JPH04182684A - Cleaning device for transfer sheet holding rotary body - Google Patents

Abstract

PURPOSE:To prevent a transfer sheet from being soiled with toner with a simple configuration by locating a toner recovery roller on the upper stream side than a fur brush in the state of the retreat position of a device, and it nearby the outer periphery of a transfer sheet holding rotary body, in the state of the operational position of the device, and arranging a toner recovery blade at a position for scratching the toner on the toner recovery roller. CONSTITUTION:The fur brush 9 is rubbed on a transfer drum 1 by a rotation counterclockwise when the cleaning action of the transfer drum 1 is carried out. The toner recovery roller 12 is rotated clockwise, that is, in the direction of the outer periphery part of the brush 9 is moved. At this time, the rotation is carried out with a relative speed difference so that the peripheral speed of the roller 12 is higher than that of the brush 9, and simultaneously, the toner recovery blade 13 is abutted on the periphery of the roller to scratch the toner stuck thereto, so that the toner does not exist on the part of a sign 12A, but it is always kept clean. Consequently, the roller 12 works as a fence member as usual. On the other hand, even if the transfer sheet 4 has the occurrence of a deformation at the retreat position, the cleaning device 7 is in contact with the roller 12, without contacting the brush 9 and the outside surface of a main body 18, and the transfer sheet 4 is not soiled with the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaning device for a transfer paper holding rotating body in an image forming apparatus.

[Conventional technology]

In an image forming apparatus such as a copying machine or a printer, a transfer paper is held on the outer peripheral surface of a transfer paper holding rotary body such as a transfer drum that is driven five times, and is formed on a latent image carrier made of a drum-shaped photoreceptor, for example. There is known an image forming apparatus that transfers a toner image thus obtained onto the held transfer paper.

FIG. 3 is a schematic diagram of the area around the transfer drum of such an image forming apparatus, in which reference numeral 1 denotes the transfer drum, which is an example of the configuration of the transfer paper holding rotating body, and 2, an example of the configuration of the latent image carrier. The drum-shaped photoreceptors shown in FIG.

An electrostatic latent image is formed on the surface of the photoreceptor 2 by charging, exposure, etc., and this electrostatic latent image is visualized as a toner image by a developing device (not shown).

A pair of registration rollers 3 provided below the transfer drum 1 sends a transfer sheet 4 toward the transfer drum 1 at appropriate timing. The transfer drum 1 is provided with a clamp member S that opens as shown by the imaginary line when the leading edge of the transfer paper 4 is to be clamped. is clamped onto the transfer drum 1 by closing. Thereafter, the transfer paper 4 is wound around the outer peripheral surface of the transfer drum 1, but at this time, due to corona discharge by the transfer charger 6, the wrapped transfer paper is wrapped around the transfer drum 1.
is electrostatically attracted to the outer peripheral surface of the At the same time, the toner image on the photoreceptor 2 is transferred onto the transfer paper 4 due to the corona discharge.

If the image forming apparatus is a one-color type,
Toner images of different colors are formed on the photoreceptor 2 each time the transfer drum rotates, and these toner images are superimposed and transferred to the same position on the transfer paper each time the transfer drum rotates. The toner image thus formed on the photoreceptor 2 is transferred to a transfer paper held by the rotating transfer drum 1.

A cleaning device 7 for the transfer drum is provided on the downstream side of the pair of registration rollers 3 in the traveling direction of the transfer paper 4 sent from this location so as to be opposed to the transfer drum 1 . This cleaning device 7 includes a casing body 18 having an opening 21 on the side facing the transfer drum 1.
The cleaning device 7 has a fur brush 9 rotatably supported at the opening of the main body 18, and when not cleaning, the cleaning device 7 is held in the retracted position shown in FIG. The fur brush 9 is spaced apart from the outer peripheral surface of the transfer drum 1.

Here, after the last transfer is completed and the transfer paper is removed from the transfer drum 1 and drained, the cleaning device 7 is rotated about the pivot shaft 11 to the operating position shown in FIG. , the fur brush 9 is in contact with the outer peripheral surface of the transfer drum 1. In this way, the cleaning device 7 is supported so as to be operable between the operating position and the retracted position.

When the cleaning device 7 is in the operating position and no transfer paper is held on the transfer drum l, the fur brush 9 is moved so that the outer circumferential portion that contacts the transfer drum 1 is different from the moving direction of the surface of the transfer drum 1. The fur brush 9 is rotated counterclockwise, and during this rotation, the fur brush 9 rubs against the outer circumferential surface of the transfer drum 1 to scrape off toner adhering to the outer circumferential surface of the transfer drum 1. This is the cleaning operation.

