Booklet producing device and image forming system

Abstract

To provide a booklet producing device and an image forming system that suppress plastic deformation of a pressure plate in a heating and pressurizing unit that addresses a plurality of sheet sizes and maintain good adhesiveness of the booklet.SOLUTION: Control means controls at least one of a predetermined temperature and pressure to be lower when heating and pressurizing a sheet of the smallest size than when heating and pressurizing a sheet of the largest size.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a booklet creating device that creates a booklet by adhering a plurality of sheets, and an image forming system having the booklet creating device.

Background Art

[0002] A method is known in which a sheet bundle composed of a plurality of sheets that have undergone image forming processing by an image forming device such as a printer or a copier as in Patent Document 1 is adhered to each other by remelting an adhesive toner by a booklet creating device to create a booklet. A heating and pressurizing unit that heats and pressurizes a sheet by a pressurizing unit in contact with a heating body as in Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When an image forming device and a booklet creating device can support a plurality of sheet sizes, the thermocompression bonding means of the booklet creating device needs to be configured to be able to heat and pressurize the largest sheet size (large-size paper). In a heating and pressurizing unit that makes the longitudinal pressure distribution uniform during pressurization of large-size paper, when pressurizing the smallest sheet size (small-size paper), the pressure concentrates at the ends of the small-size paper. Then, there is a concern that at the ends of the small-size paper where the pressure concentrates, the pressurizing part undergoes plastic deformation and a gap is formed between the pressurizing part and the heating body.

[0005] As a result, heat from the heating body is less likely to be transmitted to the pressure plate at the location with the gap, and the amount of heat applied to the adhesive toner decreases at that location, which may impair the adhesiveness of the booklet.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a booklet manufacturing apparatus and an image forming system that suppress plastic deformation of a pressure plate in a heating and pressurizing unit corresponding to a plurality of sheet sizes and maintain good adhesiveness of a booklet.

Means for Solving the Problems

[0007] Means for solving the above problems are as follows. A heating and pressurizing unit that heats and pressurizes an adhesive layer in a state where a plurality of sheets having an adhesive layer formed thereon are stacked, the heating and pressurizing unit including a pressure plate that contacts and pressurizes the sheets, a heating body that heats the pressure plate at a predetermined temperature, a receiving member that faces the pressure plate, and a pressurizing mechanism that applies pressure to the sheets sandwiched between the pressure plate and the receiving member; and a control means for controlling the predetermined temperature and the pressure. The booklet manufacturing apparatus sandwiches a plurality of sheets having an adhesive layer formed therebetween between the pressure plate and the receiving member and heats and pressurizes the adhesive layer formed on the sheets to manufacture a booklet. The control means controls at least one of the predetermined temperature and the pressure to be lower when heating and pressurizing the smallest-size sheet than when heating and pressurizing the largest-size sheet.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a booklet manufacturing apparatus and an image forming system that suppress plastic deformation of a pressure plate in a heating and pressurizing unit corresponding to a plurality of sheet sizes and maintain good adhesiveness of a booklet.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present invention, the "image forming apparatus" broadly includes apparatuses that form (record) images on a recording material (recording medium), such as a single - function printer, a copier, a multifunction machine, a commercial printer, etc. Also, a system in which an image forming apparatus and a booklet manufacturing apparatus that adheres a plurality of recording materials to produce a booklet are connected is called an image forming system.

Examples

[0011] An image forming system having an image forming apparatus and a booklet making apparatus according to the present invention will be described with reference to FIGS. 1 to 10. The present invention is not limited by the following embodiments, and it is possible to replace it with other configurations within the scope of the idea of the present invention. The image forming apparatus and the booklet making apparatus of this embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing a cross section of an image forming apparatus 101 and a booklet making apparatus 106 according to Embodiment 1. The image forming apparatus 101 and the booklet making apparatus 106 are combined to form an image forming system 100. Note that the image forming system 100 may include a form in which a part or all of the booklet making function is incorporated in the image forming apparatus 101.

[0012] In the image forming system 100 of this embodiment, an image is formed on a sheet S one by one by the image forming apparatus 101, and a plurality of sheets S are thermocompression bonded in the booklet making apparatus 106, so that a booklet in which printing and bookbinding are performed by one apparatus can be created. As the sheet S, various sheet materials having different sizes and materials can be used, such as paper such as plain paper or thick paper, a sheet material having a surface treatment such as coated paper, a plastic film, a cloth, or a sheet material having a special shape such as an envelope or index paper. Here, the sheet conveyance speed in this embodiment is 300 mm / sec. Also, the maximum basis weight of the sheet S is 90 g / m 2 is.

[0013] (Image forming apparatus main body) The image forming apparatus 101 is an electrophotographic apparatus including a housing 101A and an electrophotographic image forming unit 101B housed inside the housing 101A. The image forming unit 101B is an intermediate transfer type electrophotographic unit, and includes a primary transfer roller 107, an intermediate transfer belt 108 as an intermediate transfer member, and a process cartridge 195 disposed along the intermediate transfer belt 108. The process cartridge 195 includes a photosensitive drum 102 as an image carrier, a charging device 103 as charging means, and a developing unit 105 as developing means. Further, the image forming unit 101B includes a scanner unit 104 as exposure means. The developing unit 105 includes a developing roller 105a as developing means and a toner container 105b for storing toner (developer). The developing roller 105a is rotatably held by the toner container 105b.

[0014] The process cartridge 195 is detachable from the housing 101A. A toner cartridge 196 containing toner for supplying the developing unit 105 is detachably mounted on the image forming apparatus 101. The "housing 101A" of the image forming apparatus 101 refers to the portion excluding the process cartridge 195 and the toner cartridge 196 from the image forming apparatus 101. The housing 101A includes a frame member such as a metal frame constituting the frame of the image forming apparatus 101 and members fixed to the frame, and forms a mounting space for mounting the process cartridge 195 and the toner cartridge 196. The process cartridge 195 creates a toner image for recording an image on the sheet S using toner, and also creates an adhesive toner image as a powder adhesive for adhering the sheets S to each other. The image forming apparatus 101 of the present embodiment has a monochrome printer configuration for recording monochrome images. The image forming apparatus 101 uses black toner not only for image recording but also as an adhesive toner (adhesive). Here, in the present embodiment, only one cartridge is used and the monochrome printer configuration using a toner for both recording and adhesion has been described, but it is not limited thereto, and a toner dedicated for adhesion may be used. Further, a configuration in which a plurality of cartridges can be mounted may be adopted so that multi-color image formation and binding of booklets can be performed. At that time, the adhesive toner does not have to be black toner, and may be a dedicated adhesive toner different from the toner used for image recording.

[0015] The toner cartridge 196 and the process cartridge 195 mounted on the housing 101A are connected via a toner conveyance pipe 197. The toner cartridge 196 can supply toner to the developing unit 105 via the toner conveyance pipe 197. Below the scanner unit 104, a cassette 113a (also called a sheet tray or a storage) as a storage unit for storing the sheet S used for image formation is detachably mounted on the housing 101A. Further, one or more optional sheet feeding devices 130 including an additional cassette 113b may be connected below the housing 101A.

[0016] The intermediate transfer belt 108 is an endless belt that is movable (circumferentially movable) and is stretched around a driving roller 109a, a tensioning roller 109b, and a tension roller 110 that rotate about axes parallel to each other. The intermediate transfer belt 108 is moved (circumferentially moved, conveyed) counterclockwise in the figure by the rotation of the driving roller 109a. On the inner peripheral side of the intermediate transfer belt 108, a primary transfer roller 107 as a primary transfer member is disposed at a position facing the photosensitive drum 102 via the intermediate transfer belt 108. On the outer peripheral side of the intermediate transfer belt 108 and at a position facing the driving roller 109a via the intermediate transfer belt 108, a secondary transfer roller 111 as a secondary transfer member is disposed. A nip portion between the intermediate transfer belt 108 and the secondary transfer roller 111 forms a secondary transfer portion as a transfer portion. The intermediate transfer belt 108, the primary transfer roller 107, and the secondary transfer roller 111 are transfer means for transferring the toner image formed on the photosensitive drum 102, which is an image carrier, onto the sheet S. At a position facing the tension roller 110 via the intermediate transfer belt 108, a belt cleaner 112 as cleaning means for cleaning the intermediate transfer belt 108 is provided. The belt cleaner 112 includes a cleaning member 112a such as a blade or a brush that is disposed in contact with the intermediate transfer belt 108, and a waste toner container 198 as a collection container. The belt cleaner 112 removes deposits such as residual transferred toner from the intermediate transfer belt 108 by the cleaning member 112a and collects it in the waste toner container 198. Above the secondary transfer portion in the housing 101A, a fixing device 118 as fixing means is disposed. The fixing device 118 has a configuration of a heat fixing method that fixes the toner image by heating. The fixing device 118 includes a pair of rotating bodies (for example, a pair of rollers including a fixing roller and a pressure roller) that sandwich and convey the sheet S, and a heat source (for example, a halogen lamp or an induction heating mechanism) that heats the toner image on the sheet S via the fixing roller.

