Abstract: A driving force transmission mechanism comprising a photosensitive drum driving member, wherein the photosensitive drum driving member is engaged with an image forming apparatus driving member and receives the driving force from the image forming apparatus driving member; the image forming apparatus driving member comprises a triangular groove having a triangular cross-section and driving force transmission portion disposed in three vertex angles of the triangular groove; the photosensitive drum driving member comprises a non-distorting protrusion which is axially extended from the end face of a drum shaft and engaged with the groove on the image forming apparatus driving member; the protrusion has a position-limiting mechanism and a stressed mechanism; a projecting tooth obliquely disposed on said non-distorting protrusion is taken as the stressed mechanism; and each projecting tooth also has a mating surface which is engaged with the driving force transmission component to transmit the driving force.

Abstract: An image forming apparatus includes: an image bearing member; an electrostatic image forming device; and a developer carrying member. The developer carrying member is provided so as to be rotated in a direction opposite to a rotational direction of the image bearing member at a peripheral speed higher than that of the image bearing member. When the peripheral speed of the image bearing member is Vp (m/sec), the peripheral speed of the developer carrying member is Vs (m/sec), and a time, of movement of the developer from the surface of the developer carrying member to the image bearing member, actually measured in a gap between the image bearing member and the developer carrying member is Tsd (sec), the peripheral speeds Vp and Vs and the time Tsd satisfy the following relationship: (Vs?Vp)×Tsd<3×105 (m).

Abstract: A plurality of first viscoelastic bodies are disposed in insertion holes of a first rotary member. A plurality of second viscoelastic bodies are disposed in guide holes of a second rotary member. Each of the first and the second viscoelastic bodies has an elastic coefficient changing in accordance with aging due to use. A guide member moves a contact member along the insertion hole and the guide hole. The contact member applies a compressive load to the first viscoelastic body. The aging of the second viscoelastic body due to the compressive load applied thereto moves a position of the first viscoelastic body where the compressive load is received from the contact member toward a farther side from a rotational shaft side.

Abstract: A process unit includes a photosensitive member that carries an image; a developing device that has a developer carrying member carrying a developer to be supplied to the photosensitive member; a rotating shaft that supports the developing device rotatably for approaching and separating from the photosensitive member; a photosensitive member gear provided to the photosensitive member; and a developing gear provided to the developer carrying member. The photosensitive member gear and the developing gear engage together and driving force can be transmitted, and the rotating shaft is placed on a driving force vector between the gears or on an extended line thereof, the driving force vector being generated from engagement between the photosensitive member gear and the developing gear.

Abstract: An image forming apparatus includes a cover member which is openable and closable with respect to main assembly of the image forming apparatus; and an image reading portion, movable to first and second positions, for reading an image of an original. The cover member is movable to first and second open positions with respect to the main assembly. The image reading portion is initially rested at the first position as the cover member is moved from a closed position to the first open positions, and then is movable from the first position to the second position in interrelation with movement of the cover member from the first open position toward the second open position.

Abstract: A length L of the test pattern string is determined so as to satisfy a condition L?{P?(Q1+Q2)}×V, where a time Q is a total time of a time Q1 for which the test pattern string is transferred from an exposure position of the test pattern string to a sensor and a time Q2 from when the test pattern is detected by the sensor until a color misregistration correction value calculated on the basis of a result of detecting is reflected in image formation; a time P is a time from a timing of starting to write the test pattern string to a timing of starting to write an image in which the correction value should be reflected; and a driving speed of a second image carrier is V.

Abstract: An image forming apparatus comprising: a rotary body which rotates in accordance with an image forming operation; a rotation shaft of the rotary body; a through hole which is provided in an end portion in an axial direction of the rotation shaft; a stabilizing member which is provided to rotate together with the rotary body and stabilize the rotary body by reducing fluctuations of rotation of the rotary body under inertia, and which has an inserted portion into which the rotation shaft is inserted; a holding member which is disposed so as to be adjacent to the stabilizing member in the axial direction to hold the stabilizing member on the rotation shaft; a through hole which is formed in the longitudinal portion correspondingly to the through hole provided in the rotation shaft; and a clamp member which passes through the through hole provided in the longitudinal portion and the through hole provided in the rotation shaft.

