Scanning system for registering and reading characters

1,028,881. Automatic character reading. NATIONAL CASH REGISTER CO. Jan. 9 1964 [Feb. 8, 1963], No. 1032/64. Heading G4R. In a character recognition apparatus the character is scanned by first scanning devices along one or more parallel paths to obtain signals from which it is recognized and there are also a plurality of second sensing devices scanning the character on a number of parallel paths providing signals which pass to registration circuitry providing a registration signal which is used to connect one or more of the first scanning devices to the recognition circuitry. The characters are specially shaped so as to have parts lying in five vertical strips and recognition is made on signals representing the disposition of parts in the upper and lower halves of the character. The characters are arranged in rows of eleven across a tape, Fig. 2 (not shown), characters being sometimes misaligned, defective and badly spaced. The tape is fed through the scanner, Fig. 3 (not shown), which has a curved guide 41 with a slot 54 through which a row of characters is exposed. The exposed part of the tape is illuminated by lamps 42 and the image reflected by rotating mirror 43, through lens 44 and half-silvered mirror 46 to photo-cell units 47, 47 . Each unit has two lines of apertures and the arrangement is such that relative to the projected image the lines of apertures interlace as shown, Fig. 6 (not shown). Each aperture is connected by way of a light guide to a photo-cell. The register apertures a0-a15 sense the character first and a signal is derived which is used to select those two of the reading apertures r1-r17 which scan through the upper and lower halves of the character. The outputs of all the photo-cells are amplified in amplifiers the sensitivity of which is controlled to compensate for brightness of background by a background signal derived through sensing aperture Sel. Mounted on the guide 41 is a white strip 56 which is sensed by aperture h1 and below this is a row of clock marks 55 sensed by aperture c1 The signals A0-A15 from the registration cells, after amplification are applied to set corresponding flip-flops C0-C15, Fig. 7 (not shown), and the outputs are gated to produce a marking on one of twelve leads St1-St12. This signal is converted to a combination of markings on one of four leads and stored on four flip-flops D1-D4. The signal is reconverted to a marking on one of twelve leads and applied to relay circuit 89 which produces correspondin