Toner low level detection device

摘要

The device is employed in an electrophotographic printer for detecting the low-toner condition of a toner box. A level sensor such as a piezoelectric element and driving circuit 14d, in the toner box outputs a high or low level signal to switch transistor TR. A control driver 82 has an input A which is connected to a predetermined potential B via resistor 89, and to earth when transistor TR is switched on by the presence of an adequate level of toner.