JP3712040B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technical field of an image forming apparatus for forming an image by bringing a charging device such as a charging roller into contact with a photosensitive member to charge the photosensitive member and forming an electrostatic latent image on the charged photosensitive member. In particular, to prevent scattering of foreign matters accumulated on the cleaning member of the charging member for removing foreign matters such as toner adhering to the charging member of the charging device, and to prevent spilling under the charging member. Belongs to the technical field of image forming apparatuses.
[0002]
[Prior art]
An image forming apparatus such as an electrostatic copying machine or a printer includes a charging device that charges a photosensitive member. Conventionally, corona charging has been widely used as the charging device. However, this corona charging has the problem of causing image defects because ozone and nitrogen oxides are generated and adhere to the surface of the photoreceptor.
[0003]
Therefore, as a charging device, a contact charging method in which a charging member made of, for example, urethane rubber or the like to which a voltage is applied is brought into contact with the photosensitive member to charge the photosensitive member is proposed in, for example, Japanese Patent Application Laid-Open No. 63-149668. . According to such a contact charging method, the problems caused by the above-mentioned corona charging can be solved.
However, in the contact charging method, since the charging member is in contact with the photosensitive member, foreign matters such as toner on the photosensitive member that has passed through the cleaning device and toner scattered from the developing device adhere to the surface of the charging member. For this reason, a charging failure of the photosensitive member is caused, and image deterioration occurs.
[0004]
For this reason, various image forming apparatuses including a cleaning member for removing foreign matters such as toner adhering to the surface of the charging member have been proposed. If the cleaning member of such an image forming apparatus is always in contact with the charging member, the surface of the charging member is damaged and charging failure occurs. The cleaning member is set in contact with the charging member only when the charging member is cleaned, and is separated from the charging member when the charging member is not cleaned. In such a case, the cleaning of the charging member is generally performed periodically, and therefore, the separation / contact operation of the cleaning member is also performed periodically. According to the image forming apparatus provided with this cleaning member, the surface of the charging member is cleaned, and the charging of the photosensitive member is improved.
[0005]
Japanese Patent Laid-Open No. 6-3930 discloses a method for performing the contact / separation operation when the charging member is rotating as a timing for performing the contact / separation operation of the cleaning member with respect to such a charging member. In addition, Japanese Patent No. 2853208 discloses a method of simultaneously performing rotation and separation / contact operation of the charging member. Furthermore, as an operation method for separating and contacting the cleaning member with respect to the charging member, in most conventional image forming apparatuses, the cleaning member is moved in the radial direction of the charging member.
On the other hand, there is a method of cleaning the charging member without removably moving the cleaning member and simply reciprocating the cleaning member in the axial direction of the charging member, for example, Japanese Patent Laid-Open Nos. 7-110618 and 7-134474. Proposed in the Gazette.
[0006]
[Problems to be solved by the invention]
By the way, by repeating the cleaning of the charging member, the removed toner is gradually accumulated in the cleaning member. The cleaning member in which the toner is accumulated is brought into contact with a rotating charging member as disclosed in Japanese Patent Application Laid-Open No. 6-3930, or cleaning is performed as disclosed in Japanese Patent No. 2853208. If the charging member is rotated simultaneously with the member separation / contact operation, the cleaning member may be hit by the rotation of the charging member at the moment when the cleaning member contacts or leaves the charging member. As described above, when the cleaning member is hit by the rotation of the charging member, the toner accumulated in the cleaning member is scattered. The scattered toner contaminates the inside of the process cartridge in which the photosensitive member or the like is accommodated or the inside of the image forming apparatus main body, resulting in deterioration of image quality.
[0007]
Further, in the charging member cleaning device having the cleaning member separating / contacting mechanism, when the cleaning member is separated from the charging member, the toner deposited on the nip portion where the charging member and the cleaning member are in contact with each other on the charging member. A so-called separation streak may occur, but this separation streak causes the following problem. That is,
(1) Not only a part of the separation streak remains on the charging member in a streak pattern with respect to the rotation direction of the charging member, but also the cleaning member separating / separating operation is in the radial direction. It becomes a cause of charging failure.
