JPS57109968A - Method for detecting transfer material using temperature sensor - Google Patents

Abstract

PURPOSE:To certainly detect trouble in separation of a transfer material with simple structure, by providing one or more temperature sensors facing each material to detect its temperature, and detecting said trouble in accordance with the difference between each detection output. CONSTITUTION:The outputs of 2 temperature sensors 9a, 9b are fed to a comparator 10, and temperature is controlled with the output of either of the sensors 9a, 9b. Trouble in separation is detected in accordance with the difference between both their outputs. When jam does not occur, the sensors 9a, 9b produce the same potential, and when jam occurs, either of the potentials of the sensors drops, thus indicating jam 13 through the comparator 10, a microcomputer 12, etc. and stopping the copying process. On the other hand, a timer circuit 15 is provided in the comparator 10 to prevent an error due to scattering of the outputs of the sensors 9a, 9b at the rise time of the drum heater, thus permitting the trouble to be detected with simple structure.