Device for driving and controlling optical head for use in optical disk system
US4835752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 1987 |
| Grant date | May 30, 1989 |
| Priority date | — |
| Expiry date | Dec 14, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/08517
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device for driving and controlling an optical head by forming a spot of a light beam on an optical disk having a plurality of tracks and detecting light from the spot reflected on the optical disk by a pair of optical detectors disposed in the head. This device has: a head actuator for moving a movable portion of the optical head in the radial direction of the disk; a speed detector for detecting the track-crossing speed of the spot from outputs from the optical detectors; a reference speed generator for generating, while accessing to a target track, a reference moving speed signal in accordance with the distance to the target track obtained from the outputs from the optical detectors, the movable head portion being moved on the basis of the reference moving speed signal so that the speed of the movable portion decreases at a position near the target track before the light beam spot reaches this track; a speed error detector for obtaining the difference between outputs from the reference speed generator and the speed detector; and a magnification change circuit adapted for amplifying the outputs from the reference speed generator and the speed detector by a predetermined multiply…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.