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:
Oct. 24, 1995
Filed:
Jan. 21, 1994
Mitsuo Suda, Odawara, JP;
Kazuo Shiiki, Tsukui, JP;
Masanori Tanabe, Odawara, JP;
Shinji Narishige, Naka, JP;
Eiji Nakanishi, Ashigarashimo, JP;
Kouichi Shimizu, Odawara, JP;
Norifumi Miyamoto, Odawara, JP;
Hirotsugu Fukuoka, Hitachioota, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a magnetic disk device having a composite head with an induction type of recording head adjacent a magneto-resistance effect type of reproducing head, a read error relief is provided to relieve read errors caused by Barkhausen Noise or Base Line Shift phenomenon inherent to the magneto-resistance effect type of reproducing head. Upon occurrence of a read error, a re-try function is first executed, and a track offset function is executed for relief of the read error. However, if the read error is not relieved after the offset operation and the re-try operation have been performed a predetermined number of times, then a pseudo write-in and/or read current control operation is performed together with the offset operation and/or re-try operation for a predetermined number of times. The control operation varies the magnetic domain structure in the head magnetic film (MR film). The variation of magnetic field and/or read current in the head magnetic film causes the magnetic domain structure of the head magnetic film to be varied, so that the Barkhausen Noise or the Base Line Shift phenomenon are extinguished.