Abstract: Fixed pattern odd/even noise in the video signal output from a self-scanned photosensor array is substantially eliminated by integrating the video signal at the cell scan rate, and converting the resultant to a pulse having a width proportional to the charge current generated by a photosensor cell. Even and odd pulses corresponding to alternate sensor cell video signals are produced, and the pulse widths are compared to form a correction signal. A current sink responsive to the correction signal adjusts the output of the integrator during even cell scans to eliminate fixed pattern odd/even noise in the output video signal.In a specific embodiment, the fixed pattern odd/even noise correction system coacts with an AGC control system and a black reference control system to substantially eliminate fixed pattern odd/even noise and cell clock noise in the output video signal, and to provide an effective system immunity to variations in the parasitic capacitance of the photosensor array.

Abstract: A method and system is provided for driving a self-scanned photosensor array at high sensor cell scan rates, and sampling the sensor cells serially addressed by the array without comprising either image integrity or array frame rate.End of line (EOL) and end of frame (EOF) timing signals generated by the array are sensed and operated upon to limit the voltage amplitude swings of the signals, and to reduce noise modulation in the output video signal. A single synchronization signal is formed from the timing signals to accurately identify the last cell of a frame to be scanned, and to synchronize a row counter driving one of two flip-flops providing biphase array clock signals as the flip-flops have minimal pulse skew between complementary outputs, the effects of fixed pattern odd/even noise in the output video signal are substantially reduced. Further, the flip-flops uniquely provide large voltage amplitude swings without attendant heat generation problems.