JPH05158358A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the deformation of a transfer material carrier caused by a deformation correcting means for correcting the deformation of the transfer material carrier which holds and fixes a transfer material by actuating the deformation correcting means only as necessary. CONSTITUTION:A corona charger 19 and a conductive roller 20 are arranged inside and outside the carrier sheet 6a of a transfer drum 6, respectively, so that the transfer material P fed is attracted and held by the carrier sheet 6a, and a deformation correcting means 23 consisting of an elastic suporting member such as an elastic sheet is provided inside the sheet 6a adjacently to the upstream side of the corona charger 19, and the means 23 is allowed to abut on the inside of the sheet 6a, pressed and held as necessary so as to correct or prevent the deformation of the sheet 6a. The means 23 is constituted to move to a position where it abuts on the sheet 6a at the time of operation by a proper contacting/separating means and retreat to a position where it is separated from the sheet 6a at the time of non-operation. Thus, the deformation of the sheet 6a caused by the pressing of the means 23 is effectively prevented.

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 or a printer such as an electrophotographic system or an electrostatic recording system,
The present invention relates to, but is not limited to, an image forming apparatus that electrostatically transfers a visible developed image (toner image) formed on an image carrier to a transfer material held on a transfer material carrier. ..

[0002]

2. Description of the Related Art For example, in a color electrophotographic copying machine, a transfer drum having a drum-shaped frame around which a transfer material carrying member, usually a carrying sheet such as a high resistance film, is wound is used as a transfer material carrying body. A transfer material is supplied to and wound around this transfer drum. During this winding, electrostatic attraction is exerted between the carrier sheet and the transfer material, or the tip of the transfer material is mechanically pinched by a gripper provided on a part of the transfer drum to transfer the transfer material. Is fixed and held on the carrier sheet.

Further, mechanical deformation of the carrying sheet due to abutment of a cleaning member when cleaning the carrying sheet, and distortion of the carrying sheet due to deformation of the carrying sheet caused by electrostatic force due to charging of the carrying sheet, etc. Distortion correcting means for removing the transfer material is provided so that the transfer material supplied from the transfer material supplying means to the carrying sheet is carried in close contact with the carrying sheet without a gap.

In the process in which the transfer drum is rotated a plurality of times with respect to the transfer material thus held in close contact, toner images of a plurality of colors are electrostatically transferred from the image carrier to the transfer material by multiple transfer. In this transfer operation, a corona charging device is provided on the back surface of the carrier sheet, or a conductor roller that contacts the transfer material held on the carrier sheet is provided so that the transfer material is opposite to the toner image. This is done by applying a polar charge. After that, in order to separate the transfer material from the carrier sheet, a corona discharger is used to weaken the electrostatic attraction force (Coulomb force) generated between the transfer material and the carrier sheet, and the blade is used to separate the transfer material and the carrier sheet. The transfer material is separated by inserting in between.

[0005]

However, the distortion correcting means of the carrier sheet in the above-mentioned conventional example has a structure for releasing the distortion correcting means only by pressing and holding the carrier sheet from the inside or the outside. Therefore, the strain correcting means always applies force to the carrying sheet. Therefore, when the machine is not used for a long time, the carrier sheet is deformed. This means that the distortion correcting means originally intended to remove the distortion of the carrying sheet will reversely generate distortion,
It was extremely inconvenient.

Therefore, an object of the present invention is to prevent deformation of the carrying sheet by the distortion correcting means by operating the distortion correcting means for removing the distortion of the carrying sheet of the transfer material carrying body only when necessary. It is to provide a forming device.

[0007]

The above object is achieved by an image forming apparatus according to the present invention. In summary, the present invention is an image configured to electrostatically transfer a visible developed image formed on an image carrier to a transfer material carried on an endless traveling transfer material carrier. In the forming apparatus, the tip of the transfer material supplied from the transfer material supply means is provided at or near a position where the tip of the transfer material is held and fixed on the transfer material holding surface of the transfer material carrier, and charge is applied to the transfer material carrier. Charge applying means, a distortion correcting means provided adjacent to the charge applying means for correcting the distortion of the transfer material carrier, and the distortion correcting means selectively contacting the transfer material carrier. And an contacting / separating unit for separating the image forming apparatus from each other.

