MAGNETIC ENCODER

PROBLEM TO BE SOLVED: To provide a magnetic encoder capable of outputting a pulse signal of double cycle (1/2 period) of the conventional art. SOLUTION: Each of magnetoresistance effect elements A1, A2, A3 and A4 has at least a pin layer and a free layer whose internal magnetization direction varies based on an external magnetic field generated by a magnetic substance 11. The magnetization direction α of the pin layer is set at a first direction Z2 that is parallel to the outer peripheral side face and is perpendicular to the rotation direction ra1-ra2 or a second direction Z1 opposite to the first direction Z2, and the initial magnetization directional β0 of the free layer is set at the first direction Z2 or second direction Z1. When the inter-pole pitch between adjacent N pole and S pole in the rotation direction ra1-ra2 is set at λ, the array pitch between magnetoresistance effect elements A1, A2, A3 and A4 is set at λ/2. COPYRIGHT: (C)2007,JPO&INPIT