Optical disc device
US7995431B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2005 |
| Grant date | Aug 9, 2011 |
| Priority date | — |
| Expiry date | Aug 30, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/00727
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The optical disc device has a circuit 4 which forms a focus error signal FER for focus servo control based on reflection light from an optical disc exposed to laser light. A data processing unit 2 can control by feedback a position to which an objective lens is moved by a focusing actuator 30 based on the focus error signal. In label printing, the data processing unit controls, by feedforward, a position to which the objective lens is moved by the focusing actuator based on control data for label printing. The operation resolution of the focusing actuator in feedforward control is made higher than that in feedback control. Thus, an intended position control accuracy is achieved in feedforward control. For instance, in feedforward control, the gain of the driver circuit 40 for the focusing actuator is switched to a smaller one in comparison to that in feedback control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.