(2) Some toner in the separation line moves to the photoconductor, but some other toner spills under the charging member and accumulates at each separation operation, and is accumulated in the process cartridge or even in the image. The inside of the forming apparatus is contaminated, and the quality of the image forming apparatus is deteriorated.
[0008]
The present invention has been made in view of such circumstances, and an object of the present invention is to prevent scattering of foreign matters deposited on the cleaning member and to prevent the foreign material from falling down under the charging member. A forming apparatus is provided.
[0009]
[Means for Solving the Problems]
In order to solve this problem, the invention according to claim 1 is a photoconductor on which an electrostatic latent image is formed, a charging member that contacts the photoconductor to charge the photoconductor, and is separated from the charging member. At least a cleaning member provided so as to be able to contact and cleaning the charging member, and the charging member is rotated by rotating the charging member in a state where the cleaning member is in contact with the charging member. In the image forming apparatus, the cleaning member is separated from the charging member except when the charging member is cleaned, and is in contact with the charging member when the charging member is cleaned. In addition, the cleaning member is brought into and out of contact with the charging member in a state in which the rotation of the charging member is stopped. Charging part It is characterized by being set to the charging member in a state such that sweeping broom is set in the axial direction and oblique direction in the radial direction.
[0011]
[Action]
In the image forming apparatus of the present invention configured as described above, when the charging member is stopped, the cleaning member comes into contact with the charging member. Thereby, since the cleaning member is not hit by the rotation of the charging member, the toner deposited on the cleaning member is not scattered.
[0012]
Further, when the cleaning member moves away from the charging member, a separation streak tends to occur in the nip portion where the charging member and the cleaning member are in contact with each other. However, in the image forming apparatus according to the present invention, the cleaning member comes into contact with and separates from the charging member in the axial direction and the diagonal direction, so that the cleaning member gradually moves away from the charging member. . For this reason, the toner which exists in the nip portion and forms a separation streak is in a state where it is swept with a scissors. Since the toner adheres to the charging member with a very weak force, most of the toner adhering to the charging member is returned to the photosensitive member when the charging member comes into contact with the photosensitive member. Therefore, the occurrence of separation streaks that are to be formed on the charging member is prevented. In addition, toner does not spill under the charging member or in the image forming apparatus, and an image forming apparatus with stable quality can be obtained.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a full-color intermediate transfer type image forming apparatus to which an example of an embodiment of an image forming apparatus of the present invention is applied.
As shown in FIG. 1, the image forming apparatus 1 of this example includes a photoconductor (hereinafter also referred to as OPC) 2, a charging device 3, an exposure device 4, a developing device 5, an intermediate transfer device 6, and a cleaning device 7. In addition, although not shown, a transfer device for transferring the intermediate transfer image transferred to the transfer belt 6a of the intermediate transfer device 6 to a transfer material such as transfer paper and a fixing device for fixing the transfer image transferred to the transfer material are provided. ing.
[0014]
The charging device 3, the exposure device 4, the developing device 5, the intermediate transfer device 6, and the cleaning device 7 are arranged around the OPC 2 in the order shown in FIG. The OPC 2, the charging device 3, the developing device 5, and the cleaning device 7 are accommodated in one process cartridge 8 (a part of the process cartridge is schematically shown in FIG. 1). Has been.
[0015]
The charging device 3 in the image forming apparatus 1 of this example will be described in detail later. As shown in FIG. 2, the charging member 9 such as a charging roller for contacting the OPC 2 and charging the OPC 2 as shown in FIG. And a cleaning member 10 that cleans the surface of the charging member 9 when in contact with the charging member 9, and the vertical and horizontal directions as indicated by arrows in the figure, that is, the axial direction of the rotating shaft 9a of the charging member 9 and the charging member. 9 is provided so as to be able to move obliquely in the radial direction of 9 and holding member 11 that holds cleaning member 10. Therefore, the cleaning member 10 can also move obliquely in the axial direction of the rotating shaft 9 a of the charging member 9 and in the radial direction of the charging member 9.
