JPH05188796A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an excellent image where a releasing agent on a transfer material carrying sheet is effectively removed by having an adsorbing means provided with a contact adsorbing member and making at least a part of area where the contact adsorbing member comes in contact with a transfer material a releasing agent absorbing member. CONSTITUTION:The abutting surface of a transfer material guide 5g on the transfer material P is made a transfer material presser 101 made of a porous and liquid transmissive high polymer synthetic resin film, and a liquid absorbing member 102 such as sponge which absorbs silicone oil being the releasing agent is provided inside the presser 101. The guide 5g is movable and its root side is pivotally supported to a machine frame in parallel with the shaft center of a transfer drum 5a, so that the presser 101 made of the high polymer film being the tip part is allowed to press-contact with the transfer material carrying sheet 5f. Then, the transfer material P which is moved in a state where it is adsorbed to the sheet 5f is allowed to press-contact with the sheet 5f, so that their contactness is improved. Thus, the silicone oil 103 in the transfer material P is absorbed by the member 102 and prevented from transferring on a photosensitive drum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is one in which a transfer material is carried on a moving transfer material carrier, and a transfer electric field is applied to the transfer material to form it on an image carrier composed of a photoreceptor or an insulator. The present invention relates to an image forming apparatus provided with a transfer device for transferring a toner image on the transfer material by superimposing the toner image, and more particularly to a cleaning means for a transfer material carrier such as an electrophotographic copying machine or a printer.

[0002]

2. Description of the Related Art As described above, a toner image on a toner image is transferred to a transfer material by facing the transfer material to the image carrier such as a photoreceptor or an insulator once or a plurality of times. Various image forming apparatuses, such as electrophotographic copying machines and printers, for transferring and obtaining black and white or color images are commercially available and many have been proposed.

FIG. 6 shows an example of a color electrophotographic copying machine for forming a full-color image.

In this example, the color electrophotographic copying machine is
A drum-shaped electrophotographic photosensitive member which is an image carrier, that is, a photosensitive drum 1 is rotatably supported in an arrow direction, and a corona charger 2, an exposure optical system 3, a developing device 4, and a transfer device are provided around the photosensitive drum 1. 5 and the cleaning device 6 are arranged.

The optical system 3 is composed of a document scanning section and a color separation filter, and is a color separated light image or a light image E corresponding thereto.
Is a laser beam exposure means shown in the drawing. The photosensitive drum 1 uniformly charged by the charger 2 is irradiated with the optical image E for each separated color image to form a latent image. The developing device 4 is a rotary developing device and has four developing devices around the central axis 4b, that is, a yellow developing device 4Y, a magenta developing device 4M, a cyan developing device 4C, and a black developing device 4B.
K is arranged and a predetermined developing device is rotated to a developing position facing the photosensitive drum 1 to develop the latent image on the photosensitive drum 1,
Average particle size of resin on photosensitive drum 1 is 8 to 10 μm
An image is formed with the toner of m.

Further, the toner image on the photosensitive drum 1 is transferred from the transfer material cassette 7 to the transfer material supplied to the position facing the photosensitive drum 1 via the transport system and the transfer device 5. In this example, the transfer device 5 includes a transfer drum 5a, a transfer charger 5b, and a transfer material gripper 5 that grips and conveys the transfer material.
c, an inner charging device 5d, and an outer charging device 5e, and a transfer material carrying sheet 5f as a transfer material carrying body made of a dielectric material in the peripheral opening area of the transfer drum 5a which is rotatably driven. Is integrally stretched in a cylindrical shape. As the transfer material carrying sheet 5f, a film-shaped dielectric sheet such as polyethylene terephthalate or polyvinylidene fluoride resin film is used.

As the drum-shaped transfer device, that is, the transfer drum 5a rotates, the toner image on the photosensitive drum 1 is transferred onto the transfer material carried on the transfer material carrying sheet 5f by the transfer charger 5b, and at the same time. The transfer material is a transfer material guide 5g that is a transfer material suction means of the transfer material carrying sheet 5f.
Is applied to the transfer material carrying sheet 5f to be attracted thereto. The photosensitive drum 1 is subjected to the next image forming process after the residual toner is removed by the cleaning device 6.

In this way, a desired number of color images are transferred to the transfer material that is sucked and conveyed by the transfer material carrying sheet 5f, and a full color image is formed.

