Abstract: The present invention relates to a duplex scanning apparatus. The duplex scanning apparatus includes a scanning module, a sheet input tray, a sheet ejecting tray, a transfer channel, a sheet pick-up roller, a friction-enhancing stopper, a transfer roller assembly, a sensor, a first inverting region, a second inverting region, an inverting channel, a sheet ejecting roller assembly, a first inverting roller assembly, a second inverting roller assembly, a first switching element and a second switching element. By providing two inverting regions, the scanning time for performing a duplex scanning operation by the duplex scanning apparatus of the present invention is shortened.

Abstract: An image-forming device capable of image-forming on both sides of at least one sheet member, the device including an image-forming unit configured to form an image on the at least one sheet member, a sheet member supplying unit configured to supply the at least one sheet member, an image processing unit configured to process print job information, and an image-forming control unit configured to control, according to the print job information transmitted from the image data processing unit, image-forming operations on the at least one sheet member, wherein, in the event that a defect occurs in the at least one sheet member being supplied from the sheet member supplying unit during image formation on both sides of the at least one sheet member, the image-forming control unit transmits to the image data processing unit the print job information corresponding to the at least one sheet member at which a defect occurred.

Abstract: A method for processing a duplexed document having a first side with a first image and a second side with a second image includes scanning only the first side of the duplexed document under a first imaging condition to retrieve first information relating to each of the first image and show-through contribution of the second image; scanning only the first side of the duplexed document under a second imaging condition to retrieve second information relating to each of the first image and show-through contribution of the second image; and comparing the first information and the second information to reduce an amount of the show-through contribution.

Abstract: A method for processing a duplexed document having a first side with a first image and a second side with a second image includes scanning only the first side of the document under a first imaging condition to retrieve first information relating to each of the first image and the second image; scanning only the first side of the document under a second imaging condition to retrieve second information relating to each of the first image and the second image; and determining from the first information and the second information a show-through contribution of the second image with respect to the first side of the duplexed document.

Abstract: A double-side scan device for performing a single-side scan operation or a double-side scan operation selectively includes a document conveyer, a first transparent device, a second transparent device, and an image scan module. The image scan module moves to one side of the first transparent device to capture an image of one surface/side of a document and moves to one side of the second transparent device to capture an image of the other surface/side of the document, respectively.

Abstract: An automatic document feeder, which is capable of feeding a document for double-sided reading, includes a document feed path connecting an input tray and an output tray, a bidirectional feed path connected to a connection position of the document feed path, a bypass diverged from a branch position of the document feed path and connected to the connection position, a guide flap that changes a position thereof between a first guide position and a second guide position, and a guide flap that changes a position thereof between a third guide position and a fourth guide position.

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: Apparatus and a method is disclosed for duplex printing of a document or a book block in which two printers operating in a simplex printing mode are used on both faces of a plurality of sheets forming a document or book block. The first printer prints an image on a first side or face of a sheet, where a number of sheets are stored in an queue between the first and second printers such that as sheets are printed by the first printer, they are delivered in sequence to the queue, where sheets are fed from the queue to the second printer without the first printer having to delay printing until the second printer is ready for the next sheet, and where the second printer may have a sheet delivered to it without the second printer having to await for the first printer to print a sheet thereby to allow both the first and the second printers to print at substantially their maximum simplex printing speeds.

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 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 paper feeding mechanism for carrying a paper passing through a scanning station having a scanning module includes a partition, a paper transporting device, and a switching member movably disposed corresponding to one end of the partition. A first paper feeding channel is formed between the partition and the scanning station, and a second paper feeding channel is formed on another side of the partition. The paper transporting device carries the paper passing over the side of the partition through the first paper feeding channel with a first page of the paper facing the scanning module. Then, the paper is flipped for a second page of the paper facing the scanning module. The switching member can be selectively moved for guiding the paper passing through the first paper feeding channel or the second paper feeding channel.

