| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect a rotation angle or a moving distance of a detection object while suppressing degrading of interpolation accuracy as much as possible. <P>SOLUTION: A magnetic sensor 10 outputs an (A) phase output signal and a (B) phase output signal which have sine-wave like shapes and phases mutually different by 90 degrees from each other according to the rotation or movement of the detection object. In each of the (A) phase output signal and the (B) phase output signal, a same phase sampling value in which a difference of a sampling value and a sampling value which is obtained by shifting the sampling value by 180 degrees is minimum is extracted. An average of the extracted sampling values is calculated as an offset correction value. The sampling values of the (A) phase output signal and the (B) phase output signal are offset-corrected by using the offset value, so as to calculate the rotation angle or moving distance of the detection object. <P>COPYRIGHT: (C)2013,JPO&INPIT |
