Booklet production device, image formation system, and image formation device

Abstract

To improve the environmental performance of a booklet production device.SOLUTION: The booklet production device produces a booklet by applying heat and pressure to a plurality of sheets having powder adhesive applied to their binding margins. The booklet production device has a first adhesion mode and a second adhesion mode. In the first adhesion mode, the application amount of the powder adhesive applied to the binding margin is a first application amount, and a thermal parameter proportional to the amount of heat supplied to the plurality of sheets is a first value. In the second adhesion mode, the application amount of the powder adhesive applied to the binding margin is a second application amount, and the thermal parameter is a second value. The first value is greater than the second value. The first application amount is less than the second application amount.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a booklet producing apparatus, an image forming system, and an image forming apparatus. [Background technology]

[0002] A booklet making device makes a booklet by stapling multiple sheets on which images are printed using an electric stapler. However, metal staples prevent the booklet from being recycled. According to Patent Document 1, a post-processing device is proposed that makes a booklet by bonding multiple sheets with a powder adhesive (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-209859 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, the booklet production apparatus is also required to achieve the Sustainable Development Goals (SDGs). In particular, it is required to improve the environmental performance of the booklet production apparatus, such as by reducing the amount of powder adhesive used to produce the booklet or by reducing the frequency of replacing parts used in the booklet production apparatus. Therefore, an object of the present invention is to improve the environmental performance of the booklet production apparatus. [Means for solving the problem]

[0005] The present invention relates to, for example, A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first adhesive mode is such that an application amount of the powder adhesive applied to the binding margin is a first application amount, and a heat parameter proportional to an amount of heat supplied to the plurality of sheets by the heating means is a first value; the second adhesive mode is such that the powder adhesive is applied to the binding margin in a second application amount and the thermal parameter is a second value; the first value is greater than the second value; the first coating amount is less than the second coating amount; The present invention provides a booklet production device comprising: Effect of the Invention

[0006] According to the present invention, the environmental performance of the booklet production device is improved. [Brief description of the drawings]

[0007] [Figure 1] A diagram illustrating an image forming system (booklet production device) [Diagram 2] A diagram explaining how adhesive toner is applied to the binding margin [Diagram 3] Diagram explaining the alignment process [Figure 4] Diagram explaining the adhesive process [Diagram 5] Diagram explaining the functions of a CPU [Figure 6] Diagram explaining how to switch between glue modes [Figure 7] Flowchart explaining how to switch between glue modes [Figure 8] Diagram explaining the test method [Figure 9] Diagram explaining the test results [Figure 10] Flowchart showing a booklet production method including switching of adhesive modes [Figure 11] A diagram illustrating an image forming system (booklet production device) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0009] <Example 1> (1) Image forming system As shown in Fig. 1, the image forming system 1 has an image forming apparatus 100 and a post-processing apparatus 130. The post-processing apparatus 130 is a sheet processing apparatus connected to the image forming apparatus 100. The image forming apparatus 100 forms an image on a sheet S, which is a recording material. The intermediate conveying unit 120 conveys the sheet S on which the image has been formed to the post-processing apparatus 130. The post-processing apparatus 130 performs post-processing on the sheet S as necessary and outputs it. Note that the image forming system 1 may be understood as a booklet production apparatus, and the post-processing apparatus 130 may be understood as a booklet production apparatus.

[0010] The image forming apparatus 100 includes a sheet cassette 8, an image forming section 10, a fixing device 6, and a housing 19 that houses these components. The image forming section 10 forms a toner image on a sheet S fed from the sheet cassette 8. The fixing device 6 executes a fixing process to fix the toner image on the sheet S.

[0011] The sheet cassette 8 is provided at the bottom of the image forming apparatus 100. The sheet cassette 8 is inserted into the housing 19 so as to be removable, and can store a large number of sheets S. In this embodiment, it is assumed that the maximum size of the sheet S on which an image can be formed is A4 size (297 mm length x 210 mm width). The long side of the A4 size sheet S is parallel to the conveying direction of the sheet S. The feed roller 81 feeds the sheet S from the sheet cassette 8, and passes the sheet S to a pair of conveying rollers 82. The multi-tray 20 can also feed the sheets S one by one.

[0012] The image forming section 10 is a tandem-type electrophotographic unit including four process cartridges 7n, 7y, 7m, and 7c, an exposure device 2, and a transfer unit 3. ymc means yellow, magenta, and cyan, respectively. n means powder adhesive. In the following, as an example, the powder adhesive is called adhesive toner Tn. The letters nymc indicating the color of the toner may be omitted from the reference symbol. The color of the adhesive toner may be transparent or black. When the color of the adhesive toner is transparent, black is realized by appropriately mixing yellow, magenta, and cyan (process black). The toner type (material) used as the yellow, magenta, and cyan toner and adhesive toner is, for example, a thermoplastic resin. Examples of thermoplastic resins include polyester resin, vinyl resin, acrylic resin, and styrene acrylic resin. The process cartridges 7n, 7y, 7m, and 7c enable multiple parts responsible for the image forming process to be replaced as a whole. In other words, the process cartridges 7n, 7y, 7m, and 7c are formed by integrating a plurality of parts.

[0013] The process cartridges 7n, 7y, 7m, and 7c have corresponding developing devices Kn, Ky, Km, and Kc, photoconductor drums Dn, Dy, Dm, and Dc, and charging rollers Cn, Cy, Cm, and Cc. The structure of the process cartridges 7n, 7y, 7m, and 7c is substantially the same, except for the type of toner.

[0014] The developing devices Ky, Km, Kc each have a container for containing powder (e.g., toner) and a coating roller (coating sleeve) for coating the powder on the photosensitive drums Dn, Dy, Dm, Dc. More specifically, the developing devices Ky, Km, Kc each contain yellow, magenta, and cyan toner for forming a visible image on the sheet S. The developing device Kn contains adhesive toner Tn. The adhesive toner Tn is used to form a user image (original image) and to thermally and compress a plurality of sheets S in the post-processing device 130. An image made of the adhesive toner Tn is formed on the photosensitive drum Dn by development using the adhesive toner Tn.

[0015] The image forming unit 10 may have a fifth process cartridge that uses a toner exclusively for adhesion or a black toner. The type and number of printing toners can be changed depending on the application of the image forming apparatus 100.

[0016] The charging rollers Cn, Cy, Cm, and Cc are chargers that uniformly charge the surfaces of the corresponding charging rollers Cn, Cy, Cm, and Cc. The exposure device 2 is disposed below the process cartridges 7n, 7y, 7m, and 7c and above the sheet cassette 8. The exposure device 2 irradiates the photosensitive drums Dn, Dy, Dm, and Dc with corresponding laser beams Jn, Jy, Jm, and Jc to form electrostatic latent images. The exposure device 2 may also be called an optical scanning device.

[0017] The developing devices Kn, Ky, Km, and Kc form toner images by attaching toner to the electrostatic latent images on the photoconductor drums Dn, Dy, Dm, and Dc. The developing devices Kn, Ky, Km, and Kc may also be referred to as developing devices.

[0018] The transfer unit 3 includes a transfer belt 30 as an intermediate transfer body (secondary image carrier). The transfer belt 30 is an endless belt wound around an inner roller 31 and a tension roller 32. The outer peripheral surface (image forming surface) of the transfer belt 30 faces the photosensitive drums Dn, Dy, Dm, and Dc. Primary transfer rollers Fn, Fy, Fm, and Fc are disposed on the inner peripheral side of the transfer belt 30 so as to face the photosensitive drums Dn, Dy, Dm, and Dc.

[0019] The primary transfer rollers Fn, Fy, Fm, and Fc transfer the toner images from the corresponding photoconductor drums Dn, Dy, Dm, and Dc to the transfer belt 30. The primary transfer rollers Fn, Fy, Fm, and Fc may be called primary transfer devices. The toner images are transported to the secondary transfer section by the counterclockwise rotation of the transfer belt 30.

[0020] The secondary transfer roller 5 is disposed so as to face the inner roller 31, and forms a transfer nip 52 between the secondary transfer roller 5 and the transfer belt 30. The transfer nip 52 transfers a toner image from the transfer belt 30 to the sheet S. The transfer nip 52 may be called a secondary transfer portion. The cleaning blade 71 is a cleaning member for cleaning the toner remaining on the transfer belt 30. The toner scraped off by the cleaning blade 71 is accumulated in a collection container (not shown).

[0021] A fixing device 6 is disposed above the secondary transfer roller 5 (downstream in the conveying direction of the sheet S). The fixing device 6 applies heat and pressure to the sheet S passing through a fixing nip 61. This causes the toner image to be fixed onto the sheet S. The fixing device 6 has a fixing heater 62 for heating the toner image and the sheet S. The fixing heater 62 is, for example, a halogen heater or a ceramic heater.

[0022] As shown in FIG. 1, the switching guide 33 is a flap-shaped guide member provided downstream of the fixing device 6 in the conveying direction of the sheet S. When a single-sided printing mode in which an image is formed on one side of the sheet S is selected, the switching guide 33 guides the sheet S to a discharge roller 34. When a double-sided printing mode in which an image is formed on both sides of the sheet S is selected, the switching guide 33 guides the sheet S with an image formed on the first side to a switchback roller pair 35. The switchback roller pair 35 conveys the sheet S in a first direction. When the rear end of the sheet S is in a state in which it can enter the double-sided conveying path 36, the switchback roller pair 35 starts to reverse. As a result, the sheet S is conveyed to the double-sided conveying path 36. The double-sided conveying path 36 conveys the sheet S again to the secondary transfer unit. As a result, an image is formed on the second side of the sheet S.

[0023] The discharge roller 34 conveys the sheet S to an intermediate conveying unit 120. The intermediate conveying unit 120 has a pair of conveying rollers 121 and 122. The pair of conveying rollers 121 and 122 convey the sheet S to a post-processing device 130.

[0024] (2) After-treatment device The post-processing device 130 is a floor-standing type sheet processing device and has a function of buffering a plurality of sheets, a function of aligning a plurality of sheets, and a function of gluing a sheet stack.

[0025] In the following, the end of the sheet S on the front side in the transport direction is referred to as the leading end. The end of the sheet S on the rear side in the transport direction is referred to as the trailing end. Of the two ends of the sheet S, the end that enters the post-processing device 130 first is referred to as the first end. Of the two ends of the sheet S, the end that enters the post-processing device 130 later is referred to as the second end. Note that the leading end may be changed from the first end to the second end and the trailing end may be changed from the second end to the first end due to the switchback transport performed by the post-processing device 130.

[0026] The sheet S conveyed from the intermediate conveying unit 120 is delivered to the entrance rollers 21 of the post-processing device 130. A sheet sensor 27, also called an entrance sensor, is disposed downstream of the entrance rollers 21. When the sheet sensor 27 detects the rear end of the sheet S, the conveying roller pair 22 accelerates the sheet S. When the rear end of the sheet S, whose discharge destination is set to the upper tray 25, arrives between the conveying roller pair 22 and the conveying roller pair 24, the conveying roller pair 22 decelerates. This causes the conveying speed of the sheet S to become a predetermined discharge speed. The conveying roller pair 22 discharges the sheet S to the upper tray 25.

