JPH05323835A - Cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To provide the cleaning device for the image forming device where toner scattering in a final period of the cleaning can be prevented. CONSTITUTION:A solenoid for blade position varying drive 39 separating the cleaning blade 28 from a belt 11 after the position of the cleaning blade 28 is passed by a cleaning range on the intermediate transfer belt 11 which is the body to be cleaned is provided and a motor for driving source 41 to stop the rotation of a cleaning brush 27 before the time of separation is provided.

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, and more particularly to a cleaning device having a cleaning brush and a cleaning blade.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile or a printer, an electrostatic latent image is formed on a latent image carrier made of, for example, a photoconductor, and the electrostatic latent image is visualized as a toner image. , In the case of transferring such a toner image to a recording medium, after the toner image is transferred, the toner that has not contributed to the transfer remains on the surface of the photoconductor, so that the adhered toner is removed from the photoconductor. I am trying to collect it.

Further, in this type of image forming apparatus, the toner image on the photosensitive member is transferred to an intermediate transfer rotary member such as a transfer drum or a transfer belt by an electrostatic method or an adhesive method, and the intermediate transfer rotary member is transferred. An image forming apparatus has been proposed in which the above transfer image is further transferred to a recording medium, but the toner remains on the intermediate transfer rotator during transfer of the toner image. I am trying to collect it.

As an image forming apparatus of this type, a cleaning apparatus using a cleaning brush, a cleaning blade, or the like is often used as a cleaning device for cleaning the object to be cleaned such as the photosensitive member or the intermediate transfer rotating member.

FIG. 4 is an example of an image forming apparatus provided with such a cleaning device and is a diagram showing an outline of an embodiment of the present invention. Here, the basic structure of the image forming apparatus is shown. Then, the problems of the conventional cleaning device will be described below.

The image forming apparatus of this example is capable of obtaining a color image, and has a color image reading device 1 on the upper part thereof. Further, this image forming apparatus is a color image recording apparatus (color printer) which constitutes the main body.
2 and a lower sheet feeding unit body 3 and the like.

A drum-shaped photosensitive member 5 provided at a slightly upper side of a central portion in the color image recording apparatus 2 is adapted to be rotationally driven in a direction of an arrow shown in the drawing. The surface is uniformly charged by the charging charger 6.

An optical writing unit 4 provided above the photoconductor 5 emits a laser beam 7 which is optically modulated in accordance with an image signal, and the optical writing by the laser beam is performed on the surface of the charged photoconductor. As a result, the predetermined electrostatic latent image is formed on the surface. The developing device 8 has four color developing devices (not shown), and these are unitized. By selectively operating each developing device, images are sequentially formed on the surface of the photoconductor. Electrostatic latent images are visualized as toner images of different colors of cyan, magenta, yellow, and black, respectively.

The photoreceptor 5 has a belt driving roller 12 and
The endless intermediate transfer belt 11, which is stretched between the transfer roller 13 and the idle roller 14, is in contact with the transfer roller 13 portion. The intermediate transfer belt 11 is
A drive motor (not shown) is rotationally driven in the direction of the arrow.

The intermediate transfer belt 11 rotates in the direction of the arrow at a constant speed in synchronization with the photoconductor 5, and at this time, the toner images of different colors on the photoconductor 5 are transferred onto the intermediate transfer belt 11 at the transfer section 9. The images are transferred one after another at the same position. A predetermined bias voltage is applied to the transfer roller 13, so that the toner image on the photoconductor 5 is transferred to the intermediate transfer belt 11. For convenience, when the toner images of four colors are superposed on the intermediate transfer belt 11, a predetermined color image is obtained on the belt 11.

Each time the toner images sequentially formed on the photoconductor 5 are completely transferred to the intermediate transfer belt 11, the toner remaining on the photoconductor 5 is removed from the photoconductor 5 by the cleaning device 50, and the photoconductor 5 is removed. Is cleaned, and then the surface of the photoconductor is subjected to the charge removal action by the charge removal lamp 51.

