A device for measuring the angular velocity of a rotating object (35) is described, which device comprises a first disc (23) moving with the object and having a rotationally symmetrical pattern of interruptions (24), and a second disc (29) having a similar pattern and a detector (34) which receives radiation...http://www.google.es/patents/US5569912?utm_source=gb-gplus-sharePatente US5569912 - Optical velocity measuring with efficient use of radiation passing through patterns on discs
Optical velocity measuring with efficient use of radiation passing through ...
