Sheet thermocompression device and composite machine

Abstract

To provide a sheet thermocompression device capable of performing a stable thermocompression operation.SOLUTION: This sheet thermocompression device comprising: a loading unit on which a bundle of sheets with an adhesive layers formed is loaded; and a thermocompression unit including a pressing member 602 that presses the bundle of sheets loaded on the loading unit in a loading direction of the sheet with a direction along one side of the sheets loaded on the loading unit set as a longitudinal direction, and a heating source 601 that heats the pressing member 602. The bundle of sheets is presses by the pressing member 602 heated by the heading source 601, and the adhesive layer on the sheets is melted to bond the sheets together. The sheet thermocompression device is configured to be able to handle sheets of a prescribed size. The thermocompression unit is disposed at a position not overlapping the smallest sheet mounted on the loading unit in the loading direction, the smallest sheet being a smallest sheet of a prescribed size, and includes a temperature measurement sensor TH1 that detects the temperature of the heating source 601.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a sheet thermocompression bonding device and a multifunction peripheral including the sheet thermocompression bonding device. [Background technology]

[0002] Conventionally, a method is known in which a booklet is produced by bonding multiple sheets that have been subjected to image formation processing by an image forming device by remelting the adhesive layer (adhesive toner) on the sheets using a sheet thermocompression bonding device. Booklets produced by bonding with adhesive toner do not use metal staples such as staples, which is a great advantage in terms of safety. In addition, when cutting the sheets using a shredder or the like, there is no need to remove metal staples, which improves user convenience.

[0003] Patent Document 1 discloses a configuration in which an image forming apparatus forms a toner for printing an image on a sheet and simultaneously forms an adhesive toner on the sheet at a binding position. Then, a sheet bundle made up of a plurality of sheets on which the adhesive toner has been formed is heated and pressurized by a thermocompression unit of a sheet thermocompression device, and is subjected to an adhesive process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-237291 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the sheet thermocompression bonding device as described above, the thermocompression bonding unit is configured to include a pressing member that contacts the sheet to press the sheet, and a heat source that heats the pressing member. When the sheet thermocompression bonding device is configured to be compatible with sheets of a plurality of predetermined sizes, the thermocompression bonding unit generally has a longitudinal dimension along one side of the sheet determined according to the maximum size of the sheet among the predetermined sizes.

[0006] When a sheet smaller than the maximum size is pressed by the thermocompression unit, stress concentration occurs at the boundary between the pressurized area of ​​the pressing surface of the pressing member that receives a reaction force from the sheet and the non-pressurized area that does not contact the sheet. The inventors of the present application have found that the stress concentration can cause the pressing member to deform, resulting in areas where the thermal conductivity between the pressing member and the heat source is reduced. The reduced thermal conductivity from the heat source to the pressing member can lead to an excessive rise in the temperature of the heat source, which can lead to a decrease in the quality of the booklet produced by the thermocompression operation and a breakdown of the thermocompression unit, etc.

[0007] The present invention has been made in view of the above-mentioned problems, and has an object to provide a sheet thermocompression bonding device capable of performing a stable thermocompression bonding operation. [Means for solving the problem]

[0008] In order to achieve the above object, the sheet thermocompression bonding apparatus according to the present application comprises: a loading section on which a stack of sheets having adhesive layers formed thereon is loaded; a thermocompression bonding unit including a pressing member for pressing the stack of sheets loaded on the stacking section in a stacking direction of the sheets, the pressing member having a longitudinal direction along one side of the sheets loaded on the stacking section, and a heat source for heating the pressing member; a sheet thermocompression bonding apparatus for bonding a plurality of sheets together by pressing a stack of sheets with the pressing member heated by the heating source and melting an adhesive layer on the sheet, the sheet thermocompression bonding apparatus being configured to be compatible with a plurality of sheets of a predetermined size, The thermocompression bonding unit is characterized in that, when the smallest sheet among the specified sizes is defined as a smallest sheet, it is positioned in a position that does not overlap with the smallest sheet placed on the loading section in the loading direction, and includes a temperature measurement sensor that detects the temperature of the heat source. Effect of the Invention

[0009] According to the present invention, it is possible to provide a sheet thermocompression bonding device capable of performing a stable thermocompression bonding operation. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic cross-sectional view of an image forming apparatus and a post-processing apparatus according to the first embodiment. [Diagram 2] 4A to 4C are explanatory diagrams of a sheet aligning method in the post-processing device according to the first embodiment. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing the configuration of a heating unit of the first embodiment. [Figure 4] FIG. 2 is an explanatory diagram of a thermocompression bonding operation in the first embodiment. [Diagram 5] FIG. 4 is a diagram showing the positional relationship between a ceramic heater and a thermistor in the first embodiment. [Figure 6] FIG. 4 is an explanatory diagram showing a load applied to a heating plate during a thermocompression bonding operation in the first embodiment. [Figure 7] 4 is a flowchart of a temperature rise suppression operation in the first embodiment. [Figure 8] 4 is a diagram showing a transition of a detected temperature, an image formation interval, and a booklet production interval in the first embodiment. FIG. [Figure 9] FIG. 2 is an explanatory diagram showing a printing area of ​​an adhesive toner according to the first embodiment. [Figure 10] 4 is a graph showing the results of measuring the storage modulus of the adhesive toner of Example 1. [Figure 11] FIG. 2 is an explanatory diagram of a booklet quality test method in Example 1. [Figure 12] FIG. 4 is a schematic cross-sectional view of a modified image forming apparatus and a post-processing apparatus of the first embodiment. [Figure 13] FIG. 11 is a schematic cross-sectional view showing the configuration of a heating unit of Example 2. [Figure 14] FIG. 11 is an explanatory view showing a load applied to a heating plate during a thermocompression bonding operation in the second embodiment. [Figure 15] 13 is a diagram showing a transition of a detected temperature, an image formation interval, and a booklet production interval in Example 2. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the mode for carrying out the present invention will be described in detail by way of example based on the embodiments with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiments should be appropriately changed depending on the configuration of the device to which the invention is applied and various conditions. In other words, the scope of the present invention is not limited to the following embodiments. Furthermore, not all of the features described in the following embodiments are necessarily essential to the solution of the invention.

[0012] The sheet thermocompression bonding device of the present invention is particularly suitable for a sheet thermocompression bonding device for producing a booklet composed of a plurality of sheets bonded together. As an example of a sheet thermocompression bonding device to which the present invention is applied, a sheet thermocompression bonding device that is connected to an image forming device that forms an image on a sheet and is provided in a post-processing device to which a sheet is transported from the image forming device will be described below.

[0013] <Example 1> (Image forming device) FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a multifunction machine 1 including an image forming apparatus 100 according to a first embodiment and a post-processing apparatus 300 connected to the image forming apparatus 100. First, the overall configuration of the image forming apparatus 100 according to the first embodiment will be described with reference to FIG. The image forming apparatus 100 is a laser printer that uses an electrophotographic recording method. In the first embodiment, the post-processing apparatus 300 is described as an apparatus independent of the image forming apparatus 100, but the post-processing apparatus 300 may be considered as one apparatus that constitutes the image forming apparatus 100. The image forming apparatus 100 may also be another image forming apparatus that uses an electrophotographic recording method, such as a copying machine or a facsimile.

[0014] As shown in FIG. 1, the image forming apparatus 100 includes a sheet cassette 8 for storing sheets P as recording materials (recording media), and an image forming unit 1e (within the dashed line frame) as an image forming means. ), a fixing device (fixing unit) 6 as a fixing means, and a housing 19 that houses them. The image forming apparatus 100 has a printing function of forming a toner image on a sheet P fed from a sheet cassette 8 by an image forming unit 1e, and performing a fixing process by the fixing device 6 to produce a printed matter.

[0015] In the first embodiment, the image forming apparatus 100 is configured to be capable of forming images on a plurality of sheets P of predetermined sizes. The maximum size of the sheet P on which the image forming apparatus 100 can form an image is A4 size (297 mm length x 210 mm width), and the minimum size is A5 size (210 mm length x 149 mm width). The image forming apparatus 100 forms an image on the sheet P by transporting the sheet P in the vertical direction (the longitudinal direction is parallel to the transport direction). The sheet transport speed of the image forming apparatus 100 is 300 mm / sec.

[0016] The sheet cassette 8 is inserted into a housing 19 of the image forming apparatus 100 at the bottom of the image forming apparatus 100 so as to be removable, and is configured to be capable of storing a large number of sheets P. The sheets P stored in the sheet cassette 8 are fed from the sheet cassette 8 by a sheet feed roller 8a serving as a paper feed section, and are transported by a transport roller pair 8b. The image forming apparatus 100 further includes a multi-tray 20, and is also capable of feeding the sheets P set in the multi-tray 20 one by one.

[0017] The image forming unit 1e is a tandem-type electrophotographic unit that includes four process cartridges 7y, 7m, 7c, and 7k, a scanner unit 2, and a transfer unit 3. In the following, when there is no need to distinguish between the process cartridges 7y, 7m, 7c, and 7k, they will be collectively referred to as the process cartridges 7. The same applies to the members provided in each process cartridge 7, such as the photosensitive drum D.

[0018] The process cartridge 7 is a unit in which a plurality of parts responsible for an image forming process are integrated and replaceable. Each of the process cartridges 7y, 7m, 7c, and 7k includes a photosensitive drum D (Dy, Dm, Dc, and Dk) that is an image carrier, and a charging roller C (Cy, Cm, Cc, and Ck) that is a charger for charging the photosensitive drum D. Furthermore, each of the process cartridges 7y, 7m, 7c, and 7k includes a toner storage section K (Ky, Km, Kc, and Kk) that stores toner and supplies the toner to the photosensitive drum D. The toner storage section K is provided with a developing roller for supplying toner to the photosensitive drum D. Each of the process cartridges 7y, 7m, 7c, and 7k has a substantially common configuration, except for the type of toner stored in the four toner storage sections Ky, Km, Kc, and Kk.

[0019] The toner storage units Ky, Km, Kc, and Kk store toners for forming a visible image on the sheet P, namely, yellow toner, magenta toner, cyan toner, and black toner. In the first embodiment, the black toner is also used as an adhesive toner as a powder adhesive for performing a pressure bonding process after printing. That is, in the first embodiment, the black toner attached to the sheet can function as an adhesive layer for bonding a plurality of sheets together. In the first embodiment, the black toner is used as a toner for both visible image formation and adhesion, but any of the other color toners (yellow, magenta, and cyan) may be used as a toner for both visible image formation and adhesion. Also, a transparent toner may be prepared without adding a pigment, and the toner may be used for adhesion purposes.

[0020] The scanner unit 2 is an exposure unit disposed below the process cartridges 7 and above the sheet cassette 8. The scanner unit 2 irradiates the photosensitive drum D of each process cartridge 7 with laser light to form an electrostatic latent image. Note that the exposure unit of the electrophotographic image forming apparatus 100 is not limited to the above-mentioned configuration.

[0021] The transfer unit 3 includes a transfer belt 3a as an intermediate transfer body (secondary image carrier). The transfer belt 3a is a belt member stretched around a secondary transfer inner roller 3b and a tension roller 3c, and its outer circumferential surface faces the photosensitive drum D. Primary transfer rollers Fn, Fy, Fm, and Fc are disposed on the inner circumferential side of the transfer belt 3a at positions corresponding to the respective photosensitive drums Dn, Dy, Dm, and Dc.

