Image forming system

Abstract

To provide an image forming system that reduces power consumption in the image forming system to improve power saving properties.SOLUTION: An image forming system has a first mode in which image forming means forms a toner image and an adhesive layer on a sheet and a booklet manufacturing device manufactures a booklet by using the sheet, and a second mode in which the image forming means forms only the adhesive layer on the sheet and the booklet manufacturing device manufactures the booklet by using the sheet. When fixing means applies heat and pressure to the sheet, the temperature of the fixing means is lower in the second mode than in the first mode.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming system having an image forming apparatus capable of forming a toner image and an adhesive layer on a sheet, and a booklet producing apparatus that produces a booklet by bonding a plurality of sheets together. [Background technology]

[0002] Patent document 1 discloses an apparatus in which an image forming apparatus is used to form a layer of adhesive (toner) on the edge of a sheet, the adhesive (toner) layer is fixed onto the sheet by heating and pressurizing in a fixing section of the image forming apparatus, and then the adhesive layer formed on the edge of the sheet is heated and pressurized again in an adhesive section of a booklet production device, thereby bonding the sheets together. [Prior art documents] [Patent documents]

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

[0004] In the above-described configuration, since it is necessary to heat the sheet on which the toner image or adhesive layer is formed in each heating section of the fixing section of the image forming device and the adhesive section of the booklet production device, there is a concern that the power consumption of the entire system will be large.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide an image forming system that reduces power consumption in the image forming system and improves power saving performance. [Means for solving the problem]

[0006] One aspect of the present invention is an image forming apparatus having an image forming means capable of forming a toner image and an adhesive layer on a sheet, and a fixing means for fixing the toner image and adhesive layer to the sheet at a predetermined temperature by heating and pressurizing the sheet and clamping and transporting it, and a booklet production device for bonding multiple sheets to each other to produce a booklet by heating and pressurizing the adhesive layer fixed to the sheet while stacking multiple sheets to which the adhesive layer is fixed, the image forming system having a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet production device uses the sheet to produce a booklet, and a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet production device uses the sheet to produce a booklet, characterized in that the predetermined temperature of the fixing means when the sheet is heated and pressurized by the fixing means is lower in the second mode than in the first mode.

[0007] Another aspect is an image forming apparatus having an image forming means capable of forming a toner image and an adhesive layer on a sheet, fixing means for fixing the toner image and adhesive layer to the sheet at a predetermined temperature by heating and pressurizing the sheet and sandwiching and transporting the sheet, the fixing means having a rotating body that sandwiches and transports the sheet, and a power source that applies a voltage of a predetermined polarity to the rotating body when the fixing means heats and pressurizes the sheet, and a booklet production device that heats and pressurizes the adhesive layers fixed to the sheets in a stacked state to adhere the multiple sheets to each other to produce a booklet, the image forming system having a first mode in which the image forming means forms a toner image and an adhesive layer on the sheet, and the booklet production device uses the sheet to produce a booklet, and a second mode in which the image forming means forms only the adhesive layer on the sheet, and the booklet production device uses the sheet to produce a booklet, characterized in that the value of the voltage applied from the power source to the fixing means when the fixing means heats and pressurizes the sheet is smaller in the second mode than in the first mode.

[0008] Another aspect is an image forming apparatus having an image forming means capable of forming a toner image and an adhesive layer on a sheet, and a fixing means for fixing the toner image and adhesive layer to the sheet at a predetermined temperature by heating and pressurizing the sheet and clamping and transporting it, and a booklet production device for bonding multiple sheets to each other to produce a booklet by heating and pressurizing the adhesive layer fixed to the sheet in a stacked state, the image forming system having a first mode in which the image forming means forms a toner image and an adhesive layer on the sheet, and the booklet production device uses the sheet to produce a booklet, and a second mode in which the image forming means forms only the adhesive layer on the sheet, and the booklet production device uses the sheet to produce a booklet, characterized in that the pressure applied to the sheet by the fixing means when heating and pressurizing the sheet is smaller in the second mode than in the first mode.

[0009] In another embodiment, the image forming apparatus includes an image forming means capable of forming a toner image and an adhesive layer on a sheet, the image forming means having a rotatable image carrier that carries at least one of a toner and an adhesive, a fixing means that heats and pressurizes the sheet, and sandwiches and transports the sheet to fix the toner image and the adhesive layer to the sheet at a predetermined temperature, and a blade member that contacts the image carrier and cleans the image carrier, and a booklet is produced by bonding multiple sheets together by heating and pressurizing the adhesive layer fixed to the sheet in a state where multiple sheets to which the adhesive layer is fixed are stacked. and a booklet production device which produces a booklet using the image forming means, the image forming system having a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet production device produces a booklet using the sheet, and a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet production device produces a booklet using the sheet, characterized in that in the second mode, toner is supplied to a contact portion between the image carrier and the blade member which corresponds to a sheet area other than the area of ​​the sheet on which the adhesive layer is formed in the direction of the rotation axis of the image carrier. Effect of the Invention

[0010] According to the present invention, it is possible to provide an image forming system that reduces power consumption and improves power saving performance. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view illustrating an image forming apparatus and a booklet producing apparatus according to a first embodiment of the present invention; [Diagram 2] FIG. 1 is a diagram illustrating a cross-sectional configuration of a fixing unit according to a first embodiment. [Diagram 3] FIG. 1 is a diagram for explaining a sheet alignment method in the booklet production apparatus according to the first embodiment; [Figure 4] FIG. 1 is a cross-sectional view showing a thermocompression bonding unit in a booklet production apparatus according to a first embodiment of the present invention; [Diagram 5] FIG. 1 is a diagram for explaining a printing area of ​​adhesive toner in the first embodiment; [Figure 6] FIG. 10 is a diagram for explaining booklet production in the second mode in the first embodiment; [Figure 7] FIG. 13 is a diagram illustrating a ceramic heater for fixing and heat distribution in the fifth embodiment. [Figure 8] FIG. 23 is a cross-sectional view showing a configuration of a modified example of the seventh embodiment. [Figure 9] FIG. 11 is a cross-sectional view showing a configuration of a modified example of each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Example 1] 1. Image forming equipment (Overall device configuration example) First, the overall configuration of the apparatus will be described with reference to FIG. 1. The present invention is not limited to the following embodiments, and other configurations may be substituted within the scope of the concept of the present invention. FIG. 1 is a schematic diagram showing the cross-sectional configuration of an image forming apparatus 1 and a booklet production apparatus 300 according to a first embodiment. As shown in FIG. 1, an image forming system 400 is formed by combining the image forming apparatus 1 and the booklet production apparatus 300. Note that the image forming system 400 may include a form in which part or all of the booklet production function is incorporated in the image forming apparatus 1.

[0013] Here, the image forming apparatus 1 will be described in detail. As shown in FIG. 1, the image forming apparatus 1 includes a sheet cassette 8 as a sheet storage section for storing sheets P, an image forming unit 1e as an image forming means, a fixing device 6 as a fixing means, and a housing 19 for housing these. The image forming apparatus 1 has a printing function of forming a toner image on a sheet P fed from the sheet cassette 8 by the image forming unit 1e, and producing a printed matter by performing a fixing process by the fixing device 6. In this embodiment, the maximum size of the sheet P on which an image can be formed is A4 size (297 mm long x 210 mm wide), and the A4 size is conveyed vertically to form an image. The sheet cassette 8 is inserted into the housing 19 at the bottom of the image forming apparatus 1 so as to be removable, and stores a plurality of sheets P. The sheets P stored in the sheet cassette 8 are fed from the sheet cassette 8 by a paper feed roller 8a as a paper feed section, and are conveyed by a conveying roller pair 8b. It is also possible to feed sheets set in a multi-tray 20 one by one.

[0014] The image forming unit 1e is a tandem-type electrophotographic unit including 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 a plurality of parts that perform an image forming process are integrated and replaceable. Each process cartridge 7n, 7y, 7m, and 7c has a substantially common configuration except for the type of powder contained in the four powder containers Gn, Gy, Gm, and Gc. That is, each process cartridge 7n, 7y, 7m, and 7c includes photosensitive drums Dn, Dy, Dm, and Dc that are image carriers, charging rollers Cn, Cy, Cm, and Cc that are chargers, and powder containers Gn, Gy, Gm, and Gc that contain powder and supply it to the photosensitive drums. Of the four powder containers, the three powder containers Gy, Gm, and Gc on the right side in the figure contain yellow, magenta, and cyan printing toners Ty, Tm, and Tc, respectively, as toners for forming a visible image on the sheet P. In contrast, the powder container Gn on the leftmost side in the figure contains adhesive toner Tn, which is a powder for performing an adhesive process after printing. In this embodiment, when printing a black image such as text, it is expressed by process black in which yellow (Ty), magenta (Tm), and cyan (Tc) toners are superimposed. However, for example, the adhesive toner Tn may be black, so that a black image can be expressed by adhesive toner. Alternatively, a fifth process cartridge using black printing toner may be added to the image forming unit 1e, so that a black image can be expressed by black printing toner. Not limited to this, the type and number of printing toners can be changed depending on the purpose of the image forming device 1. The scanner unit 2 is disposed below the process cartridges 7n, 7y, 7m, and 7c and above the sheet cassette 8. The scanner unit 2 is an exposure means in this embodiment that irradiates the photosensitive drums Dn, Dy, Dm, and Dc of each process cartridge 7n, 7y, 7m, and 7c with laser light to write an electrostatic latent image. The transfer unit 3 is equipped with a transfer belt 3a as an intermediate transfer body (secondary image carrier). The transfer belt 3a is a belt member stretched between a secondary transfer inner roller 3b and a tension roller 3c, and its outer circumferential surface faces the photosensitive drums Dn, Dy, Dm, and Dc of each process cartridge 7n, 7y, 7m, and 7c.Primary transfer rollers Fn, Fy, Fm, and Fc are disposed on the inner periphery of the transfer belt 3a at positions corresponding to the photosensitive drums Dn, Dy, Dm, and Dc. A drum cleaning blade (not shown) is disposed on each photosensitive drum downstream of the primary transfer roller as a photosensitive drum cleaning means. A secondary transfer roller 5 is disposed as a transfer means at a position facing the secondary transfer inner roller 3b. A transfer nip 5n between the secondary transfer roller 5 and the transfer belt 3a is a transfer section (secondary transfer section) where a toner image is transferred from the transfer belt 3a to the sheet P. A cleaning blade 80 is disposed on the outer side of the transfer belt 3a downstream of the secondary transfer section as a transfer belt cleaning means.

