Abstract: To provide an image forming device that can effectively predict a replacement timing of a photoconductor drum. A toner image is to be formed on the photoconductor drum. The charger is configured to charge the photoconductor drum. The potential sensor is configured to measure a charge potential of the photoconductor drum. The memory stores a manufacturing date of the photoconductor drum and a failure threshold value of the charge potential related to a failure of the photoconductor drum. The processor is configured to calculate an elapsed time from the manufacturing date based on the manufacturing date, update the failure threshold value based on the elapsed time, and predict a replacement timing of the photoconductor drum based on the updated failure threshold value.

Abstract: An image forming apparatus, including: a housing; a photoconductor; a developing unit configured to form a developer image on the photoconductor; a developer cartridge storing developer, the cartridge being removably mountable on the housing, a supplier configured to supply the developer from the developer cartridge to the developing unit; and a controller configured to execute a first printing process of forming a developer image by use of the developer supplied from the developer cartridge, when the developer cartridge is being mounted on the housing, and a second printing process of forming a developer image by use of the developer remaining in the developing unit, when a usage amount of the developing unit is not less than a predetermined value and the developer cartridge is not being mounted on the housing, wherein the controller does not execute the second printing process when the usage amount is less than the predetermined value.

Abstract: An image forming apparatus includes an apparatus body, an image carrier, a developing device, a toner container, a container cover, a driver and a lock mechanism. The lock mechanism maintains the locking state if the container body is rotated in the first rotating direction by the driver, and receives a rotational drive force of the driver to switch the state thereof from the locking state to the unlocking state if the container body is rotated in the second rotating direction by the driver.

Abstract: A developer supply container includes an accommodating portion, a discharging portion, a sealing member, a first restricting portion, and a second restricting portion positioned upstream of the first restricting portion with respect to an inserting direction of the accommodating portion. The seal member is provided between the first restricting portion and the second restricting portion with respect to a rotational axis direction of the accommodating portion.

Abstract: A connecting member includes a plate body having first and second lateral sides, a tube portion extending from the first lateral side and defining a central axis, two resilient arms extending from the second lateral side, two pin holes provided at the two resilient arms respectively and defining an imaginary line passing therethrough and an imaginary plane orthogonal to the imaginary line in a way that the central axis is located on the imaginary plane, and two restricting portions extending from the second lateral side and located at two sides of the imaginary plane in a way that inner peripheries of the two restricting portions are spaced from the central axis at a distance smaller than a distance between inner peripheries of the two resilient arms and the central axis. A transmission unit of an electronic image-forming apparatus having the connecting member is also disclosed.

Abstract: In accordance with an embodiment, a waste toner-storing container includes a container main body and a backflow-preventing member. A first storing chamber of the container main body includes a first storing space capable of storing an amount of waste toner discharged from a main body of an image forming apparatus, which is below a predetermined threshold. A second storing chamber of the container main body includes a second storing space that stores waste toner overflowing from the first storing space and discharged from the first storing chamber if the amount of waste toner exceeds the predetermined threshold. The backflow-preventing member prevents waste toner stored in the second storing space from moving into the first storing chamber.

Abstract: An image forming apparatus includes an image holding member, a charging device that charges a surface of the image holding member, an electrostatic charge image forming device that forms an electrostatic charge image on the charged surface of the image holding member, a developing device that has an electrostatic charge image developer containing an electrostatic charge image developing toner and that develops the electrostatic charge image to form a toner image on the surface of the image holding member, and a transfer device that transfers the toner image onto a recording medium, wherein the transfer device includes a belt member and a transfer member, the belt member has an outer surface that contacts the image holding member, and the belt member is winding around the image holding member and the transfer member; and the toner has a binder resin containing an amorphous polyester resin.

Abstract: A developing cartridge includes: a developing roller rotatable about a first axis extending in a first direction; a developing roller gear rotatable together with the developing roller; a coupling gear rotatable about a second axis extending in the first direction; and a joint rotatable together with the coupling gear. The coupling gear is meshingly engaging with the developing roller gear. The joint is pivotally movable relative to the coupling gear about a third axis extending in a second direction. The joint includes: a first protrusion extending in a first radial direction; and a second protrusion extending in a second radial direction opposite to the first radial direction. The second protrusion is positioned away from and is aligned with the first protrusion in a diametrical direction including the first radial direction and the second radial direction. The second direction crosses the first radial direction and the second radial direction.

