Abstract: A drive transmission mechanism includes a driving coupling element having a first engaging portion and a first operating portion; and a holder having a second engaging portion and a second operating portion, wherein when the first and second engaging portion are engaged, the driving coupling element is held in a middle position to be prevented from moving therefrom to a projected position. When the driving coupling element is moved from the middle position toward a retracted position, the first and second operating portions contact each other so that the driving coupling element rotates to a second angular position where they are disengaged from each other. By the driving coupling element rotating from the first angular position to the second angular position, the driving coupling element is enabled to move to the projected position.

Abstract: An image forming apparatus includes a drive roller, a rotary drive source, a rotation signal detection portion, and a removal determination portion. The drive roller is configured to rotate in contact with a printing medium. The rotary drive source is configured to supply a rotational force to the drive roller. The rotation signal detection portion is configured to detect a rotation signal indicating that the drive roller is rotated while the rotary drive source is being powered off. The removal determination portion is configured to determine whether the printing medium that has stopped in contact with the drive roller is removed, based on detection of the rotation signal by the rotation signal detection portion.

Abstract: An image forming apparatus includes: a main body provided with a drive-force supplying part; a cartridge comprising a rotary body and a drive-force transmission part; and a moving member supporting the cartridge. The drive-force transmission part transmits a drive force transmitted from the drive-force supplying part to the rotary body. The moving member is accommodated in and withdrawn from the main body. The cartridge is attached to and detached from the moving member when moving member is withdrawn from the main body. The moving member includes a drive-force relay part having an input portion and an output portion, the input portion receiving the drive force from the drive-force supplying part, the output portion outputting the drive force from the input portion to the drive-force transmission part of the cartridge attached to the moving member.

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: A developing cartridge is provided. The developing cartridge includes a housing which accommodates developer therein, a receiving member provided which couples with a force output member of an image forming apparatus to receive a driving force, a developing roller which rotates by the driving force received by the receiving member; a detectable rotary member having a first detectable portion and a second detectable portion and rotates by the driving force from a first rotational position where the first detectable portion is detected by a detection member provided in the image forming apparatus to a second rotational position where the second detectable portion is detected by the detection member, and a cut-off mechanism which cuts off a transmission of the driving force from the receiving member to the detectable rotary member in a state where the detectable rotary member is positioned in the second rational position.

Abstract: In a drive transmission device, a transmission member moves in a rotational axis direction of an input member, and is able to move to a position for engaging with an output member and a position for not engaging with the output member. When the input member is rotating in a first direction, the transmission member engages with the output member so that the output member rotates, and when the input member rotates in a second direction opposite to the first direction, the transmission member does not engage with the output member. A gap filled with a viscous material is disposed between the output member and the transmission member, and a hole communicating with the gap is formed in the output member.

Abstract: An image forming apparatus includes gears for driving a first photosensitive drum and a second photosensitive drum. The gears includes a first drum gear, a second drum gear, and a first drive gear configured to apply a rotational force to the first drum gear and the second drum gear by meshing with the first drum gear and the second drum gear. Specific positional relations among the first photosensitive drum, the second photosensitive drum, the first drum gear, the second drum gear, and the first drive gear are configured based on exposure positions and transfer position. Such an image forming apparatus may reduce an occurrence of an image formation failure even when the dimensional unevenness of the gears occurs.

Abstract: A medium detecting device is provided. The medium detecting device includes a sensor adapted to detect magnetism of a medium being transferred; and a pressing unit adapted to press the medium toward the sensor, and the pressing unit includes at least one supporting part including a plurality of supporters to press the medium toward the sensor; and an elastic member adapted to elastically support the supporting part.

Abstract: A cartridge removably mountable to an image forming apparatus, including: a developing unit having a developing roller; two support mechanisms each configured to rotatably support the developing unit by a rotary shaft at an each end of the cartridge; and a biasing member provided on one support mechanism and configured to apply a biasing force to bring the roller into contact with a photosensitive drum, wherein a force against the biasing force is applied to the developing unit to rotate the developing unit to separate the roller from the drum, and in a projection plane orthogonal to the rotary shaft, an action point on which the biasing force acts is arranged between a first line connecting rotation centers of the roller and the drum and a second line passing through the support shaft in parallel with a slide direction of the support shaft slidably supported by the one support mechanism.

