JP3377611B2 - 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 such as a copying machine, a facsimile or a printer, and more specifically, a cleaning device for removing the developer adhering to the surface of a transfer belt which conveys a recording material, and The present invention relates to an image forming apparatus provided with a charge control device that makes the charge distribution on the surface of the transfer belt uniform.

[0002]

2. Description of the Related Art As a conventional image forming apparatus, an electrostatic latent image is formed on the surface of a latent image carrier by a well-known electrophotographic process, and the electrostatic latent image is developed by a developing device to form a latent image carrier surface. It is known that a toner image is formed, the toner image is transferred to the surface of a recording material such as recording paper conveyed by a transfer belt by a transfer device, and then fixed by a fixing device to form an image. Here, in the transfer, the recording material is interposed between the transfer belt and the latent image carrier, and a transfer device is generated to generate an electric field in a direction in which the charged toner is electrostatically attracted to the recording material. Gives a charge to the transfer belt.

[0003]

However, according to this apparatus, the developer may adhere to the surface of the transfer belt that conveys the recording paper, and the developer may stain the recording material. In addition, according to this apparatus, the transfer belt surface may be unevenly charged due to the influence of humidity or the like in the apparatus. In this case, even if the transfer belt is uniformly charged by the transfer device so as to generate an electric field in the direction in which the charged toner is electrostatically attracted to the recording material, the transfer belt is transferred due to the uneven charging. The charge distribution on the belt surface becomes uneven. As a result, the electric field acting on the charged toner becomes non-uniform, uneven transfer occurs, and adverse effects such as uneven density occur on the image formed on the surface of the recording material. In a wet type image forming apparatus using a two-component developer including a toner and a carrier or a developer including a one-component developer including a toner as a developer,
Since a toner having a small particle size is used to obtain a high quality image, it is particularly important to keep the charge distribution of the transfer belt uniform. That is, for toner with a small particle size,
This is because the influence of the change in the electric field is easily exerted, so that the image is influenced even by the non-uniform charge distribution of the transfer belt, which has not been a problem in the past. The particle size of the toner used in a normal dry image forming apparatus is usually about 10 μm, whereas the toner having a particle size of 1 μm or less may be used in the wet image forming apparatus.

[0004] The present invention has been made in view of the above problems, purpose of that, when preventing the contamination of the recording material caused by the developer adheres to the surface of the transfer belt together
Another object of the present invention is to provide an image forming apparatus capable of eliminating adverse effects such as uneven density generated in an image formed on the surface of a recording material due to uneven distribution of charges on the surface of the transfer belt.

To achieve the above Symbol purpose SUMMARY OF THE INVENTION, The invention according to claim 1, there image forming apparatus, a latent image carrier on which a latent image is formed, the latent image with a developer A developing device that develops the latent image on the surface of the carrier into a toner image, an endlessly movable transfer belt that conveys the recording material to the vicinity of the developing device, and the recording material between the latent image carrier. A transfer device for transferring an electric field between the latent image carrier and the recording member to transfer the toner image onto the surface of the recording material by applying an electric charge to the transfer belt holding the recording medium; A cleaning device for removing deposits adhering to the transfer belt surface, and a transfer belt drying device for drying the transfer belt surface.
A drying device and a charge distribution on the surface of the transfer belt that is charged by the transfer device to make the charge distribution uniform, downstream of the cleaning device in the rotation direction of the transfer belt, and of the transfer belt of the transfer device. And a charge control device arranged at a position upstream in the rotation direction.

According to a second aspect of the invention, there is provided the image forming apparatus according to the first aspect, characterized in that the charging control device is disposed in the vicinity of the transfer portion.

