Image Forming Apparatus and Gradation Correction Method

摘要

Image forming apparatus (100) creates a toner pattern on intermediate transfer belt (11) as a preprocessing of gradation correction, and calculates a cycle at which density unevenness is largest. Then, a toner image for gradation correction is formed so as to cancel cyclic unevenness at a cycle at which the largest density unevenness occurs. As a result of this, it becomes possible to suppress the deterioration of density detection accuracy and perform a highly accurate gradation correction even if density unevenness of any cycle occurs.