JP3568085B2 - Transfer transfer device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transfer / conveyance device provided in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, and particularly to a transfer / conveyance device that performs electrostatic transfer using a transfer belt.
[0002]
[Prior art]
2. Description of the Related Art In an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, an original image is exposed after a photosensitive member serving as an image carrier is charged, or a laser scanning optical system or an LED optical writing optical system is used. Optical writing according to the image information is performed, an electrostatic latent image is formed on the photoreceptor, and the latent image is developed by toner of a developing device to be visualized, and the toner image has been conveyed from a paper feeding unit. Transfer to a transfer material such as transfer paper. 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 a copy or a print. In such an image forming apparatus, a transfer device is used as a device for transferring image information formed of toner on a photoreceptor onto a transfer material, and electrostatically adsorbing the transfer material after transfer to a fixing unit. 2. Description of the Related Art A belt-type transfer / transport device using a belt is known. Hereinafter, a description will be given of an example of a basic configuration and an operation of a transfer / conveyance device provided in the image forming apparatus.
[0003]
FIG. 5 is a perspective view showing an example of a basic configuration of the transfer / transport device, and FIG. 6 is an explanatory diagram of a main portion of an image forming apparatus provided with the transfer / transport device shown in FIG. The transfer / conveying apparatus denoted by reference numeral 1 in FIG. 5 supports the belt unit 2 detachably from the main body 1A. The belt unit 2 includes a transfer belt 6 wound around a pair of rollers 4 and 5 for transferring a developed image from the drum-shaped photoconductor 3 shown in FIG. A transfer bias roller 11 for applying a transfer bias to the transfer belt 6; and a contact plate 13 for removing charges from the transfer belt 6. Further, a cleaning device 16 having a cleaning blade 16A for scraping off residual toner and transfer paper S dust adhering to the surface of the transfer belt and a high-voltage power supply 12 for applying a voltage to the transfer bias roller 11 are connected to the main body 1A shown in FIG. Is provided.
[0004]
As shown in FIGS. 5 and 6, the roller 5 has a gear 5b connected to a drive motor (not shown) and is configured to be driven to rotate, and is a drive roller. The transfer belt 6 can move in the transport direction of the transfer paper S (the direction of the arrow A in FIG. 6) at a position facing the photoconductor 3 following the rotation of the drive roller 5. As shown in FIG. 8, the transfer belt 6 has a two-layer structure. When the electric resistance measured according to JIS K6911 is 100 V DC, the surface layer 6 b has a surface resistivity of 1 × 10 ⁹ Ω ~ 1 × 10 ¹² Ω, the surface resistivity of the inner layer 6a is 1 × 10 ⁷ Ω ~ 1 × 10 ⁹ Ω and its volume resistivity is 5 × 10 ⁸ Ω · cm to 5 × 10 ¹⁰ It is set to Ω · cm.
[0005]
The rollers 4 and 5 are rotatably supported by a support 7 as shown in FIGS. The support 7 can swing about the support shaft 5 a of the roller 5, which is located downstream of the transfer position with respect to the photoconductor 3, in the transfer paper transport direction indicated by the arrow A among the rollers 4 and 5. . The support 7 is operated by a DC solenoid 8 driven on the transfer position side of the transfer belt 6 by a signal from a control plate 8A. That is, a contact / separation lever 9 is connected to the DC solenoid 8, and the contact / separation lever 9 moves the support 7 to move the transfer belt 6 toward and away from the photoconductor 3. FIG. 6 shows a state in which the transfer belt 6 is separated from the photoconductor 3, and FIG. 7 shows a state at the time of transfer in which the transfer belt 6 is in contact with the photoconductor 3.
[0006]
When 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 paper conveying means, approaches the photoreceptor 3. A drive signal is issued to drive the DC solenoid 8. Accordingly, by driving the solenoid 8, the support 7 comes close to the photoconductor 3, and the transfer belt 6 contacts the photoconductor 3, so that the transfer paper S is transferred to the photoconductor 3 at a position facing the photoconductor 3. A nip portion B that can be conveyed while being in contact with 3 is formed.
[0007]
Among the rollers 4 and 5 described above, the roller 4 located on the photoconductor 3 side is configured as a driven roller with respect to the roller 5 on the driving side, and the surface shape of the roller 4 is such that both ends are tapered in the axial direction. The transfer belt 6 is prevented from being shifted. The roller 4 is a conductive roller made of metal or the like, but only supports the belt having the electric resistance as described above, and is not electrically directly connected to other conductive members.