[0027] When the trailing end of the sheet S, the discharge destination of which is set to the lower tray 37, passes through the check valve 23, the conveying roller pair 22 stops conveying the sheet S. After that, the conveying roller pair 22 starts to rotate in the reverse direction. As a result, the sheet S switches back and is conveyed to the conveying roller pair 26. When the sheet sensor 60 provided downstream of the conveying roller pair 26 detects the leading end of the sheet S, the two rollers constituting the conveying roller pair 24 separate. As a result, the conveying roller pair 24 becomes capable of receiving the following sheet S. Furthermore, the conveying roller pair 26 stops with the preceding sheet S sandwiched between them. The conveying roller pair 26 starts to rotate in the reverse direction in response to the arrival of the following sheet S. As a result, the following sheet S is stacked on top of the preceding sheet S. By repeating the switchback of the sheet S by the conveying roller pair 26, a plurality of sheets S are stacked to form a sheet bundle. Such a sheet bundle forming operation may be called a buffer operation. A unit that realizes the buffer operation is called a buffer unit 80. It is not essential that a sheet stack is formed in the buffer unit 80. For example, the buffer unit 80 may switch back the sheets S arriving from the image forming apparatus 100 and transport the sheets S to the intermediate stacking unit 42. In this case, a sheet stack is formed in the intermediate stacking unit 42.

[0028] When the sheet stack is completed in the buffer unit 80, the conveying roller pair 26 conveys the sheet stack toward the intermediate stacking unit 42. The sheet stack passes through the conveying roller pair 28 and the sheet sensor 50. The sheet stack is further conveyed to the intermediate stacking unit 42 by the kick-out roller 29. A movable vertical alignment plate 39 is disposed in a standby position at the most downstream portion of the intermediate stacking unit 42. The sheet stack is aligned by hitting the vertical alignment plate 39.

[0029] A plurality of sheet bundles are stacked in sequence on the intermediate stacking section 42. As a result, a predetermined number of sheets S that form a booklet are stacked on the intermediate stacking section 42. When the alignment of the predetermined number of sheets S is completed, the thermocompression bonding unit 51 performs a binding operation (thermocompression bonding process) to form a booklet. The vertical alignment plate 39 moves from the standby position to the discharge position, pushing the booklet toward the discharge rollers 38. When the leading edge of the booklet is clamped by the discharge rollers 38, the vertical alignment plate 39 stops and returns to the standby position again. The discharge rollers 38 discharge the booklet received from the vertical alignment plate 39 from the discharge port 46 to the lower tray 37.

[0030] In the above description, the post-processing device 130 forms a sheet bundle consisting of a plurality of sheets S by using the buffer unit 80, and conveys the sheet bundle to the intermediate stacking unit 42. However, a single sheet S may be conveyed to the intermediate stacking unit 42.

[0031] (3) Printing area of ​​adhesive toner Tn FIG. 2A shows a printing area 211 of the adhesive toner Tn. The printing area 211 is secured in the binding margin of the sheet S. In this example, the printing area 211 extends parallel to the long side of the sheet S. The printing area 211 is provided at the end close to the long side. As a result, the post-processing device 130 stacks multiple sheets S and heats and presses the printing areas 211 of the multiple sheets S, thereby bonding the multiple sheets S together to form a booklet. The booklet in this case is a long-side bound booklet. Here, the width (length in the short side direction) of the adhesive toner image (printing area 211) is, for example, 4.0 mm. For example, the toner amount (laying amount) per unit area of ​​the adhesive toner Tn may be 0.45 mg / cm2.

[0032] 2B, a small print area 212 for adhesive toner Tn may be formed near the corner of the sheet S. This produces a booklet with corner fastenings. An image using adhesive toner Tn is not formed on the sheet S that will be the cover of the booklet.

[0033] As shown in FIG. 2C, the printing area 211 of the adhesive toner Tn may be formed on both sides of the sheet S, or may be formed only on one side of the sheet S. Whether the printing area 211 of the adhesive toner Tn is formed only on one side or on both sides can be selected in consideration of, for example, the adhesive capacity of the post-processing device 130, the adhesive capacity of the adhesive toner Tn, the type of the sheet S, and the intended use of the booklet. A booklet that is to be used as a storage version requires reliable adhesiveness. Reliable adhesiveness is also required when thick paper or a special sheet S is used as the cover of the booklet. Therefore, in these cases, the printing area 211 of the adhesive toner Tn is provided on both sides of the sheet S. When a booklet for simple, one-time use is produced, the printing area 211 of the adhesive toner Tn is formed only on one side of the sheet S.

[0034] When the adhesive toner Tn is applied to both sides of the sheet S, the adhesive toner Tn formed on the front side of one sheet S and the adhesive toner Tn formed on the back side of the other sheet S come into contact with each other and are adhered to each other. Note that the adhesive toner Tn is applied to the back side of the front cover and the front side of the back cover of the booklet, but the adhesive toner Tn is not applied to the front side of the front cover and the back side of the back cover.

[0035] (4) Booklet creation operation 3(A) to 3(D) show the booklet production operation executed in the intermediate stacking section 42. In the initial state, the intermediate stacking section 42 is empty. As an example, a sheet bundle W consisting of five sheets S is transported from the buffer section 80 to the intermediate stacking section 42. First, the intermediate stacking section 42 functions as a support member that supports the five sheets S.

[0036] The Y direction is a direction parallel to the stacking surface (stack plate) of the sheets S in the intermediate stacking section 42 and parallel to the transport direction of the sheets S transported from the kick-out roller 29 to the intermediate stacking section 42. The Y direction may be called the vertical direction. The X direction is a direction parallel to the stacking surface of the sheets S in the intermediate stacking section 42 and perpendicular to the Y direction. The X direction may be called the horizontal direction. The Z direction is a direction perpendicular to the X and Y directions (the normal direction of the stacking surface, the thickness direction of the stacked sheets S). The Z direction may be called the height direction. The opposite directions of the X, Y, and Z directions may be called the -X, -Y, and -Z directions, respectively.

[0037] The vertical alignment plate 39 and the vertical alignment roller 40 function as a first alignment unit that aligns a plurality of sheets S in a first direction (Y direction). The vertical alignment plate 39 is disposed at the most downstream portion of the intermediate stacking portion 42 in the Y direction. The vertical alignment plate 39 is a reference member (first reference member) that serves as a reference for the sheet position in the Y direction. The vertical alignment roller 40 is a conveying member that conveys the sheet S in the Y direction so that the sheet S is abutted against the vertical alignment plate 39 for alignment. The vertical alignment plate 39 includes a plurality of contact portions 39a to 39c that are spaced apart in the X direction. The plurality of contact portions 39a to 39c come into contact with the end of the sheet S. The vertical alignment plate 39 and the vertical alignment roller 40 are integrally configured as a movable unit 59 that is movable in the Y direction. The movable unit 59 is movable in the Y direction by a driving source such as a motor. That is, the positions of the vertical alignment plate 39 and the vertical alignment roller 40 in the Y direction are adjustable. The lateral alignment joggers 41a to 41c function as a second alignment unit that aligns the sheet in a second direction (X direction) perpendicular to the first direction.

[0038] The lateral alignment joggers 41a to 41c are moved in the X direction by a driving source such as a motor, and press the side edges of the sheets S stacked on the intermediate stacker 42. The lateral alignment plates 72a and 72b are reference members that serve as references for the position of the sheets S in the X direction. The lateral alignment plates 72a and 72b are disposed to face the lateral alignment joggers 41a and 41b in the X direction.

[0039] (4-1) Preparation stage As shown in FIG. 3A, the sheets S1 to S5 are conveyed toward the kick-out roller 29. The sheets S1 to S5 may be conveyed to the intermediate stacking unit 42 in a state in which the lower sheet Si protrudes in the Y direction from the upper sheet Si+1. Here, i is the index of the sheets S. Before the sheets S are stacked on the intermediate stacking unit 42, the vertical alignment plate 39 moves to a predetermined standby position in advance according to the size of the sheet S to be aligned. The standby position is set so that the end position of the sheet S in the -Y direction is constant, regardless of the size of the sheet S. In other words, the standby position is a position where the distance in the Y direction from the nip position of the kick-out roller 29 to the vertical alignment plate 39 is slightly longer than the length of the sheet in the Y direction. The horizontal alignment joggers 41a to 41c wait at a position away from the sheet S being conveyed in the X direction so as not to interfere with the conveyance of the sheet S.

[0040] (4-2) Vertical alignment stage 3(B) shows that the rear end of the first sheet S1 has passed through the nip of the kick-out roller 29, and the leading end of the sheet S1 has reached the vertical alignment roller 40. The sheet S1 abuts against the vertical alignment plate 39 and is aligned based on the position of the vertical alignment plate 39. As the vertical alignment roller 40 continues to rotate, the sheets S2 to S5 which arrive at the vertical alignment roller 40 after the sheet S1 abut against the vertical alignment plate 39 in order. As a result, the five sheets S1 to S5 are aligned in the Y direction (vertical direction) based on the position of the vertical alignment plate 39.

[0041] (4-3) Lateral alignment stage 3C shows that after the alignment of the sheets S1 to S5 in the Y direction (vertical direction) is completed, the alignment in the X direction (horizontal direction) is started. The lateral alignment joggers 41a to 41c are driven in the X direction, which is the alignment direction, to come into contact with the side edges of the sheets S1 to S5 and press the sheets S1 to S5 toward the lateral alignment plates 72a and 72b. Then, the other side edges of the sheets S1 to S5 come into contact with the contact surfaces 300 of the lateral alignment plates 72a and 72b, so that the sheets S1 to S5 are aligned in the X direction (horizontal direction) based on the positions of the lateral alignment plates 72a and 72b.

[0042] (3-4) Adhesion stage (thermocompression stage) 3(D) shows a state where the alignment of the five sheets S1 to S5 in the X and Y directions has been completed. The target position (alignment position) in the alignment operation is the position of the sheet stack W when the adhesive process (thermocompression bonding) is performed by the thermocompression bonding unit 51. As described above, the image forming apparatus 100 applies adhesive toner Tn to the sheets S1 to S5 so that the side on which the adhesive toner image is formed faces the thermocompression bonding unit 51. If the sheet S1 is the cover of a booklet, adhesive toner Tn is not applied.

[0043] The thermocompression bonding unit 51 applies a thermocompression bonding operation to the sheets S1 to S5 for which alignment has been completed. During this time, the lateral alignment joggers 41a to 41c retreat in the -X direction. This allows the intermediate stacking section 42 to be in a state in which it can receive the next plurality of sheets S. After that, the sheet stack W consisting of sheets S6 to S10 generated in the buffer section 80 is stacked on top of the sheets S1 to S5.

[0044] Thereafter, the above-mentioned four steps are repeated for the sheets S1 to S10, so that the sheets S1 to S10 are bonded together in a precisely aligned state.

[0045] As an example, the sheet bundle W is composed of five sheets S. However, the number of sheets S constituting the sheet bundle W may be two or three, etc. In other words, the number of sheets S included in the sheet bundle W may be equal to or less than the maximum number of sheets S that can be stacked in the buffer unit 80.

[0046] (5) Thermocompression unit As shown in FIG. 4A, the thermocompression bonding unit 51 has a heater 401 with a built-in heating element as a heat source, and an aluminum heating plate 402 arranged thereon. The heater 401 has a thickness of, for example, 1.0 mm. The heating plate 402 has a thickness of, for example, 1.5 mm. The heater 401 is, for example, a ceramic heater. The temperature of the heater 401 may be measured by a temperature sensor and controlled by a control circuit so that the measured temperature becomes a target temperature. For example, a target temperature (e.g., 240° C.) is set so that the surface temperature of a pressure applying portion 409 of the heating plate 402 becomes 200° C. By providing the pressure applying portion 409 on the heating plate 402, the heat and pressure of the thermocompression bonding unit 51 are concentrated at the binding position of the sheet stack W. As a result, the efficiency of heating and pressing is improved.

