DEVICE FOR MEASURING LINEAR SPEEDS WITHOUT CONTACT AND WITHOUT MARKING

摘要

For continuous measurement of the linear speed of relative travel of an object 11 in front of a measuring device 10 two fixed zones 21,22 in the path of the object are illuminated by means of two parallel laser beams emitted by a single source 15, images of the two zones illuminated are formed upon one and the same transducer 17 the output signal from which is processed electronically by autocorrelation in order to determine the time of travel of a point on the object in going from one illuminated zone to the other.