Abstract: A medium transport device includes a transport member and a guide member. The transport member supports and transports a medium. The guide member is shifted from the transport member in a width direction of the medium to guide the medium. The guide member includes contact portions that come into contact with the medium. The contact portions are spaced apart from one another in a transport direction of the medium.

Abstract: A housing includes at least one openable cover and at least one adjacent cover. The at least one openable cover swings on a hinge to separate an interior of the housing from an exterior of the housing. The at least one openable cover has a first side edge on a side of the hinge. The at least one adjacent cover is adjacent to the at least one openable cover. The at least one adjacent cover has a second side edge neighboring the first side edge of the at least one openable cover across a gap. One of the at least one openable cover and the at least one adjacent cover includes at least one projection projecting into the gap and another one of the at least one openable cover and the at least one adjacent cover includes a recess that accommodates the at least one projection in the gap.

Abstract: A bias condition determiner executes, in order, a first direct current voltage determination mode (first DC calibration) for determining a provisional reference direct current voltage that is a provisional reference for a direct current voltage of a developing bias applied to a developing roller, an inter-peak voltage determination mode (AC calibration) for determining a reference inter-peak voltage that is a reference for an inter-peak voltage of an alternating current voltage of the developing bias applied to the developing roller in an image forming operation, and a second direct current voltage determination mode (second DC calibration) for determining a reference direct current voltage that is a reference for the direct current voltage of the developing bias applied to the developing roller in the image forming operation.

Abstract: An image forming apparatus includes a paper transport unit, an image forming unit, a reading unit, a foreign matter detection signal generation circuit, and a foreign matter detection control circuit. The foreign matter detection signal generation circuit generates a first foreign matter detection signal, based on an analog image signal to be output from a line sensor. In foreign matter detection processing, when a pixel that reads foreign matter continues by a specific first consecutive number or more in a signal based on the analog image signal of each pixel to be output from the line sensor, the foreign matter detection signal generation circuit sets a level of the first foreign matter detection signal to a level indicating the presence of foreign matter.

Abstract: The developing member includes a substrate having an electroconductive outer surface; an insulating resin layer on the outer surface of the substrate; and electrically insulating domains on an outer surface of insulating resin layer, and has an outer surface including a surface of the insulating resin layer and surfaces of the domains, wherein a potential decay time constant of each of the surfaces of the domains is ?60.0 seconds, and a potential decay time constant of the surface of the electrically insulating resin layer is <6.0 seconds, and assuming that the electrically insulating domains are orthographically projected onto the outer surface of the substrate, to obtain projection images of the respective domains, each of areas of the projection images is defined as S, and each of areas of convex envelopes of the projection images is defined as H, at least one of the domains satisfies 0.05?S/H?0.80.

Abstract: A fuser has a heater, a heat roller, an endless belt, a pressure pad, and a slidable sheet. The pressure pad forms a nipping portion to nip the endless belt between the pressure pad and the heat roller. The slidable sheet is interposed between an inner circumferential surface of the endless belt and the pressure pad in the nipping portion. The slidable sheet includes a plurality of dents and a plurality of projections on a surface contacting the inner circumferential surface of the endless belt. The plurality of dents are arranged in a first part of the surface of the slidable sheet. The first part is located in a range corresponding to the nipping portion. The plurality of projections are arranged in a second part of the surface of the slidable sheet. The second part is located in a range corresponding to a portion different from the nipping portion.

Abstract: An image forming apparatus includes a memory and a processor configured to, when humidity detected by a humidity sensor is equal to or above a preset value with paper sheets stacked in a paper sheet holder being fed to an image forming unit, perform control to set a separation operation time used to separate in a separation operation a single paper sheet from multiple paper sheets stacked in the paper sheet holder to be longer than the separation operation time used when the detected humidity is lower than the preset value.

Abstract: A pressure device presses against a pressed member. The pressure device includes a support shaft and a presser that pivots about the support shaft and presses against the pressed member. A mover moves the support shaft in an axial direction of the support shaft to move the presser in the axial direction of the support shaft in a state in which the presser presses against the pressed member.

Abstract: An image forming apparatus includes a drum cartridge and developing cartridge. The drum cartridge may include a photosensitive drum rotatable about a first axis extending in an axial direction. The developing cartridge may include a developing roller rotatable about a second axis extending in the axial direction. The image forming apparatus may include a main casing including a slot extending in the axial direction. The image forming apparatus may include a first inner surface positioned inside of the slot, and a second inner surface positioned inside of the slot farther from the cover in the axial direction than the first inner surface from the cover in the axial direction. The first and second inner surfaces may be configured to press the developing roller toward the photosensitive drum.

Abstract: A developing cartridge includes: a casing, a developing roller, a first agitator, a supply roller, and a second agitator. The casing is configured to accommodate toner. The developing roller is rotatable about a developing roller rotation axis extending in a first direction. The first agitator is configured to agitate the toner. The first agitator is rotatable about a first agitator rotation axis extending in the first direction. The supply roller is positioned between the first agitator and the developing roller. The supply roller is rotatable about a supply roller rotation axis extending in the first direction. The second agitator is positioned between the supply roller and the first agitator. The second agitator is rotatable about a second agitator rotation axis extending in the first direction. A rotation locus of the second agitator is positioned outside of a rotation locus of the first agitator.

