JP2002040897A - Cleaning device, image forming device, and belt device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfactorily keep the cleaning capacity of a belt-shaped member and to stably rotate and move the belt-shaped member in a cleaning device which sweeps toner stuck on the belt-shaped member by a cleaning electric field. SOLUTION: A conductive cleaning roll 71 which is arranged so as to come into contact with the surface of a transfer material carrying belt 60 where toner is stuck, and a conductive counter roll 73 which is arranged so as to face the cleaning roll 71 with the belt 60 between them are provided. The cleaning electric field is generated between the belt 50 and the cleaning roll 71. The counter roll 73 as a sponge roll is so supported that it can be displaced to change the distance from the cleaning roll 71, and it is energized in such direction by a pressure spring 74 that the distance from the cleaning roll 71 may be made shorter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt cleaning device for cleaning toner that adheres to a belt-like member by a cleaning electric field. The present invention also relates to an image forming apparatus including a belt-shaped member and a cleaning device for cleaning the belt-shaped member, and a belt device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a printer, and a facsimile, an image is formed mainly by the following process. That is, after charging the photoreceptor as an image carrier, the image is directly exposed by an exposure device,
Alternatively, optical writing according to an image signal is performed by a laser scanning optical system or an LED light writing optical system, and an electrostatic latent image is formed on the photoconductor. Next, the electrostatic latent image is formed into a toner image by toner adhesion of a developing device, and the toner image is transferred to a transfer material such as transfer paper or a film directly or via an intermediate transfer member. 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 a series of image forming processes, an image forming apparatus using a belt-shaped member such as a photoreceptor belt or an intermediate transfer belt as an image carrier on which a toner image is formed or transferred, 2. Description of the Related Art An image forming apparatus using a transfer material transport belt, which is a belt-shaped member, as a transfer material transport member that carries and transports the image is known.

In this type of image forming apparatus, some toner remains on the surface of these belt-shaped members even after the conveyance of a toner image, a transfer material, or the like, and if left unattended, various problems are caused. I do. For this reason, a belt device in this type of image forming apparatus is provided with a cleaning device for cleaning the surface of the belt-shaped member.

The cleaning device includes a roller-shaped cleaning member (hereinafter, referred to as a cleaning roller) made of a rigid body such as a metal, which is disposed in contact with the surface of the belt-shaped member, and faces the cleaning member via the belt-shaped member. 2. Description of the Related Art There is known a cleaning device including a conductive opposing member disposed thereon and cleaning electric field forming means for forming a cleaning electric field between the cleaning roller and the opposing member. In this cleaning device, a voltage having a polarity opposite to the charging polarity of the toner is applied to the cleaning roller to form the cleaning electric field, and the toner adhering to the belt-shaped member is moved to the cleaning roller material side by the electric field. The surface of the member is cleaned.

In the belt device provided with the above-mentioned cleaning device, it is conceivable that a supporting roller for supporting the belt-shaped member is also used as the facing member from the viewpoint of miniaturization and space saving of the device. As the support roller, it is conceivable to use a rigid support roller made of, for example, metal in order to exhibit the function of the cleaning roller as a counter electrode.

However, in the above-mentioned cleaning apparatus, although there is a demand to secure a certain width of the contact nip between the belt-shaped member and the cleaning roller in order to improve the cleaning performance, the rigid cleaning roller and the cleaning roller are not used. It has been difficult to satisfy such a requirement with the configuration using the rigid support roller.

Therefore, the present inventors, as the opposing member,
At least a cleaning device has been developed in which a member having elasticity at a contact portion with the belt-shaped member is used, and the facing member and the cleaning roller are arranged on a stretched portion between the support rollers of the belt-shaped member. In this cleaning device, as the opposing member having elasticity, for example, a fixed brush 83 having a conductive brush layer as shown in FIG. 9, a flexible conductive resin film such as Mylar (trademark) as shown in FIG. 93 or a conductive sponge roller 170 as shown in FIG. 11 is used to bring such an opposing member into contact with the cleaning roller 71 at a predetermined contact pressure via a belt-like member 160. According to this, the width of the contact nip between the belt-shaped member and the cleaning roller can be secured.

