GB1038503A - A device for ascertaining the end of printing in a high-speed printing mechanism - Google Patents

Abstract

1,038,503. Electric selective signalling systems. OLYMPIA WERKE A.G. April 11, 1963 [May 24, 1962], No. 14555/63. Heading G4H. A high-speed printer receiving data from a store is characterized in that means are provided for producing an " end of print " signal when the store is empty. This feature permits a further print cycle to be initiated immediately the store is empty without waiting until the end of a fixed-length print cycle and eliminates " dead " time. As described the store is a matrix of cores or gas tubes and its condition is detected either by having a Hall generator (Fig. 7, not shown) in each core, the Hall generators being connected in parallel, or by having a single photo-cell 51, Fig. 5, which will detect if any tube is glowing. If print-hammers of the kind that have to be pre-tensioned are used before printing are employed these can be used to provide a signal when they have all returned to their normal positions. Thus in Figs. 3 and 4 those print hammers 61 or 612 corresponding to columns of the matrix storing data are displaced resulting either in the opening of a contact 515, Fig. 3, or the blocking of a light beam 67, Fig. 4, until all the hammers return to their normal position. In the printing system described data is read into the store under the control of a counter 11, Fig. 5, and is then read out by successive diagonals, under the control of clock pulses 40 produced by the moving type and a rotary switch 49. When the store is empty a pulse from the photo-cell 51 passes via a gate 50 to a control unit 14 and via a lead 27 to cause the next line of data to be read into the store. When the next line of data has been entered into the store a trigger 31 is turned on and when paper-feeding has completed a trigger 32 is turned. The next clock pulse 40 from the moving type then turns on a trigger 43 via a gate 35 to start the next print cycle.