[0022] A secondary transfer roller 5 serving as a transfer means is disposed at a position facing the secondary transfer inner roller 3b with the transfer belt 3a interposed therebetween. A transfer nip 5n formed between the secondary transfer roller 5 and the transfer belt 3a is a transfer section (secondary transfer section) that transfers a toner image from the transfer belt 3a to the sheet P. A fixing device 6 is disposed above the secondary transfer roller 5.

[0023] The fixing device 6 is a fixing section that heats and melts the toner image on the sheet P while transporting the sheet P. The fixing device 6 has a cylindrical fixing film 6a as a heating rotator, a pressure roller 6c as a pressure member that presses the fixing film 6a, and a heater 6b as a heating means that contacts the inner surface of the fixing film 6a and heats it. A fixing nip 6n is formed between the fixing film 6a and the pressure roller 6c by the pressing force of the pressure roller 6c.

[0024] (Image formation operation) Next, an image forming operation of the image forming apparatus 100 will be described. When data of an image to be printed and a command to execute printing are input to the image forming apparatus 100, the control unit of the image forming apparatus 100 starts a series of operations (conveying operations by each conveying means and image forming operations) for conveying the sheet P and forming an image on the sheet P. In Fig. 1, the conveying direction of the sheet P and the driving direction of each member are indicated by dotted lines with arrows.

[0025] In the image forming operation, first, sheets P are fed one by one from the sheet cassette 8 and conveyed toward the transfer nip 5n via the conveying roller pair 8b. In parallel with the feeding of the sheets P, the process cartridges 7 are driven in sequence, and the photosensitive drums D are rotated. At this time, the surface of the photosensitive drum D is uniformly charged by the charging roller C. The scanner unit 2 also irradiates the photosensitive drum D of each process cartridge 7 with laser light modulated based on image data, to form an electrostatic latent image on the surface of the photosensitive drum D. Then, the electrostatic latent image on the photosensitive drum D is developed into a toner image by the toner carried by the developing roller in the toner storage section K of each process cartridge 7.

[0026] The transfer belt 3a rotates in a counterclockwise direction (the direction of the arrow v) in Fig. 1. The toner image formed in each process cartridge 7 is primarily transferred from the photosensitive drum D to the transfer belt 3a by an electric field formed between the photosensitive drum D and the primary transfer roller F.

[0027] The toner image carried by the transfer belt 3a and reaching the transfer nip 5n is secondarily transferred onto the conveyed sheet P by an electric field formed between the secondary transfer roller 5 and the inner secondary transfer roller 3b.

[0028] Thereafter, the sheet P is conveyed to the fixing device 6 and subjected to a thermal fixing process. That is, when the sheet P passes through the fixing nip 6n, the toner image on the sheet P is heated and pressurized, so that the printing toner melts and then adheres to the sheet P, thereby obtaining an image fixed on the sheet P.

[0029] Downstream of the fixing nip 6n in the conveying direction of the sheet P, a switching guide 33 is provided as a guide member for switching the conveying direction of the sheet P. The conveying direction of the sheet P is switched by the switching guide 33 depending on the selected print mode, either a single-sided printing mode in which an image is formed on only one side of the sheet P, or a double-sided printing mode in which images are formed on both sides of the sheet P.

[0030] In the case of the single-sided printing mode, the switching guide 33 guides the sheet P to the pair of discharge rollers 34. The sheet P guided by the switching guide 33 to the pair of discharge rollers 34 reaches the post-processing device 300 via the intermediate conveying unit 200 having the pair of conveying rollers 201 and 202, and a series of image forming operations in the image forming apparatus 100 is completed.

[0031] On the other hand, in the case of the double-sided printing mode, the switching guide 33 guides the sheet P to the switchback roller pair 35. Then, the switchback roller pair 35 reverses the rotation direction after discharging the sheet P to the rear end in the conveying direction, thereby conveying the sheet P to the double-sided conveying path 36 for double-sided printing.

[0032] The sheet P conveyed to the double-sided conveying path 36 passes through the secondary transfer unit and the fixing device 6 again, during which an image is formed on the unprinted surface of the sheet P. Then, the switching guide 33 guides the sheet P to the pair of paper discharge rollers 34, and the sheet P reaches the post-processing device 300 via the intermediate conveying unit 200.

[0033] The post-processing device 300 of the first embodiment has a floor-standing configuration. The post-processing device 300 is equipped with a transport mechanism for transporting the sheets P, a sheet alignment mechanism provided at the bottom of the device, and a booklet making device 50 provided with a thermocompression unit 51 for heating and pressing the aligned sheet stack for a predetermined time. The booklet making device 50 is a sheet thermocompression device that heats and presses the aligned sheet stack to bond multiple sheets together. In the first embodiment, the sheet transport speed by the intermediate transport unit 200 and the transport mechanism of the post-processing device 300 is 600 mm / sec.

[0034] (After-treatment device) Next, the operation of the post-processing device 300 will be described. The sheet P conveyed from the intermediate conveying unit 200 is delivered to the conveying roller pair 21 of the post-processing device 300. An entrance sensor 27 that detects the passage of the sheet P is provided downstream of the conveying roller pair 21 in the conveying direction. Based on the trailing end passing time detected by the entrance sensor 27, the conveying roller 22 provided downstream of the entrance sensor 27 in the conveying direction accelerates the sheet P at a predetermined timing. The post-processing device 300 is provided with an upper discharge tray 25 and a lower discharge tray 37 located below the upper discharge tray 25 as discharge destinations for the sheet P.

[0035] If the discharge destination of the sheet P is the upper discharge tray 25, when the rear end of the sheet (the rear end of the sheet P in the conveying direction) reaches between the conveying roller 22 and the reversing roller 24, the sheet P is decelerated to a predetermined discharge speed and discharged to the upper discharge tray 25.

[0036] When the discharge destination of the sheet P is the lower discharge tray 37, the sheet conveyance is temporarily stopped at the timing when the trailing end of the sheet passes through the check valve 23 provided on the downstream side of the conveyance roller 22 in the conveyance direction, and the sheet P is switched back and conveyed to the inner discharge roller 26. The check valve 23 is biased in the clockwise direction in FIG. 1 by a spring (not shown).

[0037] The sheet P conveyed from the internal discharge rollers 26 is sent to the kick-out rollers 29 via the intermediate conveying rollers 28, and is conveyed to the intermediate stacking section 42 in the booklet producing device 50. A vertical alignment reference plate 39 is disposed at the most downstream portion of the intermediate stacking section 42, and the sheet stack is aligned by abutting the conveying direction end of the sheet P against the vertical alignment reference plate 39 by the half-moon roller 40.

[0038] (Sheet alignment method) Next, a method for aligning the sheets P in the sheet aligning section in the booklet producing apparatus 50 will be described with reference to FIGS. 2(a) to 2(e). 10 is an explanatory diagram of a method for aligning sheets P by a sheet alignment mechanism, and is a view of intermediate stacking section 42 viewed from a direction perpendicular to the loading surface of sheets P. In the following description, the vertical direction in which sheets P are conveyed by kick-out rollers 29 is defined as the Y direction, the horizontal direction which is the width direction of sheets P is defined as the X direction, and the loading direction in which sheets P are loaded (height direction of the sheet stack) is defined as the Z direction.

[0039] 2(a) shows a state in which the sheet P is transported to the intermediate stacking section 42. The sheet P is transported to the intermediate stacking section 42 by the kick-out roller 29. The intermediate stacking section 42 is provided with a vertical alignment reference plate 39 for aligning the position of the sheet P in the vertical direction (Y direction), and a half-moon roller 40 for pressing the sheet P against the vertical alignment reference plate 39.

[0040] The vertical alignment reference plate 39 is a regulating member that regulates the movement of the sheet P in the vertical direction (Y direction), and the sheet P is aligned by pressing the vertical end of the sheet P against the vertical alignment reference plate 39. The vertical alignment reference plate 39 is configured to be movable in the vertical direction, and the alignment position can be changed according to the size of the sheet P to be aligned. The half-moon roller 40 is supported rotatably, and transports the sheet P toward the vertical alignment reference plate 39 at a predetermined timing.

[0041] 2(b) shows a state where the vertical end of the sheet P abuts against the horizontal alignment reference plate 52. After the sheet P abuts against the vertical alignment reference plate 39, the conveying pressure of the half-moon roller 40 is adjusted so that the half-moon roller 40 slips on the sheet P.

[0042] The intermediate stacking section 42 is provided with a lateral alignment reference plate 500 for adjusting the position of the sheet P in the lateral direction (X direction), and a lateral alignment jogger 41a for pressing the sheet P against the lateral alignment reference plate 500. The lateral alignment reference plate 500 is a member for restricting the lateral movement of the sheet P, and the sheet P is aligned by pressing the lateral end of the sheet P against the lateral alignment reference plate 500. FIG. 2(c) shows a state in which the sheet P is pressed toward the lateral alignment reference plate 500 provided in the intermediate stacking section 42. The sheet P that has hit the vertical alignment reference plate 39 is pressed to the left in FIG. 2(c) toward the lateral alignment reference plate 500 by the lateral alignment jogger 41a that is installed so as to be movable in the lateral direction.

[0043] Fig. 2(d) shows a state where the lateral end of the sheet P abuts against the lateral alignment reference plate 500. The sheet P, which has been pushed to the left in Fig. 2(c) by the lateral alignment jogger 41a, abuts against the lateral alignment reference plate 500 shown by dotted lines in Figs. 2(a) to 2(d), and is aligned with high precision in both the lateral and vertical directions before being loaded onto the intermediate stacking section 42.

[0044] 2(c) and (d) is performed in a batch of four sheets in conjunction with a binding operation by a thermocompression bonding unit 51 provided in the intermediate stacker 42. The thermocompression bonding unit 51 is a sheet bonding means for subjecting a plurality of sheets P to a thermocompression process to produce a sheet stack with the left end portion bound or the right end portion bound.

[0045] A plurality of sheets P aligned in the vertical and horizontal directions are subjected to a heat and pressure treatment by the thermocompression unit 51, and a sheet bundle (booklet) aligned with high accuracy is produced by the booklet producing device 50.

[0046] The post-processing device 300 of the first embodiment is configured to be compatible with sheets P of a plurality of predetermined sizes, similar to the image forming device 100. The post-processing device 300 is configured to be capable of producing booklets of a plurality of different sheet sizes (A4, A5), with the maximum compatible sheet size being A4 (length 297 mm, width 210 mm) and the minimum compatible sheet size being A5 (length 210 mm, width 148 mm). By operating the vertical alignment reference plate 39, the half-moon roller 40, and the horizontal alignment jogger 41a in accordance with each sheet size, the sheet P is aligned so that the vertical end of the sheet P is positioned at the vertical alignment reference position 501 and the horizontal end is positioned at the horizontal alignment reference position 502. The horizontal alignment reference position 502 is an end face of the horizontal alignment reference plate 500. Fig. 2(e) shows the position of the sheet P during alignment processing for each sheet size (A4, A5), and indicates the vertical alignment reference position 501 and the horizontal alignment reference position 502 with two-dot chain lines.

[0047] (Heating unit) Next, a structure of the heating unit 600 of the thermocompression bonding unit 51 will be described. Figures 3(a)-(b) are explanatory diagrams showing the configuration of the heating unit 600. The heating unit 600 is a heating means for heating the stack of sheets P in the thermocompression bonding operation of the sheets P, and also a pressing means for pressing the stack of sheets P.

