Post-processing device and image formation system

Abstract

To secure sufficient adhesive strength while maintaining productivity in booklet manufacture.SOLUTION: A post-processing device manufactures a booklet by conveying a plurality of sheet groups to each of which adhesives are applied and overlapping the subsequent sheet groups with the preceding sheet groups. Thermal compression bonding means manufactures the booklet by applying heat and pressure to the plurality of sheet groups held by holding means. Sheet information showing conveyance time or types of sheets of the preceding sheet groups among the plurality of sheet groups is acquired. Control means controls a thermal compression bonding parameter to be applied to at least one of the subsequent sheet groups among the plurality of sheet groups in the thermal compression bonding means on the basis of the sheet information.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a post-processing device and an image forming system. [Background technology]

[0002] There is known a post-processing device that produces a booklet from a plurality of sheets on which images are formed by an image forming device. According to Patent Document 1, a post-processing device is proposed that produces a booklet by bonding a plurality of sheets with a powder adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-209858 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the transport of the sheets to be included in the booklet is delayed, the time required to produce the booklet increases, and the productivity of the post-processing device decreases. If the adhesive time of the booklet is shortened in order to maintain productivity, the sheets may peel off from the booklet. If the type of sheet transported to the post-processing device is different from the expected type, the amount of heat supplied to the sheet may be insufficient, and the sheet may peel off from the booklet. If the adhesive time is lengthened in advance, the productivity of the post-processing device decreases. In this way, it has been difficult to achieve both productivity and adhesive strength.

[0005] Therefore, an object of the present invention is to ensure sufficient adhesive strength while maintaining productivity. [Means for solving the problem]

[0006] The present invention relates to, for example, A conveying means for conveying a group of a plurality of sheets each having an adhesive applied thereto; a holding means for holding the plurality of sheet groups by overlapping a succeeding sheet group on a preceding sheet group; a thermocompression bonding means for applying heat and pressure to the group of sheets held by the holding means to produce a booklet; an acquiring means for acquiring sheet information indicating a conveying time or a sheet type of a preceding sheet group among the plurality of sheet groups; a control means for controlling, based on the sheet information, thermocompression bonding parameters to be applied to at least one subsequent sheet group with respect to the preceding sheet group among the plurality of sheet groups in the thermocompression bonding means; The present invention provides an after-treatment device having a Effect of the Invention

[0007] According to the present invention, sufficient adhesive strength is ensured while maintaining productivity. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an image forming system. [Diagram 2] Diagram explaining the adhesive printing area [Diagram 3] Diagram explaining buffer operation [Figure 4] FIG. 1 is a diagram illustrating the alignment and bonding operations; [Diagram 5] Diagram explaining the bonding operation [Figure 6] Diagram explaining the controller [Figure 7] Diagram explaining the functions of a CPU [Figure 8] Timing chart for sheet transport and thermocompression bonding [Figure 9] Timing chart for sheet transport and thermocompression bonding [Figure 10] A diagram showing a table used to determine the correction value. [Figure 11] Flowchart showing thermocompression process [Figure 12] Timing chart for sheet transport and thermocompression bonding [Figure 13] Flowchart showing thermocompression process [Figure 14] Timing chart for sheet transport and thermocompression bonding [Figure 15] Flowchart showing thermocompression process [Figure 16] FIG. 1 is a diagram illustrating an image forming system. [Figure 17] Diagram explaining the functions of a CPU [Figure 18] FIG. 1 is a diagram illustrating the alignment and bonding operations; [Figure 19] Timing chart for sheet transport and thermocompression bonding [Figure 20] Timing chart for sheet transport and thermocompression bonding [Figure 21] Timing chart for sheet transport and thermocompression bonding DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 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.

[0010] <Example 1> (1) Image forming system 1, the image forming system 1 includes an image forming apparatus 100 and a post-processing apparatus 300. The post-processing apparatus 300 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 200 conveys the sheet S on which the image has been formed to the post-processing apparatus 300. The post-processing apparatus 300 performs post-processing on the sheet S as necessary and outputs the sheet S.

[0011] The image forming apparatus 100 includes a sheet cassette 8, an image forming unit 10, a fixing unit 6, and a housing 19 that houses these components. The image forming unit 10 forms a toner image on a sheet S fed from the sheet cassette 8. The fixing unit 6 performs a fixing process to fix the toner image on the sheet S.

[0012] 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. A feed roller 81 feeds the sheet S from the sheet cassette 8, and delivers the sheet S to a pair of conveying rollers 82. The multi-tray 20 can also feed the sheets S one by one.

[0013] The image forming unit 10 is a tandem-type electrophotographic unit equipped with four process cartridges 7n, 7y, 7m, and 7c, a scanner unit 2, and a transfer unit 3. The "n" in the reference numerals means adhesive, and "ymc" means yellow, magenta, and cyan, respectively. The process cartridges 7n, 7y, 7m, and 7c are configured so that multiple parts that are responsible for the image forming process can be replaced as a whole. In other words, the process cartridges 7n, 7y, 7m, and 7c are formed by integrating multiple parts.

[0014] The process cartridges 7n, 7y, 7m, and 7c have corresponding toner storage units Kn, Ky, Km, and Kc, photosensitive drums Dn, Dy, Dm, and Dc, and charging rollers Cn, Cy, Cm, and Cc. The process cartridges 7n, 7y, 7m, and 7c have substantially the same structure, except for the type of toner.

[0015] The toner storage units Ky, Km, and Kc store yellow, magenta, and cyan toners for forming a visible image on the sheet S. The toner storage unit Kn stores adhesive toner Tn. The adhesive toner Tn is a powder adhesive used to heat-press multiple sheets S in the post-processing device 300. An adhesive toner image is formed on the photosensitive drum Dn by development with the adhesive toner Tn. The adhesive toner image is not intended to transmit visual information. Therefore, the adhesive toner image is different from a toner image (normal toner image) formed by a printing toner for recording an image such as a figure or text on the sheet S. However, in the following description, the adhesive toner Tn is applied to the sheet S in a predetermined application pattern. Therefore, the layered image of the adhesive toner Tn developed by the electrophotographic process is also treated as one of the "toner images."

[0016] When a black image such as text is printed, yellow, magenta, and cyan toners are superimposed to produce a black image (process black). However, the image forming unit 10 may have a fifth process cartridge that uses black toner. The type and number of printing toners can be changed depending on the application of the image forming apparatus 100.

[0017] 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 scanner unit 2 is disposed below the process cartridges 7n, 7y, 7m, and 7c and above the sheet cassette 8. The scanner unit 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 scanner unit 2 may also be called an exposure device or an optical scanning device.

[0018] The toner containers Kn, Ky, Km, and Kc form toner images by attaching toner to the electrostatic latent images on the photosensitive drums Dn, Dy, Dm, and Dc. The toner containers Kn, Ky, Km, and Kc may also be called developers.

[0019] 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.

[0020] The primary transfer rollers Fn, Fy, Fm, and Fc transfer the toner images from the corresponding photosensitive 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.

[0021] 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 the toner image from the transfer belt 30 to the sheet S. The transfer nip 52 may be called a secondary transfer portion.

[0022] A fixing unit 6 is disposed above the secondary transfer roller 5 (downstream in the conveying direction of the sheet S). The fixing unit 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. In other words, the printing toners Ty, Tm, and Tc and the adhesive toner Tn melt and adhere to the sheet S.

[0023] FIG. 2(A) shows a printing area 211 of adhesive toner Tn. 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 300 stacks multiple sheets S and heats and presses the printing areas 211 of the multiple sheets S, thereby adhering the multiple sheets S 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.

[0024] 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.

[0025] As shown in FIG. 1, the switching guide 33 is a flap-shaped guide member provided downstream of the fixing unit 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 portion. As a result, an image is formed on the second side of the sheet S. Note that an adhesive toner image may be formed on both the first side and the second side.

[0026] The discharge roller 34 conveys the sheet S to an intermediate conveying unit 200. The intermediate conveying unit 200 has a pair of conveying rollers 201 and 202. The pair of conveying rollers 201 and 202 convey the sheet S to a post-processing device 300.

[0027] (2) After-treatment device The post-processing device 300 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.

[0028] In the following, the end of the sheet S on the front side in the transport direction is called the leading end. The end of the sheet S on the rear side in the transport direction is called the trailing end. Of the two ends of the sheet S, the end that enters the post-processing device 300 first is called the first end. Of the two ends of the sheet S, the end that enters the post-processing device 300 later is called 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 300.

[0029] The sheet S conveyed from the intermediate conveying unit 200 is delivered to the entrance rollers 21 of the post-processing device 300. A sheet sensor 17 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.

[0030] 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.

[0031] 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 hits the vertical alignment plate 39, whereby the sheet stack is aligned.

[0032] 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 (adhesive processing) 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.

[0033] In the above description, the post-processing device 300 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.

[0034] (3) Buffer operation (overlapping operation) The buffer operation is an operation for making the succeeding sheet or sheet bundle wait in the buffer unit 80 until the post-processing of the preceding sheet bundle is completed in the intermediate stacking unit 42. The buffer operation enables the image forming system 1 to continue the image forming job including the post-processing without reducing the productivity of the image forming apparatus 100 (the number of images output per unit time).

