JPH0281077A - Brush cleaning device - Google Patents

Abstract

PURPOSE: To improve the performance and durability and to make the circumferential speed of a photoreceptor higher by successively collisionally bringing the conductive fiber of a brush roller into contact with a flicker plate and brushing off toner which is not recovered by a recovery roller. CONSTITUTION: The toner remaining on the photoreceptor drum 1 is swept by the conductive fiber 20b by the rotation of the brush roller 20 and stuck to the surface of the fiber 20b by bias impressed on the roller 20. Then, it is electrostatically shifted to the recovery roller 21 side by the bias impressed on the roller 21 and scraped by a scraper 22. The toner dropped on the bottom part of a housing 23 is recovered toward an auger roller 24 by a toner recovery blade member 26. The flicker plate 25 is attached to the member 26 and rocked as the member 26 is turned. Thus, the fiber 20b collides with the flicker plate 25 and efficiently performs brushing-off action. Therefore, the cleaning performance is improved, and the device is applied even to a high-speed machine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a brush cleaning device, and particularly to a brush cleaning device that can be applied to high-speed machines and has further improved cleaning performance and durability.

(Prior Art) In image forming apparatuses such as copying machines and printers, an electrostatic latent image is formed on an image forming member such as a photosensitive drum or a photosensitive belt, and this electrostatic latent image is developed. It is configured to form a toner and transfer this toner image onto recording paper to form a hard copy. On the other hand, in the transfer process, all the toner particles constituting the toner image are not transferred to the recording paper side and the toner particles remain on the photoreceptor, so a cleaning device is required to remove the residual toner.

A brush cleaning device is known as a cleaning device for removing this residual toner.
It is described in No. 100460. In this known brush cleaning device, a conductive brush roller having a large number of conductive fibers planted on the outer periphery is placed in contact with and facing a photosensitive drum, and a bias is applied between the photosensitive drum and the brush roller. , is configured to remove toner particles remaining on the photosensitive drum using mechanical cleaning force and electrical suction force. Furthermore, a metal collection roller is placed in contact with the brush roller, and a higher bias is applied between the brush roller and the collection roller to remove the toner adhering to the brush roller using electrostatic attraction. The toner is moved to the collection roller side, and the toner adhering to the collection roller is scraped off by a scraper.

(Problems to be Solved by the Invention) In the above-mentioned known brush cleaning device, the toner adhering to the brush roller is removed from the collection roller using electrostatic attraction from a bias source disposed between the brush roller and the collection roller. However, the electrostatic attraction cannot be applied sufficiently, and as a result, the amount of toner remaining on the conductive fibers of the brush roller gradually increases, resulting in a problem that the cleaning performance deteriorates. In particular, for example A- per minute
In high-speed machines with a copying capacity of 40 sheets or more in 4 sizes, the circumferential speed of the photoreceptor is high and the amount of toner that must be removed by the brush roller per unit time is even greater, so it is necessary to shift from the brush roller to the collection roller. We need to do this even more quickly. However, if a conventional brush cleaning device is applied to a high-speed machine as is, the transition from the brush roller to the collection roller does not occur in response to the increase in circumferential speed, and the amount of toner remaining on the brush roller gradually increases. As a result, cleaning performance gradually deteriorates. In this case, increasing the bias between the brush roller and collection roller increases the electrostatic attraction and increases the ability to transfer to the collection roller, but this requires connecting a high bias source and may cause dielectric breakdown or discharge. There is a risk that this may occur.

Furthermore, since the brush roller is in contact with the photosensitive drum and collection roller, if it is used for a long period of time, the fibers planted around the outer periphery of the brush roller may bend or become flat, resulting in uneven fiber orientation. There were also some problems.

Therefore, an object of the present invention is to provide a brush cleaning method that eliminates the above-mentioned drawbacks and maintains good cleaning performance and durability even when the circumferential speed of the photoreceptor increases and the amount of residual toner to be removed per unit time increases. It provides equipment.

