Abstract: A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and three prongs extending longitudinally outward from the end surface.

Abstract: A rotatable coupling is used with a replaceable developer cartridge and electrostatographic image devices. The coupling has a driven portion and a driving portion. The driven portion has a shaft with a connecting portion that has a plurality of helical involute teeth extending outwardly. The driving portion has an end with a gear shaft and a twisted petaline recess in the gear shaft. The sides of the recess are engageable with the helical involute teeth so that the driving portion drives the driven portion and transmit torque.

Abstract: The invention relates to a photosensitive drum driving head, which comprises drum flange, drum shaft and boss, wherein the drum flange is disposed on the end portion of a photosensitive drum and connected with the photosensitive drum; the drum shaft is axially extended from the end portion of the drum flange; the boss is axially extended from the end face of the drum shaft and engaged with a recess in a driving head of image forming apparatus; three vertical convex teeth radially extended along the boss and engaged with power transmission portions are formed on side wall of the boss, perpendicular to the drum shaft, extended along an axial line of the photosensitive drum, and provided with mating surfaces formed by longitudinal cutting angles on end faces of the vertical convex teeth; at least one mating surface is engaged with an edge of a twisted bevel of the recess.

Abstract: An image forming apparatus includes an image carrier that rotates by power generated by a driving source. A power transmission system transmits the power from the driving source to the image carrier. The power transmission system includes a coupling member to attenuate oscillation. The coupling member includes a viscous fluid, male and female fittings, and a rotating resistor. The viscous fluid provides a resistance against rotation of the image carrier. The male and female fittings are mutually fitted and rotatably supported on a rotary shaft of the image carrier penetrating through the male and female fittings in a direction in which they are mutually fitted. The rotating resistor is accommodated together with the viscous fluid in an accommodation space defined by a recess of the male fitting and a bottom inner surface of the female fitting. The rotating resistor integrally rotates with the rotary shaft.

Abstract: An image forming apparatus including a power transmission unit having a driving source, at least one image receptor which is rotatably driven by the driving source and on which a latent image is formed by exposure, and a power transmission unit which transmits power from the driving source to the image receptor. The power transmission unit includes an image receptor axial gear formed on the same axis as the image receptor, and a plurality of intermediate gears which transmits the power from the driving source to the image receptor axial gear. The number Tn of teeth of an n-th one of the plurality of intermediate gears with respect to the image receptor axial gear satisfies the following Inequality: (I/Rn)?0.2?Tn?(I/n)+0.2, where, Rn is a reduction ratio from the n-th intermediate gear to the image receptor axial gear and I and n are a natural number.

Abstract: This invention provides an image forming apparatus capable of effectively suppressing an AC color registration error, and a control method thereof. To accomplish this, the image forming apparatus according to this invention controls driving of a transfer belt so that the speed of surface of the transfer belt at the transfer position comes close to a constant speed. The image forming apparatus also controls driving of a photosensitive drum so that the error between the speed of surface of the photosensitive drum and that of the transfer belt at the transfer position becomes almost 0. Further, the image forming apparatus controls the exposure timing in accordance with fluctuations of the speed of surface at the exposure position so that the exposure interval in the sub-scanning direction on the photosensitive drum comes close to a constant interval.

Abstract: An image formation unit includes a first unit rotatably supporting an image carrier on which an electrostatic latent image is to be formed, and a second unit rotatably supporting a developer carrier configured to develop the electrostatic latent image with a developer. The first unit includes a first engagement portion formed at one end in the direction of the rotational axis of the image carrier, and a second engagement portion provided at a predetermined distance from the first engagement portion at the one end side. The second unit includes a first engaged portion engaged with the first engagement portion, a second engaged portion engaged with the second engagement portion, and a drive input portion provided between the first and second engaged portions and configured to rotate the developer carrier.

