Retrogressive scanning pattern

Claim 1

In a character recognition system having means for scanning a field, said scanning means being moved to form a scan raster comprised of a plurality of retrogressive sweeps and means responsive to said field for producing signals in accordance with the lightness or darkness of the area of the field at which said means for scanning id disposed, control means for establishing the position on said field where said means for scanning is disposed, said control means causing said scanning means to move in said plurality of retrogressive sweeps, said means responsive being sampled when said scanning means is disposed at points at which the scanning means changes direction, said scanning means changing direction at the transverse limits of said retrogressive sweeps, said system further including means for quantizing said sampled signals so that said sampling causes the sequential generation of quantized signals representative of two columns of points within said field, a first and secoNd shift register, a selection means and a pair of gates, each of said gates having a first input connected to said means for quantizing and a second input connected to said selection means, each of said shift registers being connected to the output of a different one of said gates, said selection means enabling said gates in alternating fashion so that after a retrogressive column has been scanned, each of said registers has received and stores the signals representing one column of said points.