Abstract: An image forming apparatus capable of obtaining a good image quality without color shifts is described. The image forming apparatus includes a drive coupling 1015 which couples a drive shaft 1011 and a flange 1021 of an image bearing member 613 with a play, a taper coupling 1017 supported inside the drive coupling 1015 for holding the drive shaft 1011 and the flange 1021, and a pressing member 1013. The taper coupling 1017 includes a tip portion 1061, an axial portion 1062, a rear end portion 1063. The drive coupling 1015 includes claw portions 1042 engaging with the flange 1021 of the image bearing member 613, and a body portion 1041 having a length which is shorter than the distance between the flange 1021 of the image bearing member 613 and the rear end 1063 of the taper coupling 1017 in the axial direction of the drive shaft 1011.

Abstract: A cartridge includes a casing and a photosensitive drum rotatably supported in the casing. A rotatable driven coupling member is provided on an axial end of the photosensitive drum, with the driven coupling member including a driving force receiving portion for receiving a driving force to rotate the photosensitive drum. The driven coupling member is translatable with respect to the casing in a predetermined direction, which is substantially parallel to a rotational axis of the photosensitive drum, by a force received by a driven side abutment portion of the driven coupling member. A distance between the rotational axis of the driven coupling member and the driven side abutment portion is not more than a distance between the rotational axis of the driven coupling member and the driving force receiving portion.

Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a speed setting portion, a test mode executing portion, a renewing mode executing portion, and a setting portion for setting a voltage applied to the transfer member. In a period in which the toner image exists at the transfer portion when image formation is executed at a first speed, the setting portion sets the voltage applied to the transfer member at a first target voltage last renewed. In a period in which the toner image exists at the transfer portion when the image formation is executed at a second speed, the setting portion sets the voltage applied to the transfer member at a voltage on the basis of the first target voltage last renewed and a conversion coefficient last renewed.

Abstract: A power transmission apparatus includes a drive gear disposed on a shaft of a motor; a plurality of driven gears disposed to be engaged with the drive gear; and a plurality of driven members configured to receive power from each of the plurality of driven gears, wherein the plurality of driven gears is arranged so that, when the plurality of driven gears are engaged with the drive gear, a gear engagement phase of each of the plurality of driven gears is different.

Abstract: A belt device for an image forming apparatus, includes an endless belt; a first and second support rollers, each including a rotary shaft, that support the belt with tension; a contacted member that contacts the belt; a shaft displacement device to displace any of the rotary shafts of the support rollers; and a main rotary shaft disposed at a side of the rotary shaft of the first support roller moved by the shaft displacement device along a stretching direction of the stretched surface of the endless belt that the contacted member contacts, relative to a contact portion between the endless belt and the contacted member, and at an opposite side of the contacted member in a direction perpendicular to the stretching direction of the endless belt. As the first support roller and the second roller rotate about the main rotary shaft, the endless belt is separated from the contacted member.

Abstract: An image forming apparatus includes a process cartridge that includes an image bearer including a rotary shaft and rotates about the rotary shaft; a charger to charge a surface of the image bearer; and a developing device to develop an electrostatic latent image formed on the image bearer into a visible toner image. The charger includes a charging roller that rotates about a shaft together with the image bearer during image formation and electrically charges a surface of the image bearer. A surface linear speed of the charging roller is made slower than a surface linear speed of the image bearer. The image forming apparatus includes a charging roller controller that switches the rotational speed of the charging roller to a first rotational speed slower than the linear speed of the image bearer and a second rotational speed identical to the linear speed of the image bearer.

Abstract: An image forming apparatus includes a casing, a photosensitive body, a toner accommodation component, a developing roller and an exposure unit configured to emit a laser beam toward the photosensitive body along an irradiating path. The image forming apparatus further includes a sheet feed roller configured to feed a sheet toward the photosensitive body. In some arrangements, the sheet feed roller is disposed at a position closer to the exposure unit than to the photosensitive body, and the developing device is disposed at a first height range relative to the bottom of the casing, the first height range being lower than the irradiation path. Moreover, the toner accommodation component is disposed at a second height range relative to the bottom of the casing, the second height range being higher than the irradiation path.