Manual paper feed unit 15, paper feed units 16, 17, 1
Recording paper 2 as a recording medium from either 8 or 19
1 is sent toward the transfer portion 22 between the transfer roller 10 and the belt portion that is stretched around the belt driving roller 12,
In the transfer section 22, the color images are collectively transferred to the recording paper 21. After this transfer, the recording paper is fed by the conveyor belt 23, passes through the fixing roller pair 24, and is accommodated on the tray 25 as color copy paper.

When the toner images are sequentially transferred onto the intermediate transfer belt 11, the transfer roller 10 is separated from the intermediate transfer belt 11, and the color image on the belt 11 is transferred onto the recording paper 21.
When the image is collectively transferred onto the intermediate transfer belt 11, the transfer roller 10 is pressed against the intermediate transfer belt 11, and at this time, a predetermined bias voltage is applied to the roller 10, and the color image on the intermediate transfer belt 11 is transferred onto the recording paper 21. ..

The intermediate transfer belt 11 is transferred to the transfer portion 22.
A cleaning device 26 for cleaning the intermediate transfer belt 11, which is the object to be cleaned, is provided on the downstream side in the rotation direction of the. Cleaning device 26
Includes a cleaning brush 27 formed of a roller-shaped fur brush, and a cleaning blade 28 formed of an elastic body such as rubber. The cleaning brush 27 is rotatably driven, for example, in a clockwise direction so as to rub against the surface of the intermediate transfer belt 11 which is the cleaning target, and the color image on the intermediate transfer belt 11 is recorded on the recording paper 21. After collectively transferring the toner, the toner and other foreign matters remaining on the intermediate transfer belt 11 are scraped and removed by the cleaning brush 27 that rubs.

The cleaning blade 28 is provided on the downstream side of the cleaning brush 27 with respect to the moving direction of the intermediate transfer belt 11, which is the member to be cleaned, and its edge portion abuts on the intermediate transfer belt 11 so that the cleaning brush is cleaned. Toner and the like not removed by 27 are scraped off. Reference numeral 29 is a backup roller for pressing the back side of the intermediate transfer belt portion with which the cleaning blade 28 abuts.

Here, the cleaning brush 27 and the cleaning blade 28 are configured to come in contact with and separate from the intermediate transfer belt 11, and these sequentially transfer the toner image from the photoconductor 5 onto the intermediate transfer belt 11. When it is present, it is separated from the intermediate transfer belt 11. Before the front end of the color image forming area (cleaning area) on the intermediate transfer belt 11 after the transfer of the color image that has passed through the transfer portion 22 reaches the cleaning blade 28 and the cleaning brush 27, respectively, they are both transferred. The residual toner on the belt 11 is removed by contacting the belt 11.

Then, after the color image forming area on the intermediate transfer belt 11, that is, the rear end of the cleaning area passes through the portions of the cleaning brush 27 and the cleaning blade 28, the brush 27 and the cleaning blade 28 respectively. The intermediate transfer belt 11 is separated from the intermediate transfer belt 11.

FIG. 6 shows a timing chart in the conventional cleaning device, and E is the time when the rear end portion of the color image forming area after being transferred to the recording paper 21 passes the portion of the cleaning blade 28. After this E time, the cleaning blade 28 moves the intermediate transfer belt 11
Stay away from. Conventionally, after the separation time,
The rotation of the cleaning brush 27 is stopped, and after that, the cleaning brush 27 is separated from the intermediate transfer belt 11 with a slight delay. That is, conventionally, the cleaning brush 27 was rotated for t hours even after the cleaning blade 28 was separated from the intermediate transfer belt 11.

During this time t, the cleaning brush 27
Since the surface of the belt 11 is continuously rubbed, the toner easily scatters from the rubbed portion. When such scattering occurs, toner is scattered from the gaps 31 and 32 (FIG. 4) between the cleaning device 26 and the intermediate transfer belt 11 to the outside of the cleaning device 26, and the inside of the recording device 2 is soiled with the toner. Especially during the time t, the cleaning blade 27
Is separated from the intermediate transfer belt 11, so the gap 3
The scattering of toner from No. 2 also becomes remarkable.