[0009]

However, even in the case of a cleaning apparatus using the above-described opposing member having elasticity, cleaning failure may occur over time. The inventors of the present invention have conducted intensive studies on this cleaning failure, and as a result, have found that the cause is deterioration over time due to contact between the elastic opposing member and the belt-shaped member. Specifically, when the conductive resin film is used as the facing member, the stiffness of the film is eliminated,
When a conductive brush is used, the brush falls down. In addition, when a sponge roller is used, the sponge wears over time. As described above, when the opposing member deteriorates with time, the contact pressure between the opposing member and the cleaning roller decreases with time, so that the cleaning performance decreases and cleaning failure occurs. When a cleaning failure of the photoreceptor belt or the intermediate transfer belt as an image carrier occurs, a problem such as background contamination of an image occurs, and when a cleaning failure of the transfer material conveying member occurs,
Problems such as back contamination of the transfer material may occur.

As a countermeasure against the above-mentioned inconvenience, it is conceivable to increase the contact pressure in advance by strongly pressing the opposing member against the cleaning roller or increasing the thickness of the resin film. However, if the contact pressure is excessively increased in order to prevent the contact pressure from lowering, the driving load of the belt-shaped member fluctuates, and stable rotation of the belt-shaped member is hindered. As a result, when a toner image is formed or transferred on the belt-shaped member, a banding image or image misalignment occurs. As described above, there is a problem that it is difficult to achieve both the cleaning performance and the image quality.

The present invention has been made in view of the above problems, and a first object of the present invention is to maintain good cleaning performance of a belt-shaped member and to stabilize the belt-shaped member. An object of the present invention is to provide a cleaning device that can be rotated and moved. Also, the second
The object of the present invention is to provide a cleaning device that can maintain the cleaning performance of the belt-shaped member satisfactorily and that can stably rotate and move the belt-shaped member, thereby achieving both the cleaning performance and the image quality. And a belt device used for the image forming apparatus.

[0012]

In order to achieve the first object, a first aspect of the present invention is a conductive cleaning member disposed in contact with a surface of a belt-like member to which toner is attached, And a cleaning electric field forming means for forming a cleaning electric field between the belt-shaped member and the cleaning member. In the cleaning device for cleaning the toner adhered on the belt-shaped member, as the opposed member,
Support means for using a member having at least a contact portion with the belt-shaped member having elasticity and displaceably supporting one of the cleaning member or the opposing member such that a distance from the other member changes. Urging means for urging the one member in a direction in which the distance becomes smaller is provided.

In this cleaning device, the urging means urges one of the cleaning member and the opposing member against the other member, and cleans the toner necessary for cleaning the surface of the belt-shaped portion. A contact pressure is generated between the member and the belt-shaped member. Further, by urging the one member with the urging means in a state where the one member is displaceably supported so as to change the distance from the other member, the distance between the two members is reduced due to deterioration with time of the opposing member. Even if the contact pressure of both members decreases due to the change, the one member is displaced in accordance with the decrease of the contact pressure. With this displacement,
Since the contact pressure between the two can be maintained almost constant,
A reduction in the cleaning performance of the belt-shaped member due to the reduction in the contact pressure can be prevented, and the cleaning performance of the belt-shaped member can be favorably maintained. Further, in order to maintain the cleaning performance, it is not necessary to excessively increase the contact pressure between the cleaning member and the opposing member, and the rotation of the belt-shaped member is not hindered. Therefore, the belt-shaped member can be stably rotated.

According to a second aspect of the present invention, in the cleaning device of the first aspect, the cleaning member is disposed so as to bite into the extended portion between the support rollers of the belt-shaped member. .

In this cleaning device, the cleaning member is disposed so as to bite into the extended portion between the support rollers of the belt-shaped member, and a sufficient cleaning nip width is secured. Thereby, the width of the region where the cleaning electric field works can be increased, or the chance of pressing contact between the toner adhered to the belt-shaped member and the cleaning member can be increased, so that the cleaning performance of the belt-shaped member is further improved. be able to.

According to a third aspect of the present invention, in the cleaning device according to the second aspect, the member displaceably supported by the supporting means is the opposed member, and the cleaning member is fixedly supported by the apparatus main body. Is what you do.

In this cleaning device, the opposing member is supported so as to be displaceable, and the cleaning member that receives the tension of the belt-shaped member is fixedly supported on the apparatus main body. If the cleaning member receiving the tension of the belt-shaped member is supported so as to be displaceable, and the opposing member is fixedly supported on the apparatus main body,
Since the cleaning member is urged against the tension of the belt-shaped member, the urging force of the urging means may decrease with time. When the urging force decreases, the contact pressure between the cleaning member and the opposing member may not be maintained at a predetermined pressure. Therefore, in this belt cleaning device, the cleaning member that receives the tension of the belt-shaped member is fixed and supported on the main body of the device, thereby preventing the urging force of the urging means from decreasing with time due to the tension, and preventing the contact pressure from being reduced. Can be maintained at a predetermined pressure.

