Patent ID: 7807956

Claim:
A current detection circuit which detects a current that flows through a photoreceptor device, comprising: an output terminal via which a current, which is proportional to the current that flows through the photoreceptor device, is output; an input-side transistor which is a PNP bipolar transistor provided on a current path for the photoreceptor device; a plurality of output-side transistors which are PNP bipolar transistors with the base terminals being connected to that of the input-side transistor so as to form a common base terminal, and with the emitter terminals being connected to that of the input-side transistor so as to form a common emitter terminal, thereby forming a current mirror circuit; a plurality of first switches each of which is provided for a corresponding one of the plurality of output-side transistors, and each of which is provided between the collector of the corresponding output-side transistor and the output terminal; a plurality of second switches each of which is provided for a corresponding one of the plurality of output-side transistors, and each of which is provided between the collector of the corresponding output-side transistor and the ground terminal; and a control unit which controls the ON/OFF operations of the plurality of first switches and the plurality of second switches.