JP2002240342A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain high-quality images having no color shift and no density irregularity caused by scattering toner by a compact and low-cost device, in an imaging apparatus of a toner jet system in which the toner is selectively flown from a toner carrier to an intermediate recording medium, and the formed toner image is transferred and fixed to a recording medium, thereby forming an image. SOLUTION: There are set a plurality of toner discharge devices 6 along the intermediate recording medium 3, and electromagnetic induction heaters 5 arranged to positions opposite to the toner discharge devices 6 via the intermediate recording medium 3. In accordance with a circulatory movement of the intermediate recording medium 3, the toner is selectively flown from each toner discharge device 6, and the toner image of each color is overlapped onto the intermediate recording medium. The toner image on the intermediate recording medium is gradually heated by the electromagnetic induction heaters 5 from a position opposite to the toner discharge device 6 at the upstream side to a transfer/fixing part. Since an adhesion force is generated among toners, the toners are prevented from scattering. The toners are fully melted at the transfer/fixing part, and the transfer and the fixing to the recording medium are carried out at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, such as a copying machine, a printer, a facsimile, etc., for forming a visible image using colored particles, and more particularly to a method for selectively using toner having an electrostatic charge based on an image signal. The present invention relates to an image forming apparatus that forms an image by discharging.

[0002]

2. Description of the Related Art As a printing method in a conventional image forming apparatus, an electrophotographic method and an ink jet method have become mainstream because of their superiority in image quality, speed, price and the like. In the electrophotographic method, a toner image is formed by transferring toner to an electrostatic latent image formed on an image carrier, and after transferring this onto a recording medium, pressurizing and heating to form an image. It is. In the ink jet method, an image is formed by directly discharging ink onto a recording medium by heat or vibration from a head having nozzles and an ink discharge unit.

On the other hand, with the spread of full-color copying machines and printers in recent years, it has been required to obtain high-quality images at a high speed with a simple and low-cost apparatus. A toner jet system was developed. In the toner jet method, control means for controlling transfer of toner is provided between a toner carrier and a recording medium, and an electric field is applied between them to selectively fly toner onto a recording medium to form an image. Is what you do.
According to this method, the number of components is reduced, so that the apparatus is downsized and simplified, and a high-quality image can be obtained in a short time.

In the above-described toner jet method, when toner is directly discharged onto a recording medium to form an image on the recording medium, an electrode is disposed on the back side of the recording medium and an electrode is also disposed on the side for supplying toner. Provide. Then, an electric field is formed between these electrodes to cause the charged toner to fly. For this reason, the distance between the electrodes and the strength of the electric field must be set accurately, and the thickness and material of the recording medium are limited. Further, when the recording medium is charged when the toner is ejected toward the recording medium, the toner repels due to the charge, and the toner may be diffused. For this reason, Japanese Patent Application Laid-Open No. 4-152154 discloses an apparatus in which a toner is once discharged onto an intermediate recording medium to form an image, and the image is heated and pressed onto the recording medium by a transfer fixing device. In such an apparatus, the electric field at the time of discharging toner is stabilized, and it becomes easy to control the conditions at the time of image formation. FIG.
1 is a schematic configuration diagram showing a toner jet recording apparatus described in Japanese Patent Application Laid-Open No. 4-152154.

This apparatus includes a transfer drum 101 rotatably supported, and a recording unit 1 for transferring toner onto the transfer drum 101 at a position facing the transfer drum 101.
02, a transfer corona 103 for transferring the toner image on the transfer drum 101 to a recording medium, and a transfer drum 101 after the transfer.
Cleaning means 104 for removing toner remaining on the top
And a static eliminator 105 for neutralizing the transfer drum 101. Further, a heat fixing device 108 is provided downstream of the transfer unit for heating and melting the unfixed toner image on the recording medium and pressing the unfixed toner image onto the recording medium. Further, the transfer drum 101
Along the inner peripheral surface of
A back electrode 107 to which a voltage is applied from a power source 106 and forms an electric field with the recording means 102 is provided.

The recording means 102 includes a toner case 10
9, a brush roller 110, a supply roller 111, a layer thickness regulating member 112, a scraping member 113, and a control electrode 11.
4. The control electrode 114 is composed of three layers, a reference electrode layer 115, an insulating layer 116, and a control electrode layer 117, and has a plurality of holes 118 penetrating these three layers. The brush roller 110 and the reference electrode layer 115 are grounded, and a voltage is applied to the control electrode layer 117 from a power supply 119.

