JPH10186889A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a blade turn of a cleaning blade for cleaning a transferring belt, in the case of equipping a transfer transporting device, to restrain the occurrence of the cleaning defect, damage of the transferring belt or the like, and to excellently remove toner on the blade with the relatively low contact pressure at the normal cleaning time, even in the case of composing the toner feeding line on the transferring belt in order to prevent the blade turn. SOLUTION: When this device equips the transfer transporting device, the toner feeding line is composed between paper of the image carrier in order to prevent from turning of the cleaning blade 17e of the transfer transporting device, and means for transferring this line to the transferring belt 17a is disposed. Meanwhile, the toner feeding line is made the line in a state of the strait line at a certain angle of θ from the butting line of the cleaning blade 17e on the transferring belt 17a, the not strait line, the line composed of plural lines, or the line in the staining state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a facsimile, a printer, and the like, and more particularly, to an image bearing apparatus which holds and conveys a transfer material on a belt traveling body (hereinafter, transfer belt). The present invention relates to an image forming apparatus provided with a transfer conveyance device that transfers a toner image on a body to a transfer material.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus such as a copying machine, a facsimile, a printer, or the like, after a photosensitive member serving as an image carrier is charged, an original image is directly exposed by an exposure device, or a laser scanning optical system is used. Optical writing according to the image signal is performed by a system or an LED optical writing optical system or the like, an electrostatic latent image is formed on the photoconductor, and the latent image is developed by toner of a developing device to be visualized. The toner image is transferred to a transfer material such as transfer paper or film. Then, the transfer material after the transfer is conveyed to a fixing device, and the toner image is fixed on the transfer material by the fixing device to obtain an image. In such an image forming apparatus, as a device for transferring a toner image to a transfer material and separating the transferred transfer material from a photoreceptor, and conveying the transfer material to a fixing device, a transfer conveyance device using a transfer belt is known. I have.

The transfer belt of the transfer and transfer device is an endless, medium-resistance belt running body made of an elastic member such as a rubber-based material. The transfer belt is stretched over a plurality of rollers such as a driving roller and a driven roller, and is wound around a photosensitive member. At the time of transfer, a transfer belt holding the transfer material is brought into contact with the photoreceptor, and the transfer material is nipped and conveyed at a nip portion with the photoreceptor, and is also transferred to a bias applying roller disposed on the back side of the transfer belt. The toner image on the photoreceptor is transferred to the transfer material by applying a high voltage, and the transferred transfer material is separated from the photoreceptor and transported to the fixing unit. Further, the transfer conveyance device is provided with a cleaning blade for removing toner remaining on the surface of the transfer belt after the transfer material is separated.

[0004]

In a copying machine or the like provided with a transfer / transport device, if a large number of copies having a small image area are taken or a large number of blank copies are taken by mistake,
There is no residual toner on the transfer belt, and there is no toner on the edge of the cleaning blade in contact with the transfer belt. For this reason, the coefficient of friction between the transfer belt and the cleaning blade is increased, the rubbing resistance is increased, the edge of the cleaning blade is caught on the belt surface, and the edge of the cleaning blade may be turned up. When the blade is turned up, it causes the occurrence of cleaning failure, the back contamination of the transfer material, the scattering of toner, and the damage of the transfer belt.

Therefore, as means for solving the above problem,
A line for toner supply is formed between the papers of the photoreceptor, and this line is transferred to the transfer belt to supply the toner to the edge of the cleaning blade, and the friction coefficient between the transfer belt and the cleaning blade increases due to the toner shortage. To prevent the turning of the cleaning blade.

Here, the toner supply line is formed, for example, once in a plurality of copies, written over the entire width of the image between the photosensitive members, and transferred to the transfer belt. Since the toner supply line has a larger amount of toner than the residual toner that adheres when transferred to a normal transfer material, if the toner supply line on the transfer belt is a straight line parallel to the cleaning blade, Since the toner is input to the entire width at the same time, there is a case where the supply of the toner becomes excessive and the cleaning cannot be completed. In addition, if the blade conditions are such that it can be cleaned, for example, if the contact pressure of the cleaning blade to the transfer belt is set to be high, the cleaning performance becomes excessive during normal cleaning, and the blade deterioration, which is a side effect, occurs early. Will happen.

In a cleaning device for a belt-shaped photoreceptor, as a method of improving the cleaning property in a state where the contact pressure of the cleaning blade is relatively low, a cleaning blade is moved in a direction perpendicular to the driving direction of the belt-shaped photoreceptor. A method is known in which the toner supply line is formed so as to have an inclination angle (for example, Japanese Patent Application Laid-Open No. 60-107686). In this case, the toner can be removed under normal cleaning conditions.However, if the cleaning blade has an inclination angle, a large space is required for installing the cleaning blade, and the cleaning surface of the transfer belt is flat. The cleaning blade has to be installed in the part. In other words, since the belt surface of the roller portion that supports the transfer belt is an arc-shaped curved surface, if the blade is brought into contact with the curved surface at an inclined angle, the blade pressure is not uniformly applied, causing cleaning failure. Become. Therefore, it is not preferable to install the cleaning blade with an inclination angle because the installation space becomes large and the installation position is restricted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in an image forming apparatus provided with a transfer / conveyance device, a cleaning means for cleaning a transfer belt by providing means for forming a toner supply line on the transfer belt. In addition to preventing blade turning of the blade and eliminating problems such as poor cleaning and damage to the transfer belt, even when a toner supply line for preventing blade turning is formed on the transfer belt, it is relatively easy to use during normal cleaning. A first object is to enable the toner on the belt to be satisfactorily removed with a low contact pressure.

By the way, the toner supply line for preventing the turning of the cleaning blade is usually inserted between the sheets for every several copies, but the more frequently the toner supply line is inserted, the harder the blade is turned. . However, on the other hand, useless toner is consumed or cleaning failure occurs. Further, if the background toner adheres to the transfer belt and is input to the leading end of the blade much, the toner supply line for preventing the turning-up becomes unnecessary, but the background contamination amount is greatly related to the humidity. It will be reduced to a state without it. For this reason, in a high humidity environment, it is necessary to insert a toner supply line in a relatively short cycle to prevent the cleaning blade from turning up.

