Image forming apparatus

Abstract

To reduce the occurrence of a difference in image size in spread pages.SOLUTION: An image forming apparatus comprises transfer means, fixing means, binding means, and control means. The control means causes the transfer means to transfer a first image to a first sheet before the first sheet initially passes through the fixing means, causes the fixing means to fix the first image to the first sheet, causes the transfer means to transfer a second image to a second sheet before the second sheet initially passes through the fixing means, causes the fixing means to fix the second image to the second sheet, conveys the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and causes the binding means to bind the first sheet and the second sheet to manufacture a product in which the first image and the second image are formed on spread pages.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that forms an image on a sheet. [Background technology]

[0002] Patent Document 1 describes a sheet bonding device that bonds sheets coated with toner as an adhesive together by heating and pressurizing the stacked sheets, and an image forming apparatus equipped with the same. Patent Document 2 describes a method of printing an original image onto multiple sheets of printing paper in a layout, and printing on the printing paper information indicating the order in which the multiple sheets of printing paper are to be bonded together and the boundaries of the overlap areas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-209859 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-289660 Summary of the Invention [Problem to be solved by the invention]

[0004] In an image forming apparatus, two sheets each having an image formed thereon are stacked with the images facing each other and bound together to produce a finished product with images formed on a double-page spread. However, due to the heat received from the fixing device, the sheets shrink, which can cause a difference in image size between the two sheets that make up the double-page spread, and as a result, the image quality of the double-page spread can be reduced.

[0005] Therefore, the present invention can provide an image forming apparatus that is less likely to produce differences in image size between two-page spreads. [Means for solving the problem]

[0006] One aspect of the present invention is an image forming apparatus comprising a transfer means for transferring an image onto a sheet, a fixing means for heating the sheet to fix the image onto the sheet, a binding means for binding multiple sheets together, and a control means, wherein the control means transfers a first image onto a first sheet using the transfer means before the first sheet passes through the fixing means for the first time, fixes the first image onto the first sheet using the fixing means, transfers a second image onto a second sheet using the transfer means before a second sheet passes through the fixing means for the first time, fixes the second image onto the second sheet using the fixing means, transports the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and binds the first sheet and the second sheet together using the binding means, thereby producing a finished product in which the first image and the second image are formed on a double-page spread.

[0007] Another aspect of the present invention is an image forming apparatus comprising a transfer means for transferring an image onto a sheet, a fixing means for heating the sheet to fix the image onto the sheet, a binding means for binding multiple sheets together, and a control means, wherein the control means causes the transfer means to transfer a first image onto the first sheet after the first sheet has passed through the fixing means at least once and fix the first image onto the first sheet, and causes the transfer means to transfer a second image onto the second sheet after the second sheet has passed through the fixing means at least once and fix the second image onto the second sheet, transports the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and binds the first sheet and the second sheet together using the binding means, thereby producing a finished product in which the first image and the second image are formed on a double-page spread. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an image forming apparatus in which differences in image size between two-page spreads are less likely to occur. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the hardware configuration of an image forming apparatus according to a first embodiment. [Figure 2] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Figure 3] FIG. 2 is a view showing a buffer unit of the sheet processing apparatus according to the first embodiment. [Figure 4] 3A to 3F are explanatory views (a to f) of a thermocompression bonder according to the first embodiment. [Figure 5] 3 shows an example of a toner image formed by the image forming apparatus according to the first embodiment. [Figure 6] FIG. 2 is an explanatory diagram of a method for producing a double-page spread product in the first embodiment. [Figure 7] 10 is a flowchart showing the procedure of a double-page spread product creation job in Comparative Example 1. [Figure 8] 10 is a flowchart showing the procedure of a double-page spread product creation job in the first embodiment. [Figure 9] 10 is a flowchart showing the procedure of a double-page spread product creation job in the second embodiment. [Figure 10] FIG. 10 is a schematic view of an image forming apparatus according to a second embodiment. [Figure 11] 10 is a flowchart showing the procedure of a double-page spread product creation job in the second embodiment. [Figure 12] FIG. 10 is an explanatory diagram of a method for producing a double-page spread product in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] In this disclosure, the term "image forming apparatus" broadly includes apparatuses that form (record) images on recording materials (recording media), such as single-function printers, copiers, multifunction machines, commercial printing machines, etc. The image forming apparatus may also be a system (image forming system) that connects an image forming apparatus main body that forms an image on recording materials with devices such as a sheet processing apparatus and a sheet feeding apparatus.

[0012] First Embodiment Fig. 1 is a block diagram showing the hardware configuration of an image forming apparatus 100 according to the first embodiment. Fig. 2 is a schematic diagram of the image forming apparatus 100 according to the first embodiment.

[0013] As shown in FIG. 1, the image forming apparatus 100 includes a CPU 200, a ROM 201, a RAM 202, an HDD 203, an image forming unit 101B, an operation unit 205, a conveying unit 206, a thermocompression bonding unit 167, and a network interface (IF) 208.

[0014] The CPU 200 functions as a control unit (controller) that controls the operation of the image forming apparatus 100. The CPU 200 is connected to the ROM 201, the RAM 202, and the HDD 203 via a bus, and executes various programs stored in the ROM 201 to perform, for example, an image forming operation. Note that some of the functions of the CPU 200 in this embodiment may be performed by a control device other than the CPU 200, such as a processor mounted on the sheet processing apparatus 106. In this case, the CPU 200, together with the control device that cooperates with the CPU 200, constitutes a control unit (controller) that controls the operation of the image forming apparatus 100.

[0015] Various control data used by the CPU 200 when performing an image forming operation is stored in RAM 202. The HDD 203 stores, for example, image information (print data) to be formed on a recording material during the image forming operation. The operation unit 205 includes a display unit such as a liquid crystal panel that displays information to the user, and an input unit that accepts input of setting information and a request to start the image forming operation (print instruction) from the user. The conveying unit 206 includes conveying members such as conveying rollers that convey a sheet S as a recording material (recording medium, print medium), and various motors that drive the conveying members. The thermocompression bonding unit 167 will be described later.

[0016] CPU 200 receives print data from an external computer connected via network IF 208, or receives print data from a document reading device connected to image forming apparatus 100. When CPU 200 receives a print instruction via the external computer or operation unit 205, it controls the loads (motors, power supply boards, etc.) of image forming unit 101B and conveying unit 206 to perform image formation operations. In addition, based on conditions specified by the user when the print instruction was input, it performs thermocompression processing (described later) using thermocompression bonding unit 167 as necessary.

[0017] 2, the image forming apparatus 100 includes a printer main body 101 as an image forming apparatus main body having an image forming function (printing function), and a sheet processing apparatus 106 having a sheet bonding function. In other words, the image forming apparatus 100 can be said to be an image forming system configured by the printer main body 101, which functions as an image forming apparatus even when functioning alone, and the sheet processing apparatus 106.

[0018] The image forming apparatus 100 of this embodiment forms an image on each sheet S in the printer main body 101, and then heat-presses the multiple sheets S together in the sheet processing apparatus 106, thereby producing a finished product such as a booklet that has been printed and bound in a single apparatus. Note that the sheets S can be made of a variety of sheet materials of different sizes and materials, such as plain paper or cardboard, surface-treated sheet materials such as coated paper, plastic film, cloth, or sheet materials of special shapes such as envelopes or index paper.

[0019] (printer body) The printer main body 101 is an electrophotographic device that includes a housing 101A and an electrophotographic image forming section 101B housed inside the housing 101A.

[0020] Image forming unit 101B includes an intermediate transfer belt 108 as an intermediate transfer member, a plurality of process cartridges arranged along intermediate transfer belt 108, a scanner unit 104 as exposure means, and a primary transfer roller 107. Image forming unit 101B in this embodiment includes four process cartridges 195y, 195m, 195c, and 195k corresponding to four colors: yellow, magenta, cyan, and black.

[0021] Process cartridge 195k uses black toner Tk to form a monochrome image corresponding to the black component of a color image. Process cartridge 195y uses yellow toner Ty to form a monochrome image corresponding to the yellow component of a color image. Process cartridge 195m uses magenta toner Tm to form a monochrome image corresponding to the magenta component of a color image. Process cartridge 195c uses cyan toner Tc to form a monochrome image corresponding to the cyan component of a color image.

[0022] The process cartridge 195k includes a photosensitive drum 102 as a photosensitive member, a charging device 103 as a charging means, and a developing unit 105 as a developing means. In Fig. 2, only the above elements of the process cartridge 195k are shown, but the other process cartridges 195y to 195c have the same structure.

[0023] The monochromatic images formed in the process cartridges 195y, 195m, 195c, and 195k are primarily transferred onto the intermediate transfer belt 108 so as to be superimposed on one another, and then secondarily transferred onto a sheet at the secondary transfer portion.

[0024] The developing unit 105 includes a developing roller 105a as a developer carrier and a toner container 105b that contains toner (developer). The developing roller 105a is rotatably held by the toner container 105b. Although only the developing unit 105 in the process cartridge 195k is shown in FIG. 2, the developing units in the other process cartridges 195y to 195c have the same structure.

[0025] The process cartridges 195y, 195m, 195c, and 195k are detachably attached to the housing 101A. The "housing 101A" of the printer main body 101 refers to the printer main body 101 excluding the process cartridges 195. The housing 101A includes frame members such as a metal frame that form the frame of the printer main body 101 and members fixed to the frame, and forms an attachment space into which the process cartridges 195 are attached.

[0026] The printer main body 101 can use at least one of the multiple color toners as a toner for adhering sheets together. For example, black toner Tk can be used as both a toner for recording an image on a sheet (printing toner) and an adhesive toner (powder adhesive). In this case, the process cartridge 195k forms a monochrome image corresponding to the black component of the color image and an adhesive toner image 39 (FIG. 5) to be transferred to the adhesive area of ​​the sheet.

[0027] A scanner unit 104 serving as an exposure unit is disposed below the process cartridge 195 within the housing 101A. A cassette 113 (also called a sheet tray or storage) serving as a storage unit for storing sheets S used in image formation is attached to the housing 101A below the scanner unit 104 so as to be removable from the housing 101A. Furthermore, one or more optional sheet feeding devices 130 including additional cassettes 113 may be connected below the housing 101A.

