Canon Kabushiki Kaisha

Yusuke Minato

Takenori Sueoka

Yutaka Kakehi

Tetsuya Ohta

Tatsuya Kohno

Izuru Tanaka

Ryosuke Tsuruga

Manato Kobayashi

Mitsuru Yamatani

An image forming apparatus includes an image bearing member, an image forming portion, a transfer member, a power source, an acquiring portion, and a controller capable of executing an operation in an adjustment mode. A plurality of test toner images transferred onto a recording material in the occurrence in the adjusting mode include a first test toner image transferred under application of a first test voltage and a second test toner image transferred under application of a second test voltage different from the first test voltage. In the operation in the adjustment mode, the controller adjusts the transfer voltage set for transfer on the basis of first information on variation in image density acquired in different regions of the first test toner image and second information on variation in image density acquired in different regions of the second test toner image.

Image forming apparatus operable in plural modes to set transfer voltage

In a cross-section perpendicular to a rotational axis of a first image bearing member, when a common tangential line between the first image bearing member and a second image bearing member on an intermediary transfer belt side is a rectilinear line L, a rectilinear line passing through a rotation center of the first image bearing member and a rotation center of a first transfer member is a rectilinear line P, and a rectilinear line passing through an intersection point between the rectilinear line P and the first image bearing member and perpendicular to the rectilinear line P is a rectilinear line Q, an electrode member is constituted so that the contact portion contacting an inner surface of the belt is positioned further on a first image bearing member side than the rectilinear line L is and further on a first transfer member side than the rectilinear line Q is.

Image forming apparatus

An image forming apparatus includes an image bearing member, a transfer device, an applying portion; a detecting portion, a controller, and a receiving portion. The controller executes an operation in a setting mode in which during non-image formation, test images are transferred onto the recording material at different test voltages to the transfer device and then a transfer voltage applied to the transfer device during image formation is set on the basis of a detection result of the detecting portion. In a case that the operation in the setting mode is executed to set the transfer voltage for one-side mode, the receiving portion is capable of receiving instruction information selectively instructing a setting condition of the transfer voltage set by the operation in the setting mode from setting conditions including a first setting condition and a second setting condition.

Image forming apparatus operable in plural settting modes

An image forming apparatus includes an image bearing member, an image forming portion, transfer member, a power source, a current detecting portion, an acquiring portion, and a controller capable of executing an operation in an adjustment mode. In the operation in the adjustment mode, the controller selects test toner images for setting a transfer voltage for a second side of a recording material, on the basis of information on densities of the test toner images acquired by the acquiring portion, and then adjusts the transfer voltage for the second side of the recording material on the basis of a current detected by the current detecting portion when the selected test toner images are transferred onto the recording material.

Image forming apparatus using test chart in two-sided printing

An image forming apparatus includes an image bearing member, an intermediary transfer belt, a transfer member, a voltage source for applying a voltage to the transfer member, a detecting portion for detecting a current flowing through the transfer member, and a controller for carrying out constant-voltage control so that the voltage applied to the transfer member becomes a target voltage when a recording material P passes through a transfer portion. The controller is capable of changing the voltage applied to the transfer member so that a detection result detected by the detecting portion during transfer falls within a predetermined range. The controller changes the predetermined range on the basis of the detection result detected by the detecting portion when the voltage is applied to the transfer member in a state in which the recording material P is absent in the transfer portion.

An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a current detecting portion, and a controller. In a case that the predetermined voltage is changed in a first job on the basis of the detection result of the current detecting portion during passing of the recording material through the transfer portion, in a second job subsequent to the first job, when a first recording material of the second job passes through the transfer portion, the controller changes a voltage applied to the transfer member on the basis of the predetermined voltage changed in the first job.

Image forming apparatus with controller for controlling voltage at transfer nip

An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a current detecting portion, and a controller. When the recording material passes through the transfer portion, the controller is capable of changing the predetermined voltage on the basis of a detection result of said current detecting portion so that the detection result of the current detecting portion falls within a predetermined range. A maximum changeable amount per once of the predetermined voltage is larger when a leading end portion of the recording material with respect to a recording material feeding direction passes through the transfer portion than when a central portion of the recording material with respect to the recording material feeding direction passes through the transfer portion.

An image forming apparatus includes an image bearing member, a transfer roller, a power feeding rotary member, and a controller. The controller is configured to execute the cleaning mode such that a period in which the cleaning mode is executed comprises a first application period during which a reverse polarity bias having a polarity reverse to that of the transfer bias is continuously applied to the power feeding rotary member, and a second application period during which a same polarity bias having a same polarity with that of the transfer bias is continuously applied to the power feeding rotary member.

An image forming apparatus includes an image bearing member; an electrostatic image forming unit; a developing device; an intermediary transfer member; a rotatable transfer member; a constant-voltage element; a power source; a cleaning device; an executing portion capable of executing a toner image collecting mode after jam clearance; and a controller for controlling the power source in an operation in a collecting mode so that a voltage of an identical polarity to a charge polarity of the toner is applied to the rotatable transfer member to transfer, onto the intermediary transfer member, the toner in an upstream-side end region of the toner image carried on the image bearing member with respect to the rotational direction of the image bearing member, and then a voltage of an opposite polarity to the charge polarity of the toner is applied to the rotatable transfer member.

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Kashiwa, Japan

Yusuke Minato