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:
Jan. 23, 1979
Filed:
Sep. 21, 1977
Charles R Moeller, Cardiff-by-the-Sea, CA (US);
Eastman Technology, Inc., Rochester, NY (US);
Abstract
A flux-sensitive magnetic head employs, at its back part, a structure having a thin single domain magnetic film coated thereon. A coil wraps around the coated structure, and a direct current is passed through the coil, thereby to apply a hard axis magnetic bias to the film. Signal flux appearing at the head front gap asserts a magnetic force along the hard axis of the film. Contrary to what would be expected, the signal flux causes the inductance of the coil to vary. Such inductance variation may be conveniently detected by (1) connecting the variable inductor into a tank circuit, (2) applying a high frequency ac ripple to the 'hard axis' dc bias, and (3) measuring the 'hard axis' detuning experienced by the tank circuit.