Patent ID: 9612561
Date: 2017-04-04
CPC Classifications: G03G

Claim:
1. A developing device comprising: a casing having an opening part facing to an image carrier; a supplying chamber accommodating a toner replenished from a toner container; an agitating member agitating the toner in the supplying chamber; a toner carrier supplying an electrostatic latent image formed on the image carrier with the toner from the supplying chamber; a retaining part recovering and retaining only the toner dispersed in the vicinity of the image carrier and the toner carrier; and a detecting part detecting an amount of the toner in the retaining part, wherein the retaining part is configured to include a suction fan and a toner filter and to be communicated with the inside of the casing including the opening part, and then, to recover the toner by making a pressure in the retaining part negative by using the suction fan, and further, to replenish the recovered toner from the retaining part to an upper side of the agitating member inside the supplying chamber when the detecting part detects an amount of the toner in the retaining part more than a predetermined amount in a state where the toner is needed to be replenished to the supplying chamber.