Abstract: 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.

Abstract: An image forming apparatus includes a photosensitive member, a developing member to supply a toner to the photosensitive member at a developing portion, and a transfer member to transfer a toner image to a recording material passing through a transfer portion from the photosensitive member. In a case which the transfer is performed to a shorter width recording material and thereafter, the transfer is successively performed to a longer width recording material, a control portion controls a first back contrast formed when an area of a surface of the photosensitive member corresponding to the transfer portion through which the shorter width recording material is passing reaches the developing portion, and a second back contrast formed when an area of the surface corresponding to the transfer portion through which the longer width recording material is passing reaches the developing portion so that the second back contrast is higher than the first back contrast.

Abstract: A transfer device includes an intermediate transfer member that has an outer peripheral surface to which a toner image is to be transferred, a primary transfer device that has a primary transfer member performing primary transfer of a toner image formed on a surface of an image holder to the outer peripheral surface of the intermediate transfer member, a secondary transfer device that has a secondary transfer member which is arranged in contact with the outer peripheral surface of the intermediate transfer member and performs secondary transfer of the toner image transferred to the outer peripheral surface of the intermediate transfer member to a surface of a recording medium, and a cleaning device that has a cleaning blade cleaning the outer peripheral surface of the intermediate transfer member, in which a coefficient D of dynamic friction between the intermediate transfer member and the cleaning blade is 0.2 or more and 1.

Abstract: An image forming apparatus comprises a main body casing; a fixing unit which fixes a developer to a sheet by means of heating and pressurization; a fan which is provided to discharge air inside the main body casing to outside of the main body casing; and a controller. The fixing unit includes a heating unit which heats the sheet; and a temperature sensor which detects a temperature of the heating unit. When the fixing unit is fixing the developer to the sheet, the controller is configured to: determine a heating unit temperature based on the temperature detected by the temperature sensor; stop the fan in a case of determining that the heating unit temperature is not less than a threshold value; and drive the fan in a case of determining that the heating unit temperature is less than the threshold value.

Abstract: A cleaning device includes: a cleaning brush that has bristles that rotate and contact a surface, to which toner has adhered, of a cleaning member to be cleaned, the cleaning brush removing the toner adhered to the surface of the cleaning member; a first contact member that contacts the bristles without a position of the first contact member relative to a position of the cleaning brush being changed; and a second contact member that contacts the bristles at a location downstream from the first contact member in a direction of rotation of the cleaning brush and without a position of the second contact member relative to the position of the cleaning brush being changed, and that is disposed on an extension line extended from a line between an axial center of the cleaning brush and a base of the bristles that move away from the first contact member.

Abstract: An image forming apparatus includes first and second rotatable members forming a nip therebetween, a heater disposed in inside of the second rotatable member, a first temperature sensor provided on a center of the heater, a second temperature sensor provided on an end side of the heater. A controller controls a feeding interval in which a trailing edge of a preceding sheet passes through the nip until a leading edge of a subsequent sheet reaches the nip. The controller controls the feeding interval to be a first interval in a case which a feeding speed of the sheet is a first speed and a detected temperature by the second sensor is a first temperature, and to be a second interval shorter than the first interval in a case which the feeding speed is a second speed lower than the first speed and the detected temperature is the first temperature.

Abstract: A fixing device includes: a heating section that heats in a non-contact manner a front surface of a recording medium; a feeding section that feeds the recording medium while causing the front surface to be opposed to the heating section; and a maintaining section that, in order to enable the recording medium to be fed by the feeding section while a rear surface that is opposite to the front surface, and that is in an image region where an unfixed-image is formed on the front surface is in a non-contact state, maintains the non-contact state.

Abstract: An image forming apparatus includes a temperature sensor, a conveyance control portion, a driving control portion, an adjustment processing portion, and a stop processing portion. The temperature sensor is provided apart from a contact position between a fixing member and a transferred sheet to which a toner image has been transferred. The conveyance control portion continuously executes conveyance processes of conveying the transferred sheet. The driving control portion controls driving of a heater for heating the fixing member so that a temperature detected by the temperature sensor matches a predetermined temperature. The adjustment processing portion restricts the execution of the conveyance process until an adjustment process of adjusting a formation condition of the transferred sheet is completed. The stop processing portion stops the continuous execution of the conveyance processes when the restriction on the execution of the conveyance process continues beyond a predetermined timing.

Abstract: A two-wire displacement sensor device includes an LC oscillation circuit including a coil whose inductance changes in accordance with a displacement amount of an object and an oscillation unit provided with capacitors and amplifying elements; and an interface unit serving as a signal output unit and a power supply input unit. The interface unit includes a constant current circuit that outputs at least two current values.

Abstract: An image forming apparatus include an image forming device, an image bearer, a transferrer, a cleaner, and an adhesion amount detector. The image forming device forms, on the image bearer, a toner image to be transferred to a recording medium and a toner image pattern to be input to the cleaner without being transferred to the recording medium. The cleaner cleans the image bearer. The adhesion amount detector detects a toner adhesion amount of the toner image. The toner image pattern is a belt-shaped pattern elongated in an orthogonal direction orthogonal to a traveling direction of the image bearer and having a greater amount of toner input to a portion of the cleaner corresponding to a position of the adhesion amount detector in the orthogonal direction than that input to a portion of the cleaner not corresponding to the position of the adhesion amount detector in the orthogonal direction.

