METHOD FOR DETECTING MOVING SPEED OF OBJECT

摘要

PURPOSE:To certainly detect the moving speed of an object in a non-contact state, by such simple constitution that scattered light from the object by light irradiation is cyclically received through a slit by a photoelectric multiplier to perform frequency spectrum analysis. CONSTITUTION:The scattered light from an object A by light irradiation is received through a moving slit 2 for performing repeated scanning in the direction at right angles to the optical axis at a constant speed and a constant cycle f0 by a photoelectric multiplier 3 and the light receiving signal is analyzed by a frequency analyser 4. The frequency of the frequency spectrum component by this analysis is changed in the frequency +DELTAf or -DELTAf corresponding to the moving speed and direction of the object A and the moving speed of the object is detected by this change component +DELTAf or -DELTAf. By this method, it is unnecessary to form the interference fringe due to the Doppler shift using two sets of irradiation lights to a photoelectric multiplier and the moving speed of the object is certainly detected in a non-contact state by simple optical constitution.