Canon Kabushiki Kaisha

Yutaka Kakehi

Ryosuke Tsuruga

Manato Kobayashi

Tetsuya Ohta

Tatsuya Kohno

Yusuke Minato

Takashi Fujita

Haruhiko Omata

Yasuharu Chiyoda

Hideaki Kosasa

Toshiyuki Yamada

Keisuke Mogi

Hiroshi Kokubo

Shingo Iwami

Ryo Aihara

Shin Ono

A charge eliminating apparatus configured to remove charges from a sheet on which an image is formed by a printing apparatus, includes a charge eliminating roller pair including a first charge eliminating roller and a second charge eliminating roller configured to form a nip portion together with the first charge eliminating roller, the charge eliminating roller pair being configured to remove the charges from the sheet in a state of contacting the sheet at the nip portion, a first setting unit configured to set a value of a voltage applied to the charge eliminating roller pair, and a second setting unit configured to set whether to apply the voltage to the charge eliminating roller pair, wherein the second setting unit is configured to set whether to apply the voltage to the charge eliminating roller pair without changing the value of the voltage set by the first setting unit.

Charge eliminating apparatus, image forming apparatus, and charge adjusting 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.

Image forming apparatus

An image forming apparatus includes an image forming portion, a rotatable endless belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, a guiding member, a sheet-like pressing member, and a coating member. The coating member is disposed on the pressing member so as not to contact the belt and is electrically grounded or electrically conducted to the guiding member. The coating member is formed of a material lower in surface resistivity than the pressing member.

Image forming apparatus with coated belt pressing member

An image forming apparatus, which carries out constant-voltage control of a voltage applied to a transfer memberand is capable of executing limiter control for controlling the voltage applied to the transfer memberbased on a detection result of a current detecting portionso that the detection result falls within a predetermined range, is capable of executing a first mode in which a toner image is transferred onto a recording material P and a second mode in which a plurality of test toner images are transferred onto the recording material P by applying a plurality of different voltages to the transfer member, and a controlleris capable of carrying out the limiter control while the recording material P passes through the transfer portionin executing the first mode and does not carry out the limiter control while an area onto which the plurality of test images are transferred passes through a transfer portion Nin executing the second mode.

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, which carries out constant-voltage control of a voltage applied to a transfer member and is capable of executing limiter control for controlling the voltage applied to the transfer member based on a detection result of a current detecting portion so that the detection result falls within a predetermined range, is capable of executing a first mode in which a toner image is transferred onto a recording material and a second mode in which a plurality of test toner images are transferred onto the recording material by applying a plurality of different voltages to the transfer member. A controller is capable of carrying out the limiter control while the recording material passes through the transfer portion in executing the first mode and does not carry out the limiter control while an area onto which the plurality of test images are transferred passes through a transfer portion in executing the second mode.

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, a controller, and a receiving portion. During the recording material passing through the transfer portion, the controller controls a voltage applied to a transfer member on the basis of a detection result of the current detecting portion so that a current flowing through the transfer member falls within a predetermined range. The controller sets at least one of an upper limit and a lower limit of the predetermined range on the basis of a predetermined voltage changing instruction received by the receiving portion.

An image forming apparatus includes a belt, image forming unit, first and second transfer rollers, feeding portion, stretching roller and urging member. Regarding (1) a contact point between (i) an outer common tangential line between the stretching and first transfer rollers and (ii) the first transfer roller and (2) an intersection point between (i) the outer common tangential line and (ii) a line perpendicular to the outer common tangential line and passing through a rotation center of the second transfer roller, the contact point is closer to the stretching roller than the intersection point is to the stretching roller and a distance between the contact and intersection points is 5% or more of a diameter of the first transfer roller. The urging member urges the belt from an inner belt surface at a position, close to a transfer portion, between the first transfer roller and the belt.

Image forming apparatus having transfer belt configured to avoid image defects

An image forming apparatus includes a movable endless belt, an image forming unit, a plurality of rollers including a first roller and a second roller, and an urging member. The urging member is provided on an inner peripheral surface side at a position which is adjacent to and upstream of the first roller and which is downstream of the second roller with respect to a movement direction of the belt. The urging member is supported at an upstream end portion thereof with respect to the movement direction of the belt and includes a first urging portion and a second urging portion at two different positions with respect to the movement direction of the belt. The first urging portion and the second urging portion urge the belt along a widthwise direction crossing the movement direction of the belt.

An image forming apparatus includes: an image bearing member; a toner image forming unit; an endless transfer belt; a transfer roller urged from an inner peripheral surface of the transfer belt toward the image bearing member via the transfer belt; a feeding surface forming roller, provided downstream of the transfer roller with respect to a traveling direction of the transfer belt, having such a shape that a diameter at each of end portions is smaller than a diameter at a central portion with respect to a rotational axis direction; and a stretching roller, downstream of the feeding surface forming roller with respect to the traveling direction of the transfer belt, having such a shape that a diameter at each of end portions is larger than a diameter at a central portion with respect to the rotational axis direction.

Image forming apparatus having transfer belt rollers of specific shapes

An outer roller is provided at a position offset upstream, in a rotation direction of an image carrying belt, of an inner roller. The inner and outer rollers are provided across the image carrying belt and form a transfer nip portion nipping and conveying a recording medium. A press member presses the image carrying belt from an inner circumferential side at upstream of the inner roller. The press member is provided such that a length along a belt surface of the image carrying belt between a downstream end of a part thereof in contact with the image carrying belt and an upstream end of the transfer nip portion is shorter than a length of an end margin formed on an upstream end area of the recording medium.

Image forming apparatus using press member to prevent deflection of belt

An image forming apparatus includes a pushing member pushing an image carrying belt from an inner circumferential side and a guide member guiding a recording medium toward a transfer nip portion formed with an inner-side roller and an outer-side roller. The guide member includes first and second guides and the second guide is provided such that a tip end on the side of the transfer nip portion is positioned further away from the image carrying belt than a reference line that connects a point at which a line connecting the rotational center of the inner-side roller and the rotational center of the outer-side roller intersects with the image carrying belt, and a furthest downstream contact point of a contact area in which the pushing member contacts with the image carrying belt.

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Kashiwa, Japan

Yutaka Kakehi