VARIABLE FREQUENCY PIXEL CLOCK GENERATOR WITH PHASE LOCK LOOP
Original Publication Date: 1992-Aug-31
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
In general, laser printers employ a pixel clock signal to indicate pixel positions as the laser beam is scanned across a photoresponsive surface by a reflecting polygon. In laser printers which employ an end of scan (EOS) detector, for detecting the end of a raster of pixels, the pixel clock is typically phase locked to the polygon drive motor via an EOS detector in order to compensate for low frequency changes in the motor velocity. In addition, fast-scan magnification, along the raster output direction, is accomplished by varying the spacing or resolution of the pixels placed along a single raster. More specifically, the fast scan magnification is directly related to the pixel clock frequency, as the pixel clock determines the output of individual pixels along the raster.