MAGNETIC ENCODER, ELECTRO-MECHANICAL DEVICE, MOBILE OBJECT, AND ROBOT

摘要

PROBLEM TO BE SOLVED: To structure in a simple configuration a magnetic encoder capable of detection with high resolution and high accuracy.SOLUTION: A magnetic encoder has a magnetic drum and magnetic sensors. The magnetic drum is equipped with a permanent magnet magnetized in parallel to the rotation axis of the magnetic drum and a first drum part and a second drum part so disposed as to hold the permanent magnet between them, of which either the first drum part and the second drum part are magnetized by the permanent magnet respectively to the N pole and the S pole or the first drum part and the second drum part are magnetized by the permanent magnet respectively to the S pole and the N pole. Between the first drum part and the second drum part in the rotating direction of the magnetic drums, a magnetic gap is formed. At least one of the first drum part and the second drum part is given a periodic pole tooth shape in the rotating direction of the magnetic drum to cause the magnetic gap to have a periodic shape. A plurality of magnetic sensors are disposed in a position where the pole tooth shape passes.