| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming apparatus which easily detects the extent of color slippage in real time so as not to enter a color resist correcting operation at an improper timing and realizes color slippage correction even in the case that intervals of paper are short because resist patterns of a plurality of colors are formed on the same position one over the other. SOLUTION: A color image forming apparatus provided with an image carrier for bearing a plurality of images and a color resist sensor for detecting color slippage of a plurality of colors is provided with: a detection means 50 which detects the width of a resist pattern formed by superposing resist patterns of a plurality of colors in the same position one over the other with the color resist sensor: a comparing means 51 which compares the width detected by the detection means 50 with a reference resist pattern width; and a discrimination means 52 which discriminates the necessity of color resist correction in the case that the comparing means 51 has found that the detected width is different from the reference resist pattern width. Preferably, the discrimination means 52 discriminates the necessity of resist correction when the width of resist patterns of a plurality of colors superposed one over the other changes with respect to the reference resist pattern width. |
