Abstract: This specification discloses apparatus and a process for printing data on a web of print from data related to a wider web than that to be printed upon. It includes a printer having a paper output of a narrower web than data from the wider web, and the provision of data as to the narrow and wide web width. The apparatus and process establishes the difference between the narrow web width of the printer and the wide web width and calculates the number of pages of narrow web width to be printed thereafter forming a raster output from the difference between the narrow web width and the wide web width to establish the width for printing by the printer.

Abstract: In a printer in which an elongated shuttle is driven in reciprocating fashion across a print paper with hammers mounted along the length of the shuttle being selectively fired to print dots on the paper, a timing system provides hammer fire pulses denoting the positions of the shuttle at which hammer firing should be initiated to print in the proper dot positions. Proper timing is maintained so as to allow for printing during acceleration and deceleration as well as during constant velocity movement of the shuttle by determining the average shuttle velocity between each successive pair of fence post pulses generated by a shuttle-coupled encoder. The average velocities are represented by the time lapses between occurrence of the pairs of fence post pulses which are measured and stored during each startup of the printer as well as each time the nominal operating shuttle velocity is changed as part of a change in printer operation.

Abstract: A ribbon fault detection system within an impact printer has a pair of resilient electrical contacts disposed in spaced-apart relation across the width of an ink ribbon within each of a pair of ribbon guides located between the opposite ends of a print station and a pair of spools for receiving the opposite ends of the ink ribbon and driving the ink ribbon. Each of the electrical contacts which is silicone coated to minimize ink migration and which is normally held out of engagement with a mating contact due to engagement by the ribbon is coupled in parallel with the other resilient electrical contacts so that closure of any one of the resilient electrical contacts onto its mating contact will generate an indication of a ribbon fault condition.