Pulse coder using magnetoresistance elements having an improved z-phase signal pattern

摘要

A pulse coder comprises a rotating member (1) on which first and second magnetic patterns (221, 222; 221', 222') are formed and a fixed member (3) on which first and second magnetoresistance patterns (MR5, MR6) are formed. When the first and second magnetic patterns of the rotating member directly face the first and second magnetoresistance patterns, respectively, of the fixed member, the first and second magnetoresistance patterns have a minimum resistance value and a maximum resistance value, respectively. The first and second magnetic patterns are constructed by alternately and irregularly arranging strong magnetic field generating areas and weak magnetic field generating areas.