JPH05297770A - Cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To effectively remove discharged toner by turnably supporting a flicker member at a position where the bite amount of the leading edge of the flicker member at a fur brush is small in the normally rotating direction of the fur brush and at a position where the bite amount is large in the reversely rotating direction. CONSTITUTION:The flicker member 25 is turnably rotated by a rotary supporting shaft 27 so that the free end (leading edge) of the flicker member 25 may be brought into contact with the surface of the fur brush 11 when the fur brush 11 normally rotates. Namely, in a state where the fur brush 11 rotates in the normally rotating direction, the bite amount of the leading edge of the flicker member 25 at the fur brush 11 is small and the discharged toner accumulated in the fur brush is hit to be discharged by weak impact force. When the fur brush 11 reversely rotates, the bite amount of the leading edge of the member 25 at the fur brush 11 is large and the discharged toner accumulated in the fur brush is hit to be discharged by the weak impact force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device for an image forming apparatus using an electrophotographic system such as a copying machine, a printer, and a facsimile, and more specifically, it is attached on an image carrier of the image forming apparatus. The present invention relates to a cleaning device including a fur brush that removes the waste toner and the like, and a flicker member that removes the toner attached to the fur brush by an impact generated by the contact with the fur brush.

[0002]

2. Description of the Related Art An example of a conventional image forming apparatus using an electrophotographic system such as a copying machine, a printer and a facsimile will be described with reference to FIG. In FIG. 3, the image carrier 1 is uniformly charged by the charging charger 2, and the image carrier 1 is irradiated with the document image by the exposure optical system 3, whereby the document on the image carrier 1 is scanned. An electrostatic latent image is formed. Then, after the eraser 4 removes the electric charge on the image carrier 1 corresponding to the non-image area such as the inter-recording paper area and both edges of the recording paper, the developing device 5 applies toner to the electrostatic latent image. The toner image is supplied and a toner image is formed on the image carrier 1. On the other hand, during this period, the paper feeding roller 31 is operated by the paper feeding cassette 30.
The recording paper is sent out from. This recording paper is a guide plate 3
Guided along 2 and also a pair of registrars etc. 3
After being temporarily stopped by 3, the timing of the toner image on the image carrier 1 corresponds to a predetermined position on the recording paper,
The image carrier 1 is conveyed to the transfer unit in synchronization with the moving speed of the image carrier 1.
As a result, the recording paper is charged by the transfer charger 6 arranged in the transfer section, and the toner image on the image carrier 1 is transferred onto the recording paper. The recording paper on which the toner image is transferred is discharged by the corona discharge of the separation charger 7 so that the electrostatic attraction force is removed and the image carrier 1
Separated from above. Next, the recording paper separated from the image carrier 1 is conveyed to the fixing device 36 by the guide plate 34 and the conveying device 35, and the toner image is heated and pressed to be fixed, and then a pair of ejected sheets is ejected. The paper is discharged onto the paper discharge tray 38 by the paper roller 37.

On the other hand, the toner (waste toner) remaining on the image carrier 1 without being transferred onto the recording paper in the above-mentioned transfer section is removed from the image carrier 1 by the cleaning device 9. Further, the image carrier 1 from which the waste toner has been removed is electrostatically initialized by receiving the corona discharge of the charge eliminating charger 15 and the light irradiation of the charge eliminating lamp 16, and is ready for the next image formation. Be prepared.

By the way, as the above-mentioned cleaning device 9, there is known a device for removing waste toner by using a fur brush. An example of a conventional cleaning device using this fur brush is shown in FIG. In FIG. 4, the waste toner remaining on the image carrier 1 and the image carrier 1 are first subjected to corona discharge by the pre-cleaning charger 8,
Its polarity and potential are controlled. Next, the waste toner passes through the seal 10 arranged on the inlet side of the cleaning device 9, and then the fur brush 1 for cleaning is used.
It is removed from the image carrier 1 by the electrostatic attraction force and the mechanical friction force of 1. The fur brush 11 is configured by arranging a large number of conductive fibers 11b (hereinafter, simply referred to as fibers) on the peripheral surface of the cored bar roller 11a to which a predetermined bias is applied. , Fig. 4
In, the image carrier 1 is rotationally driven in the clockwise direction, that is, in the direction opposite to the rotational direction of the image carrier 1. This fur brush 11
The waste toner remaining on the image carrier 1 without being removed by the scratching is scraped from the image carrier 1 onto the fur brush 11 by the mechanical frictional force of the cleaning blade 23 arranged on the downstream side of the fur brush 11. To be dropped. The fur brush 11 is scraped off on the fur brush 11.
The waste toner captured on the fibers 11b of the fur brush 11 is separated from the fur brush 11 by the impact force when the fibers 11b of the fur brush 11 contact the flicker bar 24.
The cleaning device 9 is dropped to a waste toner discharge part formed at the bottom of the casing. Also, the flicker bar 24
Fiber 1 is not dropped even by the mechanical removal action of
The waste toner that has adhered to 1b and remains on the fur brush 11 is applied with a high bias voltage by the impact of the contact between the flicker bar 24 and the fiber 11b weakening the adhesion to the fiber 11b. It is attracted onto the bias roller 12. Then, this bias roller 12
The waste toner adsorbed on the bias roller 12 is mechanically scraped off from the bias roller 12 by the scraper 13 arranged in contact with the peripheral surface of the bias roller 12 and dropped to the waste toner discharging portion. The waste toner thus collected in the waste toner discharging portion of the cleaning device 9 is transferred to a predetermined portion outside the cleaning device 9 by the rotation of the coil-shaped discharging member 14 arranged in the waste toner discharging portion. The waste toner is transferred to an installed waste toner bottle (not shown) and stored and discarded.

