| 摘要 |
PURPOSE:To form a high-definition latent image, to facilitate the optimized design of an image-formation lens system, and to facilitate the adjustment of the lens system in an optical unit for an electrophotographic printing device using plural beams. CONSTITUTION:The respective laser beams 5 and 6 emitted from lasers 1 and 2 are made incident on a scanner 9 so that the difference of an incident angle viewed from the rotary shaft direction of the scanner 9 may be within 5 degrees. Only one scanning laser beam 13 is made incident on a beam detector 12, and writing 17 and 18 by the 1st and the 2nd scanning laser beams 13 and 14 is performed by an independent modulator with an output signal from the detector 12 as a trigger. |
