| 摘要 |
PURPOSE:To prevent consumption of a detecting sensor, and to realize detection of high accuracy under an undesirable environment, by detecting as attenuation of light with respect to a variation of an interval of the circumferential face of a rotating object and the tip of an optical fiber. CONSTITUTION:When light source light is transmitted to an optical fiber 8, an optical beam 9 which is projected from the tip of the fiber 8 and is reflected from a circumferential face S of a rotating object 1 returns again through the inside of the fiber 8, and its intensity is grasped by a photodetector. As for the beam 9, the attenuation quantity is changed in accordance with an interval between the tip face of the fiber and the circumferential face S, namely, a variation of optical path length, therefore, displacement of the rotating object 1 can be detected by an output of a photodetector. |