Abstract: A motor control apparatus that controls a DC motor includes a detection unit configured to detect angular speed of the DC motor, a driven member configured to be driven by the DC motor, and a control unit configured to increase, when starting to drive the DC motor, a control value for controlling driving of the DC motor from a first control value to a second control value at a predetermined increase rate, wherein the control unit detects a start-up characteristic of the DC motor based on a detection result of the detection unit, and corrects the first control value or the increase rate according to a result of comparing a detected start-up characteristic and a predetermined start-up characteristic such that the start-up characteristic of the DC motor becomes closer to the predetermined start-up characteristic.

Abstract: A process cartridge includes a photosensitive cartridge and a developing cartridge. The developing cartridge includes a developing roller, an input gear, a transmission gear, and a supporting cover. The input gear includes a contact portion, an outer circumferential wall, and a gear portion. The contact portion is in contact with a coupling member to receive the driving force. The outer circumferential wall and the gear portion rotate about a rotational axis defining an axial direction when the contact portion receives the driving force. The outer circumferential wall has a curved surface whose center of radius of a curvature is coincident with the rotational axis. The transmission gear is meshingly engaged with the gear portion to transmit the driving force from the input gear to the developing roller. The supporting cover covers the curved surface of the outer circumferential wall to rotatably support the outer circumferential wall.

Abstract: A phase synchronization mode is performed at a time of subsequent rotation after image formation. After detection of a phase difference by phase detecting sensors 103a, 103d, rotation phases are synchronized between driving motors 111, 102d after a lapse of a variable time. Specifically, timing for starting the rotation phase synchronization is shifted by 20 msec for each phase synchronization control so as to vary angular positions of the photosensitive drums 101a, 101b, 101d at which phase control is started. In this manner, sliding-contact positions are distributed and development and concentration of sliding-contact damages are prevented on the photosensitive drums 101a, 101b, 101d.

Abstract: The present invention provides a driving component, and a photosensitive drum and a process cartridge comprising the driving component. The driving component comprises a gear fixed at one end of the photosensitive drum and a longitudinal regulating component. The longitudinal regulating component comprises a first motion subassembly, a groove part and a central shaft part. The groove part has an upper chute and a lower chute which are orthogonal in space. The first motion subassembly forms relative slide coordination with the upper chute along a first direction. The central shaft part has a common axis with the gear which forms relative slide coordination with the lower chute along a second direction. The first direction and the second direction are all perpendicular to the longitudinal direction of the photosensitive drum.

Abstract: An image forming apparatus includes: rotators; a drive motor configured to drive the plurality of rotators and including a hall element configured to output a hall signal according to a change of a magnetic field; a counter configured to count the hall signal; an image forming unit forming a color image on a recording medium; and a controller configured to function as: an acquiring unit controlling the image forming unit to form a test pattern on the recording medium, and acquiring correction information based on the formed test pattern; a phase managing unit managing the phases of the rotators based on a count value of the counter from the formation start timing; and a correcting unit correcting the positional deviation based on the phases which are managed by the phase managing unit, and the correction information acquired by the acquiring unit.

Abstract: A process cartridge and an image forming apparatus are provided. The process cartridge is detachably mountable in an apparatus body of the image forming apparatus, and includes a plurality of photosensitive drums, a first outer side plate which is provided on one side of the photosensitive drums in an axial direction of the photosensitive drum, a second outer side plate which is provided on the other side of the photosensitive drums in the axial direction, and opposes the first outer side plate with the photosensitive drums interposed therebetween, and a plurality of input parts which are provided on ends of the photosensitive drums at the one side, respectively. An end face of each of the input parts being provided inward with respect to the outer surface of the first outer side plate.

Abstract: An image forming apparatus is configured to reduce a velocity fluctuation of a rotating body by reducing the AC velocity component of the rotating body. The image forming apparatus may include an image bearing body with a surface on which a toner image is formed; a driving motor configured to drive the image bearing body according to an input signal; and a controller configured to control the driving motor to output a motor output velocity at a period equal to that of an AC velocity component of the image bearing body. A velocity control method for the rotating body includes sampling a continuous motor input signal at a period equal to that of an AC velocity component of a rotating velocity of the rotating body. The sampled signal is transmitted to a driving motor that drives the rotating body, which is driven based upon the discrete motor input signal.

