MULTIPLE SPEED LINE PRINTER

摘要

The control system for a line printer includes compensation circuit means for electronically changing the timing of the reference or home pulse to compensate for changes in the speed of the type characters on a continuous type carrier. The compensation circuit includes a storage register, a counter and a comparison circuit for comparing the content of the storage register and the counter. The counter when activated by a reference pulse generated from a reference mark on the moving type carrier counts subscan pulses generated from timing marks moving with the type characters. The storage register, which is programmable, stores different numeric values dependent on the speed of the type carrier representing different numbers of subscan pulses to be counted by the counter means. The comparator circuit compares the numeric value in the register with the count registered in the counting means. When an equality is detected, the comparator circuit generates a modified reference or sync pulse which is applied to sync control circuitry which checks the character signal produced by the type position circuitry of the printer controls.