Automatic optical focusing device
US4128309A · kind A · utility
16Cited by
2References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1976 |
| Grant date | Dec 5, 1978 |
| Priority date | — |
| Expiry date | Aug 16, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/0816
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to the focusing of an optical system by variation of the radius of curvature of a reflecting element, comprising two prepolarized thin plates of piezoelectric material which are joined together and each of which carries an electrode, the outer surface of one of the two thin plates being made reflective. An electrical signal characteristic of the correction to be made is applied between the two electrodes and produces a variation in the radius of curvature of the thin plates. This reflecting element is used in an optical system of the Cassegrin type or as a reflecting mirror.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.