| abstract |
A developing device effects desirable development when the amount of charging of toner, q (C/g), the amount of toner deposited on the surface of a developing roller per unit area, m (g/cm 2 ), the speed of movement of the surface of the developing roller, v (cm/sec), the available length of the developing roller, l (cm), and the magnitude of electric resistance between the surface of the developing roller and a power source for developing bias, R (Ω), are adjusted so as to satisfy the formula, |q|m≦100/vlR. The developing device produces a developed image desirable in quality and free from background fogging when the magnitude of a developing electric current, I (A), is adjusted so as to satisfy the formula, R≦200/I. Further, when a charging device, an electrostatic latent image forming device, a transfer device, a cleaning device, a discharge device, a charging and cleaning device, an electrostatic latent image forming and cleaning device, a developing and cleaning device, or a discharging and cleaning device is provided with an elastic electroconductive roller composed of an elastic roller base and a flexible conductor layer, the device is allowed to decrease size and lower price, curb the decline of capacity due to protracted use, and preclude the occurrence of dispersion of characteristic, efficiency, or performance. |