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:
Sep. 24, 1996
Filed:
Jun. 29, 1994
Masamichi Ito, Ibaraki-ken, JP;
Masahiro Takasago, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A tracking following apparatus for an optical disk device includes an objective for forming a light spot on an optical disk, a fine actuator for driving the objective, a coarse actuator for driving the fine actuator means, a detector for sensing a relative positional error between the light spot and a track on the optical disk, an RAM for keeping therein a drive signal associated with a rotation of the optical disk to drive the coarse actuator, an attenuator for reading from the RAM a drive signal associated with a disk rotation angle when the error is sensed by the detector and attenuating the signal, and an adder for adding the signal attenuated by the attenuator to the error signal sensed by the detector and thereby generating a drive signal to drive the coarse actuator.