Developing device and image forming apparatus

摘要

A developing device includes a developing roller and a transfer mechanism configured to transfer the developing roller between a contact position where the developing roller is in contact with a photosensitive drum and a separate position where the developing roller is away from the photosensitive drum. The transfer mechanism includes a bearing unit supporting a rotary shaft of the developing roller to allow rotation of the rotary shaft, a pressing member pressing the bearing unit, a shaft member, an urging member, and a wire member. The wire member connects the bearing unit and the shaft member and is configured to experience an urging force of the urging member to urge the bearing unit toward moving away from the photosensitive drum and, upon release of the urging force of the urging member, move the bearing unit close to the photosensitive drum under a pressing force of the pressing member.

主权项

1. A developing device comprising:
a developing roller configured to supply a developer to an electrostatic latent image formed on an image carrier; and a transfer mechanism configured to transfer the developing roller between a contact position where the developing roller is in contact with the image carrier and a separate position where the developing roller is away from the image carrier, wherein the transfer mechanism comprises: a bearing unit supporting a rotary shaft of the developing roller to allow rotation of the rotary shaft and being pivotally supported by a housing covering the developing roller and the transfer mechanism; a pressing member configured to press the bearing unit toward bringing the bearing unit close to the image carrier; a shaft member mounted to the housing reciprocally movably in an axial direction of the developing roller; an urging member urging the shaft member unidirectionally in the axial direction; and a rod member connecting the bearing unit and the shaft member, the rod member being configured to experience a unidirectional urging force of the urging member to urge the bearing unit toward moving away from the image carrier against a pressing force of the pressing member and, upon release of the urging force of the urging member resulting from movement of the shaft member in a direction opposite to the unidirectional urging force, move the bearing unit close to the image carrier under the pressing force of the pressing member.