JPH03191379A - Cleaning brush for electrophotographic equipment - Google Patents

Abstract

PURPOSE:To surely remove toner and sticking matter and to prevent adverse effects to a photosensitive body and image quality, caused by the variation of the contacting pressure distribution of a rubbing part to the photosensitive body by inclining a loop made of loop-like fiber toward the downstream side in the rotational directions in the circumferential direction of a roller. CONSTITUTION:In a cleaning brush, its rubbing part A to the photosensitive body is formed with conductive loop-like fiber 5, and the loop of the loop-like fiber 5 is formed so as to be inclined toward the downstream side in the rotational direction (a) of the circumferential direction of the brush roller 4. Therefore, the projecting part of the rubbing part A in the initial state of the loop-like fiber 5 is recessed and its outer diameter is uniformized, so that the uneven butting of the rubbing part A to the photosensitive body is prevented, and the occurrence of a scratch on the photosensitive body (it causes the generation of the unevenness of white and black lines) is prevented. Thus, the performance of trapping toner and removing sticking matters of the cleaning brush 11 are improved and the photosensitive body 10 is used for a long period without degrading an image.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cleaning brush for a cleaning device in an electrophotographic apparatus such as a copying machine, a printer, and a facsimile.

(Conventional technology) As is well known in electrophotographic devices such as copying machines.

A cleaning device is required to remove toner and deposits that remain on the electrostatic latent image carrier (hereinafter referred to as photoreceptor) without being transferred to the transfer paper during the transfer process.

The cleaning means of this cleaning device generally uses a blade method in which the photoreceptor is rubbed with a cleaning blade made of an elastic material such as rubber.

A magnetic brush method uses a magnet to rub the photoreceptor with a magnetic brush made by forming magnetic powder into a brush shape.

Also, a fur brush method is mainly used in which the photoreceptor is rubbed with a fur brush formed by pasting straight fibers on the surface of a roller.

Here, the fur brush method has higher cleaning performance at high speeds than the blade method.

It is widely used as a cleaning method for high-speed machines because it has a long life, is cheaper than the magnetic brush method, and is easier to maintain.

In this fur brush method, in order to reuse the photoreceptor over a long period of time, (1) it must have a high ability to remove toner adhering to the photoreceptor;

- Toner that has been removed from the photoreceptor is less likely to be re-adhered to the photoreceptor from the fur brush.

■It has a high ability to remove paper components such as talc, kaolin, and rehydrated calcium, corona products such as NOx, and filming substances of toner components that adhere to the photoreceptor.

Functions such as these are required.

A Kooning brush in this fur brush method is usually made by cutting a brush body 3 formed by weaving straight hair fibers 2 into a base fabric 1 to an appropriate width, as shown in FIG.
It is formed by adhering it in a cylindrical shape to the circumferential surface of a brush roller 4 made of a conductive metal core while ensuring conduction, and then cutting the outer circumferential end of the straight fiber 2 formed into a cylindrical shape by shirring. Ru.

Conventionally, as a Kooning brush in this type of fur brush method, for example, a volume resistivity value of lOs-101 is used.
Using a brush body 3 made of conductive fibers with a thickness of 0Ωl, a thickness of 5 to 15 denier/1 filler, and a density of about 30,000 to 100,000 fibers/1 nch2, in the order of photoreceptor → cleaning brush toner adsorption roller, A cleaning device is known that is configured to remove toner on a photoreceptor by providing a potential gradient (see Japanese Patent Application Laid-Open No. 168190/1988, Ill.).

By the way, in order to increase the toner adsorption ability of the brush body 3 in this conventional cleaning brush, the brush roller 4 should be provided with a polarity opposite to that of the toner so that the toner can be sufficiently adsorbed. It is necessary to apply a high voltage of

However, when such a high voltage is applied to the brush roller 4, the potential difference between the photoconductor and the brush body 3 increases, and the toner is captured by the brush body 3 due to the high voltage of opposite polarity. Since the polarity of the toner is reversed, this brush body 3 acts as if it were a developing brush, making it easy for toner to re-adhere from the brush body 3 to the photoreceptor, causing background smudges on the image. There is a problem with this.