[0016]
Further, as shown in FIG. 3, the cleaning member 10 is set to have a predetermined width α equal to or larger than the diameter of the charging portion 9b in the circumferential direction of the charging portion 9b of the charging member 9. The axial length β is set equal to or slightly longer than the axial length of 9b. Thus, by setting the cleaning member 10 to the predetermined width α, the charging member is coupled with the fact that the direction of the separating operation of the cleaning member 10 is oblique in the axial direction and the radial direction of the charging member 9. 9 is cleaned more efficiently, and the occurrence of separation streaks is more effectively prevented.
[0017]
Next, a specific configuration that enables the cleaning member 10 to be separated from and connected to the charging member 9 by moving the cleaning member 10 obliquely in the axial direction and the radial direction will be described.
As shown in detail in FIG. 4, in the image forming apparatus 1 of this example, the OPC 2 is accommodated in the process cartridge 8 and is rotatably supported by the frame 8 a of the process cartridge 8. Similarly, the charging device 3 is also housed in the process cartridge 8. The charging device 3 includes the above-described charging member 9 rotatably supported by the process cartridge frame 8a, the above-described cleaning member 10 of this charging member 9, the above-described holding member 11 that holds the cleaning member 10, and the process. The support base 12 that supports the holding member 11 fixed to the cartridge frame 8a, is positioned between the holding member 11 and the support base 12, and is contracted with a predetermined interval in the longitudinal direction of the holding member 11. Thus, the pair of springs 13 and 14 that constantly urges the cleaning member 9 in the direction of separating the cleaning member 9 from the charging member 9 via the holding member 11, and the holding member 11 to contact or separate the cleaning member 10 from the charging member 9. Driving means 15 for driving is provided.
[0018]
On the lower surface of the holding member 11 facing the support base 12, a pair of projecting portions 16, 17 are provided projecting toward the support base 12 at a predetermined interval in the longitudinal direction of the holding member 11. These protrusions 16 and 17 have both lower surfaces 16a and 17a which are flat surfaces, and in the drawings, right side surfaces 16b and 17b are both left and right inclined surfaces having the same inclination angle. ing. Similarly, on the upper surface of the support base 12 facing the holding member 11, the pair of protrusions 18, 19 are similarly spaced in the longitudinal direction of the support base 12 by the same predetermined distance as the distance between the pair of protrusions 16, 17. And it protrudes toward the holding member 11. These protrusions 18 and 19 have the same cross-sectional shape in the left-right direction opposite to the cross-sectional shape in the longitudinal direction of the protrusions 16 and 17, and therefore their upper surfaces 18 a and 19 a are both flat surfaces. In these drawings, the left side surfaces 18b and 19b are both gently inclined surfaces with the same inclination angle as that of the right side surfaces 16b and 17b. At this time, the pair of springs 13 and 14 are also contracted between the holding member 11 and the support base 12 with substantially the same inclination as that of the right side faces 16b and 17b and the left side faces 18b and 19b.
[0019]
The holding member 11 is movable between a contact position where the cleaning member 10 is brought into contact with the charging member 9 as shown in FIG. 4 and a separation position where the cleaning member 10 is separated from the charging member 9 as shown in FIG. It has become. In the contact position, the lower surfaces 16a and 17a of the protrusions 16 and 17 of the holding member 11 are placed on the upper surfaces 18a and 19a of the protrusions 18 and 19 of the support base 12, respectively. The support 12 is supported in a stable state. As a result, the holding member 11 makes the cleaning member 10 contact the charging member 9 stably and reliably. In the separated position, the right side surfaces 16b and 17b of the protruding portions 16 and 17 of the holding member 11 are both placed on the inclined surfaces of the left side surfaces 18b and 19b of the protruding portions 18 and 19 of the support base 12. The holding member 11 is supported on the support base 12 in a substantially stable state. In this separated position, the lower surfaces 16a and 17a of the protrusions 16 and 17 of the holding member 11 are supported on the floor surface 12a of the support base 12 with the right side surfaces 16b and 17b in contact with the left side surfaces 18b and 19b. It can also be made to do.
The holding member 11, the support base 12, and the springs 13 and 14 constitute separation / contact means 20 that brings the cleaning member 10 into contact with or away from the charging member 9.
