The toner agitator gear [A] has a cam [B] (the toner end cam) on its inner surface, and it rotates only when toner is supplied. The cam follower on the end of the toner end lever [C] rides on the surface of the toner end cam (spring pressure). The opposite end of the toner end lever alternately presses and releases the toner end arm [D] as the cam turns. The toner end plate [E], which is in the toner hopper, is mounted on the same shaft as the toner end arm. When there is sufficient toner in the hopper, the toner end plate is prevented from moving by the toner. Therefore, even when the toner end lever drops to the lowest position on the cam (releasing the toner end arm), the toner end arm does not move and the toner end sensor [F] is not activated. When there is insufficient toner in the hopper, the toner end plate can move. When the toner end lever releases the toner end arm, the toner end plate lowers and the actuator [G] on the toner end arm moves into the toner end sensor. The CPU receives a single pulse from the toner end sensor.