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:
Nov. 16, 1999
Filed:
Nov. 07, 1997
Koji Furusawa, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical disk device for projecting laser light emitted from a laser light source on an optical disk to reproduce information has a support shaft which is disposed nearly parallel with an optical axis of the laser light. The support shaft is fixed on a mount. A lens holder is rotatably disposed around the support shaft and reciprocally movable along the support shaft as well as holding an objective lens for converging the laser light upon a recording plane of the optical disk. The device also includes a tracking drive for energizing the rotation movement of the lens holder, and a focusing drive for energizing the reciprocative movement along the support shaft of the lens holder. An optical path length changing member is provided which has a change region where an optical path length is changed when the laser light is transmitted therethrough and an unchanged region where an optical path length is not changed when the laser light is transmitted therethrough is located closer to the optical disk than the lens holder and rotatably disposed around the support shaft and reciprocally movable along the support shaft. Completing the device is a linking mechanism for variably effecting the engagement or disengagement of the optical path length changing member with the lens holder.