Booklet manufacturing apparatus, control method, and program

Abstract

To solve a problem that repetition of a preliminary heating step of abutting a thermo-compression member against a pressing member and raising a temperature may accelerate the deterioration of the pressing member, in a configuration for producing a booklet obtained by binding a recording material using toner as an adhesive.SOLUTION: A booklet manufacturing apparatus is provided that produces a booklet by thermally compressing a recording material with an adhesive image formed at a predetermined location using a thermoplastic adhesive. The booklet manufacturing apparatus includes: a loading unit where recording materials are stacked: a thermo-compression unit that thermo- compresses a predetermined area of the recording material placed on the loading unit: a pressing member made of an elastic body arranged in a position facing a portion to be thermo-compressed by the thermo-compression unit; and a control unit that controls a step of thermo-compression by the thermo-compression unit. The control unit performs preheating on the pressing member by controlling thermo-compression means when predetermined conditions are met that a temperature of the pressing member reaches a threshold or less before the recording material is placed on the loading unit.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a booklet production device, a control method, and a program, and more particularly to a booklet production device, a control method, and a program that produces a bound booklet by bonding recording materials together using thermocompression bonding, which melts and pressurizes an adhesive resin powder image or the like formed on the recording material. [Background technology]

[0002] Patent Document 1 proposes a booklet production device that produces a bound booklet by bonding recording materials together using thermocompression bonding. According to Patent Document 1, a resin powder image (hereinafter referred to as an image toner image) is formed as a visible image on a recording material using an electrophotographic process, and at the same time, a resin powder image (hereinafter referred to as an adhesive toner image) that bonds recording materials P together is formed and fixed to the recording material. The recording materials with the adhesive toner images formed thereon are then stacked together and heated to melt the adhesive toner and apply pressure. The adhesive toner image formed on the recording material can be formed on both sides of the recording material, not just one side, to increase adhesion, and the adhesiveness can be controlled by the pattern of the adhesive toner image and the amount of toner.

[0003] Booklets produced using this type of booklet production technology can contain anything from at least two sheets to several dozen sheets, for example, 50 sheets, and the recording materials can be bound in various ways, such as corner binding, where the corners of the recording materials are bound, or edge binding, where the edges are bound. In the case of a booklet with only a few sheets, it is possible to bond the recording materials P together with a single thermocompression process. However, if a booklet with a large number of sheets, for example, 50 sheets, is bonded with a single thermocompression process, the amount of heat from the heating source may be insufficient to melt the adhesive toner image, resulting in insufficient adhesive strength between the recording materials, and the recording materials may peel off from the completed booklet.

[0004] Therefore, as disclosed in Patent Document 2, a configuration has been proposed in which an arbitrary number of sheets of recording material P (three sheets in this embodiment) are thermocompressed and this is repeated multiple times to produce a booklet with a large number of sheets of recording material.

[0005] Also, a configuration for performing a preheating step has been proposed, as disclosed in Patent Document 3. In Patent Document 3, a heat source that melts an adhesive toner image to bond recording materials together and a pressure member that faces the heat source across the recording materials are brought into contact with each other when the recording materials are not yet bonded together, immediately before the recording materials are bonded together, and the pressure member is heated to perform preheating that increases the adhesive strength. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-43751 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-215230 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-237291 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the booklet production device described in Patent Document 3 has a problem in that repeated preheating steps in which a heat source is brought into contact with and applied to the pressure member to raise its temperature when the pressure member is not bonded accelerates deterioration of the pressure member and causes plastic deformation. If thermocompression bonding is performed using a pressure member that has caused plastic deformation, the bonded portions between the recording materials may be deformed, which may cause problems with the quality of the completed booklet. [Means for solving the problem]

[0008] The present invention has been made in consideration of the above-described conventional example, and according to one aspect thereof, there is provided a booklet producing apparatus for producing a booklet by thermocompression bonding a recording material on which an adhesive image made of a thermoplastic adhesive is formed in a predetermined position, the booklet producing apparatus comprising: a stacking section for stacking the recording materials; a thermocompression bonding unit for thermocompressing the predetermined portion of the recording material placed on the stacking unit; a pressure member made of an elastic material and arranged at a position facing the portion to be thermocompressed by the thermocompression bonding means; and a control means for controlling the thermocompression bonding process by the thermocompression bonding means, The control unit controls the thermocompression unit to preheat the pressure member when a predetermined condition is satisfied that the temperature of the pressure member is equal to or lower than a threshold value before the recording material is placed on the stacking unit. A booklet producing device is provided. [Effects of the Invention]

[0009] As described above, according to the present invention, it is possible to provide a booklet producing apparatus that can suppress deformation of the pressure member that heats the adhesive, and thus does not impair the quality of the finished booklet. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram of an image forming apparatus and a booklet producing apparatus used in an embodiment of the present invention. [Figure 2A] 1 is a top view of a booklet producing apparatus used in an embodiment of the present invention. [Figure 2B] 1 is a top view of a booklet producing apparatus used in an embodiment of the present invention. [Figure 2C] 1 is a top view of a booklet producing apparatus used in an embodiment of the present invention. [Figure 2D] 1 is a top view of a booklet producing apparatus used in an embodiment of the present invention. [Figure 3] 1A and 1B are diagrams illustrating a configuration of a thermocompression bonding member used in an embodiment of the present invention. [Figure 4] 1 is a diagram illustrating a configuration of a booklet production device used in an embodiment of the present invention. [Figure 5] FIG. 3 is a diagram illustrating an example of an adhesive toner image used in an embodiment of the present invention. [Figure 6] 5A and 5B are diagrams illustrating the relationship between adhesive strength and toner amount in an embodiment of the present invention. [Figure 7] 1A to 1C are diagrams illustrating examples of adhesion of recording material P used in an embodiment of the present invention. [Figure 8] FIG. 2 is a diagram illustrating preheating in a first embodiment of the present invention. [Figure 9] FIG. 1 is a diagram illustrating a problem of the first embodiment of the present invention. [Figure 10] FIG. 1 is a diagram illustrating a first embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating the effect of the first embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating an application example of the first embodiment of the present invention. [Figure 13] FIG. 10 is a diagram illustrating an application example of the first embodiment of the present invention. [Figure 14] FIG. 10 is a diagram illustrating a problem of the second embodiment of the present invention. [Figure 15] FIG. 10 is a diagram illustrating the operation of the second embodiment of the present invention. [Figure 16] FIG. 10 is a diagram illustrating the effect of the second embodiment of the present invention. [Figure 17] FIG. 10 is a diagram illustrating an application example of the second embodiment of the present invention. [Figure 18] FIG. 10 is a diagram illustrating a third embodiment of the present invention. [Figure 19] FIG. 2 is a block diagram of a control unit of the booklet producing apparatus. [Figure 20] FIG. 10 is a diagram illustrating an example of a control procedure performed by a control unit of the booklet producing apparatus. [Figure 21] FIG. 10 is a diagram illustrating an example of a control procedure performed by a control unit of the booklet producing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Embodiment 1] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] (Overall configuration of image forming apparatus) First, the overall configuration of the image forming apparatus will be described with reference to FIG. 1. FIG. 1 is a schematic diagram illustrating the cross-sectional configuration of the image forming apparatus 1 according to the first embodiment. As shown in FIG. 1, the image forming apparatus 1 includes a cassette 8 for storing recording materials P, an image forming unit 1e (enclosed within a dashed line) as an image forming means, an image heating device 6 as a fixing means, and a housing 19 that houses these components. The image forming apparatus 1 has a printing function in which a toner image is formed on the recording material P fed from the cassette 8 by the image forming unit 1e, and the image is fixed by the image heating device 6 to produce a printed product. In this embodiment, the recording material P on which an image can be formed is a cut sheet, the maximum size of which is A4 size (297 mm long x 210 mm wide). Image formation is performed by transporting the A4-size recording material P vertically. The recording materials P stored in the cassette 8 are fed one by one from the cassette 8 by a paper feed roller 8a and then transported by a transport roller pair 8b. Alternatively, recording materials P set in a multi-tray 20 can be fed one by one.

[0013] The image forming unit 1e is a tandem electrophotographic unit equipped with four process cartridges 7n, 7y, 7m, and 7c, a scanner unit 2, and a transfer unit 3. A process cartridge is a unit in which multiple components responsible for the image formation process are integrated into a replaceable unit. Each of the process cartridges 7n, 7y, 7m, and 7c includes a photosensitive drum Dn, Dy, Dm, or Dc serving as an image carrier, a charging roller (not shown) that charges the photosensitive drum, and a toner container (not shown) that contains toner and supplies it to the photosensitive drum. Of the four process cartridges, the three process cartridges 7y, 7m, and 7c on the right side of the drawing are process cartridges for forming visible images on a recording material P, forming yellow, magenta, and cyan toner images, respectively.

[0014] In contrast, the process cartridge 7n on the left side of the figure forms an adhesive toner Tn image, which is toner for adhering recording materials P to each other after printing. In this embodiment, when printing a black image such as text, black is expressed using process black obtained by superimposing yellow, magenta, and cyan toners. However, for example, a fifth process cartridge using black image toner may be added to the image forming unit 1e so that black images can be expressed using black image toner. However, the type and number of image toners can be changed depending on the application of the image forming apparatus 1.

[0015] (Image toner) In this embodiment, conventionally known imaging toners can be used as the imaging toner for image formation. Among them, imaging toners using a thermoplastic resin as a binder resin are preferred. The resin that can be used as the binder resin of the imaging toner is not particularly limited as long as it is a thermoplastic resin. For example, resins that have traditionally been used in imaging toners, such as polyester resins, vinyl resins, acrylic resins, and styrene-acrylic resins, can be used. A plurality of these resins may be contained. The imaging toner is formed by containing a colorant, a magnetic material, a charge control agent, wax, external additives, etc.

[0016] (adhesive toner) In this embodiment, adhesive toner containing a thermoplastic resin can be used as an adhesive for bonding recording materials together. Resins that can be used as adhesive toners are not particularly limited as long as they are thermoplastic resins, and polyester resins, vinyl resins, acrylic resins, styrene-acrylic resins, etc., similar to those used in image toners, can be used. A plurality of these resins may be contained. Similarly to image toners, adhesive toners may contain colorants, magnetic materials, charge control agents, waxes, external additives, etc. Furthermore, as long as the adhesive properties are satisfactory, there is no problem in using image toners as adhesive toners.

[0017] (Image formation process) The scanner unit 2 is one of the exposure means in the electrophotographic system that irradiates the photosensitive drums of each process cartridge 7n, 7y, 7m, and 7c with laser light to form electrostatic latent images. The transfer unit 3 includes a transfer belt 3a as an intermediate transfer member (secondary image carrier). The transfer belt 3a is a belt member stretched over a secondary transfer opposing roller (hereinafter referred to as a secondary transfer opposing roller) 3b and a drive roller 3c, which are arranged opposite a secondary transfer roller 5 via the transfer belt 3a. The outer circumferential surface of the transfer belt 3a faces the photosensitive drums of each process cartridge 7n, 7y, 7m, and 7c. Primary transfer rollers Fn, Fy, Fm, and Fc are arranged on the inner circumferential side of the transfer belt 3a at positions corresponding to the photosensitive drums Dn, Dy, Dm, and Dc. Furthermore, a secondary transfer roller 5 serving as a transfer means is arranged opposite the secondary transfer opposing roller 3b. A transfer nip 5n between the secondary transfer roller 5 and the transfer belt 3a is a transfer portion (secondary transfer portion) that transfers a toner image from the transfer belt 3a to the recording material P.

