| 主权项 |
1. An image forming apparatus comprising:
plural recording elements that are arrayed along a crossing direction crossing a conveyance direction of a recording medium; a reading unit that sequentially reads an image formed on the recording medium for each line extending in the crossing direction along the conveyance direction by driving the recording elements while conveying the recording medium; a forming unit that drives the recording elements that are continuously arrayed along the crossing direction while conveying the recording medium, so as to form at least one reference image, having a length in the conveyance direction being set to a length in accordance with plural times of the readings by the reading unit, on the recording medium, and then makes timings for driving the recording elements continuously arrayed in the crossing direction different from each other with respect to the plural recording elements to be subjected to detection of an abnormal state thereof, so as to form detection images on the recording medium; and a detection unit that detects the recording element in the abnormal state by changing a size of at least one of a threshold value and a detected value based on the detection image read by the reading unit so that a rate at which it is determined to be the abnormal state is lowered as a difference between a timing when one end of the at least one reference image in the crossing direction is read by the reading unit and a timing when the other end thereof is read increases, when the recording element in the abnormal state is detected using the detected value and the threshold value. |
