GB1345805A - Control system for high-speed printing machines - Google Patents

Abstract

1345805 Printers HONEYWELL INFORMATION SYSTEMS ITALIA SpA 11 Nov 1971 [11 Nov 1970] 52447/71 Heading G4H In an on-the-fly printer, a count representing actual type carrier position is compared with a required character code from a store, the comparison operation being modified according to the frequency of occurrence of the relevant character on the carrier. In a chain printer, with the type chain running along the print line, the codes representing the required characters are modified (using an arithmetic unit) according to their positions in the print line, and stored. At each time at which some characters can be printed (the hammer or &c. spacing differs from the type spacing on the chain), all the stored codes are read out and compared in turn with the count, equality causing a print pulse which is gated to the appropriate hammer or &c. under control of further counters. The stored codes each contain, or are accompanied by, one or more bits specifying the frequency of occurrence of the respective character on the type chain, which disable part of the comparator to cause part of the comparands to be ignored, or modify part of one or both comparands by logic, so that the first occurrence on the type chain of the required character will be used. These bits may come from the first-mentioned counter instead. A further alternative is to also vary the effect on the comparands in accordance with signals from a sensor on the type-carrier, or manual input, specifying the frequency pattern which can be changed. The stored code of a printed character is deleted to prevent repeated printing. The print pulses are counted, together with decoded "space" commands, to cause advance to the next line when the line has been printed. The invention is also applied to drum and paper tape printers, the character codes not requiring modification according to position in the print line in these cases.