Canon Kabushiki Kaisha

Jun Shirayanagi

Teppei Nagata

Hideki Mori

Dai Kanai

Kenta Koyama

Kotaro Torikata

Makoto Matsuo

Hideki Takaoka

Masatoshi Lin

Osamu Ariizumi

Fumiyoshi Saito

A developing device includes a rotatable developing member, a developing container, a first communication opening, a second communication opening, a first feeding screw including a first rotation shaft, first and second blade portions, a second feeding screw including a second rotation shaft, third and fourth blade portions, a developer discharge opening provided upstream of an upstream end of the second communication opening in a first direction, and a third communication opening provided upstream of the upstream end of the second communication opening in the first direction. In a second direction opposite to the first direction, the third communication opening overlaps with the second blade portion. In the first direction, the third communication opening overlaps with the fourth blade portion. In the first direction, a downstream end of the third communication opening is positioned downstream of a downstream end of the developer discharge opening.

Developing device

A developing apparatus includes a developer bearing member, a first conveyance screw arranged in a first chamber to convey developer in a first direction, and a second conveyance screw arranged in a second chamber convey the developer in an opposite second direction. A toner density detector is arranged in the second chamber to detect toner density of the developer in a circulation path. The second conveyance screw includes a first blade portion having a helical shape, a second blade portion having a helical shape of a same turn direction as the first blade portion, a gap portion provided between the first and second blade portions, and a plurality of agitating portions provided in the gap portion. Each of the agitating portions has a wall portion provided to intersect a rotational axis direction of the second conveyance screw and a recessed portion having a shape in which a portion of a periphery of the wall portion is recessed.

Developing apparatus

A feeding screw for feeding a developer includes a rotation shaft, and a helical blade provided on the rotation shaft and including a plurality of threads. The helical blade includes a first blade helically formed with a single thread on the rotation shaft, a second blade helically formed with a single thread on the rotation shaft, and a third blade helically formed with a single thread on the rotation shaft. With respect to a direction along the rotation shaft, a gap is provided between a downstream end portion of the second blade and an upstream end portion of the third blade. A volume of the second blade is not more than 75% of the first blade between an upstream end portion of the second blade and the upstream end portion of the third blade with respect to the direction.

Feeding screw and developing device

A developing apparatus includes a rotatable developer carrying member, a first chamber to supply developer to the developer carrying member, and a second chamber to collect the developer from the developer carrying member. A first conveyance screw in the first chamber conveys the developer in a first conveyance direction, and a second conveyance screw conveys the developer in the second chamber. The second conveyance screw includes a rotary shaft, a first vane portion, and a second vane portion provided downstream of the first vane portion. A developer discharge portion is disposed upstream of the second vane portion in the first conveyance direction and discharges excess developer. The developer discharge portion is disposed in a predetermined area of the second chamber in which the developer is deliverable to a communication portion, and is provided in a bottom portion in the predetermined area of the second chamber.

An image forming apparatus includes a main assembly, a first openable portion provided on a first side of the main assembly, a second openable portion provided on a second side of the main assembly, a single projector portion, a first projecting portion configured to project the image from above the first openable portion onto a projection object provided on the first side or onto the first openable portion when the first openable portion is open, and a second projecting portion configured to project the image from above the second openable portion onto a projection object provided on the second side or onto the second openable portion when the second openable portion is open.

Image forming apparatus including image projector

An image forming apparatus and method for controlling an image forming apparatus is provided. The image forming apparatus includes a detecting unit, a projecting unit, and a control unit. The detecting unit is configured to detect an event that needs user work on the image forming apparatus. The projecting unit is configured to project an image onto a projection target. The control unit is configured to control projection by the projecting unit. When an event that needs user work on the image forming apparatus is detected, the projecting unit projects an image onto a projection target so that a target portion of the user work can be identified and also projects an instruction image for performing the user work.

Apparatus and method for maintenance of an image forming apparatus

A process cartridge detachably mountable to a main assembly of an image forming apparatus includes an image bearing member; a developer carrying member for developing an electrostatic image on the image bearing member; a first gear provided on the developer carrying member and a second gear driving-connected to the first gear; and a supporting portion for rotatably supporting the second gear. The supporting member is mounted on a frame of the process cartridge through a vibration damping member having a vibration transmission performance lower than that of at least the supporting portion.

Process cartridge

In a process cartridge detachably mountable to a main assembly of the apparatus and including a photosensitive member and a charging roller, a spacer member for spacing the charging roller from the photosensitive member during the transportation and the displaying is recessed relative to the photosensitive member. The spacer member receives a driving force from the main assembly of the apparatus, by which the spacer member is disengaged to contact the charging roller to the photosensitive member.

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Ushiku, Japan

Jun Shirayanagi