Fleit & Jacobson
Ferrite core magnetic head with improved reinforcement filler
 A ferrite core magnetic head useful in a video tape recorder is reinforced in regions near its magnetic gap by the application of a filling material which is a mixture of a glass composition such as a lead glass and a powdered electrically conducting and nonmagnetic material such as a conducting metal oxide or a metal. In thermal expansion coefficient, the glass for the filling material must be comparable to the core material of the head. The use of this filling material precludes cracking of the core by heat treatments during fabrication and deposition of dust on the head surface during operation. 
Victor Company of Japan, Ltd.
G G G
G11B G11B G11B
inventional inventional inventional
Kunihide Hideaki Toshio
Sakai Mizuno Konno