Variable collection of blooming charge to extend dynamic range

A method of using an imager to provide increased dynamic range comprising the steps of:

• providing the imager on a semiconductor based substrate having a sensor array formed within the substrate with a plurality of the pixels in the array being configured such that each of the pixels has photodetector coupled to a sense node through a transfer mechanism, the sense node being operatively connected to a reset mechanism;
• creating a sense node integration period and a photodetector integration period within each of the plurality of pixels during a signal frame period wherein the sense node integration period collects charge on the sense node that has bloomed from the photodetector during the photodetector integration period;
• sampling the potential level accumulated on the sense node;
• firstly applying a predetermined set of transfer functions to identify signal levels of the photodetectors;
• identifying which transfer function is applicable to the sampled potential;
• and
• secondly applying the transfer function to ascertain the light intensity from the photodetectors.

An X-Y addressable MOS imaging system comprising:

• a semiconductor based image sensor having an array of pixels with a plurality of the pixels such that each pixel within the plurality of pixels has a photodetector and a sense node with means for resetting both the photodetector and the sense node to a predetermined potential;
• means for transferring charge from the photodetector to the sense node;
• means for collecting blooming charge on the sense node;
• means for controlling the time that blooming charge is collected on the sense node;
• means for reading accumulated signal level of both the photodetector signal and the bloomed charge collected on the sense node;
• and
• means for measuring the reset level of the sense node.

An X-Y addressable MOS imager system comprising:

• a semiconductor based substrate having an active pixel sensor array formed within the substrate;
• a plurality of the pixels in the array being configured such that each of the pixels has photodetector coupled to a sense node through a transfer mechanism, the sense node being operatively connected to a reset mechanism;
• means for creating a sense node integration period and a photodetector integration period within each of the plurality of pixels during a signal frame period wherein the sense node integration period collects charge on the sense node that has bloomed from the photodetector during the photodetector integration period;
• a predetermined set of transfer functions used to identify signal levels of the photodetectors;
• sampling means for reading a potential level accumulated on the sense node;
• determination means for identifying which transfer function is applicable to the sampled potential;
• and
• means responsive to the determination means for applying the transfer function to ascertain the light intensity from the photodetectors.