[0028] The intermediate transfer belt 108 is a movable (rotatable) endless belt that is stretched around a drive roller 109a, a stretching roller 109b, and a tension roller 110 that rotate about parallel axes. The intermediate transfer belt 108 moves (rotates, conveys) counterclockwise in the drawing due to the rotation of the drive roller 109a. A primary transfer roller 107 as a primary transfer member is disposed on the inner circumferential side of the intermediate transfer belt 108, facing the photosensitive drum 102 with the intermediate transfer belt 108 interposed therebetween. A secondary transfer roller 111 as a transfer member (secondary transfer member) is disposed on the outer circumferential side of the intermediate transfer belt 108, facing the drive roller 109a with the intermediate transfer belt 108 interposed therebetween. A secondary transfer portion as a transfer portion is formed as a nip portion between the intermediate transfer belt 108 and the secondary transfer roller 111.

[0029] The secondary transfer roller 111 is an example of a transfer means that transfers a toner image from the intermediate transfer belt 108, which serves as an image carrier, to the sheet S. The intermediate transfer belt 108, the primary transfer roller 107, and the secondary transfer roller 111 form a transfer unit that transfers the toner image formed on the photosensitive drum 102 to the sheet S.

[0030] A fixing device 118 serving as a fixing means is disposed above the secondary transfer unit within the housing 101A. The fixing device 118 employs a thermal fixing system that fixes a toner image by applying heat. The fixing device 118 includes a heating element that heats the toner image on the sheet S, a pressure element that forms a nip (fixing nip) together with the heating element, and a heat source that heats the heating element. The heating element and pressure element may each be a roller, a cylindrical film, or an endless belt stretched over multiple rollers. The heat source may be, for example, a heater substrate on which a pattern of heating resistors is printed on a ceramic substrate, a halogen lamp that emits radiant heat, or a coil unit that uses electromagnetic induction to heat a conductive layer in the heating element.

[0031] As an example, fixing device 118 has a cylindrical film (heating member), a heater substrate disposed in the internal space of the film, and a pressure roller (pressure member) that is pressed against the heater substrate across the film to form a fixing nip between the film and the heater substrate. In this case, fixing device 118 heats the toner image on sheet S with the film heated by the heat of the heater substrate while sandwiching and transporting sheet S in the fixing nip.

[0032] The housing 101A also accommodates various conveying members that make up the conveying section 206 (FIG. 1). The printer main body 101 in this embodiment has, as conveying members, a feed roller 114, a separation roller pair 115, a pull-out roller pair 116, a registration roller pair 117, and a discharge roller pair 191.

[0033] (Image formation operation) When the printer main body 101 performs an image forming operation, a sheet S is fed by a feed roller 114 serving as a feeding means from a cassette 113 at the bottom of the housing 101A or from a cassette 113 of the sheet feeding device 130. A separation roller pair 115 separates and transports the fed sheets S one by one. The sheet S is transported by a drawing roller pair 116 toward a registration roller pair 117, and any skew of the sheet S is corrected when the leading edge of the sheet S hits the nip portion of the registration roller pair 117, which is in a stopped state. The registration roller pair 117 sends the sheet S to a secondary transfer unit at a timing synchronized with the formation of a toner image by the image forming unit 101B.

[0034] Meanwhile, in the image forming section 101B, the photosensitive drum 102 and the intermediate transfer belt 108 rotate, and a toner image is formed in each of the process cartridges 195y to 195k. The charging device 103 uniformly charges the surface of the photosensitive drum 102. The scanner unit 104 writes an electrostatic latent image by irradiating the photosensitive drum 102 with laser light based on print data representing an image to be recorded on the sheet S. The developing unit 105 develops this electrostatic latent image using toner, thereby developing (visualizing) it as a toner image.

[0035] Here, when the sheet processing device 106 performs thermocompression bonding, which will be described later, the scanner unit 104 writes an electrostatic latent image by irradiating the photosensitive drum 102 with laser light based on information indicating the bonding position of the sheet S. This electrostatic latent image is developed by the developing unit 105 using toner, and an adhesive toner image is formed on the surface area of ​​the photosensitive drum 102 that corresponds to a predetermined area (adhesion area) on the sheet S.

[0036] Monochrome images formed on the photosensitive drums 102 in each of the process cartridges 195y, 195m, 195c, and 195k are primarily transferred onto the intermediate transfer belt 108 so as to be superimposed on one another. As a result, toner images are formed as color images on the intermediate transfer belt 108. The color images are transported toward the secondary transfer unit by the rotation of the intermediate transfer belt 108. Then, at the secondary transfer unit, a voltage is applied to the secondary transfer roller 111, so that the toner image is transferred (secondary transfer) onto the sheet S fed from a pair of registration rollers 117. The sheet S that has passed through the secondary transfer unit is sent to the fixing device 118, and the toner image is heated and pressurized while passing through the fixing nip, softening the toner, and then fixing the image onto the sheet S.

[0037] After passing through the fixing device 118, the conveying path of the sheet S is switched by a switching unit 119. In the case of single-sided printing, the sheet S is guided to a discharge path 190 by the switching unit 119 and is discharged from the housing 101A by a pair of discharge rollers 191. In this embodiment, the printer main body 101 is connected to the sheet processing device 106 via a relay conveying unit 192. The sheet S discharged from the pair of discharge rollers 191 is delivered to the sheet processing device 106 via pairs of conveying rollers 193 and 194 of the relay conveying unit 192. Furthermore, when the relay conveying unit 192 and the sheet processing device 106 are not connected, the pair of discharge rollers 191 discharges the sheet S as a product onto a stacking tray 135 provided at the top of the housing 101A.

[0038] In the case of double-sided printing, the sheet S, on which an image has been formed on one side (front side), is guided to the reversing roller pair r1 by the switching unit 119. Then, the sheet S is reversed and conveyed (switchback conveyed) by the reversing roller pair r1, and then conveyed toward the registration roller pair 117 via the double-sided conveying path r2. The double-sided conveying unit 134, which includes the reversing roller pair r1 and the double-sided conveying path r2, functions as a re-conveying unit that conveys the sheet S, which has passed through the secondary transfer unit and the fixing device 118, toward the secondary transfer unit again. Thereafter, the sheet S passes through the secondary transfer unit and the fixing device 118, whereby an image is also formed on the other side (back side), and then the sheet S is discharged from the housing 101A by the discharge roller pair 191. As will be described later, it is also possible to perform conveying control such that the sheet S is reversed by the reversing roller pair r1 two or more times in the printer main body 101, and then discharged from the printer main body 101 after passing through the secondary transfer unit and the fixing device 118 three or more times.

[0039] 5 is a diagram showing an example of a toner image formed on a sheet S. The illustrated sheet S has formed thereon a recording toner image 38, which is a toner image for recording images such as text, figures, and photographs, and an adhesive toner image 39, which is a toner image for adhering sheets together. In the illustrated example, the adhesive toner image 39 is formed along one side (long side) of the A4-sized sheet S. The position, shape, size, etc. of the adhesive toner image 39 can be changed to suit the configuration of the thermocompression bonding unit 167, which will be described later.

[0040] (sheet processing device) The sheet processing apparatus 106 will now be described. As shown in FIG. 2, the sheet processing apparatus 106 includes a buffer section 120 as a buffer means for stacking multiple sheets S, an intermediate stacking section 156 on which the multiple sheets S are stacked, and a thermocompression bonding section 167 for thermocompression bonding the sheets S together. The thermocompression bonding section 167 is an example of a binding means (binding unit) for binding multiple sheets S together. The thermocompression bonding section 167 of this embodiment is a unit (adhesion unit, thermocompression bonding unit) that bonds the sheets S together by applying heat and pressure to the sheets S to which adhesive toner is applied as an adhesive. The sheet processing apparatus 106 also includes an upper discharge tray 125 and a lower discharge tray 137, which can be raised and lowered, as discharge destinations for discharging the products of the image forming apparatus 100. The buffer section 120, the intermediate stacking section 156, and the thermocompression bonding section 167 will be described in detail below.

[0041] The sheet processing apparatus 106 can receive sheets S on which images have been formed by the printer main body 101 one by one, and perform a thermocompression bonding process using a thermocompression bonding unit 167 in a state where multiple sheets S are stacked together to produce a bonded product. Bonded products that the sheet processing apparatus 106 can produce include a final product in which images are formed on opposing surfaces of two sheets S and these images are bonded to form a double-page spread (hereinafter referred to as a double-page spread product). The sheet processing apparatus 106 can also produce a booklet in which three or more sheets S are bonded together. The sheet processing apparatus 106 can also discharge sheets S on which images have been formed by the printer main body 101 to the upper discharge tray 125 or the lower discharge tray 137 without performing any processing on them.

[0042] (Buffer section) The buffer unit 120 will be described with reference to Fig. 3. Fig. 3 is an enlarged cross-sectional view of the buffer unit 120. The buffer unit 120 includes an inlet roller pair 121, a pre-buffer roller pair 122, a check valve 123, a reversing roller pair 124, and an inner discharge roller pair 126. The buffer unit 120 also includes an inlet sensor 127 that detects a sheet, and a separation mechanism including a plunger solenoid 145 and the like for opening and closing (contacting and separating) the reversing roller pair 124.

[0043] The entrance roller pair 121, the pre-buffer roller pair 122, the reversing roller pair 124, and the inner discharge roller pair 126 are roller pairs that sandwich and transport a sheet. The entrance roller pair 121 and the pre-buffer roller pair 122 are arranged on a transport path (entrance path) through which the sheet processing device 106 receives the sheet S. The reversing roller pair 124 is arranged on a transport path (first discharge path, see FIG. 2) that communicates with the upper discharge tray 125. The inner discharge roller pair 126 is arranged on a transport path (inner discharge path, see FIG. 2) that runs from the reversing roller pair 124 toward the thermocompression bonding unit 167. The sheet processing device 106 also includes a transport path (second discharge path, see FIG. 2) that runs from the thermocompression bonding unit 167 toward the lower discharge tray 137.

[0044] The entrance path is formed by an upper entrance guide 140 and a lower entrance guide 141. The first discharge path is formed by an upper inverting guide 142 and a lower inverting guide 143. The inner discharge path is formed by an upper inner discharge guide 146 and a lower inner discharge guide 147.

[0045] The entrance sensor 127 is disposed so as to detect a sheet received by the pair of entrance rollers 121. The entrance sensor 127 may be, for example, a reflective photosensor that irradiates the entrance path with infrared light through an opening provided in the upper entrance guide 140 and detects the light reflected from the sheet to determine the presence or absence of the sheet S. The lower entrance guide 141 may be provided with a hole larger than the spot diameter of the infrared light emitted by the entrance sensor 127 so as not to reflect the infrared light when no sheet is passing through the entrance path.

