Optical recording and reproducing apparatus having a multi-spot positioning control mechanism
US4969137A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 1988 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Feb 16, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0912
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In optically coupling a plurality of light sources to an optical system for focusing light beams from the light sources into spots on a record plane, a center axis of a light beam from a first one of the light sources is aligned to an optical axis of the focusing optical system, and the spots other than a first spot formed by the light beam from the first light source are rotated around the first spot on the record plane to position the spots to the respective target tracks, and a tracking error signal for at least one of the first spot and another spot is detected and the positions of the plurality of spots are integrally controlled based on the detected tracking error signal so that the plurality of spots can follow the respective target tracks. The target tracks to which the spots are to be positioned may be either one track or different tracks. The positioning of the spots to the target tracks may be done either manually or automatically. In the automatic method, a tracking error signal is detected for the first spot, and a deflection mechanism for radially swinging beams from the laser light sources is controlled to control the positions of the spots on the record plane and to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.