JPH10333455A - Image forming device and transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently clean a transfer material carrier, to obtain an image, without staining the backside and to prevent a failure in carrying of separating a transfer paper by providing a transfer material carrier driving control means for controlling conditions for reversely rotating the transfer material carrier. SOLUTION: In the process of forming the image, on image forming time is detected in a main control panel 30. The detected image forming time data is transmitted to a belt driving control panel 18 from the CPU of the main control panel 30. The table of the relational data between the image forming time and a belt reverse rotational amount is stored in the ROM of the belt driving control panel 18. This control panel 18 calculates the belt reverse rotational amount of a transferring/carrying belt 6 rotationally driven in a direction opposite to that at the formation of the image, based on the tiable. A belt driving motor 19 is rotationally driven to obtain the calculated belt reverse rotational amount, to drive a roller 5 on which the transferring/carrying belt 6 is wound, in the direction opposite to that in forming the image. Then, paper powder for instance heaped on a cleaning blade 16A is carried away.

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, a printer and the like, and more particularly, to an image carrier for carrying a toner image and a transfer position facing the image carrier. And a cleaning means for cleaning the surface of the transfer material carrier. The toner image is placed on the transfer paper carried by the transfer material support. The present invention relates to an image forming apparatus that performs transfer by electrically transferring and a transfer apparatus used in the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as a transfer device of this type of image forming apparatus, a transfer paper is held and transported by a transfer material carrier so as to pass through a transfer position facing an image carrier on which a toner image is formed. When the transfer paper passes through the transfer position, a predetermined transfer electric field is generated at the transfer position, and the transfer electric field causes the toner image on the image carrier to be transferred to the transfer paper side, and the toner image is transferred to the transfer paper side. The surface of the transfer material carrier after the transfer to the transfer member is cleaned by a cleaning means (for example, JP-A-8-76680 and JP-A-8-110712).

In the transfer device having the above structure, the transfer paper is carried in contact with the transfer material carrier, so that the paper dust of the transfer paper easily adheres to the transfer material carrier. In the transfer position,
Since the transfer paper is conveyed in contact with the image carrier, the paper dust of the transfer paper easily adheres to the image carrier. When the paper dust adheres to the transfer material carrier and is conveyed to the cleaning blade, which is a means for cleaning the transfer material carrier, a phenomenon occurs in which the paper dust accumulates or bites into the edge of the cleaning blade. At the portion of the cleaning blade edge where the paper dust accumulates or digs in, the toner tends to slip through, and the ability to clean the transfer material carrier is reduced, resulting in poor cleaning. As a result, there arises a problem that the transfer material carrier is stained and the back of the transfer paper is stained. Further, the toner adhering to the transfer material carrier adheres to cracks or the like of the transfer material carrier, causing problems such as transfer paper transfer failure and separation failure.

[0004]

In order to solve the above-mentioned problem, after the image formation is completed, the transfer material carrier is rotated in a direction opposite to the image forming direction while the transfer material carrier is in contact with the image carrier. There is known an image forming apparatus in which the reverse rotation amount of the transfer material carrier is constant. When the number of image formations set as one job by the operation unit of the image forming apparatus or a signal from the outside is about 10 in a row, a small amount of paper dust accumulated or cut into the edge of the cleaning blade can be removed. However, when the number of image formations set as 1 JOB is large, such as 100 or more continuous sheets, a large amount of generated paper dust accumulates or digs in. When the predetermined amount of reverse rotation is performed, the paper dust accumulates or digs into the edge of the cleaning blade. Cannot be removed, causing poor cleaning. Such a problem occurs not only when the cleaning unit is a cleaning blade, but also when the cleaning unit performs cleaning by rubbing the surface of the transfer material carrier.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to remove paper dust deposited or entangled in a cleaning means of a transfer material carrier, and to clean the transfer material carrier satisfactorily. It is an object of the present invention to provide an image forming apparatus which can obtain an image without back contamination and prevent transfer paper transfer failure and separation failure, and a transfer apparatus employed in the image formation apparatus.

[0006]

According to one aspect of the present invention, there is provided an image bearing member for carrying a toner image and a transfer paper passing through a transfer position facing the image bearing member. And a cleaning means for cleaning the surface of the transfer material carrier. The toner image is electrostatically transferred onto transfer paper carried on the transfer material carrier. In an image forming apparatus in which transfer is performed and the transfer paper carrying the transferred toner image is separated from the transfer material carrier, the transfer material carrier is reversed in a direction opposite to that in image formation. And a drive control means for controlling the transfer of the transfer material carrier.

In the image forming apparatus of the present invention, the condition for reversing the transfer material carrier is controlled by the transfer material carrier drive control means. When the amount of paper dust accumulated or entrapped in the cleaning means is small, the reverse rotation of the carrier during transfer is controlled to be small, and a small amount of paper dust accumulated or entrapped in the cleaning means is removed. When the amount of paper dust accumulated or cut into the cleaning means is large, the reverse rotation of the transfer material carrier is controlled so as to remove a large amount of paper dust accumulated or cut into the cleaning means.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, there is provided a reverse rotation amount calculating section for calculating a reverse rotation amount of the transfer material carrier in accordance with the amount of paper dust deposited or cut into the cleaning means. The reverse rotation amount of the transfer material carrier is controlled in accordance with the calculation result of the reverse rotation amount calculation section.

According to the image forming apparatus of the present invention, the reverse rotation amount of the transfer material carrier is calculated by a reverse rotation amount calculating section in accordance with the amount of paper dust deposited or cut into the transfer material carrier cleaning means. The amount of reverse rotation of the transfer material carrier is controlled by the transfer material carrier drive control means so that the transfer amount becomes equal. When the amount of paper dust accumulated or entrapped in the cleaning means is small, the amount of reverse rotation is reduced, and a small amount of paper dust accumulated or entrapped in the cleaning means is removed. When the amount of paper dust accumulated or entrapped in the cleaning unit is large, the amount of reversal is increased to remove a large amount of paper dust accumulated or entrapped in the cleaning unit.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the number of reverse rotations of the transfer material carrier is controlled in accordance with the amount of paper dust deposited or cut into the cleaning means. It is a feature.

In the image forming apparatus of the present invention, the number of reverse rotations of the transfer material carrier is controlled by the transfer material carrier drive control means in accordance with the amount of paper dust deposited or cut into the transfer material carrier cleaning means. . When the amount of paper dust accumulated or entrapped in the cleaning means is small, for example, a small amount of paper dust accumulated or entrapped in the cleaning means is removed by one reverse rotation. When the amount of paper dust accumulated or entrapped in the cleaning means is large, reversal is repeated to remove a large amount of paper dust accumulated or entrapped in the cleaning means.

According to a fourth aspect of the present invention, there is provided an image carrier for carrying a toner image, a transfer material carrier for carrying and transporting a transfer sheet so as to pass through a transfer position opposed to the image carrier, and the transfer member. Cleaning means for cleaning the surface of the material carrier, transferring the toner image electrostatically onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is In an image forming apparatus in which the transfer material carrier is reversed in a direction opposite to the direction of image formation after being separated from the transfer material carrier, a reverse rotation condition of the transfer material carrier is controlled in accordance with a set number of images to be formed in one job. And a transfer material carrier drive control means. Here, one set job indicates a series of image forming operations set by a signal from an operation unit of the image forming apparatus or from outside.

