JP3320157B2 - Image forming device - Google Patents

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 using an electrophotographic method used for a copying machine, an LBP, a facsimile, and the like.

[0002]

2. Description of the Related Art For example, as a full-color image forming apparatus, a photosensitive drum as an image carrier for forming a toner image by an electrophotographic method and a transfer material carrying member for carrying paper as a transfer material for transferring the toner image are used. Various provisions have been proposed and implemented. FIG. 7 shows an example of such a full-color image forming apparatus.

In the full-color image forming apparatus of this embodiment,
A photosensitive drum 1, which is an image carrier, is rotatably supported in the direction of the arrow. Around this photosensitive drum 1, a corona charger 2, an exposure optical system 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged. Around the transfer device 5, a cleaning device (transfer cleaner) 14 for the transfer drum 5a is arranged.

The optical system 3 includes a document scanning section and a color separation filter, and performs a color-separated light image or a light image E corresponding thereto.
Irradiates the photosensitive drum 1 with a laser beam exposure device as shown in the figure. The optical system 3 irradiates the photosensitive drum 1 negatively and uniformly charged primarily by the charger 2 with an optical image E for each decomposition so that an electrostatic latent image of each color is sequentially formed on the photosensitive drum 1. You.

The developing device 4 is a rotary developing machine, and has a central shaft 4
b, four developing units, that is, a yellow developing unit 4Y,
The developing device includes a magenta developing device 4M, a cyan developing device 4C, and a black developing device 4K. A predetermined developing device is rotated to a developing position facing the photosensitive drum 1 to develop a latent image on the photosensitive drum 1. And a toner image formed of a resin-based toner.

The toner image formed on the photosensitive drum 1 is
The image is transferred onto the recording material supplied from the recording material cassette 7 to the transfer device 5 by the transfer unit facing the photosensitive drum 1.

In the present embodiment, the transfer device 5 includes the transfer drum 5a as a transfer material carrier, and the transfer drum 5a serves as a transfer material support member in a space on the outer peripheral surface as a transfer material support member. It is composed of a cylindrical body on which a sheet (transfer sheet) 5f is stretched. Around the transfer drum 5a,
A transfer charger 5b, a suction charger 5c, a suction roller 5g, inner and outer chargers 5d and 5e, and a separation charger 5h are provided. The chargers such as the transfer charger 5b are corona chargers. The suction roller 5g is formed of a conductive roller.

The recording material supplied from the recording material cassette 7 to the transfer device 5 through the transport system is attracted by the attraction charger 5c of the transfer drum 5a and the attraction roller 5g which is the opposite pole.
The transfer drum 5a is conveyed toward the transfer section by the electrostatic rotation of the transfer drum 5a.

In the transfer section, a toner image on the photosensitive drum 1 is transferred by applying an electric field to the recording material by a transfer charger 5b comprising a corona charger inside the transfer drum 5a. The recording material on which the toner image has been transferred is again conveyed to the transfer unit by the rotation of the transfer drum 5a, and the toner image of the next color formed on the photosensitive drum 1 is transferred.

When the four color toner images are transferred in this manner, the recording material is transferred to a separate charging device 5h outside the transfer drum 5a.
The toner image is separated from the supporting sheet 5f by the separating means 8 and sent to the heat roller fixing device 9, where the toner image is mixed and fixed to a recording material to form a full-color permanent image. The paper is ejected. On the other hand, the photosensitive drum 1 and the transfer sheet 5f remove residual toner on their surfaces by the respective cleaning devices 6 and cleaning devices 14.
After being removed by cleaning with, it is again provided to the image forming step.

The paths of the recording material supplied from the cassette and the recording material supplied manually are indicated by dotted lines in the drawing.

[0012]

However, in the conventional image forming apparatus, the cleaning of the transfer sheet 5f is started during the separation of the transfer material from the transfer drum 5a.
The transfer is performed from the position where the leading end of the transfer material of the transfer sheet 5f is located.

For this reason, as shown in FIG. 8, in the circumferential direction on the downstream side in the rotation direction of the transfer drum 5a of the transfer sheet 5f from the transfer portion where the photosensitive drum 1 and the transfer drum 5a are opposed to the transfer cleaner 14. The transfer sheet 5 of the transfer material P is larger than the distance (the distance between the transfer section and the cleaning section) L2 along the transfer sheet P.
f Distance along the circumferential direction of the surface (transfer material circumferential length) L1
When the transfer cleaner 14 is activated while the position where the leading end of the transfer material P of the transfer sheet 5f is located approaches the transfer cleaner 14, when the transfer of the final color toner image is being performed, There is a problem that the shock causes a color shift of the final color toner image.