[0017] (Image forming operation) When the image forming apparatus 101 executes an image forming operation, a sheet S is fed from the cassette 113 at the lower part of the housing 101A or the cassette 113 of the sheet feeding device 130 by a feeding roller 114 as a feeding means. The separation roller pair 115 conveys the fed sheet S while separating it one by one. This sheet S is conveyed by a pulling roller 116 toward the registration roller pair 117, and the skew of the sheet S is corrected when the leading edge of the sheet S hits the nip portion of the stopped registration roller pair 117. The registration roller pair 117 feeds the sheet S into the secondary transfer portion at a timing synchronized with the progress of the toner image creation process by the image forming unit 101B.

[0018] On the other hand, in the image forming unit 101B, the photosensitive drum 102 and the intermediate transfer belt 108 rotate. The charging device 103 uniformly charges the surface of the photosensitive drum 102. The scanner unit 104 irradiates the photosensitive drum 102 with a laser beam to write an electrostatic latent image based on the image information representing the image to be recorded on the sheet S. This electrostatic latent image is developed (visualized) as a black toner image by developing with the black toner by the developing unit 105. Here, when thermocompression bonding described later is performed by the booklet making device 106, the scanner unit 104 irradiates the photosensitive drum 102 with a laser beam to write an electrostatic latent image based on the information indicating the bonding position of the sheet S. This electrostatic latent image is developed by the developing unit 105 using black toner, so that an adhesive toner image is formed in the area on the photosensitive drum 102 corresponding to the bonding position on the sheet S.

[0019] The toner image formed on the photosensitive drum 102 is transferred (primary transfer) to the intermediate transfer belt 108 by the primary transfer roller 107, and is conveyed toward the secondary transfer section as the intermediate transfer belt 108 rotates. Then, in the secondary transfer section, when a voltage is applied to the secondary transfer roller 111, the toner image is transferred (secondary transfer) to the sheet S fed from the registration roller pair 117. The sheet S that has passed through the secondary transfer section is sent to the fixing device 118, and the toner image is heated while passing through the nip section of the fixing roller and the pressure roller, causing the toner to soften and then adhere, thereby fixing the image on the sheet S.

[0020] The sheet S that has passed through the fixing device 118 has its conveyance path switched by the switching section 119. In the case of single-sided printing, the sheet S is guided to the discharge path 190 by the switching section 119 and discharged from the housing 101A by the discharge roller pair 191. In this embodiment, the image forming apparatus 101 is connected to the booklet making apparatus 106 via the relay conveyance unit 192. The sheet S discharged from the discharge roller pair 191 is delivered to the booklet making apparatus 106 via the conveyance roller pairs 193 and 194 of the relay conveyance unit 192. Also, when the relay conveyance unit 192 and the booklet making apparatus 106 are not connected, the discharge roller pair 191 discharges the sheet S as a finished product to the stacking tray 135 provided at the upper part of the housing 101A. In the case of double-sided printing, the sheet S on which an image has been formed on the first side is guided to the reversing roller pair 199 by the switching section 119. Then, after the sheet S is reversely conveyed (switchback conveyance) by the reversing roller pair 199, it is conveyed toward the registration roller pair 117 via the double-sided conveyance path 218. The sheet S passes through the secondary transfer section and the fixing device 118 to form an image on the second side opposite to the first side, and then is discharged from the housing 101A by the discharge roller pair 191.

[0021] Fig. 2(a) is a schematic diagram showing an example of a toner image formed on the sheet S. On the illustrated sheet S, a toner image (recording toner image) 38 for recording images such as text, graphics, and photographs, and a toner image (adhesive toner image) 39 for adhering the sheets to each other are formed. In this embodiment, the width Tw of the adhesive toner image 39 is 4.0 mm, and the toner amount (loading amount) per unit area is 0.40 mg / cm 2 is set. The toner amount was measured in the unfixed state after secondary transfer and before the fixing process. The position, shape, size, etc. of the adhesive toner image 39 can be changed according to the configuration of the heat and pressure unit 167 described later and the size of the sheet S. In addition, when the image forming apparatus 101 creates a booklet, in this embodiment, the adhesive toner image 39 is basically formed on both sides of the sheet S (excluding the front and back covers of the booklet). Fig. 2(b) shows the image layout of 8 surfaces (4 sheets × 2 sides) when producing a double-sided 4-sheet booklet using the sheet S of this embodiment. In the booklet of this embodiment, the adhesive toner image 39 is formed on 6 surfaces excluding the front cover (the front surface of the first sheet) and the back cover (the back surface of the fourth sheet). Here, although this embodiment assumes double-sided printing, it is not limited thereto, and for example, the adhesive toner image 39 may be formed only on the surface of the sheet.

[0022] <Configuration, manufacturing method, and measurement method of toner> Next, the composition of the toner mainly composed of the thermoplastic resin used in this example will be described. Examples of the thermoplastic resin include polyester resin, vinyl resin, acrylic resin, styrene-acrylic resin, polyethylene, polypropylene, polyolefin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, and the like. A plurality of these resins may be contained. The toner preferably further contains wax. As the wax, known waxes such as ester waxes which are esters of alcohol and acid, and hydrocarbon waxes such as paraffin wax can be used. The toner contains a black colorant and may contain a magnetic body, a charge control agent, wax, and an external additive. In order to form an adhesive portion of the toner on the sheet using the electrophotographic method, the weight average particle diameter of the toner is preferably 5.0 μm or more and 30 μm or less, and more preferably 6.0 μm or more and 20 μm or less.

[0023] A manufacturing example of the toner will be described. · Styrene 75.0 parts · N-Butyl acrylate 25.0 parts · Polyester resin 4.0 parts (Polyester resin with weight average molecular weight (Mw) of 20,000, glass transition temperature (Tg) of 75 °C, and acid value of 8.2 mgKOH / g) · Ethylene glycol distearate 14.0 parts (Ester wax obtained by esterifying ethylene glycol and stearic acid) · Hydrocarbon wax (HNP-9, manufactured by Nippon Seiro Co., Ltd.) 2.0 parts · Divinylbenzene 0.5 part The mixture obtained by mixing the above materials was kept at 60 °C and stirred at 500 rpm using a T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to be uniformly dissolved, and a polymerizable monomer composition was prepared. On the other hand, 0.10 mol / L-Na 3 PO 4850.0 parts of an aqueous solution and 8.0 parts of 10% hydrochloric acid were added, the rotation speed was adjusted to 15,000 rpm, and the mixture was heated to 70 °C. To this, 127.5 parts of a 1.0 mol / L-CaCl 2 aqueous solution was added to prepare an aqueous medium containing a calcium phosphate compound. After the above polymerizable monomer composition was introduced into the aqueous medium, 7.0 parts of t-butyl peroxy pivalate, which is a polymerization initiator, was added, and granulation was carried out for 10 minutes while maintaining a rotation speed of 15,000 revolutions per minute. Then, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and the reaction was carried out at 70 °C for 5 hours while refluxing, then the liquid temperature was set to 85 °C, and the reaction was further carried out for 2 hours. After the polymerization reaction was completed, the obtained slurry was cooled. Further, hydrochloric acid was added to the slurry to adjust the pH to 1.4, and the slurry was stirred for 1 hour to dissolve the calcium phosphate salt. Then, it was washed with three times the amount of water of the slurry, filtered, dried, and classified to obtain toner particles. Then, with respect to 100.0 parts of the toner particles, 2.0 parts of silica fine particles (number average particle diameter of primary particles: 10 nm, BET specific surface area: 170 m 2 / g) hydrophobized using dimethyl silicone oil (20% by mass) as an external additive were added, and mixing was carried out at 3,000 rpm for 15 minutes using a Mitsui Henschel mixer (manufactured by Mitsui Miike Chemical Machinery Co., Ltd.) to obtain toner. The weight average particle diameter of the obtained toner was 7.0 μm.

[0024] A method for measuring the storage elastic modulus as a viscoelastic property of the toner will be described. The storage elastic modulus of the toner is measured using a dynamic viscoelasticity measuring device (rheometer) ARES (manufactured by Rheometrics Scientific). Measuring jig: Use a parallel plate of serrated type with a diameter of 7.9 mm.

