Set of polarizing plates and front-plate-integrated liquid crystal display panel

Patent metadata

Field	Value
Publication number	US-9606394-B2
Application number	US-201415026648-A
Country	US
Kind code	B2
Filing date	Sep 29, 2014
Priority date	Oct 3, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

Provided is a set of polarizing plates comprising a front-plate-integrated polarizing plate to be disposed at a viewing side of a liquid crystal cell and a back-side polarizing plate to be disposed at a back-side of the cell. The front-plate-integrated polarizing plate includes a front-side polarizing plate and a front plate having a Young's modulus of 2 GPa or more. An amount of shrinkage observed in the front-side polarizing plate in an absorption axis direction after the front-side polarizing plate is stuck to a glass substrate and heated at 85° C. for 500 hours is taken as X, and an amount of shrinkage observed in the back-side polarizing plate in an absorption axis direction after the back-side polarizing plate is stuck to a glass substrate and heated at 85° C. for 500 hours is taken as Y, the amount of shrinkage X being smaller than the amount of shrinkage Y.

First claim

The invention claimed is:

1. A set of polarizing plates comprising a front-plate-integrated polarizing plate to be disposed at a viewing side of a liquid crystal cell, and a back-side polarizing plate to be disposed at a back-side of the liquid crystal cell,
the front-plate-integrated polarizing plate including a front-side polarizing plate and a front plate,
the front plate being disposed at a viewing side of the front-side polarizing plate and having a Young's modulus equal to or greater than 2 GPa,
the back-side polarizing plate having an amount of shrinkage Y of 0.5 mm or less in an absorption axis direction when stuck to a glass substrate and heated at 85° C. for 500 hours,
the front-side polarizing plate having an amount of shrinkage X in an absorption axis direction when stuck to a glass substrate and heated at 85° C. for 500 hours,
the amount of shrinkage X being smaller than the amount of shrinkage Y,
the front-side polarizing plate and the back-side polarizing plate each comprising a pressure sensitive adhesive layer for sticking to the liquid crystal cell, and
the pressure sensitive adhesive layer of the front-side polarizing plate and the pressure sensitive adhesive layer of the back-side polarizing plate having a thickness of 5 to 50 μm.

2. The set of polarizing plates according to claim 1 , wherein the amount of shrinkage X is 0.5 mm or less.

3. The set of polarizing plates according to claim 1 , wherein:
the front-side polarizing plate and the back-side polarizing plate have a rectangular shape having a longer side and a shorter side;
the front-side polarizing plate has an absorption axis approximately parallel to a direction of the shorter side; and
the back-side polarizing plate has an absorption axis approximately parallel to a direction of the longer side.

4. The set of polarizing plates according to claim 1 , wherein the front-side polarizing plate and the back-side polarizing plate each further include:
a polarizer composed of a polyvinyl alcohol-based resin film; and
a protective layer laminated on at least one surface of the polarizer.

5. The set of polarizing plates according to claim 4 , wherein:
at least one of the front-side polarizing plate and the back-side polarizing plate includes a liquid-crystal-cell-side protective layer laminated on a surface of the polarizer closer to the liquid crystal cell; and
the liquid-crystal-cell-side protective layer has an in-plane phase retardation.

6. The set of polarizing plates according to claim 4 , wherein the back-side polarizing plate further includes another optical layer other than the polarizer and the protective layer laminated on an outermost surface opposite to the liquid crystal cell.

7. A front-plate-integrated liquid crystal display panel comprising the set of polarizing plates according to claim 1 , and a liquid crystal cell, wherein:
the front-plate-integrated polarizing plate is stuck, at its front-side polarizing plate's side, on a viewing side of the liquid crystal cell; and
the back-side polarizing plate is stuck on a back-side of the liquid crystal cell.

8. The front-plate-integrated liquid crystal display panel according to claim 7 , having a warping amount in absolute value of 0.5 mm or less when heated at 85° C. for 240 hours.

Assignees

• Sumitomo Chemical Co

Inventors

• Kawamura Takahito

Classifications

• G02F2201/50

  Protective arrangements · CPC title

• G02F2202/28

  Adhesive materials or arrangements · CPC title

• G02B5/3025 Primary

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• C08L29/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• G02F1/133528 Primary

  Polarisers · CPC title