Patent ID: 8717703
Filing Date: 2014-05-06
Classification: G11B

Abstract:
1. A magnetic disk drive comprising: a first microactuator configured to move a first head associated with a first disk surface; a second microactuator configured to move a second head associated with a second disk surface; a voice coil motor actuator configured to move the first head and the second head; a storage unit configured to store a first inter-head offset measured in a first state at a first time, the first inter-head offset indicative of a displacement between the first head and the second head in a radial direction of the first disk surface and the second disk surface, the first state comprising a state where the first microactuator and the second microactuator are stationary; a head position detector configured to detect a position of the first head when the first head is switched to the second head at a second time after the first time; and a head position estimator configured to estimate a position of the second head based on the position of the first head, a first voltage, a first polarity of the first microactuator, a first gain of the first microactuator, a second voltage, a second polarity of the second microactuator, a second gain of the second microactuator, and the first inter-head offset, the first voltage and the second voltage applied to the first microactuator and the second microactuator, respectively, at the second time.