Abstract: Provided is a structural member including an image holding member that holds a latent image, a developing member that develops the latent image, a first driven side coupling portion that is connectable to a first driving side coupling portion and transmits a driving force to the image holding member, and a second driven side coupling portion that is connectable to a second driving side coupling portion and transmits the driving force to the developing member, wherein the first driven side coupling portion includes a first engaged portion that is engaged with a first engaging portion provided on the first driving side coupling portion at no more than two engagement places, and the second driven side coupling portion includes a second engaged portion that is engaged with a second engaging portion provided on the second driving side coupling portion at three or more engagement places.

Abstract: A developer recovery device is provided with a recovery container that receives and accommodates developer recovered from an image carrier, an agitator member that agitates the developer inside the recovery container, two shafts, to which mutually engageable cams are respectively provided, transmit rotational force to the agitator member, a spring that biases and causes to move one of the cams such that the two cams mutually engage and that causes a shaft connection between the two shafts to join, a torque limiter that carries out joining of the shaft connection, and disjoining of the shaft connection, in which the two cams are caused to move apart to disjoin the shaft connection, and a full-state determination portion that detects a shaft connection disjoined state and, based on the detected disjoined state, determines that the recovery container has become full of developer.

Abstract: A drive transmission device including at least one drive source, a drive transmission member, and a drive gear train. The drive transmission member includes an engaging part that engages a first rotary body provided within a unit detachably attachable to an image forming apparatus and a gear part that engages a motor gear attached to the at least one drive source. The engaging part and the gear part are formed together as an integrated unit. The drive gear train that transmits a driving force from the at least one drive source to a second rotary body provided within the unit includes a first gear and a second gear. The first gear engages the motor gear and the second gear is attached to the drive transmission member.

Abstract: Disclosed is a supporting mechanism including a bearing support portion that supports a bearing and is open so that the bearing is removed in a first direction that crosses a rotating shaft that is supported by the bearing, a driving shaft coupling that transmits a driving force to the rotating shaft by being connected to a rotating shaft coupling that is provided at one end of the rotating shaft, and a contact member that includes a bearing contact portion that makes contact with the bearing.

Abstract: A process cartridge comprises a photosensitive drum and a developing roller. A coupling member is provided adjacent to one axial end of the developing roller. The coupling member includes a driven portion, and an intermediary portion configured and positioned to engage with the driven portion. The intermediary portion is also configured to be movable relative to the driven portion in a direction crossing the axis of the developing roller while maintaining engagement with the driven portion. The coupling member further includes a driving portion configured and positioned to receive a driving force for rotating the developing roller. The driving portion is also configured to engage with the intermediary portion, and to be movable relative to the intermediary portion in a direction crossing the axis of the developing roller while maintaining engagement with the intermediary portion.

Abstract: An image forming apparatus includes a rotatable image bearing member for carrying a latent image; a developing device including a developer carrying member, rotatable about a rotational axis thereof, for carrying a developer and for developing a latent image formed on the bearing member; a rotatable feeding member, provided in the developing device, for feeding the developer; a first driving force receiving member, provided at one axial end portion of the developer carrying member, for receiving a driving force for driving the developer carrying member; a second driving force receiving member, provided at the other axial end portion of the developer carrying member, for receiving a driving force for driving the feeding member; a first drive inputting member for driving the first driving force receiving member; a second drive inputting member for driving the second driving force receiving member; and an abutment member, provided at each of the axial end portions of the developer carrying member, or determining

Abstract: A rotary drive device to drive a rotary body included in an image forming apparatus. The rotary drive device includes a drive source and a planetary gear mechanism to control torque from the drive source. The planetary gear mechanism includes a sun gear rotated by the torque, an annular gear coaxial to the sun gear and having inward-facing teeth, multiple planetary gears provided within the annular gear, and a carrier rotatable coaxially to the sun gear and the annular gear to rotatably support the multiple planetary gears. The annular gear is formed by injecting molten resin into a mold having a cylindrical cavity with teeth shapes along an inner circumference of the cavity from multiple pin gates provided to the mold at equal intervals along a circumference of the cavity. A number of pin gates is a non-integer multiple of a number of planetary gears.

