Abstract: A plurality of subsystems having diverse individual functions can be connected to an image forming apparatus. Each of the subsystems is made up of, for example, plural kinds of units which are different in performance from each other. Each of the units has inherent information related to the performance, and decides the operation specification of the entire image forming apparatus according to the combination of those units.

Abstract: An image forming apparatus includes at least one paper feeding section, a plurality of image forming sections, a plurality of paper output sections, a main transport path, and a plurality of paper output paths. The paper feeding section stores a recording medium therein. Any one of the image forming sections selectively forms an image on a recording medium fed from the paper feeding section and being transported on the main transport path. Each of the paper output sections receives a recording medium bearing an image formed in any one of the image forming sections. The main transport path leads from the paper feeding section and runs through the image forming sections. The paper output paths branch from an end of the main transport path into the respective paper output sections.

Abstract: An image forming device comprises: an image forming unit adapted to execute image formation on a recording medium; and a writing unit adapted to be able to execute at least an information writing operation in a non-contact manner to a non-contact IC added to the recording medium. It is controlled whether or not the image forming unit should execute the image formation on the recording medium, according to a result of the information writing operation executed by the writing unit to the non-contact IC added to the recording medium.

Abstract: An image forming apparatus capable of reducing a part of a sheet exposed outside the apparatus on standby after finishing printing a first side in both-sided printing. A transfer material P having an image formed on its first side is fed until a part thereof gets exposed outside a full-color printer 1 and is fed to a refeeding path in the full-color printer 1. The transfer material P inverted by a flapper 44 is fed to a standby position to form an image on a second side thereof and is stopped there. In the case where a preparation for forming the image on the second side is not completed, the standby position for having the transfer material P stopped is changed corresponding to length of the inverted transfer material P in a feeding direction.

Abstract: In case of both sides printing, the sheet S having an image formed on the obverse surface is conveyed to the first reversal section of the reversal device 50 disposed in a reversal path R3. In the first reversal section, the sheet S is conveyed to a U-turn reversal path by the reversal roller 56 with the first side section of the sheet S as the leading edge section. In the U-turn reversal path, a position of the first side surface section and a position of the second side surface section of the sheet S are exchanged and the sheet S is conveyed to the second reversal section. In the second reversal section, the sheet having been turned over is fed again to the register rollers 16 with a leading edge section at image forming on the obverse surface as the leading edge side. Whereby the same edge of the sheet S contacts with the register rollers 16 when the image is formed on the obverse side and when the image is formed on the reverse side.

Abstract: A paper conveying apparatus and method for flipping paper includes a paper feeding roller that can rotate in a positive direction or in a reverse direction, a motion transfer member that has one end coupled with the paper feeding roller, and a paper depressing element coupled with another end of the motion transfer member to be driven and rotated. The method of flipping paper includes: first, feeding a sheet of paper into a first paper conveying path; next, depressing the paper into a second paper conveying path while the paper is leaving the first paper conveying path; and reentering the paper from the second paper conveying path into the first paper conveying path upside down.

Abstract: An image forming apparatus includes: a main body discharge tray disposed in an image forming apparatus main body, onto which a sheet with an image recorded is discharged; a main body discharge member that discharges the sheet onto the main body discharge tray; an optional discharge device disposed above the main body discharge member, the optional discharge device having an optional transport path through which the sheet passes and an optional discharge member that discharges the sheet; a postprocessing device that performs postprocessing on the sheet; and a postprocessing transport device disposed above the main body discharge tray, the postprocessing transport device having a lower portion, an upper portion on which the sheet discharged from the optional discharge member is placed and a postprocessing transport path formed between the lower and upper portions, the postprocessing transport path transporting the sheet discharged from the main body discharge member to the postprocessing device.

Abstract: A non-gated print media crossover for a printing system includes crossover pathways which intersect at a crossover junction. A control system controls arrival of sheets of print media at the crossover junction whereby a sheet conveyed on the first crossover pathway traverses the junction in an intersheet gap between sheets traversing the junction on the second crossover pathway. The printing system includes print media processing units, such as marking engines, paper sources, and output destinations, which are connected by a conveyor system incorporating the crossover.

