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:
Mar. 10, 1992
Filed:
Aug. 21, 1990
Nobuyuki Oka, Kanagawa, JP;
Hiroshi Eto, Tokyo, JP;
Nobuyuki Yasuda, Chiba, JP;
Tetpei Yokota, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
A magnetic head position control apparatus for driving the magnetic head of a disk recording apparatus toward or away from the recording surface of a magneto-optical disk to effect position control of the magnetic head. Changes in the distance between the magnetic head and the magneto-optical disk are detected from changes in capacitance between a capacitance detection electrode mounted on the magnetic head and a surface of the magneto-optical disk. An oscillator circuit connected to the capacitance detection electrode varies its oscillation frequency in response to changes in capacitance and detects such frequency variations and controls the position of the magnetic head for maintaining it at a constant predetermined distance from the magneto-optical disk.