Optical beam tracking system for use in optical information recording and/or reproducing apparatus
US4718051A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 26, 1984 |
| Grant date | Jan 5, 1988 |
| Priority date | — |
| Expiry date | Dec 26, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0953
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A beam tracking system is used in an optical information recording and/or reproducing apparatus to optically track a record medium track. An objective lens irradiates an optical beam onto the record medium and is driven by a lens actuator to sweep the optical beam in a coarse mode relative to a predetermined track of the record medium. A carriage moves relative to the record medium for carrying the objective lens thereon and is driven by a carriage actuator to sweep the optical beam in a fine mode relative to the track. A detector detects the reflected optical beam during the sweep of the optical beam to produce a tracking signal representative of the deviation of the optical beam from the track. A pair of control circuits are connected to control the lens and carriage actuators respectively to effect the alignment of the optical beam with the track according to the tracking signal. A timing circuit is coneected to enable operation of the control circuit which controls the lens actuator and to inhibit operation of the other control circuit which controls the carriage actuator for a certain interval to effect alignment of the optical beam solely by means of the lens actuator, and th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.