(Means and Effects for Solving the Problems) A brush cleaning device according to the present invention includes a brush roller which is disposed in contact with an image forming member facing the image forming member and has conductive fibers implanted on the outer peripheral surface thereof, and a brush roller which is disposed opposite to the image forming member and has conductive fibers implanted on the outer peripheral surface. a conductive collection roller arranged in contact with the brush roller; a drive device for rotating the brush roller and the collection roller; and a scraper that comes into contact with the collection roller and scrapes off toner adhering to the outer peripheral surface of the collection roller. , a first bias source connected to the brush roller and applying a bias having a polarity opposite to the charged polarity of the toner to the brush roller; and a first bias source connected to the collection roller and having the same polarity as the first bias source. a second bias source that applies a larger bias to the collecting roller than the bias source; and a flicker plate that comes into contact with the conductive fibers of the brush roller and removes toner adhering to the conductive fibers, The present invention is characterized in that the conductive fibers are successively brought into contact with the flicker plate by the rotation of the brush roller, and the toner adhering to the conductive fibers is successively removed.

In high-speed printers and copying machines in which photosensitive drums rotate at high speeds, the amount of toner that must be removed from the photosensitive drums per unit time by brush rollers is even greater. Therefore, the toner adhering to the brush roller cannot be sufficiently transferred to the collection roller side only by the electrostatic attraction force due to the bias applied to the collection roller, resulting in poor cleaning. For this reason, in the present invention, a flicker plate is provided so that the conductive fibers of the brush roller successively collide with the flicker plate, and the toner not collected by the collection roller is successively removed. As a result, even if the amount of toner to be removed increases, the toner adhering to the brush roller can be sufficiently removed, and good cleaning performance can be maintained over a long period of time. However, if you simply hit the flicker plate against the brush roller, the toner removal effect from the brush roller will be too low. Also, if only the collection roller is attached to the brush roller, the toner will not be removed even if you try to remove it. The amount is too small to be applied to high-speed machines. That is, a brush cleaning device for high-speed machines can only be realized by combining the toner removal effect due to the electrostatic attraction of the collection roller and the mechanical toner removal effect of the flicker plate.

(Embodiment) FIG. 1 is a diagram showing the configuration of an example of a high-speed printer device equipped with a brush cleaning device according to the present invention. In this example, a photosensitive drum 1 having a photosensitive layer formed on the outer circumferential surface of a Heath drum 82 is used as an image forming member. After the outer peripheral surface of the photosensitive drum 1 is uniformly positively charged over its entire surface by the corona charger 2, an electrostatic latent image is formed by irradiating auxiliary illumination light from an auxiliary light source 3 and illumination light from a print head 4. do. The auxiliary light source 3 uniformly illuminates the entire surface of the photosensitive drum 1. Further, the print head 4 is composed of, for example, an LED array in which a large number of light emitting elements are arranged linearly across the image recording width. The LED array 4 performs a light emitting operation based on an image signal supplied from the image generating device, and irradiates the photosensitive drum 1 with a minute spot of emitted light focused by the SELFOC lens. The electrostatic latent image formed by the illumination light from the auxiliary light source 3 and the LED array 4 is developed by the developing device 5 to form a toner image.

On the other hand, the paper feed cassette 6a or 6 is synchronized with the photosensitive drum 1.
The recording paper 7 is fed from b. The recording paper 7 is taken out one by one from a paper feed cut by a paper feed roller, is transported by a transport roller, and is passed through a pair of registration rollers 8a and 8b.
After the same 31JI11 feeding timing for the photosensitive drum 1 is established, the photosensitive drum 1 is conveyed to the transfer position. In this example, a belt transfer method is used as the transfer means. This belt transfer method uses a transfer belt charged to a polarity opposite to that of the toner, electrostatically attracts the recording paper to the transfer belt, and conveys and transfers the recording paper while running the transfer belt. For this reason, the transfer belt 9 is placed opposite the photosensitive drum 1. The transfer belt 9 has an insulating dielectric layer formed on a conductive plastic sheet, and is stretched around four rollers 10a, 10b, 10c, and 10d so that it can run freely. This transfer belt 9 runs at the same speed in the same direction as the traveling direction of the photosensitive drum 1, and is charged by a corona charger 11 to a polarity opposite to that of the toner. On the other hand, the recording paper 7 conveyed in synchronization with the photosensitive drum 1 passes through a pair of rollers 10b and 10e, contacts the transfer belt 9, is electrostatically attracted to the transfer belt, and is conveyed along the transfer belt to the transfer position. Ru. At the transfer position, a transfer roller 11 made of a conductive elastic rubber roller is arranged on the back side of the transfer belt, and the elastic force of this transfer roller is used to lightly transfer the transfer belt 9 and recording paper 7 onto the surface of the photosensitive drum 1. Apply pressure. When the recording paper 7 comes into contact with the surface of the photosensitive drum, toner particles on the surface of the photosensitive drum are transferred to the recording paper side by an electric field created by the charges on the surface of the transfer belt. After the transfer, the recording paper 7 is conveyed while being electrostatically attracted to the surface of the transfer heald.
It is separated at the position of the roller 10c and enters the fixing device 12,
The toner on the recording paper is fixed. After fixing, the recording paper 7 is moved by conveyance rollers 13a, 13b and paper ejection rollers 14a, 1.
4b, and is discharged face down to the discharge stacker 15. On the other hand, the transfer belt 9 is reused after passing through a brush cleaning device 16 for cleaning the transfer belt. Further, after the photosensitive drum 1 has undergone the transfer process, the entire surface is uniformly neutralized by the static elimination lamp 17 and the potential is attenuated to a residual potential, and then the remaining toner particles are removed by the brush cleaning device 18 and the entire surface is uniformly charged again to form an electrostatic latent image. Ru.

