JP2007171691A - Image forming method and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method and an image forming apparatus which prevent blister irrespective of a mode of a recording material while achieving a high quality at a low cost in an image forming system using toner and easily form images on both sides of which at least an image on one side has a high gloss and goods smoothness. <P>SOLUTION: The image forming method includes; an image forming step 1 of forming an unfixed toner image on a sheet for a front side which has a thermoplastic light diffusing layer formed on an image formation face side of a sheet base material; a fixing step 2 of fixing the unfixed toner image on the sheet for the front side; and a sticking step of bonding a sheet for a rear side to an image non-formation face side of the sheet for the front side at least after fixing of the sheet for the front side, to produce a laminate sheet. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a laser printer, or the like that employs an electrophotographic system, an electrostatic recording system, or the like, in particular, using a recording sheet having a thermoplastic light diffusion layer on the surface, high image quality, The present invention relates to an image forming method and an image forming apparatus effective for forming a high-gloss full-color image.

In recent years, a method of creating a color image using a digital electrophotographic method has been widely used. Generally, an electrostatic latent image formed by irradiating a photosensitive member with a laser beam modulated on the basis of image information, and a yellow, magenta, cyan, or black mixed pigment with a thermoplastic binder. A method in which an electrostatic latent image is visualized as a toner image by attaching four colors of toner, and the toner image is transferred onto a recording sheet such as PPC paper or OHP sheet, and then fused and fixed by a fixing device. It has been known. In this case, a roll type fixing device is widely used as a fixing device for fixing a toner image on a recording sheet.
As such a roll-type fixing device, for example, a heating roll having a heating source inside a cylindrical cored bar and a heat-resistant rubber layer or a heat-resistant protective layer coated on the outer periphery of the cylindrical cored bar, A pressure roll that is in pressure contact with the roll and configured in substantially the same manner as the heating roll, and by nipping and conveying the recording sheet on which the unfixed toner image is formed between the heating roll and the pressure roll, A toner image may be heat-fixed.

Furthermore, in order to increase the glossiness of the image after fixing and improve the appearance of the color image, for example, the material design is such that the molecular weight of the thermoplastic binder in the toner is lowered and the toner viscosity at the time of heat melting is lowered. How to do is known.
In addition, electrophotographic full-color printers are increasingly used as image information developing methods by digital still cameras that have been widely introduced in the market in recent years, and higher image quality is required.
From such a requirement, for example, in Patent Document 1, a transparent resin layer provided with a thermoplastic resin is provided on the recording sheet surface, and the toner image is embedded in the recording sheet surface by heating and melting the transparent resin during heat fixing. A method of forming a high gloss color image is disclosed. It is also possible to obtain a more glossy image by using a toner containing a thermoplastic resin.

In such a method, for example, if a belt-type fixing device using an endless fixing belt is employed, an image with higher image quality and higher gloss can be obtained (see Patent Documents 2 and 3).
The belt-type fixing device includes a heating roll, a tension roll, a fixing belt stretched between the heating roll and the tension roll, and a pressure that is disposed to face the heating roll via the fixing belt and pressurizes the heating roll. And a recording sheet on which an unfixed toner image is formed is heated by a heating roll via a fixing belt, whereby the toner image and the transparent resin layer on the surface of the recording sheet are melted, and the toner is applied to the transparent resin layer. In addition to embedding the image, the toner image can be cooled and fixed to the surface of the recording sheet while being nipped and conveyed to the peeling portion while the surface of the recording sheet is in close contact with the fixing belt. That is, according to this aspect, in the single-sided printing, since the transparent resin layer and the toner image on the surface of the recording sheet are solidified according to the surface shape of the fixing belt, the entire surface of the recording sheet becomes a smooth surface and excellent in gloss. A color image can be obtained.

  Furthermore, Patent Document 4 discloses a technique for using a recording sheet having a polyolefin resin coating layer formed on both sides of a sheet base material to form a highly glossy image with good smoothness not only on the recording sheet surface but also on the back surface. Has already been provided.

In addition, as a recording sheet in which image information of a digital still camera is developed, a so-called borderless with no margin at the edge is generally preferred. In an image forming apparatus adopting an electrophotographic method, after forming an image by providing some margins on four sides of a recording sheet, the user cuts the margins of the recording sheet with a cutter or the like, or patent literature By using an image forming apparatus with a cutter as described in No. 5, a borderless photograph without a margin can be produced.
In this case, according to Patent Document 5, in consideration of the fact that the recording sheet is skewed or misaligned when an image is formed on the entire surface of the recording sheet using an electrophotographic image forming apparatus, for example, When a toner image larger than the sheet size is formed on the photosensitive member, the toner protrudes from the edge of the recording sheet and adheres to the transfer roll or the like when the toner image is transferred from the photosensitive member to the recording sheet. It is possible to solve the problem that the recording sheet surface is reattached on the recording sheet to be conveyed and the recording sheet surface is stained or an image defect is caused.

Further, techniques for forming a photographic image on at least one side of a recording sheet by an image forming method other than the electrophotographic method (for example, an ink jet method or a thermal transfer method) include the following.
For example, in Patent Document 6, in order to form a high gloss image such as a photographic image on a stiff support (recording sheet) like a general photograph, for example, a thin photographic paper that can obtain high gloss is used. A technique is disclosed in which after photographic printing is performed in advance, backing paper is bonded together to form a photographic print laminate into a roll shape, and the photographic print laminate is cut into a predetermined size.
Further, in Patent Documents 7 and 8, as a method for forming an image on a postcard or the like having a photographic surface, for example, a photographic paper on which an image is formed in advance and cut into a predetermined size and a back sheet (postcard) are provided. A technique has been proposed in which a laminated body is manufactured by bonding.

JP 05-216322 A JP-A 64-035452 Japanese Patent Application Laid-Open No. 2001-083834 JP 2004-205563 A JP 2004-109860 A Japanese Patent Application Laid-Open No. 09-311408 Japanese Patent Laid-Open No. 11-180077 JP 2000-352791 A

However, when performing double-sided recording using an electrophotographic image forming apparatus, for example, as shown in Patent Document 4, a recording sheet having a polyolefin resin coating layer on both sides is used, and both sides of the recording sheet are used. A configuration in which photographic images can be created must be adopted. In such a recording sheet equipped with a polyolefin-based resin coating layer on both sides, the air permeability is impaired due to the presence of the coating layer on both sides of the sheet base material. However, there is a concern about the occurrence of so-called blisters that disturb the image on the surface of the recording sheet.
In order to solve such a problem, as shown in Patent Document 4, a first fixing device disposed downstream of the image forming engine and an image smoothing further downstream of the first fixing device. And a second fixing device as a device, and it is necessary to set the temperature of the heating roll of the second fixing device in a narrow temperature range around 130 to 140 ° C. It is indispensable to control the temperature distribution in the direction, the monitoring error of the thermometer, the overshoot at the time of feedback control, the droop, and the like, and the technical problem arises that the cost increase associated with complicated and strict control is inevitable.
Incidentally, if the recording sheet is provided with a polyolefin resin coating layer only on one side, problems such as blistering may be solved, but it is difficult to form photographic images on both sides of the recording sheet.

Further, when using photographic paper, as shown in Patent Documents 6 to 8, it is possible to record a photographic image on the photographic paper and an image by an ink jet or thermal transfer system on the back side thereof, so that at least one side is recorded. Although it is possible to produce a double-sided image with high gloss and good smoothness on the side image, it is easy to produce a double-sided image with high glossiness and smoothness at least on one side easily and with high quality in an electrophotographic image forming apparatus. It has not been realized yet.
Such a technical problem is not limited to the above-described electrophotographic image forming apparatus, but a so-called electrostatic recording image forming apparatus that forms an electrostatic latent image using an electrostatic recording head using an ion flow. This also occurs in

  The present invention was made in order to solve the above-mentioned technical problems at the same time, and enables high quality at low cost in image forming systems (electrophotographic system, electrostatic recording system, etc.) using toner. However, an object of the present invention is to provide an image forming method and an image forming apparatus that can easily prevent the formation of a double-sided image having a high glossiness and smoothness at least on one side, regardless of the form of the recording material. And

  That is, in the image forming method according to the present invention, as shown in FIG. 1A, an unfixed toner image is formed on a surface sheet in which a thermoplastic light diffusion layer is formed on the image forming surface side of a sheet substrate. An image forming step 1, a fixing step 2 for fixing an unfixed toner image on the front surface sheet, and a back surface sheet adhered to the non-imaging surface side of the front surface sheet at least after fixing the front surface sheet. And a laminating step 3 for producing a laminated sheet.

