FIG. 5A shoWs an example of a ramp signal generating circuit. The ramp signal generating circuits 3 and 11 are fundamentally implemented by the same circuit. Remember that, hoWever, the control signals for controlling the sWitch S3 are different from each other in this case. The control signal for the ramp signal generating circuit 3 is a pulse
signal from the oscillator 2, While the control signal for the ramp signal generating circuit 11 is an output of the latch circuit 5.