JP2000081819A - Cleaning device, process unit and electrophotographic device - Google Patents

Abstract

(57) Abstract: The present invention provides a cleaning device that can secure a good image even when using paper that generates a lot of paper dust, and that can economically cope with changes in the external environment. And a process unit provided with the cleaning device and an electrophotographic apparatus provided with the process unit. A cleaning blade for contacting the surface of a photoreceptor and scraping off toner present on the surface of the photoreceptor; A toner receiving sheet 51 for receiving the toner scraped off by the cleaning blade in contact with the surface; and a plurality of fibers, the fibers contacting the toner receiving sheet with the surface of the photoreceptor so that the fibers come into contact with the surface of the photoreceptor. Brush 5 contacting
3 is provided, and a voltage is applied to the capture brush.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning residual toner on the surface of a photoreceptor after transferring the toner from the photoreceptor to recording paper.
The present invention relates to a cleaning device for cleaning, a process unit including the cleaning device, and an electrophotographic apparatus including the process unit.

[0002]

2. Description of the Related Art In an electrophotographic apparatus used for a copying machine, a laser printer, or the like, an electrostatic latent image is formed on the surface of a photoreceptor, and then toner is applied to form a toner image, and the toner image is transferred to recording paper. This electrophotographic apparatus is provided with a photoreceptor and is provided with a process unit for forming a toner image on the surface of the photoreceptor, for fixing a toner image of a recording sheet transferred later. Recently, the process unit is provided with a cleaning device for cleaning residual toner on the surface of the photoconductor after transferring the toner from the photoconductor to recording paper.

FIG. 7 shows an embodiment of a process unit provided with a conventional cleaning device. In FIG. 7, 1
Denotes a photosensitive drum, which is rotated about its own axis in the direction of the arrow. Reference numeral 2 denotes a developing device that applies toner to the surface of the photosensitive drum 1 to form a toner image. 3 is clear
A cleaning blade, which is disposed in contact with the surface of the photoconductor drum, and which is disposed upstream of the cleaning drum 4 in the rotation direction of the photoconductor drum, and is disposed on the surface of the photoconductor drum 1 after transfer. The cleaning blade 4 includes a toner receiving sheet 5 with which the cleaning blade 4 contacts.
And the toner receiving sheet 5 are attached to a housing 6 forming a waste toner box. That is, the photosensitive drum 1
Rotation of the cleaning blade 4 causes the photosensitive drum 1
The toner remaining on the surface is scraped off, and the scraped-off toner is received inside the housing 6 so that the toner receiving sheet 5 does not fall outside.

In recent years, from the viewpoint of environmental protection, the back of recycled paper or used paper on which an image has been formed has been started to be used again as a recording paper. I need to do it. Such a recycled paper or a backing paper has a feature that a large amount of so-called paper dust is generally generated from a cut surface of the paper. When the photoreceptor is cleaned by using the above-described conventional type of cleaning apparatus using such paper as the recording paper, paper powder generated from the paper adheres to the photoreceptor drum, Thereafter, a phenomenon occurs in which the paper dust is caught between the tip of the cleaning blade and the surface of the photosensitive drum. As a result, at the contact portion between the leading edge of the cleaning blade and the surface of the photosensitive drum, poor cleaning of the transfer residual toner on the surface of the photosensitive drum may occur, resulting in vertical streaks on the image. there were.

[0005]

As a method for solving this problem, there is a technique disclosed in Japanese Patent Application Laid-Open No. 59-49575. This technique is located upstream of the cleaning blade in the rotation direction of the photosensitive member. A toner guide plate is provided, and a cleaning band composed of an aggregate of fibers is further disposed upstream of the toner guide plate, and the tip of the aggregate of fibers is brought into contact with the photoreceptor. However, according to the experiments by the inventors of the present invention, although effective for removing paper dust, in long-term use, the transfer residual toner on the surface of the photoconductor gradually adheres to the fiber aggregate. Eventually, a phenomenon occurred in which toner spilled into the main body of the electrophotographic apparatus.