According to a fourth aspect of the present invention, in the cleaning device of the first, second or third aspect, the opposed member is a brush or a flexible resin film.

In this cleaning device, by using a brush or a resin film as the opposed member, for example, compared with the case of using a sponge roller or the like,
The configuration of the facing member can be simplified and the cost can be reduced.

According to a fifth aspect of the present invention, in the cleaning device of the first, second or third aspect, the opposed member is a rotatable roller member.

In this cleaning device, since a rotatable roller member is used as the facing member, unlike a case where a fixing member such as a brush or a resin film is used, the cleaning member always contacts the belt-shaped member at the same position. There is no. Therefore, it is possible to suppress the deterioration of the facing member with time due to the contact, and it is possible to extend the life of the facing member.

According to a sixth aspect of the present invention, there is provided an image forming apparatus comprising a belt-shaped image carrier and a cleaning device for cleaning the surface of the image carrier. Claim 1,
It is characterized in that 2, 3, 4 or 5 cleaning devices are used.

In this image forming apparatus,
By cleaning the image carrier with 2, 3, 4 or 5 belt cleaning devices, it is possible to maintain good cleaning performance of the image carrier. Can be prevented. Further, since the belt-shaped image carrier stably rotates, it is possible to prevent the occurrence of a banding image and the displacement of the image due to the hindrance of the rotation.

According to a seventh aspect of the present invention, there is provided a belt-like transfer material transport member for carrying and transporting a transfer material onto which a toner image formed on an image carrier is transferred, and a cleaning device for cleaning the surface of the transfer material transport member. In the image forming apparatus provided with the device, the cleaning device is used as the cleaning device.
It is characterized in that 3, 4, or 5 cleaning devices are used.

In this image forming apparatus,
By cleaning the transfer material transporting member with 2, 3, 4 or 5 belt cleaning devices, it is possible to maintain good cleaning performance of the transfer material transporting member. Can be prevented. Further, since the belt-shaped transfer material conveying member is stably rotated, it is possible to prevent the occurrence of a banding image and the misalignment of the image due to the obstruction of the rotational movement.

According to an eighth aspect of the present invention, there is provided a belt device comprising a belt-shaped image carrier and a cleaning device for cleaning the surface of the image carrier, wherein the cleaning device is used as the cleaning device. 5. A cleaning device according to claim 5, wherein the cleaning device is used.

In this belt device,
By cleaning the image carrier with 2, 3, 4 or 5 belt cleaning devices, it is possible to maintain good cleaning performance of the image carrier. Can be prevented. Further, since the belt-shaped image carrier stably rotates, it is possible to prevent the occurrence of a banding image and the displacement of the image due to the hindrance of the rotation.

According to a ninth aspect of the present invention, there is provided a belt-like transfer material transport member for carrying and transporting a transfer material onto which a toner image formed on an image carrier is transferred, and a cleaning device for cleaning the surface of the transfer material transport member. In a belt device provided with a device, the cleaning device is used as the cleaning device.
It is characterized by using the cleaning device of 4 or 5.

In this belt apparatus,
By cleaning the transfer material transporting member with 2, 3, 4 or 5 belt cleaning devices, it is possible to maintain good cleaning performance of the transfer material transporting member. Can be prevented. Further, since the belt-shaped transfer material conveying member is stably rotated, it is possible to prevent the occurrence of a banding image and the misalignment of the image due to the obstruction of the rotational movement.

[0030]

[Embodiment 1] Hereinafter, the present invention will be described.
An embodiment applied to an electrophotographic color laser printer (hereinafter, referred to as “laser printer”) as an image forming apparatus will be described. FIG. 2 is a schematic configuration diagram of the laser printer according to the present embodiment. This laser printer is
Four sets of toner image forming units 1Y, 1M, 1C, and 1K for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K) ,
M, C, and K are yellow, magenta, cyan,
(Indicating a black member) are sequentially arranged from the upstream side in the moving direction of the transfer paper as the transfer material (the direction of arrow A in the figure). The toner image forming units 1Y, 1M,
Each of 1C and 1K includes a photosensitive unit having photosensitive drums 11Y, 11M, 11C, and 11K as image carriers, and a developing unit. The toner image forming units 1Y, 1M, 1C, and 1K are arranged so that the rotation axes of the photosensitive drums in the respective photosensitive units are parallel and are arranged at a predetermined pitch in the transfer paper moving direction. , Is set.

