Optical disk initializing apparatus
US5784353A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1997 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Mar 10, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0917
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk initializing apparatus includes the first optical system having a gain waveguide laser, a collimator lens, diffraction gratings, and a 45.degree. mirror, the second optical system having a 680-nm red laser, a polarizing beam splitter, a collimator lens, and a .lambda./4 plate, a dichroic mirror, an objective lens, an optical sensor, a phase compensator, a voltage-current conversion amplifier, and an objective lens actuator. The first optical system outputs a first beam for initialization. The second optical system outputs a second beam having a wavelength different from that of the first beam. The dichroic mirror multiplexes the beam emerging from the first optical system and the second beam emerging from the second optical system. The objective lens focuses an output beam emerging from the dichroic mirror on a phase change recording or magneto-optical recording optical disk. The optical sensor detects a focusing error signal from a return beam of the second beam reflected by the optical disk. The phase compensator, the voltage-current conversion amplifier, and the objective lens actuator focus the objective lens in accordance with the focusing error signal output f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.