[0018] (fixing process) The image heating device 6 as a fixing unit heats, melts, and pressurizes the toner image formed on the recording material P to fix it as a permanent image on the recording material P. The image heating device 6 is a thermal fixing type fixing device that includes a halogen heater 6a as a heat source, a heat roller as the heated fixing member 6b, and a pressure roller as the pressure member 6c. The fixing member 6b may be heated by a ceramic heater as a heat source or a heat generating mechanism of an induction heating type. The fixing member 6b may also be a thin film made of a highly heat-resistant resin such as polyimide resin or polyamide-imide resin, or a metal such as stainless steel.

[0019] The heat roller is rotated by a driving means such as a motor (not shown) and is pressed against the pressure roller by a biasing member such as a spring, thereby forming a fixing nip 6n between the heat roller and the pressure roller. The power supplied to the halogen heater is adjusted by a control unit so that the temperature detected by a thermistor, a temperature detection element (not shown) abutting against the surface of the heat roller, reaches a predetermined value.

[0020] (Image formation operation) When a print instruction accompanied by image data to be printed is input to the image forming apparatus 1, a control unit (not shown) of the image forming apparatus 1 starts a series of operations (image forming operations) for conveying a recording material P and forming an image on the recording material P. In the image forming operation, the recording material P is fed one sheet at a time from the cassette 8 and conveyed toward the transfer nip 5n via the conveying roller pair 8b.

[0021] In parallel with the feeding of the recording material P, the process cartridges 7n, 7y, 7m, and 7c are sequentially driven, and the photosensitive drums Dn, Dy, Dm, and Dc are rotated. The surfaces of the rotationally driven photosensitive drums Dn, Dy, Dm, and Dc are uniformly charged by charging rollers (not shown). In addition, the scanner unit 2 irradiates the photosensitive drums Dn, Dy, Dm, and Dc with laser light modulated based on image data, thereby forming an electrostatic latent image on the surface of each photosensitive drum.

[0022] The toner stored in each process cartridge 7n, 7y, 7m, and 7c is carried by a developing roller (not shown) and developed into a toner image, which is a visible image corresponding to the electrostatic latent image formed on the photosensitive drum Dn, Dy, Dm, and Dc. Note that the adhesive toner Tn image formed on the photosensitive drum Dn by the adhesive toner Tn differs from a toner image (normal toner image) made of image toner for printing images such as text and figures on the recording material P in that it is not intended to convey visual information. However, in the following description, the adhesive toner Tn image developed by the electrophotographic process to form the adhesive toner Tn image in a predetermined pattern on the recording material P will also be treated as a "toner image."

[0023] The transfer belt 3a rotates counterclockwise (indicated by the arrow) in the figure. The toner images formed in each process cartridge 7n, 7y, 7m, and 7c are transferred (primary transfer) from each photosensitive drum onto the transfer belt 3a by an electric field formed between the photosensitive drums Dn, Dy, Dm, and Dc and the primary transfer rollers Fn, Fy, Fm, and Fc. The toner image carried on the transfer belt 3a and reaching the transfer nip 5n is transferred (secondary transfer) onto the recording material P fed and conveyed from the cassette 8 by an electric field formed between the secondary transfer roller 5 and the secondary transfer opposing roller 3b.

[0024] Thereafter, the recording material P is conveyed to the image heating device 6 and subjected to a thermal fixing process. That is, when the recording material P passes through the fixing nip 6n, the toner image on the recording material P is heated and pressurized, so that the image toner image and adhesive toner Tn image melt and then solidify, thereby being fixed to the recording material P as a permanent image.

[0025] The reversing flapper 21, which is installed downstream of the fixing nip 6n in the conveying direction of the recording material P, is a guide member for switching the conveying direction of the recording material P. The reversing flapper 21 switches the conveying direction of the recording material P depending on the selected printing mode: a single-sided printing mode in which an image is formed on only one side of the recording material P, or a double-sided printing mode in which images are formed on both sides of the recording material P.

[0026] For example, in the case of a single-sided printing mode, the reversing flapper 21 conveys the recording material P toward the pair of paper discharge rollers 22. This completes a series of image forming operations in the image forming apparatus 1, and the recording material P reaches the booklet producing apparatus 4 as a post-processing apparatus via the intermediate conveying unit 26 having the pair of intermediate conveying unit conveying rollers 24 and 25.

[0027] The booklet production device 4 described in this embodiment is a floor-standing type, and is equipped with a booklet production device 50 at the bottom, which is equipped with a recording material P alignment section and a thermocompression member 61 (shown in Figure 3) that heats and presses the aligned stack of recording materials P for a predetermined period of time.

[0028] In the double-sided printing mode, the reversing flapper 21 conveys the recording material P, which has an image formed on one side (hereinafter referred to as the front side), toward the pair of switchback rollers 23. The pair of switchback rollers 23 reverses its rotation direction after discharging the recording material P to the rear end, thereby conveying the recording material P toward the double-sided conveying path 27 for double-sided printing. The recording material P conveyed to the double-sided conveying path 27 passes through the secondary transfer unit and the fixing device 6 again, whereby an image is formed on the side of the recording material P on which no image has been formed (hereinafter referred to as the back side), and images are formed on both sides of the recording material P. The recording material P, which has images formed on both sides, is conveyed by the reversing flapper 21 toward the pair of discharge rollers 22, thereby completing a series of image formation operations in the image forming apparatus 1, and is then conveyed to the booklet production device 4 via the intermediate conveying unit 26.

[0029] (Recording material transport in booklet production equipment) Next, the operation of the booklet production device 4 will be described. The image forming apparatus 1 and the booklet production device 4 are sometimes collectively referred to as a booklet production system. The recording material P conveyed from the intermediate conveyance unit 26 passes through a rear discharge entrance conveyance roller pair 30 and a rear discharge first conveyance roller pair 31 of the booklet production device 4, passes through a discharge and reversing roller pair 32, and is discharged onto an upper discharge tray 33. If the discharge destination of the recording material P is the lower discharge tray 34, the reversing flapper 35 is switched when the trailing edge of the recording material P passes through the reversing flapper 35. At the same time, the rotation of the discharge and reversing roller pair 32 is stopped and then reversed, causing the recording material P to switch back and be conveyed to a rear discharge second conveyance roller pair 36. The recording material P conveyed from the rear discharge second conveyance roller pair 36 is conveyed via a rear discharge third conveyance roller pair 37 to a rear discharge final conveyance roller pair 38. At a predetermined timing when the rear end of the recording material P has passed the rear discharge third conveying roller pair 37, the rear discharge final conveying roller pair 38 is stopped and then rotated in the reverse direction, whereby the recording material P is conveyed to the booklet discharge roller pair 39 and discharged from the booklet discharge port 40 to the lower discharge tray 34. In the case of booklet production, as will be explained in the section on booklet production below, the recording material P is conveyed by the rear discharge final conveying roller pair 38 to an intermediate stacking section 51 in the booklet production device 4, where it is bound into a booklet. The intermediate stacking section 51 may also be simply called the stacking section.

[0030] (Booklet production) Next, the booklet production section 50 will be described. The recording materials P to be produced as a booklet are transported via a rear discharge third transport roller pair 37 to a rear discharge final transport roller pair 38, and then transported to an intermediate stacking section 51 within the booklet production device 4. A lateral alignment reference plate 52 is disposed at the most downstream portion of the intermediate stacking section 51, and the recording materials P are aligned as a stack by abutting the end of the recording materials P against this plate.

[0031] 2A to 2D, a method for aligning the recording material P will be described. The vertical direction, which is the direction in which the recording material P is conveyed, is defined as the X direction, and the horizontal direction is defined as the Y direction. (a) The recording material P is conveyed to the intermediate stacking section 51 (FIG. 2A). (b) After passing through the rear discharge final conveying roller pair 38, the recording material P is stacked on the intermediate stacking section 51 and conveyed so that the upstream end in the conveying direction hits the lateral alignment reference plate 52 by the alignment roller 53 (FIG. 2B). (c) The recording material P that strikes the horizontal alignment reference plate 52 is pushed to the left in the drawing by the vertical alignment claw 54 that is installed so as to be movable in the Y direction (FIG. 2C). (d) The recording material P is pushed to the left side in the figure by the vertical alignment claw 54, and when it hits the vertical alignment reference plate 55 (dotted line), it becomes a stack of recording material P that is aligned with high precision in both the horizontal and vertical directions (Figure 2D).

[0032] The stack of recording materials P aligned in this way is heated and pressed by a thermocompression bonding member 61, and the adhesive toner Tn image acts as an adhesive, and the stack of recording materials P bonded together becomes one booklet.

[0033] (thermocompression bonding) The thermocompression bonding member 61 will now be described. Fig. 3 is a cross-sectional view of the entire thermocompression bonding member 61. The thermocompression bonding member 61 has a configuration in which a ceramic heater 70 serving as a heat source, which is provided with a heating element 72 on a ceramic base 71 having a thickness of 1.0 mm, is mounted with a first heating plate 62 made of aluminum having a thickness of 2.5 mm. This configuration reduces the heat capacity, thereby reducing power consumption.

[0034] The first pressure plate 62 has a length equal to or greater than the maximum size of booklets that can be produced by the image forming apparatus 1 and booklet production apparatus 4 of this embodiment. The first pressure plate 62 extends in the depth direction of FIG. 3, and the size in that direction is the length. In this example, the length of the first pressure plate 62 is 300 mm, which is a length that can bond A4-sized recording material P. The length of the heating element 72 provided in the ceramic heater 70 to uniformly heat the first pressure plate 62 exceeds both ends of the first pressure plate 62. In this embodiment, the length of the heating element 72 is 320 mm. The substrate of the heat source can be made of a rigid body other than ceramic, such as metal.

[0035] The first pressure plate 62 is made of a material that has a small heat capacity and high thermal conductivity to efficiently transfer heat from the heat source, and has an elastic modulus of 1000 Pa or more so that deformation does not occur due to the pressure applied during thermocompression bonding. Preferably, a highly elastic material with an elastic modulus of 10000 Pa or more is used.

[0036] The ceramic heater 70 is controlled at a thermocompression bonding control temperature that is set to a target temperature detected by a thermistor 64 as temperature detection means supported by a heater support 63, thereby setting the surface temperature of the first heating plate 62 at a temperature at which thermocompression bonding can be performed. The heater support 63 that supports the ceramic heater 70 is made of a material such as a liquid crystal polymer, which is a type of highly heat-resistant functional resin.

[0037] The pressure lever 65 presses the thermocompression bonding member 61 downward in the figure, pressing against the stack of recording materials P, and is operated by the operation of a drive source (not shown). The pressure from the pressure lever 65 is transmitted to the first pressure plate 62 via a rigid metal stay 66, and presses the conveyed stack of recording materials P by sandwiching it between the first pressure plate 62 and the second pressure plate 67 (sometimes referred to as a pressure member). The second pressure plate 67 as a pressure member is a plate-shaped member made of silicone rubber with a thickness of 2.0 mm, and is a member for stably transmitting the pressure from the pressure lever 65 to the stack of recording materials P. The second pressure plate 67 can be made of any material other than silicone rubber, as long as it has a certain degree of deformability, an elastic modulus of 1000 Pa or less, is resistant to repeated stress, and is heat-resistant, in order to stably transmit the pressure to the stack of recording materials P.

[0038] A toner image (referred to as an adhesive toner image or adhesive image) made of adhesive toner Tn is formed by the image forming apparatus 1 on the pressurized portion of the surface of the recording material P that contacts other recording materials. Therefore, adhesive toner images do not need to be formed on the surfaces of the first and last sheets of the booklet, which correspond to the front and back covers of the booklet. Furthermore, the adhesive toner image may be formed only on at least one of the two recording materials P that contact each other. By forming an adhesive toner image in this way, the bundle of recording materials that is heated and pressurized is bound by the adhesive toner. The adhesive toner image is formed on a predetermined portion of the recording material P according to the binding method, such as line binding or corner binding.

