Optical compensation plate and deflecting plate using the same

• US 7,235,283 B2
• Filed: 01/22/2003
• Issued: 06/26/2007
• Est. Priority Date: 01/23/2002
• Status: Active Grant

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Yamaoka, Takashi, Murakami, Nao, Yano, Shuuji, Kawai, Masayuki, Adachi, Junichi, Wasai, Kanako
• Primary Examiner(s): Dye; Rena
• Assistant Examiner(s): HON, SOW FUN
• Application Number:
  US10/502,296
• Publication Number:
  US 20050122586A1
• Time in Patent Office: 1,616 Days
• Field of Search: 428/1.1, 428/1.3, 428/1.31, 428/1.5, 428 153- 155, 428/343, 428/349, 428/355.R, 428/355.EP, 428/355.N, 428/355.AC, 428/355.CN, 349117-119, 349/122, 252/299.01, 252/299.7
• US Class Current: 428/1.3
• 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 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/031 Polarizer or dye
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• CPC Class Codes: C09K 2323/06 Substrate layer characterised by chemical composition
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02F 2413/15 with twisted orientation, e.g. comprising helically oriented LC-molecules or a plurality of twisted birefringent sublayers
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer

Abstract

The present invention provides an optical compensation plate having an optical compensation layer in which cracks occurring due to an applied pressure is suppressed. By applying a curable adhesive agent onto at least one surface of the optical compensation layer and curing the adhesive, an anti-cracking layer is formed directly on the surface of the optical compensation layer. The occurrence of cracks in the optical compensation layer can be prevented by this anti-cracking layer. The optical compensation layer preferably is a layer having a cholesteric structure, and the constituent material thereof is preferably a non-liquid crystal polymer formed by polymerizing aligned liquid crystal monomers or an aligned liquid crystal polymer.

Claims

1. An optical compensation plate comprising an optical compensation layer, and an anti-cracking layer which is laminated directly on at least one surface of the optical compensation layer, wherein a microhardness of the anti-cracking layer ranges from 0.1 to 0.5 GPa, said anti-cracking layer is formed of a curable adhesive agent which comprises at least one thermosetting resin-based adhesive selected from the group consisting of an epoxy resin, an isocyanate resin and a polyimide resin, and said optical compensation layer is a cholesteric layer whose constituent molecules are aligned in the form of a cholesteric structure, wherein

the constituent molecule of the cholesteric layer is produced from a liquid crystal monomer and a chiral dopant.

the liquid crystal monomer is selected from the group consisting of:

a compound represented by the below formula (4);

a compound represented by the below formula (5);

a compound represented by the below formula (6);

a compound represented by the below formula (7);

a compound represented by the below formula (8);

a compound represented by the below formula (9);

a compound represented by the below formula (10);

a compound represented by the below formula (11);

a compound represented by the below formula (12);

a compound represented by the below formula (13);

a compound represented by the below formula (14);

a compound represented by the below formula (15);

a compound represented by the below formula (16);

a compound represented by the below formula (17);

a compound represented by the below formula (18); and

a compound represented by the below formula (19), and

the chiral dopant is selected from the group consisting of;

a compound represented by the below formula (24);

a compound represented by the below formula (25);

a compound represented by the below formula (26);

a compound represented by the below formula (27);

a compound represented by the below formula (28);

a compound represented by the below formula (29);

a compound represented by the below formula (30);

a compound represented by the below formula (31);

a compound represented by the below formula (32);

a compound represented by the below formula (33);

a compound represented by the below formula (34);

a compound represented by the below formula (35);

a compound represented by the below formula (36);

a compound represented by the below formula (37);

a compound represented by the below formula (38);

a compound represented by the below formula (39);

a compound represented by the below formula (40);

a compound represented by the below formula (41);

a compound represented by the below formula (42);

a compound represented by the below formula (43); and

a compound represented by the below formula (44)

2. The optical compensation plate according to claim 1, wherein a thickness of the ant-cracking layer ranges from 0.1 to 20 μ

m.

3. The optical compensation plate according to claim 1, wherein the thickness of the cholesteric layer ranges from 0.5 to 10 μ

m.

4. The optical compensation plate according to claim 1, wherein a helical pitch of a cholesteric alignment ranges from 0.01 to 0.25 μ

m.

5. A polarizing plate comprising a polarizer, a transparent protective layer and the optical compensation plate according to claim 1, wherein the polarizer and the optical compensation plate are laminated together via the transparent protective layer.

6. The polarizing plate according to claim 5, wherein the optical compensation plate and the transparent protective layer are directly adhered to each other by the anti-cracking layer in the optical compensation plate.

7. The polarizing plate according to claim 5, wherein, in the optical compensation plate, a pressure-sensitive adhesive layer is laminated on the surface of the optical compensation layer opposing to the surface on which the anti-cracking layer is laminated.

8. The polarizing plate according to claim 7, wherein a material of the pressure-sensitive adhesive layer is at least one resin-based pressure-sensitive adhesive selected from the group consisting of an acrylic resin, a rubber-based resin and a vinyl-based resin.

9. The polarizing plate according to claim 7, wherein a liner is further disposed on the surface of the pressure-sensitive adhesive layer.

10. The polarizing plate according to claim 5,

wherein the optical compensation plate is configured by laminating an anti-cracking layer on both surfaces of the optical compensation layer, and

one of the anti-cracking layers and the polarizer are laminated together via the transparent protective layer.

11. The polarizing plate according to claim 10, wherein, in the optical compensation plate, a pressure-sensitive adhesive layer and a liner are further disposed in this order on the surface of the anti-cracking layer on which the polarizer is not laminated.

12. A liquid crystal panel, comprising a liquid crystal cell and the polarizing plate according to claim 5.

13. A liquid crystal display comprising the liquid crystal panel of claim 12.

14. An image display apparatus, which is at least one image display apparatus selected from the group consisting of an electroluminescence (EL) display, a plasma display (PD) and a field emission display (FED), comprising the polarizing plate according to claim 5.

15. A liquid crystal panel, comprising a liquid crystal cell and the optical compensation plate according to claim 1.

16. A liquid crystal display comprising the liquid crystal panel of claim 15.

17. An image display apparatus, which is at least one image display apparatus selected from the group consisting of an electroluminescence (EL) display, a plasma display (PD) and a field emission display (FED), comprising the optical compensation plate according to claim 1.