VORRICHTUNG ZUR BESTIMMUNG DER TONERRESTMENGE IN EINEM TONERBEHAELTER

摘要

An apparatus for detecting the amount of toner in the supply hopper of an electrophotographic copying machine includes a transmitting element in the hopper for generating an ultrasonic acoustic wave and a receiving element in the hopper in operative relation to the transmitting element for receiving the ultrasonic acoustic wave reflected from toner in the hopper, the magnitude of the reflected wave being representative of the level of toner contained in the hopper.