JP3065688B2 - 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 an electrophotographic type or an electrostatic recording type, and more particularly to a method for holding a visible developed image (toner image) formed on an image carrier on a transfer material carrier. The present invention relates to an image forming apparatus that electrostatically transfers the image to a transferred transfer material.

[0002]

2. Description of the Related Art In a color electrophotographic copying machine, for example, a transfer drum having a structure in which a transfer material support member, usually a support sheet such as a high-resistance film, is wound around a drum-shaped frame is used as a transfer material support member. A transfer material is supplied to the transfer drum and wound. During this winding, the transfer material is fixed and held on the support sheet by electrostatically applying an attractive force between the support sheet and the transfer material.

In addition, mechanical deformation of the carrier sheet due to the contact of the cleaning member when cleaning the carrier sheet, and distortion of the carrier sheet due to deformation of the carrier sheet caused by electrostatic force due to electrification of the carrier sheet. A correction means for removing the transfer sheet is provided, so that the transfer material supplied to the support sheet from the transfer material supply means is closely supported on the support sheet without any gap. In addition. An elastic support member such as an elastic sheet is used for the correcting means, and the support sheet is pressed and held from inside the support sheet.

[0004] In the process of rotating the transfer drum a plurality of times with respect to the transfer material closely contacted as described above, a plurality of color toner images are electrostatically transferred from the image carrier to the transfer material by multiple transfer. This transfer operation is performed by disposing a corona charging device on the back of the carrier sheet, or by disposing a conductive roller that is in contact with the transfer material held on the carrier sheet, and opposing the toner image to the transfer material. This is done by applying a polar charge. Thereafter, the electrostatic attraction force (Coulomb force) generated between the transfer material and the support sheet is weakened by using a corona discharger to separate the transfer material from the support sheet, and the blade is moved between the transfer material and the support sheet. The transfer material is inserted between them to separate the transfer material.

[0005]

However, the pressing member, which is the means for correcting the distortion of the support sheet in the above-mentioned conventional example, has a configuration in which the support sheet is pressed and held from the inside. Since the holding sheet is deformed if pressed and held at all times, a pressing release unit of the distortion correcting unit is provided, and the correcting operation is performed only during image formation. For this reason, it is necessary to incorporate the pressure releasing means of the distortion correcting means inside the transfer drum, and there are disadvantages such as an increase in the size of the transfer drum, an increase in cost, and complicated control.

Accordingly, an object of the present invention is to eliminate the necessity of incorporating a pressing release means of a pressing member, which is a distortion correcting means, inside the transfer material carrier, thereby making it possible to reduce the size and cost of the transfer material carrier, and An object of the present invention is to provide an image forming apparatus with a simplified control system.

[0007]

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention provides an image carrier for carrying an image, a transfer material carrier for carrying a transfer material, and a method for electrostatically attracting the transfer material to the transfer material carrier at a suction position. A first pressing member that presses the back surface of the transfer material carrier at a position, and electrostatically transfers an image on the image carrier to a transfer material that is adsorbed and carried on the transfer material carrier. In the image forming apparatus, the image forming apparatus includes a second pressing member that presses the surface of the transfer material carrier, and the second pressing member is operated by the first pressing member while the transfer material carrier is stopped. An image forming apparatus is characterized in that a pressed position of the transfer material carrier is pressed.

According to one embodiment of the present invention, the image forming apparatus has a cleaning unit for cleaning a surface of the transfer material carrier, and the second pressing member is a transfer material cleaned by the cleaning unit. It contacts the surface of the carrier.

According to another embodiment of the present invention, when the transfer material is attracted to the transfer material carrier, the second pressing member presses the transfer material against the transfer material carrier. According to another embodiment, the second pressing member is a roller.

[0010]

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

FIG. 1 is a schematic sectional view showing a first embodiment of an image forming apparatus according to the present invention, in which the present invention is applied to an electrophotographic color copying machine. This color copying machine has an image carrier, that is, a photosensitive drum 1 which is rotatably supported at its center and rotates in the direction of the arrow, and an image forming means is arranged on the outer peripheral portion thereof. This image forming means may be any means. In this example, a primary charger 2 for uniformly charging the photosensitive drum 1 and a light image color-separated at a predetermined timing or a light beam L corresponding thereto are charged to the photosensitive drum. An optical system 3 including, for example, a laser beam scanning device, which forms an electrostatic latent image on the photosensitive drum 1 by forming an image on the surface of the photosensitive drum 1; 4 and a secondary charger 5 are sequentially provided in the rotation direction of the photosensitive drum 1.

