Canon Kabushiki Kaisha

Fumiyoshi Saito

Katsuya Nose

Toshihisa Yago

Naoki Mugita

Yusuke Ishida

Kosuke Takeuchi

Osamu Ariizumi

Shunsuke Tsuda

Noriyuki Okada

Jun Shirayanagi

Masahiro Ootsuka

Mitsuyoshi Arakawa

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 device includes a developing container, a developing roller, a supplying roller, a first magnet including a first magnetic pole, a second magnet including a second magnetic pole and a third magnetic pole, and a regulating member provided opposed to the third magnetic pole. During non-image formation, an operation in a mode in which the supplying roller is rotated in a direction opposite to a rotational direction of the supplying roller during image formation is executable. With respect to the rotational direction of the supplying roller during the image formation, a position where a magnet flux density of the third magnetic pole in a tangential direction to an outer peripheral surface of the supplying roller is zero is positioned downstream of an upstream end of the regulating member and upstream of the second magnetic pole.

A developing device includes a developer carrying member, a first chamber, a second chamber, a first communicating portion, a second communicating portion, and a feeding screw, provided in the second chamber, including a feeding portion having a first helical blade and including a returning portion having a second helical blade in the form of a plurality of threads, the feeding portion and the returning portion being provided so that a boundary portion therebetween opposes the second communicating portion. The first helical blade and the second helical blade satisfy the following relationship: P2&#x2265;P1, where P1 is a pitch, or lead, of the first helical blade and P2 is a lead of the second helical blade.

Developing device having a feeding screw with multiple blade portions

An image forming apparatus includes: an image bearing member, a developing device, and a controller configured to execute an operation in a forced consumption mode. The controller includes a difference calculating portion, an integrating portion, and a flag. In a case where the flag is set when a predetermined time is elapsed after the integrated value exceeds the predetermined threshold, the image formation on the predetermined number of the recording materials is effected and then the controller executes the operation in the forced consumption mode, and in a case where the flag is reset when the predetermined time is elapsed after the integrated value exceeds the predetermined threshold, the image formation on the predetermined number of the recording materials is effected and then the controller continues an image forming operation without executing the operation in the forced consumption mode.

Image forming apparatus

A developing apparatus includes a partition member disposed in a first chamber above a discharge space communicated to the discharge port positioned downstream of a return conveyance portion in the first direction, and configured to divide a space within a first chamber in a gravity direction. The partition member is configured to extend from a wall portion on a downstream side of a developer container to a position corresponding to a downstream end of a return conveyance portion or to a position further upstream beyond the position corresponding to the downstream end of the return conveyance portion in the first direction. A surface, opposed to a first conveyance screw, of the partition member is positioned downward in the gravity direction than an upper end of a first communication port and upward in the gravity direction than the first conveyance screw.

Developing apparatus

An image forming apparatus includes an image bearing member, a developing device that develops an electrostatic latent image formed on the image bearing member, a toner bottle having a storage portion storing the toner and a discharge portion made of resin and discharging the toner stored in the toner storage portion, and an attachment portion attached with the toner bottle. A driving portion drives the storage portion, a controller controls the driving portion, and a memory disposed in the toner bottle memorizes information regarding component dimensions of a molded discharge portion of the toner bottle. An information reading portion reads information regarding the component dimensions of the molded discharge portion, and the controller controls the driving portion so that a discharge amount of the toner from the discharge portion becomes a specific toner amount targeted based on the information regarding the component dimensions of the molded discharge portion.

Image forming apparatus having controlled toner discharge amount

Image forming apparatus with forced consumption mode for toner

In a developing device in which initial developer is sealed in and a developer discharge mechanism (a trickle mechanism, or an ACR mechanism) is provided, the driving-torque load generated in the developing device is suppressed, regardless of the state of distribution of the developer that is sealed in the developing device. The order of releasing seals provided over openings is defined as follows. First, a seal provided on the downstream side of a stirring chamber starts to be released. Then, a seal provided over a discharge port is released. Lastly, a seal provided on the upstream side of the stirring chamber starts to be released.

