Patent ID: 7446793

Claim:
A scanning and exposing device which exposes photosensitive drums to plural laser beams by scanning each photosensitive drum with a respective laser beam, comprising: plural laser light sources for emitting laser beams; a main scanning direction synchronizing unit configured to output a synchronous signal of each scan in the main scanning direction; a polarizing unit configured to polarize and sweep the laser beams emitting from the plural laser light sources; plural optical elements configured to reflect the laser beams polarized and swept by the polarizing unit and guide the laser beams onto respective photosensitive drums; a light amount correcting unit configured to correct the light amounts of the laser beams emitted from the plural laser light sources in accordance with the synchronous signal from the main scanning direction synchronizing unit; a light amount correction value storage unit configured to make same the correction value sets for correcting the light amounts of the laser beams to be corrected by the light amount correcting unit, and store correction value sets whose number is smaller than the number of the laser light sources, wherein the light amount correction value storage unit makes same at least two correction value sets of the light amounts of laser beams emitted from the plural laser light sources.