Abstract: An angle detection device includes: first and second rotation measuring instruments; an anomaly detection unit detecting occurrences of anomalies in the first and second rotation measuring instruments; and a switching interpolation unit configured to select a first angle signal and a first angular speed signal and output as a third angle signal and a third angular speed signal when the first rotation measuring instrument is normal, and to perform switching so that a second angle signal and a second angular speed signal are output as the third angle signal and the third angular speed signal while performing interpolation so that the difference between the first angle signal and the second angle signal is reduced stepwise if the second rotation measuring instrument is normal when an anomaly has occurred in the first rotation measuring instrument.

Abstract: A process cartridge for use with a main assembly of an electrophotographic image forming apparatus. The process cartridge includes a casing, a photosensitive drum having an axis L1, and a coupling member having an axis L2. The coupling member is movable between a first position in which the axis L2 of the coupling member is coaxial with the axis L1 of the photosensitive drum, and a second position in which the axis L2 of the coupling member is inclined with respect to the axis L1 of the photosensitive drum.

Abstract: A cartridge includes a coupling member, a transmitted member, and a rotary member. The transmitted member includes an accommodating portion configured to accommodate the coupling member, and a protruded portion integrally formed with an inner wall of the accommodating portion and protruding from the inner wall toward an inside of the accommodating portion. The coupling member includes a free end portion having a rotational force receiving portion that receives a rotational force, a connected portion connected to the transmitted member in such a manner that at least a part of the connected portion can be accommodated in the accommodating portion, and a recessed portion provided at the connected portion so that the protruded portion can enter. An inclination angle of a rotation axis of the coupling member relative to a rotation axis of the transmitted member is variable.

Abstract: An image forming device includes: first and second photosensitive drums; first and second drum cleaners for removing waste developer on the first and second photosensitive drums respectively; first developer cartridge having a first waste developer chamber; a second developer cartridge having a second waste developer chamber; a belt in contact with the first and second photosensitive drums; a belt cleaner for removing waste developer on the belt; a belt waste developer conveyer for conveying the waste developer removed by the belt cleaner; a first conveyer for conveying the waste developer removed by the first drum cleaner; a second conveyer for conveying the waste developer removed by the second drum cleaner to the second waste developer chamber; and a third conveyer for conveying the waste developer conveyed by the first conveyer and the waste developer conveyed by the belt waste developer conveyer to the first waste developer chamber.

Abstract: An image forming apparatus cartridge includes a casing, a developer roller having an axis L1, and coupling member having an axis L2. The coupling member includes (i) a first end portion operatively connected with the developer roller, (ii) a second end portion having an outermost surface, (iii) an axle portion connecting the first end portion and the second end portion to each other, and (iv) at least one projection extending from the second end portion. For at least part of the outermost surface of the second end portion, a maximum distance from the axis L2 to the outermost surface along a line perpendicular to the axis L2 increases as the distance along the axis L2 from the axle portion increases.

Abstract: An image forming apparatus including: a first and a second photosensitive members, an endless transfer belt, a transfer unit configured form a transfer nip with the endless transfer belt, a storage unit configured to store first and second delay data each indicating an amount of delay of a second exposure start timing of the second photosensitive member with respect to a first exposure start timing of the first photosensitive member, a control unit configured to control the second exposure start timing based on the first delay data until a first recording medium enters the transfer nip and control the second exposure start timing based on the second delay data after the first recording medium enters the transfer nip.

Abstract: An image forming apparatus includes an image-bearing member bearing a toner image, a transfer unit transferring the toner image on the image-bearing member to a printing medium, a cleaning member rubbing against the image-bearing member and scraping away transfer residual toner from the image-bearing member, and a lubricant applying unit applying a lubricant to the image-bearing member. The apparatus further includes a driving unit driving the lubricant applying unit and a controller controlling the driving unit such that when a period required for an area corresponding to an interval between printing media to pass through a transfer position is longer than or equal to a predetermined set period during image formation, the amount of lubricant applied by the lubricant applying unit is at least lower than that in a case where the period required is shorter than the predetermined set period.