[0020]
In the image forming apparatus of this example, the springs 13 and 14 and the protrusions 16 and 17; 18 and 19 are all provided as a pair, but any one or more of them can be provided. In that case, it is desirable to make the pressing of the cleaning member 10 to the charging member 9 as uniform as possible in the axial direction of the charging member 9. In addition, inclined surfaces are provided on both the protruding portions 16 and 17 of the holding member 11 and the protruding portions 18 and 19 of the support base 12. These inclined surfaces are provided on either the holding member 11 or the support base 12. It can also be done.
[0021]
As shown in FIG. 6, the driving means 15 for driving the holding member 11 includes a housing 21 fixed to the process cartridge frame 8a, a motor 22 accommodated in the housing 21, and a rotating shaft 22a of the motor 22. A first gear 23 attached, a driving force transmission shaft 24 rotatably provided in the housing 21, and attached to the left end of the driving force transmission shaft 24 so as to mesh with the first gear 23. The second gear 25 having a larger diameter than the second gear 25, the male screw portion 26 provided on the opposite side of the second gear 25 of the driving force transmission shaft 24, and the housing 21 are made non-rotatable and movable in the axial direction. And a connecting member 27 having a female threaded portion 27a threaded through the male threaded portion 26 and having a coupling portion 27b to which the left end of the holding member 11 is coupled. That. Although not specifically shown, the connecting portion 27b of the connecting member 27 and the left end of the holding member 11 are connected with a known structure so as to be relatively movable only in the vertical direction. The male screw portion 26 can be provided on the connecting member 27 side, and the female screw portion 27a can be provided on the driving force transmission shaft 24 side.
[0022]
In the state shown in the drawing, the connecting member 27 is located at the most advanced position from the housing 21. At the advanced position of the connecting member 27, the holding member 11 and the cleaning member 10 are set at the contact positions shown in FIG. When the motor 22 is driven in the direction in which the connecting member 27 is retracted, the rotation of the motor 22 is decelerated by the first and second gears 23 and 25 and transmitted to the male screw portion 26, and the male screw portion 26 rotates. The connecting member 27 is pulled into the housing 21. By pulling in the connecting member 27, the holding member 11 moves to the left, and the lower surfaces 16 a and 17 a of the protrusions 16 and 17 of the holding member 11 are disengaged from the upper surfaces 18 a and 19 a of the protrusions 18 and 19 of the support base 12. Then, the holding member 11 is pulled downward, that is, toward the support base 12 by the spring force of the pair of springs 13 and 14. At this time, the holding member 11 moves to the left and downward while the inclined surfaces of the right side surfaces 16b and 17b of the projecting portions 16 and 17 are in contact with and guided by the inclined surfaces of the left side surfaces 18b and 19b of the projecting portions 18 and 19. . As a result, the cleaning member 10 moves in the axial direction and obliquely downward with respect to the charging member 9 and is separated from the charging member 9. When the connecting member 27 is retracted by the set amount, the motor 22 stops and the connecting member 27 enters the retracted position. At the retracted position of the connecting member 27, the holding member 11 and the cleaning member 10 are set to the separated positions shown in FIG. It is like that.
[0023]
Further, in order to set the connecting member 27 from the retracted position to the advanced position, if the motor 22 is rotated in the reverse direction, the connecting member 27 advances from the housing 21 and the holding member 11 moves to the right. At this time, the holding member 11 moves upward and to the right while the inclined surfaces of the right side surfaces 16b and 17b of the protruding portions 16 and 17 are guided by the inclined surfaces of the left side surfaces 18b and 19b of the protruding portions 18 and 19. When the connecting member 27 advances to the maximum, the motor 22 stops, and the connecting member 27 enters the advanced position shown in FIG. 4. At the advanced position of the connecting member 27, the holding member 11 and the cleaning member 10 reach the contact positions shown in FIG. It is set up.
[0024]
Next, the control of the separation / contact operation of the cleaning member 10 with respect to the charging member 9 will be described.
FIG. 7 is a control block diagram of the separation / contact operation of the cleaning member 10.
As shown in FIG. 7, in the image forming apparatus 1 of this example, a motor 22 for separating and contacting the cleaning member 10 and a motor 36 for driving the charging member 3 are both central processing units (hereinafter also referred to as CPUs). 37). The CPU 37 normally stops the motor 22 with the cleaning member 10 set to the separated position as shown in FIG. 5 and stops the motor 36 when the charging operation is not performed. The charging member 3 is cleaned when the charging member 3 does not perform a charging operation.
