The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 1988
Filed:
Oct. 04, 1985
Hiroaki Nomura, Nagano, JP;
Seiko Epson Kabushiki Kaisha, Tokyo, JP;
Abstract
An objective lens actuator for an optical head. The objective lens has an optical axis. A first movable portion is adapted to move the objective lens in the focusing direction along the optical axis. The first movable portion includes an objective lens holder with a piston projecting from the objective lens in the direction of the optical axis. The objective lens holder secures the objective lens on the optical axis and supports a rectangular focusing coil and a four component tracking coil. A second movable portion is adapted to move the objective lens in a tracking direction, essentially perpendicular to the focusing direction and includes a guide hole shaped to slidably receive the first movable portion therein and to restrict movement of the first movable portion relative to the second movable portion to motion substantially along the focusing direction. A magnetic circuit drives the first and second movable portions in the focusing and tracking directions, respectively. The magnetic circuit includes two essentially parallel gaps, portions of the focusing and tracking coils being located in the gaps. Respective currents in the focusing and tracking coils cause the first and second movable portions to be urged in the focusing and tracking directions.