[0035] Figures 3(A) to 3(G) illustrate the buffer operation. Here, the sheet S conveyed first is denoted as S1, and the sheet S conveyed second is denoted as S2. The sheet bundle formed by overlapping sheet S1 and sheet S2 is denoted as W. The conveyance speeds of the conveyance roller pairs 22, 24, and 26 are denoted as V1 and V2 (V1 < V2). The conveyance speed V1 is the conveyance speed before acceleration, and the conveyance speed V2 is the conveyance speed after acceleration. Here, acceleration (speed increase) is an acceleration process for ensuring the necessary sheet interval (hereinafter referred to as the paper interval) when overlapping sheet S in the buffer unit 80 and when feeding the sheet bundle downstream. The sheet interval generally refers to the distance or conveyance time from the rear end of the preceding sheet Si to the front end of the subsequent sheet Si+1 (i is an arbitrary integer).

[0036] Figure 3(A) shows that the conveyance speeds of the conveyance roller pair 22 and the conveyance roller pair 24 are accelerated to V2 at the timing when the rear end (second end) of sheet S1 passes through the sheet sensor 27. Figure 3(B) shows that sheet S1 temporarily stops at the timing when the rear end of sheet S1 has moved a predetermined distance from the sheet sensor 27 and passed through the backflow prevention valve 23. The conveyance speed of the conveyance roller pair 22 returns to V1 to receive sheet S2. Figure 3(C) shows that the rotation direction of the conveyance roller pair 24 switches from normal rotation to reverse rotation, and sheet S1 is conveyed in the F1 direction at the conveyance speed V2. Sheet S2 is conveyed to the conveyance roller pair 22 at the conveyance speed V1.

[0037] FIG. 3D shows that the leading end (second end) of the sheet S1 stops at a position where it has been conveyed a predetermined distance from the pair of conveying rollers 26. In addition, at the timing when the sheet S1 is sandwiched between the pair of conveying rollers 26, the separation lever 44 separates the upper roller 24a in the direction E1. After the upper roller 24a separates from the lower roller 24b, the leading end (first end) of the sheet S2 passes through the pair of conveying rollers 24. The separation lever 44 is rotatably connected to the plunger solenoid 45 at the solenoid connection shaft. When a current flows through the plunger solenoid 45, the separation lever 44 rotates in the direction E1, and the pair of conveying rollers 24 enters a separated state. When the supply of current to the plunger solenoid 45 is stopped, the upper roller 24a moves in the direction E2 due to the pressure spring.

[0038] FIG. 3E shows that the conveying speed of the conveying roller pair 22 and the conveying roller pair 24 is accelerated to V2 after the rear end (second end) of the sheet S2 passes the sheet sensor 27. At the timing when the rear end (second end) of the sheet S2 passes the sheet sensor 27, the conveying roller pair 26 starts to rotate in the reverse direction. As a result, the sheet S1 sandwiched between the conveying roller pair 26 is conveyed in the F2 direction. At the timing when the conveying speeds of the sheets S1 and S2 become equal, the upper roller 24a moves in the E2 direction and cooperates with the lower roller 24b to sandwich the sheets S1 and S2. The conveying speed (circumferential speed) of the conveying roller pair 24 is adjusted to V2, which is the conveying speed of the sheets S1 and S2, before the conveying roller pair 24 sandwiches the sheets S1 and S2.

[0039] 3(F) shows that sheets S1 and S2 form sheet stack W after the rear end (second end) of sheet S2 passes through check valve 23. As in FIGS. 3(B) and 3(C), in FIG. 3(F) as well, when the rear end of sheet stack W passes through check valve 23, sheet stack W pauses and the rotation direction of conveying roller pair 24 switches from forward to reverse.

[0040] 3G shows that the sheet stack W is transported in the F1 direction at a transport speed V2 toward the post-processing section 71. At the timing when the sheet stack W is sandwiched between the transport roller pair 26, the separation lever 44 separates the upper roller 24a from the lower roller 24b. In other words, the upper roller 24a moves in the E1 direction.

[0041] FIG. 3H shows that the sheet S3 is newly buffered after the sheet stack W is sent to the post-processing section 71. In this case, the upper roller 24a stops once after the rear end of the sheet stack W passes through the pair of conveying rollers 24. The sheet S3 enters the pair of conveying rollers 24 while the pair of conveying rollers 24 is separated. When the rear end of the sheet S3 passes through the sheet sensor 27, the conveying speed of the pair of conveying rollers 22 is increased from V1 to V2. After that, the upper roller 24a moves in the direction of E2, and the pair of conveying rollers 24 comes into contact with each other. The rotation direction of the upper roller 24a switches from reverse to forward, and the sheet S3 is conveyed in the direction of F2 at the conveying speed V2. Before the rear end of the sheet S3 passes through the pair of conveying rollers 22, the pair of conveying rollers 24 starts conveying the sheet S3.

[0042] Here, two sheets S1 and S2 are buffered, but this is merely an example. If the third sheet S3 is also buffered, after FIG. 3(G), the leading edge of the sheet stack W stops at a position (temporary stop position) conveyed a predetermined distance from the conveying roller pair 26. Then, an overlapping operation is applied to the sheet stack W and sheet S3. The overlapping operation is the same as the overlapping operation of sheets S1 and S2 described in relation to FIG. 3(D) to FIG. 3(G).

[0043] (4) Matching operation 4(A) to 4(D) show the alignment operation of the sheets S executed in the intermediate stacking section 42. In the initial state, the intermediate stacking section 42 is empty. As an example, a sheet stack W consisting of five sheets S is conveyed from the buffer section 80 to the intermediate stacking section 42.

[0044] 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 to 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.

[0045] 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 abutting members 39a to 39c that are arranged at intervals in the X direction. The abutting members 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.

[0046] 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.

[0047] (4-1) Preparation stage As shown in FIG. 4A, the sheets S1 to S5 are conveyed toward the kick-out roller 29. The sheets S1 to S5 may be conveyed to the intermediate stacker 42 in a state in which the lower sheet Si protrudes in the Y direction from the upper sheet Si+1. Before the sheets S are stacked on the intermediate stacker 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.

[0048] (4-2) Vertical alignment stage 4(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.

[0049] (4-3) Lateral alignment stage 4C 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 500 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.

[0050] (4-4) Adhesion stage (thermocompression stage) 4(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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] (5) Thermocompression unit As shown in FIG. 5A, the thermocompression bonding unit 51 has a heater 501 and a heating plate 502. The heater 501 has a built-in heating element as a heat source. The heating plate 502 is disposed on the heater 501 and is made of, for example, aluminum. The heater 501 is, for example, a ceramic heater. The temperature of the heater 501 may be measured by a temperature sensor and controlled by a control circuit so that the measured temperature becomes a target temperature. For example, the target temperature is set so that the surface temperature of the pressure applying portion 509 of the heating plate 502 becomes 200° C. By providing the pressure applying portion 509 on the heating plate 502, 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.

[0055] The heater 501 is supported by a heater support 503 made of resin. The pressure lever 504 obtains power from a motor M8 shown in FIG. 6 in order to pressurize the sheet stack W by pushing down the thermocompression bonding unit 51 in the -Z direction (downward). The pressure force of the pressure lever 504 is transmitted to a pressure section 509 via a metal stay 505 serving as a rigid body. The pressure force of the pressure lever 504 can be controlled according to the amount by which the pressure lever 504 is moved in the -Z direction (downward). For example, the pressure force is 30 kgf.

[0056] The pressure plate 506 is made of an elastic material (e.g., silicone rubber). This is because the pressure plate 506 is a member that can stably receive pressure force. 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. 5(A) indicate the first to fifth sheets of a booklet as a finished product. Sheet S1 is the cover of the booklet. Therefore, no image of adhesive toner Tn is formed on sheet S1. An image of adhesive toner Tn is formed on the lower surfaces of the second and subsequent sheets S2 to S5 of the booklet.

[0057] As shown in Fig. 5(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.

[0058] 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.

[0059] As an example, the post-processing device 300 can produce a part of a booklet consisting of a maximum of 100 sheets S. When the production of the booklet is started, 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.

[0060] 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.

[0061] (6) Controller 6 is a diagram for explaining the controller of the image forming system 1. The printer control unit 600 is a controller that controls the image forming apparatus 100. The finisher control unit 650 is a controller that controls the post-processing device 300. The printer control unit 600 and the finisher control unit 650 are connected to each other via a communication interface, and cooperate to control the operation of the image forming system 1.

[0062] The printer control unit 600 has a central processing unit (CPU) 601 and a memory 602. The CPU 601 reads and executes a program stored in the memory 602, and controls the image forming apparatus 100 in accordance with the program. The CPU 601 executes image formation processing and sheet conveying processing in the image forming apparatus 100. The memory 602 includes a non-volatile storage medium such as a read-only memory (ROM) and a volatile storage medium such as a random access memory (RAM). The memory 602 stores programs and data, and provides a working area when the CPU 601 executes the program. The memory 602 is an example of a non-transitory storage medium that stores a program for controlling the image forming apparatus 100.

[0063] The printer control unit 600 is connected to an external device 105 such as a personal computer and a portable information device via an external interface (I / F) 104. The printer control unit 600 accepts an execution command for an image forming job for the image forming system 1 input from the external device 105. The printer control unit 600 is connected to an operation display unit 103 which is a user interface of the image forming system 1. The operation display unit 103 includes a display device (e.g., a liquid crystal panel that presents information to a user) and an input device (e.g., physical buttons and a touch sensor that accept input operations by a user). The printer control unit 600 communicates with the operation display unit 103 to control the display contents of the display device and to receive information input via the input device.

