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. 02, 1994
Filed:
Feb. 21, 1991
Ryosuke Shimizu, Yawata, JP;
Noriaki Wakabayashi, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
In a rotatable recording medium, three servo-patterns are discretely formed in the circular direction. A first servo-pattern is made of at least three-phase dibit patterns each having a period of 3 tracks; a second servo-pattern is made of two-phase dibit patterns having a period of 12 tracks and a shift of 3 tracks from each other; and a third servo-pattern is made of a dibit pattern having a period of 6 tracks and a shift of at least 1.5 tracks from the second servo-pattern. Based on reproduction signals derived from the three servo-patterns on the recording medium, relative position of a head against the recording medium is recognized with a precision up to (1/2.sup.N) of a track width using only a binary-valued process.