Developing sleeve and developing device

A developing sleeve for carrying a developer containing toner and a carrier, comprising:

• a plurality of first groove portions provided in a region for carrying the developer, said first groove portions extending in an axial direction of said developing sleeve,
• wherein each of said first groove portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first groove portions and W1 is a width an opening of each of said first groove portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second groove portions provided in the region for carrying the developer, said second groove portions extending in the axial direction of said developing sleeve,
• wherein each of said second groove portions satisfies W2<2R, where 2R is the volume-average particle size of the carrier and W2 is a width of an opening of each of said second groove portions with respect to the circumferential direction of said developing sleeve, and
• wherein each or a plurality of said second groove portions are disposed between associated first groove portions with respect to the circumferential direction of said developing sleeve.

A developing sleeve for carrying a developer containing toner and a carrier, comprising:

• a plurality of first recessed portions provided in a region for carrying the developer,
• wherein each of said first recessed portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first recessed portions and W1 is a width an opening of each of said first recessed portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second recessed portions provided in the region for carrying the developer,
• wherein each of said second recessed portions satisfies 2R/3<D2<2R, where 2R is the volume-average particle size of the carrier and D2 is a maximum depth of each of said second recessed portions, and
• wherein each or a plurality of said second recessed portions are disposed between associated first recessed portions with respect to the circumferential direction of said developing sleeve.

A developing sleeve for carrying a developer containing toner and a carrier, comprising:

• a plurality of first recessed portions provided in a region for carrying the developer,
• wherein each of said first recessed portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first recessed portions and W1 is a width an opening of each of said first recessed portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second recessed portions provided in the region for carrying the developer,
• wherein each of said second recessed portions satisfies 2R/3<W2<2R, where 2R is the volume-average particle size of the carrier and W2 is a width of an opening of each of said second recessed portions with respect to the circumferential direction of said developing sleeve, and
• wherein each or plurality of said second recessed portions are disposed between associated first recessed portions with respect to the circumferential direction of said developing sleeve.

A developing device comprising:

• a developing sleeve for carrying a developer containing toner and a carrier;
• a magnet provided inside said developing sleeve;
• a plurality of first groove portions provided in a region for carrying the developer on said developing sleeve, said first groove portions extending in an axial direction of said developing sleeve,
• wherein each of said first groove portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first groove portions and W1 is a width an opening of each of said first groove portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second groove portions provided in the region for carrying the developer on said developing sleeve, said second groove portions extending in the axial direction of said developing sleeve,
• wherein each of said second groove portions satisfies D2<2R, where 2R is the volume-average particle size of the carrier and D2 is a maximum depth of each of said second groove portions, and
• wherein each or a plurality of said second groove portions are disposed between associated first groove portions with respect to the circumferential direction of said developing sleeve.

A developing device comprising:

• a developing sleeve for carrying a developer containing toner and a carrier;
• a magnet provided inside said developing sleeve;
• a plurality of first groove portions provided in a region for carrying the developer on said developing sleeve, said first groove portion extending in an axial direction of said developing sleeve,
• wherein each of said first groove portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first groove portions and W1 is a width an opening of each of said first groove portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second groove portions provided in the region for carrying the developer on said developing sleeve, said second groove portions extending in the axial direction of said developing sleeve,
• wherein each of said second groove portions satisfies W2<2R, where 2R is the volume-average particle size of the carrier and W2 is a width of an opening of each of said second groove portions with respect to the circumferential direction of said developing sleeve, and
• wherein each or a plurality of said second groove portions are disposed between associated first groove portions with respect to the circumferential direction of said developing sleeve.

A developing device comprising:

• a developing sleeve for carrying a developer containing toner and a carrier;
• a magnet provided inside said developing sleeve;
• a plurality of first recessed portions provided in a region for carrying the developer on said developing sleeve,
• wherein each of said first recessed portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first recessed portions and W1 is a width an opening of each of said first recessed portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second recessed portions provided in the region for carrying the developer on said developing sleeve,
• wherein each of said second recessed portions satisfies 2R/3<D2<2R, where 2R is the volume-average particle size of the carrier and D2 is a maximum depth of each of said second recessed portions, and
• wherein each or a plurality of said second recessed portions are disposed between associated first recessed portions with respect to the circumferential direction of said developing sleeve.

A developing device comprising:

• a developing device for carrying a developer containing toner and a carrier;
• a magnet provided inside said developing sleeve;
• a plurality of first recessed portions provided in a region for carrying the developer on said developing sleeve,
• wherein each of said first recessed portions satisfies D1≧2R and W1≧2R, where 2R is a volume-average particle size of the carrier, D1 is a maximum depth of each of said first recessed portions and W1 is a width an opening of each of said first recessed portions with respect to a circumferential direction of said developing sleeve, and
• a plurality of second recessed portions provided in the region for carrying the developer on said developing sleeve,
• wherein each of said second recessed portions satisfies 2R/3<W2<2R, where 2R is the volume-average particle size of the carrier and W2 is a width of an opening of each of said second recessed portions with respect to the circumferential direction of said developing sleeve, and
• wherein each or a plurality of said second recessed portions are disposed between associated first recessed portions with respect to the circumferential direction of said developing sleeve.