[0048] FIG. 3(a) is a schematic cross-sectional view of the heating unit 600 according to the first embodiment when viewed in the Y direction. The heating unit 600 includes a ceramic heater 601 as a heat source, a heating plate 602 as a pressing member for heating and pressurizing the stack of sheets P stacked on the intermediate stacking unit 42, a heater support 603 for supporting the heating plate 602, and a metal stay 605 as a rigid body. The heating unit 600 incorporates the ceramic heater 601, which is a planar heating element, and the heating plate 602 is in close contact with the ceramic heater 601. The ceramic heater 601, the heating plate 602, and the heater support 603 are all elongated members whose longitudinal direction is along one vertical side (Y direction) of the sheets P stacked on the intermediate stacking unit 42. With this configuration, the heating unit 600 heats and presses the entire edge of the sheets P along that side.

[0049] The ceramic heater 601 has a ceramic substrate 71 as a base mainly composed of Al2O3 (alumina), and a heating element 73 provided on the ceramic substrate 71. The dimensions of the ceramic substrate 71 of the ceramic heater 601 are a thickness of 1.0 mm, a width of 8.0 mm, and a length of 350 mm, and the thermal conductivity λh is 22 W / mK. Here, the thermal conductivity λ was measured using a thermal conductivity measuring device (ai-Phase Mobile2, Ai-Phase Co., Ltd.). The Young's modulus of the ceramic substrate 71 of the ceramic heater 601 is 370 GPa.

[0050] The heating plate 602 has adhesive parts 602a and 602b that are adhesively treated over the entire area in the Y direction to the heater support 603 with a heat-resistant silicone adhesive. The adhesive part 602a extends in the Y direction at one end of the heating plate 602 in the X direction, and the adhesive part 602b extends in the Y direction at the other end of the heating plate 602 in the X direction. The ceramic heater 601 is provided between the adhesive parts 602a and 602b in the X direction.

[0051] The material of the heater support 603 is a heat-resistant resin, and in the first embodiment, LCP (Liquid Crystal Polymer) is used.

[0052] The heating unit 600 is provided with a temperature detection means for detecting the temperature of the ceramic heater 601. The temperature detection means in the first embodiment includes thermistors TH1 and TH2 as temperature measurement sensors. The thermistors TH1 and TH2 are supported by a heater support 603, and are provided on the surface of the heater support 603 opposite to the bonding surface to which the bonding parts 602a and 602b are bonded. In the first embodiment, the thermistors TH1 and TH2 have NTC characteristics (Negative Temperature Coefficient (NTC) characteristics). However, the configuration of the temperature detection means is not limited to this. For example, a resistor having a PTC (Positive Negative Temperature Coefficient) characteristic, various thermocouples, and radiation thermometers may be used as the temperature detection means.

[0053] The booklet production apparatus 50 is provided with a control unit 80 (see FIG. 1) that controls the temperature of the heating element 73 of the ceramic heater 601. The control unit 80 is configured to be able to adjust the temperature of the heating element 73 based on the measurement results (detected temperatures) of thermistors TH1 and TH2. The control unit 60 may be configured to be capable of executing only the control of the thermocompression bonding unit 60, or may be configured to be capable of controlling the operation of each roller of the post-processing device 300 as well.

[0054] The heating plate 602 has a pressure portion 602c protruding downward in the Z direction, and presses the sheet stack with the pressure portion 602c during the thermocompression operation. By providing the pressure portion 602c on the heating plate 602, the heat and pressure of the heating unit 600 can be concentrated only on the binding position of the sheet stack, making it possible to perform heating and pressurization processing efficiently.

[0055] FIG. 3(b) is a schematic cross-sectional view of the heating plate 602 of the heating unit 600 when viewed in the Y direction, showing the shape of the heating plate 602. The heating plate 602 of Example 1 is mainly made of aluminum material (A6063 material). The heating plate 602 has a thickness of 0.8 mm, and the pressure section A has a width of 2.0 mm and protrudes downward by 0.7 mm. The length of the heating plate 602 in the Y direction is 300 mm. The heating plate 602 according to Example 1 has a thermal conductivity λp of 237 W / mK and a Young's modulus of 68 GPa. By using a high thermal conductivity material such as aluminum (A6063 material) for the heating plate 602, it becomes easy to transfer heat from the ceramic heater 601, which is a heating source, to the sheet P. Therefore, it is preferable that the thermal conductivity λp of the heating plate 602 is at least equal to or greater than the thermal conductivity λh of the ceramic heater 601.

[0056] (Thermocompression operation) Next, the thermocompression bonding operation of the sheet stack by the thermocompression bonding unit 51 will be described. FIGS. 4(a) to 4(c) are explanatory diagrams of the thermocompression bonding operation in the intermediate stacking section 42. FIG. 4(a) is a schematic cross-sectional view of the thermocompression bonding unit 51 showing a state in which four sheets P (P1-1, P1-2, P1-3, P1-4) are stacked on the intermediate stacking section 42 and thermocompression bonded by the heating unit 600. FIG. 4(b) is a schematic cross-sectional view of the thermocompression bonding unit 51 showing a state in which four sheets P (P2-1, P2-2, P2-3, P2-4) are further stacked on the intermediate stacking section 42 from the state of FIG. 4(a) and thermocompression bonded by the heating unit 600. FIG. 4(c) is a schematic cross-sectional view of the thermocompression bonding unit 51 showing a state in which 20 sheets P are stacked on the intermediate stacking section 42 and thermocompression bonded by the heating unit 600.

[0057] The thermocompression bonding unit 51 includes a heating unit 600, a pressure lever 504 for applying pressure to and moving the heating unit 600, and a pressure plate 506 that constitutes a part of the sheet stacking surface of the intermediate stacking section .

[0058] The pressure lever 504 is located above the heating unit 600 and receives power from a drive source not shown to press the heating unit 600 down in the -Z direction (downward in Figure 4(a)) toward the sheet P (the sheet stacking surface of the intermediate stacking section 42).

[0059] The pressure plate 506 is located below the sheet stack, and is provided at a position overlapping with the heating unit 600 in the stacking direction of the sheets P, and sandwiches the sheet stack between the heating plate 602 of the heating unit 600. The pressure plate 506 is made of silicone rubber with a thickness of 2.0 mm, and is designed to stably receive the pressure. It is a component.

[0060] The sheets P stacked on the intermediate stacking unit 42 are aligned in the vertical direction (Y direction) and horizontal direction (X direction) by the above-mentioned alignment mechanism to form a sheet bundle. At this time, the sheets P are aligned so that the adhesive toner Tk, which is black toner that constitutes the adhesive layer on the sheets P, overlaps with the heating unit 600 and the pressure plate 506 in the stacking direction of the sheets P (Z direction).

[0061] In the thermocompression bonding operation, the pressure lever 504 comes into contact with a metal stay 605 disposed above the heating unit 600 and presses the heating unit 600. Then, the heating unit 600 pressed down by the pressure lever 504 presses the topmost sheet P stacked on the intermediate stacking section 42. The pressure lever 504 comes into contact with the sheet P located at the position and applies a pressure force to the sheet stack formed of four sheets P. That is, the pressure force of the pressure lever 504 is transmitted to the sheet stack via the heating unit 600.

[0062] In the first embodiment, a total pressure of 30 kgf (average surface pressure of 0.4 MPa) is applied to an A4 size sheet stack, and the sheet stack is uniformly pressed in the longitudinal position in the Y direction. In the thermocompression bonding operation, the heating unit 600 presses the sheet stack for 2 seconds and then separates. The thermocompression bonding operation is performed in a state where the heating plate 602 is heated by the ceramic heater 601. The sheet stack is sandwiched and pressed between the pressure portion 602c of the heating plate 602 and the pressure plate 506.

[0063] In the first embodiment, four sheets P are supplied to the intermediate stacking unit 42, and a thermocompression bonding operation is performed each time. Specifically, when four sheets P (P1-1 to 4) are aligned and stacked as shown in FIG. 4(a), the sheet stack is heated and pressurized by the thermocompression bonding unit 51. Then, the adhesive toner Tk melts, and the four sheets P are bonded to each other. Thereafter, as shown in FIG. 4(b), four new sheets P (P2-1 to 4) are stacked on the sheet stack on which the thermocompression bonding operation has been performed, and the thermocompression bonding operation is performed. At this time, the sheet P2-4 located at the bottom of the newly stacked sheets P is bonded to the sheet P1-1 located at the top of the sheets P originally stacked. That is, in the thermocompression bonding operation shown in FIG. 4(b), not only are the sheets P2-1 to 4 bonded to each other, but the stack of sheets P1-1 to 4 and the stack of sheets P2-1 to 4 are also bonded to each other.

[0064] In this way, the booklet production apparatus 50 functions as a sheet thermocompression bonding apparatus that bonds a plurality of sheets P to each other using the thermocompression bonding unit 51. According to the configuration of the first embodiment, stacking of the sheets P and the thermocompression bonding operation are repeatedly performed, so that a booklet (a product) with a large number of sheets can be produced. In the first embodiment, the booklet production apparatus 50 is configured so that a booklet with a maximum of 50 sheets can be produced. When the thermocompression bonding operation is continuously performed, the supply of the sheets P to the intermediate stacking section 42, the lowering operation of the heating unit 600, the pressurizing operation (for 2 seconds) of the thermocompression bonding unit 51, and the raising operation of the heating unit 600 are repeatedly performed, so that the booklet is efficiently produced.

[0065] After the bonding process by the thermocompression bonding unit 51 is completed, the bundle discharge guide (not shown) moves in parallel from the standby position toward the sheet discharge outlet 45 to push out the sheet bundle. The sheet discharge outlet 45 is provided with a pair of bundle discharge rollers 38 as shown in FIG.

[0066] The bundle discharge guide stops at a position where the leading edge of the sheet bundle passes the bundle discharge roller pair 38 and returns to the standby position again. At this time, the sheet bundle is sandwiched between the bundle discharge roller pair 38. The bundle discharge roller pair 38 discharges the sheet bundle received from the bundle discharge guide onto the lower discharge tray 37. Through the above operations, the booklet making device 50 of the post-processing device 300 performs a bonding process on the multiple sheets P, and a booklet made up of the multiple sheets P bonded together is completed.

[0067] (Temperature rise detection configuration) Next, a description will be given of the temperature rise detection configuration of the heating unit 600. Fig. 5 is a schematic top view showing the positional relationship between the ceramic heater 601 and thermistors TH1 and TH2 provided in the heating unit 600. Fig. 5 shows an A4 sheet P4 of A4 size and an A5 sheet P5 of A5 size, whose vertical position is aligned to a vertical alignment reference position 501 and whose horizontal position is aligned to a horizontal alignment reference position 502.

[0068] As described above, the heating unit 600 is provided with the thermistor TH1, which is the first temperature measuring sensor, and the thermistor TH2, which is the second temperature measuring sensor. The thermistor TH1 is located outside the A5 sheet P5 and inside the A4 sheet P4 in the vertical direction (Y direction). Specifically, the thermistor TH1 is located at a position 254 mm away from the vertical alignment reference position 501. The thermistor TH1 is located inside the A5 sheet P5 and inside the A4 sheet P4 in the vertical direction (Y direction). Specifically, thermistor TH2 is located at the center of the long side of the A4 sheet P4, 149 mm from the vertical alignment reference position 501. In other words, thermistor TH1 is located farther from the vertical alignment reference position 501 than thermistor TH2, and closer to the vertical end of the A5 sheet P5 (the end opposite the end aligned at the vertical alignment reference position 501).

