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. 18, 1999
Filed:
Jun. 28, 1996
Yutaka Osada, Fujisawa, JP;
Victor Company of Japan, Ltd., Yokohama, JP;
Abstract
An optical disk apparatus for stable tracking and reproduction of information recorded on a high density disk, the apparatus cancels various noise components in the tracking error signal. Disturbances caused in the tracking error signal, such as crosstalk from adjacent tracks, the positional shift of the photo detectors due to a change of the ambient temperature, an inclination of the disk surface to a laser beam causing a defocus of the laser beam, and defects on a disk are eliminated. The optical disk apparatus has a light source, a diffraction grid, a semi-transparent prism, a collimator lens, an objective lens, a concave lens, a cylindrical lens, a photodetecting device, a reproduction control circuit, a tracking drive circuit, and an actuator for displacing the objective lens.