In the recording means 102, toner is carried on a supply roller 111, and a toner layer having a constant thickness is formed by a layer thickness regulating member 112. The toner is charged by contact friction with the supply roller 111 or the brush roller 110, and is supplied to the brush roller 110. The brush roller 110 contacts the scraping member 113, and the brush member of the brush roller 110 is repelled by the rotation of the brush roller 110, so that the toner flies in the direction of the control electrode 114.

In the control electrode 114, a voltage is applied to the control electrode layer 117 at the time of toner ejection, and an electric field is formed between the control electrode layer 117 and the reference electrode layer 115.
Due to this electric field, the toner is attracted to the control electrode layer 117, passes through the hole 118, and adheres on the transfer drum 101. When the toner is not discharged, the control electrode layer 1
Since no voltage is applied to 17 and no electric field is formed, the toner does not pass through the hole 118. Therefore, the transfer drum 10
No toner adheres to the surface of the photosensitive drum 1. In this manner, a toner image is formed on the transfer drum 101, and is conveyed to a position facing the transfer corona 103,
Transferred by contact with 0. The recording medium 120 carrying the unfixed toner image is conveyed to the fixing device 108, and the toner image is melted and pressed on the recording medium 120.

In this apparatus, since the transfer drum 101 is used as the intermediate recording medium, it is possible to prevent the thickness of the recording medium from being limited by the distance between the electrodes and preventing the toner from being diffused due to the charging of the recording medium. it can.

[0010]

However, in the above apparatus, an intermediate recording medium is used, and a back electrode is used for discharging toner. Further, a fixing device is provided for performing transfer and fixing separately. These devices often become obstacles when trying to solve the problems of miniaturization and cost reduction of the devices, and the original advantages of the toner jet method may be lost. Further, when forming a color image, although the use of the intermediate recording medium prevents toner disturbance due to charging of the recording medium, each color toner is charged to the same polarity.
When the toners are superimposed on the intermediate recording medium, the toners may repel and scatter. When the toner scatters, an image having uneven color and uneven density is obtained.

The invention according to the present application has been made in view of the above circumstances, and an object of the invention is to provide a toner jet type image forming apparatus that uses an intermediate recording medium to prevent color and density unevenness. It is an object of the present invention to obtain a high-quality image and to reduce the size and cost.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to the present application has an endless peripheral surface that carries and transports a toner having an electrostatic charge, and an endless peripheral surface. An intermediate recording medium disposed so that the peripheral surface faces the toner carrier; an electric field forming unit that forms an electric field for transferring toner on the toner carrier to the intermediate recording medium; A transfer control unit disposed between an intermediate recording medium and the toner carrier to control the transfer of the toner; a heating device for heating and melting the toner image on the intermediate recording medium; A transfer fixing device that presses the recording medium and performs transfer and fixing at the same time, wherein the intermediate recording medium has a conductive layer along the endless peripheral surface, and the heating device is Facing intermediate recording medium Having an exciting coil at a position that provides an image forming apparatus, wherein the electromagnetic induced current is intended to generate heat the conductive layer.

The image forming apparatus can obtain an image with a simple structure and uses an intermediate recording medium, so that the intensity of the electric field at the time of discharging the toner is stable, and the image forming apparatus is always in a good condition. To form an image. In addition, by preventing the intermediate recording medium from being charged easily or effectively performing the charge removal, the scattering of the toner is prevented, and a good toner image is formed. In addition, since the toner image is heated on the intermediate recording medium and pressed against the recording medium to perform transfer and fixing at the same time, it is not necessary to provide a separate fixing device. Further, even when the thickness of the recording medium is different, stable transfer and fixing can be performed. Therefore, a high-quality image free from color unevenness and density unevenness can be obtained with a small and low-cost device. In addition, since electromagnetic induction heating is used as a heating means for the toner image, and the conductive layer of the intermediate recording medium is used as the heat generating layer, the toner image can be efficiently heated without heating a member having a large heat capacity. . Then, the toner can be heated to the melting temperature in a very short time, so that no warm-up time is required when the apparatus is started.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the electric field forming means applies a voltage between the conductive layer of the intermediate recording medium and the toner carrier. Characterized in that:

