Facsimile scan line response equalization system

Claim 1

A facsimile scan line response equalization system comprising: means providing a source of facsimile scan line video signals inherently having a non-uniform response along each scan line; means producing a scan line end reset signal; means producing a plurality of sensor signals spaced in time during the time each line is being scanned; a shift register having an input terminal, a reset terminal and a plurality of output terminals; means applying said plurality of sensor signals to said shift register input terminal to provide corresponding actuating signals sequentially along said output terminals; means applying the scan line end reset signal to said shift register reset terminal for resetting the shift register at the end of each scan line; a plurality of adjustable amplifiers so connected that each output terminal of the shift register is connected to a separate adjustable amplifier, the amplifiers having their output terminals connected to a common bus, said actuating signals actuating said amplifiers sequentially to provide a sequence of adjustable signals at said common bus; a video signal amplifier having an output terminal, a first input terminal connected to receive said scan line video signals, a second input terminal connected to receive said sequence of adjustable signals, and means utilizing said sequence of adjustable signals to modify said scan line video signals, providing modified scan line video signals at said output terminal, the adjustable amplifiers being differently adjusted to provide the proper non-uniform adjustable signals to compensate for said non-uniform response of said scan line video signals.