Abstract: A printing system for duplex printing of a banner media is disclosed. The printing system includes a drive roll, a pair of nipping rolls abuttingly coupled to the drive roll forming a first nip and a second nip with the drive roll, a media path including a printing region and a duplex region, and a diverter disposed in the media path and coupled to the drive roll. A first side of the banner media is printed in the printing region and exited partially from the first nip. Further, the partially exited banner media is re-fed into the duplex region and transferred to the printing region to print the second side of the banner media and exited from the second nip. The duplex region is capable of receiving the banner media from the first nip and the printing region is capable of exiting the banner media from the second nip simultaneously.

Abstract: A double-sided image forming apparatus includes front-side and rear-side image forming units arranged in the transporting direction in which a recording medium is transported. Each of the image forming units includes an endless belt that transports the recording medium and a recording section that records on the recording medium. The belt transfers the recording medium from one of the adjacent front-side or rear-side image forming units to the other image forming unit such that part of the recording medium is transported onto part of the belt of the other image forming unit. The recording section of each image forming unit is configured to perform recording in a single color. The image forming units are arranged so that the front and rear sides are alternately subjected to recording on a color-by-color basis in the order of the front side, the rear side, the front side, and the rear side.

Abstract: An image reading apparatus is provided with a first image reading unit and a second image reading unit. The first image reading unit reads an image on a first side of a document that is transported in a predetermined direction on a document transport path, at a first image reading position. The second image reading unit reads an image on a second side of the document that is transported in the predetermined direction on the document transport path, at a second image reading position. A transport roller and a bent portion of the document transport path are arranged in this order along the document transport direction upstream of each of the first image reading position and the second image reading position in the document transport direction.

Abstract: A removable duplex unit for an image forming peripheral having a simplex media feedpath and a reversible roller for moving media in a first direction through the peripheral and in a second direction through the duplex unit, includes an auxiliary housing adapted to be removably connected to the image forming peripheral, the auxiliary housing having therein a curved duplex media feedpath of a preselected length extending through the auxiliary housing in feeding communication with the reversible roller in the simplex media feedpath wherein the duplex feedpath in the auxiliary housing is passive and does not provide energy to media passing through the duplex media feedpath.

Abstract: A registration and measurement system for a printing machine includes two drive rollers and two opposing idler rollers. Each drive roller and idle roller combination respectively form a drive nip. A single servo or stepper motor is operably connected to the drive rollers through a gear train, allowing the motor to drive the sheet feeding nips. A rotary encoder is attached to each idler roller. Optical sensors are provided above a desired sheet path. The optical sensors and the rotary encoders are connected to a controller and are operable to deliver output signals to the controller. The controller is operable to determine the length of a sheet passing through the nips based upon the signals received from the optical sensors and the rotary encoders.

Abstract: An automatic document feeder for duplex scanning includes a scanning module, a pickup roller assembly, a first discharging roller assembly, a second discharging roller assembly, a first path, a second path, a third path, a sheet feeding tray, a first discharging tray and a second discharging tray. The first discharging tray is used as a reverse region. Since only the scanning module inside the automatic document feeder is used for scanning the document without the participation of the flatbed image scanning portion, the operative space for accommodating the scanning module in the flatbed image scanning portion is not required. As a result, the length and the overall volume thereof are reduced.

Abstract: A double-sided image forming apparatus includes a line-recording front-side image forming apparatus and a line-recording rear-side image forming apparatus which are arranged in a transportation direction of a recording medium, in which each of the front-side image forming apparatus and the rear-side image forming apparatus includes a drum, a roller having a smaller diameter than the drum, an endless belt wound around the drum and the roller, a driving power source which transports the belt by rotating the drum, and a line-recording recording unit placed to face an outer circumferential surface of the drum so as to be able to perform recording with respect to the recording medium which is laid on the outer circumferential surface of some portion of the belt which is wound around the drum.

