High-density magnetic recording and optical reproducing apparatus
US5093822A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1990 |
| Grant date | Mar 3, 1992 |
| Priority date | — |
| Expiry date | Jun 4, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10536
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high-density magnetic recording and optical reproducing apparatus for magneto-optically reproducing information magnetically recorded on information tracks on a recording medium, the apparatus comprising two laser beam sources emitting laser beams having different wavelengths respectively, an optical system for directing the laser beams from the two laser beam sources toward and onto the recording medium so as to irradiate the recording medium with laser beam spots partly overlapping each other, two photo detectors detecting the laser beams reflected from the surface of the recording medium, and a differential amplifier detecting the difference between the output signals of the two photo detectors thereby generating the differential signal as a reproduced output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.