Abstract: An image forming apparatus includes an image bearer; a transfer rotator to contact the image bearer to form a transfer nip therebetween; a bias application device to apply, to the transfer rotator, a transfer bias, a cleaning bias to remove toner adhering to the transfer rotator, and a non-image area bias smaller in absolute value than the cleaning bias; and a controller to control the bias application device and set a sheet feeding interval according to a predetermined condition. When the sheet feeding interval exceeds a predetermined threshold, the controller causes the bias application device to apply, to the transfer rotator, the non-image area bias for an application time Z and the cleaning bias for a time X?Z within the sheet feeding interval when X represents the sheet feeding interval, and the application time Z is increased as the sheet feeding interval is increased.

Abstract: A process unit includes a photoreceptor drum, a frame and seal members. The photoreceptor drum has drum flanges protruded outwardly from both end surfaces of a substrate. The frame supports the photoreceptor drum rotatably. The seal members are provided between both end surfaces of the photoreceptor drum and the frame, and support the drum flanges. Each of the seal members includes an elastic member and a hard member. The elastic member and the hard member are adhered and laminated with each other in an axial direction of the photoreceptor drum. Furthermore, the hard member is arranged so as to be brought into contact with the photoreceptor drum.

Abstract: An image forming includes an apparatus main body, a photoreceptor drum, a charging apparatus, a developing device, a transfer apparatus, a charging bias applying unit, a developing bias applying unit, a bias adjusting unit, and a print density measurement unit. The bias adjusting unit forms a non-charged area on a circumference surface of the photoreceptor drum and applies a developing bias constituted of a first electric potential to a developing roller to form a first toner image by an electric potential difference between the non-charged area and the developing roller. The charging bias applying unit forms a second toner image by an electric potential difference between the electric potential area and the developing roller. The charging bias applying unit decides a value of a charging bias corresponding to a target electric potential from measurement results of print densities of the first toner image and the second toner image.

Abstract: An image forming apparatus includes: a photoconductor; an electric charging device charging the photoconductor; an exposure device exposing a portion of the photoconductor charged by the electric charging device to light based on image information, to form an electrostatic latent image; a first charge eliminating device emitting light to the photoconductor so as to eliminate an electric charge on a surface of the photoconductor; a second charge eliminating device emitting light to the photoconductor so as to eliminate an electric charge on a surface of the photoconductor, a wavelength of the light emitted by the first charge eliminating device being different from a wavelength of the light emitted by the second charge eliminating device; and a controller selectively operating the first and second charge eliminating devices depending on an image content of the electrostatic latent image in an image forming process.

Abstract: An image forming apparatus comprises a plurality of image forming units that respectively form an image, and a plurality of voltage generation circuits that respectively generate voltages for driving the plurality of image forming units. Each of the plurality of voltage generation circuits comprises a voltage generation circuit having a transformer, and generates a voltage by a switching operation that is driven by changing an input voltage of primary side of the transformer, an oscillation circuit that generates a clock signal of a frequency that becomes a reference frequency of the switching operation and a setting unit that sets the frequency of the clock signal that the oscillation circuit generates. The setting units of the plurality of voltage generation circuits set the frequencies of the respective clock signals.

Abstract: A nonporous semiconductive roller is provided, which constantly ensures proper image formation substantially without image density unevenness attributable to the roughness of an outer peripheral extrusion surface thereof when being used as a developing roller. The semiconductive roller (1) is made of a nonporous crosslinking product of a rubber composition which contains a rubber component including only four types of rubbers including an epichlorohydrin rubber, a chloroprene rubber, a butadiene rubber and an acrylonitrile butadiene rubber.

Abstract: A developing device includes a developer carrying member and first and second conveyance members. The first conveyance member conveys a developer in a first direction through a first conveyance path to the developer carrying member. The second conveyance member conveys the developer in a second direction through a second conveyance path included in a circulation path along with the first conveyance path. The second conveyance member has a helical second screw around a second shaft. The second conveyance path includes a developer replenishing port and a developer discharge port. The second screw is approximately constant in diameter in a second section being a portion extending a predetermined distance from an end of the discharge port in the second direction when viewed in a top view. The second screw conveys the developer at a lower speed in the second section than on an upstream side with respect to the second section.

