IMAGE MAGNIFICATION AND DEMAGNIFICATION SYSTEM

摘要

An image size control system for controlling the size of the image produced by pixels generated by a raster scanner. A binary rate multiplier is used for image size control along the X-axis, the multiplier being programmed to the size image desired to vary the frequency of the pixel clock signals output by the multiplier. A control flip-flop astride the image pixel stream is driven by the multiplier clock signals to speed up or reduce the rate at which image pixels are output with consequent change in image size along the X-axis. For image size control along the Y-axis, a phase lock loop speed controller is provided for the scanning carriage drive motor with programmable frequency generator. The frequency output of the generator is settable to the image size desired, changes in image size being achieved either by increasing or decreasing the rate at which the scanning carriage is moved.