Abstract: A sheet reversing device has a vertical first conveyance path, a horizontal second conveyance path into which a sheet is carried via the first conveyance path and a horizontally third conveyance path into which the switched-back sheet is carried from the second conveyance path. A curved guide plate is disposed between the first and second conveyance paths and includes a curved guide surface for guiding the sheet to the second conveyance path, and a pivotal guide pivotably supported with a part thereof projecting from the curved guide surface. The pivotal guide pivots to retract into the inner side of the curved guide by being pushed by the sheet moving from the first conveyance path toward the second conveyance path while guiding the sheet switched back and carried out from the second conveyance path toward the third conveyance path with the part thereof projecting from the curved guide surface.

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 double-surface image forming apparatus, including: an image carrier; a registration section; an image fixing device; a sheet recirculating supplying section; a sheet reversing section, arranged on a path of the sheet recirculating supplying section, to reverse the recording sheet from the front surface to a reverse surface by a switch-back conveyance; and a sheet rotating device, arranged on a path of the sheet recirculating supplying section, to stop the sheet at a predetermined position and to rotate the stopped sheet 180° in the sheet conveying direction, wherein the sheet rotating device includes; a positive rotation conveying section; a positive-negative rotation conveying section to rotate the sheet to the sheet conveying direction and to an opposite direction of the sheet conveying direction; and a rotation center nipping section, arranged to meet a position of the rotation center of the sheet, to support the sheet.

Abstract: An image forming apparatus 1 is provided with a double-side transport unit 80 capable of clearing a paper jam. The double-side transport unit 80 is provided with a reverse transport passage 75 provided with a reverse roller 57 for switching back paper P having an image formed on one side thereof, a return transport passage 76 for transporting the paper P turned upside down through the reverse transport passage 75 to an image forming portion 10, and a reverse introduction passage 74a extending from a downstream side, with respect to a branch transport passage 74, of the second transport roller 56 that is disposed close to the reverse transport passage 75, to the reverse transport passage 75. The double-side transport unit 80 can be taken out of or put in an apparatus main body 1a in a direction perpendicular to a paper transport direction.

Abstract: The invention relates to a method of printing a substrate using an inkjet printer which includes a holder to rotatably receive a roll on which the substrate is wound, a downstream print zone and an inkjet printhead for printing the substrate at the print zone, a transport means for engaging and transporting the substrate to the print zone during which transport the substrate is unwound from the roll, and a guide element which is situated downstream of the roll in front of the transport means to guide the substrate from the roll to the transport means, the method including the steps of transporting the substrate over a predetermined distance with control of the transport means, during which transport the guide element is moved from a first position which the guide element occupies prior to the transport, to a second position such that the distance over which the substrate extends between the roll and the transport means is smaller as a result of the movement and after the substrate has been transported over th

Abstract: An image forming device in a color printer or the like includes duplex printing. Multiple media sheets are moved through a media path which includes a primary path and a duplex path. Various parameters of the image forming device control the interpage gap between sheets. Parameters include peek-a-boo duplexing, sharing of motors within the drive rollers, and sharing of power supplies.

Abstract: A sheet conveying apparatus according to the invention includes a first conveying path; a sheet reverse conveying portion; a second conveying path; a third conveying path; and a movable guide portion configured to guide the conveyed sheet. The guide portion is moved to a position where the sheet can pass when the sheet is guided from the first conveying path to the second conveying path, and the guide portion is moved to a position where the guide portion guides the sheet to the third conveying path while blocking between the first and second conveying paths such that the sheet can not intrude from the second conveying path into the first conveying path when the sheet conveyed by the sheet reverse conveying portion is conveyed in the second direction.

Abstract: An image forming apparatus includes: a main body; a process cartridge detachably attachable to the main body, the process cartridge including an image carrier configured to carry a developer image thereon and a cartridge frame; a feeding path configured to feed a recording sheet to a transfer position where the developer image carried on the image carrier is transferred to the recording sheet; and a returning path configured to return the recording sheet that has passed the transfer position to the feeding path. The cartridge frame defines at least a part of the feeding path and at least a part of the returning path.

Abstract: A sheet feeding mechanism having a pickup roller, a switch device, and a gear set is disclosed. The pickup roller drives a recording material to a first path, and the recording material proceeds from the first path to a second path or from a third path to a fourth path when the switch device is switched to a first position, and proceeds from the first path to the third path when the switch device is switched to a second position. The gear set drives the recording material from the first path to the third path when the switch device is switched to the second position and drives the recording material from the first path to the second path, from the third path to the fourth path, and from the fourth path to the first path when the switch device is switched to the first position.

