Wavelength selective optical recording and reproducing device
US4956812A · kind A · utility
6Cited by
8References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1988 |
| Grant date | Sep 11, 1990 |
| Priority date | — |
| Expiry date | Jun 20, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00453
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A wavelength selective optical recording and reproducing device has a reference wavelength in a marker hole of a medium. The optical detector is adapted to detect light which is reflected from or transmitted through the marker hole. A phase detector detects the phase of an output of the optical detector by using a high frequency signal as a reference to obtain a signal indicative of the deviation of the wavelength of the output from a desired wavelength. A wavelength regulator is responsive to the wavelength deviation to control the wavelength of the light source to be the desired wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.