Abstract: An image forming apparatus includes multiple image forming units each accommodating an image bearer and a developer bearer to develop a latent image formed on the image bearer. Each of the image forming units other than a prescribed image forming unit runs in an ordinary reverse rotation mode, in which at least one of the image bearer and the developer bearer rotates in an opposite direction during a non-image formation time period. The prescribed image forming unit runs in a special reverse rotation mode, in which at least one of the image bearer and the developer bearer rotates in the opposite direction during the non-image formation time period based on a differentiated one of a rotation time period, a start timing, a rotational speed, and a frequency of operation from those of the other image forming units, or does not run in the special reverse rotation mode.

Abstract: A process cartridge configured to be removably mounted on an apparatus body of an electrophotographic image forming apparatus includes a photosensitive unit including a photosensitive drum; a developing unit including a developing roller configured to develop an electrostatic latent image formed on the photosensitive drum, and configured to be rotatably coupled with the photosensitive unit around only a single center of rotation at one end side of the process cartridge in an axial direction of the photosensitive drum; and a link member provided at the other end side of the process cartridge in the axial direction, and configured to be rotatably coupled with the photosensitive unit and the developing unit and promote relative movement between the developing roller and the photosensitive drum.

Abstract: An image forming apparatus includes a driving unit and a circuit board. The driving unit includes a motor mount section to overlap a first image forming unit of plural image forming units in a rotation-axis direction of photoconductors, and has plural motors that drive the plural photoconductors and plural developing devices forming the image forming units, the intermediate transfer body, and the fixing device, in an assigned manner; and a driving-force transmission section to overlap the other image forming units in the rotation-axis direction, and has a driving-force transmission mechanism that transmits a driving force to the photoconductors and the developing devices forming the other image forming units. The circuit board has a circuit component that controls electric power for operating the driving unit, and is arranged to avoid overlapping the motor mount section and overlap the driving-force transmission section in the rotation-axis direction.

Abstract: There is provided an end-side member to be arranged at an end of a photoreceptor drum unit which is detachably attached to an image forming apparatus body, the image forming apparatus body including a drive shaft having a concave portion, the concave portion being a hole having a substantially triangular cross-sectional shape and twisted in an extending direction of an axial line of the drive shaft. The end-side member includes a convex-shaped bearing member which is engageable with and disengageable from the concave portion. A depression to be engaged with a rim of an opening of the concave portion is formed in at least a part of an outer circumferential surface of the bearing member.

Abstract: An electrophotographic image forming apparatus is provided including a body including an opening and a first coupler, a photoreceptor cartridge including a second coupler connected to the first coupler, a first gear connected to the second coupler, and a mounting portion, and attached to or detached from the body through the opening; and a development cartridge including a second gear connected to the first gear and attached or detached from the mounting portion through the opening while the photoreceptor cartridge is mounted in the body.

Abstract: An electrophotographic photoreceptor is used by being detachably mounted onto an apparatus main body of an electrophotographic application apparatus while being incorporated in a process cartridge. The electrophotographic photoreceptor has a photosensitive drum formed by forming a photosensitive layer containing a photoconductive material on an outer circumferential surface of a cylindrical conductive substrate; and a flange that is fitted to an open end of the photosensitive drum and transmits a rotational driving force from the apparatus main body to the photosensitive drum. In the flange, on a surface thereof receiving the rotational driving force, a driven-side power transmission portion that is configured by a cylindrical body disposed concentrically with respect to a central shaft of the photosensitive drum, and engaging projections are provided.

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: An image forming apparatus includes a rotary shaft, a first image bearing member, a nip forming member, a moving device, and a restriction device. The first image bearing member bears a visible image on a surface thereof and is rotatable about the rotary shaft which is driven directly or indirectly. The nip forming member contacts the first image bearing member to form a transfer nip therebetween. The moving device is disposed on the rotary shaft and rotates to move the nip forming member to contact and separate from the first image bearing member. The restriction device inhibits rotation of the moving member in a state in which the nip forming member is separated from the first image bearing member by the rotation of the moving device.

Abstract: An image forming apparatus and a method of controlling the image forming apparatus are provided. An image forming apparatus may determine the operation start time point of a photoconductor based on ready times of the photoconductor and devices used in image forming processes so as to minimize idling of the photoconductor.