This phenomenon is particularly noticeable in the case of new cleaning brushes, and tends to gradually decrease as the frequency of use increases.

However, since the conventional cleaning brush described above has low cleaning performance in its initial state, it is difficult to use it in high-speed machines unless it is used in combination with a cleaning member using another cleaning method.

In addition, this type of cleaning brush has extremely low ability to remove toner filming due to low-pressure rubbing of toner on the photoconductor and to remove deposits such as one component,
During long-term use of PC photoreceptors, it has been difficult to prevent the image quality from deteriorating.

Therefore, to remove these deposits.

There is a method of removing deposits from the photoreceptor by installing a foam roller that rubs the photoreceptor or a magnetic roller that brings an abrasive into contact with the photoreceptor, but this method does not perform its original function. There is a problem that the desired cleaning effect on toner powder cannot be expected.

Conventionally, as a cleaning brush to solve such problems, as shown in FIG.
A cleaning brush made of loop-shaped fibers 5 has been proposed (publication of Utility Model Publication No. 122371/1983).

In this cleaning brush, the rubbing portion A against the photoreceptor 10 is formed of loop-shaped fibers 5.

The sliding force of this sliding portion A against the photoreceptor 10 and the toner trapping ability are improved, and the ability to remove not only toner powder but also toner filming as described above and adhered substances such as paper components is increased. It is known.

Therefore, this cleaning brush suppresses the occurrence of vertical streaks and vertical band-like density unevenness in halftone images, prevents deterioration of image quality, and makes it possible to reuse the photoreceptor for a long period of time.

In addition, this cleaning brush is configured such that the photoreceptor 10 is
In the case of C photoreceptor, in addition to the above effects, one component,
It becomes possible to prevent image quality deterioration (occurrence of vertical stripes and vertical band-like density unevenness) due to adhesion of toner components.

(Problem to be Solved by the Invention) By the way, as shown in FIG. 7, the cleaning brush made of the loop-shaped fibers 5 described above has a problem in that when the fibers are woven into the base fabric 1 to form a large number of loops, each There are variations in the height and pitch of the loops.

In the rubbing part A of the loop-shaped fiber 5, there are parts where the stiffness of the loop is apparently stronger and parts where it is weaker.

Therefore, the contact state of each loop with respect to the photoreceptor 10 becomes non-uniform, and variations occur in the contact pressure distribution of the rubbing portion A of the loop-shaped fiber 5 to the photoreceptor 10.

In addition, as a method for eliminating such variations in the contact pressure distribution, as in the conventional fur brush made of straight fibers 2, the outer periphery of the loop-shaped fibers 5 wound around the roller-shaped core bar 10 is shirred. Just cut it to make the outer diameter of the cleaning brush uniform.

However, in the case of this cleaning brush, by shirring its outer circumference.

Since the loop of the rubbing portion A is cut off, the fur brush becomes no different from a conventional fur brush made of straight hair-like fibers 2.

Therefore, this conventional cleaning brush has to be used with the loops of the sliding portion A being uneven, so that the contact pressure distribution of the sliding portion A on the photoreceptor 10 as described above is affected. It was not possible to eliminate variations.

Further, although the cleaning brush does not significantly impair the ability to remove toner and deposits due to variations in the contact pressure distribution, it has a negative effect on the image forming function of the photoreceptor 10.

That is, in this conventional cleaning brush, the direction of each loop of the loop-shaped fibers 5 is as shown in FIG.
Loop-shaped fibers 5 are woven into the base fabric 1 along the axial direction of the brush roller 4, that is, perpendicular to the rotational direction of the photoreceptor 10.

Therefore, in the conventional cleaning brush composed of such loop-shaped fibers 5, the deposits on the photoreceptor 10 are removed by scratching with the loop forming the rubbing portion A.

