Phase retarder and process for producing the same
US5285303A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1991 |
| Grant date | Feb 8, 1994 |
| Priority date | — |
| Expiry date | May 24, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13363
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A phase retarder and a process for producing the same are disclosed. The phase retarder is obtained by shrinking a uniaxially stretched thermoplastic high polymer film in the direction perpendicular to the stretching direction at a lengthwise shrink of at least 2%. The phase retarder has a ratio of a retardation value (R.sub.30) measured on the phase retarder being inclined at a angle of 30.degree. with respect to the orientation axis as an axis of rotation to a retardation value (R.sub.0) measured on the phase retarder being held horizontally, each measured with a polarizing microscope, (R.sub.30 /R.sub.0) of not more than 1.10, and preferably not more than 1.07. A liquid crystal display fitted with the phase retarder exhibits broad viewing angle characteristics while achieving a satisfactory B/W display level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.