| 摘要 |
<P>PROBLEM TO BE SOLVED: To correct a magnification ratio of a primary scanning direction without using a large number of optical detection parts. <P>SOLUTION: An apparatus includes: an optical detection part 140S1 for detecting a light beam at one end in a primary direction; a storage part 160 for pre-correlating a detection interval (scanning time in the primary scanning direction) of a light beam between two points including a primary scanning range of an image carrier on each face of a rotating polygon mirror with a detection interval (one-end scanning time) of a light beam at one point nearby the primary scanning range, and storing the correlation result: a measurement part 150 for measuring the detection interval (one-end scanning time) of a light beam on each face of the rotating polygon mirror detected at the optical detection part; a reflection surface specification part 170 for specifying a correspondence of scanning direction scanning time on each face of the rotating polygon mirror on the basis of a correlation, for each of the rotating polygon mirror, between the stored one-end scanning time and measured one-end scanning time; and a correction part 180 for correcting a positional interval of exposure dots of image data for each face of the rotating polygon mirror by using the specified scanning direction scanning time for each face. <P>COPYRIGHT: (C)2012,JPO&INPIT |