Conventionally, in order to cope with this problem, when the circumferential length L1 of the transfer material is long, a method has been adopted in which the transfer drum 5a is rotated once and idle after the transfer material is separated and then cleaned. However, in this case, it is not possible to prevent image deterioration due to oil contamination of the photosensitive drum during double-sided image formation (double-sided copying).

That is, four color toner images are transferred to the front surface (first surface) of the transfer material and fixed by the fixing unit 9, and then the back surface (second surface) of the transfer material is set as the front surface. In a double-sided image formation in which the image is formed by transferring the toner image on the transfer drum 5a with the front and back reversed and forming the image on the second surface, the fixing roller of the fixing device 9 is used to fix the toner image on the first surface. The fixing oil adhering to the first surface is turned upside down during image formation on the second surface, and the transfer sheet 5 is transferred from the transfer material carried on the transfer drum 5a.
f. Then, the oil adhering to the transfer sheet 5f separates the transfer material on which the transfer of the toner image to the second surface has been completed from the transfer drum 5a, and the photosensitive drum 1 and the photosensitive drum 1 are rotated during idling of the transfer drum 5a for cleaning. Transfer sheet 5
f adheres again to the surface of the photosensitive drum 1 at the transfer section where it contacts.

For this reason, when a plurality of double-sided image formations are continuously performed, oil accumulates on the surface of the photosensitive drum 1, and when image formation is performed thereafter, toner during development is placed in a white area of the photosensitive drum. Adheres due to the adhesive force of the oil and appears as fog on the transferred image. Further, the toner adhered to the area to be a solid portion of the photosensitive drum by development is hardly separated by the adhesive force of the oil and is not sufficiently transferred onto the transfer material, so that the transferred image becomes pale.

As described above, in the system in which the transfer material is separated and the transfer drum is rotated once and idlely, the transfer sheet is cleaned of toner stains. It is not preferable because it re-adheres to the photosensitive drum at the time of rotation, causing oil stains and resulting image deterioration.

Therefore, in order to prevent image deterioration due to oil contamination of the photosensitive drum at the time of forming a double-sided image, it is necessary to clean the transfer sheet during rotation during separation of the recording material. L1 is the transfer drum 5a
Is longer than the distance L2 between the transfer portion and the cleaning portion, since the transfer of the toner image of the final color is still being performed during the separation of the transfer material, the occurrence of color misregistration is unavoidable.

The object of the present invention is not only when forming a single-sided image, but also when
Provided is an image forming apparatus that can clean a supporting member such as a dielectric sheet of a transfer material carrier without generating color shift even during double-sided image formation and can also remove fixing oil during double-sided image formation. It is to be.

[0020]

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention provides an image bearing member on which a toner image of each color is sequentially formed, and a transfer material on which a toner image of each color is sequentially superimposed and transferred at a transfer portion facing the image bearing member. The transfer material is carried by a transfer material carrier that repeatedly conveys the transfer material to the transfer unit by rotating the transfer material, and a cleaning unit that faces the transfer material carrier on the downstream side in the rotation direction of the transfer material carrier. A cleaning device for cleaning the surface of the transfer material carrier, which has been used for cleaning, the distance (L1) of the transfer material along the circumferential direction of the surface of the transfer material carrier from the transfer unit to the cleaning unit. When the length of the transfer material carrier is longer than the distance (L2) along the circumferential direction of the surface of the transfer material carrier up to the portion, during the rotation of the transfer material carrier during the transfer of the final color toner image among the toner images of the respective colors, Said The copying material is rotated while being held without being separated from the transfer material carrier, and thereafter, the transfer material is separated at the time when the copy material has passed through the transfer portion again, and during the separation of the transfer material carrier during the separation. A cleaning operation of the cleaning device, and when the distance (L1) is shorter than the distance (L2), the transfer material carrier at the time of transferring the final color toner image of the toner images of the respective colors. The image forming apparatus is characterized in that the transfer material is separated during the rotation of the transfer member, and the cleaning operation of the cleaning device is performed during the rotation of the transfer material carrier during the separation.