The present laser printer carries the toner image forming units 1Y, 1M, 1C, and 1K, an optical writing unit 2, paper feed cassettes 3, 4, a pair of registration rollers 5, and transfer paper. Transfer paper transport belt 6 as a transfer material transport member that transports so as to pass through the transfer position of the toner image forming unit
The transfer unit 6 includes a transfer unit 6 as a belt device having a zero, a fixing unit 7 of a belt fixing type, a paper discharge tray 8, and the like. The laser printer also includes a manual feed tray (not shown), a toner supply container, a waste toner bottle, a duplex / reversing unit, a power supply unit, and the like. The optical writing unit 2 includes a light source, a polygon mirror, an f-θ lens,
The surface of each of the photoconductor drums 11Y, 11M, 11C, and 11K is irradiated with a laser beam while scanning based on image data. The dashed line in FIG.
The transfer path of the transfer paper is shown. The transfer paper fed from the paper feed cassettes 3 and 4 is transported by transport rollers while being guided by a transport guide (not shown), and is transported to a temporary stop position where the registration roller pair 5 is provided. The transfer paper sent out by the registration roller pair 5 at a predetermined timing is carried by a transfer paper transfer belt 60, and is transferred so as to pass through the transfer positions of the toner image forming units 1Y, 1M, 1C, and 1K. The transfer paper on which the toner images of the toner image forming units 1Y, 1M, 1C, and 1K are transferred and a color image is formed,
After the toner image is fixed by the fixing unit 7, the toner image is discharged onto the discharge tray 8.

FIG. 3 shows the toner image forming sections 1Y, 1M,
FIG. 3 is an enlarged view showing a schematic configuration of a yellow toner image forming unit 1Y of 1C and 1K. Other toner image forming units 1M,
1C and 1K have the same configuration, respectively, and thus description thereof is omitted. In FIG. 3, the toner image forming unit 1Y includes the photoconductor unit 10Y and the developing unit 20Y as described above. Photoconductor unit 10
Y denotes a photosensitive drum 11Y, a brush roller 12Y for applying a lubricant to the photosensitive drum surface, a swingable counter blade 13Y for cleaning the photosensitive drum surface, and a uniform charging of the photosensitive drum surface. And a non-contact type charging roller 15Y. As the photoconductor drum of each photoconductor unit, a photoconductor drum having an organic photoconductor (OPC) layer on the surface and having a diameter of 30 mm was used. In the photoconductor unit having the above configuration, the photoconductor drum 1 uniformly charged by the charging roller 15Y to which an AC voltage is applied.
When the laser beam modulated and deflected by the optical writing unit 2 is irradiated on the surface of the photosensitive drum 11Y while being scanned, an electrostatic latent image is formed on the surface of the photosensitive drum 11Y. The electrostatic latent image on the photosensitive drum 11Y is stored in a developing unit 20Y described later.
And a yellow toner image is developed. At the transfer position Pt where the transfer paper 100 on the transfer paper transport belt 60 passes, the toner image on the photosensitive drum 11Y is transferred to the transfer paper 100. Photoconductor drum 1 after transfer of toner image
After a predetermined amount of lubricant is applied to the surface of 1Y by the brush roller 12Y, it is cleaned by the counter blade 13Y to prepare for the formation of the next electrostatic latent image. The developing unit 20Y uses a two-component developer containing a magnetic carrier and a negatively charged toner. A developing roller 22Y as a developer carrier is provided so as to be partially exposed from the opening of the developing case 21Y on the photosensitive drum side.
And transfer screws 23Y and 24Y, developing doctor 25
Y, a toner density sensor (T sensor) 26Y, a powder pump 27Y, and the like. The developer accommodated in the developing case 21Y is agitated and transported by the transporting screws 23Y and 24Y and is charged by friction. Then, a part of the developer is carried on the surface of the developing roller 22Y, and the developing doctor 2
After the layer thickness is regulated at 5Y, the sheet is conveyed to a developing position facing the photosensitive drum 11Y. At the developing position, the electrostatic latent image on the photosensitive drum 11Y is developed by the toner in the developer on the developing roller. The toner concentration of the developer in the developing case 21Y is detected by the toner concentration sensor 26Y, and toner is supplied by a powder pump 27Y as needed.

