IMAGE FORMING APPARATUS AND PROGRAM

PROBLEM TO BE SOLVED: To extend the life of means for collecting a toner image on a transfer body.SOLUTION: A printing control part 18 separates a first cleaning blade from a direct transfer belt when cumulative contact time of the first cleaning blade exceeds a threshold in toner concentration correction processing during monochrome printing. The printing control part 18 then brings a second cleaning blade in contact with an intermediate transfer belt and allows the direct transfer belt to approach the intermediate transfer belt to transfer a toner pattern image for concentration correction of a color "K" from the direct transfer belt to the intermediate transfer belt. After that, the printing control part 18 allows a second toner pattern concentration detection sensor to detect the toner pattern image for concentration correction of the color "K" to perform toner concentration correction of the color "K" based on the detection result, and allows the second cleaning blade to collect the toner pattern image for concentration correction of the color "K" on the intermediate transfer belt.