In a conventional type of cleaning apparatus, a housing of a process unit for mounting a cleaning blade and a toner receiving sheet is usually formed of a synthetic resin. For this reason, warpage or thermal expansion occurs in the housing made of synthetic resin due to changes in the environment or an increase in the internal temperature of the apparatus main body. The leading edge of the sheet may be separated from the surface of the photoreceptor and the toner scraped off by the cleaning blade may fall between the photoreceptor drum and the toner receiving sheet and fall into the main body of the electrophotographic apparatus.
As a countermeasure, it is necessary to use a heat-resistant grade relatively stable to heat or to mix glass fiber as a synthetic resin material for forming the housing, and the cost of the housing is reduced by using such an expensive material. It was relatively expensive.

The present invention has been made on the basis of the above circumstances, and it is possible to secure a good image even when using paper in which a large amount of paper dust is generated, and to economically cope with changes in the external environment. An object of the present invention is to provide a cleaning device that can perform the cleaning.

Another object of the present invention is to provide a highly economical process unit capable of forming an image with the cleaning device.

Another object of the present invention is to provide an electrophotographic apparatus having the process unit.

[0010]

According to a first aspect of the present invention, there is provided a cleaning device which is disposed in contact with a surface of a photoreceptor provided in a process unit and scrapes off toner present on the surface of the photoreceptor. A toner receiving sheet disposed on the upstream side of the photoconductor drum rotation direction with respect to the cleaning grade to receive the toner scraped off by the cleaning blade in contact with the surface of the photoconductor; And a capture brush for pressing the toner receiving sheet so as to contact the surface of the photoreceptor and for contacting the surface of the photoreceptor drum on the downstream side in the photoreceptor rotation direction with respect to the toner receiving sheet. It is characterized by the following.

According to the structure of the present invention, in the region where the fibers of the capture brush are in direct contact with the surface of the photoreceptor, the fibers of the capture brush capture the paper dust. In addition, since the fibers of the capture brush constantly press the toner receiving sheet into contact with the photoreceptor, the toner receiving sheet is stably in contact with the photoreceptor even when the synthetic resin housing is thermally deformed. Can be kept.

According to a second aspect of the present invention, there is provided a cleaning device which is disposed in contact with a surface of a photoreceptor provided in a process unit and scrapes off toner present on the surface of the photoreceptor. A toner receiving sheet disposed on the upstream side in the rotation direction of the photoconductor drum to receive the toner scraped off by the cleaning blade in contact with the surface of the photoconductor, and a plurality of conductive fibers, the conductive fibers comprising the toner A capture brush that presses the receiving sheet so as to contact the surface of the photoconductor drum, and that contacts the surface of the photoconductor drum on the downstream side in the photoconductor rotation direction with respect to the toner receiving sheet; Bias applying means for applying a voltage.

According to the present invention, since the bias voltage is applied to the capture brush in the region where the fiber constituting the capture brush is in direct contact with the photoreceptor surface, in addition to the physical action of the capture brush, Further, paper dust can be more efficiently removed by electrostatic action.

According to a third aspect of the present invention, in the cleaning device according to the second aspect, the voltage applied to the conductive fibers of the capture brush by the bias applying means is applied to a transfer device provided in an electrophotographic apparatus. And a voltage having a polarity opposite to that of the applied voltage.

Normally, in an electrophotographic apparatus, when a corona-type transfer device is used, paper dust adhering to the photoreceptor is often charged to the same potential as the potential polarity of the transfer bias due to the influence of the corona. According to this configuration, by setting the bias voltage applied to the conductive brush to the reverse polarity of the voltage at the time of transfer, paper dust attached to the surface of the photoconductor can be efficiently removed electrostatically.

According to a fourth aspect of the present invention, in the cleaning device according to the second or third aspect, the conductive fibers forming the capture brush have a specific resistance of 10 ⁴ to 10 ⁸ Ω · cm.
It is characterized by being.