FIG. 1 is a schematic structural view of the transfer unit 6. The transfer paper transport belt 60 used in the transfer unit 6 is a medium-resistance endless single-layer belt having a volume resistivity of 10 ⁹ to 10 ¹¹ Ωcm, and is made of PVDF.
(Polyvinylidene fluoride). The transfer paper transport belt 60 is provided between the photosensitive pair drums 11Y and 1Y of each toner image forming unit.
It is looped around four grounded support rollers 61 to 64 so as to pass through each transfer position in contact with and facing 1M, 11C, and 11K. Among these support rollers, an electrostatic attraction roller 65 to which a predetermined voltage is applied from a power supply 65a is disposed so as to face the entrance roller 61 on the upstream side in the transfer paper moving direction. The transfer paper that has passed between the two rollers 61 and 65 is electrostatically attracted onto the transfer paper transport belt 60. Further, the exit roller 62 on the downstream side in the transfer paper moving direction
Reference numeral denotes a driving roller that frictionally drives the transfer paper transport belt 60, and is connected to a driving source (not shown). In addition, a cleaning device 70 that cleans toner adhered to the surface of the transfer paper transport belt 60 is disposed in a stretched portion between the support rollers 63 and 64 of the transfer paper transport belt 60.
The configuration and operation of the cleaning device 70 will be described later in detail.

As a transfer electric field forming means for forming a transfer electric field at each transfer position, a transfer bias is applied so that the transfer bias is brought into contact with the back surface of the transfer paper conveying belt 60 forming a transfer nip in contact with the photosensitive drum. Applying member 67Y,
67M, 67C and 67K are provided. The transfer bias applying members 67Y, 67M, 67C, 67K are fixed brushes made of Mylar, and each of the transfer bias power supplies 9Y, 9M,
A transfer bias is applied from 9C and 9K. By the transfer bias applied by the transfer bias applying member, a transfer charge is applied to the transfer paper transport belt 60, and a transfer electric field of a predetermined intensity is applied between the transfer paper transport belt 60 and the surface of the photosensitive drum at each transfer position. It is formed.

In the transfer unit 6, the transfer conveyor belt 60 is connected to each of the photosensitive drums 11Y, 11M, 11C, 11C.
Backup rollers 68Y, 68M, 68 pressed against K
C and 68K are provided, and the transfer paper transport belt 60 is moved to the photosensitive drum 1 upstream in the transfer paper movement direction of each transfer position.
Partially wrapped around the 1Y peripheral surface. Thus, the contact pressure between the transfer paper 100 and each of the photosensitive drums at the transfer nip is increased, and the transfer efficiency at the transfer position is increased.

Next, a description will be given of the cleaning device 70 for the transfer paper transport belt 60, which is a feature of the present invention. In FIG. 1, a cleaning device 70 includes a cleaning roller 71 made of metal as a conductive cleaning member disposed so as to contact the surface of the transfer paper transport belt.
A facing roller 73 as a conductive facing member disposed facing the cleaning roller 71 via the transfer paper transport belt 60; and the cleaning roller 71 and the facing roller 73.
Cleaning electric field forming means for forming a cleaning electric field between the substrate and the material. In the present embodiment, the opposing roller 73 is formed of a sponge roller having an elastic foam layer made of a conductive sponge material on a cored roller.

In the present embodiment, as the cleaning electric field forming means, the cleaning roller 71 having the conductivity, a cleaning bias power supply 75 serving as a voltage applying means for applying a voltage to the cleaning roller 71, and a ground are connected. Using the opposing roller 63, a voltage having a polarity opposite to the polarity of the charged toner is applied to the cleaning roller 71 by the power supply 75. In the present embodiment, a cleaning bias power supply 75 applies a positive voltage to the cleaning roller 71 for a negatively charged toner. As a result, an electric field is generated in the cleaning nip, which is the contact portion between the transfer paper transport belt 60 and the cleaning roller 71, such that the negatively charged toner moves from above the transfer paper transport belt 60 to the cleaning roller 71 side. Due to this electric field, the toner attached to the transfer paper transport belt 60 moves to the cleaning roller 71 side, and the toner is removed from the surface of the transfer paper transport belt 60. The toner moved to the cleaning roller 71 is scraped off by the cleaning blade 72 and is removed from the surface of the roller 71.

