JP2022064666A - Image forming apparatus - Google Patents

Abstract

To form a stereoscopic toner image.SOLUTION: Every time a heating rotating body revolves, an image forming apparatus forms toner images for a plurality of times to obtain a transfer sheet on which a toner image more stereoscopic than before is printed. The image forming apparatus can perform image formation on the same point of the heating rotating body for every revolution of the heating rotating body to greatly increase the amount of toner. Since the toner image revolves while in contact with the heating rotating body, the time for transfer of thermal energy to toner can be increased, and thereby even the large amount of toner can be sufficiently fused. The image forming apparatus can thermally transfer the toner image to the transfer sheet to obtain a transfer sheet on which a stereoscopic toner image with high toner height is printed.SELECTED DRAWING: Figure 7

Description

The present invention relates to an image forming apparatus that forms a toner image on a transfer medium.

In recent years, in an electrophotographic image forming apparatus, many techniques for increasing the value of a product in which a toner image is formed on a transfer medium have been proposed. For example, an image forming apparatus that uses a special color toner (fluorescent color, white color, gold color, etc.) to create a high-value-added product that cannot be expressed by the conventional four colors of YMCK is known. Further, as a post-processing after image formation, a method of increasing the value of the deliverable by a method such as adding gold leaf or varnish by post-processing has been proposed.

Conventionally, in an electrophotographic image forming apparatus, a technique is known in which a toner image is formed on the surface of a fixing member and then the toner image is simultaneously transferred and fixed on a transfer paper. For example, in Patent Document 1, two transfer papers are used to thermally transfer the toner image formed on the first transfer paper to the surface of the fixing member, and then the toner image on the surface of the fixing member is transferred onto the second transfer paper. Has been proposed as an electrophotographic apparatus that thermally transfers the image and uses it as the final output image.

Japanese Patent Application Laid-Open No. 2003-114581

However, in Patent Document 1, an image equivalent to that of paper having good transferability can be formed on a transfer paper having poor transferability, but the value of the product is not higher than that of the transfer paper having good transferability. ..

In the present invention, by further devising the technique of the preceding example, a large-capacity toner image that could not be fixed by the conventional fixing method can be fixed on the transfer paper without changing the configuration from the conventional fixing method. It is an object of the present invention to provide a technique for giving a three-dimensional effect to a toner image.

In order to achieve the above object, the image forming apparatus of the present invention has a heating rotating body and an image forming mechanism for forming a toner image on the heating rotating body, and the heating rotating body is formed of a toner image. It is maintained at a temperature higher than the softening point, and forms a toner image in which toner images are superimposed a plurality of times each time the heating rotating body rotates at the same place on the heating rotating body, and is conveyed to the heating rotating body. It is characterized in that a toner image superimposed on the heating rotating body is simultaneously fixed on the transfer paper to be transferred.

According to the present invention, a toner image is formed on a heated rotating body that exceeds the softening point of the toner image, and the toner image is superimposed each time the toner image is rotated to obtain a large-capacity laminated toner image that cannot be formed by a conventional image forming apparatus. It can be formed. Further, by heating for a long time while rotating on the heating rotating body, the laminated toner image can be sufficiently melted even if it has a large capacity. By thermally transferring this molten toner image to the transfer paper, it is possible to obtain a transfer paper on which a toner image significantly higher than that of the conventional image forming apparatus is formed.

Sectional drawing of the printer part 101 in Example 1. Block diagram of image forming apparatus 100 in Example 1. Schematic diagram of the user operation unit 106 in the first embodiment A flowchart showing the operation of the image forming apparatus 100 in the first embodiment. Sectional drawing of the transfer paper S which forms an image on the heating rotation member 9 in Example 1. Schematic diagram of the toner image formed on the transfer paper S in Example 1. Schematic diagram of the toner image formed on the heating and rotating member 9 in the first embodiment. The figure which compares the toner height of Example 1 and the conventional example. Table of physical property values and paper passing results of transfer paper suitable for tertiary transfer in Example 1. Sectional drawing of the printer part 101 in Example 2 Schematic diagram of the toner image formed on the heating rotation member 9 in the second embodiment.

[Example 1]
FIG. 1 is a cross-sectional view of a printer unit 101 which is an image forming means of an image forming apparatus 100 to which the present invention can be applied.

