| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To generate an evaluation chart for detecting shifting in a main scanning direction in an interlaced VCSEL optical system. <P>SOLUTION: An image forming device generates an evaluation chart for detecting shifting in a main scanning direction of multibeam, on the basis of a pattern of parallel exposure group by luminous points (CH4 and CH5) at both ends in the main scanning direction and a pattern of parallel exposure group by luminous points (CH24 and CH25) in a central part in the main scanning direction. When a time interval for lighting between the CH4 and the CH5 is incorrect, a shifting quantity of CH4 and CH5 becomes large; however, in the case of CH24 and CH25, since distance in the main scanning direction is shorter than in the case of CH4 and CH5, the shifting quantity is small even if the time interval is incorrect. The device detects each shifting quantity in the main scanning direction at each exposure position as a density difference, and adjusts the time interval. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