Further, the invention of claim 3, a picture image forming apparatus, a latent image carrier on which a latent image is formed, with a developer
The latent image on the surface of the latent image carrier is developed into a toner image.
An image device and an endless device that conveys a recording material to the vicinity of the developing device.
Between the movable transfer belt and the latent image carrier,
A charge is applied to the transfer belt that holds the recording material.
An electric field between the latent image carrier and the recording member.
Generated and transferred to transfer the toner image onto the surface of the recording material.
Removes deposits on the copying device and the transfer belt surface
Cleaning device and the transfer device
The charge distribution on the surface of the transfer belt is made uniform,
Downstream of the direction of rotation of the transfer belt with respect to the leaning device
Yes, and the direction of rotation of the transfer belt with respect to the transfer device
The transfer belt is dry at a position upstream.
And a charge control device disposed at a position,
To do .

[0007]

[0008]

[0009]

[0010]

[0011]

In the image forming apparatus of the first to third aspects, when the developer adheres to the surface of the transfer belt, the developer is removed by the cleaning device. Further, in this image forming apparatus, the developer attached to the surface of the transfer belt,
After removing dust and the like by the cleaning device, the charge distribution of the transfer belt is made uniform by the charge control device so that the charge distribution on the transfer belt surface is kept uniform at the transfer portion. Particularly in the image forming apparatus according to claim 1 or 2,
Is wet with the developer from the surface of the latent image carrier.
The transfer belt surface that has become
The charge control unit averages the charge distribution of the dry transfer belt.
Make one

More particularly, in the image forming apparatus according to the second aspect, immediately after the charge control device makes the distribution of charges on the transfer belt surface constant, the portion where the charge distribution on the transfer belt surface is uniform is immediately transferred. To reach.

[0013]

Particularly, in the image forming apparatus according to the third aspect , the surface of the transfer belt which has become wet due to the developer adhering to the surface of the latent image carrier is dried by evaporating it over time. The charge control device provided in the vicinity of the dry transfer belt makes the charge distribution of the transfer belt uniform.

[0015]

[0016]

[0017]

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a copying machine) which is a wet image forming apparatus will be described below. FIG. 1 is a front view showing a schematic configuration of a copying machine according to this embodiment. In this apparatus, in the vicinity of a transport unit 4 including a transfer belt 1, a driven roller 2, a drive roller 3 and the like, a recording paper 5 as a recording material that is electrostatically attracted to and transported by the transfer belt 1 is sequentially transferred. A yellow toner image forming unit Y that forms a toner image, a magenta toner image forming unit M, a cyan toner image forming unit C, and a black toner image forming unit B are provided.

The construction of each toner image forming unit Y, M, C, B will be described. However, since the toner image forming units Y, M, C, and B have the same configuration, the description will be given only for the yellow toner image forming unit Y, and for the other toner image forming units, the yellow toner image forming unit is shown in the drawing. For the parts corresponding to those in Y, M, C, and B are added after the numbers given to those in the unit, and the description is omitted. Yellow toner image forming unit Y
Around the photosensitive drum 30Y as the latent image carrier of
A charging device 31Y, an exposure device 32Y, a developing device 33Y, a transfer device 34Y, a charge removing device 35Y, and a cleaning device 36Y are arranged in order to form a yellow toner image on the surface of the photosensitive drum 30Y by an electrophotographic process. Here, the developing device 33Y is a wet developing device that uses, as a developer, a two-component developing solution including a toner and a carrier or a one-component developing solution including a toner. Also,
The transfer device 34Y includes the photosensitive drum 30Y and the transfer belt 1.
The recording paper 5 which is interposed between the photosensitive drum 3 and the recording paper 5 is
It is composed of a transfer charger which gives electric charges to the transfer belt 1 so as to generate an electric field in a direction in which the toner image formed on the 0Y surface is electrostatically attracted.