[0069] The vertical length of the heating element 73 of the ceramic heater 601 corresponds to the long side of the A4 sheet P4. The temperature of the heating element 73 is controlled by the power application means so that the target temperature of the ceramic heater 601 (the temperature detected by thermistor TH2) becomes the set temperature (220° C. in the first embodiment). In this way, thermistor TH2 is a temperature measurement sensor provided mainly for the purpose of controlling the temperature of the ceramic heater 601 in the thermocompression bonding operation. On the other hand, thermistor TH1 is a temperature measurement sensor provided mainly for the purpose of detecting the heater temperature rise during the production of a small-sized booklet. In the first embodiment, when the thermistor TH1 detects a heater temperature rise above the threshold, the image formation interval is extended, the heater temperature rise is suppressed, and the temperature of the ceramic heater 601 is controlled to a predetermined value or lower.

[0070] The heater temperature rise during the production of a small-sized booklet will be described. FIGS. 6(a) to 6(c) are explanatory diagrams showing the load applied to the heating plate 602 during the thermocompression bonding operation. FIG. 6(a) is an AA cross-sectional view of FIG. 4(c) showing the state in which the thermocompression bonding operation is performed with 20 A4 sheets P4 stacked. FIG. 6(b) is an AA cross-sectional view of FIG. 4(c) showing the state in which the thermocompression bonding operation is performed with 20 A5 sheets P5 stacked. FIG. 6(c) is an AA cross-sectional view of FIG. 4(c) showing the state in which the thermocompression bonding operation is performed with a smaller pressure force compared to the state shown in FIG. 6(b) with 20 A5 sheets P5 stacked. For the sake of simplicity, only the ceramic heater 601, the heating plate 602, thermistors TH1 and TH2, and the sheet P are shown in FIGS. 6(a) to 6(c), and the stress that the heating plate 602 receives from the sheet P is indicated by an outlined arrow. In Figures 6(a) to (c), the size of the white arrow indicates the magnitude of the stress.

[0071] The thermocompression bonding unit 51 and the heating unit 600 in the first embodiment have longitudinal dimensions determined to accommodate an A4 sheet P4, which is the maximum sheet size that the booklet production apparatus 50 can handle. More specifically, as shown in Fig. 6(a), the thermocompression bonding unit 51 is configured so that the A4 sheet P4 is evenly pressed in the vertical direction (Y direction) by the heating plate 602. At this time, the heating plate 602 abuts against the sheet P over almost the entire area in the longitudinal direction. Therefore, during the thermocompression bonding operation, almost no uneven deformation occurs in the heating plate 602, and good adhesion between the ceramic heater 601 and the heating plate 602 is maintained.

[0072] On the other hand, in the thermocompression bonding operation of the A5 sheet P5, which is shorter in length in the vertical direction (longitudinal direction) than the A4 sheet P4, a non-pressurized region is generated at the longitudinal end of the heating plate 602, which does not come into contact with the A5 sheet P5 and does not pressurize the sheet stack, as shown in Fig. 6(b). At this time, a strong stress concentration F1 acts on the heating plate 602 at the boundary (longitudinal end of the sheet stack) between the pressurized region where the heating plate 602 presses the A5 sheet P5 and the non-pressurized region. In the configuration of the first embodiment, the stress concentration F1 is about 2.0 MPa.

[0073] As described above, when the stress concentration F1 occurs and a strong stress acts locally on the heating plate 602, the heating plate 602 elastically deforms. At this time, as shown in Fig. 6(b), a gap R1 that slightly reduces the adhesion between the ceramic heater 601 and the heating plate 602 occurs near the boundary of the non-pressurized area and on the outside of the sheet stack.

[0074] In the gap R1 where the adhesion between the ceramic heater 601 and the heating plate 602 decreases, In this state, heat transfer from the mix heater 601 to the heating plate 602 is hindered. When the thermocompression bonding operation is repeated in this state, the temperature of the portion of the ceramic heater 601 corresponding to the gap R1 gradually increases. When a booklet consisting of 50 A5 sheets P was produced using the booklet production apparatus 50 configured similarly to the first embodiment, the temperature of a portion of the ceramic heater 601 exceeded 270° C. and entered an overheated state.

[0075] It is desirable to suppress an excessive temperature rise of the ceramic heater 601, since it may cause damage to the ceramic heater 601 and its peripheral members. In order to suppress the excessive temperature rise, for example, it is possible to lower the temperature of the ceramic heater 601 during the thermocompression bonding operation. Alternatively, it is possible to reduce the amount of the gap R2 by lowering the pressure applied to the sheet by the heating unit 600 to reduce the amount of elastic deformation of the heating plate 602 as shown in Fig. 6(c). However, these measures, while suppressing the excessive temperature rise of the ceramic heater 601, may lead to a decrease in the adhesive strength of the booklet formed by bonding multiple sheets P together.

[0076] Therefore, in the first embodiment, a thermistor TH1 is disposed to detect a temperature rise in the gap R1 of the ceramic heater 601. The thermistor TH1 is disposed in a position near the gap R1 and not overlapping with the A5 sheet P5 in the Z direction, and the control unit 80 executes a temperature rise suppression operation to suppress an excessive temperature rise of the ceramic heater 601 based on the measurement result (detected temperature) of thermistor TH1. More specifically, when the detected temperature of thermistor TH1 becomes equal to or higher than a threshold value, the control unit 80 executes a temperature rise suppression operation to suppress the temperature of the ceramic heater 601 to a predetermined value or lower.

[0077] (Temperature rise suppression operation) Next, there will be described a temperature rise suppression operation for suppressing a rise in temperature of the ceramic heater 601. Fig. 7 shows a flow chart of the temperature rise suppression operation in the image forming apparatus 100 and the post-processing apparatus 300 for producing a booklet.

[0078] [STEP1] First, the image forming operation and the booklet production operation are started in STEP 1. The image forming operation and the booklet production operation are started when a JOB (command) for producing a booklet is sent from a PC or the like to the image forming apparatus 100 and the post-processing apparatus 300, which are in a ready state.

[0079] [STEP2] Next, in STEP 2, the control unit 80 determines whether or not a first detected temperature T1, which is a detected temperature of thermistor TH1 of the thermocompression bonding unit 51 provided in the post-processing device 300, has exceeded a predetermined threshold value. The step of determining the detected temperature of thermistor TH1 may be performed at predetermined time intervals, or may be performed for each image forming operation for one sheet.

[0080] [STEP3] If the first detected temperature T1 of thermistor TH1 exceeds the threshold value in the above-mentioned detected temperature determination step, the interval at which the sheet P is fed from the sheet cassette 8 by the sheet feed roller 8a of the image forming apparatus 100 is extended in STEP 3. The instruction to extend the feeding interval may be given by the control unit 80 to the control unit of the image forming apparatus 100, or the control unit 80 may be configured to be able to control the operation of the sheet feed roller 8a.

[0081] When the sheet P feeding interval is increased in the image forming apparatus 100, the image forming interval in the image forming apparatus 100 and the pressurizing interval of the sheet stack by the thermocompression bonding unit 51 of the booklet producing apparatus 50 are increased. In this manner, in the first embodiment, when it is detected that the detected temperature of thermistor TH1 is equal to or higher than a predetermined value, an image forming interval extending step is executed as a temperature rise suppression operation. The relationship between the first detected temperature T1 and the image forming interval in the first embodiment is shown in Table 1.

[0082] [Table 1]

[0083] When the first detection temperature T1 is less than 250°C, the image formation interval is 2.0 seconds. If no excessive temperature rise occurs during the thermocompression bonding operation, the image formation operation and the booklet production operation are repeatedly performed with the image formation interval at 2.0 seconds. For example, when a booklet is produced using A4 sheets P4, the detection temperature of thermistor TH1 is stable at about 220°C, and the image formation interval is not extended.

[0084] On the other hand, when the first detected temperature T1 is equal to or higher than 250° C. and lower than 260° C., the image formation interval is changed to 4.0 seconds. For example, when booklet production is performed repeatedly using A5 sheets P5, the ceramic heater 601 rises in temperature in the vicinity of the gap R1 of the ceramic heater 601. Then, when the first detected temperature T1 of thermistor TH1 is equal to or higher than 250° C. and lower than 260° C., the feeding interval of the subsequent sheets P is extended and the image formation interval is changed to 4.0 seconds.

[0085] Similarly, when the first detected temperature T1 is equal to or higher than 260° C. and lower than 270° C., the image formation interval is changed to 10.0 seconds. When the first detected temperature T1 is equal to or higher than 270° C., the image formation operation is stopped, and the image formation interval is extended. In this case, the image formation operation is stopped until the first detected temperature T1 becomes lower than 250° C. and the temperature of the ceramic heater 601 is sufficiently reduced.

[0086] The operations in STEPs 2 and 3 described above are repeatedly executed until the feeding of the last sheet P, which is the last sheet P on which the image forming operation and the booklet production operation are performed, is completed. In STEP 4, when the feeding of the last sheet is completed, the image forming operation and the booklet production operation are terminated.

[0087] 8(a) and (b) show the transitions of the first detected temperature T1 of thermistor TH1 and the second detected temperature T2 of thermistor TH2, the image formation interval by image forming apparatus 100, and the pressurization interval by thermocompression unit 51 of booklet making device 50 of post-processing device 300. Fig. 8(a) shows the transitions of the detected temperature, the image formation interval, and the pressurization interval when a 50-sheet booklet of A4 sheets P4 is made. Fig. 8(b) shows the transitions of the detected temperature, the image formation interval, and the pressurization interval when a 50-sheet booklet of A5 sheets P5 is made.

[0088] 8(a) shows, from top to bottom, a graph a-1 showing the transition of the first detected temperature T1 of thermistor TH1 and the second detected temperature T2 of thermistor TH2, a graph a-2 showing the image formation interval, and a graph a-3 showing the pressurization interval. Similarly, FIG. 8(b) shows, from top to bottom, similar graphs b-1, b-2, and b-3.

[0089] The vertical axis of graphs a-1 and b-1 is the detected temperature, and the horizontal axis is the time. In -1, the change in the first detected temperature T1 is indicated by a solid line, and the change in the second detected temperature T2 is indicated by a dotted line.

[0090] On the vertical axis of graphs a-2 and b-2, ON indicates the image forming state of image forming apparatus 100, OFF indicates the non-image forming state of image forming apparatus 100, and the horizontal axis indicates time. The timing of transition from OFF to ON corresponds to the timing when sheet feed roller 8a feeds sheet P from sheet cassette 8.

[0091] In the graphs a-3 and b-3, the vertical axis indicates the pressure applied to the sheet stack by the heating unit 600, the vertical axis indicates the separation state of the heating unit 600 from the sheet stack, and the horizontal axis indicates time.

[0092] First, the behavior of each component during booklet production using A4 sheets P4 will be described with reference to Fig. 8(a). As described above, during booklet production using A4 sheets P4, the ceramic heater 601 does not overheat, and both the first detection temperature T1 and the second detection temperature T2 remain stable at constant temperatures. Therefore, the sheet P feed interval is not extended, and the image formation interval and pressure application interval remain constant while the image formation operation and booklet production operation are performed.

[0093] Next, the behavior of each part when making a booklet from A5 sheet P5 will be described with reference to Fig. 8(b). As described above, when making a booklet from A5 sheet P5, stress concentration F1 causes elastic deformation of heating plate 602, and a gap R1 occurs that reduces the adhesion between ceramic heater 601 and heating plate 602, causing a gradual increase in temperature of part of ceramic heater 601. Graph b-1 in Fig. 8(b) shows the gradual increase in first detection temperature T1 of thermistor TH1.

