Evaluation of Phase Retardation of Curved Thin Polycarbonate Substrates for Wide-viewing Angle Flexible Liquid Crystal Displays

Shuichi HONDA  Takahiro ISHINABE  Yosei SHIBATA  Hideo FUJIKAKE  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E100-C   No.11   pp.992-997
Publication Date: 2017/11/01
Online ISSN: 1745-1353
Type of Manuscript: INVITED PAPER (Special Section on Electronic Displays)
Category: 
Keyword: 
liquid crystal display,  flexible display,  polycarbonate substrate,  optical compensation,  bending stress,  

Full Text: FreePDF(1.4MB)


Summary: 
We investigated the effects of a bending stress on the change in phase retardation of curved polycarbonate substrates and optical characteristics of flexible liquid crystal displays (LCDs). We clarified that the change in phase retardation was extremely small even for the substrates with a small radius of curvature, because bending stresses occurred in the inner and upper surfaces are canceled each other out. We compensated for the phase retardation of polycarbonate substrates by a positive C-plate and successfully suppressed light leakage in both non-curved and curved states. These results indicate the feasibility of high-quality flexible LCDs using polycarbonate substrates even in curved states.