In this embodiment, the surface sheet is intended for a sheet having a thermoplastic light diffusion layer on one side of a sheet substrate. Thereby, a glossy and vivid image can be formed. Furthermore, as this thermoplastic light diffusion layer, for example, a polyolefin-based resin is used, and among them, a polyethylene resin, a polypropylene resin, or the like may be appropriately selected.
Furthermore, the back sheet may be in any form, and includes, for example, an aspect in which a thermoplastic light diffusion layer is provided on one side of a sheet base material or an aspect in which a thermoplastic light diffusion layer is not provided.
In addition, the back side sheet has already been imaged, and the back side sheet image forming process is separate from the front side sheet forming process. However, it may be selected as appropriate, such as an image formed in the image forming process performed in the above.
According to this aspect, since at least the front surface sheet is provided with the thermoplastic light diffusion layer and the back surface sheet is bonded after the front surface sheet is formed, the occurrence of blisters is prevented regardless of the back surface sheet. At the same time, a high-gloss photographic image can be created on one side.

  In particular, when performing a series of an image forming process on the back sheet and an image forming process on the back sheet, the surface sheet in which a thermoplastic light diffusion layer is formed on the image forming surface side of the sheet base material and Image forming step 1 for forming images on the back sheet that can be adhered to the back side of the front sheet, and fixing for fixing the unfixed toner image on the front sheet and the unfixed toner image on the back sheet, respectively. What is necessary is just to provide the bonding process 3 which adhere | attaches the non-image forming surface side of both sheets after the time of fixing of the process 2 and the sheet | seat for front surfaces, and the sheet | seat for back surfaces, and produces a lamination sheet.

In this aspect, the surface sheet preferably includes a receiving layer in which a toner image can be embedded on the thermoplastic light diffusion layer. In this case, the receiving layer preferably contains a thermoplastic resin, and may be appropriately selected in consideration of viscosity, heat resistance, thickness and the like. As described above, by providing the receiving layer on the thermoplastic light diffusing layer, the toner image can be submerged with the melting of the receiving layer at the time of fixing, so that a smoother image can be formed. it can.
In this embodiment, the back sheet is preferably provided with a thermoplastic light diffusing layer on one side of the sheet base material, and is particularly preferably a postcard sheet. Thus, by providing the thermoplastic light diffusion layer, a glossy and vivid image can be formed on the back side, and the air permeability of the laminated sheet can be kept low. This is effective against curling caused by moisture absorption.
In this way, if the front surface sheet and the back surface sheet are provided with the thermoplastic light diffusion layer, and both sheets are bonded together after image formation, blistering is generated on the sheet having the front and back surfaces with the thermoplastic light diffusion layer. High-gloss photographic images can be created on both sides of the laminated sheet.

Moreover, it is preferable to provide the cutting method 4 which cuts the edge of a lamination sheet in the method invention mentioned above.
According to this aspect, when a recording sheet that does not require margins is produced, if a toner image larger than the conventional sheet size is formed, the toner image protrudes from the edge of the sheet during transfer, and a transfer member or the like. Can be eliminated, and after forming an image with a margin (edge) formed, the margin can be cut, creating a laminated sheet with no margin without contaminating the inside of the device. Can be realized. In addition, according to this aspect, it is possible to wipe away the concern about the accurate pasting of both sheets as in the prior art and the accompanying positional deviation of both sheets.
Therefore, such a cutting process 4 is performed after the bonding process 3.

  Further, as an apparatus invention that embodies the above-described method invention, as shown in FIG. 1B, unfixed toner is formed on a surface sheet in which a thermoplastic light diffusion layer is formed on the image forming surface side of a sheet substrate. An image forming means 5 for forming an image, a fixing means 6 for fixing an unfixed toner image on the front surface sheet, and for the back surface on the non-imaging surface side of the front surface sheet at least after fixing the front surface sheet. Examples include a bonding means 7 for bonding sheets to produce a laminated sheet, and a conveying means 8 for conveying the front surface sheet and the back surface sheet to each of the above means.

  Furthermore, the embodiment in which the above-described device invention is embodied as a device capable of forming a double-sided image includes a surface sheet in which a thermoplastic light diffusion layer is formed on the image forming surface side of a sheet substrate, and the back surface side of the surface sheet. Image forming means 5 for forming images on the back sheet that can be adhered to the sheet, fixing means 6 for fixing the unfixed toner image on the front sheet and the unfixed toner image on the back sheet, respectively, and the front sheet And a non-image forming surface side of both sheets are bonded to each other after the fixing of the back sheet, and a conveying means 8 for conveying the front sheet and the back sheet to each of the above means. The thing provided with.

  Moreover, it is preferable to provide the cutting means 9 which cuts the edge of a lamination sheet as an apparatus invention which actualized the method invention provided with the cutting process 4. FIG. The cutting unit 9 is disposed downstream of the bonding unit 7 in the sheet conveying direction.

In such technical means, the image forming apparatus according to the present application widely includes a copying apparatus, a printer, and the like adopting an electrophotographic system, an electrostatic recording system, or the like. The image carrier may be an image-only carrier such as a photosensitive member or a dielectric, or the image-bearing member and the image-forming carrier are disposed opposite to each other. An aspect may be provided that includes an intermediate transfer member that is temporarily transferred and held in an intermediate stage before each image on the image forming carrier is transferred to the sheet.
Furthermore, the present invention may be used for creating a multi-color image such as two colors or three colors, or for creating a single color image. However, the present invention is particularly effective for creating a high-quality full-color image. .

  Furthermore, in the basic aspect of the present invention, “at least after the fixing of the surface sheet” means at the same time as the fixing of the surface sheet or after the fixing of the surface sheet. Furthermore, this aspect also includes those in which a sheet for back surface on which an image is formed in advance is bonded. Moreover, it is also possible to print a character on the back sheet after producing the laminated sheet.

  Further, the fixing unit 6 only needs to have a pair of fixing members for nip-conveying the sheet. The mode of the fixing unit 6 can be appropriately selected in addition to a roll pair configuration, a combination of a belt and a roll, a belt pair configuration, and the like. However, it preferably includes a heating member whose surface is heated, and a fixing belt stretched with at least the heating member as one of the stretching members, and the unfixed toner on the sheet via the fixing belt. It is preferable that the image is fixed and the sheet is conveyed downstream in the rotation direction of the fixing belt while the toner image forming surface on the sheet is in close contact with the fixing belt. According to this aspect, the toner image is embedded in the thermoplastic light diffusion layer melted by the heating member, and the thermoplastic light diffusion layer can be cooled and solidified following the surface shape of the fixing belt. A glossy image surface can be obtained.

  Further, it is preferable that the fixing unit 6 also serves as the bonding unit 7. According to this aspect, not only the apparatus can be miniaturized, but also one of the front sheet and the back sheet can be bonded to the other sheet simultaneously with the image fixing of the other sheet.

Furthermore, the adhesive used for the front sheet and the back sheet may be selected as appropriate, such as the adhesive used and the application method of the adhesive. However, the adhesive surface of the back sheet is more than the fixing pressure of the fixing means 6. It is preferable to provide a pressure-sensitive adhesive layer that adheres at a high pressure and adheres at a pressure equal to or lower than the bonding pressure of the bonding means 7.
In using such a pressure-sensitive adhesive, for example, depending on the print mode and the mode of the fixing unit 6, that is, whether the fixing unit 6 is a type that also serves as the bonding unit 7 or a separate type, the surface sheet and What is necessary is just to select suitably the pressure control etc. of the bonding means 7 besides the sheet | seat conveyance order and conveyance path | route of the sheet | seat for back surfaces.

