Automatic character recognition arrangement

摘要

1,110,923. Character recognition. INTERNATIONAL STANDARD ELECTRIC CORPORATION. 29 Oct., 1965 [5 Nov., 1964], No. 45868/65. Heading G4R. In automatic character recognition apparatus, photo-cells feed first bi-stables via AND gates controlled by second bi-stables controlled by the first bi-stables. Signals obtained from a vertical column of photo-cells (1) past which a character moves horizontally are passed via amplifiers and threshold devices (3) to respective AND gates (4), one per photo-cell, which sample selected ones during each column position, the samples from a given AND gate passing via a respective first bi-stable (5), and then a respective second bi-stabie (6) enabled by clock signals in alterna. tion with the AND gates, to a store. Each AND gate is controlled by one or more of the second bi-stables directly or via an OR gate, so that a 1 (black) signal arriving at a given AND gate will be passed (a) if the corresponding second bi-stable is currently storing 0 (Fig. 2, not shown); or (b) if it and the two adjacent second bi-stables are all storing 0 (Fig. 5, not shown); or (c) if any one of these three bistables is storing 0 (Fig. 4, not shown); or (d) if either no second bi-stable or the respective second bi-stable and that above it or the respective second bi-stable and that below it is/are storing 1. The above alternatives variously thin vertical lines to one column width, improve recognition of poorly printed rounded corners, and/or remove part of horizontal lines. Remaining parts of horizontal lines may, if desired, be eliminated in the following recognition circuitry on the grounds of depth, or by grouping the photo-cell outputs via resistors before feeding the AND gates so a given AND gate only receives a 1 signal if black is encountered in several adjacent horizontal rows.