Therefore, in the present invention, under various use conditions of the image forming apparatus (temperature / humidity, presence / absence of air conditioning, etc.), useless toner used in a toner supply line for preventing turning-up is minimized, and a cleaning blade is provided. A second object is to perform control that does not cause turning over.

[0011]

According to a first aspect of the present invention, there is provided an endless medium-resistance transfer belt disposed opposite to an image carrier, and a transfer belt including the transfer belt. A bias application roller disposed on the back side of the transfer belt, and a cleaning blade for cleaning the surface of the transfer belt,
The transfer belt holding the transfer material is brought into contact with the rotating image carrier, and a high voltage is applied to a bias applying roller to transfer the toner image on the image carrier to the transfer material. In the image forming apparatus having a transfer conveyance device configured to clean the toner remaining on the transfer belt surface after the transfer material is separated by the cleaning blade,
In order to prevent the cleaning blade of the transfer conveyance device from being turned up, a line for supplying toner is formed between sheets of the image carrier, and a unit for transferring the line to the transfer belt is provided. And a straight line having a certain angle with the cleaning blade on the transfer belt.

That is, in the image forming apparatus according to the first aspect, a line for supplying toner is formed between the papers of the image carrier to prevent the cleaning blade of the transfer conveyance device from being turned up, and the line is transferred to the transfer belt. By doing so, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of turning of the cleaning blade is prevented. And, since the toner supply line is a straight line having a certain angle with the cleaning blade on the transfer belt, even if the cleaning blade is installed so as to abut perpendicularly to the driving direction of the transfer belt, The toner is not input to the entire width of the cleaning blade at the same time, and the toner on the transfer belt can be satisfactorily removed even with a relatively low contact pressure under the same conditions as in the normal cleaning.

According to a second aspect of the present invention, there is provided an endless, medium-resistance transfer belt disposed opposite to the image carrier, a bias applying roller disposed on the back side of the transfer belt, and the transfer belt. It has a cleaning blade that cleans the surface. The transfer belt holding the transfer material is brought into contact with the rotating image carrier, and the toner image on the image carrier is transferred to the transfer material by applying a high voltage to the bias applying roller. And transferring the transfer material after the transfer toward the fixing unit, and cleaning the toner remaining on the transfer belt surface after the transfer material is separated by the cleaning blade. A means for forming a toner supply line between the papers of the image carrier to prevent the cleaning blade of the conveyance device from being turned up, and a unit for transferring the line to the transfer belt; Line for feeding is characterized by non-linear.

That is, in the image forming apparatus according to the present invention, a line for supplying toner is formed between the papers of the image carrier to prevent the cleaning blade of the transfer / conveyance device from being turned up, and the line is transferred to the transfer belt. By doing so, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of turning of the cleaning blade is prevented. Further, since the toner supply line on the transfer belt is not straight, even when the cleaning blade is installed so as to abut perpendicularly to the driving direction of the transfer belt, toner is simultaneously input to the entire width of the cleaning blade. And the toner on the transfer belt can be satisfactorily removed even under a relatively low contact pressure under the same conditions as in normal cleaning.

According to a third aspect of the present invention, there is provided an endless, medium-resistance belt traveling body disposed opposite to the image carrier, a bias applying roller disposed on the back side of the belt traveling body, It has a cleaning blade for cleaning the surface of the belt traveling body, and the belt traveling body holding the transfer material is brought into contact with the rotating image carrier to apply a high voltage to the bias applying roller to form a toner image on the image carrier. An image forming apparatus including a transfer / transport device configured to transfer to a transfer material, transport the transferred transfer material toward a fixing unit, and clean the toner remaining on the surface of the belt traveling body after the transfer material is separated by the cleaning blade. The apparatus further includes means for forming a line for supplying toner between the papers of the image bearing member and transferring the line to the belt traveling member in order to prevent the cleaning blade of the transfer / conveyance device from being turned up. Line for the toner supply is characterized by made of a plurality of straight lines.

That is, in the image forming apparatus according to the third aspect, a line for supplying toner is formed between the papers of the image carrier to prevent the cleaning blade of the transfer conveying device from being turned up, and the line is transferred to the transfer belt. By doing so, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of turning of the cleaning blade is prevented. Further, since the toner supply line on the transfer belt is formed of a plurality of straight lines, even if the cleaning blade is installed so as to abut perpendicularly to the driving direction of the transfer belt, the toner is supplied over the entire width of the cleaning blade. Are not input at the same time, and the toner on the transfer belt can be satisfactorily removed even with a relatively low contact pressure under the same conditions as in normal cleaning.

According to a fourth aspect of the present invention, there is provided an endless, medium-resistance belt running body disposed opposite to the image carrier, a bias applying roller disposed on the back side of the belt running body, It has a cleaning blade for cleaning the surface of the belt traveling body, and the belt traveling body holding the transfer material is brought into contact with the rotating image carrier to apply a high voltage to the bias applying roller to form a toner image on the image carrier. An image forming apparatus including a transfer / transport device configured to transfer to a transfer material, transport the transferred transfer material toward a fixing unit, and clean the toner remaining on the surface of the belt traveling body after the transfer material is separated by the cleaning blade. The apparatus further includes means for forming a line for supplying toner between the papers of the image bearing member and transferring the line to the belt traveling member in order to prevent the cleaning blade of the transfer / conveyance device from being turned up. It said lines of toner supply is characterized by a fog-like (thin density) band.

That is, in the image forming apparatus according to the fourth aspect, a line for supplying toner is formed between the papers of the image carrier to prevent the cleaning blade of the transfer / conveyance device from being turned up, and the line is transferred to the transfer belt. By doing so, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of turning of the cleaning blade is prevented. And, since the toner supply line on the transfer belt is a band with a low density like a background stain, even if the cleaning blade is installed so as to abut vertically to the driving direction of the transfer belt,
A large amount of toner is not input into the entire width of the cleaning blade at the same time, so that the toner on the transfer belt can be satisfactorily removed even under a relatively low contact pressure under the same conditions as in normal cleaning.

[0019] To achieve the second object, the present invention provides a method according to claim 5.
According to another aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the formation of the toner supply line can be set according to use conditions of the apparatus.

