DEVELOPING DEVICE AND COLOR IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a color image forming device preventing the level difference of developing variable density and the fogging of a photoreceptor from occurring. SOLUTION: In a developing device 44, a developing roller 45 is held at the lower aperture of a housing 61 functioning also as a toner hopper, non- magnetic toner 62 is stored and a toner stirring member 63 is provided inside, and a supply roller 64 press-contacting with the roller 45 is arranged at the lower part of the device 44. A doctor blade 65 is disposed to abut on the obliquely right upper peripheral surface of the roller 45 and a conductive scooping sheet 66 is disposed to abut on the lower peripheral surface thereof. The toner at a non-image part which is not transferred to a photoreceptor drum 38 passes through the sheet 66 and is recovered in the housing 61 as the roller 45 is rotated. Bias voltage within 0 V to -250 V is applied on the sheet 66 from a power source 71, and the adhesive force of the returned toner 61 to the roller 45 is weakened to facilitate scraping by the roller 64, whereby new adhesive amount is always kept constant.