The roller 5 on the driving side is made of a material such as EPDM rubber, chloroprene rubber, or silicone rubber because of its function of increasing the gripping force on the transfer belt 6 during driving.
[0008]
The transfer bias roller 11 is provided downstream of the driven roller 4 in the moving direction of the transfer belt 6 (left side in FIGS. 6 and 7) so as to contact the inside of the transfer belt 6. The transfer bias roller 11 constitutes a contact electrode for applying a charge having a polarity opposite to the charge polarity of the toner on the photoconductor 3 to the transfer belt 6, and is connected to a high-voltage power supply 12.
[0009]
The contact plate 13 is disposed on the lower side of the transfer belt 6, not on the transfer paper transport surface, but on the inner surface of the belt near the driven roller 4, which suppresses charge injection into the transfer paper S upstream of the transfer nip. I have. The contact plate 13 detects a current flowing on the transfer belt 6 as a feedback current, and the current supplied from the transfer bias roller 11 is controlled by detecting the current. For this reason, a transfer control plate 14 for setting a supply current to the transfer bias roller 11 according to the detection current is connected to the contact plate 13, and the transfer control plate 14 is connected to the high-voltage power supply 12. ing. The position of the contact plate 13 is not limited to the inner surface of the belt near the driven roller 4, but may be another position such as the inner surface of the belt near the driving roller 5.
[0010]
In such a transfer conveyance device 1, as shown in FIG. 7, as the transfer paper S is fed out from the registration roller 10, the support 7 sets the posture in which the transfer belt 6 approaches the photoconductor 3. Then, a nip portion B having a width of about 4 to 8 mm corresponding to the length of the transfer sheet in the transport direction is formed between the photosensitive member 3 and the photosensitive member 3.
[0011]
On the other hand, the surface of the photoconductor 3 is charged to, for example, -800 V, and moves to the nip portion with the positively charged toner electrostatically adsorbed on the surface, as shown in FIG. The photoreceptor 3 is disposed near the photoreceptor 3 before reaching the nip portion, and the surface potential is reduced by a pre-transfer static elimination lamp (PTL) 15 that weakens the charge on the surface of the photoreceptor 3. In FIG. 9, the height of the charged charge is represented by the size of a circle, and the state in which the charged charge is reduced by the pre-transfer charge removing lamp 15 is shown smaller than the circle before the charge removal.
[0012]
In the nip portion B shown in FIG. 7, the toner on the photoconductor 3 is transferred onto the transfer paper S by the transfer bias from the transfer bias roller 11 located on the transfer belt 6 side. This 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 following constant current control. That is, in FIGS. 6 and 7, the current value output from the high voltage ₁ The value obtained when the value of the feedback current flowing from the contact plate 13 to the installation side via the transfer belt 6 is detected as I ₂ , Between these two,
I ₁ −I ₂ = I _OUT (However, I _OUT : Constant) (1)
I so that ₁ Control the value of. This is because the surface potential V on the transfer paper S is not affected by changes in environmental conditions such as temperature and humidity and variations in the production quality of the transfer belt 6. _P In order to eliminate a change in transfer efficiency.
[0013]
That is, the current I flowing through the transfer belt 6 and the transfer paper S to the photoconductor 3 side. _OUT The surface resistance V on the transfer paper S _P Is prevented from affecting the separation performance and the transfer performance of the transfer paper S due to the change in the ease of current flow to the transfer belt 6 due to the low resistance or the high resistance.
In the case of this configuration example I _OUT Is I at a conveying speed of 330 mm / sec and an effective transfer bias roller length of 310 mm. _OUT = 35 μA ± 5 μA, good transfer was obtained.
[0014]
By the way, when the image transfer from the photoconductor 3 is performed, the transfer paper S is also charged at the same time. Therefore, the transfer paper S is electrostatically attracted onto the transfer belt 6 and the transfer paper can be separated from the photoconductor 3 by the relationship between the true charge of the transfer belt 6 and the polarization charge generated on the transfer paper S side. . Then, the transfer sheet S itself is promoted by a peeling operation using the stiffness of the transfer sheet S utilizing the curvature separation of the photoconductor 3.
