Apparatus for actuating objective lens
US4863240A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1986 |
| Grant date | Sep 5, 1989 |
| Priority date | — |
| Expiry date | Oct 14, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2201/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus actuates an objective lens in axial and circumferential directions through annular magnetic gaps which are formed by yokes and a magnet. In order to retain the objective lens in the neutral position in the circumferential direction, two or four magnetic pieces are mounted on a lens mount and disposed near the circumferetial ends of the annular magnetic gaps in which the force caused by the magnetic potential energy in the magnetic gaps acts on the magnetic pieces to pull them back in the direction of the magnetic gaps so that a magnetic spring for retaining the objective lens at the neutral position is formed by the magnetic pieces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.