Canon Kabushiki Kaisha

Hiroto Kakinuma

Yasushi Takeuchi

Yusuke Ishida

Takanori Iida

Toshiyuki Yamada

Toshiya Kobayashi

Shiro Higashikozono

A developing device includes a developing container, a developing sleeve, a magnet and grooves provided at a surface of the sleeve and formed along a direction crossing a circumferential direction of the sleeve. In a cross-section, each of the grooves is formed by a flat bottom portion contacting a carrier particle and a pair of side surface portions provided in both sides of the flat bottom portion with respect to the circumferential direction of the sleeve and satisfies the following relationship:&#x3c;22&#xd7;, and/2&#x2264;&#x3c;2 In the above, r is a volume-average particle size of the carrier particles, w is a length of the flat bottom portion, L is a width between the side surface portions at the surface of the sleeve, and s is a depth of each of the grooves.

Developing device

A developing device includes a developing container, a developing sleeve, a magnet and grooves provided at a surface of the sleeve and formed along a direction crossing a circumferential direction of the sleeve. In a cross-section, each of the grooves is formed by a flat bottom portion contacting a carrier particle and a pair of side surface portions provided in both sides of the flat bottom portion with respect to the circumferential direction of the sleeve and satisfies the following relationship:22&#xd7;and2&#x2266;&#x3c;2 In the above, r is a volume-average particle size of the carrier particles, w is a length of the flat bottom portion, L is a width between the side surface portions at the surface of the sleeve, and s is a depth of each of the grooves.

Growing community of inventors

Moriya, Japan

Hiroto Kakinuma