[0005]

By the way, in the conventional cleaning device 9 as described above, it becomes difficult to completely collect the waste toner captured by the fur brush 11 in the waste toner discharging portion. For example, fur brush 11
As described above, most of the waste toner captured by the flicker bar 24 is mechanically removed by the flicker bar 24 and electrostatically attracted by the bias roller 12. The waste toner is not collected even by the electrostatic attraction action of the bias roller 12 or the like, and goes into the fibers 11b of the fur brush 11 and accumulates in the fur brush fibers. In addition, since the waste toner that sneaks into the fibers 11b of the fur brush 11 is often a relatively finely pulverized toner having a small particle size, the waste toner accumulates in the fur brush fibers as described above. If this happens, the contact between the fur brush 11 and the image carrier 1 causes the toner to scatter, and not only the cleaning unit but also the inside of the image forming apparatus and the recording paper itself are contaminated, and the image quality deteriorates. It may be done. In addition, as described above, if the waste toner is accumulated in the fur brush fiber, the cleaning performance of the fur brush 11 itself is deteriorated. As a result, the cleaning performance of the fur brush 11 is deteriorated to exceed the toner removing ability of the cleaning blade 23. The waste toner remains on the image carrier and the image quality is significantly reduced. Furthermore, if the image forming apparatus is used in a relatively high temperature environment or is used continuously for a long time with the waste toner remaining in the fur brush fiber, the temperature inside the machine may increase. Along with this, as the temperature of the image carrier 1 rises, the resin component (toner resin) of the developer is easily melted, and the waste toner remaining without being removed is melted on the surface of the fiber 11b of the fur brush 11. When it is worn, the electrical and mechanical characteristics of the fur brush 11 are deteriorated, and the life of the fur brush 11 and the image carrier 1 is shortened.

In order to prevent the waste toner from accumulating in the fur brush fiber, the amount of biting of the flicker bar 24 into the fur brush 11 is increased so that the fiber 11b of the fur brush 11 becomes flicker bar. It is effective to increase the impact force at the time of contact with 24 and to knock out the waste toner accumulated in the fur brush. However, it is practically impossible to increase the biting amount of the flicker bar 24 into the fur brush 11 in this manner, because the amount of driving for driving the fur brush 11 is significantly increased. That is, in the cleaning device 9 of this type, the fur brush 11 includes the image carrier 1, the flicker bar 24, and the bias roller 12.
Since it is necessary to rotate against the contact resistance with the above, a considerably large torque is already required to drive the fur brush 11. Further, in addition to this, in this type of image forming apparatus, a fixing heater 39 (FIG. 3) as a heat source of the image carrier 1, the developing device 5, and the fixing device 36 for thermally fixing the toner image on the recording paper. ) Etc. requires a lot of power. Therefore, as described above, the amount of biting of the flicker bar 24 into the fur brush 11 is increased so that the fibers 11b of the fur brush 11 become flicker bar 2.
It is not possible to secure the electric power necessary to increase the impact force when it comes into contact with the image forming apparatus 4, especially in a medium-high speed image forming apparatus having no electric power margin. The present invention has been made in view of the above points, and an object thereof is to effectively remove the waste toner accumulated in the fur brush fiber with a limited power and a simple configuration, and It is an object of the present invention to provide a low-cost and long-life cleaning device for an image forming apparatus that can maintain a function for a long period of time and obtain a stable image.

