| 摘要 |
PROBLEM TO BE SOLVED: To provide a printer and a process cartridge capable of realizing the prolongation of the life of a photoreceptor drum and restraining the lowering of image density and the unevenness of the image density caused by the fluctuation of developing potential. SOLUTION: When it is assumed that the absolute value of potential by electrification of the photoreceptor drum 1 is <=400 V and a maximum set value used for image formation of developing potential |VB-VL| being the absolute value of a potential difference between the potential VL of an exposure part where potential is lowered by exposing the drum 1 and developing bias VB is |VB-VL| max, the change width of the image density when the developing potential |VB-VL| is changed within a range satisfying following expressions (1) to (3) is <=10% of the image density to the maximum set value |VB-VL| max of the developing potential. (1) |VB-VL|<=|VB-VL|max+|VB-VL|max×0.2, (2) |VB-VL|>=|VB-VL|max-|VB-VL|max×0.2, (3) |VB-VL|max<=300 V. |
