Abstract: The present invention aims at providing a method of controlling a post-processor connected with an image-forming device that utilizes a conventional image-forming device and post-processing unit, and does not necessarily require to consistently form a sag in continuous paper. The inventive method of controlling the post-processor is carried out by the image-forming device that includes a transfer part and a fixing part, and conveys continuous paper. The image-forming device is connected with the post-processor that processed the continuous paper on which an image has been formed.

Abstract: A triplex printing system has three electrographic printer devices which enables both-sided, exactly registered printing of a paper web. For this purpose, the front side is printed in a first printer, the backside is printed in a second printer and the backside is printed again superimposed in a third printer. As a result of the arrangement of two printer chains having six printers, the structuring of a variable printing system adjustable dependent on function having a plurality of printer lanes is possible.

Abstract: An apparatus for transporting web-shaped recording media through an electrographic printer or copier has a support member which supports driving and guiding elements. The support is pivotally mounted in the housing via a support shaft. The recording medium is transported by friction by a drive roller mounted on the support, the recording medium being pressed against the toner carrier by a pressing member. The supporting shaft and the drive roller run in a coaxial manner.

Abstract: In an imaging apparatus for forming an image on a continuous recording sheet, in accordance with an electrophotographic imaging process, and fixing the image on the continuous recording sheet by applying heat and pressure using a pair of fixing rollers including a heat roller and a pressure roller, when a printing operation is finished, the printing portion of the recording sheet is discharged from the printer and the heat roller is moved from an operable position, where it is press-contacted with a pressure roller, to a retracted position, where it is spaced from the pressure roller by a predetermined amount. When the heat roller is moved toward the retracted position, it is once stopped at an intermediate position for a predetermined period of time, and then, moved further to the retracted position. Another printing operation is started, the recording sheet is pulled back so that images are formed thereon.

Abstract: An exemplified object of the present invention is to provide a guide mechanism, paper feed control method, and image-forming device that can prevent a jam or image degradation from occurring. The guide mechanism of the present invention comprises a guide part that guides continuous paper from a paper feeder part storing the continuous paper to a conveyor part while regulating a conveyance route of the continuous paper, and a driving part that drives the guide part and the paper feeder part to move relatively and automatically according to a storage amount of the continuous paper in the paper feeder part.

Abstract: This invention relates to a printing device that performs fixation after transfer, and which prevents the occurrence of no transfer even when feeding the paper backward starting printing from the next page after the final page. This printing device comprises image-formation units (3, 4) that transfer a toner image, a fixation unit (5), and a control unit (10). The control unit (10) control adjustment of the moisture content on either the final page or leading page. In order to do that, it lowers the fixation energy of the fixation unit (5) for the final page. There is a moisture-adjustment mechanism (16) that reduces the moisture content of the leading page. Heat energy is applied to the leading page by the fixation unit (5). This reduces the difference in the amount of shrinkage between the final page and the leading page, and prevents wrinkling of the leading page.

Abstract: In a multifunctional printing method and printing system, printed material is checked, verified and tracked. For that purpose different test equipments are located in-line with a printing line. Magnetic information being printed by a printing station onto the recording carrier using magnetic ink character readable toner may be in-line tested by a magnetic test equipment, which reads information from the magnetic recording zone on the carrier. Optical information may be tested by an in-line mounted optical test equipment, respectively. Further in-line test equipment is proposed such as a laser bar code scanner and an address reader. The printing line may have additional devices such as print preprocessing unwinders or print postprocessing stackers, folders or cutters.

Abstract: A print system electrographically prints two web shaped recording media which are then sent to a post-processing station. The print sides of the two recording media are offset from one another by a distance and the two recording media are crossed so that they overlie one another after leaving the printer and upon entry into the post-processing station.

Abstract: A printing assembly comprises a first printer for printing documents encoded in computer generated signals and a second printer for printing documents encoded in computer generated signals, the documents including alphanumeric characters, charts and graphics. The printers are disposed one above the other and are connected in tandem to one another via a multiple-page continuous web of paper extending along a U- or C-shaped path from a paper output port of the first printer to a paper feed port of the second printer. A computer for generating a signal encoding a multiple page document is coupled via connection componentry to the printers for transmitting odd pages in encoded form to one of the printers and even pages to the other printer.

