Focusing and tracking apparatus for an optical data storage device
US4688201A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 1985 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Jan 16, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/08
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two-stage beam positioning apparatus for use in an optical data storage device is provided. A fixed assembly includes a light beam source and detector, light beam focusing and track following apparatus. The fixed assembly is optically coupled to a movable assembly which provides coarse positioning of a focused light spot on a data storage medium such as an optical recording disc. The coarse positioning assembly is mechanically independent from the light beam source and detector assembly and, therefore, may be made very stiff and light resulting in a high bandwidth and reduced data access time. Since the light beam source and detector assembly and the focusing and track following control apparatus are mechanically isolated from the movable coarse positioning assembly, the size and mass of these components are not critical and do not affect data access time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.