Abstract: An image forming apparatus includes a revolving member, a transfer member, a guide member, and a controller. The revolving member revolves and retains a toner image on a peripheral surface thereof. The transfer member nips a transported recording medium and the revolving member at a nipping section and transfers the toner image retained by the revolving member onto the recording medium by receiving a voltage. The guide member is connected to ground, guides the recording medium to the nipping section, and is in contact with the recording medium nipped at the nipping section. The controller performs constant current control to transfer the toner image onto the recording medium if a print resistance is lower than or equal to a system resistance. The print resistance corresponds to when the voltage is applied to the transfer member in a state where the recording medium is nipped at the nipping section.

Abstract: An image-forming apparatus includes: a cover; and a separation mechanism. The separation mechanism includes a cam; a cam follower; and a release member. The release member is configured to move the cam follower from an operating position to a non-operating position in accordance with movement of the cover from a closed position to an open position. In a state where the cam follower is at the operating position, the cam follower is guided by the cam in accordance with rotation of the cam to allow the cam follower to slidably move between a protruding position and a standby position. In a state where the cam follower is at the non-operating position, the cam follower is not guided by the cam to allow the cam follower to be maintained at the standby position independently of the rotation of the cam.

Abstract: A particle collection system of an imaging apparatus includes an air flow generation device to generate an air flow for transporting airborne particles, a charging device that is located upstream of the air flow generation device in a ventilation direction to charge the floating fine particles in the air flow, and a particle collection device that is located downstream of the charging device in the ventilation direction to collect the airborne particles which are charged by the charging device. The charging device includes a discharging electrode and a counter electrode, and the particle collection device includes a tubular ventilation passage. A length of the tubular ventilation passage in the ventilation direction is greater than an opening diameter of the tubular ventilation passage, and the opening diameter of the tubular ventilation passage is less than or equal to a gap between the discharging electrode and the counter electrode.

Abstract: A belt device includes a belt wound around a plurality of rollers, one of the plurality of rollers, and a belt contact member disposed on the one of the plurality of rollers. The belt rotates along with the plurality of rollers. The belt contact member faces an edge of the belt in an axial direction of the one of the plurality of rollers and includes a flat portion and a separation portion. The flat portion forms a plane perpendicular to the axial direction of the one of the plurality of rollers. The separation portion is disposed outboard of the flat portion in a radial direction of the one of the plurality of rollers and has a surface located farther from the edge of the belt than the flat portion in the axial direction of the one of the plurality of rollers.

Abstract: An image forming apparatus includes: a sheet feeding tray that stores a sheet; a sheet thickness measurement device that measures a sheet thickness of the sheet fed from the sheet feeding tray; a hardware processor that: determines a type of the sheet of which the sheet thickness is measured, a sheet type associated with each of sheet thickness ranges, and the sheet thickness measured by the sheet thickness measurement device; and adjusts a first sheet thickness range to cause the first sheet thickness range to be expandable to at least one of an upper limit value side or a lower limit value side; and an image former that forms an image on the sheet fed from the sheet feeding tray under image forming conditions corresponding to the sheet type determined by the hardware processor.

Abstract: A process cartridge detachably mountable to an electrophotographic image forming apparatus including a main assembly side drive transmission member and a main assembly side urging member, the cartridge including a rotatable photosensitive drum; a rotatable developing roller for developing a latent image formed on the drum, the developing roller contactable to and spaceable from the drum; an urging force receiving portion for receiving an urging force from the urging member to space the roller from the drum; a cartridge side drive transmission portion capable of coupling with the main assembly side drive transmission member to receive a rotational force for rotating the roller; a releasing member capable of urging the main assembly side drive transmission member to decouple the cartridge side drive transmission member from the main assembly side drive transmission member by the urging force receiving portion receiving the urging force from the main assembly side urging member.

Abstract: The fixing device includes a heated rotating body, a pressure rotating body, a heating unit configured to heat the heated rotating body, a separation claw, and a gap rolling member. The pressure rotating body is pressed against the heated rotating body to form a fixing nip portion. The separation claw separates the recording medium from the heated rotating body or the pressure rotating body. The gap rolling member is rotatably supported by the separation claw and abuts against an outer peripheral surface of the heated rotating body or the pressure rotating body to define a gap between the heated rotating body or the pressure rotating body and a tip portion of the separation claw. The separation claw has a conveyance surface facing the recording medium passing through the fixing nip portion, and a part of an outer peripheral surface of the gap rolling member protrudes from the conveyance surface.

Abstract: A developing cartridge may include: a casing to accommodate developer; a storage medium including an electric contact surface; an elastic member extending in a first direction crossing the electric contact surface, and configured to be compressed or stretched in the first direction between a first state and a second state; and a holder including an outer surface positioned toward a side of the holder in the first direction, the electric contact surface positioned at the outer surface, and movable between first and second positions in the first direction relative to the casing. A length of the elastic member in the first direction is greater in the first state than in the second state. The electric contact surface is in the first position when the elastic member is in the first state, and the electric contact surface is in the second position when the elastic member is in the second state.

Abstract: An image forming apparatus includes a heater, a fixing device, and a controller. The heater includes a heat generator that generates heat when the heater is turned on. The fixing device may fix a developer image on a surface of an image forming medium using the heat from the heat generator. The controller detects a voltage of a power supply for supplying electric power to the heater, and determines an occurrence of an abnormality in the heater if a voltage drop amount at the time the heater is turned on as compared to a case in which the heater is turned off is smaller than a first threshold value.

Abstract: A developing cartridge may include: a casing configured to accommodate developer therein, the casing extending in the first direction; a coupling rotatable about a first axis extending in the first direction, the coupling being positioned at one side of the casing in the first direction; a detection gear rotatable about a second axis extending in the first direction, the detection gear being positioned at another side of the casing in the first direction; and a storage medium including an electric contact surface, the electric contact surface being positioned at the one side of the casing in the first direction.