Optoelectronic range measuring system - uses modulated beam with digital time raster controlled by one of two quartz crystals with lower frequency (NL 1.6.77)

摘要

The optoelectronic distance measuring system uses an LED or laser modulated by a quartz crystal. The modulated beam is divided into a range measuring and reference beam. A digital time raster is formed under the control of a quartz crystal (11). The time scale of the raster coincides with the period of the difference between the modulation frequency and a higher frequency generated by a second quartz crystal. Pref. the first quartz crystal controls a counter (26) started by a reference light path changeover unit (15a). The counter produces output pulses having an optimum frequency with respect to measuring time and accuracy.