・Figures 2a and 2b show the configuration of an example of the brush cleaning device according to the present invention, and Figure 2a is a schematic sectional view showing the overall configuration, and Figure 2 is a circuit diagram showing a bias source. It is. The brush cleaning device is a brush roller 20
The brush roller is arranged opposite to and in contact with the photosensitive drum 1. The brush roller 20 is constructed by planting a large number of conductive fibers 20b on the outer peripheral surface of a conductive roller member 20a.

As the conductive fibers 20b, conductive fibers made of rayon material or acrylic material impregnated with carbon, or fibers whose surfaces are coated with a conductive coating can be used. The length of the conductive fibers 20b is about 1.5 to 5M, and the brush roller is brought into contact with the photosensitive drum 1 so that the residual toner on the photosensitive drum 1 is scraped off by the conductive fibers. In addition, the roller member 2
Both ends of Oa are rotatably supported via insulating bearings (not shown), and a bias source V is connected via a flange.

This bias source V has a polarity opposite to the charged polarity of the toner,
The bias voltage V is set to about 200 to 400 cm higher than the residual potential of the photosensitive drum after photostatic discharge. Further, the brush roller 20 is connected to a drive device (not shown) and rotated in a direction opposite to the rotational direction of the photosensitive drum 1, and its circumferential speed V is set to ν,<v2 with respect to the circumferential speed v2 of the photosensitive drum 1.
Set it so that A collection roller 21 made of metal is placed in contact with and opposite to this brush roller 20. This recovery roller 21 is rotatably supported via an insulating bearing and is connected to a bias source VC via a flange. This bias source VC is a bias source V for the brush roller,
The polarity is set to be the same as that of , and ν is set to be larger, approximately 500 to 800 ■. Further, the collection roller 21 rotates in the same direction as the brush roller 20, and its circumferential speed ν. is set so that VC>ν. A scraper 22 made of urethane rubber or thin metal is brought into contact with this collecting roller 21 to scrape off the toner adhering to the outer peripheral surface of the collecting roller.The toner remaining on the photoreceptor 1 is made conductive by rotation of the brush roller 20. It is swept away by fiber 20b. The swept toner adheres to the surface of the conductive fiber 20b due to the bias applied to the brush roller. The toner adhering to the conductive fibers 20b is transported to a position facing the collection roller 21, and is electrostatically moved toward the collection roller 21 by the bias applied to the collection roller 21. Then, the cleaning device 16 is scraped off by the scraper 22 and removed by the auger roller 24 provided at the bottom of the housing 23.
It will be transferred to the side and collected. On the other hand, as described above, in high-speed printers and copying machines in which the photosensitive drum 1 rotates at high speed, a large amount of toner is swept away by the brush roller 20 per unit time, so the toner adhering to the brush roller is The toner is not sufficiently transferred to the collection roller 21 side, and the amount of toner remaining on the brush roller increases.

For this reason, in the present invention, a flicker plate 25 is provided, and the toner remaining on the brush roller 20 is brushed off by this flicker plate. That is, as the brush roller rotates, the conductive fibers 20b on its outer periphery collide with the flicker plate 25 one after another, and the toner adhering to the fiber surface is removed from the fiber surface by the impact force caused by the collision. .

