摘要 |
<p>A laser beam printer which detects the position of a laser beam in order to scan a photosensitive member. The laser beam is detected at a predetermined position, wherein the laser beam is detected at a time during which a rotating polygon mirror is rotating at a speed less than a predetermined speed. Laser beam detection signals are then output. A timing of the output of the detection signals is predicted, wherein the detection signals are not output at a constant interval because the rotating polygon mirror is rotating at a speed less than the predetermined speed. A signal to turn on the laser beam is generated based on the predicted timing. In another aspect, a line for the detection signals is completed or broken at a timing based on an output interval of the detection signals. <IMAGE></p> |