Patent ID: 8164611

Claim:
An image forming apparatus comprising: a light source that emits a plurality of laser beams; a first beam splitter that splits each of the laser beams into a first beam for measuring an intensity of the laser beam and a second beam for scanning a photosensitive element to form an image based on image data; a deflecting unit that deflects a direction of the second beam using a multifaceted reflecting mirror provided in a multi-stage with a common rotating axis; a second beam splitter that splits the second beam into a plurality of split beams so that each of the split beams is incident on a reflecting surface of the deflecting unit in each stage; a first photoelectric converting unit that measures an intensity of the first beam and outputs a first voltage corresponding to measured intensity of the first beam; a second photoelectric converting unit that measures an intensity of each of the split beams and outputs a second voltage corresponding to measured intensity of each of the split beams; and a control unit that updates, for each of the split beams, a driving-current correction value for correcting a driving current commonly set to for laser beams to be emitted from the light source in advance based on the first voltage and the second voltage, corrects the driving current using updated driving-current correction value, and controls intensities of the laser beams based on corrected driving current.