Optical disk recording and reproducing apparatus
US7400557B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 2005 |
| Grant date | Jul 15, 2008 |
| Priority date | — |
| Expiry date | Aug 11, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0901
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides an optical disk recording and reproducing apparatus having a circuit configuration whereby it is possible to prevent tracking drive signals from being offset even when the temperature of a tracking actuator drive circuit is increased. The output resistance of a low-pass filter 15 is composed of two serially connected resistors R2a and R2b, the resistance of the former one R2a of the serially connected resistors R2a and R2b being arranged to be lower than that of the latter one R2b and a connecting point S between the former and latter resistors R2a and R2b being connected to the input side of an A/D port 6, whereby the potential difference between a tracking output port 12 and the A/D port 6 is reduced as much as possible, and thereby the reference voltage value stored in a reference voltage value storing means 9 approaches an exact value as close as possible, which increases the accuracy of comparison results of a comparing means 7 substantially, and therefore a D/A conversion and offset cancel circuit 10 can output a tracking drive signal without offset.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.