Abstract: A photoconductive drum assembly according to one embodiment includes a photoconductive drum rotatable about a rotational axis in first and second rotational directions. A spring brake has a coiled portion wrapped around a portion of the photoconductive drum at its axial end and around the rotational axis of the photoconductive drum. The spring brake has a first arm and a second arm. The first arm is positioned to flex in an unwinding direction causing the coiled portion to unwind upon the first arm receiving a force in the first rotational direction. The first arm is positioned to flex in a winding direction and to push the second arm in an unwinding direction relieving winding of the coiled portion caused by the flexing of the first arm in the winding direction of the first arm upon the first arm receiving a force in the second rotational direction.

Abstract: Techniques related to printing using a metal-surface charging element. A printing system includes a metal-surface charging element and a power supply. The charging element is disposed to deposit electric charge on an imaging surface. The power supply may provide electric power with an alternating current (AC) component and a direct current (DC) component to the charging element.

Abstract: The invention relates to a process cartridge, which comprises a process cartridge housing, a photosensitive member, a driving force receiving opening, a retractable mechanism and a control mechanism, wherein the photosensitive member is arranged inside the process cartridge housing; the driving force receiving opening is connected with the photosensitive member and provides a driving force for the photosensitive member; the retractable mechanism allows the driving force receiving opening to extend or retract in the axial direction of the photosensitive member; and the control mechanism controls the extension and retraction of the retractable mechanism.

Abstract: There is provided an image forming apparatus including a main body and a cartridge having an image carrier and a first coupling configured to rotate the image carrier. The main body includes a second coupling, a rotator and a receiving member. The second coupling is configured to rotate together with the first coupling about a rotation axis coaxially with the first coupling. The rotator includes gear teeth. The rotator is configured to rotate the second coupling in response to receiving the drive force from the drive source, and to rotate together with the second coupling about the rotation axis coaxially with the second coupling. The rotator, which is configured to rotate about the rotation axis coaxially with the first coupling configured to rotate the image carrier, overlaps with the receiving member when viewed from an axial direction parallel to the rotation axis.

Abstract: A charging member includes a force receiving portion that receives a force in a direction in which the charging member is moved in a longitudinal direction of the charging member while rotating. The charging member is in contact with a brush member at a place different from the place of the force receiving portion. A component of the force received by the charging member at the force receiving portion in the longitudinal direction and a component of a force received by the charging member resulting from tilting of bristles in the brush member are in the same direction.

Abstract: A developing cartridge mountable to a development rotary of an electrophotographic image forming apparatus, a coupling member for transmitting a rotational force from a main assembly engaging portion to a developing roller, the coupling member being engageable and disengageable relative to the engaging portion with rotation of the rotary, the coupling member being movable among a rotational force transmitting angular positio, a pre-engagement angular position in which the coupling member is inclined relative to that in the transmitting angular position to engage with the engaging portion, and a disengaging angular position for disengaging therefrom; and an inclination regulating member movable between a regulating position for positioning the coupling member to the pre-engagement position and a retracted position, the inclination regulating member being movable from the retracted position to the regulating position by being abutted by a function member of the rotary.

Abstract: Provided is an image forming apparatus that forms an image on a recording material, the apparatus including: a first helical gear and a second helical gear that are engaged with each other; and a driving portion that applies a driving force to the first helical gear, wherein at least one of the first helical gear and the second helical gear is a helical gear in which torsional rigidity in a tooth width direction of one side end in a width direction of the gear is larger than torsional rigidity in a tooth width direction of the other side end, and wherein a twist direction of helical teeth and a rotational direction of the first helical gear due to the driving portion are set such that the other side end is engaged earlier than the one side end.

Abstract: A gear transmission device includes a first external gear driven by a drive motor attached to a first side of a frame and a first internal gear driven by the first external gear. The first internal gear includes an outer cylinder portion, an end plate, an annular opening, and an inner cylinder portion including a shaft hole. The outer cylinder portion includes internal teeth formed on an inner circumferential surface thereof. The inner cylinder portion is formed concentrically inside the outer cylinder portion. The end plate connects the outer cylinder portion, the inner cylinder portion, and the shaft hole at one end in an axial direction. In a state in which the annular opening faces a second side of the frame opposite the first side thereof, the first external gear is inserted to the annular opening to mesh with the internal teeth of the outer cylinder portion.