[0025] Measurement sample: Using a compression molding machine, a 0.1 g test piece is molded into a cylindrical sample with a diameter of 8 mm and a height of 2 mm (maintaining 15 kN for 1 minute at room temperature). The compression molding machine used is a 100 kN press NT-100H manufactured by NPa Systems.

[0026] The temperature of the serrated parallel plates is thermally controlled to 120 °C, the cylindrical sample is heated and melted, and the saw teeth are made to bite in. A load is applied vertically so that the axial force does not exceed 30 (gf) (0.294 N), and it is fixed to the serrated parallel plates. At this time, a steel belt may be used so that the diameter of the sample becomes the same as the diameter of the parallel plates. The serrated parallel plates and the cylindrical sample are gradually cooled over 1 hour until the measurement start temperature of 30.00 °C.

[0027] Measurement frequency: 6.28 radians / second Setting of measurement strain: Set the initial value to 0.1%, and perform the measurement in the automatic measurement mode.

[0028] Elongation correction of sample: Adjust in the automatic measurement mode.

[0029] Measurement temperature: The temperature is raised from 30 °C to 140 °C at a rate of 2 °C per minute.

[0030] Measurement interval: Every 30 seconds, that is, viscoelastic data is measured every 1 °C.

[0031] Figure 3 shows the measurement results of the storage modulus of the toner. As its representative values, the storage modulus Ga'(100 °C) = 2.2×10 4 Pa at 100 °C and the storage modulus Ga'(80 °C) = 3.2×10 5 Pa were obtained. The reason for selecting the value at 100 °C is that the toner on the sheet S during fixing is heated to about 100 °C while passing through the fixing nip portion 6N of the fixing device 118. Also, the reason for selecting the value at 80 °C is that during the adhesion process of the sheet bundle by the heating and pressing unit 167, the lowest toner temperature when adhering a maximum of 5 sheets at a time is about 80 °C.

[0032] (Pamphlet production device) In FIG. 1, the booklet manufacturing apparatus 106 includes a buffer unit 120 as buffer means for stacking a plurality of sheets S, an alignment unit 156 as alignment means for aligning the plurality of sheets S, and a heating and pressurizing unit 167 for thermocompression bonding the sheets S to each other. The heating and pressurizing unit 167 is an example of a sheet bonding apparatus (bonding unit, bonding means, thermocompression bonding means, laminating processing unit) for bonding sheets to each other. Further, the booklet manufacturing apparatus 106 includes a discharge upper tray 125 and a discharge lower tray 137 that are each vertically movable as discharge destinations for discharging the products of the image forming system 100.

[0033] The booklet manufacturing apparatus 106 is a booklet manufacturing apparatus that receives a plurality of sheets S on which images are formed one by one by the image forming apparatus 101, performs an adhesion process (thermocompression bonding), and discharges them as a sheet bundle (booklet). The buffer unit 120, the alignment unit 156, and the heating and pressurizing unit 167 will be described in detail later. Further, the booklet manufacturing apparatus 106 can also discharge the sheet S on which an image is formed by the image forming apparatus 101 to the discharge upper tray 125 or the discharge lower tray 137 without performing any processing.

[0034] (Buffer unit) The buffer unit 120 will be described with reference to FIG. 4. FIG. 4 is an enlarged cross-sectional view of the buffer unit 120. The buffer unit 120 includes an inlet roller pair 121, a pre-buffer roller pair 122, a backflow prevention valve 123, a reversing roller pair 124, and an inner discharge roller pair 126. Further, the buffer unit 120 includes a separation mechanism including a plunger solenoid 145 or the like for opening and closing (contacting and separating) the reversing roller pair 124 and an inlet sensor 127 for detecting a sheet. The inlet roller pair 121, the pre-buffer roller pair 122, the reversing roller pair 124, and the inner discharge roller pair 126 are each a roller pair that sandwiches and conveys a sheet. The inlet roller pair 121 and the pre-buffer roller pair 122 are arranged in a conveyance path (inlet path) for the booklet manufacturing apparatus 106 to receive the sheet S. The reversing roller pair 124 is arranged in a conveyance path 139 (see FIG. 1) that communicates with the discharge upper tray 125. The inner discharge roller pair 126 is arranged in a conveyance path (inner discharge path 166, see FIG. 1) from the reversing roller pair 124 toward the heat and pressure applying unit 167. Note that the booklet manufacturing apparatus 106 includes a discharge conveyance path 138 (see FIG. 1) that leads from the heat and pressure applying unit 167 to the discharge lower tray 137. The inlet path is formed by an inlet upper guide 140 and an inlet lower guide 141. The first discharge path is formed by a reversing upper guide 142 and a reversing lower guide 143. The inner discharge path 166 is formed by an inner discharge upper guide 146 and an inner discharge lower guide 147. The inlet sensor 127 is arranged to detect the sheet received by the inlet roller pair 121. The inlet sensor 127 can use, for example, a reflective photosensor that irradiates infrared light into the inlet path through an opening provided in the inlet upper guide 140 and determines the presence or absence of the sheet S by detecting the reflected light from the sheet. The inlet lower guide 141 may be provided with a hole having a diameter equal to or larger than the spot diameter of the infrared light emitted by the inlet sensor 127 so that the infrared light is not reflected when the sheet is not passing through the inlet path.

[0035] The backflow prevention valve 123 is disposed downstream of the buffer pre-roller pair 122 in the sheet conveyance direction in the inlet path. The backflow prevention valve 123 is rotatably disposed about the rotation axis 123a with respect to the inner discharge upper guide 146. The backflow prevention valve 123 is movable between a first position that prevents the movement (backflow) of the sheet from the first discharge path to the inlet path and a second position that allows the movement of the sheet from the inlet path to the first discharge path. The backflow prevention valve 123 is biased in the C2 direction from the second position toward the first position by a spring (not shown). The backflow prevention valve 123 is configured to move in the C1 direction from the first position toward the second position when pressurized by the sheet and return to the first position when the sheet passes through. When viewed in the axial direction of the rotation axis of the backflow prevention valve 123, the tip of the backflow prevention valve 123 in the first position overlaps with the inversion upper guide 142. Further, the tip of the backflow prevention valve 123 is formed in a comb shape so as to enable overlap with the inversion upper guide 142. Also, when viewed in the axial direction of the rotation axis of the backflow prevention valve 123, a space through which the sheet can pass is formed between the backflow prevention valve 123 in the second position and the inversion upper guide 142.

[0036] The reversing roller pair 124 is composed of a reversing upper roller 124a and a reversing lower roller 124b, and drive is supplied to both rollers. The rotation of the reversing upper roller 124a and the reversing lower roller 124b is configured to be always synchronized. Further, a separation lever 144 is connected to the reversing upper roller 124a. The separation lever 144 is rotatably supported about a lever fulcrum axis 144a with respect to the reversing upper guide 142. Also, the separation lever 144 is rotatably connected to the plunger solenoid 145 at a solenoid connection axis 144b. When an electric current flows through the plunger solenoid 145, the core moves in the D1 direction in the figure, so the separation lever 144 rotates in the E1 direction in the figure. In this case, the reversing roller pair 124 is in a separated state where the reversing upper roller 124a and the reversing lower roller 124b are separated (a state where the nip portion is opened). Also, when the electric current flowing through the plunger solenoid 145 stops, due to the biasing force of the pressurizing spring 148, the reversing upper roller 124a moves in the E2 direction, and the core of the plunger solenoid 145 moves in the D2 direction. In this case, the reversing roller pair 124 is in a contacting state where the reversing upper roller 124a and the reversing lower roller 124b are in contact (a state where the nip portion is formed).

[0037] (Buffer operation) Next, the operation of the buffer unit 120 will be described. FIGS. 5(a) to 5(h) are diagrams showing the operation of the buffer unit 120. Hereinafter, it is assumed that sheets are conveyed from the image forming apparatus 101 to the booklet manufacturing apparatus 106 in the order of sheet S1, sheet S2, and sheet S3. As will be described below, the buffer unit 120 performs an operation (hereinafter referred to as a buffer operation) of stacking a newly conveyed sheet on the sheet (bundle) while reciprocating the sheet (bundle) between the reversing roller pair 124 and the inner discharge roller pair 126. Also, the booklet manufacturing apparatus 106 accelerates the conveyance speed of the sheet inside the apparatus. Hereinafter, the conveyance speed of the sheet by the inlet roller pair 121 is set as V1, and the conveyance speed of the sheet (after acceleration) by the pre-buffer roller pair 122, the reversing roller pair 124, and the inner discharge roller pair 126 is set as V2.