[0046] The check valve 123 is disposed downstream of the pre-buffer roller pair 122 in the sheet conveying direction in the entrance path. The check valve 123 is disposed rotatably about a rotation shaft 123a relative to the inner discharge upper guide 146. The check valve 123 is movable between a first position that prevents the sheet from moving (backflowing) from the first discharge path to the entrance path and a second position that allows the sheet to move from the entrance path to the first discharge path. The check valve 123 is biased by a spring (not shown) in the direction C2 from the second position toward the first position. The check valve 123 is configured to move in the direction C1 from the first position toward the second position when pressed by the sheet, and to return to the first position after the sheet has passed.

[0047] When viewed in the direction of the rotation axis of the check valve 123, the tip of the check valve 123 in the first position overlaps with the inverted upper guide 142. In addition, the tip of the check valve 123 is formed in a comb shape so as to enable overlap with the inverted upper guide 142. In addition, when viewed in the direction of the rotation axis of the check valve 123, a space is formed between the check valve 123 in the second position and the inverted upper guide 142, allowing the sheet to pass through.

[0048] The pair of reversing rollers 124 is composed of an upper reversing roller 124a and a lower reversing roller 124b, and drive is supplied to both rollers. The upper reversing roller 124a and the lower reversing roller 124b are configured to rotate in sync at all times. A separation lever 144 is connected to the upper reversing roller 124a. The separation lever 144 is supported by the upper reversing guide 142 so as to be rotatable about a lever fulcrum shaft 144a. The separation lever 144 is rotatably connected to a plunger solenoid 145 at a solenoid connection shaft 144b.

[0049] When current flows through the plunger solenoid 145, the core moves in the direction D1 in the figure, and the separation lever 144 rotates in the direction E1 in the figure. In this case, the pair of reversing rollers 124 enters a separated state in which the upper reversing roller 124a and the lower reversing roller 124b are separated (a state in which the nip portion is open). Furthermore, when the current flowing through the plunger solenoid 145 is stopped, the biasing force of the pressure spring 148 causes the upper reversing roller 124a to move in the direction E2, and the core of the plunger solenoid 145 moves in the direction D2. In this case, the pair of reversing rollers 124 enters a contact state in which the upper reversing roller 124a and the lower reversing roller 124b are in contact (a state in which the nip portion is formed).

[0050] As will be described below, the buffer unit 120 performs an operation of stacking newly conveyed sheets on the sheets (stack) while moving the sheets (stack) back and forth between the pair of reversing rollers 124 and the pair of inner discharge rollers 126. By this operation, the buffer unit 120 can send sheets to the intermediate stacking unit 156 in a state where a predetermined number of sheets (for example, five sheets) are stacked.

[0051] 2, the stack of sheets stacked in the buffer unit 120 is transported from the inner discharge roller pair 126 to the kick-out roller pair 129 via the intermediate transport roller pair 128. Then, the sheet stack is transported by the kick-out roller pair 129 to an intermediate stacking unit 156 (processing tray) consisting of an intermediate upper guide 151, an intermediate lower guide 152, etc. In addition, downstream of the kick-out roller pair 129, a stack holding flag 150 is arranged to prevent the rear ends of the stacked sheets from floating up so that the rear ends of the sheets already stacked in the intermediate stacking unit 156 do not interfere with the leading ends of the succeeding sheets transported to the intermediate stacking unit 156.

[0052] In the intermediate stacking section 156, vertical alignment rollers 153 and horizontal alignment joggers 158 are arranged as alignment means for aligning the sheets S. The vertical alignment rollers 153 convey the sheets S in the sheet conveying direction and align the sheets by abutting the leading edge of the sheets S against a reference abutment member. The horizontal alignment jogger 158 aligns the sheets S by pressing one end of the sheets S in the sheet width direction perpendicular to the sheet conveying direction and abutting the other end of the sheets S against reference members (width alignment reference plates 172a and 172b, described later).

[0053] (Thermocompression part) The configuration and thermocompression bonding operation of the thermocompression bonding unit 167 will be described with reference to Figures 4(a) to 4(f). Each of Figures 4(a) to 4(f) is a view of the thermocompression bonding unit 167 as seen in the sheet conveyance direction (Y direction).

[0054] 4(a), the thermocompression bonding section 167 includes a heater section 171 (heating unit), a pressure stay 175, a receiving plate 180, a pressure mechanism 176, and width alignment reference plates 172a and 172b. The thermocompression bonding section 167 sandwiches the plurality of sheets S stacked on the intermediate stacking section 156 between the pressure plate 169 and the receiving plate 180 and applies heat and pressure to the sheets S, thereby performing a thermocompression bonding process as an example of a binding process for binding the plurality of sheets S.

[0055] The heater section 171 has a pressure plate 169 as a pressure member, a heater 168 as heating means, and a support member 170 that supports the pressure plate 169 and the heater 168. The support member 170 is supported by a pressure stay 175 and is movable in the Z direction integrally with the pressure stay 175. The Z direction is the height direction (stacking height direction, thickness direction) of the sheet bundle stacked in the intermediate stacking section 156.

[0056] The receiving plate 180 is disposed to face the pressure plate 169 in the Z direction. The receiving plate 180 is formed of an elastic material such as heat-resistant silicone rubber, and is supported on the frame of the thermocompression bonding unit 167. The pressure mechanism 176 includes a motor 177 as a drive source for reciprocating the pressure stay 175 in the Z direction and for applying pressure to the sheet stack.

[0057] The following describes the thermocompression bonding operation of thermocompression bonding unit 167, taking as an example a case where thermocompression bonding unit 167 produces a booklet consisting of ten sheets S1 to S10. In this example, one thermocompression bonding operation is performed every time five sheets that have been previously stacked in buffer unit 120 are loaded onto intermediate stacker 156.

[0058] 4(a) shows a state in which the alignment of the sheets S1 to S5 in the sheet conveying direction (Y direction) is completed. In this state, the heater portion 171 is located at a position separated from the sheet stack in the Z direction.

[0059] 4(b) shows a state in which the alignment of the sheets S1 to S5 in the sheet width direction (X direction) is completed. The sheets S1 to S5 are aligned by being abutted against width alignment reference plates 172a and 172b.

[0060] FIG. 4(c) shows a state in which the heater section 171 is moved in the pressure direction (-Z side) by the forward rotation of the motor 177, and the contact surface 169a (FIG. 4(a)) of the pressure plate 169 abuts against the uppermost sheet S5.

[0061] Fig. 4(d) shows a state in which sheets S1 to S5 are being thermocompression-bonded as sheets S1 to S5 are sandwiched between pressure plate 169 and receiving plate 180 by continuing forward rotation of motor 177. Fig. 4(d) also shows a state in which the next sheets S6 to S10 are being conveyed to intermediate stacker 156 in parallel with the thermocompression-bonding of sheets S1 to S5.

[0062] 4(e) shows a state in which, after the thermocompression bonding of sheets S1 to S5 is completed, the heater unit 171 moves (retreats) to the opposite side of the pressure application direction (+Z side) due to the reverse rotation of motor 177, and the pressure plate 169 moves away from sheet S5. Also, FIG. 4(e) shows a state in which the next sheets S6 to S10 are aligned, and sheets S1 to S5 abut against width alignment reference plates 172a and 172b after the heater unit 171 has retracted.

[0063] 4(f) shows a state in which the heater unit 171 is again moved toward the pressure application direction (-Z side) by the forward rotation of the motor 177, the sheets S1 to S10 are sandwiched between the pressure plate 169 and the receiving plate 180, and the sheets S6 to S10 are being thermocompression bonded together. Here, an adhesive toner image is formed on the upper surface of the sheet S5 and / or the lower surface of the sheet S6, so that the lower sheet stack (S1 to S5) and the upper sheet stack (S6 to S10) are bonded together to form a single product.

[0064] In this way, the thermocompression bonding unit 167 can produce a product consisting of more than the predetermined number of sheets by performing one thermocompression bonding operation each time a predetermined number of sheet stacks are stacked and aligned on the intermediate stacking unit 156. Here, an example has been described in which a booklet consisting of 10 sheets S1 to S10 is produced, but it is also possible to produce a booklet consisting of several tens of sheets or more.

[0065] When thermocompression bonding of all sheets constituting a part of a booklet is completed, the booklet made up of sheets S1 to S10 is pushed out of intermediate stacker 156 by a push-out member and conveyed toward bundle discharge roller pair 136 (FIG. 2). Bundle discharge roller pair 136 is a pair of rollers that can be opened and closed (contacted and separated), and receives the booklet in a separated state. When the leading edge of the booklet is received, bundle discharge roller pair 136 switches to a contact state, grips the booklet, and discharges it onto lower discharge tray 137.

[0066] The above describes the operation when producing a booklet consisting of ten sheets S1 to S10, but image forming apparatus 100 can also produce a double-page spread product using two sheets S. A double-page spread product is a final product in which images are formed on the opposing surfaces of two sheets S and these images are adhered together to form a double-page spread image.

[0067] In particular, image forming apparatus 100 of this embodiment can divide one input image into two images (first image and second image) and layout-print the images onto two sheets S, and can also create a double-page spread product in which the first and second images are glued together to form a double-page spread. By creating a double-page spread product in which one input image is layout-printed, for example, two A4-sized sheets can be used as pseudo-A3-sized recording media, and a product in which an A3-sized image is printed on a double-page spread can be output.

[0068] Furthermore, the image forming apparatus 100 of this embodiment performs inline processing in which a binding process (thermocompression bonding process) is performed following image formation in the printer main body 101 using a sheet processing apparatus 106 connected to the printer main body 101. In other words, the image forming apparatus 100 can perform processes from printing to binding in one stop to produce a double-page spread product. However, the printer main body 101 and the sheet processing apparatus 106 may be configured as independent offline devices, and a user or the like may transport sheets discharged from the printer main body 101 to the sheet processing apparatus 106, which then binds the sheets.