According to the configuration of the present invention, the capture brush can be configured using a fiber material suitable for applying a bias voltage to the capture brush.

According to the invention of claim 5, claim 2 or 3 is provided.
In the cleaning device according to the above, the specific resistance of the conductive fibers constituting the capture brush is less than 10 ⁴ Ωcm,
Further, a resistor having a resistance value of 1 to 10 MΩ is interposed between the conductive capture brush and the bias applying means.

According to the structure of the present invention, it is possible to provide a bias voltage applying means which is suitable when the specific resistance of the conductive fiber constituting the capture brush is small.

According to a sixth aspect of the present invention, there is provided a process unit comprising a photoreceptor, the cleaning device according to any one of the first to fifth aspects, and a housing for supporting the photoreceptor and the cleaning device. And

According to a seventh aspect of the present invention, there is provided an electrophotographic apparatus comprising the process unit according to the sixth aspect, a transfer device, a heat fixing device, and a recording paper supply device.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. An electrophotographic apparatus according to this embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an electrophotographic apparatus used in an electrophotographic apparatus printer, a facsimile apparatus, and the like.

In FIG. 1, reference numeral 11 denotes a process unit, 1
2 is an exposure device, 13 is a transfer device, 14 is a heat fixing device, 1
Reference numeral 5 denotes a recording paper supply device, and these devices 11 to 15 are disposed inside the main body A of the electrophotographic apparatus. The process unit 11 forms a toner image on the photosensitive drum 31 as described later. The exposure apparatus 12 uses, for example, a laser method. The transfer device 13 is disposed so as to face the surface of the photosensitive drum 31 of the process unit 11 after the toner image has been formed, and is of a corona charging type. The heat fixing device 14 is disposed downstream of the transfer device 13 in the recording paper conveyance direction, and has a heating roller 16 and a pressure roller 17. The recording paper supply device 15 has a cassette 18 for stacking and accommodating the recording paper P, a feeding roller 19, a transport roller 20, and a transport path 21.

That is, in the electrophotographic apparatus, the exposure apparatus 1
2 exposes the photosensitive drum 31 of the process unit 11 based on the image signal to form an electrostatic image. In the process unit 11, as described later, the photosensitive drum 31
A toner image is formed from the electrostatic image on the surface of the substrate. On the other hand, in the recording paper supply device 15, the recording paper P stacked and accommodated in the cassette 18 is sequentially fed by the rotation of the feeding roller 19, and the fed recording paper P is transported along the transport path 21 by the transport roller 20 that rotates sequentially. The sheet passes between the photosensitive drum 31 and the transfer device 13. The corona charging type transfer device 13 gives the recording paper P a charge having a polarity opposite to the toner charge of the toner image formed on the photosensitive drum 31,
The toner image on the photosensitive drum 31 is transferred to the recording paper P.
Further, the recording paper P is conveyed to the heat fixing device 13 and passes between the rotating heating roller 16 and the heating roller 17 to fix the transferred image by applying heat and pressure.

Next, the process unit 11 will be described with reference to FIG. FIG. 2 is an enlarged sectional view showing the process unit 11. In FIG. 2, reference numeral 31 denotes a photosensitive drum, reference numeral 32 denotes a developing device, and reference numeral 33 denotes a housing including a cleaning device, which will be described later, disposed downstream of the photosensitive drum 31 in the recording paper conveyance direction. The photosensitive drum 31 is the housing 3
3, and is rotatably supported by a rotary drive mechanism (not shown). The developing device 32 transports the toner T supplied from the housing 41 of the developing device 32 that stores the toner T, a stirrer 42 that stirs the toner T, the supply roller 43, and the supply roller 43 to the photosensitive drum 31. And a developing blade 45 that frictionally charges the toner T conveyed by the developing roller 44.

