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:
Jan. 12, 1999
Filed:
Apr. 23, 1996
Fujitsu, Limited, Kawasaki, JP;
Abstract
An optical disk apparatus comprising an optical element for dividing the reflected light into a plurality of light beams for generating a tracking error signal and a focus error signal, and deflecting these light beams into different directions from each other, a first calculating means for calculating the focus error signal on the basis of outputs from said photodetecting means, and a second calculating means for calculating the tracking error signal on the basis of the outputs from said photodetecting means in accordance with a structure of a track. The second calculating means outputs a tracking error signal by a push-pull method when a track has a successive groove. The second calculating means outputs a tracking error signal by a heterodyne method when a track has only a row of pits.