Birefringence measurement of polymeric films and the like
US7385696B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 2006 |
| Grant date | Jun 10, 2008 |
| Priority date | — |
| Expiry date | Apr 19, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/23
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Provided are methods for determining the birefringence level of optical material such as polymeric film. In one embodiment, the method uses a setup of optical components that has known system reference angle. The sample may be a stretched polymeric film that has a fast axis angle that has a predetermined orientation in the sample. The system is operated to align the direction of the fast axis of the sample with the reference angle of the system and to measure the birefringence level at a location of the sample. As one aspect of the invention, embodiments and methods are described for accurately determining birefringence levels across a very wide range and up to tens of thousands of nanometers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.