Abstract: A drive device to rotatively drive N number of image carriers. The drive device includes a single drive motor to generate torque to be transmitted to the image carriers, N number of drive gears to transmit the torque to the image carriers, an input gear rotatively driven by the torque and engaging a first drive gear to transmit the torque to the first drive gear, and N?1 number of idler gears provided between each of the drive gears, respectively, to transmit the torque from the drive gears provided on an upstream side to the drive gears provided on a downstream side in a direction of transmission of torque. The torque generated by the drive motor is sequentially transmitted from the first drive gear to the Nth drive gear via the idler gears to rotatively drive the image carriers.

Abstract: A fixing device and an image forming apparatus using this, in which even if permanent warping is produced on a roller member that forms a fixing nip portion, no collision sound is produced due to the collision of gears, the fixing device including: two roller members that form a nip portion in which a recording medium is pressed by pressure means and transported; and a drive gear that engages with a shaft portion of one of the two roller members and transmits driving force to that roller member. A key is formed in the drive gear and a key groove having a gap opened therein is formed in the shaft portion, and when a rotation velocity of the roller member increases, transmission of driving force from the drive gear to the shaft portion is suspended and the drive gear slides on the shaft portion.

Abstract: A rotary driving device includes a rotary shaft supported rotatably about an axis thereof on a predetermined supporting member, a rotary load body mounted on the rotary shaft to project radially outward from the rotary shaft in such a manner that the rotary load body can rotate integrally with the rotary shaft about the axis thereof, a driver for rotating the rotary shaft about the axis thereof, a disk mounted on the rotary shaft coaxially therewith for integral rotation with the rotary shaft, the disk having a mounting hole formed therein, a pendulum loosely fitted in the mounting hole, and an adjustment mechanism for adjusting a relative position relationship between a central axis position of the mounting hole and a center of gravity position of the pendulum under conditions where the disk is rotating.

Abstract: The image forming apparatus includes a drum cartridge having a photosensitive drum and a drum drive input member; a developing cartridge configured to be movably mounted to the drum cartridge, the developing cartridge comprising a developing roller disposed so as to face the photosensitive drum and a developing drive input member; a drum drive transmission member configured to engage with the drum drive input member and configured to transmit drum driving force to the drum drive input member while permitting a positional gap of the drum drive input member within a predetermined range; and a developing drive transmission member configured to engage with the developing drive input member and configured to transmit developing driving force to the developing drive input member while permitting a positional gap of the developing drive input member within a predetermined range.

Abstract: A drive device has a drive source; a rotatable member gear rotated by a driving force from the driving source; a follower gear, including a pair of gears which are coaxially disposed with each other and are rotatable at the same rotational speed and including an urging device for urging the pair of gears in rotational directions opposite from each other, for being rotated at the rotational speed higher than that of the rotatable member gear; a rotation detecting device for detecting rotation of the follower gear and including a flag rotatable together with said follower gear and provided coaxially with said follower gear and includes a detecting portion for detecting passing of the flag; and a driving source control portion for controlling said driving source on the basis of the computation result stored in the storing portion.

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 driving force transmission mechanism is provided. The driving force transmission mechanism includes an input member including a concave shape portion; a rotation driving shaft; and a driving force transmission member that is configured to rotate in a rotation direction of the rotation driving shaft together with the rotation driving shaft. A protrusion is formed on a surface of a tip end portion of the driving force transmission member, the surface is opposed to the concave shape portion, the protrusion is configured to be engaged, from an inner side, with an edge of the concave shape portion when the tip end portion is in a contact with the edge of the concave shape portion and is tilted.

Abstract: A rotary driving device includes a rotary shaft supported rotatably about an axis thereof on a predetermined supporting member, a rotary load body mounted on the rotary shaft to project radially outward from the rotary shaft in such a manner that the rotary load body can rotate integrally with the rotary shaft about the axis thereof, a driver for rotating the rotary shaft about the axis thereof, a disk mounted on the rotary shaft coaxially therewith for integral rotation with the rotary shaft, the disk having a mounting hole formed therein, a pendulum loosely fitted in the mounting hole, and an adjustment mechanism for adjusting a relative position relationship between a central axis position of the mounting hole and a center of gravity position of the pendulum under conditions where the disk is rotating.

Abstract: A cartridge mountable in an image forming apparatus includes a rotatable member, a hollow cylindrical portion, having first and second inner grooves, that transmits a rotational force to the rotatable member, a coupling member having a spherical base portion and an axially movable pin penetrating the spherical base portion and having first and second end portions projected outside the base portion, and a limiting portion, provided in the first inner groove, for limiting axial movement of the pin. When the coupling member is inclined to a maximum extent within a predetermined inclination range, after movement of the pin is limited, so that the first end portion moves away, and the second end portion moves toward, the rotatable member, the first end portion is disengaged from the first inner groove, whereas the second end portion is engaged with the second inner groove.

