Three transistor active pixel sensor architecture with correlated double sampling

摘要

An active pixel sensor having a plurality of pixels with at least one pixel comprising: a photodetector operatively connected to a first electrical node; a pixel signal coupling capacitor having a first side connected to the first electrical node and a second side connected to a second electrical node; a reset transistor having a first source that is connected on the first electrical node and a second source that it connected to the second electrical node; a reset gate on the reset transistor connected to a reset control buss and a drain on the reset transistor connected to a voltage supply buss; an amplifier operatively connected to the second electrical node; and a select transistor operatively coupled to the amplifier. The preferred embodiment of the invention has a gate electrode layer formed over at least a portion of the photodetector and functions also as the gate of the transistor amplifier. It is envisioned by the preferred embodiment that the gate electrode layer be either polysilicon or indium tin oxide (ITO) which are materials typically used as gate electrode materials.