[0064] The finisher control unit 650 has a CPU 651, a memory 652, and an I / O port 653. The CPU 651 reads and executes a program stored in the memory 652, and controls the post-processing device 300 according to the program. The memory 652 includes a non-volatile storage medium (e.g., ROM, SSD, HDD) and a volatile storage medium (e.g., RAM). SSD is an abbreviation for solid state drive. HDD is an abbreviation for hard disk drive. The memory 652 stores programs and data, and provides a working space when the CPU 651 executes the program. The memory 652 is an example of a non-transient storage medium that stores a program for controlling the post-processing device 300. The CPU 651, the memory 652, and the I / O port 653 are connected to each other via a bus 654. The I / O port 653 outputs control signals to various components of the post-processing device 300 and inputs signals therefrom.

[0065] The functions of the printer control unit 600 and the finisher control unit 650 may be implemented as independent hardware such as an ASIC, or may be implemented in software as a program module. ASIC is an abbreviation for application specific integrated circuit. The printer control unit 600 may be responsible for some or all of the functions of the finisher control unit 650.

[0066] The I / O port 653 is connected to the sheet sensors 27, 50, 60, and the heater 501. The I / O port 653 is connected to motors M1 to M10 serving as a drive source for conveying the sheet S and a drive source for the thermocompression bonding unit 51.

[0067] Motor M1 rotates and drives the entrance roller 21. Motor M2 rotates and drives the conveying roller pair 22. Motor M3 rotates and drives the conveying roller pair 24. Motor M4 rotates and drives the conveying roller pair 26. Motor M5 rotates and drives the kick-out roller 29. Motor M6 supplies a driving force for intermittently operating the vertical alignment roller 40 one rotation at a time. Motor M7 moves the horizontal alignment jogger 41 in the +X direction or the -X direction. Motor M8 causes the thermocompression unit 51 to perform an operation of pressing the sheet stack W. Motor M9 rotates and drives the discharge roller 38. Motor M10 drives the vertical alignment plate 39 in the +Y direction or the -Y direction.

[0068] (7) Functional configuration 7 shows functions realized by the CPU 651. The CPU 651 realizes a sensor control unit 708, a motor control unit 709, a heater control unit 710, a transport control unit 711, and a post-processing control unit 714 according to a program. Some or all of these functions may be realized by an ASIC, a digital signal processor (DSP), a field programmable gate array (FPGA), or the like. The CPU 651 may have a communication circuit 706 that executes serial communication and the like, and a timer 707 such as a real-time clock.

[0069] The communication circuit 706 is connected to the printer control unit 600 and receives job information and information about the sheet S conveyed from the image forming apparatus 100. The information about the sheet S may include the type of sheet S specified by the user, or the type of sheet S detected by the media sensor 79 connected to the printer control unit 600. The communication circuit 706 instructs the printer control unit 600 to temporarily suspend an image formation job.

[0070] The sensor control unit 708 activates the sheet sensors 27, 50, and 60, and transfers signals input from the sheet sensors 27, 50, and 60 to the transport control unit 711. The transport control unit 711 instructs the motor control unit 709 to drive the motors M1 to M5 based mainly on the input from the sensor control unit 708. This realizes transport control of the sheet S, the sheet stack W, and the booklet. The post-processing control unit 714 instructs the motor control unit 709 to drive the motors M6 to M10 and instructs the heater control unit 710 to start heating the heater 501 based on the input from the sensor control unit 708. This realizes post-processing such as vertical alignment processing, horizontal alignment processing, and thermocompression bonding operation.

[0071] The conveyance control unit 711 may include an acquisition unit 721, a judgment unit 722, a decision unit 723, and a thermocompression bonding control unit 724. The acquisition unit 721 measures the conveyance time from the timing when the leading edge of the sheet S or the sheet stack W is detected by the sheet sensor 60 to the timing when the leading edge of the sheet S or the sheet stack W is detected by the sheet sensor 50 using a timer 707. The conveyance time may be called sheet information. Alternatively, the acquisition unit 721 acquires sheet information transmitted from the printer control unit 600 using the communication circuit 706. This sheet information indicates, for example, the type of each sheet S (e.g., material, basis weight, presence or absence of coating, etc.).

[0072] The determination unit 722 determines whether or not a delay in conveying to the intermediate stacker 42 has occurred for each sheet S or for each sheet W based on the conveying time, which is the sheet information. For example, it is determined whether or not the conveying time exceeds a predetermined threshold time.

[0073] Based on the sheet information, the determination unit 723 determines thermocompression parameters to be applied to each sheet S or each sheet W. The thermocompression parameters may include, for example, a bonding time (thermocompression bonding time) by the thermocompression unit 51, a heating temperature of the heater 501, and a pressure applied to the sheet S or the sheet stack W by the pressure unit 509 pressed down by the motor M8.

[0074] The thermocompression bonding control unit 724 controls the motors M8 and M10 through the motor control unit 709 based on the thermocompression bonding parameters determined by the determination unit 723, and controls the heater 501 through the heater control unit 710.

[0075] (8) Buffer operation and thermocompression bonding The image forming system 1 can continuously produce multiple booklets. When the conveyance control unit 711 receives job information from the external device 105 via the communication circuit 706, it acquires the total number U of pages included in the job. Here, it is assumed that the total number U does not exceed the upper limit number Q (e.g. Q=100 sheets) of sheets S that can be loaded on the loading plate of the intermediate stacking unit 42. Furthermore, the number of sheets S included in one booklet is defined as M. The upper limit number of sheets S included in the sheet stack W produced in the buffer unit 80 is defined as N.

[0076] FIG. 8 is a diagram for explaining the buffer operation and thermocompression bonding. The horizontal axis indicates time. The vertical axis indicates the transport distance, and the temperature and pressure of the thermocompression bonding unit 51. In FIG. 8, the position of the leading edge of the sheet S in the transport direction is plotted. Therefore, the position of the first edge of the sheet S is plotted until the sheet S arrives at the transport roller pair 24. After the sheet S is sent out from the transport roller pair 24, the position of the second edge of the sheet S is plotted.

[0077] As shown in FIG. 8, five sheets S1 to S5 are fed from the image forming apparatus 100 to the buffer section 80 at regular intervals. The buffer section 80 forms a sheet bundle W1 by stacking the five sheets S1 to S5, and feeds the sheet bundle W1 to the intermediate stacking section 42. The thermocompression bonding unit 51 performs thermocompression bonding on the sheet bundle W1. Thereafter, the buffer section 80 prepares a sheet bundle W2 and sends it to the intermediate stacking section 42. The thermocompression bonding unit 51 performs thermocompression bonding on the sheet bundles W1 and W2 held in the intermediate stacking section 42. The buffer section 80 prepares a sheet bundle W3 and sends it to the intermediate stacking section 42. The thermocompression bonding unit 51 performs thermocompression bonding on the sheet bundles W1, W2, and W3 held in the intermediate stacking section 42. When a booklet made of the sheet bundles W1, W2, and W3 is completed, the vertical alignment plate 39 pushes out the booklet. Discharge rollers 38 discharge the booklet onto lower tray 37 .

[0078] 8, the conveying interval between each sheet S is Y1. The conveying interval between each sheet stack W is Y2. The time from when the sheet stack W is conveyed to the intermediate stacking unit 42 until the thermocompression bonding is completed is T0.

[0079] The surface temperature of the heater 501 of the thermocompression bonding unit 51 is controlled to a target temperature K1. Over the thermocompression bonding time T0, the total pressure applied to the sheet stack W is controlled to a target pressure P1.

[0080] The sheet bundle W1 remains in the intermediate stacking section 42 even after being subjected to thermocompression bonding in the intermediate stacking section 42. Thus, the succeeding sheet bundles W2 and W3 are stacked in sequence on top of the sheet bundle W1. When the sheet bundle W2 is thermocompression bonded, the sheet bundle W1 is also thermocompression bonded. When the sheet bundle W3 is thermocompression bonded, the sheet bundles W1 and W2 are also thermocompression bonded.

[0081] (9) Recovery from transport delays 9, a sudden slippage may occur in the conveying roller pair 26 or the conveying roller pair 28. As a result, the conveying time required for the sheet stack W1 to be conveyed from the sheet sensor 60 to the sheet sensor 50 may become longer than the expected time. The difference between the conveying time and the expected time is called the delay time N0.

[0082] When a transport delay of delay time N0 occurs, the time when post-processing of sheet bundle W1 is completed is also delayed by N0. The transport time margin between sheet bundle W1 and sheet bundle W2 is assumed to be N1. If N0≦N1, the post-processing time of sheet bundle W1 is kept constant, and the start time and end time of the post-processing time are each shifted by N0.

[0083] However, there may be cases where N0>N1 and the sheet stack W2 is transported to the sheet sensor 50 without delay. In this case, the sheet stack W2 may enter the intermediate stacking portion 42 before the thermocompression bonding of the sheet stack W1 is completed, causing a jam.

[0084] Therefore, the CPU 651 shortens the heat bonding time of the sheet stack W1 by the shortage time ΔN. In this case, the following relationship is established among the delay time N0, the margin N1, and the shortage time ΔN.

