JP2011107289A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a cleaning device for cleaning a surface of a charging member can demonstrate a desired cleaning function over a long period of time. <P>SOLUTION: The cleaning device 8 for cleaning the surface of the charging member (charging roller 2) includes: the cleaning member 80 including a cylindrical member 81 and an elastic foaming member 82 equipped around an outer periphery surface of the cylindrical member; an axial rod 83 loosely inserted into the cylindrical member with the direction of the central axial line aligned with the longitudinal direction of the cylindrical member; and a supporting section 84 of the axial rod 83. In this case, the supporting section 84 presses the elastic foaming member 82 to the surface of the charging member through the cylindrical member 81 so that the cleaning member 80 is rotated following the rotation of the charging member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combination machine combining two or more of these, and in particular, a cleaning device for cleaning a charging member that charges the surface of an image carrier. Is related to.

  As an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combination machine combining two or more of these, the surface of the image carrier is charged with a charging device, and an electrostatic latent image is formed in the charging area. There are known ones capable of developing an electrostatic latent image to form a visible toner image. In this type of image forming apparatus, generally, a toner image can be transferred and fixed on a recording medium such as recording paper.

  As the image carrier, a drum-type or belt-type photosensitive member can be exemplified in an electrophotographic image forming apparatus, and an image carrier made of a dielectric can be exemplified in an electrostatic recording type image forming apparatus.

  In any case, there are two main charging methods for charging the surface of the image carrier prior to the formation of the electrostatic latent image: a non-contact charging method and a contact charging method. Non-contact charging methods include a corotron method and a scorotron method in which an image carrier is charged by corona discharge. Examples of the contact charging method include a roller charging method and a brush charging method in which the image carrier is charged by a spark discharge in a minute gap generated adjacent to a contact area between the image carrier and the charging member.

  In the non-contact charging method, ozone is generated by corona discharge, and a duct or a fan for exhausting the ozone is required. Therefore, the cost is increased and the size is increased. On the other hand, since the contact charging method is substantially an ozone-less charging method, there is no need for a duct or a fan for exhausting ozone, and the cost can be reduced and the size can be reduced. For this reason, the contact charging method has become the mainstream in so-called low-end image forming apparatuses in which the image forming speed is relatively low and the cost is low.

Further, as a charging member that has been put into practical use in the contact charging method, a roller charging method using a charging roller that can rotate in contact with the surface of the image carrier can be exemplified.
However, the roller charging method is formed because the surface of the roller is contaminated because the charging roller comes into contact with the image carrier, the charging performance is impaired by the contaminants, and the image carrier cannot be uniformly charged. Unevenness tends to occur in the image.

  In general, therefore, a cleaning device for cleaning the surface layer of the charging roller is used. There are various cleaning devices, but the mainstream is the cleaning device described in Japanese Patent Laid-Open No. 2008-39880. This employs a cleaning roller made of a resin foam, which is rotatably arranged on the charging roller, and is intended to keep the charging roller clean and uniform with a cleaning roller which is a rotating body.

JP 2008-39880 A

  However, in such cleaning of the charging member by the conventional cleaning roller, contaminants are gradually accumulated in the foam cell of the cleaning roller as the cleaning roller is repeatedly used, and the cleaning effect is gradually reduced. The image carrier is non-uniformly charged, and as a result, the formed image becomes uneven.

  Therefore, the present invention charges the surface of the image carrier using a charging member that can rotate in contact with the surface, forms an electrostatic latent image in the charged area, develops the electrostatic latent image, and forms a visible toner image. An image forming apparatus including at least one image forming unit that can be formed and includes a cleaning device that cleans the surface of the charging member, wherein the cleaning device in at least one of the image forming units is conventionally To provide an image forming apparatus that can exhibit a desired cleaning performance for a longer period of time, and that can suppress the occurrence of image unevenness due to contamination of the charging member as a whole for the entire image forming apparatus. Let it be an issue.