Since the electric field forming means uses the conductive layer of the intermediate recording medium as one electrode, the distance from the other electrode, the toner carrier, is reduced. For this reason, even if the potential difference between the two electrodes is reduced, the toner on the peripheral surface of the toner carrier is electrically attracted to the intermediate recording medium. Therefore, the voltage applied between the conductive layer and the toner carrier can be reduced, and power consumption can be reduced. Further, it is not necessary to provide an electrode for forming an electric field on the back side of the intermediate recording medium on which an image is formed. Further, since the conductive layer is used as a heating layer for electromagnetic induction heating, the device can be simplified and the cost can be reduced.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, a plurality of toner carriers each carrying a toner of a different color are arranged along a direction in which the intermediate recording medium rotates. The heating device starts heating from an upstream side of a position where the most downstream toner carrier is opposed to the toner carrier.

In the above-described image forming apparatus, when a plurality of color toners are superimposed on the intermediate recording medium, the toner is heated, softened or melted, and an adhesive force is generated between the toners.
For this reason, an adhesive force acts between the toners, and it is possible to prevent the toners of the same polarity from scattering due to repulsion of each other, and it is possible to obtain an image free from color unevenness and density unevenness.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the heating device is arranged such that the toner on the intermediate recording medium is located at a position where the toner carrier on the most downstream side is opposed. The temperature is set so as to be higher than the temperature at which the adhesive force is generated between the toners and lower than the temperature at which the toner on the toner carrier causes the toner to adhere.

In the above-described image forming apparatus, by heating the toner superimposed on the intermediate recording medium, an adhesive force is generated between the toners and the toner can be prevented from being scattered.
When the temperature of the heated intermediate recording medium and the temperature of the toner are increased, the radiant heat may affect the toner on the toner carrier. If the toner on the toner carrier has an adhesive force, the ejection of the toner to the intermediate recording medium is hindered. However, in the above-described image forming apparatus, the toner on the intermediate recording medium is heated so as not to cause the toner on the toner carrier to have an adhesive force, so that the toner is smoothly discharged from the toner carrier and good. A good toner image is formed. Note that a plurality of toner carriers are arranged along the circumferential direction of the intermediate recording medium,
When toners of different colors are sequentially ejected so as to overlap each other, the toner tends to be scattered downstream of the position where the second color toner is ejected. Then, scattering is most likely to occur at a position facing the most downstream toner carrier in a state in which a plurality of color toners are superimposed. Therefore, it is desirable to perform heating under the above-described conditions not only at the position facing the most downstream toner carrier, but also at the upstream side.

According to a fifth aspect of the present invention, in the image forming apparatus according to the third aspect, the heating device is configured to detect a position of the toner on the intermediate recording medium at a position where the toner carrier on the most downstream side is opposed. The temperature is set to be 80C to 130C.

By heating the temperature of the toner to approximately the above-mentioned range, it is possible to cause the toner to have an adhesive force and not to affect the toner on the opposing toner carrier. Therefore, it is possible to prevent the toner from scattering on the intermediate recording medium, and
A good image can be formed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. This image forming apparatus includes two support rolls 1a, 1b
A drive roll 2, an endless belt-shaped intermediate recording medium 3 rotatably supported by these, and a pressure roll 4 opposed to the support roll 1b and pressed against the intermediate recording medium 3. Have. An electromagnetic induction heating device 5 for heating the intermediate recording medium 3 and the toner image carried thereon is provided on the inner side along the intermediate recording medium 3, and a yellow, magenta, cyan or black toner is provided on the outer side. Toner discharge devices 6a, 6b, 6c, and 6d that house and transfer toner to an intermediate recording medium based on image signals;
A cleaning device 7 is provided for removing the toner remaining on the intermediate recording medium after transferring the toner image to the sheet. Further, between the intermediate recording medium 3 and the toner discharge device 6, a control for controlling the transfer of toner from the toner discharge device to the intermediate recording medium 3 by changing an electric field between the intermediate discharge medium 6 and the toner discharge device 6. Devices 8a, 8b, 8c, 8
d is provided.

Next, the configuration of the image forming apparatus will be described in detail. As shown in FIG. 2, the intermediate recording medium 3 has a base layer 3a made of a sheet member having high heat resistance.
And a conductive layer 3b laminated thereon and a surface release layer 3c which is the uppermost layer. Base layer 3a
For example, a resin having high heat resistance typified by polyester, polyethylene terephthalate, polyimide amide, or the like having a thickness of about 75 μm is used. As the conductive layer 3b, for example, a layer of iron or cobalt, or a layer formed by plating a metal layer of nickel, copper, chromium, or the like with a thickness of 1 μm to 50 μm is used. The surface release layer 3c has a thickness of 30 μm.
It is preferably a sheet or a coat layer having a high degree of releasability. In this embodiment, a fluororesin layer is used.