[0038] As shown in Fig. 5(a), when the rear end of the preceding sheet S1 passes through the entrance sensor 127, the conveyance speed of the sheet S1 by the pre-buffer roller pair 122 and the inversion roller pair 124 is accelerated from V1 to V2. As a result, since the conveyance interval between the sheet S1 and the subsequent sheet S2 widens, the inversion roller pair 124 can perform the switchback of the sheet S1 without the sheet S2 colliding with the sheet S1. As shown in Fig. 5(b), when the rear end of the sheet S1 passes through the backflow prevention valve 123, the conveyance by the inversion roller pair 124 is temporarily stopped. As shown in Fig. 5(c), the inversion roller pair 124 changes the rotation direction and conveys the sheet S1 toward the inner discharge roller pair 126. As shown in Fig. 5(d), at the position where the leading end of the sheet S1 has passed through the inner discharge roller pair 126 and has been conveyed by a predetermined amount, the conveyance of the sheet S1 by the inversion roller pair 124 and the inner discharge roller pair 126 stops. Further, the upper inversion roller 124a moves in the E1 direction after the sheet S1 is clamped by the inner discharge roller pair 126. As a result, the inversion roller pair 124 is separated, and a state becomes possible to receive the subsequent sheet S2. After the upper inversion roller 124a is separated, the subsequent sheet S2 is conveyed to the inversion roller pair 124. As shown in Fig. 5(e), when the rear end of the subsequent sheet S2 passes through the entrance sensor 127, similar to the sheet S1, the conveyance speed of the sheet S2 is accelerated from V1 to V2. At the timing when the sheet S2 reaches a predetermined target position, the inner discharge roller pair 126 conveys the sheet S1 toward the inversion roller pair 124. At the timing when the speeds of the sheet S1 and the sheet S2 become substantially equal (the speed difference is substantially 0), the upper inversion roller 124a moves in the E2 direction, and the inversion roller pair 124 comes into contact. At the time of contact, the inversion roller pair 124 clamps the sheets S1 and S2 simultaneously. Further, the inversion roller pair 124 is speed-adjusted to be equal to the conveyance speed of the sheets S1 and S2 until it switches from the separated state to the contacting state. As shown in Fig. 5(f), after the rear end of the sheet S2 passes through the backflow prevention valve 123, the inversion roller pair 124 stops temporarily again. Here, the aforementioned target position is set such that the sheet S1 protrudes by a predetermined amount k from the sheet S2 in the conveyance direction from the inner discharge roller pair 126 toward the alignment unit 156.In other words, among the stack of sheets stacked in the buffer unit 120, the sheet S1 that is on the lower side in the alignment unit 156 protrudes by a predetermined amount k on the downstream side in the conveyance direction toward the alignment unit 156 compared to the sheet S2 that is on the upper side in the alignment unit 156. As shown in FIG. 5(g), the inversion roller pair 124 changes the rotation direction and conveys the sheets S1 and S2 toward the inner discharge roller pair 126. The sheets S1 and S2 are conveyed toward the alignment unit 156 by the inner discharge roller pair 126. The inversion upper roller 124a moves in the E1 direction after the sheet S1 is sandwiched by the inner discharge roller pair 126. As a result, the inversion roller pair 124 is separated, and a state is achieved in which the subsequent sheet S3 can be received. As shown in FIG. 5(h), after the rear end of the sheet S2 passes through the inversion roller pair 124, the inversion upper roller 124a moves in the E2 direction. As a result, the inversion roller pair 124 comes into contact and sandwiches and conveys the sheet S3.

[0039] By repeating the above buffer operation, the buffer unit 120 can send the sheets to the alignment unit 156 in a state where a predetermined number of sheets are stacked. Also, although the buffer operation of stacking two sheets has been described as an example here, by temporarily stopping the conveyance of the sheets S1 and S2 from the state of FIG. 5(g) and then conveying them in the reverse direction, the sheet S3 can be further stacked on the sheets S1 and S2. That is, the buffer unit 120 can create a stack of sheets with three or more (for example, five) sheets stacked by repeating the operations of FIGS. 5(d) to 5(g). Note that the target position for overlapping the sheets is determined based on the timing when the entrance sensor 127 detects the trailing edge of the sheet. Therefore, even if the conveyance direction length of the sheet changes, the buffer operation of this embodiment can overlap the sheets with each other shifted by a predetermined amount. The stack of sheets stacked in the buffer unit 120 is conveyed from the inner discharge roller pair 126 via the intermediate conveyance roller pair 128 to the kick-out roller pair 129 from the carry-in conveyance path 165 as shown in FIG. 1. Then, by the kick-out roller pair 129, the stack of sheets is conveyed to the alignment unit 156 (intermediate stacking unit, processing stage) composed of the intermediate upper guide 151, the intermediate lower guide 152, and the like. Also, downstream of the kick-out roller pair 129, a bundle pressing flag 150 is arranged to suppress the lifting of the trailing edge of the already stacked sheet so that the trailing edge of the sheet already loaded in the alignment unit 156 does not interfere with the leading edge of the subsequent sheet conveyed to the alignment unit 156.

[0040] (Alignment unit configuration) Next, the configuration of the alignment unit 156 will be described with reference to FIGS. 6 and 7. FIG. 6 is a cross-sectional view of the alignment unit 156. FIG. 7 is an exploded view showing the components of the movable unit 159. In the following description and each drawing, the direction in which the pressing member of the heating and pressing unit 167 moves with respect to the receiving member to press the sheet bundle is defined as the Z direction. The Z direction is the height direction (thickness direction) of the sheet bundle loaded on the alignment unit 156. Also, in the virtual plane orthogonal to the Z direction, the directions orthogonal to each other are defined as the X direction and the Y direction. As necessary, the directions of the arrows X, Y, and Z shown in each drawing are represented as the +X side, +Y side, and +Z side, respectively, and the opposite sides are represented as the -X side, -Y side, and -Z side, respectively. In this embodiment, the Y direction is substantially parallel to the conveyance direction in which the sheet is conveyed to the alignment unit 156 by the kick-out roller pair 129. Also, in this embodiment, the X direction is the sheet width direction orthogonal to the conveyance direction. In the following description, the Y direction may be referred to as the "longitudinal direction", and the X direction may be referred to as the "width direction" or "lateral direction".

[0041] The alignment unit 156 includes an intermediate lower guide 152 as a loading part for supporting the sheet bundle, an intermediate upper guide 151 facing the intermediate lower guide 152, and a movable unit 159 including a vertical alignment plate 154 and a vertical alignment roller 153. As shown in FIG. 7, the vertical alignment plate 154 has sheet contact portions 154a, 154b, and 154c arranged in a plurality in the sheet width direction. The sheet contact portions 154a, 154b, and 154c serve as reference positions for sheet alignment in the sheet conveyance direction (Y direction). The vertical alignment roller 153 is rotatably held by a roller holder 160. The roller holder 160 is swingable by the driving force of a solenoid 163. By the swinging of the roller holder 160, the vertical alignment roller 153 can move between a position where it contacts the sheet S on the intermediate lower guide 152 and conveys the sheet and a position where it retracts upward from the sheet S. Also, a drive motor 161 is attached to the movable unit 159. When the driving force of the drive motor 161 is transmitted through a gear train 162, the vertical alignment roller 153 rotates. The movable unit 159 is movable as an integral unit with respect to the intermediate lower guide 152 in the sheet conveyance direction (Y direction).

[0042] As shown in FIG. 6, the alignment unit 156 includes a width alignment member 155, a drive motor 158, and width alignment plates 172a and 172b (FIG. 8(a)). The width alignment member 155 is movable in the sheet width direction (X direction) by the driving force of the drive motor 158. The width alignment member 155 includes a plurality of sheet pressing portions 155a, 155b, and 155c arranged side by side in the sheet conveyance direction. As shown in FIG. 8(a), the width alignment plates 172a and 172b are composed of a plurality of plate-like members (sheet contact portions) arranged side by side in the sheet conveyance direction. The width alignment plates 172a and 172b serve as reference positions for sheet alignment in the sheet width direction (X direction).

[0043] (Alignment Unit Operation) The operation of the alignment unit 156 will be described with reference to FIGS. 8(a) to 8(f). FIGS. 8(a) to 8(f) are schematic views of the alignment unit 156 as seen from the upper side in the Z direction. Illustrations of the drive around the intermediate upper guide 151 and the heating and pressing unit 167 are omitted. When aligning a sheet bundle in the alignment unit 156, the movable unit 159 is positioned in a predetermined standby position in the sheet conveyance direction (Y direction) according to the sheet size. The standby position is a position where the distance in the Y direction from the nip position of the kick-out roller pair 129 to the sheet contact portions 154a to 154c of the longitudinal alignment plate 154 is slightly longer than the length of the sheet. Hereinafter, the operation of the alignment unit 156 will be described based on an example when a sheet bundle composed of five sheets S1 to S5 stacked in the buffer unit 120 is conveyed. Note that the number of sheets stacked in the buffer unit 120 can be arbitrarily changed and is not limited to five sheets.

