Matrix print head repetition rate control

摘要

A matrix printer hammer repetition rate control is disclosed for varying the print hammer repetition rate in accordance with printing speed, thereby maintaining constant width of printed characters without dot column sensing. A master clock is counted over each character period to generate a digital code which, after conversion to an analog signal, serves as the control voltage for a voltage controlled oscillator. The VCO output is a variable clock from which the timing for various print heads is derived. Printing data is gated to the hammer drive circuits at a variable rate proportional to the speed of the printing heads across a printing medium.