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:
Apr. 29, 2003
Filed:
Dec. 28, 2000
Eisaku Takahashi, Higashine, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
High-accuracy position signals are obtained by correcting nonlinear position sensitivities of two phase signals demodulated from two-phase servo information, into linear ones. A position sensitivity adjusting unit detects the signal level at the intersection of position signals N and Q having different phases by a predetermined track pitch which are demodulated from read signals of two-phase servo information buried and recorded in a disk medium and makes an adjustment of the gain of an AGC amplifier so that the intersection signal level coincides with a predetermined level. A sensitivity correcting unit corrects into linear position sensitivities the nonlinear position sensitivities approximated by sine functions or cosine functions relative to the actual track position X of the two position signals N and Q output from the AGC amplifier.