Abstract: An image forming apparatus includes: a toner feed body that is an endless belt holding a toner image, or is a transfer member transferring a toner image to a recording medium nipped between the endless belt and the transfer member; an electric charge imparting member that is provided so as to face a surface of the toner feed body and increases an amount of electric charges of toner adhering to the surface of the toner feed body; and a toner attracting member that is provided at a more downstream part of the toner feed body than the electric charge imparting member in a feed direction of the toner feed body and attracts the toner by being applied with a voltage having a polarity opposite to a polarity of the toner adhering to the surface of the toner feed body.

Abstract: An image forming apparatus includes an image forming unit, a fixer, first and second temperature sensors, and storage and control units. The fixer fixes an image formed on the sheet by pressing. The first temperature sensor is disposed away from the image forming unit and the fixer, and measures an ambient temperature. The second temperature sensor is disposed closer to the image forming unit than the first temperature sensor, and measures an ambient temperature. The storage unit stores one or more difference values between first and second temperatures measured by the first and second temperature sensors when a switching condition is satisfied. When a difference between the one or more difference values in the storage unit and a latest difference value is equal to or larger than a threshold, the control unit stores information indicating that a reference value for determining an abnormality is exceeded.

Abstract: An image forming apparatus includes a rotatable photosensitive member; a charging portion, an exposure portion, a developing member, a transfer unit, a contact and separation portion, a charging voltage applying portion, a detecting portion, and a controller. The controller is capable of executing an operation in an image forming mode and an operation in a detecting mode. The controller carries out control so that a charging current flowing through a charging portion during charging of the photosensitive member in the operation in the detecting mode is lower than a charging current flowing through the charging portion during charging of the photosensitive member in the operation in the image forming mode.

Abstract: A transfer belt unit for use with an image forming apparatus includes: a transfer belt; and a belt memory. The transfer belt is configured to transfer toner on a photosensitive drum of the image forming apparatus onto a sheet conveyed to a portion between the photosensitive drum and the transfer belt. The transfer belt is also configured to make contact with a cleaning roller of the image forming apparatus and to be cleaned by the cleaning roller. The belt memory includes: a first storage area configured to store therein a first rotation time period indicating a total of a period of time that the cleaning roller rotates at a first rotational speed; and a second storage area configured to store therein a second rotation time period indicating a total of a period of time that the cleaning roller rotates at a second rotational speed faster than the first rotational speed.

Abstract: A test apparatus for testing device under test (DUT) having an antenna located on the DUT is disclosed. The test apparatus includes: a housing, a socket configured to electrically connect the DUT to a load board, a gripper assembly configured to hold the DUT in place, a retractor configured to release the DUT from the gripper assembly, and an alignment plate configured to align the DUT with the socket. The gripper assembly includes a base and an extender, the base is attached to the housing, and the extender is configured to hold the DUT in place. When the retractor is disengaged from the extender, the extender is configured to hold the DUT in place. When the retractor is engaged with the extender, the extender is configured to release the DUT on the alignment plate.

Abstract: A fixing device includes a fixing roller and a pressure roller provided in a rotatable manner, a heat source for heating the fixing roller, and a controller for controlling AC power supplied to the heat source. The fixing device fixes an unfixed image on a sheet held and conveyed by the fixing roller and the pressure roller. The controller causes a current to flow including current-carrying waveforms having different phase angles in half-wave units during preset control cycles.

Abstract: In a cartridge, a housing has a developer accommodating portion and includes a first side wall and a second side wall. A coupling member is disposed at a position opposite to the developer accommodating portion with respect to the first side wall. A detection body is disposed at a position opposite to the developer accommodating portion with respect to the second side wall. A first driving force transmission member is positioned at the same side with the coupling member with respect to the first side wall, and transmits driving force from the coupling member to a rotating member. A second driving force transmission member is positioned at the same side with the detection body with respect to the second side wall, and transmits driving force from the rotating member to the detection body.

Abstract: An image forming system includes: an image forming apparatus that includes a transfer device that transfers a toner image onto a sheet and a fixing device that fixes the toner image; a sheet heating device that heats the sheet on an upstream of the fixing device in a sheet conveyance direction; a first detector that detects a temperature inside the image forming apparatus; a second detector that detects a temperature of the sheet before the sheet heating device heats the sheet; and a controller that causes the sheet heating device to heat the sheet based on a detection result by the second detector and a sheet passing condition of the sheet, and corrects at least one of a transfer current and a transfer voltage in the transfer device based on a detection result by the first detector in a case where the sheet heating device heats the sheet.

Abstract: According to one embodiment, there is provided a temperature abnormality detection circuit provided in a temperature control device includes a target temperature determination circuit, a difference arithmetic circuit, a temperature abnormality determination circuit, and a storage circuit. The temperature abnormality detection circuit is configured to determine the presence or absence of temperature abnormality by a response situation of a detected temperature by a temperature sensor, calculate a current temperature difference from the detected temperature acquired by the temperature sensor if it is determined that there is a temperature abnormality and an estimated WAE temperature value, and determine whether the temperature sensor is abnormal or the control circuit side is abnormal based on the result of comparison between the temperature difference and a preset threshold value.

Abstract: An image forming apparatus includes a rotatable image bearing member and a rotatable developing member to carry developer made up of toner particles and carrier particles adhered to surfaces of the toner particles. Where a pressing force pressing the developing member against the image bearing member is F1, a total number of the carrier particles interposed between the toner particles and the image bearing member is N1, and an adhesion Ft between a carrier particle and a toner particle, measured when the carrier particle is pressed against the toner particle with F1/N1 that is a pressing force per unit carrier particle, and an adhesion Fdr1 between the carrier particle and the image bearing member, measured when the carrier particle is pressed against the image bearing member with F1/N1, satisfy Ft?Fdr1.