Abstract: A fixing device includes a primary heater disposed opposite a fixing rotator to heat a circumferential span of the fixing rotator other than a fixing nip formed between the fixing rotator and a pressure rotator and a secondary heater disposed outboard from the primary heater in an axial direction of the fixing rotator to heat the fixing rotator at the fixing nip. The primary heater and the secondary heater heat a bi-heating span of the fixing rotator in the axial direction thereof. The secondary heater heats a mono-heating span of the fixing rotator in the axial direction thereof and generates a decreased amount of heat to be conducted to the bi-heating span of the fixing rotator. The decreased amount of heat is smaller than an increased amount of heat to be conducted to the mono-heating span of the fixing rotator that is heated by the secondary heater only.

Abstract: An image forming apparatus includes: a sheet conveyance section configured to convey a long sheet along a sheet feeding path; and an image forming section configured to form an image on the long sheet conveyed by the sheet conveyance section, the sheet conveyance section including a conveyance unit that includes a first conveyance roller and a second conveyance roller for conveying the long sheet in a sandwiching manner, and is movable along a sheet conveyance direction in a state where the long sheet is conveyed through the sheet feeding path.

Abstract: There is provided a fixing device. An endless fixing belt has an inner circumferential surface to which lubricant is applied and that is rotated. A first plate-shaped body is disposed along the inner circumferential surface and is in contact with the inner circumferential surface. A second plate-shaped body is disposed along the first plate-shaped body at a distance to cause a capillary phenomenon in the lubricant. A bent portion is provided in an end portion of the second plate-shaped body in a rotating direction of the fixing belt and is bent on an inner circumferential surface side on a downstream side of an end portion of the first plate-shaped body in the rotating direction of the fixing belt.

Abstract: A roller support device includes a roller including a cylindrical portion having a through hole, a support member attached to a portion of an outer peripheral surface of the roller adjacent to the through hole to support the roller so that the roller is rotatable, and a restricting member including a bent hook and a contact portion. The restricting member restrains the support member from moving in a first direction of a rotation axis of the roller by contacting the support member at the contact portion. The bent hook is bent so as to extend to an inside of the cylindrical portion through the through hole and oppose a portion of the inner peripheral surface surrounding the through hole. The contact portion is disposed so as to extend in a circumferential direction of an outer peripheral surface of the roller and being capable of contacting the support member.

Abstract: An image forming apparatus includes a member-to-be-cleaned, a first cleaner unit including a first attracting member, a first rotatable member and a first blade member, a second cleaner unit including a second attracting member, a second rotatable member and a second blade member, and a feeding member. The feeding member rotates around its rotational axis and is provided vertically below a first position where a toner drops by gravitation and a second position where the toner drops by gravitation. The feeding member is disposed such that vertical lines passing through the first position and the second position cross the feeding member.

Abstract: The present wet development device includes a developer carrying member, a supply member that supplies a liquid developer to the developer carrying member, a charger that charges the liquid developer on the developer carrying member, a cleaner that removes the liquid developer on the developer carrying member, and a bias applying member that applies alternating bias in contact with the developer carrying member before removing by the cleaner. In a direction in alignment with an axis of rotation of the developer carrying member, a range to which the alternating bias is applied by the bias applying, member is located within a range in which the liquid developer is supplied onto the developer carrying member.

Abstract: A positional deviation correction pattern includes a first and second pattern image portions adjacent in a sub-scanning direction at the same position in a main-scanning direction, with the same width in the main-scanning direction. Each image portion includes a first side extending in the sub-scanning direction, a second side continuing from one end of the first side and extending in a direction intersecting the sub-scanning direction, and a third side continuing from the other end and extending in a direction intersecting both the sub-scanning direction and the second side. The second sides have the same inclination angle to a virtual line parallel to the main-scanning direction. The third sides have the same inclination angle to the virtual line. A length of one image portion in the sub-scanning direction gradually increases from one end to the other end in the main-scanning direction, a length of the other image portion gradually decreases.

