JP2001060045A - Image forming device - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a highly durable image forming apparatus capable of satisfactorily passing a sheet without adsorbing a sheet even if an intermediate transfer medium has adhesiveness. An electrostatic latent image is formed on a latent image holding member, and an image forming unit that supplies a liquid developer to the electrostatic latent image to visualize the electrostatic latent image is in contact with the latent image holding member. , With adhesive on the surface,
An intermediate transfer roller 6 for transferring a visible image on the latent image holding member 1 to the surface; and an adhesive which is in contact with the intermediate transfer roller 6 and has an adhesive force on the surface which is larger in adhesive strength than the intermediate transfer roller 6; And a transfer roller 7 for transferring the visible image on the intermediate transfer roller 6 to the sheet P by heat and pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a wet type image forming apparatus for supplying a liquid developer to a latent image for development.

[0002]

2. Description of the Related Art Electrophotographic apparatuses and electrostatic recording apparatuses using a liquid developer have advantages that cannot be realized by a dry type.
In recent years, its value is being reviewed. In other words, a very fine toner of submicron size can be used, so that high image quality can be realized, and sufficient image density can be obtained with a small amount of toner, so that it is economical and has a print-like texture. Are the main advantages of the wet image forming apparatus.

On the other hand, the conventional liquid image forming apparatus using a liquid toner has some problems, and for this reason, it has long allowed the sole use of the dry technology.

[0004] One of these problems is a problem in transfer means. The first problem in transfer was degradation of image quality. That is, conventionally, the developer adhered on the latent image holding member is directly transferred to the sheet by the electric field by the transfer means, so that the transfer unevenness due to the electric field fluctuation according to the unevenness of the sheet surface has occurred. In addition, due to variations in the electrical characteristics of the paper and environmental dependency, transfer defects are likely to occur, and the quality of the transferred image has been significantly degraded.

[0005] In order to solve such a problem, there has been proposed an apparatus for temporarily transferring a latent image from a latent image carrier to an intermediate transfer medium and then transferring the image to a sheet. US Patent No. 5,148,2
No. 22, 5,166,734, 5,208,63
No. 7, for example, discloses an apparatus for transferring an image from a latent image holding member to an intermediate transfer medium by an electric field, and then transferring the image to a sheet by pressure (and heat). Since it is relatively easy to form the intermediate transfer medium from a material having a smooth surface and a small variation or variation in electric resistance, the deterioration of image quality due to transfer is improved as compared with the case where direct electric field transfer is performed on paper. However, 100% transfer efficiency cannot be achieved.

Further, since electrophoresis is used in electric field transfer, a large amount of solvent must remain in the toner image at the time of transfer. This solvent moves to the intermediate transfer medium and evaporates due to heat. Will occur.

On the other hand, JP-B-46-41679 and JP-A-62-280882 disclose pressure (and heat) in both transfer to an intermediate transfer medium and transfer to paper without using electric field transfer. An apparatus for use is disclosed. When transferring to an intermediate transfer medium by pressure and heat, deterioration of image quality is significantly suppressed. Also, in this method, it is often necessary to evaporate the solvent of the toner image almost completely before the primary transfer to the intermediate transfer medium, so that the solvent after development is squeezed as much as possible. Less solvent vapor.

However, when pressure (and heat) is used for both the transfer to the intermediate transfer medium and the transfer to the paper, it is difficult to adjust the surface energy of the intermediate transfer medium. When the surface energy of the transfer medium surface is 30
Unless it is less than about 35 dyn / cm, both transfer types are incompatible. In particular, it is difficult to transfer to a sheet of PPC paper or the like having poor smoothness, and if an attempt is made to obtain a sufficient transfer efficiency, the transfer to an intermediate transfer medium becomes inevitable.

Therefore, by using an intermediate transfer medium having an adhesive surface and utilizing adhesive force in addition to pressure (and heat), the toner image on the latent image holding member can be favorably transferred onto the intermediate transfer medium. And the transfer to paper is mainly performed by pressure (and heat).

[0010]

However, in the above-described transfer method, when a toner image is transferred to a sheet, the sheet adheres to a particularly smooth sheet because of the adhesiveness of the intermediate transfer medium. However, there is a problem that it is difficult to pass a sheet as a sheet-feeding machine.

