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:
Nov. 12, 1991
Filed:
Sep. 10, 1990
Applicant:
Inventors:
Assignee:
NGK Insulators, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
29603 ; 427130 ;
Abstract
A method of producing a ferrite/Sendust composite core for a magnetic head, in which a metal film made of any one of metals of Zn, Cr, Fe, Cd, Co, Ni, Sn and Pb is formed on a surface, where a track of the core is formed, of a gapped bar composed of ferrite and Sendust, before the gapped bar is subjected to a laser-induced etching in an alkali metal hydroxide aqueous solution. The metal film serves to prevent the formation of dull at an edge portion of the track, so that a magnetic core can be obatined having a track which is free from dulls and high in reliability.