[0069] (Image size misalignment in double-page spread images) Incidentally, when the sheet S passes through the fixing device 118, the sheet S is heated, causing moisture to evaporate and shrinking of the material. As a result, the size of the sheet S after passing through the fixing device 118 becomes slightly smaller than before passing through the fixing device 118. This phenomenon occurs when the sheet S passes through the fixing device 118 for the first time, and when the sheet S passes through the fixing device 118 for the second time or later, there is almost no shrinkage of the sheet S. "First" refers to the first time the sheet S passes through the fixing device 118 after being fed from the cassette 113 or the like.

[0070] This shrinkage of the sheet S caused by heating in the fixing device 118 also changes the size (size in the main scanning direction and sub-scanning direction) of the image formed on the sheet S. Specifically, there is a difference in the size of the image after fixing between when a toner image is transferred before the sheet S first passes through the fixing device 118 and when a toner image is transferred after the sheet S has already passed through the fixing device 118.

[0071] More specifically, if a toner image is transferred onto the sheet S before the sheet S first passes through the fixing device 118, the toner image is fixed when the sheet S first passes through the fixing device 118. In this case, not only does the sheet S shrink when the sheet S first passes through the fixing device 118 to fix the toner image, but the image transferred onto the sheet S also shrinks along with the sheet S.

[0072] On the other hand, when a toner image is transferred to the sheet S after it has already passed through the fixing device 118, the toner image is transferred to the sheet S, which is already in a shrunk state. In this case, when the sheet S passes through the fixing device 118 for the second time to fix the toner image, there is almost no shrinkage of the sheet S, and therefore there is almost no shrinkage of the image. The same applies when a toner image is transferred to the sheet S after it has passed through the fixing device 118 two or more times.

[0073] For the reasons described above, if a difference in image size occurs between the two sheets that make up the double-page spread of the product bound by the thermocompression bonding unit 167, this can cause a decrease in image quality on the double-page spread. Specifically, the position of the lines drawn across the two sheets may be misaligned, or the left-right balance of the image across the two sheets may be lost, giving an impression that is different from the input image.

[0074] Therefore, in this embodiment, when producing a double-page spread product, the number of times that the sheets that make up the double-page spread pass through the fixing device 118 before the toner image is transferred is made uniform between the two sheets, thereby making it less likely that a difference in image size will occur. A specific method for producing a product in this embodiment will be described below.

[0075] (How to create a double-page spread) Next, a method for producing a double-page spread product in this embodiment will be described. Fig. 6 summarizes examples of input images, print results for each sheet, and final products in Comparative Example 1, Example 1, and Example 2. Example 1 and Example 2 are each application examples of this embodiment. The timing of passing through the fixing device 118 and transferring the toner image differs between Comparative Example 1, Example 1, and Example 2. Details will be described later.

[0076] The print result refers to the state of both sides of the sheet S when it is discharged from the printer main body 101 to the sheet processing device 106, not the state when it is discharged from the sheet processing device 106. The final product refers to the product obtained as a result of the binding process of the first sheet and the second sheet.

[0077] The hatched areas in the print result and the final product represent adhesive toner images 39 (FIG. 5). When creating a double-page spread product, adhesive toner images 39 are formed along one side of the first sheet and one side of the second sheet, and an image corresponding to the input image is formed in the area excluding the adhesive toner images 39. In this embodiment, the first and second A4-sized sheets can be adhered together along their long sides. Note that the first and second sheets can be adhered together as long as the adhesive toner image 39 is formed on at least one of the first and second sheets.

[0078] The input image is an image (original image, document image) that the user instructs image forming apparatus 100 to print. Here, a horizontally long grid-like image is used as an example of the input image. The final product obtained when this example input image is used is a two-page spread product that has been layout printed so that a grid-like image corresponding to the left half of the input image is placed on the first sheet, and a grid-like image corresponding to the right half of the input image is placed on the second sheet.

[0079] When the size of the input image is equal to the size of two output sheets (sheets S used for image formation) arranged side by side, the CPU 200 generates two pieces of image data (first image data and second image data) by dividing the input image into two equal halves. Then, the CPU 200 executes the image formation operation using the first image data and the second image data.

[0080] In cases where the size of the input image is not the size of two sheets of output paper lined up side by side, the input image may be divided into two equal parts horizontally or vertically, and the resulting size may be enlarged or reduced to the size of the output paper before being output. For example, if the input image is A3 size and the output paper is A4 size, half the size of the input image is equal to A4, so the image is formed without being enlarged or reduced. On the other hand, if the input image is A4 size and the output paper is also A4 size, half the size of the input image is enlarged to A4 size (= square root of 2 ≒ 144%) to form the image. Furthermore, processes such as dividing and enlarging / reducing image data may be performed by a dedicated chip separate from the CPU 200.

[0081] Specific methods for producing a double-page spread product in Comparative Example 1, Example 1, and Example 2 will be described below with reference to the flowcharts in Fig. 6 and Figs. 7 to 9. Fig. 7 is a flowchart showing the procedure of an image forming job for producing a double-page spread product in Comparative Example 1 (hereinafter referred to as a double-page spread product production job). Fig. 8 is a flowchart showing the procedure for producing a double-page spread product in Example 1. Fig. 9 is a flowchart showing the procedure for producing a double-page spread product in Example 2. Unless otherwise specified, each step in the flow of Figs. 7 to 9 is realized by the CPU 200 (Fig. 1) operating the printer main body 101 and the sheet processing device 106 in accordance with a program.

[0082] In the following description, the "front side" of the sheet S refers to the surface of the sheet S (image transfer surface) that faces the intermediate transfer belt 108 (image carrier) when the sheet S, fed by the feed roller 114 (feeding means), passes through the secondary transfer unit for the first time. The "back side" of the sheet S refers to the surface of the sheet S that faces the intermediate transfer belt 108 (image carrier) when the sheet S passes through the double-sided conveying unit 134 and passes through the secondary transfer unit for the second time. Note that the "front side" and "back side" of the sheet S do not necessarily coincide with the front side and back side (front cover and back cover) of the final product. The back side of the sheet S may also be referred to as the surface of the sheet S that faces away from the intermediate transfer belt 108 when the sheet S passes through the secondary transfer unit for the first time. The front side of the sheet S is the surface of the sheet S that faces the intermediate transfer belt 108 when the sheet S passes through the secondary transfer unit for the even number of times, and the back side of the sheet S is the surface of the sheet S that faces the intermediate transfer belt 108 when the sheet S passes through the secondary transfer unit for the odd number of times.

[0083] In the following description, passing the sheet S through the secondary transfer unit without transferring a toner image onto the sheet S is referred to as "through conveyance." In this embodiment, even when the sheet S that has been conveyed through the secondary transfer unit passes through the fixing device 118, the fixing device 118 heats the sheet S in the same way as when fixing the toner image.

[0084] In the following description, the images formed by splitting using layout printing are referred to as the first split image A1 and the second split image A2, and the first split image A1 and the second split image A2 are collectively referred to as split image A1 / 2. The first split image A1 is an image formed based on the first image data when a single input image is split into the first image data and the second image data. The second split image A2 is an image formed based on the second image data when a single input image is split into the first image data and the second image data.

[0085] 7 to 9, the first sheet transport sequence and the second sheet transport sequence are executed in parallel. The positional relationship between each process in the vertical direction in the diagram roughly corresponds to the temporal relationship between the processes, and each process is executed from top to bottom. For example, in FIG. 7, S2a being located below S1b means that the first sheet passes through the fixing device 118 before the second sheet passes through the secondary transfer unit. However, the temporal relationship between the processes in the first sheet transport sequence and the second sheet transport sequence can change depending on the specific configuration of the image forming apparatus 100, the job execution conditions, etc.

[0086] [Comparative Example 1] 6 and 7, in Comparative Example 1, images are formed on the front side of the first sheet and the back side of the second sheet while the first and second sheets are being conveyed in the same manner as in normal double-sided printing. Then, a thermocompression bonding process is performed in the sheet processing device 106 so that the front side of the first sheet and the back side of the second sheet form a two-page spread.

[0087] Specifically, the conveyance sequence of the first sheet in Comparative Example 1 is as follows. After feeding the first sheet from cassette 113, CPU 200 forms a first divided image A1 on the front side of the first sheet (S1a), and fixes the first divided image A1 when the first sheet passes through fixing device 118 for the first time (S1b). After passing through fixing device 118, CPU 200 inverts and conveys the first sheet (S1c), and then passes the first sheet through the secondary transfer unit without transferring a toner image to the back side of the first sheet (S1d). Furthermore, after passing the first sheet through fixing device 118 for the second time (S1e), CPU 200 conveys the first sheet to intermediate stacker 156 of sheet processing device 106 (S1f). As a result of the first divided image A1 being formed on the front side and then inverted and conveyed once, the first sheet is stacked on intermediate stacker 156 with the first divided image A1 facing upward.

[0088] On the other hand, the conveyance sequence of the second sheet in Comparative Example 1 is as follows. After the CPU 200 feeds the second sheet from the cassette 113, the CPU 200 passes the second sheet through the secondary transfer unit (S2a) without transferring a toner image to the front side of the second sheet, and then passes the second sheet through the fixing device 118 (S2b). The CPU 200 reverses and conveys the second sheet that has passed through the fixing device 118 (S2c), and then transfers the second divided image A2 to the back side of the second sheet (S2d). Furthermore, the CPU 200 fixes the second divided image A2 when the second sheet passes through the fixing device 118 for the second time (S2e), and then conveys the second sheet to the intermediate stacker 156 of the sheet processing device 106 (S2f). After the second divided image A2 is formed on the back side, the second sheet is conveyed to the intermediate stacker 156 without being reversed and conveyed, and is thereby stacked on the intermediate stacker 156 with the second divided image A2 facing downward.

[0089] Then, in a state where the first sheet and the second sheet are stacked in intermediate stacker 156 so that divided images A1 / 2 face each other, CPU 200 causes thermocompression bonding unit 167 to thermocompress the edges of the first sheet and the second sheet (S10). Through the above procedure, a final product (top right column in FIG. 6) is produced in which divided image A1 / 2 is arranged on the inner double-page spread of the two sheets thermocompression bonded by thermocompression bonding unit 167.

[0090] In Comparative Example 1, the first divided image A1 is transferred (S1a) to the first sheet before it first passes through the fixing device 118 (S1b), whereas the second divided image A2 is transferred (S2d) to the second sheet that has already passed through the fixing device 118 once (S2b). As a result, the first divided image A1 shrinks along with the first sheet when it first passes through the fixing device 118, whereas the second divided image A2 hardly shrinks at all. As a result, as shown in the "Printed result" and "Final product" in Figure 6, a difference in image size occurs between the left and right sides of a double-page spread.