Abstract: A toner storing container stores toner and is provided attachable to and detachable from an image forming apparatus. The toner storing container includes: a container body that includes an opening, and an inner circumferential surface extending toward the opening around a center line extending in one direction; and a toner conveyer that is attached onto the inner circumferential surface of the container body. The toner conveyer projects inward from the inner circumferential surface as well as spirally extends in the one direction around the center line.

Abstract: A control device for a vehicle is provided. The control device includes an electronic control unit that is configured to: exert the torque of an input member on a fixed member and a rotating member such that the fixed member and the rotating member are separated from each other, when the thrust is exerted for making the engagement teeth mesh with each other; estimate an inclination angle of tooth surfaces based on a relative movement amount between the fixed member and the rotating member, and a relative rotational amount between the fixed member and the rotating member; estimate a frictional coefficient of the tooth surfaces based on the inclination angle; and control the thrust of the actuator according to the frictional coefficient.

Abstract: A method of controlling a color-tone density (CTD) of an image forming apparatus including a plurality of developers configured to circularly perform a developing operation. The method includes developing test patches on an OPC sequentially from a developer to be developable preferentially, measuring CTDs of the developed test patches, and controlling a development variable using the measure CTDs.

Abstract: A debugging system includes an embedded device and a terminal computer. The embedded device includes a memory unit, and the memory unit includes a first buffer, the embedded device is configured for executing at least one instruction to generate at least one real-time debugging information, and writing the real-time debugging information into the first buffer. The terminal computer is connected to an in-circuit emulator (ICE) via a first interface, and the ICE is connected to the embedded device via a second interface. The terminal computer uses polling to read the real-time debugging information stored in the first buffer via the ICE, and deletes the real-time debugging information stored in the first buffer afterwards.

Abstract: A driving pulley has a driving pulley body having a peripheral surface formed in a cylindrical shape, and a driving pulley shaft and a gear part, which are coaxial with the driving pulley body and rotate together with the driving pulley body. The driving device has an input gear and a support plate. The input gear is engaged with the gear part to input rotational driving force to the gear part. The support plate has a support hole that supports the driving pulley shaft so as to be rotatable. The support hole is a long hole extending along a concentric circle for an axis center of the input gear and supporting the driving pulley shaft so as to be movable along the concentric circle.

Abstract: A power transmission switching device includes a transmission mechanism. The transmission mechanism includes: a first gear; a second gear; a switching gear movable between a first position for mesh with the first gear and a second position for mesh with the second gear; an input gear meshed with the switching gear; and a power transmitter comprising the input gear and configured to transmit the driving power from the drive source to the switching gear. Play is formed in the power transmitter so as to allow the input gear to rotate in its rotational direction.

Abstract: An image forming apparatus includes: a belt; a first image forming unit including a first drum; a second image forming unit including a second drum; a contact-and-separation portion; an executing portion; and a controller for rotating the second drum by a predetermined angle so that when a cycle of an operation is to be repeated N times, a position of the second drum contacting the belt in an (N?1)th cycle differs from a position of the second drum contacting the belt in an Nth cycle, the cycle including receiving the image data in a state that the belt and the first and second drums are at rest and in a stand-by state that the image forming apparatus waits for an input of the image data in the first state, executing the image forming operation, and then returning the image forming apparatus to the stand-by state.

Abstract: An image forming apparatus includes a rotatable image bearing member configured to bear an electrostatic latent image, a plurality of development devices including a developer bearing member configured to bear a developer for developing the electrostatic latent image, a rotatable development device supporting member configured to support the plurality of development devices. The developer bearing member is configured to execute development while contacting the image bearing member at a development position via the developer, rotating in the same direction as rotating direction of the image bearing member at the development position, and rotating at a speed faster than a surface speed of the image bearing member.

Abstract: Based on a photosensitive drum life threshold value when each of the plurality of image formation execution modes is independently used, and a photosensitive drum life threshold value according to a usage rate of each of the image formation execution modes, the image forming apparatus having a plurality of image formation execution modes calculates a photosensitive drum life threshold value according to the usage rate. Then, the image forming apparatus compares the calculated photosensitive drum life threshold value with a remaining CT film thickness prediction value for the photosensitive drum to determine the life of the photosensitive drum.