When the transfer of the four color toner images is completed in this way, the transfer material is separated from the transfer drum 5a and discharged onto the tray 10 via the heat roller fixing device 9.

At this time, when images are formed on both sides of the transfer material, the transfer material transport guide 19 is immediately discharged from the fixing device 9.
Is driven to return the transfer material to the inversion path formed by the transport guide 20 and the transfer material stocker 21. That is, the transfer material is guided to the transport guide 20, and then temporarily stored in the transfer material stocker 21, the transfer material is turned over, and an image is formed on the other surface by the above-described image forming process.

On the other hand, after the transfer, the photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned by the cleaning device 6.

On the transfer material carrying sheet 5f on the transfer drum 5a, when powder toner is scattered from the photosensitive drum 1, the developing device 4, the cleaning device 6 or the like, or when the transfer material is jammed (paper jam). Although the toner is contaminated due to the adhered toner, the surface of the transfer material carrying sheet 5f of the transfer drum 5a is similarly cleaned by a cleaning means 11 including a fur brush 14 and a backup brush 15 or the like which opposes the brush 14 via the transfer material carrying sheet 5f. After being cleaned by the action of, the image forming process is carried out again. Such cleaning means is usually performed before transfer and during pre-rotation, and also jams (paper jams)
When it occurs, it will be held at any time.

[0013]

However, in the above-mentioned conventional example, a so-called double-sided image is formed in which the image is not formed on the surface of the transfer material after passing through the image forming portion, the fixing device 9 and the reversing path on the transfer material. There were the following drawbacks when forming.

During the single-sided image formation, the silicone oil coating unit 9c transfers to the upper roller 9a and the lower roller 9b of the fixing device 9, and the silicone oil impregnated on the transfer material transfers to the photosensitive drum 1 during the image formation on the second surface. Also, the silicon oil on the transfer material adheres to the transfer material carrying sheet 5f, and if the adhered oil cannot be removed sufficiently and the silicon oil adheres to the photosensitive drum to a certain extent or more, cleaning failure occurs and an image appears on the image. There was also a problem of streaking. Similarly, at this time, the surface of the transfer material carrying sheet 5f should be cleaned while performing one idle rotation at this time, but especially the cleaning means such as a fur brush could not sufficiently remove the silicone oil. Also, most of the silicone oil can be removed by increasing the number of idle rotations, but if this operation is performed after image formation, the copy speed will be significantly slowed, which is not preferable.

Further, even in an image forming apparatus capable of automatically forming only one side of an image, when fixing one side, silicon oil adheres to the back side on which an image has not yet been formed. Even when the apparatus is once discharged and then turned over to form an image on the back side, the silicon oil adhering to the back side is transferred to the image carrier, so that the same problem occurs.

As described above, when double-sided image formation is performed, the release agent adheres to the transfer material carrying sheet of the transfer material carrying body and the photosensitive drum of the image carrying body to cause a problem.

The present invention provides a cleaning means capable of effectively removing the release agent on the transfer material-carrying sheet in an image forming apparatus capable of double-sided image formation, which comprises means for applying a release agent to a fixing device and a transfer material carrier. It is intended to be provided.

[0018]

A first aspect of the present invention comprises an image carrier on which a toner image is formed, and a transfer material carrier for holding and transporting the transfer material by suction means for sucking the transfer material. In an image forming apparatus provided with a transfer device, a roller fixing device having a release agent applied to the surface thereof, and a cleaning means for a transfer material carrier, the adsorbing means has a contact adsorbing member. In the image forming apparatus, at least a part of the contacting portion is a release agent absorbing member.

A second invention of the present invention is the image forming apparatus according to the first invention, wherein the attraction means is an electrostatic attraction means.

A third aspect of the present invention is an image carrier on which a toner image is formed, a transfer device equipped with a transfer material carrier for holding and transporting the transfer material by suction means for sucking the transfer material, and a transfer device on the surface. An image forming apparatus comprising a roller fixing device coated with a release agent and a cleaning means for a transfer material carrier, wherein the cleaning means is a web cleaning device.

The fourth invention of the present invention is an image forming apparatus capable of forming an image only on one surface of a transfer material, and the image formation according to any one of the first to third inventions. It is a device.

According to a fifth aspect of the present invention, an image can be formed on only one surface of a transfer material, and the first surface of the transfer material is transferred by a transfer device and fixed by the fixing device, and then the transfer material is transferred by the transfer device. One of the first to third inventions, which is an image forming apparatus capable of double-sided image formation in which the second surface is transferred and the transfer material is discharged outside the machine after being fixed by the fixing device. The image forming apparatus described in 1.