[0015] The fixing device 6 is a fixing section that heats, melts, and fixes the toner image on the sheet P, and is disposed above the secondary transfer roller 5. The fixing device 6 is a thermal fixing type fixing device having a fixing film 62 as a fixing member that is heated by a fixing ceramic heater 61 as a heat source, and a pressure roller 63 as a pressure member. The fixing device 6 will be described in detail with reference to FIG. 2. FIG. 2 is a cross-sectional view of the fixing device, and the fixing device is composed of a heating member 64 and a pressure roller 63 that are in pressure contact with each other to form a fixing nip 6n. The heating member 64 is composed of a fixing ceramic heater 61, a film guide 65 that fixes the heater, and a cylindrical fixing film 62 that is loosely fitted around the film guide. The fixing film 62 is a film member that has low heat capacity and heat resistance. A heat-resistant resin such as polyimide, polyamide-imide, or PEEK may be used as the base layer, and highly heat-conductive powder such as carbon, boron nitride, alumina, or aluminum may be mixed in order to improve heat conductivity. An elastic layer such as heat-resistant silicone rubber or fluororubber is provided on the base layer. Furthermore, the surface layer is coated with a heat-resistant resin with good releasability such as fluororesin such as PTFE or PFA as a release layer to ensure separation of toner and sheets. The fixing ceramic heater 61 is made of a heater substrate, a resistance heating element pattern formed on the heater substrate, and a surface protection layer covering the resistance heating element pattern, and is attached to and supported by a film guide 65. The heater substrate is a highly heat-conductive substrate made of a ceramic material such as alumina or aluminum nitride. The resistance heating element pattern on the heater substrate is formed by screen printing a resistance heating element made of a conductive agent such as silver / palladium or ruthenium oxide and a matrix component such as glass or polyimide. The surface protection layer covering the resistance heating element pattern is made of a glass coating layer to ensure insulation and wear resistance with the fixing film.

[0016] In addition, on the surface of the heater substrate opposite to the surface forming the fixing nip 6n, a temperature detection element 66 such as a thermistor for detecting the temperature of the fixing ceramic heater 61 is arranged so as to be pressed against the surface with a predetermined pressure. Note that a plurality of temperature detection elements may be provided, for example, at the center of the sheet width direction or at a position corresponding to the adhesive region in order to detect the temperature distribution along the width direction of the sheet. By appropriately controlling the duty ratio and wave number of the voltage applied to the resistance heating element pattern according to the signal of this temperature detection element 66, the temperature control temperature in the fixing nip 6n is kept substantially constant, and heating required for fixing the toner image on the sheet P is performed. In other words, the power supply to the fixing ceramic heater 61 is controlled so that the temperature detected by the temperature detection element 66 is maintained at a predetermined temperature suitable for fixing. The film guide 65 is a guide member when the fixing film 62 rotates, and the fixing film 62 is loosely fitted around the film guide 65 with a margin. It also serves as a member for holding the fixing ceramic heater 61 and preventing heat radiation in the opposite direction to the fixing nip 6n, and is made of heat-resistant resin such as liquid crystal polymer, phenolic resin, PPS, PEEK, etc. In order to reduce the sliding resistance between the fixing film 62 and the fixing ceramic heater and film guide, heat-resistant sliding grease such as fluorine grease is applied to the inner surface of the fixing film 62.

[0017] The pressure roller 63 as a pressure member is made of a metal core 67 such as SUS, SUM, Al, etc., and a heat-resistant rubber such as silicone rubber or fluororubber or an elastic layer 68 formed by foaming silicone rubber on the outside of the metal core 67, and a release layer such as PFA, PTFE, FEP, etc. is formed on the elastic layer 68. The pressure roller 63 is sufficiently pressurized by a pressure means (not shown) using spring pressure or the like to form a fixing nip 6n required for fixing. In the fixing device in this embodiment, the pressure of the pressure means is variable by controlling the rotation of a cam provided at the end of the pressure spring, etc., and the pressure can be changed according to the type of sheet, the print mode, etc. In addition, the metal core of the pressure roller 63 is rotated by a driving means (not shown). As a result, the fixing film (rotating body) 62 loosely fitted on the outer circumferential surface of the film guide is rotated by the frictional force with the pressure roller (rotating body) 63. In addition, the fixing film 62 and the pressure roller 63 are pressed against each other to sandwich and convey the sheet between the fixing film 62 and the pressure roller 63. Furthermore, in the fixing device in this embodiment, a voltage (fixing bias) of a polarity opposite to the normal charging polarity of the toner is applied from a power source 69 to the metal core 67 of the pressure roller 63. By applying the fixing bias to the pressure roller 63, an electrostatic attraction acts on the toner on the sheet toward the pressure roller 63 side (sheet side), and image defects such as toner offset and scattering can be prevented. As a heating method for the fixing device other than the above, an induction heating method, a heat roller method, or a heating method using a halogen lamp or the like as a heat source may be used. In addition, the image forming apparatus in this embodiment is provided with a fan 70 that exhausts air from within the apparatus to the outside of the apparatus in order to suppress a rise in temperature inside the apparatus due to the fixing device, as shown in FIG. 1. By operating the fan 70, the air heated by the fixing device is exhausted to the outside of the apparatus, suppressing a rise in temperature of the members inside the apparatus and the toner in the process cartridge 7.

[0018] (Outline of Printing Toner) In this embodiment, a general printing toner can be used. Among them, a printing toner using a thermoplastic resin as a binder resin is preferred. The resin that can be used as the thermoplastic resin is not particularly limited, and resins used in general printing toners such as polyester resin, vinyl resin, acrylic resin, and styrene-acrylic resin can be used. A plurality of these resins may be contained. Among them, a printing toner using a styrene-acrylic resin is more preferred. The printing toner may contain a colorant, a magnetic material, a charge control agent, a wax, and an external additive.

[0019] (Outline of adhesive toner Tn) In this embodiment, adhesive toner Tn containing a thermoplastic resin can be used. Resins that can be used as the thermoplastic resin are not particularly limited. Examples include known thermoplastic resins such as polyester resin, vinyl resin, acrylic resin, styrene acrylic resin, polyethylene, polypropylene, polyolefin, ethylene-vinyl acetate copolymer resin, and ethylene-acrylic acid copolymer resin. A plurality of these resins may be contained. The adhesive toner Tn preferably further contains a 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 adhesive toner may contain a colorant. As the colorant, known colorants such as black colorants, yellow colorants, magenta colorants, and cyan colorants can be used. The adhesive toner Tn may contain a magnetic material, a charge control agent, wax, and an external additive. In order to form an adhesive portion on a sheet by using an electrophotographic method using an adhesive toner, the weight average particle size of the adhesive 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. In addition, a printing toner may be used as the adhesive toner as long as it satisfies the adhesive property.

[0020] (Outline of Image Forming Operation) When data of an image to be printed and a command to execute printing are input to the image forming apparatus 1, the control unit (not shown) of the image forming apparatus 1 starts a series of operations (image forming operations) to convey a sheet P and form an image on the sheet P. In the image forming operation, the sheet P is first fed one by one from the sheet cassette 8 and conveyed toward the transfer nip 5n via the conveying roller pair 8b. In parallel with the feeding of the sheet P, the process cartridges 7n, 7y, 7m, and 7c are sequentially driven, and the photosensitive drums Dn, Dy, Dm, and Dc are rotated. At this time, the photosensitive drums Dn, Dy, Dm, and Dc are uniformly charged on their surfaces by the charging rollers Cn, Cy, Cm, and Cc. In addition, the scanner unit 2 irradiates the photosensitive drums Dn, Dy, Dm, and Dc of the process cartridges 7n, 7y, 7m, and 7c with laser light modulated based on image data, and an electrostatic latent image is formed on the surface of the photosensitive drums Dn, Dy, Dm, and Dc. Next, the electrostatic latent image on the photosensitive drum Dn, Dy, Dm, Dc is developed into a toner image by the powder carried by the developing rollers Hn, Hy, Hm, Hc in the powder containers Gn, Gy, Gm, Gc of the process cartridges 7n, 7y, 7m, 7c. The adhesive toner layer formed on the photosensitive drum Dn by developing the adhesive toner Tn is different from a toner image (normal toner image) of a printing toner for recording an image such as a figure or text on a sheet P in that it is not intended to transmit visual information. However, in the following description, the layer of adhesive toner Tn developed by an electrophotographic process to apply the adhesive toner Tn to the sheet P in a predetermined application pattern is also treated as one of the "toner images."

[0021] The transfer belt 3a rotates in the counterclockwise direction (arrow V) in the figure by driving the secondary transfer inner roller 3b with a motor (not shown). The toner images formed in each process cartridge 7n, 7y, 7m, 7c are primarily transferred from the photosensitive drums Dn, Dy, Dm, Dc to the transfer belt 3a by an electric field formed between the photosensitive drums Dn, Dy, Dm, Dc and the primary transfer rollers Fn, Fy, Fm, Fc. The toner images carried on the transfer belt 3a and reaching the transfer nip 5n are secondarily transferred to the conveyed sheet P by an electric field formed between the secondary transfer roller 5 and the secondary transfer inner roller 3b. The toner remaining on the transfer belt 3a that was not transferred to the sheet P during the secondary transfer is removed from the transfer belt 3a by a cleaning blade 80. The sheet P is then conveyed to the fixing device 6 and subjected to a thermal fixing process. That is, when the sheet P passes through the fixing nip 6n, the toner image on the sheet P is heated and pressurized, causing the printing toners Ty, Tm, Tc and the adhesive toner Tn to melt and then adhere to the sheet P, resulting in an image fixed to the sheet P.

[0022] The switching guide 33 is a flap-shaped guide member for switching the conveying direction when either a single-sided printing mode in which an image is formed on one side of the sheet P or a double-sided printing mode in which an image is formed on both sides of the sheet P is selected. In the single-sided printing mode, the switching guide 33 conveys the sheet P to the pair of discharge rollers 34. On the other hand, in the double-sided printing mode, the switching guide 33 conveys the sheet P to the pair of switchback rollers 35, which reverses the rotation direction after discharging the sheet P to the rear end, thereby conveying the sheet P to the double-sided conveying path 36 for double-sided printing. The sheet P conveyed to the double-sided conveying path 36 passes through the secondary transfer section and the fixing section again to form an image on the unprinted sheet surface, and finally the switching guide 33 conveys the sheet P to the pair of discharge rollers 34. The image forming operation of the image forming apparatus 1 has been described above. Note that the operation after the sheet P is conveyed to the pair of discharge rollers 34 will be described later as the operation of the booklet producing apparatus 300. The operation panel 50 is disposed on the outside of the housing 19 and has a liquid crystal display unit that can be viewed and operated by the user through touch. The liquid crystal display unit 50a of the operation panel 50 not only displays the operating status of the image forming apparatus 1 and the status of consumables such as toner by the control unit, but also has a navigation function that guides the user to specific operations. When the user wants to change the settings of the print mode or booklet production mode, the user can change the settings by touching the setting screen displayed on the operation panel 50.