The fur brush 9 is in contact with a toner collection roller 12 supported by a casing body 18 and located below the brush 9. The fur brush 9 is rotated counterclockwise so as to be different from the moving direction of the
The toner attached to the fur brush 9 is adsorbed and collected from the fur brush 9. The toner adhering to the toner collection roller 12 is scraped off by the toner collection blade 13 supported by the casing body 18, falls into the casing body 18, and is collected into the toner collection container 14 inside the cleaning device.

Normally, an electric field is formed between the fur brush 9 and the toner collection roller 12 so that the toner is electrostatically attracted and transferred from the fur brush 9 toward the toner collection roller 12. If the toner collection roller 1
2 is also called a bias roller.

Here, as described above, with the cleaning device 7 occupying the retracted position shown in FIG. 3, the transfer paper 4 is placed on the transfer drum 1.
When conveying the transfer paper to the transfer drum 1 in order to hold the transfer paper, the leading end of the transfer paper 4 is clamped by the clamp member 5, and then the transfer paper is wound around the transfer drum 1. Nearby, a situation occurs in which the rear end of the transfer paper 4 passes through a portion of the transfer paper guide plate 16 provided between the registration roller pair 3 and the transfer drum 1.

At this time, since the trailing edge has not yet been electrostatically attracted to the outer peripheral surface of the transfer drum 1, the trailing edge tends to bounce due to the stiffness of the paper immediately after passing through the transfer paper guide plate 16.

When the rear end of the transfer paper bounces in this way, this rear end comes into contact with the fur brush 9 and the casing body 18 of the cleaning device 7 which has occupied the retracted position, and the casing body 18 and the fur brush There is a possibility that the toner attached to the paper 9 may adhere to the rear end of the transfer paper, and the transfer paper may be smeared with the toner.

Therefore, conventionally, a fence member 15 fixed to the casing body 18 is provided upstream of the fur brush 9 in the transfer paper conveyance path when conveying the transfer paper to the transfer drum.
The rear end of the transferred transfer paper 4 is placed in contact with a fence member 15 so as not to contact the fur brush 9 or the casing body 18, thereby preventing toner from adhering to the transfer paper 4.

This fence member 15 prevents the toner scattered from the fur brush 9 from flying out of the casing body 18 when the cleaning device 7 is in the operating position and performing a cleaning operation, and prevents the toner from flying out of the casing body 18. It also functions as a sealing member that prevents toner from adhering to the rear end of the transfer paper when the transfer paper is conveyed.

Since the fence member 15 is provided as described above, when the transfer paper is conveyed to the transfer drum 1 as shown in FIG. It comes to move while contacting the member 15. At this time, there is no problem if no toner adheres to the fence member 15, but in reality, scattered toner usually accumulates on the fence member 15 over time. Therefore, when the transfer paper moves while coming into contact with the fence member 15, the accumulated toner adheres to the transfer paper, and the rear end of the transfer paper becomes stained with the own toner.

In order to prevent the leading edge of the transfer paper 4 from becoming unclamped or to prevent it from being clamped in an unparallel state, the clamping member 5 and the transfer drum 1 are opened.
After the leading edge of the transfer paper enters between the clamp member 5 and the pair of registration rollers 3, the transfer paper is sometimes loosened. The transfer paper portion comes into contact with the fence member 15.

Unfortunately, the transfer paper becomes stained with toner.

[Problem to be solved by the invention]

In order to avoid such problems, for example, a bristle brush may be provided on the outer peripheral surface of the transfer drum 1 in a portion where the transfer paper is not held, and the toner adhering to the fence member 15 may be swept away with the brush. Conventionally, measures have been taken to cover the vicinity of the fence member 15 with a cover member after passing the paper, but these methods complicate the structure and are disadvantageous in terms of cost. There was a side.

Further, if the fence member 15 is provided, the cost of the cleaning device increases accordingly.

An object of the present invention is to provide the above-mentioned transfer paper with a simple structure.
To provide a cleaning device which can prevent staining due to toner and can omit a fence member.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a cleaning device for a transfer paper holding rotary body that is rotated while holding a transfer paper to which a toner image formed on a latent image carrier is transferred. A casing body having an opening on the side facing the rotating body, and the body.

a fur brush that is provided at the opening and that scrapes toner adhering to the outer circumferential surface of the rotary body by rubbing against the outer circumferential surface of the rotary body during a cleaning operation when the transfer paper is not held on the rotary body; , a toner collection roller that collects toner adhering to the fur brush, and a toner collection blade that scrapes and removes the toner on the toner collection roller and drops it into the casing body; Cleaning of the transfer paper holding rotor in an image forming apparatus in which the fur brush is supported so as to be operable between an operating position in contact with the outer peripheral surface of the holding rotor and a retracted position where the fur brush is away from the outer circumferential surface of the transfer paper holding rotor. In the device.