In order to solve the above problems, the present invention
The surface of the image carrier can be charged using a charging member that can rotate in contact with the surface, an electrostatic latent image can be formed in the charged area, and the electrostatic latent image can be developed to form a visible toner image. An image forming apparatus including at least one image forming unit provided with a cleaning device for cleaning the surface of the charging member, wherein the cleaning device in at least one of the image forming units includes a cylindrical member and the cylinder. A cleaning member including an elastically compressible foam member provided around the outer peripheral surface of the cylindrical member, a shaft rod that is loosely inserted into the cylindrical member with the center axis direction aligned with the cylindrical member longitudinal direction, A shaft rod support portion, and the shaft rod support portion presses the foam member against the surface of the charging member via the cylindrical member so that the cleaning member can be rotated by the rotation of the charging member. An image forming apparatus for supporting the shaft rod is provided.
A typical example of the rotatable charging member is a charging roller, but a charging belt or the like may be used.

  According to the image forming apparatus of the present invention, the surface of the image carrier is charged by using a charging member that can rotate in contact with the surface, an electrostatic latent image is formed in the charged area, and the electrostatic latent image is developed. In at least one of the image forming units that can form a visible toner image and includes a cleaning device that cleans the surface of the charging member, the cleaning member of the cleaning device that cleans the charging member that charges the image carrier Is an elastic foam member that is elastically compressible (compressible and elastically recoverable) around the outer peripheral surface of the cylindrical member. The foamed member is pressed against the surface of the charging member via the cylindrical member by a shaft rod that is loosely inserted into the cylindrical member with the central axis direction aligned with the longitudinal direction of the cylindrical member, and the cleaning member is charged. It is pressed to rotate following the rotation of the member.

  Thus, while the elastic foam member is compressed so as to receive a compressive force from both the charging member side and the cylindrical member side in the pressure nip portion between the charging member and the cleaning member, contaminants on the surface of the charging member are contained in the elastic foam member cell. The contaminants on the charging member can be cleaned and removed. Here, examples of the contaminant include toner and its external additive (for example, silica as a fluidizing agent).

  Thus, when the part of the cleaning member holding the pollutant in the elastic foam member cell is released from the nip portion between the charging member and the cleaning member as the charging member rotates and the driven member rotates, the elastic foam member Tries to elastically restore from the previous compressed state toward both the charging member side and the cylindrical member side, and the elastic restoring force causes vibration in the cleaning member, thereby making it easier for contaminants in the elastic foam member cell Thus, the contaminants are prevented from being accumulated in the cleaning member, and the state where the desired charging member cleaning performance can be exhibited is maintained for a long time. Accordingly, when viewed as the entire image forming apparatus, it is possible to suppress the occurrence of image unevenness due to the charging member contamination for a long time.

Examples of the cylindrical member include a case where the cylindrical member is formed of a polymer organic compound.
Examples of such a polymer material include polyethylene, polypropylene, polyester, polycarbonate, and polyimide. As the thickness of the cylindrical member, a case where the entire cleaning member including the elastic foam member provided around the cylindrical member has a thickness that can be elastically deformed in a direction crossing the longitudinal direction of the cylindrical member can be exemplified. .

  The case where the elastic foam member in the cleaning member is formed from an elastic resin foam can be illustrated. Examples of such elastic resin foams include foams such as polyurethane, polyethylene, and melamine resin.

  When the cleaning member rotates following the rotation of the charging member so that the cleaning member can smoothly follow the rotation of the charging member, the frictional force generated between the cylindrical member and the shaft rod is between the charging member and the elastic foam member. It is desirable that the friction force is smaller than

As described above, the shaft rod is supported by the shaft rod support portion, but in this case, the shaft rod may be supported rotatably or may be supported non-rotatably.
In any case, as a method of supporting the shaft rod by the shaft rod support portion, the both ends of the shaft rod protrude outward from the longitudinal direction end of the cleaning member, and the respective protruding end portions are supported by the support portion. It can be mentioned as a representative example.

