Light beam scanning, image forming apparatus, and method of adjusting the image forming apparatus

摘要

A light beam is made to scan and expose a photosensitive drum in the main scanning direction and the passing position of the light beam in the sub-scanning direction is sensed. On the basis of the result of the sensing, the light beam is shifted in the sub-scanning direction when the beam is made to scan by a scanner so that the passing position may come in a target range, which brings the passing position to the proper position. After the position control, the passing position of the light beam is confirmed and controlled so that the passing position may fall on the proper position a specific number of times consecutively. When the light beam is shifted in the sub-scanning direction, the passing position of the light beam is brought into a final target range in such a manner that the target range is forced to converge stepwise in a first range and then in a second range narrower than the first range.