With the cleaning device occupying the retracted position, in order to cause the transfer paper holding rotary body to hold the transfer paper, the fur brush is used in the transfer paper conveyance path when the transfer paper is conveyed to the transfer paper holding rotary body. The toner collection roller is located on the upstream side, and the roller is located close to the outer peripheral surface of the transfer paper holding rotary body when the cleaning device is in the operating position.

The toner collecting blade is arranged at a position to scrape off the toner on the toner collecting roller so that the toner on the toner collecting roller does not go around to a position facing the transfer paper holding rotating body. This paper proposes a cleaning device that does the following:

〔Example〕

The present invention will be explained below based on one embodiment. In this description, the same reference numerals will be used for members that achieve the same or similar functions as in the conventional example, and the description of the same parts will be omitted since it will overlap with the previous description.

FIG. 1 shows a state in which the cleaning device 7 is in the operating position and its fur brush 9 is performing a cleaning operation by rubbing against the outer peripheral surface of the transfer drum 1, and FIG. 2 shows a state in which the cleaning device 7 is in the retracted position. The fur brush 9 is separated from the transfer drum 1 and is conveying the transfer paper 4 to hold it on the transfer drum 1, and the cleaning operation and transfer paper conveyance operation are the same as in the conventional case. There is no difference.

The difference from the conventional method is that the toner collection roller 12 supported by the casing body 18 is placed to the left of the fur brush 9 in FIGS. The toner collection blade 13 that is in contact with the roller 12 has its base end fixed to the casing body 18 as shown in FIGS. (Figure) is not provided.

More specifically, with the cleaning device 7 occupying the retracted position shown in FIG.
When considering the transfer paper conveyance path when conveying the transfer paper 4 to the transfer drum 1 in order to maintain the transfer paper 4, a toner collection roller 1 is placed upstream of the fur brush 9 in this conveyance path.
2 is located. That is, the toner collection roller 12 is located at the location where the fence member 15 has been located in the past. Further, this toner collection roller 12 is located close to the outer peripheral surface of the transfer drum 1 when the cleaning device 7 is in the operating position as shown in FIG. The toner collection roller 12 has a toner collection blade 13.
It is located so as to cover the opening 21 of the casing body 18 together with the fur brush 9 and the fur brush 9 .

By arranging the toner collection roller 12 and the toner collection blade 13 as described above, the following effects can be obtained.

As mentioned earlier, the fur brush 9 is attached to the transfer drum 1.
The outer peripheral portion that is in contact with the surface of the transfer drum 1 is rotated in a counterclockwise direction different from the moving direction of the surface of the transfer drum 1, and when the transfer drum 1 is cleaned, rotation in this direction causes a rotational movement toward the transfer tram 1. Rub it.

With respect to the fur brush 9 that rotates in such a direction during the cleaning operation, the toner collection roller 12 is rotated so that the peripheral surface of the roller that contacts the fur brush 9 is in the same direction as the moving direction of the outer peripheral portion of the fur brush 9. Driven to rotate clockwise. In this case, if the peripheral speeds (linear speeds) of both are the same, the toner collection roller 12 will not rub against the fur brush 9, and toner will not easily fall from between the toner collection roller 12 and the fur brush 9. Become. For this reason, the peripheral speed of the toner collection roller 12 is made faster than that of the fur brush 9, so that the toner collection roller 12 is rotated with a relative speed difference with respect to the fur brush 9. The toner collection roller 12 rotates in this direction.

In addition, if the toner collecting blade 13 is in contact with that surface as shown in the figure, the toner collected by the toner collecting roller 12 and attached to the roller will be scraped off by the toner collecting blade 13. Toner does not go around the peripheral surface of the roller that faces the transfer drum 1. That is, there is no toner on the peripheral surface portion indicated by the reference numeral 12A in FIG. 1, and it is always kept clean.