[0094] When the first detection temperature T1 gradually increases and exceeds 250° C., the image formation interval is extended, and as a result, the pressurization interval is also extended. In Fig. 8(b), the timing S1 at which the first detection temperature T1 reaches 250° C. is shown by a two-dot chain line. When the first detection temperature T1 exceeds 250° C., the image formation interval is immediately extended as shown in graph b-2, and the pressurization interval is also extended as shown in graph b-3.

[0095] After the image formation interval is extended at timing S1, the first detection temperature T1 of thermistor TH1 continues to rise for a short time. Then, after a certain amount of time has passed since the image formation interval was extended, the first detection temperature T1 reaches a peak P1 and then gradually decreases. By extending the pressurization interval in this manner, the frequency of heat supply from the ceramic heater 601 to the sheet stack via the heating plate 602 decreases, so that even if the set temperature of the ceramic heater 601 remains the same, the amount of power supply decreases and the heater temperature rise is suppressed.

[0096] Then, after the first detection temperature T1 continues to decrease from the peak P1, the first detection temperature T1 stabilizes and remains at a constant value. Since the image formation interval and the pressurization interval are extended thereafter, the ceramic heater 601 does not overheat, and the thermocompression bonding operation is stably performed.

[0097] In the first embodiment, the excessive temperature rise of the ceramic heater 601 is suppressed by the heater temperature rise suppression control by the control unit 80. Furthermore, according to the configuration of the first embodiment, it is possible to suppress both the breakdown of the ceramic heater 601 and its peripheral members and the deterioration of the quality of the booklet.

[0098] The thermistor TH1 is preferably disposed within 50 mm from the longitudinal end of the A5 sheet P5, which is the smallest size sheet, in the longitudinal direction of the heating plate 602. By disposing the temperature measuring sensor in the vicinity of the gap R1 where excessive heating is likely to occur, excessive heating of the ceramic heater 601 can be more appropriately monitored.

[0099] (Toner composition, manufacturing method, measurement method) Next, the structure of the adhesive toner Tk containing the thermoplastic resin used in this embodiment will be described. The resin that can be used as the thermoplastic resin is not particularly limited, and a known thermoplastic resin can be used. Examples of known thermoplastic resins include polyester resin, vinyl resin, acrylic resin, styrene acrylic resin, polyethylene, polypropylene, polyolefin, ethylene-vinyl acetate copolymer resin, and ethylene-acrylic acid copolymer resin. A plurality of these resins may be contained.

[0100] The adhesive toner Tk preferably further contains a wax, which may be any known wax, such as an ester wax which is an ester of an alcohol and an acid, or a hydrocarbon wax such as paraffin wax.

[0101] The adhesive toner Tk may contain a colorant. As the colorant, a known colorant such as a black colorant, a yellow colorant, a magenta colorant, or a cyan colorant can be used. The content of the colorant in the adhesive toner Tk is preferably 1.0% by mass or less, more preferably 0.1% by mass or less. The adhesive toner Tk may contain a magnetic material, a charge control agent, a wax, and an external additive.

[0102] In order to form an adhesive portion (adhesive layer) by the adhesive toner Tk on the sheet P by using the electrophotographic method, the weight average particle diameter of the adhesive toner Tk is preferably 5.0 μm or more and 30 μm or less, and more preferably 6.0 μm or more and 20 μm or less. In addition, a printing toner may be used as the adhesive toner Tk as long as it satisfies the adhesive property.

[0103] 9(a) and 9(b) are explanatory diagrams of the printing area of ​​adhesive toner Tk. Fig. 9(a) is a schematic diagram showing the printing area (shaded area) of adhesive toner Tk when producing a booklet with long edges fixed. Fig. 9(b) is a schematic diagram showing the printing area (shaded area) of adhesive toner Tk when producing a booklet with corners fixed.

[0104] 9(a), an image made of adhesive toner Tk is formed on the end of the long side of sheet P, so that a long-side stapled booklet is produced as an end product when the post-processing device 300 produces a booklet. Also, as shown in FIG. 9(b), an image made of adhesive toner Tk is formed on one end of the long side of sheet P, so that a corner-stacked booklet is produced as an end product. In the first embodiment, the width W of the adhesive toner image is 4.0 mm, and the toner amount (laying amount) of adhesive toner Tk per unit area is 0.55 mg / cm. 2 The toner amount was measured after the secondary transfer and before the fixing process in an unfixed state.

[0105] A manufacturing example of the adhesive toner Tk will be described. Styrene 75.0 parts n-Butyl acrylate 25.0 parts Polyester resin 4.0 parts (Polyester resin with weight average molecular weight (Mw) of 20,000, glass transition temperature (Tg) of 75°C, and acid value of 8.2 mgKOH / g) Ethylene glycol distearate 14.0 parts (Ester wax made by esterifying ethylene glycol and stearic acid) Hydrocarbon wax (HNP-9, Nippon Seiro) 2.0 parts Divinylbenzene 0.5 parts

[0106] The mixture of the above materials was kept at 60°C and stirred at 500 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to dissolve uniformly, preparing a polymerizable monomer composition. did.

[0107] Meanwhile, 850.0 parts of 0.10 mol / L-Na3PO4 aqueous solution and 8.0 parts of 10% hydrochloric acid were added to a container equipped with a high-speed stirring device Clearmix (manufactured by M Technique Co., Ltd.), the rotation speed was adjusted to 15,000 rpm, and the temperature was heated to 70°C. 127.5 parts of 1.0 mol / L-CaCl2 aqueous solution were added to this to prepare an aqueous medium containing a calcium phosphate compound.

[0108] After the polymerizable monomer composition was added to the aqueous medium, 7.0 parts of t-butyl peroxypivalate, a polymerization initiator, was added, and the mixture was granulated for 10 minutes while maintaining a rotation speed of 15,000 rpm. After that, the high-speed agitator was replaced with a propeller agitator, and the mixture was reacted at 70°C for 5 hours under reflux, and then the liquid temperature was increased to 85°C and the mixture was reacted for another 2 hours.

[0109] After the polymerization reaction was completed, the resulting slurry was cooled, and then hydrochloric acid was added to the slurry to adjust the pH to 1.4 and stirred for 1 hour to dissolve the calcium phosphate salt.The slurry was then washed with three times the amount of water, filtered, dried, and classified to obtain adhesive toner particles.

[0110] Thereafter, silica fine particles (number average particle diameter of primary particles: 10 nm, BET specific surface area: 170 m) that had been hydrophobized using dimethyl silicone oil (20% by mass) were added to 100.0 parts of the adhesive toner particles as an external additive. 2 Then, 2.0 parts of 1.0 parts by weight ...

[0111] The adhesive toner Tk thus obtained had a weight average particle size of 7.0 μm.

[0112] An example of the production of a printing toner will be described. Styrene 60.0 parts Colorant 6.5 parts (CI Pigment Blue 15:3, Dainichi Seika Chemicals Co., Ltd.)

[0113] The above materials were placed in an attritor (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed using zirconia particles having a diameter of 1.7 mm at 220 rpm for 5 hours to obtain a pigment dispersion liquid.

[0114] Styrene 15.0 parts n-Butyl acrylate 25.0 parts Polyester resin 4.0 parts (Polyester resin with weight average molecular weight (Mw) of 20,000, glass transition temperature (Tg) of 75°C, and acid value of 8.2 mgKOH / g) Behenyl behenate 12.0 parts (Ester wax made by esterifying behenic acid and behenyl alcohol) Divinylbenzene 0.5 parts

[0115] The above materials were mixed and added to the pigment dispersion liquid. The resulting mixture was kept at 60° C. and stirred at 500 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to dissolve and disperse uniformly, thereby preparing a polymerizable monomer composition.

[0116] Meanwhile, 850.0 parts of 0.10 mol / L-Na3PO4 aqueous solution and 8.0 parts of 10% hydrochloric acid were added to a container equipped with a high-speed stirring device Clearmix (manufactured by M Technique Co., Ltd.), the rotation speed was adjusted to 15,000 rpm, and the temperature was heated to 70°C. 127.5 parts of 1.0 mol / L-CaCl2 aqueous solution were added to this to prepare an aqueous medium containing a calcium phosphate compound.

[0117] After the polymerizable monomer composition was added to the aqueous medium, 7.0 parts of t-butyl peroxypivalate, a polymerization initiator, was added, and the mixture was granulated for 10 minutes while maintaining a rotation speed of 15,000 rpm. After that, the high-speed agitator was replaced with a propeller agitator, and the mixture was reacted at 70°C for 5 hours under reflux, and then the liquid temperature was increased to 85°C and the mixture was reacted for another 2 hours.

[0118] After the polymerization reaction was completed, the resulting slurry was cooled, and then hydrochloric acid was added to the slurry to adjust the pH to 1.4 and stirred for 1 hour to dissolve the calcium phosphate salt.The slurry was then washed with three times the amount of water, filtered, dried, and classified to obtain toner particles.

[0119] Thereafter, silica fine particles (number average particle diameter of primary particles: 10 nm, BET specific surface area: 170 m) that had been hydrophobized using dimethyl silicone oil (20% by mass) were added to 100.0 parts of the toner particles as an external additive. 2Then, 2.0 parts of ethanol (1.0 parts / g) was added to the mixture, which was then mixed at 3000 rpm for 15 minutes using a Mitsui Henschel mixer (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) to obtain a toner.

[0120] The weight average particle diameter of the obtained toner was 7.0 μm.

[0121] The method for measuring the weight-average particle diameter of toner is explained below. The weight-average particle diameter of printing toner and adhesive toner Tk is calculated as follows. The measurement device used is a precision particle size distribution measurement device using the narrow hole electrical resistance method, "Coulter Counter Multisizer 3" (registered trademark product name, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). The measurement is performed with an effective measurement channel count of 25,000 channels.

[0122] The electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter).

[0123] Before performing measurements and analysis, the dedicated software is set up as follows.

[0124] In the "Change Standard Measurement Method (SOM)" screen of the dedicated software, set the total count number in the control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard particle 10.0 μm" (Beckman Coulter). Press the "Threshold / Noise level measurement button" to automatically set the threshold and noise level. In addition, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

[0125] In the "Pulse to particle size conversion setting" screen of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm to 60 μm.

[0126] The specific measurement method is as follows.

[0127] [Step 1] Put 200 mL of the electrolyte solution into a 250 mL round-bottom glass beaker made exclusively for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "Aperture Tube Flush" function of the dedicated software to remove dirt and air bubbles from inside the aperture tube.

[0128] [Step 2] Put 30 mL of the electrolyte solution into a 100 mL flat-bottom glass beaker. Add 0.3 mL of a solution of "Contaminon N" (a 10% aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments made of nonionic surfactants, anionic surfactants, and organic builders, manufactured by Wako Pure Chemical Industries, Ltd.) diluted 3 times with ion-exchanged water as a dispersant.

[0129] [Step 3] Prepare an ultrasonic disperser "Ultrasonic Dispersion System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.) that has two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees, and has an electrical output of 120 W. Place 3.3 L of ion-exchanged water in the ultrasonic disperser's water tank, and add 2 mL of Contaminon N to this water tank.

[0130] [Step 4] Set the beaker from step 2 in the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Then, adjust the height of the beaker so that the resonance state of the electrolyte solution in the beaker is maximized.

[0131] [Step 5] While the electrolyte solution in the beaker in step 4 is irradiated with ultrasonic waves, add the toner or adhesive toner Tk to the electrolyte solution in small amounts of 10 mg at a time and disperse it. Then, continue ultrasonic dispersion for another 60 seconds. During ultrasonic dispersion, adjust the water temperature in the water tank appropriately so that it is between 10°C and 40°C.

