| 摘要 |
PROBLEM TO BE SOLVED: To reduce the consumption of toner by concentration control and, furthermore, to realize the improvement in detection accuracy of the concentration. SOLUTION: A correction value which is the time difference between the detection timing of a patch for resist control obtained from resist position detection information detected by a detecting sensor 20 and the detection timing of the patch for resist control calculated previously is determined by a controller 21. Since the patch for concentration control in minimum size can be used, by compensating the formation position of the patch for concentration control formed on a transfer material transportation belt 8 on the basis of this correction value, the consumption of the toner by the concentration control is reduced and, furthermore, the improvement in the detection accuracy of the concentration can be realized. |