According to a sixth aspect of the present invention, an image carrier on which a toner image is formed, a transfer device equipped with a transfer material carrier for holding and transporting the transfer material by suction means for sucking the transfer material, and a surface thereof A roller fixing device coated with a release agent, a single-sided image forming unit that transfers the first surface of a transfer material by a transfer device, fixes it by the fixing device, and then discharges it outside the device, and an image on the first surface. A double-sided image forming means for transferring the second surface of the transfer material by the transfer device after fixing and discharging the second surface of the transfer material after fixing by the fixing device, and a cleaning means for the transfer material carrying member, An image forming apparatus comprising different cleaning means, wherein the cleaning means is different between one-sided image formation and two-sided image formation.

A seventh aspect of the present invention is an image carrier on which a toner image is formed, a transfer device equipped with a transfer material carrier for holding and transporting the transfer material by suction means for sucking the transfer material, and a surface thereof. A roller fixing device coated with a release agent, a single-sided image forming unit that transfers the first surface of a transfer material by a transfer device, fixes it by the fixing device, and then discharges it outside the device, and an image on the first surface. After the fixing, the second surface of the transfer material is transferred by the transfer device, and the double-sided image forming means for discharging the second surface of the transfer material after fixing by the fixing device and the cleaning means for the transfer material carrying member are used. In the image forming apparatus, the transfer material carrying member acts as a cleaning unit during the image formation, and makes more idle rotation than during the image formation on only one side.

An eighth aspect of the present invention is a multicolor image forming apparatus in which the image forming apparatus is a surface sequential transfer, and the cleaning means operates after the toner to be finally transferred to the transfer material has been transferred. The image forming apparatus according to the sixth invention or the seventh invention.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] In this embodiment, the release agent impregnated in the transfer material is prevented from transferring to the photosensitive drum. In this embodiment, the entire image forming apparatus has the same structure and operation as those of the conventional example shown in FIG. 6, and the transfer material guide 5g is constructed as shown in FIG. That is, the contact surface of the transfer material guide 5g with the transfer material P is a transfer material retainer 101 made of a porous and liquid-permeable polymer synthetic resin film, and a liquid absorbing material such as a sponge that absorbs silicon oil, which is a release agent, is provided inside. The structure having the elastic member 102 is adopted.

The width of the transfer material guide 5g is substantially the same as that of the transfer drum 5a, and is slightly larger than the maximum width of the transfer material P. The transfer material guide 5g is movable, its root side is pivotally attached to the machine frame in parallel with the axis of the transfer drum 5a, and the polymer material transfer material retainer 101 at the front end is pressed against the transfer material carrying sheet 5f. ing. As a result, the transfer material P adsorbed and moved by the transfer material carrying sheet 5f is pressed against the transfer material carrying sheet 5f, and the transfer material carrying sheet 5f and the transfer material P are transferred.
Has good adhesion. It is appropriate that the transfer material retainer 101 and the liquid-absorbent member 102 are freely rotatable and are brought into pressure contact with the transfer material carrying sheet 5f to be driven to rotate.

Further, in synchronization with the transfer material fed to the transfer drum 5a, the transfer material tip is moved between the transfer drum 5a and the transfer material guide 5g, and then the transfer material guide 5g tip is displaced toward the transfer drum 5a. A driving member that presses the transfer material may be provided.

With this structure, when the transfer material P is carried on the transfer material carrying sheet 5f which is the transfer material carrying body after the image formation on one side is completed and before the image formation on the opposite side is carried out. In addition, it is possible to prevent the silicone oil 103 of the transfer material P from being absorbed by the liquid absorbing member 102 and being transferred to the photosensitive drum 1.

Although a sponge is shown as the liquid absorbing member 102, the present invention is not limited to this. It may be felt or non-woven fabric. As a liquid absorbing property, a member having a large liquid absorbing capacity is desirable in order to prevent backflow to the transfer material P. After the double-sided image formation is performed a plurality of times, when the liquid absorption is saturated, the liquid-absorbent member 102 is replaced with the liquid-absorbent member 102 in the non-liquid-absorbing state.

