Liquid crystal display (LCD) having improved isocontrast performance and method for producing same

• US 20040041964A1
• Filed: 09/02/2003
• Published: 03/04/2004
• Est. Priority Date: 04/13/2000
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Andrews, Michael
• Application Number:
  US10/653,299
• Publication Number:
  US 20040041964A1
• Time in Patent Office: Days
• US Class Current: 349/110
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 2201/128 field shaping

Abstract

An improved liquid crystal display includes overlapped electrical conductors in a picture element (pixel) region of a liquid crystal material. The conductors are selectively defined so as to control the electric field applied to the liquid crystal material in a region associated with the liquid crystal material. By controlling the electric field in the region, the degree to which the molecules in the liquid crystal material rotate in response to the electric field can be controlled. In this manner, the contrast of the liquid crystal material in the region may be selectively controlled to, for example, improve the contrast of the liquid crystal display in multiple axes.

Claims

1. A liquid crystal display, comprising:

a liquid crystal material disposed between a pair of transparent plates;

a first electrical conductor and a second electrical conductor associated with said liquid crystal material and configured to form a picture element in an overlap region in which said first electrical conductor and said second electrical conductor overlap, said first electrical conductor and said second electrical conductor configured to apply an electric field to said liquid crystal material, said electric field causing molecules in said liquid crystal material to change state in response to said electric field in said overlap region associated with said picture element; and

wherein said overlap region is selectively defined to alter said electric field so that a degree to which said liquid crystal molecules change state in response to said electric field is controlled by said selectively defined overlap region.

2. The liquid crystal display of claim 1, wherein said selectively defined overlap region focuses said electric field on a controllable location corresponding to said picture element.

3. The liquid crystal display of claim 1, wherein said selectively defined overlap region maximizes said change in state of said liquid crystal molecules.

4. The liquid crystal display of claim 1, wherein said selectively defined overlap region controls said electric field.

5. The liquid crystal display of claim 1, wherein said selectively defined overlap region maximizes an electromotive force in said selectively defined overlap region.

6. The liquid crystal display of claim 1, wherein said first electrical conductor describes a circle in said selectively defined overlap region.

7. The liquid crystal display of claim 1, wherein said first electrical conductor describes a square in said selectively defined overlap region.

8. A method for controlling contrast in a liquid crystal display, the method comprising the steps of:

locating a liquid crystal material between a pair of transparent plates;

associating a first electrical conductor and a second electrical conductor with said liquid crystal material;

forming a picture element in a region in which said first electrical conductor and said second electrical conductor overlap, said first electrical conductor and said second electrical conductor configured to apply an electric field to said liquid crystal material, said electric field causing molecules in said liquid crystal material to change state in response to said electric field, in said region associated with said picture element; and

selectively defining said region to alter said electric field so that a degree to which said molecules change state in response to said electric field is controlled by said selectively defined region.

9. The method of claim 8, further comprising the step of using said selectively defined region to focus said electric field on a controllable location corresponding to said picture element.

10. The method of claim 8, further comprising the step of using said selectively defined region to maximize said change in state of said molecules.

11. The method of claim 8, further comprising the step of using said selectively defined region to shape said electric field.

12. The method of claim 8, wherein said selectively defined overlap region maximizes an electromotive force in said selectively defined region.

13. The method of claim 8, further comprising the step of forming said first electrical conductor into a circle in said selectively defined region.

14. The method of claim 8, further comprising the step of forming said first electrical conductor into a square in said selectively defined region.