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. 03, 1993
Filed:
Sep. 16, 1991
Katsumi Onodera, Kawasaki, JP;
Koji Ito, Kawasaki, JP;
Manabu Koike, Kawasaki, JP;
Tamotsu Hatakoshi, Kawasaki, JP;
Kazuyoshi Tomita, Kawasaki, JP;
Kazuo Nimura, Kawasaki, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
A surface of a non-magnetic base plate is first coarsened to a required surface roughness and an ultrasonic vibration is then applied to the surface of the non-magnetic base plate while the non-magnetic base plate is immersed in a liquid. Thereafter, a magnetic recording layer and a protective layer are successively formed on the surface of the non-magnetic base plate thereby to produce a magnetic recording medium. It is preferable that the frequency of a ultrasonic vibration is within a range from 200 kHz to 1600 kHz. Surface fractional properties of the magnetic recording medium can adequately be controlled without variation of the floatation height of a magnetic head during its running by varying an ultrasonic oscillation output and an ultrasonic processing time.