Position demodulating method and circuit of disk apparatus

摘要

Position information PosN and PosQ are compared and position information Pos 1 and Pos2 in which influences of an error of a position sensitivity gain appear oppositely are calculated. Subsequently, a weight gain G1 = M and a weight gain G2 = (1 - M) are obtained from the position information Pos1. A multiplication value obtained by multiplying the third position information Pos1 by the weight gain G1 and a multiplication value obtained by multiplying the fourth position information Pos2 by the weight gain G2 are added and synthesized, thereby calculating a decoded position. <IMAGE>