That is, in the image forming apparatus according to the fifth aspect, in addition to the configuration according to any one of the first to fourth aspects, a toner supply line is formed in accordance with the use conditions of the apparatus, such as temperature and humidity and presence or absence of air conditioning. Since the number of times (frequency, etc. of inserting the toner supply line) can be set, wasteful toner consumption can be minimized, and the occurrence of turning of the cleaning blade can be prevented.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is an overall configuration diagram showing an example of the configuration of an image forming apparatus having a transfer / conveyance device according to the present invention. The image forming apparatus shown in FIG. 1 is an example of a digital copying machine that can also be used as a printer, and includes an image forming unit (printer) 1 for forming an image by an electrophotographic process, and a document reading unit (scanner) 2 for reading a document image. An automatic document feeder (ADF) 3 for automatically feeding a document, a paper feed unit 4 having a plurality of feed trays 4a to 4d for feeding transfer sheets of various sizes, It includes a double-sided tray 5 for temporarily storing and refeeding paper, and a paper discharge unit (sorter) 6 for copying and printing.

The automatic document feeder (ADF) 3 is installed on the contact glass 2a of the document reading unit 2 so that it can be opened and closed with the rear end side as a fulcrum, and is used in a closed state during automatic document feeding. The original placed on the original table 3a is contacted with the contact glass 2 by a transport belt 3b via a feed roller.
After the document is read by the document reading unit 2 and the document image is read by the document reading unit 2, the document is discharged to the paper discharge unit 3c. Further, the automatic document feeder 3 is opened, and the document is manually inserted into the contact glass 2.
It can also be set on a.

An original reading section (scanner) 2 illuminates the original on the contact glass 2a with a light source 2b, a reading section 2f including an image sensor for reading the original image, and guides the original image to the reading section 2f. It comprises an optical system composed of mirror groups 2c, 2d, 2e and an imaging lens 2f,
The light source 2b and the mirror group scan the original surface while moving,
The reading section 2f sequentially reads the original image, converts it into an image signal, and transmits it to an image processing section (not shown). Since the copying machine having the configuration shown in FIG. 1 includes a developing device for one color such as red and blue in addition to a developing device for black, a color image is stored on the image sensor of the reading unit 2f. A color CCD or the like that can be read by color separation is used, and is converted into an image signal corresponding to each color by an image processing unit.

The image forming unit (printer) 1 includes a drum-shaped photosensitive member 10 serving as an image carrier, and a first charging device 11, a first optical writing device 7, and a first developing device disposed around the photosensitive member. 1
2, a second charging device, a second optical writing device 14, a second developing device 15, a registration roller 16, a transfer transport device 17, a cleaning device 18, and the like, and further downstream of the transfer transport device 17 in the transfer paper transport direction. A fixing device 19 is provided.

The first charging device 11, the first optical writing device 7, and the first developing device 12 are for forming a black image, and the first optical writing device 7 includes a laser diode 9a and a light such as a rotating polygon mirror. A laser diode 9a emits light in response to a black image signal from an image processing unit (not shown), and includes a deflector 8, a scanning imaging lens 9b such as an fθ lens, and a mirror 9c. Charged photoreceptor 10
A latent image of a black image is written thereon, and the latent image of the black image is the first latent image.
The image is developed with the black toner of the developing device 12. The second charging device, the second optical writing device 14, and the second developing device 15 are for forming a color image of one color such as red or blue.
Charges the photoreceptor 10 after the black image is formed, and the second optical writing device 14 is composed of an LED array and a lens array, and corresponds to a color image signal such as red or blue from an image processing unit (not shown). The array emits light, and a latent image of a color image such as red or blue is written on the photoreceptor 10, and the latent image of the color image is developed by the second developing device 15 with a color toner such as red or blue.

The black and color toner images formed on the photoreceptor 10 are fed from one of the plurality of paper feed trays 4a to 4d of the paper feed unit 4 or the manual feed table 4f, and are passed through the registration rollers 16. The image is transferred onto the transfer paper conveyed to the nip portion between the transfer belt 17a of the transfer conveyance device 17 and the photoconductor 10. Then, the transfer paper after the image transfer is a photoconductor 10
The toner image is fixed to the transfer paper by the heating roller 19a and the pressure roller 19b of the fixing device 19. The transfer paper after fixing is transferred to the discharge tray 6a or the multi-stage discharge tray 6b of the discharge section 6 via the discharge rollers 20 and 21 during one-sided copying.
The paper is conveyed to the tray 5 for both sides via the both-side conveyance path 22 at the time of duplex copying. Further, the toner remaining on the photoreceptor 10 after the transfer of the toner image is removed by the cleaning device 18 and the charge is removed by a charge removing device (not shown). The residual toner collected by the cleaning device 18 is sent to a waste toner tank 24 by a transport mechanism (not shown).

The configuration example of the image forming apparatus provided with the transfer / transport device according to the present invention has been briefly described above.
The image forming apparatus to which the present invention is applied is not limited to the configuration shown in the drawing, but may be an analog type copier that directly exposes a document image to a photoreceptor, or a configuration including only a printer, as long as the apparatus includes a transfer conveyance device. Alternatively, a mono-color image forming apparatus having only one optical writing device or developing device, or a color image forming device having a plurality of developing devices of black, cyan, magenta, yellow, etc., capable of forming a full-color image But it is good.

Next, the configuration and operation of the transfer / transport apparatus according to the present invention will be described in detail. FIG. 2 is a front view showing a schematic configuration of the transfer / conveyance device. In FIG. 2, the transfer conveyance device 17 includes an endless, medium-resistance transfer belt 17a disposed opposite to the photoconductor 10, a driving roller 17b and a driven roller 17c supporting the transfer belt 17a, and a transfer belt 17a. A bias applying roller 17d disposed on the back side for applying a transfer bias, and a transfer belt 17
cleaning blade 17e for cleaning the surface of a
And a mechanism (17g, 17h) for bringing the transfer belt 17a into and out of contact with the photoreceptor 10, and a mechanism (release lever 17f) for releasing the transfer / transport unit.

The release mechanism of the transfer / transport unit is released by turning the transfer / transport unit clockwise about the drive roller 17b by tilting the release lever 17f in the direction of the arrow in the drawing. This mechanism is provided to make it easy to remove jammed paper in the event of a jam and to ensure the detachability of the transfer / transport unit and the photosensitive drum unit during maintenance.

