Frequency controllable optical device
US5267067A · kind A · utility
4Cited by
10References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 3, 1992 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Feb 3, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/18
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical cell having an optically active material, for example a liquid crystal is disclosed, the transparency of which is a function of the electrical voltage applied together with a control circuit, wherein said optically active material presents an electrical impedance variable with the frequency of the signal applied and said control circuit has a voltage source and means for controlling the frequency of the signal delivered by said voltage source. The cell has applications in attenuating light, notably in a sun screen or automobile rear-view mirror.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.