Buchstabenleser fuer standardisierte Buchstaben

1,209,361. Character recognition. INTERNATIONAL BUSINESS MACHINES CORP. 26 Feb., 1968 [28 Feb., 1967], No. 9109/68. Heading G4R. _ Character recognition apparatus performs a main scanning cycle, comprising a recognition scan of one character interleaved in time with a registration scan of another, data from the registration scan controlling a subsequent main scanning cycle. Vertical and horizontal deflection voltages for flying-spot scanner 22, 24 are supplied by respective integrators 52, 54. The scanner beam is positioned at the right hand end of a line of characters, then the beam executes a curlicue pattern progressing horizontally leftwards until the first character (2 in Fig. 3) is encountered when the flip-flops 64, 66 are reset to release resettable amplifiers 30, 28 to follow the deflection voltages (minus the curlicue, filtered off at 70, 68) which they do as if the voltages were zero when release occurred, i.e. they specify the subsequent changes. The curlicue follows round the outline of the character, positive movements of the vertical and horizontal amplifiers 30, 28 being followed and held by track-holds 144, 104 respectively. After the character has been followed round once, the track-holds 144, 104 hold voltages representing the top and right edges of the character respectively, these voltages being applied via switches 148, 102 to vertical and horizontal potential dividers 94, 92, tapped voltages from which are applied to a normalization matrix 32 as in Specification 1,013,036 to specify a matrix subdivision of the character. The scanner now performs the path consisting of straight line segments 1-13 shown in Fig. 3 under control of gating logic 72, for recognition of the first character and registration of the second, the points at which to change from one segment to the next being indicated by comparison of the vertical and horizontal deflection voltages (from amplifiers 30, 28) with voltages tapped from the voltage dividers 94, 92. The comparisons are done by voltage discriminators 82-91 (Fig. 2A, left) except where otherwise stated. When during scan segment 2, the beam reaches the centre of the first character, discriminator 108 (Fig. 2B) produces a start-of-vertical-scan signal from OR 112. This signal resets the horizontal amplifier 28 to ground, locks the horizontal centre in voltage divider 92 to ground via switch 114, sets flip-flop 168 (Fig. 2A) and resets flipflop 178. When the character is encountered in scan segment 3, thresh