Patent attributes
An image forming apparatus according to the present invention irradiates a polygon mirror with laser beams from different directions, allows the polygon mirror to reflect the laser beams toward different optical axis directions to perform main scanning operation for the laser beams at a predetermined deflection angle. First and second beam detectors are disposed at the beam incident ends in the scanning direction of first and second light scanning sections to detect the start of light beam scanning operation such that the second beam detector detects it at an earlier timing than the first beam detector does. The detection result of the first beam detector is used to set sampling start timing in common between first and second image data. Based on the detection results of the first and second beam detectors, first and second image data are written into a memory, and the first and second laser source sections are controlled based on the image data read out from the memory.
