| 摘要 |
A length L of the test pattern string (210) is determined so as to satisfy a condition L‰¤{P-(Q 1 +Q 2 )}×V, where a time Q is a total time of a time Q 1 for which the test pattern string (210) is transferred from an exposure position of the test pattern string to a sensor (115a, 115b, 115c) and a time Q 2 from when the test pattern string (210) is detected by the sensor (115a, 115b, 115c) until a color misregistration correction value calculated on the basis of a result of detecting is reflected in image formation; a time P is a time from a timing of starting to write the test pattern string to a timing of starting to write an image in which the correction value should be reflected; and a driving speed of a second image carrier (114) is V. |
