ROTATION DETECTOR

PROBLEM TO BE SOLVED: To provide a rotation detector capable of preventing a collision fault of a chip or the like mounted to a tongue-like holding part even when the tongue-like holding part is inserted in a hollow part, deviating from a predetermined position or a predetermined direction. SOLUTION: The rotation detector 100 detects the rotating state of a rotor by measuring the change of a bias magnetic field following the rotation of the rotor, by a magnetic detecting element formed at the chip 11. The chip 11 is mounted to the tip part of an upper face 51u of the tongue-like holding part 51 in a case body 50, and the tongue-like holding part 51 is inserted and arranged in the hollow part 71 of a cylindrical magnet 70 generating the bias magnetic field. An insertion guide 72 is provided for limiting the upward movement of the tongue-like holding part 51 when the tongue-like holding part 51 is inserted and arranged in the hollow part 71. COPYRIGHT: (C)2009,JPO&INPIT