[0039] The number of sheets of recording material P to be thermocompression bonded is desirably set appropriately taking into consideration the time required for thermocompression bonding and the productivity of booklet production. In the embodiment described in this specification, a stack of five stacked and aligned recording materials P is thermocompression bonded. In the thermocompression bonding, the stack of recording materials P is pressed for two seconds while the temperature of the first pressure plate 62 is at the target temperature for thermocompression bonding, and then the first pressure plate 62 and the stack of recording materials P are separated, thereby completing the production of the booklet through the thermocompression bonding process.

[0040] For example, a booklet consisting of 50 sheets of recording material P is produced by the following process. The first thermocompression bonding is performed on a predetermined number of sheets, for example, the first to fifth sheets of recording material P, to produce a booklet consisting of five sheets of recording material P. Here, a booklet is formed by adding a predetermined number of sheets at a time, and a booklet in the process of being formed is called a temporary booklet. Also, in the following explanation, when indicating the number of recording material P, it will be indicated by the order in which they are stacked on intermediate stacker 51. This order is the order in which images are formed, and corresponds to the order in which counting begins from the cover of the booklet. The second thermocompression bonding is performed on the sixth to tenth sheets of recording material P that are stacked on top of the temporary booklet made up of the five sheets of recording material P that have been completed in advance, thereby producing a temporary booklet made up of 10 sheets of recording material P. The third thermocompression bonding is performed on the 11th to 15th sheets of recording material P that are stacked on top of the temporary booklet made up of the previously completed 10 sheets of recording material P, thereby producing a temporary booklet made up of 15 sheets of recording material P. The fourth thermocompression bonding is performed on the 16th to 20th sheets of recording material P that are stacked on top of the previously completed temporary booklet consisting of 15 sheets of recording material P, thereby producing a temporary booklet consisting of 20 sheets of recording material P.

[0041] By repeating this process 10 times, a booklet of 50 sheets is completed. When five or fewer sheets of recording material P are to be thermocompressed, the thermocompression bonding is performed for that number of sheets. The predetermined number of sheets that constitutes a unit of a temporary booklet is five in the above example, but is not limited to this value. The number of sheets that constitutes a unit of a temporary booklet may be an appropriate number that can be thermocompressed depending on the temperature of the first pressure plate 62, the pressure during bonding, and the like. While this explanation focuses on the production of a booklet, an image is formed on the recording material P in the image forming process prior to the production of the booklet, and at that time, an adhesive toner image using adhesive toner required for thermocompression bonding is also formed on the recording material P.

[0042] (Positional relationship between recording material P and ceramic heater) The positional relationship between the recording material P aligned by the horizontal alignment reference plate 52 and the ceramic heater 70 will be described using FIG. 4. The size of the recording material P to be used in a booklet is freely selectable by the user within the limitations of the booklet production device, and various sizes of recording material P are shown in the figure, including A4, B5, and A5. Regardless of its size, the recording material P is aligned in the X direction at the same reference alignment position by the horizontal alignment reference plate 52, and in the Y direction at the same reference alignment position by the vertical alignment reference plate 55, and is ready for thermocompression bonding. In other words, using a predetermined corner point (the lower left corner in FIG. 4) of the recording material P, which is a rectangular cut sheet material, as the reference point, the recording material P is aligned to the vertical and horizontal (XY) alignment positions of the booklet production device regardless of its size. This also applies to recording materials of sizes that do not conform to ISO standards, such as letter size and legal size.

[0043] In this way, the alignment position of the recording material P to be thermocompressed is the same regardless of the size. The reference position of the ceramic heater 70 is also set to the side where the horizontal alignment reference plate 52 and the vertical alignment reference plate 55, where the recording material P is waiting, so that adhesion at the edge of the recording material P of various sizes is ensured.

[0044] (adhesion form) FIG. 5 illustrates an example of an adhesive configuration based on different patterns of adhesive toner Tn images formed on recording material P. FIG. 5(a) illustrates a corner-fastening booklet configuration in which adhesive toner Tn images are formed on the corners of recording material P to bond the corners. FIG. 5(b) illustrates an edge-fastening booklet configuration in which adhesive toner Tn images are formed on the left long edge of recording material P to bond the edges. When producing a booklet with n pages, adhesive toner Tn images are formed on both sides of the recording materials P up to page n, except for the first side of the first page, which serves as the cover, that face each other when the recording materials P are aligned. The booklet is then produced by thermocompression bonding every five sheets as described above. While FIG. 5 illustrates an example in which adhesive toner Tn images are formed on both sides of recording material P, they may also be formed on only one side of recording material P. Whether adhesive toner Tn images are formed on one side or both sides can be determined based on factors such as the booklet production device, adhesive toner, type of recording material, and desired functionality of the booklet. For example, in the case of a booklet to be kept as a keepsake, or when thick paper or a special recording material P is used for the cover of the booklet, the adhesive toner Tn image is formed on both sides to ensure reliable adhesion. On the other hand, in the case of a booklet for simple temporary use, the adhesive toner Tn image is formed on only one side. These are just examples, but it is sufficient to select as appropriate.

[0045] A booklet is completed by repeating this thermocompression bonding process, and a bundle discharge guide (not shown) moves parallel from its standby position toward the booklet discharge outlet 40 to push out the bundle of recording materials P. A pair of booklet discharge rollers 39 is provided at the booklet discharge outlet 40, and the bundle discharge guide stops and returns to its standby position when the leading edge of the completed booklet passes the pair of booklet discharge rollers 39. The pair of booklet discharge rollers 39 receives the completed booklet from the bundle discharge guide and discharges the booklet from the booklet production device 4 onto the lower discharge tray 34, thereby completing the series of booklet production steps.

[0046] (Adhesive strength) FIG. 6(a) shows an example of the results of measuring the relationship between the toner amount of the adhesive toner Tn image between recording materials P and the adhesive force. The adhesive force is measured as the peak force when the thermocompressed recording materials P are peeled off as shown in FIG. 6(b). The toner amount is the amount of toner measured before the adhesive toner Tn image is fixed by the image heating device 6, and is measured per unit area of 1 cm. 2 As shown in Figure 6(a), the adhesive force is proportional to the toner amount.

[0047] On the other hand, after examining the adhesive strength between recording materials P required for the completed booklet, it was found that an adhesive strength of approximately 0.5 N / cm or more would cause the recording material P to tear and peel off, and it was determined that this was not a problem as adhesive strength for a booklet. The adhesive strength of 0.5 N / cm obtained in this examination was obtained when using plain Office 70 (70 g / m) paper manufactured by Canon Marketing Japan Inc. as the recording material P. 2 ) was confirmed.

[0048] 6(b), the adhesive strength is measured by fixing one open edge of any page of the completed booklet, pulling the other edge, and measuring the force at the point when the bonded recording material P peels away from the recording material P. Although the adhesive strength P was confirmed using several types of recording material P, it will vary depending on various factors such as the type of recording material P, the purpose of the booklet, and the environment in which the booklet is produced, and is not limited to this numerical value.

[0049] As shown in Figure 6(a), the amount of adhesive toner required to obtain an adhesive force of 0.5 N / cm or more is 0.6 mg / cm 2 Therefore, in the image forming apparatus 1 and the booklet producing apparatus 4 described in this embodiment, the total amount of adhesive toner between the recording materials P to be adhered is 0.6 mg / cm 2 We try to make it so that it becomes like this.

[0050] (Booklet production) Next, an example of producing a booklet by stacking 50 sheets of recording material P will be described using FIG. 7. The back surface of the first recording material P will be the front cover (= front cover) of the completed booklet, and is not the surface that will be adhered to other recording materials P, so no adhesive toner Tn image is formed on it. The opposite surface, the front surface of the first recording material P, will be the surface that will be adhered to the back surface of the second recording material P, so an adhesive toner Tn image according to the binding position is formed on it. The second to fifth recording materials P have adhesive toner Tn images formed on their front and back surfaces, thereby bonding each recording material P together. Five sheets of recording material P with adhesive toner Tn images formed in this way are stacked, and the adhesive toner Tn images are melted and thermocompressed by the booklet production unit 50 described above to produce a five-sheet temporary booklet.

[0051] Next, the sixth to tenth sheets of temporary booklets are produced. The basic process for producing the sixth to tenth sheets of temporary booklets is the same as that for the first to fifth sheets of temporary booklets, but with the following differences. Unlike the first sheet of recording material P, the sixth sheet of recording material P does not become the cover of the completed booklet, but is adhered to the front surface of the fifth sheet of recording material P of the previously completed first to fifth sheets of temporary booklets, and therefore an adhesive toner Tn image is formed on the back surface of the sixth sheet of recording material P. The sixth to tenth sheets of recording material P are overlapped and aligned on the previously completed first to fifth sheets of temporary booklets, and are thermocompression bonded by the thermocompression bonding member 61. Next, the eleventh to fifteenth sheets of recording material P are overlapped and aligned in the same manner, and the thermocompression bonding is repeated to produce the first to fifteenth sheets of temporary booklets.

[0052] In this way, the thermocompression bonding process is repeated, and the final 46th to 50th sheets of recording material P are stacked, aligned, and thermocompressed to complete a booklet of 50 sheets. The surface of the 50th sheet of the final 46th to 50th sheets of recording material P is the cover (= back cover) that is not adhered to the other recording materials P, so no adhesive toner Tn image is formed on the surface.

[0053] (preheating) Next, we will explain the preheating performed to stabilize the adhesive strength. In this embodiment, a booklet is completed by repeatedly thermocompressing every five sheets of recording material P. The ceramic heater 70, which is the heat source that melts the adhesive toner when thermocompressing every five sheets, directly contacts the recording materials P that are multiples of five, such as 5, 10, 15, ..., in FIG. 7, and melts the adhesive toner Tn images. On the other hand, among the recording materials P that are additionally bonded to the temporary booklet, the recording materials P that are multiples of five + 1, such as the first, sixth, and eleventh sheets, which are the furthest from the ceramic heater 70, are subjected to heat transfer via the adhesive toner Tn images of the four intervening recording materials P. To the intermediate recording materials P, heat is transferred via the intermediate recording materials P, although less heat is transferred than to the four intervening recording materials P. Therefore, the amount of heat received by each of the recording materials P and adhesive toner Tn images for the fifth, fourth, third, second, and first sheets of recording material P in the order in which they are additionally placed on the temporary booklet placed in the intermediate stacking section 51 varies depending on the number of the recording material P. That is, the amount of heat received by the recording material P and adhesive toner Tn image decreases in the order of the fifth, fourth, third, second, and first sheets, and the adhesive strength between each of the recording materials P differs. In other words, the farther away from the ceramic heater 70, the smaller the amount of heat received by the recording material P and adhesive toner Tn image, and the adhesive strength between each of the recording materials P differs depending on the amount of heat. In order to stabilize the adhesive strength between the recording materials P, it is appropriate to stabilize the amount of heat received by the recording materials P.

[0054] To achieve this, if thermocompression bonding is performed every two sheets, which is the minimum number of sheets required to bond recording materials P to each other, rather than every five sheets, the amount of heat would be stabilized and the adhesive strength would also be stabilized, but this would reduce productivity in booklet production and increase the time required to produce the booklet. In this embodiment, taking productivity into consideration, thermocompression bonding is repeated every five sheets of recording material P. The heating of the ceramic heater 70, which is the heat source, is controlled so as to provide an amount of heat that melts the adhesive toner Tn images formed on the five sheets of recording material P and ensures reliable adhesion, but there are cases where the amount of heat is insufficient.

