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:
Feb. 12, 1991
Filed:
Feb. 13, 1987
Hiroshi Kanai, Hitachi, JP;
Takeo Sonobe, Hitachi, JP;
Seiichi Hayashi, Mito, JP;
Masayoshi Sunada, Hitachi, JP;
Kazuo Kikuchi, Hitachi, JP;
Yasumasa Saito, Katsuta, JP;
Toshiaki Suematsu, Hitachi, JP;
Tetsuro Hatakeyama, Hitachi, JP;
Yousuke Nagano, Hitachi, JP;
Shinji Mizunuma, Hitachi, JP;
Hitoshi Ishida, Hitachi, JP;
Junichi Enomoto, Hitachi, JP;
Kazuei Saito, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An alignment disk having an adjust signal recorded thereon to maintain data interchangeability of a magnetic disk drive apparatus and loadable and unloadable to and from the magnetic disk drive apparatus, and method and apparatus for verifying a tracking errors of the magnetic disk drive apparatus are disclosed; the magnetic disk drive apparatus including magnetic head means for recording and reproducing data on and from a magnetic recording medium, a head carriage for carrying the magnetic head means, and drive means for driving the head carriage radially of a track of the magnetic recording medium; the alignment disk having a set of track diameter adjust signal pairs recorded on tracks equal to or larger in number than the number of phases of a stepping motor for driving the head carriage and corresponding to at least the excitation phases of the stepping motor; the set of track diameter adjust signal pairs each having an inner track signal and an outer track signal extending inward and outward from a center of the track; and the set of track diameter adjust signal pairs being arranged symmetrically about a rotation axis of the disk.