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. 24, 1993
Filed:
Jul. 16, 1991
Applicant:
Inventors:
Koichi Suda, Narashino, JP;
Shinichi Nomura, Narashino, JP;
Assignee:
Seiko Seiki Kabushiki Kaisha, , JP;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ; G01B / ;
U.S. Cl.
CPC ...
73105 ;
Abstract
A magnetic disk inspection apparatus for inspecting protuberance on a surface of the magnetic disk. The apparatus includes an inspection head detecting the protuberance by a piezosensor, and rotating speed control circuit controlling a rotating speed of the magnetic disk held by a rotary holder member. The rotating speed control circuit generates a different speed increasing rate for each of concentric zones formed by dividing into a plurality of sections in a radial direction of the magnetic disk to keep a floating height of the inspection head in a predetermined constant value.