In the present embodiment, the developing device 4 is a horizontally movable developing device which moves in a tangential direction in opposition to the outer peripheral surface of the photosensitive drum 1, and includes, for example, a magenta developer, a cyan developer, and a yellow developer. Four developing devices 4M, 4C, 4 for separately storing four color developers of a developer and a black color developer, respectively.
Y, 4BK. This horizontally movable developing device 4
Transports a desired developing device to a position facing the outer peripheral surface of the photosensitive drum 1 by a moving mechanism (not shown) in response to irradiation of a light image of a selected color by the optical system 3 or light beam L corresponding thereto. The electrostatic latent image on the photosensitive drum 1 is developed by electrostatically flying a developer, that is, a toner, to form a toner image of a selected color.

The toner image formed on the photosensitive drum 1 is
The image is transferred to the transfer material P carried and transported by the transfer material carrier. In this embodiment, the transfer material carrier is a rotatably supported transfer drum 6, which is positioned in the rotation direction of the photosensitive drum 1 and is in contact with the surface of the photosensitive drum 1, or The photosensitive drum 1 is slightly opposed to the photosensitive drum 1. The transfer drum 6 may have the same configuration as the transfer drum used in the above-described conventional image forming apparatus, for example, and is formed by winding a support sheet 6a for supporting a transfer material between both cylindrical end frames in a cylindrical shape. It has the following configuration. Further, at a transfer position facing the photosensitive drum 1, a transfer corona charger 7 facing the photosensitive drum 1 facing the back surface (surface opposite to the holding surface) of the support sheet 6a is provided.

The transfer drum 6 is driven to rotate in the direction of the arrow in the figure, and a corona charger 19 for suction is provided on the upstream side of the transfer position where the corona charger 7 is disposed, toward the back surface of the supporting sheet 6a. Conductive rollers 20 are arranged on the holding surface side opposite to the suction corona charger 19 with the sheet 6a interposed therebetween. The conductive roller 20 also functions as a deformation preventing member for preventing deformation of the support sheet 6a, as described later, and is configured to be able to abut / release the transfer drum 6 by appropriate contact / separation means.

On the other hand, on the downstream side of the transfer position, two corona dischargers 10 and 11 for removing electricity are arranged with the carrier sheet 6a interposed therebetween. Pressing rollers 12 and 13 for separating the material P from the supporting sheet 6a are disposed with the supporting sheet 6a interposed therebetween, and a separating blade 14 is disposed near the holding surface on the holding surface side. Further downstream, a brush roller 15 as a cleaning means for cleaning the supporting surface of the supporting sheet 6a and, if necessary, a corona discharger for removing an adhesive force (residual Coulomb force and van der Waals force). Alternatively, a brush type static eliminator 16 is provided.

As shown in FIG. 1, around the photosensitive drum 1, a static eliminator 2 for removing electrostatic charges on the surface of the photosensitive drum 1 is provided.
7. A cleaning blade 28 for removing residual toner is provided. If necessary, the separation blade 14
A corona discharger 29 may be installed in the vicinity of, for the purpose of preventing the image from being disturbed due to the peeling discharge occurring when the transfer material P is separated from the supporting sheet 6a, and performing an AC corona discharge.

The transfer material P separated from the carrier sheet 6a by the separation blade 14 is sent to a fixing device 18 including a pair of fixing rollers by a conveyor 17, where the toner image on the transfer material P is fixed.

A guide for guiding the transfer material P sent from the paper supply unit to the suction position via a pair of registration rollers 21, immediately upstream of the suction corona charger 19 and the conductive roller 20. 22 are provided.

In the present embodiment, at the suction position where the leading end of the transfer material P is sucked to the support sheet 6a, the distortion correcting means 23 constituted by an elastic support member such as an elastic sheet of 150 μm, for example, is used. The support sheet 6a is pressed and held from the inside in order to correct or prevent mechanical deformation by the brush roller 15 or the like or electrostatic deformation by the corona charger 19. The distortion correcting means 23 as the first pressing member
Is preferably applied in the direction in which the support sheet 6a is stretched, that is, in the direction opposite to the direction in which the support sheet 6a moves, whereby the thrust direction of the support sheet 6a (the direction orthogonal to the tangential direction). Can be reduced. It is also possible to regulate the circumferential discharge distribution of the corona charger 19. As described above, the conductive roller 20, which is the second pressing member, which also functions as a deformation preventing member for preventing deformation of the support sheet 6a, is at the position shown by the solid line in FIG.
That is, when not in use, the device can be retracted to the position shown by the dotted line in FIG. The operation of the conductive roller 20 will be described later.

