Apparatus for optically recording information on opto-magnetic record medium having a minimized leakage magnetic field
US5126983A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1990 |
| Grant date | Jun 30, 1992 |
| Priority date | — |
| Expiry date | Apr 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10576
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus for recording opto-magnetically information on an opto-magnetic record medium in the form of the direction of the magnetization stored in a magnetic layer including an objective lens for projecting a laser light beam onto the magnetic layer of the opto-magnetic record medium, a device for generating a bias magnetic field which is applied to the magnetic layer in a direction perpendicular thereto, a supporting device for supporting the objective lens movably in a focusing direction parallel to an optical axis of the objective lens as well as in a tracking direction perpendicular both to the optical axis and an information track direction, and a driving device for moving the objective lens in the focusing and tracking directions to perform the focusing and tracking control. The driving device includes a magnetic circuit for generating a driving magnetic field and focusing and tracking coils mechanically coupled with the objective lens, portions of the focusing and tracking coils being inserted into the driving magnetic field to generate forces for moving the objective lens in the focusing and tracking directions. The magnetic circuit is so constructed that a magnetic flux l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.