JP2000162936A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely remove the post processing material accumulation of the surface of an image carrier in an image forming device. SOLUTION: This image forming device is provided with a cleaning means having a first and a second cleaning members 26 and 27. The member 26 always abuts on the surface of the image carrier 11. The abutting force of the member 26 to the surface of the carrier 11 obtained when the carrier 11 moves in a reversely rotating direction is larger than that obtained when the surface of the carrier 11 moves in a normal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, a charging device for uniformly charging the surface of an image carrier around an image carrier, and a statically attenuated surface of the charged image carrier by partially exposing the potential of the image carrier by exposure. An exposure device for forming an electrostatic latent image, a developing device for supplying toner to an electrostatic latent image on the surface of the image carrier to visualize the image, a transfer device for transferring the toner image to a transfer medium, and the surface of the image carrier after the transfer process A cleaning device or the like is provided for recovering toner (residual toner) remaining on the image carrier and paper dust and the like remaining on the surface of the image carrier.

The conventional cleaning apparatus includes a first cleaning member having a cleaning blade that has one end abutting against the surface of the image carrier and scrapes residual toner and paper dust from the surface of the image carrier. A cleaning member provided downstream of the cleaning blade in the direction of movement of the surface of the image carrier, such that a residual toner or paper dust stays in a region where the edge of the cleaning blade contacts the surface of the image carrier. There is one in which the moving direction of the surface of the carrier is reversed, and the remaining toner or the like that has accumulated is transported to a portion where the brush abuts on the surface of the image carrier to be scraped off (Japanese Patent Laid-Open Nos. 4-90585 and 4-90585). -274476, JP-A-2-158790, JP-A-3-917
No. 88).

[0004]

In recent image forming apparatuses, in order to reduce the diameter of a toner, a material obtained by kneading a coloring material or a wax with a styrene acrylic or polyester resin is ground to a particle size of about 5 to 15 μm. 0.1 ~
A powder obtained by externally adding about 5% of a post-treatment material such as silica or strontium titanate to adjust the surface condition is used.

When this type of toner is used, the post-processing material falls from the resin particles to the image bearing surface due to the mechanical and electrical actions acting from the developing step to the cleaning step.
The post-processing material on the surface of the image carrier is captured by the edge of the cleaning blade in contact with the surface of the image carrier and aggregates,
A post-treatment material pool is formed. The post-treatment material pool has a stronger fixing force than the residual toner and paper powder. In the process of forming the post-processing pool, the post-processing material rubbed against the surface of the image carrier by the pressing force of the edge of the cleaning blade against the surface of the image carrier adheres to the surface of the image carrier in a granular manner.

In order to prevent this sticking, it is necessary to reverse the moving direction of the image carrier and remove the post-processing pool from the surface of the image carrier by a brush as a second cleaning member. It is necessary to increase the pressure contact force to the surface of the image carrier by setting the amount of biting into the image carrier large, and to scrape off with a somewhat strong force. However, while the image carrier is moving in the normal direction, the amount of the bite of the brush is large, and if the brush is in contact with the image carrier surface with a strong pressing force, the contact portion between the brush and the image carrier surface is Processing pools will occur.

On the other hand, if the direction of movement of the surface of the image carrier is reversed to remove the stagnation at the edge of the cleaning blade as described above, the direction of the force acting on the edge of the cleaning blade is switched. In addition, a larger load acts on the edge than in the case where the normal rotation state is maintained, and wear is likely to occur. As the edge wear progresses, residual toner and paper dust are left unwiped, which causes deterioration in image quality.

[0008] In order to solve the above-mentioned problems in the conventional image forming apparatus, it is an object of the present invention to reliably remove the post-processing material of the toner fixed on the surface of the image carrier. Another object of the present invention is to reduce wear of the first cleaning member caused by reversing the moving direction of the image carrier.

