COMPOSITE POLARIZING PLATE WITH WIDE FIELD OF VIEW AND LIQUID CRYSTAL DISPLAY

• US 20090059136A1
• Filed: 02/16/2007
• Published: 03/05/2009
• Est. Priority Date: 02/21/2006
• Status: Abandoned Application

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Okamura, Mari
• Application Number:
  US12/279,862
• Publication Number:
  US 20090059136A1
• Time in Patent Office: Days
• US Class Current: 349/96
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation

Abstract

There is provided a wide viewing angle composite polarizing plate, comprising a linear polarization plate and an optical compensation film which comprises a transparent substrate showing an in-plane phase difference, and an optical anisotropic layer formed on one surface of the transparent substrate, said optical anisotropic layer being positive uniaxial and having an optical axis in a normal direction to the film, wherein, when the optical anisotropic layer side of said optical compensation film is used as the joint face, the phase retardation axis of the transparent substrate constituting said optical compensation film is substantially in parallel to the absorption axis of said linear polarization plate; and wherein, when the transparent substrate side of said optical compensation film is used as the joint face, the phase retardation axis of the transparent substrate is substantially orthogonal to the absorption axis of said linear polarization plate.

Claims

1. A wide viewing angle composite polarizing plate, comprising a linear polarization plate and an optical compensation film which comprises a transparent substrate showing an in-plane phase difference, and an optical anisotropic layer formed on one surface of the transparent substrate, said optical anisotropic layer being positive uniaxial and having an optical axis in a normal direction to the film,

wherein, when the optical anisotropic layer side of said optical compensation film is used as a joint face, a phase retardation axis of the transparent substrate constituting said optical compensation film is substantially in parallel to an absorption axis of said linear polarization plate;

and

wherein, when the transparent substrate side of said optical compensation film is used as a joint face, a phase retardation axis of the transparent substrate is substantially orthogonal to an absorption axis of said linear polarization plate.

2. The wide viewing angle composite polarizing plate of claim 1, wherein said transparent substrate showing an in-plane phase difference is a transparent resin film which is selected from cellulose resin films, cyclic polyolefin resin films and polycarbonate resin films and which is stretched.

3. The wide viewing angle composite polarizing plate of claim 1, wherein said optical anisotropic layer is formed as a coating layer containing a rod-form liquid crystal compound.

4. The wide viewing angle composite polarizing plate of claim 3, wherein said optical anisotropic layer is formed as a coating layer containing a nematic liquid crystal compound.

5. The wide viewing angle composite polarizing plate of claim 1, wherein said optical anisotropic layer contains a side-chain liquid crystal polymer, the side chain of which is oriented in a normal direction to the film.

6. The wide viewing angle composite polarizing plate of claim 1, wherein said linear polarization plate comprises a polarizer having a transparent protective film laminated on its one surface, and wherein said linear polarization plate is laminated on said optical compensation film so that the other surface of the polarizer, having no transparent protective film laminated thereon, faces the optical compensation film side.

7. The wide viewing angle composite polarizing plate of claim 1, wherein a retardation film is held between said optical compensation film and said linear polarization plate.

8. A liquid crystal display comprising the wide viewing angle composite polarizing plate defined in claim 1, and an in-plane switching mode liquid crystal cell.

9. The liquid crystal display of claim 8, wherein an optical compensation film side of said wide viewing angle composite polarizing plate is laminated on one surface of said in-plane switching mode liquid crystal cell, with a backlight disposed outside the wide viewing angle composite polarizing plate;

and wherein a front side polarizing plate is laminated on the other surface of said liquid crystal cell so that both of an in-plane phase difference and a phase difference in the thickness direction are substantially zero between a polarizer constituting said front side polarizing plate and the liquid crystal cell.