Device for detecting an empty paper tray in an electrophotographic apparatus

摘要

A paper detecting device is provided that may be constructed using a tray-rotatable-cam that can rotate around a shaft through a limited range. The tray-rotatable-cam is rotated into operating position by the insertion of the paper tray into the electrophotographic apparatus. A height-adjusting-beam is positioned substantially perpendicularly to the tray-rotatable-cam and is able to rotate on its own shaft through a limited range to raise the height of the shaft supporting the sensor-activating-blade. The shaft supporting the sensor-activating-blade is at a substantially perpendicular orientation to the height-adjusting-beam. A torsion spring installed on the same shaft as the height-adjusting-beam to provide the force to lift the shaft, and sensor-activating-blade to their operational height. The torsional spring also prevent the shaft and sensor-activating-blade from being caught in the paper tray when the paper tray is inserted or removed from the electrophotographic apparatus. When the cut medium in the paper tray is exhausted, the sensor-activating-blade rotates through a hole in the paper stand and activates a photo sensor signaling the absence of paper in the paper tray.