For this reason, for example, when this cleaning brush is used on a selenium-based photoreceptor, the strength of the contact pressure of the rubbing portion A will appear on the image as uneven shading such as white streaks or black streaks. .

Also, when using this cleaning brush for an OPC type photoreceptor, there is not much effect at the initial stage, but the CTL/i? of the 020 layer of this photoreceptor? (Surface layer) becomes non-uniform over time, resulting in uneven sensitivity and potential, and uneven shading appears on the image.

The present invention has been made in view of the above-mentioned points, and its purpose is to be able to reliably remove toner and deposits, and to reduce the contact pressure of the sliding portion of the leaning brush against the photoreceptor as described above. It is an object of the present invention to provide a cleaning brush capable of eliminating adverse effects on a photoreceptor and image quality due to distribution variations.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention includes forming the rubbing portion of the cleaning brush on the photoreceptor with conductive loop-shaped fibers, and forming The loop of the loop-shaped fiber is inclined toward the downstream side in the rotational direction in the circumferential direction.

(Function) According to the present invention, since the loop of the sliding portion of the cleaning brush is inclined toward the downstream side in the rotational direction of the brush roller in the circumferential direction, the sliding portion contacts the photoreceptor. The connection is
Soft and even.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

However, in order to avoid complicating the explanation, illustrations and disclosures thereof will be omitted to avoid complicating the explanation, as well as the configuration and operation within the range that can be clearly recalled from the description of this specification, as well as the above-mentioned and other objects and novel features of the present invention. , or simplify it.

In the cleaning brush according to the present invention, as shown in FIG.
It is formed so as to be inclined toward the downstream side in the circumferential rotation direction a of the brush roller 4.

This cleaning brush is formed as follows.

That is, 1. As shown in FIG. 2, the cleaning brush according to the present invention, as shown in FIG. A brush body 3 formed by weaving shaped fibers 5 is attached to a brush roller 4 made of a conductive core metal.
The original shape is formed by adhering it into a cylindrical shape while ensuring conductivity.

Here, each loop 5a of the loop-shaped fibers 5 is configured such that the number of fibers per bundle is about 12 to 48 filaments.

At this point, the cleaning brush is similar to the conventional cleaning brush, with each loop 5a of the loop-shaped fibers 5
The heights of the sliding portions A are irregularly formed.

The reason for the variation in the height of the rubbing portion A is that each loop 5 when weaving the loop fibers 5 into the base fabric 1
This is largely due to the unevenness of the height of a, and the accuracy of this rubbing portion is about ±0.3.

Therefore, in this embodiment, as shown in FIG. 2, a member (for example, a metal roller, a metal blade, etc.) that presses into contact with the brush body 3 of the cleaning brush whose height of the rubbing portion A remains uneven is used. ), and in this state, rotate this cleaning brush until the protruding part of the rubbing part A is absorbed and its diameter becomes the desired outer diameter, thereby removing each loop of the loop-shaped fiber 5. 5a is the brush roller 4
is inclined toward the downstream side in the circumferential direction of rotation a,
The height of the rubbing portion A was made uniform. A leaning brush is formed as shown in FIG.

Further, in the cleaning brush of this embodiment, each loop 5a of the brush body 3 is formed in a loop along the rotational direction of the brush roller 4, as shown in FIG.

In this way, in order to arrange both legs of each loop 5a of the brush body 3 along the circumferential direction of the brush roller 4, for example, the direction in which the loop-shaped fibers 5 are woven into the base fabric 1 must be adjusted. This is achieved by setting the amount of twist in advance when adhering the brush body 3 to the brush roller 4 (in the case of spiral winding).