[0047] The heater 401 is supported by a heater support 403 made of resin. The pressure lever 404 obtains power from a motor M1 shown in FIG. 5 in order to pressurize the sheet stack W by pushing down the thermocompression bonding unit 51 in the -Z direction (downward). The pressure of the pressure lever 404 is transmitted to the pressure section 409 via a metal stay 405 serving as a rigid body. The pressure of the pressure lever 404 can be controlled according to the amount of movement of the pressure lever 404 in the -Z direction (downward). For example, the average surface pressure acting on the sheet stack W is, for example, 0.2 MPa.

[0048] The pressure plate 406 is a receiving member made of an elastic material (e.g., silicone rubber). The elastic material is used because the pressure plate 406 is a member that can stably receive pressure. The thickness of the pressure plate 406 is, for example, 2.0 mm. The thermocompression bonding unit 51 presses the sheet stack W1 consisting of sheets S1 to S5, and then separates from the sheet stack W1. Sheets S1 to S5 in FIG. 4A indicate the first to fifth sheets of a booklet as a product. Sheet S1 is the cover of the booklet. Therefore, no image of adhesive toner Tn is formed on sheet S1. Images of adhesive toner Tn are formed on the lower surfaces of the second and subsequent sheets S2 to S5 of the booklet.

[0049] As shown in Fig. 4(B), a sheet stack W2 is stacked on top of the sheets S1 to S5 that have been thermocompression bonded. The sheets W2 are made up of sheets S6 to S10. The thermocompression bonding unit 51 applies a thermocompression bonding operation to the sheet stack W2 stacked on the sheet stack W1. As a result, a booklet made up of many sheets S is produced.

[0050] The sheets S6 to S10 that are stacked later are included in the same booklet as the sheets S1 to S5. Therefore, an image of the adhesive toner Tn is formed on the lower surface of each of the sheets S6 to S10.

[0051] As an example, the post-processing device 130 can produce a part of a booklet consisting of a maximum of 100 sheets S. When the production of the booklet starts, the buffer section 80 buffers a maximum of five sheets S at a time to produce a sheet bundle W, and supplies the sheet bundle W to the intermediate stacking section 42. Each time a sheet bundle W arrives, the thermocompression bonding unit 51 performs a thermocompression operation consisting of a lowering operation, a pressurizing operation, and a lifting operation. By repeating the buffering operation and the thermocompression bonding operation, the productivity of the image forming apparatus 100 is not reduced, and booklets are produced efficiently.

[0052] When the thermocompression bonding operation on the sheet stack W including the last page of the booklet is completed in the intermediate stacking section 42, the vertical alignment plate 39 moves from the standby position to the discharge position. In other words, the vertical alignment plate 39 moves in parallel toward the discharge outlet 46, thereby pushing out the completed booklet. Discharge rollers 38 are provided at the discharge outlet 46. When the leading edge of the booklet slightly passes the discharge rollers 38, the vertical alignment plate 39 stops and returns to the standby position again. The discharge rollers 38 discharge the booklet onto the lower tray 37.

[0053] (6) Adhesion control (6-1) Basic Concept A booklet produced using adhesive toner Tn can be easily recycled. If the adhesive toner Tn used to produce the booklet can be reduced, the environmental performance of the image forming system 1 can be improved. On the other hand, reducing the adhesive toner Tn reduces the adhesive performance of the booklet, and the adhesive sheets S may peel off. Therefore, a method is required to reduce the amount of adhesive toner Tn used while maintaining the adhesive performance of the booklet.

[0054] The environmental performance of the image forming system 1 may be improved from another perspective. For example, adhesion control may be realized that can extend the life of consumable members (e.g., heater 401, pressure plate 406) used by the thermocompression bonding unit 51.

[0055] In other words, if the amount of adhesive toner Tn used is reduced or the lifespan of consumable members used by the thermocompression bonding unit 51 is extended, the environmental performance of the image forming system 1 is improved. It is also important to maintain the usability of the image forming system 1. For example, the number of sheets S on which the image forming system 1 forms images per unit time is sometimes called the image formation speed or throughput. Therefore, if the throughput can be maintained as much as possible, usability will also be maintained.

[0056] In the following, among a plurality of control parameters that affect the adhesive performance, at least one control parameter is set to improve the adhesive performance, and at least one other control parameter is set to improve the environmental performance (deteriorate the adhesive performance). In other words, by balancing at least two control parameters, the adhesive performance is maintained and the environmental performance of the image forming system 1 is improved. There are various combinations of at least two control parameters. Therefore, several combinations are exemplified below.

[0057] (6-2) Combination of adhesion time and amount of adhesive toner applied In the first embodiment, the adhesive time is the time required for the thermocompression bonding unit 51 to heat and press the adhesive toner Tn. The application amount of the adhesive toner Tn is the application amount of the adhesive toner Tn used in the binding margin of the sheets S. If the application amount of the adhesive toner Tn is reduced, the adhesive performance is reduced. On the other hand, if the adhesive time is extended, the adhesive performance is improved. Therefore, the adhesive performance is maintained by balancing the reduction in the application amount of the adhesive toner Tn and the increase in the adhesive time.

[0058] (6-3) Downtime If the adhesion time becomes long, the throughput of the image forming apparatus 100 decreases. Therefore, when downtime occurs in the image forming apparatus 100, the amount of adhesive toner Tn applied is reduced and the adhesion time is extended. Note that downtime is a time during which a toner image cannot be formed on the sheet S. For example, downtime is a delay time that occurs when the image forming apparatus 100 extends the interval between image formations or temporarily stops image formation in order to reduce defects during image formation. Such downtime occurs almost independently of the adhesion process. Therefore, even if the adhesion time is extended during downtime, the extension of the adhesion time does not reduce the throughput.

[0059] (6-3-1) Specific examples An example of an event that causes downtime is toner purging. Toner purging is a control that is executed to maintain the cleaning performance of the cleaning blade 71. When a predetermined start condition is satisfied, the image forming apparatus 100 causes the process cartridges 7n, 7y, 7m, and 7c to supply toner to the transfer belt 30, and the transfer belt 30 conveys the toner to the cleaning blade 71. The predetermined start condition is, for example, that the number of sheets on which images are continuously formed reaches a threshold number. By periodically supplying toner to the cleaning blade 71, the coefficient of friction between the cleaning blade 71 and the transfer belt 30 is maintained within an appropriate range. As a result, cleaning defects are less likely to occur.

[0060] It is difficult to simultaneously perform toner purging and image formation. If toner purging is performed during image formation, an unintended image will be formed on the sheet S. Therefore, the image forming apparatus 100 temporarily extends the image formation interval and performs toner purging during the extended image formation interval. The image formation interval is, for example, the distance from the rear end of the preceding sheet S to the front end of the succeeding sheet S or the time equivalent to that distance (transport time). The image forming apparatus 100 cannot perform image formation while toner purging is being performed. This results in downtime.

[0061] Another event that may cause downtime is cool-down control (cooling control) that is executed to suppress an increase in the internal temperature of image forming apparatus 100. Conditions for starting cool-down control include, for example, the internal temperature exceeding a threshold temperature, or the number of sheets S on which images have been continuously formed exceeding a threshold number. Cool-down control may include, for example, extending the image formation interval or temporarily stopping image formation.

[0062] Yet another event that can cause downtime is calibration, which is a control that corrects image density and image formation position when a predetermined start condition is met.

[0063] Another event that may cause downtime is detection of remaining toner. Detection of remaining toner refers to detecting the amount of toner remaining in the process cartridge 7.

[0064] The adhesion modes of the image forming system 1 may include a throughput priority mode and an environment priority mode. When the image forming system 1 is producing a booklet in the throughput priority mode, a downtime occurrence condition may be met. When the downtime occurrence condition is met, the image forming apparatus 100 switches the adhesion mode from the throughput priority mode to the environment priority mode. In other words, the image forming apparatus 100 operates in the environment priority mode during the downtime. The throughput priority mode is, for example, a mode in which the amount of adhesive toner Tn applied is large and the adhesion time is short. The environment priority mode is, for example, a mode in which the amount of adhesive toner Tn applied is small and the adhesion time is long.

[0065] (6-4) Control system FIG. 5 shows a control system of the image forming system 1. The dashed lines indicate optional functions. The CPU 501 executes a control program stored in the memory 502 to realize various functions. Some or all of these functions may be realized by a hardware circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA). The memory 502 is a storage device that may include a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), a solid state drive (SDD), and the like. The counter 503 counts the number of sheets S on which images are continuously formed.

[0066] The environmental sensor 504 is a sensor that detects the temperature or humidity of the environment in which the image forming apparatus 100 is installed, or the internal temperature of the image forming apparatus 100. The image sensor 505 is an image sensor that reads a test image formed on the photoconductor drum D, the transfer belt 30, or the sheet S. The remaining amount sensor 506 is a sensor that detects the remaining amount of toner contained in the process cartridge 7. The operation unit 507 includes a display that displays information to the user, and a touch device (input device) used by the user to input information.

[0067] A high-voltage power supply 531 generates a charging bias (charging voltage) supplied to the charging roller C and a developing bias (developing voltage) supplied to the developing roller of the developing device K. The CPU 501 can adjust the maximum density of the toner image by adjusting the charging bias or the developing bias.

[0068] The thermocompression bonding unit 51 includes a motor M1 that drives a pressure lever 404, and a heater 401. A motor M2 drives a feed roller 81 to rotate, for example.

[0069] The CPU 501 has a plurality of adhesion modes. The determination unit 511 determines whether or not a switching condition for the adhesion mode is satisfied. For example, the determination unit 511 may determine whether or not a downtime occurrence condition is satisfied. The switching unit 512 switches the adhesion mode based on the determination result of the determination unit 511. The application amount setting unit 513 sets the application amount corresponding to the adhesion mode set by the switching unit 512 to the exposure unit 2 corresponding to the process cartridge 7n. The application amount is set to the exposure unit 2 because the application amount of the adhesive toner Tn is changed according to the exposure amount. The application amount may be changed by adjusting the charging bias or the developing bias of the process cartridge 7n. For example, the application amount of the adhesive toner Tn applied on the photosensitive drum Dn may be changed by changing the potential difference between the surface potential in the exposure area on the photosensitive drum Dn and the surface potential of the developing roller of the developing device Kn. The adhesion time setting unit 514 sets the adhesion time (heating and pressing time) corresponding to the adhesion mode set by the switching unit 512 to the thermocompression bonding unit 51.

[0070] The temperature setting section 515 sets a target temperature of the heater 401 of the thermocompression bonding unit 51. The pressure setting section 516 sets the pressure applied by the pressure lever 404 of the thermocompression bonding unit 51.

[0071] The purge control unit 521 starts a toner purge in accordance with the count value of the counter 503. The purge control unit 521 controls the process cartridges 7y, 7m, and 7c and the transfer belt 30 to execute a toner purge.

[0072] The cooling control unit 522 starts the cool-down control when the internal temperature detected by the environment sensor 504 exceeds the threshold temperature. When the cool-down control starts, the cooling control unit 522 may instruct the interval control unit 525 to lengthen the image formation interval. This causes the internal temperature to gradually decrease.

