Objective-lens actuator
US5548449A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1994 |
| Grant date | Aug 20, 1996 |
| Priority date | — |
| Expiry date | Jun 7, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0935
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
It is the object of the invention to provide the actuator for the objective lens, suitable for the optical disc apparatus with high speed access property and high drive sensitivity especially in the track drive direction, and to solve problems concerning with manufacturing processes, by using metallic leaf springs with high reliability for supporting the lens holder to make its movements to be translation motions in both focus and tracking drive directions. The lens holder 22, a movable object, is supported by four leaf springs 21a to 21d, thereby its movements is pure translation motions in both focus and tracking drive directions. The drive sensitivity in the track drive direction is largely increased by designing and improving configurations of the magnetic circuit and the focus and tracking drive coils. For tracking drive motion, a pair of tracking drive coils are fixed to two opposite sides of the focus drive coils, and the magnetic circuit contains two plate magnets 15 and two bar magnets 16, such that the arrangement of magnets is line symmetrically with respect to the axis of the objective lens. The lens holder 22 is supported by the actuator base 11 is provided with an air…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.