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. 26, 1989
Filed:
Nov. 03, 1988
Masuo Tada, Osaka, JP;
Kazuhiko Akamatsu, Hyogo, JP;
Takaaki Fukumoto, Hyogo, JP;
Toshiaki Ohmori, Hyogo, JP;
Tadashi Hyono, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A method for forming a fine unevenness over a surface of a base plate (9) for a magnetic disc comprises the step of bombarding the surface of the base plate (9) with a jet of gas mixed with fine ice particles (4) that are formed by mixing a flow of fine pure water droplets from a spray (2) and a counter directed flow of nitrogen gas cooled by being bubbled through a quantity of liquid nitrogen held in a reservoir (6). The obtained unevenness can be controlled by varying the size of the ice particles, the jet pressure, the distance between the jet nozzle providing the size of the ice particle jet and the receiving surface of base plate (9), the duration of spraying and the spraying angle with respect to the base plate.