An image forming apparatus of the type in which the toner image on the photoconductor is directly transferred onto the recording paper without using the intermediate transfer belt 11 is also provided with a cleaning device for cleaning the photoconductor. Even in such a configuration, or in the cleaning device 50 shown in FIG. 4, the same problem occurs.

[0021]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cleaning device for an image forming apparatus capable of preventing toner scattering at the end of cleaning.

[0022]

In order to achieve the above-mentioned object, the present invention provides a cleaning brush which is rotationally driven so as to rub the surface of an object to be cleaned, and a moving direction of the surface of the object to be cleaned. A cleaning blade that is provided on the downstream side of the cleaning brush, the edge portion of which contacts the surface, and the cleaning area of the surface of the object to be cleaned has passed through the cleaning blade,
Cleaning blade displacement driving means for separating the cleaning blade from the surface, and after the cleaning area has passed the cleaning brush, before the cleaning blade separates from the surface, or at the same time, the rotation of the cleaning brush is stopped. Cleaning brush rotation driving means, and cleaning brush displacement driving means for separating the cleaning brush from the surface after the cleaning region has passed through the cleaning brush and before or at the same time as the cleaning blade separates from the surface. A cleaning device for an image forming apparatus including the above is proposed.

In order to achieve the above object, the present invention provides
A cleaning brush that is rotationally driven so as to rub the surface of the object to be cleaned, and a cleaning blade that is provided on the downstream side of the cleaning brush with respect to the moving direction of the surface of the object to be cleaned and has an edge portion abutting the surface. A cleaning blade displacement driving means for separating the cleaning blade from the surface after the cleaning area on the surface of the object to be cleaned has passed the cleaning blade, and the cleaning blade after the cleaning area has passed the cleaning brush. Before or at the same time as the cleaning brush is separated from the surface, a cleaning brush rotation driving means for driving the cleaning brush at a low speed to stop the cleaning brush,
An image forming apparatus comprising: a cleaning brush displacement driving unit that separates the cleaning brush from the surface after the cleaning area has passed through the cleaning brush and before or at the same time as the cleaning blade separates from the surface. It proposes a cleaning device.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings.

As described above, FIG. 4 is a diagram showing an image forming apparatus having the cleaning device 26 according to one embodiment of the present invention. The basic structure and operation of the image forming apparatus have been described above. Is omitted. FIG. 1 is a configuration diagram showing a main part of a cleaning device 26 according to an embodiment of the present invention, and its basic configuration is as described above. In this figure,
A solenoid 34 is connected to the shaft of the cleaning brush 27 via a tension spring 33.

The cleaning blade 28 is fixed to a blade holder 36 which is swingably provided around a fulcrum shaft 35. A torsion coil spring 37 is attached to the fulcrum shaft 35, and the cleaning blade 28 is supported by the force of this spring.
The edge portion 28a of the above contacts the intermediate transfer belt 11 with a predetermined pressure. The blade holder 36 has a tension spring 38
The solenoid 39 is connected via.

FIG. 5 shows a timing chart corresponding to the embodiment of the present invention, and E, as described above, shows the color image on the intermediate transfer belt 11 on the recording paper 21 after being transferred to the recording paper 21. The rear end portion of the color image forming area of is the portion of the cleaning blade 28 (the portion of the edge portion 28a)
It is time to pass through. That is, it is the time when the rear end of the cleaning area on the surface of the intermediate transfer belt 11 which is the object to be cleaned passes the cleaning blade. At this time, after the machine E, the solenoid 39 is excited,
The blade holder 36 is pulled via the spring 38, and the cleaning blade 28 is separated from the surface of the intermediate transfer belt 11.

The spring 38, the solenoid 39, etc. constitute an example of a cleaning blade displacement driving means for separating the cleaning blade from the surface of the object to be cleaned after the cleaning area on the surface of the object to be cleaned has passed the cleaning blade. .. After the cleaning blade 28 is separated, the blade holder 36 is stopped by the stopper pin 40, so that the cleaning blade 28 is held in a position separated from the intermediate transfer belt 11 (see FIG. 3).

