Imaging array with improved dynamic range utilizing parasitic photodiodes within floating diffusion nodes of pixels

摘要

A pixel sensor having a main photodetector and a parasitic photodiode and a method for reading out that pixel sensor are disclosed. The pixel sensor is read by reading a first potential on a floating diffusion node in the pixel sensor while the floating diffusion node is isolated from the main photodiode. The pixel sensor is then exposed to light such that the floating diffusion node and the photodetector are both exposed to the light. A second potential on the floating diffusion node is then readout while the floating diffusion node is isolated from the main photodiode. After the first and second potentials are readout, a third potential on the floating diffusion node is readout. The main photodiode is then connected to the floating diffusion node, and a fourth potential on the floating diffusion node is readout. First and second light intensities are determined from the readout potentials.