Further, it is preferable that the adhesive surface of the back sheet is provided with a heat-sensitive adhesive layer that can be thermally welded at a temperature lower than the melting temperature of the toner.
In using such a heat-sensitive adhesive, if the image is fixed by the fixing unit 6 before the sheets are bonded, the heat-sensitive adhesive melts. For example, depending on the print mode or the mode of the fixing unit 6 In addition to the sheet conveyance order and conveyance path of the front sheet and the back sheet, the temperature control of the fixing unit 6 may be selected as appropriate.

The conveying means 8 conveys one sheet of the front sheet or the back sheet in advance and conveys the other sheet in the subsequent direction, and at least the non-image forming side of the surface sheet in the laminating means 7 And the non-resin layer-provided surface side of the back sheet are superposed and conveyed.
Further, the conveying unit 8 may be appropriately selected according to the mode of the fixing unit 6 and the print mode. For example, the conveying unit 8 has another path for retracting the previously conveyed sheet, or a reversible switchback tray. In addition to the above-mentioned ones, there may be mentioned those provided with an intermediate tray that can accommodate the previously conveyed sheet.

  Further, the conveying means 8 is a reversing means for reversing the conveying surface of one of the front-side sheets or the back-side sheets, and a switching capable of switching the conveying path of the one sheet to the reversing means side. It is preferable to adjust the timing at which the one sheet reversed by the reversing means and the other sheet transported downstream are merged, and at least the laminating means 7 superimposes and conveys both sheets. In this aspect, the reversing means may be appropriately selected as long as it reverses the sheet conveying surface, and examples thereof include a switchback tray. Furthermore, the switching means may be appropriately selected such as a switching gate capable of switching the sheet conveyance path.

  Furthermore, the present invention preferably includes a control device that can control at least the image forming unit 5, the fixing unit 6, and the conveying unit 8 based on the print mode information. In this case, examples of the print mode information include image input information from a personal computer, and image forming mode information set by a user interface or the like.

  According to the image forming method of the present invention, an image forming step of forming an unfixed toner image on the surface sheet, a fixing step of fixing the unfixed toner image, and at least the surface of the surface sheet after fixing A low-cost, high-quality image forming method using toner (electrophotographic method, electrostatic recording method, etc.). In addition, it is possible to prevent blisters regardless of the mode of the recording material, and to easily create a double-sided image with at least one-side image having high gloss and good smoothness.

Furthermore, according to the embodiment embodied as a method capable of forming a double-sided image, the image forming process of the front sheet and the back sheet can be performed in series while exhibiting the same effects as the method invention described above. In particular, if the back sheet is provided with a thermoplastic light diffusion layer, a laminated sheet having photographic images formed on both sides can be produced.
Furthermore, if a cutting step is provided, the margin can be cut after forming the image by forming a margin (edge), thus creating a laminated sheet with no margin without staining the inside of the apparatus. it can.
Further, according to the image forming apparatus of the present invention, the above-described image forming method can be easily realized.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
Embodiment 1
FIG. 2 shows Embodiment 1 of an image forming apparatus to which the present invention is applied. In FIG. 1, an image forming apparatus 10 according to the present embodiment includes a printer device 11 that creates an image. An image reading unit 12 for reading a document on the upper portion of the printer device 11 and an image for inputting image settings. An information input unit 13 is provided, and a cutting unit 14 for attaching and cutting sheets is provided at a lower portion of one side surface of the printer 11.
Further, the printer device 11 is provided with multi-stage sheet trays 52 to 54 for supplying sheets such as paper at the lower part of the printer housing 20, and a color image is formed on the sheets from the sheet trays 52 to 54 above the printer apparatus 11. A possible image forming engine 30 and a fixing device 80 for fixing an unfixed toner image on a sheet that has passed through the image forming engine 30 are provided. In addition, a sheet conveyance path 50 serving as a conveyance path for sheets from the sheet trays 52 to 54 is formed at a portion facing the image forming engine 30.

  The image forming engine 30 used in the present embodiment employs an electrophotographic system, and is in four colors: yellow (Y color), magenta (M color), cyan (C color), and black (K color). The image forming units 31 (31 a to 31 d) are arranged in parallel on the intermediate transfer belt 40. Therefore, the toner images of the respective colors formed by the respective image forming units 31 (31a to 31d) are sequentially primary-transferred and multiplexed on the intermediate transfer belt 40, and the multiplexed toner images are transferred to the secondary transfer device. The images are transferred onto the sheets conveyed from the sheet trays 52 to 54 and guided to the fixing device 80. Note that the color arrangement of the four-color image forming units 31 is not limited to this order, and may be any other order.

The image forming unit 31 (31a to 31d) in the present embodiment includes a photosensitive drum 32 that forms and supports each color component toner image, a charging roll 33 that charges the photosensitive drum 32, and a charged photosensitive drum 32. A laser exposure device 34 for forming a latent image on the photosensitive drum 32, a developing device 35 for developing an electrostatic latent image on the photosensitive drum 32, and a toner image on the photosensitive drum 32 are primarily transferred onto the intermediate transfer belt 40. For example, a primary transfer roll 36, a cleaner 38 that cleans residual toner remaining on the photosensitive drum 32, and a static elimination roll 37 that neutralizes the surface of the photosensitive drum 32 after cleaning are provided.
In the present embodiment, the laser exposure unit 34 exposes the entire four-color image forming unit 31 with one laser exposure unit 34.

  The intermediate transfer belt 40 is stretched around a plurality of stretching rolls 41 to 43, and is circulated and conveyed, for example, with the stretching roll 42 as a driving roll and the stretching roll 41 as a driven roll. The rolls 45 are arranged to face each other with the stretch roll 43 as a backup roll. Further, a belt cleaner 46 for removing residual toner on the intermediate transfer belt 40 is disposed at a position facing the tension roll 42 of the intermediate transfer belt 40.

Here, the sheet conveying system in the present embodiment has, for example, three sheet trays 52 to 54 in which sheets of a predetermined size are accommodated, and the sheets are placed near the sheet trays 52 to 54 at a predetermined timing. A pick-up roll 55 to be sent out, a nudger roll 56 and a retard roll 57 to roll the sheets are provided, and only the uppermost one sheet can be sent out.
The sheet conveyance system includes a vertical conveyance path 63 that extends substantially vertically upward from each of the sheet trays 52 to 54, and a main conveyance that includes a sheet conveyance belt 644 that extends substantially horizontally on the downstream side of the vertical conveyance path 63. A retraction conveyance path 65 extending downward in a substantially Y shape in the vicinity of the most downstream of the main conveyance path 64, and a reverse conveyance path 66 extending substantially horizontally from the middle of the retraction conveyance path 65 and leading to the vertical conveyance path 63. It consists of The evacuation conveyance path 65 includes a switchback tray 67. The conveyance reversing roll pair 68 enables forward feeding and reverse feeding and adjusts the sheet feeding timing. The main conveyance path 64 is provided with a registration roll (hereinafter referred to as a registration roll) 643 for adjusting the sheet conveyance timing on the downstream side of the fixing device 80 and communicates with the cutting unit 14 on the most downstream side.
Further, the main conveyance path 64 is provided with a switching gate 69 capable of switching the sheet conveyance between the main conveyance path 64 side and the retreat conveyance path 65 side. The retreat conveyance path 65 is provided with a switching gate 70 capable of switching the sheet conveyance between the main conveyance path 64 side and the reverse conveyance path 66 side.

In the present embodiment, as shown in FIG. 3, the fixing device 80 includes a heating roll 81 with a built-in heating source, an endless belt 83 laid over the heating roll 81 and the stretching roll 82, and a heating roll. A pressure roll 84 is provided at a site facing 81.
The heating roll 81 includes a release layer made of, for example, a PFA tube on the surface of a metal cylindrical core 86 in which, for example, a halogen heater 85 is incorporated.
On the other hand, the pressure roll 84 includes a metal cylindrical core 88, an elastic layer 89 formed on the surface of the core 88, such as silicone rubber having a rubber hardness (JIS-A) of about 40 °, and the like. For example, a release layer made of a PFA tube or the like formed on the surface of the elastic layer 89 is used.
Furthermore, the endless belt 83 is a member in which a highly smooth coating layer made of fluorine rubber, silicone rubber, or the like is formed on the surface of an endless film substrate made of, for example, thermosetting polyimide, and includes a heating roll 81 and a stretching roll. It is stretched by 82 and is circulated and moved following a heating roll 81 that is driven to rotate.
In this embodiment, the fixing pressure P _{1 in} the pressure contact area between the heating roll 81 and the pressure roll 84 is set to 15 g / cm ² , for example.