[0025]
In cleaning the charging member 3 with both the motors 22 and 36 stopped, the CPU 37 first drives the motor 22 to set the cleaning member 10 to the contact position as described above. Thereafter, the motor 22 is stopped. Therefore, when the cleaning member 10 contacts the charging member 3, the charging member 3 is stopped. Next, the CPU 37 drives the motor 36 to rotate the charging member 3. Thereby, cleaning of the charging member 3 by the cleaning member 10 is performed. When the motor 36 is driven for a predetermined time and cleaning of the charging member 3 is completed, the CPU 37 stops the motor 36 and then drives the motor 22 in the reverse direction to set the cleaning member 10 to the separated position as described above. Thereafter, the motor 22 is stopped, and the cleaning of the charging member 3 is completed.
As described above, the CPU 37 drives and controls the motors 22 and 36 so that the cleaning member 10 is detached when the cleaning member 10 is detached from the charging member 3 with the charging member 3 stopped. It has become.
[0026]
The developing device 5 includes yellow, magenta, cyan, and black developing devices 28, 29, 30, and 31 as in the conventional full-color image forming device. Reference numerals 29, 30, and 31 are arranged along the outer periphery of the OPC. In this case, the arrangement order of the developing devices 28, 29, 30, and 31 for the respective colors is arbitrarily set without being limited to the above-described order. In the following description, for convenience of explanation, it is assumed that the developing units 28, 29, 30, and 31 are arranged in the order of the above-described colors, that is, yellow, magenta, cyan, and black.
[0027]
The cleaning device 7 also includes a cleaner housing 32 and a cleaning blade 33 as in the conventional full-color image forming device. In that case, the cleaner housing 32 is formed integrally with the frame 8a of the process cartridge 8 as shown in the figure. The cleaner housing 32 may be formed separately from the frame body 8a and attached to the frame body 8a.
[0028]
As described above, in the image forming apparatus 1 of this example, the OPC 2, the charging member 9, the cleaning member 10 of the charging member 9, the contact / separation unit 20 that contacts / disconnects the cleaning member 10 to / from the charging member 9, and the separation / contact unit 20 are driven. The driving means 15, the developing device 5, and the cleaning device 7 are accommodated in one process cartridge 8 (note that the developing device 5 and the cleaning device 7 are accommodated in the process cartridge 8. However, these are also housed in the process cartridge 8 in the same manner as in the prior art).
Reference numerals 34 and 35 shown in FIGS. 4 and 5 are both conductive wires that electrically join the motor 22 to the power supply on the image forming apparatus main body side.
[0029]
The operation of the image forming apparatus 1 of this example configured as described above will be described.
First, at normal time, the cleaning member 10 is set at the separation position shown in FIG. In image formation, the surface of the OPC 2 is charged by the charging member 9 as in the conventional general image forming apparatus, and then the image is exposed as an electrostatic latent image on the charged portion of the OPC 2 by the exposure device 4. . The electrostatic latent image on the OPC 2 is developed in order by the yellow, magenta, cyan, and black developing devices 28, 29, 30, and 31 to be visualized, and the developed image on the OPC 2 is intermediate. Firstly transferred to a transfer device 6 and sent to a transfer device (not shown). After color matching is performed by this transfer device and transferred to a transfer material (not shown), fixing is performed by a fixing device (not shown). Thus, a desired image can be obtained on the transfer material.
[0030]
After the developed image is transferred to the transfer material, the residual toner remaining on the OPC 2 is removed by the cleaning blade 33 of the cleaning device 7 and accommodated in the cleaner housing 32. Thus, after the image formation is completed by the image forming apparatus 1 and the OPC 2 is neutralized, the OPC 2 is charged again by the charging member 9 for the next image formation, and thereafter the same image forming process is performed.