[0044] FIG. 8(a) shows a state where the first sheet S1 and the second sheet S2 are being conveyed toward the alignment portion 156. The movable unit 159 (vertical alignment plate 154 and vertical alignment roller 153) has completed moving to the standby position according to the sheet size. The width alignment member 155 is standing by at a position slightly outside from the side end position of the sheet bundle so as not to interfere with the conveyance of the sheet bundle. FIG. 8(b) shows a state where the rear end of the first sheet S1 has passed through the nip of the kick-out roller pair 129 and the leading end of the sheet S1 has reached the vertical alignment roller 153. The vertical alignment roller 153 has been lowered to the contact position in advance by energizing the solenoid 163 and is rotating by the drive motor 161. The sheet S1 is conveyed in the +Y direction by the vertical alignment roller 153 and abutted against the vertical alignment plate 154, thereby being aligned in the sheet conveyance direction. After that, each time a subsequent sheet S2 to S5 passes through the kick-out roller pair 129, each sheet is conveyed in the +Y direction by the vertical alignment roller 153 and abutted against the vertical alignment plate 154, thereby being aligned in the sheet conveyance direction. FIG. 8(c) shows a state where the five sheets S1 to S5 are respectively abutted against the vertical alignment plate 154 and the alignment in the sheet conveyance direction is completed. In this state, the width alignment member 155 is moved in the sheet width direction (X direction) by the driving force of the drive motor 158 (FIG. 6). The sheets S1 to S5 move toward the width alignment plates 172a and 172b by having one side end pressed by the sheet pressing portions 155a, 155b, and 155c of the width alignment member 155. FIG. 8(d) shows a state where the side ends of the sheets S1 to S5 are respectively abutted against the width alignment plates 172a and 172b. Thereby, the sheets S1 to S5 are aligned in the sheet width direction. After that, thermocompression bonding is performed in a state where a plurality of sheets with an adhesive layer formed thereon are stacked by the heating and pressing unit 167 described later. In this embodiment, thermocompression bonding is performed on the five sheets S1 to S5. Further, when creating a booklet composed of six or more sheets, in parallel with the thermocompression bonding on the sheets S1 to S5, the alignment portion 156 prepares to receive the sheets after the sixth sheet. Specifically, the width alignment member 155 is moved in the retraction direction (-X side). FIG. 8(e) shows the paper position after XY alignment of the sheet S in the A4 size, and FIG. 8(f) shows the paper position after XY alignment of the sheet S in the A5 size.In this embodiment, Y alignment is performed so that one end of the sheet S is aligned with the vertical alignment reference position G of the heating and pressing unit 167 (one-side reference). Here, the heating and pressing unit 167 is a device that performs long-edge binding in the vertical direction with respect to the sheet end. The maximum sheet width (Sa) that the heating and pressing unit 167 can handle is 297 mm, which corresponds to the A4 size (297 mm in length × 210 mm in width). Also, the minimum sheet width (Sb) that the heating and pressing unit 167 can handle is 210 mm, which corresponds to the A5 size (210 mm in length × 149 mm in width). If the applicable sheet width is between A4 as the maximum size and A5 as the minimum size, booklet production is possible. For example, B5 (257 mm in length × 182 mm in width) etc. are also possible.

[0045] (Heating and Pressing Unit) Using FIG. 9, the configuration of the heating and pressurizing unit 167 according to this embodiment will be described. FIG. 9 is a perspective view of the heating and pressurizing unit 167. The heating and pressurizing unit 167 is an example of a sheet bonding device (bonding unit, bonding means, thermocompression bonding means, laminating processing unit) for bonding sheets together. As shown in FIG. 9, the heating and pressurizing unit 167 includes a heating unit 171 as a heating and pressurizing means including a pressure plate 169, a receiving member 180 facing the pressure plate 169 and receiving the pressing force of the heater part, and a drive system including a motor 177. The receiving member 180 is composed of a receiving plate 181 formed of an elastic material, a receiving plate support 182 made of a heat-resistant resin member for supporting the receiving plate 181, and a highly rigid metal receiving-side frame 183 for supporting the receiving plate support 182. The receiving plate 181 uses a silicone rubber sheet as the material, with a plate thickness of 3 mm (thickness in the Z direction) and a rubber hardness of 70° (ISO7619 standard). In this embodiment, a silicone rubber having heat resistance and appropriate elasticity is used, but it is not limited thereto, and materials having necessary heat resistance, elasticity, and corresponding to the applied pressure may be used. The heating unit 171 has a pressure plate 169, a ceramic heater (heating element) 168, and a metal stay 170. The pressure plate 169 is an example of a pressurizing member for pressurizing a stack of sheets to be bonded. The pressure plate 169 is plate-shaped with the Z direction as the thickness direction and elongated in the Y direction. The pressure plate 169 uses an aluminum material (A6063 material). The pressure plate 169 is basically composed of a thickness of 0.8 mm. Also, the length of the pressure plate 169 in the Y direction is 300 mm. Here, the Young's modulus of the aluminum material (A6063) used for the pressure plate 169 is 68 GPa, and the thermal conductivity λ p was 237 W / mK. By using a high thermal conductivity material such as an aluminum material (A6063) for the pressure plate 169 and making the thickness thin, it becomes easy to transfer the heat of the ceramic heater 168, which is the heat source, to the sheet. Table 1 shows the mechanical strength (literature value) of aluminum (A6063 material). The A6063 material has the characteristic that the mechanical strength (tensile strength, yield strength) is likely to decrease in a high temperature region of 150°C or higher.

[0046]

Table 1

[0047] The ceramic heater 168 is an example of a heating means for heating a pressing member. The ceramic heater 168 is a heater substrate on which a pattern of a heating resistor is formed on a ceramic substrate. The ceramic heater 168 is arranged to contact the pressure plate 169. The dimensions of the ceramic heater 168 are a thickness of 1.0 mm, a width of 8.0 mm, and a length of 350 mm, and the thermal conductivity λ h was 22 W / mK. Here, the thermal conductivity λ was measured by a thermal conductivity measuring device (ai-Phase Mobile2, Ai Phases Co., Ltd.). Also, the Young's modulus of the ceramic heater 168 was 370 GPa. The heater support 603 is a member for supporting the ceramic heater 168, and is fixed to the pressure plate 169 and the rigid metal stay 170. Here, the material of the heater support 603 is a heat-resistant resin, and LCP (Liquid Cristal Polymer) was used in this embodiment.

[0048] The metal stay is made of iron with a thickness of 1.8 mm, and its rigidity is further enhanced by bending it into a U shape. A lift plate 172 is fixed to the metal stay 170 of the heating unit 171. The contact portions between the lift plate 172 and the metal stay 170 are 172g and 172h, and the lift plate 172 moves integrally with the heating unit 171. In this embodiment, the aforementioned width alignment plates 172a and 172b are formed integrally with the lift plate 172 by bending a part of the sheet metal member constituting the lift plate 172. Also, since the lift plate 172 has a slight gap with respect to the guide shaft 173 (172i, 172j), when the pressure plate 169 contacts the sheet bundle, as shown by the dotted line M, it can swing in the Y direction and can move somewhat following the sheet surface.

[0049] The heating and pressing unit 167 can thermally bond the sheet bundle loaded on the alignment unit 156 along one side extending in the Y direction by using a pressing plate 169 extending in the Y direction. The alignment unit 156 and the heating and pressing unit 167 of this embodiment can perform so-called long-edge binding, in which a sheet such as A4 size is aligned in a direction where the long side is parallel to the sheet conveyance direction (long-side feeding direction), and thermally bonded in an adhesive region along the long side (Fig. 2(a)). The drive system (pressing mechanism) of the heating and pressing unit 167 includes a motor 177 as a drive source, a gear train 178, a pinion gear 179, and a rack gear 175. The gear train 178, the pinion gear 179, and the rack gear 175 are examples of a drive transmission mechanism that converts the rotation of the motor 177 into the moving direction (Z direction) of the heating unit 171 and transmits it to the heating unit 171.