Further, in the present embodiment, the sheet tray 53 accommodates a front sheet 60 for the laminated sheet 62 produced by bonding two sheets together, and the sheet tray 54 has a back sheet for the laminated sheet 62. While 61 (for example, a general postcard) is accommodated, plain paper 51 is accommodated in the sheet tray 52. In this case, the laminated sheet 62 includes, for example, a photographic surface (front surface) provided on one side and a destination surface (back side) provided on the other side, such as New Year's cards (FIG. 4B). )reference).
In the present embodiment, the front surface sheet 60 and the back surface sheet 61 are formed of, for example, polyethylene resin, polypropylene resin, or the like on one side of each of the sheet base materials 601 and 611 as shown in FIG. Polyolefin resin coating layers 602 and 612 are provided. Furthermore, a receiving layer 603 formed of, for example, a polyester resin, a styrene-acrylic ester resin, a styrene-methacrylic ester resin, or the like is provided on the surface of the surface sheet 60 on the polyolefin-based resin coating layer 602. The toner images 604 and 614 are more easily embedded at the time of heat fixing.

Also, an adhesive provided with a pressure-sensitive adhesive that can be adhered to the other surface of the sheet base 611 on the other side of the sheet base 611 that is not formed on the polyolefin-based resin coating layer 612 when a predetermined pressure or more is applied. Layer 615 is formed. In this embodiment, the pressure at which the pressure-sensitive adhesive adheres (reaction pressure P ₀ ) is, for example, 40 g / cm ² , and is set to a value larger than the fixing pressure P ₁ of the fixing device 80. When the apparatus 80 passes, it is prevented from being bonded by the fixing pressure P ₁ of the fixing apparatus 80.
Examples of such a pressure-sensitive adhesive base resin include natural rubber, modified natural rubber, synthetic rubber such as styrene-butadiene rubber and acrylonitrile-butadiene rubber, ethylene / vinyl acetate copolymer resin, acrylic ester resin, A solution or emulsion of a vinyl chloride resin or hinylidene chloride resin is used. Furthermore, in this case, it is preferable to use a pigment such as silica, kaolin, clay, calcium carbonate, aluminum hydroxide, titanium oxide, zinc oxide, melamine resin particles, benzoguanamine resin particles, and starch particles for the purpose of controlling adhesiveness. . Further, in the pressure-sensitive adhesive, as long as the adhesion, blocking resistance, and heat resistance are not impaired, rosin resins and derivatives thereof, terpene resins, coumarone indene resins, xylene resins, Alkylphenol resins and petroleum resins can be used in combination.
Moreover, as a usage form of such a pressure-sensitive adhesive, for example, a microcapsule or the like is used, but the present invention is not limited to this and may be appropriately selected.

Further, as shown in FIG. 2, the image information input unit 13 used in the present embodiment displays a personal computer 131 capable of sending image input information such as print settings and image settings, and the image input information. And a monitor 132. In the present embodiment, the image information input unit 13 is disposed on the upper portion of the printer device 11. However, the present invention is not limited to this mode, and for example, a wired connection such as a network connection may be selected as appropriate. There is no problem.
The image reading unit 12 also includes a transparent platen 121 on which a document can be placed, a platen cover 122 that covers the platen 121 so as to be openable and closable, and an automatic document feeder 123 that automatically conveys the document onto the platen cover 122. And.

Further, the cutting unit 14 discharges the sheet fed from the printer device 11 to a discharge tray 191, a laminating device 140 capable of bonding sheets in the housing 15, a cutting device 160 for cutting the edge of the sheet. A sheet conveyance path 190 is provided.
As shown in FIG. 4A, the bonding apparatus 140 used in the present embodiment includes a pair of pressure rolls 141 and forms a pressure contact area at a position opposite to the pressure roll 141.
In this embodiment, the pressure roll 141 is made of a metal cylindrical core 142 and an elastic layer made of urethane rubber, EPDM rubber or the like having a rubber hardness (JIS-A) of about 70 ° formed on the surface of the core 142. A layer 143 and a release layer on the surface of the elastic layer 143 are provided.
In this case, the bonding pressure P _{2 in} the pressure contact area of the pressure roll 141 is set to 40 g / cm ² , for example.
Therefore, in the present embodiment, the relationship between the fixing pressure P1 of the fixing device 80, the fixing pressure P2 of the bonding device 140, and the reaction pressure P0 of the pressure sensitive adhesive is set so as to satisfy P1 <P0 ≦ P2. ing.

As shown in FIGS. 5 to 7, the cutting device 160 includes a front and rear cutting unit that cuts a sheet in a direction perpendicular to the sheet conveyance direction, and a side cutting unit that cuts the sheet in the sheet conveyance direction. Is.
In this embodiment, as shown in FIGS. 5A and 5B, the front / rear cutting unit moves in a direction perpendicular to the sheet conveying direction, and a circular cutter unit 162 provided with the circular cutter 161 is disposed. And a plurality of conveying rolls 163 and 164 which are provided on both sides of the circular cutter unit 162 and prevent the meandering and lifting of the sheet. Further, a sensor 165 for detecting the position of the sheet is disposed further upstream of the transport roll 163 on the upstream side in the sheet transport direction.
As shown in FIG. 6, the circular cutter unit 162 according to this aspect includes a rotary blade 171 and a rotary blade holder 172 supported by the support frame 176 and accommodating the rotary blade 171, and a drive motor 173 as a drive source. And a drive pulley 174 that can transmit the driving force from the drive motor 173 to the rotary blade holder 172, and the rotary blade holder 172 can be moved forward and backward in the X direction in the figure as the drive pulley 174 rotates. Is. A fixed blade 175 is disposed at a position corresponding to the rotary blade 171 on the sheet contact surface side, and the rotary blade 171 and the fixed blade 175 cut the sheet in a direction perpendicular to the sheet conveying direction. ing.

Further, as shown in FIG. 7A, a slitter 180 is used as the side cutting portion. The slitter 180 includes two rotary shafts 181 and 182, one rotary shaft 181 is provided with a rotary blade (inner blade) 183 slidable in the axial direction, and the other rotary shaft 182 has a shaft. A rotary blade (outer blade) 184 whose movement in the direction is constrained by a flange 185 is provided, and two transport rolls 186 are provided inside the rotary blades 183 and 184, respectively, in order to stabilize sheet transportability. It is a thing. A pressure spring 187 is disposed on the rotary shaft 181 provided with the inner blade 183 so as to be sandwiched between the inner blade 183 and the transport roll 186, and the inner blade 183 is moved outward by the pressure spring 187. It is energized. The inner blade 183 is arranged in contact with the outer blade 184 disposed on the other rotary shaft 182 by a biasing force of the pressure spring 187 with a lap margin R provided.
In this embodiment, two pairs of rotary blades 183 and 184 are provided and the both ends in the sheet conveying direction are cut. However, the present invention is not limited to this, and a plurality of rotary blade pairs on the rotary shafts 181 and 182 are provided. A mode in which one sheet is divided into a plurality of sections and a mode in which the cutting size is made variable by providing a plurality of rotating shafts may be appropriately selected.

  FIG. 8 shows a control device 200 for the image forming process used in the present embodiment. In the figure, a control device 200 is constituted by a microcomputer system comprising a CPU 201, a ROM 202, a RAM 203, and input / output interfaces 204, 205. For example, a personal computer capable of sending image input information such as print settings and image settings. Signals from the (PC) 131, the start switch 134 and the like are taken into the CPU 201 via the input interface 204. The CPU 201 executes an image forming process program (see FIG. 9) preliminarily incorporated in the ROM 202, for example, generates control signals corresponding to the respective modes such as a laminated sheet manufacturing mode and a normal print mode, and each mode. A control signal corresponding to single-sided printing or double-sided printing is generated, and the image forming engine 30, fixing device 80, registration rolls 642 and 643, switching gates 69 to 71, a bonding device 140, a cutting device are output via the output interface 205. 160 etc. are controlled.