FIG. 3 is an explanatory view of a transfer belt contact / separation mechanism. The transfer belt 17a contact / separation mechanism is constituted by an electromagnetic spring clutch 17g with a cam, a contact / separation lever 17h, a contact / separation arm 17i, a spring 17j and the like. It is configured. The contact / separation arm 17i is fixed to the shaft of the contact / separation lever 17h, and a pressing spring 17j is inserted between the lower end of the contact / separation arm 17i and the base of the transfer / transport unit. The upper end of the contact / separation arm 17i contacts the support 17k of the transfer belt 17a to support the transfer belt.

FIG. 3A shows a state in which the contact / separation lever 17h is pressed down by the cam of the electromagnetic spring clutch 17g against the pressing force of the spring 17j, and the transfer belt 17a is separated from the photosensitive member 10. It will be in the state that was done. When the image forming operation is not performed, the transfer belt 17a is
2A, the image forming operation is started, and the transfer paper S sent to the registration roller 16 is aligned with the leading edge of the image on the photoconductor 10 by the registration roller. When the leading end of the transfer paper S comes close to the contact portion between the photoconductor 10 and the transfer belt 17a, the electromagnetic spring clutch 17g is turned on.
As shown in FIG. 3B, the contact / separation lever 17h moves upward, and the contact / separation arm 17i moves upward due to the pressing force of the spring 17j.
Push up k. As a result, the transfer belt 17a comes into contact with the photoconductor 10 to form a nip portion W, and the toner image is transferred to the transfer paper S at the nip portion. After the end of the transfer, the electromagnetic spring clutch 17g is turned off, the cam returns to the state shown in FIG. 3A, and the contact / separation lever 17h is pushed downward to lower the contact / separation arm 17i, whereby the transfer belt 17a is moved. It is separated from the photoconductor 17a.

The transfer belt contact / separation mechanism is used to prevent substances or oil components in the material of the transfer belt from adhering to the photoreceptor due to prolonged contact, and to control the pattern density on the photoreceptor by a P sensor. It is provided to prevent the toner image from being transferred to the transfer belt when detecting.

Next, the basic structure and operation of the transfer / transport apparatus will be described with reference to FIGS. FIG. 4 is an explanatory diagram of the configuration and operation of the transfer / transport device including the electrical system.
2A shows a state in which the transfer belt 17a is separated from the photoconductor 10, and FIG. 2B shows a state in which the transfer belt 17a is in contact with the photoconductor 10. FIG. 5 is a cross-sectional view of the transfer belt,
FIG. 6 is an explanatory diagram of a transfer step by the transfer / conveyance device.

As shown in FIG. 5, the transfer belt 17a
It has a layered structure, and the electrical resistance measured by JIS K6911 is such that when DC100V is applied,
The surface layer 170a has a surface resistivity of 1 × 10 ^{9 on the} belt surface.
Ω to 1 × 10 ¹² Ω, the surface resistivity of the inner layer 170b is 1 ×
10 ⁷ Ω to 1 × 10 ⁹ Ω and the volume resistivity is 5
It is set to a value of × 10 ⁸ Ω · cm to 5 × 10 ¹⁰ Ω · cm.

In FIG. 4, a bias applying roller 17d for applying a transfer bias is provided downstream of the driven roller 17c in the moving direction of the transfer belt 17a and in contact with the back side of the transfer belt 17a. ,
A contact electrode is provided to apply a charge having a polarity opposite to the charge polarity of the toner on the photoconductor 10 to the transfer belt 17a, and is connected to a high-voltage power supply 25.

Driving roller 17b and driven roller 17c
Is for detecting a current flowing on the transfer belt 17a as a feedback current, and the current supplied from the bias applying roller 17d is controlled by detecting this current.
For this reason, a transfer control plate 26 for setting the supply current to the bias applying roller 17d according to the detected current is connected to each of the rollers 17b and 17c. It is connected.

In such a transfer and transfer device 17,
As the transfer paper S is fed out from the registration rollers 16, the transfer belt 17a is moved by the contact / separation mechanism shown in FIG.
Is set so that the support 17k contacts the transfer belt 17a with the photoreceptor 10, and the position of the transfer belt 17a changes from the separated state of FIG. 4A to the contact state of FIG.
A nip portion W having a width (for example, about 12 mm) that allows the transfer paper S to be conveyed while being in contact with the photoconductor 10 is formed at a position facing the photoconductor 10. On the other hand, the photoreceptor 10
The surface is charged to, for example, -800 V, and as shown in FIG. 6, the toner moves to the nip portion while positively charged toner is electrostatically attracted to the surface.

In the nip portion W shown in FIG. 4B, the toner on the photoreceptor 10 is transferred to the transfer paper S by the transfer bias from the bias applying roller 17d located on the back side of the transfer belt 17a as shown in FIG. Transfer to the top. The transfer bias is applied from the high voltage power supply 12 in the range of -1.5 kV to -6.5 kV. The transfer bias is variably set as a result of the constant current control as described below. That is, FIG. 4 (A), the (B), the time of the current value output from the high voltage power supply 12 and I _1, detects a feedback current flowing through the ground side through the transfer belt 17a the rollers 17b, from 17c If the value was I _2, between these _{two, I 1 -I 2 = I OUT} ( However, I _OUT: constant) controlling the value of I ₁ so that the relation is obtained. this is,
Temperature, regardless of variations occurring in the production quality of the environmental conditions change or transfer belt 17a such as humidity, is done to eliminate the change in the transfer efficiency by stabilizing the surface potential V _P on the transfer sheet S .

[0040] That is, the transfer belt 17a and the transfer paper by Mitateru the current flowing into the photosensitive member 10 side as I _OUT through S, the transfer belt 17a due to low resistance or high resistance of the surface resistance V _P on the transfer sheet S This prevents a change in the ease of current flow to the transfer paper S from affecting the separation performance and transfer performance. In the case of this embodiment, I _OUT is conveying speed 330 mm / sec, the effective bias applying roller length 310mm, I _OUT = -35μ
Good transfer was obtained when A ± 5 μA was set.