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: An image forming apparatus capable of preventing image defects, such as color shift, from being caused, by preventing increased transfer pressure from being applied by a primary transfer section to thereby prevent a surface speed difference from being generated between the photosensitive drum and the intermediate transfer belt. The image forming apparatus includes a photosensitive drum and an intermediate transfer belt that rotates in contact with the photosensitive drum, respective brushless DC motors for driving the photosensitive drum for rotation and the intermediate transfer belt for rotation, and a controller for controlling the brushless DC motors. The controller performs control such that the brushless DC motor applies assist torque to the photosensitive drum, for offsetting load torque acting thereon, thereby enabling the photosensitive drum to be friction-driven by the intermediate transfer belt.

Abstract: An image forming apparatus includes a developing roller, a conveyance roller which conveys a sheet; a driving source which provides a driving force to the developing roller and the conveyance roller, a developing driving gear mechanism which transmits the driving force of the driving source to the developing roller, and a conveyance driving gear mechanism which transmits the driving force of the driving source to the conveyance roller. The developing driving gear mechanism includes a developing driving switching mechanism which causes a rotating direction of the developing roller when the first driving source rotates in a first direction to be same as the rotating direction of the developing roller when the first driving source rotates in a second direction reverse to the first direction.

Abstract: A driving force transmission unit includes on a driving force transmission path a first driving rotary body with a plurality of first contact portions, a first driven rotary body with a plurality of first contact targets, a second driving rotary body with a plurality of second contact portions, and a second driven rotary body with a plurality of second contact targets. Each of the plurality of the first contact portions and each of the plurality of the first contact targets are disposed such that peaks of periodical shock generated as a first connecting portion defined by one of the first contact portions contacting one of the first contact targets changes from one to another do not overlap with peaks of periodical shock generated as a second connecting portion defined by one of the second contact portions contacting one of the second contact targets changes from one to another.

Abstract: An image forming apparatus which reduces a time period required to detect a phase of a photosensitive drum without an increase in costs. The apparatus performs exposure control according to a phase of rotation of the drum. A reference position serving as a reference for rotation of the drum is detected when the drum is rotating at a predetermined speed. After the speed of the drum is reduced from the predetermined speed, a first time period is measured which has elapsed from detection of the reference position to a command to stop rotation of the drum. After rotation of the drum is started again, a third time period is measured which has elapsed from reaching of the predetermined speed to detection of the reference position. The phase of the photosensitive drum for performing the control is determined based on the first time period and the third time period.

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: An driving apparatus includes a plurality of image bearing bodies each of which is rotatable and capable of bearing a latent image and a developer image, a rotatable belt provided so as to face the image bearing bodies, a plurality of image-bearing-body-driving units for rotating the image bearing bodies, a belt driving unit for rotating the belt, and a control unit. The control unit causes the image-bearing-body-driving units and the belt driving unit to start rotating the image bearing bodies and the belt so that the image bearing bodies and the belt rotate at a first speed. When the control unit detects that the image bearing bodies and the belt rotate at the first speed, the control unit causes the image-bearing-body-driving units and the belt driving unit to accelerate rotation speeds of the image bearing bodies and the belt to a second speed faster than the first speed.

Abstract: A belt controller, an image forming apparatus, a belt controlling method, and a recording medium storing an image forming control program adjust a position of a belt. Each of the belt controller, the image forming apparatus, the belt controlling method, and the recording medium storing an image forming control program detects a position of the belt and transmits a position detection signal, determines whether a degree of misalignment of the belt is equal to or greater than a specified threshold before the belt starts moving based on the position detection signal, presses the belt to reduce the degree of misalignment of the belt when the degree of misalignment of the belt is equal to or greater than the specified threshold, and performs feedback control to adjust the position of the belt according to the degree of misalignment of the belt after pressing the belt.

Abstract: An exposure portion scans, in an axial direction, light which is emitted from a light source based on image data of a document sheet, and applies the light to surfaces of image carriers, to form an electrostatic latent image on each image carrier. The cleaning member is disposed so as to contact with each image carrier and removes residual toner on each image carrier, to perform cleaning. The driving mechanism causes each image carrier to shuttle in the axial direction with a predetermined amplitude while the image carrier is driven to rotate. The detecting member detects positional information representing a position, in the axial direction, obtained when each image carrier shuttles. The control portion controls, based on a result of detection by the detecting member, a time when scanning on each of the image carriers by the exposure portion is to be started.

