Rotating storage media control loops having adaptive feed forward insertion of signals including harmonics
US7145304B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2005 |
| Grant date | Dec 5, 2006 |
| Priority date | — |
| Expiry date | Oct 8, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0953
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An adaptive feed forward controller inserts signals into control loops of an optical disc player and/or recorder at a frequency of the rotation of the disc and one or more harmonics thereof, while at the same time maintaining the stability of the control loops. This makes the control loops more responsive to harmonic components of eccentric and/or tilt motion of a track being followed, a characteristic of poor quality optical discs. The quality of playback or recording such discs is thereby improved. Signal processing forming the control loops including the adaptive feed forward controller is carried out by a software controlled processor on an integrated circuit chip within the optical disc instrument. A signal representing the frequency of rotation of the disc, which is used in the signal processing, can be derived from the control loop rather than by directly measuring rotation with a transducer in the rotating system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.