[0085] ΔN = N0 - N1 Eq1 This formula means the following. Due to a delay in conveying the sheet stack W1, the start time of thermocompression bonding is N0 later than the specified time. However, because the thermocompression bonding time of the sheet stack W1 is shortened by the shortage time ΔN, the end time of thermocompression bonding of the sheet stack W1 is N1 later than the specified time. This makes it less likely that a jam will occur.

[0086] If the heat bonding time of the sheet bundle W1 is shortened, the heat amount required to achieve the target adhesive strength of the sheet bundle W1 falls short of the target heat amount. As a result, the sheet S may peel off from the booklet. As described above, when the sheet bundle W2 is heat bonded, the sheet bundle W1 is also heat bonded. Therefore, the CPU 651 adds the heat amount that is insufficient for the preceding sheet bundle W to the heat amount for heat bonding of the succeeding sheet bundle W. This compensates for the heat amount of the preceding sheet bundle W. As an example, the insufficient time ΔN of the sheet bundle W1 is converted into at least one of a correction value ΔT of the heating time for the sheet bundle W2, a correction value ΔK of the heating temperature, and a correction value ΔP of the pressure.

[0087] 10A shows an example of a table that holds the relationship between the shortage time ΔN and the heating time correction value ΔT, the heating temperature correction value ΔK, and the pressure correction value ΔP. This table is stored in memory 652. CPU 651 refers to the table based on the shortage time ΔN and determines the correction values ​​ΔT, ΔK, and ΔP that correspond to the shortage time ΔN.

[0088] The compensation of the heating amount according to the shortage time ΔN is realized by adjusting any one of a plurality of thermocompression bonding parameters (heating time, heating temperature, and pressure). For example, only the heating time may be adjusted, only the heating temperature may be adjusted, or only the pressure may be adjusted. Alternatively, the combination of the heating time and the heating temperature may be adjusted, or the combination of the heating time, the heating temperature, and the pressure may be adjusted. When three parameters are present, there are six combinations to be adjusted. Therefore, the problem is which thermocompression bonding parameter should be prioritized. For example, the thermocompression bonding parameter that has the least effect on the life (durability), temperature rise, or power consumption of the thermocompression bonding unit 51 may be determined to have a higher priority (priority order). In the first embodiment, the correction value ΔT of the heating time has the highest priority. The correction value ΔK of the heating temperature has the second highest priority. The correction value ΔP of the pressure force has the third highest priority. In terms of the life, temperature rise, and power consumption of the thermocompression bonding unit 51, the heating time, heating temperature, and pressure force when no transport delay occurs are set with a margin. In other words, the maximum temperature and pressure are not used when there is no transport delay, and the design allows the heating temperature or pressure to be increased when necessary.

[0089] According to FIG. 10A, when the shortage time ΔN of the sheet stack W1 is 0 ms<ΔN≦150 ms, the CPU 651 extends the heating time of the sheet stack W2 by +50 ms to +150 ms. This compensates for the heating amount. For example, if reducing power consumption is important, +50 ms may be adopted. On the other hand, if reliable adhesion is important, +150 ms may be adopted. The correction value ΔT may be calculated to be proportional to ΔN and to be +50 ms to +150 ms. In this way, ΔN may be correlated with the correction values ​​ΔT, ΔK, and ΔP.

[0090] When the shortage time ΔN of the sheet stack W1 is 150 ms<ΔN≦300 ms, the CPU 651 determines that the heating amount of the sheet stack W1 is not sufficiently compensated for by simply correcting the heating time of the sheet stack W2. Therefore, the CPU 651 increases the correction value ΔK of the heating temperature while keeping the correction value ΔT of the heating time set to the maximum of +150 ms.

[0091] When the shortage time ΔN of the sheet stack W1 is 300 ms<ΔN≦450 ms, the CPU 651 determines that the heating amount of the sheet stack W1 cannot be sufficiently compensated for by simply correcting the heating time and heating temperature of the sheet stack W2. Therefore, the CPU 651 sets the correction value ΔT to +150 ms, sets the correction value ΔK to +30° C., and increases the pressure correction value ΔP by +1.5 kgf to +4.5 kgf.

[0092] In this manner, the thermocompression bonding parameters for the thermocompression bonding of the sheet bundle W2 are adjusted based on the predetermined table, whereby the amount of heat applied to the sheet bundle W1 is compensated for by the thermocompression bonding of the sheet bundle W2.

[0093] For example, there may be cases where the shortage time ΔN can be compensated for by only the heating time correction value ΔT (0 ms<ΔN≦150 ms). In this case, as shown in the timing chart of FIG. 9, the CPU 651 extends the heating time for the thermocompression bonding of the sheet stack W2 by ΔT. This sufficiently compensates for the heating amount of the sheet stack W1.

[0094] On the other hand, there may be cases where the heating amount needs to be compensated for by two thermocompression parameters (correction value ΔT, correction value ΔK) for the shortage time ΔN (150 ms<ΔN≦300 ms). In this case, the CPU 651 extends the heating time for thermocompression bonding of the sheet stack W2 by ΔT, increases the heating temperature by ΔK, and changes the target temperature from K1 to K2 (K2>K1). This sufficiently compensates for the heating amount for the sheet stack W1.

[0095] There are cases where the shortage time ΔN needs to be compensated for by three thermocompression parameters (correction value ΔT, correction value ΔK, correction value ΔP) (300 ms<ΔN≦450 ms). The CPU 651 extends the heating time for the sheet stack W2 by ΔT, increases the heating temperature by ΔK, and increases the amount of pressure by ΔP. This sufficiently compensates for the amount of heat for the sheet stack W1.

[0096] (10) Flowchart 11 is a flow chart showing the thermocompression bonding process executed by the CPU 651 in accordance with the control program. For generalization, i is used as an index for distinguishing each sheet stack W.

[0097] In S1101, the CPU 651 (acquisition unit 721) acquires the conveying time of the i-th sheet bundle Wi. The acquisition unit 721 acquires the time from the timing when the leading edge of the sheet bundle Wi is detected by the sheet sensor 60 to the timing when the leading edge of the sheet bundle Wi is detected by the sheet sensor 50 as the conveying time.

[0098] In S1102, the CPU 651 (obtaining unit 721) obtains the shortage time ΔN based on the conveying time of the sheet bundle Wi. The obtaining unit 721 may calculate the shortage time ΔN using the above-mentioned formula.

[0099] In S1103, the CPU 651 (determination unit 722) determines whether the i-th sheet stack Wi will be insufficiently heated based on the shortage time ΔN. For example, if the shortage time ΔN exceeds 0, the determination unit 722 determines that insufficient heating will occur, and the process proceeds from S1103 to S1104. If the shortage time ΔN does not exceed 0, the determination unit 722 determines that insufficient heating will not occur, and the process proceeds from S1103 to S1106.

[0100] In S1104, the CPU 651 (determination unit 723) determines the correction value of the thermocompression bonding parameter to be applied to the subsequent sheet stack i+1 based on the shortage time ΔN. For example, the determination unit 723 may obtain a combination of the type of thermocompression bonding parameter corresponding to the shortage time ΔN and the correction value thereof from the table shown in FIG.

[0101] In S1105, the CPU 651 (determination unit 723) determines the thermocompression bonding parameters to be applied to the sheet stack i+1 based on the correction values. For example, the determination unit 723 adds the correction value ΔT to the default value of the heating time to determine the heating time to be applied to the sheet stack i+1. The determination unit 723 adds the correction value ΔK to the default value of the heating temperature to determine the heating temperature to be applied to the sheet stack i+1. The determination unit 723 adds the correction value ΔP to the default value of the pressure to determine the pressure to be applied to the sheet stack i+1. The default values ​​are stored in advance in the memory 652.

[0102] In S1106, the CPU 651 (thermocompression bonding control unit 724) controls the thermocompression bonding unit 51 using the thermocompression bonding parameters determined in S1104 to perform thermocompression bonding.

[0103] In S1107, the CPU 651 determines whether the booklet is complete. For example, if the booklet is made of sheet bundles W1, W2, and W3, when the thermocompression bonding of the sheet bundle W3 is completed, the CPU 651 determines that the booklet is complete and proceeds from S1107 to S1108. If the thermocompression bonding of the sheet bundle W3 is not completed, the CPU 651 determines that the booklet is not complete and returns from S1107 to S1101.

[0104] In S1108, the CPU 651 controls the motors M9 and M10 to discharge the booklet from the intermediate stacker 42 to the lower tray 37.

[0105] In this way, the CPU 651 corrects the thermocompression parameters (eg, heating time, heating temperature, pressure) for the thermocompression of the sheet bundle W2 based on the shortage time ΔN of the sheet bundle W1, thereby making it difficult for insufficient pressing of the sheet bundle W1 to occur.

[0106] (11) When distributing heat to multiple sheet stacks (11-1) Basic Concept Up to this point, when a transport delay occurs in the sheet bundle W1, a plurality of thermocompression bonding parameters applied to the thermocompression bonding of the subsequent sheet bundle W2 are corrected. However, when a transport delay occurs in the preceding sheet bundle Wi, the thermocompression bonding parameters for the subsequent sheet bundles Wi+1, Wi+2, ... may be adjusted. In other words, the insufficient heat quantity corresponding to the shortage time ΔN may be compensated for in the subsequent sheet bundles Wi+1, Wi+2, ....