Further, if the paper stuck to the intermediate transfer medium is forcibly peeled off by a peeling claw or the like, the intermediate transfer medium is easily scratched. Since the surface of the intermediate transfer medium directly bears a transferred image, there is a problem that if there is a flaw, an image defect such as transfer omission is likely to occur.

The present invention has been made in view of the above circumstances,
Highly durable image formation that allows the medium to pass through well without adsorbing the medium to be transferred even if the intermediate transfer medium has adhesiveness, and that allows the medium to be peeled off without damaging the surface of the medium. It is intended to provide a device.

[0013]

In order to solve the above-mentioned problems, the present invention forms an electrostatic latent image on an image carrier, and applies a liquid developer to the electrostatic latent image. Image forming means for supplying and visualizing an image, an intermediate transfer medium which is in contact with the image carrier, has an adhesive surface, and transfers a visible image on the image carrier to the surface, A transfer medium that is in contact with the intermediate transfer medium and has an adhesive property to increase the adhesive force on the surface thereof compared to the intermediate transfer body, and transfers the visible image on the intermediate transfer medium to the transfer target by heat and pressure, Is provided.

According to a second aspect of the present invention, there is provided an image forming means for forming an electrostatic latent image on an image carrier and supplying a liquid developer to the electrostatic latent image to visualize the electrostatic latent image; An intermediate transfer medium that is in contact with the body and has an adhesive surface, and transfers a visible image on the image carrier to the surface; and an intermediate transfer medium that is in contact with the intermediate transfer medium and has a first adhesive force on the surface. And a region having a second adhesive strength weaker than the first adhesive strength,
A transfer medium for transferring a visible image on the intermediate transfer medium to a transfer object by heat and pressure, and a transfer medium which is brought into contact with a second adhesive area of the transfer medium and is attracted to the transfer medium Peeling means for peeling the body.

According to a third aspect of the present invention, there is provided an image forming means for forming an electrostatic latent image on an image carrier and supplying a liquid developer to the electrostatic latent image to make the electrostatic latent image a visible image; An intermediate transfer medium that is in contact with the body, has an adhesive surface, and transfers a visible image on the image carrier to the surface, and has an adhesive surface in contact with the intermediate transfer medium, A transfer medium for transferring the visible image on the intermediate transfer medium to the transfer target by heat and pressure,
A cleaning unit which is in contact with the transfer medium and has an adhesive property on its surface to increase the adhesive strength of the transfer medium and removes dirt adhering on the transfer medium.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows an image forming section of a wet electrophotographic recording apparatus according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a latent image holder as an image carrier rotatably provided in the direction of the arrow.
This is a photosensitive drum in which an organic or amorphous silicon photosensitive layer is provided on a conductive substrate. The first to fourth portions are arranged around the latent image holding member 1 in the rotation direction.
Well-known corona charger (or scorotron charger)
2a to 2d, first to fourth exposure units (latent image forming means) 3
a to 3d, first to fourth developing devices 4a to 4d, a pre-transfer drying device 11, a transfer device 5, and a cleaning device 12 are provided.

On the latent image holding member 1, a silicone-based or fluorine-based release layer is applied on the photosensitive layer, and the transfer speed is about 50 to 400 mm / sec. Transfer can be performed on the surface of the roller 6.

The chargers 2a to 2d charge the surface of the latent image holding member 1 uniformly.

The exposure units 3a to 3d expose the surface of the latent image holding member 1 with an image-modulated laser beam to form an electrostatic latent image on the surface.

The developing devices 4a to 4d store a liquid developer and visualize the electrostatic latent image and squeeze the surplus developer. The liquid developer is, for example, a hydrocarbon-based insulating solvent such as Isopar G, L, M (trade name of Exxon) or Norper 12, 13, 15 or the like, a metal soap for charge control,
And the glass transition point to which the pigment is added is −50 ° C. to 50 ° C.
And the like in which an acrylic resin or the like in the range described above is dispersed.

The transfer device 5 transfers a visible image onto a sheet P as a transfer object, and has an intermediate transfer roller 6 as an intermediate transfer medium and a transfer roller 7 as a transfer medium. A heater 9 is built in the transfer roller 7.

The intermediate transfer roller 6 has a metal roller of 50 to 2
It has a structure in which an adhesive silicone or an urethane having a thickness of about 000 μm is applied, and has a surface hardness of 1 to 60 °. Regarding the adhesive strength, the surface hardness is 60 ° even if no tackifier (tackifier) is given to the material itself.
If it is less than (JIS-A), art paper or OHP will stick to the intermediate transfer member, and primary transfer can be performed with it, so that all the intermediate transfer members having tackiness can be said to be sticky intermediate members.

