A ramp voltage generating apparatus according to the present invention includes
a ramp voltage generating circuit for generating a plurality of ramp voltages out
of phase with each other from one ramp voltage, and a control circuit. The ramp
voltage generating circuit includes a plurality of voltage generating circuit portions
connected in parallel to a voltage input terminal. Each voltage generating circuit
portion includes a voltage output terminal, a capacitor, an operational amplifier,
a first switch, a second switch and a third switch. The control circuit turns on
the third switches while shifting the time point of switching each of the third
switches from off to on state, and the control circuit turns off the first switches
and, also, turns on the second switches during the period including the fall time
point of the ramp voltage input to the voltage input terminal.