Transmissive or reflective liquid crystal display

• US 8,023,071 B2
• Filed: 08/17/2006
• Issued: 09/20/2011
• Est. Priority Date: 11/25/2002
• Status: Expired due to Fees

• Current Assignee: E Ink California, LLC (E Ink Corporation)
• Original Assignee: SiPix Imaging, Inc. (E Ink Holdings Incorporated)
• Inventors: Li, Ying-Syi, Liang, Rong-Chang, Zang, HongMei, Tseng, Scott C-J
• Primary Examiner(s): Chien; Lucy P
• Application Number:
  US11/507,033
• Publication Number:
  US 20070042135A1
• Time in Patent Office: 1,860 Days
• Field of Search: None
• US Class Current: 349/86
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• 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 1/13475 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 a liquid crystal display with improved contrast ratio, switching performance, reflectivity at the Dmin state and structural integrity, and methods for its manufacture. The liquid crystal display of the present invention comprises microcups as display cells, wherein the microcups are formed from a microcup composition and filled with a liquid crystal composition.

Claims

1. A process for the manufacture of a liquid crystal display, which process comprises:

a) forming microcups from a microcup composition comprising a thermoplastic, a thermoset, or a precursor thereof, and a speed enhancing filler material selected from the group consisting of low resistance fillers, conductive fillers, and fillers having a high dielectric constant;

b) filling the microcups with a liquid crystal composition;

c) sequentially overcoating a sealing composition into the microcups; and

d) hardening the sealing composition when it is on top of the liquid crystal composition.

2. The process of claim 1 wherein said speed enhancing filler material is a metal oxide, polyether block amide elastomer, or polyaniline.

3. The process of claim 1 wherein said speed enhancing filler material is a fiber material.

4. The process of claim 1 wherein said speed enhancing filler material is zirconia, barium titanate, strontium titanate, or lead zirconate titanate.

5. The process of claim 1 wherein said thermoplastic, thermoset, or precursor thereof is selected from the group consisting of a multifunctional acrylate, a multifunctional methacrylate, a vinyl ether, an epoxide, and an oligomer or a polymer thereof.

6. The process of claim 1 wherein said low resistance filler has volume resistance less than or equal to about 10¹⁰ ohm cm.

7. The process of claim 1 wherein said high dielectric constant is equal to or higher than about 5.

8. The process of claim 1 wherein said conductive filler is poly(3,4)ethylenedioxythiophene.

9. The process of claim 1 wherein the concentration of the speed enhancing filler material is no less than about 1% of the microcup composition.

10. A process for the manufacture of a liquid crystal display, which process comprises:

a) forming microcups from a microcup composition comprising a thermoplastic, a thermoset, or a precursor thereof, and a speed enhancing filler material selected from the group consisting of low resistance fillers, conductive fillers, and fillers having a high dielectric constant;

b) filling the microcups with a liquid crystal composition and a sealing composition;

c) floating the sealing composition to top of the liquid crystal composition, and

d) hardening the sealing composition during or after it floats to top of the liquid crystal composition.

11. The process of claim 10 wherein said speed enhancing filler material is a metal oxide, polyether block amide elastomer, or polyaniline.

12. The process of claim 10 wherein said speed enhancing filler material is a fiber material.

13. The process of claim 10 wherein said speed enhancing filler material is zirconia, barium titanate, strontium titanate, or lead zirconate titanate.

14. The process of claim 10 wherein said thermoplastic, thermoset, or precursor thereof is selected from the group consisting of a multifunctional acrylate, a multifunctional methacrylate, a vinyl ether, an epoxide, and an oligomer or a polymer thereof.

15. The process of claim 10 wherein said low resistance filler has volume resistance less than or equal to about 10¹⁰ ohm cm.

16. The process of claim 10 wherein said high dielectric constant is equal to or higher than about 5.

17. The process of claim 10 wherein said conductive filler is poly(3,4)ethylenedioxythiophene.

18. The process of claim 10 wherein the concentration of the speed enhancing filler material is no less than about 1% of the microcup composition.