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:
Sep. 05, 1978
Filed:
Dec. 20, 1976
Applicant:
Inventors:
Teizou Tamura, Yokohama, JP;
Katsuo Konishi, Yokohama, JP;
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
29603 ; 5128 / ; 51328 ; 360121 ; 360122 ;
Abstract
A head chip having a track width of a gap smaller than a thickness of a core enables a high density recording of a video signal. The track width of the gap is machined before a bulk is sliced into individual head chips to save manufacturing time and enhance yield. An efficient machining of the track width is achieved using a plurality of hard metal wires such as piano wires spanned on rollers each having a plurality of precisely spaced grooves thereon and reciprocating the metal wires while dropping grinding liquid thereon. In this manner, the occurrence of chipping of core material is minimized or the size of chipping, if any, is minimized.