[0015]
However, in the case of such electrostatic attraction, in a case of high humidity due to a change in environmental conditions, current easily flows through the transfer sheet S, so that the transfer sheet cannot be separated properly. For this reason, since the resistance value on the surface layer 6b of the transfer belt 6 shown in FIG. 8 is set slightly higher, the transfer of the true charge to the transfer paper S in the nip portion B is delayed, and further, The transfer bias roller 11 is located downstream of the nip portion B in the transfer paper transport direction. Thus, the transfer of the true charges from the transfer belt 6 to the transfer sheet S is delayed, so that the electrostatic attraction relationship between the transfer sheet S and the photoconductor 3 is avoided.
[0016]
To delay the transfer of the true charge used in this case means that no charge is generated on the transfer sheet S on the upstream side until the transfer sheet S reaches the nip portion on the photoconductor 6 side. This prevents the transfer paper S from being wound around the photoconductor 3 and also prevents the transfer paper S from separating from the photoconductor 3 from being poorly separated.
[0017]
Further, on the transfer belt 6 side, it is better to select a material having a small resistance change due to an environmental change. As a conductive material for controlling the resistance, an appropriate amount of carbon, zinc oxide or the like is added, and a rubber belt is used as an elastic belt. In such a case, it is desired to select a material having a low hygroscopicity and a stable resistance value, such as chloroprene rubber, EPDM rubber, silicone rubber, and epichlorohydrin rubber.
[0018]
The current I flowing to the photoconductor 3 side _OUT Is not unique and can be reduced when the transport speed is low, and increased when the transport speed is high or when the pre-transfer neutralization lamp 15 is not used.
[0019]
On the other hand, the transfer paper S that has passed through the nip portion B is electrostatically attracted and conveyed in accordance with the movement of the transfer belt 6, and the drive roller 5 separates the curvature. For this reason, the diameter of the drive roller 5 is set to 16 mm or less. Further, when such a driving roller 5 is used, high-quality 45K paper (stiffness: 21 cm in width) ³ / 100]) is possible.
[0020]
The transfer paper S separated from the transfer 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 unit 17. In the fixing unit 17, the toner on the transfer sheet S is melted by heating and pressed against the transfer sheet S to fix the toner on the transfer sheet S.
[0021]
When the transfer of the image onto the transfer sheet S and the separation of the transfer belt 6 are completed, the contact / separation lever 9 is released in response to the excitation of the DC solenoid 8 being released, and the support 7 is separated from the photoconductor 3. Then, the surface is cleaned by the cleaning device 16.
The cleaning device 16 includes a cleaning blade 16 </ b> A. By rubbing the transfer belt 6, toner transferred from the surface of the photoreceptor 3 or scattered around the transfer belt 6 without being transferred is attached. In this case, the toner and paper dust of the transfer paper S are scraped off.
[0022]
The transfer belt 6 rubbed by the cleaning blade 16A 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 turn-up of the cleaning blade 16A. A material such as polyvinylidene fluoride, ethylene tetrafluoride, or the like is coated. The toner or paper dust scraped off from the surface of the transfer belt 6 is stored in the waste toner collecting container (not shown) from the main body 1A by the toner collecting coil 16B.
[0023]
[Problems to be solved by the invention]
As described above, an example of the basic configuration and operation of a belt transfer type transfer / transport apparatus having a transfer belt has been described. The area was about 10 mm wider than both ends of the effective image area on the belt.
However, the toner on the transfer belt exists not only outside the effective image area but also to the end of the transfer belt due to toner scattering or the like. If the cleaning blade tries to clean the toner at the end of the transfer belt, the edge of the cleaning blade may be caught on the end of the transfer belt, and the cleaning blade may be involved. Therefore, the length of the cleaning blade is shorter than the width of the transfer belt, and the toner at the end of the transfer belt cannot be cleaned and remains on the transfer belt. For this reason, if toner adheres to the end of the transfer belt on the front side of the apparatus, there is a problem that the hand is stained with the toner when the hand is inserted during a jam processing or the like.
[0024]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a transfer conveyance device having a cleaning unit that can clean toner at an end of a transfer belt and can prevent hand stains due to toner at the end of a transfer belt. The purpose is to provide.
Further, in addition to the above objects, it is another object of the present invention to reduce the cost of the transfer belt cleaning unit, save space, and reduce the number of replacement parts.
[0025]
[Means for Solving the Problems]
In order to achieve the above object, the transfer conveyance device according to claim 1 has a blade system as a main unit and a bias roller system as a sub unit as a cleaning unit of the transfer belt, and a bias roller cleaning system as a sub cleaning unit. And a cleaning blade as the main cleaning means, and a sub-means. Bias roller and the bias roller The length is different from the bias roller blade, Bias roller and the bias roller The blade of the bias roller is longer than the cleaning blade of the main means, and has a wider cleaning range than the cleaning blade of the main means.