Abstract: Document processing systems and methods are presented in which one or more pages of a print job are segmented into two or more parts, with the first part being transferred and affixed to the printed medium prior to transferring and affixing the second part, in order to facilitate high TMA (pile height) printing while mitigating adverse retransfer, blur, fusing, and hollow character effects.

Abstract: A transmission mechanism of an image forming apparatus includes: a first transmitting section transmitting a driving force of a drive mechanism to a first transporting roller; and a second transmitting section transmitting the driving force of the first transmitting section to a second transporting roller. The first transmitting section has a first gear rotatable integrally with the first transporting roller. The second transmitting section has a second gear engaged with the first gear; a shaft extended in a direction intersecting the rotational axes of the first and second transporting rollers, and rotatable integrally with the second gear; a third gear rotatable integrally with the shaft; and a fourth gear engaged with the third gear and rotatable integrally with the second transporting roller. The image forming apparatus is capable of transporting a paper favorably along a re-transporting path.

Abstract: A method and apparatus for a modular printing system having individual units comprising input modules, transporter modules, marking engine modules, fuser modules and exit modules each with its own support structure and cabinet. The modular units have common matching interface configurations for paper feed and electrical connections so as to permit numerous combinations and variations of printing systems capable of monochrome, color, duplex, hybrid and simplex printing by modular interconnection as opposed to built-up systems.

Abstract: A printer including a printing unit for printing on a sheet, a cassette containing stacked sheets and located below the printing unit, a supply unit that feeds the sheet from the cassette toward the printing unit, a sheet support plate positioned in the printing unit where the sheet is placed during printing, and an opening formed on the sheet support plate. A cover plate is located in the printing unit and moves between a covering position to cover the opening and an uncovering position to uncover the opening. The cover plate is at the covering position during printing, and the cover plate is at the uncovering position when a pair of feed-out rollers rotates in a reverse direction to guide the sheet through the opening of the sheet support plate to a refeed position between the cassette and the supply unit.

Abstract: An image forming apparatus includes: an image carrier that rotates; a developing unit that visualizes an electrostatic latent image carried on the image carrier with a color developer into a developer image; a transfer unit that transfers the developer image carried on the image carrier to a sheet in a predetermined transfer position; a fixing unit that fixes the developer image transferred by the transfer unit to the sheet; a transport unit that transports the sheet to which the color developer image has been fixed by the fixing unit, and returns the sheet to the transfer position for transferring a developer image of another color developer to be superposed on the developer image having been fixed to the sheet; and an adjustment unit that performs adjustment to reduce a time difference between time for returning the sheet by the transport unit and time for an integer number of rotations of the image carrier.

Abstract: An image forming apparatus includes: a main body of the image forming apparatus; a component of the image forming apparatus attached to the main body of the image forming apparatus; a medium re-feeding path formed in the main body of the image forming apparatus, wherein a medium is turned over while being conveyed through the medium re-feeding path for a double-sided printing; and a guide provided at the component, the guide being adjacent to the medium re-feeding path and configured to guide the medium along the medium re-feeding path.

Abstract: The sheet conveying apparatus includes a first curl forming part provided downstream of a fixing part for fixing a toner image to a sheet, for curling the sheet; a second curl forming part provided downstream of the first curl forming part, for curling the sheet in a direction opposite to a direction in which the sheet is curled in the first curl forming part, in which a curling amount of the sheet in the second curl forming part is set to be smaller than that in the first curl forming part, and the curling amount of the sheet in the second curl forming part is variable according to rigidity of the sheet. Thus, a shape of the curled sheet can be reliably reformed with a simple structure.

