Optical pickup device which can be adapted to plurality of types of optical disks
US5870371A · kind A · utility
14Cited by
8References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Sep 23, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup device includes two objective lenses having numerical apertures different from each other, a lens holder for holding these objective lenses in common, a cylinder fixed to the lens holder, and four tracking coil pairs affixed onto a cylindrical surface of the cylinder. Two tracking coil pairs are displaced from the remaining two tracking coil pairs by a predetermined angle. When one objective lens is used, two tracking coil pairs corresponding to the objective lens are used for tracking control of the objective lens. The remaining two tracking coil pairs are used for positioning control of the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.