PRINT HAMMER LIMIT CONTROL

摘要

PRINT HAMMER LIMIT CONTROL A hammer limit control for an on-the-fly line printer comprises a counter which counts compare signals from a compare circuit which detects coincidences of print data and type position data in synchronism with the motion of an endless type carrier. The counter maintains a running count of the number of compare signals for a control interval having a duration which is a function of the printing interval of a print line cycle. A hammer on storage device stores a plurality of compare counts registered by the counter at the end of each of a plurality of control intervals. An adder adds the running count registered in the counter to the total count stored in the storage means and stores the total sum in a hammer on register. When the total sum in the hammer on register equals a maximum number, a limit comparator generates a control signal which inhibits further comparisons by the compare circuit. The content of the hammer on storage device is updated each control interval by transferring the compare count registered in the compare counter to the storage device and by deleting the oldest count in the hammer on storage after a predetermined number of control intervals. The maximum number is stored in a register which is programmable.