[0023] 2. Booklet production device and booklet production operation The cross-sectional configuration of the booklet making apparatus 300 according to the first embodiment and the booklet making operation will be described with reference to FIG. 1. The sheet P on which the image is formed by the image forming apparatus 1 reaches the booklet making apparatus 300 via the intermediate conveying unit 200 having the conveying roller pairs 201 and 202. The booklet making apparatus 300 is of a floor standing type, and is equipped with a sheet alignment unit at the bottom and a thermocompression bonding unit 51 as a heating and pressing means for heating and pressing the aligned sheet stack for a predetermined time. The sheet P conveyed from the intermediate conveying unit 200 is delivered to the conveying roller pair 21 of the booklet making apparatus 300. The conveying roller pair 22 accelerates the sheet at a predetermined timing based on the time when the rear end passes the entrance sensor 27. If the sheet is to be discharged to the upper discharge tray 25, the sheet is decelerated to a predetermined discharge speed when the rear end of the sheet reaches between the conveying roller pair 22 and the reversing roller 24, and is discharged to the upper discharge tray 25.

[0024] When the thermocompression bonding unit 51 is performing the booklet production process, the sheet is discharged to the lower discharge tray 37. In this case, the check valve 23, which is biased clockwise by a spring (not shown), stops the sheet transport once when the rear end of the sheet leaves the tray, and then switches back the sheet to be transported to the inner discharge rollers 26. The sheet P transported from the inner discharge rollers 26 passes through the intermediate transport rollers 28 and is sent to the kick-out rollers 29, and is transported to the intermediate stacking section 42. A vertical alignment reference plate 39 is disposed at the most downstream portion of the intermediate stacking section 42, and the sheet bundle is aligned by abutting the end of the sheet in the transport direction against this plate. The method of aligning the sheet P will be described with reference to FIG. 3. Here, the horizontal direction of the sheet P is defined as the X direction, the vertical direction is defined as the Y direction, and the height direction is defined as the Z direction. In FIG. 3(a), a half-moon roller 43 for pushing the sheet P that has left the kick-out rollers 29 into the vertical alignment reference plate 39 is rotatably supported in the intermediate stacking section 42. The half-moon roller 43 conveys the sheet toward the vertical alignment reference plate 39 at a predetermined timing. In FIG. 3(b), the conveying pressure of the half-moon roller 43 is adjusted to a pressure that makes the sheet slip on the sheet after it contacts the vertical alignment reference plate 39. In addition, downstream of the kick-out roller 29, a stack holding flag 30 that suppresses lifting of the trailing end of the sheet is rotatably supported so that the trailing end of the sheet stacked on the intermediate stacking section 42 does not interfere with the leading end of the following sheet. After the sheet reaches the vertical alignment reference plate, in FIG. 3(c), the horizontal alignment jogger 41a performs an alignment operation until it hits the horizontal alignment reference plate 500 (dotted line), and in FIG. 3(d), the sheet stack is aligned at a predetermined position. After the alignment of a predetermined number of sheets is completed, a heat and pressure treatment is performed by a thermocompression unit 51 as a sheet bonding means. The thermocompression unit 51 heats and presses a plurality of sheets P to create a sheet stack. The sheet stack aligned in the vertical and horizontal directions is subjected to a heat and pressure treatment by the thermocompression unit 51, making it possible to produce a sheet stack (booklet) that is aligned with high accuracy.

[0025] The structure of the thermocompression bonding unit 51 will be further described with reference to FIG. 4. FIG. 4 is a cross-sectional view of the thermocompression bonding unit 51. The thermocompression bonding unit 51 has a 1.5 mm thick aluminum heating plate 502 disposed on a 1.0 mm thick ceramic heater 501 incorporating a heating element as a heat source. The ceramic heater 501 is temperature-controlled to a constant target temperature of, for example, 240° C. by a temperature detection means and a power application means (not shown) supported by a heater support 503, thereby controlling the surface temperature of the heating plate 502 to, for example, 200° C. The ceramic heater is supported by a resin heater support 503. A pressure lever 504 obtains power from a drive source (not shown) to press down the thermocompression bonding unit in the −Z direction (downward) and apply pressure to the sheet stack. The pressure of the pressure lever 504 is transmitted through a metal stay 505 as a rigid body, and the average surface pressure on the sheet stack is, for example, 0.2 MPa, and the pressure range on the sheet stack P is 4.0 mm in the X direction (horizontal direction) and 300 mm in the Y direction (vertical direction). Here, the receiving member 506 is a silicone rubber plate with a thickness of 2.0 mm, which is a member for stably receiving the pressure force. The pressure applied to the sheet stack can be controlled by the pressing amount of the pressure lever 504. Then, the thermocompression unit 51 heats and presses the sheet stack, and then separates it. Through the above process, the adhesive toner Tn applied to the sheets acts as an adhesive by thermal melting and fixing, and the sheets are bonded together. In the booklet production device of this invention, a configuration is adopted in which these heating and pressing processes are performed every five sheets. Therefore, when producing a booklet of, for example, 15 sheets, the above process is performed three times in total, every five sheets.

[0026] Next, the printing area of ​​the adhesive toner Tn in this embodiment will be described with reference to FIG. 5. As shown in FIG. 5(a), the adhesive toner Tn forms an image on the end of the long side of the sheet, so that the booklet produced by the booklet producing device can produce a long booklet as a finished product. In this embodiment, the adhesive toner is applied to the front and back sides of the sheet, except for the front and back covers, using the double-sided printing mode when producing the booklet. FIG. 5(b) is a view of the sheet viewed from the short side, and as shown in FIG. 5(b), the adhesive toner Tn is applied to the front and back sides of the sheet, so that when multiple sheets are bonded together, the adhesive toners of the sheets are in contact with each other. The adhesive toner is applied only to the surfaces of the front and back covers that will be the inside of the booklet. Here, the width W of the printing area of ​​the adhesive toner is set to 4.0 mm. Also, as shown in FIG. 5(c), the adhesive toner Tn is formed on a part of the end of the long side, so that the booklet can be produced as a finished product with corners. In this embodiment, the toner amount (laying amount) per unit area of ​​the adhesive toner Tn is 0.50 mg / cm 2 That is, 0.50 mg / cm2 on the front and back sides of the sheet 2 The amount of toner was measured after the secondary transfer and before the fixing process in an unfixed state.

[0027] 1 again, after the binding process by the thermocompression bonding unit 51 is completed, a bundle discharge guide (not shown) moves in parallel from the standby position toward the sheet discharge outlet 45 to push out the sheet bundle. A bundle discharge roller 38 is provided at the sheet discharge outlet 45. The bundle discharge guide stops at a position where the leading edge of the sheet bundle slightly passes the bundle discharge roller 38 and returns to the standby position again. The bundle discharge roller 38 discharges the sheet bundle received from the bundle discharge guide to the lower discharge tray 37.

[0028] 3. Method for controlling image forming operation and booklet production operation according to booklet production mode Next, the image forming operation according to the booklet production mode, which is a feature of this embodiment, and the control method of the booklet production operation will be described in detail. First, two booklet production modes that the booklet production device of this embodiment has will be described. The first mode is a booklet production mode in which an adhesive layer and a toner image are formed in each of the adhesion area and the image formation area in the image formation operation, and then the above-mentioned booklet production operation is performed by the booklet production device. Specifically, as shown in FIG. 6(a), when a blank sheet is set in the sheet cassette 8 or the multi-tray 20 of the image forming device 1 and a booklet is produced, a booklet with a desired image formed in the image formation area on the sheet is produced as an output. On the other hand, this embodiment has a second mode as a booklet production mode different from the first mode. The second mode is a mode in which an adhesive layer is formed in the adhesion area in the image formation area in the image formation operation, and then the booklet production operation is performed by the booklet production device. Specifically, as shown in FIG. 6(b), when a printed material on which a desired image has already been printed in the image forming area is set in the sheet cassette 8 or multi-tray 20 of the image forming device 1 and a booklet is produced, a booklet of the sheets set as the output is produced.

[0029] As a use case, an environment is assumed in which a large office or the like has multiple image forming devices with only a printing function such as a single function printer (SFP), but only one image forming device with a booklet making device capable of making booklets. When only the printed matter to be made into a booklet is set in the image forming device with the booklet making device among the printed matters outputted by the multiple SFPs and made into a booklet, the second mode is used. In addition, as another use case, it is assumed that the second mode is used when it is desired to make a printed matter provided by a third party into a booklet. That is, it is a mode used when making a printed matter outputted by another image forming device into a booklet without changing the image in the image forming area. It is also assumed that a booklet with all pages being blank is made. Specifically, as shown in FIG. 6(c), when a blank sheet is set in the sheet cassette 8 or the multi-tray 20 of the image forming device 1 and a booklet is made, a booklet with all pages being blank is made as an output. In this case, the second mode can also be used. One use case envisioned is for users to use it to create notebooks, doodle books, sketchbooks, etc. from a blank sheet of paper.

[0030] In this embodiment, the control contents of the image forming operation and the booklet production operation are changed between the first mode and the second mode. In this embodiment, a form in which the control of the fixing device 6 of the image forming apparatus is changed between the first mode and the second mode will be described. Specifically, a form in which the fixing temperature in the second mode is set lower than the fixing temperature in the first mode will be described. First, when a user produces a booklet, the booklet production mode can be selected as the first mode or the second mode according to the use case described above. In this embodiment, the booklet production mode can be selected by the user touching the setting screen displayed on the operation panel 50. A control method of the fixing device 6 during image formation when the first mode is selected as the booklet production mode will be described. In the fixing device 6, the power supply to the fixing ceramic heater 61 is controlled based on the detected temperature of the temperature detection element 66 so as to maintain a suitable temperature during fixing. In this embodiment, while the sheet is passing through the fixing nip, the detected temperature of the temperature detection element 66 is controlled so as to be maintained at a predetermined target temperature (fixing temperature).