In this embodiment, as shown in FIG. 4, the rotating shaft 71a of the cleaning roller 71 is
6 and rotatably supported by the side plate 600 of the transfer unit 6, and the rotating shafts 73 a at both ends of the opposing roller 73 are rotatable by the elongated holes 600 a formed in the side plate 600 via the bearings 77. I support it. This bearing 77
And a long hole 600a formed in the side plate 6a of the transfer unit 6.
The opposing roller 73 can be displaced so that the distance from the cleaning roller 71 changes. Further, the bearing 77 of the opposing roller 73 is used.
Further, a pressure spring 74 as urging means for urging the opposing roller 73 in a direction in which the distance from the cleaning roller 71 becomes smaller is attached. Specifically, the pressing spring 74
One end is fixed to the elongated hole 600a, and the other end is attached to the bearing 77 of the opposing roller 73. The pressure spring 74 urges the bearing 77 of the opposing roller 73,
The opposing roller 73 is pressed toward the cleaning roller 71 via the transfer paper transport belt 60. In this way, by pressing the opposing roller 73 against the cleaning roller 71 by the pressing spring 74, the contact pressure of the cleaning roller 71 against the transfer paper transport belt 60 necessary for cleaning the surface of the transfer paper transport belt 60 is reduced. And good cleaning performance is obtained.

In the present embodiment, the pressure roller 74 urges the opposing roller 73 against the cleaning roller 71, so that the distance between the two rollers changes due to the deterioration of the opposing roller 73 with time. Even if the contact pressure of the roller decreases, the opposing roller 73 is displaced so as to approach the cleaning roller 71 in accordance with the decrease in the contact pressure. By this displacement, the contact pressure between the two rollers can be maintained substantially constant. Therefore, it is possible to prevent a decrease in the cleaning performance of the transfer paper transport belt 60 due to a decrease in the contact pressure, and to maintain a good cleaning performance. it can. In order to maintain the cleaning performance, the cleaning roller 7
There is no need to excessively increase the contact pressure between the transfer roller 1 and the opposing roller 73, and the rotation of the transfer paper transport belt 60 is not hindered. Therefore, the transfer paper transport belt 60 can be stably rotated.

As described above, according to the present embodiment, the cleaning performance of the transfer material conveying belt 60 can be maintained satisfactorily, so that the back surface of the transfer paper 100 can be prevented from being stained for a long period of time. Since the conveyor belt 60 rotates stably, it is possible to prevent the occurrence of a banding image and the misalignment of the image due to the obstruction of the rotational movement. Therefore, it is possible to achieve both cleaning performance and image quality. Further, in the present embodiment, as the opposing member of the cleaning roller 71, the opposing roller 73 that rotates with the rotational movement of the transfer paper conveying belt 71 is used. No contact with 60. Therefore, it is possible to suppress the deterioration of the facing member with time due to the contact, and it is possible to extend the life of the facing member.

In the above embodiment, the opposing roller 73, which is a sponge roller, is used as the opposing member of the cleaning roller 71. However, as shown in FIG. 5, a fixed brush 83 having a conductive brush layer may be used. Further, as shown in FIG. 6, a flexible conductive resin film 93 such as Mylar (trademark) may be used as the facing member.
By using these opposing members, the configuration of the opposing members can be simplified and the cost can be reduced as compared with a case where a sponge roller is used as the opposing members.

[Modification 1] Next, a description will be given of an improved example of the first embodiment for ensuring a sufficient cleaning nip width, which is a contact portion between the cleaning roller 71 and the transfer sheet conveying belt 60. FIG. 7 is a schematic configuration diagram of the transfer unit 6 according to the present modification. In this modification,
The cleaning roller 71 is disposed so as to bite into the extending portion between the support rollers of the transfer paper transport belt 60 by a predetermined amount. By arranging the cleaning roller 71 in this manner, the transfer paper conveyance belt 60 is wound around a part of the cleaning roller 71, so that a sufficient cleaning nip width is secured and the width of the area where the cleaning electric field works is increased. Alternatively, the chance of pressing contact between the toner adhered to the transfer paper transport belt 60 and the cleaning roller 71 can be increased.

In the present modification, similarly to the first embodiment, the rotating shaft of the opposing roller 73 is supported so as to be displaceable toward the cleaning roller 71, while the rotating shaft of the cleaning roller 71 is connected to the transfer unit 6. Rotatable on the side plate of
In addition, the distance from the opposing roller 73 is fixed and supported so as not to change. Here, in this modified example, the cleaning roller 71
Is disposed so as to bite into the transfer paper transport belt 60 by a predetermined amount, so that the cleaning roller 71 receives the tension of the transfer paper transport belt 60. In such a configuration, if the cleaning roller 71 that receives the tension of the transfer paper transport belt 60 is movably supported and the opposing roller is fixedly supported on the side plate of the transfer unit 6, the tension of the transfer paper transport belt 60 is reduced. Therefore, the urging force of the pressure spring 74 may decrease with time. When the urging force decreases, the cleaning roller 71
There is a possibility that the contact pressure between the roller and the opposing roller 73 cannot be maintained at a predetermined pressure. Therefore, in the present modification, the urging force of the pressure spring 74 is prevented from being reduced with time by fixedly supporting the cleaning roller 71 that receives the tension of the transfer paper transport belt 60,
The contact pressure can be maintained at a predetermined pressure.

