MAGNETIC DISK DEVICE AND TRACK ECCENTRICITY COMPENSATION METHOD FOR MAGNETIC DISK DEVICE

PROBLEM TO BE SOLVED: To compensate track eccentricity of a high frequency by controlling a magnetic head position by the eccentricity compensation signal calculated by using the parameter determined in accordance with the transmission function from a voice coil operation signal to a magnetic head position error signal and the detected position error information. SOLUTION: As a procedure to determine the parameter, a switch 21 is connected to a test signal generator 9 and a test signal 23 consisting of a specific frequency +α is first inputted as a voice coil operation signal 19. An eccentricity compensation parameter calculator 10 makes the Fourier analysis of the position error signal 14 and determines a gain TA1 and phase difference TB1 at the specific frequency +α. Next, the calculator is inputted with a test signal 24 of a specific frequency -α from a test signal generator 9 and determines a gain TA2 and phase difference TB2 at the specific frequency -α. The interference of the track eccentricity is removed by the linear interpolation of the gain TA1, 2, TB1, 2, by which the transmission function from the voice coil operation signal 19 to the position error signal 14 is obtd.