DETECTING METHOD OF LIGHT SPOT INTERVAL, SETTING METHOD OF SCANNING LINE PITCH, DETECTING DEVICE OF LIGHT SPOT INTERVAL, SETTING DEVICE OF SCANNING LINE PITCH AND MULTIBEAM SCANNING DEVICE

摘要

PROBLEM TO BE SOLVED: To detect an interval between two light spots obliquely arranged of a multibeam scanning device. ;SOLUTION: A single photodetector arranged out of a scanning area and having the length of a light receiving surface commonly detecting plural light spots in the direction orthogonal to scanning, a light receiving surface 64A is scanned by two light spots SP1, SP2 for detecting an interval at a prescribed scanning speed: v, a rectangular-shaped signal is obtained based on the output of the photodetector, the detecting process of the time interval: (t) of rectangular-shaped signals corresponding to the respective light spots is repeated while rotating the arranging direction of light spots SP1, SP2 by rotating a light source part, the maximum value t_max of the time interval: t of the signals is obtained and the interval of light spots is obtained as v.t_max from the value and the scanning speed (v).;COPYRIGHT: (C)1998,JPO