[0091] [Example 1] As shown in the middle of FIG. 6 and FIG. 8, in the first embodiment, both the first divided image A1 and the second divided image A2 are transferred onto a sheet that has never passed through the fixing device 118.

[0092] Specifically, the conveyance sequence of the first sheet in Example 1 is the same as the conveyance sequence of the first sheet in Comparative Example 1. That is, after feeding the first sheet from the cassette 113, the CPU 200 forms a first divided image A1 on the front side of the first sheet (S3a), and fixes the first divided image A1 when the first sheet passes through the fixing device 118 for the first time (S3b). The CPU 200 inverts and conveys the first sheet that has passed through the fixing device 118 (S3c), and then passes the first sheet through the secondary transfer unit without transferring a toner image to the back side of the first sheet (S3d). Furthermore, after the CPU 200 passes the first sheet through the fixing device 118 for the second time (S3e), the CPU 200 conveys the first sheet to the intermediate stacking unit 156 of the sheet processing device 106 (S3f). As a result of the first divided image A1 being formed on the front side and then being inverted and conveyed once, the first sheet is stacked on the intermediate stacking unit 156 with the first divided image A1 facing upward.

[0093] On the other hand, the conveying sequence of the second sheet in the first embodiment is as follows. After the CPU 200 feeds the second sheet from the cassette 113, it forms the second divided image A2 on the front side (S4a) and fixes the second divided image A2 when the second sheet passes through the fixing device 118 for the first time (S4b). Then, the CPU 200 conveys the second sheet that has passed through the fixing device 118 to the intermediate stacking section 156 of the sheet processing device 106 without ever inverting or conveying the second sheet (S4c). By conveying the second sheet to the intermediate stacking section 156 without inverting or conveying the second sheet after the second divided image A2 has been formed on the front side, the second sheet is stacked on the intermediate stacking section 156 with the second divided image A2 facing downward.

[0094] Then, in a state where the first sheet and the second sheet are stacked in intermediate stacker 156 so that divided images A1 / 2 face each other, CPU 200 causes thermocompression bonding unit 167 to thermocompress the edges of the first sheet and the second sheet (S10). Through the above procedure, a final product (center of the right column in FIG. 6) is produced in which divided image A1 / 2 is arranged on the inner double-page spread of the two sheets thermocompression bonded by thermocompression bonding unit 167.

[0095] Here, in Example 1, the first divided image A1 is transferred to the first sheet before it first passes through the fixing device 118 (S3b), and the second divided image A2 is transferred to the second sheet before it first passes through the fixing device 118 (S4b). As a result, the first divided image A1 shrinks together with the first sheet when it first passes through the fixing device 118, and the second divided image A2 shrinks together with the second sheet when it first passes through the fixing device 118. As a result, as shown in the "Printed result" and "Final product" in the middle of Figure 6, both divided images A1 / 2 shrink slightly compared to when they were transferred, preventing a difference in image size from occurring between the left and right sides of a double-page spread.

[0096] In other words, in the first embodiment, the control means performs the following control when producing a finished product in which a first image and a second image are formed on a double-page spread made up of a first sheet and a second sheet. The control means transfers the first image to the first sheet by the transfer means and fixes the first image on the first sheet by the fixing means before the first sheet passes through the fixing means for the first time. The control means also transfers the second image to the second sheet by the transfer means and fixes the second image on the second sheet by the fixing means before the second sheet passes through the fixing means for the first time. Furthermore, the control means transports the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and binds the first sheet and the second sheet by the binding means.

[0097] This configuration makes it possible to provide an image forming apparatus that is less likely to produce differences in image size between two-page spreads.

[0098] Furthermore, in the first embodiment, the number of times the first sheet is reversed and conveyed is smaller than in the second embodiment described below, which reduces the time from inputting a job to producing a double-page spread product to outputting the final product, thereby improving the productivity of the image forming apparatus 100.

[0099] [Example 2] As shown in the lower part of FIG. 6 and FIG. 9, in the second embodiment, both the first divided image A1 and the second divided image A2 are transferred onto a sheet that has passed through the fixing device 118 at least once.

[0100] Specifically, the conveyance sequence of the first sheet in the second embodiment is as follows: After the CPU 200 feeds the first sheet from the cassette 113, the CPU 200 passes the first sheet through the secondary transfer unit without transferring a toner image to the front surface of the first sheet (S5a), and passes the first sheet through the fixing device 118 (S5b). After the CPU 200 reverses and conveys the first sheet that has passed through the fixing device 118 (S5c), the CPU 200 transfers the first divided image A1 to the rear surface of the first sheet (S5d), and fixes the first divided image A1 when the first sheet passes through the fixing device 118 for the second time (S5e). After the CPU 200 reverses and conveys the first sheet that has passed through the fixing device 118 for the second time (S5f), the CPU 200 passes the first sheet through the secondary transfer unit without transferring a toner image to the front surface of the first sheet (S5g). Furthermore, after the CPU 200 passes the first sheet through the fixing device 118 for the third time (S5h), it transports the first sheet to the intermediate stacking section 156 of the sheet processing device 106 (S5i). As a result of the first inversion transport being performed once after the first divided image A1 has been formed on the front surface, the first sheet is stacked on the intermediate stacking section 156 with the first divided image A1 facing upward.

[0101] On the other hand, the conveying sequence of the second sheet in Example 2 is the same as the conveying sequence of the second sheet in Comparative Example 1. That is, after the CPU 200 feeds the second sheet from the cassette 113, the CPU 200 passes the second sheet through the secondary transfer unit (S6a) without transferring a toner image to the front side of the second sheet, and then passes the second sheet through the fixing device 118 (S6b). The CPU 200 reverses and conveys the second sheet that has passed through the fixing device 118 (S6c), and then transfers the second divided image A2 to the back side of the second sheet (S6d). Furthermore, the CPU 200 fixes the second divided image A2 when the second sheet passes through the fixing device 118 for the second time (S6e), and then conveys the second sheet to the intermediate stacking unit 156 of the sheet processing device 106 (S6f). After the second divided image A2 is formed on the back surface, the second sheet is transported to the intermediate stacking section 156 without being reversed, so that the second sheet is stacked on the intermediate stacking section 156 with the second divided image A2 facing downward.

[0102] Then, in a state where the first sheet and the second sheet are stacked in intermediate stacker 156 so that divided images A1 / 2 face each other, CPU 200 causes thermocompression bonding unit 167 to thermocompress the edges of the first sheet and the second sheet (S10). Through the above procedure, a final product (center of the right column in FIG. 6) is produced in which divided image A1 / 2 is arranged on the inner double-page spread of the two sheets thermocompression bonded by thermocompression bonding unit 167.

[0103] In the second embodiment, divided images A1 / 2 are transferred to the first and second sheets after they have passed through the fixing device 118 at least once (S5b, S6b). That is, the first divided image A1 is transferred to the first sheet, which is already in a shrunk state, and the second divided image A2 is transferred to the second sheet, which is already in a shrunk state. Therefore, even when the first and second sheets pass through the fixing device 118 for the second time to fix the images, there is almost no shrinkage of the first and second sheets, and the size of divided image A1 / 2 is unlikely to become smaller than when it was transferred. As a result, as shown in the "Printed Result" and "Final Product" in the lower part of FIG. 6, both divided images A1 / 2 are output at substantially the same size as when they were transferred, preventing a difference in image size between the left and right sides of a spread page.

[0104] In other words, in the second embodiment, the control means performs the following control when producing a finished product on which a spread page made up of a first sheet and a second sheet and a second image are formed. After the first sheet has passed through the fixing means at least once, the control means transfers the first image to the first sheet using the transfer means and fixes the first image on the first sheet using the fixing means. Also, after the second sheet has passed through the fixing means at least once, the control means transfers the second image to the second sheet using the transfer means and fixes the second image on the second sheet using the fixing means. Furthermore, the control means transports the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and binds the first sheet and the second sheet using the binding means.

[0105] This configuration makes it possible to provide an image forming apparatus that is less likely to produce differences in image size between two-page spreads.

[0106] Furthermore, according to the second embodiment, for each of the first and second sheets, when the sheet first passes through the secondary transfer unit, the sheet is conveyed through, and an image is transferred after the sheet is conveyed in reverse by the duplex conveying unit 134. That is, the control unit causes the first sheet fed by the feeding unit to pass through the transfer unit and the fixing unit for the first time without forming an image on the first side (front side) of the first sheet, and then conveys the first sheet in reverse by the re-conveying unit. Furthermore, when the first sheet passes through the transfer unit for the second time, the control unit transfers the first image to the second side (rear side) of the first sheet, which is opposite to the first side. Furthermore, the control unit causes the second sheet fed by the feeding unit to pass through the transfer unit and the fixing unit for the first time without forming an image on the third side (front side) of the second sheet, and then conveys the second sheet in reverse by the re-conveying unit. Furthermore, when the second sheet passes through the transfer unit for the second time, the control unit transfers the second image to the fourth side (fourth side) of the second sheet, which is opposite to the third side (rear side).

[0107] The above configuration enables further improvement in image quality in the final product compared to Example 1 for the following reasons. In Example 1, the first and second sheets first pass through the fixing device 118 after the divided image A1 / 2 is transferred. This means that the size of the divided image A1 / 2 in the final product is smaller than the size of the divided image A1 / 2 at the time of transfer. Furthermore, if there is a difference in the amount of shrinkage between the first and second sheets when they first pass through the fixing device 118, or if there is uneven shrinkage within a single sheet, size differences, misalignment, distortion, and the like may occur in the divided image A1 / 2. In contrast, in Example 2, the divided image A1 / 2 is transferred to the first and second sheets, which are already in a shrunk state when they first pass through the fixing device 118. Therefore, there is almost no shrinkage of the first and second sheets after the divided image A1 / 2 is transferred. Therefore, slight size differences, etc., in the divided image A1 / 2 can be suppressed, enabling further improvement in image quality in the final product.

[0108] Furthermore, according to the second embodiment, the number of times (one time) that the first sheet passes through the fixing device 118 before the divided image A1 (first image) is transferred is equal to the number of times (one time) that the second sheet passes through the fixing device 118 before the divided image A2 (second image) is transferred. This makes it possible to avoid, for example, a slight size difference between the divided images A1 / 2 that may occur due to the sheet shrinking slightly when passing through the fixing device 118 for the second time. Note that the number of times that the first and second sheets pass through the fixing device 118 before the divided images A1 / 2 are transferred may be set to two (or a predetermined number of times greater).