The transfer material retainer 101 made of a polymer synthetic resin film promotes the releasability between the transfer material P and the liquid-absorbent member 102, and is a tetrafluoroethylene resin film Poaflon (registered trademark of Sumitomo Electric Industries, Ltd.). ) Or the like is used.

[Second Embodiment] FIG. 2 shows an example of another image forming apparatus to which the present invention is applied.

A transfer material path for image formation on one side is shown by a dotted line. The front end of the transfer material supplied from the transfer material cassette comes to the position of the adsorption charger 202. The adsorption charging device 202, the transfer material carrying sheet 5f, and the attraction roller 201 facing the transfer material via the transfer material are arranged to electrostatically adsorb the transfer material on the transfer material carrying sheet 5f of the transfer drum 5a. Let The attraction roller 201 is electrically conductive and is electrically grounded to inject charges for attraction.

Yellow developing device 4Y, cyan developing device 4C,
The magenta developing device 4M and the black developing device 4BK are alternatively arranged to approach the photosensitive drum 1 (in the figure, the magenta developing device 4M approaches the photosensitive drum 1). The reversal path 203 is formed by temporarily stopping the transfer material fed into the path 203 by the transfer material transport guide 19, and setting the trailing end of the transfer material at the time of feeding as the leading end, in the direction opposite to the reversing path 203. It is configured to be pulled out from the sheet and guided to the double-sided intermediate tray 204. The adsorption roller 201 is configured to adsorb the release agent from the transfer material as described later. Other than that, the arrangement is different, but it is the same as the image forming apparatus which is the base of the previous embodiment. The transfer material fed from the transfer material cassette 7 is held in the nip portion between the transfer drum 5a and the suction roller 201, and is electrostatically charged. The container 202 is adapted to adsorb the transfer material carrying sheet 5f from the front end to the rear end.

Multicolor image formation by carrying the transfer material on the transfer material carrying sheet 5f is performed as described above, the transfer material is separated from the transfer drum 5a by the outer charger 5e, and fixed by the fixing device 9. In the case of double-sided copying, the transfer material path for image formation on the opposite side is the transfer material transport guide 1 as shown by the chain line.
At 9 the reversal path 203 is sent out toward the reversal path 203.
When it is moved back and forth, it is guided to a path to the double-sided intermediate tray 204 by a guide (not shown) and stocked in the double-sided intermediate tray 204. Then, the transfer material on which one side has been copied is sent again toward the nip portion between the transfer drum 5a and the suction roller 201, and the suction charging device 202 and the suction roller 201 again electrostatically transfer the transfer material onto the transfer material carrying sheet 5f. Transfer drum 5a that is adsorbed and forms a multicolor image on the second surface
Then, the transfer material is separated from the sheet, fixed by the fixing device 9, and discharged to the outside of the machine by the transfer material transport guide 19.

The present embodiment is characterized in that the suction roller 201, which is a contact member of the suction means to the transfer material, is a member having a liquid absorbing property. Examples of the conductive and liquid-absorbing member include a nonwoven fabric in which carbon is dispersed and conductivity is imparted, a member in which carbon is dispersed in felt, or a sponge inside has a mesh that is permeable to silicon oil. Those wrapped with a grounded stainless steel mesh are suitable.

[Embodiment 3] The entire structure of the double-sided multicolor image forming apparatus and the operation thereof are the same as those in FIG.

As shown in FIG. 3, the cleaning means 11 for the transfer drum is constructed by arranging a web cleaning device 13 of a winding type on the outside of the transfer material carrying sheet 5f and a backup brush 15 on the inside thereof. ..

The web cleaning device 13 includes a web take-up roll 13b having a cleaning web 13a wound around the same width as the transfer drum 5a and a web take-up roll 13c for taking up the cleaning web 13b taken out from the web take-up roll 13b. Rolls 13b, 1
It comprises a web pressing roller 13d for pressing the cleaning web 13a against the transfer drum 5a between 3c. The web feeding roll 13b is rotatably supported by being given an appropriate resistance.
3c is connected to a rotary drive source, and is controlled so that the cleaning web 13a is wound to a fixed length with respect to the number of rotations of the transfer drum 5a. Web pressing roller 13d
Is rotatably rotatably supported, and a bearing for supporting the shaft for rotatably moves forward and backward toward the transfer drum 5a, and urges the cleaning web 13a toward the transfer drum 5a by a spring (not shown). Transfer material carrying sheet 5f on drum 5a
Of the transfer drum 5a and the position that forms the nip including the busbar of
It takes a position away from.

