Optical information recording and reproducing apparatus
US5568461A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1995 |
| Grant date | Oct 22, 1996 |
| Priority date | — |
| Expiry date | Apr 20, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00736
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical information recording and reproducing apparatus for recording and reproducing an information signal on/from both concave portions and convex portions of guide grooves formed on a recording medium is disclosed. The optical information recording and reproducing apparatus includes: an optical portion for focusing a light beam emitted from a light source on the recording medium; a focusing control portion for controlling a focal point of the light beam; a tracking control portion for controlling the position of the light beam; a selection portion for selecting which of the concave portions and the convex portions of the guide grooves are used for recording or reproducing; a polarity inverting portion for inverting the polarity of an output signal from the tracking control portion depending on a result selected by the selection portion; a waveform setting portion for setting a modulation pattern for the light; and a signal reproduction portion for demodulating the information signal from a light reflected or transmitted by recorded marks recorded on the recording medium; wherein at least one of the focusing control portion, the tracking control portion, the waveform setting p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.