| 摘要 |
A threshold for detecting a position of a lateral edge of a sheet is more accurately determined, whereby the accuracy of detection of the lateral edge position of the sheet is improved. A line sensor includes a plurality of element blocks. Each element block includes a plurality of pixels. The threshold for detecting the lateral edge position is determined based on a light level and a dark level of signals output from an element block that is actually used to detect the lateral edge position of the sheet. |
