Circular polarizing plate and bendable display device

Patent metadata

Field	Value
Publication number	US-10036840-B2
Application number	US-201414766046-A
Country	US
Kind code	B2
Filing date	Jan 29, 2014
Priority date	Feb 7, 2013
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

There is provided a circularly polarizing plate capable of realizing a bendable display apparatus in which an excellent reflection hue is obtained and a color change due to bending is suppressed. A circularly polarizing plate according to the present invention is used in a bendable display apparatus. The circularly polarizing plate includes: a polarizer; and a retardation film arranged on one side of the polarizer. In-plane retardations of the retardation film satisfy a relationship of Re(450)<Re(550)<Re(650), and a slow axis direction of the retardation film is adjusted so as to form an angle of from 20° to 70° with respect to a bending direction of the display apparatus.

First claim

The invention claimed is:

1. A circularly polarizing plate to be used in a bendable display apparatus, comprising:
a polarizer; and
a retardation film arranged on one side of the polarizer, the retardation film being formed of a single resin film,
wherein in-plane retardations at 450 nm, 550 nm, and 650 nm of the retardation film satisfy a relationship of Re(450)<Re(550)<Re(650),
wherein a ratio of Re(450) to Re(550) is 0.8 or more and less than 1.0,
wherein a ratio of Re(550) to Re(650) is 0.8 or more and less than 1.0,
wherein a slow axis direction of the retardation film is adjusted so as to form an angle of from 20° to 70° with respect to a bending direction of the display apparatus,
wherein the retardation film is a stretched film, and
wherein the display apparatus is an organic electroluminescence display apparatus.

2. The circularly polarizing plate according to claim 1 , wherein at least part of the display apparatus is bent with a radius of curvature of 10 mm or less.

3. The circularly polarizing plate according to claim 1 , wherein an absolute value of a photoelastic coefficient of the retardation film is 2×10 −12 (m 2 /N) or more.

4. The circularly polarizing plate according to claim 1 , further comprising another retardation film arranged on another side of the polarizer.

5. A bendable display apparatus, comprising the circularly polarizing plate of claim 1 .

6. The circularly polarizing plate according to claim 1 , wherein the single resin film is composed of at least one resin selected from the group consisting of a polycarbonate resin, a polyvinyl acetal resin, a cycloolefin-based resin, an acrylic resin, and a cellulose ester-based resin.

7. The circularly polarizing plate according to claim 1 , wherein the retardation film has a thickness of from 20 μm to 100 μm.

Assignees

• Nitto Denko Corp

Inventors

• Takeda Kentarou
• Yaginuma Hironori
• Sumimura Hiroshi
• Murakami Nao

Classifications

• G02B27/288

  Filters employing polarising elements, e.g. Lyot or Solc filters (G02B5/3016 takes precedence) · CPC title

• G02B5/3083

  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 title

• H01L51/5281

  Electricity · mapped topic

• H01L2251/5338

  Electricity · mapped topic

• G02F2001/133637

  Physics · mapped topic