[0007]

In order to solve the above-mentioned problems, the present invention is a toner remaining on an image carrier after transferring a toner image formed on the image carrier to a recording paper. A fur brush that rotates while contacting at least the image carrier and a flicker member that removes toner adhering to the fur brush by an impact generated by contact with the fur brush are provided as means for removing the toner. In the cleaning device, with respect to the normal rotation direction of the fur brush at the time of cleaning the image carrier, the biting amount of the tip end portion of the flicker member with respect to the fur brush is small, and the fur brush is rotated in the reverse rotation direction. The support end of the flicker member at a position where the amount of biting of the tip of the flicker member with respect to the fur brush increases. And rotatably supported configuration.

In order to solve the above problems, the present invention further provides a fur brush for temporarily rotating the fur brush in a reverse direction in a direction in which the amount of biting of the tip end portion of the flicker member with respect to the fur brush increases. It has a reverse rotation mode, and when operating in this fur brush reverse rotation mode,
A drive source for driving equipment other than the fur brush or a fixing heater of a fixing device for fixing the toner image on the recording paper is turned off.

[0009]

According to the present invention, the amount of biting of the tip portion of the flicker member with respect to the fur brush is small with respect to the forward rotation direction of the fur brush during cleaning of the image carrier, In the reverse rotation direction, the biting amount of the tip of the flicker member with respect to the fur brush increases, so that the fibers 11b of the fur brush 11 contact the flicker bar 24 by reversing the fur brush. The impact force at that time increases, and the waste toner accumulated in the fur brush is knocked out.

Further, according to the present invention, during the operation in the fur brush reverse rotation mode in which the fur brush is temporarily rotated in the direction in which the amount of biting of the tip portion of the flicker member with respect to the fur brush increases, Since the drive source for driving equipment other than the fur brush or the fixing heater of the fixing device for fixing the toner image on the recording paper is turned off, the electric power required to temporarily rotate the fur brush in the reverse direction is generated. Secured enough.

[0011]

Embodiments of the present invention will be described in detail below with reference to the drawings. However, for the purpose of avoiding complication of the description, the illustration and disclosure of the configuration and operation of the range clearly conceivable from the description of this specification, and the above and other objects and novel features of the present invention are omitted. , Or simplify.

The basic structure of the image forming apparatus in this embodiment is the same as that of the image forming apparatus shown in FIG. That is, the image forming apparatus according to the present exemplary embodiment includes the charger 2 for uniformly charging the image carrier 1 and the image carrier 1.
An exposure optical system 3 for forming an electrostatic latent image of a document thereon, an eraser 4 for erasing unnecessary charges in a non-image area on the image carrier 1, and a latent image by supplying toner to the electrostatic latent image. Developing device 5 that visualizes toner, transfer charger 6 that transfers the toner image on image carrier 1 onto recording paper, separation charger 7 that weakens the electrostatic attraction of recording paper to image carrier 1, image carrier Body 1
A cleaning device 9 for removing the waste toner remaining on the upper surface,
The image carrier 1 is composed of a static eliminator charger 15 and a static eliminator 16 for electrostatically initializing the image carrier 1, and a fixing device 36 for fixing the toner image on the recording paper.

Further, the cleaning device 9 in this embodiment is also basically constructed in the same manner as the conventional one.
The fur brush 11, the bias roller 12, the scraper member 13, and the flicker member 25 are provided. In the configuration of the cleaning device 9, the difference from the conventional example is that, with respect to the forward rotation direction of the fur brush 11 during cleaning of the image carrier 1, as shown in FIG. Of the flicker member 2 in the reverse rotation direction of the fur brush 11 as shown in FIG.
The support end of the flicker member 25 is rotatably supported by the rotation support shaft 27 via the flicker holder 26 so that the amount of biting of the fur brush 11 at the tip end of 5 becomes large.

By the way, generally, the cleaning ability of the fur brush 11 for cleaning the image carrier 1 is dominated by the electrostatic force of the fiber 11b.
When the contact efficiency between b and the waste toner remaining on the image carrier 1 is basically reduced, the fiber 11b cannot capture the waste toner only by its electrostatic force. Therefore, in a normal cleaning device, the fur brush 11 is rotated in the direction of the arrow with respect to the image carrier 1 so that the fibers 11b of the fur brush 11 and the waste toner remaining on the image carrier 1 come into contact with each other. Is configured to increase.