In another aspect of the present invention, when a plurality of the transfer materials are simultaneously supported on the transfer material carrier, the distance (L1) of the transfer material along the circumferential direction of the surface of the transfer material carrier is:
The distance between the leading end of the first transfer material of the plurality of transfer materials and the trailing end of the last transfer material is set. In still another embodiment, the separated transfer material is a toner of each color. After the image is transferred to one surface and fixed, the toner image of each color is transferred to the other surface as a double-sided transfer material.The transfer of the final color toner image is transferred to the other surface. The final color toner image among the toner images of the respective colors is transferred.

[0022]

【Example】

Embodiment 1 FIG. 1 is a sectional view showing an embodiment of the image forming apparatus of the present invention. The present invention is particularly effective when forming a double-sided image in a full-color copying machine. The image forming apparatus of FIG. 1 shows such a full-color copying machine.

This image forming apparatus has a digital color image reader unit at the upper part and a digital color image printer part at the lower part.

In the reader section, the original 30 is placed on an original platen glass 31, and is exposed and scanned by an exposure lamp 32, so that a reflected light image from the original 30 is condensed by a lens 33 to a full color sensor 34, and color separation is performed. Obtain an image signal. The color-separated image signal is processed by a video processing unit (both not shown) through an amplifier circuit and sent to a printer unit.

In the printer section, the photosensitive drum 1 is supported rotatably in the direction of the arrow. Around the photosensitive drum 1, a pre-exposure lamp 11, a corona charger 2, a laser exposure optical system 3, a potential sensor 12, and four developing devices 4 of different colors
Y, 4C, 4M, 4K, on-drum light amount detecting means 13, transfer device 5, and cleaning device 6 are arranged.

In the laser optical system 3, an image signal from the reader section is converted into an optical signal by a laser output section (not shown), and the converted laser light is reflected by the polygon mirror 3a, and the lens 3b and the mirror 3c. Through the photosensitive drum 1
Projected onto the surface of

At the time of image formation in the printer section, the photosensitive drum 1 is rotated in the direction of the arrow, and after the charge is removed by the pre-exposure lamp 11, the photosensitive drum 1 is uniformly charged by the charger 2, and the light image E To form a latent image on the photosensitive drum 1.

Next, a predetermined developing device is operated to develop the latent image on the photosensitive drum 1 to form a toner image on the photosensitive drum 1. The developing devices 4Y, 4C, 4M, and 4K are operated by the respective eccentric cams 24Y, 24C, 24M, and 24K.
The photosensitive drum 1 is selectively approached in accordance with each separation color.

The transfer device 5 includes a transfer drum 5a on which a recording material carrying sheet (transfer sheet) 5f made of a dielectric sheet is stretched, and a transfer charger 5 is provided around the transfer drum 5a.
b, a suction charger 5c, a suction roller 5g, inner and outer chargers 5d and 5e, and a separation charger 5h. The toner image formed on the photosensitive drum 1 is stored in a recording material cassette 7a,
On the recording material supplied to the transfer device 5 from 7b or 7c,
The image is transferred at the transfer section facing the photosensitive drum 1 and the recording material is 4
When the color toner image is transferred, the toner image is separated from the supporting sheet 5f by the action of the separating claw 8a, the push-up roller 8b, and the separating charger 5h and sent to the heat roller fixing device 9, where it is fixed and full-color permanent image Is discharged to the tray 10 after the
On the other hand, after the residual toner on the surface of the photosensitive drum 1 is cleaned and removed by the cleaning device 6, the photosensitive drum 1 is subjected to the image forming process again basically in the same manner as described in the conventional image forming apparatus. It is.

As described above, the present invention exerts its essence particularly when a full-color double-sided image is formed.

In the present image forming apparatus, when an image is formed on both sides of a recording material, the conveyance path switching guide 19 is driven immediately after the recording material is discharged from the fixing device 9, and the conveyance path is passed through the conveyance vertical path 20. After the recording material is once fed into the reversing path 21a, the recording material is retreated in a direction opposite to the feeding direction with the rear end when the reversing roller 21b is fed by reverse rotation, and the recording material is positioned on the lower side of the intermediate tray. 22. Thereafter, the recording material is supplied to the transfer device 5, the image is attracted to the transfer drum 5a side, and the image is formed on the other surface of the recording material by the above-described image forming process.