[0073] The calibration unit 523 starts calibration when the count value of the counter 503 reaches a predetermined threshold value. The calibration unit 523 controls the image forming apparatus 100 to form a test image on the sheet S. The calibration unit 523 causes the image sensor 505 to read the test image, and corrects the image density and the image forming position based on the reading result. The remaining amount detection unit 524 detects the remaining amount of toner contained in the process cartridges 7n, 7y, 7m, and 7c using the remaining amount sensor 506.

[0074] The interval control unit 525 controls the image formation interval by controlling the operation timing of the motor M2. For example, when the sheet S passes through the fixing device 6, curling may occur on the sheet S. The user can switch the image formation interval from the normal interval to a long image formation interval through the operation unit 507, thereby reducing curling on the sheet S. Feeding and conveying multiple sheets S at this long image formation interval may be called a curl suppression mode.

[0075] (6-5) Examples of specific control methods As an example, when the number of sheets S on which images are formed becomes equal to or greater than a predetermined threshold, the CPU 501 switches the adhesive mode and executes toner purging. For example, the threshold number is set to 30 sheets. In toner purging, the toners Ty, Tm, and Tc are transported to the cleaning blade 71 by the transfer belt 30. For example, the downtime caused by the toner purging is 1.0 second.

[0076] The counter 503 includes a purge counter Cp. The purge counter Cp is incremented by +1 each time an image is formed on one sheet S. The CPU 501 (determination unit 511) determines whether the purge counter Cp is equal to or greater than a predetermined threshold Cpth (e.g., 30). When the purge counter Cp is equal to or greater than the predetermined threshold Cpth, the CPU 501 executes a toner purge in accordance with the timing at which the thermocompression bonding unit 51 executes the bonding process. When the toner purge is completed, the CPU 501 resets the purge counter Cp to 0.

[0077] FIG. 6A is a diagram for explaining the timing of toner purging and the adhesion conditions. As an example, it is assumed that a booklet consisting of 20 sheets S is produced. The post-processing device 130 performs the adhesion process for every 5 sheets S. The count value of the purge counter Cp at the start of printing is 18. The threshold value Cpth is 30 sheets. Nb indicates the number of sheets S until the next adhesion process is performed. When the adhesion process is performed, Nb is reset to a predetermined value (e.g., 5 sheets). Note that Nb is a count-down counter that subtracts 1 for each sheet S.

[0078] The purge counter Cp is incremented every time an image is formed on a sheet S. The adhesion time after the fifth sheet S and the adhesion time after the tenth sheet S are both 2.0 seconds. This is because the count value of the purge counter Cp is less than the threshold value Cpth. Therefore, toner purge is not executed.

[0079] On the other hand, the adhesion time after the 15th sheet S is set to 3.0 seconds. This is because the count value of the purge counter Cp is equal to or greater than the threshold value Cpth. Therefore, the CPU 501 executes toner purge. Thereafter, the purge counter Cp is reset to 0. The adhesion time after the 20th sheet S is 2.0 seconds. This is because the count value of the purge counter Cp is less than 30. Therefore, toner purge is not executed. In this way, the CPU 501 (determination unit 511) determines whether or not to execute toner purge based on the count value of the purge counter Cp when the adhesion process is executed.

[0080] Furthermore, the CPU 501 extends the adhesion time during the period in which the toner purge is performed, and reduces the amount of adhesive toner Tn applied to the five sheets S to be adhered during the extended adhesion time.

[0081] (6-6) Flowchart 7 shows a control method executed according to a control program by the CPU 501. When applying the adhesive toner Tn, the CPU 501 executes the following processes.

[0082] In S701, the CPU 501 (determination unit 511) acquires information required to determine whether to switch the adhesion mode. For example, the determination unit 511 reads out the count value of the purge counter Cp from the memory 502.

[0083] In S702, the CPU 501 (determination unit 511) determines whether or not the switching condition is satisfied based on the acquired information. For example, the determination unit 511 may execute the determination using the following formula.

[0084] Cp ≧ Cmth (Eq1) Cmth = Cpth - Nb (Eq2) Here, Cmth is a threshold value that specifies the adhesive mode switching condition. Cp is the count value of the purge counter Cp. Cpth is a threshold value for toner purging (e.g., 30 sheets). The CPU 501 executes the adhesive process and the toner purging in parallel at the timing of the first adhesive process that arrives after Cp becomes equal to or greater than Cpth.

[0085] According to FIG. 6A, at the time when adhesive toner Tn is applied to the 10th sheet S, Cp=27 and Cmth=29. Therefore, the switching condition is not satisfied. On the other hand, at the time when adhesive toner Tn is applied to the 11th sheet S, Cp=28 and Cmth=25. Therefore, the switching condition is satisfied. When the switching condition is satisfied, the CPU 501 proceeds from S702 to S703.

[0086] In S703, the CPU 501 (switching unit 512) sets the adhesion mode to the environment-priority mode. For example, the application amount is set to 0.40 mg / cm2. The adhesion time is set to 3.0 seconds. After that, the CPU 501 proceeds from S703 to S704.

[0087] On the other hand, if the switching condition is not satisfied in S702, the CPU 501 proceeds from S702 to S711.

[0088] In S711, the CPU 501 (switching unit 512) sets the adhesion mode to the throughput priority mode. For example, the application amount is set to 0.45 mg / cm2. The adhesion time is set to 2.0 seconds. After that, the CPU 501 proceeds from S711 to S704.

[0089] In S704, the CPU 501 determines whether or not the booklet production is completed. If the booklet production is not completed, the CPU 501 returns from S704 to S701. If the booklet production is completed, the CPU 501 ends the control method.

[0090] The condition for executing the bonding process is that the number of sheets S that have arrived at the thermocompression bonding unit 51 has reached a predetermined number (e.g., 5 sheets). The condition for starting the toner purge is that the bonding mode is set to the environment-priority mode and that the thermocompression bonding unit 51 has started the bonding process. Alternatively, the condition for starting the toner purge is that the purge counter Cp is equal to or greater than the threshold value Cpth and that a predetermined number of sheets S (e.g., 5 sheets) have been carried into the intermediate stacking section 42.

[0091] In this manner, the application amount of adhesive toner and the adhesion time (heating and pressurizing time) may be determined based on the count value of the purge counter Cp.

[0092] However, image formation cannot be performed while toner purging is being performed. Therefore, downtime (e.g., 1.0 second downtime) occurs. That is, when toner purging is performed, a time lag of 1.0 second occurs when the sheet S is transported from the image forming apparatus 100 to the post-processing apparatus 130. The time required to produce a booklet when toner purging is performed and the adhesion time is 2.0 seconds is the same as the time required to produce a booklet when toner purging is performed and the adhesion time is 3.0 seconds. This is because a 1 second delay always occurs as long as toner purging is performed.

[0093] On the other hand, the adhesive strength between the sheets S in the booklet increases as the adhesive time increases. This is because, as the adhesive time increases, the amount of heat applied to the adhesive toner Tn increases, and the adhesive toner Tn melts more appropriately. In other words, the adhesive force acting between the toner particles increases. Furthermore, the toner penetrates into the gaps between the paper fibers of the sheets S. As a result, the so-called anchor effect comes into play, and the adhesive force increases.

[0094] Regarding the relationship between the amount of adhesive toner Tn applied and adhesive strength, the smaller the amount applied, the smaller the adhesive strength. This is because the smaller the amount of adhesive toner Tn applied, the larger the area of ​​direct contact between the surfaces of two adjacent sheets S without the toner interposed therebetween. This causes the adhesiveness to decrease. In particular, the less smooth the sheet S is, that is, the more uneven the surface of the sheet S is, the lower the adhesiveness becomes.

[0095] When the amount of adhesive toner Tn applied to the sheet S is reduced in order to reduce the consumption of adhesive toner Tn, the adhesive strength between the sheets S is reduced. Therefore, in the first embodiment, the adhesive strength is maintained by extending the adhesive time. That is, even if the amount of adhesive toner Tn applied is reduced, the adhesive strength between the sheets S is maintained. However, if the adhesive time is simply extended, the time required to produce a booklet will be extended. Therefore, in the first embodiment, the adhesive time is extended in accordance with the downtime caused by the image forming apparatus 100. This maintains the booklet production time and reduces the consumption of adhesive toner Tn. This improves the environmental performance of the booklet production apparatus.

[0096] However, depending on the material of the sheet S, the sheet S may discolor or deform due to heating and pressurization for a long time. The CPU 501 may set an upper limit time for adhesion time according to the type of sheet S specified by the user through the operation unit 507. In other words, the CPU 501 may adjust the application amount according to the upper limit time according to the type of sheet S. The memory 502 may store a table that stores the upper limit time according to the type of sheet S, and a table that stores the relationship between the upper limit time and the application amount. The CPU 501 may determine the upper limit time and the application amount using these tables.

[0097] If the amount of adhesive toner Tn applied is extremely reduced, the adhesive strength will be insufficient no matter how much the adhesive time is extended. Therefore, the CPU 501 determines the amount of reduction in adhesive toner Tn according to the extension time of the adhesive time within a range in which the adhesive strength can be maintained.

[0098] (6-7) Booklet production conditions and performance evaluation Here, a description will be given of the results of a booklet performance evaluation test carried out to confirm the effects of Example 1. In the performance evaluation test, various combinations of the application amount of adhesive toner Tn and the adhesion time were prepared, and the adhesive strength of the booklet was compared with the application amount of adhesive toner Tn consumed in producing the booklet.

[0099] In the evaluation test, a booklet consisting of 20 sheets S was produced. At this time, the count value of the purge counter Cp at the start of printing was 18. As shown in FIG. 6A, after an image was formed on the 15th sheet S, toner purging was performed.

[0100] In the first embodiment, the environment-priority mode was applied to the 11th to 15th sheets S in accordance with the timing of the toner purge. That is, the application amount was set to 0.40 mg / cm2. The bonding time of the bonding process executed when the 15th sheet S was conveyed to the thermocompression bonding unit 51 was set to 3.0 seconds.

[0101] The coating amount of Comparative Example I is 0.45 mg / cm2, and the adhesion time is 2.0 seconds. In other words, the throughput priority mode is applied even during toner purging in Comparative Example I. The coating amount of Comparative Example II is 0.40 mg / cm2, and the adhesion time is 2.0 seconds.

[0102] 8(A) shows the produced booklet 800. A test piece 801 was cut out from the booklet 800. The short side of the test piece 801 was 20 mm. The long side of the test piece 801 was 50 mm.

[0103] Fig. 8(B) shows the test environment. An upper holding member 811 held the first to thirteenth sheets S of the test piece 801. A lower holding member 812 held the fourteenth to twentieth sheets S. A digital force gauge 813 (FGP-2, manufactured by Nidec-Shimpo Corporation) was further connected to the upper holding member 811. The digital force gauge 813 was gradually pulled upward, and the measurement value (adhesion strength) of the digital force gauge 813 when the sheet S was peeled off was obtained.

[0104] The adhesive strength should be 1.0 N / cm or more per unit distance in the width direction of the test piece 801. Therefore, in the evaluation test, an adhesive strength of 1.0 N / cm or more was judged as OK. An adhesive strength of less than 1.0 N / cm was judged as NG.

[0105] The reason why the adhesive strength was measured in the section between the 13th sheet S and the 14th sheet S is because this section is the section in which the application amount and adhesion time were changed in Comparative Example I, Comparative Example II, and Example 1. In other words, the largest difference in adhesive strength occurs in this section.

[0106] The consumption amount of adhesive toner Tn for producing booklet 800 was calculated from the difference between the weight of the powder container of developing device K before producing booklet 800 and the weight of the powder container of developing device K after producing booklet 800.