Abstract: An image forming apparatus, including an image forming unit; a resin-made frame to support the image forming unit; a drive source arranged on a one-end side of a transmission path to generate driving force; a gear arranged on the other-end side of the transmission path to be rotated, while one of axial ends of a shaft of the gear is supported by the frame; a metal-made first supporting member fixed to the frame to support the other of axial ends of the shaft of the gear thereon; a metal-made second supporting member fixed to the frame to support the drive source thereon and; an endless belt; a first pulley supported by the second supporting member to transmit the driving force to the endless belt, the first pulley being; and a second pulley having the endless belt strained there-around and supported by the first supporting member, is provided.

Abstract: A transmission device for a photosensitive drum includes a sleeve having at least one guiding groove, a transmission unit having a shaft disposed in the sleeve and capable of moving and rotating at the same time, an elastic member, and a gear member receiving the sleeve and the elastic member so that the elastic member exerts elastic force on the shaft of the transmission unit. The transmission unit has two engagement blocks and a receiving space between them. Each engagement block has an inclined outer surface, an inner surface, an inclined top surface and an engagement concave connecting the inner and outer surfaces. The engagement concaves are opened toward opposite directions for engagement with two pillars of a drive member of an electronic image forming apparatus respectively. As a result, the transmission device can be connected with and separated from the drive member smoothly.

Abstract: A transmission device for a photosensitive drum includes a sleeve having at least one guiding groove, a transmission unit having a shaft disposed in the sleeve and capable of moving and rotating at the same time, an elastic member, and a gear member receiving the sleeve and the elastic member so that the elastic member exerts elastic force on the shaft of the transmission unit. The transmission unit has two L-shaped engagement blocks defining a receiving space therebetween. Each L-shaped engagement block has an inclined outer surface, an inner surface, an inclined top surface and an engagement concave connecting the inner and outer surfaces are is rotatably secured to a base. The engagement concaves are opened toward opposite directions for engagement with two pillars of a drive member of an electronic image forming apparatus. Accordingly, the transmission device can be connected with and separated from the drive member smoothly.

Abstract: The invention relates to a transmission device for engagement with a photosensitive drum having a drum axis L, where a sleeve is coaxially coupled to the photosensitive drum. The transmission unit includes a shaft that is rotatable about the drum axis L relative to the sleeve and movable along the drum axis L relative to the sleeve and has a base at one end of the shaft; and at least two engagement blocks extending from two opposite sides of the base away from the drum axis L, where each engagement block is rotatable around a pivotal axis provided at the two opposite sides of the base, and the pivotal axis is perpendicular to the drum axis L. Accordingly, the transmission device can be connected with and separated from the drive member smoothly.

Abstract: An image forming apparatus (10) capable of releasing pressure of toner accumulated between photoreceptor drums and cleaning blades without affecting the life of the photoreceptor drums includes photoreceptor drums (21A to 21D), an intermediate transfer belt (31), cleaning blades (250A to 250D), a cam mechanism (36), and a drive motor (26). The photoreceptor drums (21B to 21D) bear a toner image. The toner image is transferred from the photoreceptor drums (21A to 21D) to the intermediate transfer belt. The cleaning blades (250A to 250D) remove toner remaining on the photoreceptor drums (21A to 21D) after the toner image transfer. The cam mechanism (36) switches, after an image forming process, a contact state of the photoreceptor drums (21A to 21D) and the intermediate transfer belt (31) to a separation state. The drive motor (26) rotates the photoreceptor drums (21B to 21D) backward after switching the contact state to the separation state.

Abstract: A bearing member placed at an end of a photosensitive drum, and a shaft member is attached thereto. The bearing member has a cylindrical body and a retaining portion placed in the cylindrical body, retaining a torque transmission pin provided in the shaft member, and removably provided. The retaining portion is provided with swaying grooves at least two grooves extending in an axial direction of the cylindrical body, placed opposite each other, and whose bottoms have each a curved surface exhibiting a bow with respect to the axial direction; inlet grooves at one end thereof connected to the respective swaying grooves and at the other end thereof connected to outside of the retaining portion and placed at an upstream position with respect to the swaying grooves along a direction of rotation of the cylindrical body; and a pedestal interposed, at one end, between the two swaying grooves.