When the image is transferred from the photoreceptor 10, the transfer paper S is also charged at the same time. Therefore,
Due to the relationship between the true charge of the transfer belt 17a and the polarization charge generated on the transfer paper S side, the transfer paper S can be electrostatically attracted onto the transfer belt 17a to separate the transfer paper from the photoreceptor 10. Then, the transfer paper S using the curvature separation of the photoconductor 10
The separation operation of the transfer paper S is promoted by the peeling operation based on the strength of its own waist.

However, in such electrostatic attraction, when the humidity is high due to a change in environmental conditions, the current easily flows through the transfer sheet S, so that the transfer sheet cannot be separated properly.
Therefore, the surface layer 17 of the transfer belt 17a shown in FIG.
0a, the transfer of the true charge to the transfer paper S at the nip W is delayed because the resistance value is set slightly higher, and the bias applying roller 17d is further moved in the transfer paper transport direction than the nip W. At the downstream side. This allows
The transfer of the true charges from the transfer belt 17a to the transfer sheet S is delayed so as to avoid an electrostatic attraction relationship between the transfer sheet S and the photoconductor 10.

To delay the transfer of the true charge used in this case means that no charge is generated on the transfer sheet S upstream from the transfer sheet S to the nip portion on the photosensitive member 19 side. This prevents the transfer sheet S from being wound around the photoconductor 10, and also prevents separation failure of the transfer sheet S from the photoconductor 10.

Further, it is better to select a transfer belt 17a having a small resistance change due to an environmental change.
As a conductive material for controlling resistance, carbon, zinc oxide and the like are added in an appropriate amount, and when a rubber belt is used as the elastic belt, chloroprene rubber, EPDM rubber, silicone rubber, epichlorohydrin rubber, etc. have a low hygroscopic property, It is desired to select a material having a stable resistance value.

The current I _OUT flowing to the photoconductor 10 side
Is not unique and can be reduced when the transport speed is low, and increased when the transport speed is high.

On the other hand, the transfer paper S that has passed through the nip W
The toner is conveyed electrostatically in accordance with the movement of the transfer belt 17a,
Curvature separation is performed by the roller 17b on the driving side. For this reason, the diameter of the drive roller 17b is set to 18 mm or less. Furthermore, in the case of using such a drive roller 17b is fine 45K paper (stiffness: horizontal 21 [cm ^3/100]) experimental result that separation is possible of is obtained.

The transfer belt 17 is driven by the driving roller 17b.
The transfer paper S separated from the heat roller 19a and the pressure roller 1 that constitute the fixing device 19 are guided by a guide plate.
7b. In the fixing device 19, the toner on the transfer paper S is melted by heating and pressed against the transfer paper S to fix the toner on the transfer paper S.

The transfer belt 17a, on which the transfer of the image to the transfer paper S and the separation has been completed, the support 17k is lowered by the contact / separation mechanism shown in FIG. Then, the belt surface is cleaned by the cleaning unit 23. The cleaning unit 23 includes a cleaning blade 17e. By rubbing the transfer belt 17a, toner transferred from the surface of the photoreceptor 10 or scattered around the transfer belt 17a without being transferred is attached. In this case, the toner and paper dust of the transfer paper S are scraped off.

The transfer belt 17a rubbed by the cleaning blade 17e has a low friction coefficient to prevent a phenomenon such as an increase in driving force due to an increase in rubbing resistance or a turning-up of the cleaning blade 17a. -Based resin material, for example, polyvinylidene fluoride, ethylene tetrafluoride and the like. The toner or paper dust scraped off from the surface of the transfer belt 17a is conveyed and stored in the waste toner tank 24 of the image forming apparatus main body shown in FIG. 1 by the collecting screw 23a.

The basic configuration and operation of the transfer / transport device have been described above. However, in an image forming apparatus equipped with such a transfer / transport device 17, a large number of copies having a small image area are taken, or a blank copy is mistakenly taken. When a large number of sheets are taken, there is no residual toner on the transfer belt 17a, and there is no toner on the edge of the cleaning blade 17e in contact with the transfer belt 17a. For this reason,
The coefficient of friction between the transfer belt 17a and the cleaning blade 17e increases, the rubbing resistance increases, the edge of the cleaning blade 17e is caught on the belt surface, and the edge of the cleaning blade 17e may be turned up. When the blade is turned up, it causes the occurrence of cleaning failure, the back contamination of the transfer material, the scattering of toner, and the damage of the transfer belt.

To solve the above problem,
In the present invention, in order to prevent the cleaning blade 17e from being turned up, a line for supplying the toner is formed between the sheets of the photoreceptor 10, and a means for transferring the line to the transfer belt 17a is provided. That is, a toner supply line is formed between the sheets of the photoreceptor 10, this line is transferred to the transfer belt 17a and toner is supplied to the edge of the cleaning blade 17e, and the transfer belt 17a and the cleaning blade 17e are To prevent the coefficient of friction from increasing
The occurrence of turning of the cleaning blade 17e is prevented.

Here, as the toner supply line, for example, a line having a thickness of about 2 mm is written between the sheets of the photoreceptor so as to fill the entire image width at a rate of once for a plurality of copies. 17e. However, since the toner supply line has a larger amount of toner than the residual toner adhered when the toner is transferred to a normal transfer sheet, the toner supply line on the transfer belt 17a is a straight line parallel to the cleaning blade 17e. , Cleaning blade 1
As the toner is simultaneously input to the entire width of 7e, the toner supply becomes excessive and the cleaning may not be completed. Further, if the blade conditions are such that it can be cleaned, for example, if the contact pressure of the cleaning blade 17e to the transfer belt 17a is set high, the cleaning performance becomes excessive during normal cleaning, and the blade deterioration which is a side effect is caused. Happens early.

Therefore, in the present invention, for example, as shown in FIG. 7, the toner supply line is written on the transfer belt 17a so as to be a straight line inclined by an angle θ from the contact line of the cleaning blade 17e. ). As a result, the toner is not simultaneously input to the entire width of the cleaning blade 17e.
Since the cleaning performance by the cleaning blade 7e is very easy, the contact pressure of the cleaning blade 17e can be reduced, and the toner on the transfer belt can be satisfactorily removed even at a relatively low contact pressure under the same conditions as in normal cleaning. Accordingly, the cleaning blade 17e hardly deteriorates.

On the other hand, as the toner supply line, FIG.
A line having a wavy shape as shown in FIG. 9 or a line having a bent line as shown in FIG. 9 may be used.