[0026]
That is, in the transfer / transport apparatus according to the first aspect, since the cleaning sub-means of the bias roller type is provided in addition to the cleaning main means of the blade type, the sub-means outside the cleaning area of the cleaning blade as the main means is used. It can be cleaned with a bias roller, and is a secondary means rather than a cleaning blade which is the main cleaning means. Bias roller and the bias roller By extending the blade of the bias roller, the cleaning range of the bias roller, which is a sub-means, is wider than that of the cleaning blade of the main means, and the toner adhered to the end of the transfer belt can be reliably cleaned. It is possible to prevent the hands from being stained by the toner at the end.
[0027]
The transfer conveyance device according to claim 2, wherein the transfer belt cleaning unit has a blade system as a main unit, a bias roller system as a sub unit, and a blade as a cleaning system for a bias roller as a cleaning sub unit, and The cleaning blade, which is the main cleaning means, and the blade of the bias roller, which is the auxiliary means, have the same length, but the mounting positions of the respective blades are different, and the blade of the bias roller is the main means. Attached to the front side of the device rather than the cleaning blade And the bias roller is also displaced closer to the front side of the apparatus than the cleaning blade that is the main means. It is characterized by:
[0028]
In other words, the transfer / conveying apparatus according to the second aspect has the bias roller type cleaning sub-unit in addition to the blade type cleaning main unit. Therefore, the outside of the cleaning area of the cleaning blade as the main unit is the sub-unit. The cleaning can be performed by the bias roller, and the cleaning blade serving as the main unit and the blade of the bias roller serving as the sub-unit have a length only when the blade of the bias roller is displaced closer to the front side of the apparatus than the cleaning blade of the main unit. Does not change, the toner adhered to the front end of the transfer belt can be reliably cleaned, the hand can be prevented from being stained by the toner at the end of the transfer belt, and the cleaning blade which is the main means And bias roller blade can use the same , It is possible to reduce the cost.
[0029]
According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the cleaning blade as the main cleaning means and the blade of the bias roller as the auxiliary means are supported by the same member. It is characterized in that the blades are integrated.
[0030]
The cleaning blade of the main cleaning means and the blade of the bias roller are used as two parts, but in the transfer conveyance device according to the third aspect, the two blades are supported and integrated by the same member to reduce the cost. It is possible to save space and reduce the number of replacement parts.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the illustrated examples.
[0032]
FIG. 1 is a schematic configuration diagram of a transfer / conveyance device showing one embodiment of the present invention, and FIG. 2 is an enlarged view showing a main part of a transfer belt cleaning device of the transfer / conveyance device. The basic configuration of the transfer conveyance device according to the present invention is substantially the same as the configuration shown in FIGS. 5 to 9 except for the transfer belt cleaning device 20, and the same components are denoted by the same reference numerals and have already been described. The description of the configuration and operation is omitted.
[0033]
1 and 2, a cleaning device 20 for cleaning the surface of the transfer belt 6 is provided with a cleaning blade 21 made of polyurethane as a main cleaning mechanism to clean residual toner and paper dust adhering to the transfer belt 6. In addition to wiping with the blade 21, a bias roller 22, which is a cleaning member by an electric field, is provided as a sub-cleaning mechanism, and the toner and the like that have passed through the cleaning blade 21 are electrostatically removed from the transfer belt 6 by the bias roller 22. ing. A predetermined voltage is applied to the bias roller 22 by a cleaning bias power supply 26. Further, the toner and the like attached to the bias roller 22 are wiped off by the bias roller cleaning blade 24. The toner and the like wiped off from the surface of the transfer belt 6 and the bias roller are conveyed to and stored in a waste toner collecting container (not shown) by a toner collecting coil 23 disposed below the cleaning device 20.
[0034]
As a method of driving the bias roller 22 of the sub-cleaning mechanism, for example, the drive roller 5 of the transfer belt 6 and the bias roller 22 are connected via a gear or the like, and are rotated. The bias roller 22 rotates in the direction opposite to the drive roller 5 of the transfer belt, and rotates in the same direction as the traveling direction of the transfer belt 6. The rotation speed of the bias roller 22 is the same as that of the transfer belt 6 due to the gear ratio and the like.