[0050] The pinion gear 179 is connected to the motor 177 via the gear train 178. The pinion gear 179 meshes with the rack gear 175. The gear train 178, the pinion gear 179, and the rack gear 175 constitute a speed reduction mechanism for obtaining the pressing force required for thermocompression bonding of the sheet bundle. Note that, as the speed reduction mechanism, for example, a worm gear or a planetary gear mechanism may be used. The rack gear 175 is guided by a columnar guide shaft 173 extending in the Z direction and reciprocates in the Z direction. The guide shaft 173 is fixed to the frame of the heating and pressing unit 167. A compression spring 174 that generates a force for pressing the pressure plate 169 against the sheet is disposed between the rack gear 175 and the lower surface 172c of the lift plate 172. When the heating unit 171 is separated in the Z direction, the rack gear 175 abuts against the upper surface 172d of the lift plate 172 by the compression spring 174. The photointerrupter 176 is held integrally with the rack gear 175 and detects a change in the relative position between the rack gear 175 and the lift plate 172. The means for raising and lowering the heating unit 171 is the motor 177, and the rotation of the motor 177 is transmitted to the rack gear 175 by the pinion gear 179 meshing with the rack gear 175 via the gear train 178 from a motor gear (not shown). When the heating and pressing unit 167 performs thermocompression bonding of the sheet bundle, the rack gear 175 moves in the pressing direction (-Z side) by the driving force transmitted from the motor 177. As a result, the lift plate 172 and the heating unit 171 move in the pressing direction (-Z side), and the pressure plate 169 abuts against the sheet bundle. After pressing the sheet bundle S, the heating unit 171 separates.

[0051] As shown in Fig. 10(a), the pressure plate 169 is basically composed of a thickness of 0.8 mm, has a cross-sectional shape in which the central portion in the X direction protrudes in the pressing direction (-Z direction), and has a shape extending in the Y direction. The tip of the protruding portion 169a of the pressure plate 169 that contacts the upper surface of the sheet bundle corresponds to the pressing center position (X1-X1' cross-section) of the heating and pressing unit 167. Further, the protruding portion 169a has a curved surface shape with a diameter of 2.5 mm and protrudes 0.7 mm in the -Z direction in order to concentrate the pressing force of the heating and pressing unit 167 and increase the surface pressure during booklet pressing. As a result, the pressure plate 169 presses the sheet bundle in the X direction with a width of about 2.0 mm. Incidentally, the pressure plate 169 is adhesively treated over the entire region in the Y direction with a heat-resistant silicone adhesive to the heater support 603 at the adhesive portions 603a and 603b. Incidentally, the ceramic heater 168 is in a state of being pressed against the pressure plate 169 side by the contact pressure of a spring of a thermistor TH (not shown) installed on the heater support 603. The receiving plate support 182 has a sheet guide portion 182a as a sheet guide for conveying the sheet to the heating and pressing unit 167 and a receiving plate support portion 182b that supports the receiving plate 181 and receives the pressing force of the heater portion. Here, the receiving plate support portion 182b has a function of adjusting the longitudinal pressing force distribution at the pressing center position (X1-X1' cross-section) of the heating unit 171, and the details will be described later. Further, the receiving side frame 183 is flat on the contact surface with the receiving plate support 182. As the material of the receiving plate support 182, a heat-resistant PPS material (polyphenylene sulfide material) is used in this embodiment.

[0052] Further, the heating unit 171 has a thermistor TH as temperature detection means (not shown) for detecting the temperature of the ceramic heater 168. The thermistor TH in this embodiment uses a resistor having NTC characteristics (Negative Temperature Coefficient), but it is not limited thereto, and a resistor having PTC characteristics (Positive Negative Temperature Coefficient), various thermocouples, or a radiation thermometer may be used. The thermistor TH is arranged at a position 149 mm from the vertical alignment reference position G as the sheet reference position, corresponding to the center of the long side of A4 size in the heating and pressurizing unit 167. The control unit of the booklet manufacturing apparatus 106 can perform temperature control by power application means (not shown) so that the detected temperature of the thermistor TH becomes a set temperature (220°C) which is a predetermined temperature.

[0053] If sufficient adhesion between the pressure plate 169 and the ceramic heater 168 is obtained, when the set temperature of the ceramic heater 168 is set to 220°C, the surface temperature of the pressure plate 169 can be adjusted to 190°C. Thereby, it is possible to make the toner temperature at the time of adhering a maximum of 5 sheets at a time 80°C or higher, which is the reference temperature.

[0054] (Operation of the heating and pressurizing unit) The thermocompression operation of the thermocompression unit 167 will be described with reference to FIGS. 10(a) to 10(f). Each of FIGS. 10(a) to 10(f) is a view of the thermocompression unit 167 in the sheet conveyance direction (Y direction). FIG. 10(a) shows the same state as FIG. 8(c), that is, the state where the alignment of the sheets S1 to S5 in the sheet conveyance direction (Y direction) is completed. In this state, the heating unit 171 is at a position separated from the sheet bundle in the Z direction. FIG. 10(b) shows the same state as FIG. 8(d), that is, the state where the alignment in the width direction of the sheets S1 to S5 is completed. The sheets S1 to S5 are aligned in the sheet width direction (X direction) by being abutted against the width alignment plates 172a and 172b. FIG. 10(c) shows the state where the heating unit 171 moves in the pressing direction (-Z side) due to the forward rotation of the motor 177, and the protruding portion 169a of the pressing plate 169 abuts against the uppermost sheet S5. FIG. 10(d) shows the state where, by continuing the drive of the motor 177, the sheets S1 to S5 are sandwiched between the pressing plate 169 and the receiving plate 181, and the thermocompression of the sheets S1 to S5 is in progress. The compression spring 174 is pushed by the lower surface of the rack gear 175 and contracts, and the repulsive force of the compression spring 174 is increasing. Due to the repulsive force of this compression spring 174, the sheets S1 to S5 are pressed against the pressing plate 169 with a predetermined pressing force via the lift plate 172 and the heating unit 171. In this embodiment, the pressing time is set to 3.0 seconds. The motor 177 is controlled to generate a predetermined pressing force by stopping at a predetermined rotation amount after the photointerrupter 176 is blocked by the rib 172e of the lift plate 172. Further, FIG. 10(d) shows the state where the next sheets S6 to S10 are conveyed to the alignment unit 156 in parallel with the thermocompression of the sheets S1 to S5. FIG. 10(e) shows the state where, after the thermocompression of the sheets S1 to S5 is completed, the heating unit 171 moves (retracts) to the opposite side of the pressing direction (+Z side) due to the reverse rotation of the motor 177, and the pressing plate 169 is separated from the sheet S5. Further, FIG. 10(e) shows the state where the alignment of the next sheets S6 to S10 is performed, and the sheets S1 to S5 are abutted against the width alignment plates 172a and 172b after the retraction of the heating unit 171.Figure 10(f) shows a state in which, due to the forward rotation of the motor 177, the heating unit 171 moves again in the pressing direction (-Z side), the sheets S1 to S10 are sandwiched between the pressing plate 169 and the receiving member 180, and thermocompression bonding of the sheets S6 to S10 is in progress. The motor 177 is controlled to generate a predetermined pressing force by stopping after rotating a predetermined amount after the photointerrupter 176 is shielded from light by the rib 172e of the lift plate 172. Thereby, the operating length of the compression spring 174 when thermocompression bonding the sheets S1 to S5 in FIG. 10(d) and when thermocompression bonding the sheets S6 to S10 in FIG. 10(f) can be made the same. That is, even if the thickness of the sheet S aligned with the heating and pressing unit changes, the thermocompression bonding can be performed with a constant pressing force for pressing the sheet bundle. Further, since an adhesive toner image is formed on the upper surface of the sheet S5 and / or the lower surface of the sheet S6, the sheet bundle composed of the sheets S1 to S5 and the sheet bundle composed of the sheets S6 to S10 are thermocompression bonded.

[0055] In this way, each time a predetermined number of sheet bundles are aligned by the alignment unit 156, the heating and pressing unit 167 performs one thermocompression bonding operation, so that a booklet composed of more than a predetermined number of sheets can be created. Here, an example of creating a booklet composed of 10 sheets S1 to S10 has been described, but a booklet composed of several tens or more sheets can also be created. Also, although a sequence of performing the thermocompression bonding operation for each predetermined number of sheets has been described, the thermocompression bonding operation may be performed for any number of sheets, such as thermocompression bonding 2 sheets first and then performing the thermocompression bonding operation for each 1 sheet thereafter. Incidentally, by adjusting the rotation amount from when the photointerrupter 176 is shielded from light by the rib 172e until the motor 177 stops, the pressing force can be set to an arbitrary pressure. In this embodiment, the maximum value of the total pressing force applied to the sheet bundle is 30 kgf. Here, the pressing force applied to the sheet bundle can be measured by sandwiching a pressure-sensitive sensor sheet having a piezoelectric element between the sheet pressing portions using a roller pressure distribution measurement system (PINCH) manufactured by Nitto Co., Ltd.