In the case of the linear toner supply line inclined at an angle θ with respect to the contact line of the cleaning blade shown in FIG. 7, if the angle θ is too large, the paper interval becomes longer, and the copy speed (CPM (copy) 8/9), it is desirable to increase the size as much as possible without affecting the CPM. Similarly, in the case of the toner supply line as shown in FIGS. It is desirable to form with.

As another embodiment of the present invention, FIG.
0, the toner supply line is connected to the transfer belt 1
There is a method of writing as if it is made up of a plurality of short straight lines on 7a. As a specific example, a toner supply line in which a plurality of straight lines are arranged in a bent line as shown in FIG. 10A, or a toner supply line in which a plurality of straight lines are alternately shifted as shown in FIG. There is a supply line, or a toner supply line in which a plurality of straight lines are arranged in a straight line inclined with respect to the contact line of the cleaning blade as shown in FIG. With such a toner supply line, toner is not simultaneously input to the entire width of the cleaning blade 17e, and the cleaning performance of the cleaning blade 17e becomes very easy. Therefore, the toner on the transfer belt can be satisfactorily removed even with a relatively low contact pressure under the same conditions as in the normal cleaning, thereby preventing the deterioration of the cleaning blade 17e.

Further, as another example of the toner supply line, as shown in FIG. 11, a band-like line with a low density such as background dirt, which can be seen slightly, may be used. The same effect as described above can be obtained.

In the case of the toner supply line composed of a plurality of straight lines in FIG. 10, if the interval between the plurality of straight lines in the belt running direction is too large, the paper interval becomes longer, and the copy speed (CP
M (the number of copies / minute)), it is desirable to make the interval as large as possible without affecting the CPM.

The embodiment of the toner supply line according to the present invention has been described above. However, since the toner supply line for preventing the cleaning blade from being turned up is usually inserted between sheets of several copies, The more frequently the toner supply line is inserted, the harder the blade is turned up. However, on the other hand, useless toner is consumed or cleaning failure occurs. Also, if the background toner adheres to the transfer belt and is input to the tip of the blade in a large amount, there is no need for a toner supply line for preventing turning-up. However, as shown in FIG. 12, the amount of scum on the transfer belt is greatly related to the humidity, and decreases to almost no state at a humidity of 90%. For this reason, in a high humidity environment, it is necessary to insert a toner supply line in a relatively short cycle to prevent the cleaning blade from turning up.

Therefore, in the present invention, the formation of the toner supply line can be set according to the use conditions of the apparatus (Claim 5), and the various use conditions (temperature / humidity, presence / absence of air conditioning, etc.) of the image forming apparatus can be set. And the like), control is performed to minimize useless toner used in the toner supply line for preventing turning-up and to prevent turning-up of the cleaning blade.

As a specific example, when an image forming apparatus such as a copying machine is used in a summer environment (high temperature, high humidity environment), as shown in FIG. For example, it is assumed that a setting is made such that a toner supply line for turning over is inserted every 15 copies. Also,
In a normal office environment (with air conditioning), the temperature and humidity are adjusted to be substantially constant, and there is appropriate soiling. Therefore, it is necessary to set the toner supply line approximately once every 30 copies. I just need. On the other hand, when used in a winter environment (low-temperature, low-humidity environment), as shown in FIG. 12, there is much background contamination on the transfer belt. . The setting of the number of copies of the toner supply line for preventing the turn-up is set by a service person using a key input or the like from an operation unit (operation panel) of the apparatus.

Next, means for forming the toner supply line will be described. In an image forming apparatus such as a digital copying machine (or a printer, a facsimile, or the like) shown in FIG. 1 having optical writing devices 7 and 14 for forming image data into a latent image using a laser beam or an LED array, If the pattern of the toner supply line as shown in FIGS. 7 to 11 is provided in advance in the storage area of the image data, the pattern is used as the image data when the toner supply line is formed, and the optical writing device 7 is used. , 14 can easily form a latent image of the toner supply line between the sheets of the photoreceptor. FIG. 13 shows an example of a toner supply line forming unit in an image forming apparatus having an optical writing device using laser light.
2 shows an example of a toner supply line forming unit in an image forming apparatus having an optical writing device using an LED array. FIG. 15 shows a block diagram of a control system.

The optical writing device 7 shown in FIG. 13 deflects the laser light from the laser diode 9a, which is turned on by a control signal from the image processing controller shown in FIG. 9b to scan the photosensitive member 10 and form a latent image on the photosensitive member 10 by a laser beam that is scanned one after another, and stores the latent image in advance outside the image area of the photosensitive member 10 (between sheets) when necessary. A latent image is formed by laser light in accordance with the image data of the toner supply line pattern stored in the area. Then, if this latent image is developed with toner of a developing device (not shown) and directly transferred to a transfer belt (not shown), a toner supply line as shown in FIGS. Is formed.

The optical writing device 14 shown in FIG. 14 is turned on by a control signal from the image processing controller shown in FIG.
Light from the ED array is passed through the lens array to the photoreceptor 10.
The LED array has a function of forming a latent image by exposing the LED array on the outer side of the image area of the photoconductor 10 (between sheets) when necessary according to the image data of the toner supply line pattern stored in the storage area in advance. Forms a latent image. Then, if this latent image is developed with toner from a developing device (not shown) and directly transferred to a transfer belt (not shown),
A toner supply line as shown in FIG. 11 is formed.

The above example is an example of the toner supply line forming means in the digital image forming apparatus having the configuration shown in FIG. 1. Next, an exposing device for directly exposing the original image to the photosensitive member will be described. An example of a means for forming a toner supply line in an image forming apparatus having the same will be described. In an image forming apparatus that directly exposes a document image to a photoreceptor by an exposure device, a pattern for forming an image forming line for toner supply is printed on a non-image area on a contact glass on which the document is placed. And the like. 16 to 1
8 shows an example of a toner supply line forming means in an image forming apparatus having an exposure device.

