Optical compensation plate and deflecting plate using the same

• US 20050122586A1
• Filed: 01/22/2003
• Published: 06/09/2005
• 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
• Granted Patent: US 7,235,283 B2
• Time in Patent Office: Days
• US Class Current: 359/487
• 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, wherein an anti-cracking layer of a curable adhesive agent is laminated directly on at least one surface of the optical compensation layer.

2. The optical compensation plate according to claim 1, wherein a microhardness of the anti-cracking layer ranges from 0.1 to 0.5 GPa.

3. The optical compensation plate according to claim 1, wherein the curable adhesive agent comprises at least one adhesive selected from the group consisting of a photocuring resin-based adhesive and a moisture-curing resin-based adhesive.

4. The optical compensation plate according to claim 1, wherein the curable adhesive agent is at least one thermosetting resin-based adhesive selected from the group consisting of an epoxy resin, an isocyanate resin and a polyimide resin.

5. The optical compensation plate according to claim 3, wherein the moisture-curing resin-based adhesive is an isocyanate resin-based adhesive.

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

m.

7. The optical compensation plate according to claim 1, wherein the optical compensation layer is a cholesteric layer whose constituent molecules are aligned in the form of a cholesteric structure.

8. The optical compensation plate according to claim 7, wherein the thickness of the cholesteric layer ranges from 0.5 to 10 μ

m.

9. The optical compensation plate according to claim 7, wherein the constituent molecules of the cholesteric layer are non-liquid crystal polymers, and the non-liquid crystal polymer is a polymer obtained by polymerizing or cross-linking liquid crystal monomers which are aligned in the form of a cholesteric structure.

10. The optical compensation plate according to claim 9, wherein a helical pitch of a cholesteric alignment ranges from 0.01 to 0.25 μ

m.

11. The optical compensation plate according to claim 7, wherein the constituent molecules of the cholesteric layer are liquid crystal polymers, and the liquid crystal polymers are aligned in the form of a cholesteric structure.

12. 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.

13. The polarizing plate according to claim 12, 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.

14. The polarizing plate according to claim 12, 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.

15. The polarizing plate according to claim 14, 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.

16. The polarizing plate according to claim 12,

wherein the optical compensation plate is configured by laminating the anti-cracking layers 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.

17. The polarizing plate according to claim 16, 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.

18. The polarizing plate according to claim 14, wherein a liner is further disposed on the surface of the pressure-sensitive adhesive layer.

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

20. A liquid crystal display comprising, the liquid crystal panel of claim 19.

21. 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.

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

23. A liquid crystal display comprising the liquid crystal panel of claim 22.

24. 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 12.