Disc eccentricity measuring apparatus and method thereof and apparatus for recording and/or reproducing disc-shaped recording medium
US6266304A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1994 |
| Grant date | Jul 24, 2001 |
| Priority date | — |
| Expiry date | Sep 21, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0953
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A recording and/or reproducing apparatus for a disc-shaped recording medium which includes an optical head, a motor driven table for rotating the disc-shaped recording medium, a slider for moving the optical head relative to the motor driven table in a radial direction of the disc-shaped recording medium, an error signal generator for generating an error signal exhibiting the amount of the relative shifting of a spot of a light beam irradiated from the optical head on the disc-shaped recording medium with respect to a track on the disc-shaped recording medium, and a controller which detects a peak value and a trough value of the error signal supplied from the error signal generator and compares the difference between the detected peak value and the detected trough value with a reference threshold value to generate a drive signal for the slider on the basis of the comparison, wherein the drive signal from the controller is supplied to the slider to shift the optical head relative to the motor driven table in the radial direction of the disc-shaped recording medium to correct for eccentricity of the disc-shaped recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.