Output circuit provided with source follower circuit having depletion type MOS transistor

Claim 1

An output circuit for use in a solid state image pickup device, said output circuit comprising a source follower type circuit and a reset transistor, wherein said source follower type circuit comprises a resistor element and a depletion type MOS transistor which are coupled to each other, wherein said depletion type MOS transistor comprises: a drain region connected to a power supply; a source region connected to said resistor element; and a control gate provided above a floating gate and insulated from said floating gate, said source region serving as an output terminal of said output circuit, and wherein said reset transistor has a grounded drain, a source connected to the control gate of said depletion type MOS transistor for accumulating information charges externally supplied thereto and a gate for receiving an externally supplied reset pulse signal, the source of said reset transistor serving as an input terminal of the output circuit, and wherein said reset transistor is responsive to said reset pulse signal for periodically initializing the potential level of said input terminal.