Abstract: An image forming apparatus includes a housing; a driving portion provided in the housing and configured to generate a driving force; an interchangeable member interchangeably provided in the housing and having a driving-force-receiving portion at which the driving force is received, the interchangeable member being configured to rotate by receiving the driving force at the driving-force-receiving portion; a driving-force-transmitting portion provided in the housing and connecting the driving portion and the interchangeable member to each other, the driving-force-transmitting portion being configured to transmit the driving force from the driving portion to the interchangeable member; and a connecting-and-disconnecting mechanism that allows the driving force to be transmitted between the driving portion and the driving-force-transmitting portion when the interchangeable member rotates, and prevents the driving force from being transmitted between the driving portion and the driving-force-transmitting portion w

Abstract: A driving device includes a motor, and first and second gears having gear teeth engaged with each other. At least one of the first gear and the second gear includes a crowning portion formed at a tooth surface of each of the gear teeth such that the center of the tooth surface is more convex than both ends of the tooth surface in a tooth width direction. A height of the crowning portion is determined to effectively compensate for misalignment between the first gear and the second gear.

Abstract: A process cartridge comprises a photosensitive drum and a developing roller. A coupling member is provided adjacent to one axial end of the developing roller. The coupling member includes a driven portion, and an intermediary portion configured and positioned to engage with the driven portion. The intermediary portion is also configured to be movable relative to the driven portion in a direction crossing the axis of the developing roller while maintaining engagement with the driven portion. The coupling member further includes a driving portion configured and positioned to receive a driving force for rotating the developing roller. The driving portion is also configured to engage with the intermediary portion, and to be movable relative to the intermediary portion in a direction crossing the axis of the developing roller while maintaining engagement with the intermediary portion.

Abstract: An image forming apparatus includes: a frame that includes a pair of standing walls spaced apart from each other, and a linking section linking the pair of standing walls; and an intermediate transfer section that includes support rolls extending between the pair of standing walls and supported by the pair of standing walls, and an intermediate transfer belt held by the support rolls and circulating. The apparatus further includes built-in bodies, at least, into each of which a photoreceptor roll having a shaft with protruding both ends and rotatable around the shaft is incorporated, and which are arranged along the intermediate transfer belt while being supported in a state that the both ends of the shaft penetrate the pair of standing walls, and each of which is fixed to a first standing wall of the pair of standing walls by a screw.

Abstract: An image forming apparatus that is capable of reducing velocity fluctuation due to variation of friction torque between a photosensitive drum and an intermediate transfer medium depending on a toner image. An exposure unit forms a latent image on an image bearing member rotated by a first drive unit. A development unit develops the latent image to form a toner image. A primarily transfer unit transfers the toner image to an intermediate transfer medium rotated by a second drive unit. A secondary transfer unit transfers the toner image to a sheet. A control unit controls the drive units so that a peripheral velocity difference between the image bearing member and the intermediate transfer medium becomes a first value at starting, and controls so that the peripheral velocity difference becomes a second value larger than the first value when minute toner reaches the position of the primarily transfer unit.

Abstract: A cartridge is provided to be used in a main assembly of an electrophotographic image forming apparatus. The main assembly includes a rotatable driving coupling member including a driving force transmitting portion for transmitting a driving force and a driving side abutment. The cartridge is demountable in a direction substantially perpendicular to a rotational axis of the driving coupling member, and includes a rotatable driven coupling member with a driving force receiving portion for receiving the driving force. The cartridge also includes a driven side abutment to be abutted by the driving side abutment. The driven coupling member is slidable in a predetermined direction that is substantially parallel with a rotational axis of the receiving coupling member.

Abstract: A first and second electrostatic image code is located outside a developing zone. A transfer belt provided with an electrostatic image recording track capable to transfer the electrostatic code between the first drum and second drum. A transferring voltage applies to a side of the transfer belt for the first drum to transfer the first electrostatic image code onto the electrostatic image recording track. An electroconductive member is in parallel with the electrostatic image code and a surface of the electrostatic image code detected within a predetermined gap. An induced current generated in the electroconductive member relative to the lines of the electrostatic image codes which control the first drum or the second drum on the basis of a detection result of the detecting means such that the toner image on the second drum transferred onto a recording material on the transfer belt and overlaid on the toner image transferred onto the recording material from the first drum.