[0009]

According to a first aspect of the present invention, there is provided an image forming apparatus for developing an electrostatic latent image formed on a surface of an image carrier with toner and transferring the latent image to a transfer medium. A driving means for driving the image carrier so that the moving direction can be switched between a normal direction and a reverse rotation direction; a first cleaning member abutting on the surface of the image carrier; and an image rather than the first cleaning member. A second cleaning member disposed on the upstream side in the normal movement direction of the carrier, and a cleaning means for removing the residue from the surface of the image carrier; and the moving direction of the image carrier is in the normal direction. At some time, the residue is dropped from the surface of the image carrier by the at least first cleaning member, and the residue remaining at the tip of the first cleaning member is moved to the second direction with the moving direction of the image carrier being the reverse direction. To the cleaning member, and the second cleaning member conveys the image to the surface of the image carrier. In the image forming apparatus, the cleaning efficiency of the second cleaning unit with respect to the surface of the image carrier when the image carrier is moving in the reverse direction is determined when the image carrier is moving in the normal direction. And a cleaning efficiency adjusting means for adjusting the cleaning efficiency to be greater than the cleaning efficiency of the image forming apparatus.

In the image forming apparatus of the first invention, the cleaning efficiency adjusting means adjusts the cleaning efficiency of the second cleaning means with respect to the surface of the image carrier as described above, so that the image carrier is moved in the reverse direction. For example, while the residue remaining at the tip of the first cleaning member including the post-processing material pool can be removed by the second cleaning member, the second cleaning is performed when the image carrier is moving in the normal direction. It is possible to prevent formation of a post-processing material pool at a portion where the member contacts the surface of the image carrier.

The cleaning efficiency adjusting means moves the second cleaning member away from the surface of the image carrier when the image carrier is moving in the normal direction, and the image carrier is moving in the reverse direction. Sometimes, the second cleaning member may be brought into contact with the surface of the image carrier.

Alternatively, the second cleaning means comprises a brush whose outer periphery is constantly in contact with the surface of the image carrier, and the cleaning efficiency adjusting means comprises a brush for adjusting the cleaning efficiency when the image carrier is moving in the normal direction. The brush may be rotated so that the outer periphery follows the surface of the image carrier, and the rotation of the brush may be stopped when the image carrier is moving in the reverse direction.

According to a second aspect of the present invention, there is provided an image forming apparatus for developing an electrostatic latent image formed on a surface of an image carrier with toner and transferring the latent image to a transfer medium, wherein the image carrier is rotated in a direction reverse to a normal direction. And a first cleaning member that is in contact with the surface of the image carrier, and is disposed upstream of the first cleaning member in the normal movement direction of the image carrier. A cleaning means for removing residues from the surface of the image carrier, wherein when the moving direction of the image carrier is a normal direction, the image is formed by the at least first cleaning member. The residue is dropped from the surface of the carrier, and the residue retained at the tip of the first cleaning member is transported to the second cleaning member with the moving direction of the image carrier being the reverse direction. In the image forming apparatus for dropping from the surface of the image carrier, The driving means for the carrier may set the acceleration when switching the moving direction of the surface of the image carrier from the normal direction to the reverse direction smaller than the acceleration at the time of starting the movement of the surface of the image carrier in the normal direction. Is provided.

At the time of switching the moving direction of the image carrier, a large load acts on the tip of the first cleaning member which is in contact with the surface of the image carrier. Since the acceleration for switching the direction is set as described above, the load acting on the first cleaning member can be reduced.

According to a third aspect of the present invention, there is provided an image forming apparatus for developing an electrostatic latent image formed on a surface of an image carrier with toner and transferring the latent image to a transfer medium. A first cleaning member that contacts the surface of the image carrier, and a driving unit that rotationally drives the switch so that the rotation direction can be switched.
A second cleaning member disposed on the upstream side in the normal movement direction of the image carrier with respect to the cleaning member, and cleaning means for dropping residues from the surface of the image carrier. When the rotation direction is the normal direction, the residue is dropped from the surface of the image carrier by the at least first cleaning member and stays at the tip of the first cleaning member with the rotation direction of the image carrier being the reverse direction. Transporting the residue to a second cleaning member,
An image forming apparatus, wherein the image carrier is dropped from the surface of the image carrier by the second cleaning member, comprising: a number-of-rotations counter for counting the number of rotations of the image carrier; The present invention provides an image forming apparatus characterized by switching the rotation direction of the image carrier when detecting the image.

