Optical tracking system for an optical recording arrangement with plurality of beams
US5113378A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 2, 1990 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Jan 2, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0033
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording device which writes and reads data by radiating laser beams from an optical head onto an optical recording medium. A diffraction grating is provided on the optical head and a plurality of laser beams are generated. Some of the laser beams are positioned on a track guide on the above-mentioned optical recording medium. Some of the other laser beams are positioned on another track guide and a plurality of tracking beams are thus constituted. The optical recording device is also provided with a tracking detection circuit for outputting a tracking error signal indicating the difference between the amounts of reflected light to a photo detector which receives light reflected from the above-mentioned optical recording medium for tracking beams and for switching the above-mentioned tracking beams used for tracking. The plurality of tracking beams enables tracking to be performed even when a track guide has defects by switching tracking beams, thereby improving tracking reliability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.