Device including an even number of equally spaced magneto-resistors for detecting rotation or straight motion of a moving body

A movement detector device for a moving body comprising;

• a magnet having pole faces;
• an even number of magneto-resistors each fixedly mounted in a plane above one of said pole-faces of said magnet and located in the direction of movement of a ferromagnetic part to be detected arranged on a moving body, said part having a plurality of detection portions spaced apart by an equal pitch;
• said magneto-resistors being spaced to equally divide a distance corresponding to said pitch of the part to be detected, and further being separated from the body by a gap;
• said magneto-resistors being interconnected in series with each other;
• output signal pickup points provided at locations where connecting portions appear between the adjacent magneto-resistors;
• and
• a signal processor circuit for differentially amplifying a pair of signals among the signals taken out from the output signal pickup parts, those signal having a phase difference equal to 1/2 a period, and outputting the outputs rendered to the differential amplification as detection signals.