The housing 33 is made of a synthetic resin, and has a waste toner box 33a and a frame 33b communicating with the waste toner box 33a and surrounding the upper portion of the photosensitive drum 31 from above. A charging brush 34, which is an example of a charging member, is arranged on the frame 33 b of the housing 33 on the upstream side in the rotation direction of the photosensitive drum with respect to the developing device 32, in contact with the surface of the photosensitive drum 31. The charging brush 34 has a length corresponding to the length of the photosensitive drum 31, is arranged along the axial direction of the photosensitive drum 31, and is attached to the frame 33 b by the attaching member 35.

A cleaning device 36 is provided on the frame 33 b of the housing 33 between the transfer device 13 and the charging brush 34. This cleaning device 3
6 will be described with reference to FIG. FIG. 3 shows the cleaning device 36 in an enlarged manner.

The cleaning device 36 has a toner receiving sheet 51 and a cleaning blade 52 positioned upstream of the toner receiving sheet 51 in the rotation direction of the photosensitive drum. Capture brush 5 positioned between blade 52
3 are arranged. The cleaning blade 52 is made of, for example, polyurethane, and is attached to the frame 33b by an attachment member 54. The cleaning blade 52 scrapes off toner (transfer residual toner) adhering to the surface of the photosensitive drum 31. The toner receiving sheet 51 is an elastic sheet made of, for example, polyester or urethane and having a thickness of about 0.1 mm, and has a length corresponding to the length of the photosensitive drum 31. They are arranged along the axial direction. Then, the toner receiving sheet 51 is
The box 33a is attached to the tip of an attachment portion 55 formed by projecting the lower surface of the box 33a toward the photosensitive drum by means such as a double-sided adhesive tape. Toner receiving sheet 51
Is a case in which the toner remaining after the transfer is performed by the transfer device 13 passes through the toner receiving sheet 51 and the cleaning blade 52 receives the toner (transfer residual toner) scraped off from the surface of the photosensitive drum 31. 32
Of the waste toner box 32, and the leading end thereof is in contact with the surface of the photosensitive drum 31 with elasticity toward the downstream side in the rotating direction of the photosensitive drum.

The capture brush 53 is formed by arranging a number of fibers (hairs) 61 having a uniform length and arranging them at a predetermined density on a cloth 62. The length corresponding to the length of the photosensitive drum 31 will be described later. As described above, it has a width that covers both the toner receiving sheet 51 and the surface of the photosensitive drum 31. The capture brush 53 is arranged along the photoconductor drum axis direction such that the fibers 61 face the photoconductor drum side at the front end side of the mounting portion 55 formed in the box 33a of the housing 33, and the cloth 62 is formed, for example. It is adhered to the tip of the mounting portion 55 using a double-sided tape. In addition, the capture brush 53 has a part (for example, half) of the flocking width of the fiber 61 pressed from outside to the toner receiving sheet 51 that is in contact with the surface of the photoconductor drum 31, and this part is pressed. Is in contact with the surface of the photosensitive drum 31 reliably. The remaining portion of the flocking width of the fiber 61 is in direct contact with the surface of the photosensitive drum 31 on the downstream side in the photosensitive drum rotation direction with respect to the toner receiving sheet 51.

The capture brush 53 is formed by depositing a fiber 61 made of, for example, rayon onto a cloth 62 at about 50,000 filaments / inc.
planted with h ^2, length 3.5mm fiber 61, the longest contact depth 1mm between the photosensitive drum 31, to set a flocked width 5 mm, the fibers of a portion of the width of which approximately 2.5mm of the fiber flocked width 61 is pressed into contact with the toner receiving sheet 51, and the remaining portion is brought into contact with the surface of the photosensitive drum 31.

The fibers 61 constituting the capture brush 53
By using a material mainly composed of rayon as a material for forming, the capture brush used in the present embodiment can be formed of an appropriate material. However, the fiber 61 constituting the capture brush 53 is not limited to rayon, and the same effect can be obtained by forming the fiber 61 from a chemical fiber such as nylon, polyester, polypropylene, or silk or cotton.