Here, as the cleaning web 13a, a bundle of acrylic ultrafine fibers (average diameter 5 μm) is pressed,
A cloth-shaped non-woven fabric (thickness 150 μm) was used.
In addition, a non-woven fabric made of resinous ultrafine fibers such as nylon, polyester and rayon can be used.

In such a non-woven fabric, since the ultrafine fibers are exposed on the surface thereof, the effect of peeling off the deposits on the surface of the dielectric transfer material carrying sheet 5f is great and the cleaning effect is extremely high.

The cleaning web 13a has a high ability to clean the release agent (silicon oil), and can remove stains on the surface of the transfer material carrying sheet 5f after double-sided image formation, resulting in excellent transfer and excellent image quality. I could always get a color image of.

It is also effective for cleaning the charged toner (average volume particle size 8 μm) strongly adhered to the surface of the transfer material carrying sheet 5f.

Further, since the adhered substances such as the silicone oil and the toner as the release agent which have been once cleaned are trapped between the fine fibers on the surface of the non-woven fabric, they are re-adhered to the surface of the transfer material carrying sheet 5f or cleaned. It is possible to prevent toner scattering around the means 11.

In order to clean the transfer material carrying sheet 5f by the web cleaning device 13 as described above, the transfer drum 5a is normally idled before the transfer is performed (the image is not formed on the image carrying member, and the transfer material is transferred to the transfer drum 5a). The web cleaning device 13 is operated by rotating the web cleaning device 13 without carrying it.

[Embodiment 4] In the previous embodiment provided with the web cleaning device, the transfer material carrying sheet was cleaned during the pre-rotation performed before the transfer, but after the transfer and separation of the second side of the double-sided image. By cleaning the transfer material carrying sheet 5f, it is possible to more reliably prevent the silicone oil of the release agent from adhering to the surface of the photosensitive drum 1. At this time, in order to obtain a double-sided image, the image leading edge of the second surface of the transfer material attracted to the transfer drum 5a with the second surface facing outward is the cleaning start position (cleaning position where the cleaning web 13a and the transfer material carrying sheet 5f should come into contact with each other). Web 13a nip position)
The cleaning material may be cleaned by bringing the cleaning web 13a into close contact with the surface of the transfer material before reaching the point. This can prevent the transfer of silicone oil, which is a release agent, from the transfer material to the photosensitive drum 1.

[Embodiment 5] In FIG. 3, when cleaning is performed by a web cleaning device during double-sided image formation (when the second image is formed after fixing the second surface, after the second surface is transferred, and the second surface is jammed) , The feeding amount of the cleaning web 13a is increased, the cleaning ability is enhanced, and the silicone oil is removed more reliably than during normal single-sided image formation (when the transfer drum is pre-rotated, after the first surface is transferred, and when the first surface is jammed). It is good to In this embodiment, the cleaning web 1 for image formation on one side is used.
The feed amount of 3a was 1 mm, and the feed amount of the cleaning web during double-sided image formation was 2 mm. At this time, the switching of the feed amount is performed by a signal from a mode selection switch including selection of single-sided recording and double-sided recording provided in the image forming apparatus.

Further, by thus setting the feeding amount of the cleaning web 13a as required, the amount of the cleaning web 13a used can be saved. That is, the feed amount of the cleaning web 13a needs to be sufficient to clean the maximum dirt on the transfer drum 5a, and if the feed amount is constant, the feed amount of 2 mm is always required in the above example.

[Embodiment 6] The entire image forming apparatus in this embodiment is similar to that shown in FIG. 6, but the cleaning means is different.

This will be described with reference to FIG. In this embodiment, a web cleaning device 13 and a fur brush 14 are provided.

In the conventional example, the transfer material carrying sheet 5 is used.
Although the fur brush 14 is used as the cleaning means for f, the silicon oil cannot be sufficiently removed only by cleaning with the fur brush 14. On the other hand, with the web cleaning device 13, the web pressing roller 13
Since the cleaning web 13a is pressed at d, the transfer material-carrying sheet 5f is rubbed against the transfer material-carrying sheet 5f fairly strongly. Therefore, the web cleaning device 13 is used only when images are formed on both sides, and the fur brush 14 is used when images are normally formed on one side, so that the silicone oil is sufficiently removed and the transfer material carrying sheet is used. The life of 5f could be extended. In this embodiment, an OPC drum having a diameter of 80 mm is used as the photosensitive drum 1, and a polyethylene terephthalate dielectric sheet is stretched around the frame body having a diameter of 160 mm as the transfer drum 5a as a transfer material carrying sheet 5f. I used one.