[0132] [Step 6] Using a pipette, drip the electrolyte solution (step 5) in which the toner or adhesive toner Tk is dispersed into the round-bottom beaker (step 1) placed in the sample stand, and adjust the measurement concentration to 5%. Then, measure until the number of particles reaches 50,000.

[0133] [Step 7] The measurement data is analyzed using the dedicated software that comes with the device, and the weight average particle diameter is calculated.

[0134] The method for measuring the storage modulus as a viscoelastic property of the toner is described below. The storage modulus of adhesive toner Tk is measured using a dynamic viscoelasticity measuring device (rheometer) ARES (manufactured by Rheometrics Scientific). Measurement tool: A serrated parallel plate with a diameter of 7.9 mm is used.

[0135] Measurement sample: Using a pressure molding machine, mold a 0.1g sample into a cylindrical sample with a diameter of 8mm and a height of 2mm (maintain 15kN for 1 minute at room temperature). The pressure molding machine used is a 100kN press NT-100H manufactured by NPa Systems.

[0136] The temperature of the serrated parallel plate is adjusted to 120°C, the cylindrical sample is heated and melted, the sawtooth is inserted, and a load is applied vertically so that the axial force does not exceed 30 (gf) (0.294N) to fix it to the serrated parallel plate. A steel belt may be used at this time so that the diameter of the sample is the same as that of the parallel plate. The serrated parallel plate and the cylindrical sample are slowly cooled down to the measurement start temperature of 30.00°C over one hour.

[0137] Measurement frequency: 6.28 rad / sec Measurement distortion setting: Set the initial value to 0.1%, and perform the measurement in automatic measurement mode. Sample elongation correction: Adjusted in automatic measurement mode. Measurement temperature: 30°C to 140°C at a rate of 2°C per minute. Measurement interval: Measure viscoelastic data every 30 seconds, i.e., every 1°C.

[0138] FIG. 10 is a graph showing the measurement results of the storage modulus of adhesive toner Tk. As representative values, the storage modulus Ga(100°C) at 100°C and the storage modulus Ga(80°C) at 80°C were obtained. Here, Ga(100°C)=2.2×104 Pa, Ga(80°C)=3.2×105 Pa. Here, during fixing, the adhesive toner Tk on the sheet P was heated to about 100°C while passing through the fixing nip portion 6N of the fixing device 6, so the storage modulus Ga(100°C) at 100°C was obtained. In addition, during the adhesive processing of the sheet stack by the thermocompression bonding unit 51, the storage modulus Ga(80°C) at the minimum toner temperature of 80°C when the maximum number of sheets, 5, was adhered at one time was obtained. In detail, as shown in FIG. 4(a), the surface temperature of the heating plate and the set temperature of the temperature detection means were set so that the toner temperature between P1-3 and P1-4 was 80°C or higher when P1-1 to P1-4 were adhered at one time. Here, the maximum basis weight of the sheet P in this embodiment is 90 g / m 2 It is.

[0139] (Comparative experiment) In order to verify the effect of Example 1, a comparative experiment was conducted on booklet production by Example 1 and Comparative Examples 1 to 3. In this comparative experiment, the experimental conditions were changed as follows: [a] sheet size, [b] total pressure, [c] set temperature, and [d] presence or absence of heater temperature rise suppression control. Here, [b] total pressure is the total pressure applied by the heating unit 600 to the sheet stack stacked on the intermediate stacker 42. [c] set temperature is the control value of the second detection temperature T2 of thermistor TH2, and is an index for the control unit 80 to control the heating element 73. In addition, the experimental results (evaluation items) were evaluated as follows: [e] temperature rise result of the ceramic heater 601, and [f] booklet adhesive strength.

[0140] First, the experimental conditions of the comparative experiment are described. Condition 1 is the same as the configuration of Example 1 described above, [a] the sheet size is A5 size, [b] the total pressure is 30 kgf, [c] the set temperature is 220°C, and [d] heater temperature rise suppression control is enabled or disabled.

[0141] Condition 2 is Comparative Example 1 in which the presence or absence of heater temperature rise suppression control [d] is changed to none in comparison with Condition 1. Condition 3 is Comparative Example 2 in which the set temperature [c] is reduced to 200°C in comparison with Condition 1. Condition 4 is Comparative Example 3 in which the total pressure [b] is reduced to 15 kgf in comparison with Condition 1. Condition 5 is Comparative Example 4 in which the sheet size [a] is changed to A4 size in comparison with Condition 2.

[0142] Next, the evaluation items of the comparative experiment will be described. [e] The temperature rise result of the ceramic heater 601 was evaluated using the peak P1 of the first detection temperature T1 detected by the thermistor TH1 during the process of producing a booklet of 50 sheets P. Specifically, if the peak P1 was 270°C or higher, it was NG, and if it was less than 270°C, it was OK.

[0143] [f] A booklet quality test method for evaluating booklet adhesive strength in a comparative experiment will be described with reference to Figs. 11(a) and (b). Figs. 11(a) and (b) are explanatory diagrams of the booklet quality test method.

[0144] First, as shown in Fig. 4(a), a booklet composed of four sheets P is produced by the image forming apparatus 100 and the thermocompression bonding unit 51. At this time, the thermocompression bonding unit 51 produces a booklet for a strength test by a single heating and pressure treatment.

[0145] Next, of the sheets constituting the booklet, sheets P1-1 and P1-2 are peeled off from the booklet. Then, as shown in Fig. 11(a), the two booklets consisting of the sheets P1-3 and P1-4 were cut out to have a width W of 20 mm and a length L of 50 mm to prepare a test piece H including the adhesive part S composed of the adhesive toner Tn.

[0146] 11(b), the test piece H was held by an upper holding member 80a on the sheet P1-3 side, and held by a lower holding member 80b on the sheet P1-4 side. A digital force gauge M (FGP-2, manufactured by Nidec-Shimpo Corporation) was connected to the upper holding member 80a. The digital force gauge M was then gradually raised upward, and the peel force when the adhesive portion S peeled off was measured by the digital force gauge M, and the peak value of the peel force was recorded.

[0147] The above-mentioned peeling force was measured five times under each condition, and the average value was taken as the booklet adhesive strength of the adhesive portion S. The inventors of the present application have confirmed through careful study that the adhesive strength of the booklet is practically desirable to be 1.0 N / cm or more per unit distance in the width direction of the test piece H. In this test, therefore, the booklet strength was judged to be OK if it was 1.0 N / cm or more as the quality standard, and the booklet strength was judged to be NG if it was less than that, and [f] the booklet adhesive strength was evaluated. The adhesive strength between the sheets P1-3 and P1-4 was measured here because the area between them is the farthest from the heating plate compared to the other adhesive areas, is a place where heat is difficult to supply, and is a place where the booklet adhesive strength may be an issue.

[0148] In this comparative experiment, the A4 size GF-C081 manufactured by Canon Inc. was used as the sheet P. [a] In the experiment using the A5 sheet size, the A4 size GF-C081 was cut in half and used to eliminate the influence of factors other than the sheet size.

[0149] Next, the details of the experimental conditions and the experimental results are described. The experimental conditions and the experimental results in the comparative experiment are shown in Table 2. In Table 2, the column [e] Temperature rise result of ceramic heater 601 shows the peak P1 of the first detection temperature T1 detected by thermistor TH1, and the column [f] Booklet adhesive strength shows the peak value of the peel force measured by digital force gauge M.

[0150] [Table 2]

[0151] [Condition 1] In condition 1 (Example 1), the peak P1 of the first detection temperature T1 was 258°C and did not exceed 270°C, so [e] the temperature rise result of the ceramic heater 601 was OK. [f] The booklet adhesive strength was 1.1 N / cm, which was OK. In other words, it was confirmed that Example 1 can ensure good adhesive strength while suppressing excessive temperature rise of the ceramic heater 601. It was done.

[0152] [Condition 2] In condition 2 (Comparative Example 1), the peak P1 of the first detection temperature T1 was 275°C, exceeding 270°C, so [e] the temperature rise result of the ceramic heater 601 was NG. [f] The booklet adhesive strength was 1.1 N / cm, which was OK. That is, in Comparative Example 1 in which the heater temperature rise suppression control was not executed, the excessive temperature rise of the ceramic heater 601 cannot be suppressed. If the booklet production operation is repeatedly executed under such experimental conditions, this may cause damage to the ceramic heater 601 or deformation of the heater support 603, which may cause a breakdown of the booklet production device 50 or the post-processing device 300.

[0153] [Condition 3] In condition 3 (Comparative Example 2), the peak P1 of the first detection temperature T1 was 240°C and did not exceed 270°C, so [e] the temperature rise result of the ceramic heater 601 was OK. [f] The booklet adhesive strength was 0.7 N / cm and was NG. In Comparative Example 2, the set temperature [c] was reduced to 200°C compared to Example 1 and Comparative Example 1, so that the excessive temperature rise of the ceramic heater 601 was suppressed even without executing the heater temperature rise suppression control. On the other hand, because the set temperature [c] was low, the amount of heat given to the sheet P decreased and the booklet adhesive strength fell below the target value of 1.0 N / cm. That is, in Comparative Example 2, a good adhesive force cannot be secured.

[0154] [Condition 4] In condition 4 (Comparative Example 3), the peak P1 of the first detection temperature T1 was 248°C and did not exceed 270°C, so [e] the temperature rise result of the ceramic heater 601 was OK. [f] The booklet adhesive strength was 0.5 N / cm, which was NG. In Comparative Example 3, [b] the total pressure was reduced to 15 kgf, so the stress concentration F2 (see FIG. 6(c)) at the boundary between the contact portion and the non-contact portion of the heating plate 602 with respect to the A5 sheet P5 was weakened. In this condition, the stress concentration F2 is about 1.0 MPa. Then, the elastic deformation amount of the heating plate 602 is reduced, and the decrease in the adhesion between the ceramic heater 601 and the heating plate 602 is suppressed, so that the excessive temperature rise of the ceramic heater 601 is suppressed. On the other hand, [b] the total pressure was low, so the pressure acting on the sheet P was reduced and the booklet adhesive strength fell below the target value of 1.0 N / cm. That is, in Comparative Example 3, a good adhesive strength cannot be secured.

[0155] [Condition 5] In condition 5 (comparative example 4), the peak P1 of the first detection temperature T1 was 220°C and did not exceed 270°C, so [e] the temperature rise result of the ceramic heater 601 was OK. [f] The booklet adhesive strength was 1.1 N / cm, which was OK. In this way, in a configuration in which the adhesion between the ceramic heater 601 and the heating plate 602 is unlikely to decrease due to the relationship between the heating plate 602 and the sheet P, the ceramic heater 601 does not overheat and a good adhesive strength is ensured even if the heater temperature rise suppression control is not executed.

[0156] As described above, in the first embodiment, the temperature sensor is disposed at a position that does not overlap the smallest sheet, which is the smallest size that the booklet production device 50, which is a sheet thermocompression bonding device, in the stacking direction of the sheet P. With this configuration, during the thermocompression bonding operation of the sheet P, which is smaller than the largest sheet, such as the smallest sheet, the temperature sensor detects an excessive temperature rise of the ceramic heater 601. Furthermore, according to the configuration of the first embodiment, even if there is a large difference between the longitudinal width of the heating plate 602 and the pressing width of the sheet P, and the adhesion between the ceramic heater 601 and the heating plate 602 may decrease, the excessive temperature rise of the ceramic heater 601 can be suppressed while maintaining a good adhesive force. In other words, in a sheet thermocompression bonding device that can handle a plurality of sheet sizes, it is possible to suppress the deterioration of the booklet quality and perform the thermocompression bonding operation stably.