  Each end of the shaft rod may protrude outward from the longitudinal end of the cleaning member, and a meandering prevention member for the cleaning member may be provided at the shaft rod protruding end.

  With respect to the circumferential arrangement of the elastic foam member of the cleaning member to the cylindrical member, for example, the elastic foam member may be formed in a cylindrical shape, and the cylindrical member may be fitted therein. In order to facilitate the formation of the member, a mode in which a belt-like elastic foam member is spirally wound around the outer peripheral surface of the tubular member may be used. Further, in order to save material, a gap may be formed between adjacent portions in the longitudinal direction of the cylindrical member of the band-shaped elastic foam member wound spirally around the cylindrical member.

  As described above, according to the present invention, the surface of the image carrier is charged by using a charging member that can rotate in contact with the surface, an electrostatic latent image is formed in the charged area, and the electrostatic latent image is developed. An image forming apparatus that can form a visible toner image and includes at least one image forming unit provided with a cleaning device that cleans the surface of the charging member, wherein at least one of the image forming units In the image forming apparatus, the above-described cleaning device can exhibit a desired cleaning performance for a longer period of time than before, and as a result, the image forming apparatus as a whole can suppress the occurrence of image unevenness due to contamination of the charging member for a longer period of time. An apparatus can be provided.

1 is a diagram illustrating an outline of a configuration of an example of an image forming apparatus according to the present invention. FIG. 2 is a cross-sectional view of a charging roller and its cleaning device in the image forming apparatus of FIG. 1. FIG. 2 is a diagram illustrating a cleaning device in the image forming apparatus of FIG. 1 as viewed from a direction crossing its longitudinal direction. It is a perspective view of the elastic foam member of the cleaning apparatus shown in FIG. 2, FIG. It is a figure which shows the other example of the cleaning apparatus of a charging roller. It is a figure which shows the further another example of the cleaning apparatus of a charging roller. It is a figure explaining charging roller cleaning by the cleaning device concerning the present invention compared with charging roller cleaning by the conventional cleaning device. It is a figure which shows the charging roller cleaning effect confirmation experiment result by the cleaning apparatus shown in FIG. 2 etc. with the cleaning effect by the conventional type cleaning apparatus.

Hereinafter, an example of an image forming apparatus according to the present invention and a charging member cleaning apparatus used therein will be described with reference to the drawings.
FIG. 1 schematically shows the configuration of an example of an image forming apparatus according to the present invention.

The image forming apparatus shown in FIG. 1 is a printer that forms a monochrome image.
A printer 10 shown in FIG. 1 includes a drum-type photosensitive member 1 as an image carrier. Around the photoreceptor 1, a charging roller 2, an image exposure device 3, a developing device 4, a transfer roller 5, and a cleaning device 6 are arranged in this order.

  In FIG. 1, a fixing device 7 is disposed on the left side of the transfer roller 5. In this example, the fixing device 7 includes a fixing roller 71 having a built-in heat source such as a heater lamp and a pressure roller 72 facing the fixing roller 71.

  Although the cleaning device 8 is provided for the charging roller 2, the cleaning device 8 will be described in detail later.

  According to this image forming apparatus 10, the photosensitive member 1 is rotated in the clockwise direction in the figure by a photosensitive member driving motor (not shown), and the surface thereof is uniformly charged to a predetermined potential by the charging roller 2. At this time, a charging voltage is applied to the charging roller 2 from a charging power supply (not shown). The charging roller 2 may contact the surface of the photosensitive member 1 and can be rotated counterclockwise. In this example, the charging roller 2 contacts the photosensitive member 1 and rotates counterclockwise. It is configured to be driven to rotate by an omitted drive unit.

