IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an image-forming device furnished with a structure making feasible a return to normally charged toner by enabling accelerating the electrostatic charging in weakly charged toner as object, and suppressing noise as a result of a vibrating electric field. SOLUTION: This image-forming device is constituted by equipping weak charge toner separating means (bias roller facing with respect to developing sleeve held in contact or noncontact state), and a pair of electrodes 4 and 5 provided with a plane held in contact with the weak charge toner separating means and curved toward the developer circulating part. In such a case, if assuming a range between electrodes in a contact part with the weakly charged toner separating means as d1, the range between the electrodes 4 and 5 orthogonal to the lengthwise direction of the above weakly charged toner separating means in the lateral direction located on the upstream side of the developer circulation as d2, the range between electrodes in the lateral direction of the electrodes 4 and 5 on the downstream side of the developer circulation as d3, the effective length in the lateral direction of the electrodes located on the upstream side of the developer circulation as L1, and the effective length in the lateral direction of the electrodes located on the downstream side of the developer circulation as L2, a oscillating electric field is formed between the electrodes 4 and 5, so as to satisfy the inequality, d1