[0008]

Embodiments of the present invention will be described in detail below 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, showing the case where 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 an arrow, and an image forming means is arranged on the outer peripheral portion thereof. This image forming means may be any means, but in the present example, the pre-exposure lamp 30 for neutralizing and initializing the photosensitive drum 1 and the primary charger 2 for uniformly charging the photosensitive drum 1 are used.
And an optical image color-separated at a predetermined timing or a light ray L corresponding thereto is formed on the surface of the photosensitive drum 1 to form an electrostatic latent image on the photosensitive drum 1, for example, a laser beam scanning device. An optical system 3 including the above, a developing device 4 for converting the electrostatic latent image on the photosensitive drum 1 into a visible image, and a secondary charger 5 are sequentially provided in the rotating direction of the photosensitive drum 1.

In the present embodiment, the developing device 4 is a horizontally movable developing device which faces the outer peripheral surface of the photosensitive drum 1 and moves in a tangential direction. For example, a magenta developer, a cyan developer, and a yellow developer. Four developing devices 4 for separately storing four color developers (toners) of color developer and black developer
It is equipped with M, 4C, 4Y and 4BK. This horizontal movement type developing device 4 corresponds to the irradiation of the optical image of the selected color or the light ray L corresponding thereto by the optical system 3, and moves a desired developing device to the outer periphery of the photosensitive drum 1 by a moving mechanism (not shown). The electrostatic latent image on the photoconductor drum 1 is developed by electrostatically flying the developer, that is, toner, by electrostatically transporting the developer to a position facing the surface so that a toner image of a selected color is formed. It is configured.

The toner image formed on the photosensitive drum 1 is transferred to the transfer material P carried and carried by the transfer material carrier. In this embodiment, the transfer material carrier is a transfer drum 6 which is rotatably supported.
Is located in the rotation direction of the photoconductor drum 1 and
The surface of the photosensitive drum 1 is in contact with or slightly separated from the surface of the photosensitive drum 1. The transfer drum 6 may have, for example, a configuration similar to that of the transfer drum used in the above-described conventional image forming apparatus, and a carrying sheet 6a carrying a transfer material is cylindrically wound between both end frames. It has a configuration. At the transfer position facing the photoconductor drum 1, a transfer corona charger 7 facing the back surface (the surface opposite to the holding surface) of the carrying sheet 6a and facing the photoconductor drum 1 is provided. There is.

The transfer drum 6 is rotationally driven in the direction of the arrow in the figure, and an adsorption corona charger 19 is provided toward the back surface of the carrying sheet 6a upstream of the transfer position where the corona charger 7 is arranged, and is also carried. Conductor rollers 20 are arranged on the holding surface side so as to face the attraction corona charger 19 with the sheet 6a interposed therebetween.

On the other hand, on the downstream side of the transfer position, two corona dischargers 10 and 11 for eliminating static electricity are arranged with the carrying sheet 6a interposed therebetween, and the transfer held by the carrying sheet 6a is provided downstream thereof. Pressing rollers 12 and 13 for separating the material P from the carrying sheet 6a are provided with the carrying sheet 6a interposed therebetween, and a separating blade 14 is provided near the holding surface side in the vicinity thereof. Further downstream is a brush roller 15 for cleaning the carrying surface of the carrying sheet 6a.
And, if necessary, a corona discharger or a brush type charge eliminator 16 for removing the adhesion force (residual Coulomb force and van der Waals force) is provided.

As shown in FIG. 1, a static eliminator 27 for removing electrostatic charges on the surface of the photosensitive drum 1 and a cleaning blade 28 for removing residual toner are arranged around the photosensitive drum 1. In addition, if necessary, a corona discharger 29 is installed near the separating blade 14 for the purpose of preventing image disturbance due to peeling discharge that occurs when the transfer material P is separated from the carrying sheet 6a. AC corona discharge is recommended.

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

Directly upstream of the suction corona charger 19 and the conductor roller 20, a guide for guiding the transfer material P sent from the paper feeding section to a suction position via a pair of registration rollers 21, 21. 22 is provided.

