Patent ID: 7136085

Claim:
An image-forming apparatus, comprising: at least one imaging optical system configured to form an electrostatic latent image on an evenly charged scanning surface of a medium to be scanned moving in a sub scanning direction by scanning the scanning surface in a main scanning direction perpendicular to the sub scanning direction by periodically deflecting a laser beam emitted from a laser light source with a rotary deflector; a pixel clock generation part configured to generate a pixel clock signal for controlling timing of emission of the laser beam by the laser light source and change a phase of the pixel clock signal; a region setting part configured to set length of each of a plurality of regions in the main scanning direction based on image writing magnifications in a line in the main scanning direction, the regions being formed by dividing part of the scanning surface corresponding to the line in the main scanning direction; and a phase control part configured to control the changing of the phase of the pixel clock signal region by region based on the image writing magnifications, wherein the formed image is transferred to a transfer medium and output.