| 摘要 |
PROBLEM TO BE SOLVED: To perform toner density control without reducing the productivity of copying regardless of either state of a transferring belt being in contact or noncontact with a photoreceptor, and to maintain the stable toner density control even if transferring efficiency is varied. SOLUTION: A density sensor 20 provided on the downstream side of a transferring position detects the density pattern on the photoreceptor 3 in the timing when it passes the transferring position, and either timing when the transfer belt 6 is held in contact or uncontact with the photoreceptor 3, and performs the toner density control corresponding to the density pattern on the either timing. The density pattern is formed at either timing when the transferring belt 6 is brought into contact or uncontact with the photoreceptor 3 in a prescribed mode beforehand, and a compensation factor is obtained by the ratio of respective detection values of the density sensor 20 at the time of either timing to perform the toner density control based on the detection value compensated by the compensation factor. |
