Method for servo demodulation and disk storage apparatus

摘要

According to one embodiment, in a method for servo demodulation, a first demodulated signal and a second demodulated signal, which are calculated from amplitude values of burst signal patterns of a first area and a second area, are generated in order to generate a position error signal of a reader, based on a servo pattern read from a disk by the reader. Further, in the method for servo demodulation, a square-root of sum of squares of the first and the second demodulated signals is calculated, and an optimal compensation coefficient of a linearity correction function to be used in linearity compensation of the position error signal is calculated based on a maximum value and a minimum value of the square-root of sum of squares.

主权项

1. A method of servo demodulation in a disk storage apparatus comprising a reader and a disk where servo patterns are recorded, each of the servo patterns comprising a first area and a second area, wherein phases of a magnetization pattern of the first area and a magnetization pattern of the second area are mutually different in a cross track direction, and each of the first area and the second area includes burst signal patterns, the method comprising:
generating a plurality of first and second demodulated signals calculated from amplitude values of the plurality of burst signal patterns of the first and second areas, in order to generate a position error signal of the reader, based on the servo pattern read from the disk by the reader; calculating a plurality of square-roots each corresponding to a square-root of a sum of squares of the first and second demodulated signals; and calculating an optimal compensation coefficient of a linearity correction function to be used in linearity compensation of the position error signal based on a maximum value and a minimum value of the plurality of square-roots.