As described above, according to this cleaning brush, the rubbing portion A on the photoreceptor is formed of the loop-shaped fibers S, and each loop 5a of the loop-shaped fibers 5 extends in the circumferential direction of the brush roller 4. By being inclined to , the protruding part of the rubbing part A at the initial stage of this loop-shaped fiber 5 is dented,
Since its outer diameter is made uniform, uneven contact of the rubbing portion A with the photoconductor is eliminated, and the occurrence of scratches on the photoconductor (which causes uneven white lines and black lines on the image) is eliminated. ) can be prevented.

Furthermore, as described above, by arranging both legs of the looped fibers 5 in the circumferential direction of the brush roller 4, each loop 5a makes soft contact with the photoreceptor, reducing damage to the photoreceptor. At the same time, the loop 5a does not hold paper powder or the carrier of the two-component developer and damage the photoreceptor, unlike the conventional loop, so that image quality can be improved.

As shown in FIG. 3, the shape of the brush body 3 in the axial direction of this cleaning brush is not much different from the conventional fur brush shown in FIG. 6, but as described above, each loop 5a, Since the brush body 3 is formed along the circumferential direction of the brush roller 4, it is possible to form a brush body 3 that is stronger than the conventional fur brush, and is different from the conventional loop shape shown in FIG. Unlike a brush body made of fibers, sufficient removal performance can be obtained without removing deposits on the photoreceptor by scratching them.

In addition, in this cleaning brush, even when a bias is applied to the brush body 3 to increase the adsorption of toner, there is a phenomenon in which the polarity of the toner is reversed due to the potential difference between the brush body 3 and the toner when they come into contact with each other. Since this is less likely to occur, re-adhesion of toner from the brush body onto the photoconductor, which is conventional, is prevented.

Here, the reason why toner polarity reversal is less likely to occur in this brush body 3 is that in conventional fur brushes, the cut surface of the tip is sharp due to the straight hair-like fibers, which may cause leakage when coming into contact with toner. However, in this example,
Since this brush body 3 is formed of loop-shaped fibers 5, the tip of the warp is smooth, and leakage current is less likely to occur when it comes into contact with toner.

On the other hand, the object of the present invention can also be achieved by a linear leaning brush.

In this cleaning brush, as shown in FIG. 4, the rubbing portion A on the photoreceptor is formed by mixing loop-like fibers 5 and straight hair-like fibers 2.

A feature is that the outer diameter of the straight fibers 2 is larger than the outer diameter of the loop fibers 5.

This cleaning brush first weaves straight fibers 2 and loop fibers 5 into separate base fabrics 1.
Alternatively, each brush body may be alternately wound around the brush roller 4 and bonded.

These straight hair-like fibers 2 and loop-like fibers 5.

- The original shape is formed by weaving it into a sheet of base fabric 1, wrapping it around a brush roller 4, and gluing it.

Next, the outer circumference of only the straight hair fibers 2 is shirred so that the outer diameter thereof is approximately 1 larger than the outer diameter of the loop fibers 5.
It is cut to be about 2cm larger.

In the cleaning brush formed in this way, the rubbing portion of the straight hair fibers 2 contacts the photoreceptor before the rubbing portion of the loop fibers 5, so that the cleaning brush is different from the conventional straight hair fibers. It is possible to obtain higher cleaning performance than a cleaning brush made of a fur brush made only of fibers, and
Unlike conventional cleaning brushes made only of loop-shaped fibers, there is no need to excessively rub and damage the photoreceptor.

Therefore, this cleaning brush can improve its ability to remove toner filming without sacrificing its original cleaning ability, and allows the photoreceptor to be reused over a long period of time without deteriorating image quality. becomes possible.

FIG. 5 shows the basic configuration of a cleaning device using the cleaning brush 11 according to the present invention.

In FIG. 5, the cleaning brush 11 is rotatably disposed within the cleaning device main body 12 so that its sliding portion A bites into the photoreceptor 10 by approximately II.