In the image forming apparatus according to the fourth aspect, the control of the reverse rotation condition of the transfer material carrier is performed in accordance with the number of image formation sheets equal to the number of transfer papers carried and carried by the transfer material carrier. The reverse rotation condition of the transfer material carrier can be controlled in accordance with the amount of paper dust accumulated or bitten into the cleaning means. Further, since the set number of images to be formed for one job is the CPU of the main control plate of the image forming apparatus, which is input from the operation unit of the image forming apparatus or a signal from the outside, etc. It is possible to grasp the amount of paper dust that has accumulated or digged in.

According to a fifth aspect of the present invention, there is provided an image carrier for carrying a toner image, a transfer material carrier for carrying and transporting a transfer sheet so as to pass through a transfer position facing the image carrier, and the transfer member. Cleaning means for cleaning the surface of the material carrier, transferring the toner image electrostatically onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is In an image forming apparatus in which the transfer material carrier is reversed in a direction opposite to the direction of image formation after being separated from the transfer material carrier, a reverse rotation condition of the transfer material carrier is controlled according to a set image forming time of one job. And a transfer material carrier drive control means.

In the image forming apparatus according to the present invention, the control of the reverse rotation condition of the transfer material carrier is performed in accordance with the image forming time of the image forming apparatus. In addition, the reverse rotation condition of the transfer material carrier can be controlled. The set image forming time of one job is determined by the CP of the main control plate of the image forming apparatus.
Since the value calculated by U is used, the amount of paper dust accumulated or cut into the cleaning means can be grasped by a simple method.

According to a sixth aspect of the present invention, there is provided an image carrier for carrying a toner image, a transfer material carrier for carrying and transporting a transfer sheet so as to pass through a transfer position facing the image carrier, and the transfer material. Cleaning means for cleaning the surface of the material carrier, transferring the toner image electrostatically onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is In an image forming apparatus in which the transfer material carrier is reversed in a direction opposite to the direction of image formation after being separated from the transfer material carrier, a set number of image formation times or image formation time of one job, and usage history of the cleaning unit And a drive control means for controlling the reverse rotation condition of the transfer material carrier.

According to the image forming apparatus of the present invention, even if the cleaning means deteriorates due to abrasion or the like and the paper dust easily accumulates, the set number of images to be formed per one job or the image forming time can be reduced. Since the reverse rotation condition of the transfer material carrier is controlled according to the use history of the cleaning means, it is possible to control the amount of paper dust accurately.

According to a seventh aspect of the present invention, in the image forming apparatus of the fifth or sixth aspect, the image forming time is a rotation time of the image carrier.

In the image forming apparatus of the present invention, in the step of forming an image according to the set conditions, the image forming apparatus detects the rotation time of the image carrier by the main control plate of the image forming apparatus, And In accordance with the detected rotation time of the image carrier, controlling the reverse rotation of the transfer material carrier,
The paper dust accumulated or bitten into the cleaning means is removed.

According to an eighth aspect of the present invention, in the image forming apparatus of the fifth or sixth aspect, the image forming time is a rotation time of the transfer material carrier.

In the image forming apparatus of the present invention, in the step of forming an image in accordance with the set conditions, the image forming apparatus detects the rotation time of the transfer material carrier by the main control plate, and sets the time as the image forming time. The reverse rotation of the transfer material carrier is controlled in accordance with the detected rotation time of the transfer material carrier, and the paper dust accumulated or cut into the cleaning means is removed.

According to a ninth aspect of the present invention, in the image forming apparatus of the sixth aspect, the use history of the cleaning means is a cumulative number of image formations of the image forming apparatus.

In the image forming apparatus according to the ninth aspect, the cumulative use number of the image forming apparatus is used as the use history of the cleaning means, so that the use history can be grasped by a simple method.

According to a tenth aspect of the present invention, in the image forming apparatus of the sixth aspect, the use history of the cleaning means is the cumulative rotation time of the image carrier. (Hereinafter, margin)

According to a tenth aspect of the present invention, in the step of forming an image in accordance with the set conditions, the image forming apparatus calculates an accumulated rotation time of the image carrier by a main control plate of the image forming apparatus, and performs the cleaning. Use history of means.

According to an eleventh aspect of the present invention, in the image forming apparatus of the sixth aspect, the use history of the cleaning means is the cumulative rotation time of the transfer material carrier.

In the image forming apparatus according to the present invention, in the step of forming an image under the set conditions, the image forming apparatus calculates a cumulative rotation time of the transfer material carrier by a main control plate of the image forming apparatus. The usage history of the cleaning means is used. Since the accumulated rotation time of the transfer material carrier rubbed by the cleaning means is used as the usage history, it is possible to accurately grasp deterioration of the cleaning means such as wear.

According to a twelfth aspect of the present invention, in the image forming apparatus of the first to sixth aspects, after the image forming step is completed,
A toner image is formed on the image carrier to be supplied to the transfer material carrier cleaning means, and the toner image is placed on the transfer material carrier with the image carrier and the transfer material carrier in contact with each other. To form a toner image on the transfer material carrier,
The transfer material carrier is configured to be reversed.

In the image forming apparatus of the present invention, after the image forming step is completed, the toner image formed on the image carrier is transferred onto the transfer material carrier. The toner on the transfer material carrier is transported to the transfer material carrier cleaning means, and is deposited or bites into the cleaning means. Thereafter, the transfer material carrier is reversed, and the transfer material carrier removes the toner and paper dust that have accumulated or bitten into the cleaning means. When the toner and the paper dust are carried away together, the paper dust is easily carried away and the paper dust can be removed satisfactorily as compared with the case where only the paper dust is carried away. Further, in the present image forming apparatus, the reverse rotation condition of the transfer material carrier is controlled according to the amount of paper dust deposited or eroded into the cleaning means, and when the amount of paper dust is large, the reverse rotation of the transfer material carrier is also controlled. More. Generally, as the reverse rotation of the transfer material carrier increases, the cleaning means is more likely to be worn or chipped. However, in the present image forming apparatus, since the toner is positively accumulated or bite into the cleaning unit as described above, it is possible to prevent abrasion or chipping of the cleaning unit due to an increase in reverse rotation.

According to a thirteenth aspect of the present invention, in the image forming apparatus of the twelfth aspect, the step of forming a toner image on the transfer material carrier is performed a plurality of times.

In the image forming apparatus according to the thirteenth aspect, the step of forming a toner image on the transfer material carrier is performed a plurality of times, and the amount of the toner deposited or cut into the cleaning means of the transfer material carrier is increased. Improve the ability to remove paper dust.

According to a fourteenth aspect of the present invention, in the image forming apparatus of the twelfth aspect, a plurality of toner images are formed on the image carrier, and the image carrier and the transfer material carrier are brought into contact with each other. Thus, the plurality of toner images are transferred onto a transfer material carrier to form a toner image on the transfer material carrier.

In the image forming apparatus according to the present invention, toner images are formed in any number of positions corresponding to positions where paper dust easily accumulates in the cleaning means or positions where the cleaning ability is inferior in the axial direction of the image carrier. Then, the plurality of toner images are transferred onto the transfer material carrier, and the toner is selectively deposited or bitten into the cleaning means. By selectively depositing or biting the toner at a position where the paper dust of the cleaning means easily accumulates, or at a position where the cleaning ability is inferior, the paper dust can be satisfactorily removed. In addition, the ability to remove paper dust is increased by forming a plurality of toner images in the rotation direction of the image carrier and increasing the amount of toner deposited or bitten into the cleaning unit.