Abstract: An image forming apparatus is provided with an image forming station including photoconductive drums and adapted to form toner images on surfaces of the respective photoconductive drums, and a drive control unit for rotating and driving the photoconductive drums. The image forming station includes a reference pulse output section for generating a reference pulse having a cycle equal to or an integral multiple of a rotation cycle of the photoconductive drums and outputting the reference pulse to the drive control unit. The drive control unit includes a phase peak detector for detecting phase peaks of surface speeds of the photoconductive drums, a phase difference detector for detecting phase differences between an edge of the reference pulse and the phase peaks, and a phase synchronization controller for synchronizing phases of the surface speeds of the photoconductive drums by controlling rotation speeds of the photoconductive drums according to the phase differences.

Abstract: An image forming apparatus having an improved power-transmission assembly to drive a developing cartridge mounted in a main body of the apparatus. The apparatus includes a main body, at least one driving coupling unit rotatably located in a side region of the main body, at least one driven coupling unit connected to a rotator inside a developing cartridge, and a coupling holder in which the driving and driven coupling units are connected to each other to enable a power-transmission from the driving coupling unit to the driven coupling unit. The driving coupling unit includes a first spherical portion to come into contact with one side of an inner surface of the coupling holder when received in the coupling holder. The driven coupling unit includes a second spherical portion to come into contact with the other side of the inner surface of the coupling holder when received in the coupling holder.

Abstract: A process cartridge comprises an electrophotographic photosensitive drum and a developing roller. A coupling member is provided that receives a rotating force for rotating the electrophotographic photosensitive drum and transmits the rotating force to the electrophotographic photosensitive drum through a drum flange. The drum flange has (i) a first regulated portion capable of being regulated by a first regulating portion, (ii) a second regulated portion capable of being regulated by a second regulating portion, (iii) a connecting portion that is connected with the coupling member so that a rotational axis of the coupling member is inclineable relative to a rotational axis of the drum flange, and (iv) a gear portion that transmits the rotational force from the coupling member to the developing roller.

Abstract: A drive mechanism of the present invention includes: a housing part composed of a first resin cover and a second resin cover; a first sheet metal member housed in the housing part; a first rotation transmission wheel group disposed on the first sheet metal member on a side directed to the first resin cover; a second rotation transmission wheel group disposed on the first sheet metal member on a side directed to the second resin cover; a positioning part rotatably supporting a first rotation transmission wheel of the first rotation transmission wheel group; and a pin member positioned by inserting into the positioning part via the first resin cover.

Abstract: A photoconductor drum support structure includes a photoconductor drum that is supported to rotate about a rotation axis; a drum shaft that passes through the photoconductor drum, and is disposed along a rotation axis; a notch formed on the first end in the rotation axis direction of the drum shaft; a drum frame that retains the photoconductor drum to rotate, the drum frame including an opening that is formed on the first end in the rotation axis direction on the drum frame, and enables insertion of the first end of the drum shaft, an engaging portion that is engaged with the notch formed on the drum shaft inserted into the opening, and that regulates displacement of the drum shaft towards the second end.

Abstract: An image forming apparatus includes: a driving source configured to generate power; a first rotator configured to be drivingly rotated by the power generated by the driving source; a first power transmission system configured to transmit the power from the driving source to the first rotator; a second rotator configured to be drivingly rotated by the power generated by the driving source; and a second power transmission system configured to transmit the power to the second rotator from the first power transmission system. A damper having a torsion spring constant and a torsion viscous damping constant making a maximum positional change value of the first rotator equal to or smaller than a predetermined positional change value is disposed between the first power transmission system and the second power transmission system.

Abstract: The present invention is capable of changing the system speed quickly and highly accurately while using a CVT device with an advantage in its quietness to transmit a driving force to rotative parts. Specifically, in the case of using a sheet of thick paper as a recording sheet, the controller changes, for each of the pulleys, the distance between the pulley segments (S204) while starting up the DC motor as the driving source (S202). After that, the controller performs the feedback control on the rotation of the DC motor, based on a detection signal received from the encoder of the load shaft of the driven pulley, to achieve the target rotation speed of the load shaft (S206: NO, S207).

