IMAGE FORMING APPARATUS AND IMAGE FORMING PROGRAM

PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming program with which transfer failure occurring due to accumulation of toner can be accurately detected compared with a case where only a difference between the density of a current reference toner image and the density of a reference toner image when the use of an intermediate transfer body is started is used.SOLUTION: When a first difference between the density of a current reference toner image obtained by forming a reference toner image on an intermediate transfer body 32 and detecting the density of the reference toner image and the density of the reference toner image detected earlier than the present time by a predetermined period is equal to or smaller than a predetermined first threshold, and a second difference between the detected density of the current reference toner image and the density of the reference toner image detected when the use of the intermediate transfer body 32 is started is equal to or larger than a predetermined second threshold, an image forming apparatus outputs failure information on the intermediate transfer body 32.SELECTED DRAWING: Figure 1 【課題】現在の基準トナー像の濃度と、中間転写体の使用が開始された際の基準トナー像の濃度との差分のみを用いる場合と比較して、トナーの蓄積により発生する転写不良を精度良く検出することができる画像形成装置、及び画像形成プログラムを提供する。【解決手段】中間転写体３２に基準トナー像を形成し、基準トナー像の濃度を検出し、検出した現在の基準トナー像の濃度と、現在より予め定めた期間前に検出した基準トナー像の濃度と、の第１差分が予め定めた第１閾値以下であって、かつ検出した現在の基準トナー像の濃度と、中間転写体３２の使用が開始された際に検出した基準トナー像の濃度と、の第２差分が予め定めた第２閾値以上である場合に、中間転写体３２に関する不具合情報を出力する。【選択図】図１