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. 11, 1994
Filed:
Jul. 08, 1992
Nobuhiro Umebayashi, Tsukuba, JP;
Kazuya Fukunaga, Ibaraki, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
A magnetic recording medium in which the center of a magnetic head can be brought to a centerline of a reference track, thereby enhancing the reliability of the magnetic recording medium, the reference track being provided at a predetermined position of a magnetic layer of the medium, a number of magnetic head-tracking optical tracks are provided respectively at positions spaced predetermined distances from the reference track in a direction perpendicular to the direction of travel of the magnetic head, and a data track is formed between any two adjacent ones of the magnetic head-tracking optical tracks, the reference track having a pair of reference recess regions arranged symmetrically with respect to an arbitrary point on the centerline of the reference track, and a flat portion with no recess formed adjacent to each of the reference recess regions, the recess in each reference recess region being formed by cutting by a laser.