[0107] 12 shows a case in which the heat amount shortage in the sheet bundle W1 is distributed and compensated for between the heat bonding of the sheet bundle W2 and the subsequent heat bonding of the sheet bundle W3. The CPU 651 (determination unit 723) determines a correction value ΔT1 of the heating time to be added to the sheet bundle W2 and a correction value ΔT2 of the heating time to be added to the sheet bundle W3 based on the shortage time ΔN.

[0108] 10B is a table showing the relationship between the shortage time ΔN and the correction value ΔT. This table is also determined when the thermocompression unit 51 is designed, and is stored in the ROM area of ​​the memory 652. The CPU 651 refers to the table based on the shortage time ΔN, and determines the correction values ​​ΔT1 and ΔT2. The CPU 651 adds the correction value ΔT1 to the default value of the heating temperature for the sheet bundle W2 to determine the heating temperature for the sheet bundle W2. The CPU 651 adds the correction value ΔT2 to the default value of the heating temperature for the sheet bundle W3 to determine the heating temperature for the sheet bundle W3. The CPU 651 performs thermocompression bonding on each sheet bundle W using the thermocompression parameters determined for each sheet bundle W.

[0109] (11-2) Flowchart Fig. 13 is a flowchart showing the thermocompression bonding executed by the CPU 651 according to a control program. Compared to the flowchart of Fig. 11, S1301 to S1303 are added between S1103 and S1106 in Fig. 13. Therefore, the explanation of Fig. 11 is used for the matters common to Fig. 13 and Fig. 11. If it is determined in S1103 that the i-th sheet bundle Wi is insufficiently heated, the CPU 651 proceeds from S1103 to S1301.

[0110] In S1301, the CPU 651 (determination unit 722) determines whether or not it is necessary to distribute the amount of heat to the following multiple sheet stacks W based on the shortage time ΔN. For example, if the shortage time ΔN exceeds a predetermined positive threshold value Nth, the determination unit 722 determines that distribution is necessary, and the process proceeds from S1301 to S1302. On the other hand, if the shortage time ΔN does not exceed the threshold value Nth, the determination unit 722 determines that distribution is not necessary, and the process proceeds from S1301 to S1104.

[0111] In S1302, the CPU 651 (determination unit 723) determines correction values ​​for distribution to the following multiple sheet bundles Wi+1 and Wi+2 based on the shortage time ΔN. For example, the determination unit 723 may refer to a table stored in the memory 652 based on the shortage time ΔN to obtain the correction values ​​ΔT1 and ΔT2.

[0112] In S1303, the CPU 651 (determination unit 723) determines the thermocompression bonding parameters of the (i+1)th sheet bundle Wi+1 and the (i+2)th sheet bundle Wi+2 based on the acquired correction values ​​for distribution. After that, the CPU 651 proceeds from S303 to S1106.

[0113] As shown in FIG. 12, the thermocompression parameters for the sheet bundles W2 and W3 are corrected based on the shortage time ΔN of the sheet bundle W1. This makes it difficult for insufficient compression of the sheet bundle W1 to occur. This is the same in the second to fourth embodiments. Here, for the sake of simplicity, only the correction value ΔT of the heating time is calculated. However, this is merely an example. As described in relation to FIG. 10(A), the correction value ΔK of the heating temperature and the correction value ΔP of the pressure may also be distributed to multiple subsequent sheet bundles W.

[0114] <Example 2> (1) Basic Concept In the first embodiment, a case has been described in which a shortage of the amount of heat caused by a delay in conveying the sheet stack W when the sheet stack W is fed to the intermediate stacking section 42 is compensated for by thermocompression bonding of the succeeding sheet stack W. In the second embodiment, it is assumed that the sheets S are conveyed to the intermediate stacking section 42 one by one. Therefore, the thermocompression bonding unit 51 performs thermocompression bonding every time one sheet S is stacked on the intermediate stacking section 42.

[0115] As an example, the types of sheets S are plain paper, thick paper i (e.g., grammage = 120 g / m 2 ), and cardboard II (e.g. basis weight = 150 g / m 2 ) is employed. The buffer unit 80 operates as follows for these types of sheets S. In the case of plain paper, the buffer unit 80 stacks multiple sheets S together to create a sheet bundle W, and transports the sheet bundle W to the intermediate stacker 42. In the case of thick paper i and thick paper ii, the buffer unit 80 does not stack multiple sheets S together. In other words, the buffer unit 80 sends out the sheets S one by one to the intermediate stacker 42. This is because if multiple sheets of thick paper are stacked together in the buffer unit 80, friction will occur between the multiple sheets S, causing problems with the images on the sheets S.

[0116] The heating temperatures required for plain paper, thick paper I, and thick paper II are different. For example, the target heating temperature for plain paper is 200 degrees. The target temperature for thick paper I is 220 degrees. The target temperature for thick paper II is 240 degrees.

[0117] However, when a user thermocompresses a plurality of sheets S of different types, there is a possibility that a sheet S of a type different from the type instructed by the user may be conveyed. If the thermocompression unit 51 performs thermocompression at a heating temperature for a type different from the instructed type, the amount of heat may be insufficient, resulting in insufficient compression. In the second embodiment, when the amount of heat is insufficient because the type of the preceding sheet S is different from the type assumed in advance, the CPU 651 changes the thermocompression parameters of the succeeding sheet S. This makes it difficult for insufficient compression to occur. In the second embodiment, the description of matters common to the first embodiment will be omitted.

[0118] (2) Heat recovery when the type of sheet is different from the expected Before the transport of the sheet S begins, the CPU 651 (acquisition unit 721) receives predicted type information from the printer control unit 600 indicating the type of the sheet S to be transported to the post-processing device 300. The predicted type information indicates, for example, a type specified by a user. After the transport of the sheet S begins, the CPU 651 (acquisition unit 721) receives confirmed type information from the printer control unit 600 indicating the type of the sheet S. The confirmed type information indicates the type actually detected by the media sensor 79 that detects the type of the sheet S. The CPU 651 (determination unit 722) determines whether the predicted type information and the confirmed type information match.

[0119] FIG. 14 is a timing chart when the type of sheet S is different from the expected type. The predicted type information indicates that the type of sheets S1 to S3 is cardboard i. On the other hand, the confirmed type information indicates that the types of sheets S1 and S3 are cardboard i, and the type of sheet S2 is cardboard ii. The heating temperature of sheet S2 should be 240 degrees. However, the conveyance of sheets S2 and S3 has already started, and it is not possible to wait for the temperature rise of the thermocompression bonding unit 51. Therefore, the thermocompression bonding of sheet S2 is performed at 220 degrees. In this case, there is a concern that the heating amount of sheet S2 will be insufficient, resulting in insufficient bonding. Therefore, the CPU 651 compensates for the insufficient heating amount of sheet S2 with the succeeding sheet S3. Here, the insufficient heating amount ΔW of sheet S2 is compensated for by the correction value ΔT of the heating time of the succeeding sheet S3. The insufficient heating amount ΔW may be calculated by the formula Eq2.

[0120] ΔW=(K2-K1)×T0 Eq2 where K2 is the target temperature required for the actual type of sheet S2. K1 is the target temperature required for the predicted type. In the example shown in Figure 11, K2 = 240 degrees and K1 = 220 degrees. T0 is the default thermocompression time.

[0121] 10C is a table that holds the relationship between the insufficient heating amount ΔW and the correction value ΔT of the heating time. This table is also determined when the thermocompression bonding unit 51 is designed, and is stored in the memory 652. The CPU 651 refers to the table based on the insufficient heating amount ΔW, and determines the correction value of the thermocompression bonding parameter to be applied to the succeeding sheet S. As a result, the heating amount of the sheet S2 is compensated for by the sheet S3.

[0122] FIG. 15 is a flow chart showing the thermocompression bonding method executed by the CPU 651 in accordance with the control program.

[0123] In S1501, the CPU 651 (acquisition unit 721) acquires from the memory 652 the predicted type information for the ith sheet Si.

[0124] In S1502, the CPU 651 (acquisition unit 721) acquires from the image forming apparatus 100 the finalized type information for the ith sheet Si.

[0125] In S1503, the CPU 651 (determination unit 722) determines whether the predicted type information and the finalized type information match. If the two match, the CPU 651 proceeds from S1503 to S1106. If the two do not match, the CPU 651 proceeds from S1503 to S1504.

[0126] In S1504, the CPU 651 (acquisition unit 721) acquires the amount of heat shortage ΔW. For example, the acquisition unit 721 acquires the amount of heat shortage ΔW by using Eq2.

[0127] In S1505, the CPU 651 (determination unit 723) acquires a correction value based on the amount of heat shortage ΔW. For example, the determination unit 723 refers to a table stored in the memory 652 and acquires a correction value ΔT corresponding to the amount of heat shortage ΔW.

[0128] In S1506, the CPU 651 (determination unit 723) determines the thermocompression bonding parameters of the (i+1)th sheet Si+1 based on the correction value. For example, the determination unit 723 determines the heating temperature T0+ΔT of the sheet Si+1 by adding the correction value ΔT to the default heating time T0 of the sheet Si+1. Thereafter, the CPU 651 executes S1106 to S1108.

