| 摘要 |
PROBLEM TO BE SOLVED: To provide an image forming device being excellent in the uniformity of a dot and capable of forming a high-difinition image small in noise by forming a vibration electric field in a developing area based on the toner grain size and the carrier grain size. SOLUTION: A developing device adopted in this image forming device is constituted so as to transport a developer consisting of a toner and a carrier while holding it on a developing sleeve 2 and to make the toner deposite with respect to an electrostatic latent image formed on a photoreceptor drum 10. In this case, a vibration electric field making the toner move between the photoreceptor drum 10 and the developing sleeve 2 is formed, when a phase time for making the toner move to the electrostatic latent image in the vibration electric field is made to t1 , the cycle of the vibration electric field is made to T, the mass average size of the toner is made to Lt, and the mass average grain size of the carrier is made to Lc, the respective conditions are set so as to satisfy 1.0×10<-4> <t1 <2> /Lt<1.0×10<-3> (sec<2> /m) and T<2> /Lc<0.005 (sec<2> /m). |
