| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost and high-precision magnetic encoder device that reduces a temperature drift in offset of a magnetic detection element without imposing a heavy burden on a CPU. SOLUTION: An offset arithmetic circuit 651 calculate the offset value Voffma of an A-phase signal Va, and a difference operator 653 calculates a difference value dVoffa which is a difference between an offset reference value Voffna stored in advance in an offset storage circuit 652 and the offset value. Next, a comparator 655 makes a comparison between the difference value and a threshold Vca set in advance in a threshold setting circuit 654, and when the difference value is greater than the threshold, the offset reference value Voffna is updated by the offset value Voffma. The A-phase signal Va is corrected by the offset reference value thus updated, and an angle signal of a magnetic encoder device (not shown) is calculated using the A-phase signal Va thus corrected and a B-phase signal Vb' similarly obtained. COPYRIGHT: (C)2009,JPO&INPIT
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