[0107] The evaluation paper used was Red Label Presentation (Canon, A4 size). The average surface pressure was 0.2 MPa. The surface temperature of the heating plate 402 was 200°C.

[0108] Figure 9 shows the evaluation results. The coating amount and adhesion time are those during toner purging. When toner purging was not performed, the coating amount was the normal amount (0.45 mg / cm2) and the adhesion time was also the normal time (2.0 seconds).

[0109] In Comparative Example I, the throughput priority mode continues even during toner purging, so the application amount is large and the adhesion time is short. The adhesion strength is 1.0 N / cm. Therefore, the evaluation result is OK (passed). The toner consumption required to produce 800 booklets was 195 mg.

[0110] In Comparative Example II, the amount of adhesive toner Tn applied was small, and the adhesion time was short. Because the amount of adhesive toner Tn applied was small, the amount of toner consumed to produce the booklet 800 was 189 mg. However, because the amount of adhesive toner applied to the 11th to 15th sheets S was small, the adhesive strength of the booklet 800 was 0.8 N / cm. Therefore, the evaluation result was NG (failed).

[0111] The amount of application in Example 1 is small. The amount of toner consumed to produce booklet 800 was 189 mg. Meanwhile, the adhesion time was 3.0 seconds. The adhesive strength was 1.0 N / cm. Therefore, the evaluation result was OK. In Example 1, the extension of the adhesion time was performed in accordance with the toner purging. Therefore, the booklet production time of Comparative Example I, the booklet production time of Comparative Example II, and the booklet production time of Example 1 were equal. In this way, Example 1 can reduce the amount of toner consumption while maintaining the booklet production time and adhesive strength.

[0112] In the first embodiment, the adhesion time is extended and the amount of adhesive toner Tn applied is reduced in accordance with downtime that occurs in the image forming apparatus 100. That is, the adhesion mode is switched from the throughput priority mode to the environment priority mode in synchronization with the occurrence of downtime. This reduces the amount of toner consumed, improving the environmental performance of the image forming system 1. In addition, the frequency of replacing the process cartridge 7n is reduced, improving usability. In addition, the cost of producing booklets is reduced, improving usability.

[0113] In the first embodiment, the adhesion process and the toner purge are performed in synchronization. Specifically, the toner purge is performed in conjunction with the first adhesion process that arrives after the count value of the purge counter Cp exceeds a threshold value. However, this is merely an example. As shown in FIG. 6B, in order to emphasize the cleaning performance of the cleaning blade 71, the toner purge and the adhesion process may be performed simultaneously at the stage where the purge counter Cp exceeds a predetermined threshold value. That is, instead of performing the adhesion process for every five sheets S, the adhesion process may be performed for less than five sheets S in accordance with the toner purge timing. When the adhesion process is applied to a sheet stack W consisting of less than five sheets S, less heat is required for adhesion. Therefore, the CPU 501 may further reduce the temperature of the heating plate 402, further reduce the pressure, or further reduce the application amount.

[0114] In the first embodiment, toner purging is described as an example of an event that causes downtime. However, the environment priority mode may be applied in conjunction with other events, such as cool-down control, calibration, and toner remaining amount detection. In this case, the extension time of the adhesion time is set to be equal to or less than the downtime caused by the event.

[0115] <Example 2> (1) Basic Concept In the second embodiment, an extension of the image formation interval is described as an event that causes downtime. The image forming apparatus 100 feeds a plurality of sheets S at an image formation interval that can achieve a preset target throughput. However, when the sheets S that have been placed in a high humidity environment pass through the fixing device 6, the sheets S may curl. In such a case, the user switches the operation mode of the image forming apparatus 100 from the normal mode (non-curl suppression mode) to the curl suppression mode through the operation unit 507. In other words, the user places more importance on the booklet quality than the time required to produce the booklet, and selects the curl suppression mode (low throughput) as the operation printing mode. When the curl is reduced, the alignment of the sheets S in the thermocompression bonding unit 51 is improved, and the quality of the booklet is improved.

[0116] The image formation interval in the curl suppression mode is longer than the image formation interval in the normal mode. Therefore, the CPU 501 can make the adhesion time in the curl suppression mode longer than the adhesion time in the normal mode. Also, the CPU 501 can make the application amount in the curl suppression mode less than the application amount in the normal mode. The description of the first embodiment is used for the description of matters common to the first embodiment in the second embodiment.

[0117] (2) Application amount and adhesion time in curl suppression mode The difference between the image formation interval in the curl suppression mode and the image formation interval in the non-curl suppression mode is 1.0 second. In other words, the adhesion time in the curl suppression mode (e.g., 3.0 seconds) is extended by 1.0 second from the adhesion time in the non-curl suppression mode (e.g., 2.0 seconds). In this way, even if the adhesion time is extended by about 1.0 second in the curl suppression mode, the booklet production time in the curl suppression mode does not change.

[0118] Therefore, the CPU 501 (adhesion time setting unit 514) extends by about 1.0 second the adhesion time of the adhesion process executed every time a predetermined number of sheets S (e.g., 5 sheets) are transported to the thermocompression bonding unit 51. Furthermore, the CPU 501 (application amount setting unit 513) reduces the application amount of adhesive toner Tn to all sheets S in the curl suppression mode. For example, when the application amount in the non-curl suppression mode is 0.45 mg / cm2, the application amount in the curl suppression mode is reduced to 0.40 mg / cm2.

[0119] In the curl suppression mode, the amount of adhesive toner Tn applied onto the sheet S is small, but the adhesive time is extended. Thus, adhesive strength is maintained. Also, the adhesive time is extended within the range of the extension time of the image formation interval. Thus, the booklet production time is also maintained. In this way, the amount of adhesive toner Tn used can be reduced, and the environmental performance of the image forming system 1 is improved.

[0120] (3) Flowchart FIG. 10 shows a control method of the second embodiment executed by the CPU 501.

[0121] In step S1001, the CPU 501 (determination unit 511) acquires an operation mode as information required for the determination. The operation mode is selected by the user via the operation unit 507, for example.

[0122] In S1002, the CPU 501 (determination unit 511) determines whether the operation mode is the curl suppression mode. If the operation mode is the curl suppression mode, the CPU 501 proceeds from S1002 to S1003.

[0123] In S1003, the CPU 501 (interval control unit 525) sets the image formation interval to a long interval.

[0124] In S1004, the CPU 501 (switching unit 512) sets the adhesion mode to the environment-priority mode. As a result, the application amount setting unit 513 reduces the application amount. Also, the adhesion time setting unit 514 lengthens the adhesion time. After that, the CPU 501 proceeds from S1004 to S1005.

[0125] On the other hand, if the non-curl suppression mode is selected in S1002, the CPU 501 proceeds from S1002 to S1011. In S1011, the CPU 501 (interval control unit 525) sets the image formation interval to a short interval.

[0126] In S1012, the CPU 501 (switching unit 512) sets the adhesion mode to the throughput priority mode. As a result, the application amount setting unit 513 increases the application amount. Also, the adhesion time setting unit 514 shortens the adhesion time. After that, the CPU 501 proceeds from S1012 to S1005.

[0127] In S1005, CPU 501 controls image forming apparatus 100 and post-processing device 130 to produce a booklet. Image forming apparatus 100 forms images corresponding to, for example, 20 sheets S, and sequentially discharges the 20 sheets to post-processing device 130. Post-processing device 130 performs a bonding process every time five sheets S arrive at thermocompression unit 51.

[0128] In S1006, the CPU 501 determines whether or not the production of the booklet is completed. For example, when the booklet is discharged onto the lower tray 37, the CPU 501 determines that the production of the booklet is completed.

[0129] In this way, in the second embodiment, the adhesive time and the application amount are set based on the image formation interval. Compared to the first embodiment, in the second embodiment, the application amount of the adhesive toner Tn on all the sheets S is reduced. Therefore, in the second embodiment, the toner consumption amount is further reduced.

[0130] In the second embodiment, the "curl suppression mode" in which the image formation interval is extended is described as an example. The technical idea of ​​the second embodiment is applicable to the image forming system 1 having a plurality of operation modes each having a different image formation interval. In other words, when an operation mode using a relatively long image formation interval is selected, the adhesion time is extended and the coating amount is reduced.

[0131] For example, a user may place more importance on reducing toner consumption than on the booklet production time. In this case, the CPU 501 may further extend the image formation interval to further reduce toner consumption (consumption priority mode).

[0132] <Example 3> (1) Basic Concept In the first and second embodiments, the environmental performance of the image forming system 1 is improved by extending the adhesion time and reducing the amount of application. In the third embodiment, in addition to extending the adhesion time and reducing the amount of application, a lower target temperature of the heater 401 is adopted. This makes it possible to extend the life of the heater 401, and improves the environmental performance of the image forming system 1.

[0133] When the target temperature of heater 401 is lowered, the durability of components of thermocompression unit 51, such as heater 401, heating plate 402, and pressure plate 406, is improved. For example, deterioration of the silicone rubber plate used as pressure plate 406 is suppressed.

[0134] However, when the target temperature of the heater 401 decreases, the amount of heat applied to the adhesive toner Tn per unit time decreases, which may result in a decrease in the adhesive strength between the sheets S. Therefore, in the third embodiment, the total amount of heat applied to the adhesive toner Tn is maintained by extending the adhesive time, and the adhesive strength is maintained.

[0135] As described in the first and second embodiments, when downtime (e.g., an extension of the image formation interval) occurs in the image forming apparatus 100, the adhesion time setting unit 514 extends the adhesion time, and the application amount setting unit 513 reduces the application amount. Furthermore, the temperature setting unit 515 lowers the target temperature of the heater 401. This reduces the consumption of the adhesive toner Tn without extending the booklet production time, and improves the durability of the thermocompression bonding unit 51.

[0136] The reduction amount of adhesive toner Tn and the reduction amount of the target temperature of heater 401 are determined in advance based on the adhesive strength required for the booklet, the toner consumption amount, and the target life of thermocompression bonding unit 51. Combinations of adhesive time, application amount, and target temperature corresponding to downtime (e.g., image formation interval) are stored in memory 502. CPU 501 reads out from memory 502 the combination of adhesive time, application amount, and target temperature corresponding to the specified downtime or image formation interval.

[0137] When emphasis is placed on reducing the consumption of adhesive toner Tn, the target temperature of heater 401 is set to a high temperature and the application amount is set to a low amount. Conversely, when emphasis is placed on the durability of thermocompression bonding unit 51, the target temperature of heater 401 is set to a low temperature and the application amount is set to a large amount. In these cases, the bonding time is extended so as to ensure sufficient adhesive strength. Note that when sufficient adhesive strength is ensured, the bonding time may not be extended and the target temperature of heater 401 and the application amount may be balanced.

[0138] When it is desired to improve only the durability of the thermocompression bonding unit 51, the application amount may not be reduced, and only the target temperature of the heater 401 may be significantly lowered. In this case, the bonding time is extended so as to ensure sufficient bonding strength.

[0139] (2) Flowchart The flowchart of the embodiment 3 is the same as the flowchart of the embodiment 1 and the flowchart of the embodiment 2. However, the target temperature of the heater 401 in the environment priority mode is lower than the target temperature of the heater 401 in the throughput priority mode.

[0140] Thus, in the third embodiment, in addition to extending the adhesion time and reducing the amount of adhesive toner Tn applied, the target temperature of the heater 401 is also reduced. This achieves the effects described in the first and second embodiments, and also improves the durability of the thermocompression bonding unit 51.