Abstract: A driving force transmission device that transmits a driving force to a rotation body includes a flange member provided in the rotation body, a through shaft that is connected to the flange member to transmit the driving force to the rotation body via the flange member, and an intermediate transmission member that is provided in the through shaft to transmit the driving force to the flange member from the through shaft.

Abstract: An image forming apparatus includes: a driving source including only a first driving motor and a second driving motor; a first transfer system that transfers a first driving force generated by the first driving motor; and a second transfer system that transfers a second driving force generated by the second driving motor. The first transfer system transfers the first driving force only to each image carrier and each developing roller. The second transfer system transfers the second driving force to at least a belt driving roller of an intermediate transfer unit, a fixing roller, and a sheet conveyance roller.

Abstract: A bearing member includes a concave section receiving a spherical body therein, and swing grooves into which end sections of a rotating force transmission pin are inserted. The swing groove at least includes a parallel part an axis and a curved part, an undercut section is not provided in the concave section when the concave section is viewed from an opened side of the concave section in a direction of the axis of the bearing member, and a clearance between the two swing grooves in a direction which is orthogonal to the direction of the axis on the opened side of the concave section is shorter than a distance between both ends of the rotating force transmission pin in the direction which is orthogonal to the axis of the bearing member even when the shaft member is mounted on the bearing member in a posture inclined at the most.

Abstract: In one aspect of the invention, a transmission device for a photosensitive drum having a drum axis, which is adapted for engagement with a drive member of an electronic image forming apparatus, comprises a flange detachably attachable to the photosensitive drum coaxially to the drum axis, the flange having a receiving hole; and a transmission unit disposed to the flange coaxially to the drum axis. The transmission unit includes a shaft disposed in the receiving hole of the flange and being rotatable about the drum axis relative to the flange and movable along the drum axis relative to the flange; and an engagement structure being coaxial with the shaft and defining a receiving space for receiving the drive member.

Abstract: An intermediate transfer member (ITM) module including a frame; a backup roll and a drive roll rotatably disposed along a first end portion of the frame. A tension roll is rotatably disposed along a second end portion of the frame. An ITM belt forms as an endless loop around the backup roll, the drive roll and the tension roll such that rotation of the drive roll causes the ITM belt to translate and the tension roll and the backup roll to rotate. The drive roll and the backup roll form a transfer nip with a transfer roll. A drive mechanism is coupled between the drive roll and the backup roll and includes a plurality of gears. The drive mechanism overdrives the backup roll relative to the drive roll while limiting an amount of tension of the ITM belt in the second transfer nip.

Abstract: Provided is an image forming apparatus, including first and second drive portions respectively transmitting a drive force to first and second photosensitive drums, the first and second drive portions each including: a transmission gear rotated by the drive force; an idler gear rotated in mesh with the transmission gear; and a drive gear rotated in mesh with the idler gear. When a meshing angle of the idler gear is an angle from a meshing position between the idler gear and the transmission gear to a meshing position between the idler gear and the drive gear with respect to a rotation center of the idler gear, the meshing angles of the idler gears of the first and second drive portions are substantially equal to each other, and rotational phases of the idler gears of the first and second drive portions match with each other.

Abstract: A driving force transmission mechanism includes a body that includes a transmission member, which transmits a driving force and includes a rotatable first surface and two first projections, and an installation unit that includes a receiving member including a second surface, which faces the first surface and which is rotatable by receiving the force when the installation unit is installed, and two second projections, which receive the force from the first projections by contacting the first projections when the first surface rotates, and that is removably installed in the body in a direction, in which the second surface moves parallel to the first surface, to couple the transmission member and the receiving member. The body includes a contact member that contacts, to rotate the receiving member, one of the second projections when the installation unit is installed while a line segment connecting the second projections is intersecting an installation direction.

