METHOD AND APPARATUS FOR PROCESS MAGNIFICATION ADJUSTMENT

A magnification adjustment method for a document processing system having a fixed frequency clock source providing a fixed frequency output signal to a plurality of raster output scanners (ROSs) and a numerically controlled oscillator (NCO)-based adjustable frequency clock source providing an adjustable frequency output signal to the ROSs is disclosed. The method includes: using a controller to determine a frequency setting for a phase increment control input signal to the adjustable frequency clock source; starting the document processing system; using the controller to set a phase accumulator control input to the frequency setting; sending a message to a ROS control module prior to imaging, including the correct clock source to use for the next image, the correct clock source being either the fixed frequency clock source or the adjustable frequency clock source; and applying the correct clock source synchronously to the beginning of an inter image panel zone.