FIG. 2 is a block diagram of the controller unit 102 and the printer unit 101, which are image processing means, of the image forming apparatus 100. As shown in FIG. 2, the operation of the image forming apparatus 100 is integrally controlled by the CPU 103 in the controller unit 102. The controller unit 102 is provided with an interface 104, and an external device such as a computer is connected to the controller unit 102. Further, a document reading means 105 and a user operation unit 106 are connected to the controller unit 102.

FIG. 3 is a diagram showing an outline of the user operation unit 106, which includes a display unit 107 using a liquid crystal panel or the like, a mode selection button 108 for selecting an image formation mode described later, and a copy button 109 for instructing a copy start. ing.

FIG. 4 is a flowchart illustrating a schematic operation in which the CPU 103 operates the image forming apparatus 100 to process and copy an image read by the document reading means 105. In this embodiment, a mode for outputting transfer paper in which the amount of toner is significantly increased from that of a conventional image forming apparatus is referred to as a three-dimensional printing mode, and its operation will be described below.

In step S1, for example, the printed image is read from the document reading means 105 and the printing operation is started. In step S2, the print mode is selected by pressing the mode selection button 108 of the user operation unit 106 shown in FIG. 3, and the operation of the image forming apparatus branches depending on whether normal printing or stereoscopic printing is performed in step S3. do.

When the three-dimensional printing mode is selected, the height of the image to be placed on the transfer paper is specified in step S10. The height may be specified, for example, a magnification specification such as 3 times or 5 times based on the height of normal printing, a numerical value specification such as a height of 20 μm, or a selection formula such as high / slightly high. The CPU 103 determines the number of times of image formation to be placed on the heating rotating body 9 based on the information input in step S10. In this embodiment, the number of image formations is N (N is a positive integer). For example, if it is desired to increase the amount of toner by 10 times the conventional amount, N is 10.

The printer unit 100 forms toner images of each color of yellow, magenta, cyan, and black on the four image forming stations Y, M, C, and K in FIG. 1, and multiple toner images are formed on the first intermediate transfer belt 7. To form. (Hereinafter, the symbols Y, M, C, and K are omitted for those common to image forming stations.) The toner is a binder resin such as a styrene resin or a polyester resin, carbon black, magnetite, a dye, a pigment, or the like. It is composed of an agent, a mold release agent such as wax, a charge control agent, and the like in an appropriate amount. Such non-magnetic toner can be produced by a method such as a pulverization method or a polymerization method.

At each image forming station, the photosensitive drum 1 is rotationally driven counterclockwise in FIG. A charging roller 2, an exposure device 3, a developing device 4, a primary transfer roller 5, and a drum cleaner 6 are arranged around each photosensitive drum 1 in substantially order along the rotation direction thereof. The surface of the photosensitive drum 1 is charged to a predetermined potential by the charging roller 2, and then exposed by the exposure apparatus 3, so that an electrostatic latent image is formed on the photosensitive drum 1. The electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image of each color of yellow, magenta, cyan, and black by the developer 4 of each color. These four-color toner images are sequentially transferred onto the intermediate transfer belt 7 by the primary transfer roller 5 and superposed.

At the time of the primary transfer, the toner remaining on the photosensitive drum 1 without being transferred to the intermediate transfer belt 7 is removed by the drum cleaner 6. The four-color toner images superimposed on the intermediate transfer belt 7 are secondarily transferred onto the transfer paper S by using the electrostatic force of the belt. At the time of the secondary transfer, the toner remaining on the intermediate transfer belt 7 without being transferred to the transfer paper S is removed by the intermediate transfer belt cleaner 6T. The intermediate transfer belt 7 is made by dispersing carbon black, which is a conductive material, in polyimide, which is a resin.

The film thickness is 50 to 200 μm, the volume resistivity is 1 × 10 ⁹ to 1 × 10 ¹³ Ω · cm, and the surface resistivity is 1 × 10 ⁹ to 1 × 10 ¹³ Ω / cm ² . As the resin, polyethylene terephthalate (PET), polycarbonate (PC), polyamide (PA), polyphenylene sulfide (PPS), polyethersalphon (PES), polyetheretherketone (PEEK) and the like can be used as the thermoplastic resin. Further, as the thermosetting resin, polyimide (PI) can be used. As the conductive material, carbon black carbon fiber, metal fine particles, or the like can be used.