As described above, according to the present modification, the cleaning nip width can be sufficiently ensured, so that the cleaning performance can be further improved, and the urging force of the pressure spring 74 due to the tension of the transfer paper transport belt 60 is reduced. And the contact pressure between the cleaning roller 71 and the opposing roller 73 can be more reliably maintained.

[Second Embodiment] In the first embodiment, the case where the cleaning device of the present invention is applied to the cleaning device 70 of the transfer paper transport belt 60 as a belt-shaped member has been described. In the present embodiment, a case will be described in which the present invention is applied to a cleaning device for a belt-shaped intermediate transfer body as an image carrier.

FIG. 8 shows a belt-like intermediate transfer belt 201.
1 shows an example of the configuration of an intermediate transfer unit 200 as a belt device in a laser printer using a printer. In this laser printer, the intermediate transfer belt 201 is wound around a plurality of support rollers 202 to 205 and is driven to rotate in a direction indicated by an arrow in FIG. The toner images formed on the photoconductor drums 11Y, 11M, 11C, and 11K of the respective toner image forming units are transferred to primary transfer rollers 206Y, which are provided to face the photoconductor drums with the intermediate transfer belt 201 interposed therebetween.
The images are sequentially transferred onto the intermediate transfer belt 201 by the primary transfer electric fields formed by 206M, 206C, and 206K.
The color image on the intermediate transfer belt 201 is
In a secondary transfer unit provided near the fourth color black toner image forming unit, the secondary transfer unit passes between the grounded support roller 203 and the secondary transfer roller 207 to which a predetermined secondary transfer bias is applied. Is secondarily transferred onto the transfer paper 100 conveyed at a time.

The intermediate transfer unit 20 shown in FIG.
0, a cleaning device 210 for cleaning toner adhered to the surface of the intermediate transfer belt 201 after the secondary transfer
Is provided. As in the case of the transfer unit 6 in FIG. 1 described above, the cleaning device 210 supports the rotation shaft of the opposing roller 213 so as to be displaceable so that the distance from the cleaning roller 211 changes, and also uses a pressing spring 214. , The opposing roller 213 is
It is energizing one. With this configuration, the opposing roller 2
13, the contact pressure between the two rollers can be maintained substantially constant even if the distance between the two rollers changes due to the aging deterioration of the intermediate transfer belt. The cleaning performance of 201 can be prevented from lowering, and the cleaning performance can be maintained satisfactorily. Further, in order to maintain the cleaning performance, it is not necessary to excessively increase the contact pressure between the cleaning roller 211 and the opposing roller 213, and the rotation of the intermediate transfer belt 201 is not hindered. Therefore, the intermediate transfer belt 201
Can be rotated and moved stably.

As described above, according to the present embodiment, since the cleaning performance of the intermediate transfer belt 201 can be maintained excellent, it is possible to prevent the image from becoming dirty due to poor cleaning over a long period of time. Further, since the intermediate transfer belt 201 rotates stably, it is possible to prevent generation of a banding image and misalignment of the image due to the hindrance of the rotation. Therefore, it is possible to achieve both cleaning performance and image quality. Note that, in the present embodiment as well, in order to ensure a sufficient cleaning nip width, the configuration shown in the above-described modification can be adopted.

In this embodiment, the case where the present invention is applied to a cleaning device for a belt-shaped intermediate transfer member as an image carrier has been described. However, the present invention can be applied to a cleaning device for a belt-shaped photosensitive member as an image carrier. The same effect can be obtained.

In each of the above embodiments, a laser printer having four sets of toner image forming units for forming four color images of yellow, magenta, cyan and black has been described. Can be applied irrespective of the number of toner image forming units, and a similar effect can be obtained.

[0051]

According to the first to fifth aspects of the present invention, it is possible to maintain excellent cleaning performance of the belt-shaped member and to stably rotate the belt-shaped member. is there.

In particular, according to the invention of claim 2, since the cleaning nip width can be sufficiently secured, there is an excellent effect that the cleaning performance can be further improved.

In particular, according to the third aspect of the invention, the urging force of the urging means is prevented from decreasing with time due to the tension of the belt-shaped member, and the contact pressure between the cleaning member and the opposing member is more reliably maintained. There is an excellent effect that can be.

