Canon Kabushiki Kaisha

Hiroki Takayanagi

Yuji Bessho

An image forming apparatus includes an image carrier, an image forming unit, an intermediate transfer belt, a power supply, a transfer member to transfer toner image on the intermediate transfer belt to a recording medium, and a sensor to detect, as density information, a density of the recording medium toner image. In an adjustment mode, (i) a test recording medium is output as a test chart by applying multiple levels of test voltages to the transfer member to transfer test toner images to the test recording medium, (ii) the transferred test toner images are detected via the sensor, and (iii) a transfer voltage is adjusted based on the sensor detection. In the adjustment mode, test toner image groups are set, one test toner image group is extracted based on an index value, and the transfer voltage is adjusted based on the density information of the extracted test toner image group.

Image forming apparatus

An image forming apparatus provides a configuration capable of suppressing an increase in the resistance of an intermediate transfer belt. The image forming apparatus includes an electrification unit for electrifying an intermediate transfer belt to suppress an increase in resistance of the intermediate transfer belt.

An image forming apparatus includes a detecting portion to detect a test toner image formed on an image bearing member, and a shielding member is provided between the detecting portion and the image bearing member and reciprocates between first and second positions. A first opposing portion includes a first member opposed to the image bearing member and provided at a position opposing the image bearing member through an opening in a process of movement of the shielding member, an electrically grounded electroconductive member is disposed in a side opposite a side of the first member opposed to the image bearing member; and a second opposing portion is disposed opposed to the image bearing member and provided at position opposing the image bearing member through the opening in the process of movement of the shielding member from the second position to the first position.

An image forming apparatus comprises a drum for carrying a toner image; a transfer member for contacting the drum to form a transfer nip, the transfer member being capable of electrostatically transferring the toner image from the drum onto a sheet; a fixing unit provided, downstream of the transfer member with respect to a sheet feeding direction, for fixing the toner image on the sheet by a fixing nip; a first current path provided between the fixing nip and a ground potential; a feeding unit, provided downstream of the fixing unit, for feeding the sheet while nipping by a feeding nip; a guiding member, disposed downstream of the feeding unit, for feeding the sheet passing through the transfer nip; and a second current path provided between the feeding nip and the ground potential, the second path having an electric resistance which is lower than that of the first path.

Image forming apparatus with recording material separation feature

An image forming apparatus includes an image bearing member, an image forming device for forming a toner image on the image bearing member, a recording material, a transfer device for transferring the toner image from the image bearing member to the recording material, a transfer belt for carrying the recording material, a first cleaning member, a second cleaning member, and a voltage control device. When continuously forming toner images on sheets of the recording material, a detection toner image is formed on the image bearing member between images to be formed on sheets of the recording material. The first cleaning member cleans the image bearing member. The second cleaning member cleans the transfer belt. The voltage control device controls the voltage applied to the transfer device so that the number of operations to clean the detection toner image is higher for the second cleaning member than the first cleaning member.

An image forming apparatus includes an image bearing member; an image forming portion for forming a toner image on the image bearing member; an intermediary transfer belt for carrying the toner image transferred from the image bearing member; a transfer belt for carrying and conveying a recording material; an attraction portion for electrostatically attracting the recording material to the transfer belt; a transfer portion for transferring the toner image from the intermediary transfer belt onto the recording material attracted to the transfer belt; and an electrode member, disposed downstream of the attraction portion and upstream of the transfer portion with respect to a movement direction of the transfer belt, being contacted to an inner surface of the transfer belt.

Electrostatic image forming apparatus having electrode for suppressing electric discharge

An image forming apparatus includes an image bearing member that is rotatable, a toner image forming portion that is able to form a toner image to be transferred to a transfer material and a control toner image not to be transferred to a transfer material on the image bearing member, a transfer member that transfers the toner image formed on the image bearing member to the transfer material, a detecting portion that detects a density of the control toner image, an adjustment portion that adjusts a toner image formation condition of the toner image forming portion based on an output of the detecting portion, a cleaning member that electrostatically cleans the transfer member, and a controller which changes a voltage or a current to be applied between the transfer member and the cleaning member based on the density of the control toner image.

Image forming apparatus with cleaning voltage or current control based on density of a control toner image

An elastic layer and a top layer of an intermediate transfer belt are configured such that an elastic modulus in a sub-scanning direction is larger than an elastic modulus in a main-scanning direction. Accordingly, when a toner image is transferred onto the intermediate transfer belt, a pressure applied to and affect on a toner is reduced as well as deformation at a sliding-contact portion between the intermediate transfer belt and a cleaning blade can be suppressed.