[Embodiment 7] In Embodiment 6, the cleaning method of the transfer material carrying sheet 5f is completely separated between the one-sided image formation and the two-sided image formation. Even if the cleaning with the fur brush 14 and the cleaning with the cleaning web 13a are used together, the effect of the present invention is effective, and by doing so, the cleaning performance is further improved.

[Embodiment 8] FIG. 5 is a diagram in which the transfer material P1 having an image already fixed on one surface (front surface) is adsorbed on the transfer material carrying sheet 5f with the back surface facing up. At this time, since a considerable amount of silicone oil of the release agent is attached to the surface, the transfer material carrying sheet 5f is naturally soiled by the silicone oil at this moment. (However, since the transfer material is passed over the photosensitive drum 1, the silicone oil on the front side does not flow.) After that, the transfer drum 5a finishes the transfer of the toner of the color to be superimposed finally at the time of image formation on the back surface, and transfers the transfer material. After P1 is separated from the transfer drum 5a, the transfer material carrying sheet 5f is cleaned by the cleaning means 11 (web cleaning device 13) provided while rotating three times in idle. By doing so, the silicone oil adhering to the transfer material carrying sheet 5f was almost removed, and did not reach the surface of the photosensitive drum 1.

At this time, if the silicon oil is to be completely removed by a single idle rotation cleaning without idle rotation, a considerable pressure must be applied to the transfer material carrying sheet 5f to clean it. Since the bending of 5f is generated and the rubbing force is increased, the life of the transfer material carrying sheet 5f is shortened, which is not preferable.

The idle rotation as described above is performed only when images are formed on both sides, and is not performed during normal image formation. If the cleaning is performed by idling the transfer drum 5a even during the normal image formation on only one side, not only the copy speed is lowered but also the surface of the transfer material carrying sheet 5f is rubbed more than necessary, which is not preferable either. .. In addition,
In this embodiment, the photosensitive drum 1 has an O diameter of 80 mm.
The diameter of the PC drum is 160 mm as the transfer drum 5a.
The base material of the skeleton was a polyethylene terephthalate dielectric sheet which was stretched around the transfer material carrying sheet 5f.

Although this embodiment is effective regardless of the type of cleaning means, the use of a web cleaning device is particularly effective for removing silicone oil and toner.

When the cleaning means shown in FIG. 4 is used, the web cleaning device 13 is used only when images are formed on both sides.
The cleaning means is used, and the fur brush 14 is used during normal one-sided image formation, and the toner of the color to be superimposed is finally transferred, and the transfer material is the transfer drum 5a.
After the separation, the silicon oil was removed sufficiently and the life of the transfer material carrying sheet 5f could be extended by performing cleaning during the idle rotation of three rotations. Further, the effects of the present invention are the same even when both of these cleaning means are used simultaneously when forming images on both sides.

Although each of the embodiments relates to a multicolor image forming apparatus which adopts a frame sequential method of developing one color and transferring one color, instead of this, a plurality of colors are formed on the photosensitive drum. The effects of the present invention are effectively exhibited even in a multicolor image forming apparatus that employs a batch transfer method in which an image is formed by superimposing and developing and transferring the image onto a transfer material at a time.

In each of the embodiments, an image forming apparatus in which double-sided image formation is automatically performed is described, but it is also effective in an image forming apparatus in which an image can be formed on only one side and the image can be formed by manually turning it over. Is.

The present invention can also be applied to an image forming apparatus in which an image is formed on one surface of a transfer material, and then the transfer material path that does not pass through the reverse path is passed, and the image is formed by superimposing on the same surface.