Abstract: A sheet feeding device including: a sheet feeding roller for sending sheets out one-by-one; a sheet stacking section in which a plurality of sheets can be stacked, and which pushes a sheet against the sheet feeding roller; an upper guide member able to move between a guiding position at which, at a time of double-sided printing, the upper guide member re-feeds to the image forming section an inverted sheet which is sent-in by a sheet re-feeding section, and a withdrawn position, at which sheet feeding of the sheet stacking section is possible; and a lower guide member which is rotatable and which abuts leading ends of sheets stacked in the sheet stacking section, wherein a guide path, which guides a sheet which is re-fed at the time of double-sided printing, is formed due to the upper guide member and the lower guide member rotating interlockingly.

Abstract: An image forming apparatus includes: an apparatus main body that is provided with an image forming section that forms image on a sheet; a first guide member that guides the sheet along a sheet conveying path and is configured to be displaceable relative to the apparatus main body; a second guide member that guides the sheet along the sheet conveying path and is configured to be displaceable relative to the apparatus main body; and a single detecting unit that detects that both of the first guide member and the second guide member are respectively disposed at normal guide positions for guiding the sheet.

Abstract: Sheet print media are printed/marked with both transient and permanent marking which may be juxtaposed or the transient marking overprinted to change the meaning or message of text on the appearance of an image over time. Applications include advertising and labels for articles of commerce. The method applies to plain paper or coated print media for subsequent ultraviolet radiation.

Abstract: A sheet supplying device, which supplies a sheet to an image forming section, has a sheet feeding roller, a sheet stacking section, and a guiding member. The sheet feeding roller sends sheets out one-by-one. The sheet stacking section can be stacked with plural sheets and pushes a sheet against the sheet feeding roller. The guiding member is able to move between a guiding position and a withdrawn position. At the guiding position, at a time of double-sided printing, the guiding member re-supplies to the image forming section an inverted sheet which is sent-in by a sheet re-supplying section. At the withdrawn position, the guiding member is moved toward the sheet feeding roller and feeding of the sheet of the sheet stacking section is possible.

Abstract: There is provided a method to image a dual-sided thermal media including a plurality of contiguous, alternating first and second thermally imageable panels distinguished by one or more associated sense marks, each of the imageable panels including a first and second imageable sides. The method includes determining a starting panel of the alternating first and second thermally imageable panels of the thermal media on which to start imaging one or more received pages of data, determining a starting side of the first and second imageable sides of the starting panel according to number of the one or more received pages of data, advancing the thermal media to the starting panel using at least one of the of the one or more associated sense marks, and imaging the thermal media with the one or more received pages of data starting at the determined starting side of the advanced to determined panel.

Abstract: An image forming apparatus transfers a toner image on a recording medium in a transfer unit and fixes the toner image on the recording medium in a fixing unit. The image forming apparatus performs duplex image formation in a first mode and a second mode. The first mode is a mode in which a toner image is transferred and fixed on a second side of a recording medium after a toner image is transferred and fixed on a first side thereof. The second mode is a mode in which, after a toner image is transferred and fixed on a first side of a recording medium fed at first, a second side of the recording medium is subjected to fixing without transferring thereon a toner image.

Abstract: A method for achieving accurate page margins on a media and a duplex imaging apparatus thereof. The method comprises: detecting a leading edge position by an edge sensor and a first left-to-right position of the media by an alignment sensor in a first imaging path; imaging a first side of the media in a print zone of the duplex imaging apparatus; removing the media from the print zone and disposing the media in a second imaging path; detecting a leading edge position by the edge sensor and a second left-to-right position of the media by the alignment sensor; determining a carrier reset distance by calculating a difference between first and second left-to-right positions, and shifting a print image by a distance substantially equal to the carrier reset distance thereby achieving accurate page margins for imaging a second side of the media with the print image. In another embodiment, the first left-to-right position can be determined by feeding the media into a preset first left-to-right position.