[0055] As mentioned above, the thermocompression member 61 has a small heat capacity to save energy and provide a quick response with high temperature responsiveness. Silicone rubber is selected as the elastic material for the pressure member 67, which also has the function of insulating heat.

[0056] In this way, the thermocompression bonding member 61 has a small heat capacity. However, if the entire thermocompression bonding member 61 is cold or if the ambient environment in which the booklet production process is performed is low, heat from the ceramic heater 70, which serves as the heat source, may be transferred to the thermocompression bonding member 61 or the components supporting it, resulting in a loss of heat. In such a case, the pressure member 67 is also cold, so heat is transferred to the pressure member 67 via the recording material P, resulting in an even greater shortage of heat required for thermocompression bonding. In such a state, the amount of heat is insufficient to melt the adhesive toner Tn image, resulting in insufficient adhesive strength between the recording materials P. When adhesive strength is insufficient, the controlled temperature of the ceramic heater 70, which serves as the heat source, can be increased to reliably melt the adhesive toner Tn image and obtain sufficient adhesive strength, but this can result in the following problems.

[0057] If a heat quantity sufficient to reliably melt the adhesive toner Tn images on the first and second sheets of recording material P shown in FIG. 7 is applied, the adhesive toner Tn images formed on the fifth and fourth sheets of recording material P in contact with the thermocompression bonding member 61 will receive too much heat. As a result, the adhesive toner Tn images will melt more than is appropriate for adhesion, and will soak into the fibers of the recording material P. The adhesive toner Tn images that have soaked into the fibers of the recording material P will no longer be able to contribute to adhesion, resulting in insufficient adhesive force.

[0058] To resolve such problems, it is effective to maintain the thermocompression member 61 and the pressure member 67 at a constant temperature at which optimal adhesion is always obtained, but maintaining a constant temperature all the time is not desirable from the viewpoint of energy conservation.

[0059] Therefore, a preheating step of raising the temperatures of the thermocompression bonding member 61 and the pressure member 67 prior to bonding of the recording material is effective.

[0060] The booklet production unit 50 used in the first embodiment of the present invention includes a preheating process to stabilize adhesive strength. In the preheating process, the heated thermocompression bonding member 61 is brought into contact with the pressure member 67 and heated by controlling heating before thermocompression bonding of the recording materials P to each other, which is a timing when no recording material P is present between the thermocompression bonding member 61 and the pressure member 67. The preheating contact time is set to 3 seconds. The purpose of this process is to prevent heat loss from the thermocompression bonding member 61 and the pressure member 67 by raising their temperatures before thermocompression bonding, thereby reliably melting the adhesive toner Tn image and stabilizing adhesive strength.

[0061] Next, the results of confirming the effect of the temperature rise and adhesive strength of the pressure member 67 when the preheating step is performed are shown in Fig. 8. This confirmation was performed in an environment where the ambient temperature is approximately 25°C, simulating a standard office environment.

[0062] As shown in FIG. 8A, by preheating the recording material P prior to thermocompression bonding, the temperature of the pressure member 67 during booklet production can be increased by approximately 10°C compared to when preheating is not performed. Without preheating, the temperature of the pressure member 67 during thermocompression bonding is less than 120°C. However, when preheating is performed for three seconds, the temperature of the pressure member 67 rises to approximately 170°C, and the temperature during thermocompression bonding is slightly less than 130°C, which is approximately 10°C higher. In this embodiment, the preheating time is set to three seconds. However, although a longer preheating time would allow the temperature of the pressure member 67 to rise more, this would also reduce productivity in booklet production. Therefore, it is desirable to set this time according to the specifications of the booklet production unit 50, etc.

[0063] When the temperature of the pressure member 67 is raised by approximately 10°C by carrying out the preheating process, the adhesive strength becomes 0.6 N / cm, which is approximately 20 to 30% higher, as shown in Figure 8(b), and this is sufficient to ensure the adhesive strength of 0.5 N / cm required for the booklet mentioned above.

[0064] Next, before the sixth to tenth temporary booklets are bonded by thermocompression, the first to fifth previously completed temporary booklets are preheated while they are still in the booklet production unit 50, and then the sixth to tenth temporary booklets are thermocompressed, and similarly, thermocompression bonding is repeated for five additional booklets at a time. This allows booklets to be produced with stable adhesive strength.

[0065] (Plastic deformation of pressure-applied member) Next, the phenomenon that is the problem of the present invention will be explained. Although the adhesive force between the recording materials P is stabilized by performing the preheating process, the following problem may occur. The problem is that the pressure member 67, which is made of silicone rubber as an elastic material, may undergo plastic deformation as shown in FIG. 9 due to repeated preheating processes. The plastic deformation is a plastic deformation phenomenon that occurs in the portion of the pressure member 67 made of silicone rubber that comes into contact with the first pressure plate 62. In this embodiment, as shown in FIG. 9(a), the plastic deformation occurs in a width of about 2.5 mm and a length of about 300 mm, which corresponds to the first pressure plate 62.

[0066] This section explains the plastic deformation of silicone rubber. The heat resistance temperature of silicone rubber varies depending on the presence, amount, and type of various additives, but for standard silicone rubber it is approximately 220°C. Preheating is a process in which a heated thermocompression bonding member 61 is pressed against a pressure member 67, repeatedly raising the temperature of the pressure member 67. Therefore, even at temperatures that do not exceed the heat resistance temperature of silicone rubber, the elasticity characteristic of rubber deteriorates and is lost. If the limit at which rubber can maintain its elasticity is exceeded, it will enter plastic deformation, a state in which it cannot return to its original state from the state deformed by pressure, even if the deforming force applied as pressure is released.

[0067] FIG. 9(b) shows an example of the shape of plastically deformed silicone rubber measured. The horizontal axis in the figure represents the width of the pressure member 67 in the short direction, and the vertical axis represents the amount of concave deformation of the silicone rubber surface. FIG. 9(b) shows that plastic deformation of approximately 2.5 mm in width and an average of approximately 50 μm in depth has occurred. When bonding is performed using a plastically deformed pressure member 67, the bonding portion of the recording material P may be deformed, as shown in FIG. 9(c), which will impair the quality of the finished booklet. In this embodiment, it was found that when the depth of the plastic deformation shown in FIG. 9(b) exceeds approximately 30 μm, deformation of the recording material P occurs, impairing the quality of the finished booklet.

[0068] Unlike the thermocompression bonding process, the preheating process involves heating and pressurizing the pressure member 67 in the absence of the recording material P, which accelerates the deterioration of the silicone rubber and shortens the time it takes for plastic deformation to occur. In other words, it was found that this reduces the number of times booklets can be produced, thereby shortening the life of the booklet production unit 50.

[0069] (Features of the present invention) The booklet production device of this embodiment includes a booklet production unit 50. The booklet production unit 50 performs a preheating process to obtain stable adhesive strength and also suppresses plastic deformation of the pressure member 67 made of silicone rubber, so that the quality of the completed booklet is not compromised even if the booklet production unit 50 is used for a long period of time.

[0070] When a booklet consisting of 50 sheets is produced by repeating the thermocompression bonding, the following changes occur in the thermocompression bonding member 61.

[0071] In the above description, preheating is performed by directly pressing the heated thermocompression bonding member 61 against the pressure member 67. However, preheating may also be performed by pressing the heated thermocompression bonding member 61 against already-bonded temporary booklets placed in the intermediate stacking unit 51. In this embodiment, preheating is performed after the first to fifth sheets are thermocompression bonded, and by the time the sixth sheet of recording material P of the sixth to tenth temporary booklets to be produced is conveyed to the booklet production unit 50, preheating is performed while the previously completed first to fifth temporary booklets are still in the booklet production unit 50. Thereafter, thermocompression bonding is performed on the sixth to tenth sheets. Subsequently, thermocompression bonding is performed on the eleventh to fifteenth temporary booklets in the same manner, and so on for subsequent stacks of recording media P. In this manner, a booklet of the desired number of sheets, for example, 50 sheets, with stable adhesive strength can be completed.

[0072] By repeating the preheating step and the thermocompression step to produce a booklet in this way, the temperature of the pressure member 67 rises. Furthermore, the presence of a temporary booklet in the middle of production in the booklet production unit 50 also raises the temperature of the atmosphere in the booklet production unit 50, reducing the amount of heat escaping from the thermocompression member 61 and the pressure member 67, and stabilizing the adhesive force.

[0073] By producing the booklets in this way, the adhesive strength becomes stable, and there is less need to perform a preheating process to stabilize the adhesive strength. Although the example of producing 50 booklets has been explained, the same applies when repeatedly producing two booklets, which is the minimum number of sheets to be subjected to thermocompression bonding.

[0074] On the other hand, if the repeated thermocompression bonding is completed and the state where booklet production is stopped continues for a long time, the temperatures of the thermocompression bonding member 61 and the pressure member 67 will drop, and the stable adhesive force as described above will no longer be obtained. It has also been found that if the booklet production unit 50 changes to such a state, it will be necessary to carry out the preheating process again.

[0075] Therefore, in this embodiment, if a stable adhesive force can be obtained without performing a preheating process and raising the temperature of the pressure member 67, the preheating process is not performed (= stopped), thereby suppressing plastic deformation of the silicone rubber that is the pressure member 67.

[0076] FIG. 10 shows the results of checking the relationship between the temperature of the pressure member 67 during thermocompression bonding and the adhesive strength, and the relationship between the temperature of the pressure member 67 before and during the thermocompression bonding process.

[0077] 10(a) shows that in order to stably obtain the adhesive strength of 0.5 N / cm required for a booklet, the temperature of the pressure member 67 during thermocompression bonding should be approximately 120 to 140° C. Although a temperature of 140° C. during thermocompression bonding results in higher adhesive strength, raising the temperature of the pressure member 67 during thermocompression bonding is not desirable from the perspective of deterioration of the silicone rubber.

[0078] Therefore, in this embodiment, the execution of the preheating step is determined so that the temperature of the pressure member 67 during thermocompression bonding falls within the range of 120 to 130°C.

[0079] 10(b) shows the results of checking the temperature of the pressure member 67 before the thermocompression bonding process on the horizontal axis and the temperature of the pressure member 67 during the thermocompression bonding process on the vertical axis, with and without the preheating process. From Fig. 10(b), it can be seen that when the temperature of the pressure member 67 before the thermocompression bonding process is about 70°C or lower, by performing the preheating process, it is possible to raise the temperature of the pressure member 67 during the thermocompression bonding process to about 120°C, which is enough to obtain an adhesive strength of 0.5 N / cm required for a booklet.

[0080] On the other hand, if the preheating step is performed when the temperature of the pressure member 67 before the thermocompression bonding step exceeds approximately 80°C, the temperature of the pressure member 67 during the thermocompression bonding step will be approximately 140°C, which will increase the adhesive strength but is not suitable for deteriorating the silicone rubber. Also, if the temperature of the pressure member 67 before the thermocompression bonding step exceeds approximately 60°C, it will be possible to raise the temperature of the pressure member 67 during the thermocompression bonding step to approximately 120°C, which will provide the adhesive strength of 0.5 N / cm required for a booklet, even without performing the preheating step.

[0081] Therefore, in this embodiment, the preheating step is performed when the temperature of the pressure member 67 before the thermocompression bonding step is 70° C. or less, which is the temperature at which reliable adhesiveness can be obtained.