[0129] In this way, according to the second embodiment, the insufficient heat quantity caused by the preceding sheet S being of a different type than expected is compensated for by the succeeding sheet S. This ensures sufficient adhesive strength while maintaining productivity.

[0130] In the above example, only the heating time is corrected among the multiple thermocompression bonding parameters, but this is merely an example. As mentioned in the first embodiment, other thermocompression bonding parameters (e.g., heating temperature, pressure) may be corrected in addition to or instead of the heating time.

[0131] <Example 3> (1) Basic Concept Although the post-processing device 300 of the first embodiment has the buffer unit 80, the buffer unit 80 is not essential. Therefore, the third embodiment relates to a thermocompression bonding process in the case where the post-processing device 300 does not have the buffer unit 80. Note that, among the matters described in the third embodiment, the description of the matters described in the first or second embodiment will be omitted.

[0132] (After-treatment device) 16 shows an image forming system 1 of a third embodiment. The image forming system 1 includes an image forming apparatus 100 and a post-processing apparatus 301. The post-processing apparatus 301 is disposed on the upper portion of the image forming apparatus 100. The post-processing apparatus 301 does not include a buffer unit 80.

[0133] The sheet S discharged from the discharge rollers 34 is pulled into a conveying path existing inside the post-processing device 301 by the inlet rollers 21. In addition, a sheet sensor 27 is arranged upstream of the inlet rollers 21 in the conveying direction of the sheet S. A kick-out roller 29 is arranged downstream of the inlet rollers 21. The kick-out rollers 29 convey the sheet S to the intermediate stacking unit 42. A sheet sensor 50 is arranged upstream of the kick-out rollers 29.

[0134] As already described, the intermediate stacking section 42 has the vertical alignment plate 39 and the thermocompression bonding unit 51, and performs thermocompression bonding on the multiple sheets S or the sheet stack W stacked in the intermediate stacking section 42. When the vertical alignment plate 39 moves from the standby position to the discharge position, the booklet held in the intermediate stacking section 42 is discharged to the discharge tray 77.

[0135] (2) Hardware 17 shows electrical hardware of post-processing device 301 related to embodiment 3. Compared with post-processing device 300 of embodiment 1, post-processing device 301 only omits motors M2 to M4 and sheet sensor 60 related to buffer unit 80. Therefore, the description of post-processing device 301 is the same as that of post-processing device 300, except for the buffer operation.

[0136] (3) Matching operation 18(A) to 18(D) show the alignment operation of the sheet S in the embodiment 3. Here, the vertical direction (longitudinal direction) of the sheet S is defined as the Y direction. The horizontal direction (short direction) of the sheet S is defined as the X direction. The height direction of the sheet S is defined as the Z direction.

[0137] As shown in FIG. 18(A), the sheet S is sent to the intermediate stacking section 42 by the kick-out roller 29. As shown in FIG. 18(B), the vertical alignment roller 40 is supported so as to be freely rotatable. The vertical alignment roller 40 transports the sheet S toward the vertical alignment plate 39 at a predetermined timing. The predetermined timing is, for example, a timing when a predetermined time has elapsed since the leading edge of the sheet S is detected by the sheet sensor 50. When the trailing edge of the sheet S abuts against the abutment members 39a to 39c of the vertical alignment plate 39, the vertical alignment roller 40 slips. This causes the position of the sheet S in the vertical direction to be aligned.

[0138] As shown in Fig. 18(C), when the sheet S reaches the contact members 39a to 39c, the lateral alignment joggers 41a to 41c start moving in the +X direction. As shown in Fig. 18(D), the lateral alignment joggers 41a to 41c move in the +X direction until the end of the sheet S abuts against the contact surface 500. This aligns the sheet S at a predetermined position in the lateral direction.

[0139] 18(C) and 18(D) are linked to the thermocompression bonding process by the thermocompression bonding unit 51. The thermocompression bonding unit 51 bonds the multiple sheets S together by thermocompression bonding the multiple sheets S. The thermocompression bonding unit 51 applies thermocompression bonding to the sheet stack W aligned in the vertical and horizontal directions, thereby producing a booklet that is aligned with high precision.

[0140] (4) Recovery from transport delays FIG. 19 is a timing chart showing that thermocompression bonding is performed by the thermocompression bonding unit 51 every time five sheets S are transported to the intermediate stacking section 42. Similarly to the sheet stack W1, the sheet stacks W2 and W3 are transported and thermocompression bonded. As shown in FIG. 19, the transport interval of the sheets S is Y1. The transport interval of the sheet stack W is Y2. The time from when the sheets are transported into the intermediate stacking section 42 until the thermocompression bonding is completed is T0. Therefore, T0 is the default thermocompression bonding time (heating time and pressurizing time).

[0141] The CPU 651 controls the heater 501 of the thermocompression unit 51 until the surface temperature of the heater 501 reaches the target temperature K1. The CPU 651 controls the motor M8 so that the total pressure applied to the sheet stack W reaches the target pressure P1. Heating and pressing are performed during the thermocompression time T0.

[0142] 20 shows an example in which a delay in conveying the sheet S occurs. In this example, the acquisition unit 721 uses the timer 707 to measure the time (conveyance time) required for the leading edge of the sheet S to be conveyed from the sheet sensor 27 to the sheet sensor 50. Slippage occurs suddenly at the inlet rollers 21, and the conveyance time of the sheet S5 becomes longer than the specified time. As in the first embodiment, the delay time at this time is N0.

[0143] In the third embodiment, the method of compensating for the heat amount when a transport delay occurs is the same as in the first embodiment. That is, the CPU 651 (acquisition unit 721) obtains the transport time of the last sheet S of the five sheets S constituting the sheet bundle Wi as the transport time of the sheet bundle Wi. The CPU 651 (acquisition unit 721) obtains the delay time N0 based on the transport time of the sheet bundle Wi. Furthermore, the CPU 651 (acquisition unit 721) calculates the shortage time ΔN from the delay time N0 and the margin N1. The CPU 651 (determination unit 723) determines the correction value of the thermocompression bonding parameter to be applied to the subsequent sheet bundle W based on the shortage time ΔN. The CPU 651 (determination unit 723) corrects (determines) the thermocompression bonding parameter using the correction value. The correction value may be determined based on a table stored in the memory 652. As the correction value, at least one of the correction value ΔT of the heating time, the correction value ΔK of the heating temperature, and the correction value ΔP of the pressure is determined.

[0144] According to the third embodiment, even in the post-processing device 301 having no buffer unit 80, the CPU 651 corrects the thermocompression parameters for the following sheet stack W2 based on the shortage time ΔN of the sheet stack W1. This ensures sufficient adhesive strength while maintaining productivity.

[0145] <Example 4> (1) Basic Concept In the second embodiment, in the post-processing device 300 having the buffer unit 80, the shortage of the heating amount caused by the delay in conveying the preceding sheet S is compensated for by the thermal parameters of the succeeding sheet S. As in the third embodiment, the second embodiment is also applicable to the image forming system 1 having the post-processing device 301. That is, the shortage of the heating amount caused by the difference between the actual type of the sheet S conveyed to the intermediate stacking unit 42 and the expected type is compensated for by correcting the thermocompression parameters of the succeeding sheet S. In the fourth embodiment, the matters explained in the first to third embodiments are omitted.

[0146] (2) Recovery when the sheet type is different from what was expected Before the conveyance of the sheet S starts, the CPU 651 (acquisition unit 721) receives from the printer control unit 600 predicted type information indicating the type of the sheet S to be conveyed to the post-processing device 301. The predicted type information indicates, for example, a type specified by a user. Furthermore, after the conveyance of the sheet S starts, the CPU 651 (acquisition unit 721) receives from the printer control unit 600 confirmed type information indicating the type of the sheet S determined by the image forming apparatus 100. The confirmed type information indicates the type actually detected by the media sensor 79 that detects the type of the sheet S. The CPU 651 (determination unit 722) determines whether the predicted type information and the confirmed type information match.

[0147] FIG. 21 is a timing chart when the type of sheet S is different from the expected type. The predicted type information indicates that the type of sheets S1 to S3 is cardboard i. On the other hand, the confirmed type information indicates that the types of sheets S1 and S3 are cardboard i, and the type of sheet S2 is cardboard ii. The heating temperature of sheet S2 should be 240 degrees. However, the conveyance of sheets S2 and S3 has already started, and it is not possible to wait for the temperature rise of the thermocompression bonding unit 51. Therefore, the thermocompression bonding of sheet S2 is performed at 220 degrees. In this case, there is a concern that the heating amount of sheet S2 will be insufficient, resulting in insufficient bonding. Therefore, the CPU 651 compensates for the insufficient heating amount of sheet S2 with the succeeding sheet S3. Here, the insufficient heating amount ΔW of sheet S2 is compensated for by the correction value ΔT of the heating time of the succeeding sheet S3. The insufficient heating amount ΔW may be calculated by the formula Eq2.

[0148] where K2 is the target temperature required for the actual type of sheet S2. K1 is the target temperature required for the predicted type. In the example shown in Figure 11, K2 = 240 degrees and K1 = 220 degrees. T0 is the default thermocompression time.

[0149] The method of compensating for the insufficient heating amount in the fourth embodiment is the same as the compensating method in the second embodiment. That is, the CPU 651 executes the method shown in Fig. 15. As a result, in the fourth embodiment, both the productivity and the adhesive strength are maintained.

