Objective lens driving device for tracking and focus corrections
US4408313A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 15, 1980 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | Dec 15, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0932
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An objective lens driving device useable in an information reading-out apparatus for projecting a light spot onto a record medium which has been spirally or concentrically recorded with one or more information tracks and for reading-out the information, which drives the objective lens in a direction perpendicular to its optical axis and the information track, thereby correcting relative positional error, i.e. tracking error, between the information track and the light spot. It comprises at least one set of objective lens driving means, each set including a movable member movable together with the objective lens, a coil wound around a stationary yoke, and an objective lens supporting means for movably supporting the objective lens in a direction perpendicular to the optical axis of the objective lens and information track, said coil being supplied with an electric current corresponding to a tracking error signal representing the relative positional error so as to displace the movable member and objective lens and information track and thereby to correct the tracking error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.