| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image forming device capable of setting magnetic particles without causing the alteration and the deterioration of an image forming body by controlling so that toner concentration in a magnetic brush may be a 1st set value in the operation. SOLUTION: The toner concentration in the magnetic brush in the operation when toner left after transfer is recovered and discharged is controlled within 2 to 7% as the 1st set value TC11 lower than the developer concentration to be ordinarily set to 5 to 10% in a developing means. A 2nd set value TC12 is 2% of the lower limit value of the toner concentration, and a 3rd set value TC13 is 7% of the upper limit value of the toner concentration. When the concentration is equal to or under the 2nd set value TC12 (2%), the deterioration of carrier and the alteration of the image forming body are caused due to the adhesion of the magnetic particles to the image forming body when applying bias and the breakdown and toner filming on the image forming body. When it is equal to or above the 3rd set value TC13, image fogging is caused by the adhesion of the magnetic particles to the image forming body and faulty cleaning. |
