HEAD CONTROL DEVICE IN DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a head control device in a disk device which is capable of detecting the position of a head and of correctly calculating position deviations to a target track center and in which the generation of a seek fault is made not to be generated even when a tolerance is generated in the phase difference between both phases by using detection outputs of two phases. SOLUTION: Differences from a zone 1 to a zone 4 in one track are detected from combinations of polarities of A phase and B phase whose phases are different and position deviations to a target track center are calculated from detection outputs of B phase in accordance with respective zones. Dead zones 25 are provided in B phase in a range in which the error of the phase difference between both phases is generated. Thus, even when the error is preset in the phase difference, the position deviation of a head can be correctly calculated.