Next, an image forming process of the image forming apparatus 10 according to the present embodiment will be described. In particular, here, a laminated sheet production mode in which images are produced on the front sheet 60 and the back sheet 61 and the laminated sheets 62 are produced by bonding both sheets together will be described.
Now, when print information of, for example, double-sided printing is input from the input processing unit, a double-sided printing operation is started according to the flowchart of FIG.
That is, when a monochrome toner image is formed on the surface of, for example, the black photosensitive drum 32 by a known electrophotographic process, the toner image is moved at a substantially same speed as the photosensitive drum 32 by the primary transfer roll 36. The image is transferred onto the intermediate transfer belt 40.
When one sheet for back surface 61 is sent out from the sheet tray 54 and conveyed to the registration roll 642 of the main conveyance path 64 by the conveyance roll 641 of the vertical conveyance path 63, the sheet 61 for back surface is temporarily stopped after being temporarily stopped by the registration roll 642. The monochromatic toner image on the intermediate transfer belt 40 is transferred to the surface of the back surface sheet 61 on which the polyolefin resin coating layer 612 is formed in accordance with the image writing timing on the upper side.

Thereafter, when the back surface sheet 61 passes through the sheet transport belt 644 and is transported to the fixing device 80, the unfixed toner image on the surface of the back surface sheet 61 is fixed by the fixing device 80, and a smooth image is formed on the sheet surface. Formed (see FIG. 3).
That is, in the nip region between the heating roll 81 and the pressure roll 84 of the fixing device 80, the toner and the polyolefin resin are melted on the image forming surface of the back sheet 61 by the heating from the heating roll 81. In this state, when the back surface sheet 61 is conveyed while the image forming surface side is in close contact with the endless belt 83, the heat of the endless belt 83 is dissipated before reaching the facing portion of the tension roll 82. As a result, the heated toner image 614 and the polyolefin resin on the back surface sheet 61 can be solidified. In this way, by cooling the back surface sheet 61 in close contact with the endless belt 83, the toner image 614 and the polyolefin-based resin coating layer 612 on the surface of the sheet can be made smooth, and the endless belt of the back surface sheet 61 can be made. The peelability from 83 can be kept good and a high gloss image can be obtained.
Thereafter, the back sheet 61 after fixing is conveyed to the switchback tray 67 by switching the path of the switching gate 69 (see FIG. 10).
As a print mode, when the single-sided printing laminated sheet 62 that does not create an image on the back sheet 61 is manufactured, the above-described image forming process and fixing process are omitted, and the back sheet 61 sent from the sheet tray 54 is used. Is immediately conveyed to the switchback tray 67.

Subsequently, the surface sheet 60 is imaged. That is, when a toner image is formed on the surface of each photosensitive drum 32, the toner image is transferred onto the intermediate transfer belt 40 by the primary transfer roll 36. On the other hand, when one surface sheet 60 is sent out from the sheet tray 53, it is conveyed to the secondary transfer roll 45 in accordance with the timing of image writing on the surface sheet 60, and the polyolefin resin coating layer 602 of the surface sheet 60 is formed. For example, a full-color toner image on the intermediate transfer belt 40 is transferred onto the formed surface.
Next, when the front surface sheet 60 on which the toner image is formed is conveyed to the fixing device 80 by the sheet conveying belt 644, the front surface toner image 604 is fixed by the fixing device 80 in the same manner as the back surface sheet 61. In particular, in this case, since the surface sheet 60 is provided with the receiving layer 603 in which the toner can be embedded on the polyolefin resin coating layer 602, a smoother and higher gloss image can be obtained.

The front surface sheet 60 after fixing is temporarily stopped by the registration roll 643, and is sent again at the same timing as the back surface sheet 61 sent out from the switchback tray 67, before the laminating device 140. Then, it is polymerized with the back sheet 61 (see FIG. 4A and FIG. 10). Thereafter, the front surface sheet 60 and the back surface sheet 61 are polymerized and conveyed into the bonding apparatus 140 and are pressure-fixed by the bonding apparatus 140.
That is, the pressure-sensitive adhesive applied to the non-image-forming surface side of the back sheet 61 reacts by the pressure of the pressure roll 141, and the front sheet 60 and the back sheet 61 are bonded to form a laminated sheet 62. (See FIG. 4B).

  FIG. 4B shows a cross section of the laminated sheet 62 at this time. As shown in the figure, the laminated sheet 62 is obtained by laminating a front sheet 60 and a back sheet 61. That is, the image forming surface of the surface sheet 60 has a smooth surface in which the color toner image 604 is embedded in the receiving layer 603. Further, the image forming surface of the back sheet 61 is also filled with black toner 614 in the polyolefin resin coating layer 612, and the surface thereof is kept smooth. Further, an adhesive layer 615 made of a pressure-sensitive adhesive is formed on the non-image-forming side of the front surface sheet 60 and the back surface sheet 61, and the adhesive layer 615 adheres both sheets.

Then, when the laminated sheet 62 after the lamination passes through the sheet conveyance path 190 and is conveyed into the cutting device 160, both the longitudinal direction and the width direction are cut into predetermined dimensions.
That is, as shown in FIGS. 5A and 5B, after the sensor 165 detects the entry of the laminated sheet 62, the cutting position at the tip of the laminated sheet 62 is set to the same position as the circular cutter unit 162. After the quantitative conveyance, the conveyance of the laminated sheet 62 is stopped. Then, when the circular cutter 161 moves in the direction perpendicular to the sheet conveying direction, the leading end of the laminated sheet 62 is cut. Thereafter, the circular cutter 161 is returned to the original position, and the laminated sheet 62 is conveyed again. Then, when the laminated sheet 62 is conveyed to the cutting planned position at the rear end of the laminated sheet 62, the conveyance of the laminated sheet 62 is stopped, and the circular cutter 161 is similarly moved to cut the rear end of the laminated sheet 62.
As shown in FIG. 11, when the laminated sheet 62 passes through the slitter 180, both sides in the sheet width direction are cut by the rotary blades 183 and 184 while the sheet is prevented from meandering and lifting by the conveying roll 186. Is done.
Thus, the laminated sheet 62 that has been cut is sent out from the sheet conveyance path 190 to the discharge tray 191.

Here, a single circular cutter unit 162 is used as the front / rear cutting unit used in the present embodiment, but the present invention is not limited to this, and for example, in FIGS. 12 (a) and 12 (b). Needless to say, one having a plurality of circular cutter units 162 as shown may be used. According to such an aspect, not only the cutting processing speed is increased and productivity is improved, but also it is effective for sheet division, cutting size change, and the like.
Furthermore, the cutting part for front and rear is not limited to the aspect using the circular cutter 161, and a reciprocating cutter 300 shown in FIG. 13 may be used. In other words, this embodiment includes a movable blade 301 that can be moved up and down by a moving mechanism and a drive mechanism (not shown), and a fixed blade 302 that is disposed to face the movable blade 301. By moving and meshing with the fixed blade 302, the front and rear of the laminated sheet 62 can be cut. Also in this aspect, the same effects as in the aspect using the circular cutter 161 are obtained. In this embodiment, the sensor 165 is provided and the laminated sheet 62 is stopped at the cutting position as in the embodiment using the circular cutter 161.

  In the present embodiment, the back surface sheet 61 provided with the adhesive layer 615 in advance is used. However, the present invention is not limited to this. For example, the adhesive toner containing the adhesive toner in the image forming unit 31d. A mode in which the developing device 39 is disposed may be appropriately selected. In this case, at the time of non-image formation of the image forming engine 30, after the adhesive toner is attached onto the photosensitive drum 32, the adhesive-coated toner is primarily transferred to the intermediate transfer belt 40, and the intermediate transfer belt 40 is moved to the secondary transfer position. The adhesive layer 615 can be formed by transporting the adhesive toner to the adhesive surface side of the sheet 61 for the back surface.