[0035]
The cleaning blade 21 and the bias roller cleaning blade 24 are attached and supported on the same blade holder 25 made of, for example, a sheet metal, and are integrated. The pressure of the blades may be pressurized by a spring or the like, but in the illustrated example, both the blades are not pressurized by a spring or the like, and the blade holder 25 to which the two blades 21 and 24 are fixed is placed in the case of the cleaning device 20. At this time, the tips of the blades 21 and 24 are pressed against the transfer belt 6 and the bias roller 22 so that the transfer belt 6 and the bias roller 22 are pressed by the amount of bite of each blade. By using such a pressurizing method, parts such as springs can be omitted, and costs can be reduced.
[0036]
1 and 2, the transfer belt cleaning device 20 includes a bias roller type sub-cleaning mechanism in addition to a blade type main cleaning mechanism as the transfer belt cleaning device 20, so that the cleaning blade 21 is cleaned. The outside of the area can be cleaned by the bias roller 22, and if the bias roller 22 and the bias roller cleaning blade 24 are made longer than the cleaning blade 21, the cleaning range of the bias roller 22 is expanded more than the cleaning blade 21. The toner at the end of the transfer belt can be reliably cleaned. Therefore, it is possible to solve the problem that the hand is stained by the toner at the end of the transfer belt at the time of a jam clearance or the like.
[0037]
As described above, if the bias roller 22 and the bias roller cleaning blade 24 are made longer than the cleaning blade 21, the toner at both ends of the transfer belt 6 can be surely cleaned. Since the length of the cleaning blade 24 is different from that of the cleaning blade 24, two types of blades must be manufactured, which increases the cost. In addition, since the toner attached to the end of the transfer belt is particularly problematic on the front side of the apparatus, it is sufficient that at least the toner attached to the end of the transfer belt on the front side of the apparatus can be cleaned.
[0038]
From the above, as another configuration of the present invention, in the transfer conveyance device having the configuration shown in FIGS. 1 and 2, the lengths of the cleaning blade 21 and the bias roller cleaning blade 24 are the same, and the mounting position of each blade is set. Make them different. More specifically, the bias roller cleaning blade 24 is shifted toward the front side of the apparatus relative to the cleaning blade 21 and attached. Hereinafter, the embodiment will be described.
[0039]
FIG. 3 is an enlarged view of the cleaning blade, the cleaning blade for the bias roller, and the blade holder. FIG. 4 is a diagram showing the cleaning belt, the bias roller, and the cleaning range and the length of the cleaning blade for the bias roller with respect to the transfer belt width and the effective image area. is there.
[0040]
In FIG. 3, the cleaning blade 21 and the bias roller cleaning blade 24 are attached to a blade holder 25 made of sheet metal or the like. The cleaning blade 21 and the bias roller cleaning blade 24 are all the same in thickness, material, length, and the like, but are different in the attachment position with respect to the blade holder 25. Is staggered and attached to the front side of the device. Further, as shown in FIG. 4, the bias roller 22 is also shifted from the cleaning blade 21 to the front side of the apparatus, and cleans the cleaning blade 21 outside the cleaning range of the cleaning blade 21 on the front side of the apparatus. The end of the transfer belt on the front side of the apparatus can be cleaned, and the toner attached to the bias roller 22 can be removed by the bias roller cleaning blade 24. Therefore, it is possible to reliably remove the toner at the end of the transfer belt on the front side of the apparatus, and it is possible to solve the problem that the hand is stained by the toner at the end of the transfer belt at the time of jam clearance or the like. In addition, the same cleaning blade 21 and bias roller cleaning blade 24 can be used. Further, since the cleaning blade 21 and the bias roller cleaning blade 24 are integrated by being attached to the same blade holder 25, cost reduction, space saving, and replacement parts can be achieved. The number can be reduced. In the configuration of the present embodiment, toner remains at the end of the transfer belt on the rear side of the apparatus, but the end of the transfer belt on the rear side of the apparatus is out of the effective image area and out of the transfer range of the transfer paper. There is no problem because there is no need to take any steps during jam processing.