[0056] Next, in order to confirm the effects of this embodiment, a comparative verification is performed between this embodiment, Comparative Example 1, and Comparative Example 2. The comparative verification was performed on the booklet adhesion strength before and after the durability test by booklet production. Here, in this embodiment, by appropriately adjusting the temperature control, pressure control, and sheet number control of the heating and pressurizing unit with respect to Comparative Example 1 and Comparative Example 2, while suppressing the plastic deformation of the heating plate after durability, good booklet adhesion strength is ensured.

[0057] FIG. 11(a) is a schematic cross-sectional view taken from the X1-X1' plane in FIG. 10(f) when 20 sheets of A4-sized sheet S are laminated and thermocompression-bonded using the heating and pressurizing unit 167 in this embodiment. For simplicity, only the ceramic heater 168, the pressure plate 169, the thermistor TH, and the sheet S (20 sheets of A4) are shown. As shown in FIG. 11(a), since the heating and pressurizing unit 167 and the heating unit 171 of this embodiment are sized to match the largest sheet size of A4, the sheet S can be uniformly pressurized. The arrows F1 and F2 shown in FIG. 11(a) are the pressures received by the pressure plate 169 when the heating unit 171 pressurizes the sheet S. Since the stress received by the pressure plate 169 is uniform in the longitudinal direction of the pressure plate 169, the pressure plate 169 does not deform, and the ceramic heater 168 and the pressure plate 169 maintain good adhesion.

[0058] On the other hand, FIG. 11(b) is a schematic cross-sectional view taken from the X1-X1' plane when 20 sheets of A5-sized sheet S are laminated and thermocompression-bonded using the thermocompression-bonding unit in this embodiment. It can be seen that a strong stress concentration F1 occurs at the pressurizing position of the end of the A5-sized sheet bundle of the pressure plate 169. In F1 in this embodiment, stress concentration occurs, and F1 is about 2.0 MPa. Due to the influence of locally strong stress, the pressure plate 169 undergoes plastic deformation, and a portion R1 where the adhesion with the ceramic heater 168 slightly decreases occurs outside the sheet bundle. Incidentally, the average stress F2 received by the pressure plate 169 in this embodiment is about 0.5 MPa.

[0059] Here, it was found that plastic deformation at the R1 position may become significant after a durability test in which the booklet production (A5 size) of the heating and pressurizing unit 167 is repeated. Specifically, when the set temperature of the thermistor TH is made the same during the production of booklets of A4 and A5 size paper, plastic deformation of the pressure plate 169 at the R1 position becomes significant. When the plastic deformation of the pressure plate 169 becomes significant, heat transfer from the ceramic heater 168 to the pressure plate 169 is inhibited by the influence. As a result, as shown in Fig. 11(c), when creating an A4 booklet, the temperature at the plastic deformation part (R2) of the pressure plate 169 decreases, heating from the pressure plate 169 to the booklet becomes insufficient, and it was found that the adhesive strength of the booklet decreases. In this embodiment, as will be described in detail in the comparative experiment described later, by lowering the set temperature of the thermistor TH during the production of booklets using A5 size paper compared to during the production of booklets using A4 size paper, the influence of plastic deformation after durability of the pressure plate 169 is suppressed.

[0060] To verify the effects of this embodiment, as shown in Table 2, a list of comparative verification results according to this embodiment, Comparative Examples 1 to 3, and Modification Example 1 is shown. This embodiment, Comparative Examples 1 to 3, and Modification Example 1 set, as setting conditions, (a) sheet size, (b) total pressure, (c) set temperature of the thermistor TH, and (d) pressurization time, and performed booklet production. Also, the booklet adhesion strength was measured for (e) the booklet adhesion strength at the initial stage (before the durability test) of the heating and pressurizing unit and (f) the booklet adhesion strength after the durability test of the heating and pressurizing unit.

[0061]

Table 2

[0062] In the comparative verification, in order to confirm the effect on the plastic deformation of the pressure plate 169, a durability test was conducted to produce 10,000 booklets made of 20 sheets of A5-sized paper per booklet, and the booklet adhesion strength before and after durability was evaluated. Here, when conducting the durability test for producing booklets made of A5-sized paper, the reason for using 20 sheets per booklet is that when there is a certain thickness of the sheet bundle, stress concentration on the heating plate due to the sheet ends of A5-sized paper becomes prominent. Also, the method for testing the quality of the booklet adhesion strength in this comparative verification will be described. First, booklets are produced by the image forming system 100 and the heating and pressurizing unit 167. At this time, booklets of 20-sheet bundles were created under each test condition. Here, the adhesion treatment of the paper bundle by the heating and pressurizing unit 167 will be performed in groups of 5 sheets. In this booklet adhesion strength test, for the sheet S, A4 size of GF-C081 manufactured by Canon Inc. was used. In the experiment with A5-sized sheets, by cutting the A4 size of GF-C081 in half and using it, the influence other than the sheet size was excluded for comparison.

[0063] Next, a method for creating test pieces for conducting the quality test of the booklet adhesion strength from the produced booklets will be described. Fig. 12(a) shows A4-sized paper, and Fig. 12(b) shows A5-sized paper. Test piece E or test piece F is created from 2 booklets each. From the 20-sheet bundles of booklets made of A4-sized and A5-sized sheets, S1 to S18 corresponding to pages 1 to 18 are peeled off and removed from the booklet, leaving a 2-booklet with only S1 and S2 adhered. Then, in the case of A4-sized paper, as shown in Fig. 12(a), a test piece E of A4-sized paper including the adhesion part D is created by cutting it to dimensions of width (W) 20 mm and length (L) 50 mm. At this time, test piece E is created as E1 to E14 in order from the vertical alignment reference position G. Similarly, in the case of A5-sized paper, as shown in Fig. 12(b), a test piece F of A5-sized paper including the adhesion part D is created by cutting it to dimensions of width (W) 20 mm and length (L) 50 mm. At this time, test piece F is created as F1 to F10 in order from the vertical alignment reference position G.

[0064] Next, as shown in Fig. 12(c), one of the test pieces E or F was held by the upper holding member, and the other was held by the lower holding member. Further, the upper holding member was connected to a digital force gauge M (manufactured by Nidec-Shimpo Corporation, FGP-2). Then, the digital force gauge was gradually pulled upward, and the peeling force when the adhesive portion D was peeled off was measured by the digital force gauge, and the peak value of the peeling force was recorded. The measurement was performed 5 times each, and the average value was taken as the booklet adhesion strength of the adhesive portion D. In addition, as a result of the study by the present authors, it was confirmed that in practical use, the adhesion strength as a booklet is desirably 1.0 N / cm or more per unit distance in the width direction of the test piece. Therefore, as a quality standard, 1.0 N / cm or more was judged as OK for the booklet strength, and less than that was judged as NG for the booklet strength. Here, the reason for measuring the adhesion strength between S19 and S20 for each sheet size is that, particularly in the case of A5 size paper, when there is a certain thickness of the sheet bundle, stress concentration on the heating plate due to the sheet end becomes remarkable. Also, in this measurement of the booklet strength, in the case of A4 size paper, among E1 to E14 described above, the adhesion force of E12 was measured. This is because it corresponds to the position R2 where the adhesion between the pressure plate 169 and the ceramic heater 168 described above is a concern. Also, in the case of A5 size paper, among F1 to F10 described above, the adhesion force at the center, F5, was measured as a representative value.

[0065] (This Example) Regarding the set temperature of the thermistor TH, the set temperature of A5-size paper (150°C) was set lower than that of A4-size paper (220°C). Also, the pressurization time was set such that the pressurization time of A5-size paper (5.0 seconds) was longer than that of A4-size paper (3.0 seconds). The total pressure was 30 kgf for both A4 and A5-size papers. The booklet adhesion strength for both A4 and A5-size papers was such that the initial booklet strength and the booklet strength after durability exceeded the reference value of the adhesion strength (1.0 N / cm), ensuring good adhesion. This is because by lowering the set temperature of A5-size paper, plastic deformation of the pressure plate 169 was suppressed, and good adhesion between the pressure plate 169 and the ceramic heater 168 could be ensured even after durability. As a result, even when creating an A4 booklet after durability with an A5 booklet, the temperature at R1 of the pressure plate 169 did not drop compared to the surroundings, and the booklet could be sufficiently heated, obtaining good adhesion. Also, in the case of A5-size paper, although the set temperature was lowered compared to A4-size paper, by increasing the pressurization time, it was possible to adjust the amount of heat for heating the booklet. As a result, for A5-size paper, good adhesion was obtained both initially and after durability.