Abstract: According to the present invention, there is provided a continuous medium printing apparatus including a printing section, a determining section, instructing unit, wherein the determining section is controlled in its reading operation for acquiring printed image data from continuous paper in accordance with first instructing signal supplied from the instructing unit, and the printing section is controlled in its printing operation on the continuous paper in accordance with a second instructing signal supplied from the instructing unit.

Abstract: The invention provides a continuous medium printing apparatus which can exert a transporting force to act upon a continuous medium without additional provision of a new tractor mechanism or some other transport mechanism. In the continuous medium printing apparatus, upon automatic loading of a continuous medium, a control section controls a charging operation of a charging section so that a leading end portion of the continuous medium may be electrostatically attracted to an image forming drum. The image forming drum to which the continuous medium is attracted is rotated in a printing transporting direction to exert a transporting force to act upon the continuous medium to transport the continuous medium in the printing transporting direction. The present invention is applicable to an apparatus which prints on a continuous medium such as continuous recording paper (continuous paper), for example, by electrophotography.

Abstract: An image recording apparatus for recording a two-color image on both surfaces of a continuous recording medium includes a toner image recording portion which has a toner carrier and transfers a toner image formed on a surface of the toner carrier onto the recording medium, a tractor for feeding the recording medium on which the toner image is transferred, and a both side fixing machine for receiving the recording medium fed by the tractor to fix the toner image transferred on the recording medium. In this image recording apparatus, guide rollers come into contact with non-printing portions on both side ends of the recording medium to apply tension to the recording medium by a spring and thereby gives a predetermined slack to the recording medium to absorb a difference in speed resulted between the tractor and the both side fixing machine.

Abstract: An image forming apparatus includes a reverse side print mechanism for printing on the reverse side of continuous paper, a surface print mechanism for printing on the surface of the continuous paper, and a width detecting mechanism for detecting a width of the continuous paper. The apparatus further includes a controller which, based on the detected paper width, determines a print start position on the reverse side of the continuous paper and controls the reverse side print mechanism to start printing from the determined print start position. Thus, even if the paper width is changed, the reverse side print start position can be set to a predetermined position.

Abstract: A method and a device for controlling a drive unit which conveys a striplike laterally pre-printed recording medium, whereby a sensor is sensitized with respect to a regularly re-occurring mark of the recording medium. The recording medium is continuously scanned by the sensor during the printing operation and the speed at which the recording medium is conveyed is adjusted according to scanned signals from the sensor.

Abstract: A double-side printing apparatus for printing on double surfaces of a recording medium is constructed to prevent both an adverse influence on an image forming unit from a fixing unit and an offset of a toner image on the recording medium. The double-side printing apparatus includes a first image forming unit for forming the toner image on one surface of the recording medium, a second image forming unit, provided downstream of the first image forming unit, for forming a toner image on the other surface of the recording medium, a first fixing unit for fixing the toner image on one surface of the recording medium by a light, a second fixing unit, provided downstream of the first fixing unit, for fixing the toner image on the other surface of the recording medium, and a preventing member, provided between the first fixing unit and the second image forming unit, for preventing the light from the first fixing unit from reaching a photo sensitive body of the second image forming unit.

Abstract: A perfecting apparatus for executing prints on double surfaces of a recording medium is capable of minimizing a blank space on the recording medium. The perfecting apparatus has a first image forming unit, disposed downstream in a carrying direction of the recording medium, for forming a toner image on one surface of the recording medium, a second image forming unit, disposed upstream in the carrying direction of the recording medium, for forming the toner image on the other surface of the recording medium, a fixing unit for fixing the toner images onto the double surfaces of the recording medium, and a control unit for controlling the first and second image forming units. The control unit controls, when in one-side printing, the first image forming unit disposed downstream in the carrying direction. A distance between the fixing unit and the first image forming unit is short, and hence the blank space on the recording medium can be minimized.

Abstract: The invention provides a double-sided printing apparatus which includes a first image forming process unit, a second image forming process unit, a first fixing station, a second fixing station and a transport system all disposed in a first housing. The transport system includes a transport direction changing element which contacts with one of surfaces of a medium to change the transporting direction of the medium so that the medium is sent out to the second fixing station. While the medium is transported in a substantially vertical direction in the single double-sided printing apparatus, the height of the transport path of the medium is suppressed so as not to become very high, thereby miniaturizing the apparatus.