Image forming apparatus with cleaning member

An image forming apparatus includes a pair of regulating members, for regulating movement of a recording material conveyed from a secondary transfer portion toward an intermediary transfer belt side, configured to be contactable to the recording material at both end portions with respect to a width direction perpendicular to a conveyance direction of the recording material; a moving mechanism capable of moving a position of the pair of regulating members with respect to the width direction; a recording material size detecting portion for obtaining width information of the recording material with respect to the width direction perpendicular to the conveyance direction; and a width control portion for controlling the moving mechanism so that the pair of regulating members to a position correspondingly to the width information obtained by the recording material size detecting portion.

An image forming apparatus includes an image bearing member; a rotatable transfer roller; a contact separation unit; a driving force transmission portion; a cleaning member; and a control portion. The cleaning member is for removing toner adhering to the transfer roller by contacting with the transfer roller when the transfer roller is in contact with and separated from the image bearing member. The cleaning member cleans the transfer roller in: (i) a first mode in which the cleaning member cleans the transfer roller while the transfer roller in contact with the image bearing member rotates at a first peripheral velocity, and (ii) a second mode in which the cleaning member cleans the transfer roller while the transfer roller separated from the image bearing member rotates at a second peripheral velocity. The control portion controls a voltage applied to the cleaning member according to the peripheral velocity of the transfer roller.

Image forming apparatus with cleaning member to remove toner from transfer roller

An image forming apparatus includes an image bearing member, a rotatable transfer roller, a contact separation unit, a driving force transmission portion, a cleaning member, and a control portion. The cleaning member cleans the transfer roller in: (i) a first mode in which the transfer roller rotates with a first peripheral velocity difference while the transfer roller is in contact with the image bearing member, and (ii) a second mode in which the transfer roller rotates with a second peripheral velocity difference while the transfer roller is separated from the image bearing member. The control portion controls a voltage applied to the cleaning member such that a value of the voltage in the first mode or the second mode, which has a smaller peripheral velocity difference between the first peripheral velocity difference and the second peripheral velocity difference, is smaller than the value of the voltage in the other mode.

Image forming apparatus with a cleaning member to remove toner from a transfer roller

An image forming apparatus has: an intermediate transfer member to which a primary transfer voltage having a positive polarity is applied and the toner image is primarily transferred in which a reverse voltage having a negative polarity is applied; a primary transfer device which primarily transfers the toner image by applying the primary transfer voltage; a secondary transfer device which secondarily transfers the toner image by applying a secondary transfer voltage; and a resistance adjusting device which controls at least either the primary transfer device or the secondary transfer device in such a manner that while the intermediate transfer member rotates once, a first correction voltage is applied to the area where the primary transfer voltage has been applied and a second correction voltage higher than the first voltage is applied to the area where the reverse voltage has been applied.

Image forming apparatus with voltage control

An image forming apparatus is capable of reducing the time when it is unable to perform image formation due to a temperature change of an image bearing member. The apparatus includes a rotatable image bearing member; an electrostatic image forming device for continuously forming electrostatic images on the image bearing member based on forming image amount information; a toner image forming device for developing the electrostatic image and forming a toner image; a primary transferring device for transferring the toner image on the image bearing member to a rotatable intermediate transferring member; a simultaneously transferring and fixing device for transferring the toner image on the intermediate transferring member to a recording material and heating and fixing it; a detector detects a temperature of the image bearing member; and a starting device starts the electrostatic image forming device based on a detection result and the forming image amount information.

Image forming apparatus capable of reducing time unable to perform image formation due to temperature change of image Bearing member

An image forming apparatus including an image bearing member for bearing a toner image and a contact transfer member. The contact transfer member has a temperature-dependent resistance value and contacts the image bearing member. The contract transfer member is applied with a voltage so as to transfer the toner image on the image bearing member to a transfer material, wherein the contact transfer member is heated or cooled in such a way that the resistance value of the contact transfer member is changed in response to the type of the transfer material.

Image forming apparatus with resistance controlled transfer member

An image forming apparatus is capable of reducing the time when it is unable to perform image formation due to a temperature change of an image bearing member. The apparatus includes a rotatable image bearing member; an electrostatic image forming device for continuously forming electrostatic images on the image bearing member based on forming image amount information; a toner image forming device for developing the electrostatic image and forming a toner image; a primary transferring device for transferring the toner image on the image bearing member to a rotatable intermediate transferring member; a simultaneously transferring and fixing device for transferring the toner image on the intermediate transferring member to a recording material and heating and fixing it; a detector detects a temperature of the image bearing member; and a starting device starts the electrostatic image forming means based on a detection result and the forming image amount information.

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Abiko, Japan

Hiroki Takayanagi