PURPOSE: To prevent discharge paper from jamming in time of mass copying, by displacing a single dischrged paper receiving tray at a time when a paper discharging quantity by a detecting device accords with the preset paper discharging quantity, in case of a copying device for an electrostatic copying machine or the like.

CONSTITUTION: A motor circuit 13 is turned to ON or OFF by output O1 of a control circuit 12 and rotates c.w. or c.c.w by output O2. Next, a position detection sensor SW3 is connected to input 11 of the control circuit 12 and situated in a position capable of detecting an upper limit position of a discharged paper receiving tray 9. A shiting direction of a rack 16 corresponds to a downward direction to c.w. rotation 14a of a motor M1 and an upward direction 17b to a reverse direction 14b, respectively. Discharged paper housing capacity at a time when the discharged paper receiving tray 9 is displaced in maximum to the downward direction 17a is made so as to become larger capacity than paper feeding source capacity or equal to it in design. And, a gear ratio between gears 15a and 15b and a c.w. speed of the motor M1 is set so as to make the preset paper discharging quantity at the specified time equal to a displacement value of the downward direction of the discharged paper receiving tray 9.