As in the prior art, a transfer cleaner 14 is provided downstream of the transfer section in the rotation direction of the transfer drum 5a in order to remove toner and fixing oil attached to the recording material carrying sheet 5f of the transfer drum 5a. I have. A backup brush 15 facing the transfer cleaner 14 is provided inside the supporting sheet 5f at that position.

In this embodiment, as shown in FIG. 2, the transfer cleaner 14 is of a web type provided with a web 14c as a cleaning member in order to also remove oil, and the web cleaner pulled out from one roller 14a is used. 14c
Is wound around the other roller 14b. In the middle of the transfer sheet, the transfer sheet 5 is pressed by the pressing roller 14d.
The toner and oil on the transfer sheet 5f are cleaned while being rubbed against the transfer sheet 5f. The web 14b used in this embodiment is made of the following nonwoven fabric.

Fiber material of nonwoven fabric: Synthetic fiber of nylon and polyester Fiber thickness: 90% of average thickness of 4 μm and 10 μm or less in thickness Fiber density of nonwoven fabric: 0.17 g / cm ³ Average spacing between fibers: 2.5 μm Non-woven fabric thickness: 500 μm

By cleaning using the web 14c made of such a nonwoven fabric, the oil on the transfer sheet 5f was almost completely removed.

As the fibers of the nonwoven fabric constituting the web 14c, in addition to the above, fibers using polypropylene, rayon, acrylic, nylon, polyester, vinylon alone, and synthetic fibers thereof can be used. And there was no significant difference in cleaning performance.

The fiber density of the nonwoven fabric is 0.005 to
0.80 g / cm ³ , preferably 0.1 to 0.5 g / c
m ³ , and the oil removal ability was excellent in this range.

When the above-mentioned various fibers are woven into a cloth instead of a non-woven fabric, uneven wiping of the oil occurs in the weaving direction.
The range of the setting condition was narrow, which was not preferable.

The nonwoven fabric is composed of an oil removal layer and an oil absorption layer.
It can be formed in a layer, whereby the oil absorption performance can be improved.

The cleaning member is not a strip-shaped web,
A non-woven fabric provided in a roller shape may be used, and such a roller-shaped cleaning member has an advantage that the transfer cleaner can be simplified as compared with a web-type cleaning member.

FIG. 3 is a diagram showing an image forming sequence to which cleaning control is added according to the present embodiment. FIG.
(A) and (b) show the case of the present invention, in which the distance (transfer material circumferential length) L1 along the circumferential direction of the surface of the transfer sheet 5f of the transfer material P shown in FIG. At a distance (transfer-to-cleaning unit distance) L2 along the circumferential direction of the transfer sheet 5f in the downstream direction of rotation of the transfer drum 5a from the transfer unit where the transfer drum 1 and the transfer drum 5a are opposed to the transfer cleaner 14. FIG. 3A shows a case where L1 is longer than L2, and FIG. 3B shows a case where L1 is shorter than L2. FIG. 3C shows a conventional case where the distance L1 is longer than the distance L2.

The transfer drum 5a has a diameter of 180 mm,
At this time, the distance L2 between the transfer section and the cleaning section is 270.
mm.

In FIG. 3A, during the rotation of the transfer drum 5a during the transfer operation of the final color toner image (black toner image (K)), the transfer material is rotated without being separated from the transfer drum while being carried. Thereafter, when the transfer material passes through the transfer portion again, the transfer material is separated, and during the rotation of the transfer drum at the time of the separation, the cleaning operation of the transfer cleaner 14 is performed, and the transfer sheet 5 is removed.
Clean f. That is, since the transfer sheet 5f is cleaned after the transfer of the final color toner image, the transfer sheet is cleaned while preventing a color shift without applying a shock due to the cleaning to the transfer of the final color toner image. can do.

In FIG. 3B, during the rotation of the transfer drum 5a during the transfer operation of the final color toner image, the operation of separating the transfer material from the transfer drum and the operation of cleaning the transfer cleaner 14 are performed. In contrast, in FIG. 3C, the separation operation is performed during the rotation of the transfer drum 5a during the transfer operation of the final color toner image, but the cleaning operation of the transfer cleaner 14 is not performed during the rotation, and the next operation is performed. This is performed while the transfer drum is rotating.

As described above, by controlling the transfer cleaner 14 to clean the transfer sheet 5f in the sequence shown in FIG. 3A, the length L1 of the transfer material in the circumferential direction is larger than the distance L2 between the transfer portion and the cleaning portion. The transfer sheet can be cleaned while preventing color misregistration.