Abstract: An improved drive system for transmitting rotational force between an imaging machine and an imaging cartridge. A first coupling member comprises a first mating structure configured to transfer or receive rotational force, and a second coupling member comprises a second mating structure configured to transfer or receive rotational force. The first coupling member comprising a locating cone in the center of said first coupling member, said locating cone adapted to locate in an opening of the second coupling member whereby the first coupling member is centered in relation to the second coupling member, and the first mating structure of the first coupling member is directed into contact with the second mating structure of the second coupling member.

Abstract: An inkjet printer has a printing head, a sheet conveying mechanism, a carriage mounting a printing head and configured to be reciprocally movable in a printing area and non-printing area. A cap is provided to be movable between a capping position an uncap position. A controller of the inkjet printer is configured to execute a printing process, a standby process, and a capping process in which the controller causes the carriage to move to the non-printing area and moves the cap from the uncap position to the capping position. The controller causes the carriage to move into the printing area when the next printing command is received after the standby process is finished and before the carriage moving process has been completed.

Abstract: A belt conveyance apparatus including a driving roller to rotate and drive a belt, a first detector to detect surface speed of the belt, and a second detector to detect rotation speed of the driving roller. There is a first calculator to calculate a first deviation from target speed based on the surface speed and the target speed, and a memory to store a correction value corresponding to the first deviation. A second calculator calculates a second deviation from the target speed corrected by the first deviation based on the target speed, the first deviation and the rotation speed of the driving roller. A controller controls the rotation speed of the driving roller based on the second deviation. There is also a switch to switch the first deviation to the correction value stored in the memory when controller judges that the first detector is abnormal.

Abstract: A CPU for controlling a first motor for rotating and driving a photoconductive drum and a second motor for rotating and driving an intermediate transfer belt determines the rotation speed of the photoconductive drum at the time of image formation on the basis of information on a load torque of the second motor detected when the second motor is driven at a predetermined rotation speed and the rotation speed of the first motor is gradually changed in a state where no high voltage is applied to a primary transfer roller and information on a load torque of the second motor detected when the second motor is driven at a predetermined rotation speed and the rotation speed of the first motor is gradually changed in a state where a high voltage is applied to the primary transfer roller.

Abstract: A drive transmitter, which is includable to a process unit and an image forming apparatus, includes a first gear, a second gear, and a rotation regulator. The first gear has at least one tooth. The second gear has multiple teeth, one of which is meshed with the at least one tooth of the first gear and rotated with the first gear. The first gear continuously rotates and the second gear remains stationary when not in mesh. The number of rotations of the second gear per unit time is smaller than the number of rotations of the first gear. The rotation regulator regulates rotation of the second gear such that a tip of the second gear meshing with the first gear is located downstream from an intersection start point in a rotation direction of the second gear and upstream from an intersection end point in the rotation direction.

Abstract: A transfer-and-transport device includes a substantially annular belt stretchable in a direction of rotation thereof, a transfer roller by which an outer peripheral surface of the belt is pressed against a photoconductor, supporting rollers supporting the belt in a tensed state, and a cleaning member cleaning the outer peripheral surface of the belt. One supporting roller is a driving roller provided, in the direction of rotation of the belt, on an upstream side of the transfer roller. Another supporting roller is a releasing-side roller provided, in the direction of rotation of the belt, on a downstream side of the transfer roller. The cleaning member is in contact with the belt in an area from, in the direction of rotation of the belt, a midpoint of a portion wrapped around the driving roller toward the upstream side to a midpoint of a portion wrapped around the releasing-side roller.

Abstract: An image forming apparatus is provided that includes a first transmission mechanism transmitting a driving force from a driving source to a first development roller, a second transmission mechanism transmitting the driving force from the driving source to a second development roller, and a drive switching mechanism disposed between the driving source and the first transmission mechanism and between the driving source and the second transmission mechanism, the drive switching mechanism including a switching gear movable along a rotational axis direction of the first development roller, between a first position to transmit the driving force to the first transmission mechanism and the second transmission mechanism, and a second position to restrict the driving force from being transmitted from the driving source to the first transmission mechanism and allow the driving force to be transmitted from the driving source to the second transmission mechanism.