Abstract: An image forming apparatus, including: a motor having a winding in which a plurality of coils are connected to one another, the motor configured to rotate an image bearing member by a switchover of a direction of a current flowing through each of the plurality of coils; and a control device configured to switch over the direction of the current flowing through each coil to put a brake on the motor separately from the switchover of the direction of the current flowing through each coil to drive the motor, wherein the control device switches over the direction of the current, according to a brake signal having a period larger than a period of a drive signal for driving the motor, to put a brake on the motor to control a rotation speed of the image bearing member.

Abstract: Described herein is an exemplary method wherein the photoreceptor surface velocity is nominally set at a speed fractionally different than the intermediate belt (ITB) nominal surface speed. The photoreceptor speed can be preemptively altered through a velocity ramp profile whenever an event is scheduled to occur that will result in ITB transient vibration. As a result, the photoreceptor speed is not allowed to cross over or equal the belt speed at any instant during the transient event. This allows the photoreceptor to remain dynamically decoupled from the ITB, since the apparent disturbance torque imposed by the belt remains constant and does not reverse sign.

Abstract: An image forming apparatus includes a unit, which is detachably attachable to a main body of the apparatus and has a portion to be detected, and a detecting device which detects the portion to be detected in the unit. It is determined that the unit is in an unused state since both of a first state in which the portion to be detected is detected by the detecting device and a second state in which the portion to be detected is not detected by the detecting device are confirmed, and thereafter, the first state or the second state is maintained. Furthermore, there is provided a restricting member which inhibits the first state or the second state from being maintained.

Abstract: A multi-pass type image forming apparatus allows driving-couplings to couple with and separate from an image-carrier and developing units simultaneously. The apparatus includes a main body, a cover to open or close the main body, an image-carrier unit including an image-carrier and first driven-coupling connected to the image-carrier, developing units including a developing roller and a second driven-coupling connected to the developing roller, first and second driving-couplings to transmit drive power to the first and second driven-couplings, a link unit to move in a first direction in linkage with opening/closing operations of the cover, and a guide unit to be rotatable about the first driving-coupling in linkage with the link unit, the guide unit being moved when rotated about the first driving-coupling so as to couple or separate the first and second driving-couplings to or from the first and second driven-couplings.

Abstract: A cartridge that can be detachably installed within an imaging device, which includes a cartridge casing, a photosensitive drum driving assembly located on the casing, and a control mechanism for controlling extension and retraction of a force receiving head in the photosensitive drum driving assembly. The control mechanism includes a control rod, which can rotate around a pivot on the cartridge casing, and a elastic means mounted on the control rod. The cartridge of the invention uses a control mechanism to control extension and retraction of the force receiving head in the photosensitive drum driving assembly, and as a result when the cartridge is removed of the imaging device, the force receiving head does not become stuck by a driving head of the imaging device.

Abstract: A device for transmitting a rotational force to an electrophotographic photosensitive drum. The device includes a flange connectable with the drum. A coupling member is provided with a rotational force transmitting portion engageable with the flange.

Abstract: In an image forming apparatus, a computing unit computes phase shift amounts A(i) for every correction relative phase angle ?(j) based on an amplitude B of a reference compressional wave ?a, an amplitude C(i) of a detection compressional wave ?(i), and a relative phase angle ?(i). A setting unit specifies the phase shift amounts A(i), and sets a correction relative phase angle ?(j) corresponding to the specified phase shift amounts A(i). A correction unit corrects, based on the correction relative phase angle ?(j) set by the setting unit, a relative phase shift between a periodic variation in the circumferential speed of a first image bearing member and a periodic variation in the circumferential speed of a second group image bearing member by operationally controlling at least one of first and second drive units.

Abstract: A control unit sets a first feedback gain for suppressing an angular speed variation of a first frequency, which causes a misalignment of images to be overlaid with each other, to the first nd feedback unit in a first image forming mode in which images formed on the first and the second image carriers are overlaid, and sets a second feedback gain for suppressing an angular speed variation of a second frequency, which causes a periodic uneven density on an image that is to be formed with a uniform density, to the first feedback unit in a second image forming mode in which an image is formed using the first image carrier.

Abstract: An image forming apparatus includes an endless belt member; a drive unit moving the endless belt member; a first detecting unit detecting a rotating speed of the drive unit; a second detecting unit detecting an endless transport speed of the endless belt member; and a control unit controlling the rotating speed of the drive unit based on a first detection signal from the first detecting unit or a second detection signal from the second detecting unit selectively depending on a selection condition. Upon selection of the first detection signal in accordance with the selection condition, the control unit corrects the rotating speed of the drive unit using the second detection signal such that an average value of the endless transport speed of the endless belt member approaches a target average value.