When the moving direction of the image carrier is switched, a large load acts on the tip of the first cleaning member. However, in the image forming apparatus of the third invention, the image carrier is rotated a predetermined number of times as described above. Since the switching of the moving direction of the image carrier is performed when it reaches, the frequency of the switching operation of the moving direction can be reduced,
The load acting on the first cleaning member and the resulting wear can be reduced.

Since the formation of the post-processing material pool is particularly promoted during non-image formation, if the rotation number counting means counts the number of rotations of the image carrier during non-image formation, the switching frequency of the image carrier is determined. Is reduced to the minimum necessary, and the load acting on the first cleaning member and the wear resulting therefrom can be reduced more reliably.

[0018]

(First Embodiment) FIG. 1 shows an image forming apparatus according to a first embodiment of the present invention.

The photosensitive drum 11 as an image carrier is formed by coating an organic photosensitive layer comprising a charge generation layer and a charge transport layer on a conductive group such as aluminum, and the periphery thereof is indicated by an arrow A1. A charging device 12 for uniformly charging the surface of the photosensitive drum 11 along the normal rotation direction, and is charged based on image information read by an image reader or the like or print information supplied from an external device such as a personal computer. An exposure device 13 including a general laser optical system for partially attenuating the potential of the surface of the photosensitive drum 11 by exposure to form an electrostatic latent image, and electrostatically applying an electrostatic latent image on the surface of the photosensitive drum 11 A developing device 14 for supplying toner to the image forming apparatus, a transfer charger 15 and a separation charger 16 for transferring a toner image to a transfer medium such as a transfer paper 18 supplied from a paper feeder (not shown). The transfer device 19 and cleaning device 20 is provided that. The transfer paper 18 is sent to a fixing device (not shown) by a transport device (not shown), and after the transferred toner image is thermally fixed, is discharged out of the device. After the transfer step, the surface of the photosensitive drum 11 is neutralized by the optical neutralizer 21.

The toner has a particle size of 5 to 15 by kneading a colorant or a wax with styrene acrylic or polyester resin.
Resin particles pulverized to about μm
About 5% of silica or strontium titanate is externally added.

The cleaning device 21 includes a cleaning blade 26 as a first cleaning member and a brush 27 as a second cleaning member in a housing 25. The brush 27 is provided upstream of the cleaning blade 26 in the normal rotation direction of the photosensitive drum 11 as indicated by the arrow A1.

The cleaning blade 26 has a base end fixed to the housing 25 and a front end 26a in contact with the surface of the photosensitive drum 11. The edge 26a of the cleaning blade 26 is in contact with the surface of the photoconductor drum 11 so as to form an acute angle with respect to the normal rotation direction of the photoconductor drum 11 indicated by an arrow A1.

As shown in FIG. 3, the brush 27 is formed by implanting straight-haired fibers 27b on the outer periphery of a shaft 27a. The cross-sectional shape of the brush 27 is semicircular, and one half in the circumferential direction is a circular portion 27 c and the other half is a flat portion 27.
d. The shaft 27 a is rotatably supported on the housing 25 around its axis, and is connected to a drive mechanism having a motor 28.

The housing 25 of the cleaning device 20 includes a cleaning blade 26 and a brush 27,
A rotating paddle (not shown) for carrying out the collected post-processing material, residual toner and paper dust to the outside is provided.

In FIG. 1, a control device indicated by reference numeral 30 includes a motor 31 for rotating the photosensitive drum 11 and a motor 28 for rotating the shaft 27a of the brush 27.
Are connected, and the rotation of these motors 31 and 28
Stop, rotation direction, rotation speed, and the like are controlled. Further, a counter 32 for counting the number of rotations of the photosensitive drum 11 is connected to the control device 30.

The operation of the cleaning device 20 will be described. Normally, the rotation angle position of the brush 27 is at the position shown in FIG. 1, and the flat portion 27d of the brush 27 faces the photosensitive drum 11. At this angular position, the brush 27 is not in contact with the photosensitive drum 11.

