Transmissive or reflective liquid crystal display and process for its manufacture

• US 8,282,762 B2
• Filed: 04/03/2006
• Issued: 10/09/2012
• Est. Priority Date: 01/11/2001
• Status: Expired due to Fees

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Liang, Rong-Chang
• Primary Examiner(s): McNally, Daniel
• Application Number:
  US11/398,749
• Publication Number:
  US 20060262249A1
• Time in Patent Office: 2,381 Days
• Field of Search: 156/99, 156/109, 156/145, 156/272.2, 156/324, 349/86, 349/93, 349/190
• US Class Current: 156/272.2
• 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 1/1341 Filling or closing of cells
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take 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. The invention also relates to a process for forming a liquid crystal display, which process comprises forming a plurality of cells followed by filling each of said cells with a liquid crystal composition and said process is carried out continuously or semi-continuously.

Claims

1. A process for forming a liquid crystal display, which process comprises:

(a) forming a plurality of cells;

(b) filling said cells with a liquid crystal composition comprising a chiral material;

(c) overcoating a sealing composition onto the entire surface of the liquid crystal composition in said cells wherein said sealing composition is not attached to a conductive substrate; and

(d) hardening said sealing composition to enclose said liquid crystal composition within said cells;

wherein said process is carried out continuously.

2. The process of claim 1 wherein said sealing composition is immiscible with said liquid crystal composition and has a specific gravity lower than that of said liquid crystal composition.

3. The process of claim 2 wherein said sealing composition comprises a thermoplastic or thermoset precursor.

4. The process of claim 1 wherein said cells are formed on a conductive film.

5. The process of claim 4 further comprising laminating a second conductive film onto the filled and sealed cells.

6. The process of claim 1 which is carried out in a roll-to-roll manner.

7. The process of claim 1 which is carried out on a web.

8. The process of claim 1 wherein said cells are formed by microembossing.

9. The process of claim 1 wherein said cells are formed by imagewise exposure.

10. The process of claim 1 wherein said sealing composition comprises a material selected from the group consisting of polyvalent acrylate or methacrylate, cyanoacrylates, polyvalent vinyl, polyvalent epoxide, polyvalent isocyanate, polyvalent allyl, and oligomers or polymers containing crosslinkable functional groups.

11. The process of claim 1 wherein said liquid crystal composition further comprises a guest dye.

12. The process of claim 1 wherein said hardening of said sealing composition is accomplished by solvent evaporation, interfacial reaction, moisture, heat or radiation.

13. A process for forming a liquid crystal display, which process comprises:

(a) forming a plurality of cells;

(b) filling said cells with a liquid crystal composition comprising a chiral material;

(c) overcoating a sealing composition onto the entire surface of the liquid crystal composition in said cells wherein said sealing composition is not attached to a conductive substrate; and

(d) hardening said sealing composition to enclose said liquid crystal composition within said cells;

wherein said process is carried out semi-continuously.

14. The process of claim 13 wherein said sealing composition is immiscible with said liquid crystal composition and has a specific gravity lower than that of said liquid crystal composition.

15. The process of claim 14 wherein said sealing composition comprises a thermoplastic or thermoset precursor.

16. The process of claim 13 wherein said cells are formed on a conductive film.

17. The process of claim 16 further comprising laminating a second conductive film onto the filled and sealed cells.

18. The process of claim 13 which is carried out on a web.

19. The process of claim 13 wherein said cells are formed by microembossing.

20. The process of claim 13 wherein said cells are formed by imagewise exposure.

21. The process of claim 13 wherein said sealing composition comprises a material selected from the group consisting of polyvalent acrylate or methacrylate, cyanoacrylates, polyvalent vinyl, polyvalent epoxide, polyvalent isocyanate, polyvalent allyl, and oligomers or polymers containing crosslinkable functional groups.

22. The process of claim 13 wherein said liquid crystal composition further comprises a guest dye.

23. The process of claim 13 wherein said hardening of said sealing composition is accomplished by solvent evaporation, interfacial reaction, moisture, heat or radiation.