| 摘要 |
<p>PURPOSE:To attain a highly accurate interpolation by comparing detection voltages obtained from the before and behind loops which polarities are inverted, deciding a rough area to be interpolated, that is, a segment, and detecting coordinates. CONSTITUTION:In an area where X<A holds Vn-2 becomes a smaller value, while an area where X>B holds, Vn becomes a smaller value. In light of the characteristic of a circuit, a value larger than an intersection point C1 between Vn-1 and Vn-2 and an intersection point C2 between Vn and Vn-1 is preferably used. Therefore interpolation is made to meet inequalities A<=X<=B. Namely, if a pickup is positioned at a right side from X=5(n-1)mm, polarity inversion can be detected the moment the loop of Ln is driven. If the pickup satisfies 5(n-1)mm<X<B, Sn-2 is selected as a segment. Whereas the pickup satisfies B<X<5nmm, a segment Sn-1 is selected. Thus a value larger than the intersection points C1 and C2 can be always obtained as a detection voltage, and an interpolation area can be optimized.</p> |