[0109] (Variation 1) In Examples 1 and 2, after divided image A1 is fixed by fixing device 118, the sheet is reversed and conveyed using duplex conveying unit 134 (re-conveying means) so that divided images A1 and A2 face each other at thermocompression bonding unit 167. Then, the first sheet passes through the secondary transfer unit and fixing device 118 again, and then is conveyed to thermocompression bonding unit 167. This is because if the first sheet on which divided image A1 is fixed by fixing device 118 is conveyed to thermocompression bonding unit 167 without reverse conveyance, divided image A1 will face downward at intermediate stacking unit 156. In other words, image forming apparatus 100 of this embodiment is configured so that the image transfer surface of sheet S immediately before it is discharged from printer main body 101 faces downward at intermediate stacking unit 156 (face-down configuration). The image transfer surface is the sheet surface that faces the image carrier (intermediate transfer belt 108) when sheet S passes through the secondary transfer unit.

[0110] As a modified example, if the image transfer surface of the sheet S immediately before being discharged from the printer main body 101 faces upward in the intermediate stacking section 156 (face-up configuration), additional inversion and conveyance is performed on the second sheet instead of the first sheet.

[0111] In the face-up configuration, for example, in Example 1 (FIG. 8), the first sheet that first passes through fixing device 118 (S3b) is conveyed to intermediate stacker 156 without being reversed. Also, the second sheet that first passes through fixing device 118 (S4b) is reversed and conveyed by duplex conveying unit 134, and the second sheet passes through the secondary transfer unit and fixing device 118 again before being conveyed to thermocompression bonding unit 167. This allows divided image A1 on the first sheet and divided image A2 on the second sheet to face each other in thermocompression bonding unit 167. In Example 2 (FIG. 9), the second sheet that first passes through fixing device 118 (S6e) is reversed and conveyed by duplex conveying unit 134, and the second sheet passes through the secondary transfer unit and fixing device 118 again before being conveyed to thermocompression bonding unit 167.

[0112] (Variation 2) In the first embodiment, an example was described in which no image is formed on the back side of divided image A1 / 2 in the spread product, but an image may also be formed on the back side of divided image A1 / 2 in the spread product. That is, an image may be formed on the outer surfaces of the first sheet and the second sheet that are bonded together by thermocompression bonding unit 167. In other words, when producing a spread product, the control means may transfer a third image to the surface of the first sheet opposite to the surface on which the first image is formed, and transfer a fourth image to the surface of the second sheet opposite to the surface on which the second image is formed, thereby making it possible to produce a product in which the third image and the fourth image are formed on the back sides of the spread pages in the product.

[0113] In this case, it is preferable to control the conveyance of the first and second sheets so that the number of times the first sheet passes through the fixing device 118 before the third image is transferred is equal to the number of times the second sheet passes through the fixing device 118 before the fourth image is transferred. This makes it less likely that a difference in size will occur between the third and fourth images. For example, in Example 2 (FIG. 9), instead of through-conveying the front surfaces of the first and second sheets (S5d, S6b), the third image is transferred to the front surface of the first sheet, and the fourth image is transferred to the front surface of the second sheet. This makes it possible to equalize the number of times the first sheet passes through the fixing device 118 before the third image is transferred (0 times) and the number of times the second sheet passes through the fixing device 118 before the fourth image is transferred (0 times).

[0114] The conveyance of the first and second sheets may be controlled so that the number of times the first sheet passes through fixing device 118 before the third image is transferred and the number of times the second sheet passes through fixing device 118 before the fourth image is transferred are both at least one. The third and fourth images may be divided from a single input image, or may correspond to two input images, respectively.

[0115] Second Embodiment In the first embodiment, when producing a double-page spread product, the first sheet or the second sheet is subjected to additional inversion and transport after the image has been transferred, and the first sheet and the second sheet are transported to the thermocompression bonding unit 167 so that the sheet surfaces that make up the double-page spread face each other. However, if the first sheet and the second sheet are transported in the thermocompression bonding unit 167 (binding means) so that the sheet surfaces that make up the double-page spread face each other, it is not necessarily necessary to perform additional inversion and transport on the sheet after the image has been transferred.

[0116] Hereinafter, as the second embodiment, a configuration that enables the creation of a double-page spread product by switching the transport path of each sheet after an image has been transferred will be described. Here, a configuration to which this embodiment is applied will be described based on Example 2 of the first embodiment. Elements with the same reference numerals as the first embodiment have basically the same configuration and function as those described in the first embodiment unless otherwise specified, and differences from the first embodiment will be mainly described.

[0117] 10 is a schematic diagram of an image forming apparatus 100 according to the second embodiment. The image forming apparatus 100 of this embodiment differs from the first embodiment in that a shortcut path 131 and a switching guide 132 are provided inside the sheet processing apparatus 106.

[0118] The shortcut path 131 branches off from the entrance path downstream of the entrance roller pair 121 and merges with the inner discharge path between the inner discharge roller pair 126 and the intermediate conveyance roller pair 128. A conveyance path that runs from the entrance roller pair 121 to the intermediate conveyance roller pair 128 via the pre-buffer roller pair 122, the reversing roller pair 124, and the inner discharge roller pair 126 is called a reversing path 133. The reversing path 133 and the shortcut path 131 are examples of a first conveyance path and a second conveyance path that branch off midway along the path from the fixing device 118 (fixing means) to the thermocompression bonding unit 167 (binding means) in the image forming apparatus 100. The reversing path 133 is an example of a first conveyance path along which the sheet S is reversed and conveyed, and the shortcut path is an example of a second conveyance path along which the sheet is conveyed without being reversed.

[0119] The switching guide 132 is disposed at a branching point where the reverse path 133 and the shortcut path 131 branch off. The switching guide 132 is movable between a position where the switching guide 132 guides the sheet S sent out from the inlet roller pair 121 to the reverse path 133 and a position where the switching guide 132 guides the sheet S sent out from the inlet roller pair 121 to the shortcut path 131. The switching guide 132 is an example of a switching member that switches the conveying path of the sheet S between the reverse path 133 (first conveying path) and the shortcut path 131 (second conveying path).

[0120] In this embodiment, when producing a double-page spread product, the CPU 200 (Figure 1) uses the switching guide 132 to control the transport paths of the first sheet and the second sheet so that the sheet surfaces constituting the double-page spread face each other in the thermocompression bonding section 167 (binding means).

[0121] 11 is a flowchart showing the procedure of a double-page spread product creation job in the second embodiment. A specific control example will be described below with reference to the flowchart.

[0122] The first sheet conveyance sequence in the second embodiment is as follows: After the CPU 200 feeds the first sheet from the cassette 113, the CPU 200 passes the first sheet through the secondary transfer unit (S7a) without transferring a toner image to the front side of the first sheet, and passes the first sheet through the fixing device 118 (S7b). The CPU 200 reverses and conveys the first sheet that has passed through the fixing device 118 (S7c), transfers the first divided image A1 to the back side of the first sheet (S7d), and fixes the first divided image A1 when the first sheet passes through the fixing device 118 for the second time (S7e). The CPU 200 sends the first sheet that has passed through the fixing device 118 for the second time to the sheet processing device 106 without reversely conveying it, conveys it via the shortcut path 131 (S7f), and stacks it on the intermediate stacking unit 156 (S7g). After the first divided image A1 is formed on the back surface, the first sheet is not turned over and is transported via a shortcut path 131, so that the first sheet is stacked on an intermediate stacking section 156 with the first divided image A1 facing upward.

[0123] On the other hand, the second sheet conveyance sequence in the second embodiment is as follows. After the CPU 200 feeds the second sheet from the cassette 113, the CPU 200 causes the second sheet to pass through the secondary transfer unit (S8a) without transferring a toner image to the front side of the second sheet, and then causes the second sheet to pass through the fixing device 118 (S8b). The CPU 200 reverses and conveys the second sheet that has passed through the fixing device 118 (S8c), and then transfers the second divided image A2 to the back side of the second sheet (S8d). Furthermore, the CPU 200 fixes the second divided image A2 when the second sheet passes through the fixing device 118 for the second time (S8e), and then sends the second sheet to the sheet processing device 106 without reversely conveying it. The CPU 200 then conveys the second sheet via the reverse path 133 without passing through the shortcut path 131 (S8f), and stacks the second sheet on the intermediate stacker 156 (S8g). After the first divided image A1 is formed on the back surface, the second sheet is conveyed in an inverted state in the inversion path 133, and is then stacked on the intermediate stacking section 156 with the second divided image A2 facing downward.

[0124] Then, in a state where the first sheet and the second sheet are stacked in intermediate stacker 156 so that divided images A1 / 2 face each other, CPU 200 causes thermocompression bonding unit 167 to thermocompress the edges of the first sheet and the second sheet (S10). Through the above procedure, a final product (top right column in FIG. 6) is produced in which divided image A1 / 2 is arranged on the inner double-page spread of the two sheets thermocompression bonded by thermocompression bonding unit 167.

[0125] In this embodiment, the number of times that the sheets pass through the fixing device 118 before the toner image is transferred is the same for the two sheets that make up a double-page spread. This makes it possible to provide an image forming apparatus that is less likely to produce differences in image size on a double-page spread.

[0126] Furthermore, compared to the first embodiment, the sheet surfaces constituting the double-page spread can be placed face-to-face in the thermocompression bonding unit 167 (binding means) without additionally inverting and conveying the first or second sheet after the image has been transferred. Therefore, compared to, for example, Example 2 of the first embodiment, the time from input of a double-page spread product creation job to the discharge of the last sheet from the printer main body 101 can be shortened, improving the productivity of the printer main body 101. Furthermore, the time from input of a double-page spread product creation job to the output of the final product can be shortened, improving the productivity of the image forming apparatus 100 as a whole.

[0127] (Variation) FIG. 11 illustrates an example in which transport control using the shortcut path 131 is applied based on Example 2 of the first embodiment. However, the present invention is not limited to this example, and transport control using the shortcut path 131 may be combined with Example 1 of the first embodiment (FIG. 8). Specifically, in the transport sequence for the first sheet in Example 1, the first sheet, on whose front surface the first divided image A1 has been transferred and which has passed through the fixing device 118 (S3b), is transported to the intermediate stacker 156 via the shortcut path 131 without being reversed. The transport sequence for the second sheet may be the same as in Example 1. This method also allows the first sheet to be transported to the intermediate stacker 156 with the first divided image A1 facing upward. Furthermore, the productivity of the image forming apparatus 100 can be improved compared to Example 1.