[0157] In the first embodiment, the control unit 80 controls the amount of heat generated by the heating element 73 based on the measurement result of thermistor TH2, and performs an overheating suppression operation to suppress an overheating of the ceramic base material 71 of the ceramic heater 601 based on the measurement result of thermistor TH1. With this configuration, the temperature of the heating plate 602 is kept at an appropriate temperature while suppressing an overheating of the ceramic heater 601, thereby enabling a stable thermocompression bonding operation to be performed.

[0158] In the first embodiment, the post-processing device 300 having the thermocompression bonding unit 51 is arranged next to the image forming apparatus 100, but the application of the present invention is not limited to this configuration. For example, as in a modified example shown in Fig. 12, the post-processing device 300 including the thermocompression bonding unit 51 may be arranged on the upper part of the main body of the image forming apparatus 100. Fig. 12 is a schematic cross-sectional view showing a schematic configuration of the image forming apparatus 100 according to a modified example of the first embodiment.

[0159] In the configuration of the first embodiment, the thermistor TH1 for detecting an excessive temperature rise of the ceramic heater 601 is arranged at a position that does not overlap with the A5 sheet P5, which is the smallest sheet, in the stacking direction, but the application of the present invention is not limited to this configuration. For example, a part of the thermistor TH1 may overlap with an edge of the A5 sheet P5 in the stacking direction. Even in this configuration, an excessive temperature rise of the ceramic heater 601 can be detected by the thermistor TH1 that is arranged at a position farther from the vertical alignment reference position 501 than the thermistor TH2 and closer to the gap R1.

[0160] In the configuration of the first embodiment, two temperature measuring sensors (thermistors) are provided, but three or more may be provided. For example, among sheets of a predetermined size that the booklet production device 50 can handle, the first sheet, the second sheet, and the third sheet are arranged in descending order of vertical size. In addition, in the sheet stacking direction, the first temperature measuring sensor is arranged at a position overlapping the first sheet and not overlapping the second and third sheets. The second temperature measuring sensor is arranged at a position overlapping the first and second sheets and not overlapping the third sheet, and the third temperature measuring sensor is arranged at a position overlapping all sheets. In such a configuration, the first temperature measuring sensor may detect an excessive temperature rise of the ceramic heater 601 during the thermocompression bonding operation of the second sheet, and the second temperature measuring sensor may detect an excessive temperature rise of the ceramic heater 601 during the thermocompression bonding operation of the third sheet.

[0161] In the configuration of the first embodiment, when the thermistor TH1 detects that the ceramic heater 601 has risen to a predetermined temperature or higher, the interval between the image forming operation and the booklet making operation is extended as a temperature rise suppression operation, but the present invention is not limited to such a configuration. For example, the image forming interval may not be extended, but the conveying interval of the sheet P conveyed to the post-processing device 300 may be extended to extend the pressurizing interval in the booklet making operation. In addition, if the first detection temperature T1 falls below a predetermined temperature value after the pressurizing interval of the booklet making operation is extended, the pressurizing interval may be controlled to be shortened. In addition, if the first detection temperature T1 exceeds a threshold value, an alarm or the like may be used to notify the user of the abnormal temperature rise, and the user may decide whether to extend the pressurizing interval or stop the booklet making operation. In the first embodiment, the control unit 80 acquires the first detection temperature T1 of the thermistor TH1 disposed outside the A5 sheet P5 in the longitudinal direction and performs the temperature rise suppression operation. However, a configuration may also be adopted in which a user or another device monitors the first detected temperature T1 and determines whether or not to perform the temperature rise suppression operation.

[0162] <Example 2> Next, a second embodiment of the present invention will be described. Only differences between the configuration of the second embodiment and the configuration of the first embodiment will be described below. In the configuration of the second embodiment, the same reference numerals are used for the image forming apparatus 100, the post-processing apparatus 300, and other components that are similar to those of the first embodiment, and descriptions thereof will be omitted. The second embodiment differs from the first embodiment in that a polyimide sheet 604 is provided between the ceramic heater 601 and the heating plate 602.

[0163] (Heating unit) The structure of the heating unit 600 according to the second embodiment will be described. Fig. 13 is an explanatory diagram showing the configuration of the heating unit 600 according to the second embodiment, and is a schematic cross-sectional view of the heating unit 600 as seen in the Y direction. As shown in Fig. 13, in the heating unit 600, a polyimide sheet 604 is provided as an intermediate member between a ceramic heater 601 and a heating plate 602 in the stacking direction of the sheets P.

[0164] The polyimide sheet 604 is a member for maintaining good heat transfer from the ceramic heater 601 to the heating plate 602. The polyimide sheet 604 according to Example 2 has a thickness of 20 μm, a width of 8.0 mm, and a length of 350 mm. The width and length of the polyimide sheet 604 are the same dimensions as those of the ceramic heater 601, and the thickness is made thin so as not to inhibit the heat transfer from the ceramic heater 601 to the heating plate 602. The thermal conductivity λh of the polyimide sheet 604 is 0.20 W / mK, and the Young's modulus is approximately 5.0 GPa.

[0165] 14 is an explanatory diagram showing the load applied to the heating plate 602 according to the second embodiment during the thermocompression bonding operation, and is a schematic cross-sectional view from the X direction showing the state in which the thermocompression bonding operation is performed with 20 A5 sheets P5 stacked. Even in the configuration of the second embodiment, stress concentration F3 acts on the boundary between the pressure region and the non-pressure region of the heating plate 602 for the A5 sheets P5 in the Y direction, and the heating plate 602 elastically deforms. Then, a gap R3 occurs that reduces the adhesion between the ceramic heater 601 and the heating plate 602 via the polyimide sheet 604.

[0166] In the second embodiment, the polyimide sheet 604 is sandwiched between the ceramic heater 601 and the heating plate 602, so that the gap R3 is reduced. Therefore, the polyimide sheet 604 suppresses the inhibition of heat transfer from the ceramic heater 601 to the heating plate 602.

[0167] Fig. 15 shows the transition of the first detected temperature T1 of thermistor TH1 and the second detected temperature T2 of thermistor TH2, the image formation interval by image forming apparatus 100, and the pressurization interval by thermocompression unit 51 of booklet production apparatus 50 of post-processing apparatus 300. Fig. 15 shows the transition of the detected temperature, the image formation interval, and the pressurization interval when a booklet of 50 A5 sheets P5 is produced by booklet production apparatus 50 according to Example 2.

[0168] 15 shows, from the top, a graph c-1 showing the transition of the first detection temperature T1 of thermistor TH1 and the second detection temperature T2 of thermistor TH2, a graph c-2 showing the image formation interval, and a graph c-3 showing the pressurization interval. The vertical and horizontal axes of each graph are the same as those of the graph according to Example 1 shown in FIG. 8(a).

[0169] In the configuration of Example 2, the control unit 80 controls the heating element 73 so that the target temperature of the ceramic heater 601 during the thermocompression bonding operation is 225° C. The reason that the target temperature is set higher than 220° C. in Example 1 is that the polyimide sheet 604 is newly provided, and the amount of heat given to the sheet P is the same in Example 2 and Example 1. In other words, in Example 2, the amount of heat due to the provision of the polyimide sheet 604 is compensated for by setting the target temperature of the ceramic heater 601 higher.

[0170] As described above, when making a booklet from A5 sheets P5, the heating plate 602 is elastically deformed by the stress concentration F3, and a gap R3 that reduces the adhesion between the ceramic heater 601 and the heating plate 602 is generated, causing a gradual increase in the temperature of a part of the ceramic heater 601. Graph c-1 in Fig. 15 shows how the first detection temperature T1 of thermistor TH1 gradually increases.

[0171] When the first detection temperature T1 gradually increases and exceeds 250°C, the image formation interval is extended, and as a result, the pressurization interval is also extended. In FIG. 15, the timing S1 at which the first detection temperature T1 reaches 250°C is shown by a two-dot chain line. When the first detection temperature T1 exceeds 250°C, the next image formation interval is immediately extended as shown in graph c-2, and the pressurization interval is also extended as shown in graph c-3. On the other hand, after the timing S1 at which the image formation interval is extended, the first detection temperature T1 of the thermistor TH1 continues to rise for a short time. Then, after a certain amount of time has passed since the image formation interval was extended, the first detection temperature T1 reaches a peak P1 and then gradually decreases. As a result of the pressurization interval being extended in this manner, the frequency of heat supply from the ceramic heater 601 to the sheet stack via the heating plate 602 decreases, and the heater temperature rise is suppressed, as in the first embodiment.

[0172] On the other hand, in the configuration of Example 2, the first detection temperature T1 rises more slowly and reaches S1 later than in Example 1. Specifically, in the configuration of Example 1, the first detection temperature T1 reaches 250° C. at the timing of the image forming operation of the 29th A5 sheet P5, whereas in the configuration of Example 2, the first detection temperature T1 reaches 250° C. at the timing of the image forming operation of the 40th A5 sheet P5. Therefore, in Example 2, the image forming interval and the pressurizing interval are extended at a later timing compared to Example 1, so that the time required to produce a booklet of 50 A5 sheets P5 is shortened, and the booklet production time is reduced by 12%.

[0173] In this way, in Example 2, the polyimide sheet 604 as the intermediate member suppresses the inhibition of heat transfer caused by the decrease in adhesion between the ceramic heater 601 and the heating plate 602 that occurs when a small-sized sheet stack is pressed. That is, in Example 2, the polyimide sheet 604 functions as a gap filling member for reducing the gap that occurs between the ceramic heater 601 and the heating plate 602, and also as a heat transfer member.

[0174] (Comparative experiment) Next, a comparative experiment according to Example 2 will be described. The evaluation items of the comparative experiment are [e] the temperature rise result of the ceramic heater 601 and [f] the booklet adhesive strength, similar to the comparative experiment described in Example 1. The test conditions of Example 2, [a] sheet size, [b] total pressure, and [d] the presence or absence of heater temperature rise suppression control, are also similar to those of Example 1. The experimental conditions and experimental results in Example 2 are shown in Table 3 as Condition 6. For reference, Table 3 also shows the experimental conditions and experimental results of Example 1.

[0175] [Table 3]

[0176] In Example 2, the peak P1 of the first detection temperature T1 was 252°C, which did not exceed 270°C, so [e] the temperature rise result of the ceramic heater 601 was OK. [f] The booklet adhesive strength was 1.1 N / cm, which was OK. That is, it was confirmed that Example 2 can ensure good adhesive strength while suppressing excessive temperature rise of the ceramic heater 601.

[0177] Furthermore, in comparison with Example 1, the set temperature [c] of the ceramic heater 601 in Example 2 is Although the first detection temperature T1 was high, the peak P1 of the first detection temperature T1 was low. In this way, by interposing a heat transfer member such as the polyimide sheet 604 between the ceramic heater 601 and the heating plate 602 that reduces the gap, it is possible to effectively suppress the heater from overheating and to shorten the booklet production time.

[0178] In the configuration of Example 2, the polyimide sheet 604 is used as an intermediate member between the ceramic heater 601 and the heating plate 602, but the configuration is not limited to this. As the intermediate member, it is preferable that the intermediate member has heat resistance since it is exposed to high temperatures, and has a lower rigidity than the ceramic heater 601 and the heating plate 602 in order to improve the adhesion between the ceramic heater 601 and the heating plate 602. Since the rigidity G of the intermediate member is determined by the product of its Young's modulus E and cross-sectional area J (G=E×D), it is preferable that the intermediate member has a "low Young's modulus E" or a "small cross-sectional area J". As the intermediate member, for example, a heat-resistant thin resin sheet material, a metal sheet material, heat-resistant grease, etc. may be used in addition to a polyimide sheet material.

