Varying a scanning beam as a function of bearing temperature of an optical lens actuator
US5343459A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1993 |
| Grant date | Aug 30, 1994 |
| Priority date | — |
| Expiry date | Apr 16, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/126
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit arrangement for scanning optical recording carriers comprises a scanning device, a first control loop for focusing a light beam of the scanning device directed onto the information plane of the recording carrier and a second control loop for guiding the light beam on an information track. The first control loop exhibits a first control amplifier which is supplied with focus error signals and the second control loop exhibits a second control amplifier which is supplied with track error signals. The control amplifiers drive actuators which mechanically guide the scanning device. To compensate for the temperature response of the control gain, controlling elements connected to temperature sensors via gain controllers are arranged in the first and second control loop, which controlling elements temperature-dependently change the gains.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.