Objective lens and optical disk driving apparatus using the same
US6081496A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1997 |
| Grant date | Jun 27, 2000 |
| Priority date | — |
| Expiry date | Dec 29, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0956
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An objective lens for focusing a laser beam onto an optical information medium is disclosed. The objective lens comprises a lens body and a flange portion arranged on the periphery of the lens body. The surface of the lens body facing the optical information medium is formed with a convex shape having a radius of curvature R as follows: 0.05 m<R<0.5 m. In this way, a dynamic pressure is generated due to the convex-shaped surface and the rotation of the optical disk. This generates a buoyancy which overcomes the maximum acceleration of the objective lens. In this manner, it becomes possible to avoid collision of the objective lens with the optical information medium even in the presence of relative tilts, such as tangential tilts, radial tilts, and shift tilts, between the optical information medium and the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.