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

Patent metadata

Field	Value
Publication number	US-9606395-B2
Application number	US-201415026659-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. The set of polarizing plates satisfies the formula: (R a −F t )<(F a −R t ), where F a and F t represent ratios of dimensional change observed in the front-side polarizing plate in absorption and transmission axis directions, respectively, after the front-side polarizing plate is heated at 85° C. for 100 hours, and R a and R t represent ratios of dimensional change observed in the back-side polarizing plate in absorption and transmission axis directions, respectively, after the back-side polarizing plate is heated at 85° C. for 100 hours.

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, 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 front-side polarizing plate including a polarizer and a first protective layer on a viewing side of the polarizer, the front plate and the first protective layer of the front-side polarizing plate being integrated together by an ultraviolet curing type resin or a pressure sensitive adhesive; and
a back-side polarizing plate to be disposed at a back side of the liquid crystal cell,
the set of polarizing plates satisfying the following formula:
( R a −F t )<( F a −R t )  [I],

where F a represents a ratio of dimensional change observed in the front-side polarizing plate in an absorption axis direction after the front-side polarizing plate is heated at 85° C. for 100 hours and F t represents a ratio of dimensional change observed in the front-side polarizing plate in a transmission axis direction after the front-side polarizing plate is heated at 85° C. for 100 hours, and R a represents a ratio of dimensional change observed in the back-side polarizing plate in an absorption axis direction after the back-side polarizing plate is heated at 85° C. for 100 hours and R t represents a ratio of dimensional change observed in the back-side polarizing plate in a transmission axis direction after the back-side polarizing plate is heated at 85° C. for 100 hours.

2. The set of the polarizing plates according to claim 1 , wherein:
the back-side polarizing plate includes a polarizer; and
the polarizer of the front-side polarizing plate is larger in thickness than the polarizer of the back-side polarizing plate.

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 polarizer of the front-side polarizing plate is composed of a polyvinyl alcohol-based resin film, and
wherein the back-side polarizing plate includes a polarizer composed of a polyvinyl alcohol-based resin film and a protective layer laminated on at least one surface of the polarizer of the back-side polarizing plate.

5. The set of polarizing plates according to claim 4 , wherein
the front-side polarizing plate includes a liquid-crystal-cell-side protective layer laminated on a surface of the polarizer opposite to the viewing side of the polarizer, the liquid-crystal-cell-side protective layer having an in-plane phase retardation; or
the back-side polarizing plate includes a liquid-crystal-cell-side protective layer laminated on a viewing side surface of the polarizer, the liquid-crystal-cell-side protective layer having 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 the 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

• G02F1/133528 Primary

  Polarisers · 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

• G02F2001/133567

  Physics · mapped topic

• G02F2001/133562

  Physics · mapped topic

• G02F1/133562

  on the viewer side · CPC title