[0082] As described above, in this embodiment, if the temperature of the pressure member 67 before thermocompression bonding is below a threshold, for example, below 70°C, preheating is performed to ensure reliable adhesive strength. On the other hand, if the temperature of the pressure member 67 exceeds the threshold, for example, above 70°C, the thermocompression bonding process is performed without preheating to suppress plastic deformation of the silicone rubber. This type of preheating control is the basic control in this embodiment. Furthermore, as described above, the preheating process is controlled so that the ceramic heater 70 is maintained at 180°C for three seconds when the temperature of the pressure member 67 is below 70°C.

[0083] (Temperature of pressure member) Next, a description will be given of the calculation of the temperature of the pressure member 67 that determines whether or not to perform the preheating step. In this embodiment, the calculation is based on the temperature of the pressure member 67 obtained through experiments, with the following factors related to the thermocompression bonding step as conditions: The temperature of the ambient environment in which the image forming device 1 and the booklet producing device 4 are installed. The content of the most recent booklet production and the time since the booklet production was completed. The type of recording material used in the booklet to be produced, such as thin paper, regular paper, thick paper, special paper, etc. Regarding the specifications of the booklet to be produced, is it a booklet that does not require the production of a temporary booklet, or is it a booklet that requires the production of a temporary booklet? Specifically, in this embodiment, is it a booklet that is made up of five or fewer sheets of recording material, or is it a booklet that is made up of more than five sheets of recording material? - The number of sheets of recording material that will make up the booklet to be produced and the number of copies of the booklet.

[0084] By examining these factors in combination (measuring the temperature of the pressure member), the above factors are used as parameters to correlate the estimated temperature of the pressure member. The correlation between this parameter and the estimated temperature may be stored, for example, in a table. By referring to the combination of results obtained in this way, the temperature of the pressure member 67 is estimated and used to determine whether to perform the preheating process.

[0085] In this embodiment, the decision to perform the preheating step is made based on an estimate from the results of investigation, but it is also possible to make a configuration in which a thermistor, which is a temperature detection element, is brought into contact with the pressure member and the temperature measured is used to determine whether or not to perform the preheating step. Temperature can also be measured using a thermopile, which is a non-contact temperature measurement element, and it is desirable to select an appropriate method depending on the configuration and specifications of the booklet production unit 50.

[0086] Next, as an effect of this embodiment, we confirmed the plastic deformation of the pressure member by repeating the preheating step and the thermocompression bonding step. Plastic deformation can be recognized by observing the surface, but this was substituted by measuring the hardness of the silicone rubber. The hardness (or softness) of silicone rubber can be measured using a commercially available hardness tester using a durometer conforming to, for example, JIS K 6253 standard, and in this embodiment, the larger the value, the harder the material.

[0087] The hardness of silicone rubber changes depending on the composition, formulation, crosslinking conditions, etc. of the silicone rubber. Under the conditions of heat and pressure used in this embodiment, silicone rubber generally undergoes softening degradation, resulting in a decrease in hardness. By measuring the decrease in hardness of the silicone rubber, it was determined that the silicone rubber was in a state of progressive deterioration and plastic change, losing its elasticity as rubber.

[0088] In the control of the booklet production device described below, the preheating step is performed using a conventional control method, which is performed every time a booklet is produced, and a proposed example of the present embodiment, in which a preheating step is performed by maintaining the ceramic heater 70 at 180°C for three seconds if the temperature of the pressure member 67 is below 70°C. 70°C is an example of a predetermined threshold in the present embodiment, and preheating can be performed if the temperature is below the predetermined threshold. Two conditions were set for thermocompression bonding: repeated production of two booklets, which results in a large temperature rise in the pressure member 67 and severe conditions for deterioration of the silicone rubber, and repeated production of five temporary booklets to produce 50 booklets.

[0089] Figure 11 shows the results of measuring the change in hardness of the silicone rubber of the pressure member using the above combinations. In addition to the change in hardness, the figure also shows the results of a sensory evaluation of the deformation of the completed booklets. The sensory evaluation, which confirmed the deformation of the booklets, was marked with a circle if the deformation was not noticeable and was a problem; a triangle if the deformation was noticeable with careful observation but not a problem; an x if the deformation was easily noticeable in an instant and was problematic; and an ▲ if the deformation was undesirable in between. As shown in the figure, when two booklets were repeatedly produced using conventional control, the decrease in hardness was significant, and it can be seen that the deformation of the booklet was quickly noticeable. On the other hand, when 50 booklets were produced using the proposed example, the decrease in hardness was small, and 500,000 booklets could be produced without any noticeable deformation.

[0090] Similarly, in the proposed example, even when two-sheet booklets were repeatedly produced, the hardness decreased more than when a 50-sheet booklet was produced, but the decrease in hardness did not reach a level where deformation of the booklet was noticeable, making it possible to produce 500,000 booklets.

[0091] Thus, it was confirmed that the effect of this embodiment is that booklets with secured adhesiveness can be produced throughout the life of the booklet producing unit 50.

[0092] In this embodiment, the controlled temperature of the ceramic heater 70 during the preheating step is set to 180°C, but the controlled temperature is not limited to this example, depending on factors that affect adhesive strength, such as the adhesive toner formulation, the configuration of the thermocompression bonding member 61, the product specifications of the booklet production device 4, and the ambient temperature used. The controlled temperature of the ceramic heater 70 during the preheating step is set to an optimum temperature as appropriate in accordance with changes in the aforementioned factors that affect adhesive strength, but a lower controlled temperature within a range in which stable adhesiveness can be obtained is desirable from the perspective of suppressing deterioration of the silicone rubber.

[0093] Furthermore, the controlled temperature during the preheating process does not have to be a fixed value, for example, 180°C, but may be a temperature that is arbitrarily set variably depending on factors that affect the adhesive strength described above, the conditions of the booklet to be produced, the total number of booklets produced, etc.

[0094] (Pressure force during preheating process) Next, the pressure applied when performing the preheating step will be described as an application example of the first embodiment. In the above-described embodiment, the pressure applied during the preheating step was 294 N (30 kgf), the same as that used in the thermocompression bonding step. However, subsequent studies have revealed that the purpose of the preheating step is to raise the temperature of the pressure member 67, and that the same pressure as that used in the thermocompression bonding step is not necessary.

[0095] Figure 12 shows the results of examining the pressure applied during preheating and the temperature rise of the pressure-applied member. As shown in Figure 12, it was found that within the pressure applied range of 294 N to 196 N (20 kgf) and 147 N (15 kgf), the same as in the thermocompression bonding process, the difference in pressure applied has little effect on the temperature rise of the pressure-applied member. This shows that as long as there is enough contact area to transfer the amount of heat required to raise the temperature of the pressure-applied member from the thermocompression bonding member 61, even if the pressure applied is reduced, there is little effect on the temperature rise of the pressure-applied member.

[0096] As mentioned above, it is known that the plastic deformation of the silicone rubber forming the pressure-applying member is greatly affected by temperature and pressure. Therefore, reducing the pressure applied to the pressure-applying member 67 within a range that still allows the temperature of the pressure-applying member 67 to rise to a temperature at which the desired stable adhesive strength can be obtained is a useful means of avoiding deformation of the silicone rubber composition, and is desirable to implement as needed. For example, in the preheating step, the pressure applied between the thermocompression-bonding member 61 and the pressure-applying member 67 may be less than the 294 N pressure applied for thermocompression bonding; in the example shown in Figure 12, it may be 147 N, half of that pressure.

[0097] As described above, the preheating process for stabilizing the adhesive strength between recording materials P is performed when the temperature of the pressure member 67 falls below a predetermined temperature of 70°C, which is a case where there is a possibility that the adhesive strength may be insufficient. However, the following control is also possible.

[0098] As thermocompression bonding is repeated to produce a booklet, the temperature of the pressure member 67 rises, making the preheating step unnecessary, but as time passes since thermocompression bonding, the temperature of the pressure member 67 drops, making it desirable to perform the preheating step. The temperature drop is affected by the ambient temperature of the booklet production unit 50, but is most significantly affected by heat accumulation in the booklet production unit 50 due to repeated thermocompression bonding. For example, even after performing thermocompression bonding once, the temperature of the booklet production unit 50 rises, but then drops again immediately. On the other hand, when thermocompression bonding is repeated, the temperature of the booklet production unit 50 rises with heat accumulation, so the temperature drop is gradual.

[0099] 13 shows an example of the temperature drop of the pressure member 67 when thermocompression bonding is repeated once and ten times from a temperature of approximately 50°C in the booklet production unit 50. As shown, the temperature drop of the pressure member 67 varies depending on the thermocompression bonding performed immediately before. Therefore, it is possible to check the relationship between the temperature drop of the pressure member 67 due to the number of thermocompression bonding operations and the elapsed time, and then control the execution of the preheating step based on the number of thermocompression bonding operations performed immediately before and the elapsed time.

[0100] As described above, the preheating process is basically performed only when there is a possibility that the adhesive strength between recording materials may be insufficient, and when the preheating process is performed, control is performed such as reducing the pressure and optimizing the temperature.

[0101] By adopting such a configuration, it is possible to suppress plastic deformation of the pressure member 67 made of silicone rubber throughout the life of the booklet production device 4, and it is possible to provide a booklet production device 4 that does not impair the quality of the finished booklet.

[0102] (Booklet production control) By executing the above control by the control unit of the booklet production apparatus 4, it is possible to suppress plastic deformation of pressure members made of materials that undergo plastic deformation due to preheating, such as silicone rubber. This prevents deterioration in the quality of booklets produced by the booklet production apparatus using adhesive toner. It also makes it possible to extend the interval between pressure member replacements, which is economical. Note that, because booklet production by the booklet production apparatus 4 is linked to image formation by the image forming apparatus 1, the control unit of the image forming apparatus 1 may also control the booklet production apparatus 4. In this case, it can be said that the control unit of the image forming apparatus 1 functions as the control unit of the booklet production apparatus 4. The configuration of the control unit of the booklet production apparatus 4 and its control procedure are described below.

[0103] FIG. 19 shows a block diagram of the control unit of the booklet production apparatus 4. FIG. 20 shows an example of the control procedure. In FIG. 19, a control unit 1901 having a CPU and the like controls the booklet production apparatus 4 by executing a program 1911 stored in a memory unit 1910, for example. The control unit 1901 receives a detection signal from a thermistor 64, which is a temperature sensor, and can detect the temperature of the heating element 72 via the heater support 63. The control unit 1901 can also control the heating of the heating element 72 and can control drive motors 1922 for driving the pressure lever, which is a drive source for pressing the pressure lever 65 against and separating it from the pressure member 67. The control unit 1901 also drives drive motors 1922 for transporting the recording medium P transported from the image forming apparatus 1 to the booklet production apparatus 4. The drive motors 1922 also drive, for example, the reversing flapper 35, the rear discharge second transport roller pair 36, the rear discharge third intermediate transport roller pair 37, the rear discharge final transport roller pair 38, the booklet discharge roller pair 39, the alignment rollers 53, and the vertical alignment reference plate 54. Power for driving the motors, heaters, etc. is supplied from a power supply unit (not shown).