According to a fifteenth aspect of the present invention, in the image forming apparatus of the twelfth aspect, the image carrier is rotated on the image carrier in accordance with the amount of paper dust deposited or cut into the cleaning means of the transfer material carrier. The present invention is characterized in that a toner image whose length in the direction is variable is formed.

In the image forming apparatus according to the fifteenth aspect, the amount of toner deposited or edged in the cleaning means is changed according to the amount of paper dust accumulated or edged in the cleaning means. In other words, when the amount of paper dust is small, the length of the toner image is shortened, a small amount of toner is deposited or bitten into the cleaning means, and a small amount of paper dust and toner are removed together by the transfer material carrier, Remove paper dust. When the amount of paper dust is large, increase the length of the toner image,
By increasing the amount of toner that accumulates or digs into the cleaning means and removes a large amount of paper dust and toner together with the transfer material carrier, the paper dust can be satisfactorily removed. Further, when the amount of paper dust is large and the amount of reverse rotation of the transfer material carrier is large, abrasion or chipping of the cleaning means is likely to occur. For this reason, by changing the amount of toner that accumulates or bites into the cleaning unit, wear or chipping of the cleaning unit during reverse rotation is prevented.

According to a sixteenth aspect of the present invention, in the image forming apparatus of the twelfth to fifteenth aspects, the toner image is a toner pattern for detecting image density.

In the image forming apparatus of the present invention, a toner image to be deposited or cut into the cleaning means of the transfer material carrier can be formed by using the image density detecting toner pattern forming means of the image forming apparatus. .

According to a seventeenth aspect of the present invention, in the image forming apparatus of the twelfth aspect, a toner image is formed on an image carrier at a position corresponding to a roller or a roller of a sheet feeding device or a sheet conveying device of the image forming device. It is characterized by having comprised so that it may perform.

In the image forming apparatus of the present invention, a toner image is formed on an image carrier at a position corresponding to a roller or a roller of a sheet feeding device or a sheet conveying device of the image forming device, and the toner image is transferred to a transfer material. The transfer material is transferred onto the carrier, and is positively deposited or cut into the cleaning means of the transfer material carrier. In the present image forming apparatus, the transfer paper is rubbed by the rollers of the paper feeder, and the transfer paper is taken out from the paper feed tray or the like. Further, in the paper transport device, the transfer paper is transported in contact with transport rollers and relay rollers. For this reason, a large amount of paper dust is generated at a position corresponding to the roller or the roller of the sheet feeding device or the sheet transport device, and a large amount of paper dust is accumulated or bites into the position of the cleaning unit corresponding to the roller or the roller. Therefore, the toner is positively deposited or bitten into a position corresponding to the roller or the roller of the cleaning means, and the toner and the paper powder are removed together by the transfer material carrier, so that the paper powder deposited or bitten into the cleaning means is removed. Is removed.

According to an eighteenth aspect of the present invention, in the image forming apparatus according to any one of the first to seventeenth aspects, the transfer material carrier is reversed when the transfer material carrier is in contact with the image carrier. It is characterized by having comprised.

In the image forming apparatus according to the eighteenth aspect, after the image formation is completed, the transfer material carrier is reversed in the state where the same transfer material carrier as in the image formation is in contact with the image carrier. The operation of bringing the image carrier into and out of contact with the carrier becomes unnecessary.

According to a nineteenth aspect of the present invention, in the image forming apparatus according to any one of the first to seventeenth aspects, the transfer material carrier is reversed when the transfer material carrier is separated from the image carrier. It is characterized by having done.

According to the image forming apparatus of the present invention, the transfer material carrier reversely rotates in a state where the transfer material carrier and the image carrier are in contact with each other. The attached paper dust does not adhere to the transfer material carrier. Therefore, the next time the transfer material carrier rotates in the same direction as the image formation, the paper dust transferred from the image carrier does not newly accumulate or bite into the cleaning means. Further, the driving torque when the transfer material carrier is reversed is reduced.

The twentieth aspect of the present invention is directed to the first to the first aspects.
In the image forming apparatus according to the ninth aspect, the transfer material carrier is a transfer conveyance belt.

In the image forming apparatus according to the twentieth aspect, a transfer conveyance belt is used as the transfer material carrier. In the transfer conveyance belt, when paper dust accumulated or bitten into the cleaning unit causes cleaning failure, the belt shape is apt to cause a phenomenon that toner adheres to cracks. Therefore, the paper dust accumulated or bitten into the cleaning means is removed to prevent transfer paper transfer failure and separation failure.

According to a twenty-first aspect of the present invention, there is provided a transfer material carrier for carrying and transporting transfer paper so as to pass through a transfer position facing an image carrier on which an image to be transferred is formed, and the transfer material carrier. Cleaning means for cleaning the surface of the body, wherein the transfer paper carrying the transferred image is separated from the transfer material carrier, and then the transfer material carrier is rotated in the reverse direction to the image forming direction. A transfer material carrier drive control means for controlling the reverse rotation condition of the material carrier is provided.

In the transfer apparatus of the present invention, the condition for reversing the transfer material carrier is controlled by the transfer material carrier drive control means. When the amount of paper dust accumulated or entrapped in the cleaning means is small, the reverse rotation of the carrier during transfer is controlled to be small, and a small amount of paper dust accumulated or entrapped in the cleaning means is removed. When the amount of paper dust accumulated or cut into the cleaning means is large, the reverse rotation of the transfer material carrier is controlled so as to remove a large amount of paper dust accumulated or cut into the cleaning means.

[0048]

DETAILED 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) as an image forming apparatus will be described below. First, the configuration and operation of the entire copying machine will be described with reference to FIG. A charging device 21, an exposure device, a developing device 22, a transfer device 23, a photoconductor cleaning device 2 are provided around the photoconductor 3 as an image carrier.
4 and a static eliminator 25 are provided. After the photoconductor is uniformly charged by the charging device 21, the photoconductor is irradiated with light from the exposure device to form an electrostatic latent image. This electrostatic latent image is developed by the developing device 22 to form a toner image as a visible image. This toner image is electrostatically transferred onto transfer paper by a transfer device 23 described later. On the other hand, the untransferred toner is collected from the photoreceptor after transfer by the photoreceptor cleaning device 24, and the residual charge is removed by the charge removing device 25 in preparation for the next charging. A control system of the copying machine according to the present embodiment will be described with reference to a block diagram shown in FIG. The main control board 30 is a CP that performs overall signal processing.
U31, ROM 32 for storing a program to be executed by the CPU 31, read / write RAM 33 used for a work area, etc., input / output ports (I / O) 34, 3
5, a timer 37 and the like. A setting signal from the operation unit 36 of the copying machine main body is transmitted to the CP via the I / O 34.
When incorporated in U31, conditions such as various modes and the number of copies are confirmed. In addition, the CPU 31 supplies the photosensitive member 3 via the I / O 35 to a main motor power supply, a charging device, an exposure device, a developing device, and the like (not shown).
A control signal relating to the formation of a toner image thereon is sent. Also, the CPU 31 sends an I / O 35 to a transfer device described later.
Is transmitted via the control signal.