A first transport guide plate for supplying a recording paper 5 as a recording material to the transfer belt 1 from a paper feeding device (not shown) is provided upstream of the yellow toner image forming unit Y in the rotational direction of the transfer belt 1. 6 is provided. On the other hand, a separation charger 7 for separating the recording paper 5 from the transfer belt 1 is provided downstream of the black toner image forming unit B in the rotation direction of the transfer belt 1. The separation charger 7 removes electricity from the transfer belt 1 and the recording paper 5,
By weakening the electric attraction between the transfer belt 2 and the recording paper 5, the recording paper 5 is separated from the surface of the transfer belt 2 due to its rigidity. A second transport guide plate 8 for guiding the recording paper 5 separated from the surface of the transfer belt 1 to a fixing device (not shown) is provided near the separating portion.

A first static eliminator 9 as a pre-static eliminator for removing charges remaining on the surface of the transfer belt 1 is provided downstream of the separation charger 7 in the rotational direction of the transfer belt 1. A transfer belt cleaning device 10 for removing the developer, dust, and the like adhering to the surface of the transfer belt 1 is provided downstream of the first static eliminator 9 in the rotational direction of the transfer belt 1. This transfer belt cleaning device 10
A cleaning roller 11 which is provided in contact with the transfer belt 1 and removes a developer and the like from the surface of the transfer belt 1 by rotating at a peripheral speed difference from the transfer belt 1, and an arrow a in FIG.
As shown by (1), it is composed of a fan 12 for generating an air flow toward the surface of the cleaning roller 11 and evaporating the developer adhering to the surface of the cleaning roller 11 to dry the surface. In addition, the cleaning device 1
A second static eliminator 13 for removing charges on the surface of the transfer belt 1 and making the charge distribution on the surface of the transfer belt 1 uniform is provided downstream of the transfer belt 1 in the rotational direction of 0. The second static eliminator 13 is the "charge controller" described in the claims.
And is also a "post-static elimination device" described in the claims. The second static eliminator is a static eliminator charger 14
And a counter electrode 15 provided on the opposite side of the static elimination charger 14 to the transfer belt 1.

The operation of this device configured as described above will be described. In forming an image, a paper feeding device (not shown) feeds the recording paper 5 to the first conveyance guide plate 6,
The conveyance guide plate 6 conveys the recording paper 5 to the surface of the transfer belt 1. The transfer belt 1 attracts the recording paper 5 transported by the first transport guide plate 6 to the surface thereof by the electric charge applied by the transfer device 34Y. Here, the transfer belt 1 is rotated in the direction of arrow b by the rotational force transmitted from the drive roller 3 driven by a drive mechanism (not shown), and the transfer paper 5 is transferred to the toner image forming units Y, M, C, B.
Of the photoconductor drums 36Y, 36M, 36C,
It is conveyed at the same speed as the peripheral speed of 36B.

On the surface of the photosensitive drum 36Y which rotates at the same speed as the transfer belt 1, each device arranged around the photosensitive drum forms a yellow toner image. That is, the charging device 31Y uniformly charges the surface of the photosensitive drum 30Y, the exposure device 32Y forms an electrostatic latent image on the surface of the photosensitive drum 30Y, and the developing device 33Y supplies yellow toner to the electrostatic latent image. Finally, a yellow toner image is formed.
The transfer device 34Y transfers the yellow toner image onto the surface of the recording paper 5 conveyed by the transfer belt 1 to the nip portion NY formed by the transfer belt 1 and the photoconductor drum 30Y. That is, the transfer device 34Y applies an electric charge to the transfer belt 1 to generate an electric field in the vicinity of the nip portion N, and the photosensitive drum 3
6Y transfer the yellow toner image on the surface of the transfer sheet 5
Electrostatically move in the direction to transfer the yellow toner image onto the transfer paper 5. Further, the charge removing device 35 removes the residual charge on the surface of the photosensitive drum 36, and the cleaning device 36
Y removes the yellow toner remaining on the surface of the photosensitive drum 36Y.