Abstract: A design method of a drive unit includes: deriving a minimum reference contact pressure Fa causing any of the shaft portion among the plurality of the shaft portions to result in damage; and designing the shaft portions or the gears to be of form such that the plurality of shaft portions and the plurality of gears satisfy the relationship F/D×L<Fa, given that, with the plurality of shaft portions and the plurality of gears linked to the drive source and the rotated components, the load acting on a single of the shaft portions among the plurality of shaft portions is F (N), the diameter of the single of the shaft portions is D (mm), and the length of axial contact between the single of the shaft portions and the gear mounted thereon is L (mm).

Abstract: A printing apparatus for performing printing using a recording material includes a plurality of storing units, a movement unit, and an execution unit. The plurality of storing units store the recording material. The movement unit moves one storing unit of the plurality of storing units to a replaceable position. The execution unit execute check processing for checking an operation of a storing unit if all of one storing unit or a plurality of the storing units determined to be lacking the recording material are moved to the replaceable position by the movement unit.

Abstract: An image forming apparatus includes a latent image carrier, a first developing unit, a second developing unit, a transfer unit, a removing member, and a fixing unit. An average circularity of particles having an average particle diameter of no less than 100 nm and no more than 300 nm among particles included in a second external additive is less than an average circularity of particles having an average particle diameter of no less than 100 nm and no more than 300 nm among particles included in a first external additive.

Abstract: A color image forming apparatus includes an image bearing member for carrying an electrostatic latent image, a plurality of developing devices for developing the electrostatic latent image, a supporting member for moving the developing devices sequentially to a developing position opposing the image bearing member, and a detecting device for detecting developer remainder in the developing device. In addition, a determining portion determines the developer remainder. In the developing device in which the detecting operation is effected after the developing operation, the determining portion determines the developer remainder from the information relating to the detected developer remainder. In the developing device of the developing devices for which the detecting operation is effected before the developing operation, the determining portion determines the developer remainder from the information relating to the detected developer remainder and a deduced consumption amount.

Abstract: A developing device is usable with an electrophotographic image forming apparatus including a shaft and a rotary unit mounting the device. When mounted, the device is movable perpendicular to a shaft axial direction in response to movement of the rotary unit and the shaft is not movable in that direction. The device includes a developing roller that contacts and separates from a drum in response to movement of the rotary unit, and a coupler transmitting a rotating force to the roller. The coupler includes a portion engaging the shaft to receive a rotating force and a portion transmitting the received rotating force to the roller. The coupler takes a first position for transmitting the rotational force to the roller, a position before the coupler engages the shaft and is inclined away from the first position, and a position for the disengagement of the coupler and the shaft.

Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic image; a rotatable supporting member swingably supporting the rotatable supporting member, the rotatable supporting member being provided with a first gear portion and being rotatable while carrying a plurality of developing devices for developing the electrostatic image with toner; a drive transmission device for transmitting a rotational force to the rotatable supporting member, the drive transmission device being provided with a second gear portion engaged with first gear portion at an engagement position; and an opposing portion provided opposed to the rotatable supporting member with a gap therebetween which is smaller than an amount of engagement between the first gear portion and the second gear portion.

Abstract: An image forming apparatus includes an image carrier, and a rotation device having image-forming devices each containing a toner and forming a toner image on the image carrier with the toner. The apparatus further includes: a detector attached to at least one of the image-forming devices to detect a quantity of the toner, thereby outputting an analog signal representing the quantity; and a transmission path transmitting the analog signal to the outside of the rotation device. The transmission path includes: a rotation terminal mounted on and rotating with the rotation device; and a contact terminal provided outside the rotation device, and maintaining continuity with the rotation terminal by contacting a surface of the rotation terminal even when the rotation terminal rotates. The apparatus further includes a correction section correcting the analog signal transmitted by the transmission path, according to a contact resistance between the rotation terminal and the contact terminal.

Abstract: An image forming apparatus rotationally moves a plurality of recording material storage units that store a recording material and includes a moving unit configured to move the recording material storage unit to a replacement position, and a detection unit configured to detect an in-motion status in which the recording material storage unit is moving to the replacement position. In addition, a determination unit determines either a first state or a second state of the image forming apparatus as the state of the image forming apparatus that is to replace the in-motion status and should be reported to a user when the detection unit detects the in-motion status should not be reported to a user.