Next, the configuration and operation of the transfer device will be described. FIGS. 2A and 2B are schematic configuration diagrams of the transfer device. The transfer device shown in FIGS. 2A and 2B supports the belt unit 2 detachably from the image forming apparatus main body. The belt unit 2 includes a transfer / transport belt 6 as a transfer material carrier wound around a pair of rollers 4 and 5 for transferring a toner image from the photoreceptor 3 as an image carrier to the transfer paper S. A DC solenoid 8 for bringing the photosensitive member 3 into and out of contact with the photoreceptor 3, a contact / separation lever 9, a bias roller 11 for applying a transfer bias to the transfer and conveyance belt 6, and a contact plate 13 for removing charges from the transfer and conveyance belt 6. ing. A high-voltage power supply 12 for applying a voltage to a cleaning device 16 having a cleaning blade 16A and a bias roller 11 for scraping off residual toner and transfer paper S on the surface of the transfer conveyance belt 6 is provided to the image forming apparatus main body. Is provided. Further, as shown in the block diagram of FIG.
A control signal is sent to the high voltage power supply 12 via a DC solenoid 8 via a belt drive motor 19 via a belt drive control plate 18 serving as a transfer material carrier drive control unit which will be described later.

The roller 5 around which the transfer conveyance belt 6 is wound has a gear connected to a belt drive motor 19 driven by a control signal sent from the main control plate 30 via the belt drive control plate 18. And is driven to rotate. The transfer conveyance belt 6 can move in the conveyance direction of the transfer paper S at a transfer position facing the photoconductor 3 following the rotation of the roller 5.

The rollers 4 and 5 are rotatably supported by a support 7. The support 7 is provided between the rollers 4 and 5 in the transfer paper transport direction indicated by the arrow A.
The roller 5 can swing about the support shaft 5a of the roller 5 located on the downstream side of the transfer position with respect to. This support 7
The transfer position side of the transfer conveyance belt 6 is
It is operated by a DC solenoid 8 driven by a signal from the DC solenoid. That is, a contact / separation lever 9 is connected to the DC solenoid 8, and the contact / separation lever 9 is
To move the transfer / conveyance belt 6 toward and away from the photoreceptor 3.

The main control plate 30 detects the leading end of the transfer paper S conveyed in a state where it is aligned with the leading end position of the image formed on the photoreceptor 3 by the registration roller 10 serving as a sheet conveying means. When approaching the body 3, a drive signal is issued to drive the DC solenoid 8.
By driving the solenoid 8, the support 7 comes close to the photoconductor 3 as shown in FIG. 2B, and the transfer / conveyance belt 6 contacts the photoconductor 3. A nip portion B is formed at a position opposite to the nip portion B so that the transfer paper S can be transported while being in contact with the photoconductor 3.

Among the rollers 4 and 5, the roller 4 located on the photosensitive member 3 side is configured as a driven roller to the roller 5 on the driving side. The surface shape of the roller 4 is tapered at both ends in the axial direction so as to prevent the transfer / conveyance belt 6 from being shifted. The roller 4 is a conductive roller made of metal or the like, but only supports the transfer / transport belt 6, and is not electrically directly connected to other conductive members. On the other hand, for the roller 5 on the driving side, a material such as EPDM rubber, chloroprene rubber, or silicone rubber is selected because of its function of increasing the gripping force on the transfer conveyance belt 6 during driving.

A charge supply means for supplying a transfer bias by applying a transfer bias to the surface of the transfer conveyance belt 6 opposite to the photosensitive member 3 side is constituted by the bias roller 11 and the high voltage power supply 12. . The bias roller 11
The transfer conveyance belt 6 is provided so as to contact the inside of the transfer conveyance belt 6 on the downstream side of the roller 4 in the moving direction (left side in FIGS. 2A and 2B). The bias roller 11 applies the photosensitive member 3 to the transfer conveyance belt 6.
A contact electrode for applying a charge having a polarity opposite to the charge polarity of the above toner is formed, and is connected to the high voltage power supply 12.

The contact plate 13 in FIGS. 2 (a) and 2 (b) is disposed on the belt inner surface near the driven roller 4 on the lower side of the transfer paper transfer belt 6 which is not the transfer paper transfer surface. The injection of charge into the transfer paper S on the upstream side of B is suppressed. The contact plate 13 is used to transfer the transfer belt 6.
This is for detecting the current flowing upward as a feedback current, and the detection of this current controls the supply current from the bias roller 11. For this reason, the contact plate 13 includes
A transfer current control plate 14 for setting a supply current to the bias roller 11 according to the detected current is connected. The transfer current control plate 14 is connected to the high voltage power supply 12.

Although not shown, the contact plate 1
3, the roller 4 is grounded, and the transfer / transport belt 6
The current flowing upward can be detected as a feedback current, and the current supplied from the high voltage power supply 12 via the bias roller 11 can be controlled by detecting this current. Also, the roller 5 may be a conductive roller, and the same control may be performed.

In the transfer device having the above configuration, FIG.
As the transfer paper S is fed out from the registration roller 10, the support 7 is set at a position where the transfer conveyance belt 6 approaches the photoconductor 3, as shown in FIG. Width 4 to 8 corresponding to the length along the transport direction
A nip portion B of about mm is formed.

On the other hand, the surface of the photosensitive member 3 is, for example, -8.
It is charged to 00V, and moves to the nip portion B with the positively charged toner electrostatically attracted to the surface. The photoreceptor 3 is arranged near the photoreceptor 3 before reaching the nip portion B, and its surface potential is reduced by a pre-transfer neutralization lamp (PLT) 15 that weakens the charge on the surface of the photoreceptor 3.

In the nip portion B, the toner on the photoconductor 3 is transferred to the bias roller 11
Is transferred onto the transfer paper S by the transfer bias applied from the printer. This transfer bias is -1.5 kV to -6.5 kV.
The voltage is applied from the high voltage power supply 12 within the range described above. As a result of the constant current control described below, the transfer bias is variably set. That is, in FIGS. 2A and 2B, the current value output from the high-voltage power supply 12 is defined as I1, and the value when a feedback current value flowing from the contact plate 13 to the ground side via the transfer conveyance belt 6 is detected. Is I2, I1 is controlled so that the relationship shown by the following equation 1 is obtained between the two.

I1−I2 = Iout (where Iout is constant)

The above-described control stabilizes the surface potential Vp on the transfer sheet S, regardless of changes in environmental conditions such as temperature and humidity and variations in the production quality of the transfer conveyance belt 6, thereby reducing the change in transfer efficiency. This is to eliminate them. In other words, the current flowing to the photoconductor 3 side through the transfer conveyance belt 6 and the transfer paper S is regarded as Iout, so that the current to the transfer conveyance belt 6 on the transfer paper S due to the reduction of the surface resistance Vp or the increase in the resistance is obtained. Is prevented from affecting the separation performance and transfer performance of the transfer paper S. In the case of this embodiment, the transport speed is 330 mm / sec, and the effective bias roller length is 31.
At 0 mm, the control target value of the Iout is 35 μA
When set to ± 5 μA, good transfer was obtained. Note that the control target value of the current Iout flowing to the photoconductor 3 side is not uniquely determined, and can be reduced when the transfer speed of the transfer paper S is low. If the pre-neutralization lamp 15 is not used, the number will be increased.

When the image is transferred from the photosensitive member 3, the transfer paper S is also charged at the same time. Accordingly, the transfer paper S is electrostatically attracted onto the transfer / transport belt 6 to separate the transfer paper from the photoreceptor 3 due to the relationship between the true charge of the transfer / transport belt 6 and the polarization charge generated on the transfer paper S side. Can do. Then, the transfer paper S is promoted by a peeling operation based on the stiffness of the transfer paper S utilizing the curvature separation of the photoconductor 3.

