Optical head using birefringent diffraction grating
US5493555A · kind A · utility
24Cited by
7References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1995 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Jun 6, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10543
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light radiated from a light source is focused on an optical disc by a focusing lens. A light reflected from the optical disc is introduced to a signal detection system. In the signal detection system, the introduced light is diffracted by a birefringent diffraction grating element utilizing an optical crystal. The diffracted light is received by a photodetector. Consequently, focus and track errors are detected, and information stored in the optical disc is re-produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.