Patent ID: 7027254

Claim:
A head positioning control method for a disk device for positioning a head to a predetermined position of a disk, comprising: a step of demodulating a position signal of said disk read by said head; a step of calculating the demodulation position according to said demodulation result; a step of calculating control quality according to the position errors between said demodulation position and a target position and controlling actuator which drives said head; wherein said calculation step comprises a step of correcting said demodulation result including PosN and PosQ obtained by a four phase offset signal of said position signal with a dynamically-obtained correction value which depends on an actual moving speed of said head and obtaining the demodulation position; and a step of detecting said moving speed of the head based on said position signal read by said head, wherein said demodulation step further comprises: a step of demodulating track number and offset information from said position signal, and said calculation step comprises: a step of selecting said track number as said demodulation position when the moving speed of said head is faster than a predetermined speed; and a step of calculating a demodulation position by correcting said PosN and PosQ with said correction value obtained by compensated moving speed with a gain according to recording positions of the offset information in said position signal of said disk.