| 摘要 |
PURPOSE:To provide an image forming device which has an advantage such that a latent image of a test patch can. be developed without causing more than two of three development means disposed around an image holder to simultaneously carry out developing work. CONSTITUTION:Three developing units 3K, 3R, 3B are disposed around a photoreceptor drum 1 with the black developing unit 3K located downstream of the other two, the black developing unit 3K developing a test patch; the middle red developing unit 3R, the blue developing unit 3B located upstream of the other two, and the black developing unit 3K located downstream of the other two are used in that order in developing work. The upstream blue developing unit 3B develops a blue latent image on the photoreceptor drum 1 and, since it takes long before a latent image of the test patch formed between the blue and black latent images reaches the downstream black developing unit 3K after developing of the rear end of the blue latent image has been completed, the two developing units 3B, 3K do not simultaneously carry out developing work. |