Abstract: An image forming apparatus is provided with: a controller capable of changing a developing bias, which is to be applied to a developing roller configured to carry developer thereon; a peripheral speed ratio of a developing roller to a photosensitive member; a control method by the controller, and a program for operating the controller. A configuration is provided where the developing roller makes contact with the photosensitive member when a developing bias is made to be lower during the non-developing than during a developing phase. The configuration can suppress press fogging at room temperature and low humidity conditions.

Abstract: A process cartridge for use with a main assembly of an electrophotographic image forming apparatus. The process cartridge includes a casing, a photosensitive drum having an axis L1, and a coupling member having an axis L2. The coupling member is movable between a first position in which the axis L2 of the coupling member is coaxial with the axis L1 of the photosensitive drum, and a second position in which the axis L2 of the coupling member is inclined with respect to the axis L1 of the photosensitive drum.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes a rotatable photosensitive drum; a charging roller for contacting and electrically charging the drum; a spacer for supporting a rotation shaft of the charging roller to space the drum from the charging roller; and an urging member for contacting the spacer to urge the charging roller toward the drum; wherein the spacer is movable between a first position for spacing the charging roller from the drum and a second position for contacting the charging roller to the drum, and an urging force of the urging member applied to the spacer is smaller when the spacer is in the second position than when the spacer is in the first position.

Abstract: In a constitution provided with no primary-transfer roller, in order to ensure a contact length between each of photosensitive drums and an intermediary transfer belt, the photosensitive drums are disposed with projecting amounts of a plurality of levels with respect to a stretching surface of the intermediary transfer belt, and therefore an apparatus is liable to be increased in a height direction. In order to avoid this, four image bearing members are arranged, along the intermediary transfer belt, with the same projection amount with respect to the stretching surface of the intermediary transfer belt, and a depressing member for depressing a belt surface between two central image bearing members toward an outside is provided.

Abstract: An image forming device includes a tripod type constant-velocity joint through which a rotary member shaft of a rotary member is connected to the drive shaft of a motor. The constant-velocity joint includes a pair of outer rings each having three axially extending track grooves in its inner periphery, and a tripod member having three protrusions formed on each of the axial ends thereof and axially slidably received in the corresponding track grooves. The outer rings and the tripod member are formed of synthetic resin. One of the outer rings and the tripod member are inseparably coupled to the drive shaft so that the other of the outer rings is always disconnected from the tripod member when the rotary member is pulled away from the motor.

Abstract: A toner bottle driving device control method includes driving one of multiple toner bottle driving devices connected to a single toner container at a time, detecting abnormality of a toner bottle driving device being driven, determining a first abnormality phase of the toner bottle driving device being driven when a number of times the abnormality is detected exceeds a threshold, inhibiting the toner bottle driving device being in the first abnormality phase from driving until the first abnormality phase is resolved, driving a drivable toner bottle driving device containing a non-empty toner bottle when the toner bottle contained in the toner bottle driving device being driven is determined as empty, determining that the multiple toner bottle driving devices are in a second abnormality phase when each of the multiple toner bottle driving devices is determined as being in the first abnormality phase, and inhibiting image formation.

Abstract: An image forming apparatus includes an image bearer rotating in a first direction while bearing a toner image thereon in a normal image forming operation; a toner image forming device to form the toner image on the image bearer; a transferring device to transfer the toner image to a recording medium eventually; a cleaning blade to block toner remaining on image bearer without being transferred; and a controller. The controller controls the image bearer to perform an inverse rotation operation in which the image bearer rotates in a second direction opposite to the first direction after controlling the toner image forming device to perform a special image forming operation such that the amount of toner input to the cleaning blade in the special image forming operation is greater than the amount of toner input to the cleaning blade in the normal image forming operation, and then stopping the image bearer.