FIG. 2 is a block diagram of a control device for controlling the operation of the image forming apparatus shown in FIG. After turning on the power of the image forming apparatus, the CPU 200 controls the image forming apparatus according to a control program stored in the ROM 201. RA
M202 functions as a work area (work area) of the CPU 200, and an area for storing various control data is backed up so as to retain its contents even when the power is turned off. The operation unit 203 can set various modes of the image forming operation. An analog-to-digital converter (A / D) 204 converts an analog input signal from a potential sensor (not shown) or a fixing thermistor that detects the temperature of the fixing roller into a digital signal, and converts the analog input signal into a digital signal.
0 is output to perform necessary control. The high voltage control circuit 205 controls a high voltage output to be supplied to the above-described corona charger 19 for adsorption, corona dischargers 10 and 11 for static elimination in accordance with a control signal from the CPU 200. An input / output device (I / O) 206 controls input / output signals of a load, a sensor, and the like of the image forming apparatus. As typical examples, for example, a motor driving unit 207 that drives the transfer drum 6 and the photosensitive drum 1, a conductor A control signal is supplied to a conductive roller driving unit 208 for bringing the roller 20 into contact with and releasing from the transfer drum 6, a registration roller driving unit 209 for driving the registration roller 21 for synchronously feeding the transfer material P to the suction position, and the like. I do.

Next, a control mode of the image forming apparatus according to the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIG.

When the power is turned on and the CPU 200 starts control, the pre-exposure lamp (not shown) is turned on, the primary charger 2, the secondary charger 5, and the neutralizer 27 are turned on, and the photosensitive drum 1 is electrically operated. And the cleaning blade 28
To remove residual toner. Simultaneously with this operation, the static eliminators 10 and 11 are urged to release the contact of the conductive roller 20 with the supporting sheet 6a, so that the transfer drum 6 is also electrically neutralized by the static eliminators 10 and 11, and the brush is removed. The transfer drum 6 is cleaned by the roller 15 and the brush type static eliminator 16 (block S300). Thereafter, the conductive roller drive unit 208 is operated, and the conductive roller 20 is again brought into contact with the cleaned support sheet 6a (the position indicated by the solid line in FIG. 1).
(Block S301). Thereby, the correction means 23
Of the carrier sheet 6a is canceled, and deformation of the carrier sheet 6a until the start of the copying operation is prevented. That is,
The conductor roller 20 functions as a deformation preventing member for the supporting sheet 6a.

Next, the temperature of the fixing roller 18 is detected by a fixing thermistor (not shown), and the process waits until the temperature reaches a predetermined temperature at which fixing is possible (block S302). Operation unit 203
Is instructed to start the image forming operation (block S3).
03), the developing device used, the transfer material size, etc. determined from the color mode set by the operation unit 203 are temporarily stored in the RAM 202, and the image forming operation is started. At this time, the conductive roller 20 that is in contact with the support sheet 6a is turned off to prevent the deformation of the support sheet 6a (block S3).
04). Thereafter, the motor driving unit 207 is operated to rotate the transfer drum 6 and the photosensitive drum 1 (block S30).
5). Next, as a pre-stage of the image forming operation, a pre-rotation process of removing the charge of the transfer drum 6 is performed to ensure the potential control and the suction operation of the photosensitive drum 1 (block S30).
6). Then, the transfer material P is fed from a paper supply unit (not shown) (block S307), and waits until the registration roller rotation timing so that the position of the development material and the transfer material described later match (block S308).

At a predetermined timing, the registration roller driving unit 2
09 to release the registration rollers 21 and 21 (block S309), and to operate the conductive roller drive unit 208 to bring the conductive roller 20 into contact with the supporting sheet 6a as shown by the solid line in FIG. Block S310),
This enables the transfer material P to be attracted. Here, the transfer material P sent out by the registration rollers 21 and 21 is electrostatically adsorbed and held on the support sheet 6a by the corona charger 19 (block S311). At this time, the latent image forming operation on the photosensitive drum 1 and the subsequent developing operation are started almost simultaneously.

