Patent ID: 6603116
Filing Date: 2003-08-05
Classification: H04N

Abstract:
An image forming apparatus, comprising:a light source including a plurality of light emitting elements arranged in line for simultaneously emitting a plurality of parallel light beams, said light source arranged with an angle smaller than 90Â° relative to a sub-scanning direction of said plurality of parallel light beams; a light beam controlling mechanism configured to control said plurality of parallel light beams to simultaneously scan a plurality of lines on a surface of a photoconductive member in a main scanning direction; a sensor configured to detect one of said plurality of parallel light beams and to generate a line synchronous signal upon detecting the one of said plurality of parallel light beams; and a signal controller configured to synchronize and to modulate a plurality of parallel image data streams that respectively drive said plurality of light emitting elements of said light source to emit said plurality of parallel light beams in accordance with said plurality of parallel image data streams; wherein said signal controller comprises: a plurality of FIFOs configured to delay said plurality of parallel image data streams, respectively; a PLL circuit configured to generate a PLL clock signal having an integral multiple frequency of a pixel clock signal; a frequency divider configured to divide said PLL clock signal into a plurality of clock signals having a same frequency and having phases sequentially varied; a synchronous clock generator configured to select one of said plurality of clock signals having the same frequency and having the phases sequentially varied; and a plurality of drivers configured to drive said plurality of light emitting elements, respectively, with said one of said plurality of clock signals selected by said synchronous clock generator.