[0062]

EFFECTS OF THE INVENTION As described above, (1) By using at least a part of the portion of the adsorbing means that comes into contact with the transfer material as a release agent absorbing member, the release agent is transferred to the image carrier during double-sided image formation. Can be achieved without adding any special means, whereby the transfer material can be adsorbed to the transfer material carrier and the transfer of the release agent onto the image carrier can be prevented. Images can be obtained. (2) By using a web cleaning device as the cleaning means for the transfer material carrier, it is possible to remove the release agent stain on the transfer material carrier that occurs after double-sided image formation, and always obtain a good transfer image. At the same time, it was possible to prevent poor cleaning of the image bearing member (due to oil adhesion). (3) The cleaning means for the transfer material carrier is made different between one-sided image formation and two-sided image formation, so that the image carrier is not soiled by the release agent and the image carrier is poorly cleaned. It was effective in eliminating the problem and providing a good image. (4) When a double-sided image is formed, the cleaning means is operated after the transfer, and the surface is cleaned while idling more than when the single-sided image is formed. It was effective in eliminating streaks on the image on the transfer material due to the above cleaning failure and providing a good image.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a first embodiment.

FIG. 2 is a vertical sectional view of an image forming apparatus according to a second exemplary embodiment.

FIG. 3 is a vertical cross-sectional view of the main parts of Examples 3, 4, and 5.

FIG. 4 is a vertical cross-sectional view of a main part of Examples 6 and 7.

FIG. 5 is a vertical cross-sectional view of a main part of an eighth embodiment.

FIG. 6 is a vertical sectional view of a conventional image forming apparatus.

[Explanation of symbols]

 1 Photosensitive Drum 5 Transfer Device 5a Transfer Drum 5f Transfer Material Supporting Sheet 5g Transfer Material Guide 9 Heat Roller Fixer 9c Silicon Oil Application Unit 11 Cleaning Means 13 Web Cleaning Device 14 Fur Brush 15 Backup Brush

Claims (8)

[Claims] 1. A transfer device having an image carrier on which a toner image is formed, a transfer material carrier for holding and transporting a transfer material by suction means for adsorbing the transfer material, and a release agent applied on the surface. In the image forming apparatus including the roller fixing device and the transfer material carrying member cleaning means, the suction means has a contact suction member, and at least a part of the contact suction member contacting the transfer material absorbs the release agent. An image forming apparatus, which is a member. 2. The image forming apparatus according to claim 1, wherein the attraction unit is an electrostatic attraction unit. 3. A transfer device having an image carrier on which a toner image is formed, a transfer material carrier for holding and transporting the transfer material by suction means for adsorbing the transfer material, and a release agent applied on the surface. An image forming apparatus comprising a roller fixing device and a cleaning means for a transfer material carrier, wherein the cleaning means is a web cleaning device. 4. The image forming apparatus according to claim 1, which is an image forming apparatus capable of forming an image on only one surface of a transfer material. 5. An image can be formed on only one surface of the transfer material, and the first surface of the transfer material is transferred by a transfer device and fixed by the fixing device, and then the second surface of the transfer material is transferred by the transfer device. The image forming apparatus according to any one of claims 1 to 3, wherein the image forming apparatus is capable of performing double-sided image formation by discharging the transfer material after fixing by the fixing device. 6. An image carrier on which a toner image is formed, a transfer device equipped with a transfer material carrier for holding and transporting the transfer material by suction means for adsorbing the transfer material, and a release agent applied on the surface. And a roller fixing device, a first side of the transfer material is transferred by the transfer device, fixed by the fixing device, and then discharged to the outside of the machine, and an image on the first face is transferred by the transfer device after fixing. An image forming apparatus including a double-sided image forming unit that transfers the second surface of a transfer material and discharges it out of the apparatus after fixing by the fixing device, and an image forming apparatus that includes a cleaning unit of a transfer material carrier, and a plurality of different cleaning units, An image forming apparatus, wherein cleaning means is different between one-sided image formation and two-sided image formation. 7. A transfer device having an image carrier on which a toner image is formed, a transfer material carrier for holding and transporting the transfer material by suction means for adsorbing the transfer material, and a release agent applied on the surface. And a roller fixing device, a first side of the transfer material is transferred by the transfer device, fixed by the fixing device, and then discharged to the outside of the machine, and an image on the first face is transferred by the transfer device after fixing. In the image forming apparatus including the double-sided image forming unit for transferring the second surface of the transfer material and discharging the second material after fixing by the fixing device, and the cleaning unit for cleaning the transfer material carrier, when forming images on both sides,
An image forming apparatus characterized in that the transfer material carrying member is rotated more idly than when an image is formed on only one side by using a cleaning means. 8. The image forming apparatus is a multi-color image forming apparatus of frame-sequential transfer, and the cleaning means operates after the toner to be finally transferred to the transfer material has been transferred. 7. The image forming apparatus according to item 7.