Tilt control apparatus with tilt target value based on bit error rate signal
US5886962A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 1998 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | Feb 4, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0956
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The tilt control apparatus of the invention controls to minimize an error in an orthogonal relationship between an optical disk and an optical axis of a light beam irradiated onto the optical disk. The tilt control apparatus includes: an optical pickup for irradiating the light beam onto the optical disk, thereby reproducing information recorded on the optical disk; an orthogonality error detector for outputting an orthogonality error signal corresponding to the error in the orthogonal relationship between the optical disk and the optical axis; a tilting mechanism for tilting the optical axis; a tilt controller for controlling such that the optical disk falls at right angles with the optical axis by driving the tilting mechanism in response to the orthogonality error signal; a pulse width variation detector for outputting a pulse width variation signal corresponding to a variation in a pulse width of an information reproduced signal obtained from the optical pickup; and a target value variable circuit for varying a control target value of the tilt controller based on the pulse width variation signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.