The photosensitive drum 11 has the transfer device 19
The toner 15 and the paper dust remain after the transfer process. The post-processing material that has fallen from the resin particles is present on the photosensitive drum 11. The residual toner 15, the paper dust, and the dropped post-processing material are conveyed to the contact portion with the edge 26a of the cleaning blade 26 by the rotation of the photosensitive drum 11 in the direction of the arrow A1, and are scraped off by the cleaning blade 26. Then, it is collected in the housing 25.

Based on the input signal from the counter 32, the control device 30 controls the number of rotations of the photosensitive drum 11 and the image forming apparatus during a non-image forming process, that is, a cleaning process after forming one image. The number of rotations of the photosensitive drum 11 after the start and before the execution of the image forming process is counted. When the number of rotations of the photosensitive drum 11 during non-image formation reaches a predetermined number, the edge 2 of the cleaning blade 26
A process for removing the post-processing material pool formed in 6a (post-processing material pool removal process) is started. In particular,
The rotation direction of the photosensitive drum 11 is reversed as shown by the arrow A2. Further, in synchronization with this, the motor 28 is rotationally driven, and as shown in FIG.
The brush 27 is rotated in the direction of the arrow B1 until c becomes an angular position facing the photosensitive drum 11. In the state shown in FIG. 2, the brush 27 is in contact with the surface of the photoconductor drum 11, and the amount of bite is such that a pressing force enough to scrape off the post-processing material pool attached to the photoconductor drum 11 is obtained. It is set to be. The photosensitive drum 11
As shown by θ in FIG. 2, the photosensitive drum 11
The surface of the cleaning blade 26 that is in contact with the edge 26 a is driven to rotate until it passes through the contact portion of the brush 27. As described above, at the rotation angle position shown in FIG. 2, the brush 27 is in contact with the surface of the photosensitive drum 11 with a sufficient pressure contact force, so that the post-processing material pool on the surface of the photosensitive drum 11 is reliably It is scraped off and falls into the housing 25. Further, the edge 26 of the cleaning blade 26 on the surface of the photosensitive drum 11
Residual toner and paper dust staying in the contact portion with a are also scraped off by the brush 27 and fall into the housing 25.

After the post-processing material pool removal process is completed, the brush 27 is driven to rotate in the direction of arrow B2 to return to the non-contact angular position shown in FIG.

As described above, the brush 27 is
The surface of the photosensitive drum 11 contacts the surface of the photosensitive drum 11 only when the post-processing material accumulation removing process is performed. In normal times, the brush 27 is not in contact with the surface of the photosensitive drum 11. There is no possibility that a post-processing material pool is formed in a contact portion with respect to.

In the post-processing material accumulation removing process, the rotation direction of the photosensitive drum 11 is switched from the normal rotation direction indicated by the arrow A1 to the reverse rotation direction indicated by the arrow A2. Photoconductor drum 11
Is set smaller than the acceleration at the time of starting rotation in the normal rotation direction indicated by arrow A1. When the rotation direction of the photosensitive drum 11 is reversed, the direction of the force acting on the cleaning edge 26a is switched, so that a large load acts on the edge 26a. However, if the acceleration at the time of the reverse rotation is set to be small as described above, the edge 26a Can be reduced. Therefore, in the image forming apparatus of the first embodiment, the progress of the abrasion of the cleaning blade 26 can be reduced, and the deterioration of the image quality due to the residual toner and unwiped paper dust caused by the abrasion of the cleaning blade can be prevented. . When a stepping motor is used as the motor 31 for driving the photosensitive drum 11, the rate of the input pulse at the start of the reverse rotation may be increased more gradually than at the start of the normal rotation.

The edge 2 of the cleaning blade 26
The formation of the post-processing material pool in 6a
Is accelerated as it rotates. In particular, when the photosensitive drum 11 rotates in a state where the toner is not supplied to the surface of the photosensitive drum 11, the formation of the post-processing material pool is rapidly promoted. This is a state in which a fixed amount of toner is constantly present on the surface of the photosensitive drum 11, that is, at the time of image formation, residual toner mixed with the edge 26a of the cleaning blade 26 and the post-processing material are separated to form a post-processing material pool. It is conceivable that the toner pool drops from the edge 26a due to gravity or the like before the is accelerated, and the post-processing material drops off together with the toner at that time, so that the post-processing material hardly accumulates on the edge 26a.