In particular, according to the invention of claim 4, there is an excellent effect that the structure of the facing member can be simplified and the cost can be reduced.

In particular, according to the fifth aspect of the present invention, it is possible to suppress the deterioration with time due to the contact of the opposing member with the belt-shaped member, so that there is an excellent effect that the life of the opposing member can be extended.

According to the sixth to ninth aspects of the present invention, by providing the cleaning device capable of maintaining the cleaning performance of the belt-shaped member satisfactorily and stably rotating the belt-shaped member, There is an excellent effect that both cleaning performance and image quality can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a transfer unit of a laser printer according to an embodiment.

FIG. 2 is a schematic configuration diagram of the laser printer.

FIG. 3 is an enlarged view showing a schematic configuration of a toner image forming unit of the laser printer.

FIG. 4 is an explanatory diagram illustrating a support mechanism for a cleaning member and a facing member according to the embodiment.

FIG. 5 is a partially enlarged view showing another configuration example of the cleaning device according to the embodiment.

FIG. 6 is a partially enlarged view showing still another configuration example of the cleaning device.

FIG. 7 is a partially enlarged view of a transfer unit according to a modification.

FIG. 8 is a schematic configuration diagram of an intermediate transfer unit of a laser printer according to another embodiment.

FIG. 9 is a diagram showing an example of a conventional facing member.

FIG. 10 is a view showing another example of a conventional facing member.

FIG. 11 is a view showing still another example of the conventional opposing member.

[Explanation of symbols]

 Reference Signs List 1 toner image forming unit 6 transfer unit (belt device) 9 transfer bias power supply 10 photoreceptor unit 11 photoreceptor drum 20 developing unit 60 transfer paper transport belt 61-64 support roller 70 cleaning device 71 cleaning roller 73 facing roller 74 pressure spring 75 Cleaning bias power supply 76 Bearing (for cleaning roller) 77 Bearing (for opposed roller) 83 Fixed brush 93 Resin film 100 Transfer paper 200 Intermediate transfer unit (belt device) 201 Intermediate transfer belt 202-205 Support roller 210 Cleaning device 211 Cleaning roller 213 Opposing roller 214 Pressure spring 600 Transfer unit side plate 600a Slot

Claims (9)

[Claims] An electroconductive cleaning member disposed in contact with the surface of the belt-like member to which toner has adhered; a conductive opposing member disposed opposite to the cleaning member via the belt-like member; A cleaning electric field forming means for forming a cleaning electric field between the belt-shaped member and the cleaning member, wherein the cleaning member cleans toner adhered on the belt-shaped member by the cleaning electric field. Support means for using a member having a contact portion with the belt-shaped member having elasticity, and displaceably supporting one of the cleaning member or the opposing member such that the distance to the other member changes.
A biasing means for biasing the one member in a direction in which the distance is reduced. 2. The cleaning device according to claim 1, wherein the cleaning member is disposed so as to bite into a portion between the support rollers of the belt-shaped member by a predetermined amount. 3. The cleaning device according to claim 2, wherein a member supported by said support means so as to be displaceable is said opposed member, and said cleaning member is fixedly supported by an apparatus main body. 4. The cleaning device according to claim 1, wherein the opposing member is a brush or a flexible resin film. 5. The cleaning device according to claim 1, wherein the opposed member is a rotatable roller member. 6. An image forming apparatus comprising a belt-shaped image carrier and a cleaning device for cleaning the surface of the image carrier, wherein the cleaning device is a cleaning device according to claim 1, 2, 3, 4, or 5. An image forming apparatus using: 7. An image comprising a belt-shaped transfer material transport member for carrying and transporting a transfer material onto which a toner image formed on an image carrier is transferred, and a cleaning device for cleaning the surface of the transfer material transport member. 6. An image forming apparatus, wherein the cleaning device according to claim 1, 2, 3, 4, or 5 is used as the cleaning device. 8. A belt device comprising a belt-shaped image carrier and a cleaning device for cleaning the surface of the image carrier, wherein the cleaning device according to claim 1, 2, 3, 4, or 5 is used as the cleaning device. A belt device characterized by using: 9. A belt comprising a belt-shaped transfer material transport member for carrying and transporting a transfer material onto which a toner image formed on an image carrier is transferred, and a cleaning device for cleaning the surface of the transfer material transport member. A belt device, wherein the cleaning device according to claim 1, 2, 3, 4, or 5 is used as the cleaning device.