The secondary transfer inner roller 7 has an elastic layer provided on a metal cylinder and has a radial resistance value of 1 × 10 ⁷ to 1 × 10 ¹⁰ Ω. A constant voltage power supply (not shown) is connected to the secondary transfer inner roller 7, and the secondary transfer is such that a current of about 10 to 100 μA flows between the secondary transfer inner roller 7 and the secondary transfer outer roller 8. A negative bias voltage (same polarity as the toner) is applied to the inner roller. As a result, the toner image on the intermediate transfer belt 7 is electrostatically transferred onto the transfer paper S.

The toner image on the transfer paper S is conveyed to the heating rotating body 9 and the pressurized rotating body 10 by a conveying means (not shown). In the heating rotating body 9, for example, a silicone rubber layer of 10 mm is provided as an elastic layer on a metal roller having a diameter of 60 mm, and a copolymer of ethylene tetrafluoride and perfluoroalkoxyethylene (hereinafter, PFA) is mainly provided on the surface layer thereof. A detachable layer made of a tube made of a material is provided by 40 μm. The pressurized rotating body 10 is formed by, for example, providing a silicone rubber layer of 10 mm as an elastic layer on a metal roller having a diameter of 40 mm, and further providing a release layer made of PFA resin by 40 μm on the surface layer thereof.

As the material of the metal roller for both the heating rotating body 9 and the pressurized rotating body 10, a metal such as SUS (stainless steel) or aluminum or an alloy can be used. As the elastic layer, rubber having high heat resistance such as fluororubber can be used in addition to silicone rubber. In addition to PFA, the surface layer includes polytetrafluoroethylene (hereinafter, PTFE), tetrafluorinated ethylene / fluorinated propylene copolymer (hereinafter, FEP), and ethylene / tetrafluorinated ethylene copolymer (hereinafter, ETFE). Fluororesin such as, and heat-resistant resin such as silicone resin can be mixed or used alone.

A heat source (for example, a halogen heater) (not shown) is included inside the rotating heating body 9, and heat energy is applied from the inside so that the surface layer of the rotating heating body 9 reaches a predetermined temperature (for example, 150 ° C.) at which the toner image can be melted. The temperature is controlled. Further, the toner image on the transfer paper can be heated by forming a heating nip having a width of about 10 mm by pressure contacting the pressurized rotating body with a predetermined load (for example, about 100 N).

The temperature of the toner image is, for example, about 20 to 40 ° C. immediately after the secondary transfer, which is significantly lower than the glass transition point 55 ° C. of the toner resin of this embodiment. When the toner image comes into contact with the heated rotating body 9, heat energy is directly transmitted to the toner image, and the temperature of the portion in contact with the surface layer of the heated rotating body 9 exceeds 100 ° C. Since this temperature is higher than the softening point of the toner resin of 100 ° C., the toner image is melted and exhibits an adhesive force with the surface layer of the heated rotating body 9. Further, the thermal energy enters the layer of the toner image, and the adhesive force between the melted toner particles is also developed. In the conventional printing mode, the toner particles in contact with the transfer paper S are sufficiently melted and a strong adhesive force is developed between the toner particles and the transfer paper, so that the toner image can be fixed on the transfer paper.

Toner softening point is measured using a constant load extrusion type thin tube reometer (trade name: flow characteristic evaluation device Flow Tester CFT-500D, manufactured by Shimadzu Corporation) and according to the manual attached to the device (leometer). conduct. In this device, while applying a constant load from the top of the measurement sample with a piston, the temperature of the measurement sample filled in the cylinder is raised and melted, and the melted measurement sample is pushed out from the die at the bottom of the cylinder. A flow curve showing the relationship between and temperature can be obtained.

In the present invention, the softening point is the "melting temperature in the 1/2 method" described in the manual attached to the flow characteristic evaluation device flow tester CFT-500D. The melting temperature in the 1/2 method is calculated as follows. First, 1/2 of the difference between the piston descent amount Smax at the time when the outflow ends and the piston descent amount Smin at the time when the outflow starts is obtained (this is defined as X. X = (Smax-Smin) /. 2). The temperature of the flow curve when the amount of descent of the piston becomes X in the flow curve is the softening point.

The three-dimensional printing mode is characterized in that the toner image is tertiaryly transferred from the transfer paper S to the heating rotating body 9. For tertiary transfer, as shown in FIG. 5A, a high thermal permeable layer M formed of aluminum, copper, or the like having a high thermal effusivity is formed on the surface of the conventional transfer paper S (FIG. 5C). prepare. The high heat permeability layer M is formed by adhering aluminum, copper, or the like as a metal foil having a thickness of several tens to several hundreds of μm onto transfer paper, or by vapor deposition. Alternatively, as shown in FIG. 5B, the high heat infiltration layer M may be used as a single layer sheet.