As described above, in the image forming apparatus of the first embodiment, when the number of rotations of the photosensitive drum 11 at the time of non-image formation in which the formation of the post-processing material pool is promoted reaches a predetermined value, the post-processing is performed. The material pool removing process is executed, and the execution of the post-process material pool removing process is minimized. The reverse rotation of the photosensitive drum 11 during the post-processing material pool removal process promotes the wear of the cleaning blade 26 as described above. Therefore, if the execution frequency of the post-processing material pool removal process is reduced, the cleaning blade 26
Wear can be reduced.

In the first embodiment, when the number of rotations of the photosensitive drum 11 at the time of non-image formation reaches a predetermined number, the process of removing the post-processing material from the cleaning blade 26 is executed. Alternatively, the post-processing material pool may be removed when the number of rotations of the photosensitive drum 11 during non-image formation reaches a predetermined number.

In the first embodiment, the brush 27
The photosensitive drum 11 and the photosensitive drum 11 are driven by separate motors 28 and 31. However, a driving force transmission mechanism including a one-way clutch or the like is provided, and the brush 27 moves the photosensitive drum 11 in conjunction with the reverse rotation of the photosensitive drum 11. May be rotated to the contact position.

The cross-sectional shape of the brush 27 is not limited to a semicircle, and any shape may be used as long as the outer periphery of the brush 27 can be brought into contact with and non-contact with the outer periphery of the photosensitive drum 11 depending on the angular position of the shaft 27a. Specifically, the cross-sectional shape of the brush 27 may be an elliptical shape or the like, and the shaft 27a may be provided eccentrically with respect to the center of the cross-section of the brush 27 having a circular cross-section.

(Second Embodiment) A second embodiment of the present invention shown in FIG.
The image forming apparatus according to the embodiment includes a brush 27 of the cleaning device 20.
Has a circular cross section, and the shaft 27a
Except for being provided so as to pass through the center of the cross section, the configuration is the same as that of the above-described first embodiment, and the same elements are denoted by the same reference numerals.

The operation of the cleaning device 20 will be described.
Normally, the brush 27 is rotating in a direction indicated by an arrow B2, that is, in a direction following the normal rotation direction of the photosensitive drum 11 indicated by an arrow A1. The residual toner, paper dust and post-processing material on the surface of the photosensitive drum 11 are scraped off by the edge 26a of the cleaning blade 26, and are also scraped off from the surface of the photosensitive drum 11 by the brush 27. However, the amount of the brush 27 biting into the surface of the photoconductor drum 11, the rotation speed, and the like depend on the pressing force of the brush 27 against the photoconductor drum 11, and the post-processing material pool is formed at the contact portion between the brush 27 and the photoconductor drum 11 The value is set so as not to be performed.

When the control device 30 detects that the number of rotations of the photosensitive drum 11 during non-image formation has reached a predetermined number based on an input signal from the counter 32, a post-processing material removing process is executed.

Specifically, first, the rotation direction of the photosensitive drum 11 is switched to the direction indicated by the arrow A2. As in the first embodiment, the acceleration of the photosensitive drum 11 at the time of the reverse rotation is set to be smaller than the acceleration at the time of starting the normal rotation indicated by the arrow A1 from the stationary state. Therefore, the load acting on the cleaning edge 26a due to reversing the rotation direction of the photosensitive drum 11 can be reduced, and the wear of the cleaning blade 26 can be suppressed.

The photosensitive drum 11 is rotated in the reverse direction indicated by an arrow A2 until the contact portion of the edge 26a with the surface of the photosensitive drum 11 in the normal state passes through the contact portion of the brush 27, as indicated by θ in FIG. Rotate in the direction. In synchronization with this, the rotation of the brush 27 that follows the rotation of the photosensitive drum 11 is stopped. When the rotation of the brush 27 is stopped, the pressing force of the brush 27 against the surface of the photosensitive drum 11 increases. The amount by which the brush 27 bites into the surface of the photoconductor drum 11 is determined by the pressing force of the brush 27 against the surface of the photoconductor drum 11 when the rotation is stopped.
The setting is such that the post-processing material pool can be reliably scraped off from the surface of the photosensitive drum 11.

