Patent GB-711498-A (GB)
Title: Apparatus for synthesizing facsimile signals from coded signals
IPC: H04L21/00
Filed: 1951-07-30
Abstract: 711,498. Facsimile telegraphy. EASTMAN KODAK CO. July 30, 1951 [July 29, 1950], No. 17954/51. Class 40 (3) An arrangement for producing a recorded character corresponding to its coded representation comprises means for transforming the coded signal into a single signal at a terminal corresponding to the character, the single signal being utilized to apply priming action simultaneously to a number of devices arranged in columns and rows and the columns of devices being sequentially subjected to further biasing action so that selected devices in the columns are operated to control recording members to produce the selected character. The character may be represented by a six-unit binary code and the arrangement includes a circuit for deriving a single signal from a coded representation. The single signal derived from the converter 18 and appropriate to the six-unit signal on a tape applies a negative voltage to selected members of the double triodes 10 arranged in seven columns. The double triodes are normally conducting and are cut off solely when negative pulses are applied to both grids. A sequence switching arrangement comprising seven double triodes 20 each connected and operating as a self-restoring trigger circuit, is initiated into action by a negative impulse applied over connection 120 from the converter 18. Negative pulses are applied simultaneously to the valves 10 in a column and to the columns in sequence. The valves 10 rendered operative in a column operate associated circuits 111 each comprising a doubletriode valve 11 of which the right-hand side is non-conducting so that a power valve W conducts and energizes coil W1. A negative pulse is inverted and makes the right-hand side conducting and the left-hand side non-conducting so that the valve B conducts and coil B1 is energized to operate the printing stylus 13, the recording type being fed so that the successive columnar portions are recorded. The arrangement described produces 35 elemental areas formed by 7 columns and 5 rows. The circuit, Fig. 2, for converting the six-unit code represented by perforations in a tape 30 to a single impulse at a terminal allotted to a character comprises feelers 17 co-operating with an electrode 32 at a negative potential. Normally the left-hand sides of the flip-flop tubes 33 are conducting and the negative pulse from each feeler 17 engaging a perforation renders the left-hand side of one or more of the valves 33 non-conducting so that a positive pulse is applied to the right-hand grids and via condenser 35 to the right-hand section of one or more devices 34. A triode 36 is made conducting and applies a negative pulse via conductor 120 to the first of the valves 20 controlling the sequential switching of the columns of valves 10. High resistances 39 are connected to the right-hand anode circuits of the valves 33 except for the valves 33 which are triggered by the operated feeler or feelers, and since, for example, in the case of the numeral " 2 the feeler 17 transfers current from the left-hand side to the right-hand side of the double triode located fourth from the left, the valve 38 corresponding to the figure "2" becomes conducting so that a negative impulse is produced at the output of this valve at the terminal allocated to the figure "2." When the final valve 20 of the sequence circuit is restored a negative impulse is applied to a normally conducting valve 41 which cuts off and a negative impulse at its cathode is applied through the right-hand sections of the double diodes 34 to the grids of the right-hand sides of the flipflop triodes 33 which are restored to their normal condition. Modified arrangements.-An arrangement for recording solely digits comprises ten feelers and applies the negative pulse directly to the matrix of valves 10, Fig. 1, without the use of the decoder, Fig. 2. A further modification, Fig. 5 (not shown), for producing printed addresses from perforated business cards simultaneously senses a number of sets of six-unit binary code perforations, and by employing a corresponding number of decoders and valve matrices effects the simultaneous printing of a number of lines on the address or like label. Specification 711,497 is referred to.