On the other hand, the transfer paper S passing through the nip B
Is electrostatically attracted in accordance with the movement of the transfer conveyance belt 6,
Curvature separation is performed by the roller 5 on the driving side. For this reason, the diameter of the roller 5 is set to 16 mm or less. Furthermore,
When such a roller 5 is used, an experimental result has been obtained that it is possible to separate high-quality 45K paper (rigidity 21 [cm 3/100]).

The transfer paper S separated from the transfer / conveyance belt 6 by the driving roller 5 is guided by a guide plate and conveyed between a heating roller 17a and a pad roller 17b constituting the fixing section 17. You. The fixing unit 17 heats and melts the toner on the transfer paper S and presses the toner on the transfer paper S to fix the toner on the transfer paper S.

The surface of the transfer conveying belt 6 is cleaned by the cleaning device 16. Cleaning device 16
Is provided with a cleaning blade 16A. When the toner transferred from the surface of the photoreceptor 3 or scattered around the transfer conveyance belt 6 without being transferred is attached by rubbing the transfer conveyance belt 6. The toner and the paper powder of the transfer paper S are scraped off. The toner or paper dust scraped off from the surface of the transfer conveyance belt 6 is
The waste toner is stored in a waste toner collecting container (not shown) by the collecting screw 16B. The cleaning blade 1
The surface layer of the transfer conveyance belt 6 rubbed with 6A is made of a fluorine-based resin material having a low friction coefficient, such as a fluorine-based resin material, in order to prevent an increase in driving force due to an increase in rubbing resistance or a phenomenon such as turning up of the cleaning blade 16A. It is made of polyvinylidene fluoride, ethylene tetrafluoride or the like.

When the above-described image formation is performed, the transfer paper S is carried on the transfer / transport belt 6 in a contact state. The paper dust adhering to the transfer / conveyance belt 6 is conveyed to the cleaning blade 16A, and accumulates or bites into the edge of the cleaning blade. For this reason, the paper dust deposited or bitten on the cleaning blade 16A is removed.

The operation of removing paper dust is shown in FIG.
A description will be given based on (b). When the transfer of the image onto the transfer paper S and the separation are completed, the DC solenoid 8 is driven and the support 7 comes close to the photoreceptor 3, and as shown in FIG. It is in contact with the photoconductor 3. Thereafter, the transfer conveyance belt 6 is moved to the main control plate 3.
When the excitation of the DC solenoid 8 is released by a signal from 0, the contact / separation lever 9 is released, the support 7 is separated from the photoreceptor 3, and as shown in FIG. And the photoconductor 3 are separated from each other. On the other hand, during the image forming process,
In the main control board 30 shown in FIG. 4, an interrupt signal is input to the CPU 31 at regular intervals from the timer 36 so as to detect the image forming time, and the CPU 31 is configured to count up the timer data for each interrupt. Output I for driving the main motor of the photoconductor
When the port of / O35 is active, it counts up, accumulates the rotation time of the photoconductor 3, and sets it as the image forming time. The image forming time data detected in this way is sent from the CPU 31 to the belt drive control plate 18. ROM 18C in the belt drive control plate 18 stores data on the relationship between the image forming time and the amount of belt reversal shown in Table 1. The reverse rotation amount calculation unit 18A of the belt drive control plate 18 calculates the belt reverse rotation amount by which the transfer conveyance belt 6 is driven to rotate in the direction opposite to that during image formation based on Table 1. The belt drive control unit 18B of the belt drive control plate 18 drives the belt drive motor 19 to rotate the belt 5 so that the calculated belt reversal amount is obtained, and rotates the roller 5 around which the transfer / transport belt 6 is wound in reverse to the time of image formation. Drive in the direction. Transfer conveyor belt 6
Is driven by the rotation of the roller 5 in the direction opposite to the time of image formation in a reverse rotation amount according to the image forming time, and removes the paper dust accumulated or entangled in the cleaning blade 16A.

[Table 1]

After the operation of removing the paper dust is completed, the contact / separation lever 9 is released in response to the excitation of the DC solenoid 8 being released, and the transfer / conveyance belt 6 is separated from the photoreceptor 3. The transfer conveyance belt 6 is driven to rotate in the same direction as that during image formation, and the cleaning means 16 removes toner that cannot be removed by cleaning during the image forming process.

Next, a second embodiment applied to a copying machine which is an image forming apparatus of the present invention will be described. The basic configuration and operation of this copying machine are the same as those of the first embodiment, and thus the description is omitted. The basic configuration and operation of the transfer device are the same as those of the transfer device shown in FIGS. 2A and 2B, and the description of the same components will be omitted. Here, the cleaning means 16 for the transfer and conveyance belt is used.
The configuration and operation related to the removal of the paper dust accumulated or entangled in the sheet will be described.

When the transfer of the image onto the transfer paper S and the separation are completed, as shown in FIG.
When the photoconductor 6 is in contact with the photoconductor 3, the transfer / conveyance belt 6 is rotated in reverse according to the image forming time. That is, during the image forming process, an interrupt signal is input to the CPU 31 at regular intervals from the timer 36 so that the main control plate 30 shown in FIG. 4 detects the image forming time, and the CPU 31 counts up the timer data for the interrupt. It is configured. Belt drive motor 1 for transfer / transport belt 6
9 to drive the belt drive control plate 18 so as to drive
When the port O35 is active, the count is incremented, and the rotation time of the transfer / conveyance belt 6 is integrated, and this is used as the image forming time. The image forming time data detected in this way is sent from the CPU 31 to the belt drive control plate 18. In the reverse rotation amount calculation unit 18A of the belt drive control plate 18, R
Based on Table 1 stored in the OM18C, the transfer conveyance belt 6
Is calculated. The belt drive control unit 18B of the belt drive control plate 18 rotationally drives the belt drive motor 19 so that the calculated belt reversal amount is attained, and the transfer / conveyance belt 6 moves in the direction opposite to the image formation time and during the image formation time. The cleaning blade 16 is rotated by the amount of reverse rotation according to
Take away the paper dust that has accumulated or penetrated A.

As described above, when the transfer and separation of the image onto the transfer paper S are completed and the transfer / transport belt 16 is in contact with the photosensitive member 3, the transfer / transport belt 6 is moved according to the image forming time. Rotate in the opposite direction to when forming, and
The transfer / conveyance belt 6 releases the contact / separation lever 9 in response to the release of the excitation of the DC solenoid 8, and as shown in FIG. 3B, the transfer / conveyance belt and the photoconductor 3 are separated from each other. The transfer conveyance belt 6 can be rotated in a direction opposite to the direction at the time of image formation according to the formation time.

Next, in a third embodiment applied to a copying machine which is an image forming apparatus of the present invention, removal of paper dust accumulated or cut into the cleaning means 16 of the transfer / transport belt will be described based on a flowchart shown in FIG. The configuration and operation relating to will be described.

