Optical pickup device capable of accurate tracking with simple structure
US6307687A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 2000 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | May 11, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/13727
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two-group lens is comprised of a first lens and a second lens. The first lens is driven in an optical-axis direction by a magnetic circuit including a variable-distance use coil. As the first lens is driven, the second lens is also driven in an opposite direction to the first lens by a magnetic circuit including a mass-body driving coil, where the center-of-gravity position of movable part of an objective lens driver is kept at a generally constant position. The variable-distance use coil is disposed with the same gap as the mass-body driving coil. Thus, the distance between the first lens and the second lens can be held constant with a simple structure, without involving any complex structure, so that an accurate tracking can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.