[0104] If the control unit 1901 also functions as the n control unit of the image forming apparatus 1, the transport mechanism and image forming mechanism of the image forming apparatus 1 are also subject to drive control, but the control of the mechanisms of the image forming apparatus 1 will be omitted here. A storage unit (or memory) 1901 stores a program 1911 for operating the control unit 1901 according to the procedure shown in FIG. 20, and this program is loaded into RAM and executed by the control unit 1901. The storage unit 1901 also stores an estimated temperature table 1912 for determining the estimated temperature of the pressure member 67 from parameters. The parameters include, for example, the ambient temperature, the details of the last booklet production (for example, the number of booklets and the number of copies), the time elapsed since the last booklet production was completed, and the type of recording material to be used for the booklet to be produced. Further parameters include whether the booklet to be produced is one that does not require the production of a temporary booklet or one that requires the production of a temporary booklet, the number of sheets of recording material constituting the booklet to be produced, and the number of copies of the booklet. Whether the booklet to be produced is one that does not require the production of a temporary booklet or one that requires the production of a temporary booklet can be determined from the number of booklets to be produced. That is, if the number of sheets to be thermocompressed per one time (for example, 5 sheets) exceeds the number of sheets of the booklet to be produced, it can be determined that the production of a temporary booklet is necessary, and if the number does not exceed this, it can be determined that the production of a temporary booklet is unnecessary. Therefore, instead of the parameter indicating whether the booklet does not require the production of a temporary booklet or whether the booklet requires the production of a temporary booklet, the number of sheets to be thermocompressed per one time can be used as a parameter.

[0105] FIG. 20 shows an example of a control procedure for the booklet production apparatus 4. The procedure in FIG. 20 is realized by the control unit 1901, particularly, for example, its CPU, executing the program 1911. The procedure in FIG. 20 is initiated, for example, a predetermined time before the recording material P on which an image and an adhesive toner image are formed is discharged from the image forming apparatus 1 and placed on the intermediate stacker 51 of the booklet production apparatus 4. This predetermined time includes at least the time required for preheating, i.e., the time required to move the pressure lever 65 to the preheating position, the preheating time, the time required to return the pressure lever 65 to the retracted position, and the time required for controlling these. These times are constant, and the transport time from the start of image formation on the recording medium P to its arrival at the intermediate stacker 51 can also be considered constant. In this way, the timing for starting the process in FIG. 20 can be determined by delaying the time required for preheating and the transport time from the start of image formation on the recording medium P. The process in FIG. 20 is initiated at the timing determined in this manner. In addition to the controls shown in Figure 20, the booklet production device 4 also controls the rollers that transport the recording material P, the flaps that switch the transport path, and the vertical and horizontal alignment claws, but here we will focus on the processes for pre-heating and thermal fixation.

[0106] 20 begins, the control unit 1901 first acquires the temperature of the heating element 67 (S2001). If a temperature sensor for measuring the temperature of the heating element 67 is provided, the temperature can be acquired by acquiring a temperature signal from the temperature sensor, but in this example, an estimated temperature is acquired by referring to the estimated temperature table 1912. The parameters include at least one of the ambient temperature, the details of the last booklet production (e.g., the number of sheets and number of copies of the booklet), the time elapsed since the last booklet production was completed, the type of recording material used, the number of sheets to be pressed per operation, the number of sheets of recording material for the booklet to be produced, and the number of copies of the booklet.

[0107] The ambient temperature may be detected by an ambient temperature sensor (not shown). The number of sheets and copies of the last booklet produced, the type of recording material used, and the number of sheets and copies of the booklet to be produced may be obtained from the control unit of the image forming apparatus 1. The time elapsed since the completion of the last booklet production may be measured by a timer (not shown) started at the timing of booklet ejection. The number of sheets pressed per press may be a separately set value. Note that if the control unit of the image forming apparatus 1 also functions as the control unit 1901 of the booklet production device 4, the parameters that are supposed to be obtained from the control unit of the image forming apparatus 1 may be values held by the control unit 1901 of the booklet production device 4 without needing to be obtained. The estimated temperature table 1912 stores, for example, estimated temperatures of the heating element 67 measured in advance corresponding to these parameters. In S2001, the estimated temperature can be obtained by identifying the parameter values.

[0108] Next, the control unit 1901 determines whether the acquired temperature is equal to or lower than a predetermined value, which is a threshold (S2002). In this example, 70°C is used as the threshold. If the acquired temperature is equal to or lower than the threshold, the heating element 72 is heated, and the pressure lever 65 is driven by the drive motors 1922 to press the first pressure plate 62 against the pressure member 67, thereby performing preheating (S2003). The pressure, temperature, and time at this time are as described above; for example, preheating may be performed by applying a pressure of 147 N at a temperature of 180°C for 3 seconds. If the acquired temperature exceeds the threshold, step S2003 is skipped.

[0109] After preheating has been performed according to the conditions, the control unit 1901 waits until the recording materials P to be thermocompressed are aligned and placed on the intermediate stacking unit 51 (S2004). Here, if the recording materials P to be thermocompressed are discharged from the image forming apparatus 1 and then aligned at their respective vertical and horizontal alignment positions, it may be determined that the recording materials P are aligned and placed on the intermediate stacking unit 51. At this time, if the number of recording materials P to be thermocompressed is less than the number of sheets to be thermocompressed per one time, it may be determined in step S2004 that the recording materials P are aligned and placed on the intermediate stacking unit 51 once that number has been reached. If the number of recording materials P to be thermocompressed is equal to or greater than the number of sheets to be thermocompressed per one time (for example, five sheets), it may be determined in step S2004 that the recording materials P are aligned and placed on the intermediate stacking unit 51 once the number of sheets to be thermocompressed per one time (for example, five sheets) has been reached. At this time, a stack of recording materials P that have already been heat-pressed may be placed below the number of recording materials P to be pressed at one time.

[0110] When the recording material P to be thermocompression bonded is aligned and placed on the intermediate stacker 51, the control unit 1901 heats the heating element 72 and drives the pressure lever 65 by the drive motors 1922 to press the first pressure plate 62 against the pressure member 67, thereby performing thermocompression bonding (S2005). For example, the conditions for this may be a pressure of 294 N at a temperature of 180°C for 3 seconds.

[0111] Thereafter, the control unit 1901 determines whether the production of the booklet by the thermocompression bonding process is complete (S2006). If the production is complete, the control unit 1901 drives the necessary drive motors 1922 to eject one completed booklet from the intermediate stacker 51 onto the lower paper ejection tray 34 (S2007). On the other hand, if the booklet is incomplete and the stack of recording materials P placed on the intermediate stacker 51 is a temporary booklet, the booklet production process is repeated from step S2002.

[0112] As described above, according to this embodiment, in a configuration in which recording materials are thermocompressed using adhesive toner, the frequency of preheating can be reduced by preheating a pressure member made of an elastic material according to its temperature. This can reduce plastic deformation of the pressure member. Furthermore, by reducing the pressure on the pressure member during preheating compared to during thermocompression bonding, plastic deformation of the pressure member can be further reduced. In particular, for pressure members using silicone rubber as the elastic material, as described in the embodiment, suppressing plastic deformation can reduce deterioration in the quality of the produced booklet.

[0113] 20, the temperature of the pressure member 67 is obtained using the estimated temperature table 1912 in Fig. 19, and in step S2002 it is determined whether the temperature is equal to or lower than a threshold value, but the parameters used for estimating the threshold value or some of them may also be used as the determination criterion. For example, it may be determined whether to perform preheating based on a combination of the number of times booklet production has been performed (which may be the number of copies, for example) and the time elapsed since the last production.

[0114] 19 is assumed to record temperatures associated with parameter values. Here, information indicating that preheating is necessary may be recorded instead of temperatures below a threshold value (e.g., 70°C), and information indicating that preheating is not necessary may be recorded instead of temperatures above a threshold value (e.g., 70°C). By referring to such a table, it is possible to determine whether preheating is necessary in S2002 of FIG. 20 based on the information recorded in the table, without having to estimate a temperature in particular.

[0115] [Embodiment 2] The problem with the second embodiment of the present invention is the same as that with the first embodiment, that is, plastic deformation caused by deterioration of the pressure member 67 made of silicone rubber. However, this embodiment focuses on plastic deformation that occurs partially in the pressure member 67 and addresses this partial plastic deformation. The second embodiment also uses the same booklet production device 4 as the first embodiment, and a description of common features will be omitted. As described above, the booklet production apparatus 4 of this embodiment is capable of producing booklets with recording material P of A4 size as the maximum size and A5 size as the minimum size. In the booklet production apparatus 4 capable of producing booklets with recording material P of sizes ranging from the minimum A5 size to the maximum A4 size, it has been found that when booklets are repeatedly produced with the smallest A5 size recording material P, the following plastic deformation occurs in the silicone rubber of the pressure member 67. As described above, the effective lengths of the thermocompression bonding member 61 and the pressure member 67 are 300 mm for the first pressure plate 62 of the thermocompression bonding member 61 and 320 mm for the pressure member 67, which are lengths that can reliably thermocompress the 298 mm long side of the largest size A4 recording material P. Therefore, when a booklet is made by bonding the 210 mm long side of the smallest size A5 recording material P, there will be a portion of the thermocompression bonding member 61 and the pressure member 67 where no recording material P exists (hereinafter referred to as a non-recording material portion). In this embodiment, when a booklet is made using the smallest size A5 recording material P, the difference of 87 mm (= 297 - 210 mm) between the long sides of the A4 size and the A5 size is the non-recording material portion, which is the area on the pressure member 67 where no recording material P exists. When thermocompression bonding is performed to produce a booklet using A5-sized recording material P, the 87 mm non-recording material portion is thermocompression bonded while being in direct contact with the pressure member 67 in a state where the ceramic heater 70, which is a heat source provided in the thermocompression bonding member 61, is generating heat. The pressure member 67 in the portion where the recording material P is present receives the amount of heat transferred via the recording material P and the adhesive toner Tn image, while the non-recording material portion receives the amount of heat required to melt the adhesive toner Tn image directly from the thermocompression bonding member 61. In this way, the amount of heat received by the pressure member 67 in the non-recording material portion is greater than that in the portion where the recording material P is present, and it was found that this has a significant impact on the deterioration of the silicone rubber that makes up the pressure member 67, and that the pressure member 67 may even undergo plastic deformation. On the other hand, the silicone rubber deteriorates little in the area where the recording material P is present, and the elasticity, a characteristic of rubber, can be maintained. No adverse effects are observed when booklets are produced using only A5-sized recording material P with such a partially deteriorated pressure member 67. However, when booklets are produced using recording material P larger than A5, such as A4-sized recording material P, the following adverse effects may be observed. The phenomenon recognized as a problem is that, as shown in Fig. 14, fold marks due to differences in deterioration of the silicone rubber appear on booklets produced in A4 size, with the boundary being the paper edge position where the A5 size of the silicone rubber that is the pressure member 67 is aligned. This phenomenon is not limited to when booklets are repeatedly produced using the smallest A5 size recording material P. It also occurs when booklets are repeatedly produced using recording material P that is smaller than the maximum size of recording material P that can be produced by the booklet production device 4 (A4 size in this embodiment).

[0116] In a second embodiment of the present invention, when a booklet is produced using recording material P that is smaller than the maximum size for which the booklet can be produced, the alignment position of the small-sized recording material P is not fixed as shown in Figure 4, but is changed for each booklet produced. This distributes and levels the non-recording material portions, preventing partial deterioration of the silicone rubber that forms the pressure member 67. An improved example of the second embodiment is shown in Figure 15.