At the start of image formation, the operation unit 36 of the copying machine main body
When the setting signal for the job from is input to the CPU 31 via the I / O 34, conditions such as various modes and the number of copies are confirmed. In the CPU 31, various modes,
Based on the condition of the number of copies, for example, the rotation time of the photoconductor, which is the image forming time of the set job, is calculated. The copying machine forms an image based on the set conditions. When the image formation is completed, the CPU 31
The data of the accumulated number of copies of the copying machine stored in the copying machine is read, the data of the number of copies set this time is integrated, and the result is newly stored in the RAM 33. RAM3
The data stored in No. 3 is data on the cumulative number of copies of the copying machine and is used as a cleaning history of the cleaning means. The rotation time of the photoconductor, which is the image forming time of the set job,
The CPU 31 sends both the data of the cumulative number of copies of the copying machine stored in the RAM 33 to the belt drive control plate 18. ROM 18C in the belt drive control plate 18 stores data on the relationship between the rotation time of the photoconductor and the cumulative number of copies, which are the image forming times shown in Table 2, and the amount of belt reversal. Reverse rotation amount calculation unit 18A of belt drive control plate 18
Then, based on Table 2, the amount of belt reversal by which the transfer conveyance belt 6 is driven to rotate in the direction opposite to that during image formation is calculated. The belt drive control unit 18B of the belt drive control plate 18 rotates the belt drive motor 19 so that the calculated belt reversal amount is attained, and the roller 5 around which the transfer conveyance belt 6 is wound.
Is driven in the direction opposite to the direction during image formation. Transfer conveyor belt 6
The cleaning blade 1 is driven by the rotation of the roller 5 and is rotated in the reverse direction in the direction opposite to that during image formation by the reverse rotation.
Remove the paper dust that has accumulated or bitten into 6A. Further, in response to the excitation of the DC solenoid 8 being released, the contact / separation lever 9 is released, and the transfer conveyance belt and the photoconductor 3 are separated. The belt drive control unit 18B of the belt drive control plate 18 rotationally drives the belt drive motor 19 so that the calculated belt reversal amount is obtained, and the transfer conveyance belt 6 responds to the image forming time in the direction opposite to the image forming time. The paper is accumulated in the cleaning blade 16A and is taken away by being rotated in the reverse direction.

[Table 2]

As described above, the amount of reverse rotation is calculated according to the use history of the cleaning means and the image forming time, and the operation of rotating the reverse transfer transfer belt 6 in the direction opposite to that during image formation is performed in the following manner. As in the case of the first embodiment, the contact / separation lever 9 is released in response to the excitation of the DC solenoid 8 being released,
The transfer may be performed in a state where the transfer conveyance belt and the photoconductor 3 are separated from each other. Further, as in the second embodiment, the operation may be performed in a state where the DC solenoid 8 is operated and the transfer / conveying belt and the photosensitive member 3 are in contact with each other by the contact / separation lever 9.

Although the rotation time of the photoconductor 3 is calculated by the CPU 31 based on the set conditions as the set image forming time of the job, the transfer conveyance belt 6 is used.
The calculated rotation time may be used. Also, CP
In addition to the method of calculating from the condition set in U31, as shown in the first and second embodiments, a timer 36 is used to detect the image forming time with the main control plate 30 during the image forming process. Interrupt signal is CPU at intervals
The interrupt may be input to the counter 31 and the interrupt may be counted up. Further, in addition to the set image forming time of the job, the set number of copies of the job input to the CPU 31 from the operation unit may be used.

Further, the accumulated rotation time of the photosensitive member or the accumulated rotation time of the transfer / transport belt is stored in the RAM 33 as the use history of the cleaning means, and every time an image forming job is set, the photosensitive member of the job is set. The rotation time or the rotation time of the transfer conveyance belt is detected, and the accumulated rotation time of the photoconductor or the accumulation rotation time of the transfer conveyance belt stored in the RAM 33 is referred to. What integrated the rotation time may be used. In this case, the usage history of the cleaning means is
This is the cumulative rotation time of the photoconductor or the cumulative rotation time of the transfer conveyance belt. The cumulative rotation time of the photoconductor or the cumulative rotation time of the transfer conveyance belt is newly stored in the RAM 33.

Next, according to a fourth embodiment applied to a copying machine which is an image forming apparatus of the present invention, according to a flowchart shown in FIG. 6, removal of paper dust deposited or cut into the transfer / transport belt cleaning means 16 will be described. The configuration and operation relating to will be described.

The condition setting at the start of image formation, image formation time detection of the set conditions, and image formation are the same as those of the third embodiment. After the completion of the image forming process, a toner pattern for image density control detection is formed on the photoconductor 3. The toner pattern is transferred onto the transfer / transport belt 6 by a transfer bias applied from a bias roller 11 located on the transfer / transport belt 6 side in a state where the transfer / transport belt 6 is in contact with the photoconductor 3 to form the nip portion B. Transfer to The transfer conveyance belt is rotationally driven to a position where the toner pattern transferred to the transfer conveyance belt 6 reaches the cleaning blade 16A, and the toner pattern is deposited or bites on the edge of the cleaning blade. The CPU 31 detects the accumulated number of copies and the set image forming time of one job, and sends the data to the belt drive control plate 18. The reverse rotation amount calculation unit 18A of the belt drive control plate 18 calculates the amount of reverse rotation of the transfer conveyance belt 6 to rotate in the direction opposite to that during image formation based on the data stored in the ROM 18A. The belt drive control unit 18B of the belt drive control plate 18 rotationally drives the belt drive motor 19 so that the calculated amount of belt reversal is achieved.
The rotation of the cleaning blade 1 is driven by the rotation of the cleaning blade 1 in a direction opposite to the image formation time in accordance with the image formation time.
The toner and paper dust that have accumulated or bitten into 6A are removed together.

Further, a step of forming a toner pattern for image density control detection on the photoreceptor 3 and transferring the toner pattern onto the transfer / conveying belt 6 to form a toner pattern on the transfer / conveying belt 6 is performed. It may be repeated several times.
The transfer conveyance belt is rotated to the position where the toner pattern transferred a plurality of times on the transfer conveyance belt 6 reaches the cleaning blade 16A, and the toner pattern accumulates or digs into the edge of the cleaning blade. By increasing the amount of toner deposited or digged into the cleaning means, the ability to remove paper dust is improved.

Further, in the axial direction on the photoreceptor 3, toner images are formed at arbitrary positions corresponding to a position where paper dust easily accumulates in the cleaning means or a position where the cleaning ability is poor, and the toner image is transferred. The image is transferred onto the conveyor belt 6. The transfer / transport belt is configured such that the toner images at any several places transferred onto the transfer / transport belt 6 are cleaned by the cleaning blade 16.
The toner image is rotated and driven to a position at which the toner image reaches A, and the toner image is selectively deposited or cut into the edge of the cleaning blade. The toner is selectively removed or accumulated in a position where the paper dust of the cleaning means easily accumulates or a position where the cleaning ability is inferior, and the paper dust is satisfactorily removed by reversing the transfer material conveying belt. In addition, by forming a plurality of toner images in the rotation direction of the photoreceptor 3 and increasing the amount of toner deposited or edged in the cleaning means, the ability to remove paper dust is improved.

The length of the toner image formed on the photoconductor 3 in the rotation direction of the photoconductor may be varied.
When the image forming time is short, the length of the toner image formed on the photoconductor 3 in the transfer and transfer direction of the transfer paper is short, and when the image forming time is long, the toner image formed on the image carrier is not long. The length of the transfer paper in the transfer conveyance direction is increased, and the length of the toner image is made variable according to the image forming time. As a result, when the image forming time is short, the amount of toner that accumulates or bites into the cleaning unit is small, and when the image forming time is long, the amount of toner that accumulates or bites into the cleaning unit increases.