[0179] The disclosure of this embodiment includes the following configuration. (Configuration 1) a loading section on which a stack of sheets having adhesive layers formed thereon is loaded; a thermocompression bonding unit including a pressing member for pressing the stack of sheets loaded on the stacking section in a stacking direction of the sheets, the pressing member having a longitudinal direction along one side of the sheets loaded on the stacking section, and a heat source for heating the pressing member; a sheet thermocompression bonding apparatus for bonding a plurality of sheets together by pressing a stack of sheets with the pressing member heated by the heating source and melting an adhesive layer on the sheet, the sheet thermocompression bonding apparatus being configured to be compatible with a plurality of sheets of a predetermined size, The thermocompression unit is arranged in a position in the stacking direction so as not to overlap with the smallest sheet placed on the stacking section, when the smallest sheet among the specified sizes is defined as the smallest sheet, and is characterized in that it includes a temperature measurement sensor that detects the temperature of the heat source. (Configuration 2) 2. The sheet thermocompression bonding apparatus according to claim 1, further comprising a control unit that performs a temperature rise suppression operation for suppressing a temperature rise of the heat source based on a measurement result of the temperature measurement sensor. (Configuration 3) The sheet thermocompression bonding device described in configuration 1 or 2 is characterized in that, when the largest size sheet among the specified sizes is defined as the largest sheet, the pressing member overlaps with the longitudinal direction of the largest sheet loaded on the loading section from one end to the other end in the loading direction. (Configuration 4) The sheet thermocompression bonding device according to any one of configurations 1 to 3, characterized in that the temperature measuring sensor is positioned in the longitudinal direction at a position within 50 mm from the longitudinal end of the smallest sheet loaded on the stacking section. (Configuration 5) The sheet thermocompression bonding device according to any one of configurations 1 to 4, characterized in that if the temperature measurement sensor is a first temperature measurement sensor, the thermocompression bonding unit has a second temperature measurement sensor arranged at a position overlapping the smallest sheet placed on the stacking section in the stacking direction. (Configuration 6) 6. The sheet thermocompression bonding apparatus according to any one of configurations 1 to 5, wherein the heat source includes a base that is long in the longitudinal direction, and a heating element provided on the base. (Configuration 7) 7. The sheet thermocompression bonding apparatus according to configuration 6, wherein the thermal conductivity of the pressing member is equal to or higher than the thermal conductivity of the base. (Configuration 8) 8. The sheet thermocompression bonding apparatus according to claim 6 or 7, wherein the base is a ceramic substrate. (Configuration 9) The sheet thermocompression bonding device according to any one of configurations 1 to 8, characterized in that the thermocompression bonding unit has an intermediate member sandwiched between the pressing member and the heating source in the loading direction, the intermediate member having a lower rigidity than the pressing member and the heating source. (Configuration 10) The sheet thermocompression bonding device described in configuration 2 is characterized in that, when the measurement result of the temperature measuring sensor exceeds a predetermined threshold, the control unit extends the interval between the pressurizing operation by the pressing member of the sheets loaded in the stacking section as the temperature rise suppression operation. (Configuration 11) The sheet thermocompression bonding device according to any one of configurations 1 to 10, characterized in that the loading section has an alignment mechanism that aligns the vertical position of the sheet loaded on the loading section along the longitudinal direction with the horizontal position perpendicular to the vertical direction. (Configuration 12) a loading section on which a stack of sheets having adhesive layers formed thereon is loaded; a thermocompression bonding unit including: a pressing member that presses the stack of sheets loaded on the stacking section in a sheet loading direction, the pressing member having a longitudinal direction along one side of the sheets loaded on the stacking section; a heat source that includes a heating element and heats the pressing member; a first temperature measuring sensor that detects the temperature of the heat source; and a second temperature measuring sensor that is disposed at a position different from the first temperature measuring sensor in the longitudinal direction and detects the temperature of the heat source; a sheet thermocompression bonding apparatus for bonding a plurality of sheets together by pressing a stack of sheets with the pressing member heated by the heating source and melting an adhesive layer on the sheet, the sheet thermocompression bonding apparatus being configured to be compatible with a plurality of sheets of a predetermined size, the stacking section has an alignment mechanism that aligns the longitudinal positions of the plurality of sheets of a predetermined size to a reference position, When a sheet having a minimum size among the predetermined sizes is defined as a minimum sheet, the first temperature measuring sensor is disposed at a position farther from the reference position than the second temperature measuring sensor, A sheet thermocompression bonding device further comprising a control unit that controls the heat generation amount of the heating element based on the measurement result of the second temperature measuring sensor, and performs a temperature rise suppression operation that suppresses a temperature rise of the heating source based on the measurement result of the first temperature measuring sensor. (Configuration 13) The sheet thermocompression bonding device described in configuration 12, characterized in that the control unit extends the interval between the pressurizing operation by the pressing member of the sheets loaded in the stacking section as the temperature rise suppression operation when the measurement result of the first temperature measuring sensor exceeds a predetermined threshold value. (Configuration 14) an image forming apparatus for forming an image on a sheet; A post-processing device including the sheet thermocompression bonding device according to any one of the configurations 1 to 13, and a conveying mechanism that conveys a sheet on which an image has been formed by the image forming device to the sheet thermocompression bonding device; A multifunction peripheral comprising: (Configuration 15) an image forming apparatus for forming an image on a sheet; A post-processing device including the sheet thermocompression bonding device according to configuration 2 and a conveying mechanism that conveys a sheet conveyed from the image forming device to the sheet thermocompression bonding device; Equipped with The control unit extends an interval between image formation on a sheet in the image forming apparatus as the temperature rise suppression operation when a measurement result of the temperature measuring sensor exceeds a predetermined threshold. [Explanation of symbols]

[0180] 42: intermediate loading section, 51: thermocompression unit, 601: ceramic heater (heat source), 602: heating plate (pressure member), TH1: thermistor (temperature measurement sensor)

Claims

1. a loading section on which a stack of sheets having adhesive layers formed thereon is loaded; a thermocompression bonding unit including a pressing member for pressing the stack of sheets loaded on the stacking section in a stacking direction of the sheets, the pressing member having a longitudinal direction along one side of the sheets loaded on the stacking section, and a heat source for heating the pressing member; a sheet thermocompression bonding apparatus for bonding a plurality of sheets together by pressing a stack of sheets with the pressing member heated by the heating source and melting an adhesive layer on the sheet, the sheet thermocompression bonding apparatus being configured to be compatible with a plurality of sheets of a predetermined size, The thermocompression unit is arranged in a position in the stacking direction so as not to overlap with the smallest sheet placed on the stacking section, when the smallest sheet among the specified sizes is defined as the smallest sheet, and is characterized in that it includes a temperature measurement sensor that detects the temperature of the heat source.

2. 2. The sheet thermocompression bonding apparatus according to claim 1, further comprising a control unit that performs a temperature rise suppression operation for suppressing a temperature rise of the heat source based on a measurement result of the temperature measurement sensor.

3. The sheet thermocompression bonding device according to claim 1, characterized in that, when the largest size sheet among the specified sizes is defined as the largest sheet, the pressing member overlaps with the longitudinal direction of the largest sheet loaded on the loading section from one end to the other end in the loading direction.

4. 2. The sheet thermocompression bonding apparatus according to claim 1, wherein the temperature measuring sensor is disposed at a position within 50 mm from an end in the longitudinal direction of the smallest sheet loaded on the loading section.

5. The sheet thermocompression bonding device according to claim 1, characterized in that, when the temperature measurement sensor is a first temperature measurement sensor, the thermocompression bonding unit has a second temperature measurement sensor arranged in a position overlapping with the smallest sheet placed on the stacking section in the stacking direction.

6. 2. The sheet thermocompression bonding apparatus according to claim 1, wherein the heat source includes a base member elongated in the longitudinal direction and a heating element provided on the base member.

7. 7. The sheet thermocompression bonding apparatus according to claim 6, wherein the thermal conductivity of the pressing member is equal to or higher than the thermal conductivity of the base body.

8. 7. The sheet thermocompression bonding apparatus according to claim 6, wherein the base is a ceramic base material.

9. 2. The sheet thermocompression bonding apparatus according to claim 1, wherein the thermocompression bonding unit includes an intermediate member sandwiched between the pressing member and the heat source in the stacking direction, the intermediate member having a rigidity lower than that of the pressing member and the heat source.

10. The sheet thermocompression bonding device according to claim 2, characterized in that the control unit extends the interval between the pressing operations of the pressing member on the sheets loaded in the stacking section as the temperature rise suppression operation when the measurement result of the temperature measuring sensor exceeds a predetermined threshold value.

11. 2. The sheet thermocompression bonding apparatus according to claim 1, wherein the loading section has an alignment mechanism that aligns a vertical position of the sheet loaded on the loading section along the longitudinal direction with a horizontal position perpendicular to the vertical direction.

12. a loading section on which a stack of sheets having adhesive layers formed thereon is loaded; a thermocompression bonding unit including: a pressing member that presses the stack of sheets loaded on the stacking section in a sheet loading direction, the pressing member having a longitudinal direction along one side of the sheets loaded on the stacking section; a heat source that includes a heating element and heats the pressing member; a first temperature measuring sensor that detects the temperature of the heat source; and a second temperature measuring sensor that is disposed at a position different from the first temperature measuring sensor in the longitudinal direction and detects the temperature of the heat source; a sheet thermocompression bonding apparatus for bonding a plurality of sheets together by pressing a stack of sheets with the pressing member heated by the heating source and melting an adhesive layer on the sheet, the sheet thermocompression bonding apparatus being configured to be compatible with a plurality of sheets of a predetermined size, the stacking section has an alignment mechanism that aligns the longitudinal positions of the plurality of sheets of a predetermined size to a reference position, When a sheet having a minimum size among the predetermined sizes is defined as a minimum sheet, the first temperature measuring sensor is disposed at a position farther from the reference position than the second temperature measuring sensor, A sheet thermocompression bonding device characterized by further comprising a control unit that controls the heat generation amount of the heating element based on the measurement result of the second temperature measuring sensor, and performs a temperature rise suppression operation that suppresses the temperature rise of the heating source based on the measurement result of the first temperature measuring sensor.

13. The sheet thermocompression bonding device according to claim 12, characterized in that the control unit extends the interval between the pressing operations by the pressing member of the sheets loaded in the stacking section as the temperature rise suppression operation when the measurement result of the first temperature measuring sensor exceeds a predetermined threshold value.

14. an image forming apparatus for forming an image on a sheet; A post-processing device including the sheet thermocompression bonding device according to any one of claims 1 to 13 and a conveying mechanism that conveys a sheet on which an image has been formed by the image forming device to the sheet thermocompression bonding device; A multifunction peripheral comprising:

15. an image forming apparatus for forming an image on a sheet; a post-processing device including the sheet thermocompression bonding device according to claim 2 and a conveying mechanism for conveying a sheet conveyed from the image forming device to the sheet thermocompression bonding device; Equipped with The control unit extends an interval between image formation on a sheet in the image forming apparatus as the temperature rise suppression operation when a measurement result of the temperature measuring sensor exceeds a predetermined threshold.

Images