Abstract: The invention provides a continuous medium printing apparatus which can exert a transporting force to act upon a continuous medium without additional provision of a new tractor mechanism or some other transport mechanism. In the continuous medium printing apparatus, upon automatic loading of a continuous medium, a control section controls a charging operation of a charging section so that a leading end portion of the continuous medium may be electrostatically attracted to an image forming drum. The image forming drum to which the continuous medium is attracted is rotated in a printing transporting direction to exert a transporting force to act upon the continuous medium to transport the continuous medium in the printing transporting direction. The present invention is applicable to an apparatus which prints on a continuous medium such as continuous recording paper (continuous paper), for example, by electrophotography.

Abstract: A printing machine in which an endless web of sheet material is adapted to move along a path of movement. A recording device, in communication with the web of sheet material, prints information thereon. A fixing device, associated with the recording device, substantially permanently fixes the printed information to the web of sheet material. An inverter, positioned after the fixing device in the path of movement of the web of sheet material, inverts the sheet material enabling information to be printed on one side of the web of sheet material before inversion and information to be printed on the other side of the web of sheet material after inversion thereof.

Abstract: In a multifunctional printing method and printing system, printed material is checked, verified and tracked. For that purpose different test equipments are located in-line with a printing line. Magnetic information being printed by a printing station onto the recording carrier using magnetic ink character readable toner may be in-line tested by a magnetic test equipment, which reads information from the magnetic recording zone on the carrier. Optical information may be tested by an in-line mounted optical test equipment, respectively. Further in-line test equipment is proposed such as a laser bar code scanner and an address reader. The printing line may comprise additional devices such as print preprocessing unwinders or print postprocessing stackers, folders or cutters.

Abstract: An electrophotographic printer has an automated sheet loading system which adjusts the position of the continuous recording sheet by moving the sheet forward and backward so that one of the perforated lines or the recording sheet is aligned with a reference line of the printer upon depression of a key switch by an operator.

Abstract: The present invention relates to a printer with a single printing motor and a single non-contact heating element characterized in that it includes a printing width and a paper path width greater than that of a double web width between 18.5" (46.99 cm) and 20.5" (52.07 cm), and selective control of the writing heads. The writing heads are controlled either in order to use them in a single group to print a centered double-width web, or to use them in two groups of heads to concomitantly print two single-width webs separated by a margin. Both groups of heads or each group of heads can be supplied with one color of ink.

Abstract: A system for double-sided imaging on a continuous-web substrate having first and second substrate surfaces, the system including an imaging device including a toner-image bearing surface having selectively formed thereon first and second images. The system further includes a web-feeder system which selectively brings the first and second substrate surfaces into operative engagement with the toner-image bearing surface, to transfer thereto the first and second images, respectively, in accordance with a preselected imaging sequence.

Abstract: There is provided an image recording apparatus which does not cause a print shift or a color drift caused by vibration and a widthwise shift due to speed variation in a conveying direction of a continuous sheet such as rolled paper or folded paper, in which a variation in speed is prevented by rollers which wind and clamp the sheet on and between an upper and a lower roller which are driven by the conveying force of the sheet, so as to prevent occurrence of vibration in the conveying direction, and a guide roller having pins adapted to be engaged in sprocket holes of the sheet are provided between the set-up positions of the tractors.

Abstract: A laser printer capable of printing on a strip of fan fold paper includes a photosensitized drum for generating thereon a toner image to be transferred to the surface of the paper strip. The drum is associated with tractor assemblies operable in synchronism with the speed of the drum so as to determine travel speed of the paper strip passing by the drum. The laser printer further includes a fixing unit having a pair of fixing rollers for pressing the paper strip therebetween and a roller drive mechanism to drive the fixing rollers so as to determine travel speed of the paper strip passing through the fixing unit. A tension unit is disposed between the drum and the fixing unit for applying a tension to and thereby taking up slack of such portion of the paper strip that runs between the drum and the fixing unit. The tension unit includes a tensioning plate supported for pivotal motion and a helical tension spring for urging the tensioning plate. A sensing mechanism senses displacement of the tensioning plate.

