| 摘要 |
PROBLEM TO BE SOLVED: To measure accurately floating quantity of a head from a medium recording plane by controlling energizing quantity for a heater provided at the head. SOLUTION: Amplitude of a read-out signal from a preamble part in a servo area of the number of frames (m) per one round of a recording medium is measured over a frequency (n) while increasing electric power quantity energized to the heater in a state in which the head is positioned on a track on the recording medium by an amplitude measuring part 140, and an average amplitude is calculated from an amplitude measured value in which only the number in which the number of frames (m) is multiplied by the frequency (n) is measured in an average amplitude calculating part 142. A contact discriminating part 144 calculates average amplitude change quantity per unit heater electric power quantity as a contact discrimination value, when the contact discrimination value is less than the prescribed threshold value, it is discriminated that the head contacts to the recording medium, a floating quantity calculating part 146 calculating floating quantity of the head from the recording medium plane from heater electric power quantity at the time of discrimination of contact. COPYRIGHT: (C)2008,JPO&INPIT
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