According to the image forming apparatus 10 according to the present embodiment, there is no occurrence of blisters and the like, and a smooth and high gloss sheet surface can be obtained.
Further, in the present embodiment, the sheet conveyance order, the conveyance path, and the like may be appropriately selected according to the print mode, the mode of the adhesive layer 615, and the like.
◎ Deformation

FIG. 14 shows a modification of the image forming apparatus 10 according to the first embodiment. The basic configuration of the image forming apparatus 10 according to this modification is the same as that of the first embodiment, but differs from the first embodiment in that an attached tray 59 that communicates from the retreat conveyance path 65 to the main conveyance path 64 is provided. .
That is, in this modification, an attachment tray 59 is provided below the fixing device 80, the attachment tray 59 is connected to the retreat conveyance path 65, and the back surface sheet 610 can be accommodated in the attachment tray 59. .

In this modified embodiment, a heat-sensitive adhesive is used for the adhesive layer 615 of the back surface sheet 610, and the laminating apparatus 140 applies the heat-sensitive property to one pressure roll 141 out of a pair of pressure rolls 141. A heating roll capable of melting the adhesive is used.
Examples of the heat-sensitive adhesive include a heat seal adhesive and a hot melt adhesive. Furthermore, the base resin of the heat seal adhesive includes, for example, polyolefin resin, polyester resin, ethylene / vinyl acetate copolymer resin, polyacrylate resin, vinyl chloride / vinyl acetate copolymer resin, ethylene / acrylic acid copolymer resin, etc. An organic solvent solution or an aqueous dispersion is used.

Furthermore, as the base material for the hot melt adhesive, a thermoplastic material that generally melts in a temperature range of 60 ° C. to 180 ° C. is exemplified, and more preferably at a toner melting temperature (generally a temperature range of 100 ° C. to 120 ° C.) or less. A thermoplastic material that melts in a certain temperature range of 60 ° C. to 100 ° C. is preferable. For example, wax is used in addition to polymer and resin. Such polymers, resins and waxes include, for example, alkyds (modified polyesters), asphalt and coal tar bitumen, coumarone-indene resins, rosin and derivatives thereof, pentene resins, waxes (minerals, plants and petroleum), Ethylene / ethyl acrylate copolymer, ethylene / vinyl acetate copolymer, polyethylene, polyvinyl acetate and its copolymer, polycarbonate, polystyrene and its copolymer, polypropylene, polyvinyl ether, polyamide, polyester (thermoplastic), Examples thereof include polyisobrene, polyurethane, and thermoplastic elastomer (SBS, SIS, SEBS, etc.).
Such heat-sensitive adhesives are dry at room temperature and are not sticky, but once heated above their melting point, the heat-seal adhesive is plasticized and sticky, and it can be used for surfaces with light pressure. The sheet 60 and the back surface sheet 610 can be bonded together.

Next, a laminated sheet production mode of the image forming apparatus 10 according to this modification will be described.
Here, an image is not created on the back sheet 610, for example, a full-color image is created on the front sheet 60, and the back sheet 610 is pasted on the front sheet 60 after the image creation to produce the laminated sheet 62. The image forming process performed will be described.

Now, when printing information for single-sided printing is input from the input processing unit, the printing operation is started according to the flowchart of FIG.
That is, when a full-color toner image is formed on the surface of each photosensitive drum 32, the toner image is transferred onto the intermediate transfer belt 40 by the primary transfer roll 36. Further, when one surface sheet 60 is sent out from the sheet tray 53, it is conveyed to the secondary transfer roll 45 in synchronization with the image writing timing on the surface sheet 60, and on the intermediate transfer belt 40 on the surface sheet 60. Transfer a monochrome toner image. Thereafter, when the back sheet 610 passes through the sheet transport belt 644 and is transported to the fixing device 80, the unfixed toner image on the surface of the back sheet 610 is fixed by the fixing device 80. Then, the front surface sheet 60 after fixing is temporarily stopped by the registration roll 643.

On the other hand, the back surface sheet 610 in the attachment tray 59 is discharged from the attachment tray 59 in accordance with the feeding timing of the front surface sheet 60 stopped by the registration roll 643. That is, when the back sheet 610 is sent out from the attached tray 59, it enters the retreat conveyance path 65 and is guided to the main conveyance path 64 by switching the switching gates 69 and 70. At this time, the front sheet fed from the registration roll 643 and the rear sheet 610 from the retreat conveyance path 65 are merged and conveyed.
The superposed and transported front sheet 60 and back sheet 610 are pasted by the laminating apparatus 140, the peripheral edge is cut by the cutting apparatus 160, and sent to the discharge tray 191.

This modification can prevent the back surface sheet surface from being contaminated and can prevent the adhesive layer 615 from melting in the fixing device 80 in a mode in which a heat-sensitive adhesive is used for the back surface sheet. Of course, a pressure-sensitive adhesive may also be used in this modified embodiment.
Further, in this modified embodiment, as long as unnecessary melting of the adhesive layer 615 in the fixing device 80 is avoided, the embodiment is not limited to the embodiment in which the attachment tray 59 is provided as in the present embodiment. In the fixing device 80, the temperature of the fixing device 80 is controlled to be equal to or lower than the thermal temperature when the fixing device 80 passes through the fixing device 80. An intermediate tray (not shown) for temporarily storing the plurality of back surface sheets 610 may be provided in front of the bonding apparatus 140 or the like.
Furthermore, as another aspect, a bypass conveyance path (not shown) in which the back surface sheet 610 does not pass through the transfer unit and the fixing device 80 may be appropriately selected, such as an aspect in which conveyance is possible before the bonding apparatus 140. .

In this modified embodiment, the back surface sheet 61 provided with the adhesive layer 615 in advance is used. However, the present invention is not limited to this. For example, an adhesive application unit 650 is provided in the retreat conveyance path 65. The back surface sheet 61 to which the adhesive layer 615 in the sheet tray 54 is not applied is accommodated, the sheet is conveyed in advance, and when the sheet is retracted to the retreat conveyance path 65 after image creation, the adhesive application unit 650 A heat sensitive adhesive may be applied to the non-image-forming surface of the back sheet 61. According to such an aspect, it is also possible to create an image on the back surface sheet 61 in the sheet conveyance tray 54.
In this case, the mode of the adhesive, the sheet to which the adhesive is applied, the sheet transport path, the sheet transport order, and the like may be appropriately selected.
Embodiment 2

FIG. 16 shows a second embodiment of the image forming apparatus 10 to which the present invention is applied. The basic configuration of the image forming apparatus 10 according to the present embodiment is the same as that of the first embodiment, but differs from the first embodiment in that the fixing device 400 also serves as a bonding device.
In other words, in this embodiment, the laminating apparatus in the cutting unit 14 is omitted, and a path 401 for returning the reversed sheet to the main conveying path 64 on the upstream side of the fixing apparatus 400 is provided in the retreat conveying path 65. is there.
As shown in FIG. 17, the fixing device 400 according to the present embodiment has the same configuration as that of the first embodiment, but the control device 200 controls the temperature of the heating roll 81 and the pressure of the pressure roll 84. It has become.

Moreover, in this Embodiment, the laminated sheet preparation mode is demonstrated below as what uses the pressure sensitive adhesive as the sheet | seat 61 for back surfaces.
Here, as an example of the laminated sheet production mode, for example, a monochrome image is created on the back surface sheet 61, and then, for example, a full color image is created on the front surface sheet 60 and both sheets are adhered to produce the laminated sheet 62. The process which was made will be described (see FIG. 18).

Now, when print information for double-sided printing, for example, is input from the image information input unit 13, a double-sided printing operation is started according to the flowchart of FIG.
That is, when a monochrome toner image is formed on the surface of the black photosensitive drum 32, the toner image is transferred onto the intermediate transfer belt 40 by the primary transfer roll 36.
On the other hand, when one sheet for the back surface 61 is sent out from the sheet tray 54, it is conveyed to the secondary transfer roll 45 in accordance with the timing of image writing on the sheet for the back surface 61, and on the intermediate transfer belt 40 on the sheet for back surface 61. Transfer a monochrome toner image.