[0031] It is preferable to set the fixing temperature as low as possible from the viewpoint of power saving. However, if the fixing temperature is set too low, the toner and the sheet cannot be sufficiently heated in the fixing nip due to the insufficient heat supply, and the adhesion of the toner to the sheet does not appear, resulting in the following fixing failure. For example, when a user touches a sheet after fixing, a part of the toner image is microscopically damaged or falls off, causing a dot-like white spot (white dot) on the toner image, or the density of the toner image decreases when the user rubs it, causing a fixing failure. In addition, a problem occurs in which a part of the toner stains the user's hands. Therefore, it is preferable to set the fixing temperature of the fixing device as low as possible within a range in which the above-mentioned fixing failure does not occur. In the first mode of this embodiment, the fixing temperature of the fixing device is set to 220° C. based on the above-mentioned idea. In other words, the toner image in the image forming area of ​​the output booklet is set to a temperature as low as possible within a range in which the fixing failure does not occur. On the other hand, when the second mode is selected as the booklet production mode, the fixing temperature of the fixing unit is set to 210° C., a lower temperature than in the first mode, and the amount of heat generated by the fixing unit is made smaller than in the first mode. The purpose is to improve power saving.

[0032] The reason why the fixing temperature can be lowered in the second mode will be explained. In the second mode, the toner image transferred onto the sheet at the transfer nip 5n is only the adhesive area, and the toner image is not transferred to the image forming area. The toner in the adhesive area becomes the adhesive part of the booklet by being heated and pressed in the booklet making operation in the booklet making device after passing through the fixing device. That is, the toner image in the adhesive area is not directly touched by the user or visible to the user. Therefore, by setting the fixing temperature low, even if the above-mentioned fixing failure occurs, the quality of the booklet as the final product is not affected, and there is no problem of the user's hands getting dirty when picking up the booklet. For the above reasons, in this embodiment, the fixing temperature in the second mode is set lower than the fixing temperature in the first mode to improve power saving. In addition to improving power saving, lowering the fixing temperature in the second mode also leads to improved booklet quality. As in the use case described in Figure 6(b), when printed materials with already formed images are made into booklets, the higher the fixing temperature, the more likely it is that the image on the printed materials will discolor or the sheets will curl or become deformed. In order to improve the quality of the booklet, it is desirable to keep the fixing temperature as low as possible.

[0033] However, if the fixing temperature is set too low, the toner image in the adhesive region may be offset to a large extent, which may result in a significant reduction in the amount of toner in the adhesive region. If the amount of toner in the adhesive region is extremely reduced, sufficient adhesion cannot be ensured after the heating and pressure treatment in the booklet production operation, which may result in a reduction in the adhesive strength of the booklet. Therefore, it is preferable to lower the fixing temperature in the second mode within a range in which the adhesive strength of the booklet can be maintained. Note that this embodiment focuses on the difference in the amount of heat required by the fixing device in the first mode and the second mode, and does not change the fixing temperature according to the difference due to the amount of toner placed on the sheet. Therefore, even if a printing toner is used as the adhesive toner and the amount of toner placed on the adhesive region is the same as the amount of toner placed on the image forming region, in this embodiment, the fixing temperature in the second mode can be lowered compared to the first mode. For example, when the amount of toner placed on the adhesive region in the first mode is 0.50 mg / cm 2, the toner amount in the image forming area is 0.50 mg / cm 2 The fixing temperature is 220° C. when the toner amount in the adhesion area is 0.50 mg / cm 2 in the second mode. 2 Nevertheless, the fixing temperature can be set to 210° C., which is lower than that in the first mode. That is, this embodiment is characterized in that the fixing temperature is changed depending on the booklet production mode even if the amount of toner carried on the sheet is the same.

[0034] 4.Performance evaluation test Here, the results of a performance evaluation test conducted to confirm the effect of this embodiment will be described. In the performance evaluation test, the power consumption of the fixing unit and the fixing property were measured and compared under different fixing temperature conditions in the first and second modes when producing booklets. Red Label Presentation (Canon, A4 size) was used as the evaluation paper, and 20 booklets were produced in each of the first and second modes. In the first mode, a blank sheet was set in the sheet cassette 8, and a patch image of 1.5 cm x 1.5 cm was formed as a toner image in the image formation area, and then the booklet was produced. The toner amount (laying amount) per unit area of ​​the patch image was 0.50 mg / cm, the same as the adhesive toner Tn. 2 On the other hand, in the second mode, a sheet on which a 1.5 cm x 1.5 cm patch image has already been printed (fixed) is set in the sheet cassette 8, and a booklet is produced without forming a new toner image in the image forming area.

[0035] In the evaluation test, in this embodiment, the fixing temperature of the fixing unit is set to 220° C. in the first mode and 210° C. in the second mode to produce a booklet. In addition, as a comparative example, an example in which the fixing temperatures in the first mode and the second mode are set to the same value was also evaluated. As Comparative Example 1, a case in which the fixing temperatures in the first mode and the second mode are both 220° C. was evaluated, and as Comparative Example 2, a case in which the fixing temperatures in the first mode and the second mode are both 210° C. was evaluated. In the evaluation test, the sheet conveying speed in the image forming apparatus was set to 320 mm / sec, the number of prints per minute was set to 60 ppm, the power consumed by the fixing unit was measured with a power meter, and the average power consumption during booklet production was measured.

[0036] To evaluate fixability, the patch image area of ​​the output booklet was rubbed back and forth five times with Silbon paper (Nikon Corporation) with a load of 50 g / cm2 applied, and it was confirmed whether or not "white spots" occurred on the patch image after rubbing. The evaluation results are shown in Table 1. Table 1 shows the power consumption of the fixing device and the occurrence of fixing failure (white spots) in Comparative Example 1, Comparative Example 2, and this embodiment, and indicates "X" if white spots occurred after rubbing the patch image area, and "O" if they did not occur.

[0037] [Table 1]

[0038] First, in Comparative Example 1, the fixing temperature in the first mode was 220°C, and the average power consumption of the fixing device during booklet production was 710W. When the patch image portion of the output booklet was rubbed by the above-mentioned method to check the fixing property, no fixing failure such as "white spots" occurred. In Comparative Example 1, the fixing temperature was also 220°C in the second mode, and the average power consumption during booklet production was 710W, which was the same value as in the first mode. In the second mode, the patch image portion of the output booklet was also rubbed by the above-mentioned method to check the fixing property, and no fixing failure such as "white spots" occurred.

[0039] Next, in Comparative Example 2, the fixing temperature in the first mode was 210°C, and the average power consumption of the fixing unit during booklet production was 680W, which was lower than that of Comparative Example 1. However, when the patch image portion of the output booklet was rubbed to check the fixability, a "white dot" occurred in a part of the patch image, resulting in poor fixing. This was caused by the low fixing temperature, which was unable to supply sufficient heat to the toner and the sheet. On the other hand, in Comparative Example 2, the fixing temperature was 210°C even in the second mode, and the average power consumption during booklet production was 680W. In the second mode, the patch image portion of the output booklet was already fixed while it was set in the sheet cassette 8, so that rubbing the patch image portion did not cause poor fixing such as "white dots". Finally, the results of this embodiment will be described. The fixing temperature in the first mode was 220°C, and the average power consumption of the fixing unit during booklet production was 710W. Furthermore, when the patch image portion of the output booklet was rubbed by the above-mentioned method to check the fixability, poor fixing such as "white dots" did not occur. On the other hand, since the fixing temperature in the second mode is set to 210° C., which is lower than that in the first mode, the average power consumption during booklet production is suppressed to 680 W. In addition, in the second mode, the patch image portion of the output booklet is already fixed while it is set in the sheet cassette 8, so that even if the patch image portion is rubbed, no fixing failure such as “white spots” occurs. Furthermore, since the fixing temperature is low, the amount of curl of the sheet is also suppressed compared to Comparative Example 1. In this way, by setting the fixing temperature in the second mode lower than that in the first mode, it is possible to reduce the power consumption of the fixing device without causing fixing failure such as “white spots”. As described above, in this embodiment, by suppressing the fixing temperature in the second mode lower than that in the first mode, it is possible to improve power saving without impairing the quality of the booklet, which is the output product.

[0040] Furthermore, by setting the fixing temperature low, the temperatures of the fixing film 62 and the sliding grease are also low, so that, for example, the wear of the fixing film 62 relative to the number of revolutions of the fixing film 62 can be suppressed, and the thermal deterioration of the sliding grease can be suppressed, leading to an improvement in the life of the fixing device. In addition, when the toner or the sliding grease is heated during fixing, for example, the wax contained in the toner and the oil component contained in the sliding grease volatilize. It is known that the oil component then recrystallizes in the air, generating ultra-fine particles (UFP: Ultra Fine Particle) with a particle size of 100 nm or less. The amount of UFP generated tends to increase as the fixing temperature increases, and lowering the fixing temperature as in this embodiment also leads to a reduction in the amount of UFP generated.

[0041] In addition, by making the fixing temperature in the second mode lower than that in the first mode as in this embodiment, the temperature rise in the image forming apparatus in the second mode becomes gentle. Therefore, the air volume of the fan 70 in the second mode may be made weaker than that in the first mode, or the operation time of the fan may be made shorter than that in the first mode. This makes it possible to reduce the power consumption of the fan in the second mode, and further improve power saving. In addition, when a large number of booklets are continuously produced, in order to prevent the temperature inside the apparatus from becoming high and adversely affecting the members in the apparatus and the toner in the process cartridge 7, a control (temperature rise suppression control) may be provided to temporarily stop the booklet production during booklet production and cool the inside of the apparatus. When such a control is provided, in this embodiment, the temperature rise in the image forming apparatus in the second mode becomes gentler than that in the first mode. Therefore, it is preferable to execute the temperature rise suppression control less frequently in the second mode than in the first mode. This can increase the productivity of booklet production in the second mode, and can reduce the time during which the temperature rise suppression control is performed (time during which the device is operating to cool the inside of the device even though booklets are not produced), thereby reducing the power consumption required for booklet production. In this embodiment, the sheet temperature after passing through the fixing unit in the second mode is lower than that in the first mode. If the moving time of the sheet from the fixing unit to the thermocompression bonding unit 51 is extremely short, and a difference occurs in the sheet temperature when bonding in the thermocompression bonding unit between the first mode and the second mode, and a difference occurs in the adhesive strength of the booklet, the adhesive conditions of the thermocompression bonding unit may be changed. For example, it is preferable to set the pressure of the thermocompression bonding unit stronger than in the first mode, the pressure time longer, or the temperature of the heating plate higher in the second mode, so that the adhesive strength of the booklet does not deteriorate more than in the first mode. From the viewpoint of power saving, it is desirable to change the above adhesion conditions within a range in which the power consumption of the entire apparatus (image forming apparatus and booklet producing apparatus) is smaller in the second mode than in the first mode.

