Moving body speed detecting device which produces and detects a magnetic pole on the body surface

摘要

According to this invention, a device for detecting the speed of transference of a moving body, having a construction such that the device comprises a magnetizing element for forming a magnetic pole on a surface of a moving body made of a magnetic material and disposed in the vicinity of the moving body, a magnetic field detecting circuit provided adjacent to the moving body, for linking therewith the magnetic field of the magnetic pole formed by the magnetizing element and for outputting an electrical voltage in accordance with a variation of the magnetic field caused by the transference of the moving body, and an output signal processing circuit for processing a signal output by the magnetic field detecting circuit and for determining the speed of transference of the moving body can be obtained, and by utilizing the device mentioned above, an effect whereby a signal corresponding to the displacement speed of a moving body is continuously obtained and therefore, a moving body need not be precisely fabricated with a specific configuration such as forming concave and convex portions on the surface of the moving body, and moreover, to continuously obtain precise information about the speed of the moving body, because even when the moving body moves at an extremely low speed, an increment of a ripple and a phase shift can not occur, can be realized.