[0128] In the second embodiment, a configuration has been exemplified in which the first conveying path (reverse path 133) that reverses and conveys a sheet and the second conveying path (shortcut path 131) that conveys a sheet without reversing it are arranged inside the sheet processing apparatus 106. However, the present invention is not limited to this, and the first conveying path and the second conveying path may be arranged in the printer main body 101 or the relay conveying unit 192, for example.

[0129] Third Embodiment In the first embodiment, a configuration was described in which one input image is allocated and printed on two sheets to create a double-page spread product. In the third embodiment, a case in which two input images are printed on two sheets to create a double-page spread product will be described. Hereinafter, elements with the same reference symbols as those in the first embodiment will have basically the same configurations and functions as those described in the first embodiment unless otherwise specified, and differences from the first embodiment will be mainly described.

[0130] Specific methods for producing double-page spread deliverables in Comparative Example 2, Example 3, and Example 4 will be described below with reference to Fig. 12. Fig. 12 summarizes examples of input images, print results of each sheet, and final deliverables in Comparative Example 2, Example 3, and Example 4. Example 3 and Example 4 are each application examples of this embodiment.

[0131] In this embodiment, two pieces of image data (a first input image and a second input image) are input to the image forming apparatus 100. The first input image is image data representing a first image to be formed on one side of a double-page spread in the final product, and the second input image is image data representing a second image to be formed on the other side of the double-page spread in the final product. In other words, in this embodiment, layout printing in which one input image is divided and formed on multiple sheets is not performed. In other words, in this embodiment, when instructed to form the first input image and the second input image on different sheets, the control means forms the first image on the first sheet based on the first input image, and forms the second image on the second sheet based on the second input image.

[0132] When this input image example is used, the final product is a double-page spread product in which a first output image B1 (letter "A") based on the first input image is arranged on the first sheet, and a second output image B2 (letter "B") based on the second input image is arranged on the second sheet. The first output image B1 and the second output image B2 are collectively referred to as output images B1 / 2. The first output image B1 is an example of the first image, and the second output image B2 is an example of the second image. Except for the differences in the input images, each item in FIG. 12 corresponds to FIG. 6 of the first embodiment. Specific methods for producing the double-page spread products in Comparative Example 2, Example 3, and Example 4 will be described below.

[0133] Comparative Example 2 12, in Comparative Example 2, the first and second sheets are conveyed in the same manner as in normal double-sided printing, and a first output image B1 is formed on the front side of the first sheet, and a second output image B2 is formed on the back side of the second sheet. Then, a thermocompression bonding process is performed in the sheet processing device 106 so that the front side of the first sheet and the back side of the second sheet form a two-page spread.

[0134] The transport sequence of the first and second sheets in Comparative Example 2 is the same as that in Comparative Example 1 except that output image B1 / 2 is formed instead of divided image A1 / 2, and therefore a description thereof will be omitted. In other words, if "first divided image A1" is read as "first output image B1" and "second divided image A2" is read as "second output image" in FIG. 7, the flowchart showing the steps of the double-page spread deliverable production job in Comparative Example 2 will be obtained.

[0135] In Comparative Example 2, the first output image B1 is transferred to the first sheet (S1a) before it passes through the fixing device 118 for the first time, whereas the second output image is transferred to the second sheet (S2d) after it has already passed through the fixing device 118 once (S2b). As a result, the first output image B1 shrinks along with the first sheet when it passes through the fixing device 118 for the first time, whereas the second output image hardly shrinks at all. As a result, as shown in "Printed result" and "Final product" in Figure 6, a difference in image size occurs between the left and right sides of a double-page spread.

[0136] [Example 3] As shown in the middle of FIG. 12, in the third embodiment, both the first output image B1 and the second output image B2 are transferred onto a sheet that has never passed through the fixing device 118.

[0137] The conveyance sequence of the first and second sheets in the third embodiment is the same as that in the first embodiment except that output image B1 / 2 is formed instead of divided image A1 / 2, and therefore the description thereof will be omitted. In other words, if "first divided image A1" is read as "first output image B1" and "second divided image A2" is read as "second output image" in Fig. 8, the flowchart showing the procedure of the double-page spread deliverable production job in the third embodiment will be obtained.

[0138] In the third embodiment, the first output image B1 is transferred to the first sheet before it first passes through the fixing device 118 (S3b), and the second output image is transferred to the second sheet before it first passes through the fixing device 118 (S4b). As a result, the first output image B1 shrinks together with the first sheet when it first passes through the fixing device 118, and the second output image B1 shrinks together with the second sheet when it first passes through the fixing device 118. As a result, as shown in the "Printed result" and "Final product" in the middle of Fig. 12, both output images B1 / 2 shrink slightly compared to when they were transferred, which prevents a difference in image size from occurring between the left and right sides of a double-page spread.

[0139] In other words, in the third embodiment, the control means performs the following control when producing a finished product in which a first image and a second image are formed on a double-page spread made up of a first sheet and a second sheet. The control means transfers the first image to the first sheet by the transfer means and fixes the first image on the first sheet by the fixing means before the first sheet passes through the fixing means for the first time. The control means also transfers the second image to the second sheet by the transfer means and fixes the second image on the second sheet by the fixing means before the second sheet passes through the fixing means for the first time. Furthermore, the control means transports the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and binds the first sheet and the second sheet by the binding means.

[0140] This configuration makes it possible to provide an image forming apparatus that is less likely to produce differences in image size between two-page spreads.

[0141] [Example 4] As shown in the lower part of FIG. 12, in the fourth embodiment, both the first output image B1 and the second output image B2 are transferred onto a sheet that has passed through the fixing device 118 at least once.

[0142] The transport sequence of the first and second sheets in the fourth embodiment is the same as that in the second embodiment except that output image B1 / 2 is formed instead of divided image A1 / 2, and therefore the description thereof will be omitted. In other words, if "first divided image A1" is read as "first output image B1" and "second divided image A2" is read as "second output image" in Fig. 9, the flowchart showing the procedure of the double-page spread deliverable production job in the fourth embodiment will be obtained.

[0143] In Example 4, the first output image B1 is transferred to the first sheet after passing through the fixing device 118 at least once (S5b), and the second output image B2 is transferred to the second sheet after passing through the fixing device 118 at least once (S6b). In other words, the first output image is transferred to the first sheet, which is already in a shrunk state, and the second output image is transferred to the second sheet, which is already in a shrunk state. Therefore, even when the first and second sheets pass through the fixing device 118 for the second time to fix the images, there is almost no shrinkage of the first and second sheets, and the size of the output image B1 / 2 is unlikely to become smaller than when it was transferred. As a result, as shown in the "Printed Result" and "Final Product" in the lower part of Figure 6, both output images B1 / 2 are output at substantially the same size as when they were transferred, preventing a difference in image size between the left and right sides of a spread page.

[0144] In other words, in Example 4, the control means performs the following control when producing a finished product in which a first image and a second image are formed on a double-page spread made up of a first sheet and a second sheet. After the first sheet has passed through the fixing means at least once, the control means transfers the first image to the first sheet using the transfer means and fixes the first image to the first sheet using the fixing means. Also, after the second sheet has passed through the fixing means at least once, the control means transfers the second image to the second sheet using the transfer means and fixes the second image to the second sheet using the fixing means. Furthermore, the control means transports the first sheet and the second sheet to the binding means so that the first image and the second image face each other, and binds the first sheet and the second sheet using the binding means.

[0145] This configuration makes it possible to provide an image forming apparatus that is less likely to produce differences in image size between two-page spreads.

[0146] (Variation) In Examples 3 and 4, an example was described in which, when producing a double-page spread product, the first sheet or the second sheet is subjected to additional inversion transport after the image is transferred, and the first sheet and the second sheet are transported to the thermocompression bonding unit 167 so that the sheet surfaces that make up the double-page spread face each other. However, the present invention is not limited to this, and the transport paths of the first sheet and the second sheet may be controlled using the shortcut path 131 and the switching guide 132 described in the second embodiment so that the sheet surfaces that make up the double-page spread face each other in the thermocompression bonding unit 167 (binding means).

[0147] (Other variations) In this embodiment, a tandem color printer configuration including four process cartridges is exemplified, but the number of types of toner may be five or more, or three or less. Furthermore, instead of using at least one of the multiple color toners as both a toner for recording an image on a sheet (printing toner) and an adhesive toner, a toner dedicated to adhesive use may be used. In this case, the process cartridge using the adhesive toner forms only the adhesive toner image 39 (FIG. 5).

[0148] Furthermore, the printer main body 101 may be a monochrome image forming apparatus equipped with only one process cartridge 195 that uses black toner Tk as both a printing toner and an adhesive toner.

[0149] Furthermore, the thermocompression bonding unit 167 is an example of a binding means for binding multiple sheets, and a stapler that uses staples to bind sheets or a stapler that performs staple-less binding without using staples may also be used as the binding means. Staple-less binding includes a method of integrating a stack of sheets by folding back a piece of a sheet cut out from the sheet, and a method of integrating a stack of sheets by clamping the sheets with a toothed jaw and entangling the sheet fibers.

[0150] Furthermore, in each of the above-described embodiments, an example has been described in which the image forming apparatus 100 applies adhesive toner to a sheet and then adheres it using the thermocompression bonding unit 167. However, it is also possible to use a sheet to which adhesive toner has already been applied as a recording material, and only perform adhesion using the thermocompression bonding unit 167.

[0151] In the above-described embodiments, the two sheets constituting a spread page pass through the fixing device 118 the same number of times before the image is transferred. Alternatively, the difference in image size between the two images (first image and second image) formed on the spread page may be reduced by changing the magnification of the image formed by the image forming unit 101B, taking into account sheet shrinkage. The image magnification is a set value that represents the ratio of enlarging or reducing the image formed on the actual sheet relative to the size of the input image. For example, when the first and second sheets are transported using the transport sequence of Comparative Example 1 (FIG. 7), the magnification of the second divided image A2 is set slightly smaller than the magnification of the first divided image A1. In this case, the size of the second divided image A2 immediately after transfer is smaller than the size of the first divided image A1 immediately after transfer, but the first divided image A1 shrinks together with the first sheet when the first sheet passes through the fixing device 118 for the first time. This reduces the size difference between the first divided image A1 and the second divided image A2 in the final product. This modification can also be applied to the third embodiment in which two input images are input. In this case, the same advantages as those of the above example can be obtained by setting the magnification of the first output image relative to the first input image and the magnification of the second output image relative to the second input image to different values.

