Birefringent plate and manufacturing method for the same
US4874664A · kind A · utility
25Cited by
2References
6Claims
0Family size
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Inventors
Key dates
| Filing date | Nov 10, 1987 |
| Grant date | Oct 17, 1989 |
| Priority date | — |
| Expiry date | Nov 10, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/252
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A birefringent plate comprising a transparent substrate and an obliquely evaporated film formed on the transparent substrate, is free from the visual angle dependence because the obliquely evaporated film is formed into a multilayer composition and the neighboring layers have a different evaporation direction. Moreover, a manufacturing method for the birefringent plate, using a device constituted of a vacuum chamber and a crucible having a large number of inclined through holes, is capable of making the film thickness of the obliquely evaporated film uniform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.