Patent ID: 7692713

Claim:
A solid-state image pickup device, comprising: a photosensor array portion; a control unit for determining an accumulation end of photocarrier-accumulation of the photosensor array portion when a maximum value signal among signals outputted from pixels of the photosensor array portion reaches a predetermined voltage; and an amplifier circuit for amplifying a signal, which is outputted from each of the pixels of the photosensor array portion, with reference to the maximum value signal and for outputting the signal; wherein the amplifier circuit includes: a level-shift circuit for level-shifting a signal outputted from each of the pixels such that the maximum value signal is set to be a reference voltage, and an amplifier for amplifying the level-shifted signal from the level-shift circuit and for outputting the level-shifted signal, wherein the photosensor array portion includes at least a pair of photosensor arrays, and the pair of photosensor arrays and the amplifier circuit are used for detecting focus, and wherein the level-shift circuit includes: an operational amplifier, a level-shift capacitor connected to an input of the operational amplifier, a level-shift switch connected to the level-shift capacitor, a first variable element connected to a negative input side of the operational amplifier, and a second variable element connected between an output of the operational amplifier and the first variable element.