Patent GB-845548-A (GB)
Title: Apparatus for interpreting intelligence patterns
IPC: G06V10/44
Filed: 1956-10-19
Abstract: 845,548. Character recognition. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 19,1956 [Oct. 20, 1955], No. 31860/56. Class 106 (1). The numerals or characters of an intelligence pattern are interpreted by sensing means detecting the presence of intersections and bounded regions in each of the entities and differentiating by the types of intersections and bounded regions therein. The scanning device need not be light and the representations may be magnetic, sonic, chemical or electrostatic. The recognition of numerals is described, using the detection of triple intersections by a central vertical line, upper and lower inlets to left and right, long vertical and black lines and the presence of lakes (Fig. 13, not shown). The area containing the numeral is scanned by a light spot bit by bit in vertical sweeps giving black or white (1, 0) responses, and a memory device stores the respective signals allowing coded signal representations of the combinations to be recorded and interpreted as the presence or absence of the various characteristics of the numerals. The provision of a Shape Rules Circuit and a memory trigger storage enables a decoder of Christmas tree shape to detect the numeral being scanned and operate the appropriate punch or output. The Shape Rules circuit modifies the coded numbers in a marking register and the shape memory triggers are turned on or the contents of the marking register modified by the logical coincidence of certain events involving the presence of white or black, the contents of the register and the state of the temporary triggers. The flow diagram, Fig. 1, shows scan, control and recognition circuits. The light spot from C.R.T. scanner 70 is reflected by the symbols on a document 74 to give a signal at photo-tubes 76 which is fed to a Black-White circuit 80 comprising anplifiers and limiters giving black and white signals at leads B, B, respectively. The line scanning is vertically upwards in thirty-two steps, only sixteen of which are used for recognition purposes, and the beam is unblanked for only a short period at each elemental area. The horizontal frame scan is from left to right and a complete absence of black in any vertical scan indicates end of character. The recognition circuits comprise shape rule circuit 96 and storage means comprising a marking register 97 and memory triggers 98, the latter storing the findings of circuits 96. The marking register has 16 storage positions, one for each area of vertical scan, each assigned an arbitrary coded number. White is coded -, black is coded 1, white following black horizontally is coded 2, black following a white coded 2 is coded 5, a white area between a lower black intercept and a middle black intercept is coded 3, and a white area between a middle black and an upper black is coded 4, Figs. 14 and 16. Coded 3 and 4 at the end of character indicate lower and upper right inlet respectively. Each coded number is fed from the shape rules circuit 96, via digit encode circuit 120 into the marking register 97. A series of coded 0's actuates the reset and endof-character circuit 132, the signal being fed to " O.K. to Punch " lead 136 and the decoder circuit 100. The character recognised proceeds to control the punch 102. The circuits of cathode followers, multi-grid switches, inverters, " And " and " 0 + " circuits, limiters, amplifiers, photo-multipliers, triggers, multivibrators, counters, peakers, core and relay drivers deflection units and core-shifting registers are described (Figs. 19-74, not shown). The document is carried on a standard electric typewriter which is stationary for a period of 32 vertical sweeps before spacing in the usual way, although in a modification the light spot sweeps vertically over a continuously-moving document. The travel of the carriage is reset by closing contacts in a relay circuit, the register counters being neutralized during this period. Only photo-multiplier signals of a certain magnitude are passed by a limiter circuit to the video circuits..The action and timing of the control circuits, i.e. marking register, reset and black white determination are described in detail in the Specification. The marking register (Fig. 30, not shown) comprises three sixteen-position shift registers made up of magnetic cores which store binary information, and each position is coded 1 or #1 so as to determine in the decoding circuits which of the coded 0-5 is appropriate for feeding to the programme rules circuit (Figs. 3F, 3G, 3H, not shown). Rule 1 circuit comprises an " OR " circuit 514 fed by a coded 0, 3 or 4 and an " AND " circuit 516 receiving the black lead B from Black White cable 388 and the output of the " OR " circuit, so that a coded 1 is fed back to the Encode circuit and the marking register, if a black signal follows a coded 0, 3 or 4. Rule 3 uses an " AND " circuit 518 to detect a white B following a coded 1 and feeds a coded 2 to the marking register. Rules 4-8 detect triple intersection, i.e. a black-whiteblack-white-black sequence, which is at least two bits wide. Primer trigger P 0  is " On " for the first black and Primer trigger P 1  is " on " if trigger P 0  is " on " and a white area is sensed. Similarly triggers P 2 , P 3  and P 4  go " On " for subsequent black and white sensings, and finally a memory trigger M 0  is in the " On " condition. Rule 9 detects the lower left inlet basic shape, requiring detection of triple intersection (M 0  is ON), and a coded 0 present in the lower of the two white areas. Connected to the input of the " AND " circuit of memory trigger M 1  are M 0 , P 0  in " On position (indicating passing of first black intercept), #P 2  in OFF position (second black not reached), an " in 0 " from Rule circuit input cable 460 and a fifth input lead #P 5  which determines that the presence of the lower inlet is detected after the detection of the triple intersection. Similarly the other memory triggers react to Rule circuits which indicate upper left inlet, lower and upper right inlet, lake basic shape, long vertical black line and the small left inlet, respectively. Other Rule circuits are utilized for the process of expanding and preventing imperfections in the numeral characters giving wrong indications, as, for example, serifs and other lines in the figures 7 and 2. As shown in Fig. 3I, the connections " M 0  "-" M 7  " from the memory triggers feed through relay drivers 574-581 to relays R 0 - R 7  controlling switches in the Christmas Tree Shape Decoder which determine which character is sensed, the O.K. to Punch signal on line 318 energizing the slow relay R 10  and line 414 to punch or print the character recognized.