| 摘要 |
PURPOSE:To make jamming processing easy, by detecting the winding of copied material on a photoreceptor through the change in discharge current flowing between the photoreceptor and a high voltage discharger, for the quick detection and simplicity in the hardware. CONSTITUTION:When a switch 6 is closed, a corona discharge with a discharge resistor 7 is caused between a photoreceptor 1 and a discharger 2 making corona discharge through a DC high voltage power supply 3-1. In this case, taking a discharge current flowing through the discharge as I(muA), a voltage drop V(v)=IXR is caused across a detection resistor 4. Thus, when the voltage drop across the detection resistor 4 is a normal value or less, or a prescribed value to be set or less, a control circuit 5 is operated for the dispaly for users. As the resistor 4, an element having reverse characteristics as the temperature change of the discharge current I, that is, negative characteristics to temperature, is used so that an output voltage V at normal state is made constant, allowing quick detection and simplified device. |