The housing 33 is connected to the developing device main body 32 to form the process unit 11.
This process unit 11 is an electrophotographic apparatus main body A.
The operation of the process unit 11 configured as described above, which is detachably mounted on the photoconductor drum 31 and can be removed or replaced when necessary such as replacement of the photosensitive drum 31, will be described.

The photosensitive drum 31 is rotated in the direction of the arrow. A DC bias voltage of -1.1 kV is applied to the charging brush 34 from a power supply (not shown), and the surface of the photoconductor 31 is uniformly charged by the charging brush 34. Next, the surface of the photosensitive drum 1 is exposed by the exposure device 12 based on an image signal, and an electrostatic latent image is formed. Next, the electrostatic latent image formed on the surface of the photoconductor drum 31 is developed by the developing device 32 to form a visible image of toner. Next, the transfer device 13 transfers the toner image formed on the surface of the photosensitive drum 31 to recording paper. Then, the toner not transferred to the recording paper (transfer residual toner) is moved from the transfer position while being adhered to the surface of the photosensitive drum 31. Further, the toner adhering to the surface of the photosensitive drum 31 slips through the contact surface of the toner receiving sheet 51 and is scraped off by the cleaning blade 52.
The scraped-off toner is guided by the toner receiving sheet 51 and guided toward the entrance of the waste toner box 33a of the housing 33, and is further collected by the collection roller 56 provided at the entrance of the waste toner box 33a. It is sent inside and collected.

Here, the paper dust generated by separating from the recording paper at the transfer position adheres to the surface of the photosensitive drum 31.
Then, the attached paper dust moves with the rotation of the photosensitive drum 31 and slips through the contact surface of the toner receiving sheet 51. However, some of the fibers 61 of the capture brush 53 are located downstream of the toner receiving sheet 51 in the photoconductor drum rotation direction,
For example, a fiber 61 having a half of the flocking width is in contact with the surface of the photosensitive drum 31. Therefore, the paper dust that has passed through the contact surface of the toner receiving sheet 51 is caught and captured by the fibers 61 of the capture brush 53 that is in contact with the surface of the photosensitive drum 31. Particularly, the fibrous paper dust is effectively caught on the fibers 61 of the capture brush 53. As a result, the paper dust adhering to the surface of the photosensitive drum 31 slips through the toner receiving sheet 51 and moves to reach the tip of the cleaning blade 52 which is in contact with the surface of the photosensitive drum 31 and is caught. Can be suppressed. In some cases, paper dust may not be caught on the capture brush 53. In this case, the paper dust is separated from the surface of the photosensitive drum 31 by the cleaning blade 52. Therefore, the transfer residual toner on the surface of the photosensitive drum 31 at the contact portion between the tip of the cleaning blade 52 and the photosensitive drum 31 under the influence of the paper dust generated from the recording paper composed of the recycled paper or the printed paper. Can be prevented from occurring in a situation where a cleaning defect occurs and vertical streaks appear on the image.

The other portion of the fiber 61 of the catching brush 53 is in pressure contact with the toner receiving sheet 51 to always directly contact the toner receiving sheet 51 with the surface of the photosensitive drum 31. Therefore, when the housing 33 made of synthetic resin is warped or thermally expanded under the influence of a change in the environment or an increase in the internal temperature of the apparatus body, and the mounting portion 55 formed on the housing 33 is deformed. However, it is possible to stably maintain a state in which the toner receiving sheet 51 attached to the attaching portion 55 is in contact with the photosensitive drum 31 without coming off the surface. Therefore, the leading end of the toner receiving sheet 51 separates from the surface of the photosensitive drum 31 and the cleaning blade 5
2, it is possible to prevent the transfer residual toner scraped off by 2 from falling into the inside of the electrophotographic apparatus main body A through the space between the photosensitive drum 31 and the toner receiving sheet 51, and to form the housing 33. As a synthetic resin, it is not necessary to use an expensive material such as a thermally stable heat-resistant grade or a glass fiber-containing product, so that the material cost is low and the economy is high.

