Imaging Array with Non-Linear Light Response

An apparatus comprising:

• an array of pixel sensors, each pixel sensor comprising a dual-ported photodiode or photogate characterized by ports having first and second gates, and a charge conversion circuit, said charge conversion circuit generating a voltage signal that is a function of a charge on said dual-ported photodiode when said first gate in said dual-ported photodiode is activated to transfer a charge on said dual-ported photodiode to said charge conversion circuit;
• and
• a controller that applies a potential to said second gates in said dual-ported photodiodes, each second port passing charge stored in said photodiode connected to said second port when a potential in said photodiode exceeds said applied potential,
• wherein, during an exposure of said array to an image, said first gates in said pixel sensors are held at a first port gate potential and wherein said controller varies said potential on said second gates during an exposure, said potential on said second gate being less than said first gate potential for part of said exposure.