Patent GB-943011-A (GB)
Title: Improvements relating to electrically controlled multiple character printers
Inventor: BROWN NORMAN
IPC: G06K15/10
Filed: 1959-04-07
Abstract: 943,011. Telegraphy. ELECTRIC & MUSICAL INDUSTRIES Ltd. April 7, 1961 [April 7, 1959], No. 11795/59. Heading H4P. A printing apparatus which forms a number of characters simultaneously comprises a plurality of styli which are moved back and forth over a recording medium and are controlled to produce marks on the medium, the printed characters being built up from these marks, and includes a first store for storing groups of signals, each group comprising the printing signals required to cause a stylus to print a particular character as the stylus is moved over the recording medium, means responsive to code signals representing characters to be printed for selecting corresponding printing signals in pre-arranged order from the first store, means for applying the selected signals to a second store, and means for deriving signals from the second store and for applying them to the stylus controlling means to cause the various styli to print the corresponding characters. The code signals representing characters to be printed are stored in a register 9 which will store 72 six-unit character signals at a time. Under the control of pulses from a clock 7, the stored six-unit signals are fed one at a time to a decoder 10 which passes a signal to the appropriate one of 64 gates 11. Each gate represents one character, e.g. " space," A, B, C, &c., and is opened by a pulse from unit 8 after each six-unit signal has been passed to the decoder. The gates feed to the 64 columns of a 72 row store 13 and also to 64 bi-stable circuits 16a, 17a, &c. which are set to their one state if the corresponding gate 11 has passed a signal to store 13. A counter 10a counts 72 pulses from unit 8 and permits read-in in succession to the 72 rows of store 13 of the signals from gates 11. Thus if, for example, the second and sixth characters in register 9 represent a " space " then the first column in store 13 will be set in a one state in its second and sixth rows. When all the six-unit signals have been decoded store 13 will contain 72 one states and counter 10a will have counted 72 pulses whereupon it sends a pulse over line 10b to unit 8 which then sends pulses over line 8b. The 64 units 16, 17, &c. have identical circuitry which is such that the pulses in line 8b are fed via unit 16 to the first column of a format store 12 if bi-stable circuit 16a is in a one state, i.e. if there is a " space " signal stored in register 9, but are fed to the following unit 17, if the circuit 16 is in its zero state. The signals stored in store 12 are the printing signals necessary for printing each of the 64 characters. The pulses fed to the units 16, 17, &c. are also fed to the columns " space," A, &c. of store 13, so that read-out of a column in store 13 occurs only if the lead 12a, connected to the store 13, also carries a signal, indicating the presence of a one state in the corresponding position in the format of the character under consideration. A final store 15 has 72 rows and 72 columns, the columns being connected to the read-out lines 14 of store 13. Thus, in the example cited above, space " format signals feed via lead 12a and store 13 to the second and sixth rows of store 15. A counter 23 in unit 16 counts the pulses passing therethrough and when 72 pulses have been counted, i.e. when all the format signals have been read out of the " space " column of store 12, gate 20 is closed so that pulses in line 8b pass via gates 18 and 21 to unit 17 but no more pulses pass to the " space " column of store 12. Read-out of the format of character A is now effected. This process continues for the formats of all the characters represented in register 9 and when the process is complete store 15 carries the formats of the characters in register 9, stored in the correct order. Read-out is effected column by column, the signals read out being used to control the 72 styli 3. Meanwhile, a signal is obtained from the final unit of the 64 units 16, 17, &c. which is passed via lead 8c to unit 8. On receipt of this signal, unit 8 rests all the bi-stable circuits 16a, 17a, &c. to their zero state in preparation for the inspection of a new set of 72 characters. The manner of clearing and replenishing register 9 is not detailed. In other embodiments of the invention more than one stylus is used for each character position. If a sufficiently large number of styli is used the scanning of a character position is performed merely by moving the record sheet past the styli. A matrix of styli may be used for each character so that no scanning is performed, the record sheet being moved between printing cycles. Printing is made by pressing an ink ribbon on to the recording medium or by xerography.