As described above, in the second embodiment, the post-processing material pool is reliably scraped off from the surface of the photoconductor drum 11 by the post-processing material pool removal process. Since the force is small, it is possible to prevent a post-processing material pool from being formed at a contact portion of the brush 27 with the photosensitive drum 11.

Further, by executing the post-processing material removing process when the number of rotations of the photosensitive drum 11 at the time of non-image formation in which the formation of the post-processing material pool is promoted reaches a predetermined value,
Since the frequency of the post-processing material removal process has been reduced,
Wear of the cleaning blade 26 can be reduced.

In the second embodiment, the photosensitive drum 11
And the brush 27 are driven by separate motors 28 and 31, however, a driving force transmission mechanism having a one-way clutch or the like may be provided so that the brush 27 is driven to rotate only when the photosensitive drum 11 rotates forward. Further, the cross-sectional shape of the brush is not limited to a circle or a semicircle.

The present invention is not limited to the above embodiment, and various modifications are possible.

First, the means for improving the cleaning efficiency of the second cleaning means with respect to the surface of the image carrier when the image carrier is rotated in the reverse direction is not limited to the means for adjusting the pressing force as in the above-described embodiment. The cleaning efficiency may be adjusted by changing the number of rotations, the rotation direction, and the like. For example, a mechanism for moving the brush toward and away from the image carrier surface is provided,
Normally, the brush may be kept out of contact with the surface of the image carrier, and the brush may be brought into contact with the surface of the image carrier when the cleaning blade removal process is performed. Further, the second cleaning means is not limited to a brush, but may be a roller, a film, a blade, or the like.

In the above embodiment, the photosensitive drum 1
A counter for counting the number of rotations of 1 is used to directly count the number of rotations during non-image formation. However, a means for measuring the rotation time and rotation distance of the photoconductor is provided, and the measurement values of these means are used indirectly. Alternatively, the number of rotations during idle rotation may be counted.

The image carrier is not limited to the photosensitive drum, but may be a photosensitive belt, a transfer belt, a transfer drum, or the like, and includes a so-called intermediate transfer member.

[0049]

As is apparent from the above description, in the image forming apparatus of the first invention, the cleaning efficiency of the second cleaning means with respect to the surface of the image carrier is determined, and the image carrier moves in the normal direction. When the image carrier is moved in the reverse direction, the cleaning efficiency at the time is provided with cleaning efficiency adjusting means for adjusting the cleaning efficiency to be larger than the cleaning efficiency when the image carrier is moving in the reverse direction. The residue remaining at the tip of the first cleaning member including the processing material pool can be removed by the second cleaning member, while the residue of the second cleaning member is moved when the image carrier is moving in the normal direction. It is possible to prevent the post-processing material pool from being formed at the contact portion with the surface of the image carrier.

In the image forming apparatus according to the second aspect of the present invention, the acceleration when switching the moving direction of the surface of the image carrier from the normal direction to the reverse direction is greater than the acceleration when the rotation of the surface of the image carrier starts in the normal direction. Since it is small, the load acting on the first cleaning member when switching the moving direction of the image carrier can be reduced. Therefore, the progress of the wear of the first cleaning member can be suppressed, and the deterioration of the image quality due to the unwiped residue on the surface of the image carrier caused by the wear can be prevented.

Further, in the image forming apparatus of the third invention,
Since the rotation direction of the image carrier is switched when the image carrier reaches a predetermined number of rotations, the frequency of the operation of switching the moving direction can be reduced, and the load acting on the first cleaning member is reduced. can do. In particular, if the rotation direction of the image carrier is switched when the number of rotations of the image carrier during non-image formation reaches a predetermined number, the switching frequency of the image carrier is suppressed to the minimum necessary, The load acting on the first cleaning member can be reduced more reliably.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an image forming apparatus according to the first embodiment of the present invention.

FIG. 3 is a schematic perspective view showing a brush.

