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. 10, 1996
Filed:
Sep. 09, 1993
Tatsuaki Ishida, Osaka, JP;
Ryuji Sugita, Osaka, JP;
Kiyokazu Tohma, Osaka, JP;
Yasuaki Ban, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka-Fu, JP;
Abstract
A magnetic tape having a polymer substrate and a magnetic layer which is formed directly on a surface of the substrate or on a primer layer formed on the substrate and contains cobalt, oxygen and optionally nickel, in which a coercive force is at least 120 kA/m and a squareness ratio is at least 0.9 in a hysteresis loop which is obtained when a magnetic field is applied in a plane of the magnetic layer in a longitudinal direction of the magnetic tape, and on the hysteresis loop, an intensity of the applied magnetic field, at which a magnetization when the applied magnetic field is increased is 99% of the magnetization when the applied magnetic field is decreased, is not larger than 400 kA/m, and preferably, a ratio of a value of magnetization at an intersection between a tangential line drawn at a point which gives a residual magnetization at the applied magnetic field of 0 (zero) and a tangential line drawn at a point which gives a coercive force with a magnetization of 0 in a second quadrant to said residual magnetization is at least 0.9, which magnetic tape has improved high density recording/reproducing properties.