Development device, process cartridge, and image forming apparatus

A development device, comprising:

• a developer carrier that develops an electrostatic latent image to obtain a toner image;
• a first chamber that houses a first rotary conveying body which conveys a developer to the developer carrier;
• and
• a second chamber that houses a second rotary conveying body which rotates to convey the developer in a second direction opposite to a first direction in which the first rotary conveying body conveys the developer, wherein
• the first chamber and the second chamber are partitioned by a partition member including first and second opening sections at each end thereof, whereby the developer is circulated and moved via the opening sections when the first and second rotary conveying bodies rotate,
• a first curved surface is provided in at least one of four sections where internal walls in which bearings of the first rotary conveying body and the second rotary conveying body are positioned intersect with internal walls that are parallel to the bearings,
• a second curved surface is provided in a second of the four sections, the first curved surface and the second curved surface are disposed on the same end of the development device,
• the second curved surface faces the first curved surface through the first opening section, and
• an abutting member, extending from at least one of bearings of the first rotary conveying body and the second rotary conveying body, rotates along with the bearing of the rotary conveying body in which the abutting member is installed, is disposed between a rotary conveying body and the internal wall in which the bearing is positioned, is a planar member extending radially from the bearing of the rotary conveying body, and abuts an internal wall that is parallel to the bearing from which the abutting member extends.

A process cartridge configured to detachably connect to an image forming apparatus, the process cartridge comprising:

• a development device;
• and
• an image carrier that supports an electrostatic latent image,
• the development device including
• a developer carrier that develops an electrostatic latent image to obtain a toner image;
• a first chamber that houses a first rotary conveying body which conveys a developer to the developer carrier;
• and
• a second chamber that houses a second rotary conveying body which rotates to convey the developer in a second direction opposite to a first direction in which the first rotary conveying body conveys the developer, wherein
• the first chamber and the second chamber are partitioned by a partition member including first and second opening sections at each end thereof, whereby the developer is circulated and moved via the opening sections when the first and second rotary conveying bodies rotate,
• a first curved surface is provided in at least one of four sections where internal walls in which bearings of the first rotary conveying body and the second rotary conveying body are positioned intersect with internal walls that are parallel to the bearings,
• a second curved surface is provide in a second of the four sections, the first curved surface and the second curved surface are disposed on the same end of the development device,
• the second curved surface faces the first curved surface through the first opening section, and
• an abutting member, extending from at least one of bearings of the first rotary conveying body and the second rotary conveying body, rotates along with the bearing of the rotary conveying body in which the abutting member is installed, is disposed between a rotary conveying body and the internal wall in which the bearing is positioned, is a planar member extending radially from the bearing of the rotary conveying body, and abuts an internal wall that is parallel to the bearing from which the abutting member extends.

An image forming apparatus comprising:

• a development device,
• the development device including
• a developer carrier that develops an electrostatic latent image to obtain a toner image;
• a first chamber that houses a first rotary conveying body which conveys a developer to the developer carrier;
• and
• a second chamber that houses a second rotary conveying body which rotates to convey a developer in a second direction opposite to the direction in which the first rotary conveying body conveys the developer, wherein
• the first chamber and the second chamber are partitioned by a partition member including first and second opening sections at each end thereof, whereby the developer is circulated and moved via the opening sections when the first and second rotary conveying bodies rotate,
• a first curved surface is provided in at least one of four sections where internal walls in which bearings of the first rotary conveying body and the second rotary conveying body are positioned intersect with internal walls that are parallel to the bearings,
• a second curved surface is provided in a second of the four sections, the first curved surface and the second curved surface are disposed on the same end of the development device,
• the second curved surface faces the first curved surface through the first opening section, and
• an abutting member, extending from at least one of bearings of the first rotary conveying body and the second rotary conveying body, rotates along with the bearing of the rotary conveying body in which the abutting member is installed, is disposed between a rotary conveying body and the internal wall in which the bearing is positioned, is a planar member extending radially from the bearing of the rotary conveying body, and abuts an internal wall that is parallel to the bearing from which the abutting member extends.

An image forming apparatus comprising:

• a process cartridge including a development device and an image carrier, the process cartridge being detachable to the image forming apparatus,
• the development device including
• a developer carrier that develops an electrostatic latent image to obtain a toner image;
• a first chamber that houses a first rotary conveying body which conveys a developer to the developer carrier;
• and
• a second chamber that houses a second rotary conveying body which rotates to convey the developer in a second direction opposite to a first direction in which the first rotary conveying body conveys the developer, wherein
• the first chamber and the second chamber are partitioned by a partition member including first and second opening sections at each end thereof, whereby the developer is circulated and moved via the opening sections when the first and second rotary conveying bodies rotate,
• a first curved surface is provided in at least one of four sections where internal walls in which bearings of the first rotary conveying body and the second rotary conveying body are positioned intersect with internal walls that are parallel to the bearings,
• a second curved surface is provided in a second of the four sections, the first curved surface and the second curved surface are disposed on the same end of the development device,
• the second curved surface faces the first curved surface through the first opening section, and
• an abutting member, extending from at least one of bearings of the first rotary conveying body and the second rotary conveying body, rotates along with the bearing of the rotary conveying body in which the abutting member is installed, is disposed between a rotary conveying body and the internal wall in which the bearing is positioned, is a planar member extending radially from the bearing of the rotary conveying body, and abuts an internal wall that is parallel to the rotary conveying body from which the abutting member extends.