Abstract: A duplex image forming apparatus including a main body, a recording medium receiving unit disposed on one side of the main body to receive at least first and second recording media, a recording medium supplying unit to feed the first recording medium to a recording medium supplying path, an image forming unit to form an image on a first side of the fed first recording medium, an exiting and reversing unit to discharge the first recording medium formed with the image on the first side from the main body through a direct exiting path in an exiting mode, or to reverse a feeding direction of the first recording medium in a reversing mode, and a duplex feeding unit to resupply the image forming unit with the first recording medium, a rear end of the first recording medium and a front end of the second recording medium being overlapped, to feed the overlapped first and second recording media along the duplex feeding path, and to separate the first recording medium and the second recording medium on the duplex feedi

Abstract: An ADU is turned around a first hole section that operates as fulcrum and opened by a first angle relative to the lateral side of an apparatus main body when dissolving a jam. The lateral side cover is temporarily taken away from a stationary side plate when maintenance the inside of a color copying machine. Then, a second engaging pin is put into a second hole section to engage the lateral side cover with the stationary side plate. The ADU is turned around the second hole section that operates as fulcrum and opened by a second angle greater than the first angle.

Abstract: A double-side recording apparatus which inverts a recording medium after the end of the recording of a first face, and then performs the recording of a second face, includes: a recording unit which performs recording on the recording medium; a transportation unit which transports the recording medium to a position where the recording unit can perform the recording; a movement unit which moves a movable member capable of engaging with the recording unit to an engagement position and a non-engagement position; an inversion unit which inverts the recording medium sent from the transportation unit and returns the inverted recording medium to the transportation unit; a power source which is common to the transportation unit, the movement unit, and the inversion unit;

Abstract: A first and second printing engine are disposed with an intermediate transport belt in U-shaped arrangement. The method employs printing sheets serially on one side in the first engine inverting the sheet and transporting the sheets through about 180° change in direction without rotation. The commonality of the leading edge is thus maintained before and after inverting. The sheet is then fed to the second engine for duplex printing on the second side of the sheet. The second engine may have a media sheet input rotation for simplex printing serially with the duplex printing.

Abstract: An image forming apparatus includes: a main body; an image forming portion for forming a toner image on a recording material; a fixing unit for fixing the toner image on the recording material and including a nip forming member which forms a fixing nip that nips and conveys the recording material; a reverse roller unit for including a reverse roller, and the reverse roller rotates backward to convey the recording material to the image forming portion again after conveying the recording material which has passed through the fixing nip in a same direction as a conveying direction at the fixing nip; and a delivery roller for delivering the recording material which has passed through the fixing nip, out of the main body. The reverse roller unit is attached to the fixing unit, and is removably installable in the main body integrally with the fixing unit.

Abstract: An image forming apparatus includes a transfer unit, a fixing unit, a discharging unit, and multiple guide members. The transfer unit transfers an image onto a transfer sheet. The fixing unit fixes the image to the transfer sheet by application of heat and conveys the fixed transfer sheet to a further downstream portion of the image forming apparatus. The discharging unit discharges the transfer sheet to an external portion of the image forming apparatus. The multiple guide members form a sheet conveyance path that has first and second paths including a hollow portion defined by the multiple guide members to enable an air current generated during image forming to pass therethrough.

Abstract: In a method and system for printing, individual pages of a print medium are transported. With a printing unit, a side of the respective individual page facing it is printed and the applied toner image is fixed. With an inverter, the individual pages with the fixed toner image are inverted after the first printing event and resupplied to the printing unit for printing on an other side. The printing unit has first and second printing groups respectively comprising first and second exposure units, first and second charge corona devices, and first and second developer stations. Individual pages are supplied in succession to both of the first and second printing groups, and the printing groups respectively print two varicolored print images on the same side of the same individual page.

Abstract: Document processing systems and methods are presented in which one or more pages of a print job are segmented into two or more parts, with the first part being transferred and affixed to the printed medium prior to transferring and affixing the second part, in order to facilitate high TMA (pile height) printing while mitigating adverse retransfer, blur, fusing, and hollow character effects.

Abstract: A sheet conveying apparatus includes a first conveying path through which a sheet is conveyed; a reversal conveyance driving unit which drives to reversely convey the sheet conveyed through the first conveying path; a second conveying path which branches off with the first conveying path and through which the sheet reversely conveyed by the reversal conveyance driving unit is conveyed; and a movable unit which causes a branch position between the first conveying path and the second conveying path to move on a downstream side in a conveying direction of the sheet which is conveyed through the first conveying path, after a trailing end of the sheet which is conveyed through the first conveying path passes the movable unit.