As a result, the photosensitive drum 1 is constantly cleaned by the brush roller to which no excess toner is attached, and the cleaning performance is further improved. Further, in this example, a flicker plate 25 is attached to the toner collection wing member 26. This toner collection wing member 26 rotates in the direction of the arrow and functions to collect the toner that has fallen to the bottom of the housing 23 in the direction of the auger roller 24 . By attaching the flicker plate 25 to the toner collection wing member 26,
The rotation of the toner collection spring member causes the tip of the flicker plate to swing in the radial direction of the brush roller, and as a result, the conductive fibers 2
The entire area from the tip to the base of the conductive fiber 20b collides with the flicker plate 25, making it possible to more efficiently remove the flicker plate and effectively remove toner adhering to the tip and base portions of the conductive fibers 20b. It can be dropped.

Further, in this example, since the brush roller 20 is rotated in the opposite direction to the rotation direction of the photosensitive drum, residual toner on the photosensitive drum can be effectively removed even if the brush roller is rotated at a low speed.

Furthermore, since the collecting roller 21 is rotated in the same direction as the rotating direction of the brush roller, and the relationship between their circumferential velocities is set to be v) < vc, the sliding contact with the photosensitive drum and the flicker plate Even if the conductive fibers fall to the rear in the direction of rotation, the collection roller will cause them to fall to the front. As a result, the brush roller's sliding contact with the collection roller can correct the conductive fibers' hair fall, thereby extending the life of the brush roller. can be further extended.

The present invention is not limited to the embodiments described above, and various changes and modifications are possible. For example, although the above-described embodiment has been described using a printer as an example, it is of course applicable to a copying machine as well.

Furthermore, although the description has been made using a photosensitive drum as an example of the image forming member, the present invention can also be applied to a belt-shaped photosensitive member.

Further, as the collection roller, not only a metal roller but also a collection roller having an electrically conductive roller coated with an insulating layer on the outer periphery can also be used.

Further, in the above-described embodiment, only one flicker plate is arranged, but a plurality of flicker plates can be arranged in parallel to form a multi-stage structure.

If the flicker plates are arranged in multiple stages, the amount of toner removed by the brush roller can be further increased.

(Effects of the Invention) As explained above, according to the present invention, a collection roller is provided to remove toner adhering to the brush roller, and a flicker plate is further arranged to cause the conductive fibers to collide with the flicker plate. Since the toner not removed by the recovery roller is removed by collision with the flicker plate, the cleaning performance is further improved and it can be sufficiently applied to high-speed machines in which the photosensitive drum rotates at high speed. In particular, since the flicker plate can be constructed by simply attaching a metal or resin plate, the cleaning performance can be improved with a simple structure.

Furthermore, since the direction of rotation of the brush roller is opposite to the direction of rotation of the photosensitive drum, and the collection roller is rotated in the same direction as the brush roller and set at a higher speed than the circumferential speed of the brush roller, the photosensitive drum and flicker plate The falling of the bristles due to sliding contact with the collection roller can be corrected by sliding contact with the collecting roller, and as a result, the falling of the brush roller's bristles can be effectively prevented and the life of the brush roller can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an example of a printer device including a plastic cleaning device according to the present invention, and FIGS. 2A and 2B are diagrams showing the configuration of an example of the brush cleaning device according to the present invention.

Claims (1)

[Claims] 1. A brush roller that is placed in contact with and facing the image forming member and has conductive fibers planted on its outer peripheral surface, and a conductive roller that is placed in contact with and faces the brush roller. a collection roller, a drive device for rotationally driving the brush roller and the collection roller, a scraper that comes into contact with the collection roller and scrapes off toner adhering to the outer peripheral surface of the collection roller;
a first bias source connected to the brush roller and applying a bias to the brush roller having a polarity opposite to the charging polarity of the toner; and a first bias source connected to the collection roller and having the same polarity as the first bias source. The brush includes a second bias source that applies a larger bias to the collecting roller than the bias source, and a flicker plate that contacts the conductive fibers of the brush roller and removes toner adhering to the conductive fibers. A brush cleaning device characterized in that the conductive fibers are sequentially brought into contact with the flicker plate by rotation of a roller, and the toner adhering to the conductive fibers is sequentially removed. 2. The brush cleaning device according to claim 1, wherein the flicker plate is oscillated. 3. The direction of rotation of the brush roller is opposite to the direction of rotation of the image forming member, the direction of rotation of the collection roller is the same as the direction of rotation of the brush roller, and the circumferential speed v_b of the brush roller is set to be the same as the direction of rotation of the collection roller. The brush cleaning device according to claim 1 or 2, characterized in that the peripheral speed v_c is set so that v_b<v_c.