| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of outputting an image pattern for evaluation so as to detect the fine change of a beam pitch in the subscanning direction of a light beam, and an evaluation chart. <P>SOLUTION: In a copying machine 1, when outputting the image pattern for evaluation, a first beam and a second beam are not continuously emitted from a first light source and a second light source respectively but discontinuously emitted for a predetermined pulse light emitting time shorter than one-dot pulse light emitting time, whereby the synthetic latent image by the first light beam and the second light beam adjacent to each other in the subscanning direction are restrained from being formed, and the deviation of the pitch P between the first light beam and the second light beam is set so that a large density difference or a visual gradation difference between image patterns 22 for evaluation can be provided. <P>COPYRIGHT: (C)2007,JPO&INPIT |
