Ricoh Company, Ltd.

Kentarou Nodera

Tatsuya Kubo

Susumu Tateyama

Yuji Suzuki

Yoshitaka Fujinuma

Hiroyuki Uenishi

Shinnosuke Koshizuka

Akihiro Takayama

Kohichi Yamazaki

A development device includes a developer bearer to carry the developer to a development range, a magnetic field generator disposed inside the developer bearer for generating magnetic force, a developer regulator for adjusting an amount of the developer, a developer supply compartment disposed adjacent to the developer bearer, separated by a side wall from a portion where the developer bearer is provided, a developer agitator provided in the supply compartment, and a blocker disposed above the side wall of the supply compartment across a supply gap through which the developer moves from the supply compartment. The magnetic field generator has an attraction magnetic pole and a regulation magnetic pole. The blocker prevents the developer blocked by the developer regulator from moving along a magnetic force line of the regulation magnetic force toward the circumferential surface of the developer bearer.

Development device and image forming apparatus incorporating same

A developing device, process cartridge and image forming apparatus of a premix developing system, with which developer splashed by the transport member is not discharged from the discharge port, fluctuations of the amount of developer discharged to the outside are not produced, and the output image quality is stable. The transport member comprises, in a part thereof in the longitudinal direction, a cutaway region where the screw part is not formed. The discharge port faces the cutaway region, and is formed such that the longitudinal length thereof is smaller than that of the cutaway region. A wall part, which protrudes toward the interior of the transport route from a partition wall where the discharge port is formed, is then installed upstream of the transport route in relation to the discharge port and within the range of the cutaway region.

Developing device, process cartridge, and image forming apparatus having a discharge port facing a section of a transport member without a screw part

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Kanagawa, Japan

Kentarou Nodera