Hitachi Koki Co., Ltd.

Masami Yamaki

Masayasu Anzai

Yukio Otome

Yasuyuki Tsuji

Koji Doi

Youji Hirose

Katsuhiko Suzuki

Youichi Takeuchi

Koutaro Yamada

Akira Takizawa

In a multi-stage roll magnetic brush type of developing device, at least two opposite direction rotation rolls which rotate in an opposite rotation direction to that of a photosensitive body are arranged adjacently and oppositely to a photosensitive body, and at least one same direction rotation developing roll which rotates in the same rotation direction as that of the photosensitive body is arranged adjacently, oppositely to the photosensitive body and upstream of the opposite direction rotation developing rolls in the rotation direction of the photosensitive body. Thus, the path of carrying the developer by the same direction rotation developing roll and the opposite direction rotation developing rolls can be optimized. In the wide area printing at high speed, an image with stabilized printing quality can be obtained without an increase in the production cost.

Developing device for electrophotograph-type printer

Growing community of inventors

Ibaraki, Japan

Masami Yamaki