The transfer roller 7 is provided on a metal roller by 50 to 1
It is coated with an adhesive silicone or urethane having a thickness of about 000 μm, and has a surface hardness of about 10 to 70 °. The adhesive force on the surface of the transfer roller 7 is larger than the adhesive force on the surface of the intermediate transfer roller 6.

The transfer roller 7 is brought into contact with a peeling claw 15 as a peeling means, and the paper P is peeled off from the transfer roller 7 by the peeling claw 15 so that the paper can be passed well.

A cleaning means 14 is rolled on the side surface of the intermediate transfer roller 6 so that dust and the like on the intermediate transfer roller 6 are removed by the cleaning means 14.

At the time of image formation, the surface of the latent image holding member 1 is uniformly charged by the charger 2a, and then is exposed to a laser beam image-modulated by the exposure section 3a to form an electrostatic latent image on the surface. You. Thereafter, the developing device 4a containing the liquid developer visualizes the electrostatic latent image and squeezes the surplus developer. The liquid developer or toner adhering to the electrostatic latent image may be directly transferred to the transfer step and transferred to the sheet P by the transfer device 5.
Here, a second electrostatic latent image is continuously formed by the second charger 2b and the second laser exposure unit 3b, and the first developing device 4a
Is developed by a second developing device 4b which contains a second developer of a color different from the liquid developer contained in the second developer. Therefore, after the second development, 2
A color toner image is formed. Similarly, the third and fourth developments are performed, and a full-color toner image is formed on the latent image holding member 1. Thereafter, the toner image is dried almost completely by the pre-transfer drying means 11, and subsequently transferred onto the intermediate transfer roller 6 by the adhesive force of the intermediate transfer roller 6.

The transfer roller 7 and the intermediate transfer roller 6 are heated to 50 to 200 ° C. by the heater 9, and the toner image transferred onto the intermediate transfer medium 6 reaches the transfer area in a heated state. Then, the sheet P is sandwiched between the intermediate transfer roller 6 and the transfer roller 7, and is transferred to the sheet P by applying a load of 0.2 to 20 kg as a linear pressure in the longitudinal direction.

The transfer at this time is mainly performed by the latent image carrier 1
And the adhesiveness of the surface of the intermediate transfer roller 6, the transfer can be performed with or without heating the latent image holding member 1. Further, the contact pressure between the latent image holding member 1 and the intermediate transfer roller 6 only needs to be in reliable contact.
For example, the linear pressure in the longitudinal direction of the latent image holding member 1 is 0.0
It suffices that the pressure be 2 kg / cm or more. However, in order to further enhance the stability, the pressure is usually applied to about 0.1 to 20 kg / cm.

The paper P onto which the toner image has been transferred is attracted to the intermediate transfer roller 6 and the transfer roller 7 having the stronger adhesive force. In this embodiment, since the adhesive force of the transfer roller 7 is greater than the adhesive force of the intermediate transfer roller 6, the sheet P is always attracted to the transfer roller 7. The sheet attracted to the transfer roller 7 is peeled off by the peeling claw 15, and good paper passing is enabled.

Further, there is no possibility that the intermediate transfer roller 6 may be damaged as in the case where the separation claw is brought into contact with the intermediate transfer roller 6 to perform separation. A slight scratch on the surface of the intermediate transfer roller 6 leads to an image defect.

When the paper P is peeled by bringing the peeling claw 15 into contact with the transfer roller 7, some scratches occur on the surface of the transfer roller 7, but the transfer roller 7 contacts only the back surface of the paper P. Therefore, it is hard to lead to image defects.

FIG. 2 is a perspective view showing a transfer device according to a second embodiment of the present invention, and FIG. 3 is a front view thereof.

Parts that are the same as the parts shown in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

In the second embodiment, the transfer roller 7 has adhesiveness as in the first embodiment described above.
The transfer roller 7 causes the transfer roller 7 to adhere.

An adhesive area 17 is formed on the surface of the transfer roller 7, and a weak adhesive area or a non-adhesive area (hereinafter referred to as a low adhesive area 18) is formed on a part of the surface. The low-adhesion regions 18 are formed along the circumferential direction of the transfer roller 7 with a predetermined width. Low adhesion area 18
Does not strongly adsorb the paper, but because the adhesive force of the adhesive area 17 is sufficiently strong, the paper is adsorbed on the transfer roller 7 instead of the intermediate transfer roller 6 and conveyed. The adhesive area 17 and the low adhesive area 18 on the transfer roller 7 have the same hardness, thereby preventing the occurrence of transfer unevenness and the like.

