| 摘要 |
PURPOSE:To always form an excellent image without color mixture even in the case that the electric charge quantity of first developing toner is not lowered by lowering the potential of a host writing part according to the lapse of time. CONSTITUTION:In a multicolor image forming device constituted by orderly arranging plural image forming units consisting of electrifiers 4 and 15, the writing parts 10 and 20 and developing devices 5 and 6 around a photosensitive body 1, the potential of the host wiring part 10 is lowered according to the lapse of time or adjusted according to humidity. That means, a humidity sensor 31 is fitted to the first developing device 5 and the potential of a latent image part is raised or lowered according to the value thereof. Besides, the second electrifier 15 is moved to the downstream side of the rotating direction of the body 1 according to the lapse of time or in the case that the humidity is high in order to increase the electrification quantity of the toner after second electrification. That means, the nearer the charger 15 is moved to the downstream side, the lower the potential before the second electrification becomes, whereby more current can be made to flow by the body 1 and the electrification quantity of the toner can be increased. |