In this embodiment, at the adsorption position where the tip of the transfer material P is adsorbed to the carrying sheet 6a, the strain correcting means 23 composed of an elastic supporting member such as an elastic sheet having a thickness of 150 μm is used as the carrying sheet. The carrier sheet 6a is provided on the inner side of 6a, and in order to correct or prevent mechanical deformation by the brush roller 15 or deformation by electrostatic force by the corona charger 19, the carrying sheet 6a is selectively pressed and held from the inside. Further, the distortion correcting means 23 can be retracted to a position shown by a solid line in FIG. 1 when operating and to a position shown by a dotted line in FIG. 1 when not operating, that is, when not in use, by an appropriate contacting / separating means not shown. It is configured. It is preferable that the elastic force of the strain correcting means 23 acts in the direction in which the carrying sheet 6a is stretched, that is, in the direction opposite to the moving direction of the carrying sheet 6a, whereby the thrust direction of the carrying sheet 6a (tangential line). The strain in the direction orthogonal to the direction can be reduced. It is also possible to regulate the circumferential discharge distribution of the corona charger 19.

On the other hand, the conductor roller 20 is in the position shown by the solid line in FIG. 1 in contact with the transfer drum 6 during operation, and is in the position shown by the dotted line in FIG. 1 away from the transfer drum 6 when not in operation, that is, when not in use. It is configured to be able to evacuate to. The operation mode of the conductor 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. The CPU 200 controls the image forming apparatus according to the control program stored in the ROM 201 after the image forming apparatus is powered on. RA
The M202 functions as a work area (work area) of the CPU 200, and the area for storing various control data is backed up so as to retain the contents even when the power is turned off. The operation unit 203 can set various modes of the image forming operation. An analog-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 to convert the analog signal into a CPU 20.
It is output to 0 and the necessary control is performed. The high-voltage control circuit 205 controls the high-voltage output supplied to the adsorption corona charger 19, the static elimination corona dischargers 10, 11 and the like described above according to the control signal from the CPU 200. An input / output device (I / O) 206 controls an input / output signal such as a load or a sensor of the image forming apparatus, and as a typical example, a motor drive unit 207 that drives the transfer drum 6 or the photoconductor drum 1, a conductive unit. A conductor roller driving unit 208 that abuts and releases the body roller 20 on the transfer drum 6, and a correction unit driving unit 2 that abuts and releases the distortion correcting unit 23 on the transfer drum 6.
A control signal is supplied to 09 or the like.

Next, the control mode of the image forming apparatus of 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 30 is turned on and the primary charger 2
The secondary charger 5 and the static eliminator 27 are turned on to electrically neutralize the photosensitive drum 1, and the cleaning blade 28 removes the residual toner. Simultaneously with this operation, the correction means driving unit 209 is turned on, the distortion correction means 23 comes into contact with the transfer drum 6, and the transfer drum 6 is also electrically neutralized by the urging of the static eliminators 10 and 11, and the brush roller The transfer drum 6 is cleaned by 15 and the brush type static eliminator 16 (block S300). After that, the correction means drive unit 208 is turned off to retract the distortion correction means 23 to the position shown by the dotted line in FIG. 1 so that no force acts on the cleaned carrier sheet 6a (block S301). The distortion correcting unit 23 is configured to be held at the retracted position shown by the dotted line away from the transfer drum 6 while the power is off, that is, when the correcting unit driving unit 209 is off.

Next, the temperature of the fixing roller 18 is detected by a fixing thermistor (not shown), and the process waits until a predetermined fixing temperature is reached (block S302). Operation unit 203
When the start of the image forming operation is instructed from (block S3
03), the developing device used, the transfer material size and the like 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. Next, in order to validate the distortion correcting means 23, the correcting means driving unit 209 is turned on, and the correcting means 23 is brought into contact with the carrying sheet 6a.
Is moved to the solid line position (block S304). After that, the motor driving unit 207 is operated to rotate the transfer drum 6 and the photosensitive drum 1 (block S305). Then
As a pre-stage of the image forming operation, a pre-rotation process for eliminating the charge on the transfer drum 6 is performed in order to ensure the potential control of the photosensitive drum 1 and the suction operation (block S306). And
The transfer material P is fed from a paper feeding unit (not shown) (block S3
07), and waits until the registration roller rotation timing so that the position of the developing material and the position of the transfer material described later match (block S3).
08).