[0042] In addition, in this embodiment, the fixing temperature of the fixing unit is changed to improve power saving, but the sheet conveying speed of the image forming apparatus can be changed to improve productivity in booklet production. For example, the fixing temperature may be fixed at 220° C., and the sheet conveying speed in the first mode may be set to 320 mm / sec, while the sheet conveying speed in the second mode may be set to 370 mm / sec, which is faster than the first mode. When the sheet conveying speed is increased, the time during which the fixing film 62 and the sheet are in contact with each other in the fixing nip 6n is shortened. That is, the time during which heat can be supplied from the fixing film 62 is shortened, and as a result, the amount of heat supplied to the sheet and the toner on the sheet is reduced. Therefore, as described above, when a user touches a sheet after fixing, a part of the toner image is microscopically damaged or falls off, causing dot-like white spots (white spots) on the toner image, or the density of the toner image is reduced when the user rubs the sheet, causing fixing failure.

[0043] However, in the second mode, the toner image transferred onto the sheet at the secondary transfer unit in the image forming apparatus is only the adhesive area, and no toner image is transferred to the image forming area. The toner in the adhesive area becomes the adhesive part of the booklet by being heated and pressed in the booklet production operation in the booklet production device after passing through the fixing device. That is, the toner image in the adhesive area is not directly touched or visible to the user. Therefore, by setting the conveying speed faster, even if the above-mentioned fixing failure occurs, the quality of the booklet, which is the final product, is not affected, and there is no problem of the user's hands getting dirty when picking up the booklet. For the above reasons, it is possible to set the sheet conveying speed in the second mode faster than that in the first mode, shorten the time required for booklet production, and as a result, increase the productivity of booklet production. In addition, the decrease in power for supplying heat to the toner on the sheet is greater than the increase in power for increasing the conveying speed, improving power saving.

[0044] In addition, in this embodiment, a toner image is not formed in the image forming area, but an electronic watermark (texture watermark) in which information at the time of booklet production is embedded in the image forming area may be formed as a dot pattern with a low coverage rate. By forming a texture watermark in the image forming area of ​​the booklet, the device that produced the booklet and the booklet production conditions can be identified and traced from the texture watermark of the booklet, which is the output, and security can be improved. For example, as shown in FIG. 6(b), when a printout output by another image forming device is made into a booklet under the same fixing temperature condition as the second mode, the fixing temperature condition is embedded in the image forming area as a texture watermark in a state that is not visible to the user. In this way, it becomes possible to know that the device that output the printout is different from the device that made the booklet afterwards, and that no additions or corrections were made to the image in the image forming area when the booklet was made. If a dot pattern with a low coverage rate is used as the texture watermark, the above-mentioned fixing failure does not occur even under a low fixing temperature condition.

[0045] Furthermore, if a background watermark with information from another image forming apparatus already embedded therein is present on a printed matter output by another image forming apparatus, it may overlap with the background watermark at the time of booklet production, resulting in a risk of reduced identification accuracy. Therefore, the background watermark may be embedded in the toner image in the adhesive region. For example, the identification accuracy may be improved by forming a pattern of hollow dots (a pattern in which areas without adhesive toner are regularly provided) in the toner image in the adhesive region. Alternatively, the identification accuracy may be improved by forming printing toners Ty, Tm, and Tc as a dot pattern in the toner image in the adhesive region. Furthermore, a barcode or a matrix type two-dimensional code may be formed in the adhesive region.

[0046] Also, the pattern of the background watermark may be changed for each page of the booklet, and information based on the page number may be embedded. By doing so, for example, after producing a booklet of a contract or confidential document, it is possible to know if a part of a page has been removed or tampered with, thereby improving the security of the booklet. Note that even when producing a booklet in the first mode, the background watermark as described above may be formed in the adhesive area and the image formation area. In this way, by forming a background watermark on a sheet when producing a booklet, it is possible to improve the security of the output booklet.

[0047] [Example 2] Next, a second embodiment will be described. The basic configuration of the image forming apparatus and the booklet making apparatus is the same as that of the first embodiment described with reference to FIG. 1. Therefore, the description of the image forming apparatus described in the first embodiment will be used, and a detailed description will be omitted here. In this embodiment, a form in which the output of the fixing bias of the fixing device is changed between the first mode and the second mode will be described. As shown in FIG. 2, in the fixing device of this embodiment, a voltage (fixing bias) of a polarity opposite to the normal charging polarity of the toner, which is a predetermined polarity, is applied from the power source 69 to the core metal part of the pressure roller (rotating body) 63. By applying the fixing bias to the pressure roller 63, an electrostatic attraction acts on the toner on the sheet toward the pressure roller 63 side (sheet side), preventing offset and scattering of the toner. In this embodiment, in the first mode, when the sheet passes through the fixing device, a voltage of +1500V is applied to the pressure roller 63 as the fixing bias. On the other hand, in the second mode, the output of the power source 69 is turned off, and the fixing bias is not applied to the pressure roller 63.

[0048] In the second mode, since there is no unfixed toner in the image forming area, offset or scattering of toner does not occur in the image forming area. On the other hand, in the unfixed toner in the adhesion area, the electrostatic attraction to the sheet is reduced compared to the first mode, and minor offset or scattering is likely to occur. However, the adhesion area is an area in the booklet, which is the final product, that is not visible to the user, and even if minor offset or scattering occurs, the quality of the booklet is not impaired. In this way, by making the output of the fixing bias in the second mode smaller than the output in the first mode, it is possible to reduce the power consumption of the power source 69 and improve power saving. In this embodiment, the fixing bias is completely turned off at 0V, but it is not limited to this, and any voltage lower than that in the first mode may be used, for example, +500V. The level of offset and scattering varies depending on the toner characteristics, the physical properties of the fixing film, the pressure roller, etc. It is preferable to lower the output according to the configuration of the fixing unit within a range where extremely bad offset and scattering do not occur and do not adversely affect the adhesive strength of the booklet. The same effect can be obtained by applying a voltage of the same polarity as that of the toner to the fixing film 62 as a rotating body.

[0049] [Example 3] Next, a third embodiment will be described. The basic configurations of the image forming apparatus and the booklet producing apparatus are the same as those of the first embodiment described with reference to FIG. 1. Therefore, the description of the image forming apparatus described in the first embodiment will be used, and a detailed description will not be repeated here. In this embodiment, a form in which the pressure of the fixing unit is changed between the first mode and the second mode will be described. In the fixing unit of this embodiment, in order to form a fixing nip 6n, a pressure roller 63 is pressed against a fixing ceramic heater 61 via a fixing film 62 by a pressure means such as a spring pressure. In addition, the pressure of the pressure means can be changed by controlling the rotation of a cam provided at the end of the pressure spring.

[0050] The smaller the pressure applied by the fixing unit, the smaller the elastic deformation of the pressure roller 63, so the fixing nip 6n becomes narrower, and the time during which the fixing film 62 and the sheet are in contact at the fixing nip 6n becomes shorter. That is, the time during which heat can be supplied from the fixing film 62 becomes shorter, and as a result, the amount of heat supplied to the sheet and the toner on the sheet decreases. Therefore, when a user touches a sheet after fixing, a fixing failure such as the generation of white spots or a decrease in the density of the toner image occurs. On the other hand, if the pressure applied by the fixing unit is set high, the sliding resistance at the fixing nip portion increases, the torque of the motor driving the pressure roller 63 increases, and the power consumption of the motor tends to increase. Therefore, it is preferable to set the pressure applied by the fixing unit as low as possible within a range in which the above-mentioned fixing failure does not occur. In the first mode of this embodiment, the pressure applied by the fixing unit is set to 20 kgf based on the above-mentioned idea. That is, the pressure applied by the fixing unit is set to as low as possible within a range in which the toner image in the image forming area of ​​the output booklet does not cause a fixing failure. On the other hand, when the second mode is selected as the booklet production mode, the pressure of the fixing unit is set to 15 kgf, a lower value than in the first mode, and the torque of the motor that drives the pressure roller is set to be smaller than in the first mode. The purpose is to improve energy conservation by reducing the power consumption of the motor.

[0051] The reason why the pressure can be reduced in the second mode will be explained. In the second mode, in the image forming apparatus, the toner image transferred onto the sheet at the secondary transfer unit is only the adhesive area, and the toner image is not transferred to the image forming area. The toner in the adhesive area becomes the adhesive part of the booklet by being heated and pressurized in the booklet production operation in the booklet production device after passing through the fixing device. That is, the toner image in the adhesive area is not directly touched by the user or visible to the user. Therefore, by setting the pressure to a low level, even if the above-mentioned fixing failure occurs, the quality of the booklet, which is the final product, is not affected, and there is no problem of the user's hands getting dirty when picking up the booklet. For the above reasons, in this embodiment, the pressure of the fixing unit in the second mode is set lower than that in the first mode, reducing the power consumption of the motor driving the pressure roller, and as a result, improving power saving.

[0052] Furthermore, by reducing the pressure of the fixing unit, the sliding resistance between the fixing ceramic heater 61 and the fixing film 62 can be reduced, and for example, it is possible to suppress wear on the inner surface of the fixing film 62 relative to the rotation speed of the fixing film 62. It is also possible to reduce the sliding resistance with the bearing portion that supports the rotating shaft of the metal core of the pressure roller. Thus, in this embodiment, by setting the pressure of the fixing unit in the second mode lower than the pressure of the first mode, it is possible to improve power saving and also to improve the life of the fixing unit.

[0053] [Example 4] Next, a fourth embodiment will be described. The basic configuration of the image forming apparatus and the booklet production apparatus is the same as that of the first embodiment described with reference to FIG. 1. Therefore, the description of the image forming apparatus described in the first embodiment will be used, and detailed description will be omitted here. In this embodiment, control for preventing contamination of the fixing unit that may occur when a large amount of booklet production is repeated only in the second mode will be described. In the first to third embodiments, a form for improving power saving by setting the fixing temperature, fixing bias, and pressure force lower than those in the first mode has been described. As described above, the toner in the adhesion area in the second mode is more likely to cause fixing defects such as white spots and offset than in the first mode.