Then, the low adhesion area 1 on the transfer roller 7
The peeling claws 15, 15 are in contact with 8, 18, whereby the paper P is peeled.

The adhesive area 17 on the surface of the transfer roller 7 is
Of the same material as in the embodiment of
Reference numeral 8 is made of a low-adhesive material such as silicone, urethane, or acrylic. In addition, since the low-adhesion region 18 comes into contact with the peeling claws 15, 15, it is preferable to select a material having good releasability.

In the second embodiment, the transfer roller 7
Since the low tackiness area 18 is formed on the surface of the sheet P and the peeling claws 15 are brought into contact with the low tackiness area 18, the sheet P can be easily peeled from the transfer roller 7.

FIG. 4 shows a third embodiment of the present invention.

According to the third embodiment, when the adhesive transfer roller 7 is used, dust such as paper dust adheres by repeatedly adsorbing the paper P, and the adsorbing force is reduced. This prevents the transfer roller 6 from losing its attractive force and failing to pass the paper properly.

A cleaning roller 21 as cleaning means is in contact with the upper surface of the transfer roller 7. The cleaning roller 21 has adhesiveness, and the adhesive force is greater than the adhesive force of the transfer roller 7. As the cleaning roller 21, for example, a roller having a thickness of about 100 to 5000 μm coated with adhesive silicone or adhesive urethane on a metal roller is used.

Dust such as paper dust adsorbed on the surface of the transfer roller 7 is adsorbed and collected on the surface by the attraction force of the cleaning roller 21. The cleaning roller 21 is driven by the transfer roller 7 and can always clean the surface of the transfer roller 7. .

The cleaning roller 21 is provided detachably and can be easily removed from the apparatus. Therefore, even if the cleaning roller 21 becomes dirty, cleaning and replacement by the user can be easily performed, and the maintainability can be improved.

In this embodiment, an endlessly running holding belt 23 is used as a latent image holding member, and a toner image is formed on the holding belt 23 so that the intermediate transfer roller 6
It is designed to be transcribed on top.

FIG. 5 shows a transfer device according to a fourth embodiment of the present invention.

In this embodiment, a cleaning belt 25 is used as a cleaning member.

The use of the cleaning belt 25 makes it possible to increase the surface area of the cleaning roller and extend its life.

FIG. 6 shows a transfer device according to a fifth embodiment of the present invention.

In this embodiment, the cleaning member 31 is of a take-up type, and includes a contact / separation mechanism 32 for bringing the cleaning member 31 into and out of contact with the transfer roller 7.

The cleaning member 31 is wound between the feeding shaft 33 and the winding shaft 34 and wound up. The contact / separation mechanism 32 includes a driving unit 35, a turning lever 36 that is turned by the driving unit 35, and a pressing roller 37 attached to the tip of the turning lever 36.

When the transfer roller 7 is to be cleaned, the rotating lever 36 is rotated downward by the driving unit 35 as shown in FIG. Thus, the cleaning member 31 is pressed against the transfer roller 7 by the pressing roller 37 to clean the transfer roller 7.

When the cleaning of the cleaning roller 7 is stopped,
As shown in FIG. 7, the rotation lever 36 is rotated upward by the drive unit 35. As a result, the pressing of the cleaning member 31 by the pressing roller 37 is released, and the cleaning of the transfer roller 7 is stopped.

Since the transfer roller 7 need not always be cleaned, the cleaning member 3 according to this embodiment is not required.
By periodically bringing the cleaning roller 31 into contact with the transfer roller 7, the time until the winding of the cleaning member 31 is completed can be lengthened and the life can be extended.

FIG. 8 shows a transfer apparatus according to a sixth embodiment of the present invention.

In this embodiment, the intermediate transfer roller 6 is cleaned by the transfer roller 7 during a non-printing operation.

As shown in FIG. 8, during a normal printing operation, the toner image is transferred from the intermediate transfer roller 6 to the paper P.
At this time, a slight transfer residual image is generated on the intermediate transfer roller 6 on a rough paper such as plain paper. At this time, paper dust adheres to the surface of the intermediate transfer roller 6 to a small extent.

