Patent ID: 8804274
Filing Date: 2014-08-12
Classification: G11B

Abstract:
1. A disk storage apparatus comprising: a disk configured to divide and record servo information to detect a position in a radial direction in a plurality of servo areas; a read controller configured to read the servo information from each of the servo areas using a head; and a servo controller comprising a combined position generator including a state observer and a combined position calculator, and configured to calculate a combined position based on the servo information read from each of the servo areas by the read controller and a predicted position calculated by the state observer, and to control a seek operation of the head based on the combined position, wherein the servo controller is configured to: store the servo information read during the seek operation in a memory; determine whether a state offset as an error between an actual position of the head and the combined position has occurred; and correct the predicted state by the state observer based on the servo information stored in the memory and the combined position when an occurrence of the state offset is detected.