[0117] FIG. 15 shows an example of A5 size, but the alignment position of the recording material P in the horizontal direction is changed. FIGS. 15(1) to 15(5) show examples of alignment positions 1 to 5, respectively. The first booklet is made at alignment position 1, the second at alignment position 2, the third at alignment position 3, the fourth at alignment position 4, and the fifth at alignment position 5. From the sixth booklet onward, the sixth booklet is made at alignment position 1 again, and the seventh at alignment position 2. Thereafter, thermocompression bonding is performed repeatedly using alignment positions numbered as the remainder of the number of booklets made modulo 5 (however, if the remainder is 0, 5 is used). In this way, multiple alignment positions are determined, and the positions are offset from one another. In this example, the multiple alignment positions are the same in the short direction of the recording material, but are offset from one another so that they are at different positions in the long direction. By cyclically aligning the recording material at multiple offset alignment positions in this way, the non-recording material portions of the pressure member 67 can be dispersed. Next, the effect of dispersing and leveling the non-recording material portions will be described. To confirm the effect, booklets consisting of 10 sheets of A5-size recording material P were repeatedly produced, and the hardness of the silicone rubber at the edge positions of the A5-size recording material P was periodically measured. Booklets were also periodically produced using A4-size recording material P, and a sensory evaluation of the fold marks on the completed booklets was performed. The hardness was measured at the alignment position of the edge of the A5-size recording material P shown in FIG. 4 in the conventional example, and is shown as the average value of the positions corresponding to the edge of the A5-size recording material P at each of the five alignment positions in this embodiment. The sensory evaluation was performed using the same ranking as in the first embodiment.

[0118] The results are shown in Figure 16. As shown in Figure 16, in the conventional example, when 100,000 booklets had been produced, the change in hardness from the initial state was 12°, and even in the sensory evaluation, an undesirable level of crease marks was recognized at the boundary of the A5 size (indicated by ▲). In contrast, in the second embodiment, when 100,000 booklets had been produced, the change in hardness was 3° or less, and no crease marks were recognized (indicated by ◯). After that, booklet production was repeated, and even when checking at 500,000 booklets, the change in hardness was about 6°, and no crease marks were recognized. In this way, the effect of the second embodiment was confirmed.

[0119] Next, an application example of the second embodiment will be described. An embodiment has been described in which the horizontal alignment position of the recording material P is divided into five parts for each thermocompression bonding so as to evenly level the non-recording material portion. However, it has been found that the following phenomenon occurs even when the alignment position is shifted within a fixed five-part division.

[0120] 17(a), the lateral alignment position of the recording material P is set to five stages to evenly level the non-recording material portion, but the boundary between the non-recording material portion and the recording material P is in the same position every five times. This boundary position is repeated at the same position on the silicone rubber pressure member 67, and it was found that the change in hardness of the silicone rubber at this boundary portion is greater than the change in hardness outside the boundary position.

[0121] The results of the hardness change are shown in Figure 17(b). As shown in Figure 17(b), it can be seen that the change in hardness differs between boundary positions and non-boundary positions. As an application example of the second embodiment, as shown in Figure 17, the position at which the lateral alignment reference plate 52 regulates the edge of the recording material P is not fixed to five levels, but is changed in 3 mm increments in the conveyance direction of the recording material as a control specification that changes the position for each thermocompression bonding.

[0122] By dispersing the boundaries aligned at fixed positions in this way, deterioration of the silicone rubber at those boundaries is further suppressed. Controlling the alignment position of the recording material P used to create a booklet in this way is an effective means of suppressing deterioration of the silicone rubber that is the pressure member 67, and it is desirable to control this in accordance with the specifications of the booklet production device 4.

[0123] (Booklet production control) Fig. 21 shows an example of a control procedure of this embodiment by the control unit 1901. The configuration of the control unit 1901 may be the same as that of the first embodiment. The processing in Fig. 21 is processing in which steps S2101-S2103 are added to Fig. 20, so these additional steps will be explained, and explanations of steps common to Fig. 20 will be omitted. Also, the start of Fig. 21 may be triggered in the same way as Fig. 20.

[0124] The control unit 1902 first drives the lateral alignment plate 52 to move it to the bottom (S2101). The bottom is a reference position when producing a booklet of the maximum size recording material P in this embodiment.

[0125] Next, the control unit 1901 determines whether the size of the recording material P of the booklet to be produced is the maximum size of the booklet that can be produced (S2102). In this example, it is determined whether it is A4 size. If it is determined to be the maximum size, the process branches to step S2001 and the booklet is produced using the same control as in the first embodiment.

[0126] On the other hand, if it is determined that the size is not the maximum, the control unit 1901 drives the lateral alignment plate 52 to move it a predetermined distance (S2103). In the example of FIG. 15, if the lateral alignment plate 52 is at any of alignment positions 1 to 4, the predetermined distance is (A4 longitudinal length - A5 longitudinal length) / 4, and the direction of movement is upward in FIG. 15, i.e., toward the recording material P with respect to the lateral alignment position. This movement shifts the lateral alignment position by one-fourth of the length of the non-recording portion for each booklet. Also, if the lateral alignment plate 52 is at alignment position 5, the direction of movement is (A4 longitudinal length - A5 longitudinal length), and the direction of movement is downward in FIG. 15, i.e., toward the opposite side of the recording material P with respect to the lateral alignment position. This movement returns the lateral alignment position to the bottom. In other words, if the lateral alignment plate 52 reaches the top of the predetermined alignment positions, it is returned to the bottom. In this control, the first booklet starts from alignment position 2 in FIG. 15, but since the object of this embodiment is to shift the alignment position for each booklet, the start position can be anywhere.

[0127] According to an improved example of the second embodiment, the predetermined distance in step S2103 is a fixed distance, such as 3 millimeters upward in FIG. 15 . In this case, if the movement of the lateral alignment reference plate 52 causes the top edge of the booklet to extend beyond the ceramic heater 70, the lateral alignment reference plate 52 can be returned to the bottom. To do this, the cumulative value of the movement distance of the lateral alignment reference plate 52 in step S2103 is subtracted from the length obtained by subtracting the longitudinal length of the booklet from the longitudinal length of the ceramic heater 70. If this value is less than 0, the lateral alignment reference plate 52 can be returned to the bottom. In this case, the lateral alignment plate 52 is returned to the bottom, and the cumulative value of the movement distance of the lateral alignment reference plate 52 is reset to 0. Thereafter, the control unit 1901 executes the booklet production process from S2001.

[0128] As described above, according to this embodiment, it is possible to produce high-quality booklets over the life of the booklet production apparatus 4, as long as the booklet is of a size that can be produced by the booklet production apparatus 4. More specifically, even if booklets are repeatedly produced using recording material P of a size smaller than the maximum size that can be produced by the booklet production apparatus 4 of this embodiment, the completed booklets are of high quality and do not have any noticeable creases. Furthermore, it is now possible to continue producing such high-quality booklets over the life of the booklet production apparatus 4.

[0129] In the process of FIG. 21, the position of the lateral alignment reference plate 52 is changed every time thermocompression bonding is performed, for example, every time five sheets of recording material are thermocompression bonded, but it may also be changed every time a booklet is discharged.

[0130] [Embodiment 3] Similar to the second embodiment, the objective of the third embodiment of the present invention is to suppress deterioration of the silicone rubber that is the pressure member 67 when producing a booklet using recording material P that is smaller than the maximum size for which a booklet can be produced. The third embodiment also uses the same booklet production device 4 as the first and second embodiments, and a description of the common parts will be omitted. The third embodiment will also be described by taking an example in which an A5-sized recording material P, which is the smallest size recording material P, is used. In the third embodiment, as shown in Fig. 17(a), a sheet serving as a recording material substitute member 56 is provided below the lateral alignment reference plate 52 in the drawing. The lateral alignment reference plate 52 regulates the position of the A5-sized recording material P so that it is aligned downstream in the conveyance direction of A4, which is the largest size recording material P that can be used to produce a booklet in this embodiment, as shown in Fig. 18(b). 15 and 17(a), when the position of A5-sized recording material P is restricted by the lateral alignment reference plate 52, a non-recording material portion is generated on the upstream side in the conveying direction of the recording material P, as shown in the figures. In the third embodiment, a sheet, which is a recording material substitute member 56 provided on the lateral alignment reference plate 52, is present in this non-recording material portion generated on the upstream side in the conveying direction of the recording material P. Note that "upstream" here refers to the lower side of the figure, i.e., the upstream side in the conveying direction when the booklet is discharged, and is the side of the lateral reference plate 52 on which no recording material P is present, as shown in FIG. In this embodiment, the sheet serving as the recording material substitute member 56 is also moved in accordance with the movement of the lateral alignment reference plate 52 to change the position at which it regulates the recording material P. By doing so, the sheet serving as the recording material substitute member 56 is present in the non-recording material P portion that would otherwise be located upstream in the conveyance direction of the recording material P (lower side in the drawing). As a result, even in the non-recording material portion, the thermocompression bonding member 61 comes into contact with the silicone rubber serving as the pressure member 67 via the sheet, and does not come into direct contact. The following describes the sheet serving as the recording material substitute member 56. When a booklet is normally produced, what exists between the thermocompression bonding member 61 and the pressure member 67 is the recording material P. Even if the sheet serving as the recording material substitute member 56 is formed from the recording material P, it is possible to avoid the non-recording material P portions that are the objective of the third embodiment, but repeated thermocompression bonding using the same recording material P will damage general recording materials P such as office paper. Therefore, in this embodiment, a sheet of fluororesin or polyimide resin is used as a material that is durable enough to withstand repeated thermocompression bonding without breaking and that is heat resistant to the heat from the thermocompression bonding member 61. Such a material can be used as the sheet serving as the recording material substitute member 56. In this embodiment, as an example, a 200 μm-thick sheet made of polyimide resin is used as the recording material substitute member 56. The recording material substitute member 56 is attached upstream of the lateral alignment reference plate 52 in the recording material conveyance direction. Its width is sufficient to cover the pressure member 67. The width is the widthwise direction of the pressure member 67. Furthermore, the length of the recording material substitute member 56 is sufficient to be greater than the difference between the length of the largest recording material (the lengthwise direction of the heating member 67) that can be produced by the booklet production device 4 and the length of the smallest recording material. As in the second embodiment, a booklet is produced by the booklet producing unit 50 equipped with the thermocompression bonding member 61 equipped with a sheet that is the recording material alternative member 56. As a result, at least in the non-recording material portion upstream of the lateral alignment reference 52, the ceramic heater 70 and the pressure member 67 come into contact with each other via the recording material alternative member 56, and plastic deformation due to heat during preheating can be suppressed. With the above configuration, booklets were repeatedly produced using the smallest size A5 recording material P, as in the second embodiment. Furthermore, booklets were periodically produced using the largest size A4 recording material P. During this booklet production process, the silicone rubber pressure member 67 was checked for creases due to deterioration. As a result, as in the second embodiment, no creases were observed over the life of the booklet production device 4, and the change in the hardness of the silicone rubber was within 10°, confirming that there were no problems with the third embodiment as well. (Modification of the third embodiment) In the above configuration, when a booklet is produced using recording materials smaller than the maximum size, the recording material substitute member 56 can cover the pressure member 67 on the upstream side in the booklet discharge direction, but not on the downstream side. However, if the top edge of the booklet to be produced (e.g., the top edge in FIG. 18B) is aligned with the top edge of the maximum-size booklet, as shown in FIG. 18B, the recording material substitute member 56 can cover the non-recording material portion of the pressure member 67, eliminating any uncovered portion. To achieve this, a control procedure can be performed to set the lateral alignment reference plate 52 (also referred to as the lateral alignment reference member) to such a position. Therefore, instead of performing steps S2102 and S2103 in FIG. 21, in step S2101, the lateral alignment reference plate 52 can be moved to a position where the top edge of the booklet to be produced is aligned with the top edge of the maximum-size booklet. As a result, as shown in FIG. 18B, the non-recording material portion of the pressure member 67 is covered by the recording material substitute member 56, eliminating any portion that comes into direct contact with the ceramic heater 70. This also reduces the amount of heat transferred to the pressure member 67, suppressing plastic deformation thereof and preventing deterioration in the quality of the booklet produced.