The toner layer formed on the high heat infiltration layer M is not sufficiently heated because the heat energy from the heating rotating body 9 is taken away by the high heat infiltration layer M, so that it is not melted. Therefore, almost no adhesive force is developed between the high heat permeation layer M and the toner layer in contact with the high heat permeation layer M. Therefore, the toner image moves from the transfer paper S to the surface layer of the heating rotating body 9 due to the adhesive force between the toner layer melted in contact with the surface layer of the heating rotating body 9 and the surface layer of the heating rotating body 9. This phenomenon is an image defect due to insufficient melting of toner called cold offset. In the present invention, the toner image can be tertiary-transferred to the heated rotating body 9 by using a sheet having a high heat permeability that causes cold offset.

The CPU 102 controls the heating rotary body 9 so as to perform N tertiary transfers on the rotating body 9. In step S11 of FIG. 4, N toner images are developed so as to form an image N times on the heating rotating body 9. The N toner images are formed as toner images on the stations of each color of FIG. 1, and are formed on the high heat permeability layer M on the transfer paper S via the intermediate transfer belt 7. At this time, as shown in FIG. 6, the distance between the toner images N times on the high heat permeability layer M is controlled so as to be the interval of the peripheral length L of the heating rotating body 9.

When the high heat permeability layer M is sequentially conveyed by the nip portions of the heating rotating body 9 and the pressurized rotating body 10, the toner image of the high heat penetrating rate layer M is generated every time the heating rotating body 9 orbits. The surface layer of 9 is tertiary-transferred N times to form an image in a larger amount than that of the conventional image forming apparatus (step S13 in FIG. 4).

FIG. 7A illustrates a state in which an image is formed once on the heated rotating body 9, and FIG. 7B illustrates a state in which an image is formed N times on the heated rotating body 9. In FIG. 7 (c), as the transfer paper S immediately after the image is formed N times on the heating rotating body 9, the general transfer paper S used in the normal printing mode in which the high heat permeation layer M is not formed is used. When the toner image formed N times on the heated rotating body 9 and melted on the belt comes into contact with the transfer paper without the high heat permeable layer M, a large adhesive force is developed between the toner image and the transfer paper S, and the toner image is the molten toner. The fluororesin surface layer, which has high releasability, is transferred (thermally transferred) to the transfer paper S (step S14 in FIG. 4).

When the toner on the image heating belt 9 is thermally transferred to the transfer paper S, the temperature and driving speed of the heating member 9 and the contact load with the pressurized rotating body 10 are set according to the total amount of toner during normal printing. You may change and adjust from.

When normal printing is selected in step S3 of FIG. 4, which describes a normal printing mode as a conventional example, the toner image formed in the shape of a photosensitive drum in step S20 passes through the intermediate transfer belt 7 and is stepped. An image is formed on the transfer paper S in S21. At this time, since there is no high heat permeation layer M on the transfer paper S, the toner layer melted in contact with the heating rotating body 9 is heat-fixed to the transfer paper S as it is.

FIG. 8 shows the weight and height of the toner image-formed on the final transfer paper in this example and the conventional example. The number of times the image was formed on the heating member was 10 times and 3 times. The toner weight is the result of measuring the weight by separating only the toner image from the final transfer paper. The height is the toner height from the surface of the transfer paper measured by an optical microscope. From FIG. 8, it can be confirmed that the toner weight and the toner height on the final transfer paper are increased by about 3 times and 5 times when the toner amount of the conventional example is 1.

ここで、bは熱浸透率（単位はJ/(m² s^0.5 K)）であり、添え字のM、Tはそれぞれ、高熱浸透層Ｍおよびトナー像の熱浸透率であることを示す。この式のTがトナーの軟化点より低い温度（例えば９０℃）になるような転写紙が本発明に適した高熱浸透率層Ｍの条件である。 Next, a material suitable for the high heat permeability layer M for causing cold offset will be supplemented. It is generally known that the interface temperature T when two substances having a temperature difference come into contact with each other can be calculated by the following formula.

Here, b is the thermal effusivity (unit: J / (m ² s ^0.5 K)), and the subscripts M and T are the thermal effusivity of the high thermal effusivity layer M and the toner image, respectively. A transfer paper having a temperature (for example, 90 ° C.) where T of this formula is lower than the softening point of the toner is a condition of the high heat permeability layer M suitable for the present invention.

