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:
Feb. 21, 1995
Filed:
Jul. 08, 1993
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ; G11B / ; G11B / ;
U.S. Cl.
CPC ...
360 75 ; 360 7703 ; 360109 ; 360110 ;
Abstract
The spacing between a magnetic disk surface and a magnetic head tends to greatly decrease with an increasing request for higher density records. Measuring and controlling the small spacing is important for stabilized recording or reading. A substrate is attached to a side of a support which supports the magnetic head. Light is irradiated onto a surface of the substrate and totally reflected thereby. The small spacing is measured by measuring the quantity of the totally reflected light. An actuator is controlled such that the measured small spacing is maintained at a target value to thereby realize constant small-spacing control.