Abstract: An image forming apparatus is provided. The image forming apparatus includes electrostatic latent image carriers, developer devices, an endless belt, a cleaning roller, a first motor, a first gear train, being coupled to the cleaning roller to rotate in a predetermined direction when the first motor rotates in a first direction and decoupled from the cleaning roller when the first motor rotates in a second direction, a second gear train, being coupled to the cleaning roller to rotate in the predetermined direction when the first motor rotates in the second direction and decoupled from the cleaning roller when the first motor rotates in the first direction, and a third gear train, being coupled to at least one of the developer devices when the first motor rotates in the first direction and decoupled from the at least one of the developer devices when the first motor rotates in the second direction.

Abstract: A driving mechanism includes: a looped metallic transmission belt; a first shaft member; a second shaft member; and a pulley that is connected to the second shaft member so as to be rotatable about a second rotational axis, in which the first shaft member includes: a rotatably supported portion that is disposed at one end; and an extended portion that is disposed at another end so as to be continuous with the rotatably supported portion, in which a portion between the contact portion and the rotatably supported portion is flexurally deformed, the extended portion being rotatable about a diagonal rotational axis that is inclined at a predetermined angle relative to the first rotational axis, and the pulley includes a inclined outer surface that is inclined, such that a portion that is most separated from the first shaft member is substantially parallel with the extended portion.

Abstract: An image forming apparatus including plural image forming units each having an image-carrier includes: a cylindrical image-carrier body holding an image; a rotary shaft inserted in the image-carrier body, and rotatably supporting the image-carrier body; a coupling member fitted to an end portion of the rotary shaft, transmitting a rotational-drive-force to the rotary shaft; an engaging member projecting from a circumferential surface of the rotary shaft, being engaged to an engaged portion formed in the image-carrier body to disable relative rotation of the image-carrier body to the rotary shaft; and an attaching member continuously inserted into a first through hole formed in the coupling member and a second through hole formed in the rotary shaft and fixed thereto such that an angle formed between the engaging member and the attaching member is substantially 90 degrees as seen in an rotary shaft axial-direction, attaching the coupling member and the rotary shaft.

Abstract: An image forming apparatus including a drive source, a rotating body, a processing unit, and a joint to switch transmission and disconnection of the driving force by moving along an axial direction, is provided. The joint is rotatable by the driving force transmitted from the rotating body in a coaxial position with respect to the rotating body and switches transmission and disconnection of the driving force by moving along the axial direction. The rotating body includes an input rotating body, which is subject to the driving force input in the rotating body and rotatable by the driving force, and an output rotating body, which is arranged coaxially with respect to the input rotating body and rotatable integrally with the input roller to output the driving force. The rotating body provides accommodating space, which accommodates at least a part of the joint when the joint is separated from the processing unit.

Abstract: Provided is an image forming apparatus provided with an image forming unit. The image forming apparatus includes a movable member configured to be displaced relative to an apparatus main body; a cover configured to be displaced between a position where an opening portion provided on the apparatus main body is opened and a position where the opening portion is closed; a link that displaces the movable member in conjunction with the cover; a driving pulley and a driven pulley; and an endless belt that is looped around and stretched between the driving pulley and the driven pulley and transmits a driving force from the driving pulley to the driven pulley. The belt overlaps with the link in a direction parallel to a rotational axis of the driving pulley.

Abstract: A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and three prongs extending longitudinally outward from the end surface.

Abstract: A control unit temporarily stops an image carrier when transfer of an image formed using a developer to a recording medium ends. Thereafter, the control unit controls a drive source to intermittently drive the image carrier N times. A measuring unit measures an amount of rotation of the image carrier when the image carrier is intermittently driven. A determination unit determines an amount of rotation for stop instruction issuance that will be applied to a next drive. The amount of rotation for stop instruction issuance is based on an amount of inertial rotation measured from when a stop instruction is issued until when the image carrier stops rotating, and a target amount of rotation for each time the image carrier is driven.