As shown in FIG. 3, a positive voltage of about 1000 V is applied from the power supply 30 to the conductive layer 3b, and the conductive layer 3b is used to fly the toner between the conductive layer 3b and the toner carrying roll 22. An electric field is formed. The voltage applied to the conductive layer 3b can be reduced by shortening the distance between the intermediate recording medium 3 and the toner carrying roll 22.

The electromagnetic induction heating device 5 is disposed so as to face the inner peripheral surface of the intermediate recording medium 3, and heats the conductive layer 3b to heat the toner image carried on the intermediate recording medium. As shown in FIG. 2, an iron core 5a having an E-shaped cross section, an exciting coil 5b wound around the iron core 5a, and an exciting circuit 5c for applying an alternating current to the exciting coil 5b. And the main part is constituted. When an AC current is applied to the exciting coil 5b, a magnetic flux indicated by an arrow H around the exciting coil 5b repeatedly generates and disappears. The electromagnetic induction heating device 5 is arranged such that the magnetic flux H crosses the conductive layer 3b of the intermediate recording medium 3.

When the fluctuating magnetic field traverses the conductive layer as described above, an eddy current indicated by an arrow B is generated in the conductive layer so as to generate a magnetic field that hinders the change of the magnetic field. Due to the skin effect, the eddy current flows almost concentratedly on the surface of the conductive layer 3b on the side of the exciting coil 5b, and generates heat in proportion to the skin resistance of the conductive layer 3b.

The frequency of the alternating current applied to the exciting coil 5b is preferably 20 kHz to 100 kHz. When the frequency is 20 kHz or more, the absorptivity to the conductive layer 3b is improved, and up to 100 kHz, an exciting circuit can be assembled using inexpensive elements. Here, when an alternating current of 20 kHz to 100 kHz is applied to the exciting coil, the skin depth δ is several μm to several hundred μm. For this reason,
If the thickness of the conductive layer 3b is less than about several μm, the electromagnetic energy cannot be absorbed by the conductive layer, so that the energy efficiency deteriorates. On the other hand, when the thickness of the conductive layer 3b is about 50 μm or more, the heat capacity of the conductive layer 3b increases, and heat is diffused into the conductive layer by heat conduction. A predetermined portion of 3c cannot be heated. Therefore, the thickness of the conductive layer 3b is
It is desirable that it is about 10 μm to 50 μm.

If the resistance value of the conductive layer 3b is too small, the heat generation efficiency when an eddy current is generated deteriorates. Therefore, the intrinsic volume resistivity of the conductive layer 3b is 1.5 × 10 ⁻ at 20 ° C. environment. ⁸
Ωm or more is desirable. In particular, the intrinsic volume resistivity is 1.5 × 10
By using the conductive layer 3b of ^{-8 Ωm~6.0} × 10 ^{-8 Ωm,} the thickness of the conductive layer 3b can be obtained a sufficient heating value be 1 m to 10 m.

The electromagnetic induction heating device 5 heats the toner so that the temperature of the toner gradually increases from the position where the toner discharge device 6 is opposed to the position upstream of the position where transfer and fixing are performed. As shown in (1), heating is started near the position where the most upstream toner discharge device 6a is opposed. Then, the temperature of the toner is set to about 80 ° C. at the position where the second toner discharge device 6b faces, and the temperature of the toner is set to about 130 ° C. at the position where the fourth toner discharge device 6d faces. Is set to Further, the heating is further continued downstream of the fourth toner ejection device 6d, and immediately before the position where the support roll 1b and the pressure roll 4 face each other, the toner is sufficiently melted and may be pressed against the recording medium. It is a temperature that can be used.

Next, the toner discharge device 6 and the control device 8 will be described with reference to FIG. The toner discharging device 6 includes a toner carrying roll 22 having an endless peripheral surface inside a container 21 containing the toner T and carrying the toner on the peripheral surface and driving the toner T around the peripheral surface, and a toner for stirring the toner T. The stirring member 23, the toner supply roll 24 that supplies the toner T to the toner carrying roll 22 by rotating in the same direction as the toner carrying roll 22 and the toner T supplied to the toner carrying roll 22. And a blade 25 for charging the toner T with a constant layer thickness.

