Patent · US Expired

Apparatus for driving objective lens in tracking direction

US4479051A · kind A · utility

19Cited by
3References
98Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 14, 1980
Grant dateOct 23, 1984
Priority date
Expiry dateApr 14, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/093
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An apparatus for driving an objective lens which projects a light spot onto an information track or tracks recorded spirally or concentrically on a disc-shaped record medium to read out information, in order to correct a tracking error, comprises a pair of leaf springs for supporting the objective lens movably in a tracking direction perpendicular to the optical axis of objective lens as well as to the track direction, a movable member made of magnetic material and being coupled with the movable member to move in the tracking direction in conjunction with the objective lens, first and second magnetic members made of magnetic material and arranged in such a manner that the movable member is interposed between the first and second magnetic members at their one end portions via gaps, a third magnetic member made of magnetic material for coupling the first and second magnetic members at their other end portions, first and second coils wound on the one end portions of the first and second magnetic members, respectively, and magnetic flux producing means such as a permanent magnet and an electromagnet for producing a constant magnetic flux through the first, second and third magnetic mem…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.