Patent ID: 7826168

Claim:
A correction table creation method of head position control for creating correction signals for correcting components synchronizing rotation of a disk, comprising steps of: measuring position error components synchronizing rotation of said disk from an average waveform of a position error between a detected position based on a position signal from a head for at least reading said disk and a target position; generating correction signals from a filter function in time units, that is created from measured frequency characteristics of a position control system of said head and repeat frequency of the rotation of said disk, and said measured position error component; and storing said correction signals in the correction table, wherein said generation step further comprises a step of generating said correction signal RRO by the filter function in time unit F(x) defined by the following Expression (13), where RPE is an average waveform of said position error signal, RRO is a correction signal, Ns is a number of servo sectors of one rotation of a track of said disk, and a(m)+jb(m) is said frequency characteristics, that is m time of the rotation frequency of said disk: RRO ⁡ ( q ) = ∑ k = 0 N s - 1 ⁢ RPE ⁡ ( k ) ⁢ F ⁡ ( k - q ) ⁢ ⁢ F ⁡ ( x ) = ∑ m = 1 N s / 2 - 1 ⁢ { a ⁡ ( m ) ⁢ ⁢ cos ⁢ ⁢ ( 2 ⁢ ⁢ π ⁢ ⁢ mx / N s ) - b ⁡ ( m ) ⁢ ⁢ sin ⁢ ⁢ ( 2 ⁢ ⁢ π ⁢ ⁢ mx / N s ) } ⁢ ( 2 / N s ) . ( 13 )