US Patent 7531784 Semiconductor device and electronic appliance using the same

An object is to provide a photoelectric conversion device capable of detecting a wider range of illuminance without expansion of a range of an output voltage or output current. The photoelectric conversion device has a photoelectric conversion device including a photoelectric conversion element and an amplifier circuit electrically connected to the photoelectric conversion element, and a bias switching unit for reversing a bias to be applied to the photoelectric conversion device. The bias to be applied to the photoelectric conversion device is reversed with use of the bias switching unit, whereby the photoelectric conversion device can detect a wider range of illuminance without expansion of a range of an output voltage or output current.