[0131] (Other variations) In the above embodiment, the heating temperature and heating time of the thermocompression bonding member during the preheating step are constant. However, either or both of the heating temperature and heating time may be variable. If they are variable, the control unit 1901 controls the preheating at a temperature and time according to the acquired (or estimated) temperature of the pressure member 67. These times and temperatures may be registered in a table in which the time and / or temperature are given using the temperature value of the pressure member 67 as a parameter, and may be specified by the table. The temperature and time registered in the table may be determined experimentally so that the temperature of the pressure member 67 during thermocompression bonding is, for example, 120°C or slightly higher. A booklet producing apparatus characterized in that the temperature is controlled at a fixed temperature or a variable temperature depending on the temperature of a pressure member.

[0132] [Other Examples] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0133] Summary of embodiments The above embodiments can be summarized as follows: (Item 1) A booklet producing apparatus for producing a booklet by thermocompression bonding a recording material on which an adhesive image made of a thermoplastic adhesive is formed in a predetermined position, a stacking section for stacking the recording materials; a thermocompression bonding unit for thermocompressing the predetermined portion of the recording material placed on the stacking unit; a pressure member made of an elastic material and arranged at a position facing the portion to be thermocompressed by the thermocompression bonding means; and a control means for controlling the thermocompression bonding process by the thermocompression bonding means, The control unit controls the thermocompression unit to preheat the pressure member when a predetermined condition is satisfied that the temperature of the pressure member is equal to or lower than a threshold value before the recording material is placed on the stacking unit. A booklet production device characterized by: (Item 2) The booklet production device according to item 1, The control means estimates the temperature of the pressure member based on the correlation between a predetermined parameter and the temperature of the pressure member, and determines that the predetermined condition is satisfied when the estimated temperature is equal to or lower than the threshold value. A booklet production device characterized by: (Item 3) The booklet production device according to item 1, The control means determines whether preheating is necessary based on the association between a predetermined parameter and the necessity of preheating, and when it is determined that preheating is necessary, determines that the predetermined condition is satisfied. A booklet production device characterized by: (Item 4) The booklet production device according to item 2 or 3, The predetermined parameters include at least one of the environmental temperature of the booklet producing device, the number of sheets and copies of the last booklet produced, the time elapsed since the completion of the last booklet production, the type of recording material used for the booklet, the number of sheets of recording material to be thermocompressed by the thermocompression bonding means per operation, the number of sheets of recording material for the booklet to be produced, and the number of copies of the booklet to be produced. A booklet production device characterized by: (Item 5) The booklet production device according to item 1, Further, a measuring means for measuring the temperature of the pressure member is provided, The control means acquires the temperature of the pressure member by the measurement means, and determines that the predetermined condition is satisfied when the temperature of the pressure member is equal to or lower than the threshold value based on the acquired temperature. A booklet production device characterized by: (Item 6) The booklet production device according to item 2 or 5, The control means changes the time or temperature or both of the preheating time and the temperature depending on the temperature of the pressure member. A booklet production device characterized by: (Item 7) A booklet production device according to any one of items 1 to 6, The pressure applied to the pressure member by the thermocompression bonding means during the preheating is smaller than the pressure applied to the pressure member by the thermocompression bonding means during the thermocompression bonding of the recording material. A booklet production device characterized by: (Item 8) A booklet production device according to any one of items 1 to 7, The control means can move the pressure member in the longitudinal direction, and the control means further includes an alignment reference member for determining the position of the pressure member in the longitudinal direction of the recording material placed on the stacking section, When the size of the booklet to be produced is smaller than the maximum size of the booklet that can be produced, the control means moves the position of the alignment reference member to perform the preheating and the thermocompression bonding. A booklet production device characterized by: (Item 9) Item 8: The booklet production device according to item 8, The position of the alignment reference member is changed for each thermocompression bonding. A booklet production device characterized by: (Item 10) Item 8: The booklet production device according to item 8, The position of the alignment reference member is changed for each booklet. A booklet production device characterized by: (Item 11) A booklet production device according to any one of items 8 to 10, The recording medium substitute member is provided on the side of the alignment reference member opposite to the side on which the recording medium is aligned. A booklet production device characterized by: (Item 12) A booklet production device according to any one of claims 1 to 7, an alignment reference member that can be moved in the longitudinal direction of the pressure member by the control means and that determines the position of the pressure member in the longitudinal direction of the recording material placed on the stacking section; a recording material substitute member provided on the side of the alignment reference member opposite to the side on which the recording material is aligned, When the size of the booklet to be produced is smaller than the maximum size of the booklet that can be produced, the control means performs the preheating and the thermocompression bonding by moving the position of the alignment reference member so that the side of the booklet to be produced that faces the alignment reference member is aligned with the corresponding side of the booklet of the maximum size. A booklet production device characterized by: (Item 13) A booklet production device according to any one of items 1 to 12, The adhesive is a toner containing a thermoplastic resin. A booklet production device characterized by: (Item 14) an image forming apparatus for forming an image including the adhesive image using toner containing the thermoplastic resin; and a booklet producing apparatus according to item 13, which receives the recording material on which the adhesive image has been formed in a predetermined portion from the image forming apparatus and produces a booklet. A booklet production system characterized by: (Item 15) A control method for a booklet producing apparatus that produces a booklet by thermocompression bonding a recording material on which an adhesive image made of a thermoplastic adhesive is formed in a predetermined portion, the booklet producing apparatus having a thermocompression bonding means, a pressure member made of an elastic body that is arranged in a position facing the portion that is thermocompression bonded by the thermocompression bonding means, and a control means that controls the thermocompression bonding process by the thermocompression bonding means, the control method comprising: placing the recording materials in a stack on a stacking section; the control means causes a thermocompression bonding means to thermocompress the predetermined portion of the recording material placed on the stacking section; the control means controls the thermocompression bonding means to preheat the pressure member when a predetermined condition is satisfied that the temperature of the pressure member is equal to or lower than a threshold value before the recording material is placed on the stacking portion. A control method comprising: (Item 16) Item 16. A program for causing a computer to execute the control method described in Item 15.

[0134] The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0135] 1 image forming apparatus, 4 booklet making device, 34 lower paper discharge tray, 39 booklet discharge roller pair, 40 booklet discharge port, 50 booklet making unit, 51 intermediate stacking unit, 52 horizontal alignment reference plate, 53 alignment roller, 54 vertical alignment claw, 55 vertical alignment reference plate, 56 recording material substitute member, 61 thermocompression member, 62 first pressure plate, 63 heater support, 64 thermistor, 65 pressure lever, 67 pressure member, 70 ceramic heater, 72 heating element, 1901 control unit

Claims

1. A booklet producing apparatus for producing a booklet by thermocompression bonding a recording material on which an adhesive image made of a thermoplastic adhesive is formed in a predetermined position, a stacking section for stacking the recording materials; a thermocompression bonding unit for thermocompressing the predetermined portion of the recording material placed on the stacking unit; a pressure member made of an elastic material and arranged at a position facing the portion to be thermocompressed by the thermocompression bonding means; and a control means for controlling the thermocompression bonding process by the thermocompression bonding means, The control unit controls the thermocompression unit to preheat the pressure member when a predetermined condition is satisfied that the temperature of the pressure member is equal to or lower than a threshold value before the recording material is placed on the stacking unit. A booklet production device characterized by:

2. The booklet production device according to claim 1, The control means estimates the temperature of the pressure member based on the correlation between a predetermined parameter and the temperature of the pressure member, and determines that the predetermined condition is satisfied when the estimated temperature is equal to or lower than the threshold value. A booklet production device characterized by:

3. The booklet production device according to claim 1, The control means determines whether preheating is necessary based on the association between a predetermined parameter and the necessity of preheating, and when it is determined that preheating is necessary, determines that the predetermined condition is satisfied. A booklet production device characterized by:

4. The booklet producing apparatus according to claim 2 or 3, The predetermined parameters include at least one of the environmental temperature of the booklet producing device, the number of sheets and copies of the last booklet produced, the time elapsed since the completion of the last booklet production, the type of recording material used for the booklet, the number of sheets of recording material to be thermocompressed by the thermocompression bonding means per one time, the number of sheets of recording material for the booklet to be produced, and the number of copies of the booklet to be produced. A booklet production device characterized by:

5. The booklet production device according to claim 1, Further, a measuring means for measuring the temperature of the pressure member is provided, The control means acquires the temperature of the pressure member by the measurement means, and determines that the predetermined condition is satisfied when the temperature of the pressure member is equal to or lower than the threshold value based on the acquired temperature. A booklet production device characterized by:

6. The booklet producing apparatus according to claim 2 or 5, The control means changes the time or temperature or both of the preheating time and the temperature depending on the temperature of the pressure member. A booklet production device characterized by:

7. The booklet production device according to claim 1, The pressure applied to the pressure member by the thermocompression bonding means during the preheating is smaller than the pressure applied to the pressure member by the thermocompression bonding means during the thermocompression bonding of the recording material. A booklet production device characterized by:

8. The booklet production device according to claim 1, The pressure member can be moved in the longitudinal direction by the control means, and the pressure member further includes an alignment reference member for determining the position of the pressure member in the longitudinal direction of the recording material placed on the stacking section, When the size of the booklet to be produced is smaller than the maximum size of the booklet that can be produced, the control means moves the position of the alignment reference member to perform the preheating and the thermocompression bonding. A booklet production device characterized by:

9. The booklet producing apparatus according to claim 8, The position of the alignment reference member is changed for each thermocompression bonding. A booklet production device characterized by:

10. The booklet producing apparatus according to claim 8, The position of the alignment reference member is changed for each booklet. A booklet production device characterized by:

11. The booklet producing apparatus according to claim 8, The recording medium substitute member is provided on the side of the alignment reference member opposite to the side on which the recording medium is aligned. A booklet production device characterized by:

12. The booklet production device according to claim 1, an alignment reference member that can be moved in the longitudinal direction of the pressure member by the control means and that determines the position of the pressure member in the longitudinal direction of the recording material placed on the stacking section; a recording material substitute member provided on the side of the alignment reference member opposite to the side on which the recording material is aligned, When the size of the booklet to be produced is smaller than the maximum size of the booklet that can be produced, the control means performs the preheating and the thermocompression bonding by moving the position of the alignment reference member so that the side of the booklet to be produced that faces the alignment reference member is aligned with the corresponding side of the booklet of the maximum size. A booklet production device characterized by:

13. The booklet production device according to claim 1, The adhesive is a toner containing a thermoplastic resin. A booklet production device characterized by:

14. an image forming apparatus for forming an image including the adhesive image using toner containing the thermoplastic resin; and a booklet producing apparatus according to claim 13, which receives the recording material on which the adhesive image has been formed in a predetermined portion from the image forming apparatus and produces a booklet. A booklet production system characterized by:

15. A control method for a booklet producing apparatus that produces a booklet by thermocompression bonding a recording material on which an adhesive image made of a thermoplastic adhesive is formed in a predetermined portion, the booklet producing apparatus having a thermocompression bonding means, a pressure member made of an elastic body that is arranged in a position facing the portion that is thermocompression bonded by the thermocompression bonding means, and a control means that controls the thermocompression bonding process by the thermocompression bonding means, the control method comprising: placing the recording materials in a stack on a stacking section; the control means causes a thermocompression bonding means to thermocompress the predetermined portion of the recording material placed on the stacking section; the control means controls the thermocompression bonding means to preheat the pressure member when a predetermined condition is satisfied that the temperature of the pressure member is equal to or lower than a threshold value before the recording material is placed on the stacking portion. A control method comprising:

16. A program for causing a computer to execute the control method according to claim 15.

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