In the toner discharge device 6, the rotation of the toner supply roll 24 supplies the toner T to the outer peripheral surface of the toner carrying roll 22. The toner T is transported to a position facing the blade 25 by the rotation of the toner carrying roll 22. The blade 25 has an elastic member such as a urethane rubber sheet attached to one end of a metal plate. The blade 25 comes into contact with the toner T to make the layer thickness of the toner T constant, and at the same time, rubs and charges the toner T. In this embodiment, a negatively charged toner is used. Also,
The toner carrying roll 22 is made of a conductive material and is electrically grounded. The toner carrying roll 22 may be provided with a predetermined potential instead of being grounded as long as an electric field for moving the toner is formed between the toner carrying roll 22 and the intermediate recording medium 3. By applying a predetermined positive potential, the toner supplied from the toner supply roll 24 can be attracted aerobically.

The control device 8 includes a base 26 made of an insulating material, a plurality of holes 27 through which the toner T passes,
And an output signal unit 29 that applies a voltage to the electrode 28 in accordance with an image signal. An electric field is formed between the electrode 28 and the toner carrying roll 22. I have. This electrode 28 and the toner carrying roll 22
Is about 0 μm to 200 μm, and in this embodiment, the distance is 50 μm.
It is about μm.

A predetermined voltage of about several hundred volts is applied to the image portion from the signal output portion 29 to the electrode 28, and the toner T on the toner carrying roll 22 flies in the direction of the control device 8. Further, since a positive voltage is applied to the conductive layer 3b of the intermediate recording medium 3, the negative toner T is electrically attracted to the conductive layer 3b and adheres to the surface of the intermediate recording medium 3. . Also, when making it a non-image part,
A voltage equal to or lower than a predetermined value is applied from the signal output unit 29 to the electrode 28, and the potential difference between the toner carrying roll 22 and the electrode 28 is such that the toner T on the toner carrying roll 22 does not fly. For this reason, no toner adheres to the intermediate recording medium 3 and no image is formed. In addition, the toner carrying roll 2
The electric field between the recording medium 2 and the intermediate recording medium 3 does not have such a potential difference that the toner T on the toner carrying roll 22 separates from the surface of the toner carrying roll 22 and flies.

Next, the operation of the image forming apparatus will be described. When the intermediate recording medium 3 passes through a position facing the toner ejection device 6a, a voltage is applied to the electrode 28 of the control device from the signal output unit 29 in accordance with the image signal, and the toner flies from the toner ejection device 6a. , Intermediate recording medium 3
A first color toner image is formed. At the same time, the intermediate recording medium 3 enters a heating area facing the electromagnetic induction heating device 5. At this time, an alternating current is supplied from the excitation circuit of the electromagnetic induction heating device 5 to the excitation coil, and an eddy current is generated in the conductive layer of the intermediate recording medium to generate heat. Thereby, the temperatures of the conductive layer and the surface release layer rise, and the toner image carried on the peripheral surface of the intermediate recording medium 3 is gradually heated.

Further, the intermediate recording medium 3 sequentially passes through the positions facing the toner discharge devices 6b, 6c and 6d with the orbital drive, and the toner flies from each of the toner discharge devices 6 so that the toner images of the respective colors are superimposed. Is done. Then, the intermediate recording medium 3 and the toner image are heated to about 80 ° C. by the electromagnetic induction heating device 5 at a position facing the second toner ejection device 6b.
About 130 at the position facing the fourth toner ejection device 6d.
Heat to ° C. The above toner is approximately
When heated to 80 ° C., tackiness occurs, toners adhere to each other, and scattering due to electrostatic repulsion is prevented. After passing through the position facing the fourth toner ejection device 6d, the toner is further heated and the toner is sufficiently melted.

The intermediate recording medium 3 carrying the fused full-color toner image reaches the pressure contact portion between the support roll 1b and the pressure roll 4, and the paper is discharged from a paper tray (not shown) in synchronization with the transport timing. The sheet is conveyed, fed between the intermediate recording medium 3 and the pressure roll 11, and pressed. As a result, the fused toner image is pressed against the paper,
Transfer and fixing are performed simultaneously. The toner image on the paper is
It is rapidly cooled in close contact with paper at room temperature, coagulated and solidified, and is separated from the paper. On the other hand, after the toner image is transferred to the paper, the toner remaining on the intermediate recording medium 3 is removed by the cleaning device 7.