[0141] <Example 4> (1) Basic Concept In the first and second embodiments, the environmental performance of the image forming system 1 is improved by extending the bonding time and reducing the amount of coating. In the third embodiment, the temperature of the heater 401 is lowered to improve the durability of the heater 401. In the fourth embodiment, in addition to extending the bonding time and reducing the amount of coating, the pressure of the pressure lever 404 is reduced. This makes it possible to extend the life of the thermocompression bonding unit 51, and improves the environmental performance of the image forming system 1. More specifically, when the pressure is reduced, the durability of the heater 401, the heating plate 402, the pressure plate 406, etc. is improved. When the pressure is reduced, for example, deformation of the silicone rubber plate that is the pressure plate 406 is suppressed. Furthermore, the power consumption of the motor M1 that drives the pressure lever 404 is reduced. Thus, the environmental performance of the image forming system 1 is improved.

[0142] However, when the pressure is reduced, the adhesion between the adhesive toners Tn and between the sheet S and the adhesive toner Tn is reduced. As a result, the contact thermal resistance increases, the amount of heat applied to the adhesive toner Tn per unit time decreases, and the adhesive strength between the sheets S may decrease. Therefore, in the fourth embodiment, the total amount of heat applied to the adhesive toner Tn is maintained by extending the adhesion time, and the adhesive strength is maintained. This improves the durability of the thermocompression bonding unit 51 and maintains the adhesive strength.

[0143] As described in the first to third embodiments, when downtime (e.g., an extension of the image formation interval) occurs, the adhesion time can be extended and the application amount can be reduced. In the fourth embodiment, the pressure is also reduced at the timing when the adhesion time is extended as described in the first to third embodiments. This maintains the booklet production time and improves the durability of the thermocompression bonding unit 51. As described in the first to third embodiments, a reduction in the consumption of adhesive toner Tn and a reduction in power consumption are also achieved.

[0144] The reduction amount of adhesive toner Tn and the reduction amount of pressure are determined in advance based on the adhesive strength required for the booklet, the toner consumption amount, and the target life of thermocompression bonding unit 51. Combinations of adhesive time, application amount, (target temperature is optional), and pressure corresponding to downtime (e.g., image formation interval) are stored in memory 502. CPU 501 reads out from memory 502 the combination of adhesive time, application amount, (target temperature), and pressure corresponding to the specified downtime or image formation interval.

[0145] When emphasis is placed on reducing the consumption of adhesive toner Tn, the pressure may be set to a high value and the application amount may be set to a low amount. Conversely, when emphasis is placed on the durability of the thermocompression bonding unit 51, the pressure may be set to a low value and the application amount may be set to a large amount. When it is desired to improve only the durability of the thermocompression bonding unit 51, only the pressure may be significantly reduced without reducing the application amount.

[0146] (2) Flowchart The flowchart of the fourth embodiment is the same as the flowcharts of the first, second and third embodiments. However, the pressure for the environment priority mode set by the pressure setting unit 516 is lower than the pressure for the throughput priority mode.

[0147] Thus, in the fourth embodiment, in addition to extending the adhesion time and reducing the amount of adhesive toner Tn applied, the pressure applied by the pressure lever 404 is also reduced. This achieves the effects described in the first, second, and third embodiments, and also improves the durability of the thermocompression bonding unit 51.

[0148] In addition, one of the pressure and the amount of application may be reduced and the other may be increased so that the bonding time and the adhesive strength are kept constant. Also, at least one of the pressure and the amount of application may be reduced and the bonding time may be extended so that the adhesive strength is maintained.

[0149] <Other> (1) Parameters that improve environmental performance and parameters that improve throughput As described above, the coating amount, the target temperature of the heater 401, the pressure of the pressure lever 404, and the bonding time are exemplified as parameters related to environmental performance and throughput. If any of the coating amount, the target temperature, and the pressure is reduced, the environmental performance improves, and if any of them is increased, the throughput improves. If the bonding time is extended, the environmental performance may improve. If the bonding time is shortened, the throughput improves. Therefore, the environment priority mode and the throughput priority mode are formed by combining at least two parameters out of these four parameters. That is, all of the four parameters may be appropriately combined, or three of the four parameters may be appropriately combined, or two of the four parameters may be appropriately combined, so that the adhesive strength is sufficiently secured. In this way, the combination of the selection of the adhesive time, the coating amount, the temperature of the heater 401, and the pressure and the selection of the increase or decrease thereof is arbitrary as long as the adhesive strength is maintained and the environmental performance is improved.

[0150] (2) Outline of adhesive toner Tn For example, a toner containing a thermoplastic resin may be used as the adhesive toner Tn according to the first to fourth embodiments. Examples of the thermoplastic resin include known thermoplastic resins such as polyester resin, vinyl resin, acrylic resin, styrene-acrylic resin, polyethylene, polypropylene, polyolefin, ethylene-vinyl acetate copolymer resin, and ethylene-acrylic acid copolymer resin. A plurality of these resins may be used.

[0151] The adhesive toner Tn may further contain a wax. As the wax, for example, known waxes such as ester waxes, which are esters of alcohol and acid, and hydrocarbon waxes such as paraffin wax may be used.

[0152] The adhesive toner Tn may contain a colorant. As the colorant, a known colorant such as a black colorant, a yellow colorant, a magenta colorant, or a cyan colorant can be used.

[0153] The adhesive toner Tn may contain a magnetic material, a charge control agent, a wax, and an external additive. In order to form an adhesive portion on the sheet S using the adhesive toner by using the electrophotographic method, the adhesive toner Tn has a weight average particle diameter of 5.0 μm or more and 30 μm or less. The weight average particle diameter may be 6.0 μm or more and 20 μm or less. A printing toner may be used as the adhesive toner Tn as long as it satisfies the adhesive property.

[0154] (3) Placement of post-treatment device 1, the post-processing device 130 having the thermocompression bonding unit 51 is disposed beside the image forming apparatus 100, but this is merely an example. As shown in FIG. 11, the post-processing device 130 and the thermocompression bonding unit 51 may be disposed on the upper part of the main body of the image forming apparatus 100.

[0155] <Technical ideas derived from examples> (Item 1) A heating means (e.g., a heater 401) for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressure applying means (e.g., a pressure lever 404, a pressure plate 406) for applying pressure to the sheets to which heat has been applied by the heating means to produce a booklet; A control means (e.g., CPU 501) for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, In the first adhesion mode, the powder adhesive is applied to the binding margin in a first application amount, and a heat parameter (e.g., adhesion time; temperature of the heater 401) proportional to the amount of heat supplied to the plurality of sheets by the heating means is a first value; the second adhesive mode is such that the powder adhesive is applied to the binding margin in a second application amount and the thermal parameter is a second value; the first value (e.g., 3.0 seconds; 300° C.) is greater than the second value (e.g., 2.0 seconds; 200° C.); The first coating amount (e.g., 0.40 mg / cm2) is less than the second coating amount (e.g., 0.45 mg / cm2); A booklet production apparatus (e.g., image forming system 1) characterized by the above.

[0156] As described in the first and second embodiments, in the environment-priority mode, the amount of adhesive toner Tn applied is reduced. This improves the environmental performance of the booklet production apparatus. If the amount of application is reduced, the adhesive strength may decrease. Therefore, the amount of heat supplied to the sheet S in the thermocompression bonding unit 51 is increased. This maintains the adhesive strength even when the environmental performance is improved. The amount of heat may be adjusted according to at least one of the temperature and heating time of the heater 401. (Item 2) the thermal parameter is a heating time for the heating means to heat the plurality of sheets, the first value is a first heating time, and the second value is a second heating time; The heating means is heating the plurality of sheets in the first bonding mode for the first heating time; heating the plurality of sheets in the second bonding mode for the second heating time. 2. The booklet production device according to item 1,

[0157] In this way, the adhesive strength of the booklet may be maintained by extending the adhesive time (heating time) according to the reduction in the application amount. (Item 3) The heating means is heating the plurality of sheets at a first temperature in the first bonding mode; heating the plurality of sheets at a second temperature in the second bonding mode; the first temperature is lower than the second temperature; 3. The booklet production device according to item 2,

[0158] As described in the third embodiment, the durability of the heater 401 may be improved by lowering the temperature of the heater 401. This further improves the environmental performance of the booklet production apparatus. In addition, both the amount of coating and the temperature of the heater 401 may be reduced. In either case, the required adhesive strength is achieved by extending the adhesive time. (Item 4) the thermal parameter is a temperature of the heating means, the first value is a first temperature, and the second value is a second temperature; The heating means is heating the plurality of sheets at the first temperature in the first bonding mode; heating the plurality of sheets at the second temperature in the second bonding mode; 2. The booklet production device according to item 1,

[0159] If the amount of toner applied is reduced to improve environmental friendliness, the adhesive strength is reduced. Therefore, CPU 501 may increase the temperature of heater 401 to increase the adhesive strength. This may ensure sufficient adhesive strength for the booklet. In this case, CPU 501 may maintain the adhesive time constant. In other words, CPU 501 can reduce the amount of toner applied without causing downtime. (Item 5) 5. The booklet producing apparatus according to any one of items 1 to 4, characterized in that the pressure applying means applies pressure to the plurality of sheets in parallel with the heating means heating the plurality of sheets.

[0160] Like the thermocompression bonding unit 51, pressure and heat may be applied simultaneously to the sheets S. This allows a plurality of sheets S to be bonded together efficiently. (Item 6) a pressure applied by the pressurizing means to the plurality of sheets in the first adhesion mode is lower than a pressure applied by the pressurizing means to the plurality of sheets in the second adhesion mode; 6. The booklet producing apparatus according to item 5,

[0161] As mentioned in the fourth embodiment, in the environment-first mode, the pressure of the pressure lever 404 may be reduced. This improves the durability of the pressure lever 404 and improves the environmental performance of the image forming system 1. The CPU 501 increases the adhesion time according to the reduction in the application amount and the reduction and amount of the pressure. This also maintains the adhesive strength of the booklet. (Item 7) the booklet production device is connected to an image forming device that forms images on the plurality of sheets and supplies the plurality of sheets to the booklet production device; The control means selecting the first adhesion mode when a throughput, which is the number of sheets on which images are formed per unit time in the image forming apparatus, is a first throughput; selecting the second adhesion mode when the throughput in the image forming apparatus is a second throughput; the first throughput is lower than the second throughput; 7. The booklet producing device according to any one of items 1 to 6,

[0162] As shown in FIG. 6(A) and other figures, there is a trade-off between environmental performance and throughput. Therefore, CPU 501 may select the adhesion mode depending on the throughput. For example, when the internal temperature of image forming apparatus 100 rises, CPU 501 reduces the throughput. CPU 501 may set the adhesion mode to the environmental priority mode during the period when the throughput is reduced. This improves the environmental performance of image forming system 1. Note that when the internal temperature of image forming apparatus 100 drops, CPU 501 increases the throughput. Also, CPU 501 sets the adhesion mode to the throughput priority mode. (Item 8) the control unit switches the throughput from the second throughput to the first throughput when a downtime occurs in the image forming apparatus during which the image forming apparatus cannot form an image. 8. The booklet producing apparatus according to item 7,

[0163] In this embodiment, downtime refers to time that occurs when throughput drops, rather than when image forming apparatus 100 stops completely (e.g., a sheet jam). When downtime occurs, the booklet production time becomes longer. However, this extension of the booklet production time is not caused by thermocompression bonding unit 51. Therefore, CPU 501 increases the bonding time by utilizing downtime that occurs unrelated to thermocompression bonding unit 51. In other words, the bonding time is also extended by utilizing the fact that downtime extends the booklet production time. Therefore, the booklet production time is not extended due to the extension of the bonding time. (Item 9) 9. The booklet producing apparatus according to item 8, wherein the downtime occurs in association with control relating to cleaning of a member (e.g., transfer belt 30) involved in the formation of the image in the image forming apparatus.

