Amplifying type solid-state imaging apparatus and method for driving the same

An amplifying type solid-state imaging apparatus, comprising:

• an amplifying type photoelectric conversion device comprising:
• a first region provided in a semiconductor substrate so as to include a part of a surface of said semiconductor substrate, for accumulating a charge generated by photoelectric conversion as a signal charge;
• a first drain region which is a high impurity concentration layer formed in said first region;
• a first gate region including a surface-proximate portion of said substrate of said first region excluding said first drain region, an insulating film formed on said first region, and a first electrode formed on said insulating film;
• a second gate region including a second region provided adjacent to said first gate region, and a second gate electrode provided on said second region with said insulating film being inserted therebetween;
• a second drain region provided to the outside of said first region and adjacent to said second region;
• wherein a first transistor having said surface-proximate region of said substrate of said first region as a channel is formed between said first drain region and said semiconductor substrate, and a second transistor having a region between said first region and said second drain region as a channel is formed, a change in an operational characteristic of said first transistor which is generated by said signal charge being used as an output signal;
• a signal line for carrying a signal output from said transistor of said amplifying type photoelectric conversion device;
• a clamp circuit connected to said signal line, for clamping a voltage of said signal line at a first voltage;
• a sample hold circuit connected to said clamp circuit, for sample-holding a difference signal representing a difference between said first voltage and a second voltage output from said transistor after said resetting operation;
• an output line connected to said sample hold circuit;
• and
• a controlling circuit for controlling said clamp circuit and said sample hold circuit and for reading out said difference signal held in said sample hold circuit to said output line.

A method for driving an amplifying type solid-state imaging apparatus, said amplifying type solid-state imaging apparatus comprising:

• an amplifying type photoelectric conversion device, comprising a transistor formed on a surface of a semiconductor, said transistor accumulating a charge generated by incident light as a signal charge in a charge accumulation region proximate to the surface of said semiconductor substrate and outputting a signal in accordance with said signal charge;
• and
• a signal line for carrying a signal output from said transistor;
• said method comprising the steps of:
• outputting a signal in accordance with accumulated said signal charge from said transistor of said amplifying type photoelectric conversion device to said signal line;
• clamping a voltage of said signal line at a first voltage;
• discharging said signal charge accumulated in said transistor from said charge accumulation region, thereby outputting a second voltage from said transistor;
• sample-holding a difference signal representing a difference between said first voltage and said second voltage;
• and
• reading out said sample-held difference signal.