Abstract: An image forming apparatus includes an image bearing member, a developer bearing member bearing and conveying a developer to a development position facing the image bearing member, a first chamber, disposed so as to face the developer bearing member, from which the developer is supplied to the developer bearing member, and a second chamber, disposed so as to face the developer bearing member, in which the developer after development in the developer bearing member is collected. In addition, a conveying member is rotatably disposed in the first and second chambers and conveys developer in the first and second chambers for circulating developer between the first and second chambers, and an executing portion executes a first mode in which image formation is performed at a first image forming speed and a second mode in which image formation is performed at a second image forming speed lower than the first image forming speed.

Abstract: There is provided a torque transmitting member that appropriately maintains conductivity between an image forming apparatus body and a photosensitive drum and can suppress the occurrence of conduction failure. A torque transmitting member, which is disposed at an end portion of a photosensitive drum unit and transmits torque, includes: an cylindrical end member that includes a bearing portion at one end portion thereof and a fitting portion, which is inserted into a photosensitive drum, at the other end portion thereof; and a conductive conducting shaft member that is disposed so as to extend along a cylindrical shaft of the end member and includes a conductive material, which is elastically deformed, on at least a part thereof.

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: An image forming apparatus includes a switchback roller which switches between a normal rotation direction and a reverse rotation direction, first and second gear train for rotating the switchback roller in the normal and reverse rotation directions, respectively, a switching unit including a pendulum gear which is movable among a first engagement position where the pendulum gear is engaged with the first gear train, a second engagement position where the pendulum gear is engaged with the second gear train, and a disengagement position where the pendulum gear is not engaged with the first gear train and the second gear train. The switching unit is switchable among a first mode where the pendulum gear is held at the first engagement position, a second mode where the pendulum gear is held at the second engagement position, and a third mode where the pendulum gear is held at the disengagement position.

Abstract: An electrophotographic photosensitive drum comprises a cylinder having a photosensitive layer formed thereon, with the cylinder being rotatable about an axis thereof. A driving force transmitting part is securely fixed to one axial end of the cylinder. The driving force transmitting part includes (i) a gear encircling a peripheral portion of the driving force transmitting part and (ii) a projection disposed on a side of the gear opposite from the cylinder, with the projection having a base and a free end. At least a portion of a cross-section of the projection at the base is offset from a corresponding portion of a cross-section of the projection at the free end, as seen in a direction of the axis.

Abstract: A drive transmission device includes a first pulley rotationally driven by a driving unit; a second pulley; a belt extended around the first pulley and the second pulley; and a supply unit for supplying a voltage such that the first pulley and the belt are attracted to each other and that the second pulley and the belt are attracted to each other.

Abstract: A rotating-body driving device that includes a rotating body; a driving source; a reduction gear that includes an output shaft and a gear rotating at a non-integer ratio of rotation period to a rotation period of the output shaft, and the reduction gear reducing rotation speed of the driving source; a pulse-signal generating unit; a pulse-count storage unit; a speed-fluctuation storage unit that stores therein a rotation speed fluctuation of the output shaft; and a driving-source control unit. The driving-source control unit detects the speed fluctuation information associated with the accumulated number of pulse signals from the speed-fluctuation storage unit, and performs for the driving source a feedforward control to set off the rotation speed fluctuation.

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 rotation driving force transmitting member is disposed between a motor section and a main body of a photoreceptor drum. The rotation driving force transmitting member has a convex member which is provided on the photoreceptor drum side and includes a twisted convex portion with an elliptical cross-section and a concave member which is provided on the motor section side and includes a twisted concave portion with an elliptical cross-section, the concave portion being fitted in the convex portion. The rotation driving force transmitting member transmits rotation driving force by the motor section to the photoreceptor drum via the convex member and the concave member in a state where the convex member is subjected to a drawing force toward the concave member side, due to rotation of the motor section in a state where the convex portion and the concave portion are fitted in each other.

