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:
Aug. 11, 1992
Filed:
Feb. 14, 1991
NGK Insulators, Ltd., , JP;
Abstract
A composite magnetic head core with a writing/reading track and two erasing tracks, including a first ferrite block, and a second and a third ferrite block bonded to opposite surfaces of the first block interposed therebetween. The opposite abutting surfaces of the first block have respective first and second recessed portions, and a first rectangular protrusion and two second rectangular protrusions which protrude from the first and second recessed portions, respectively. The first protrusion is positioned between the two second protrusions in a direction of width of the writing/reading and erasing tracks. The first protrusion cooperates with the second block, to define a writing/reading magnetic gap of the writing/reading track, while the second protrusions cooperate with the third block, to define two erasing magnetic gaps of the erasing tracks. The first protrusion has a width defining the width of the writing/reading track, and a longitudinal end defining a depth of the writing/reading magnetic gap. Similarly, each second protrusion has a width defining the width of the erasing tracks, and a longitudinal end defining a depth of the erasing magnetic gaps. The protrusions are formed by etching the opposite surfaces of the first block through appropriate etching masks.