Embodiment 2 FIG. 4 is a block diagram showing another embodiment of the image forming apparatus of the present invention. In the first embodiment, the transfer sheet 5f is cleaned by using one web-type transfer cleaner 14 as the transfer cleaner. However, the web-type cleaner or the roller-type cleaner rubs strongly on the transfer sheet. Since the life of the transfer sheet is shortened, it is not preferable to remove the toner and the fixing oil with one cleaner. Cleaning by rubbing is necessary to remove oil, but if only toner is removed,
This is possible with relatively weak cleaning such as a fur brush.

In this embodiment, as shown in FIG. 4, a fur brush type transfer cleaner 16 for removing toner is used.
Was provided with a web-type transfer cleaner 18 for removing oil. A backup brush 15 is provided for these cleaners 16 and 18 with the transfer sheet 5f interposed therebetween.
The web-type transfer sheet cleaner 18 installed for oil removal is basically the same as that used in the first embodiment. For oil removal, a roller-type cleaner may be used.

Web type cleaner 18 for removing oil
Is preferably operated only during double-sided image formation in order to rub the surface of the transfer sheet 5f, and is used in combination with a fur brush type transfer cleaner 16 for removing toner in order to prevent clogging with toner. Is preferred.

In this embodiment, the distance L2 between the transfer section and the cleaning section in the present invention is different from the transfer sheet 5
The distance f is set to the distance from the transfer section facing the photosensitive drum 1 to the position of the transfer cleaner 16 for removing the toner.

The image forming sequence in this embodiment is as follows.
The description is omitted because it is the same as in the first embodiment. The present invention is also effective when two transfer cleaners are installed in this way,
Even when the transfer material circumferential length L1 is longer than the transfer portion-cleaning portion distance L2, the transfer sheet 5f can be cleaned while preventing color shift.

Embodiment 3 When the peripheral length of the transfer drum 5a is twice or more the length of the transfer material, the throughput (processing amount) at the time of continuous image formation
To speed up image formation, a method of forming an image by carrying two or more transfer materials on a transfer drum has been implemented, but the present invention can be applied to such a case.

In this case, the length L1 of the transfer material in the circumferential direction is defined as a distance between the front end of the first transfer material and the rear end of the last transfer material among a plurality of transfer materials simultaneously supported on the transfer drum 5a. Set the distance to FIG. 5 is a diagram for explaining this. Two transfer materials P1 and P2 are carried on the transfer drum 5a. The length L1 in the circumferential direction of the transfer material is from the leading end P1a of the first transfer material P1 to the rear end of the second transfer material P2. P
2b, and includes the sheet interval between the rear end P1b of the transfer material P1 and the front end P2a of the transfer material P2.

FIG. 6 is an image forming sequence to which the cleaning control according to the present embodiment is added. If the transfer material circumferential distance L1 is longer than the transfer portion-cleaning portion distance L2, both of the transfer materials P1 and P2 are transferred from the transfer drum during rotation of the transfer drum during the transfer operation of the final color toner image. The transfer material is rotated while being held without being separated. Thereafter, the transfer material is separated when the sheet passes through the transfer portion again, and the cleaning operation of the transfer cleaner 14 is performed during the rotation of the transfer drum at the time of the separation. The case of forming images on both sides is the same as in Examples 1 and 2.

As described above, by employing the sequence of the transfer cleaner shown in FIG. 6, two transfer materials are simultaneously carried, and the length L1 in the circumferential direction of the transfer material is larger than the distance L2 between the transfer portion and the cleaning portion. The transfer sheet can be cleaned while preventing color misregistration.

[0055]