The latent image forming operation is performed while the surface of the photosensitive drum 1 is uniformly charged by the primary charger 2 while the optical system 3
By exposing the required image.
For example, when a color image that has passed through the green filter is first irradiated, an electrostatic latent image mainly composed of a magenta component of the color image is formed on the photosensitive drum 1. In synchronization with the feeding of the latent image, the developing device 4 performs a horizontal movement in a tangential direction with respect to the photosensitive drum 1, and a developing device 4M containing magenta developer is arranged at a position facing the photosensitive drum 1. As a result, the magenta developer (toner) flies electrostatically and adheres to the latent image, and the developing operation is performed. As a result, a magenta toner image is formed on the photosensitive drum 1 (block S312). In this case, the registration rollers 21, 21
Is synchronized with the timing of latent image formation by the optical system 3 so that they coincide at the transfer position. At this transfer position, the corona charger 7 for transfer is operated to generate a transfer electric field, and an electric charge is applied to the carrier sheet 6a, so that the applied electric charge causes the toner image developed on the photosensitive drum 1 to be transferred. Toner is transfer material P
The toner image adheres to the upper surface and the toner image is transferred (block S313).

After the toner remaining on the photosensitive drum 1 is neutralized by the neutralizer 27, it is removed by the cleaning blade 28, and the surface of the photosensitive drum 1 is cleaned. On the other hand, the transfer material P adsorbed on the support sheet 6a moves with the rotation of the transfer drum 6 while carrying the transferred toner image, and passes between the corona dischargers 10 and 11,
At this time, the corona dischargers 10, 11 are not energized. The pressing rollers 12, 13 are also separated from the supporting sheet 6a, the brush roller 15 and the corona discharger or the brush type static eliminator 16 are also separated from the supporting sheet 6a, and the conductive roller 20 is also attracted. Since the operation has been completed, the transfer material P is separated from the support sheet 6a (blocks S314 and S315), so that the transfer material P does not disturb the toner image on the transfer material P supported by the Coulomb force without disturbing the corona charger 19 and the conductor. The sheet passes through the space between the rollers 20 and is again sent to the transfer position. Note that the urging of the corona charger 19 and the contact operation of the conductive roller 20 with the transfer material P
Since the toner image is completed before the leading end of the toner image reaches the positions of the corona charger 19 and the conductive roller 20, no charge for suction is applied to the transfer material P when the toner image passes between them. Further, since the image formation with the magenta developer has been completed before the leading end of the toner image reaches the transfer position, the optical system 3 has already irradiated the photosensitive drum 1 with a color image passed through a red filter, A latent image is formed, and the developing device 4 shifts the developing device so that the corresponding developing device 4C faces the photosensitive drum 1. Accordingly, the latent image on the photosensitive drum 1 is applied to the cyan developer (toner).
As a result, a cyan toner image is formed on the photosensitive drum 1. For this reason, at the transfer position, the toner image formed by the cyan developer is transferred on the toner image formed by the magenta color developer that has already been transferred.

In this manner, the optical system 3 sequentially applies the green filter, the red filter, and the blue filter to form a latent image obtained by color separation of the same image on the photosensitive drum 1 a predetermined number of times, and the developing device 4 A developer corresponding to this, that is, a magenta color developer, a cyan color developer, and a yellow color developer is supplied to the photosensitive drum 1 from each of the developing units 4M, 4C, and 4Y to form a desired color image as a whole. is there. It is needless to say that the order of applying the filter and the developer can be appropriately selected as needed.

After the last toner image, in this embodiment, the toner image formed by the yellow developer is transferred onto the transfer material P (block S316), the corona chargers 10, 1
When the transfer material P passes between the charging devices 1
0 and 11 are energized to perform charge elimination.
2, 13 are actuated and pressed against the support sheet 6a,
The curvature of the support sheet 6a at this portion is increased to assist in the separation of the transfer material P from the support sheet 6a. In addition, the separating blade 14 comes into contact with or approaches the support sheet 6a to separate the leading end of the transfer material P from the support sheet 6a (block S317), and sends the transfer material P to the fixing device 18 via the conveyor 17 so that the transfer material P The multiply-transferred toner image is fixed (block S318). At the time of separation, it is preferable to urge the corona discharger 29 to prevent image disturbance due to peeling discharge.

These series of image forming operations are repeated for the required number of sheets (block S319). When the required number of images have been formed, the surface of the carrier sheet 6a from which the transfer material P has been separated is cleaned by the brush roller 15 after the rotation. Is performed (block S320). At this time, if the residual toner maintains an electrostatic adhesion, cleaning is not sufficiently performed, so that a corona discharger or a brush type static eliminator 16 is used.
To remove the electrostatic adhesion force, so that cleaning can be performed effectively. Thereafter, the motor is stopped (block S321), the conductive roller 20 is again brought into contact with the carrier sheet 6a that has been cleaned (block S322), and the carrier sheet 6a by the distortion correcting means 23 until the next image forming operation. To prevent deformation.