Abstract: In a developing cartridge, a drive-force receiving member includes: a first cylindrical part having a gear part transmitting drive force to a developing roller; a second cylindrical part disposed radially inward of the first cylindrical part and in contact with a support part; and a receiving part receiving drive force from outside of the developing cartridge. The receiving part is disposed outward of the first and second cylindrical parts in an axial direction in which a rotational axis extends. The receiving part has an internal space in communication with a gap between the first and second cylindrical parts. The receiving part is disposed to overlap the gap between the first and second cylindrical parts when the receiving part is viewed in the axial direction. The receiving part has an outward end in the axial direction, at least part of the outward end of the receiving part being closed.

Abstract: A photosensitive-body cartridge includes a cartridge frame, a photosensitive drum accommodated in the cartridge frame, and a contact member. The photosensitive drum includes: a first rotational shaft extending in a first direction to permit the photosensitive drum to rotate together with the first rotational shaft; a drum body extending in the first direction and having a first end and a second end in the first direction; a pressing member provided on the first end of the drum body and applying pressing force to the drum body toward the second end; and a bearing member provided on the second end of the drum body and receiving the first rotational shaft. The contact member is attachable to the cartridge frame and supported by the cartridge frame. The contact member contacts the bearing member in the first direction by the pressing force.

Abstract: An image forming apparatus having: a rotating member adapted to support an image; a first drive source configured to generate a drive force; a transmission mechanism configured to transmit the generated drive force toward the rotating member, the mechanism including an upstream gear and a downstream gear configured to receive the drive force therefrom; a sensor configured to output a signal indicating a rotational status of the rotating member; a control circuit configured to generate a control signal appropriate for non-uniform rotation of the rotating member, on the basis of the signal outputted by the sensor; and an actuator configured to cause a rotation axis of the first drive source or the transmission mechanism to pivot, in accordance with the control signal, thereby changing a force with which the upstream gear pushes the downstream gear into rotation such that the non-uniform rotation is cancelled out.

Abstract: A drive receiving member for transferring rotational driving force from an image forming apparatus to components of an imaging cartridge is provided. A distal end of the member includes at least one substantially rigid drive lug for receiving rotational driving force from the imaging device. In some constructions the distal end also includes at least one catch member extending beyond the drive lug to facilitate movement of the coupling member from a retracted position to an extended position when the cartridge is installed in the imaging device. In other constructions, an actuator may be provided to initiate movement of the coupling member from the extended position to a retracted position during removal of the cartridge from the imaging device.

Abstract: The rotary power transmission mechanism includes a flange member fitted to one end of a cylindrical member, a shaft inserted through an axial center of the flange member, and a pin member inserted through the shaft in a radial direction of the shaft. The flange member has a first contact portion and a second contact portion that have point symmetry with respect to an axial center of the shaft. When the pin member is rotated in one direction by the shaft rotating in the one direction, the first contact portion contacts a first end portion of the pin member and the second contact portion contacts a second end portion of the pin member. The pin member, when rotating in the one direction, pushes against the first contact portion and the second contact portion, rotates the flange member in the one direction, and thereby transmits rotary power to the cylindrical member.

Abstract: An image forming device includes at least two image cylinders that rotate with a time varying velocity; at least two image cylinder gears respectively attached to each image cylinder; and at least one pinion gear that drives the at least two image cylinder gears. The time varying velocity of the image cylinder gear is due to a runout of the pinion gear. The spacing between the centers of the image cylinders is determined by S 12 = k ? ? ? ? ? D p + ? 360 ? ? ? ? D p where S12 is the distance between the centers of the two image cylinders gears; k is an integer; ? is the angle between the pitch point of the two gears; and Dp is the diameter of the pinion gear.

Abstract: A gear transmission device includes a first external gear driven by a drive motor attached to a first side of a frame and a first internal gear driven by the first external gear. The first internal gear includes an outer cylinder portion, an end plate, an annular opening, and an inner cylinder portion including a shaft hole. The outer cylinder portion includes internal teeth formed on an inner circumferential surface thereof. The inner cylinder portion is formed concentrically inside the outer cylinder portion. The end plate connects the outer cylinder portion, the inner cylinder portion, and the shaft hole at one end in an axial direction. In a state in which the annular opening faces a second side of the frame opposite the first side thereof, the first external gear is inserted to the annular opening to mesh with the internal teeth of the outer cylinder portion.