Abstract: A static eliminating device includes a substrate provided with a plurality of light emitters that irradiates light as static eliminating light onto a surface of a photosensitive body, and a plurality of limiting resistors that is provided on a same surface as the light emitters. One ends of each of the plurality of light emitters are connected to a power source via the plurality of limiting resistors. The static eliminating device further includes: a first switching section that supplies power from the power source to the plurality of limiting resistors and the plurality of light emitters at a ON state; and a second switching section that supplies power from the power source to the limiting resistors at the ON state, but does not supply the power to the light emitters.

Abstract: A fixing device has a flexible endless fixing member; a heater to heat the fixing member; a nip forming member to contact the fixing member directly or via a slide member; a pressure member, rotatably disposed opposite the fixing member and the nip forming member; and a back curl correction structure that includes a drive roller disposed on a side where a back curl appears in the recording sheet; a driven roller disposed opposite the drive roller; an auxiliary nip portion to feed the recording sheet; a guide member to guide the recording sheet fed out from the auxiliary nip portion to bend in a direction opposite a curled direction of the back curl of the recording sheet. A driving connection between the drive roller and the pressure member is performed by a connection between a drive roller side connection gear and a pressure member side connection gear.

Abstract: An image forming apparatus includes an image forming device that forms an image on a sheet, a fixing device including a fixing member that fixes the image formed on the sheet and a polishing device that polishes a surface of the fixing member, and circuitry that determines whether an interruption required operation is to be performed, at a time while image formation is being performed by the image forming device to execute an image forming job, or at a time after image formation is executed for one job and before image formation is to be executed for a subsequent job, controls the image forming device to stop image formation to perform the interruption required operation, based on a determination indicating that the interruption required operation is to be performed, and controls the polishing device to polish the surface of the fixing member concurrently with the interruption required operation.

Abstract: A control portion switches first and second modes based on information which influences a toner charging amount. In the first mode, a driving input to the developer bearing member is stopped in response to image formation completion before or at the same time when a trailing end of a charging area reaches the development position, and an application of the development voltage is stopped after the trailing end reaches the development position. In the second mode, The driving input to the developer bearing member is stopped in response to image formation completion before or at the same time when the trailing end reaches the development position, and the application of the development voltage is stopped at a timing after the trailing end reaches the development position and earlier than that in the first mode, or at the same time when the trailing end reaches the development position.

Abstract: An image forming apparatus includes a drum unit movable between an inside position inside a main body casing and an outside position outside the main body casing. The drum unit includes a photoconductive drum extending in an axial direction intersecting a moving direction of the drum unit from the outside position toward the inside position, and a transporter transporting toner removed by a cleaner toward a waste toner container. The transporter includes a transportation member transporting the toner along the moving direction, a transportation tube accommodating the transportation member and having an outlet, and a shutter movable between a closed position to close the outlet and an open position to open the outlet. The shutter includes a protruding section protruding along the axial direction from a shutter main body when the shutter is in the closed position, the protruding section being upstream of the photoconductive drum in the moving direction.

Abstract: An image carrier unit of the present disclosure includes an image carrier, a charging device, a unit housing and a drive mechanism. The charging device is fittable to and removable from the unit housing in a direction perpendicular to its longitudinal direction, and has a charging member and a cleaning member for cleaning the charging member. The drive mechanism has a biasing member for biasing a rotating shaft of the cleaning member in a first direction extending along its axial direction, and a moving member for moving the rotating shaft of the cleaning member in a second direction opposite to the first direction. An engaging portion to engage with an engaged portion provided on the unit housing side is formed at one longitudinal end portion of the charging device, and an engagement state between the engaging portion and the engaged portion is retained by biasing force of the biasing member.