  In this way, image exposure corresponding to the image to be formed from the image exposure apparatus 3 is performed on the photosensitive member charged area charged to a predetermined potential, and an electrostatic latent image is formed on the photosensitive member 1. This electrostatic latent image is developed by the developing roller 41 of the developing device 4 to which a developing bias is applied from a power supply (not shown) to become a visible toner image.

  Note that image exposure by the image exposure apparatus 3 is performed based on image information supplied from a scanner, a computer, etc. (not shown).

  On the other hand, the recording medium S is supplied from a recording medium supply unit such as recording paper (not shown), and is temporarily put on standby by a timing roller pair (not shown). In the recording medium S, the image formation target area of the recording medium S is just between the photosensitive member 1 and the transfer roller 5 at the timing when the toner image on the photosensitive member 1 arrives between the photosensitive member 1 and the transfer roller 5. The toner image on the photosensitive member 1 is transferred to the recording medium S by the transfer roller 5 that is fed between the photosensitive member 1 and the transfer roller 5 so that the transfer voltage is applied from a transfer power supply (not shown). .

  The recording medium S onto which the toner image has been transferred in this manner passes through the fixing device 7 so that the transferred toner image is fixed under heat and pressure, and then discharged onto a recording medium discharge tray (not shown).

  In this example of the cleaning device 6, the transfer residual toner remaining on the photoreceptor 1 is removed and cleaned by the cleaning blade 61, and the removed transfer residual toner and the like is stored in the storage unit 62.

  The transfer residual toner or the like on the photoconductor 1 is not completely removed by the cleaning device 6, and the charging roller 2 that rotates in contact with the photoconductor 1 is contaminated with contaminants. The contaminants here are mainly toner and its external additives (for example, silica as a fluidizing agent).

  If the charging roller 2 continues to be used while the contamination of the charging roller 2 is left as it is, the charging performance is impaired by the contaminants, and the photosensitive member 1 cannot be uniformly charged, and the formed image is uneven. It comes to occur.

Therefore, the printer 10 is provided with the cleaning device 8 for the charging roller 2 as described above.
FIG. 2 is a sectional view of the charging roller 2 and the cleaning device 8 corresponding thereto. As shown in FIG. 2, the cleaning device 8 includes a cleaning member 80 and a shaft rod 83 inserted therein.

The cleaning member 80 includes a cylindrical member 81 and an elastic foaming member 82 that is provided around the outer peripheral surface of the cylindrical member and that can be elastically compressed, in other words, can be compressed and deformed and elastically restored.
The shaft 83 is loosely inserted into the tubular member 81 with the central axis direction aligned with the longitudinal direction of the tubular member.

FIG. 3 shows the cleaning device 8 as viewed from the direction crossing its longitudinal direction.
In the cleaning device 8, both ends in the longitudinal direction of the tubular member 81 are set to the same positions as both ends in the longitudinal direction of the elastic foam member 82, or extend beyond both ends in the longitudinal direction of the foam member 82. This is because the foam member 82 is entirely supported by the tubular member 81 from the inside to prevent the foam member from being damaged. In the example shown in FIG. 3, both ends in the longitudinal direction of the cylindrical member 81 are extended to the outside from both ends in the longitudinal direction of the elastic foam member 82.

  Both end portions of the shaft rod 83 extend outward from both ends in the longitudinal direction of the cylindrical member 81 of the cleaning member 80, and are rotatably supported by the shaft rod support portion 84 at each protruding end portion. As will be described later, when the cleaning member 80 is driven and rotated by the charging roller 2, the shaft rod 83 does not need to be rotatably supported as long as there is no hindrance to the driven rotation.

  When the cleaning member 80 is rotated following the rotation of the charging roller 2, the frictional force generated between the cylindrical member 81 and the shaft rod 83 is smaller than the frictional force generated between the charging roller 2 and the foaming member 82. What is necessary is just to select the material of each member.

