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:
Apr. 07, 1986
Shozi Yoshikawa, Tokyo, JP;
Masanori Doi, Tokyo, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
An apparatus for controlling the tracking of an optical disk by moving an objective lens and a carriage supporting the objective lens. The apparatus comprises a lens tracking mechanism comprising an actuator and a lens tracking circuit, and an equivalent circuit having the same response characteristic as the lens tracking mechanism. The lens tracking mechanism moves the lens in real time in the radial direction of the disk in accordance with a tracking error signal representing the distance between a laser beam spot and a target track. The carriage is moved also in the radial direction of the disk in accordance with a sine-wave signal approximating the eccentricity of the disk. The eccentricity has been detected from the distance over which the lens is moved when the carriage is not moved. This distance is not detected by measuring, but obtained from the output signal which the equivalent circuit generates in response to the tracking error signal.