IP Library › Granted Patent US 7,671,949
Granted Patent B2
US 7,671,949 · App. 10/500,287 · Granted Mar 2, 2010

Polarizing plate with optical compensation function, and liquid crystal display device using the same

Assignee: Nitto Denko Corporation
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Quick Facts
Patent No.
US 7,671,949
App. No.
10/500,287
Granted
Mar 2, 2010
Kind
B2
Abstract

A polarizing plate with optical compensation function, including a polarizing layer and an optically compensating layer, wherein the optically compensating layer includes an optically compensating A-layer including a stretched polymer film and an optically compensating B-layer including a cholesteric liquid crystal layer.

Claims (20)

1. A liquid crystal display comprising:

a polarizing plate having a polarizing layer, an optically compensating A-layer and an optically compensating B-layer; and

a VA-type liquid cell adjacent to the polarizing plate,

wherein the VA-type liquid crystal cell is compensated only by the optically compensating A-layer and the optically compensating B-layer,

wherein the optically compensating A-layer comprises a polymer film,

wherein the optically compensating B-layer comprises a cholesteric liquid crystal layer,

wherein the optically compensating A-layer is on a side of the optically compensating B-layer opposed to the polarizing layer,

wherein the optically compensating A-layer meets requirements indicated by the following formulae (I) and (II):

20 (nm)≦Re≦300 (nm)  (I)

1.2≦Rth/Re  (II)

wherein, in the formulae,

Re (retardation value in normal direction)=(nx−ny)·d

Rth (retardation value in thickness direction)=(nx−nz)·d;

where nx, ny and nz respectively denote refractive indices of X axis, Y axis and Z axis in the optically compensating A-layer; the X axis denotes an axial direction presenting a maximum refractive index within the optically compensating A-layer, the Y axis denotes an axial direction perpendicular to the X axis within the optically compensating A-layer, and the Z axis denotes a thickness direction perpendicular to the X axis and the Y axis; ‘d’ denotes the thickness of the optically compensating A-layer, and

wherein Re (retardation value in normal direction) of the optically compensating B-layer is about 0.

2. The liquid crystal display according to claim 1 , wherein the polarizing plate further comprises at least one of an alignment layer and a base.

3. The liquid crystal display according to claim 1 , wherein the polymer film is either a stretched film or a liquid crystal film.

4. The liquid crystal display according to claim 1 , further comprising a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer being arranged on one of the surfaces of the polarizing plate.

5. The liquid crystal display according to claim 1 , wherein the polarizing layer and the optically compensating A-layer are arranged so that an angle formed by an absorption axis of the polarizing layer and a slow axis of the optically compensating A-layer is not smaller than 85° and not larger than 95°.

6. The liquid crystal display according to claim 1 , wherein a selective reflection wavelength range of the cholesteric liquid crystal layer is in a range not larger than 350 nm.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 29, 2004
From: SASAKI, SHINICHI; YAMAOKA, TAKASHI; MURAKAMI, NAO; YOSHIMI, HIROYUKI
To: NITTO DENKO CORPORATION
Reel/Frame 016089/0599 →
Priority Claims (1)
JP 2002-041686 · Feb 19, 2002 · national
Continuity (1)
Related Publication 20050078245A1 · Apr 14, 2005