Abstract: A printing method usable with an image forming apparatus includes initiating driving of a plurality of photosensitive bodies and a transfer belt, printing an image by transferring toner images formed on the plurality of photosensitive bodies to the transfer belt and finally transferring the toner images, which are transferred to the transfer belt, to paper, and stopping the driving of the plurality of photosensitive bodies and the transfer belt after the printing is completed. The initiating of the driving of the plurality of photosensitive bodies and the transfer belt includes applying drive initiating signals with a time interval to a first driving unit and a second driving unit to respectively drive the plurality of photosensitive bodies and the transfer belt to enable the plurality of photosensitive bodies and the transfer belt to simultaneously begin rotating/moving.

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: 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: In full-color printing, one of first and second rotary members is activated with a time lag after the other of the first and second rotary members is activated such that the phase difference between the first and second rotary members is an adjusted phase difference. In addition, every time monochrome printing is performed, the time lag is changed.

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 driving force transmitting apparatus includes a driving source, a drive pulley rotatable by a driving force supplied from the driving source, a follower pulley rotatable with a member to be rotated, and a belt member extending around a cylindrical surface of the driving pulley and a cylindrical surface of the follower pulley. In addition, an intermediate transmission member contacts the driving pulley and the follower pulley, and the intermediate transmission member has a rigidity higher than that of the belt member.

Abstract: An image forming apparatus includes an operating portion that moves between a first operating position in which each of positioning members is moved to each of positioning positions and a second operating position in which each of the positioning members is moved to each of releasing positions through each of transmitting members and each of transmitted members when a first transmitting member and a first transmitted member are coupled to each other, and that carries out the movement to a first operating position to move a second positioning member to a second positioning position through a second transmitting member and a second transmitted member and carries out the movement to a second operating position to move the second positioning member to a second releasing position when the first transmitting member and the first transmitted member are decoupled from each other.

Abstract: A developing device used with an image forming apparatus has a driving shaft with a rotating force applying portion, and a movable member on which the developing device is mountable. The developing device includes a developing roller and a coupling member for transmitting a rotating force to the developing roller. The coupling member includes a rotating force receiving portion and a rotating force transmitting portion for transmitting a force received through the rotating force receiving portion to the developing roller. The coupling member can be in a rotational force transmitting angular position, a pre-engagement angular position, and a disengaging angular position. In response to movement of the movable member the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position, and by moving from the rotational force transmitting angular position to the disengaging angular position the coupling member is disengaged from the driving shaft.

Abstract: The instant application discloses an image forming apparatus including housing with cover member for covering and uncovering opening in communication with internal space, drive portion for generating drive force which is intermittently transmitted by clutch mechanism. Clutch mechanism includes transmission member with first transmission portion which receives drive force from drive portion and second transmission portion which engages with image forming portion; link mechanism which reciprocates transmission member in first direction in which transmission member moves away from image forming portion and second direction opposite to first direction; and flexible linker which connects cover member to link mechanism. When cover member uncovers opening, link mechanism coordinating with cover member by means of linker moves transmission member in first direction. When cover member covers opening, link mechanism coordinating with cover member moves transmission member in second direction.

Abstract: A clutch mechanism includes a transmission element rotatable in a first direction and a second direction opposite to the first direction, integrally including a plurality of projections including a first planar surface and a second planar surface at each side of the projections in the direction of rotation of the transmission element, a rotation restriction device including a first restriction surface and a second restriction surface to contact the first planar surface and the second planar surface, to lock rotation of the transmission element, and a moving device including an actuator to move the rotation restriction device to contact and separate from the transmission element. The first restriction surface contacts the first planar surface while the transmission element rotates in the first direction, and the second restriction surface contacts the second planar surface while the transmission element rotates in the second direction.

Abstract: An image forming apparatus is disclosed that includes an image carrier, a driving source, a rotation detection unit, and a control unit that performs fluctuation pattern recognition processing, control pattern construction processing, speed fine-adjustment processing, and remaining pattern recognition processing. The control unit is configured to perform control pattern correction processing for setting a frequency band of a remaining speed fluctuation to be detected by the remaining pattern recognition processing narrower than a frequency band of a speed fluctuation to be detected by the fluctuation pattern recognition processing and correcting the speed control pattern so as to be a pattern capable of reducing even the remaining speed fluctuation based on a remaining speed fluctuation pattern recognized by the remaining pattern recognition processing.