Therefore, in the cleaning device 9 of the present embodiment, when the image carrier 1 is cleaned, that is, when the fur brush 11 is normally rotated, the free end (tip end) of the flicker member 25 is the fur brush 11. The flicker holder 26 is contacted with the surface by its own weight.
The flicker member 25 is rotatably supported by the rotation support shaft 27 via. As a result, the angle θ formed by the fur brush 11 and the flicker member 25 becomes an acute angle, and when the fur brush 11 rotates forward (when the image carrier 1 is cleaned), the free end (tip portion) of the flicker member 25. But,
A force is applied in a direction away from the surface of the fur brush 11.
Therefore, when the fur brush 11 is rotating in the forward rotation direction (clockwise direction in FIG. 1), the amount of the tip of the flicker member 25 biting into the fur brush 11 is small and the impact force is relatively weak. Since the waste toner accumulated in the fur brush is knocked out by this, the driving torque of the fur brush 11 can be small. Here, in the present embodiment, as described above, the flicker member 25 is configured to come into contact with the surface of the fur brush 11 by its own weight.
When there is a margin in the driving power of the above, the flicker member 25 may be pressed against the surface of the fur brush 11 by a spring or the like.

On the other hand, during the non-image forming operation of the image forming apparatus in this embodiment, that is, when the fur brush 11 is rotated in the reverse direction, as shown in FIG. 2, the amount of the tip of the flicker member 25 biting into the fur brush 11. Becomes large, and the waste toner accumulated in the fur brush is knocked out by a relatively strong impact force. However, in this case, as described above, a very large torque is required to drive the fur brush 11. Therefore, in the cleaning device 9 of the present embodiment, when the drive source other than the fur brush 11 and the fixing heater 39 are turned off, and there is enough power, for example, immediately after the power of the main body of the image forming apparatus is turned on. The fur brush 11 is configured to rotate in the reverse direction for a predetermined time when the image carrier 1 and the developing device 5 are stopped, or when the fixing heater 39 of the fixing device 36 is temporarily turned off. It Here, during operation of the fur brush reverse rotation mode in which the fur brush 11 is temporarily reverse rotated,
Necessary to positively turn off the fur brush 11 by positively turning off the drive source that drives devices other than the fur brush 11, or the fixing heater 39 of the fixing device 36 that fixes the toner image on the recording paper. It may be configured to secure a sufficient electric power. Further, by configuring the flicker member 25 with an elastic body such as a rubber plate, even if the fur brush 11 becomes unstable in rotation due to a large torque during the reverse rotation of the fur brush 11, even if the torque fluctuation becomes large. The torque fluctuation can be absorbed by the flicker member 25.

[0017]

According to the present invention, the waste toner accumulated in the fur brush fiber can be effectively removed by the limited electric power and the simple structure, and the function of the fur brush can be maintained for a long time and stable. An image can be obtained, and the fur brush is temporarily reversed so that the hair collapse of the fibers is corrected and the life of the fur brush is extended.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a cleaning device of the present invention during a cleaning operation.

FIG. 2 is a schematic cross-sectional view of the cleaning apparatus of the present invention when the fur brush rotates in the reverse direction.

FIG. 3 is a schematic sectional view of a conventional image forming apparatus.

FIG. 4 is a schematic sectional view of a conventional cleaning device.

[Explanation of symbols]

 1 Image Carrier 5 Developing Device 9 Cleaning Device 11 Fur Brush 11a Core Bar Roller 11b Fiber 12 Bias Roller 13 Scraper Member 23 Cleaning Blade 25 Flicker Member 26 Flicker Holder 27 Rotating Spindle 36 Fixing Device 39 Fixing Heater

Claims (3)

[Claims] 1. A method for removing toner remaining on an image carrier after transferring a toner image formed on the image carrier to a recording paper, at least contacting the image carrier. In a cleaning device provided with a fur brush that rotates while a flicker member that removes toner adhering to the fur brush by an impact generated by contact with the fur brush, a normal brush of the fur brush at the time of cleaning the image carrier is provided. The amount of biting of the tip of the flicker member with respect to the fur brush is small in the rotational direction, and the amount of biting of the tip of the flicker member with respect to the fur brush in the reverse rotating direction of the fur brush. In the image forming apparatus, the support end of the flicker member is rotatably supported at a position where the creepage becomes large. Packaging equipment. 2. The cleaning device according to claim 1, wherein the flicker member is formed of an elastic body. 3. A fur brush reverse rotation mode for temporarily rotating the fur brush in a reverse direction in a direction in which the amount of biting of the tip end portion of the flicker member with respect to the fur brush increases. 2. The cleaning device according to claim 1, wherein a driving source for driving a device other than the fur brush or a fixing heater of a fixing device for fixing the toner image on a recording paper is turned off during the operation of.