Abstract: A toner cartridge converting device is provided with a driving module to change gaps between a photoreceptor drum and respective toner cartridges using a positioning groove formed in a radial direction of the photoreceptor drum. Each fixing rod of the toner cartridges can slide into the positioning groove and slide out of the positioning groove with following the displacement of the groove, so that the converting operation to the toner cartridges can be finished. Due to the configuration space required by the driving module is smaller, and the quantity of elements is less than the conventional driving unit and easy in repair and maintenance, so that the structure of the driving module is simplified and the repair cost is reduced.

Abstract: A drive transmission system includes a shaft member storing grease in a shaft outer circumferential small diameter section. A drive transmission gear is provided including a gear inner circumferential sliding section and a gear inner circumferential large diameter section. A gear moving device is provided to move the drive transmission gear reciprocally along the shaft member in a shaft direction. A restriction device is provided to restrict a movement range of the drive transmission gear along the shaft member in the shaft direction to enable the gear inner circumferential large diameter section to face the shaft outer circumferential small diameter section substantially continuously.

Abstract: A rotating part for an image forming apparatus includes a drive member for transmitting power; and a driven member that is rotated by the drive member. The drive member has a male part formed in a direction of a rotation axis, and the driven member has a female part that is formed in the direction of the rotation axis and into which the male part is inserted. The male part is a hexagonal male part whose cross section perpendicular to the rotation axis assumes a hexagonal shape. The female part is a twisted triangular female part that assumes a triangular cross sectional profile in a direction perpendicular to the rotation axis, and a triangle which forms a cross section of a base and a cross section of a top is twisted at a predetermined angle with respect to the rotation axis.

Abstract: A drive unit includes a drive pulley connected to a drive source, a driven pulley connected to a target to be moved, at least one relay pulley for transmitting power from the drive pulley to the driven pulley, a plurality of belts including a first belt entrained around the drive pulley and the relay pulley, and a second belt entrained around the relay pulley and the driven pulley, a first tension application device, and a second tension application device. The first tension application device contacts the first belt to provide tension thereto. The second tension application device contacts the second belt to provide tension thereto. A cyclic speed variation component of the first belt in one rotation period transmitted to the driven pulley via the relay pulley and a speed variation component of the second belt in one rotation period transmitted to the driven pulley counteract each other.

Abstract: An image forming apparatus includes a drive source that generates a driving force, an image forming object on which an electrostatic latent image is to be formed and that includes a rotatable shaft extending therethrough and rotates with the driving force that is input to one end of the rotatable shaft, and an extracting member that is provided at another end of the rotatable shaft of the image forming object and extracts, from the rotatable shaft, a driving force to be transmitted to a driven member excluding the image forming object.

Abstract: An image forming apparatus includes a first image supporting member for forming a first image; a second image supporting member arranged adjacent to the first image supporting member for forming a second image; a first drive unit for driving the first image supporting member through a first driving force having a first phase; a second drive unit for driving the second image supporting member through a second driving force having a second phase shifted from the first phase; and a transfer unit for transferring the first image and the second image to a printing medium.

Abstract: In the case of a standard sized sheet, a first controller sets a linear velocity D of an image bearing member at a first velocity and sets a linear velocity S of a toner bearing member so that S/D, which is a ratio of the linear velocity S to the linear velocity D, has a first value and a second controller sets the thickness of the toner layer carried on the toner bearing member at a first layer thickness. In the case of a long sheet, the first controller sets the linear velocity D at a second velocity slower than the first velocity and sets the linear velocity S so that the S/D has a second value larger than the first value and the second controller sets the thickness of the toner layer at a second layer thickness smaller than the first layer thickness.

Abstract: A gear switching mechanism for a printing machine comprises at least one pair of input and driven gears, each pair rotationally mounted on a corresponding common axle. The input gear of each pair may be coupled to a common drive, while each driven gear is coupled to a separate output. A rotational gear coupling is mounted to translate along each axle to selectively engage and disengage the corresponding pair of input and driven gears. The rotational gear coupling includes a cam follower that slides along a cam profile of a cam shuttle. The shuttle defines a cam profile that is normal to the common axles. In one embodiment, the cam shuttle translates linearly, while in another embodiment, the shuttle rotates. The cam profile is configured to selectively engage and disengage the rotational couplings of each pair of input and driven gears.

