Device for detecting rotating speed of thin shape motor

摘要

A device for detecting rotating speed of a thin shape motor including a vertical shaft rotatably supported on a base plate, a rotor of a planar shape secured to the vertical shaft in a spaced apart relation from the base plate, and a stator provided downwardly from the rotor on the base plate, comprises a rotatable disc of a diameter smaller than that of the rotor secured to the vertical shaft and having speed detecting indices on a peripheral surface thereof, and a luminous element and a light-receiving element provided outwardly of the rotor. A light-projecting optical fiber and a light-receiving optical fiber are further provided to extend along the base plate such that one end of the light-projecting optical fiber is located to oppose the luminous element, while one end of the light-receiving optical fiber is located to oppose the light-receiving element, and that the other ends of the two optical fibers are placed in opposition to the peripheral surface of the rotatable disc.