  The pair of left and right shaft rod support portions 84 press the shaft rod 83 so as to press the foaming member 82 against the surface of the charging roller 2 via the tubular member 81 so that the cleaning member 40 rotates following the rotation of the charging roller 2. I support it.

As shown in FIG. 2, the dimensional relationship of each part is as follows. As shown in FIG. 2, the radius of the charging roller 2 is R1, the radius of the shaft 83 is R2, the thickness of the cylindrical member 81 is T1, the thickness of the foam member 82 is T2, When the distance between the center of the charging roller 2 and the center of the shaft rod 83 is L, the shaft rod 83 of the cleaning device 8 is disposed at a position where L <R1 + R2 + T1 + T2.
Here, R1, R2, T1, and T2 are the radius and thickness when no external force is applied to the member, and L is the cleaning device 8 in the normal arrangement state (the foam member 82 is compressed in the nip). This is the distance between the center of the charging roller 2 and the center of the shaft 83 when placed.
In FIG. 2, the cleaning device 8 is disposed above the charging roller 2, but is not limited to this positional relationship.

  As for the material of each part of the cleaning device 8, generally speaking, the cylindrical member 81 can be exemplified by a case where it is made of a polymer organic compound. Examples of such a polymer material include polyethylene, polypropylene, polyester, polycarbonate, and polyimide. More specifically, for example, polypropylene can be mentioned.

  Although the thickness of the cylindrical member 81 is not particularly limited, in this example, the entire cleaning member 80 including the elastic foam member 82 provided around the cylindrical member can be elastically deformed in a direction crossing the longitudinal direction of the cylindrical member. The thickness is sufficient to provide flexibility.

Generally speaking, the elastic foam member 82 can be exemplified by an elastic resin foam. Examples of such elastic resin foams include foams such as polyurethane, polyethylene, and melamine resin. The physical properties of the foam are not particularly limited, but those having a high cell density or a high density to form an elastic layer having a cleaning effect for the charging roller 2 may be adopted. The foam structure may be a closed bubble type (single bubble type) or a continuous bubble type, but the open bubble type has better cleaning performance.
As a more concrete thing of the foaming member 82, what consists of a continuous foam type polyurethane foam can be mentioned, for example.

  In addition to the above, the cleaning device 8 includes a meandering prevention member 85 of the cleaning member 80. That is, as shown in FIG. 3, a flange-shaped meandering prevention member 85 is provided in a portion of the shaft 83 that protrudes outward from the end in the longitudinal direction of the cleaning member, closer to the cleaning member than the support portion 84. What is necessary is just to set the magnitude | size of the meandering prevention member 85 according to the thickness of the cylindrical member 81, the magnitude | size of a cross section, etc. FIG. The shaft rod support portion 84 may also serve as a meandering prevention member.

  According to the cleaning device 8 described above, the cleaning member 80 has an elastic foam member 82 that can be elastically compressed (compressible and elastically recoverable) around the outer peripheral surface of the cylindrical member 81. The foam member 82 is pressed against the surface of the charging roller 2 via the cylindrical member 81 by the shaft rod 83 disposed at a fixed position with respect to the charging roller 2 by the shaft rod support portion 84, and the cleaning member 80 is charged. It is pressed to rotate following the roller rotation.

  Thus, the elastic foam member 82 is contaminated on the surface of the charging roller 2 while being compressed so as to receive a compressive force from both the charging roller 2 side and the cylindrical member 81 side at the pressure nip portion between the charging roller 2 and the cleaning member 80. A substance can be allowed to enter the elastic foam member cell, and contaminants on the charging roller 2 can be cleaned and removed.

