Transmissive or reflective liquid crystal display and novel process for its manufacture

• US 6,784,953 B2
• Filed: 03/11/2003
• Issued: 08/31/2004
• Est. Priority Date: 01/11/2001
• Status: Expired due to Fees

• Current Assignee: E Ink California, LLC (E Ink Holdings Incorporated)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Tseng, Scott C-J, Li, Weijin, Liang, Rong-Chang, Li, Ying-Syi, Phan, Xuan
• Primary Examiner(s): Parker, Kenneth
• Application Number:
  US10/386,752
• Publication Number:
  US 20030169387A1
• Time in Patent Office: 539 Days
• Field of Search: 349/156, 349/189, 349/86, 349/92
• US Class Current: 349/86
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: C09K 19/60 Pleochroic dyes
• CPC Class Codes: G02F 1/133377 Cells with plural compartments or having plurality of liquid crystal microcells partitioned by walls, e.g. one microcell per pixel
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13475 in which at least one liquid crystal cell or layer is doped with a pleochroic dye, e.g. GH-LC cell G02F1/13476 takes precedence

Abstract

This invention relates to liquid crystal (LC) displays comprising cells of well-defined shape, size and aspect ratio which cells are filled with a liquid crystal composition preferably containing dichroic dye(s), and novel processes for their manufacture.

Claims

1. An array of cells for an LC display wherein each of said cells comprises:

(a) surrounding partition walls,

(b) a liquid crystal composition filled therein, and a polymeric top-sealing layer which is formed from a sealing composition having a specific gravity lower than that of said liquid crystal composition and sealingly adheres to the surface of the partition walls to enclose said liquid crystal composition within each cell.

2. The LC display of claim 1 wherein the cells are substantially uniform in size and shape.

3. The LC display of claim 1 wherein the cells are non-spherical.

4. The LC display of claim 1 wherein the cells are formed from microcups with an opening area ranging from about 0.04 to about 100 μ

m².

5. The LC display of claim 4 wherein the cells are formed from microcups with an opening area ranging from about 1 to about 25 μ

m².

6. The LC display of claim 1 wherein the cells are formed from microcups with an opening having a circular, polygonal, hexagonal, rectangular or square shape.

7. The LC display of claim 1 wherein the cells have a depth in the range from about 0.5 to about 10 microns.

8. The LC display of claim 7 wherein the cells have a depth in the range from about 2 to about 6 microns.

9. The LC display of claim 1 wherein the cells have an opening to wall ratio in the range from about 0.05 to about 20.

10. The LC display of claim 9 wherein the cells have an opening to wall ratio in the range from about 0.2 to about 9.

11. The LC display of claim 1 wherein selected cells in a pre-determined area are filled with the LC composition comprising guest dye(s) of a predetermined color.

12. The LC display of claim 11 wherein cells which are filled with the LC composition comprising guest dye(s) of a predetermined color are adjacent to each other.

13. The LC display of claim 11 wherein cells which are filled with the LC composition comprising guest dye(s) of a predetermined color are stacked on top of each other.

14. The LC display of claim 1 wherein the LC composition is colored by a guest dye.

15. The LC display of claim 14 wherein the guest dye color is a subtractive or additive color system.

16. The LC display of claim 1 wherein the display comprises more than one layer of microcup array filled with liquid crystal composition.

17. The LC display of claim 1 wherein said LC display is multi-color and wherein color filters are laminated or coated onto the display.

18. The LC display of claim 17 wherein said filters are red, green, and blue color filters.

19. The LC display of claim 1 wherein said LC composition is partially filled in each of said cells.

20. The LC display of claim 19 wherein said partially filled LC composition is in contact with said polymeric top-sealing layer.