Abstract: The image forming apparatus includes an intermediate transfer member onto which an image is transferred, a transfer part transferring the image formed on the intermediate transfer member onto a transfer, a detection part detecting a transfer which is conveyed, and a both-surface conveying part reversing the transfer with an image being formed on a first surface, and conveying the transfer to the transfer part again, wherein a timing when forming an image on a second surface of the transfer by the image forming part is switched based on a size in a conveying direction of a transfer which is designated and a size of the conveyed transfer.

Abstract: In an image forming device, a fixing unit thermally fixes a development image transferred onto a first surface of a recording medium, the recording medium having a second surface opposite to the first surface. The conveying wall defines a conveying path, along which the recording medium is conveyed from the fixing unit in a conveying direction, the recording medium being conveyed along the conveying path with the first surface of the recording medium confronting the conveying wall, the recording medium having a pair of lateral parts in a direction orthogonal to the conveying direction, the recording medium being curled at the pair of lateral parts to bring the first surface to face outwardly and the second surface to face inwardly.

Abstract: By providing a rib formed to be inclined with respect to the conveyance direction on a guide member provided at the upstream side of the conveyance section where a contact member that cools rapidly the sheet subjected to fixing processing is provided, a problem of the occurrence of uneven gloss on the surface of a toner image by contact between a sheet and a guide member or a conveyance roller in a conveyance section that conveys the sheet subjected to fixing processing is solved.

Abstract: An image forming device having a printing unit, an intermediate tray, and a stapler fixed at a predetermined position, which stacks printed paper printed by the printing unit in the intermediate tray after either a face-down process or a face-up process when performing a normal operation and staples the printed paper when a number of sheets thereof reaches a predetermined number, the image forming device includes: an input unit allowing input of a choice of the face-down process or the face-up process and a choice of one-side printing or two-side printing; and a control unit controlling the image forming device so as to stack the printed paper in the intermediate tray after the printing unit performs two-side printing if a process selected using the input unit is different from one which is performed in the normal operation.

Abstract: A sheet conveyance apparatus includes a sheet conveyance path, a first conveyance mechanism located upstream in the sheet conveyance path, and a first drive mechanism configured to drive the first conveyance mechanism. The apparatus further includes a second conveyance mechanism located downstream in the sheet conveyance path, a second drive mechanism configured to drive the second conveyance mechanism, a first intermediate conveyance mechanism located between the first and second conveyance mechanisms in the sheet conveyance path, and a first drive transmission mechanism configured to intermittently transmit drive force from the first drive mechanism to the first intermediate conveyance mechanism. The sheet conveyance apparatus can be provided in an image forming apparatus.

Abstract: A recording apparatus, in which a recording medium is fed from one side of the recording apparatus, and the recording medium that has been recorded is ejected from the one side of the recording apparatus, is capable of making its size when not in use smaller than the size when in use and also achieving a reduction in the depth dimension of the recording apparatus as compared with the case where a feed tray and a discharge tray are rotary storage trays. The recording apparatus includes a feed tray on which a recording medium is stacked and which is rotated to move between an in-use position and a stowed position, and an eject tray on which the recording medium that has been recorded is stacked and which moves between an in-use position and a stowed position in a discharge direction of the recording medium.

Abstract: In an image forming apparatus, an AC bias is supplied to a conveyance belt, and the amount of charge on the printing side of a recording sheet is decreased. The charge of positive polarity and the charge of negative polarity which are different from each other are generated on the printing side of the sheet, so that both the charges are cancelled by each other and the charge on the printing side of the sheet is eliminated. Moreover, the charge eliminator eliminates the charge on the printing side of the sheet by the time the sheet is electrostatically attached to the conveyance belt and conveyed to a position where the sheet confronts the head.

Abstract: A feeder includes a feed unit and a re-feed unit. A feed unit feeds a recording medium (such as a sheet of paper) on a feed tray to a printer engine. A re-feed unit feeds the recording medium having passed through the printer engine again to the printer engine. A roller pair for paper feeding and another roller pair for paper re-feeding share one drive roller. That is, the drive roller and a driven roller constitute the former roller pair, whereas the drive roller and another driven roller constitute the latter roller pair, thereby enabling the downsizing of the feeder.

Abstract: An image forming apparatus that forms an image on a surface of a transfer sheet, then, reverses the transfer sheet on which the image has been formed on the surface and then, forms an image on the reverse side of the transfer sheet, wherein there is provided a correcting section that changes a relative position between the transfer sheet and the image on the surface in accordance with an outer shape of the transfer sheet and further changes a relative position between the transfer sheet and the image on the reverse side of the transfer sheet in accordance with an outer shape of the transfer sheet.