[00037]

As described above, in the image forming apparatus according to the present invention, a good toner image is formed on an intermediate recording medium by the toner jet method, and the toner image is transferred and fixed on the recording medium. In addition, it is possible to prevent the toner image from being disturbed due to toner scattering. Further, good transfer and fixing can be always performed even on recording media having different thicknesses. Further, since a fixing device is not required, the device can be simplified and the cost can be reduced. Further, since the electromagnetic induction heating is used as a heating means of the toner image, the toner image can be efficiently heated, and time for warm-up at the start of the apparatus is not required.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of an electromagnetic induction heating device and an intermediate recording medium used in the image forming apparatus shown in FIG.

FIG. 3 is a schematic cross-sectional view of a toner discharge device, a control device, and an intermediate recording medium used in the image forming apparatus shown in FIG.

FIG. 4 is a diagram illustrating a temperature of toner at each position on an intermediate recording medium of the image forming apparatus illustrated in FIG. 1;

FIG. 5 is a schematic configuration diagram illustrating an example of a conventional toner jet recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support roll 2 Drive roll 3 Intermediate recording medium 4 Pressure roll 5 Electromagnetic induction heating device 6 Toner discharge device 7 Cleaning device 8 Control device 21 Container 22 Toner carrying roll 23 Toner stirring member 24 Toner supply roll 25 Blade 26 Base 27 Hole 28 Electrode 29 Signal output unit 101 Transfer drum 102 Recording means 103 Transfer corona 104 Cleaning means 105 Static eliminator 106 Power supply 107 Back electrode 108 Thermal fixing device 109 Toner case 110 Brush roller 111 Supply roller 112 Layer thickness regulating member 113 Scratching member 114 Control electrode 115 Reference electrode layer 116 Insulating layer 117 Control electrode layer 118 Hole 119 Power supply 120 Recording medium

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G03G 15/24 B41J 3/16 D 2H200 H05B 6/14 G03G 15/00 115 3K059 F term (reference) 2C162 AE12 AE25 AE31 AE47 AE69 AE74 AE83 CA03 CA12 CA24 2H029 DB00 DB05 DB06 DB13 2H030 AD01 AD04 AD17 BB23 BB42 2H033 AA01 BA11 BA24 BA58 BB18 BB28 BE06 BE09 2H078 AA01 BB10 CC06 DD51 DD57 2H200 GB47 AGB23A08

Claims (5)

[Claims] An endless peripheral surface carries and transports toner having an electrostatic charge, and has an endless peripheral surface, and is disposed so that the peripheral surface faces the toner carrier. An intermediate recording medium; an electric field forming unit that forms an electric field for transferring toner on the toner carrier to the intermediate recording medium; and an electric field forming unit that is disposed between the intermediate recording medium and the toner carrier. Transfer control means for controlling transfer, a heating device for heating and melting the toner image on the intermediate recording medium, and a transfer fixing device for pressing a recording medium against the melted toner image and performing transfer and fixing simultaneously. The intermediate recording medium has a conductive layer along the endless peripheral surface, the heating device has an exciting coil at a position facing the intermediate recording medium, and the electromagnetic induction current The conductive layer An image forming apparatus characterized in that to generate heat. 2. The image forming apparatus according to claim 1, wherein the electric field forming unit applies a voltage between a conductive layer of the intermediate recording medium and the toner carrier. . 3. A plurality of toner carriers each carrying a toner of a different color are arranged along a direction in which the intermediate recording medium circulates, and the heating device is arranged such that the toner carrier on the most downstream side faces the toner carrier. 2. The image forming apparatus according to claim 1, wherein heating is started from an upstream side of a position where the image is formed. 4. The heating device according to claim 1, wherein the toner on the intermediate recording medium is at a temperature higher than a temperature at which an adhesive force is generated between the toners at a position where the toner carrier on the most downstream side is opposed.
The image forming apparatus according to claim 3, wherein radiant heat to the toner carrier is set to be lower than a temperature at which the toner on the toner carrier causes tackiness. 5. The heating device is set such that the temperature of the toner on the intermediate recording medium is 80 ° C. to 130 ° C. at a position where the toner carrier on the most downstream side is opposed. The image forming apparatus according to claim 3, wherein: