Two axis electromagnetic actuator
US5136558A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1989 |
| Grant date | Aug 4, 1992 |
| Priority date | — |
| Expiry date | Jun 20, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K41/0356
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An optical disc player/recorder incorporates a laser, and an electromagnetically driven objective lens. The objective lens is mounted to a lensholder which is movable with respect to a base. A single pair of permanent magnets are mounted to the lensholder, and two pair of electromagnetic coils are mounted to the base. The coils and magnets are positioned such that one set of coils is collinear with the direction of magnetization of the permanent magnets and the other set of coils is perpendicular to the direction of magnetization of the magnets. Electromagnetic fields generated by the coils are used to move the objective lens in either a focus direction or a tracking direction. The magnets are mounted on the moveable objective lensholder, while the coils are attached in a heat-sink relationship to the fitted base. The objective lens rests on top of the objective lensholder which is suspended with respect to the base by a pair of flexures. A mirror is provided between the flexures to allow incoming laser light to enter from the side of the optical head, thereby reducing the total overall height of the system. A position sensor may be provided to detect the position of the lensholder…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.