Canon Kabushiki Kaisha

Tatsuya Kohno

Yutaka Kakehi

Ryosuke Tsuruga

Manato Kobayashi

Yusuke Minato

Takenori Sueoka

Atsushi Matsumoto

Dai Kanai

Shozo Aiba

Yuusuke Torimaru

Takahito Fuse

Mitsuru Yamatani

Hiroaki Ishida

An image forming apparatus includes an image bearing member and a developer bearing member. A first period is from when rotational drive of the developer bearing member is started until increased to a speed at which the image forming apparatus performs image forming. A first absolute value of a difference between a developer bearing member surface potential Vdc and an image bearing member surface potential Vd, as determined when the image bearing member is facing the developer bearing member, is obtained during the first period. The value |Vdc−Vd| obtained during the first period is smaller than the value |Vdc−Vd| obtained after the first period. During the first period, the image bearing member surface potential Vd at the facing position is a first potential and, after the first period, the image bearing member surface potential Vd at the facing position becomes a second potential different from the first potential.

Image forming apparatus

An image forming apparatus includes an image forming portion, a belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, an urging member, a first position changing mechanism, a storing portion, a controller, and an operating portion. The controller controls the first position changing mechanism on the basis of a kind of a recording material on which an image is formed, first set information stored in the storing portion, and first input information for changing setting of a position of the urging member inputted to the controller through the operating portion.

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 forming portion, a belt, an inner roller, an outer member, an inner roller position changing mechanism, an acquiring portion, and a controller. In a case that information acquired by the acquiring portion shows that first and second recording materials are coated paper, the controller controls a position changing mechanism so that a position of the inner roller when a toner image is transferred onto the second recording material is changed to a second position. In a case that the information acquired by the acquiring portion shows that the first and second recording materials are plain paper, the controller controls the position changing mechanism so that the position of the inner roller when the toner image is transferred onto the second recording material is maintained at a first position.

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 a belt, an outer roller, stretching rollers including an inner roller and an upstream roller, a voltage source, a supporting member, a moving mechanism, a sensor, and a controller. On the basis of a first detection result of the sensor acquired under application of a test bias in a state in which the supporting member is disposed at a first position, the controller determines a first transfer bias to be applied to the outer roller or the inner roller during an operation in a first mode. On the basis of a second detection result of the sensor acquired under application of the test bias in the state in which the supporting member is disposed at a second position, the controller determines a second transfer bias to be applied to the outer roller or the inner roller during an operation in a second mode.

An image forming apparatus includes an endless belt, an inner roller, an upstream roller, a pressing member, and a guiding member. In a cross-section perpendicular to a rotational axis of the inner roller, a downstream free end of the guiding member is disposed downstream of a pressing portion normal line Lc with respect to a feeding direction of the sheet, where L is a reference line which is a common tangent of the inner roller and the upstream roller in a contact portion relative to the belt, Ld is a pressing portion tangent line, parallel with the reference line, of the belt in a region where the pressing member contacts the belt, and Lc is the pressing portion normal line passing through a contact point between the belt and the pressing portion tangent line Ld and perpendicular to the reference line L.

Growing community of inventors

Abiko, Japan

Tatsuya Kohno