As a result, the toner collection roller 12 also functions as the conventional fence member 15. That is, as shown in FIG. 2, the cleaning device 7 occupies the retracted position,
When the transfer paper 4 is conveyed to the transfer drum 1, even if the transfer paper 4 becomes slack as shown in the figure, this part comes into contact with the toner collection roller 12, so that this part is removed by the fur brush 9 and the casing body 18. Do not touch the outside surface of the

Moreover, since no toner adheres to the peripheral surface portion 12A (FIG. 1) of the toner collection roller 12, the transfer paper 4 is not stained with toner. Even if the rear end of the transfer paper 4 bounces after passing through the transfer paper guide plate 16 and comes into contact with the toner collection roller 12, the rear end will not be stained with toner. Also, as shown in Figure 1, there is a cleaning group! ! The fur brush 9 rotates when the fur brush 7 occupies the operating position and performs the cleaning operation.
The scattered toner is collected by the toner collection roller 12.
The toner is prevented from flying out of the cleaning device, and the toner is prevented from adhering to the outer surface of the casing body 18. Therefore, at this time as well, the toner collection roller 12 functions as a sealing member for the conventional fence member 15. Further, in the illustrated example, the toner collection roller 12 and the toner collection blade 13 cover the opening 21 of the casing body 18,
The toner scattering prevention effect is ensured.

In this way, the conventional fence member 15 is completely unnecessary.

In order to prevent toner from adhering to the peripheral surface portion 12A of the toner collection roller 12, the toner collection roller 12 is
Although it must be rotated clockwise in the figure, the fur brush 9 does not necessarily have to be rotated counterclockwise as shown, and may be rotated clockwise.

In this case, the rotation direction of the fur brush 9 is determined so that the local portion that contacts the transfer drum 1 is the same as the moving direction of the surface of the transfer drum 1. By increasing the circumferential speed of the fur brush 1, the fur brush 9 can slide against the transfer drum 1 without interfering with the toner scraping function. On the other hand, when the fur brush 9 rotates clockwise, the toner collection roller 12 rotates in a sliding state against the fur brush 9. In any case, even if the fur brush 9 is configured to rotate in such a direction, it is possible to prevent the transfer paper from being stained by toner as described above.

The present invention can also be applied to an image forming apparatus in which the transfer paper 4 is simply electrostatically attracted and held on the outer peripheral surface of the transfer drum 1 without using the ramp member 5 as shown in FIG. . In addition to the transfer drum, the present invention can also be applied to a device that uses an endless transfer belt as the transfer paper holding rotary member.

〔Effect of the invention〕

According to the present invention, the fence member can be omitted, the configuration can be simplified, and the cost can be reduced. In addition, when the transfer paper is conveyed to the transfer paper holding rotating body, the transfer paper is not loosened, or the transfer paper is not loosened after that. Even if the edge bounces and comes into contact with the toner collection roller, the peripheral surface of the toner collection roller facing the transfer paper holding rotating body remains clean and free of toner. There is no risk of staining the transfer paper, and this function can be achieved with an extremely simple configuration.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the area around the transfer drum equipped with a cleaning device according to an embodiment of the present invention, and FIG. 2 shows the operation from FIG. 3 is a schematic diagram of the area around the transfer drum equipped with a conventional cleaning device, and FIG. 4 is an operational view from FIG. 3 showing the cleaning device in its operating position. 1...Transfer drum 9 as a transfer paper holding rotating body...
Fur brush 12... Toner recovery roller 13... Toner recovery blade 18... Casing body 21... Opening agent Norio Hoshino, patent attorney

Claims (1)

[Scope of Claims] A cleaning device for a transfer paper holding rotating body that is rotated while holding a transfer paper onto which a toner image formed on a latent image carrier is transferred, the cleaning device facing the transfer paper holding rotating body. A casing body having an opening on the side, and a casing body provided at a portion of the opening of the body, which rubs against the outer circumferential surface of the transfer paper holding rotary body during a cleaning operation when the transfer paper is not held by the rotary body. a fur brush that scrapes toner adhering to the outer circumferential surface of the fur brush; a toner collection roller that collects the toner adhering to the fur brush; and a toner that scrapes off the toner on the toner collection roller and causes it to fall into the casing body. a recovery blade, and is movably supported between an operating position where the fur brush contacts the outer circumferential surface of the transfer paper holding rotating body and a retracted position where the fur brush is separated from the outer circumferential surface of the transfer paper holding rotating body. In a cleaning device for a transfer paper holding rotary body in an image forming apparatus, the transfer paper is rotated to hold the transfer paper in order to cause the transfer paper holding rotary body to hold the transfer paper while the cleaning device occupies the retracted position. The toner collection roller is located upstream of the fur brush in the transfer paper conveyance path when the transfer paper is conveyed to the body, and the toner recovery roller is positioned on the transfer paper holding rotary body when the cleaning device is in the operating position. The toner collecting blade is positioned close to the outer circumferential surface of the toner collecting blade, and the toner collecting blade scrapes off the toner on the toner collecting roller so that the toner on the toner collecting roller does not go around to a position facing the transfer paper holding rotary body. A cleaning device characterized in that the cleaning device is arranged at a position.