[0152] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0153] Summary of the Disclosure The present disclosure includes at least the following: (Configuration 1) a transfer means for transferring an image onto the sheet; a fixing means for heating the sheet to fix the image to the sheet; a binding means for binding a plurality of sheets; a control means; Equipped with The control means transferring a first image to the first sheet by the transfer means before the first sheet passes through the fixing means for the first time; fixing the first image to the first sheet by the fixing means; transferring a second image to the second sheet by the transfer means before the second sheet first passes through the fixing means; fixing the second image to the second sheet by the fixing means; conveying the first sheet and the second sheet to the binding means so that the first image and the second image face each other; binding the first sheet and the second sheet by the binding means to produce a product in which the first image and the second image are formed on a double-page spread. An image forming apparatus characterized by: (Configuration 2) a transfer means for transferring an image onto the sheet; a fixing means for heating the sheet to fix the image to the sheet; a binding means for binding a plurality of sheets; a control means; Equipped with The control means After the first sheet has passed through the fixing means at least once, a first image is transferred to the first sheet by the transfer means; fixing the first image to the first sheet by the fixing means; a second image is transferred to the second sheet by the transfer means after the second sheet has passed through the fixing means at least once; fixing the second image to the second sheet by the fixing means; conveying the first sheet and the second sheet to the binding means so that the first image and the second image face each other; binding the first sheet and the second sheet by the binding means to produce a product in which the first image and the second image are formed on a double-page spread. An image forming apparatus characterized by: (Configuration 3) When instructed to allocate and form one input image onto two sheets, the control means divides the input image into first image data and second image data, forms the first image on the first sheet based on the first image data, and forms the second image on the second sheet based on the second image data. 3. The image forming apparatus according to claim 1, wherein: (Configuration 4) when instructed to form the first input image and the second input image on different sheets, the control means forms the first image on the first sheet based on the first input image, and forms the second image on the second sheet based on the second input image. 3. The image forming apparatus according to claim 1, wherein: (Configuration 5) a feeding means for feeding a sheet toward the transfer means; a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means; Further provided with the control means reverses and conveys the first sheet and the second sheet using the re-conveying means so that the number of times the first sheet passes through the fixing means after being fed by the feeding means and before the first image is transferred is equal to the number of times the second sheet passes through the fixing means after being fed by the feeding means and before the second image is transferred. 3. The image forming apparatus according to configuration 2. (Configuration 6) a feeding means for feeding a sheet toward the transfer means; a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means; Further provided with The control means after first passing the first sheet fed by the feeding means through the transfer means and the fixing means without forming an image on a first surface of the first sheet, the first sheet is reversed and conveyed by the re-conveying means; When the first sheet passes through the transfer means for a second time, the transfer means transfers the first image to a second surface of the first sheet opposite to the first surface; after first passing the second sheet fed by the feeding means through the transfer means and the fixing means without forming an image on a third surface of the second sheet, the second sheet is reversed and conveyed by the re-conveying means; When the second sheet passes through the transfer means for a second time, the second image is transferred by the transfer means to a fourth surface of the second sheet opposite to the third surface. 3. The image forming apparatus according to configuration 2. (Configuration 7) a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means, the control means causes the first sheet to pass through the transfer means and the fixing means again using the re-conveying means after the first image is fixed by the fixing means so that the first image and the second image face each other in the binding means, and then conveys the first sheet to the binding means; 7. The image forming apparatus according to any one of configurations 1 to 6. (Configuration 8) a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means, the control means causes the second sheet to pass through the transfer means and the fixing means again using the re-conveying means after the second image has been fixed by the fixing means so that the first image and the second image face each other in the binding means, and then conveys the second sheet to the binding means; 7. The image forming apparatus according to any one of configurations 1 to 6. (Configuration 9) a first conveying path and a second conveying path branched in the middle of a path from the fixing unit to the binding unit, the first conveying path along which the sheet is reversed and conveyed, and the second conveying path along which the sheet is conveyed without being reversed; a switching member that switches a sheet transport path between the first transport path and the second transport path; Further provided with the control unit controls the conveyance paths of the first sheet and the second sheet using the switching member so that the first image and the second image face each other in the binding unit. 7. The image forming apparatus according to any one of configurations 1 to 6. (Configuration 10) the binding means bonds the first sheet and the second sheet by applying heat and pressure to the first sheet and the second sheet in a state in which an adhesive is applied to at least one of the first sheet and the second sheet, 10. The image forming apparatus according to any one of configurations 1 to 9. (Configuration 11) an image forming unit that has the transfer means, forms an image on the first sheet and the second sheet using a printing toner, and applies an adhesive toner as the adhesive to at least one of the first sheet and the second sheet; 11. The image forming apparatus according to claim 10, (Configuration 12) When producing the final product, the control means transfers a third image to a surface of the first sheet opposite to a surface on which the first image is formed, and transfers a fourth image to a surface of the second sheet opposite to a surface on which the second image is formed, thereby producing the final product in which the third image and the fourth image are formed on the back side of the double-page spread of the final product; and controlling conveyance of the first sheet and the second sheet so that the number of times the first sheet passes through the fixing means before the third image is transferred thereon is equal to the number of times the second sheet passes through the fixing means before the fourth image is transferred thereon; 12. The image forming apparatus according to any one of configurations 1 to 11. [Explanation of symbols]

[0154] 111... Transfer means (secondary transfer roller) / 114... Feeding means (feeding roller) / 118... Fixing means (fixing device) / 167... Binding means (thermocompression bonding unit) / 200... Control means (CPU)

Claims

1. a transfer means for transferring an image onto the sheet; a fixing means for heating the sheet to fix the image to the sheet; a binding means for binding a plurality of sheets; a control means; Equipped with The control means transferring a first image to the first sheet by the transfer means before the first sheet passes through the fixing means for the first time; fixing the first image to the first sheet by the fixing means; transferring a second image to the second sheet by the transfer means before the second sheet first passes through the fixing means; the fixing means fixes the second image to the second sheet; conveying the first sheet and the second sheet to the binding means so that the first image and the second image face each other; a final product in which the first image and the second image are formed on a double-page spread by binding the first sheet and the second sheet with the binding means; An image forming apparatus characterized by:

2. a transfer means for transferring an image onto the sheet; a fixing means for heating the sheet to fix the image to the sheet; a binding means for binding a plurality of sheets; a control means; Equipped with The control means after the first sheet has passed through the fixing means at least once, a first image is transferred to the first sheet by the transfer means; fixing the first image to the first sheet by the fixing means; a second image is transferred to the second sheet by the transfer means after the second sheet has passed through the fixing means at least once; the fixing means fixes the second image to the second sheet; conveying the first sheet and the second sheet to the binding means so that the first image and the second image face each other; a final product in which the first image and the second image are formed on a double-page spread by binding the first sheet and the second sheet with the binding means; An image forming apparatus characterized by:

3. When instructed to allocate and form one input image onto two sheets, the control means divides the input image into first image data and second image data, forms the first image on the first sheet based on the first image data, and forms the second image on the second sheet based on the second image data.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. when instructed to form the first input image and the second input image on different sheets, the control means forms the first image on the first sheet based on the first input image, and forms the second image on the second sheet based on the second input image.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. a feeding means for feeding a sheet toward the transfer means; a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means; Further provided with the control means reverses and conveys the first sheet and the second sheet using the re-conveying means so that the number of times the first sheet passes through the fixing means after being fed by the feeding means and before the first image is transferred is equal to the number of times the second sheet passes through the fixing means after being fed by the feeding means and before the second image is transferred.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

6. a feeding means for feeding a sheet toward the transfer means; a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means; Further provided with The control means after first passing the first sheet fed by the feeding means through the transfer means and the fixing means without forming an image on a first surface of the first sheet, the first sheet is reversed and conveyed by the re-conveying means; When the first sheet passes through the transfer means for a second time, the transfer means transfers the first image to a second surface of the first sheet opposite to the first surface; after first passing the second sheet fed by the feeding means through the transfer means and the fixing means without forming an image on a third surface of the second sheet, the second sheet is reversed and conveyed by the re-conveying means; When the second sheet passes through the transfer means for a second time, the second image is transferred by the transfer means to a fourth surface of the second sheet opposite to the third surface.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

7. a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means, the control means causes the first sheet to pass through the transfer means and the fixing means again using the re-conveying means after the first image has been fixed by the fixing means so that the first image and the second image face each other in the binding means, and then conveys the first sheet to the binding means; 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

8. a re-conveying means for reversing the sheet that has passed through the fixing means and conveying it again toward the transfer means, the control means causes the second sheet to pass through the transfer means and the fixing means again using the re-conveying means after the second image has been fixed by the fixing means so that the first image and the second image face each other in the binding means, and then conveys the second sheet to the binding means; 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. a first conveying path and a second conveying path branched off midway along a path from the fixing unit to the binding unit, the first conveying path along which the sheet is reversed and conveyed, and the second conveying path along which the sheet is conveyed without being reversed; a switching member that switches a sheet transport path between the first transport path and the second transport path; Further provided with the control unit controls the transport paths of the first sheet and the second sheet using the switching member so that the first image and the second image face each other in the binding unit.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

10. the binding means bonds the first sheet and the second sheet by applying heat and pressure to the first sheet and the second sheet in a state in which an adhesive is applied to at least one of the first sheet and the second sheet, 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

11. an image forming unit having the transfer means, forming an image on the first sheet and the second sheet using a printing toner, and applying an adhesive toner as the adhesive to at least one of the first sheet and the second sheet; 11. The image forming apparatus according to claim 10.

12. When producing the final product, the control means transfers a third image onto a surface of the first sheet opposite to a surface on which the first image is formed, and transfers a fourth image onto a surface of the second sheet opposite to a surface on which the second image is formed, thereby producing the final product in which the third image and the fourth image are formed on the back side of the double-page spread of the final product; and controlling conveyance of the first sheet and the second sheet so that the number of times the first sheet passes through the fixing means before the third image is transferred thereon is equal to the number of times the second sheet passes through the fixing means before the fourth image is transferred thereon; 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images