[0031]
By the way, the residual toner remaining on the OPC 2 after the transfer is removed from the OPC 2 by the cleaning blade 33 and accommodated in the cleaner housing 32, but a part of the toner is not removed and passes through the cleaning blade 33. Then, it moves toward the charging member 9 and adheres to the charging member 9. Further, toner scattered from the developing device during image formation for a predetermined period may also adhere to the charging member 9, or dust and dust scattered around the photoreceptor 2 may adhere to the charging member 9. . For this reason, in the image forming apparatus 1 of this example, the cleaning process is periodically performed, and the foreign matter attached to the charging member 9 is removed by the cleaning member 10.
[0032]
In this cleaning process, first, the motor 22 is driven in a predetermined rotation direction, and the cleaning member 10 is set to the contact position shown in FIG. In this state, the charging member 9 is rotated, and the foreign matter attached to the charging member 9 is removed by the cleaning member 10. The foreign matter removed by the cleaning member 10 is accommodated in the cleaner housing 32 in the process cartridge 8, or in the case where an accommodating portion is provided in the process cartridge 8 separately from the cleaner housing 32, it is accommodated in the accommodating portion. . When the charging member 9 is rotated for a predetermined time, the charging member 9 is stopped, and then the motor 22 is driven again in the reverse rotation direction, and the cleaning member 10 is set to the separation position shown in FIG. Thereby, the cleaning member 10 is separated from the charging member 9, and the cleaning process is completed.
[0033]
When it is time to replace the photosensitive member 2 or the like, the process cartridge 8 is removed from the image forming apparatus main body, and a new process cartridge 8 is attached to the image forming apparatus main body. Therefore, since the cleaning member 10 is also replaced at this time, it is not necessary to replace the cleaning member 10 again. In that case, since the cleaning member 10 is almost almost replaced, it is hardly wasted even if the cleaning member 10 is replaced together.
[0034]
As described above, according to the image forming apparatus 1 of this example, when the charging member 9 is stopped, the cleaning member 10 is separated from and connected to the charging member 9. The cleaning member 10 can be prevented from being hit by the rotation. Thereby, it is possible to reliably prevent the toner accumulated on the cleaning member 10 from being scattered.
[0035]
In addition, the cleaning member 10 is moved away from the charging member 9 by moving the cleaning member 10 in the axial direction and the oblique direction of the radial direction with respect to the charging member 9. When the charging member 9 is separated from the charging member 9, the charging member 9 is in contact with the photosensitive member because the toner that is present in the nip where the charging member 9 and the cleaning member 10 are in contact and forms a separation streak is swabbed. Sometimes, most of the toner adhering to the charging member can be returned to the photoreceptor. Therefore, the toner can be prevented from spilling under the charging member or in the image forming apparatus, and an image forming apparatus with stable quality can be obtained.
[0036]
Further, the OPC 2, the charging member 9, the cleaning member 10 of the charging member 9, the separating / contacting means 20 for separating and contacting the cleaning member 10 with respect to the charging member 9, and the driving means 15 for driving the separating / contacting means 20 are provided as one process cartridge. Since it is housed in 8, the positional accuracy between the charging member 9 and the cleaning member 10 can be extremely stabilized. Thereby, since the cleaning member 10 can be reliably and almost uniformly contacted by the charging member 9, the charging member 9 can be more reliably cleaned by the cleaning member 10. In addition, since the positional accuracy between the charging member 9 and the cleaning member 10 can be stabilized, it is not necessary to make the positional accuracy so high, and the charging member 9 and the cleaning member 10 can be easily attached.
[0037]
Further, since the driving unit 15 is accommodated in the process cartridge 8, the driving unit 15 is accommodated even if the cleaning member 10 is accommodated in the process cartridge 8 as compared with the case where the driving unit 15 is provided on the image forming apparatus main body side. No mechanical connection between the image forming apparatus main body and the cleaning member 10 is required, and only an electrical connection for connection to the power supply on the image forming apparatus main body side is required. Therefore, despite the movement of the cleaning member 10 with respect to the charging member 9, the cleaning condition can be stabilized and simplified, and foreign matters such as toner adhering to the surface of the charging member 9 can be more reliably removed. be able to. And the structure between the drive means 15 and the cleaning member 10 can be simplified, and cost can be reduced.
[0038]
Since the foreign matter on the surface of the charging member 9 can be more reliably removed in this manner, the life of the process cartridge 8 that accommodates the cleaning member 10 and the drive unit 15 can be extended.
