Tracking error detection apparatus for an optical disk
US5247501A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1990 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | Jan 31, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/13
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A recording and/or reproducing apparatus for from an optical disk includes a tracking error signal forming device for forming a tracking error signal by taking the difference of detection output signals from at least a pair of light beam detectors provided in an optical pickup having an actuator for shifting an objective lens in a focusing direction or in a tracking direction. Also provided is, a tracking servo device for moving the objective lens in the tracking direction on the basis of the output signal from the tracking error signal forming device to effect a tracking servo, a period detection device for detecting whether the period of a tracking servo indicating a relative movement between a track on an optical disk and a light beam from the optical disk is not more than a predetermined value, and a d.c. component switching device for switching the gain of an amplifier stage stepwise, with the amplifier stage being adapted for amplifying a detection output signal of one of at least a pair of light beam detectors and supplying the amplified signal to the tracking error signal forming device. An offset eliminating device controls the d.c. component switching device to effect swi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.