| 摘要 |
PROBLEM TO BE SOLVED: To provide an offset value calculation method capable of more accurately obtaining an offset value of a sine wave signal outputted from an MR element for position detection. SOLUTION: The method acquires data MRA, MRB denoting levels of sine wave signals outputted from the MR element when an object for position detection is moved at a prescribed speed by means of sampling for a prescribed sampling periodΔt extremely shorter than the period of the sine wave signals, calculates 2nd order differential parameters DDMRA, DDMRB equivalent to 2nd order differential values of the sine wave signals on the basis of the acquired data MRA(n), MRA(n), uses the 2nd order differential parameters DDMRA, DDMRB to calculate offset value data tmpA, tmpB, respectively, corresponding to the acquired plural data, and calculates the offset values P, Q by averaging the offset value data tmpA, tmpB, respectively. COPYRIGHT: (C)2007,JPO&INPIT
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