Abstract: A housing body includes a first part forming a part of a first transporting path in which a medium is transported. An image forming unit is accommodated in the housing body and is adapted to form an image onto at least one face of the medium. A door cover is attached to the housing body, and the door cover includes a second part adapted to face the first part when the door cover is closed, thereby forming the part of the first transporting path together with the first part. A double-sided printing unit is detachably mounted to the second part and includes a second transporting path. The second transporting path is connected to the first transporting path and is adapted to transport the medium while turning inside out, so that the image forming unit forms images on both sides of the medium.

Abstract: An image input scanner having two scan heads for simultaneous scanning of both sides of a sheet includes two calibration surfaces. A first calibration surface is disposed on the carriage on which a first scan head is mounted. A second calibration surface is disposed on the document handler.

Abstract: A two-side image forming apparatus of the present invention is provided with a first sheet-transferring path, for use in one-side image formation, for transferring, to a printed sheet storage section via an image transcribing section, a sheet supplied from an unprinted sheet storage section; and a second sheet-transferring path, connected to the first sheet-transferring path, for supplying a tuned-over one-side printed sheet to the image transcribing section, the two-image forming apparatus being controlled so that a plurality of sheets are transferred concurrently in an overall sheet-transferring path when performing two-side image forming operation, the overall sheet-transferring path including the first sheet-transferring path and the second sheet-transferring path. With this arrangement, it is possible to attain a significant improvement in process efficiency.

Abstract: The present invention is an image forming apparatus having no two-sided printing mechanism in which, by setting a front side printed paper sheet in a manual paper feed section, the paper sheet is taken from the manual paper feed section and a back side printing is executed. At this moment, when a paper detecting switch 24 detects presence of a paper sheet on a manual paper feed tray 23 at the end of the front side printing, a message meaning to remove the paper sheet and thereafter to set the front side printed paper sheet is given. Whether the paper sheet is removed or not is detected according to a change-over of the paper detecting switch 24, and the back side printing is executed after the paper sheet is removed and the front side printed paper sheet is set. As a result, erroneous back side printing on an improper paper sheet can be prevented and a two-sided printing can be correctly executed.

Abstract: A method of printing with a duplexed printhead print assembly having first and second print engines arranged in an opposing in-line sequential configuration along a paper path. The method includes the steps of pushing a top sheet of paper from a paper tray of the print assembly past a paper sensor of the first print engine of the printhead, drawing said sheet into the first print engine, and sensing a position and size of the sheet using the paper sensor. The method also includes the steps of printing image data onto the sheet via the first and second print engines, and binding the printed sheet into a document using a binding assembly of the print assembly.

Abstract: When first print information is input, a print length thereof is calculated so as to calculate a length of a double-sided printed material 1 to be finally produced. Then, print information blocks 2 to be printed on a back surface of the recording medium is selected. The print information blocks 2 are selected according to a priority thereof, and a single print information block 2 to be selected last is selected, based on the length of the double-sided printed material, so that all the margins have the same length within a predetermined allowable range when the selected print information blocks 2 are sequentially arranged to be printed on the back surface. After the second print information is thus determined, the first print information is printed on the front surface of the recording medium and is cut by a cutter unit, and then the second print information is printed on the back surface thereof.

Abstract: A duplex/simplex automatic sheet feeder includes a sheet input tray, a sheet output tray, a first sheet-feeding path, a temporary storage region, a first sheet-feeding mechanism, a second sheet-feeding path and a second sheet-feeding mechanism. The temporary storage region and the first sheet-feeding mechanism are configured such that in a simplex feeding mode a sheet from the first sheet-feeding path is transferred to the sheet output tray through the temporary storage region, and in duplex and simplex feeding modes the sheets in the sheet output tray are arranged in the same order as in the sheet input tray.