Abstract: A cap sheet metal (and pivot sheet metal) is configured to be able to move linearly with a cap arm (and an arm stay) via engagement between an engagement hole and a fitting shaft. Furthermore, the cap sheet metal (and the pivot sheet metal) can move pivotally with respect to the cap arm (and the arm stay) using the fitting shaft, which engages with the engagement hole, as a pivotal shaft. Thus, even if, for example, the direction of biasing toward the applying roller deviates or a positional relationship with the applying roller deviates slightly, the liquid holding member moves and pivots in the bias direction depending on the deviation. As a result, the contacting pressure of a contacting portion on the applying roller can be made uniform.

Abstract: A rotary developing device that rotates about a rotational axis includes plural developing units, an energized member, a hollow cylindrical unit, a first energizing member, a rotatable unit, a second energizing member, a first conductive member, and a second conductive member. Each developing unit develops a latent image formed on an image holding member into a visible image, and is rotatable about the rotational axis so as to be sequentially movable to a developing position facing the image holding member. The hollow cylindrical unit is arranged along the rotational axis. The rotatable unit is supported rotatably with respect to the hollow cylindrical unit. One end of the first conductive member is connected to the first energizing member supported on an outer periphery of the hollow cylindrical unit. The second conductive member connects the second energizing member supported by the rotatable unit to the energized member supported in a developing unit.

Abstract: A developing cartridge is detachably mountable to a main assembly of an image forming apparatus, and includes a frame, a developer carrying member, a first portion to be engaged provided on one side of the frame, and a second portion to be engaged provided on the other side of the frame with respect to the direction crossing the axial direction of the developer carrying member. In addition, a cover member includes a first engaging portion engageable with the first portion to be engaged and a second engaging portion engageable with the second portion to be engaged for covering an exposed portion of the developer carrying member by being detachably mounted to the frame. The cover member is detachably mountable to the frame in a first state by engaging the first engaging portion with the first portion to be engaged and by engaging the second engaging portion with the second portion to be engaged.

Abstract: An image forming apparatus includes an image carrier that holds a toner image, a rotary developing device including a plurality of developing units to develop an electrostatic latent image on the image carrier with toner by supplying the toner from the developing unit opposing the image carrier, a foreign-substance receiving plate that receives a falling foreign substance, a transfer unit that transfers the toner image from the image carrier onto a recording medium, and a fixing unit that fixes the transferred toner image on the recording medium. Each of the developing units includes a developer container that stores developer containing magnetic carriers and toner, and a developing roller that supplies the toner in the developer for development of the electrostatic latent image. The rotary developing device further supports a foreign-substance collecting member that magnetically collects a magnetic foreign substance on the foreign-substance receiving plate.

Abstract: The color image forming apparatus performs registration control and is operable in first and second image forming modes. Contact control in the first image forming mode is different from that in the second image forming mode. The control section causes an alignment correction amount to vary between registration control corresponding to image forming for a second or subsequent sheet in the first image forming mode and registration control corresponding to image forming for a second or subsequent sheet in the second image forming mode. An engine control section causes a color deviation correction amount for contact control of a process unit when shifting from image forming for a first sheet to image forming for a second sheet to vary between the first and second image forming modes.

Abstract: In a rotary-type image forming apparatus in which detection of electrostatic capacitance is performed when a developing apparatus is in a posture less affected by a toner density within the developing apparatus, a toner in the developing apparatus, which is located at a development position during the detection of the electrostatic capacitance, is avoided from being uselessly consumed. The image forming apparatus has a remaining amount detection mode of detecting a toner remaining amount on condition that a developing roller of one developing apparatus positioned opposite to another developing apparatus, for which the toner remaining amount is to be detected, stands by in a state spaced from a drum.

Abstract: An image forming apparatus cartridge includes a casing and a developer roller having an axis L1, with the developer roller being rotatably supported in the casing to permit rotation about the axis L1. The cartridge also includes a first gear connected to the developer roller and a second gear in meshing engagement with the first gear. The cartridge further includes a coupling member having an axis L2, with the coupling member having (i) a first end portion connected to the second gear and operatively connected with the developer roller so as to be capable of transmitting a rotational force to the developer roller via the first and second gears, (ii) a second end portion having a recess formed therein and including at least two projections provided at diametrically opposed positions, and (iii) a connecting portion connecting the first end portion and the second end portion.

