Varifocal optical element
US4872743A · kind A · utility
45Cited by
18References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1988 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Jan 11, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical element whose focal length is variable comprises a medium whose refractive index is variable by temperature, a heating device for imparting heat to the medium to cause an index gradient resulting from a temperature distribution to be created in the medium, and a device for controlling the amount of heat imparted to the medium by the heating device to vary the shape of the index gradient formed in the medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.