Abstract: A document handling system includes an imaging area; a light source located in proximity to the imaging area; a raster imaging scanning system located in proximity to the imaging area; and a looped document path, located in proximity to the imaging area, having an entrance and an exit. The exit of the looped document path is positioned such that an exiting document is placed upon the imaging area a second time. Alternatively, the document handling system includes a semicircular document path, located in proximity to a first imaging area, having an entrance and an exit; and a second imaging area located in proximity to the exit of the semicircular document path. A bi-directional fiber optic element is located between the first and second imaging areas to transmit light from the light source to the second imaging area and light reflected from the second imaging area to the first imaging area.

Abstract: A printing apparatus includes a base coupled to a copying device and a printing device. A feed mechanism is provided which is operable to couple to the base in one of either a first position or a second position, whereby the feed mechanism is operable to feed a document to the copying device in the first position and the feed mechanism is operable to manipulate a printing medium to allow the printing device to print to a plurality of sides of the printing medium in the second position.

Abstract: An image forming apparatus includes: an image forming apparatus main body; an image forming section that is arranged within the image forming apparatus main body, and that forms an image in a recording medium; a discharging member that discharges the recording medium on which the image is formed by the image forming section; a driving source that normally and reversely rotates the discharging member; and a both-face printing assembly body that returns the recording medium pulled-back by reversely rotating the discharging member to the image forming section, the driving source and the both-face printing assembly body being separately freely attached and detached with respect to the image forming apparatus main body.

Abstract: An image forming apparatus and an image forming method using the same. The image forming apparatus includes a discharge unit which has a driving roller rotating in forward and reverse directions and first and second driven rollers engaged with the driving roller to rotate together therewith, a duplex print unit which feeds the paper again to a developing unit so that the paper printed on a first surface is subsequently printed on a second surface, and a control unit which controls a rotational direction of the driving roller so as to move a first sheet of paper between the driving roller and the first driven roller and move a second sheet of paper between the driving roller and the second driven roller. Accordingly, the image forming apparatus is capable of controlling the forward movement of the second sheet of paper without interference with the reverse movement of the first sheet of paper, thereby decreasing a time required to perform duplex printing.

Abstract: Embodiments of device and methods for winding media are illustrated and described.

Abstract: An image forming system includes a document conveying section that reversely conveys documents such that a front side and back side of the documents pass through a reading position, an image reading section for reading images on the documents conveyed to the reading position and generating image data, an image forming section for forming images on recording media, according to the image data, an input section for inputting designation whether the images are to be formed on both sides or on one side of the recording media, and a control section for controlling image reading by the image reading section and image forming by the image forming section, wherein the control section controls the image forming section to form an image according to image data in a condition where a single job includes both single-sided and double-sided image recording, correspondingly to the designation inputted via the input section.

Abstract: When a recording material is conveyed to a double surface conveying portion, a second conveying roller pair is forward driven to convey the recording material conveyed by a first conveying roller pair forward driven. A control portion performs control so that the driving of the second conveying roller pair is stopped and the second conveying roller pair is separated in timing in which the first conveying roller pair is switched from forward driving to reverse driving.

Abstract: The present invention realizes resource saving and energy saving by grasping and managing a usage efficiency of an image forming apparatus. To accomplish this, a method in accordance with the present invention is an information processing method of managing usage information on a job which is issued from an information processing apparatus to an image forming apparatus, which includes: a step of acquiring the usage information from the information processing apparatus or the image forming apparatus; a step of deriving the number of logical pages and the number of physical sheets from the usage information acquired in the acquisition step; and a step of outputting usage efficiency information of the image forming apparatus using the number of logical pages and the number of physical sheets derived in the derivation step.

Abstract: In an information processing apparatus when the body pages are set to start from the back side of the cover, the cover is printed on the first side of the first sheet, the first page of the body is printed on the second side of the first sheet, and the second and subsequent pages of the body are printed on both sides of the second and subsequent sheets. When the body pages are set to start from a sheet different from the cover, the cover is printed on the first side of the first sheet, only a background image of the cover is printed on the second side of the first sheet, which is the back side of the cover, and the body pages are printed on both sides of the second and subsequent sheets.

