Solid-state image sensing device providing a logarithmically proportional output signal

An image sensitive device, comprising:

• a first MOS transistor having a gate, a source and a drain, said first MOS transistor operating in a subthreshold region;
• a second MOS transistor having a gate, a source and a drain, said second MOS transistor operating in a subthreshold region, and said gate of the second MOS transistor being connected to the gate and drain of the first MOS transistor;
• photoelectric current generating means for generating a photoelectric current proportional to an intensity of incident light, said photoelectric current being provided to the drain of the first MOS transistor;
• and
• a capacitor connected to the source of the second MOS transistor;
• wherein a voltage resulting from a connection between the source of the second MOS transistor and the capacitor is logarithmically proportional to an integrated amount of the photoelectric current.