When the developing unit 4BK of the black developer is opposed to the photosensitive drum 1 without using the filter in the optical system 3, normal black-and-white copying is performed. In this case, since the transfer is performed only once, the operation of each component corresponding to the last image formation in color copying is performed. If necessary, a black toner image may be formed by a white exposure and a black developer in the final stage of the color image developing process, and the black toner image may be further superimposedly transferred on the multi-transferred color image.

In this embodiment, the distortion correcting means 23
Before the transfer material P is electrostatically attracted and held on the support sheet 6a, the unevenness of the support sheet 6a is corrected,
In addition, when the transfer drum is not performing an image forming operation, the conductive roller 20 is operated to operate the transfer sheet 6a.
To prevent deformation of the carrier sheet 6a due to the pressing of the distortion correcting means 23 during this time, so that an attracted state that causes a local gap does not occur, and therefore, jamming or transfer loss occurs. There is no danger of causing. As described above, in the present embodiment, there is no need to provide a unit for releasing the pressing of the distortion correcting unit 23, and therefore, the transfer drum 6
There are advantages such as miniaturization and cost reduction, and simplification of the control system.

FIG. 4 is a schematic sectional view showing a second embodiment of the image forming apparatus according to the present invention. As in the first embodiment, the present invention is applied to an electrophotographic color copying machine. Is shown. In this embodiment, a supporting sheet deformation preventing member 30 is further added to the configuration of the first embodiment, and the other components are the same as those of the first embodiment. Therefore, detailed description thereof will be omitted.

When the carrier sheet deformation preventing member 30 is actuated, it moves to the position shown by the solid line in FIG.
It is configured to absorb the pressing force of the elastic supporting member 3 on the supporting sheet 6a. During image formation, the toner image is retracted to the position shown by the dotted line in FIG. 4 so as not to disturb the toner image transferred onto the transfer material P. By providing the carrier sheet deformation preventing member 30, the deformation of the carrier sheet 6a by the distortion correcting means 23 when the transfer drum 6 stops can be more reliably prevented.

Hereinafter, the control mode of the second embodiment of the present invention will be described with reference to the flowchart of FIG. Parts corresponding to those in the flowchart of FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted unless necessary.

When the power is turned on and the CPU 200 starts the control, the pre-exposure lamp (not shown) is turned on, the primary charger 2, the secondary charger 5, and the neutralizer 27 are turned on, and the photosensitive drum 1 is electrically operated. And the cleaning blade 28
To remove residual toner. Simultaneously with this operation, the static eliminators 10 and 11 are urged, and the supporting sheet deformation preventing member 30
The contact of the transfer drum 6 with the carrier sheet 6a is released, the transfer drum 6 is also electrically discharged by the charge removers 10 and 11, and the transfer drum 6 is cleaned by the brush roller 15 and the brush type charge remover 16 (block S300). Next, the carrying sheet deformation preventing member 30 is again brought into contact with the cleaned carrying sheet 6a (the position indicated by the solid line in FIG. 4), and the conductive roller 20 remains off (retreats to the position indicated by the dotted line in FIG. 4). (Block S500). Thus, the carrier sheet deformation preventing member 30 cancels the pressing of the distortion correcting means 23 on the carrier sheet 6a, and prevents the carrier sheet 6a from being deformed until the start of the copying operation.

Next, the temperature of the fixing roller 18 is detected by a fixing thermistor (not shown), and the process waits until the temperature reaches a predetermined temperature at which fixing is possible (block S302). Operation unit 203
Is instructed to start the image forming operation (block S3).
03), the developing device used, the transfer material size, etc. determined from the color mode set by the operation unit 203 are temporarily stored in the RAM 202, and the image forming operation is started. At this time, the carrier sheet deformation preventing member 30 that has been in contact with the carrier sheet 6a is retracted (the position indicated by the dotted line in FIG. 4) to prevent the carrier sheet 6a from deforming (block S501). Thereafter, the motor driving unit 207 is operated to rotate the transfer drum 6 and the photosensitive drum 1 (block S305).

