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:
Aug. 20, 1996
Filed:
Sep. 08, 1994
Tsuyoshi Okada, Yokosuka, JP;
Kazuo Shibuya, Yokohama, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The present invention aims at providing an optical head feed device capable of driving stably a coarse positioning actuator even in presence of fluctuation in static frictional force and/or load and reducing the position error of a precision positioning actuator with respect to the center of movement. The optical feed device is so configured that the low-frequency component of displacement of the tracking precision positioning actuator may be detected. Pulse generation means generates drive pulses for the coarse positioning actuator at predetermined time periods so that the output of the detected low-frequency component may come within a fixed range. If a fixed time has elapsed since a drive pulse was outputted and thereafter the low-frequency component of displacement of the precision positioning actuator does not change or the change value is small, the magnitude and time width of the drive pulse are changed and the drive pulse with the magnitude and time width thus changed, is outputted again.