Optical recording and/or reproducing apparatus having a temperature adjusting device
US5051975A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1989 |
| Grant date | Sep 24, 1991 |
| Priority date | — |
| Expiry date | Feb 2, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B17/32
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an optical recording and/or reproducing apparatus which optically carries out operations of recording and/or reproducing of information on a data carrier, by irradiating a beam from an optical head to the data carrier. In the apparatus according to the present invention, the angle between the optical axis of the beam from the optical head and the surface of said data carrier is detected, and a temperature adjusting device brings about a difference in temperature between both surfaces of the data carrier on the basis of the detected result in respect to the angle. Then, the difference in temperature generates a thermal strain, and this thermal strain functions to cancel the strain which the data carrier has previously had. As a result, the surface of the data carrier is kept on a level, so that this surface can be vertical to the optical axis of the beam from the optical head. Therefore, in the optical recording and/or reproducing apparatus, easily maintained is the right angles between the surface of the data carrier and the optical axis of the beam, and the mechanism for focalizing the beam can be simplified to miniaturize the optical head. Further…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.