Developing device and image forming apparatus including the same

摘要

A developing device includes a supplying chamber, an agitating member, a toner carrier, a retaining part and a detecting part. The supplying chamber accommodates a toner replenished from a toner container. The agitating member agitates the toner in the supplying chamber. The toner carrier supplies an electrostatic latent image formed on an image carrier with the toner from the supplying chamber. The retaining part recovers and retains the toner dispersed in the vicinity of the image carrier and the toner carrier. The detecting part detects an amount of the toner in the retaining part. The retaining part is moreover configured to replenish the recovered toner from the retaining part to 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.

主权项

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.