Canon Kabushiki Kaisha

Akinobu Saito

Yoshihiro Mitsui

Masamichi Sato

Toshiaki Takeuchi

Yuhei Terui

Kentaro Yamawaki

Tomonori Matsunaga

Yuichiro Hirata

Noriyoshi Umeda

Go Shindo

Shinichi Agata

Shohei Kototani

Yasukazu Ikami

Takuya Oka

Kosuke Ikada

Kazunori Hashimoto

Katsuhiro Kojima

A process cartridge includes a seal member contacting an image bearing member upstream in the rotation direction of the image bearing member from a cleaning member and allowing the developer to move from upstream in the rotation direction from the contact part between the seal member and the image bearing to downstream from the contact part while regulating movement from downstream to upstream from the contact part. The developer has surface protrusions containing an organic silicon polymer, wherein either (i) the work function of the seal member is greater than the work function of the developer when the developer has a negative charging polarity and is smaller than the work function of the developer when the developer has a positive charging polarity, or (ii) the absolute value of the difference between the work function of the seal member and the work function of the developer is within a predetermined range.

Process cartridge, image forming apparatus and cleaning apparatus

A developing device includes a developer carrying member, a developing frame, and a regulating member. The regulating member includes a curved surface portion contactable to a surface of the developer carrying member, and satisfies the following relationships: 200 MPa&#x2264;HM&#x2264;1100 MPa, and 0.08 mm&#x2264;Rb&#x2264;0.3 mm, where HM is a Martens hardness of toner contained in the developer under a maximum load of 2.0&#xd7;10N, and Rb is a radius of curvature of the curved surface portion.

Developing device, process cartridge and image forming apparatus

Growing community of inventors

Yokohama, Japan

Akinobu Saito