Photodetector adapted to provide additional color information

A method for generating a color image of a scene comprising a plurality of color pixels, said method comprising:

• projecting an image of said scene on an array of pixel sensors, each pixel sensor generating one color pixel of said color image, each pixel sensor comprising a first photodetector comprising:
• a first main photodiode characterized by a first light conversion efficiency as a function of wavelength of a light signal incident on said pixel sensor;
• and
• a first floating diffusion node comprising a first parasitic photodiode characterized by a second light conversion efficiency as a function of said wavelength, said second light conversion efficiency, being different from said first light conversion efficiency as a function of wavelength, said first floating diffusion node also being illuminated by said light signal;
• generating first and second light intensity values for each pixel sensor from said first main photodiode and said first floating diffusion node in each of said pixel sensors;
• generating a third light intensity value corresponding to each pixel sensor utilizing a corresponding one of a plurality of second photodetectors having a third light conversion efficiency as a function of wavelength that is different from first and second light conversion efficiencies;
• and
• generating each color pixel utilizing said first, second, and third light intensity values corresponding to that pixel,
• wherein said plurality of second photodetector comprises one second photodetector that is shared by a plurality of said pixel sensors.

A color imaging system, comprising:

• a plurality of pixel sensors, each pixel sensor comprising a plurality of first photodetectors and a plurality of second photodetectors and wherein there are fewer second photodetectors than first photodetectors;
• a filter on one of the plurality of first photodetectors and the plurality of second photodetectors;
• the plurality of first photodetectors, comprising a first main photodiode characterized by a first light conversion efficiency as a function of wavelength of a light signal incident thereon producing a first measurement;
• a first floating diffusion node comprising a first parasitic photodiode characterized by a second light conversion efficiency as a function of said wavelength, said second light conversion efficiency, being different from said first light conversion efficiency as a function of wavelength, said first floating diffusion node also being illuminated by said light signal and producing a second measurement;
• the plurality of second photodetectors, comprising a second main photodiode with a third light conversion efficiency as a function of said wavelength, said third light conversion efficiency being different from said first and second light conversion efficiencies, said second photodiode providing a third measurement;
• and
• a controller that generates an intensity of light in each of a plurality of wavelength bands for said pixel sensor utilizing the first, second and third measurements to produce a color image.