Abstract: An image forming device has: an image forming body on which an image is formed in a state in which the image forming body is charged; a charging device having plural discharge portions, and charging the image forming body by discharging of plural discharge portions; and a control section that, when forming the image on the image forming body, operates the plural discharge portions, and when not forming the image on the image forming body, switches between a state of operating some of the plural discharge portions and decreasing output of or stopping the discharge portions other than the some discharge portions, and a state of operating some other of the plural discharge portions and decreasing output of or stopping the discharge portions other than the some other discharge portions.

Abstract: An image forming apparatus includes an image bearing member on which an electrostatic image is to be formed; a rotatable supporting member, configured to support a developing device for developing the electrostatic image and configured to rotationally move the developing device toward a developing position, provided movably in a rotational axis direction with respect to a main assembly of the image forming apparatus; an urging member for urging the rotatable supporting member in the rotational axis direction. In addition, a regulating portion regulates a position of the rotatable supporting member, with respect to the rotational axis direction, urged by the urging member.

Abstract: A developing device includes: a developing roll; a bearing member that supports the developing roll rotatably, the bearing member including plural outer side surfaces, and distances from a center of a rotation axis of the developing roll to the outer side surfaces being different; and a supporting member that supports the bearing member in a positioning state where one of the plural outer side surfaces is in contact with a reference surface, the outer side surface in contact with the reference surface being changeable.

Abstract: A controller unit determines the operation mode of a device when an error relating to a color cartridge has been detected. When the controller unit determines that the operation mode of the device is a toner replacement priority mode, the controller unit determines whether or not the number of times a monochrome printing job has been executed is equal to or greater than a threshold value without resolving the error. When the number of times a monochrome printing job has been executed is equal to or greater than a threshold value without resolving the error, the controller unit switches the operation mode of the device to a monochrome performance priority mode.

Abstract: A printing apparatus includes a plurality of container units containing a recording material. In a case where it is determined that a container unit is lacking in the recording material when printing is executed based on print data, the printing apparatus moves the container unit determined to be lacking in the recording material to a replaceable position. In a case where the container unit determined to be lacking in the recording material is not a specific container unit among the plurality of container units and the printing based on the print data is canceled without replacing the container unit determined to be lacking in the recording material, the printing apparatus moves the specific container unit to a specific position in preparation for printing using the specific container unit.

Abstract: A charge bias causing the surface potential of a photosensitive drum to be lower than that in image formation is applied to a charge roller during a period in which the stop position of a rotary is moved from an unknown state to a home position to cause a developing bias to be applied to a developing roller to be smaller than that in the image formation.

Abstract: An image forming apparatus includes a first rotating unit, an image carrier, an electrostatic latent image forming unit, a third rotating unit, an intermediate transfer body, first and second transfer units, and the following elements. A developing device includes a rotating body, a second rotating unit, plural developing units. A supply unit supplies a bias to a developer carrying member of each developing unit. A setting unit sets the bias to a first condition to develop the latent image of a first color at least while the latent image is being located at the developing position, and sets the bias to a second condition to suppress transferring of the toner in the subsequent developing unit to the image carrier after the second rotating unit starts rotating the rotating body from a waiting position and before stopping rotating the rotating body and locates the subsequent developing unit at the developing position.

Abstract: An image forming apparatus includes an image bearing member; a developing device; and a movable member for rotationally moving the developing device. The movable member includes a rotation shaft member, a first member which is engaged with the rotation shaft member at one end portion, a second member which is engaged with the rotation shaft member at the other end portion, a first guide portion, and a second guide portion. The apparatus further includes a first swingable supporting member for rotatably supporting the movable member at the one end portion; a second swingable supporting member for rotatably supporting the movable member at the other end portion; an urging portion for urging the movable member toward the image bearing member; a first preventing member for preventing movement of the first member; and a second preventing member for preventing movement of the second member.

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: An image forming apparatus includes a rotatable image bearing member; a plurality of rotatable developer carrying members; a plurality of developing devices in each of which a respective one of the developer carrying members is provided; and a developing device supporting member rotatable in a direction of codirectional peripheral movement with the image bearing member where the supporting member and the image bearing member are opposed to each other and integrally supporting the plurality of said developing devices. The peripheral speed of the developing device supporting member divided by a peripheral speed of the image bearing member at the time when each of the developer carrying members departs from the surface of the image bearing member and is still rubbing the surface of the image bearing member with the developer is larger than 0 and smaller than 1.

