GB1022517A - Specimen identification - Google Patents

Abstract

1,022,517. Character recognition. INTERNATIONAL BUSINESS MACHINES CORPORATION. Nov. 30, 1964 [Dec. 13, 1963], No. 48517/64. Addition to 982,989. Heading G4R. The OR-autocorrelation function or a function thereof of a character to be recognized is derived and compared with that of reference characters to identify the unknown character. The OR-autocorrelation function represents the searching of vectors of pre-determined length and direction on the character in which the tail of the vector is located on a single point and the head may be one of a group of points. The character is scanned vertically by a flying-spot scanner 22 (Fig. 2, not shown) and the results recorded in a shift register 40 under control of clock pulses wherein a central index position representing the tail of a vector is gated at A51-A56 with groups of points selected by OR-gates OR41-OR46 to produce output pulses representative of the OR-autocorrelation function. In a preferred embodiment the outputs from selected AND-gates are combined through weighted resistors and integrators to produce the second difference function which is passed through ternary converters to give a Π1 or 0 output according to the positive, negative or zero value of the second difference function. The ternary outputs are amplified to produce positive and negative signals on two lines each, which are applied to appropriate character lines whereby the line having the highest signal identifies the character.