Patent GB-865779-A (GB)
Title: Improvements relating to electrically controlled multiple character printers
Inventor: FROGGATT ROBERT JUSTIN
IPC: B41J2/39
Filed: 1956-07-21
Abstract: 865,779. Facsimile printers; electric distributers. ELECTRIC & MUSICAL INDUSTRIES Ltd. July 15, 1957 [July 21, 1956], No. 22651/56. Class 40(3) [Also in Group XVI] An electrically-controlled multiple-character printer comprises a plurality of styli which simultaneously receive transverse movement relative to a medium on which characters are to be printed, a storage device for storing signals representing characters to be printed, decoding means to which the signals are applied in a repetitive cycle and from which energizing signals are applied selectively to the styli, the cycle time of the decoding means being short compared with the time taken for a stylus to scan the area allocated for the printing of a character, or that for a number of styli to scan the area allocated to a line of characters, so that the signals representing a character to be printed are applied to the decoding means a plurality of times during the reproduction of a character or line of characters. The characters in a line assumed to be one hundred and forty, are reproduced by the same number of stylus members operated over fourteen channels, each controlling ten stylus members to produce dots on the recording sheet. The characters represented by pulse combinations in a 6-unit code are fed at input 2 to a gate 1 having fourteen output channels a1 ... a14 leading to circulating registers 4, 5 . . . individually connected to character staticisers 6, 7 . . . which pass the pulses of the 6-unit code to an associated decoding tree or matrix 18, which may be similar to that described in U.S.A. Specification 2,682,814, passing an output over one of forty-eight connections, allocated to the characters or symbols used, to an associated gate Gl of forty-eight similar gates. A character drum 16 carries forty-eight rings of studs arranged according to the dots required for the printing of the corresponding character. The arrangement is such that ten characters are staticised during the rotation of the drum through one degree so that output pulses pass selectively through the gates G1 corresponding to the ten characters, and by means of a counter 17, producing a series of ten pulses, the gates G2 are sequentially opened for the characters in which dots are to be printed so that trigger circuits 12 . . . 14 are selectively energized. At the end of the cycle of counter 17, a resetting pulse is applied over conductor 19, and the circuits 12 . . . 14 which have been energized pass pulses via elements E to the monostable triggers 20 which operate the stylus magnets. This operation is repeated 360 times during the revolution of the drum 16. The alternative arrangement shown in Fig. 4c employs a storing and repeating register arrangement, Fig. 4a, comprising a rectangular array of magnetic cores, in conjunction with a distributer arrangement, Fig. 4b, comprising series connected static magnetic cores and transistors. Distributer arrangement, Fig. 4b. The distributer comprising magnetic cores 36, 38, 40 . . . arranged in series, in a closed ring, with transistor amplifiers 37, 39 . . . is operated by clock pulses Ta, Tc derived from the binary-coded character generator, and at the commencement of the printing of a line of characters a double-strength pulse CLL is applied to the core 36 which is released to be operated by a pulse Ta and as an inhibiting control to the other cores 38, 40 . . . of the ring. On the occurrence of the next Ta pulse, the core 36 passes a pulse to the amplifier 37 producing an output pulse f1a and a full strength pulse to change the core 38 from its inhibited condition for operation by the next pulse Tc. At the end of the cycle, the final amplifier provides a pulse of f6c and a pulse for the core 36 which operates to initiate the next cycle of the distributer. For the commencement of a new printing cycle, a pulse CLL primes the core 36 for operation by the next Ta pulse and applies a temporary inhibition to the remaining cores 38, 40 . . . . Storing and repeating arrangement. The 6-unit code combinations of pulses are applied simultaneously as half-strength pulses through leads 21<SP>1</SP> . . . 21<SP>6</SP> to cores 22<SP>1</SP> . . . 22<SP>6</SP> which also receive half strength pulses from gating circuit 31 at intervals denoted by the outputs f 1c, f 2c . . . f 6c from the distributer so that "1" pulses produce full strength pulses from amplifiers 24<SP>1</SP> . . . 24<SP>6</SP> which pass as half strength pulses over corresponding leads 35 and as half strength pulses interlacing the cores 25<SP>1</SP> . . . 30<SP>1</SP>, 25<SP>2</SP> . . . 30<SP>2</SP> . . . 25<SP>6</SP> . . . 30<SP>6</SP> so that the pulses f 1c, f 2c . . . in conjunction with the half strength pulses pass full strength pulses via amplifiers 32<SP>1</SP> . . . 32<SP>6</SP> to the cores 22<SP>1</SP> . . . 22<SP>6</SP> so that during the second sequence of pulses f 1a . . . and f 1c . . . the code combinations are via amplifiers 24<SP>1</SP> . . . 24<SP>6</SP> stored, and half strength pulses are selectively applied to the lower members b1 . . . b6 of the twelve output leads 35. When a core 33<SP>1</SP> . . . 33<SP>6</SP> is not inhibited by a full strength pulse from the amplifier 32<SP>1</SP> . . . 32<SP>6</SP> a pulse f 1c . . . f 6c operates amplifiers 34<SP>1</SP> to 34<SP>6</SP> to produce half strength pulses selectively over the upper members a1 . . . a6 of the twelve output leads 35. The cores 33<SP>1</SP> . . . 33<SP>6</SP>, if not inhibited, are set to "0" by the previous f 1a . . . f6a pulses. Modified line printer, Fig. 4c. In this arrangement having thirteen stores such as that shown in Fig. 4a, the outputs on the leads 35 are applied to a decoding matrix 44 having six horizontal rows of forty-eight magnetic cores a, b . . ., a<SP>1</SP>, b<SP>1</SP> . . ., a<SP>11</SP>, b<SP>11</SP>. . . allocated to the fortyeight characters employed. A drum 45, having forty-eight commutator rings allocated to the characters and formed with conducting studs arranged to effect the printing of dots where required for the various characters during the cycles of the decoder, is provided with connections to the forty-eight columns of magnetic stores so that the selected cores in the sequentially conditioned columns pass pulses to the amplifiers 58 and stylus-operating arrangement 57 to actuate those styli devices Sl, S2 . . . which are required to print dots in the first cycle of the stores 41, 46 . . . In the ensuing cycles of the stores, dots are printed where required for the characters until the end of the printing cycle for a line of characters. At the end of a cycle of decoding the six originals applied to the matrix 44, the pulse f6c is amplified at 54 and applied to inhibit core 48 when the output pulse initiated by f6c is fed back from amplifiers 49, 50. The pulse from amplifier 54 is also fed to core 55 to remove the inhibited condition imposed by the pulse CLL so that the pulses f 1c . . . f6c can now be effective on the store 46 and the matrix 47. Similar operations are successively applied to the remaining stores, but the rate of decoding of the characters is so great relative to the rotational speed of the drum that the characters are effectively decoded simultaneously. Multiple printing arrangement. The dots are printed by stylus members 60 linked by members 61 to actuating devices 59 simultaneously operated to pass a carbon sheet against paper fed over a platen 63. The members 60 pass through a guide plate 64 actuated by a member 65 to make, for example, seventeen strokes during the operative printing cycle, and a further five strokes to provide spacing between the lines of print. The spacing of the consecutive printing strokes is effected by the feed of the paper over the platen 63.