Thereafter, when the back surface sheet 61 is conveyed to the fixing device 400 integrated with the laminating device, the unfixed toner image on the surface of the back surface sheet 61 is fixed by the fixing device 400.
The back surface sheet 61 is conveyed to the switchback tray 67 by switching the conveyance path by the switching gate 70 (see FIG. 18).
Further, when producing the single-sided laminated sheet 62 that does not produce an image on the back sheet 61, the sheet fed from the sheet tray 54 is immediately transferred to the switchback tray 67 without performing the above-described image forming process and fixing process. What is necessary is just to convey.

Subsequently, the surface sheet 60 is imaged. That is, when a toner image is formed on the surface of each photosensitive drum 32, the toner image is transferred onto the intermediate transfer belt 40 by the primary transfer roll 36. On the other hand, when one surface sheet 60 is sent out from the sheet tray 53, the sheet 60 is conveyed to the secondary transfer roll 45 in accordance with the timing of image writing on the surface sheet 60, and on the intermediate transfer belt 40 on the back sheet 61. Transfer a full-color toner image.
Next, the front surface sheet 60 on which the toner image is formed is temporarily stopped at the registration roll 643 in front of the fixing device 400, sent out from the switchback tray 67 and temporarily stopped at the registration roll 402. Then, the sheet is superposed with the back sheet 61 in front of the fixing device 400 (see FIGS. 4A and 18). Thereafter, when the front surface sheet 60 and the back surface sheet 61 are polymerized and transported into the fixing device 400, the unfixed toner image on the front surface sheet 60 is heated and fixed, and both sheets are attached to the pressure roll 84. It is fixed by pressure. The laminated sheet 62 to which the front surface sheet 60 and the back surface sheet 61 are bonded is cut at the peripheral edge by the cutting device 160 and sent to the discharge tray 191.

In such an image forming process, the fixing device 400 according to this aspect can ensure optimum fixing performance and sheet bonding performance as shown in FIG.
That is, the fixing device 400 is necessary because the thickness of the sheet is different between the case where the fixing is performed by transporting only the back surface sheet 61 and the case where the fixing is performed by superposing the front surface sheet 60 and the back surface sheet 61. Since the amount of heat is also different, the temperature is controlled to an optimum temperature according to the sheet conveyance mode.
Further, according to such a fixing device 400, the pressure of the pressure roll 84 when conveying only the back surface sheet 61 is P ₂ , the pressure of the pressure roll 84 when bonding both sheets is P ₃ , and the feeling. Assuming that the reaction pressure of the pressure-sensitive adhesive is P ₀ , the relationship between the pressures satisfies P ₂ <P ₀ ≦ P _3, and can be controlled to an optimum pressure according to the sheet conveyance mode.

In this embodiment, the back surface sheet 61 is transported in advance, but the sheet transport order, transport path, and the like may be appropriately selected according to the print mode, the mode of the adhesive, and the like. In FIG. 20, “one-side fixing temperature setting” is not limited to the fixing temperature setting of the back surface sheet 61, but indicates each temperature setting of the front surface sheet 60 or the back surface sheet 61 corresponding to the sheet conveyance order. Is.
Further, each setting process of the fixing device 400 has been described as an embodiment using a pressure-sensitive adhesive. However, when a heat-sensitive adhesive is used, temperature control may be appropriately performed instead of pressure control.
In addition, it is possible to use an aspect in which the adhesive is applied during the conveyance of the sheet, but in this case, the sheet conveyance order, the conveyance path, and the like may be appropriately selected as described above.

In the image forming apparatus 10 and the image forming method used in the present embodiment, the front surface sheet 60 is fixed in a state where the front surface sheet 60 and the back surface sheet 61 are arranged in a superposed manner. However, the water vapor generated from the front end of the sheet at the time of fixing diverges from the rear end portion (pre-nip portion) of the sheet not adhered, or the water vapor contained in the back surface sheet 61 is fixed at the time of fixing the toner image on the back surface sheet 61. Since it has already been diverged, no blister is generated, and good toner fixing and sheet bonding can be achieved.
Furthermore, according to the present embodiment, the same effects as those of the first embodiment can be obtained, and the fixing device 400 can also be used as a bonding device, and it is not necessary to provide the bonding device. Can be
◎ Deformation

FIG. 21 shows a modification of the image forming apparatus 10 according to the second embodiment. The basic configuration of the image forming apparatus 10 according to the present modification is the same as that of the second embodiment, but differs from the second embodiment in that an attached tray 59 that communicates from the retreat conveyance path 65 to the main conveyance path 64 is provided. .
That is, in this modified embodiment, an auxiliary tray 59 is provided below the reverse conveyance path 66, the auxiliary tray 59 is connected to the retreat conveyance path 65, and the back surface sheet 610 is accommodated in the auxiliary tray 59. .

Next, an example of the laminated sheet production mode of the image forming apparatus 10 according to this modification will be described.
Here, in a print mode in which an image is not created on the back sheet 610, the back sheet 610 provided with a heat-sensitive adhesive is used, and for example, a full-color image is created on the top sheet 60, and the top sheet 60 after image formation is performed. An image forming process in which the back sheet 610 is pasted to produce the laminated sheet 62 will be described.

Now, when printing information for single-sided printing is input from the input processing unit, the printing operation is started according to the flowchart of FIG.
That is, when a full-color toner image is formed on the surface of each photosensitive drum 32, the toner image is transferred onto the intermediate transfer belt 40 by the primary transfer roll 36. Further, when one surface sheet 60 is sent out from the sheet tray 54, the sheet 60 is conveyed to the secondary transfer roll 45 in accordance with the timing of image writing onto the surface sheet 60, and on the intermediate transfer belt 40 on the surface sheet 60. Transfer the color toner image. The front surface sheet 60 is temporarily stopped by the registration roll 643 after the toner image is transferred.

On the other hand, the back surface sheet 610 in the attachment tray 59 is discharged from the sheet tray 59 at the same timing as the front surface sheet 60 stopped by the registration roll 643.
That is, when the back surface sheet 610 is sent out from the sheet tray 59, it enters the retreat conveyance path 65 and is guided to the main conveyance path 64 by the path switching of the switching gate 70. At this time, the front surface sheet 60 delivered from the registration roll 643 and the back surface sheet 610 delivered from the registration roll 402 in the retreat conveyance path 65 are merged and conveyed.
When the front surface sheet 60 and the back surface sheet 610 are polymerized and conveyed into the fixing device 400, the unfixed toner image on the front surface sheet 60 is heated and fixed, and a heat-sensitive adhesive between the two sheets is formed. The two sheets are bonded by heating and welding to produce a laminated sheet 62. Thereafter, the peripheral edge of the laminated sheet 62 is cut by the cutting device 160 and sent out to the discharge tray 191.

In this embodiment, the back surface sheet 610 for non-image formation can be transported to the front of the laminating device (fixing device 400) without inserting the transfer unit or the fixing device 400, so that the surface of the sheet is contaminated. Can be prevented. Further, in this aspect, by using a heat-sensitive adhesive as an adhesive for bonding the front surface sheet 60 and the back surface sheet 610, pressure control on the pressure roll 84 of the fixing device 400 is unnecessary. be able to.
Furthermore, when an image is also created on the back sheet 61 in the sheet tray 54, for example, an adhesive application unit may be appropriately provided on the conveyance path. In this case, the conveyance path, the sheet conveyance order, and the like may be appropriately selected.

In this example, the image forming apparatus according to the first embodiment is used to examine the relationship between the temperature of the heating roll and the pressure roll of the fixing device and the image level difference.
As a comparative example, as shown in FIG. 24, a first fixing device 510 disposed downstream of the image forming engine 500 and an image smoothing device further downstream of the first fixing device 510 are provided. The relationship between the temperature of the heating roll 521 and the pressure roll 522 of the second fixing device 520 and the image level difference was examined using an image forming apparatus including the second fixing device (belt fixing device) 520 (patent). Reference 4).
The result of the comparative example is shown in 25 (a). As shown in the figure, when the temperature of the heating roll 521 and the pressure roll 522 is lower than 130 ° C., the receiving layer does not melt and the toner image is not embedded in the receiving layer, resulting in a step on the image surface. Moreover, generation | occurrence | production of the blister was seen when the temperature of the heating roll 521 and the pressure roll 522 became higher than 140 degreeC. Thus, it was confirmed that the surface temperatures of the heating roll 521 and the pressure roll 522 must be maintained at 130 to 140 ° C. in order to obtain a high gloss image forming surface having no image level difference.