[0054] If the booklet production operation is repeated under conditions where poor fixing or offset is likely to occur, a part of the toner that is microscopically missing or has fallen off from the toner image may transfer to the surface of the fixing film 62 or the pressure roller and aggregate, which may cause so-called contamination. This is particularly likely to occur when the surfaces of the fixing film 62 or the pressure roller 63 are rough or have paper powder or filler from the sheets attached to the surface. If contamination occurs, it may adversely affect the sheet conveyance performance or cause a further decrease in fixing performance. In this embodiment, in order to prevent the above-mentioned contamination, when only booklet production in the second mode is performed continuously beyond a predetermined number of sheets (first number of sheets), the setting of the fixing unit in the second mode is changed.

[0055] In this embodiment, when only the booklet production in the second mode is performed on a predetermined number of sheets (=200 sheets), the fixing temperature when fixing the next 20 sheets is set to 10° C. higher. For example, when the fixing temperature in the second mode is 210° C. as in the first embodiment, after the predetermined number of sheets (=200 sheets) are passed, the fixing temperature from the 201st sheet to the 220th sheet is set to 220° C. By setting the fixing temperature high and raising the temperature of the toner transferred to the fixing film 62 or the pressure roller, the adhesion to the sheet is increased, and the toner is transferred again to the sheet to suppress contamination. Then, after fixing the predetermined number of sheets (second number of sheets), 20 sheets, at the fixing temperature of 220° C., the fixing temperature is returned to 210° C. and the production of the booklet is continued.

[0056] Also, in order to more effectively heat the toner transferred to the fixing film 62 or the pressure roller, the sheet conveying interval may be extended. Furthermore, by increasing not only the fixing temperature but also the pressure, the fixing nip may be widened and the contact time with the sheet may be extended, so that the toner transferred to the fixing film 62 or the pressure roller may be easily transferred back to the sheet. The likelihood of contamination occurring and the ease of transfer vary depending on the toner characteristics, the physical properties of the fixing film and the pressure roller, and the like. Therefore, it is preferable to set the predetermined number of sheets that triggers the change of the fixing device settings, the number of sheets for which the settings of the fixing device are changed thereafter, the fixing temperature, the amount of change in the pressure, and the like to optimal values ​​according to the configuration of the fixing device, without being limited to the above-mentioned values.

[0057] In addition, in a situation where contamination is likely to occur, the setting of the fixing unit may be changed for several sheets including the last page of the booklet, instead of changing the setting after a predetermined number of sheets as described above. For example, when producing a booklet of 30 sheets, the fixing temperature may be increased, the sheet conveying interval may be extended, or the pressure may be increased for the 26th to 30th sheets as described above. In this way, even if minor contamination occurs during booklet production in the second mode, the quality of the back cover of the booklet, the printed matter of the next job, and the front cover of the booklet of the next job is not impaired. For example, when a booklet is produced in the second mode, if minor contamination occurs on the fixing film or pressure roller, the contamination may be transferred again to the back cover of the booklet (a back cover where no toner image exists in the adhesive area), thereby impairing the quality of the back cover.

[0058] In addition, after a booklet is produced in the second mode, when a normal printing operation that does not produce a booklet is performed in the next job, the contamination may be re-transferred onto the sheet of the next job (on the sheet on which the toner image does not exist in the adhesive area), impairing the quality of the printed image. In addition, even when booklet production is repeated, the contamination may be re-transferred onto the front cover of the booklet in the next job (on the front cover on which the toner image does not exist in the adhesive area), impairing the quality of the front cover of the booklet. Therefore, when producing a booklet in the second mode, the contamination attached to the fixing film or pressure roller surface is always re-transferred in advance onto the sheet on which the adhesive area exists at the end of the booklet production operation. This makes it possible to maintain the quality of the back cover, the printed matter of the next job, and the front cover of the booklet of the next job. Note that the ease of occurrence of contamination and the ease of re-transfer vary depending on the toner characteristics, the physical properties of the fixing film and the pressure roller, etc. Therefore, it is preferable to set the optimal value according to the configuration of the fixing device, rather than being limited to the above-mentioned value, for the number of sheets for which the setting of the fixing device is changed.

[0059] [Example 5] Next, a fifth embodiment will be described. The basic configurations of the image forming apparatus and the booklet producing apparatus are the same as those of the first embodiment described with reference to FIG. 1. Therefore, the description of the image forming apparatus described in the first embodiment will be used, and detailed description will not be repeated here. In this embodiment, a form in which the heat distribution of the fixing unit is changed between the first mode and the second mode will be described. FIG. 7 is a diagram for explaining the resistive heating element pattern of the fixing ceramic heater 61, the heat distribution, and the adhesive area on the sheet in this embodiment.

[0060] The fixing ceramic heater 61 of this embodiment employs a heater capable of varying the heat generation distribution in the sheet width direction (the direction intersecting the sheet conveying direction on the sheet surface). As an example, as shown in FIG. 7(a), a heater having a resistance heating element pattern including resistance heating elements 85 and 86 narrowed in the sheet conveying direction at the center in the width direction and a resistance heating element 87 narrowed in the sheet conveying direction at the end in the width direction will be described. When electricity is applied between the power supply electrodes 88 and 89 via a current control means such as a triac, the resistance heating elements 85 and 86 generate heat, and a heat generation distribution in which the heat generation amount is high at the center in the width direction is obtained as shown in 1A of FIG. 7(b). On the other hand, when electricity is applied between the power supply electrodes 88 and 90, the resistance heating element 87 generates heat, and a heat generation distribution in which the heat generation amount is high at the end in the width direction is obtained as shown in 1B of FIG. 7(b). In this embodiment, the heat generation distribution in the width direction is variable by controlling the current ratio between the power supply electrodes 88, 89 and between the power supply electrodes 88, 90. In this embodiment, in the fixing device in which the heat generation distribution in the width direction is variable as described above, the fixing temperature of the image forming area relative to the fixing temperature of the adhesive area in the second mode is smaller than that in the first mode. For example, in the case of a heater as shown in FIG. 7(a), in the first mode, the current ratio between the power supply electrodes 88, 89 and between the power supply electrodes 88, 90 is made approximately equal, and control is performed to obtain a substantially uniform heat generation distribution along the sheet width direction. In this way, the adhesive area (adhesive layer area) and the image forming area (toner image area) are uniformly heated, and the unfixed toner in the adhesive area and the unfixed toner in the image forming area are well fixed onto the sheet. On the other hand, in the second mode, the ratio of current flow between power supply electrodes 88 and 90 is increased relative to the current flow between power supply electrodes 88 and 89, and control is performed to obtain a heat generation distribution in which the heat generation amount at the sheet width direction end is high. At this time, by controlling the fixing temperature of the temperature detection element disposed at a position corresponding to the adhesion region to be the same temperature as in the first mode, it is possible to reduce the heat generation amount in the image forming region where there is no unfixed toner while satisfactorily fixing the unfixed toner in the adhesion region onto the sheet. That is, in the second mode, by setting the fixing temperature lower than that in the first mode, it is possible to reduce the heat generation amount of the fixing unit and improve power saving.

[0061] Furthermore, as a resistive heating element pattern for improving power saving, a pattern in which the resistive heating element is divided in the sheet width direction and electricity is applied in the sheet conveying direction may be adopted as shown in Fig. 7(c). When electricity is applied between the power supply electrodes 91 and 92, the resistive heating element 94 generates heat, and the resulting heat distribution is a distribution in which heat is generated mainly only in the image forming area as shown in Fig. 7(d) 2A. On the other hand, when electricity is applied between the power supply electrodes 93 and 92, the resistive heating element 95 generates heat, and the resulting heat distribution is a distribution in which heat is generated mainly only in the adhesive area of ​​Fig. 7(e) as shown in Fig. 7(d) 2B. Note that, for simplicity, the resistive heating element is divided perpendicular to the sheet width direction in Fig. 7(c), but it may be divided obliquely to suppress uneven heat generation in the divided portion. 7(c), in the first mode, current is applied between the power supply electrodes 91, 92 and between the power supply electrodes 93, 92, and the control is performed to obtain a substantially uniform heat distribution along the sheet width direction. This causes the adhesive region and the image forming region to be uniformly heated, and the unfixed toner in the adhesive region and the unfixed toner in the image forming region are fixed satisfactorily onto the sheet.

[0062] On the other hand, in the second mode, the amount of current passing between the power supply electrodes 91 and 92 is controlled to be smaller than that in the first mode, so that a heat generation distribution is obtained that reduces the fixing temperature. At this time, the fixing temperature of the temperature detection element disposed at a position corresponding to the adhesion area is controlled to be the same temperature as that in the first mode, so that the unfixed toner in the adhesion area can be fixed well on the sheet while the amount of heat generation in the image forming area where there is no unfixed toner can be reduced. That is, in the second mode, the fixing temperature is made smaller than that in the first mode, so that it is possible to reduce the amount of heat generation in the fixing device and improve power saving. In the case of a heater as shown in FIG. 7(c), the amount of heat generation in the area other than the adhesion area can be significantly reduced, and power saving can be significantly improved. In addition, by reducing the amount of heat generation in the image area of ​​the fixing device, not only power saving can be improved, but also the quality of the booklet can be improved (reduction of discoloration of the printed image, suppression of curling), the life of the fixing device can be improved, the temperature rise in the device can be suppressed, and the effect of reducing the amount of UFP emissions can be improved. In this embodiment, a ceramic heater type fixing unit has been described, but similar effects can be obtained with other types of fixing units, such as an electromagnetic induction heating (IH) heater or a halogen heater type that heats the fixing member with radiant heat, as long as the heat distribution in the sheet width direction can be changed. In each heating method, power saving can be improved by setting the "ratio of the heat generated by the image forming area to the heat generated by the adhesive area" to be smaller in the second mode than in the first mode.

[0063] As described in the first embodiment, the toner in the adhesive region becomes the adhesive portion of the booklet by being heated and pressurized in the booklet production operation in the booklet production device after passing through the fixing device. That is, the toner image in the adhesive region is not directly touched or visually recognized by the user. Therefore, even if the fixing temperature in the adhesive region is set lower than the fixing temperature in the image formation region, it does not affect the quality of the booklet, which is the final product. Therefore, when a heater capable of varying the heat distribution is adopted as in this embodiment, the fixing temperature of the temperature detection element disposed at a position corresponding to the adhesive region may be set lower than the fixing temperature of the temperature detection element disposed at a position corresponding to the image formation region even in the first mode. For example, by setting the fixing temperature in the adhesive region to 210° C. and the fixing temperature in the image formation region to 220° C. in the first mode, it is possible to reduce the power consumption of the fixing unit in the first mode more than in the first embodiment, and improve power saving.