Sealing apparatus for developing device

A developing unit includes a developer carrier, and first and second chambers to collect and circulate developer. A partition separates the first and second chambers and has first communication portion disposed more downstream in the second chamber and a second communication portion disposed more upstream in the second chamber. A first conveying member is disposed in the first chamber, and a second conveying member is disposed in the second chamber and includes a spiral blade portion, a reverse spiral blade portion helically wound in an opposite direction of the spiral blade portion and disposed downstream of the spiral blade portion, and a discharging portion provided downstream of the reverse spiral blade. An upstream end of the first communication portion is positioned farther than a downstream end of the second communication portion from a center of the developer carrier in a rotational axis direction of the developer carrier.

Developing unit

An image forming apparatus includes an image bearing member, a developing device, a driving device, and a controller. The developing device includes a developing container, a first feeding member, a second feeding member, a developer carrying member, a content sensor, and a sealing member. Wherein when the controller executes an initializing operation for removing the sealing member from the first opening and the second opening while driving the first feeding member and the second feeding member, the controller provides notification of abnormality when the controller discriminates that an amount of the developer in the second chamber is larger than a predetermined amount at a predetermined timing on the basis of an output of the content sensor.

Image forming apparatus having toner content sensor

A developing unit includes a developing container, a developing sleeve, a developer regulating member, and a magnetic field generating portion. The magnetic field generating portion includes a drawing-up pole and a cut pole. In addition, in a peak-to-peak area, the magnetic field generating portion includes at least one of an Fr flat area in which Fr is substantially constant and an Fr attenuation area in which Fr attenuates toward the cut pole side from the drawing-up pole side, and is configured that F&#x3b8; is oriented toward the same direction as a direction of rotation of the developing sleeve in the entire peak-to-peak area.

An image forming apparatus includes an image bearing member, a developing device, a supplying device, and a controller. The controller can execute a normal supply mode and a forced supply mode on the basis of a difference between a toner supply amount in the normal supply mode and a supply amount of the toner to be supplied to the developing device. In a case where the flag is set when a predetermined time is elapsed after the difference exceeds the predetermined threshold, image formation is effected and then interrupted, and then the controller executes the operation in the forced supply mode, and in a case where the flag is reset when the predetermined time is elapsed after the difference exceeds the predetermined threshold, the image formation is effected and then said controller continues an image forming operation without executing the operation in the forced supply mode.

Image forming apparatus with forced supply mode for forcedly supplying toner

A developing device includes a developer carrying member, a first chamber, a second chamber, a first feeding member, and a second feeding member. The second feeding member includes first to third spiral portions and a disk portion. The disk portion includes a projected portion. When the disk portion is seen in an axial direction of the second feeding member, on the basis of a line connecting a rotation center of the disk portion and an upstream end portion of the third spiral portion with respect to a feeding direction of the third spiral portion, the projected portion is provided within a range from a position deviated by 90 degrees toward a downstream side with respect to a rotational direction of the disk portion to a position deviated by 30 degrees toward an upstream side with respect to the rotational direction of the disk portion.

An image forming apparatus includes an image forming unit including a containing unit that contains a developer including toner and forms an image based on image data by using the toner, a supply unit that supplies the toner into the containing unit, a consumption amount calculation unit that calculates, based on information related to a density of an image corresponding to the image data, a consumption amount in the containing unit, a detection unit that detects a toner density of the developer in the containing unit, a correction amount calculation unit that calculates, based on the information and the toner density detected by the detection unit, a correction amount by which the consumption amount is corrected, and a controller that controls the supply unit based on the consumption amount and the correction amount calculated by the correction amount calculation unit.

Image forming apparatus supplying toner based on toner density of developer contained in containing unit and method for controlling image forming apparatus

A controller for an image forming apparatus includes a difference calculating portion for calculating a difference between a consumption value depending on an amount of the toner consumed every predetermined unit and a reference value; and a difference integrating portion. When an integrated value of the difference is larger than a predetermined threshold, the controller executes an operation in a forced consumption mode so that the toner is consumed in an amount corresponding to a predetermined value obtained by multiplying the predetermined threshold by a coefficient of less than 1. When the operation is executed, the integrating portion sets, at a reset value, a value obtained by subtracting the predetermined value from the integrated value at that time. After the operation is executed, the controller executes the operation every time when an integrated value obtained by integrating the reset value and the difference is larger than the predetermined threshold.

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Toride, Japan

Fumiyoshi Saito