Registration rollers 21 and 2 at a predetermined timing
1 is released (block S309), the conductor roller driving unit 208 is operated to move the conductor roller 20 to the position shown by the solid line in FIG. 1 and contact the carrier sheet 6a (block S310), and the transfer material P is transferred. Enables suction operation. Here, the transfer material P sent out by the registration rollers 21, 21 is electrostatically carried by the corona charger 19 by the carrying sheet 6.
It is adsorbed and held by a (block S311). At this time,
Almost at the same time, the latent image forming operation for the photosensitive drum 1 and the subsequent developing operation are started.

The latent image forming operation is performed by exposing a desired image by the optical system 3 in a state where the surface of the photosensitive drum 1 is uniformly charged by the primary charger 2. For example, when a color image that has first passed through the green filter is 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 transfer of the latent image, the developing device 4 horizontally moves in the tangential direction with respect to the photosensitive drum 1, and the developing device 4M containing the magenta developer is arranged at a position facing the photosensitive drum 1. Therefore, the magenta developer (toner) electrostatically flies and adheres to the latent image, and as a result of the developing operation, a magenta toner image is formed on the photosensitive drum 1 (block). S312). In this case, the timing of feeding the registration rollers 21 and 21 and the timing of latent image formation by the optical system 3 are synchronized with each other so that they coincide with each other at the transfer position. At this transfer position, the transfer corona charger 7 is actuated to generate a transfer electric field, and charges are applied to the carrying sheet 6a, so that the applied charge causes the toner image developed on the photosensitive drum 1 to be developed. Toner adheres on the transfer material P, and the toner image is transferred (block S313).

The toner remaining on the photosensitive drum 1 is discharged by the static eliminator 27 and then removed by the cleaning blade 28 to clean the surface of the photosensitive drum 1.
On the other hand, the transfer material P adsorbed to the carrying 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 dischargers 10, 11 are not energized. Further, the pressing rollers 12 and 13 are also the supporting sheet 6
a), the brush roller 15 and the corona discharger or the brush type static eliminator 16 are also separated from the carrying sheet 6a, and the conductor roller 20 has also completed the adsorption operation, so Since they are separated (blocks S314 and S315), the transfer material P passes between the corona charger 19 and the conductor roller 20 and is transferred again without disturbing the toner image on the transfer material P carried by Coulomb force. Sent to the location. The urging of the corona charger 19 and the contact operation of the conductor roller 20 with the transfer material P are completed before the tip of the toner image on the transfer material P reaches the positions of the corona charger 19 and the conductor roller 20. Therefore, the electric charge for adsorption is not given to the transfer material P when passing through this period. Further, since the image formation with the magenta color developer is completed before the front end of the toner image reaches the transfer position, the optical system 3 has already irradiated the color image that has passed through the red filter onto the photosensitive drum 1. ,
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. Therefore, the cyan developer (toner) electrostatically flies and adheres to the latent image on the photosensitive drum 1, and the developing operation is performed. As a result, a cyan toner image is formed on the photosensitive drum 1. It Therefore, at the transfer position, the toner image of the cyan color developer is transferred in a state of being superimposed on the toner image of the magenta color developer that has already been transferred.

In this way, the optical system 3 sequentially applies the green filter, the red filter, and the blue filter to sequentially form the latent images which are color-separated for the same image a predetermined number of times on the photosensitive drum 1, and the developing device 4 Supplies the corresponding developers, that is, the magenta color developer, the cyan color developer and the yellow color developer from the developing devices 4M, 4C and 4Y to the photoconductor drum 1 to form a desired color image as a whole. To do. Needless to say, the order of applying the filter and the developer can be appropriately selected as necessary.

Then, after the final toner image, in the present embodiment, the toner image of the yellow developer is transferred onto the transfer material P (block S316), the corona chargers 10 and 1 are used.
When the transfer material P passes between 1 and 1, the charger 1
0 and 11 are energized to eliminate static electricity and press roller 1
2, 13 are actuated and pressed against the carrier sheet 6a,
The curvature of the carrying sheet 6a at this portion is increased to assist the peeling of the transfer material P from the carrying sheet 6a. Further, the separating blade 14 comes into contact with or comes close to the carrying sheet 6a to separate the leading end of the transfer material P from the carrying sheet 6a (block S317), and sends it to the fixing device 18 via the conveyer 17 so as to be on the transfer material P. The multiple-transferred toner image is fixed (block S318). At the time of separation, it is preferable that the corona discharger 29 is energized to prevent the image from being disturbed due to peeling discharge.