As described above, the amount of reverse rotation is calculated according to the image forming time, and the transfer conveyance belt 6 is driven to rotate in the direction opposite to that during image formation according to the amount of reverse rotation to deposit or bite into the cleaning blade 16A. As in the first embodiment, the operation of removing the toner and paper dust together releases the contact / separation lever 9 as the excitation of the DC solenoid 8 is released, and separates the transfer / conveyor belt and the photoconductor 3. It may be performed in a state where it is done. When the transfer / conveying belt 16 is in contact with the photoconductor 3, the transfer / conveying belt 6 is rotated in reverse according to the image forming time, and further, when the excitation of the DC solenoid 8 is released, the contact / separation lever 9 is released. Is released, and the transfer conveyance belt 6 can be reversed in accordance with the image forming time while the transfer conveyance belt and the photoconductor 3 are separated from each other.

Next, a fifth embodiment applied to a copying machine which is an image forming apparatus of the present invention will be described with reference to FIG.
The configuration and operation relating to the removal of the paper dust accumulated or entangled in the cleaning means 16 of the transfer conveyance belt will be described.

Setting of conditions at the start of image formation, detection of image forming time under the set conditions, use history of cleaning means,
Thirdly, the image formation is the same as that of the embodiment. After completion of the image forming process, the sheet feeding roller 5 of the sheet feeding device 50 of the copying machine is used.
1. A toner image 40 is formed on the photoconductor 3 corresponding to the position of the call roller 52, the reverse roller 53, or the grip conveyance roller.

Here, the configuration and operation of the sheet feeding device 50 of the copying machine will be described. The paper feed device 50 is a paper feed roller 5
1, a call roller 52, a reverse roller 53, and a grip transport roller (not shown). When a paper feed signal is input from the main control plate 30, the paper feed roller 51 is driven, and the call roller 52 is further rotated via a relay gear to feed the top sheet of a paper tray (not shown). The reverse rotation roller 53 is in contact with and pressurizes the transfer paper from the back surface of the transfer paper. At this time, the paper feed roller 51 and the call roller 52 rub the surface of the paper to be fed, and the reverse rotation roller 52 rubs the back surface of the paper. Therefore, paper dust is easily generated in a portion corresponding to the roller. Further, since the fed transfer paper is conveyed while being in contact with the grip conveyance roller, paper dust is likely to be generated in a portion corresponding to the grip conveyance roller.

On the other hand, the toner image 40 formed on the photoconductor 3 corresponding to the position of the paper feed roller 51, the call roller 52, the reverse rotation roller 53, or the grip conveyance roller of the paper feed device 50.
Is transferred onto the transfer conveyance belt 6 by the transfer bias applied from the bias roller 11 in a state where the transfer conveyance belt 6 is in contact with the photoconductor 3. The transfer conveyance belt is rotated to a position where the toner image 40 transferred to the transfer conveyance belt 6 reaches the cleaning blade 16A, and the toner is input to the edge of the cleaning blade. Thereafter, the CPU 31 detects the cumulative number of copies and the image forming time of the set job, and sends the data to the belt drive control plate 18. The reverse rotation amount calculation unit 18A of the belt drive control plate 18 calculates the belt reverse rotation amount by which the transfer conveyance belt 6 is driven to rotate in the direction opposite to that during image formation, based on the data stored in the ROM 18C. The belt drive control unit 18B of the belt drive control plate 18 rotationally drives the belt drive motor 19 so that the calculated amount of belt reversal is achieved. Is rotated in the reverse direction by the reverse rotation amount, and removes together the toner and paper dust accumulated or bitten on the cleaning blade 16A.

Next, a case where a toner image is formed on the photosensitive member 3 corresponding to the position of the roller or the roller of the sheet conveying device of the copying machine will be described. In the case of a copying machine that performs vertical transfer of a transfer sheet, the vertical transfer is performed by a grip transfer roller incorporated in a sheet feeding device, an intermediate roller, an intermediate roller, a registration roller, and the like of the sheet transfer device. The transfer paper is conveyed from the paper feeding device to the transfer conveyance device by contacting a grip conveyance roller, an intermediate roller, an intermediate roller, a registration roller, and the like. At this time, paper dust is likely to be generated at the position where these rollers or rollers are in contact. Therefore, a toner image is formed on the photoconductor 3 corresponding to the position of the grip conveyance roller, the intermediate roller, the intermediate roller, or the registration roller, and the toner image is transferred onto the transfer conveyance belt 6. Then, the transfer / conveying belt 6 is reversed in accordance with the image forming time to remove the toner and the paper dust together.

Next, a sixth embodiment applied to a copying machine, which is an image forming apparatus according to the present invention, will be described with respect to a configuration and an operation relating to removal of paper dust accumulated or cut into the cleaning means 16 of the transfer conveyance belt. .

When the transfer of the image onto the transfer paper S and the separation have been completed, the DC solenoid 8 is driven, the support 7 comes close to the photosensitive member 3, and the transfer / transport belt 16 moves to the photosensitive member 3.
In contact with After this, the transfer conveyance belt 6
When the excitation of the DC solenoid 8 is released by a signal from the main control plate 30, the contact / separation lever 9 is released,
The support 7 is separated from the photoconductor 3, and the transfer / conveying belt and the photoconductor 3 are separated. The belt controller 18B of the belt drive control plate 18 drives the belt drive motor 19 to rotate in the opposite direction to the image formation so that the transfer and transport belt 6 rotates 5 to 20 mm in the opposite direction to the image formation. The roller 5 around which the belt 6 is wound is driven in a direction opposite to that in image formation. The transfer conveyance belt 6 is driven to rotate by 5 to 20 mm in the opposite direction to that during image formation by following the rotation of the roller 5, and removes the paper dust accumulated or bitten on the cleaning blade 16A. Again, the belt control unit 18B of the belt drive control plate 18 drives the belt drive motor 19 to rotate in the direction opposite to that during image formation so that the transfer conveyance belt 6 rotates 5 to 20 mm in the direction opposite to image formation. . The transfer conveyance belt 6 is again driven to rotate by 5 to 20 mm in a direction opposite to that in the image formation, and the cleaning blade 1 is rotated.
Remove the paper dust that has accumulated or bitten into 6A.

After completion of the image formation, the DC solenoid 8 is driven, the support 7 comes close to the photosensitive member 3, and the transfer / conveying belt 16 is in contact with the photosensitive member 3. The reversal of the transfer / conveying belt 6 may be performed several times in response to a signal from the belt controller 18B of 18 to remove paper dust accumulated or cut into the cleaning blade 16A.

In the first to sixth embodiments, only the example in which the transfer material carrier is a transfer / conveying belt has been described. However, the present invention is also applicable to a transfer drum and a transfer roller. Yes, a similar effect can be obtained.

[0091]

According to the first to twenty-first aspects of the present invention, the paper dust deposited or entangled in the cleaning means of the transfer material carrier is removed, and the cleaning of the transfer material carrier is maintained satisfactorily. In addition, there is an excellent effect that an image without back stains can be obtained, and transfer failure and separation failure of transfer paper can be prevented.

Further, according to the invention of claims 4 to 11, the amount of paper dust accumulated or edged in the cleaning means of the transfer carrier is grasped by a simple method, and accumulated in the cleaning means of the transfer material carrier. Alternatively, there is an excellent effect that the paper dust that has penetrated can be removed.

According to the invention of claim 6, even if the cleaning means of the transfer carrier is deteriorated by use,
There is an excellent effect that paper dust deposited or eroded in the cleaning means of the transfer material carrier can be removed.