Abstract: A rotating-body restraining device includes a first gear provided on a rotational shaft of a rotating body and rotated together with the rotating body, a second gear that meshes with the first gear, a third gear provided on a rotational shaft of the second gear and rotated together with the second gear, and a restraining member that is movable toward the third gear and that restrains the third gear from rotating by moving to a position where the restraining member meshes with the third gear. The numbers of teeth included in the first, second, and third gears are Za, Zb, and Zc, respectively. Zb is not equal to the product of Za and an integer n. Zc is an integral multiple of a value obtained by dividing the least common multiple of Za and Zb by Za.

Abstract: An image forming apparatus includes: an image forming apparatus main body, an image forming unit that is provided in the image forming apparatus main body and forms an image on a recording medium, and a transport unit transporting the recording medium, wherein the image forming apparatus main body has a forward port for forwarding the recording medium having the image thereon by the image forming unit to outside of the image forming apparatus main body, and further has a guide unit by which the recording medium forwarded to the outside of the image forming apparatus main body is guided to be retrieved into the image forming apparatus main body, and to be led to the transport unit.

Abstract: A developing device includes developing units each including a first gear and a development roller; a rotation supporting member; a cam member having a cam surface surrounding the rotation axis, and being secured to and rotating together with the rotation supporting member; and a driving force transmission member including a cam receiving roller and a second gear. The cam surface includes a curved surface whose curvature is less than a curvature of the cam receiving roller so that, as the first gear approaches a driving position where the first gear receives the driving force from the second gear by the rotation of the cam member, the cam receiving roller is moved away from the rotation axis once, after which the cam receiving roller is moved towards the rotation axis, thereby starting engagement of the first gear with the second gear before the first gear reaches the driving position.

Abstract: In an image forming apparatus of a rotary type, when a pause is made during continuous image formation, the time taken to restart image formation after the pause is shortened so as to reduce stress on the user. In the image forming apparatus, it is determined beforehand whether the next image formation mode is a color mode or a mono mode, and a developing device to be first used in the next image formation mode is moved to a developing standby position.

Abstract: A developing device is provided that includes a developing container, a developing roller, a developer supplying roller, a sheet member, a communication hole, and a filter member. The communication hole is provided so as to be connected to an enclosed space defined by an inner wall of the developing container defining a smaller one of spaces provided by dividing the developing container by a plane including a rotation axis of the developer supplying roller and a rotational axis of the developing roller, a phantom plane which is included in the plane and extends from a surface of the developer supplying roller to the inner wall of the developer container, the sheet member, a surface of the developing roller, and a surface of the developer supplying roller.

Abstract: An electrophotographic image forming apparatus includes a drum cartridge with an image bearing drum and charger for charging a surface of the drum. The apparatus further includes a rotary supporting a plurality of developing devices each having a developer carrying member for developing an electrostatic latent image formed on the drum, with the rotary being swingably mounted to the main assembly through a supporting member and being rotatable, relative to the supporting member, to bring the developing device to a developing position for developing the latent image. A locking member is provided for spacing between the developing device positioned in the developing position and the image bearing member, the locking member being demountably mounted between the drum cartridge and the rotary, and the locking member being effective to prevent an urging member from moving from a position urging the drum cartridge to the main assembly.

Abstract: An image forming apparatus is configured to control the timing to switch a development unit by a development rotary after forming an image, based on the size of the image to be formed. Accordingly, if the switching of the development unit is completed within a time period corresponding to a trailing edge margin of an image area, a subsequent color image can be formed without idling an intermediate transfer member, so that the image forming apparatus can suppress or reduce degradation of the throughput.

Abstract: An electrophotographic image forming apparatus includes a drum cartridge with an image bearing member and charging device for charging a surface of the image bearing member. The apparatus further includes a rotary supporting a plurality of developing devices each having a developer carrying member for developing an electrostatic latent image formed on the image bearing member, with the rotary being swingably mounted to the main assembly of the apparatus through a supporting member and being rotatable, relative to the supporting member, to bring the developing device to a developing position for developing the electrostatic latent image. A spacer member is provided for spacing between the charging device and the surface of the image bearing member, the spacer member being mounted between the image bearing member and the charging device.