[0064] [Example 6] Next, a sixth embodiment will be described. The basic configuration of the image forming apparatus and the booklet making apparatus is the same as that of the first embodiment described with reference to FIG. 1. Therefore, the description of the image forming apparatus described in the first embodiment will be used, and a detailed description will be omitted here. In this embodiment, a form in which toner purge control is periodically performed on areas other than the adhesive area when making a booklet in the second mode will be described. When making a booklet in the second mode, the toner image transferred to the transfer belt 3a in the primary transfer process is only the adhesive area. That is, in areas other than the adhesive area, toner is not supplied onto the transfer belt 3a, and there is no toner (secondary transfer residual toner) remaining on the transfer belt 3a after the secondary transfer. The sliding property between the cleaning blade (blade member) 80, which cleans the toner and adhesive that could not be formed on the sheet, and the transfer belt 3a changes depending on the amount of secondary transfer residual toner sent to the cleaning blade 80. For example, a toner external additive such as silica that has been detached from the toner acts as a sliding material between the cleaning blade 80 and the transfer belt 3a, thereby maintaining good sliding property. Therefore, for example, when a large number of booklets are produced in the second mode, the secondary transfer residual toner is not sent to the cleaning blade 80 for a long period of time in the area other than the area (adhesive area) of the sheet where the adhesive layer is formed in the rotation axis direction of the transfer belt 3a, and the sliding property of the cleaning blade 80 deteriorates. If the sliding property of the cleaning blade 80 deteriorates, the friction coefficient between the cleaning blade 80 and the transfer belt 3a increases, and the blade may turn over, causing a cleaning failure, or the torque of the motor driving the transfer belt 3a may increase. Therefore, in this embodiment, when producing booklets in the second mode, toner purge control is periodically performed. The toner purge control here refers to a control in which toner is transferred from at least one of the process cartridges 7n, 7y, 7m, and 7c to the transfer belt 3a at a timing when image formation is not performed, such as between sheets, and sent to the contact portion between the transfer belt 3a and the cleaning blade 80. In this control, the toner is transferred to the area of ​​the transfer belt 3a corresponding to the image formation area.

[0065] In this embodiment, when making a booklet in the second mode, toner purge control is performed every 50 sheets. Specifically, a predetermined amount of toner is sent from the process cartridge to the cleaning blade 80 between every 50 sheets. When the purged toner passes through the transfer nip 5n, a voltage of the same polarity as the normal charging polarity of the toner, which is a predetermined polarity, is applied to the secondary transfer roller 5, and the toner is electrostatically prevented from adhering to the secondary transfer roller. At this time, the toner purge is performed in the area other than the adhesive area in the sheet width direction. Regarding the adhesive area, since the adhesive toner is transferred to the transfer belt 3a even in the second mode, a sufficient amount of secondary transfer residual toner is sent to the cleaning blade 80 corresponding to the adhesive area. Therefore, from the viewpoint of reducing toner consumption, in this embodiment, toner purge is performed only in the area other than the adhesive area. In this way, in the second mode, by periodically supplying toner to the cleaning blade 80 corresponding to the area other than the adhesive area, the friction coefficient between the cleaning blade 80 and the transfer belt 3a can be stabilized within an appropriate range. This makes it possible to prevent problems such as poor cleaning. Furthermore, since the torque increase of the motor that drives the transfer belt 3a can be suppressed, the power consumption of the motor can be reduced, and as a result, power saving can be improved. The sliding property between the cleaning blade 80 and the transfer belt 3a varies depending on the toner characteristics, and the physical properties and configurations of the transfer belt 3a and the cleaning blade 80. Therefore, it is preferable that the frequency and timing of performing the toner purge are not limited to the above-mentioned values, but are set to optimal values ​​depending on the toner characteristics, and the physical properties and configurations of the transfer belt 3a and the cleaning blade 80.

[0066] In addition, in this embodiment, the cleaning blade 80 in contact with the transfer belt 3a has been described, but toner purge control may be performed on the drum cleaning blade as the photosensitive drum cleaning means. For example, at a timing when image formation is not performed, such as between sheets, a voltage of the same polarity as the normal charging polarity of the toner is applied to the primary transfer roller, and purged toner developed from the powder container is sent to the drum cleaning blade. In this way, by periodically supplying toner to the drum cleaning blade, the friction coefficient between the drum cleaning blade and the photosensitive drum can be stabilized within an appropriate range, thereby preventing problems such as poor cleaning. Furthermore, since the torque increase of the motor that drives the photosensitive drum can be suppressed, the power consumption of the motor can be reduced, and as a result, power saving can be improved.

[0067] [Example 7] Next, a seventh embodiment will be described. The basic configuration of the image forming apparatus and the booklet producing apparatus is the same as that of the first embodiment described with reference to FIG. 1. Therefore, the description of the image forming apparatus described in the first embodiment will be used, and a detailed description will be omitted here. This embodiment is characterized by having a third mode as a booklet producing mode, which is different from the first and second modes described so far. In the third mode, in the image forming operation, a toner image is not formed in either the adhesive area or the image forming area, and then the booklet producing operation is performed by the booklet producing apparatus. Specifically, this is a mode in which a printed matter in which adhesive toner has already been fixed in the adhesive area and a desired image has been printed in the image forming area is set in the sheet cassette 8 or multi-tray 20 of the image forming apparatus 1, and a booklet is produced. As an output, a booklet is produced in which the sheets are bonded together in the adhesive area while the image forming area remains as it is with the image already printed. The difference from the second mode is that adhesive toner has already been fixed to the adhesive area of ​​the sheet set in the sheet cassette 8 or the multi-tray 20. As a use case, a case is assumed in which a desired image is printed in the image area on a sheet and adhesive toner is printed in the adhesive area by an SFP having only a printing function, and then the sheet is made into a booklet by an image forming apparatus having a booklet making device capable of making booklets. In particular, when the adhesiveness is satisfied even if a printing toner is used as the adhesive toner, it is easy to form an adhesive toner image in the adhesive area even in the SFP without preparing a special process cartridge containing the adhesive toner Tn. In this embodiment, it is also possible to include a sheet in which adhesive toner has already been fixed to the adhesive area and the image forming area is blank.

[0068] In this embodiment, the setting of the fixing device of the image forming apparatus in the above-mentioned third mode is changed between the first and second modes. Specifically, at least one of the fixing temperature, fixing bias output, and pressure of the fixing device in the third mode when producing a booklet is made smaller than the value in the second mode. In the third mode, there is no unfixed toner in the image forming area or the adhesion area of ​​the sheet passing through the fixing device. Therefore, the fixing temperature, fixing bias output, and pressure are reduced as much as possible to improve power saving. In this embodiment, the fixing temperature, fixing bias, and pressure are set to values ​​smaller than the values ​​in the second mode, that is, the fixing temperature is 150° C., the fixing bias output is 0 V, and the pressure is 10 kgf in the third mode. However, if the fixing temperature is reduced too much, the viscosity of the sliding grease on the inner surface of the fixing film increases, and the sliding resistance increases, which may deteriorate the sheet conveyance. In addition, if the pressure is reduced too much, a sufficient fixing nip cannot be secured and the sheet cannot be sandwiched and conveyed, which may deteriorate the sheet conveyance. Therefore, in this embodiment, the fixing temperature and pressure are lowered as much as possible within a range where sheet conveyance is ensured, and are set to the above-mentioned values. In this way, in this embodiment, a new third mode is provided as a booklet production mode, and the fixing device setting in the third mode is changed from the first and second modes to improve power saving. Regarding the toner purge control described in the sixth embodiment, it is preferable to perform toner purging in the entire area in the sheet width direction in the third mode. In this embodiment, the sheet in the third mode is set in the sheet cassette 8 or the multi-tray 20 of the image forming apparatus 1, and a booklet is produced, but the sheet feed position is not limited to this. For example, as shown in FIG. 8, a new paper feed unit 100 may be provided in the booklet production apparatus 300, and the sheet may be fed directly from this paper feed unit to the thermocompression unit 51, thereby producing a booklet in the third mode without going through the image forming apparatus. In this case, booklet production is completed only by the booklet production apparatus, and the image forming apparatus does not need to operate, so that further power saving can be improved.

[0069] Furthermore, when power is supplied to the image forming apparatus and the booklet producing apparatus through one power cable and one outlet, the ratio of the amount of power supplied to the fuser 6 of the image forming apparatus and the amount of power supplied to the thermocompression bonding unit 51 of the booklet producing apparatus may be changed for each of the first, second and third modes. Specifically, the "ratio of the amount of power supplied to the thermocompression bonding unit to the amount of power supplied to the fuser" may be set to have a relationship of "first mode < second mode < third mode". In particular, in order to shorten the start-up time in the initial operation when producing a booklet, it is necessary to heat the fuser and the thermocompression bonding unit simultaneously, and it is desirable to appropriately distribute the power supplied from one power cable between the fuser and the thermocompression bonding unit.

[0070] The fixing temperature of the fixing unit has a relationship of "first mode>second mode>third mode", and the amount of power required to start up the fixing unit in the initial operation has a relationship of "first mode>second mode>third mode". Therefore, in the booklet production mode in which the fixing temperature is low and the amount of power required to start up the fixing unit is small, it is preferable to increase the amount of power supplied to the thermocompression bonding unit and shorten the start-up time of the thermocompression bonding unit. Therefore, the "ratio of the amount of power supplied to the thermocompression bonding unit to the amount of power supplied to the fixing unit" has a relationship of "first mode<second mode<third mode". Furthermore, it is preferable to set the start-up time of the thermocompression bonding unit to a relationship of "first mode>second mode>third mode", thereby improving power saving as described above and shortening the start-up time in the initial operation when producing a booklet.

[0071] In each embodiment, the booklet making device 300 having the thermocompression bonding unit 51 is arranged next to the image forming apparatus 1, but the present invention is not limited to this. For example, as shown in FIG. 9, the top-mounted booklet making device 301 and the thermocompression bonding unit 51 may be arranged on the top of the image forming apparatus main body.

[0072] [Note] The above embodiment discloses at least the following image forming system.

[0073] (Item 1) an image forming means capable of forming a toner image and an adhesive layer on a sheet; and a fixing means for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressurizing, and conveying the sheet; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having an image forming system, characterized in that the predetermined temperature of the fixing means when the sheet is heated and pressed by the fixing means is lower in the second mode than in the first mode.