In the image forming apparatus shown in FIG. 16, the exposure lamp of the exposure apparatus is turned on by a signal from a sequence controller of a control unit (not shown), and the image formed by the lens is instantaneously laid on the belt-shaped photosensitive member. It has a function of forming an image, and is shown in FIGS. 7 to 11 at a position where a latent image is formed before or after the image area on the photoconductor on the exposure surface outside the image area on the contact glass. By providing such a toner supply line pattern, the pattern is formed as a latent image before or after the image area on the photoconductor. Then, if this latent image is developed with toner of a developing device (not shown) and transferred to a transfer belt (not shown), a toner supply line is formed on the transfer belt.

The above-described patterns are formed as latent images by the same number as the number of times of exposure of the exposure apparatus. However, the patterns formed into latent images other than when necessary can be erased by the eraser which is the next process. There is also a means for forming the pattern as a latent image when necessary by enlarging or reducing the exposure area.

In the image forming apparatus shown in FIG. 17, the exposure lamp of the exposure device is turned on by a signal from a sequence controller of a control unit (not shown), and the exposure lamp and the first mirror and the second and third mirrors scan the lens. Has a function of forming a latent image on a drum-shaped photoreceptor by the light imaged by, and on the exposure surface outside the image area on the contact glass,
By providing a toner supply line pattern as shown in FIG. 7 to FIG. 11 at a position where a latent image is formed before or after the image area on the photoconductor, the image is formed before or after the image area on the photoconductor. The pattern is formed as a latent image. Then, if this latent image is developed with toner of a developing device (not shown) and transferred to a transfer belt (not shown), a toner supply line is formed on the transfer belt.

The above-described patterns are formed as latent images by the same number as the number of times of exposure of the exposure apparatus. However, the patterns formed as latent images other than when necessary can be erased by the eraser which is the next process. Further, means for forming the pattern as a latent image when necessary by shortening the scanning area,
There is also a means for changing the lighting timing of the exposure lamp and exposing the pattern when necessary to form a latent image.

In the image forming apparatus shown in FIG. 18, the exposure lamp of the exposure apparatus is turned on, the contact glass is moved by a signal from a sequence controller of a control unit (not shown),
It has the function of forming a latent image on the belt-shaped photoreceptor by light formed by the lens, and forms a latent image on the contact glass surface outside the image area before or after the image area on the photoreceptor. By providing a pattern of the toner supply line as shown in FIGS. 7 to 11 at the position to be formed, the pattern is formed as a latent image before or after the image area on the photoconductor. Then, if this latent image is developed with toner of a developing device (not shown) and transferred to a transfer belt (not shown), a toner supply line is formed on the transfer belt.

The above patterns are formed as latent images by the same number as the number of times of movement of the contact glass. However, the patterns formed as latent images other than when necessary can be erased by the eraser which is the next process. There are also means for forming the pattern as a latent image when necessary by shortening the moving distance, and means for forming a latent image by exposing the pattern when necessary by changing the lighting timing of an exposure lamp.

[0072]

As described above, in the image forming apparatus according to the first aspect, a line for supplying toner is formed between the sheets of the image carrier to prevent the cleaning blade of the transfer / conveyance apparatus from being turned up. By transferring the line to the transfer belt, toner is supplied to the edge portion of the cleaning blade, and the friction coefficient between the transfer belt and the cleaning blade due to the toner shortage is prevented from increasing,
The occurrence of turning of the cleaning blade is prevented. And, since the toner supply line is a straight line having a certain angle with the cleaning blade on the transfer belt, even if the cleaning blade is installed so as to abut perpendicularly to the driving direction of the transfer belt, The toner is not simultaneously input to the entire width of the cleaning blade, so that the toner on the transfer belt can be removed satisfactorily even with a relatively low contact pressure under the same conditions as in the normal cleaning, and the toner supply line can be removed. Of the cleaning blade and scattering of toner can be prevented, and deterioration of the cleaning blade can be prevented.

In the image forming apparatus according to the present invention, a line for supplying toner is formed between the papers of the image carrier so as to prevent the cleaning blade of the transfer conveying device from being turned up, and the line is transferred to the transfer belt. Accordingly, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of the turning of the cleaning blade is prevented. Further, since the toner supply line on the transfer belt is not straight, even when the cleaning blade is installed so as to abut perpendicularly to the driving direction of the transfer belt, toner is simultaneously input to the entire width of the cleaning blade. The toner on the transfer belt can be satisfactorily removed even with a relatively low contact pressure under the same conditions as in normal cleaning, and it is possible to prevent poor cleaning and toner scattering when forming a toner supply line. Deterioration of the cleaning blade can also be prevented.

In the image forming apparatus according to the third aspect, a line for supplying toner is formed between the papers of the image carrier to prevent the cleaning blade of the transfer / conveyance device from being turned up, and the line is transferred to the transfer belt. Accordingly, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of the turning of the cleaning blade is prevented. Further, since the toner supply line on the transfer belt is formed of a plurality of straight lines, even if the cleaning blade is installed so as to abut perpendicularly to the driving direction of the transfer belt, the toner is supplied over the entire width of the cleaning blade. Can be removed at the same time, and the toner on the transfer belt can be satisfactorily removed even with a relatively low contact pressure under the same conditions as during normal cleaning, resulting in poor cleaning and toner scattering when forming a toner supply line. And the deterioration of the cleaning blade can be prevented.

In the image forming apparatus according to the present invention, a line for supplying toner is formed between the papers of the image carrier to prevent the cleaning blade of the transfer / conveyance device from being turned up, and the line is transferred to the transfer belt. Accordingly, the toner is supplied to the edge portion of the cleaning blade, so that the coefficient of friction between the transfer belt and the cleaning blade due to running out of toner is prevented from increasing, and the occurrence of the turning of the cleaning blade is prevented. Since the toner supply line on the transfer belt is a band with a low density like a background stain,
Even when the cleaning blade is installed so as to be perpendicular to the driving direction of the transfer belt, a large amount of toner is not input to the entire width of the cleaning blade at the same time. Even when the contact pressure is low, the toner on the transfer belt can be satisfactorily removed, and poor cleaning and toner scattering at the time of forming the toner supply line can be prevented, and deterioration of the cleaning blade can be prevented. In addition, there is an advantage that a line can be easily formed in a software manner as compared with a line such as a curve.