Further, the fact that the fibers 61 of the capturing brush 53 press the toner receiving sheet 51 into contact with the surface of the photosensitive drum 31 means that the fibers 61 of the capturing brush 53 position the toner receiving sheet 51 outside the photosensitive drum 31. And press. For this reason, the paper dust captured by the fibers 61 of the capture brush 53 and the transfer residual toner scraped off by the cleaning blade 52 are transferred to the toner receiving sheet 51.
Of the electrophotographic apparatus main body A
Is guided to the waste toner box 33a of the housing 33 without falling into the inside of the housing 33. Therefore, the cleaning device 3
6, the paper dust captured by the capture brush 53 and the toner scraped off by the cleaning blade 52 are prevented from falling from the capture brush 53 into the main body A of the electrophotographic apparatus.

As described above, the cleaning device 36 according to the present embodiment is capable of obtaining excellent image quality and excellent in economical efficiency. In this embodiment, the cleaning device 36 includes the excellent cleaning device 36. The process unit 11 and an electrophotographic apparatus including the process unit 11 can be obtained.

A specific example will be described. Using a conventional electrophotographic apparatus without a capture brush and the electrophotographic apparatus of the present example with a capture brush, a paper passing test for printing on the back of recycled paper and printed paper was performed up to 10,000 sheets. . As a result, in the conventional apparatus, the fibrous paper dust was caught between the cleaning blade and the photoreceptor at about 5,000 sheets, and a black streak appeared on a white background on the image. In the apparatus (1), a good image could be maintained without clogging of the paper dust between the cleaning blade 52 and the photosensitive drum 31 through a paper passing test.

In an electrophotographic apparatus in which the housing 33 is formed of a normal ABS resin, when printing is performed in a low-temperature environment without the capture brush 53 of the present invention, the printing starts from about 10 sheets at the start of printing. In some cases, the toner scraped off by the cleaning blade may fall into the main body of the electrophotographic apparatus up to about one sheet. This phenomenon occurs when printing is performed in a state in which the electrophotographic apparatus is cold due to conditions such as a low-temperature environment, because the housing is rapidly heated by the heat fixing device provided in the electrophotographic apparatus. This occurs because a gap is formed between the receiving sheet 51 and the photosensitive drum 33. On the other hand, when the same test was performed using the above-described electrophotographic apparatus of this embodiment, no toner leakage occurred.

Next, a second embodiment will be described with reference to FIGS. In this embodiment, the capture brush 53 has conductivity in the first embodiment, and a bias voltage is applied. That is, the process unit and the electrophotographic apparatus to which this embodiment is applied are those shown in FIGS. 2 and 1 described in the first embodiment.

The capture brush 53 used in this embodiment will be described with reference to FIG. The capture brush 53 includes a large number of conductive fibers 7 as in the first embodiment.
1 are arranged side by side and planted on the fabric 72. A large number of conductive fibers 71 are made of, for example, rayon as a main component, and have conductive carbon dispersed therein to reduce the specific resistance to 10%.
It was adjusted to 6 Ωcm. Then, a large number of conductive fibers 71 are transferred to the raw cloth 72 with a flocking density of 50,000 filaments / in.
The hair is planted so as to be sewn in ch ²
A conductive paste 73 is adhered from the back surface of the substrate. The conductive paste 73 is for bonding the conductive fibers 71 and for establishing conduction with the fibers. The conductive paste 73 used here is made of a so-called polyurethane resin as a main component and carbon is dispersed, and has a specific resistance of 10 ² Ω.
cm or less. Further, the capture brush 53 is attached to the mounting portion 5 formed on the process unit 11.
A conductive double-sided tape 74 is attached to the back surface of the conductive paste 73 to adhere to the conductive paste 5c.