[0066] (Comparative Example 1) The total pressure, set temperature, and pressurization time of the thermistor TH were the same for both A4 and A5-size papers. Here, the total pressure was 30 kgf, the set temperature was 220°C, and the pressurization time was 3.0 seconds. The booklet adhesion strength for both A4 and A5-size papers was such that the initial booklet strength exceeded the reference value of the adhesion strength (1.0 N / cm), ensuring good adhesion. On the other hand, after durability, the adhesion decreased in the case of A4-size paper. This is because, by keeping the set temperature of A5-size paper (220) high without lowering it compared to A4-size paper, plastic deformation of the pressure plate 169 became significant, and the adhesion between the pressure plate 169 and the ceramic heater 168 decreased. As a result, the temperature at R1 of the pressure plate 169 dropped compared to the surroundings, and the booklet could not be sufficiently heated, resulting in a decrease in adhesion.

[0067] (Comparative Example 2) For Comparative Example 1, the set temperature was changed to 150°C. The total pressure was 30 kgf and the pressurization time was 3.0 seconds. For both A4 and A5 size papers, the conditions were the same. The booklet adhesion strength for both A4 and A5 size papers was below the reference value of the adhesion strength (1.0 N / cm) under the initial conditions, indicating insufficient adhesive force. This is the result of insufficient heating of the booklet due to the decrease in the set temperature, leading to a decrease in the adhesive force. Since the initial adhesiveness was poor, the test results of the booklet adhesion strength after durability are omitted.

[0068] (Comparative Example 3) For Comparative Example 1, the total pressure was changed to 20 kgf. The set temperature was 220°C and the pressurization time was 3.0 seconds. For both A4 and A5 size papers, the conditions were the same. The booklet adhesion strength for both A4 and A5 size papers was below the reference value of the adhesion strength (1.0 N / cm) under the initial conditions, indicating insufficient adhesive force. This is the result of insufficient pressurization of the booklet due to the decrease in the total pressure, leading to a decrease in the adhesion between the papers and a decrease in the adhesive force. Since the initial adhesiveness was poor, the test results of the booklet adhesion strength after durability are omitted.

[0069] (Modification Example 1) This is a modification example of this embodiment. The set temperature is the same (220 °C) for A4 and A5 size papers. On the other hand, the total pressure is set to be lower for A5 size paper (20 kgf) than for A4 size paper (30 kgf). Also, the pressing time is set to be longer for A5 size paper (7.0 seconds) than for A4 size paper (3.0 seconds). The booklet adhesion strength for both A4 and A5 size papers shows that the initial booklet strength and the booklet strength after durability exceed the reference value of the adhesion strength (1.0 N / cm), ensuring good adhesion. This is because by reducing the total pressure of the A5 size paper, plastic deformation of the pressure plate 169 is suppressed, and good adhesion between the pressure plate 169 and the ceramic heater 168 can be ensured even after durability. As a result, the temperature at R2 of the pressure plate 169 does not drop compared to the surroundings, and the booklet can be sufficiently heated. Also, in the case of A5 size paper, although the total pressure is lower than that of A4 size paper and the adhesion between the papers decreases, by lengthening the pressing time to sufficiently heat the booklet, good adhesion is obtained both initially and after durability. Also, the method of maintaining good adhesion of the booklet even when the heating temperature is lowered is not limited to lengthening the pressing time. For example, the amount of heat required for adhesion may be reduced by decreasing the number of sheets adhered at one time. For example, the number of sheets adhered at one time may be reduced from 5 to 3. Also, plastic deformation of the pressure plate may be suppressed by lowering both the heating temperature and the pressure.

[0070] As described above, according to this embodiment, in a heating and pressing unit that creates booklets corresponding to a plurality of sheet sizes, the set temperature of the ceramic heater or the pressure of the pressing member at each sheet size is appropriately controlled. Thereby, it is possible to suppress plastic deformation of the heating plate and maintain good adhesion of the booklet. Specifically, regarding the set temperature of the ceramic heater, by lowering the set temperature of the smallest size paper compared to the largest size paper, it is possible to suppress plastic deformation of the heating plate. Also, regarding the total pressure of the heating and pressing unit, by lowering the total pressure of the smallest size paper compared to the largest size paper, it is possible to suppress plastic deformation of the heating plate.

[0071] In this embodiment, A4 as the maximum size and A5 as the minimum size have been described, but it is not limited thereto. Regarding the set temperature of the thermistor TH, for example, even in the case of B5 size, by applying a set temperature lower than that of A4 which is the maximum size, it is possible to suppress plastic deformation of the heating plate. Regarding the total pressing force of the heating and pressing unit, also in the case of B5 size, by applying a pressing force smaller than that of A4 which is the maximum size, it is possible to suppress plastic deformation of the heating plate.

[0072] [Appendix] The above embodiment discloses at least the following booklet manufacturing apparatus and image forming system.

[0073] (Item 1) A heating and pressing unit that heats and presses an adhesive layer in a state where a plurality of sheets having an adhesive layer formed thereon are stacked, including a pressing plate that presses in contact with the sheet, a heating body that heats the pressing plate at a predetermined temperature, a receiving member facing the pressing plate, and a pressing mechanism that applies pressure to the sheet sandwiched between the pressing plate and the receiving member. Control means for controlling the predetermined temperature and the pressure. Having A booklet manufacturing apparatus that sandwiches a plurality of sheets having an adhesive layer formed therebetween between the pressing plate and the receiving member and heats and presses the adhesive layer formed on the sheet to manufacture a booklet, The control means is characterized in that it controls at least one of the predetermined temperature and the pressure to be lower when heating and pressing a sheet of the minimum size than when heating and pressing a sheet of the maximum size.

[0074] (Item 2) The booklet manufacturing apparatus according to Item 1, wherein the control means controls the pressing time of the pressing mechanism when heating and pressing the sheet, The booklet manufacturing apparatus is characterized in that the control means makes the pressurization time when heating and pressurizing a sheet of the minimum size longer than the pressurization time when heating and pressurizing a sheet of the maximum size.

[0075] (Item 3) The booklet manufacturing apparatus according to Item 1 or 2, wherein the booklet manufacturing apparatus is characterized in that the number of sheets for which the adhesive layer is heated and pressurized at one time is made smaller when heating and pressurizing a sheet of the minimum size than when heating and pressurizing a sheet of the maximum size.

[0076] (Item 4) The booklet manufacturing apparatus according to any one of Items 1 to 3, and an image forming apparatus for forming an adhesive layer on a sheet, characterized by having the same.

Explanation of Signs

[0077] 167 Heating and Pressurizing Unit 168 Ceramic Heater (Heating Element) 169 Pressurizing Plate 180 Receiving Member 181 Receiving Plate

Claims

1. A heating and pressing unit that heats and presses an adhesive layer in a state where a plurality of sheets with an adhesive layer formed thereon are stacked, comprising: a pressing plate that contacts and presses the sheets; a heating element that heats the pressing plate at a predetermined temperature; a receiving member facing the pressing plate; and a pressing mechanism that applies pressure to the sheets sandwiched between the pressing plate and the receiving member. A booklet manufacturing apparatus that manufactures a booklet by heating and pressing the adhesive layer formed on the sheets by sandwiching a plurality of sheets with an adhesive layer formed therebetween between the pressing plate and the receiving member. Control means for controlling the predetermined temperature and the pressure. It has A booklet manufacturing apparatus that manufactures a booklet by heating and pressing the adhesive layer formed on the sheets by sandwiching a plurality of sheets with an adhesive layer formed therebetween between the pressing plate and the receiving member. The control means is characterized in that it controls so that at least one of the predetermined temperature and the pressure is lower when heating and pressing the smallest-sized sheet than when heating and pressing the largest-sized sheet.

2. The control means controls the pressing time of the pressing mechanism when heating and pressing the sheets. The booklet manufacturing apparatus according to claim 1, wherein the control means makes the pressing time when heating and pressing the smallest-sized sheet longer than the pressing time when heating and pressing the largest-sized sheet.

3. The booklet manufacturing apparatus according to claim 1, wherein the number of sheets whose adhesive layer is heated and pressed at one time is made smaller when heating and pressing the smallest-sized sheet than when heating and pressing the largest-sized sheet.

4. An image forming system, characterized by comprising: the booklet manufacturing apparatus according to any one of claims 1 to 3; and an image forming apparatus that forms an adhesive layer on a sheet. ​

Images