| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can specify, when periodic abnormality has occurred to an output image, a component causing the abnormal image in an accurate and quick manner.SOLUTION: An image output unit 208 forms a test image (halftone image) on a sheet. An image sensor 207 reads the test image formed on the sheet. A CPU 201 specifies to which of rotating components, including a photoconductor drum 10, charging roller 130, primary transfer roller 105, and secondary transfer roller 106 abnormality has occurred according to the period of density unevenness of the read test image. When forming the test image with the image output unit 208, the CPU 201 causes the image output unit 208 to form the test image on the sheet while changing the driving speed of any of the plurality of rotating components, so as to make the periods of density unevenness, which results from the rotation of the respective rotating components, different from each other.</p> |