Here, after the rear end of the cleaning area on the intermediate transfer belt 11 has passed the cleaning brush 27 and before the cleaning blade 28 is separated from the intermediate transfer belt 11, or simultaneously with this separation, cleaning is performed. The rotation of the brush 27 is stopped as shown in FIG. 5 (in the example of FIG. 5, the cleaning brush 28 is separated before the cleaning blade 28 is separated from the intermediate transfer belt 11).
7 rotation has stopped).

As shown in FIG. 1, the cleaning brush 2
A motor 41 is directly connected to the motor 7, or is connected to the motor 7 via a universal joint or the like. As described above, the motor 41 is a cleaning brush rotation driving means for stopping the rotation of the cleaning brush after the cleaning area has passed the cleaning brush and before the cleaning blade is separated from the surface of the object to be cleaned. The cleaning brush 27 is stopped by stopping the rotation of the motor 41, for example, at such timing.

On the other hand, as shown in FIG. 5, after the rear end of the cleaning area on the intermediate transfer belt 11 has passed the cleaning brush 27 and before the cleaning blade 28 is separated from the surface of the intermediate transfer belt 11. Alternatively, at the same time as this separation, the cleaning brush 27 is separated from the surface of the intermediate transfer belt 11 by the excitation of the solenoid 34 (see FIG. 2). Again,
In the example of FIG. 5, the cleaning brush 27 is separated from the surface of the intermediate transfer belt 11 before the separation of the cleaning blade 28. Further, as shown in FIG. 5, the cleaning brush 27 may be separated from the surface of the intermediate transfer belt 11 after the rotation of the cleaning brush 27 is stopped. The brush 27 may be separated from the intermediate transfer belt 11 at the same time when it is separated from the intermediate transfer belt 11 or when the cleaning brush 27 is stopped.

In any case, the spring 33 and the solenoid 3
4 is a cleaning brush displacement drive for separating the cleaning brush from the surface of the object to be cleaned after the cleaning area has passed through the cleaning brush and before or at the same time as the cleaning blade is separated from the surface of the object to be cleaned. It constitutes an example of the means.

When the cleaning brush 27 is connected to the motor 41 via a universal joint, the solenoid 3
By the excitation of No. 4, only the cleaning brush 27 is displaced and driven. In any case, the cleaning blade 28
Is separated from the intermediate transfer belt 11, which is the member to be cleaned, or at the same time, the cleaning brush 27 that has finished the actual cleaning operation is stopped and separated, so that the scattering of toner is stopped during this period.
It is possible to prevent the toner from scattering from the brush 27.
Particularly, from the clearance 32 (FIG. 4), the cleaning device 26
It is possible to effectively suppress the scattering of the toner to the outside and prevent the toner from being contaminated in the image forming apparatus for a long period of time.

Incidentally, FIG. 3 shows the cleaning device 26.
The cleaning brush 27 and the cleaning blade 28 are both separated from the intermediate transfer belt 11.

The above is the embodiment of the cleaning device corresponding to claim 1, but in the embodiment of the cleaning device corresponding to claim 2, the rear end portion of the cleaning area on the intermediate transfer belt 11 is the cleaning brush. After passing through the cleaning brush 27, before the cleaning blade 28 separates from the surface of the intermediate transfer belt, or simultaneously with this separation, the cleaning brush 27 is driven to rotate at a low speed to stop the cleaning brush 27. A rotary drive means is configured. Other configurations are the same as those in the previous embodiment.

The motor 41 shown in FIGS. 1 to 3 constitutes an example of the structure of the cleaning brush rotation driving means.
Also in this embodiment, before the cleaning blade 28 is separated from the intermediate transfer belt 11, or at the same time,
Cleaning brush 2 after the actual cleaning operation
7 rotates at a low speed, and then the rotation is stopped, so that toner scattering can be effectively suppressed. The cleaning blade 28 is separated from the intermediate transfer belt 11 when the scattering of toner is stopped. In this way, it is possible to prevent the toner from scattering and at the same time prevent the toner from being contaminated in the image forming apparatus for a long period of time. During the normal cleaning operation by the cleaning brush 27, the brush 27 is rotationally driven at a speed faster than the above-described low speed rotation so that the function of scraping and removing the toner can be performed.