Abstract: A ticket issuing apparatus includes a feed passage which is branched into plural guides at one end thereof which are connected with each of a plurality of medium accommodating parts and arranged in strata, and merged into one. The apparatus has a feed passage which passes through the upper, rear and lower parts of the medium accommodating parts in this order and is guided to a front wall thereof. A medium separating part, a magnetic processing part and a printing part are respectively disposed along the feed passage, and a discharge stacker is connected with the other end of the feed passage. The medium handling apparatus removes curl of the medium before it is issued by returning the medium to the medium accommodating parts by a given amount.

Abstract: In the case that recording paper of a roll (20) has run out during an image forming process, when the length of a piece of the remaining recording paper left last is longer than the first reference length possible to feed the paper in the inside and outside of a roll unit (RU), the paper is delivered, and when the length of the remaining piece is slightly shorter than the first reference length, the front end of the remaining piece is projected to the outside of the roll unit (RU), and when the length of the remaining piece is shorter than the second reference length impossible to feed the paper in the inside of the roll unit (RU), the remaining piece is dropped inside of the roll unit (RU) by a reverse feeding, thereby, a removal of the remaining piece is facilitated. Thus, the removal of the remaining piece may always be performed well.

Abstract: A printer for printing endless paper webs on both sides has two printing stations with a web turnover station therebetween. The paper web is fed in parallel side-by-side to the two printing stations which are on the same rollers. The drive of the web through the printer is by a positive drive, using pins to engage holes in the paper web, for example, into the first printing station. The drive of the paper web thereafter is by friction drive to permit slippage in the drive to compensate for variations in paper length during heating, etc. The slippage is controlled by brakes or other drag inducing devices acting on one or both of the two portions of the paper web.

Abstract: An image forming apparatus includes a paper feed station from which sheets can be fed from a plurality of roll sheets only by placing the roll sheets in the station, a recording station for recording desired images on the sheets, and a processing station for delivering the sheets on which the images are recorded. The recording station includes a platen roller and a driving pinch roller for pushing and conveying a fed sheet while the sheet is drawn by suction by a suction chamber, a carriage unit for recording an image on the sheet on the suction chamber while moving along the sheet, and a pair of paper delivery rollers for delivering the sheet on which the image is recorded. The processing station includes a table on which the delivered sheets can be sequentially stacked in a predetermined position, and a biasing spring for biasing the pivotal distal end portion of the table.

Abstract: A fixing system for fixing toner images onto an image printing system such that the image printing medium bearing the toner images on the obverse side and the reverse sides thereof is passed through a nip area between a pair of fixing rollers. In the nip area, a rotation speed of a first fixing roller, which comes into contact with a not-yet fixed toner image, which is formed on the obverse side of the image printing medium, is set to be substantially equal to a rotation speed of a second fixing roller, which comes in contact with a not-yet fixed toner image, formed on the reverse side of the image printing medium. This is accomplished by setting the diameters of the various layers of the first fixing roller to be equal to that of the second fixing roller. When the image printing medium is moved through the nip area by the fixing rollers, a moving speed of the upper side of the image printing medium is equal to that of the lower side thereof.

Abstract: A method and arrangement for adjusting density in electrophotographic printing are disclosed. A toner mark is printed at a predetermined location on each of sheets of a continuous stationery. A toner mark sensor is provided to detect density of the toner mark printed on each of the sheets. A controller performs density control based on a result from detecting density of toner mark printed on every other page of the sheets.

Abstract: An electronic printing system comprises a substrate supply for supplying a substrate along a paper path configured in an arc. The substrate is controllably transported through the electronic printing system past a plurality of printheads. The printheads are arranged above the paper path, in an arc configuration corresponding to the paper path configuration. As the substrate passes under each printhead, a printed image is generated on the substrate. A plurality of rollers are arranged to have at least one roller under the substrate at each location corresponding to a printhead location. Finally, a dryer is located after the last of the plurality of printheads for fixing the printed image to the substrate.

Abstract: An electrographic printer with a printing unit that comprises a photoconductor provided with a toner image during the printing process and which further comprises a corona device arranged at a distance from the photoconductor that generates an electrical field during the printing process for transferring the toner image onto an endless carrier material is provided. The printer, in a first operating mode, can print a first web section of the endless carrier material conducted along a transport path and, in a second operating mode, can simultaneously print a second web section conducted along a parallel transport path and arranged next to the first web section at a distance therefrom. The length of the electrical field generated by the corona device is adjustable according to whether a first web section or a first and second web section is transported along the transport path.