The series of image forming operations are repeated for the required number of sheets (block S319), and when the required number of image forming operations are completed, the transfer material P is separated and the carrying sheet 6a is separated.
After the surface of is cleaned by the brush roller 15, a rotation process is performed (block S320). At this time, if the residual toner maintains the electrostatic adhesive force, the cleaning is not sufficiently performed, so the corona discharger or the brush type static eliminator 16 is used to remove the electrostatic adhesive force. So that cleaning can be performed effectively. After that, the motor is stopped (block S321), the distortion correcting means 23 is retracted to the position indicated by the dotted line in FIG. 1 again (block S322), and the retracted position is maintained until the next image forming operation is started. This prevents deformation of the carrying sheet 6a due to.

When the developing unit 4BK for developing the black color developer is opposed to the photosensitive drum 1 in the developing device 4 without using a 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 final image formation in color copying is performed. Further, if necessary, a black toner image may be formed by white exposure and a black developer in the final stage of the color image developing process, and the black toner image may be further superimposed and transferred to the color image transferred in multiple.

In this embodiment, the distortion correcting means 23
However, in the previous stage of electrostatically attracting and holding the transfer material P to the carrying sheet 6a, the uneven deformation of the carrying sheet 6a is corrected,
Since it does not cause a suction state that causes a local gap, it causes a suction failure or jamming (paper jam).
Can be effectively prevented, and therefore, it is possible to prevent deterioration of image quality such as transfer omission, deterioration of color reproducibility, and deterioration of the carrying sheet. Further, since the strain correcting means 23 is configured to contact the carrying sheet 6a and press and hold the carrying sheet 6a only during the operation, the deformation of the carrying sheet 6a due to the pressing of the distortion correcting means 23 is effectively prevented. As a result, it is possible to effectively prevent improper adsorption of the transfer material and jamming, and it is possible to prevent transfer failure, deterioration of image quality such as deterioration of color reproducibility, and deterioration of the carrying sheet.

Although the elastic supporting member is used as the strain correcting means 23 in the above embodiment, it is needless to say that the strain correcting means may be constituted by other constitutions or materials.

FIG. 4 is a schematic sectional view showing the essential parts of 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. The case where it is applied is shown. In the present embodiment, a pair of rollers 24 and 25 are arranged near the upstream and downstream of the corona charger 19 and inside the transfer drum 6 as the distortion correcting means, and the conductive roller 20 carries the carrying sheet 6a. It also has a function as a strain correcting means for preventing deformation of the. These rollers 24 and 25 and the conductor roller 20 are moved to the position shown by the solid line in FIG.
Further, when not in operation, that is, when not in use, it is configured to be held at the position shown by the dotted line in FIG.

The rollers 24 and 25 serve to correct the irregular deformation of the carrying sheet before the transfer material P is received and adsorbed on the carrying sheet 6a, and the conductive roller 20 is shown in FIG. As shown in the drawing, the transfer material P is formed in a crown shape having a diameter difference a between the center portion and the end portion in the axial direction, and the transfer material P introduced between the carrying sheet 6a and the conductor roller 20 is The carrier sheet 6a is adsorbed from the central portion. Therefore, the distortion is pushed out to the periphery, and the electrostatic attraction between the carrying sheet 6a and the transfer material P can be favorably realized. According to the experiment, the diameter difference a is 50 μm.
Even within m to 1 mm, the adsorption failure can be almost eliminated.

Since the operating modes of the rollers 24, 25 and 30 are the same as those of the first embodiment described above with reference to FIG. 3, the description thereof will be omitted. Further, since other configurations are the same as those of the first embodiment, corresponding parts are designated by the same reference numerals and the description thereof will be omitted. Further, in the present embodiment, the conductor roller 20 is grounded, but it may be connected to a voltage applying means such as a bias power source to form a charge applying means together with the corona charger 19.

FIG. 6 is a schematic sectional view showing an essential part of a third embodiment of the image forming apparatus according to the present invention. Like the first embodiment, the present invention is applied to an electrophotographic color copying machine. The case where it is applied is shown. In this embodiment, the distortion correcting means is constituted by a pair of rollers 31 and 32 which are arranged to face each other with the carrying sheet 6a in between immediately upstream of the electrostatic attraction means composed of the corona charger 19 and the conductor roller 20. Is. The rollers 31, 32 and the conductor roller 20 are moved to the position shown by the solid line in FIG. 6 during operation, and are held at the position shown by the dotted line in FIG. 6 when not in operation, that is, when not in use. There is.