Abstract: An image recording apparatus includes first to fifth transport paths. The first path transports a sheet from a sheet feeding section to a sheet output section through a first confluence, an image recording section, a first bifurcation, and a second confluence in that order. The second path transports a sheet from the first bifurcation down to a switchback section through a second bifurcation and a third bifurcation in that order. The third path transports a sheet from the third bifurcation to the first confluence through a third confluence, and vice versa. The third path is positioned between the switchback section and a portion of the first transport path located in the image recording section. The fourth path transports a sheet from the second bifurcation to the third confluence, and vice versa. The fifth path transports a sheet from the second bifurcation to the second confluence.

Abstract: An image forming apparatus that is capable of normally performing second side printing on a transfer material, even if the transfer material put on standby after completion of first side printing is pulled out by a user. A transfer material having image formed on its first side is fed until it is partly exposed to the outside of a printer, and is then fed to a refeeding path in the printer and further fed to a standby position prior to image formation on the second side of the transfer material. When it is detected that the transfer material caused to stop at the standby position is pulled out by a user, a warning to stop pulling out the transfer material is given to the user.

Abstract: An image forming apparatus having therein an image forming device that transfers an image onto a transfer sheet and a reversing device that reverses the transfer sheet, wherein the image forming device transfers an image on the front surface of the transfer sheet, then, the reversing device reverses the sheet, and the image forming device transfers an image onto the rear surface of the sheet and the image forming apparatus further has therein a correcting device that corrects the overall skew of the transfer sheet depending on an inclination of a leading side of a transfer sheet in the conveyance direction set in advance before an image is formed on the front surface, and corrects the overall skew of the transfer sheet depending on an inclination of a leading side of a transfer sheet in the conveyance direction set in advance before an image is formed on the rear surface.

Abstract: A fixing device has a roller pair; a cover for defining a forward transport path, and a backward transport path for transporting a sheet discharged from the roller pair back to an image former for forming toner images on both sides of the sheet. A sheet detection arm has opposite ends extending respectively in the forward and backward transport paths. A first shaft in the cover is mounted to a center of pivotal movement of the sheet detection arm and extends orthogonal to the sheet transport direction. A secondary shaft transmits rotation of the first shaft when the cover is closed, but not when the cover is opened. A sensor detects whether the sheet is being transported forward or backward based on rotation of the second shaft. The sheet detection arm pivots out of the backward transport path in response to opening of the cover.

Abstract: An image forming system is given, in advance, unique setting as a behavior to be performed when an error occurs regarding postprocessing. In a case where the postprocessing becomes inexecutable during the operation of the system, the system either cancels the postprocessing to continue printing (Steps S20, S22) or stops printing to generate an error (Step S18), based on the unique setting. A user arbitrarily decides the unique setting, which enables optimum control of the operation that the system should perform when the postprocessing becomes inexecutable.

Abstract: The length of recording paper being conveyed to an image forming section is detected. If it is found that the length is shorter as a result of the detection, the recording paper is conveyed to a reversing section to be refed to the image forming section to continue conveyance of the recording paper as in the normal image formation, but without performing the image formation. As a result, the sequence of the recording paper ejected to the paper output section is the same as that of normal printing. Thus a user can easily decide the paper on which the image formation is not carried out normally.

Abstract: A power transmission apparatus and an image forming apparatus are provided. The a power transmission apparatus of transmitting driving power to first and second movable members includes: a driving unit which receives the driving power from a driving power source, and which rotates in forward and backward directions; a first driven unit which transmits the driving power to the first movable member; an elastic clutch which is provided between the driving unit and the first driven unit to selectively allow the driving power from the driving unit to be conveyed to the first driven unit based on the direction of the driving power; a second driven unit to convey the driving power to the second movable member regardless of the direction of the driving power so as to allow the second movable member to rotate bi-directionally. The first movable member may be, e.g., a photosensitive body. The second movable member may be, e.g., exit rollers for ejecting processed printing medium out of the image forming apparatus.

Abstract: An image forming apparatus capable of performing a double-side printing process is described. The transportation efficiency and the productivity can be improved by narrowing the distance between adjacent print sheets for use in absorbing the disparity in the transportation of print sheets.