[0164] Cleaning control is necessary to maintain the quality of the image printed on the sheet S. When cleaning control is started, downtime occurs. Therefore, this downtime may be utilized to extend the bonding time. (Item 10) 9. The booklet producing apparatus according to item 8, wherein the downtime occurs due to an increase in an internal temperature of the image forming apparatus.

[0165] When the internal temperature of image forming apparatus 100 rises, CPU 501 reduces the throughput to reduce the internal temperature of image forming apparatus 100. Thus, the downtime for reducing the internal temperature may be utilized to extend the bonding time. (Item 11) 9. The booklet producing apparatus according to item 8, wherein the downtime occurs according to the number of sheets on which images are continuously formed in the image forming apparatus.

[0166] As described in the first embodiment, the toner purge is executed according to the purge counter Cp. Therefore, the downtime caused by the toner purge may be utilized to extend the adhesion time. (Item 12) 9. The booklet production apparatus according to item 8, wherein the downtime occurs in association with execution of a calibration for maintaining an image forming capability of the image forming apparatus.

[0167] The image forming apparatus 100 performs calibration in order to maintain the quality (e.g., image density, image forming position) of the image formed on the sheet S. Therefore, the downtime caused by the calibration may be utilized to extend the adhesion time. (Item 13) 9. The booklet production apparatus according to item 8, wherein the downtime occurs in association with detection of a remaining amount of a consumable used to form the image in the image forming apparatus.

[0168] The image forming apparatus 100 detects the remaining amount of toner held in the process cartridge 7n etc. using the remaining amount sensor 506. In order to detect the remaining amount more accurately, it is necessary to stop image formation, which causes downtime. Therefore, the downtime caused by the detection of the remaining amount of toner may be utilized to extend the adhesion time. (Item 14) the booklet production device is connected to an image forming device that forms images on the plurality of sheets and supplies the plurality of sheets to the booklet production device; The control means selecting the first adhesion mode when an image forming interval corresponding to a distance or time from a trailing edge of a preceding sheet to a leading edge of a succeeding sheet in the image forming device is a first image forming interval; selecting the second adhesion mode when the image formation interval in the image forming device is a second image formation interval; the first imaging interval is longer than the second imaging interval; 2. The booklet production device according to item 1,

[0169] It may be necessary to lengthen the image formation interval as described in the second embodiment. The CPU 501 may extend the bonding time by utilizing the processing time secured by lengthening the image formation interval. (Item 15) Item 15. The booklet producing apparatus according to item 14, wherein the first image forming interval has a higher ability to suppress curling occurring on the plurality of sheets than the second image forming interval has a higher ability to suppress curling occurring on the plurality of sheets.

[0170] As described in the second embodiment, it is effective to widen the image formation interval in order to reduce curling that occurs in the sheet S. Therefore, when a mode that suppresses curling is selected, the adhesion mode may be set to the environment-priority mode. (Item 16) The sheet conveying device further includes a support member (e.g., intermediate stacking unit 42) for supporting sheets constituting a booklet conveyed from the image forming device, Each time a predetermined number of sheets are conveyed to the support member, the heating means performs a heating process and the pressing means performs a pressing process; the control means, when a condition for executing an operation that will cause a downtime during which the image forming apparatus is unable to form an image, is satisfied, waits until the predetermined number of sheets are conveyed to the support member, and then executes the operation. 16. A booklet production device according to any one of items 1 to 15,

[0171] 6A, the thermocompression bonding unit 51 may execute the bonding process every time a predetermined number of sheets S arrive at the intermediate stacker 42. In other words, the timing at which the execution condition of an event that causes downtime is satisfied does not necessarily coincide with the execution timing of the bonding process. In this case, the CPU 501 may execute the bonding process at the earliest execution timing of the bonding process. (Item 17) The image forming apparatus further includes a support member for supporting sheets constituting a booklet conveyed from the image forming apparatus, Each time a predetermined number of sheets are conveyed to the support member, the heating means performs a heating process and the pressing means performs a pressing process; when an execution condition for an operation that causes a downtime during which the image forming apparatus is unable to form an image is satisfied, the control means causes the heating means to execute the heating process, causes the pressing means to execute the pressing process, and executes the operation before the predetermined number of sheets are conveyed to the support member. 16. A booklet production device according to any one of items 1 to 15,

[0172] 6B, when an execution condition of an event that causes downtime is satisfied, a bonding process may be executed together with the event. In this case, the thermocompression bonding unit 51 does not need to wait for a predetermined number of sheets S to arrive at the intermediate stacker 42. In this case, the CPU 501 may reduce the amount of application, lower the temperature of the heater 401, or lower the pressure, depending on the number of sheets S actually stacked on the intermediate stacker 42. (Item 18) 18. The booklet producing apparatus according to any one of items 1 to 17, wherein the control means determines the first value depending on the material of the plurality of sheets.

[0173] The adhesion time that causes deformation of the sheet S differs depending on the material of the sheet S. Therefore, the CPU 501 may determine the adhesion time in each adhesion mode depending on the material of the sheet S. (Item 19) 19. The booklet producing device according to any one of items 1 to 18, wherein the control means determines a combination of the first value and the application amount according to an adhesive strength required for the booklet.

[0174] CPU 501 may determine a combination of the first value (e.g., adhesion time, temperature of heater 401) and the application amount according to the adhesive strength required for the booklet. The adhesive strength required for the booklet differs depending on the application of the booklet. Therefore, CPU 501 may determine a combination of adhesion time, temperature of heater 401, pressure, and application amount according to the adhesive strength required for the booklet. (Item 20) a heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first adhesive mode, a coating amount of the powder adhesive applied to the binding margin is a first coating amount, and a pressure applied by the pressure means is a first pressure force; In the second adhesive mode, the powder adhesive is applied to the binding margin in a second application amount, and the pressure applied by the pressure means is a second pressure force. The first pressure is higher than the second pressure, the first coating amount is less than the second coating amount; A booklet production device comprising:

[0175] As mentioned in the fourth embodiment and the like, there is a trade-off between the pressure and the amount of application. Therefore, when the amount of application is reduced, the pressure is increased to maintain the adhesive strength required for the booklet. This reduces the amount of toner consumed. On the other hand, when the pressure is reduced, the amount of application may be increased to maintain the adhesive strength required for the booklet. This improves the durability of the thermocompression bonding unit 51 and may improve the environmental performance of the image forming system 1. (Item 21) a heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first bonding mode, a time during which the heating means heats the plurality of sheets is a first heating time, and a temperature of the heating means is a first temperature; the second bonding mode, a time during which the heating means heats the plurality of sheets is a second heating time, and a temperature to which the heating means heats the plurality of sheets is a second temperature; The first heating time is longer than the second heating time, the first temperature is lower than the second temperature; A booklet production device comprising:

[0176] As mentioned in the third embodiment, there is a trade-off between the bonding time and the temperature of the heater 401. When the temperature of the heater 401 decreases, the durability of the thermocompression bonding unit 51 improves, but the bonding strength may decrease. Therefore, when the temperature of the heater 401 decreases, the bonding time may be increased to maintain the bonding strength required for the booklet. This may improve the environmental performance of the image forming system 1. (Item 22) a heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first adhesion mode, a time during which the heating means heats the plurality of sheets is a first heating time, and a pressure applied by the pressure means is a first pressure; the second adhesion mode, a time during which the heating means heats the plurality of sheets is a second heating time, and a pressure applied by the pressure means is a second pressure force; the first heating time is longer than the second heating time, The first pressure is lower than the second pressure. A booklet production device comprising:

[0177] As mentioned in the fourth embodiment, there is a trade-off between the bonding time and the pressure. Therefore, when the durability of the thermocompression bonding unit 51 is improved by reducing the pressure, the CPU 501 may increase the bonding time. This may improve the environmental performance of the image forming system 1. (Item 23) An image forming system having a booklet production device (e.g., a post-processing device 130) and an image forming device, The image forming apparatus includes: An image forming means (e.g., image forming unit 10) for forming images on a plurality of sheets; a discharge means (e.g., an intermediate conveying unit 120, a discharge roller 34) for discharging the plurality of sheets to the booklet producing device, The booklet production device is a booklet production device according to any one of items 1 to 22. 1. An image forming system comprising: (Item 24) Item 24. The image forming system according to item 23, wherein the image forming apparatus has an application unit (e.g., a process cartridge 7n, a transfer unit 3) that applies the powder adhesive to each binding margin of the plurality of sheets.

[0178] As illustrated in FIG. 2(A) to FIG. 2(C), the process cartridge 7n and the transfer unit 3 apply powder adhesive to the binding margin. (Item 25) 25. The image forming system according to item 24, wherein the powder adhesive is a toner (e.g., adhesive toner Tn).

[0179] This allows the powder adhesive to be applied to the sheet S using the image forming unit 10 and an electrophotographic process. (Item 26) an image forming means for forming images on a plurality of sheets; an application means for applying a powder adhesive to the binding margins of the plurality of sheets; a discharge means for discharging the plurality of sheets to a booklet producing device; A control means for controlling the coating means, The booklet production device includes: a heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet, The control means has a first adhesion mode and a second adhesion mode, the first adhesive mode is such that an application amount of the powder adhesive applied to the binding margin is a first application amount, and a heat parameter proportional to an amount of heat supplied to the plurality of sheets by the heating means is a first value; the second adhesive mode is such that the powder adhesive is applied to the binding margin in a second application amount and the thermal parameter is a second value; the first value is greater than the second value; the first coating amount is less than the second coating amount; 1. An image forming apparatus comprising: (Item 27) A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, the control means has a first adhesion mode and a second adhesion mode, each of which is defined by a plurality of control parameters; the plurality of control parameters include an application amount of the powder adhesive to the binding margin, an amount of heat applied by the heating means, and a pressure applied by the pressure applying means; In the first adhesion mode, at least one of the control parameters is set to a corresponding first value, and at least one other of the control parameters is set to a corresponding second value; in the second adhesion mode, at least one of the plurality of control parameters is set to a corresponding third value, and at least one other of the plurality of control parameters is set to a corresponding fourth value; a combination of the first value and the second value is set so that an adhesive strength of the powder adhesive achieves a target strength, and environmental performance of at least one of the powder adhesive, the heating means, and the pressurizing means is improved compared to a combination of the third value and the fourth value; a combination of the third value and the fourth value is set so that the adhesive strength of the powder adhesive achieves the target strength, and a production time of the booklet made from the plurality of sheets is improved as compared to a combination of the first value and the second value. A booklet production device comprising:

[0180] Thus, in the environment-priority mode, any one of the application amount, the amount of heat (heating temperature, heating time), and the pressure is set to a value that improves environmental performance. In this case, the adhesive strength decreases. Therefore, the other control parameters are set to increase the adhesive strength. This improves environmental performance while maintaining the adhesive strength at the target strength. For example, when the application amount is reduced, the heating time, heating temperature, or pressure is increased. When the heating temperature is reduced, the heating time is increased. When the pressure is reduced, the heating time is increased.

