Developing device

Abstract

A developing device includes a developing unit having a developing frame defining therein a developing chamber and a developing roller rotatably disposed in the developing chamber, and a developing agent unit including a developing agent container that accommodates therein a developing agent, and an agitator disposed in the developing agent container and rotatable about a rotation axis in a rotational direction to agitate the developing agent. The developing agent container includes an arcuate bottom wall whose center of radius of a curvature is coincident with the rotation axis, and an arcuate protruding wall protruding from the bottom wall toward the developing chamber and positioned downstream of the bottom wall in the rotational direction. The protruding wall is formed with an opening providing a fluid communication between an interior of the developing agent container and the developing chamber. The opening has a downstream end in the rotational direction in an operational state. The bottom wall and the protruding wall have inner surfaces extending diagonally upward from a lowermost point of the bottom wall to the downstream end in the operational state.

Description

technical field [0001] The invention relates to a developing device with a developing chamber and a toner box. Background technique [0002] Generally, an image forming apparatus such as a laser printer has a developing device that supplies a developer (hereinafter referred to as “toner”) to an electrostatic latent image formed on a photoreceptor. A conventional developing device has a toner cartridge and a developing chamber. In the toner cartridge, an agitator is provided to supply toner to the developing chamber through the opening. In the developing chamber, a toner supply roller and a developing roller are provided for supplying toner to the photosensitive drum. [0003] In such a developing device, a cylindrical toner container and a developing chamber are juxtaposed with each other in a substantially horizontal direction and communicate with each other. If the amount of toner in the developing chamber reaches a predetermined amount, a part of the toner flows into t...

AI Technical Summary

Problems solved by technology

[0005] In this case, there is a problem that the toner remaining in the developing chamber has a polarity opposite to the intended polarity, or accumulation of toner occurs in the remaining toner

These adverse phenomena occur when deteriorated toner and new toner are mixed to a certain extent by the movement of the toner between the toner container and the developing chamber, that is, shortly after the new toner is supplied to the remaining toner

[0006] However, according to a conventional developing device having a large-volume developing chamber, it takes some time to mix the deteriorated toner and the new toner

As a result, image degradation cannot be suppressed shortly after new toner is supplied

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