[0150] <Other> In the above embodiment, the thermocompression bonding parameters are determined based on the shortage time ΔN, but this is merely an example. The thermocompression bonding parameters to be applied to the succeeding sheet S or sheet bundle W may be determined based on the delay time N0 or transport time for the preceding sheet S or sheet bundle W. In other words, the shortage time ΔN may be replaced with the delay time N0 or transport time of the preceding sheet bundle Wi.

[0151] <Technical ideas derived from examples> (Item 1) A conveying means for conveying a group of a plurality of sheets each having an adhesive applied thereto; a holding means for holding the plurality of sheet groups by overlapping a succeeding sheet group on a preceding sheet group; a thermocompression bonding means for applying heat and pressure to the group of sheets held by the holding means to produce a booklet; an acquiring means for acquiring sheet information indicating a conveying time or a sheet type of each of the plurality of sheet groups; a control means for controlling a thermocompression bonding parameter to be applied to at least one of the plurality of sheet groups in the thermocompression bonding means based on the sheet information; The post-treatment device has

[0152] The inlet roller 21, the pair of conveying rollers 26, 28, and the kick-out roller 29 are an example of a conveying means. The adhesive toner Tn is an example of a powder adhesive. The sheet S and the sheet stack W are an example of a sheet group. The sheet group may be formed of a single sheet S or a sheet stack W. As shown in FIG. 4(B) and FIG. 18(D), the intermediate stacking unit 42 holds a plurality of sheet groups by stacking a succeeding sheet group on a preceding sheet group. The CPU 651 acquires sheet information and controls thermocompression parameters to be applied to at least one succeeding sheet group among the plurality of sheet groups based on the sheet information of the preceding sheet group. The sheet information is, for example, a conveying time, a delay time N0, a shortage time ΔN, predicted type information, and determined type information. This ensures sufficient adhesive strength while maintaining the productivity of the post-processing device 300. (Item 2) the control means adjusts thermocompression bonding parameters applied to the i-th sheet group, as well as thermocompression bonding parameters of the (i+1)-th sheet group superimposed on the i-th sheet group, according to a transport time of the i-th sheet group among the plurality of sheet groups. Item 1. A post-treatment device according to item 1.

[0153] 9, the thermocompression bonding parameters of the (i+1)th sheet group may be corrected according to the delay time N0 or the shortage time ΔN. This may ensure sufficient adhesive strength while maintaining productivity. (Item 3) When the conveying time of the i-th sheet group is longer than a predetermined threshold time, the control means reducing the thermocompression time as the thermocompression parameter applied to the i-th sheet group by the thermocompression bonding means; increasing at least one of a thermocompression bonding time, a heating temperature, and a pressure force as the thermocompression bonding parameters applied to the (i+1)th sheet group by the thermocompression bonding means; Item 3. The post-treatment device according to item 2.

[0154] The CPU 651 may determine whether the transport time of the i-th sheet group is longer than a predetermined threshold time. That is, the CPU 651 determines whether a transport delay occurs. The CPU 651 may determine whether the delay time N0 is longer than a margin N1. The CPU 651 may reduce the thermocompression bonding time applied to the i-th sheet group, and increase at least one of the thermocompression bonding time, the heating temperature, and the pressure applied to the (i+1)-th sheet group. This may ensure sufficient adhesive strength while maintaining productivity. (Item 4) the control means further increases at least one of a thermocompression bonding time, a heating temperature, and a pressure as the thermocompression bonding parameters to be applied to the (i+2)th sheet group superimposed on the (i+1)th sheet group. Item 3. The post-treatment device according to item 3.

[0155] As described with respect to Fig. 10(B), the thermocompression parameters for the subsequent groups of sheets may be corrected so that the amount of heat supplied to the preceding groups of sheets is sufficient, thereby ensuring sufficient adhesive strength while maintaining productivity. (Item 5) 5. The post-processing device according to item 3 or 4, wherein a priority order is set in advance for the thermocompression bonding parameters, that is, the thermocompression bonding time, the heating temperature, and the pressure force, and which of the thermocompression bonding time, the heating temperature, and the pressure force is increased is determined according to the priority order.

[0156] 10A, the thermocompression bonding time, the heating temperature, and the pressure may have an order of priority. The CPU 651 may select a pair of thermocompression bonding parameters according to the order of priority. For example, the order of priority may be determined so as to emphasize the durability of the thermocompression bonding unit 51. (Item 6) a storage means for storing a combination of a transport time of an ith sheet group among the plurality of sheet groups, a type of the thermocompression bonding parameter applied to the (i+1)th sheet group and an increment thereof, and a type of the thermocompression bonding parameter applied to the (i+2)th sheet group and an increment thereof, The post-processing device described in item 4, wherein the control means acquires from the memory means a combination of the type of thermocompression parameters to be applied to the (i+1)th sheet group and their increments, corresponding to the transport time of the i-th sheet group, and the type of thermocompression parameters to be applied to the (i+2)th sheet group and their increments.

[0157] The shortage time ΔN is an example of the transport time of the i-th sheet group. The memory 652 and the table shown in FIG. 10(A) are examples of storage means. The correction values ​​ΔT, ΔK, and ΔP are examples of the increments. The table may be realized by a mathematical function or a program module. (Item 7) The post-processing device described in item 1, wherein when the amount of heat supplied from the thermocompression means to the i-th sheet group among the multiple sheet groups is insufficient due to the i-th sheet group arriving late at the holding means, the control means increases the amount of heat supplied from the thermocompression means to the i+1-th sheet group stacked on top of the i-th sheet group.

[0158] In this way, if the i-th group of sheets is delayed, the amount of heat applied to the i+1-th group of sheets may be increased above a prescribed amount, and the heat applied to the i+1-th group of sheets will also propagate to the i-th group of sheets, thereby increasing the amount of heat applied to the i-th group of sheets. (Item 8) The post-processing device described in item 1, wherein, when the amount of heat supplied from the thermocompression bonding means to the i+1th sheet group superimposed on the i-th sheet group is insufficient due to the i+1th sheet group among the multiple sheet groups arriving late at the holding means, the control means increases the amount of heat supplied from the thermocompression bonding means to the i+1th sheet group superimposed on the i-th sheet group and the amount of heat supplied from the thermocompression bonding means to the i+2th sheet group superimposed on the i+1th sheet group.

[0159] In this way, when the i-th sheet group is delayed, the amount of heat applied to the i+1-th sheet group and the i+2-th sheet group may be increased from a specified amount. The heat applied to the i+1-th sheet group also propagates to the i-th sheet group. The heat applied to the i+2-th sheet group also propagates to the i-th sheet group via the i+1-th sheet group. This increases the amount of heat applied to the i-th sheet group. (Item 9) 7. The post-processing device according to claim 6, wherein the control means distributes the heat amount that is insufficient due to a delay in the i-th sheet group relative to the heat amount required to achieve a target adhesive strength for the i-th sheet group, between the heat amount for the i+1-th sheet group and the heat amount for the i+2-th sheet group.

[0160] Due to the delay of the i-th sheet group, the amount of heat supplied to the i-th sheet group is insufficient. Therefore, to compensate for this shortage, the amount of heat supplied to the subsequent multiple sheet groups may be increased. In Fig. 10(B), the amount of heat is distributed to two sheet groups, but the amount of heat may be distributed to three or more sheet groups. (Item 10) the acquiring means acquires, as the sheet information, the transport time of each sheet group transported by the transport means through a predetermined transport section; the control means adjusts a thermocompression bonding parameter applied to the i-th sheet group in accordance with a transport time of the i-th sheet group among the plurality of sheet groups. Item 1. A post-treatment device according to item 1.

[0161] In FIG. 1, the section from sheet sensor 60 to sheet sensor 50 is an example of a predetermined conveyance section. In FIG. 16, the section from sheet sensor 27 to sheet sensor 50 is an example of a predetermined conveyance section. The CPU 651 may adjust the thermocompression bonding parameters applied to the i-th sheet group according to the conveyance time of the i-th sheet group. As illustrated in FIG. 9, the default thermocompression bonding time is T0. There may be a conveyance delay of conveyance time N0 for the sheet bundle W1. In this case, the difference between the default thermocompression bonding time T0 and the conveyance time N0 may be used as the actual thermocompression bonding time. This may mean that the end time of the thermocompression bonding of the sheet bundle W1 is not changed from the specified time. Alternatively, considering the margin N1, the end time of the thermocompression bonding of the sheet bundle W1 may be shifted. When N0 < N1, the thermocompression bonding time of the sheet bundle W1 is maintained at T0. When N0 > N1, the thermocompression bonding time of the sheet bundle W1 becomes T0 - ΔN. ΔN is the difference between N0 and N1. In particular, when N0 > N1, it is necessary to make up for the subsequent sheet groups. (Item 11) The post-processing apparatus according to item 1, wherein each of the plurality of sheet groups is a single sheet or a sheet bundle composed of a plurality of sheets.

[0162] As described in Examples 1 and 3, the sheet group may be a sheet bundle W composed of a plurality of sheets S. As described in Examples 2 and 4, the sheet group may be composed of a single sheet S. (Item 12) The post-processing apparatus according to item 1, further comprising production means for producing a sheet bundle composed of a plurality of sheets as the sheet group.