Abstract: An image forming apparatus stabilized in transferability of an image from the photosensitive member to the intermediate transfer belt. The image forming apparatus includes photosensitive drums and an intermediate transfer belt (ITB) that rotates in contact with each drum, brushless DC motors for driving the drum and the ITB for rotation. Rotary encoders associated with the drum and the ITB detect respective rotational speeds thereof. A controller sets a target value for the drum-associated rotary encoder for making the surface speeds of the drum and the belt equal to each other during normal printing operation, from a detection value from the drum-associated rotary encoder in a state of the drum being friction-driven by the belt at the primary transfer section, and controls the drum-associated motor such that the target value becomes a detection value.

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 transfer unit that is detachably attachable to a housing of the image forming apparatus and includes: a transfer member configured to contact the image carrier; a movable frame that supports the transfer member and configured to rotate around a fulcrum shaft; a driving input member coaxially arranged with the fulcrum shaft and configured to connect to a first driving transmitting member, and a second driving transmitting member supported by the movable frame and configured to transmit a driving force inputted by the driving input member to the transfer member. The image forming apparatus further includes a contact/separation unit configured to press the transfer member against the image carrier and to separate the transfer member from the image carrier by moving the movable frame around the fulcrum shaft while the transfer unit is attached to the image forming apparatus.

Abstract: An image forming apparatus includes image bearing members that bear formed images; a driving source that rotationally drives the image bearing members and whose rotational direction is switchable between a first direction and a second direction; a first driving-force transmitting unit that transmits a rotational driving force of the driving source rotationally driven in the first direction as a unidirectional rotational driving force to the image bearing members; and a second driving-force transmitting unit that transmits a rotational driving force of the driving source rotationally driven in the second direction as a unidirectional rotational driving force to one or more of the image bearing members and does not transmit the rotational driving force to a remaining one or more of the image bearing members. The first and second driving-force transmitting units are switched therebetween by changing the rotational direction of the driving source.

Abstract: A transmission device for a photosensitive drum includes a sleeve, a transmission unit disposed in the sleeve and capable of moving and rotating at the same time, an elastic member, and a shell receiving the sleeve and the elastic member so that a relatively larger radius section and a relatively smaller radius section of the elastic member exert elastic force on the sleeve and the transmission unit, respectively. The transmission unit has two engagement blocks and a receiving space between them. Each engagement block has an inclined outer surface, an inner surface, an inclined top surface and an engagement concave connecting the inner and outer surfaces. The engagement concaves are opened toward opposite directions for engagement with two pillars of a drive member of an electronic image forming apparatus respectively. As a result, the transmission device can be connected with and separated from the drive member smoothly.

Abstract: An image forming apparatus includes a body, an image carrier provided in the body and configured to form an image thereon, a first gear to transmit a rotation driving force to the image carrier, a first rotary shaft to which the image carrier and the first gear are attached, a second gear to mesh with the first gear and transmit the rotation driving force to the first gear, a second rotary shaft to which the second gear is attached, a drive source configured to drive to rotate the image carrier via the first gear and the second gear, a first holder to hold the first rotary shaft of the first gear, and a second holder to hold the second rotary shaft of the second gear, and a relative position between the first holder and the second holder therein is adjustable.

Abstract: A drive transmission device includes a first coupling member to be coupled to a drive shaft and including a first contact surface, a second coupling member to be coupled to a driven shaft and including a second contact surface, and an intermediate coupler disposed between the first and second coupling members. The intermediate coupler includes: a first intermediate contact surface opposed to the first contact surface and contacting the first contact surface with a first rolling member interposed in between; and a second intermediate contact surface opposed to the second contact surface and contacting the second contact surface with a second rolling member interposed in between. One of the contact surfaces and a corresponding one of the intermediate contact surfaces are formed point-symmetrically with respect to the center of a corresponding one of the rolling members.

Abstract: A power transmitting device having a structure to allow a photoconductor to stably form a visible image on a printing medium. The power transmitting device interconnects a rotator and a drive motor, the drive motor generating drive power to drive the rotator. The power transmitting device includes at least one gear to be rotated upon receiving power from the drive motor, a rotating shaft having one end penetrating the gear and a coupler to interconnect the other end of the rotating shaft and the rotator. An outer diameter of the coupler, an outer diameter of the rotator and an outer diameter of the gear satisfy the following relation: 0.7D1<Dc<D2, where, D1: outer diameter of the rotator, D2: outer diameter of the gear and Dc: outer diameter of the coupler.