Image forming apparatus having a plurality of image-forming modes and method of controlling the apparatus

摘要

When the image-forming modes are switched over, the difference between the scan speeds of image-forming modes before and after the mode switching is checked. If the difference is not less than a predetermined set value, the adjustment of a laser beam is executed first, and then image formation is started. If the difference between the scan speeds of image-forming modes before and after the mode switching is less than the predetermined set value, the image formation is started immediately without making adjustment of the laser beam.