Transmissive or reflective liquid crystal display and process for its manufacture

• US 20040169813A1
• Filed: 03/05/2004
• Published: 09/02/2004
• Est. Priority Date: 01/11/2001
• Status: Active Grant

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Liang, Rong-Chang, Li, Ying-Syi, Li, Weijin, Tseng, Scott C.J., Phan, Xuan Thanh
• Granted Patent: US 7,095,477 B2
• Time in Patent Office: Days
• US Class Current: 349/187
• 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. A LC display comprising display cells and said display cells are individually sealed with a top-sealing layer wherein said display cells are filled with a liquid crystal composition and said top-sealing layer is hardened in situ.

2. The LC display of claim 1 wherein said top-sealing layer is formed from a sealing composition having a specific gravity lower than that of said liquid crystal composition.

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

4. The LC display of claim 1 wherein said display cells are non-spherical.

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

m².

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

m².

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

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

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

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

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

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

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

14. The LC display of claim 12 wherein said display cells which are filled with the liquid crystal composition comprising guest dye(s) of a predetermined color are stacked on top of each other.

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

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

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

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

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

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

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