Magnification Controlling System Used In An Image Forming Apparatus

摘要

A magnification controlling system used in an image forming apparatus has a sensor module for reading a first image and a second image form a document conveyed in a predetermined speed. The first and second images are converted into a base and a reference image by an A/D converter. A processor calculates the shifting offset between the base image and the reference image to produce a reference speed. The processor calculates the predetermined and reference speed to produce a control signal and then sends the control signal to a pulse producing circuit. The pulse producing circuit provides plurality of pulse signals in a predetermined time according to the control signal. The pulse producing circuit sends the pulse signals to a step motor or an image forming module in the image forming apparatus for controlling document conveying speed of the step motor or scanning speed of the image forming module.