Thereafter, the same operation as in the flowchart for the first embodiment of FIG. 3 is performed up to block S321. After the motor is stopped in block S321, the carried sheet deformation preventing member 30 is again applied to the carried sheet 6a that has been cleaned. (Block S502), and the carrier sheet 6a by the distortion correcting means 23 until the next image forming operation is performed.
To prevent deformation.

In this embodiment, the distortion correcting means 23
Before the transfer material P is electrostatically attracted and held on the support sheet 6a, the unevenness of the support sheet 6a is corrected,
In addition, when the transfer drum is not performing an image forming operation, the carrier sheet deformation preventing member 30 having a shape capable of contacting the surface of the carrier sheet 6a with a large area is brought into contact with the carrier sheet 6a, and the distortion during this time is reduced. Since the deformation of the supporting sheet 6a due to the pressing of the correcting means 23 is prevented, the supporting sheet 6a can be more reliably formed than when the conductive roller 20 is also used as the supporting sheet deformation preventing member as in the first embodiment. Deformation can be prevented, and the adsorption state of the transfer material that causes a local gap is completely prevented.
Therefore, also in the present embodiment, there is no need to provide a means for releasing the pressing of the distortion correcting means 23, so that the size and cost of the transfer drum 6 can be reduced, and the control system can be simplified. There is. The size, shape, and the like of the support sheet deformation preventing member 30 are not limited to those shown in the drawings.

In the above embodiment, the case where the present invention is applied to an electrophotographic color copying machine has been described. However, the present invention is applicable to various copying machines such as an electrophotographic system and an electrostatic recording system having a configuration other than the embodiment. The present invention is equally applicable to an image forming apparatus such as a printer. Needless to say, various modifications and changes can be made to the configuration, control mode, and the like of the image forming apparatus and the control system as needed.

[0040]

As described above, the present invention provides an image carrier for carrying an image, a transfer material carrier for carrying a transfer material,
A first pressing member for pressing the back surface of the transfer material carrier at the suction position when the transfer material is electrostatically attracted to the transfer material carrier at the suction position, and transferring the image on the image carrier; An image forming apparatus for electrostatically transferring a transfer material adsorbed and supported on a material carrier has a second pressing member that presses the surface of the transfer material carrier, while the transfer material carrier is stopped. Since the second pressing member is configured to press the position of the transfer material carrier pressed by the first pressing member, (1) the transfer material carrier is deformed by the first pressing member, It is possible to prevent the occurrence of transfer omission due to the occurrence of a local gap between the transfer material and the transfer material carrier. (2) Since the transfer material is not attracted at all so as to cause a local gap, paper jam due to deformation of the transfer material carrier can be prevented without providing a means for releasing the pressing of the first pressing member. The size and cost of the transfer material carrier can be reduced, and the control system can be simplified. And so on.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a block diagram of a control device for controlling the operation of the image forming apparatus according to the first embodiment of the present invention shown in FIG.

FIG. 3 is a flowchart illustrating a control mode of the image forming apparatus according to the first exemplary embodiment of the present invention illustrated in FIG.

FIG. 4 is a schematic sectional view showing a second embodiment of the image forming apparatus according to the present invention.

FIG. 5 is a flowchart illustrating a control mode of the image forming apparatus according to the second exemplary embodiment of the present invention illustrated in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Corona charger 3 Optical system 4 Developing device 6 Transfer drum 6a Carry sheet 19 Corona charger 20 Conductor roller 23 Strain correction means 30 Carrier sheet deformation prevention member

Claims (4)

(57) [Claims] An image carrier that carries an image; a transfer material carrier that carries a transfer material; and a transfer material carrier that is electrostatically attracted to the transfer material carrier at a suction position. A first pressing member for pressing the back surface of the transfer material carrier,
An image forming apparatus for electrostatically transferring an image on the image carrier to a transfer material adsorbed and carried on the transfer material carrier, comprising: a second pressing member for pressing a surface of the transfer material carrier. An image forming apparatus, wherein the second pressing member presses the position of the transfer material carrier pressed by the first pressing member while the transfer material carrier is stopped. 2. The image forming apparatus according to claim 1, further comprising a cleaning unit configured to clean a surface of the transfer material carrier, wherein the second pressing member contacts the surface of the transfer material carrier cleaned by the cleaning unit. The image forming apparatus according to claim 1, wherein: 3. The image forming apparatus according to claim 1, wherein the second pressing member presses the transfer material against the transfer material carrier when the transfer material is attracted to the transfer material carrier. . 4. The image forming apparatus according to claim 1, wherein the second pressing member is a roller.