の関係から計算し、図９に示す。もし物質が不明であったり、文献値が得られず計算で熱浸透率が分からない場合は、熱浸透率を直接測定することも可能である。例えば、測定したい転写紙の表面にモリブデン（Ｍｏ）の薄膜（厚さ１００ｎｍ）をスパッタリングで形成した後、光加熱式サーモリフレクタンス法熱物性顕微鏡（商品名：Ｔｈｅｒｍａｌ Ｍｉｃｒｏｓｃｏｐｅ；株式会社ベテル製）を用いて測定することもできる。 For the thermal effusivity b, the values of thermal conductivity λ [W / (m ・ K)], density ρ [kg / cm ³ ], and specific heat capacity C [J / (kg ・ K)] are obtained from general literature values. Quote,

It is calculated from the relationship of and shown in FIG. If the substance is unknown, or if the literature value is not available and the thermal effusivity is not known by calculation, the thermal effusivity can be measured directly. For example, after forming a thin film of molybdenum (Mo) (thickness 100 nm) on the surface of the transfer paper to be measured by sputtering, a photoheated thermoreflectance method thermophysical microscope (trade name: Thermal Microscope; manufactured by Bethel Co., Ltd.) is used. It can also be measured using.

In addition, for comparison with the calculation, paper with aluminum foil or copper foil attached, PET resin, or paper containing limestone as the main component is used with two levels of temperature control conditions for the heating rotating body 9 (Condition 1: Condition 1:). FIG. 9 shows the results of actually confirming the paper passage at 150 ° C. and condition 2: 190 ° C. and confirming whether or not a cold offset occurs. According to the results of FIG. 9, it can be predicted that the interface temperature T calculated is cold offset at 90 ° C. or lower, and the presence or absence of cold offset confirmed by actually passing the transfer paper having each high thermal conductivity layer M is checked. The confirmation results match. It can also be seen that the thermal effusivity between PET and limestone is required for cold offset.

Therefore, when the transfer paper is used as a means for transporting the toner image to the heating rotating body 9 in the three-dimensional printing mode of the present invention, the thermal effusivity of the surface in contact with the toner is 1000 J / (m ² S ^0.5 K) or more. It is inferred that it is necessary. The surface layer of the high thermal conductivity layer M is not limited to a metal and may be a non-metal such as limestone or ceramic. However, when the thermal effusivity is 10000 J / (m ² S ^0.5 K) or more, the toner interface is preferable. The temperature T becomes lower, and the cold offset can be stably performed.

[Example 2]
In the configuration of the image forming apparatus of this embodiment, as shown in FIG. 10, the secondary transfer outer roller 8 of Example 1 is replaced with the second intermediate belt 81, and the heating rotating body 9 is not the roller of Example 1. It is characterized by being a heating rotary belt 91. In addition, the part common to the first embodiment other than the configuration is omitted.

The surface layer of the second intermediate transfer belt 81 is composed of a substance having a thermal effusivity of 1000 J / (m ² S ^0.5 K) or more, similar to the high thermal effusivity layer M of the transfer paper S of Example 1. For example, the second intermediate transfer belt 81 can be made of nickel having a thickness of 100 μm. In addition to nickel, pure metals such as SUS (stainless steel), aluminum, copper, and zinc, or alloys are suitable as the material of the metal base material.

The second intermediate transfer belt 81 is stretched with a predetermined tension by the first tension roller 81A and the second tension roller 81B.

The first tension roller 81A is provided with an elastic layer on the surface of a metal cylinder, and has a radial resistance value of 1 × 10 ⁷ to 1 × 10 ¹⁰ Ω. Further, the metal cylinder of the first tension roller 81A is electrically grounded.

The second tension roller 81B is a metal cylinder that rotates according to the rotation of the second intermediate transfer belt 81, and is electrically grounded via an electric resistance sufficiently higher than the resistance value of the first tension roller 81A. Has been done.

A constant voltage power supply (not shown) is connected to the secondary transfer inner roller 71, and the secondary transfer is such that a current of about 10 to 100 μA flows between the secondary transfer inner roller 71 and the first tension roller 81A. A negative bias voltage (same polarity as the toner) is applied to the inner roller. As a result, the toner image on the intermediate transfer belt 7 is electrostatically transferred onto the second intermediate transfer belt 81. The toner image conveyed by the second intermediate transfer belt 81 is heated by the heating rotating body 9 to develop the adhesiveness of the toner, and the toner image is tertiaryly transferred from the second intermediate transfer belt 81 onto the heating belt 91. ..

