Optical recording and/or reproducing apparatus
US5168487A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 1990 |
| Grant date | Dec 1, 1992 |
| Priority date | — |
| Expiry date | Jul 23, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0903
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording and/or reproducing apparatus comprising a light beam generator, a photodetector, an optical path forming device for causing a light beam from the light beam generator to impinge upon an optical disc and for guiding the light beam emanating from the optical disc to the photodector, and a signal generating circuit block operative to obtain based on a detection output obtained from the photodetector a first signal representing a tracking condition of the light beam in relation to a record track portion on the optical disc and a second signal different in phase by substantially ninety degrees from the first signal and to produce a tracking error signal which satisfies the following equation: EQU St=Sl/{K.(Sl.sup.2 +S2.sup.2).sup.1/2+S2} where St stands for the tracking error signal, Sl stands for the first signal, S2 stands for the second signal and K stands for a constant equal to or more than 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.