Canon Kabushiki Kaisha

Tohru Saitou

Tatsuya Nakamura

Kimio Nakahata

Masahide Hirai

Hiromichi Yamada

Katsuhiko Nishimura

Masuo Yamazaki

Yasuo Yoda

Takashi Shibuya

Masami Takeda

Tohru Kosaka

An image forming apparatus including a rotatable developing member having a plurality of developing devices for developing an image bearing member at a first developing station, and a second single developing device arranged upstream of the rotatable developing member for developing the image bearing member exclusively at a second developing station different from the first developing station. The second developing device has a cover portion covering the rotatable developing member, and a portion of the cover portion is disposed at a position spaced apart from a rotation axis of the rotatable developing member by a predetermined length in a horizontal direction away from the image bearing member. The rotatable developing member rotates in an opposite direction with respect to the direction of rotation of the image bearing member to prevent toner from scattering toward the optical system.

Image forming apparatus having a rotatable first developing member, and

This invention relates to a color image forming apparatus for forming a color image with dry developer, capable of preventing deterioration of image quality, resulting from contamination of optical components by the non-magnetic developer scattered from the developing unit. For this purpose there are provided, along the moving direction of an image bearing member effecting endless movement, charging means, optical means, first developing means utilizing developer containing a magnetic component, second developing means utilizing non-magnetic developer of a color different from that of the developer of the first developing means, and transfer means maintained in contact with or close to the image bearing member for transferring a developed image from the image bearing member to a recording material such as paper. A space containing the second developing means is enclosed by the shape of the first developing means, transfer means and image bearing member.

Image forming apparatus for forming color image with dry developer

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Yokohama, Japan

Tohru Saitou