The transfer belt 1 transfers the recording paper 5 having the yellow toner image adhered to the surface thereof by the above operation.
Nip portion NM formed by transfer belt 1 and magenta toner image forming unit M, nip portion NC formed by transfer belt 1 and cyan toner image forming unit C, and nip formed by transfer belt 1 and black toner image forming unit B It is sequentially conveyed to the part NB. Then, the magenta toner image forming unit M forms a magenta toner image on the recording paper 5 in the nip portion NM, the cyan toner image forming unit forms a cyan toner image in the nip portion NC, and the nip portion N.
In B, the black toner image forming unit B sequentially transfers the black toner images onto the transfer paper 5, and the toner images are superposed on the surface of the transfer paper 5. The operation of each toner image forming unit M, C, B to form a toner image and the operation of transferring the toner image to the recording paper 5 are the same as the operation of the yellow toner image forming unit Y.

By the above operation, the separating device 7 separates the recording paper 5 on which the four color toner images are superposed from the surface of the transfer belt 1. That is, the separation device 7
Part of the electric charge electrostatically adsorbing the recording paper 5 distributed on the transfer belt 1 is removed, and the electrostatic adsorption force between the transfer belt 1 and the recording paper 5 is weakened. The weakened electrostatic attraction force and the rigidity of the recording paper 5 combine to separate the recording paper from the surface of the transfer belt 1. Then, the recording paper 5 separated from the surface of the transfer belt 1 is conveyed by the second conveyance guide plate 8 to a fixing device (not shown), and the fixing device fixes the toner image on the recording paper. The recording paper 5 on which the fixing is completed is discharged to the outside of the apparatus by a mechanism (not shown).

The portion of the transfer belt 1 from which the recording paper 5 is separated reaches the vicinity of the first static eliminator 9 by the rotation of the transfer belt 1. As described above, the transfer belt 1 is charged with electric charges for transferring the toner images to the recording paper 5 by the transfer devices 34Y, 34M, 34C, and 34B, so that part of the electric charges is separated by the separation charger 7. Although removed, electric charges still remain in the vicinity of the first static eliminator 9. This residual charge electrostatically adsorbs foreign matter such as developer and dust.
If left as it is, it is difficult for the transfer belt cleaning device 10, which will be described in detail later, to remove the foreign matter. Therefore, the first static eliminator 9 removes the electric charges remaining on the surface of the transfer belt 1 by corona charging to remove foreign matters such as developer and dust that have adhered to the surface of the transfer belt 1 during the image formation process. The transfer belt cleaning device 10 facilitates removal.

The portion of the transfer belt 1 from which the residual charge has been removed by the first static eliminator 9 reaches the vicinity of the transfer belt cleaning device 10 by the rotation of the transfer belt 1. The cleaning roller 11 of the cleaning device 10 rotates with a peripheral speed difference from the transfer belt 1 in a state of being in contact with the transfer belt 1 to remove the developer, dust, and the like adhering to the surface of the transfer belt 1. As described above, the electric charge on the surface of the transfer belt 1 is removed to some extent by the first static eliminator, and the force of electrostatically adsorbing foreign matter to the transfer belt 1 is weakened. Foreign matter can be efficiently removed from the surface.

The portion of the transfer belt 1 from which foreign substances such as developer and dust have been removed by the cleaning device 10 reaches the vicinity of the second static eliminator 13 by the rotation of the transfer belt 1. As described above, the charge on the surface of the transfer belt 1 is removed by the first charge removing device 9, so that the charge distribution is once uniform. The charge distribution is only uniform in the presence of foreign matter such as dust. Therefore, when the foreign matter is removed by the cleaning device 10 thereafter, the foreign matter is removed together with the electric charge carried by the foreign matter, so that the transfer belt 1 after the foreign matter is removed.
The charge distribution on the surface becomes non-uniform. Therefore, the second static eliminator 13 is provided in order to make the charge distribution of the transfer belt 1 after the foreign matter is removed uniform. The second static eliminator 13 removes the electric charge distributed on the transfer belt 1 by corona charging the transfer belt 1 after the foreign matter is removed by the static eliminator charger 13, and the transfer belt 1 after the foreign matter is removed. To make the charge distribution uniform. As a result, the unevenly distributed charges on the surface of the transfer belt 1 cause the charged developer to be transferred to the photosensitive drums 36Y and 36Y.
It is possible to prevent an image defect such as density unevenness from occurring by adversely affecting the electric field that is electrostatically moved from M, 36C, and 36B toward the transfer paper 5. (Hereafter, margin)

