Optical recording apparatus for recording auxillary signals used for focus control
US5253241A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1991 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Aug 30, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/094
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording apparatus for automatically compensating for focus offset which cannot be compensated for with a conventional focus servo circuit. A plurality of auxiliary signals differing from one another in the frequency domain is generated, a rotational synchronism signal is generated by detecting an index mark put on the optical disk in advance to indicate the reference point of the rotational phase, and a switching signal is generated in response to the rotational synchronism signal. In response to the switching signal, a plurality of auxiliary signals and an information signal are consecutively outputted and recorded onto a track of the optical disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.