Abstract: An image forming apparatus includes: a photosensitive drum; a development roller; a transfer roller; a drum driving unit that includes a forwardly and reversely rotatable motor; a forward transport unit; a reverse transport unit; and a transfer potential control unit that is configured to control a surface potential of the transfer roller to have a reverse polarity to that of the developer on the photosensitive drum during the forward rotation of the motor and control the surface potential of the transfer roller to be a potential that has the same polarity as the developer on the photosensitive drum and is equal to or higher than a surface potential of the photosensitive drum during the reverse rotation of the motor.

Abstract: A connection assembly of the photo-conductor drum is applied for linking a driving shaft. The connection assembly of the photo-conductor drum includes a drum gear and a connector. A first connection part arranged at an end of the drum gear. An end of the connector forms a second connection part corresponding to the first connection part. Another end of the connector forms a joint end. The joint end includes a central pillar, and a plurality of protrusions extending from a periphery of the central pillar. The second connection part could detachably connect to the first connection part. The joint end is detachably connected to the driving shaft. Therefore, by replacing the damaged drum gear or damaged connector only, the costs, quantity of the waste and the maintenance expend would be reduced.

Abstract: An image forming apparatus includes: an image forming apparatus main body, a driven member removably disposed in the image forming apparatus main body, a rotary driver that rotates by current flowing, and after the blockage of the current flowing, continuously rotates due to an inertial force, a coupling part that has a driving-side member and a driven-side member, wherein when the driven-side member is mounted to the image forming apparatus main body, the driving-side member and a driven-side member are facing each other, and when the driving-side member and the driven-side member engage each other in the rotating direction, the rotary driver and the driven-side member are coupled to transmit the rotation of the rotary driver to the driven-side member, and a controller that controls so that, when the driven-side member is mounted to the image forming apparatus main body, the current flows to the rotary driver, and after the elapse of a certain period of time the current flow to the rotary driver is blocked.

Abstract: An image forming apparatus has a high-speed mode and a low-speed mode and includes a speed switch unit configured to select the high-speed mode or the low-speed mode by switching a rotation direction of a drive source. The speed switch unit includes a drive gear attached to a rotating shaft of the drive source; a first drive gear series transmitting a rotating power of the drive source upon rotation in a first direction to an image carrier; and a second drive gear series transmitting a rotating power of the drive source upon rotation in a second direction to the image carrier, the second drive gear series having a larger reduction ratio than the first drive gear series. The speed switch unit causes the drive gear to be selectively connected to the first drive gear series or the second drive gear series depending on the rotating direction of the drive source.

Abstract: An image forming apparatus is provided and includes: a rotating member; an engaging member to be removably engaged with the rotating member; a driving force transmitting member to be rotated and driven by a driving source; and a connecting portion that connects the engaging member to the driving force transmitting member so that the engaging member and the driving force transmitting member are movable in a misaligned direction and an axial direction. The connecting portion includes a connecting member, a pair of spherical members provided on respective ends of the connecting member, at least one of which is movable in the axial direction with respect to the engaging member and the driving force transmitting member, and a pair of fixing members that fix the pair of spherical members to the engaging member and the driving force transmitting member.

Abstract: A control unit sets a first feedback gain for suppressing an angular speed variation of a first frequency, which causes a misalignment of images to be overlaid with each other, to the first and feedback unit in a first image forming mode in which images formed on the first and the second image carriers are overlaid, and sets a second feedback gain for suppressing an angular speed variation of a second frequency, which causes a periodic uneven density on an image that is to be formed with a uniform density, to the first feedback unit in a second image forming mode in which an image is formed using the first image carrier.

Abstract: A first rotary body is configured to rotate by a drive force input from an external source and has a first outer peripheral surface. A second rotary body is configured to rotate by following a rotation of the first rotary body through the friction generated between the first outer peripheral surface and the second outer peripheral surface. A first gear is configured to rotate together with the first rotary body. A second gear is configured to rotate together with the second rotary body and is directory engaged with the first gear. The first gear had a first pitch circle and the second gear has a second pitch circle. A radius of the first pitch circle is smaller than the radius of the first rotary body, and a radius of the second pitch circle is larger than the radius of the second rotary body.