[0181] In the throughput priority mode, any one of the coating amount, the amount of heat (heating temperature, heating time), and the pressure is set to a value that improves the throughput. In this case, the adhesive strength decreases. Therefore, the other control parameters are set to increase the adhesive strength. This improves the throughput while maintaining the adhesive strength at the target strength. For example, when the heating time is reduced, any one of the coating amount, the heating temperature, and the pressure is increased. (Item 28) In the first bonding mode, the application amount is set to the first value and the heat amount is set to a second value so that environmental performance of the powder adhesive is improved; In the second bonding mode, the application amount is set to the third value and the heat amount is set to the fourth value so as to improve a production time of the booklet; The first value (e.g., 0.40 mg / cm2) is less than the third value (e.g., 0.45 mg / cm2), The second value (e.g., 3.0 seconds) is greater than the fourth value (e.g., 2.0 seconds); 28. A booklet production apparatus according to item 27, characterized in that: (Item 29) In the first bonding mode, a heating temperature of the heating means is set to the first value and a heating time by the heating means is set to a second value so that environmental performance related to the heating means is improved; In the second bonding mode, a heating temperature of the heating means is set to the third value and a heating time of the heating means is set to the fourth value so as to improve a production time of the booklet; the first value is less than the third value; the second value is greater than the fourth value; 28. A booklet production apparatus according to item 27, characterized in that: (Item 30) In the first bonding mode, a pressure applied by the pressure applying means is set to the first value and a heating time by the heating means is set to a second value so that environmental performance related to the pressure applying means is improved; in the second bonding mode, the pressing force of the pressing means is set to the third value and the heating time of the heating means is set to the fourth value so as to improve the production time of the booklet, the first value is less than the third value; the second value is greater than the fourth value; 28. A booklet production apparatus according to item 27, characterized in that:

[0182] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0183] 401... heater, 404... pressure lever, 501... CPU

Claims

1. A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first adhesive mode is such that an application amount of the powder adhesive applied to the binding margin is a first application amount, and a heat parameter proportional to an amount of heat supplied to the plurality of sheets by the heating means is a first value; the second adhesive mode is such that the powder adhesive is applied to the binding margin in a second application amount and the thermal parameter is a second value; the first value is greater than the second value; the first coating amount is less than the second coating amount; A booklet production device comprising:

2. the thermal parameter is a heating time for the heating means to heat the plurality of sheets, the first value is a first heating time, and the second value is a second heating time; The heating means is heating the plurality of sheets in the first bonding mode for the first heating time; heating the plurality of sheets in the second bonding mode for the second heating time.

2. The booklet producing apparatus according to claim 1.

3. The heating means is heating the plurality of sheets at a first temperature in the first bonding mode; heating the plurality of sheets at a second temperature in the second bonding mode; the first temperature is lower than the second temperature; 3. The booklet producing apparatus according to claim 2.

4. the thermal parameter is a temperature of the heating means, the first value is a first temperature, and the second value is a second temperature; The heating means is heating the plurality of sheets at the first temperature in the first bonding mode; heating the plurality of sheets at the second temperature in the second bonding mode; 2. The booklet producing apparatus according to claim 1.

5. 2. The booklet producing apparatus according to claim 1, wherein said pressure applying means applies pressure to said plurality of sheets in parallel with said heating means applying heat to said plurality of sheets.

6. a pressure applied by the pressurizing means to the plurality of sheets in the first adhesion mode is lower than a pressure applied by the pressurizing means to the plurality of sheets in the second adhesion mode; 6. The booklet producing apparatus according to claim 5.

7. the booklet production device is connected to an image forming device that forms images on the plurality of sheets and supplies the plurality of sheets to the booklet production device; The control means selecting the first adhesion mode when a throughput, which is the number of sheets on which images are formed per unit time in the image forming apparatus, is a first throughput; selecting the second adhesion mode when the throughput in the image forming apparatus is a second throughput; the first throughput is lower than the second throughput; 2. The booklet producing apparatus according to claim 1.

8. the control unit switches the throughput from the second throughput to the first throughput when a downtime occurs in the image forming apparatus during which the image forming apparatus cannot form an image.

8. The booklet producing apparatus according to claim 7.

9. 9. The booklet producing apparatus according to claim 8, wherein the downtime occurs in association with control relating to cleaning of members involved in the formation of the image in the image forming apparatus.

10. 9. The booklet producing apparatus according to claim 8, wherein the downtime occurs due to an increase in an internal temperature of the image forming apparatus.

11. 9. The booklet producing apparatus according to claim 8, wherein the downtime occurs according to the number of sheets on which images are continuously formed in the image forming apparatus.

12. 9. The booklet producing apparatus according to claim 8, wherein the downtime occurs in association with execution of a calibration for maintaining an image forming capability of the image forming apparatus.

13. 9. The booklet producing apparatus according to claim 8, wherein the downtime occurs in association with detection of a remaining amount of a consumable used for forming the image in the image forming apparatus.

14. the booklet production device is connected to an image forming device that forms images on the plurality of sheets and supplies the plurality of sheets to the booklet production device; The control means selecting the first adhesion mode when an image forming interval corresponding to a distance or time from a trailing edge of a preceding sheet to a leading edge of a succeeding sheet in the image forming device is a first image forming interval; selecting the second adhesion mode when the image formation interval in the image forming device is a second image formation interval; the first imaging interval is longer than the second imaging interval; 2. The booklet producing apparatus according to claim 1.

15. The booklet producing apparatus according to claim 14 , wherein the first image forming interval has a higher ability to suppress curling of the sheets than the second image forming interval has a higher ability to suppress curling of the sheets.

16. The image forming apparatus further includes a support member for supporting sheets constituting a booklet conveyed from the image forming apparatus, Each time a predetermined number of sheets are conveyed to the support member, the heating means performs a heating process and the pressing means performs a pressing process; the control means, when a condition for executing an operation that will cause a downtime during which the image forming apparatus is unable to form an image, is satisfied, waits until the predetermined number of sheets are conveyed to the support member, and then executes the operation.

2. The booklet producing apparatus according to claim 1.

17. The image forming apparatus further includes a support member for supporting sheets constituting a booklet conveyed from the image forming apparatus, Each time a predetermined number of sheets are conveyed to the support member, the heating means performs a heating process and the pressing means performs a pressing process; when an execution condition for an operation that causes a downtime during which the image forming apparatus is unable to form an image is satisfied, the control means causes the heating means to execute the heating process, causes the pressing means to execute the pressing process, and executes the operation before the predetermined number of sheets are conveyed to the support member.

2. The booklet producing apparatus according to claim 1.

18. 2. The booklet producing apparatus according to claim 1, wherein the control means determines the first value in accordance with materials of the plurality of sheets.

19. 2. The booklet producing apparatus according to claim 1, wherein the control means determines a combination of the first value and the application amount in accordance with an adhesive strength required for the booklet.

20. A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first adhesive mode, a coating amount of the powder adhesive applied to the binding margin is a first coating amount, and a pressure applied by the pressure means is a first pressure force; the second adhesive mode, a coating amount of the powder adhesive applied to the binding margin is a second coating amount, and a pressure applied by the pressure means is a second pressure force; The first pressure is higher than the second pressure, the first coating amount is less than the second coating amount; A booklet production device comprising:

21. A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first bonding mode, a time during which the heating means heats the plurality of sheets is a first heating time, and a temperature of the heating means is a first temperature; the second bonding mode, a time during which the heating means heats the plurality of sheets is a second heating time, and a temperature to which the heating means heats the plurality of sheets is a second temperature; The first heating time is longer than the second heating time, the first temperature is lower than the second temperature; A booklet production device comprising:

22. A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, The control means has a first adhesion mode and a second adhesion mode, the first adhesion mode, a time during which the heating means heats the plurality of sheets is a first heating time, and a pressure applied by the pressure means is a first pressure; the second adhesion mode, a time during which the heating means heats the plurality of sheets is a second heating time, and a pressure applied by the pressure means is a second pressure force; The first heating time is longer than the second heating time, The first pressure is lower than the second pressure. A booklet production device comprising:

23. An image forming system having a booklet production device and an image forming device, The image forming apparatus includes: an image forming means for forming images on a plurality of sheets; a discharge means for discharging the plurality of sheets to the booklet producing device, The booklet production device is a booklet production device according to any one of claims 1 to 22.

1. An image forming system comprising:

24. 24. The image forming system according to claim 23, wherein the image forming apparatus has an application unit that applies the powder adhesive to each binding margin of the plurality of sheets.

25. 25. The imaging system of claim 24, wherein the powder adhesive is a toner.

26. an image forming means for forming images on a plurality of sheets; an application means for applying a powder adhesive to the binding margins of the plurality of sheets; a discharge means for discharging the plurality of sheets to a booklet producing device; A control means for controlling the coating means, The booklet production device includes: a heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet, The control means has a first adhesion mode and a second adhesion mode, the first adhesive mode is such that an application amount of the powder adhesive applied to the binding margin is a first application amount, and a heat parameter proportional to an amount of heat supplied to the plurality of sheets by the heating means is a first value; the second adhesive mode is such that the powder adhesive is applied to the binding margin in a second application amount and the thermal parameter is a second value; the first value is greater than the second value; the first coating amount is less than the second coating amount; 1. An image forming apparatus comprising:

27. A heating means for applying heat to the plurality of sheets having the powder adhesive applied to the binding margins; a pressurizing unit that applies pressure to the sheets to which heat has been applied by the heating unit to produce a booklet; A control means for controlling the heating means and the pressurizing means, the control means has a first adhesion mode and a second adhesion mode, each of which has a plurality of control parameters; the plurality of control parameters include an application amount of the powder adhesive to the binding margin, an amount of heat applied by the heating means, and a pressure applied by the pressure applying means; In the first adhesion mode, at least one of the control parameters is set to a corresponding first value, and at least one other of the control parameters is set to a corresponding second value; In the second adhesion mode, at least one of the control parameters is set to a corresponding third value, and at least one other of the control parameters is set to a corresponding fourth value; a combination of the first value and the second value is set so that an adhesive strength of the powder adhesive achieves a target strength, and environmental performance of at least one of the powder adhesive, the heating means, and the pressurizing means is improved compared to a combination of the third value and the fourth value; a combination of the third value and the fourth value is set so that the adhesive strength of the powder adhesive achieves the target strength, and a production time of the booklet made from the plurality of sheets is improved as compared to a combination of the first value and the second value. A booklet production device comprising:

28. In the first bonding mode, the application amount is set to the first value and the heat amount is set to a second value so that environmental performance of the powder adhesive is improved; In the second bonding mode, the application amount is set to the third value and the heat amount is set to the fourth value so as to improve a production time of the booklet; the first value is less than the third value; the second value is greater than the fourth value; 28. The booklet producing apparatus according to claim 27.

29. In the first bonding mode, a heating temperature of the heating means is set to the first value and a heating time by the heating means is set to a second value so that environmental performance related to the heating means is improved; In the second bonding mode, a heating temperature of the heating means is set to the third value and a heating time of the heating means is set to the fourth value so as to improve a production time of the booklet; the first value is less than the third value; the second value is greater than the fourth value; 28. The booklet producing apparatus according to claim 27.

30. In the first bonding mode, a pressure applied by the pressure applying means is set to the first value and a heating time by the heating means is set to a second value so that environmental performance related to the pressure applying means is improved; in the second bonding mode, the pressing force of the pressing means is set to the third value and the heating time of the heating means is set to the fourth value so as to improve the production time of the booklet, the first value is less than the third value; the second value is greater than the fourth value; 28. The booklet producing apparatus according to claim 27.

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