Abstract: In the system and method, a conveyor having a sequence of sheet supports is moved through a printer. During a first pass: two-side printable sheets are placed into sheet supports of a first segment of the sequence; one-pass printable sheets are excluded from a skipped second segment of sheet supports, and the two-side printable sheets are verso-printed. The printed sheets are then flipped. During a second pass: the two-side printable sheets are recto-printed; one-pass printable sheets are introduced into the second segment and are recto-printed. The printed sheets are delivered to an output holder in order. The one-pass printable sheets have a printable recto side and a ventro side that is a vector of contamination to the printer, at least when printed second.

Abstract: An apparatus and method for printing images on both sides of a recording medium. The timing of starting conveying the next recording medium is determined from a schedule that satisfies three conditions. The first condition a leading end of the next medium reaches a housing section, while maintaining a page gap, when the medium passes completely through the housing section. The second condition both media are not at a recording-medium supply position and the leading end of the next medium reaches the supply position, while maintaining a page gap, when the medium passes completely through the supply position. The third condition when the medium is turned upside down, both media are not at a reversing path section, and the leading end of the next medium reaches the reversing path section, while maintaining a page gap, when the medium passes completely through the reversing path section.

Abstract: Provided is an image forming apparatus including an image forming section forming images on image forming faces of a recording medium, a condition setting section individually setting an operating condition of the image forming section for forming the image on a first image forming face of a recording medium and another operating condition of the image forming section for forming the image on a second image forming face of the recording medium opposite to the first image forming face in the manual duplex mode, and a control section controlling the image forming section on the basis of each operating condition set by the condition setting section.

Abstract: An image forming apparatus includes a first frame plate and a second frame plate, which has an extended portion horizontally extending by a predetermined length compared with the first frame plate. The first and second frame plates are oppositely disposed spaced apart by a predetermined width from each other. An open and close unit, which includes a recording medium conveying system, is disposed within an area of the extended portion between the first and second frame plates and is configured to freely open and close with respect to the image forming apparatus. And a drive controlling mechanism is configured to control the recording medium conveying system. The extended portion supports at least a portion of the drive controlling mechanism so as to be separately mounted on a side of the image forming apparatus.

Abstract: A method of operating a fuser for duplex printing includes equilibrating the fuser roll surface temperatures by rotating the rolls at a speed faster than the process speed between fusing an image on a first side of the media and fusing an image on a second side of the media.

Abstract: An image reader has an original tray for feeding an original from a bundle of originals, a first transport passage for transporting the original fed by the original tray, a scanner for reading an image on one side of the original from one side of the transported original, and a CIS for reading an image on the other side of the original from the opposed side to the one side of the transport passage. To read both sides of an original, the image reader is provided with a mode of reading both sides simultaneously using the scanner and the CIS and a mode of reading both sides of the original only by the scanner with the original reversed using a third transport passage, a fourth transport passage, and a fifth transport passage without using the CIS.

Abstract: An image forming apparatus operating in a double-sided print mode, includes a charger for charging an image carrier, a charge voltage loader for applying a charge voltage to the charger, an image forming device for forming an image on a recording material, and a controller for controlling the charge voltage applied by the charge voltage loader to the charger. When an image is formed on both sides of a plurality of recording materials, the controller changes the charge voltage applied by the charge voltage loader from a first to a second voltage when an image is formed on first and second sides of the recording material in a period in which an image is formed on the recording sheet, and does not change the charge voltage during an interval between a first recording material and a second recording material to the second charge voltage.

Abstract: The image processing apparatus comprises a reading unit which simultaneously reads image data from two, an obverse and a reverse, surfaces of a document, and a compressing unit which compresses received image data. The apparatus further comprises a controlling unit which orchestrates a flow of image data from the reading unit to the compressing unit in such a manner that the image data corresponding to the obverse surface and the reverse surface is input into the compressing unit at different timing.