The pair of rollers 31 and 32 correct the distortion of the carrier sheet 6a due to mechanical or electrostatic force, and bring the transfer material P fed from the transfer material supplying means into close contact with the corrected carrier sheet 6a. And serves to feed between the corona charger 19 and the conductor roller 20. Of course, at least one of the rollers 31 and 32 may be formed in the crown shape as described above.

Also in the present embodiment, the rollers 31, 32 as such a correction means act so that the gap between the transfer material P and the carrying sheet 6a is actually maintained at 50 μm or less, and the suction failure occurs. It did not wake up, and it also prevented jamming.

In each of the above embodiments, the case where the present invention is applied to an image forming apparatus having a structure in which a transfer sheet is electrostatically adsorbed to a carrying sheet has been described. It is needless to say that the present invention can be applied to an image forming apparatus having a structure in which a sheet is fixedly held on a carrying sheet. Further, in each of the above embodiments, the case where the present invention is applied to an electrophotographic color copying machine is shown, but the present invention is applicable to various copying machines such as an electrophotographic method and an electrostatic recording method having configurations other than the embodiments. It is equally applicable to image forming apparatuses such as printers. Further, it goes without saying that various modifications and changes can be made to the configuration, control mode, etc. of the image forming apparatus and the control system as necessary.

[0039]

As described above, the image forming apparatus according to the present invention is provided with the distortion correcting means for preventing the deformation of the transfer material carrier, which is disposed at or near the position where the transfer material is supplied. Except when necessary, for example, at least when the transfer material carrier is stopped, the transfer material carrier is kept retracted to a release position away from the transfer material carrier, and the pressing force of the distortion correcting means is not applied to the transfer material carrier. As a result, the transfer material is not adsorbed to a local gap. Therefore, it is possible to reliably prevent improper adsorption of the transfer material and jamming (paper jam) due to the deformation of the transfer material carrier, and prevent deterioration of image quality such as transfer omission and deterioration of color reproducibility and deterioration of the transfer material carrier. Therefore, there is a remarkable effect that a high-quality image without image distortion can always be obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-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 that controls 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 embodiment of the present invention shown in FIG.

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

5 is a front view showing a conductor roller of the image forming apparatus of the second embodiment of the present invention shown in FIG.

FIG. 6 is a schematic sectional view showing a main part of a third embodiment of the image forming apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 2 Corona charger 3 Optical system 4 Developing device 6 Transfer drum 6a Carrying sheet 19 Corona charger 20 Conductor roller 23 Strain correction means (elastic support member) 24, 25 Strain correction means (pair of rollers) 31, 32 Distortion correction means (pair of rollers)

Claims (4)

[Claims] 1. An image forming apparatus configured to electrostatically transfer a visible developed image formed on an image carrier to a transfer material held on a transfer material carrier which travels endlessly. , A charge imparting means for imparting an electric charge to the transfer material carrier, which is provided at or near a position for holding and fixing the tip of the transfer material supplied from the transfer material supply means on the transfer material holding surface of the transfer material carrier. And a strain correcting means that is provided adjacent to the charge applying means and corrects the strain of the transfer material carrier, and selectively displaces the strain correcting means with respect to the transfer material carrier. An image forming apparatus comprising: a contacting / separating unit. 2. The elasticity provided in the inside of the transfer material carrier, wherein the charge applying means is provided inside the transfer material carrier, and the distortion correcting means is provided inside the transfer material carrier adjacent to the upstream side of the charge applying means. The image forming apparatus according to claim 1, wherein the image forming apparatus is a supporting member. 3. The charge applying means is provided inside the transfer material carrier, and the distortion correcting means is provided inside the transfer material carrier adjacent to the upstream side and the downstream side of the charge applying means, respectively. The image forming apparatus according to claim 1, wherein the pair of rollers is provided. 4. The charge applying means is provided inside the transfer material carrier, and the distortion correcting means is disposed adjacent to and upstream of the charge applying means so as to sandwich the transfer material carrier. 2. A pair of rollers as described above.
Image forming device.