MAGNETIC SENSITIVE RESISTANCE ELEMENT SENSOR FOR DETECTING REVOLUTION

摘要

PURPOSE:To improve accuracy by inclining the pattern of magnetic sensitive resistance elements formed by resistance-value division of reference potential to the pattern of a plurality of magnetic sensitive resistance elements arranged so as to face magnets for detecting the revolution of a body of revolution and alternately bringing the two patterns close to each other. CONSTITUTION:FG magnets 5 are shaped onto the outer circumferential surface of a magnet 2 for driving a rotor 1 while being alternately magnetized at N and S at regular magnetizing pitches lambda. A magnetic sensitive resistance element sensor 7 is fixed to a stator not shown by a fixing member 7c. The sets A-D and E-H of the magnetic sensitive resistance elements are arranged to the sensor 7 at the intervals of 3/8lambda in a sensor pattern 7a, and the A-D and E-H of each set are disposed at lambda/4 and the FG magnets 5 are detected. A reference- positional preparation pattern 7b is folded back at a middle point X, and divided into mutually adjacent I and J groups, and the direction of a magnetic field is inclined at a approximately 20 deg. to the FG magnets 5. Accordingly, detection being stable to a temperature change and having high accuracy is conducted.