Precise MOS imager transfer function control for expanded dynamic range imaging

摘要

There is provided an imaging system comprising a MOS pixel array including rows of pixels. Each pixel includes a light detecting element, a reset node connected to the light detecting element for controlling dissipation of photogenerated charge produced by the light detecting element, and a sense node connected to the light detecting element for measuring photogenerated charge produced by the light detecting element. A charge control voltage generation circuit is provided including a circuit topology for producing a plurality of charge control voltages selected to control dissipation of photogenerated charge produced by the light detecting element, in accordance with a corresponding pixel transfer function. A switch circuit is connected to the voltage generation circuit and connected to the pixel array to apply voltages produced by the charge control voltage generation circuit to reset nodes of pixels, application by the switch circuit of each of the charge control voltages to the reset nodes of each of the pixels in the pixel array being characterized by a voltage application settling time, ts, that is less than about a specified duration of each control voltage in the plurality of control voltages.