In the above two embodiments, the cleaning target is the intermediate transfer belt.
A belt-shaped or drum-shaped photosensitive member carrying a toner image,
A drum-shaped intermediate rotating body to which the toner image on the photoconductor is transferred can also be applied. For example, the cleaning device 50 shown in FIG. 4 also has a roller-shaped cleaning brush 50a that contacts the photoconductor 5 to remove residual toner on the photoconductor 5 after the toner image is transferred, and a cleaning blade 50b. Such cleaning device 50
The toner can be prevented from being scattered by constructing the above completely the same as in the above-mentioned respective embodiments. In this case, after performing a series of copying operations, that is, copying operations for multiple sheets,
Cleaning blade 50b and cleaning brush 50
When “a” is separated from the photoconductor 5, the “cleaning region on the surface of the member to be cleaned” becomes the cleaning region in the entire series of copying operations, and the rear end of this region passes the cleaning blade 50b or the cleaning brush 50a. After that, they are separated from the photoconductor 5, respectively.

[0038]

According to the constitutions of claims 1 and 2,
In a cleaning device using a cleaning brush and a cleaning blade, it is possible to effectively prevent the toner from scattering outside the cleaning device at the end of cleaning, so that the inside of the image forming apparatus is not likely to be contaminated with the toner for a long period of time. ..

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a main part of a cleaning device according to an embodiment of the present invention.

FIG. 2 is an operation diagram from FIG. 1 showing a state where the cleaning brush is separated from the intermediate transfer belt.

FIG. 3 is an operation diagram from FIG. 2 showing a state in which the cleaning blade is separated from the intermediate transfer belt.

FIG. 4 is an overall configuration diagram of an image forming apparatus provided with a cleaning device of the present invention.

FIG. 5 is a timing chart corresponding to one embodiment of the present invention.

FIG. 6 is a timing chart of a conventional example.

[Explanation of symbols]

 11 Intermediate Transfer Belt as Cleaning Object 26 Cleaning Device 27 Cleaning Brush 28 Cleaning Blade 28a Edge Part

Front page continuation (72) Inventor Makoto Arai 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (2)

[Claims] 1. A cleaning brush that is rotationally driven so as to rub the surface of the object to be cleaned, and a cleaning brush that is provided on the downstream side of the cleaning brush with respect to the moving direction of the surface of the object to be cleaned and has an edge portion. After the cleaning blade abutting against the cleaning area of the surface of the object to be cleaned has passed the cleaning blade, the cleaning blade displacement driving means for separating the cleaning blade from the surface, and the cleaning area after passing the cleaning brush. Before or after the cleaning blade is separated from the surface, or at the same time, after the cleaning brush rotation driving means for stopping the rotation of the cleaning brush and after the cleaning area passes through the cleaning brush, A cleaning device for an image forming apparatus, comprising: a cleaning brush displacement driving unit that separates the cleaning brush from the surface before or simultaneously with separation from the surface. 2. A cleaning brush which is rotationally driven so as to rub against the surface of the object to be cleaned, and a cleaning brush which is provided on the downstream side of the cleaning brush with respect to the moving direction of the surface of the object to be cleaned and whose edge portion is the surface. After the cleaning blade abutting against the cleaning area of the surface of the object to be cleaned has passed the cleaning blade, the cleaning blade displacement driving means for separating the cleaning blade from the surface, and the cleaning area after passing the cleaning brush. So, before the cleaning blade separates from the surface, or at the same time, by driving the cleaning brush at low speed,
Cleaning brush rotation driving means for stopping the cleaning brush and separating the cleaning brush from the surface after the cleaning region has passed through the cleaning brush and before or at the same time as the cleaning blade separates from the surface. A cleaning device for an image forming apparatus, comprising: a cleaning brush displacement driving means.