Further, as is apparent from the prior art, the OPC 2, the cleaning member 10 and the like cannot be used semi-permanently and need to be replaced at arbitrary timings depending on the usage status of the image forming apparatus 1, but the cleaning member 10 is replaced with the OPC 2. In addition, by accommodating the charging member 9 in the same process cartridge 8, it becomes possible to exchange them easily and simultaneously, and the burden on the user can be reduced.
[0039]
In the image forming apparatus 1 of the above-described example, the present invention is applied to a full-color image forming apparatus. However, the present invention is not limited to this, and at least a photoconductor and this photoconductor are used. As long as the image forming apparatus includes at least a charging member to be charged and a cleaning member for the charging member, the image forming apparatus can be applied to any image forming apparatus.
[0040]
【The invention's effect】
As is clear from the above description, according to the image forming apparatus of the present invention, when the charging member is stopped, the cleaning member is separated from and connected to the charging member. The cleaning member can be prevented from being hit by the rotation. Thereby, it is possible to reliably prevent the toner accumulated on the cleaning member from being scattered.
[0041]
Further, when the cleaning member is moved away from the charging member by moving the cleaning member away from the charging member by moving the cleaning member away from the charging member by moving the cleaning member in an axial direction and a diagonal direction in the radial direction. In addition, since the toner that exists in the nip where the charging member and the cleaning member are in contact and forms a separation streak is swept away, the toner adheres to the charging member when the charging member contacts the photosensitive member. Most of the toner can be returned to the photoreceptor. Accordingly, it is possible to prevent the separation of the charging member, and it is possible to prevent the toner from spilling under the charging member or in the image forming apparatus, and an image forming apparatus having a stable quality can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a full-color intermediate transfer type image forming apparatus to which an example of an embodiment of an image forming apparatus of the present invention is applied.
FIG. 2 is a diagram for explaining a cleaning member separating operation in the image forming apparatus shown in FIG. 1;
3 is a plan view showing a cleaning member and a holding member thereof in the image forming apparatus shown in FIG. 1. FIG.
4 shows a photosensitive member, a charging member, a cleaning member, and a driving unit housed in a process cartridge used in the image forming apparatus shown in FIG. 1, wherein the cleaning member is in contact with the charging member. FIG.
FIG. 5 shows a photosensitive member, a charging member, a cleaning member, and a driving unit housed in a process cartridge used in the image forming apparatus shown in FIG. 1, and shows a state in which the cleaning member is separated from the charging member. FIG.
FIG. 6 is a diagram showing a cleaning member driving unit used in the image forming apparatus shown in FIG. 1;
FIG. 7 is a control block diagram of the separation / contact operation of the cleaning member used in the image forming apparatus shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Photoconductor (OPC), 3 ... Charging apparatus, 4 ... Exposure apparatus, 5 ... Developing apparatus, 6 ... Intermediate transfer apparatus, 7 ... Cleaning apparatus, 8 ... Process cartridge, 8a ... Process cartridge 8 9 ... Charging member, 10 ... Cleaning member, 11 ... Holding member, 12 ... Support base, 13,14 ... Spring, 15 ... Drive means, 16, 17, 18, 19 ... Protrusion, 20 ... Separation Means, 21... Housing, 22 .. motor for separating and connecting the cleaning member 10, 23... First gear, 24... Driving force transmission shaft, 25. Motor for driving charging member 3, 37... Central processing unit (CPU)

Claims (1)

A photosensitive member on which an electrostatic latent image is formed; a charging member that contacts the photosensitive member to charge the photosensitive member; and a cleaning member that is detachably attached to the charging member and cleans the charging member; An image forming apparatus configured to perform cleaning of the charging member by rotating the charging member in a state where the cleaning member is in contact with the charging member.
The cleaning member is spaced apart from the charging member except during cleaning of the charging member, and is in contact with the charging member during cleaning of the charging member,
Furthermore, in a state where the rotation of the charging member is stopped, the cleaning member is separated from the charging member ,
The cleaning member is set in a state in which the direction of the contact / separation operation with respect to the charging member is set in an axial direction and a diagonal direction of the charging member so as to sweep the charging member with a scissors. Image forming apparatus.

Images