[0074] (Item 2) Item 1, an image forming system according to the present invention, An image forming system characterized in that, when a booklet is produced in succession in the second mode in excess of a predetermined number of sheets, from the sheet next to the predetermined number of sheets, at least one of the predetermined temperature and the sheet transport interval when heating and pressurizing the sheet by the fixing means in the second mode is made larger than before the predetermined number of sheets in the second mode was exceeded.

[0075] (Item 3) Item 2. The image forming system according to item 2, An image forming system characterized in that the specified number of sheets is a first number of sheets, and when a booklet is produced with a number of sheets exceeding a second number of sheets different from the first number of sheets, or when pressure and heat are applied to a stack of sheets including the final page of the booklet, at least one of the specified temperature and the sheet transport interval is returned to its original value.

[0076] (Item 4) The image forming system according to any one of items 1 to 3, the image forming system has a third mode in which the booklet producing device produces a booklet by using a sheet on which an adhesive layer has been formed in advance, without the image forming means forming a toner image or an adhesive layer on the sheet; an image forming system, characterized in that the predetermined temperature when the sheet is heated and pressed by the fixing means is lower in the third mode than in the second mode.

[0077] (Item 5) an image forming means capable of forming a toner image and an adhesive layer on a sheet; and a fixing means for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressurizing, and pinching and conveying the sheet, the fixing means having a rotating body for pinching and conveying the sheet; a power source that applies a voltage of a predetermined polarity to the rotating body when the sheet is heated and pressed by the fixing means; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having An image forming system, characterized in that the value of the voltage applied from the power source to the fixing means when the sheet is heated and pressurized by the fixing means is smaller in the second mode than in the first mode.

[0078] (Item 6) Item 6. The image forming system according to item 5, An image forming system characterized in that, when a booklet is produced in succession in the second mode in excess of a predetermined number of sheets, from the sheet next to the predetermined number of sheets, at least one of the voltage and the sheet transport interval when heating and pressurizing the sheet by the fixing means in the second mode is made larger than before the predetermined number of sheets in the second mode was exceeded.

[0079] (Item 7) Item 7. The image forming system according to item 6, an image forming system characterized in that the specified number of sheets is a first number of sheets, and when a booklet is produced with a number of sheets exceeding a second number of sheets different from the first number of sheets, or when pressure and heat are applied to a stack of sheets including the final page of the booklet, at least one of the voltage and the sheet transport interval is returned to its original value.

[0080] (Item 8) The image forming system according to any one of items 5 to 7, the image forming system has a third mode in which the booklet producing device produces a booklet by using a sheet on which an adhesive layer has been formed in advance, without the image forming means forming a toner image or an adhesive layer on the sheet; an image forming system, characterized in that a value of the voltage when the fixing means heats and presses the sheet is smaller in the third mode than in the second mode.

[0081] (Item 9) an image forming means capable of forming a toner image and an adhesive layer on a sheet; and a fixing means for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressurizing, and conveying the sheet; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having an image forming system, characterized in that the pressure applied to the sheet by the fixing means when the fixing means heats and presses the sheet is smaller in the second mode than in the first mode.

[0082] (Item 10) Item 9. The image forming system according to item 9, An image forming system characterized in that, when a booklet is produced in succession in the second mode in excess of a predetermined number of sheets, from the sheet next to the predetermined number of sheets, at least one of the pressure and the sheet transport interval when heating and pressurizing the sheet by the fixing means in the second mode is made larger than before the predetermined number of sheets in the second mode.

[0083] (Item 11) Item 11. The image forming system according to item 10, An image forming system characterized in that the specified number of sheets is a first number of sheets, and when a booklet is produced with a number of sheets exceeding a second number of sheets different from the first number of sheets, or when pressure and heat are applied to a stack of sheets including the final page of a booklet, at least one of the pressure and the sheet transport interval is returned to its original value.

[0084] (Item 12) The image forming system according to any one of items 9 to 11, the image forming system has a third mode in which the booklet producing device produces a booklet by using a sheet on which an adhesive layer has been formed in advance, without the image forming means forming a toner image or an adhesive layer on the sheet; an image forming system, characterized in that the pressure applied when the sheet is heated and pressed by the fixing means is smaller in the third mode than in the second mode.

[0085] (Item 13) The image forming system according to any one of items 1 to 12, the fixing unit is capable of changing the predetermined temperature in a width direction intersecting a sheet conveying direction on a sheet surface, An image forming system characterized in that, when the sheet is heated and pressurized by the fixing means, the magnitude of the specified temperature for heating the toner image area relative to the specified temperature for heating the adhesive layer area is smaller in the second mode than in the first mode.

[0086] (Item 14) An image forming means capable of forming a toner image and an adhesive layer on a sheet, the image carrier being rotatable and carrying at least one of the toner and the adhesive and a fixing unit for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressing, and conveying the sheet. a blade member that comes into contact with the image carrier to clean the image carrier; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having In a second mode, the image forming system is characterized in that toner is supplied to the contact portion between the image carrier and the blade member, which corresponds to a sheet area other than the area of ​​the sheet on which the adhesive layer is formed in the direction of the rotation axis of the image carrier. [Explanation of symbols]

[0087] 1. Image forming device 1e Image forming unit 6 Fixing unit 51 Thermocompression unit 80 Cleaning Blade 200 Intermediate transport unit 300 Booklet making device

Claims

1. an image forming means capable of forming a toner image and an adhesive layer on a sheet; and a fixing means for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressurizing, and conveying the sheet; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having an image forming system, characterized in that the predetermined temperature of the fixing means when the sheet is heated and pressed by the fixing means is lower in the second mode than in the first mode.

2. The image forming system according to claim 1, characterized in that when a booklet is produced in the second mode in succession exceeding a predetermined number of sheets, from the sheet next to the predetermined number of sheets, at least one of the predetermined temperature and the sheet transport interval when heating and pressurizing the sheet by the fixing means in the second mode is made larger than before the predetermined number of sheets in the second mode was exceeded.

3. 3. The image forming system according to claim 2, wherein the predetermined number of sheets is a first number of sheets, and when a booklet is produced that exceeds a second number of sheets different from the first number of sheets, or when pressure and heat are applied to a stack of sheets including the final page of a booklet, at least one of the predetermined temperature and the sheet transport interval is returned to its original value.

4. the image forming system has a third mode in which the booklet producing device produces a booklet by using a sheet on which an adhesive layer has been formed in advance, without the image forming means forming a toner image or an adhesive layer on the sheet; 2. The image forming system according to claim 1, wherein the predetermined temperature when the sheet is heated and pressed by the fixing means is lower in the third mode than in the second mode.

5. an image forming means capable of forming a toner image and an adhesive layer on a sheet; and a fixing means for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressurizing and pinching and conveying the sheet, the fixing means having a rotating body for pinching and conveying the sheet; a power source that applies a voltage of a predetermined polarity to the rotating body when the sheet is heated and pressed by the fixing means; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having an image forming system, characterized in that the value of the voltage applied from the power source to the fixing means when the sheet is heated and pressurized by the fixing means is smaller in the second mode than in the first mode.

6. The image forming system according to claim 5, characterized in that when a booklet is produced in the second mode in succession exceeding a predetermined number of sheets, from the sheet next to the predetermined number of sheets, at least one of the voltage and the sheet transport interval when heating and pressurizing the sheet by the fixing means in the second mode is made larger than before the predetermined number of sheets in the second mode was exceeded.

7. 7. The image forming system of claim 6, wherein the predetermined number of sheets is a first number of sheets, and when a booklet is produced that exceeds a second number of sheets different from the first number of sheets, or when pressure and heat are applied to a stack of sheets including the final page of a booklet, at least one of the voltage and the sheet transport interval is returned to its original value.

8. the image forming system has a third mode in which the booklet producing device produces a booklet by using a sheet on which an adhesive layer has been formed in advance, without the image forming means forming a toner image or an adhesive layer on the sheet; 6. The image forming system according to claim 5, wherein the value of the voltage when the fixing means heats and presses the sheet is smaller in the third mode than in the second mode.

9. an image forming means capable of forming a toner image and an adhesive layer on a sheet; and a fixing means for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressurizing, and conveying the sheet; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having an image forming system, characterized in that the pressure applied to the sheet by the fixing means when the fixing means heats and presses the sheet is smaller in the second mode than in the first mode.

10. The image forming system according to claim 9, characterized in that when a booklet is produced in the second mode in succession exceeding a predetermined number of sheets, from the sheet next to the predetermined number of sheets, at least one of the pressure and the sheet transport interval when heating and pressurizing the sheet by the fixing means in the second mode is made larger than before the predetermined number of sheets in the second mode was exceeded.

11. 11. The image forming system of claim 10, wherein the specified number of sheets is a first number of sheets, and when a booklet is produced that exceeds a second number of sheets different from the first number of sheets, or when pressure and heat are applied to a stack of sheets including the final page of a booklet, at least one of the pressure and the sheet transport interval is returned to its original value.

12. the image forming system has a third mode in which the booklet producing device produces a booklet by using a sheet on which an adhesive layer has been formed in advance, without the image forming means forming a toner image or an adhesive layer on the sheet; 10. The image forming system according to claim 9, wherein the pressure applied when the sheet is heated and pressed by the fixing means is smaller in the third mode than in the second mode.

13. the fixing unit is capable of changing the predetermined temperature in a width direction intersecting a sheet conveying direction on a sheet surface, 2. The image forming system according to claim 1, wherein when the sheet is heated and pressed by the fixing means, the magnitude of the predetermined temperature for heating the toner image area relative to the predetermined temperature for heating the adhesive layer area is smaller in the second mode than in the first mode.

14. An image forming means capable of forming a toner image and an adhesive layer on a sheet, the image carrier being rotatable and carrying at least one of the toner and the adhesive and a fixing unit for fixing the toner image and the adhesive layer to the sheet at a predetermined temperature by heating, pressing, and conveying the sheet. a blade member that comes into contact with the image carrier to clean the image carrier; an image forming apparatus having a booklet producing device that produces a booklet by bonding a plurality of sheets to each other by heating and pressurizing the adhesive layers fixed to the sheets in a stacked state; An image forming system having: a first mode in which the image forming means forms a toner image and an adhesive layer on a sheet, and the booklet making device uses the sheet to make a booklet; a second mode in which the image forming means forms only an adhesive layer on a sheet, and the booklet producing device produces a booklet using the sheet; having In a second mode, the image forming system is characterized in that toner is supplied to the contact portion between the image carrier and the blade member, which corresponds to a sheet area other than the area of ​​the sheet on which the adhesive layer is formed in the direction of the rotation axis of the image carrier.

Images