The cleaning device main body 12 includes a charger 13 and a cleaning brush 11 for applying alternating current and a voltage of the same polarity as the toner for the purpose of controlling the toner powder on the photoreceptor 1o and the polarity and potential of the photoreceptor 10. Flicker bar for knocking toner powder off 14. A toner suction roller 15 consisting of a conductive roller that rotates in the opposite direction to the cleaning brush 11 and sucks and removes toner powder from the cleaning brush 11 using an applied bias voltage. A scraper blade 16 for removing toner powder adhering to the toner suction roller 15, a toner discharging coil 17 for discharging the removed toner powder from the cleaning device main body 12, and the like are arranged at predetermined positions.

Here, the charger 13 does not need to be provided in machines other than high-speed machines because they have a high margin of cleaning ability.

Further, a bias voltage having a polarity opposite to that of the toner is applied to the brush roller 4 of the cleaning brush 11.

Further, the bias voltage applied to the toner adsorption roller 15 is set to be higher than that of the cleaning brush II and have the same polarity.

In FIG. 5, the photoreceptor 10 is equipped with the above-mentioned cleaning device while the toner remaining without being transferred remains attached to the surface of the photoreceptor 10 when development and transfer are performed by a well-known image forming means. moved to the site.

By rotating in the direction of the arrow in FIG. 5, the cleaning brush 11 traps and removes toner powder on the photoreceptor 10 with its rubbing portion A, and also removes the toner powder on the photoreceptor 10.
to remove deposits on the photoreceptor 10.

The toner powder trapped by the cleaning brush 11 is mechanically knocked off by a flicker bar 14 and is electrostatically attracted by a toner adsorption roller 15 .

The toner powder adsorbed by the toner adsorption roller 15 is mechanically scraped off by a scraper blade 16.

Foreign matter such as toner powder and paper powder removed from the cleaning brush 11 in this manner is discharged to the outside of the cleaning device by the toner discharge coil 17.

(Effects of the Invention) According to the present invention, it is possible to eliminate variations in the contact pressure distribution of the rubbing portion of the cleaning brush on the photoconductor.
It is possible to prevent the occurrence of sensitivity unevenness, potential unevenness, etc. of the photoreceptor, and it is also possible to prevent the occurrence of density unevenness on an image. Furthermore, since the toner trapping performance and adhesion removal performance of the cleaning brush are improved, the photoreceptor can be used for a long period of time without deteriorating images.

[Brief Description of the Drawings] Fig. 1 is a schematic sectional view of an embodiment of the present invention, Fig. 2 is a schematic side view showing the manufacturing method of the above embodiment, Fig. 3 is a central longitudinal sectional view of Fig. FIG. 4 is a schematic sectional view of another embodiment of the present invention, FIG. 5 is a schematic sectional view of a cleaning device using a cleaning brush according to the present invention, FIG. 6 is a schematic sectional view of a conventional cleaning brush, and FIG. 1 is a schematic enlarged side sectional view showing how another conventional cleaning brush is arranged on a photoreceptor. DESCRIPTION OF SYMBOLS 1... Base fabric, 2... Straight hair fiber, 3°° brush body, 4... Brush roller, 5... Loop-shaped fiber, 10
...Photoreceptor-11...Cleaning brush. %6 Figure %7 Figure

Claims (1)

[Scope of Claims] 1. A cleaning brush for removing toner and deposits remaining without being transferred on an electrostatic latent image carrier of an electrophotographic device, the cleaning brush having the above-mentioned electrostatic charge. The rubbing portion on the latent image carrier is formed of conductive loop-shaped fibers, and the loops of the loop-shaped fibers are inclined toward the downstream side in the rotational direction of the roller in the circumferential direction. Cleaning brush for electrophotographic equipment. 2. A cleaning brush for removing toner and deposits remaining without being transferred on the electrostatic latent image carrier of an electrophotographic device, which is applied to the electrostatic latent image carrier of this cleaning brush. The rubbing portion is formed by mixing loop fibers and straight fibers, and the outer diameter of the straight fibers is
A cleaning brush for an electrophotographic device, characterized in that the brush has a larger outer diameter than the loop-shaped fiber.