US Patent 7501634 Method and system for distribution of an exposure control signal for focal plane arrays

A large format imager includes an array of pixels for converting electromagnetic radiation into electrical signals and a trigger to from an optical pulse so as to trigger the pixels to generate an integration period. Each pixel includes a photodiode to convert light intensity of high-frequency radiation into an electrical charge, a reset switch to reset the photodiode, circuitry to enable sampling of the electrical charge produced by the photodiode, a photoswitch to convert an optical trigger pulse, received from the trigger, into an electrical signal, an inverter to produce a control signal corresponding to the electrical signal produced by the photoswitch, and control circuitry to locally generate integration control signals. The integration control signals control a start of an integration period for the photodiode, duration of the integration period for the photodiode, and the sampling of the electrical charge produced by the photodiode. The large format imager may also include a trigger for producing an electrical pulse so as to trigger the pixels to generate an integration period and tree type electrical distribution system for propagating the electrical pulse to all the pixels, wherein each pixel includes a global repeater circuit to propagate a first edge of said electrical pulse along said tree type electrical distribution system and a local repeater circuit to provide a local array of pixels with the first edge of the electrical pulse.