According to the fifth aspect of the invention, the first to fourth aspects are described.
In addition to the above configuration, the formation of the toner supply line (the number of times (frequency) of inserting the toner supply line) can be set in accordance with the use conditions of the apparatus such as the temperature and humidity and the presence or absence of air conditioning. The toner consumption can be minimized, and the occurrence of turning of the cleaning blade can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating a configuration example of an image forming apparatus including a transfer / conveyance device according to the present invention.

FIG. 2 is a front view illustrating a schematic configuration of a transfer / conveyance device.

FIG. 3 is an explanatory diagram of a transfer belt contact / separation mechanism of the transfer / conveyance device.

FIG. 4 is an explanatory diagram of a configuration and an operation including an electrical system of the transfer and transfer device.

FIG. 5 is a partial cross-sectional view of the transfer belt.

FIG. 6 is an explanatory diagram of a transfer step by the transfer / conveyance device shown in FIG. 4;

FIG. 7 is a perspective view of the transfer belt according to the first embodiment, in which a toner supply line formed of a straight line inclined with respect to a contact line of a blade is formed.

FIG. 8 is a plan view of the transfer belt according to the second embodiment of the present invention, in which a wavy toner supply line is formed.

FIG. 9 is a view showing another embodiment of the second embodiment, and is a plan view of a transfer belt on which a bent toner supply line is formed.

FIG. 10 is a diagram showing an embodiment of claim 3,
(A), (B), (C) is a plan view of a transfer belt on which a toner supply line composed of a plurality of straight lines is formed.

FIG. 11 is a plan view of the transfer belt according to the fourth embodiment, in which a toner supply line composed of a background-stained band is formed.

FIG. 12 is a diagram illustrating a relationship between background contamination on a transfer belt and humidity.

FIG. 13 is a diagram illustrating an example of a toner supply line forming unit, and is a schematic configuration diagram of a main part of an image forming apparatus having an optical writing device using laser light.

FIG. 14 is a diagram illustrating another example of a toner supply line forming unit, and is a schematic diagram illustrating a main configuration of an image forming apparatus having an optical writing device using an LED array.

FIG. 15 is a block diagram of a control system of the image forming apparatus shown in FIG. 10 or FIG.

FIG. 16 is a view showing still another example of the toner supply line forming means, and is a schematic view of a main configuration of an image forming apparatus having an exposure device.

FIG. 17 is a view showing still another example of a toner supply line forming unit, and is a schematic configuration diagram of a principal part of an image forming apparatus having an exposure device.

FIG. 18 is a view showing still another example of the toner supply line forming means, and is a schematic configuration diagram of a principal part of an image forming apparatus having an exposure device.

[Explanation of symbols]

 7 First Optical Writing Device 10 Photoconductor (Image Carrier) 11 First Charging Device 12 First Developing Device 13 Second Charging Device 14 Second Optical Writing Device 15 Second Developing Device 17 Transfer Conveying Device 17a Transfer Belt ( Belt running body) 17b drive roller 17c driven roller 17d bias applying roller 17e cleaning blade 19 fixing device 23 cleaning unit 25 high voltage power supply 26 transfer control plate S transfer paper (transfer material)

Claims (5)

[Claims] An endless, medium-resistance belt running body disposed opposite an image carrier, a bias applying roller disposed on the back side of the belt running body, and cleaning the surface of the belt running body. A cleaning blade which transfers the toner image on the image carrier to the transfer material by applying a high voltage to a bias applying roller by bringing the belt traveling body holding the transfer material into contact with the rotating image carrier; An image forming apparatus comprising: a transfer conveyance device configured to convey a transfer material after transfer toward a fixing unit and to clean toner remaining on the surface of the belt traveling body after separation of the transfer material with the cleaning blade. A means for forming a toner supply line between the papers of the image carrier to prevent the cleaning blade of the apparatus from being turned up, and a means for transferring the line to the belt traveling body; The image forming apparatus according to claim 1, wherein the in is a straight line having a certain angle with the cleaning blade on the belt traveling body. 2. An endless, medium-resistance belt running body disposed opposite to an image carrier, a bias applying roller disposed on the back side of the belt running body, and cleaning the surface of the belt running body. A cleaning blade which transfers the toner image on the image carrier to the transfer material by applying a high voltage to a bias applying roller by bringing the belt traveling body holding the transfer material into contact with the rotating image carrier; An image forming apparatus comprising: a transfer conveyance device configured to convey a transfer material after transfer toward a fixing unit and to clean toner remaining on the surface of the belt traveling body after separation of the transfer material with the cleaning blade. A means for forming a toner supply line between the papers of the image carrier to prevent the cleaning blade of the apparatus from being turned up, and a means for transferring the line to the belt traveling body; An image forming apparatus, wherein the in is not a straight line. 3. An endless, medium-resistance belt running body disposed opposite to the image carrier, a bias applying roller disposed on the back side of the belt running body, and cleaning the surface of the belt running body. A cleaning blade which transfers the toner image on the image carrier to the transfer material by applying a high voltage to a bias applying roller by bringing the belt traveling body holding the transfer material into contact with the rotating image carrier; An image forming apparatus comprising: a transfer conveyance device configured to convey a transfer material after transfer toward a fixing unit and to clean toner remaining on the surface of the belt traveling body after separation of the transfer material with the cleaning blade. A means for forming a toner supply line between the papers of the image carrier to prevent the cleaning blade of the apparatus from being turned up, and a means for transferring the line to the belt traveling body; An image forming apparatus comprising: a plurality of straight lines; 4. An endless, medium-resistance belt running body disposed opposite an image carrier, a bias applying roller disposed on the back side of the belt running body, and cleaning the surface of the belt running body. A cleaning blade which transfers the toner image on the image carrier to the transfer material by applying a high voltage to a bias applying roller by bringing the belt traveling body holding the transfer material into contact with the rotating image carrier; An image forming apparatus comprising: a transfer conveyance device configured to convey a transfer material after transfer toward a fixing unit and to clean toner remaining on the surface of the belt traveling body after separation of the transfer material with the cleaning blade. A means for forming a toner supply line between the papers of the image carrier to prevent the cleaning blade of the apparatus from being turned up, and a means for transferring the line to the belt traveling body; The image forming apparatus, wherein the in is a background-dirty band. 5. The image forming apparatus according to claim 1, wherein the toner supply line is formed by:
An image forming apparatus characterized in that it can be set according to the use conditions of the apparatus.