Abstract: A drive gear for a generally cylindrical imaging component. The drive gear includes a body for engaging the generally cylindrical imaging component; a cylindrical shaft attached to the body, the cylindrical shaft having an end surface; and three prongs extending longitudinally outward from the end surface.

Abstract: A photosensitive drum assembly and a process cartridge and a process cartridge having an improved structure in which a protrusion for receiving a driving force transmitted from a main body of an image forming apparatus may not be easily worn or damaged. The photosensitive drum assembly that is capable of being combined with a driving shaft including a twisted hole with a non-circular cross-section having a plurality of corners, includes: a support disposed at one side of the photosensitive drum; and an insertion body disposed at one side of the support and including a plurality of protrusions that are capable of being inserted in the twisted hole, wherein at least portions of each of the plurality of protrusions based on a cross-section of each protrusion that is perpendicular to the driving shaft, closely contacts two side surfaces of the twisted hole that constitute one of the plurality of corners of the twisted hole, respectively.

Abstract: An electrophotographic photosensitive drum unit includes a cylinder having a photosensitive layer at an outer periphery thereof. A drum flange is provided at one end of the cylinder, with the drum flange including a plurality of projections provided inside of the drum flange and projected radially inwardly of the drum flange, and with a space diametrically between the projections. A radially inner part of each projection has an overhang.

Abstract: An image forming apparatus for forming image on a recording medium includes a photosensitive member, a motor, a belt, and a drive member to rotate the belt, the drive member including a driven coupling. The apparatus also includes a drive coupling to rotate by a driving force generated by the motor, the drive coupling being movable in an axial direction to take an engagement position at which the driving force is transmittable to the driven coupling, and a release position. The apparatus further includes a transfer member to transfer a toner image onto the recording medium or the belt, a voltage application unit to apply a voltage to the transfer member, and a control unit to cause the voltage application unit to apply the voltage to the transfer member after the drive coupling moves to the engagement position and the driving force is transmitted to the driven coupling.

Abstract: An image forming unit includes a first rotating body having a first gear; a first unit that rotatably supports the first rotating body; a second rotating body having a second gear; a second unit that rotatably supports the second rotating body; and a biasing part that biases the second unit toward the first unit, wherein a drive force is generated by transmitting rotation from the first gear to the second gear in order to transmit the rotation from the first rotating body to the second rotating body, and the biasing part biases the second unit in a biasing direction substantially perpendicular to a driving direction of the drive force.

Abstract: A process cartridge includes an electrophotographic photosensitive drum and a frame for supporting the electrophotographic photosensitive drum. The process cartridge also includes a first portion-to-be-positioned for being positioned to a first main assembly side positioning portion provided in the main assembly of an apparatus, a second portion-to-be-positioned for being positioned to a second main assembly side positioning portion provided in the main assembly of the apparatus, and a longitudinal positioning portion to be positioned by a main assembly side longitudinal positioning portion provided in the main assembly of the apparatus. The apparatus still further includes a portion-to-be-urged for receiving an inclined downward elastic force of a first main assembly side elastic member provided in the main assembly of the apparatus to urge the longitudinal positioning portion and the second portion-to-be-positioned.

Abstract: A rotary driving apparatus that is capable of controlling a rotational speed correctly even when an anomaly occurs. A drive unit rotates a rotating member. A rotating body is rotated with the rotating member. A detection unit detects scales formed on the rotating body. A calculation unit calculates rotation information about the rotating member based on the detection result by the detection unit. A control value setting unit sets a control value to a predetermined value when the rotation information falls outside a predetermined range and a count of determinations that the rotation information falls outside the predetermined range is smaller than a predetermined count, and sets the control value based on the rotation information when the rotation information falls outside the predetermined range and the count of determinations is larger than the predetermined count. A control unit controls the drive unit based on the set control value.