The state of the electric potential on the surface of the transfer belt 1 of this apparatus, which has been described above, will be described below.
The following description focuses on one point. FIG. 2 is an explanatory diagram showing the state of the potential on the surface of the transfer belt 1. In FIG. 2, the vertical axis represents the potential on the surface of the transfer belt 1, and the horizontal axis represents the transfer belt 1.
Indicates the position of. Here, in order to electrostatically adsorb the charged developer from the photoconductor drums 30Y, 30M, 30C, and 30B to the transfer paper 5, the transfer devices 34Y and 3Y are provided.
4M, 34C, and 34B give positive charges to the transfer belt 1. Based on this, the state of the electric potential of the transfer belt 1 will be specifically described below. As shown in the first potential level 50 in Figure 2, the outer side surface of the transfer belt 1,
After the transfer paper 5 is separated, the potential before the charge removal by the first charge removal device 9 is −800V. Even if the transfer belt cleaning device 10 tries to remove foreign matter such as developer and dust attached to the surface of the transfer belt 1 under the condition of this surface potential, the foreign matter cannot be easily removed because it is electrostatically adsorbed. Therefore, the first charge removal device 9 sets the first charge removal amount 51 to 7
The electrostatic attraction force between the foreign matter and the transfer belt 1 is weakened by removing the static electricity by 00 V and setting the surface potential of the transfer belt 1 to the second potential level 52 of −100 V. In this state, the transfer belt cleaning device 10 The foreign matter is removed.
However, in the state where the charge is removed by the first charge eliminating device (second potential level 52), the potential on the surface of the transfer belt 1 is uniform with the foreign matter adhering to the surface of the transfer belt 1. When the foreign matter is removed, locally uneven potentials are generated. Therefore, the second static eliminator 13 again performs static erasing at 100 V, which is the second static eliminator 53, and changes the potential of the surface of the transfer belt 1 to the third potential level 5.
A local potential nonuniformity is eliminated by setting 0V which is 4. Here, since the non-uniformity of the electric potential on the surface of the transfer belt 1 caused by removing the foreign matter is local,
The non-uniformity is not shown at the second potential level 52 in FIG. Although not shown, the surface potential is 0 V (3rd
The transfer belt 1 having the potential level 54) is given a positive charge for transfer by each of the transfer devices 34Y, 34M, 34C, and 34B, and after passing through the transfer device 34B, minus 400 is applied.
The voltage becomes 0 V, and the separation charger 7 removes the electric charge to weaken the electrostatic attraction of the recording paper 5 to the transfer belt, and the voltage becomes minus 800 V (first potential level 50). Transfer belt 1
Focusing on one point on the surface, the state described above is repeated with the image formation. As is clear from the above description, the static elimination amount of the first static eliminator 9 as the front static eliminator is 70
0V (first charge removal amount 51) is 100V (second charge removal amount) which is the charge removal amount according to the charge removal amount of the second charge removal device as the post charge removal device.
It is larger than the static elimination amount 53).

In addition to the configuration of the embodiment described above, as shown in FIG. 3, a fan 16 as a transfer belt drying device may be provided upstream of the second charge removing device 13 in the rotational direction of the transfer belt 1. . If the fan 16 is provided, by generating an air flow in the direction of arrow c, the developing solution adhering to the surface of the transfer belt 1 can be evaporated and the transfer belt can be dried. Therefore, the function of the second static eliminator is not impaired when the transfer belt 2 is wet with the developer.