The heating means 9 rotates and drives a heating belt 91 having a circumference of 500 mm by being stretched by a first heating roller 92, a second heating roller 93, and a third heating roller 94.

Further, the peripheral length of the heating belt 91 is preferably long because it is the rate-determining factor of the image length in the transport direction that can be created in the three-dimensional printing mode. Therefore, the advantage of using the heating belt 91 different from that of the first embodiment as the heating means 9 is that the belt body has a smaller cross-sectional area than the heating roller and it is easy to obtain a peripheral length.

The heating belt 91 is provided with a silicone rubber layer of 400 μm as an elastic layer on the front side of an endless metal base material made of a nickel alloy having a thickness of 60 μm, and a release layer made of PFA resin provided on the front side thereof by 15 μm.

As the material of the metal base material, in addition to nickel, pure metal such as SUS (stainless steel), aluminum, copper, zinc, or an alloy can be used.

As the elastic layer, rubber having high heat resistance such as fluororubber can be used in addition to silicone rubber.

As the surface layer, in addition to PFA, a fluororesin such as PTFE, FEP, or ETFE, or a heat-resistant resin such as a silicone resin can be mixed or used alone.

The first, second, and third heating rollers 92, 93, and 94 are metal cylinders containing a heat source such as a halogen heater, respectively, and heat energy is applied from the inside of the heating belt 91 to heat the surface layer of the heating belt 91 to a predetermined temperature. For example, the temperature is controlled by using a thermistor detection temperature (not shown) inside the heating belt 91 on the upstream side of the first heating roller 92 so as to keep the temperature around 150 ° C. in the vicinity of the first heating roller 92.

FIG. 11 schematically shows the process of laminating the toner images N times on the heating belt 91 and finally heat-fixing them on the transfer paper S in the three-dimensional printing mode in the second embodiment. As shown in FIG. 11A, the N-layer toner is image-formed at each station, first transferred to the intermediate transfer belt 7, then secondarily transferred to the second intermediate transfer belt 81, and then transferred to the second intermediate transfer belt 81. , Tertiary transfer to the heating belt 91. Since the toner image of N times transferred thirdly is formed so as to have an interval of the peripheral length L of the heating belt 91, the toner image of N layers for N times is laminated on the heating belt 91 ( FIG. 11 (b). Finally, as shown in FIG. 11C, the toner image of the N layer is collectively transferred onto the transfer paper S, so that a stereoscopic image can be formed on the transfer paper S.

The difference from the first embodiment is that the user prepares the transfer paper having the high heat permeability layer M by circulating the high heat permeability layer M as a rotating body (second transfer belt 81) in the image forming apparatus. Can be mentioned as a merit.

7 Intermediate transfer belt 9 Heating rotating body 81 Second intermediate transfer belt 91 Heating rotating belt L Perimeter of heating rotating body 9 S Transfer paper M High heat permeability layer formed on transfer paper or transfer sheet with high heat permeability

Claims (5)

With a heating rotating body,
It has an image forming mechanism that forms a toner image on the heated rotating body, and has an image forming mechanism.
The heating rotating body is maintained at a temperature higher than the softening point of the formed toner image, and the toner image is superposed on the same place on the heating rotating body a plurality of times each time the heating rotating body orbits. An image forming apparatus characterized in that an image is formed and a toner image superimposed on the heated rotating body is simultaneously transferred and fixed on a transfer paper conveyed to the heated rotating body. It has a device for inputting an image pattern to form an image on transfer paper.
The image forming apparatus according to claim 1, wherein the image pattern is formed a plurality of times at intervals of the peripheral length of the heated rotating body. The image forming apparatus according to claim 1, wherein the peripheral length of the heated rotating body on which the toner image is formed is equal to or larger than the length in the conveying direction of the toner image forming an image in the conveying direction of the transfer paper. The means for transporting the toner image from the image forming mechanism to the heating rotating body is a transfer sheet having a thermal effusivity of 1000 J / (m ² S ^0.5 K) or more on the surface in contact with the toner. The image forming apparatus according to claim 1. The means for transporting the toner image from the image forming mechanism to the heating rotating body is characterized by a rotating body having a thermal effusivity of 1000 J / (m ² S ^0.5 K) or more on the surface in contact with the toner. The image forming apparatus according to claim 1.

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