| 摘要 |
PURPOSE:To measure the rotating speed of a low-speed rotating body to be measured with high precision, by rotating either of a signal modulator and a receiving part at a known speed and the other at the same speed with the body to be measured, CONSTITUTION:The rotating speed of a motor 11 is known previously and plural slip rings 16-19 are provided to its rotating shaft 12 at specific intervals. A rotating frame 13 is equipped with a light source 7 as a signal source and a photodetecting element 8 as the receiving part which face each other with the the circumferential edge part of a pulse disk 4 inbetween, and they rotate together with the rotating shaft 12 in one body. Then, t=1/(n¦N1+N2¦), where N1 and N2 are the rotating speeds of the body 1 to be measured and motor 11, (n) is the number of pulse cuts of the pulse disk 4, and (t) is the photodetection pulse period of the photodetecting element. In this case, N1 and N2 are different in sign when the body 1 to be measured and motor 11 rotate in the same direction. |
