Developing roller having developing sleeve including portions with different transportation capacities

A developing device, comprising:

• a conveying screw configured to convey a developer;
• and
• a developing roller including,
• a magnet roller including a plurality of magnets configured to attract the developer;
• and
• a developing sleeve provided outside of the magnet roller and configured to carry and convey a developer while bearing the developer by a magnetic force of the magnet roller,
• wherein the surface of the developing sleeve is configured such that a transportation capacity of the developer in end portions of the developing sleeve which correspond to a vicinity of ends of the magnet roller is smaller than the transportation capacity of the developer in a central portion of the developing sleeve which corresponds to a central portion of the magnet roller, and
• wherein the developer comprises a two-component developer including a toner and a carrier.

An image forming apparatus, comprising:

• a transfer sheet feeding device configured to feed a transfer sheet;
• and
• a developing device including,
• a conveying screw configured to convey a developer;
• and
• a developing roller including,
• a magnet roller including a plurality of magnets configured to attract the developer;
• and
• a developing sleeve provided outside of the magnet roller and configured to carry and convey a developer while bearing the developer by a magnetic force of the magnet roller,
• wherein the surface of the developing sleeve is configured such that a transportation capacity of the developer in end portions of the developing sleeve which correspond to a vicinity of ends of the magnet roller is smaller than the transportation capacity of the developer in a central portion of the developing sleeve which corresponds to a central portion of the magnet roller, and wherein the developer comprises a two-component developer including a toner and a carrier.

A developing roller system used in a developing device, comprising:

• means for providing a magnetic field to attract a developer;
• and
• means for carrying and conveying the developer while bearing the developer by a magnetic force of the means for providing the magnetic field, the means for carrying and conveying provided outside of the means for providing the magnetic field,
• wherein the surface of the means for carrying and conveying is configured such that a transportation capacity of the developer in end portions of the means for carrying and conveying which correspond to a vicinity of ends of the means for providing the magnetic field is smaller than the transportation capacity of the developer in a central portion of the means for carrying and conveying which corresponds to a central portion of the means for providing the magnetic field, and wherein the developer comprises a two-component developer including a toner and a carrier.

A developing device, comprising:

• means for conveying a developer;
• and
• means for rolling including,
• means for providing a magnetic field to attract the developer;
• and
• means for carrying and conveying the developer while bearing the developer by a magnetic force of the means for providing the magnetic field, said means for carrying and conveying provided outside of the means for providing the magnetic field,
• wherein the surface of the means for carrying and conveying is configured such that a transportation capacity of the developer in end portions of the means for carrying and conveying which correspond to a vicinity of ends of the means for providing the magnetic field is smaller than the transportation capacity of the developer in a central portion of the means for carrying and conveying which corresponds to a central portion of the means for providing the magnetic field, and wherein the developer comprises a two-component developer including a toner and a carrier.

An image forming apparatus, comprising:

• means for feeding a transfer sheet;
• and
• means for developing including,
• a means for conveying a developer;
• and
• means for rolling including,
• means for providing a magnetic field to attract the developer;
• and
• means for carrying and conveying the developer while bearing the developer by a magnetic force of the means for providing the magnetic field, the means for carrying and conveying provided outside the means for providing the magnetic field,
• wherein the surface of the means for carrying and conveying is configured such that a transportation capacity of the developer in end portions of the means for carrying and conveying which correspond to a vicinity of ends of the means for providing the magnetic field is smaller than the transportation capacity of the developer in a central portion of the means for carrying and conveying which corresponds to a central portion of the means for providing the magnetic field, and wherein the developer comprises a two-component developer including a toner and a carrier.