Two axis linear motor for optical focusing and tracking system in optical recording
US4587466A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1982 |
| Grant date | May 6, 1986 |
| Priority date | — |
| Expiry date | Dec 9, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2201/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A two axis linear motor for carrying the objective lens for optical focusing and optical tracking in an optical recording system has a stationary structure for providing a magnetic field and a moving armature structure. The stationary structure may have two permanent magnets and several pole pieces to properly shape the field with respect to the armature. In one embodiment, a central elongated pole piece and two parallel adjacent elongated pole pieces which are associated with two permanent magnets to form flux gaps with the central pole piece. Flux returns to the magnets through a lower pole piece to which the central pole piece is attached. The central and lower pole pieces have an aperture through which the laser beam may pass on its way to and from the objective lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.