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:
May. 09, 1989
Filed:
Feb. 12, 1987
Toshihiro Matsushita, Kanagawa, JP;
Shin-ichi Satoh, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A method of inspecting surface defects in a magnetic disk. First, a predetermined inspection signal is recorded on a randomly selected track of the magnetic disk during a first rotation of the disk. Second, during a second rotation of the disk, the inspection signal is read and a read signal is produced. Then, during a third rotation of the disk, the value of the read signal is compared with a reference value to determine whether any surface defect exists, and a seek operation is performed to move to the next track of the magnetic disk which is inspected. During one of the second and third rotations of the disk, the read signal is used to set a new reference value to be used in a surface defect inspection of a new track to be inspected.