In this embodiment, the conductive fiber 71 is formed by an appropriate configuration as described above as the conductive fiber. However, the conductive fiber is not limited to this and may be polyester, nylon, polypropylene, or the like. Carbon fibers or the like dispersed in the above-mentioned chemical fibers, or those subjected to a conductive treatment by other means can also be used. In addition, an epoxy resin, silicone, or the like can be used for the conductive pace. .

Then, as shown in FIG.
Is disposed over the surfaces of the toner receiving sheet 51 and the photosensitive drum 31 in the same manner as in the first embodiment, and is mounted on the mounting portion 33c formed in the housing 33 of the process unit 11. In addition, a bias voltage is applied to the conductive fiber 71 of the capture brush 53 from a power source E disposed in the electrophotographic apparatus main body A by a terminal (not shown) by a bias voltage application unit. Here, the voltage applied to the conductive fibers 71 of the capture brush 53 is a voltage having a polarity opposite to that of the voltage applied to the recording paper by the corona transfer type transfer device 13 during transfer. For example, the applied bias voltage is, for example, DC-500V. The transfer device 13 provided in the apparatus main body A of the electrophotographic apparatus uses a corona transfer method. In the transfer device 13, the voltage applied to the wire is set to +4.5 kV, and transfer is performed by plus corona ions. . That is, the transfer device 13 of the normal corona transfer system
Is used, the paper dust adhering to the photosensitive drum 31 due to the influence of the transfer corona at the time of transfer is often charged to the same potential as the potential polarity of the transfer bias. Therefore, by setting the bias voltage applied to the conductive fibers 71 to a polarity opposite to the voltage applied at the time of transfer in the transfer device 13, paper dust attached to the surface of the photosensitive drum 31 is efficiently removed electrostatically. be able to.

When such a capture brush 53 is provided, in addition to the physical action of the capture brush 53 in the first embodiment, since a bias voltage is applied, the capture brush 53 is exposed by an electrostatic action. Paper dust can be efficiently removed from the surface of the body drum 31.

As a result of examining the specific resistance of the conductive fiber 71 provided on the capture brush 53, the specific resistance of the conductive fiber 71 is set in a range of 10 ⁴ to 10 ⁸ Ωcm. That is, a good paper dust removing effect was confirmed when the resistance value of the conductive fiber was 10 ⁸ Ωcm or less. With respect to a resistance value higher than this, the effect of bias voltage application was not observed, and the effect was merely a physical paper dust capturing effect.

Further, it was confirmed that a resistance value of less than 10 ⁴ Ωcm easily caused abnormal discharge and the like to the photosensitive drum 31. In this case, as shown in FIG. 6, by selectively interposing a resistance value R of 1 M to 10 MΩ between the power source E and the conductive fiber of the capture brush 53, abnormal discharge can be prevented and sufficient paper can be prevented. A powder removing effect can be obtained.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications. For example, the process unit is not limited to the above-described embodiment,
At least a combination of a photoconductor and a cleaning device may be used. The electrophotographic apparatus only needs to include at least a transfer device, a heat fixing device, and a recording paper supply device.

[0048]

According to the cleaning device of the first aspect of the present invention, paper dust existing on the photosensitive drum is captured in the area where the fibers of the capture brush are in direct contact with the surface of the photosensitive member, and the capture brush is provided with a brush. Since the fiber constantly presses the toner receiving sheet against the photoconductor, the toner receiving sheet can stably maintain the contact state with the photoconductor even when thermal deformation of the housing made of synthetic resin occurs. . Therefore, according to the present invention, it is possible to obtain an economical cleaning device that can obtain a stable image for a long period without being affected by paper dust even when printing is performed on recording paper made of recycled paper or backing paper. it can.

According to the second aspect of the present invention, in the region where the fiber constituting the capture brush is in direct contact with the surface of the photoreceptor,
Since the bias voltage is applied to the capture brush, paper dust can be more efficiently removed by the electrostatic action in addition to the physical action by the conductive capture brush.