Therefore, as shown in FIG. 9, the transfer roller 7 having a higher adhesiveness than the intermediate transfer roller 6 during the non-printing operation is used.
As a result, transfer residual images, paper dust, and the like on the intermediate transfer roller 6 are collected. In this case, the non-printing operation, that is, the cleaning mode needs to be performed for one rotation of the intermediate transfer roller 6 or more.

When a cleaning member is separately provided for the intermediate transfer roller 6, or when cleaning is not particularly required, the paper interval in continuous printing may be short as shown in FIG.

However, as in the sixth embodiment,
When the cleaning of the intermediate transfer roller 6 is performed by also using the cleaning member of the transfer roller 7, as shown in FIG. 11, the paper interval operation for continuous printing must be performed for a time equal to or more than one rotation of the intermediate transfer roller 6.

The transfer residual image is generated on the intermediate transfer roller 6 only when printing plain paper having a rough surface.
When printing on art paper or an OHP sheet, 100% transfer can be performed from the intermediate transfer roller 6 to the transfer-receiving body, and there is no paper powder or the like adhering.

Therefore, if the sixth embodiment is applied only when printing plain paper having poor smoothness according to the paper type, the paper interval time at that time becomes longer, but the special paper is not used. The cleaning means for the intermediate transfer roller 6 can be omitted without increasing the paper interval time.

In all of the above-described embodiments, as shown in FIG. 1, the adhesive transfer roller 7 is heated, and the sheet P is adsorbed to the transfer roller 7 by the adsorbing means 41 before transfer. It is possible to easily preheat the paper.

The suction means 41 has a configuration in which a simple metal roller or an elastic roller coated with rubber or the like is pressed against the transfer roller 7, and there is no need to apply an electric field or the like. The paper P is introduced between the transfer roller 7 and the suction means 41, where it is suctioned to the transfer roller 7 by adhesive force. Immediately after the suction, the sheet is preheated by the heating means 8 for heating the transfer roller 7.

In the transfer of a toner image to a sheet, the effect of preheating the sheet increases as the transfer speed increases.

FIG. 12 shows the relationship between the transfer speed and the transfer efficiency.

This is a normal PPC paper (64 g / m ² )
, The transfer roller 7 at 90 ° C., and the intermediate transfer roller 6 at 7 ° C.
It is an experimental result when transferring to a 0 degreeC and applying a load of 4 kg / cm between both, and transferring.

When the transfer speed is 20 mm / sec, transfer can be performed at an efficiency of 95% or more without preheating the paper, but at a speed of 100 mm / sec, the transfer efficiency is reduced to less than 10%. Here, before the transfer, the sheet was attracted to the transfer roller 7 and the preheating length was set to 50 mm. As a result, the transfer efficiency increased to 95% or more. When the transfer speed was increased to 200 mm / sec in this state, the transfer efficiency was reduced to less than 50%.
When the preheating time was set to 0.5 mm and the preheating time was also set to 0.5 second, the transfer efficiency was restored to 95% or more.

As described above, the transfer speed is 20 mm / sec.
Above, there is an effect of preheating the paper, and there is a great possibility that the effect will be further increased if the type of paper is changed.

According to the present invention, the paper can be reliably attracted without being influenced by environmental changes such as humidity with a relatively simple configuration as compared with electrostatic attraction or the like. it can.

Also, after the transfer is completed, the paper is transferred to the transfer roller 7.
, The heating is continued. As a result, the solvent in the image that remains very slightly further evaporates, so that it is possible to minimize the amount of solvent vapor discharged outside the apparatus through the paper.

[0073]

As described above, according to the present invention, the adhesive force of the transfer medium is made larger than the adhesive force of the intermediate transfer medium. , And good paper passing is possible.

Further, since there is no need to peel the transferred body by bringing the peeling claw into contact with the intermediate transfer medium, the transferred body can be peeled without damaging the intermediate transfer medium, and good image quality can be obtained.

Further, since the cleaning medium having adhesiveness is brought into contact with the transfer medium to remove dust such as paper dust on the transfer medium, it is possible to prevent the adhesiveness of the transfer medium from deteriorating.

Further, paper dust and transfer residual toner adhering to the intermediate transfer medium can be collected on the transfer medium during the non-printing operation, and the cleaning means dedicated to the intermediate transfer medium can be omitted.