FIG. 4 is a schematic configuration diagram illustrating an image forming apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 photoconductor drum 12 charging device 13 exposure device 14 developing device 19 transfer device 20 cleaning device 26 cleaning blade (first cleaning member) 27 brush (second cleaning member) 28, 31 motor 30 control device 32 counter

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DA41 EA09 EC06 EC09 EE04 EF07 EF11 EG06 JA03 JC01 JC07 JC16 JC18 2H034 AA01 AA02 BA02 BA04 BA05 BD01 BD03 BD06 BD07 BD10 BF01 BF07 BF08 CA01 CA04 9A001 BB06

Claims (6)

[Claims] 1. An image forming apparatus for visualizing an electrostatic latent image formed on a surface of an image carrier with toner and transferring the image onto a transfer medium, wherein the image carrier is moved in a normal direction and a reverse direction. , A first cleaning member in contact with the surface of the image carrier, and a second cleaning member disposed upstream of the first cleaning member in the normal movement direction of the image carrier. And a cleaning means for removing residues from the surface of the image carrier. When the moving direction of the image carrier is a normal direction, the at least first cleaning member is moved from the surface of the image carrier. The residue is dropped, and the residue retained at the tip of the first cleaning member is transported to the second cleaning member with the moving direction of the image carrier being the reverse direction, and the surface of the image carrier is moved by the second cleaning member. In the image forming apparatus, the image carrier is reversed. Above when moving countercurrent second
An image forming apparatus comprising: a cleaning efficiency adjusting unit that adjusts the cleaning efficiency of the cleaning unit to the surface of the image carrier to be greater than the cleaning efficiency when the image carrier is moving in the normal direction. . 2. The cleaning efficiency adjusting means moves the second cleaning member away from the surface of the image carrier when the image carrier is moving in the normal direction, and moves the image carrier in the reverse direction. 2. The image forming apparatus according to claim 1, wherein the second cleaning member is brought into contact with the surface of the image carrier during the operation. 3. The image forming apparatus according to claim 2, wherein the second cleaning unit includes a brush whose outer periphery is constantly in contact with the surface of the image carrier, and the cleaning efficiency adjusting unit includes a brush for adjusting the cleaning efficiency when the image carrier is moving in a normal direction. 2. The image forming apparatus according to claim 1, wherein the brush is rotated so that the outer periphery follows the surface of the image carrier, and the rotation of the brush is stopped when the image carrier is moving in the reverse direction. 4. An image forming apparatus for visualizing an electrostatic latent image formed on a surface of an image carrier with toner and transferring the latent image to a transfer medium, wherein the image carrier is moved in a normal direction and a reverse direction. , A first cleaning member in contact with the surface of the image carrier, and a second cleaning member disposed upstream of the first cleaning member in the normal movement direction of the image carrier. And a cleaning means for removing the residue from the surface of the image carrier. When the moving direction of the image carrier is the normal direction, the at least first cleaning member causes the cleaning member to move away from the surface of the image carrier. The residue is dropped off, and the moving direction of the image carrier is set to the reverse direction,
In the image forming apparatus, the residue remaining at the tip of the first cleaning member is conveyed to a second cleaning member, and is dropped from the surface of the image carrier by the second cleaning member. An image forming apparatus, wherein the acceleration at the time of switching the moving direction of the surface of the image carrier from the normal direction to the reverse direction is set smaller than the acceleration at the time of starting the movement of the surface of the image carrier in the normal direction. 5. An image forming apparatus for developing an electrostatic latent image formed on a surface of an image carrier with toner and transferring the latent image to a transfer medium, wherein the image carrier is rotated in a normal direction and a reverse direction. A first cleaning member abutting on the surface of the image carrier, and a second cleaning member disposed upstream of the first cleaning member in the normal movement direction of the image carrier. A cleaning member for removing residues from the surface of the image carrier, wherein at least the first cleaning member causes the surface of the image carrier to rotate when the rotation direction of the image carrier is a normal direction. , And the rotation direction of the image carrier is set to the reverse direction,
In the image forming apparatus, the residue remaining at the tip of the first cleaning member is conveyed to a second cleaning member and dropped off from the surface of the image carrier by the second cleaning member. An image forming apparatus comprising: a rotation number counting unit that performs rotation of the image carrier when the rotation number counting unit detects that the image carrier has rotated a predetermined number of times. 6. The image forming apparatus according to claim 5, wherein said rotation number counting means counts the rotation number of the image carrier during non-image formation.