  As shown in FIG. 7A, the portion of the cleaning member 80 that holds the pollutant in the cell of the foaming member 82 is charged with the rotation of the charging roller 2 and the driven rotation of the cleaning member 80 as shown in FIG. When the foaming member 82 is released from the nip portion between the cleaning member 80 and the cleaning member 80, the foaming member 82 tries to elastically recover from the compression state so far toward both the charging roller 2 side and the cylindrical member 81 side. 80 is vibrated, so that the pollutant in the cell of the elastic foam member 82 is easily ejected out of the cell, thus preventing the contaminant from being accumulated in the cleaning member 80, and for a long time. The state in which the charging roller cleaning performance can be exhibited is maintained. Accordingly, when viewed as the entire image forming apparatus 10, it is possible to suppress the occurrence of image unevenness due to the contamination of the charging roller 2 for a long period of time.

  In the conventional type cleaning device shown in FIG. 7B, since the elastic foam member 820 is directly provided around the shaft rod 830, the foam member 820 is used for the rotation of the charging roller 2 and the driven rotation of the cleaning member 800. At the same time, when released from the nip portion between the charging roller 2 and the cleaning member 800, only the elastic state is restored from the compression state so far toward the charging roller 2 side, and vibration due to the elastic restoring force hardly occurs. . Therefore, compared with the cleaning device 8 shown in FIG. 7A, the contaminants removed from the charging roller 2 are less likely to be released from the cells of the foam member 820, and the contaminants are gradually accumulated, so that the cleaning performance is higher than that of the cleaning device 8. Will decrease in a short time.

  The cleaning member 80 of the cleaning device 8 described above is applied to a foam square material like a method of cutting and polishing a foam by inserting a shaft into the foam square material used in conventional cleaning roller production. Although it can be obtained by inserting the cylindrical member 81 and cutting and polishing the foam square material, it is difficult to obtain high accuracy because the cylindrical member 81 is a flexible cylindrical member. In that case, the cylindrical foaming member 82 as shown in FIG. 4 may be formed, and the cleaning member 80 may be configured by inserting the cylindrical member 81 therein.

In addition, as shown in FIG. 5, a foam member may be provided around the tubular member 81 by spirally winding a strip-like foam member 82 ′ around the tubular member 81.
Further, in order to save the foam member material and reduce the cost of the cleaning device, the strip-like foam member 82 ″ may be spirally wound around the tubular member 81 as shown in FIG.

FIG. 8 shows experimental results for confirming the cleaning effect of the cleaning device 8.
In this experimental method, the cleaning effect of each cleaning device is measured by measuring the dirt improving property when the charging roller 2 previously contaminated with the contaminant is rotated a predetermined number of times (when the cumulative rotational speed reaches the predetermined rotational speed). It is a method to confirm. The amount of stain improvement is substituted by the amount of change in color (lightness L * by the Lab color system). The conditions of each cleaning device are as shown in the following table.

Fig. 7 (B) type conventional cleaning device Cleaning device 8 type device charging roller 2 diameter 9.5mm 9.5mm
Charging roller material Epichlorohydrin rubber Epichlorohydrin rubber
Cleaning device shaft diameter 4.0mm Shaft bar diameter 4.0mm
Shaft material Stainless steel Stainless steel Cleaning member outer diameter 8.0mm 10.0mm
Tubular member outer diameter-6.0 mm
Cylindrical member thickness-0.2mm
Foam thickness 2.0mm 2.0mm
Charge roller biting into foam member 0.75mm 0.75mm
Cylindrical material-Polypropylene Foam material Polyurethane Polyurethane
Foam structure Open bubble Open bubble Cleaning member rotation with respect to charging roller Driven rotation Fixed shaft rod
Cleaning member driven rotation

In FIG. 8, ◆ indicates the cleaning effect confirmation experiment result of the conventional cleaning device as shown in FIG. 7B, and ■ indicates the cleaning effect confirmation experiment result of the cleaning device of type 8 cleaning device.
In FIG. 8, for both the ◆ mark and the ■ mark, a plurality of different stain improving properties are plotted in the vertical axis direction for the same rotational speed. The reason for this is that the width of the charging roller 2 in the rotational axis direction is about 220 mm, 10 mm, 60 mm, 110 mm, 160 mm, 210 mm from one end of the roller and 10 mm from the other end of the roller slightly shifted in the circumferential direction of the roller. This is because the dirt improving property at each position of 60 mm, 110 mm, 160 mm, and 210 mm was evaluated.