[0163] The buffer unit 80 is an example of the production means. Note that the intermediate stacking unit 42 of the post-processing apparatus 301 is also an example of the production means. (Item 13) The post-processing apparatus according to item 12, wherein the conveyance means is configured to convey the sheet bundle produced by the production means to the holding means.

[0164] As shown in FIG. 1, the pairs of conveying rollers 26 and 28 and the kick-out roller 29 are an example of a conveying means. (Item 14) Item 13. The post-processing device according to item 12, wherein the holding means has the creating means.

[0165] As shown in FIGS. 18(A) to 18(D), the intermediate stacking section 42 may function as a sheet stack making means. (Item 15) Each of the plurality of sheet groups is made up of a single sheet, The acquiring means acquires the sheet information indicating the type of each sheet, The post-processing device described in item 1, wherein the control means adjusts thermocompression parameters applied to the (i+1)th sheet that is placed on top of the i-th sheet in the holding means when the type of the i-th sheet transported to the holding means is different from a previously assumed type.

[0166] As described in the second and fourth embodiments, the predicted type information and the confirmed type information are examples of sheet information. When the predicted type differs from the actual type, the amount of heat may be insufficient. In this case, the amount of heat may be increased for the subsequent sheet S. This maintains productivity and ensures sufficient adhesive strength. (Item 16) Item 16. The post-processing device according to item 15, wherein the control means adjusts thermocompression parameters applied to the (i+2)th sheet that is superimposed on the (i+1)th sheet in the holding means when the type of the i-th sheet transported to the holding means is different from a previously assumed type.

[0167] In this way, when a shortage in the amount of heat is caused for the i-th sheet Si, the CPU 651 may distribute the amount of heat to the subsequent sheets Si+1, Si+2, . . . (Item 17) Item 16. The post-processing device according to item 15, wherein the type of the sheet is at least one of the material, basis weight, and presence or absence of coating of the sheet, which is related to the amount of heat required for thermocompression bonding of the sheet.

[0168] In Examples 2 and 4, the basis weight of the sheet S is mainly illustrated. However, the type of the sheet may be a material related to the amount of heat, and may be coated or not coated. (Item 18) An image forming system having an image forming apparatus and a post-processing apparatus, The image forming apparatus includes: an image forming means for forming images on a plurality of sheets; an application means for applying adhesive to the plurality of sheets; a discharge unit for sequentially discharging the plurality of sheets to the post-processing device, The post-treatment device includes: a conveying means for conveying a group of a plurality of sheets, each of which is coated with an adhesive, the group being composed of sheets discharged from the image forming apparatus; a holding means for holding the plurality of sheet groups by overlapping a succeeding sheet group on a preceding sheet group; a thermocompression bonding means for applying heat and pressure to the group of sheets held by the holding means to produce a booklet; an acquiring means for acquiring sheet information indicating a conveying time or a sheet type of a preceding sheet group among the plurality of sheet groups; a control means for controlling, based on the sheet information, thermocompression bonding parameters to be applied to at least one subsequent sheet group with respect to the preceding sheet group among the plurality of sheet groups in the thermocompression bonding means; An image forming system comprising:

[0169] The image forming unit 10 is an example of an image forming means. The process cartridge 7n and the transfer belt 30 are an example of an application means.

[0170] 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]

[0171] 42: intermediate loading section, 51: thermocompression unit, 651: CPU

Claims

1. A conveying means for conveying a group of a plurality of sheets each having an adhesive applied thereto; a holding means for holding the plurality of sheet groups by overlapping a succeeding sheet group on a preceding sheet group; a thermocompression bonding means for applying heat and pressure to the group of sheets held by the holding means to produce a booklet; an acquiring means for acquiring sheet information indicating a conveying time or a sheet type of a preceding sheet group among the plurality of sheet groups; a control means for controlling, based on the sheet information, thermocompression bonding parameters to be applied to at least one subsequent sheet group to the preceding sheet group among the plurality of sheet groups in the thermocompression bonding means; The post-treatment device has

2. the control means adjusts thermocompression bonding parameters applied to the i-th sheet group, as well as thermocompression bonding parameters of the (i+1)-th sheet group superimposed on the i-th sheet group, according to a transport time of the i-th sheet group among the plurality of sheet groups. The post-treatment device according to claim 1 .

3. When a conveying time of the i-th sheet group is longer than a predetermined threshold time, the control means reducing the thermocompression time as the thermocompression parameter applied to the i-th sheet group by the thermocompression bonding means; At least one of a thermocompression bonding time, a heating temperature, and a pressure force is increased as the thermocompression bonding parameters applied to the (i+1)th sheet group by the thermocompression bonding means. The post-treatment device according to claim 2 .

4. the control means further increases at least one of a thermocompression bonding time, a heating temperature, and a pressure as the thermocompression bonding parameters to be applied to the (i+2)th sheet group superposed on the (i+1)th sheet group. The post-treatment device according to claim 3 .

5. 5. The post-processing device according to claim 3, wherein a priority order is set in advance for the thermocompression bonding parameters, that is, the thermocompression bonding time, the heating temperature, and the pressure force, and which of the thermocompression bonding time, the heating temperature, and the pressure force is increased is determined according to the priority order.

6. a storage means for storing a combination of a transport time of the i-th sheet group, a type of the thermocompression bonding parameter applied to the i+1-th sheet group and an increment thereof, and a type of the thermocompression bonding parameter applied to the i+2-th sheet group and an increment thereof, The post-processing device according to claim 4, wherein the control means acquires from the memory means a combination of the type of thermocompression parameters to be applied to the (i+1)th sheet group and their increments, corresponding to the transport time of the i-th sheet group, and the type of thermocompression parameters to be applied to the (i+2)th sheet group and their increments.

7. 2. The post-processing device according to claim 1, wherein when the amount of heat supplied from the thermocompression means to the i+1th sheet group stacked on top of the ith sheet group becomes insufficient due to the ith sheet group among the multiple sheet groups arriving late at the holding means, the control means increases the amount of heat supplied from the thermocompression means to the i+1th sheet group stacked on top of the ith sheet group.

8. 2. The post-processing device according to claim 1, wherein, when the amount of heat supplied from the thermocompression bonding means to the i+1th sheet group superimposed on the i-th sheet group is insufficient due to the i-th sheet group among the multiple sheet groups arriving late at the holding means, the control means increases the amount of heat supplied from the thermocompression bonding means to the i+1th sheet group superimposed on the i-th sheet group and the amount of heat supplied from the thermocompression bonding means to the i+2th sheet group superimposed on the i+1th sheet group.

9. 7. The post-processing device according to claim 6, wherein the control means distributes the heat amount that is insufficient due to a delay in the i-th sheet group compared to the heat amount required to achieve a target adhesive strength for the i-th sheet group, between the heat amount for the i+1-th sheet group and the heat amount for the i+2-th sheet group.

10. the acquiring means acquires, as the sheet information, the transport time of each sheet group transported by the transport means through a predetermined transport section; the control means adjusts a thermocompression bonding parameter to be applied to the i-th sheet group in accordance with a transport time of the i-th sheet group among the plurality of sheet groups. The post-treatment device according to claim 1 .

11. The post-processing device according to claim 1 , wherein each of the plurality of sheet groups is a single sheet or a sheet stack made up of a plurality of sheets.

12. 2. The post-processing device according to claim 1, further comprising a preparing unit for preparing a sheet bundle consisting of a plurality of sheets as the sheet group.

13. The post-processing device according to claim 12 , wherein the transporting means is configured to transport the sheet bundle prepared by the preparing means to the holding means.

14. The post-treatment device of claim 12 , wherein the holding means comprises the creating means.

15. Each of the plurality of sheet groups is made up of a single sheet, The acquiring means acquires the sheet information indicating the type of each sheet, 2. The post-processing device according to claim 1, wherein the control means adjusts thermocompression parameters applied to the (i+1)th sheet that is placed on top of the i-th sheet in the holding means when the type of the i-th sheet transported to the holding means is different from a previously assumed type.

16. The post-processing device according to claim 15, wherein the control means adjusts thermocompression parameters applied to the i+2-th sheet that is superimposed on the i+1-th sheet in the holding means when the type of the i-th sheet transported to the holding means is different from a previously assumed type.

17. The post-processing device according to claim 15 , wherein the type of the sheet is at least one of the material, basis weight, and presence or absence of coating of the sheet, which is related to the amount of heat required for thermocompression bonding of the sheet.

18. An image forming system having an image forming apparatus and a post-processing apparatus, The image forming apparatus includes: an image forming means for forming images on a plurality of sheets; an application means for applying adhesive to the plurality of sheets; a discharge unit for sequentially discharging the plurality of sheets to the post-processing device, The post-treatment device includes: a conveying means for conveying a group of a plurality of sheets, each of which is coated with an adhesive, the group being composed of sheets discharged from the image forming apparatus; a holding means for holding the plurality of sheet groups by overlapping a succeeding sheet group on a preceding sheet group; a thermocompression bonding means for applying heat and pressure to the group of sheets held by the holding means to produce a booklet; an acquiring means for acquiring sheet information indicating a conveying time or a sheet type of a preceding sheet group among the plurality of sheet groups; a control means for controlling, based on the sheet information, thermocompression bonding parameters to be applied to at least one subsequent sheet group with respect to the preceding sheet group among the plurality of sheet groups in the thermocompression bonding means; An image forming system comprising:

Images