Further, as shown in FIG. 3, the second static eliminator 13 in the above-described embodiment is provided with a photosensitive drum 36Y.
From the nip portion NY as a transfer portion where the transfer is performed from the transfer belt 1 to the transfer paper 5, in the rotation direction of the transfer belt 1, and
It may be provided in the immediate vicinity of the nip portion NY. If this configuration is adopted, the portion of the transfer belt 1 where the electric field distribution is made uniform by the second static eliminator 13 immediately reaches the nip portion NY, so that the charge distribution is uniform before reaching the nip portion. The electric charge distribution in the portion where is not affected by humidity or the like does not become non-uniform again. Further, by providing the second static eliminator 13 at this position, even if the transfer belt 1 becomes wet with the developing solution in the vicinity of each toner image forming unit, the portion of the transfer belt 1 wet with the developer becomes the second portion. Before reaching the vicinity of the static eliminator 13, since it has already dried, the second
The function of the static eliminator is not impaired by the fact that the transfer belt surface is wet.

The first static eliminator 9 described above may be provided at the position where the recording paper 5 is separated from the surface of the transfer belt 1, that is, at the position where the separation charger 7 was provided. According to this configuration, since the first static eliminator 9 can be used also as a separation charger, it is not necessary to separately provide a separation charger.

[0033]

Effects of the Invention According to the invention of claims 1 to 3, the developer adhering to the transfer belt surface is removed by the cleaning device, it is possible to prevent the recording material from being contaminated by the developer. Further, according to the present invention, before the transfer device transfers the toner image from the latent image carrier to the recording material, the charge control device makes the charge distribution on the transfer belt surface uniform, so that the charge is transferred to the transfer belt surface. The non-uniform distribution can prevent the occurrence of image defects such as density unevenness caused by the non-uniform electric field that conveys toner from the transfer belt toward the recording material. Further, according to the present invention, after the cleaning device removes the foreign material such as the developer and dust on the transfer belt surface, the charge control device makes the charge distribution on the transfer belt surface uniform, so that the charge on the surface of the transfer belt becomes Unlike the case where the foreign matter adhering to the surface of the transfer belt is removed and transferred as it is after the distribution is made uniform, the charge distribution of the transfer belt once the charge distribution has been made uniform is obtained when the charge carried along with the foreign matter is removed. To
It does not become non-uniform again. Therefore, the charge distribution on the transfer belt after removing the foreign matter becomes nonuniform, and accordingly, the electric field that conveys toner from the transfer belt toward the recording material becomes nonuniform, resulting in image defects such as density unevenness in the image. Can be prevented. Especially in claim 1 or 2
According to this, the transfer belt surface with the developing solution attached is dried.
Dry on the machine and then transfer to the dry transfer plate.
The charging belt keeps the belt constant, so the transfer belt gets wet.
The charging control device is fully functional
It can be prevented from running out. Therefore, the transfer pattern
Once the toner is wet in the transfer area with the developer.
However, the charge control device works well, and the transfer belt surface
Charge distribution can be made uniform, so transfer
Suppress the occurrence of electric field disturbance for transfer in the device,
Therefore, it is possible to prevent the occurrence of image defects on the surface of the recording material.
it can.

More particularly , according to the second aspect of the invention, immediately after the charge control device makes the charge distribution on the transfer belt surface uniform, the portion where the charge distribution on the transfer belt surface is made constant is transferred to the transfer device. Therefore, by the time the transfer belt reaches the transfer device, the charge distribution on the surface of the transfer belt may become non-uniform again due to, for example, the influence of humidity in the image forming apparatus. Can be prevented. Therefore, it is possible to more effectively prevent the electric field for transfer from becoming non-uniform due to the non-uniform charge on the surface of the transfer belt, and the image from being disturbed.