Abstract: A printer for optionally printing the front side and back side of a band-shaped recording medium has a feed device to move the recording medium from the front side printing and fixing stations to a turn-overs station where it is turned over and returned to the printing and fixing station to print the back side. Pairs of driven rollers are provided in the paper channel to move the recording medium, wherein the frictional forces on the recording medium by the rollers can be set. The rollers are reversible and can also be swivelled out for certain printing modes and recording media sizes. Automatic threading of the recording medium is provided.

Abstract: A continuous web substrate duplex printing system which can utilize a single and otherwise conventional or existing xerographic print engine (normally printing conventional cut sheet print substrates) of a standard width without substantial structural modification. Separate first and second image transfer stations are positioned in line with one another in the direction of movement of the endless surface imaging member, with said second image transfer station downstream of the first, for respectively transferring print images to the first and second sides of the continuous web sequentially without requiring a dual width imaging member or dual imaging members for duplex printing.

Abstract: A printer has one or more fans in the vicinity of a fixing device to blow air directly onto a continuous form when printing is stopped and when rollers in the fixing device are separated. The fan or fans can be provided on a pressure roller side of the continuous form, in which case the continuous form shields a heat roller from the air flow of the fans. In the alternative, the fan or fans can be on the heat roller side, in which case a shield extending along the circumference of the heat roller, duct, or both is used to protect the heat roller from the air flow and/or the continuous form from direct heat radiation. A pair of rollers are disposed downstream of the fixing device and are rotated while the continuous form is stopped so as to maintain tension on the continuous form.

Abstract: An electrographic printer has an intermediate medium for simultaneously printing a first web section of an endless medium and a second web section arranged next to and at a distance from the first web section. Both web sections are drawn along a path past the intermediate medium by a transport system. During the printing process, a tensioning device biases the first and second web sections against the intermediate medium. A web-tensioning unit located downstream relative to the direction of transport of the transport device, applies a traction force to the web sections in the direction of travel. In addition, a first compensation device and a second compensation device separated from the first compensation device are provided between the transport device and tensioning device. The compensation devices bias the first or second web sections as appropriate, against the direction of transport during the printing process.

Abstract: The invention relates to a developer station for electrophotographic printing apparatus operating in multicolor simplex and duplex mode and having continuous paper. The developer station contains a plurality of adjacent developer chambers with developer drums and transport drums arranged within. The adjacent developer chambers are separated by partition walls with openings though which the drums pass. The drums driven together are positively connected with each other by coupling elements arranged in the area of the openings and having associated toner-proof seals.

Abstract: In a continuous form printer, a passage of the leading edge of the continuous form sheet is detected by a top sensor located along a feeding path thereof. A system determines whether the detection of the leading edge by the top sensor is correct, by comparing the feeding amount of the continuous form sheet after the feeding is started until the leading edge is detected with the distance between a feeding start position and the top sensor.

Abstract: A sheet feeding apparatus includes a guiding path for guiding a sheet, a detector for detecting the presence/absence of the sheet in the guiding path, a power-supply switch for turning on and off a power supply, and a determination device for determination whether the sheet comprises a rolled sheet or a cut sheet according to whether the detector detects or does not detect the sheet, respectively, when the power-supply switch has been turned on. A rolled sheet holder for holding the rolled sheet and covering an insertion port for leading the cut sheet or the rolled sheet to a feeding device.

Abstract: An image forming apparatus includes a plurality of process units contacting a continuous recording medium and transferring images on the recording medium, a separating and contacting mechanism for controlling at least one of the recording medium and each of the process units to a separated state where the recording medium and the process unit are separated from each other and a contacting state where the recording medium and the process unit contact each other, and a controller for controlling the separating and contacting mechanism at a position where the process unit confronts a non-printing region on the recording medium so as to put the recording medium and the process unit to the contacting state.

Abstract: The present invention provides an image recording apparatus with an image recording unit for recording an image on a recording medium, a first conveyor for conveying the recording medium to an image recording portion of the image recording unit while bending the recording medium along a drive convey roller by means of the drive convey roller, and a second conveyor for conveying an elongated recording medium having a plurality of pin holes to the first conveyor. A guide capable of changing a contact area between the recording medium and the drive convey roller at a curved portion of the recording medium along the drive convey roller is also provided.

