| 摘要 |
PROBLEM TO BE SOLVED: To make a kind of image forming device cope with plural purposes, to obtain a sharp image of high quality and further, to increase a recording speed, while attaining sufficient fixing performance. SOLUTION: Developing units 13M-13K house a first developer having toner fixed at a low speed and a high temperature and developing units 14M-14K house a second developer having the toner whose fixation is easier than that of the first developer. The moving speeds (image forming speeds) of a photorecetor drum 11 and a transfer drum 80 can be switched in two stages of V1 and V2 (>V1) and the moving speeds of a carrying belt 70 and a fixing unit 76 can be switched in three stages of V1, V2 and V10 (<V1). At the time of executing full color printing, in a low speed mode, four developing units 13 are used, the photoreceptor drum and the transfer drum are controlled to be at the moving speeds V1 and the carrying belt and the fixing unit are controlled to be at the moving speeds V1 up to the completion of a transfer and then, at the moving speeds V10. At the time of executing monocolor printing, in a high speed mode, one of the developing units 14 is used, the pohotoreceptor drum - the fixing unit are controlled to be always at the moving speeds V2 and in the low speed mode, one of the developing units 13 is used and the photoreceptor drum - the fixing unit are controlled to be always at the moving speeds V1. |