[0035]

Further, in particular, according to the invention of claim 3 , the surface of the transfer belt on which the developing solution is adhered is dried as the developing solution evaporates with the passage of time, and the dried portion is charged. Since it is kept constant by the control device, it is possible to prevent the charging control device from not fully functioning due to the transfer belt being in a wet state. Therefore, even when the transfer belt is in a wet state after passing through the transfer portion, it is dried before it reaches the charging control device, so that it is possible to prevent the occurrence of a defective image on the surface of the recording material as in the third aspect. it can.

[0037]

[0038]

[0039]

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of an electrophotographic copying machine according to an embodiment.

FIG. 2 is an explanatory diagram showing a potential on a surface of a transfer belt of the electrophotographic copying machine shown in FIG.

FIG. 3 is a front view showing a schematic configuration of an electrophotographic copying machine according to a modified example.

[Explanation of symbols]

1 transfer belt 2 driven roller 3 drive roller 4 Transport unit 5 Recording paper 6 First transport guide plate 7 Separation Charger 8 Second transport guide plate 9 First static eliminator 10 Transfer belt cleaning device 11 Cleaning roller 12 fans 13 Second static eliminator 14 Static eliminator charger 15 Counter electrode 16 fans 30 photoconductor drum 31 Charging device 32 exposure equipment 33 Developing device 34 Transfer device 35 Static eliminator 36 Cleaning device 50 First potential level 51 First charge removal amount 52 Second potential level 53 Second charge removal amount 54 Third potential level Y Yellow toner image forming unit M magenta toner image forming unit C Cyan toner image forming unit B Black toner image forming unit NY nip part NM nip part NC nip part NB Nip part

Continuation of front page (56) Reference JP-A-3-179467 (JP, A) JP-A-6-43729 (JP, A) JP-A-6-110288 (JP, A) JP-A-6-3886 (JP , A) JP 6-19369 (JP, A) JP 59-123861 (JP, A) JP 64-44457 (JP, A) JP 63-34573 (JP, A) JP 5-204230 (JP, A) JP-A-4-70783 (JP, A) JP-A-5-273860 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/01 -15/01 117 G03G 15/16 G03G 15/10-15/10 112 G03G 15/11

Claims (3)

(57) [Claims] 1. A latent image carrier on which a latent image is formed, a developing device for developing a latent image on the surface of the latent image carrier with a developing solution to form a toner image, and a recording material near the developing device. Between the latent image carrier and the recording member by applying an electric charge to the transfer belt that holds the recording material between the endlessly movable transfer belt and the latent image carrier. A transfer device for generating an electric field on the transfer material to transfer the toner image onto the surface of the recording material; a cleaning device for removing deposits adhering to the transfer belt surface; and a transfer belt drying device for drying the transfer belt surface.
A uniform charge distribution on the surface of the transfer belt charged by the transfer device, downstream of the cleaning device in the rotation direction of the transfer belt, and the rotation direction of the transfer belt with respect to the transfer device. An image forming apparatus, comprising: a charge control device disposed at a position upstream. 2. The image forming apparatus according to claim 1, wherein the charge control device is disposed in the vicinity of a transfer portion. 3. A latent image carrier on which a latent image is formed, and a toner by developing the latent image on the surface of the latent image carrier with a developer.
ー Move the developing device to form an image and the recording material near the developing device.
The transfer belt that holds the recording material is held between the endlessly movable transfer belt that is conveyed and the latent image carrier.
By applying an electric charge to the transfer belt,
An electric field is generated between the recording material and the recording material to form the toner image.
A transfer device for transferring to the surface of the recording material, and a cleaner for removing adhered matter adhering to the surface of the transfer belt.
Of the transfer belt charged by the transfer device and the transfer device.
The load distribution is uniform with respect to the cleaning device.
Downstream of the transfer belt in the rotation direction, and in the transfer device
On the other hand, at the position upstream of the transfer belt in the rotation direction,
Charging control installed at the dry position of the transfer belt
An image forming apparatus comprising: a device.