Abstract: In a continuous form printer, a passage of the leading edge of the sheet is detected by a top sensor located along a feeding path thereof. If the top sensor detects the leading edge of the sheet while the sheet is fed in a reverse direction, the control unit of the printer determines whether the detection of the leading edge by the top sensor is correct or not, by feeding the sheet once in the forward direction and then feeding the sheet in the reverse direction and by checking whether the top sensor again detects the leading edge of the sheet being fed in the reverse direction.

Abstract: A continuous web substrate printing system which can utilize a single otherwise conventional or existing xerographic print engine (normally printing conventional cut sheet print substrates) having an endless photoreceptor belt with a belt seam requiring a section of that belt to be unimaged in each belt rotation, yet provide continuous directly abutting images on the printed web, to avoid paper scrap. A special simplex or duplex continuous web printing substrate supply module may be docked with the cut sheet print engine to form an integral web printing system. It has a web feeding and image transfer system for appropriately feeding the continuous web printing substrate uncut into the print engine for image transfers to one or both sides of the web from the imaging surface of the print engine.

Abstract: A plural mode printing system utilizing a cut sheet print engine for printing conventional cut sheet print substrates, in which page print images are generated and transferred to the cut sheets at an image transfer station. This plural mode printing system selectively provides printing onto either the cut sheets or onto an uncut continuous web printing substrate, in the same cut sheet print engine. An independently moveable continuous web printing substrate supply module is selectively operatively docked with the cut sheet print engine. That web printing module has a web feeding and image transfer assistance system for feeding the continuous web uncut into the cut sheet printing engine for transferring the page print images onto the web instead of onto cut sheets when the print engine is operatively docked with the web printing substrate module. The web printing module does not itself need to print.

Abstract: A continuous web substrate duplex printing system which can utilize a single otherwise conventional or existing xerographic, print engine (normally printing conventional cut sheet substrates) without substantial structural modification, and without requiring plural print engines on opposite sides of the web. The continuous web may be fed uncut into the print engine to two transfer stations alternatingly engaging a single endless belt imaging surface, which two alternating transfer stations are in line with one another in the direction of movement of the imaging surface, with web inversion and a controlled expandable/contractible web loop in between those two transfer stations, for respectively transferring the page print images onto the two respective sides of the continuous web in sequential batches of plural first and second side images, in the proper page sequence and positions and without any spaces between page images along the web.

Abstract: A continuous web substrate duplex (both sides) printing system which can utilize a single otherwise conventional or existing xerographic print engine (normally printing conventional cut sheet print substrates) without substantial structural modification, instead of requiring plural print engines on opposite sides of the web. This may be accomplished as shown by operatively docking a special duplex continuous web printing substrate supply module with the cut sheet print engine to form an integral duplex web printing system. Here, this duplex web printing module has an integrated fusing system with translating and half-surface-speed roll fusers for fusing the transferred images on both sides of the web with those two separate moving fusers, with each fuser fusing images on one side of the web after respective separate transfers of sequences of plural first and second web side images.

Abstract: A turn-over apparatus for a printer for printing on both sides of a web-shaped recording medium has two acutely angled deflectors to turn the recording medium over. The angles of the deflectors are such that the converging ends of the deflectors are spaced apart. Automatic threading of the recording medium is provided.

Abstract: An electrographic printer device is designed for printing web-shaped recording media (10) having different web widths in different operating modes, such as single-colored and multi-colored simplex printing, single-colored and multi-colored duplex printing and for simultaneously printing two recording medium webs in parallel operation. To this end, the units of the printer device such as intermediate carrier (11), transfer printing station (15) and fixing station (18) comprise a usable width of at least twice the web width of a narrow recording medium. The printer device further contains a deflection means (28) following the fixing station (18) and engageable as needed and having an allocated return channel to the transfer printing station (15) via which the recording medium (10) is turned and resupplied to the transfer printing station (15) in single-color or multi-color duplex mode.

Abstract: An electrographic printer device for printing tape-shaped recording media (10) in duplex and simplex printing contains two transfer printing stations (15/1,15/2) that can be pivoted against and away from the photoconductive drum (11). The first transfer printing station (15/1) serves for transferring toner images allocated to the front side, the second transfer printing station (15/2) serves for transferring back side toner images. A mechanical buffer storage (29) and a turn-over means (28) with preceding intermediate fixing station in the form of a photoflash fixing station (31) are arranged between the transfer printing stations (15/1,15/2).