Reproducing apparatus which can play multiple types of discs and biases focusing error signal based on disc type
US5463602A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1995 |
| Grant date | Oct 31, 1995 |
| Priority date | — |
| Expiry date | Jan 17, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B19/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disc reproducing apparatus can play multiple types of discs. The apparatus biases a focusing error signal based on the disc type. An analyzer receives reflected light of a light beam irradiated from an optical pick-up to a disc. A focus error signal is generated based on the signal supplied the analyzer. A switch selectively provides one of first and second bias voltages. A control controls which of the first and second bias voltages the switch provides based on the type of disc. The bias voltage is added to the focus error signal. An object lens of the optical pickup is driven based on the focus error signal with the bias voltage added.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.