Further, since the transfer medium is heated and the transfer medium is attracted to the transfer medium, the transfer medium can be heated in advance before the transfer, so that good transfer is possible even if the transfer speed is increased. Become.

Further, even after the transfer is completed, the transferred object is continuously heated until immediately before the peeling, so that the solvent remaining on the transferred object can be efficiently evaporated by any chance, and the leakage of the solvent vapor to the outside of the apparatus can be prevented. Can be.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing a transfer device according to a second embodiment of the present invention.

FIG. 3 is a front view showing a transfer device.

FIG. 4 is a front view showing a transfer device according to a third embodiment of the present invention.

FIG. 5 is a front view showing a transfer device according to a fourth embodiment of the present invention.

FIG. 6 is a front view illustrating a transfer device according to a fifth embodiment of the present invention during cleaning.

FIG. 7 is a front view illustrating a state where the transfer device is not cleaned.

FIG. 8 is a front view illustrating a paper passing mode of a transfer device according to a sixth embodiment of the present invention.

FIG. 9 is a front view illustrating a non-sheet passing mode of the transfer device.

FIG. 10 is a diagram showing a normal sheet passing timing.

FIG. 11 is a diagram illustrating a sheet passing timing when the intermediate transfer roller is cleaned.

FIG. 12 is a graph showing the relationship between transfer speed and transfer efficiency.

[Explanation of symbols]

 P: paper (transfer member) 1: latent image carrier (image carrier) 2a to 2d: chargers 3a to 3d: exposure units 4a to 4d: developing device 5: transfer device 11: drying unit before transfer 6: intermediate Transfer roller (intermediate transfer medium) 7 Transfer roller (transfer means) 9 Heating means 15 Peeling claw (peeling means) 17 Adhesive area 18 Non-adhesive area 21 Cleaning roller (cleaning member) 35 Contact / separation mechanism 41 ... Suction means

Claims (7)

[Claims] 1. An image forming means for forming an electrostatic latent image on an image carrier and supplying a liquid developer to the electrostatic latent image to visualize the electrostatic latent image; An intermediate transfer medium that has an adhesive property and transfers a visible image on the image carrier to the surface; and an adhesive that is in contact with the intermediate transfer medium and has a larger adhesive force on the surface than the intermediate transfer body. And a transfer medium for transferring a visible image on the intermediate transfer medium to a transfer object by heat and pressure. 2. An image forming means for forming an electrostatic latent image on an image carrier and supplying a liquid developer to the electrostatic latent image to visualize the electrostatic latent image; An intermediate transfer medium that has an adhesive property and transfers a visible image on the image carrier to the surface; a region that is in contact with the intermediate transfer medium and has a first adhesive force on the surface; A transfer medium for transferring a visible image on the intermediate transfer medium to a transfer target by heat and pressure, the transfer medium having a region having a second adhesive force weaker than the first adhesive force; 2 is contacted with the adhesive area,
An image forming apparatus, comprising: a separation unit configured to separate a transfer target object adsorbed on the transfer medium. 3. An image forming means for forming an electrostatic latent image on an image carrier, supplying a liquid developer to the electrostatic latent image to visualize the electrostatic latent image, and contacting the image carrier with a surface image. An intermediate transfer medium that has an adhesive property and transfers the visible image on the image carrier to the surface; and an intermediate transfer medium that is in contact with the intermediate transfer medium and has an adhesive property on the surface and has an adhesive property on the intermediate transfer medium. A transfer medium for transferring a visual image to a transfer object by heat and pressure; and a dirt that is in contact with the transfer medium and has an adhesive property on a surface thereof, which has a greater adhesive strength than the transfer medium, and adheres to the transfer medium. An image forming apparatus comprising: a cleaning unit that removes the toner. 4. The image forming apparatus according to claim 3, wherein the dirt adhering to the intermediate transfer medium is adsorbed on the transfer medium, and the dirt adsorbed on the transfer medium is removed by a cleaning unit. 5. The image forming apparatus according to claim 1, wherein the transfer medium is heated beforehand by a heat of the transfer medium before a visible image is transferred. 6. The method according to claim 1, wherein the transfer medium is heated after the transfer of the visible image by the heat of the transfer medium.
The image forming apparatus according to claim 1. 7. The method according to claim 1, wherein the transfer medium is heated before the transfer of the visible image by the heat of the transfer medium, and further heated after the transfer of the visible image. The image forming apparatus according to claim 1.