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

• US 7,141,279 B2
• Filed: 11/21/2003
• Issued: 11/28/2006
• 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: Liang, Rong-Chang, Tseng, Scott C-J, Li, Ying-Syi
• Primary Examiner(s): Pyon, Harold
• Assistant Examiner(s): HON, SOW FUN
• Application Number:
  US10/718,990
• Publication Number:
  US 20040170776A1
• Time in Patent Office: 1,103 Days
• Field of Search: 428/1.3, 428/1.5, 359237-238, 359/296, 359/242, 204/450, 204/600, 345/105, 345/107, 349/86, 349 89- 90
• US Class Current: 428/1.5
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: C09K 2323/02 Alignment 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 1/1334 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 a liquid crystal display with improved contrast ratio, switching performance, reflectivity at the Dmin state and structural integrity, and methods for its manufacture.

Claims

1. A liquid crystal display comprising microcups as display cells which are:

a) formed from a microcup composition comprising a thermoplastic, a thermoset or a precursor thereof and a first liquid crystal composition;

b) filled with a second liquid crystal composition; and

c) sealed with a sealing layer formed from a sealing composition having a specific gravity lower than that of the second liquid crystal composition.

2. The liquid crystal display of claim 1 wherein said micro cup composition is an embossable composition.

3. The liquid crystal display of claim 1 wherein the liquid crystal in the first liquid crystal composition has a concentration no greater than its solubility limit in the microcup composition.

4. The liquid crystal display of claim 1 wherein said thermoplastic, thermo set or precursor thereof is a multifunctional acrylate or methacrylate, vinyl ether, epoxide or an oligomer or polymer thereof.

5. A liquid crystal display comprising microcups as display cells which are:

a) formed from a microcup composition comprising a thermoplastic, a thermoset or a precursor thereof and a speed enhancing comonomer or oligomer;

b) filled with a liquid crystal composition; and

c) sealed with a sealing layer formed from a sealing composition having a specific gravity lower than that of the liquid crystal composition.

6. The liquid crystal display of claim 5 wherein said microcup composition is an embossable composition.

7. The liquid crystal display of claim 5 wherein said speed enhancing comonomer or oligomer comprises a poly(ethylene glycol) or poly(propylene glycol) moiety.

8. The liquid crystal display of claim 7 wherein said poly(ethylene glycol) or poly(propylene glycol) moiety is poly(ethylene glycol) monoacrylate, poly(ethylene glycol) monomethacrylate, poly(ethylene glycol) diacrylate, poly(ethylene glycol) dimethacrylate, poly(propylene glycol) monoacrylate, poly(propylene glycol) monomethacrylate, poly(propylene glycol) diacrylate or poly(propylene glycol) dimethacrylate.

9. The liquid crystal display of claim 5 wherein said thermoplastic, thermoset or precursor thereof is a multifunctional acrylate or methacrylate, vinyl ether, epoxide or an oligomer or polymer thereof.

10. A liquid crystal display comprising two or more layers of microcups wherein said microcups are:

a) formed from a microcup composition comprising a thermoplastic, a thermoset or a precursor thereof and a first liquid crystal composition;

b) filled with a second liquid crystal composition; and

c) sealed with a sealing layer formed from a sealing composition having a specific gravity lower than that of the second liquid crystal composition.

11. The liquid crystal display of claim 10 wherein the liquid crystal has a concentration no greater than its solubility limit in the microcup composition.

12. The liquid crystal display of claim 10 wherein said thermoplastic, thermoset or precursor thereof is a multifunctional acrylate or methacrylate, vinyl ether, epoxide or an oligomer or polymer thereof.

13. The liquid crystal display of claim 10 wherein said two or more layers of microcups are sandwiched between two conductor films.

14. A liquid crystal display comprising two or more layers of microcups, wherein said microcups are formed from a microcup composition comprising a thermoplastic, a thermoset or a precursor thereof and a first liquid crystal composition;

wherein said two or more layers of microcups are arranged in a staggered manner, wherein said microcups are filled with a second liquid crystal composition and sealed with a sealing layer formed from a sealing composition having a specific gravity lower than that of the second liquid crystal composition.

15. A liquid crystal display comprising two or more layers of microcups wherein said microcups are:

a) formed from a microcup composition comprising a thermoplastic, a thermoset or a precursor thereof and a speed enhancing comonomer or oligomer;

b) filled with a liquid crystal composition; and

c) sealed with a sealing layer formed from a sealing composition having a specific gravity lower than that of the liquid crystal composition.

16. The liquid crystal display of claim 15 wherein said speed enhancing comonomer or oligomer comprises a poly(ethylene glycol) or poly(propylene glycol) moiety.

17. The liquid crystal display of claim 16 wherein said poly(ethylene glycol) or poly(propylene glycol) moiety is poly(ethylene glycol) monoacrylate, poly(ethylene glycol) monomethacrylate, poly(ethylene glycol) diacrylate, poly(ethylene glycol) dimethacrylate, poly(propylene glycol) monoacrylate, poly(propylene glycol) monomethacrylate, poly(propylene glycol) diacrylate or poly(propylene glycol) dimethacrylate.

18. The liquid crystal display of claim 15 wherein said thermoplastic, thermoset or precursor thereof is a multifunctional acrylate or methacrylate, vinyl ether, epoxide or an oligomer or polymer thereof.

19. The liquid crystal display of claim 15 wherein said two or more layers of microcups are sandwiched between two conductor films.

20. A liquid crystal display comprising two or more layers of microcups, wherein said microcups are formed from a microcup composition comprising a thermoplastic, a thermoset or a precursor thereof and a speed enhancing comonomer or oligomer;

wherein said two or more layers of microcups are arranged in a staggered manner;

wherein said microcups are filled with a liquid crystal composition and sealed with a sealing layer formed from a sealing composition having a specific gravity lower than that of the liquid crystal composition.