Patent ID: 7697234

Claim:
A storage apparatus comprising: a positioning control unit which positions a head to a target track of a rotating storage medium and causes the head to follow it; a compensation control unit which applies a compensation signal to the positioning control unit so that a rotation disturbance vibration component detected by an acceleration velocity sensor is cancelled out; a position error detection unit which detects, at predetermined timing, respective position errors according to the positioning control unit in the case in which the compensation control unit is enabled and the case in which the compensation control unit is disabled; and a compensation control switching unit which switches the compensation control unit either between an enabled state and a disabled state based on the magnitude relation of two position errors detected by the position error detection unit, wherein the position error detection unit discretely detects the respective position errors according to the positioning control unit in the case in which the compensation control unit is enabled and the case in which the compensation control unit is disabled in a predetermined period and detects a square integration value of the positioning errors over the predetermined period; and the compensation control switching unit disables the compensation control unit if both the two position errors are less than a predetermined threshold value and enables or disables the compensation control unit based on the magnitude relation of the two square integration values if at least either one of the two position errors exceeds a predetermined threshold value.