Compensation apparatus for radial and vertical runout of an optical disc
US5742573A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 1996 |
| Grant date | Apr 21, 1998 |
| Priority date | — |
| Expiry date | May 3, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0953
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for compensating for radial and vertical runout of an optical disc using an actuator having a lens for focus of a laser beam and wherein the focus and tracking currents control the position of the lens in the vertical and radial directions is disclosed. The apparatus focuses the actuator lens along at least one revolution of a track on an optical disc and producing lens position signals. Structures provided which responds to the lens position signals to produce the frequency content of surface height and track deviations of the optical disc using a frequency transform technique. The surface height and track deviations frequency content are stored and a signal representing the focusing and tracking actuator currents and in response to the focusing and tracking actuator current signals and the stored surface height and track deviation frequencies the lens position is controlled thereby reducing focusing and tracking errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.