On the other hand, the results of this example are shown in FIG. As shown in the figure, according to this embodiment, it was confirmed that the image step and the blister can be suppressed in a wide fixing temperature region of 130 ° C. to 155 ° C.
Further, as a configuration capable of realizing a reduction in size corresponding to the fixing device (a type that is also used as a bonding device) according to the second embodiment, the first fixing device 510 of the image forming apparatus of the comparative example is eliminated and a second fixing device ( Belt fixing device) When image fixing using only 520 is performed, as shown in FIG. 25B, even if strict temperature control is performed, there is no temperature range in which the sense of level difference on the sheet surface is zero, and practical use is achieved. It was confirmed that it was not possible.

(A) is explanatory drawing which shows the outline | summary of the image forming method concerning this invention, (b) is explanatory drawing which shows the outline | summary of the image forming apparatus concerning this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram illustrating an image forming apparatus according to a first embodiment to which the present invention is applied. FIG. 2 is an explanatory diagram illustrating a fixing device used in Embodiment 1. (A) is explanatory drawing which shows the bonding apparatus used in Embodiment 1, (b) is explanatory drawing which shows the sheet | seat for surface and the sheet | seat for back surfaces used in Embodiment 1. FIG. (A) is a top view of the cutting part for front and rear of the cutting apparatus used in Embodiment 1, (b) is sectional drawing of the said cutting part for front and rear. FIG. 3 is an explanatory diagram showing a circular cutter unit of a front / rear cutting unit used in the first embodiment. (A) is a top view of the slitter of the side cutting part used in Embodiment 1, (b) is sectional drawing of the said slitter. 3 is a block diagram showing an image forming process control system used in Embodiment 1. FIG. 3 is a flowchart showing processing contents in a laminated sheet production mode of Embodiment 1; FIG. 6 is an explanatory diagram illustrating operations of the front sheet and the back sheet according to the first embodiment. (A) is explanatory drawing which shows the operation | movement of the slitter of the side cutting part used in Embodiment 1. FIG. (A) is a top view which shows another aspect of the cutting part for front and rear used in Embodiment 1, (b) is sectional drawing of the cutting part for front and rear shown to (a). It is explanatory drawing which shows another aspect of the cutting part for front and back used in Embodiment 1. FIG. FIG. 5 is an explanatory diagram illustrating a modification of the image forming apparatus illustrated in the first embodiment. 6 is a flowchart showing the processing content of a laminated sheet production mode according to a modification of the first embodiment. It is explanatory drawing which shows the image forming apparatus of Embodiment 2 to which this invention was applied. FIG. 6 is an explanatory diagram illustrating a fixing device used in a second embodiment. FIG. 10 is an explanatory diagram illustrating operations of the front surface sheet and the back surface sheet according to the second embodiment. 5 is a flowchart showing the processing content of a laminated sheet production mode of a second embodiment. FIG. 10 is an explanatory diagram illustrating fixing condition setting processing of the fixing device according to the second embodiment. FIG. 10 is an explanatory diagram illustrating a modification of the image forming apparatus illustrated in the second embodiment. 10 is a flowchart showing the processing content of a laminated sheet production mode according to a modification of the second embodiment. 3 is a graph showing the relationship between the temperature of a heating roll and a pressure roll in a fixing device and an image level difference using the image forming apparatus shown in the first embodiment. It is explanatory drawing which shows an example of the conventional image forming apparatus. (A) is a graph showing the relationship between the temperature of the heating roll and pressure roll in the fixing device and the image step when using a conventional image forming apparatus including a fixing device and an image smoothing device; ) Is a graph showing the relationship between the temperature of the heating roll and pressure roll and the image step when only the second fixing device is provided as a fixing device in the conventional image forming apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image formation process, 2 ... Fixing process, 3 ... Bonding process, 4 ... Cutting process, 5 ... Image forming means, 6 ... Fixing means, 7 ... Bonding means, 8 ... Conveying means, 9 ... Cutting means

Claims (15)

An image forming step of forming an unfixed toner image on a surface sheet on which a thermoplastic light diffusion layer is formed on the image forming surface side of the sheet substrate;
A fixing step of fixing an unfixed toner image on the surface sheet;
An image forming method comprising: a laminating sheet by adhering a back sheet to the non-image-forming side of the front sheet at least after fixing the front sheet. An image forming step of forming an image on the surface sheet on which the thermoplastic light diffusion layer is formed on the image forming surface side of the sheet base material and the back surface sheet that can be bonded to the back surface side of the surface sheet;
A fixing step of fixing the unfixed toner image on the front sheet and the unfixed toner image on the back sheet, respectively;
An image forming method comprising: a laminating step in which a non-image forming surface side of both sheets is bonded to each other after fixing the front surface sheet and the back surface sheet. The image forming method according to claim 1 or 2,
Furthermore, the image forming method characterized by including the cutting process which cuts the edge of a lamination sheet. An image forming means for forming an unfixed toner image on a surface sheet in which a thermoplastic light diffusion layer is formed on the image forming surface side of the sheet substrate;
Fixing means for fixing an unfixed toner image on the surface sheet;
Bonding means for producing a laminated sheet by adhering the back sheet to the non-image-forming side of the front sheet at least after fixing the front sheet;
An image forming apparatus comprising: a conveying unit configured to convey the front surface sheet and the back surface sheet to the respective units. An image forming means for forming an image on each of the surface sheet on which the thermoplastic light diffusion layer is formed on the image forming surface side of the sheet base material and the back sheet that can be bonded to the back surface side of the surface sheet;
Fixing means for fixing the unfixed toner image on the front sheet and the unfixed toner image on the back sheet, respectively;
Bonding means for producing a laminated sheet by adhering the non-image forming sides of both sheets after fixing the front sheet and the back sheet;
An image forming apparatus comprising: a conveying unit configured to convey the front surface sheet and the back surface sheet to the respective units. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus comprising a cutting means for cutting the edge of the laminated sheet. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus, wherein the surface sheet includes a receiving layer in which a toner image can be embedded on a thermoplastic light diffusion layer. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus, wherein the back sheet has a thermoplastic light diffusion layer formed on one side of a sheet substrate. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus, wherein the fixing unit also serves as a bonding unit. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus, wherein the back sheet is a postcard sheet. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus comprising a pressure-sensitive adhesive layer that is bonded to a bonding surface of a back sheet at a pressure higher than a fixing pressure of a fixing unit and is bonded at a pressure equal to or lower than a bonding pressure of a bonding unit. . The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus comprising a heat-sensitive adhesive layer that can be thermally welded at a temperature lower than a melting temperature of toner on an adhesive surface of a back sheet. The image forming apparatus according to claim 4 or 5, wherein:
The fixing unit includes a heating member whose surface is heated, and a fixing belt that is stretched with at least the heating member as one of the stretching members,
The unfixed toner image on the sheet is fixed via the fixing belt, and the sheet is conveyed downstream in the rotation direction of the fixing belt with the toner image forming surface on the sheet being in close contact with the fixing belt. An image forming apparatus. The image forming apparatus according to claim 4 or 5, wherein:
An image forming apparatus, further comprising a control device capable of controlling at least the image forming unit, the fixing unit, and the conveying unit based on the print mode information. The image forming apparatus according to claim 4 or 5, wherein:
The conveying means is a reversing means for reversing the conveying surface of one of the sheets for the front side or the sheet for the front side of the sheet for the back surface,
Switching means capable of switching the conveyance path of the one sheet to the reversing means side,
An image forming apparatus characterized by adjusting a timing at which the one sheet reversed by the reversing unit and the other sheet conveyed following are merged, and superimposing and conveying both sheets by at least a bonding unit.

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