Abstract: An active pixel imaging system and method to generate an differential output signal consisting of the differences in a viewed image between adjacent detected flames. A buffered electrical charge storage capacity of the active pixel sensor is utilized to provide a system with reduced complexity and hardware requirements. In the imaging system, when a particular active pixel sensor is activated it generates a voltage signal corresponding to a previous frame's detect light intensity before the pixel is reset to generate a voltage signal corresponding to a present frame's detected light intensity. A differential output circuit is used to generate a differential output signal based on these two generated voltage signals.

Abstract: The single-polysilicon active pixel comprises a photo site located on a substrate for generating and storing charge carriers, the charge carriers being generated from photonic energy incident upon the photo site and semiconductor substrate, a photo gate, a transfer transistor and output and reset electronics. The gate of the transfer transistor and the photo gate are defined in a single layer of polysilicon disposed on the semiconductor substrate. The source of transfer transistor is a doped region of substrate, referred to as a coupling diffusion, which provides the electrical coupling between the photo gate and the transfer transistor. The coupling diffusion allows for the transfer of a signal stored in a photo site under the photo gate to the output electronics for processing. The single-polysilicon active pixel may be operated by biasing the transfer transistor to the low operating voltage of the pixel, for example, 0 volts.

Abstract: The imaging pixel according to the present invention includes a floating gate pixel node capable of nondestructive readout and active source follower output circuitry suitable for combination with other like imaging pixels to form an imaging array.