Optical recording and reproducing apparatus and recording medium having multilayer recording membranes
US5263011A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1991 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Oct 30, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0945
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical recording and reproducing apparatus stably set the gains (focus, tracking) corresponding to the respective layers at the insertion time of a recording medium having a multilayer record membrane. The optical recording and reproducing apparatus uses a recording medium having a multilayer membrane construction wherein the recording membranes are formed in a stage shape, is not superposed in the inner periphery or the outer periphery with respect to the laser transmission side, and has a circuit for detecting the number of the recording membranes, and a circuit for switching to a focus gain or a tracking gain in conformity with the recording medium, and a focus driving circuit for effecting a focus drawing-in operation. The driving circuits are driven so that they may be rotated or run into a condition of effecting capable of focus drawing-in operation, and thereafter the focus drawing-in operation is effected in the specific position of the recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.