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. 04, 2011
Filed:
Oct. 22, 2010
Hiroto Kikuchi, Nagano, JP;
Hiroto Kikuchi, Nagano, JP;
Fuji Electric Device Technology Co., Ltd., Tokyo, JP;
Abstract
A master disk for magnetic transfer of a reference servo signal in a spiral mode, having a pattern including a plurality of dots groups, which are disposed at different radial positions of the master disk with a first pitch, and correspond to the reference servo signal in the spiral mode. Each of the plurality of dot groups includes a plurality of dots, successively disposed with a second pitch along a circumferential direction of the master disk at a same one of the radial positions. Each of the plurality of dots is of a ferromagnetic material, and has four sides, two opposing sides thereof extending in the circumferential direction, and the other two opposing sides thereof extending in a radial direction of the master disk.