Light spot position control system and method by sampling servo
US4785442A · kind A · utility
33Cited by
10References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1987 |
| Grant date | Nov 15, 1988 |
| Priority date | — |
| Expiry date | Jul 10, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/09
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A light spot position control system of the invention uses an optical disc in which a servo area and a data area are alternately formed along a rotating direction of a rotary recording medium, wherein error signals obtained from the servo areas are sampled, the latest sample value is compared with at least one-preceding sample value, a check is made to see if the latest sample value is correct or incorrect, and when the latest sample value is decided to be incorrect, the preceding error signal held is directly used as a light spot position control signal without updating the current error signal holding value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.