Optical displacement sensor and torque sensor employing relatively movable slit patterns

摘要

PCT No. PCT/GB95/02017 Sec. 371 Date May 9, 1997 Sec. 102(e) Date May 9, 1997 PCT Filed Aug. 25, 1995 PCT Pub. No. WO96/06330 PCT Pub. Date Feb. 29, 1996An optical displacement sensor is used to measure the rotary displacement between two shafts which rotate together. By connecting the shafts together by means of a torsion bar, the sensor may be used to measure transmitted torque. The sensor comprises first and second coaxial discs mounted on the shafts and having slots formed therein. A light source directs light through the slots onto an array of photodetectors and a data processor determines the displacement or torque from the positions on the array of images of the slot edges.