| 摘要 |
PROBLEM TO BE SOLVED: To enable detection of a lateral end position of a recording material even if the carrying speed of the recording material is quick and the size of the recording material is small.SOLUTION: Detection processing of a lateral end position includes: a light amount adjustment of a light-emitting element; a process to decide the threshold value for detection of the lateral end position; and a process to read the lateral end position. If a sensor is provided between a transfer roller pair and a registration roller pair as in a prior art, sufficient processing time cannot be secured. Therefore, not only a sensor between a registration front roller pair and a registration roller pair is provided, but also light amount adjustments is performed (S606, S607) before the registration roller pair stopping for skewing correction is driven. Moreover, the processes to decide the threshold value and to read the lateral end position are performed (S608-S611) after driving the registration roller pair is resumed. Like this, by performing a part of the process related to the detection process of the lateral end position ahead of schedule, the carrying speed of a recording material becomes fast and the lateral end position of the recording material becomes detectable even if the size of the recording material becomes small. |
