed on an array substrate which sandwiches a liquid crystal in combination with an opposite substrate provided in a face-to-face relationship therewith, a TFT connected to the drain bus line, and a pixel electrode which has stripe-shaped electrodes, along with spaces, connected to the TFT and provided in parallel with the drain bus line, stripe-shaped electrodes in the vicinity of the drain bus line having an electrode width formed narrower than the width of internal electrodes located inside the same.

Claims

1. A substrate for a liquid crystal display, comprising:

a substrate which sandwiches a liquid crystal in combination with an opposite substrate provided in a face-to-face relationship therewith;

a bus line formed on the substrate;

a switching element connected to the bus line; and

a pixel electrode having stripe-shaped electrodes, along with spaces therebetween, connected to the switching element and provided in parallel with the bus line, at least one of stripe-shaped electrode in the vicinity of the bus line being formed with an electrode width narrower than that of electrodes located inside the same.

2. A substrate for a liquid crystal display according to claim 1, wherein the total area of the spaces of the pixel electrode is 50% of the total area of the electrode region or less.

3. A substrate for a liquid crystal display according to claim 1, wherein the pixel electrodes has the strip-shaped electrodes and spaces also in the vicinity of a boundary between a plurality of alignment separating regions for separating the alignment of the liquid crystal.

4. A substrate for a liquid crystal display according to claim 1, wherein the pixel electrode is formed such that an electrode length of the stripe-shaped electrodes in the vicinity of the bus line is longer than an electrode length of the stripe-shaped electrodes located inside the same.

9. A liquid crystal display comprising an array substrate and an opposite substrate combined in a face-to-face relationship to seal a liquid crystal therebetween, wherein a substrate for a liquid crystal display according to any of claims 1 through 8 is used as the array substrate.

10. A liquid crystal display according to claim 9, wherein the liquid crystal includes liquid crystal molecules which have negative dielectric anisotropy and which are vertically aligned when no voltage is applied and a polymer for determining a pre-tilt angle of the liquid crystal molecules and/or a tilting direction at the time of driving of the same.

11. A liquid crystal display according to claim 9, wherein an alignment regulating structure is provided at least on the opposite substrate.

5. A substrate for a liquid crystal display, comprising:

a substrate which sandwiches a liquid crystal in combination with an opposite substrate provided in a face-to-face relationship therewith;

a bus line formed on the substrate;

a switching element connected to the bus line; and

a pixel electrode having stripe-shaped electrodes, along with spaces therebetween, connected to the switching element and provided in parallel with the bus line between the switching element and the bus line.

6. A substrate for a liquid crystal display according to claim 5, wherein the pixel electrode has a plurality of stripe-shaped electrodes and spaces in the region which is connected to the switching element and wherein at least one of the stripe-shaped electrodes is cut at the connecting region to form a gap between the switching element and the end of the stripe-shaped electrode.

7. A substrate for a liquid crystal display according to claim 6, wherein the gap has a length in the range from 0.5 μ

m to 5 μ

m inclusive.

8. A substrate for a liquid crystal display according to claim 5, wherein the width of the stripe-shaped electrodes is in the range from 0.5 μ

m to 5 μ

m inclusive.

12. A liquid crystal display comprising:

an array substrate and an opposite substrate combined in a face-to-face relationship to seal a liquid crystal which is in contact with an alignment film or electrode; and

a polymer layer for determining a pre-tilt angle of liquid crystal molecules of the liquid crystal and/or a tilting direction at the time of driving of the same is formed on the alignment film or electrode.

13. A liquid crystal display according to claim 12,

wherein the thickness of the polymer layer is in the range from 10 Å

to 5000 Å

inclusive.

14. A liquid crystal display according to claim 12, wherein the alignment of the polymer in the polymer layer at the top surface thereof in contact with the liquid crystal is different from an aligning direction determined by the alignment film or electrode.

15. A liquid crystal display according to claim 14, wherein the polymer is in different states of alignment and formation in a plurality of regions.

16. A liquid crystal display according to claim 14, wherein the polymer has optical anisotropy.

17. A substrate for a liquid crystal display, comprising:

a substrate which sandwiches a liquid crystal in combination with an opposite substrate provided in a face-to-face relationship therewith; and

stripe-shaped electrodes and spaces cyclically arranged in different directions in each predetermined region on the substrate, at least either stripe-shaped electrodes or spaces being formed with different electrode widths or space widths in a region in the vicinity of a boundary between the predetermined region and themselves and in regions other than the region in the vicinity of the boundary.

18. A substrate for a liquid crystal display according to claim 17, wherein the electrode width of the stripe-shaped electrodes is equal to or narrower than the width of the spaces in the vicinity of the boundary between the predetermined region and themselves and wherein the electrode width of the stripe-shaped electrodes is equal to or wider than the width of the spaces in the regions other than the region in the vicinity of the boundary.

19. A substrate for a liquid crystal display according to claim 17, wherein the electrode width of the stripe-shaped electrodes continuously changes.

20. A substrate for a liquid crystal display according to claim 17, wherein a pixel electrode is formed by the stripe-shaped electrodes and the spaces.

21. A liquid crystal display comprising an array substrate and an opposite substrate combined in a face-to-face relationship to seal a liquid crystal therebetween, wherein a substrate for a liquid crystal display according to any of claims 17 through 20 is used as the array substrate.

22. A liquid crystal display according to claim 21, wherein the liquid crystal includes liquid crystal molecules which have negative dielectric anisotropy and which are vertically aligned when no voltage is applied and a polymer for determining a pre-tilt angle of the liquid crystal molecules and/or a tilting direction at the time of driving of the same.

23-38. -38. (canceled)

39. A liquid crystal display comprising:

a pair of substrates provided in a face-to-face relationship;

an alignment film formed on each of the surfaces of the substrates in a face-to-face relationship;

a liquid crystal layer including a nematic liquid crystal and an optically setting element which is set such that an aligning direction at an azimuth angle of liquid crystal molecules substantially matches a direction at an azimuth angle of the alignment control performed by the alignment film; and

an electrode structure for generating an electric field having a component in parallel with the substrate surfaces in the liquid crystal layer.

40. A liquid crystal display according to claim 39, wherein an anchoring energy in a direction at an azimuth angle acting on liquid crystal molecules on the surface of the alignment film is 3×

10<sup>−

5</sup> J/m² or less.

41. A liquid crystal display according to claim 39, wherein a structure having concave-convex shapes on the surface of the alignment film is used as a factor for determining the alignment of the liquid crystal molecules.