Patent ID: 6646668
Filing Date: 2003-11-11
Classification: G03G,H04N

Abstract:
An image forming apparatus comprising:a light beam generator configured to generate light beams; a scanner configured to reflect the light beams generated by the light beam generator toward a scanned surface and to scan the light beams on the scanned surface; a first light beam detector configured to detect the light beams which are scanning on the scanned surface by the scanner; an image forming area definer configured to define image forming starting and finishing points, respectively, in accordance with an output of the first light beam detector, so as to define an image forming area; a second light beam detector provided at a later stage of the first light beam detector in a scanning direction, and configured to detect the light beams which are scanned on the scanned surface within the image forming area which is defined by the image forming area definer; a third light beam detector including a plurality of pairs of sensor patterns provided on the scanning direction of the light beams, each of the pairs of sensor patterns provided in a direction perpendicular to the scanning direction of the light beams, so as to detect inclination of the light beams; and a controller configured to detect information of a relationship between the image forming starting and finishing points defined by the image forming area definer and the second light beam detector in accordance with a set value for the image forming area definer and a response of the second light beam detector, and to detect information of the inclination of the light beams detected by the sensor patterns of each of the pairs of sensor patterns of the third light beam detector, so as to determine an image forming area when an image is formed in accordance with the information of the relationship between the starting and finishing points and the information of the inclination of the light beams.