Abstract: An image reading apparatus according to the present invention allows the period of generation of a load signal NRD, the load value in counter circuits 21 and 31, and the comparative value in pulse generator circuits 22 and 32 to be changed corresponding to the multiplication rate of a PLL circuit 14. Accordingly, the pulse width and the phase length of the signals generated in signal generator circuits 12A and 12B are enhanced in the controllable accuracy by increasing the multiplication rate of the PLL circuit 14. Hence, even if the driving frequency is lowered, the pulse width and the phase length of the signals generated in signal generator circuits 12A and 12B can favorably be maintained in the controllable accuracy.