From this experimental result, it can be seen that the cleaning effect of the cleaning device of the type of the cleaning device 8 is high, and the cleaning performance is maintained even when the cumulative number of rotations increases. Adherence of contaminants could be confirmed in the cell of the foam member, but it was not clogged.
On the other hand, according to the conventional type cleaning roller, no improvement in dirt is observed after 1500 revolutions. It was confirmed that the pollutant was clogged in the cell of the foam member.

  In this experimental result, the cleaning effect differs from the point of 300 rotations in the apparatus 8 type cleaning device, the outer diameter of the cylindrical member is 6.0 mm, and the outer diameter of the entire cleaning member is larger than that of the conventional cleaning roller. It is thought that it is. However, the cleaning member of the apparatus 8 type cleaning device has only a large area of about 120% of the conventional cleaning roller, and it is considered that the cleaning effect after 1500 revolutions is not affected.

  Although the image forming apparatus 10 described above is a monochrome image forming apparatus, the present invention can also be applied to a color image forming apparatus such as a tandem type color image forming apparatus, a so-called cycle type (for example, a four-cycle type color image forming apparatus). .

  Further, in an image forming apparatus provided with a plurality of sets of image carriers and their charging members, the cleaning device according to the present invention can be provided for a smaller number of charging members than the total number of the plurality of sets.

  INDUSTRIAL APPLICABILITY The present invention can be used to provide an image forming apparatus in which a cleaning device that cleans the surface of a charging member that charges an image carrier can exhibit a desired cleaning performance over a longer period of time than before.

DESCRIPTION OF SYMBOLS 10 Printer 1 Photoconductor 2 Charging roller 3 Image exposure apparatus 4 Developing apparatus 41 Developing roller 5 Transfer roller 6 Cleaning apparatus 7 Fixing apparatus 71 Fixing roller 72 Pressure roller 8 Cleaning apparatus 80 Cleaning member 81 Cylindrical members 82, 82 ', 82 Elastic foam member 83 Shaft bar 84 Shaft bar support 85 Serpentine prevention member

Claims (6)

  The surface of the image carrier can be charged using a charging member that can rotate in contact with the surface, an electrostatic latent image can be formed in the charged area, and the electrostatic latent image can be developed to form a visible toner image. An image forming apparatus including at least one image forming unit provided with a cleaning device for cleaning the surface of the charging member, wherein the cleaning device in at least one of the image forming units includes a cylindrical member and the cylinder. A cleaning member including an elastically compressible foam member provided around the outer peripheral surface of the cylindrical member, a shaft rod that is loosely inserted into the cylindrical member with the center axis direction aligned with the cylindrical member longitudinal direction, A shaft rod support portion, and the shaft rod support portion presses the foam member against the surface of the charging member via the cylindrical member so that the cleaning member can be rotated by the rotation of the charging member. An image forming apparatus that supports the shaft rod.   The image forming apparatus according to claim 1, wherein the cylindrical member is formed of a polymer organic compound and is elastically deformable in a direction crossing a longitudinal direction of the cylindrical member.   The image forming apparatus according to claim 1, wherein the foam member is formed of an elastic resin foam.   The frictional force generated between the cylindrical member and the shaft rod is smaller than the frictional force generated between the charging member and the foam member when the cleaning member rotates following the rotation of the charging member. 2. The image forming apparatus according to 2 or 3.   5. The shaft rod according to claim 1, wherein each end of the shaft protrudes outward from a longitudinal end of the cleaning member, and the meandering prevention member of the cleaning member is provided at the shaft rod protruding end. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the foaming member of the cleaning member is spirally wound around the cylindrical member.

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