As described above, in the image forming apparatus according to the present invention, the distance (L1) of the transfer material along the circumferential direction of the surface of the transfer material carrier is equal to the transfer material carrier from the transfer section to the cleaning section. When the distance is longer than the distance (L2) along the circumferential direction of the surface, the transfer material is separated from the transfer material carrier during rotation of the transfer material carrier during the transfer of the final color toner image of the toner images of each color. The transfer device is rotated while being held without being separated, and thereafter, the transfer material is separated when it passes through the transfer unit again, and the cleaning operation of the cleaning device is performed during rotation of the transfer material carrier at the time of the separation. And thereby
The transfer material carrier can be cleaned without applying a shock due to cleaning to the transfer of the final color toner image. Further, in the image forming apparatus of the present invention, when the distance (L1) is shorter than the distance (L2), the rotation of the transfer material carrier during the transfer of the final color toner image among the toner images of the respective colors is performed. Then, the transfer material is separated, and a cleaning operation of the cleaning device is performed during rotation of the transfer material carrier at the time of the separation. That is, when the distance (L1) is shorter than the distance (L2), even if the cleaning is performed during the rotation of the transfer material carrier where the transfer material is separated immediately after the transfer of the final color, the cleaning shock is not generated. No effect on transcription is apparent. Therefore, according to the present invention, with the above configuration, the transfer material after the transfer can be quickly discharged out of the apparatus, and high throughput can be maintained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image forming apparatus of the present invention.

FIG. 2 is a schematic diagram illustrating a transfer cleaner that cleans a transfer sheet of a transfer drum of the image forming apparatus of FIG. 1;

FIG. 3 is a diagram showing an image forming sequence in which cleaning control is added in the image forming apparatus of FIG. 1;

FIG. 4 is a configuration diagram showing another embodiment of the image forming apparatus of the present invention.

FIG. 5 is an explanatory diagram showing two transfer materials carried on a transfer drum of the image forming apparatus of FIG. 4;

FIG. 6 is a diagram illustrating an image forming sequence in which cleaning control is added in the image forming apparatus of FIG. 4;

FIG. 7 is a schematic configuration diagram illustrating an example of a conventional image forming apparatus.

FIG. 8 shows a circumferential length L1 of a transfer material carried on a transfer drum of an image forming apparatus and a distance L between a transfer unit and a cleaning unit.
FIG. 4 is an explanatory diagram showing a relationship with 2.

[Explanation of symbols]

 Reference Signs List 1 photosensitive drum 5 transfer device 5a transfer drum 5f transfer sheet 9 fixing device 14, 16, 18 transfer cleaner 14a web

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI G03G 21/14 G03G 21/00 310 (72) Inventor Satoshi Tamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-3-68971 (JP, A) JP-A-4-166875 (JP, A) JP-A-4-204957 (JP, A) JP-A-4-18585 (JP, A) JP-A-59-45480 (JP, A) JP-A-3-68975 (JP, A) JP-A-5-188796 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15 / 00 G03G 15/01 G03G 15/14-15/16 G03G 21/00 G03G 21/10 G03G 21/14

Claims (3)

(57) [Claims] An image bearing member on which a toner image of each color is sequentially formed, and a transfer material on which a toner image of each color is sequentially superimposed and transferred at a transfer portion facing the image bearing member, and rotated. By doing so, the transfer material is carried by the transfer material carrier that repeatedly conveys the transfer material to the transfer unit, and the cleaning unit that faces the transfer material carrier on the downstream side in the rotation direction of the transfer material carrier. And a cleaning device for cleaning the surface of the transfer material carrier, wherein the distance (L1) of the transfer material along the circumferential direction of the surface of the transfer material carrier is from the transfer unit to the cleaning unit. Is longer than the distance (L2) along the circumferential direction of the surface of the transfer material carrier of the transfer material carrier during the rotation of the transfer material carrier during the transfer of the final color toner image of the toner images of the respective colors. Lumber The transfer material is rotated while being held without being separated from the transfer material carrier, and thereafter, the transfer material is separated at the time when the transfer material passes through the transfer portion again. When the cleaning operation of the cleaning device is performed, and the distance (L1) is shorter than the distance (L2), the rotation of the transfer material carrier during the transfer of the final color toner image of the respective color toner images is performed. An image forming apparatus, wherein the transfer material is separated and a cleaning operation of the cleaning device is performed while the transfer material carrier is rotating at the time of separation. 2. A plurality of transfer materials are simultaneously carried on a transfer material carrier, and a distance (L1) of the transfer material along a circumferential direction of a surface of the transfer material carrier is equal to a distance (L1) of the plurality of transfer materials. 2. The image forming apparatus according to claim 1, wherein the distance is set to a distance from a leading end of the first transfer material to a trailing end of the last transfer material. 3. The transfer material to be separated is a double-sided transfer material in which a toner image of each color is transferred to one surface and fixed, and then a toner image of each color is also transferred to the other surface. 3. The image forming apparatus according to claim 1, wherein the transfer of the final color toner image is a transfer of a final color toner image of the respective color toner images transferred to the other surface.