[0041]
【The invention's effect】
As described above, the transfer / conveying apparatus according to claim 1 has a bias roller type cleaning sub-unit in addition to the blade type cleaning main unit. Is Bias roller and the bias roller Since the blade of the bias roller is longer and has a wider cleaning range than the cleaning blade of the main unit, the outside of the cleaning area of the cleaning blade as the main unit can be cleaned by the bias roller as the sub unit, and the main unit. The cleaning blade can clean the end portion of the transfer belt that could not be cleaned due to entanglement or the like. In addition, since the toner stain attached to the end of the transfer belt on the front side of the apparatus can be reliably removed, it is possible to prevent the problem that the hand is stained by the toner at the end of the transfer belt during the jam processing.
[0042]
The transfer conveyance device according to claim 2 has a bias roller type cleaning sub-unit in addition to the blade type cleaning main unit, and a cleaning blade serving as a main cleaning unit and a bias roller blade serving as a sub-unit. Since the length of the bias roller is not changed just because the blade of the bias roller is shifted to the front side of the apparatus from the cleaning blade of the main means, it is possible to reliably clean the toner attached to the front end of the transfer belt, It is possible to prevent a problem that a hand is stained by toner at an end of the transfer belt during a jam processing. Further, since the length of the cleaning blade as the main unit and the length of the bias roller as the sub-unit are the same, the same material can be used as the material and the like, and only the mounting position of the bias roller blade is shifted toward the front side of the apparatus. Thus, the end of the transfer belt can be cleaned, so that two types of blades are not required, and one type of blade can be used in common, thereby reducing costs.
[0043]
According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the cleaning blade serving as the main unit and the bias roller blade serving as the sub-unit are supported and integrated by the same member. Cost reduction, space saving, and reduction in the number of replacement parts can be further achieved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a transfer conveyance device showing one embodiment of the present invention.
FIG. 2 is an enlarged view showing a main part of a transfer belt cleaning device of the transfer / conveyance device shown in FIG. 1;
FIG. 3 is an enlarged view of a cleaning blade, a cleaning blade for a bias roller, and a blade holder.
FIG. 4 is a diagram illustrating a cleaning range and a length of a cleaning blade, a bias roller, and a bias roller cleaning blade with respect to a transfer belt width and an effective image area.
FIG. 5 is a perspective view illustrating an example of a basic configuration of a transfer / conveyance device.
6 is an explanatory diagram of a main configuration of an image forming apparatus provided with the transfer / conveyance device shown in FIG. 5;
7 is a diagram illustrating a state at the time of transfer of the image forming apparatus illustrated in FIG. 6;
FIG. 8 is a partial sectional view of a transfer belt having a two-layer structure.
FIG. 9 is an explanatory diagram of development and transfer steps in the image forming apparatus shown in FIGS.
[Explanation of symbols]
1 Transfer and transfer device
3 Photoconductor (image carrier)
4 driven rollers
5 Drive roller
6 Transfer belt
8 DC solenoid
9 Release lever
10 Registration roller
11 Transfer bias roller
13 Contact plate
20 Transfer belt cleaning device
21 Cleaning blade
22 Cleaning bias roller
23 Toner recovery coil
24 Cleaning blade for bias roller
25 Blade holder
26 Cleaning bias power supply

Claims (3)

In a transfer transport device having a transfer belt that transfers image information formed on an image carrier onto a transfer material, and that electrostatically transports the transfer material,
The cleaning means for the transfer belt has a blade method as a main means, a bias roller method as a sub means, a blade as a cleaning method for a bias roller as a cleaning auxiliary means, and a cleaning blade as the cleaning main means. The length of the bias roller and the bias roller blade is different from that of the auxiliary means, and the bias roller and the bias roller blade are longer than the main means cleaning blade and have a wider cleaning range than the main means cleaning blade. A transfer conveyance device characterized by the above-mentioned. In a transfer transport device having a transfer belt that transfers image information formed on an image carrier onto a transfer material, and that electrostatically transports the transfer material,
The cleaning means for the transfer belt has a blade method as a main means, a bias roller method as a sub means, a blade as a cleaning method for a bias roller as a cleaning auxiliary means, and a cleaning blade as the cleaning main means. The length of the bias roller blade is the same as that of the secondary roller, but the mounting position of each blade is different, and the bias roller blade is located closer to the apparatus than the main cleaning blade. A transfer conveyance device, wherein the transfer roller is mounted so as to be displaced , and the bias roller is also displaced closer to a front side of the apparatus than a cleaning blade as a main means . 3. The transfer conveying device according to claim 1, wherein the cleaning blade as the main cleaning unit and the blade of the bias roller as the auxiliary unit are supported by the same member, and the two blades are integrated. A transfer conveyance device characterized by the above-mentioned.

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