LASER BEAM SCANNING OPTICAL DEVICE

摘要

PURPOSE: To provide a laser scanning optical device capable of detecting the deviation in the imaging positions of a laser beam from above a recording medium and correcting the imaging positions by simple constitution. CONSTITUTION: A member 6 having plural openings 9 and light shielding parts 10 in a scanning direction is arranged at an angleθwith a surface 11 which is optically equiv. to the surface to be scanned of the photoreceptor. Further, a photodiode 7 is arranged in parallel with the surface 11 in such a manner that the light transmitted through the openings 9 is detected. The laser beam is scanned in order of (a) to (h). The transmitted light quantity is maximized in the position where the spot diameter is min., by which the imaging positions of the laser beam are judged from the output value of the photodiode 7 and the time.