Further, according to the twelfth to seventeenth aspects of the present invention, there is an excellent effect that the paper dust deposited or cut into the cleaning means of the transfer material carrier can be satisfactorily removed. Further, preventing the abrasion or chipping of the cleaning means, maintaining that the transfer material carrier is properly cleaned, and obtaining an image without back stains,
There is an excellent effect that transfer paper transfer failure and separation failure can be prevented.

According to the thirteenth to fifteenth aspects of the invention, there is an excellent effect of improving the ability to remove paper dust.

According to the sixteenth aspect of the present invention, there is no need to separately provide a toner image forming means, so that there is an excellent effect that a simple apparatus can be realized.

Further, according to the invention of claim 14 or claim 17, there is an excellent effect that the paper dust can be satisfactorily removed even at a position where the paper dust of the cleaning means easily accumulates or bites.

Further, according to the eighteenth aspect of the present invention, there is an excellent effect that the paper dust deposited or cut into the cleaning means of the transfer material carrier can be removed by a simple operation.

Further, according to the nineteenth aspect of the present invention, there is an excellent effect that the paper dust accumulated or bitten into the cleaning means can be removed without increasing the amount of paper dust piled or dig into the cleaning means.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a copying machine according to an embodiment.

FIG. 2A is a schematic configuration diagram of a transfer device according to an embodiment before a sheet is passed. FIG. 2B is a schematic configuration diagram of the transfer device according to the embodiment during paper passage.

FIGS. 3A and 3B are explanatory diagrams illustrating a relationship between an image carrier and a transfer device according to the embodiment.

FIG. 4 is a block diagram of a control system of the copying machine according to the embodiment.

FIG. 5 is a flowchart according to a third embodiment.

FIG. 6 is a flowchart according to a fourth embodiment.

FIG. 7 is an explanatory diagram of a toner image according to a fifth embodiment.

[Explanation of symbols]

 Reference Signs List 3 Photoconductor 6 Transfer / conveying belt 8 DC solenoid 16 Cleaning means 16A Cleaning blade 18 Belt drive control plate 18A Reverse rotation amount calculation unit 18B Belt drive control unit 19 Belt drive motor 30 Main control plate

Claims (21)

[Claims] An image carrier for carrying a toner image; a transfer material carrier for carrying and transporting a transfer sheet so as to pass through a transfer position facing the image carrier; Cleaning means for cleaning, the toner image is electrostatically transferred onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is transferred from the transfer material carrier. An image forming apparatus for reversing a transfer material carrier in a direction opposite to the direction in which an image is formed after separation is provided, wherein the image forming apparatus includes a transfer material carrier drive control unit for controlling a reverse rotation condition of the transfer material carrier. Forming equipment. 2. The image forming apparatus according to claim 1, further comprising a reverse rotation amount calculating section for calculating a reverse rotation amount of the transfer material carrier in accordance with an amount of paper dust deposited or cut into the cleaning means. An image forming apparatus configured to control a reverse rotation amount of the transfer material carrier in accordance with a calculation result of the unit. 3. The image forming apparatus according to claim 1, wherein the number of reverse rotations of the transfer material carrier is controlled in accordance with the amount of paper dust deposited or cut into the cleaning means. apparatus. 4. An image carrier for carrying a toner image, a transfer material carrier for carrying and transporting transfer paper so as to pass through a transfer position facing the image carrier, and a surface of the transfer material carrier. Cleaning means for cleaning, the toner image is electrostatically transferred onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is transferred from the transfer material carrier. In an image forming apparatus in which the transfer material carrier is reversed in a direction opposite to the direction of image formation after separation, the transfer material carrier for controlling the reversal condition of the transfer material carrier according to a set number of images to be formed in one job. An image forming apparatus comprising a drive control unit. 5. An image carrier for carrying a toner image, a transfer material carrier for carrying and transporting a transfer sheet so as to pass through a transfer position facing the image carrier, and a surface of the transfer material carrier. Cleaning means for cleaning, the toner image is electrostatically transferred onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is transferred from the transfer material carrier. In the image forming apparatus in which the transfer material carrier is reversed in the direction opposite to the direction in which the image is formed after the separation, the transfer material carrier controlling the reverse rotation condition of the transfer material carrier according to the set image forming time of one job. An image forming apparatus comprising a drive control unit. 6. An image carrier for carrying a toner image, a transfer material carrier for carrying and transporting transfer paper so as to pass through a transfer position facing the image carrier, and a surface of the transfer material carrier. Cleaning means for cleaning, the toner image is electrostatically transferred onto the transfer paper carried on the transfer material carrier to perform transfer, and the transfer paper carrying the transferred toner image is transferred from the transfer material carrier. In the image forming apparatus in which the transfer material carrier is rotated in the reverse direction after image separation, the transfer is performed according to the set number of images to be formed or the image forming time of one job and the use history of the cleaning unit. An image forming apparatus comprising: a transfer material carrier drive control means for controlling a reverse rotation condition of the material carrier. 7. The image forming apparatus according to claim 5, wherein the image forming time is a rotation time of the image carrier. 8. The image forming apparatus according to claim 5, wherein the image forming time is a rotation time of the transfer material carrier. 9. The image forming apparatus according to claim 6, wherein the use history of said cleaning means is a cumulative number of image formations of said image forming apparatus. 10. An image forming apparatus according to claim 6, wherein the use history of said cleaning means is the cumulative rotation time of said image carrier. 11. The image forming apparatus according to claim 6, wherein the use history of said cleaning means is the cumulative rotation time of the transfer material carrier. 12. The image forming apparatus according to claim 1, wherein after the image forming step is completed, a toner image is formed on the image carrier to be supplied to cleaning means for the transfer material carrier, and the image is formed. In a state where the carrier and the transfer material carrier are in contact with each other, the toner image is transferred onto the transfer material carrier, and a toner image is formed on the transfer material carrier. An image forming apparatus comprising: 13. The image forming apparatus according to claim 12, wherein the step of forming a toner image on the transfer material carrier is performed a plurality of times. 14. An image forming apparatus according to claim 12, wherein a plurality of toner images are formed on an image carrier, and said plurality of toner images are contacted with said image carrier and said transfer material carrier. An image forming apparatus configured to transfer the toner image onto a transfer material carrier to form a toner image on the transfer material carrier. 15. The image forming apparatus according to claim 12, wherein the length of the image carrier in the rotation direction is formed on the image carrier in accordance with the amount of paper dust deposited or cut into the transfer material carrier cleaning means. An image forming apparatus configured to create a variable toner image. 16. An image forming apparatus according to claim 12, wherein said toner image is a toner pattern for detecting image density. 17. The image forming apparatus according to claim 12, wherein a toner image is formed on an image carrier at a position corresponding to a roller or a roller of a sheet feeding device or a sheet conveying device of the image forming device. An image forming apparatus comprising: 18. The image forming apparatus according to claim 1, wherein said transfer material carrier is reversed when said transfer material carrier is in contact with said image carrier. Image forming apparatus. 19. The image forming apparatus according to claim 1, wherein the transfer material carrier is reversed in a state where the transfer material carrier is separated from the image carrier. Image forming apparatus. 20. The image forming apparatus according to claim 1, wherein the transfer material carrier is a transfer conveyance belt. 21. A transfer material carrier for supporting and transporting a transfer sheet so as to pass through a transfer position facing an image carrier on which a toner image is formed, and cleaning for cleaning the surface of the transfer material carrier. A transfer device that reverses the transfer material carrier in a direction opposite to the direction of image formation after the transfer paper carrying the toner image is separated from the transfer material carrier. A transfer device comprising a transfer material carrier drive control means for controlling.