Optical tracking control apparatus for controlling a tracking of a light beam which scans an information recording disc using pre-formatted guide tracks having an interrupted signal format
US4933925A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1986 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Oct 31, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24082
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical tracking control apparatus comprises a differential amplifier for differentially amplifying signals respectively reproduced from two mutually adjacent track turns of a guide track on both sides of an intermediate part in which an information signal is recorded and reproduced on and from a disc, a zero crossing detector for detecting a zero crossing of an output signal of the differential amplifier and for producing a switching pulse signal, and a polarity inverting circuit responsive to the switching pulse signal for alternately inverting the polarity of a crosstalk component reproduced from the two mutually adjacent track turns of the guide track as crosstalk for every one-half period of the switching pulse signal. An output signal of the polarity inverting circuit is used as a tracking error signal for controlling the tracking of the light beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.