According to the third aspect of the invention, by setting the bias voltage applied to the conductive brush to the reverse polarity of the voltage at the time of transfer, paper dust attached to the surface of the photoreceptor can be efficiently removed electrostatically. .

According to the fourth aspect of the present invention, the capture brush can be formed using a fiber material suitable for applying a bias voltage to the capture brush.

According to the fifth aspect of the present invention, it is possible to provide a bias voltage applying means suitable for the case where the specific resistance of the conductive fiber constituting the capture brush is small.

According to the sixth aspect of the present invention, it is possible to obtain a process unit having an economical cleaning device capable of obtaining a stable image for a long period without being affected by paper dust.

According to the seventh aspect of the present invention, it is possible to obtain an electrophotographic apparatus including the process unit according to the sixth aspect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an electrophotographic apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a process unit according to the embodiment.

FIG. 3 is a sectional view showing a cleaning device according to the embodiment;

FIG. 4 is a sectional view showing a cleaning device according to a second embodiment.

FIG. 5 is a sectional view showing a capture brush provided in the cleaning device of the embodiment.

FIG. 6 is a diagram showing a mode in which means for applying a voltage to the capture brush is different in the cleaning device of the embodiment.

FIG. 7 is a sectional view showing a conventional process unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Process unit, 12 ... Exposure apparatus, 13 ... Transfer apparatus, 14 ... Heat fixing apparatus, 15 ... Paper supply apparatus, 31 ... Photoconductor drum, 32 ... Developing apparatus, 33 ... Housing, 34 ... Charging brush, 36 ... Cleaning device, 51: Toner receiving sheet, 52: Cleaning blade, 53: Capture brush, 61: Fiber, 62: Fabric, 71: Conductive fiber, 72: Fabric, A: Electrophotographic apparatus body.

Claims (7)

[Claims] A cleaning blade disposed in contact with a surface of a photoreceptor provided in a process unit to scrape off toner present on the surface of the photoreceptor; A toner receiving sheet that receives the toner scraped off by the cleaning blade in contact with the surface of the photoreceptor; and a plurality of fibers that contact the toner receiving sheet with the surface of the photoreceptor. A cleaning brush for pressing and contacting the toner receiving sheet and directly contacting the surface of the photoreceptor on the downstream side in the photoreceptor rotation direction with respect to the toner receiving sheet. 2. A cleaning blade disposed in contact with a surface of a photoreceptor provided in a process unit and scraping off toner present on the surface of the photoreceptor, and a cleaning blade upstream of the cleaning blade in a rotation direction of the photoreceptor. A toner receiving sheet disposed to receive the toner scraped off by the cleaning blade in contact with the surface of the photoreceptor; and a plurality of conductive fibers, wherein the conductive fibers move the toner receiving sheet onto the surface of the photoreceptor. A capture brush that presses against the toner receiving sheet and directly contacts the surface of the photoconductor on the downstream side in the photoconductor rotation direction with respect to the toner receiving sheet; and a bias that applies a voltage to conductive fibers of the capture brush. A cleaning device comprising: an application unit. 3. A voltage applied to the conductive fibers of the capture brush by the bias applying means is a voltage having a polarity opposite to a voltage applied to a transfer device provided in an electrophotographic apparatus. Item 3. A cleaning device according to Item 2. 4. The cleaning device according to claim 2, wherein the conductive fibers forming the capture brush have a specific resistance of 10 ⁴ to 10 ⁸ Ω · cm. 5. The conductive brush constituting the capture brush has a specific resistance of less than 10 ⁴ Ω · cm, and a resistance value of 1 to 1 between the conductive capture brush and the bias applying means.
The cleaning device according to claim 2, wherein a resistance of 0 MΩ is interposed. 6. A process unit comprising at least a photoconductor, the cleaning device according to claim 1, and a housing supporting the photoconductor and the cleaning device. 7. An electrophotographic apparatus comprising: the process unit according to claim 6; a transfer device; a thermal fixing device; and a recording paper supply device.