JPH0455308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus such as an electrophotographic copying apparatus, and more particularly to a cleaning device for removing untransferred developer remaining on an image carrier.

[Prior art]

An electrophotographic copying apparatus using a photoreceptor as an image carrier is comprised of basic processes of charging, exposure, development, transfer, fixing, and cleaning.
In the charging step, an electrostatic charge is applied to the entire surface of the photoreceptor in a dark place. Corona discharge is generally used for this charging.

In the exposure process, an original image is irradiated onto a charged photoreceptor through a lens and a mirror.

On the surface of the photoreceptor, the potential attenuates depending on the amount of exposure, and an electrostatic latent image is formed.

In the developing process, colored toner having a charge of opposite polarity to the surface of the photoreceptor is adsorbed to the surface of the photoreceptor.
Visualize the latent image.

The developed image on the photoreceptor is transferred onto paper by a corona discharge transfer method or the like in a transfer step.

After the transfer, untransferred toner remaining on the surface of the photoreceptor is cleaned by a cleaning device.

As a conventional cleaning device, there is one shown in FIG. This cleaning device removes the residual toner on the photoreceptor 41 by rotating a fur brush 42 and rubbing it against the photoreceptor 41, and then transfers it electrostatically using a collection roll 43. It has a structure in which it is physically scraped off by a blade 44, which is a post-scraping member, and collected into the case.

FIG. 2 shows another conventional device. This cleaning device is a conductive fur brush 42a.
By applying a voltage of opposite polarity to the toner to the conductive fur brush 42a and rubbing it against the surface of the photoreceptor 41,
The toner is electrostatically and physically transferred to the conductive fur brush 42a, and the toner is further transferred to the conductive fur brush 42a.
The toner is transferred to a collection roll 43 to which a voltage higher than the bias voltage applied to a is applied, and finally the toner is scraped off from the collection roll 43 with a blade 44.

[Problems with conventional technology]

These conventional devices are superior in cost performance compared to devices that use air suction to remove toner scraped off with a fur brush, which has been known for a long time.
Although it has advantages such as miniaturization and low noise, it has the following disadvantages.

As shown in FIGS. 1 and 2, since no measures have been taken to prevent backflow of the toner scraped off from the collection roll 43 by the blade 44 and accumulated in the case, the toner once captured is For some reason, the cleaning performance was reduced due to backflow.

Furthermore, if the cleaning device is removed from the copier main body, tilted slightly, or subjected to slight vibration, the toner accumulated in the case will flow back and contaminate the fur brush and collection roll, and even cause the case to open. This caused contamination of the interior and exterior of the aircraft.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned drawbacks of the conventional technology, and the developer that has been cleaned may flow back from the storage section and re-adhere to the working section that directly performs cleaning, such as the fur brush, or overflow from the opening. It is an object of the present invention to provide a cleaning device in which a storage part is divided and shielded from a working component to prevent such damage.

[Key points of the invention]

In order to achieve the above object, the present invention provides a cleaning means for cleaning untransferred toner on an image bearing pair, a collection roll for collecting the toner cleaned by the cleaning means, and a collection roll that comes into contact with the collection roll to collect the toner. In a cleaning device that integrally includes a scraping means for scraping off toner from the roll and a storage section for storing the toner scraped off by the scraping means, the cleaning device abuts in a trailing direction with respect to a rotating direction of the collection roll. A sealing member is provided, and the collecting roll, the scraping means, and the sealing member shield the storage portion from the action portion where the cleaning means is placed, so that the toner in the storage portion is not transferred to the action portion during the cleaning action. It is characterized by preventing backflow.

[Embodiments of the invention]

Embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 3 is a sectional view of a main part of an image forming section of an electrophotographic copying apparatus to which the present invention is applied.

The electrophotographic copying apparatus includes a photoreceptor 1, a developing device 2, a transfer section 3, a cleaning device 4, a static eliminator 5, and a charger 6.

The photoreceptor 1 is formed by forming a photoconductor layer of a photoconductive material such as Se, CdS, ZhO, or an organic semiconductor to an appropriate thickness on a metal substrate such as Al.
It is rotatably supported by the main body of the copying machine (not shown).

The developing device 2 includes a toner hopper 7 and a developing hopper 8, and the developing hopper 8 and the toner hopper 7 communicate with each other via a supply roll 9. Toner 10 is stored in the toner hopper 7, and a detection unit (not shown) detects a decrease in the amount of toner in the development hopper 8.
Toner is replenished into the developing hopper 8 by detecting this and rotating the replenishing roll 9 appropriately.
Further, within the developing hopper 8, a stirring roll 11 and a developing roll 12 are rotatably provided. In the developing hopper 8, the developer 13 is stirred by the stirring roll 11, and the developer 13 is attracted by the developing roll 12 which is magnetized with a plurality of poles, and is conveyed in the direction of the arrow. At this time, the amount of developer adsorbed onto the developing roll 12 is regulated to be constant by the regulating plate.

On the other hand, the electrostatic latent image formed on the surface of the photoconductor 1 in the exposure section 14 is transferred to the developing roll 1 near the developing device 2.
The toner 10 in the developer 13 on the surface of the developer 2 is adsorbed to form a toner image. At this time, a bias having the same polarity as that of the latent image is applied from the power supply 16 to the conductive sleeve on the outer periphery of the developing roll 12 to prevent toner from adhering to the low potential part of the latent image corresponding to the background part of the document. There is.

The toner image on the surface of the photoconductor 1 enters the transfer section 3 as the photoconductor 1 rotates in the direction of the arrow, and the paper 15 is sent out from a paper feeder (not shown) after synchronizing the position with the toner image. It will be done.

In the transfer section 3, a corona discharge having the same polarity as the latent image is applied to the toner image from the back side of the paper 15, and the toner image is transferred onto the paper 15. The paper 15 on which the toner image has been transferred is separated from the photoreceptor 1 by a separation section 17, fixed by a fixing section (not shown), and then discharged outside the machine.

On the other hand, the photoreceptor 1 from which the paper 15 has been separated from its surface by the separating section 17 enters the cleaning device 4 while retaining untransferred residual toner.

The cleaning device 4 includes a substrate 19 disposed within a casing 18, a conductive fur brush 23, a recovery roll 20, a blade 12, and a seal member 22.

The substrate 19 is rotatably supported by the casing 18 via a bearing, and is made of an aluminum pipe or a paper tube whose surface is conductively treated.
Conductive fur brushes 23 are implanted on the surface of the substrate 19. Further, the tip of the conductive fur brush 23 has a constant nip width and is in contact with the surface of the photoreceptor 1. The conductive fur brush 23 is made by mixing carbon into a resin (acrylic, nylon, etc.) fibrous material to have a volume resistance of 10 ⁵ Ω·cm or less. Furthermore, a bias having the same polarity as the electrostatic latent image is applied to the conductive fur brush 23 by a power source 24, and the bias reaches the surface of the image carrier through the conductive fur brush 23.

The collection roll 20 is made of metal or a conductive material, and as shown in FIG. There is. The collar 27 is a member for preventing toner from entering the supporting portion of the bearing portion 18b and hindering the rotation of the flange 26, and is generally made of felt, sponge rubber, or the like. A flange 28 is provided at the other end of the recovery roll 20, and the flange 28 is coupled to the recovery roll 20 by concave-convex fitting, press-fitting, adhesion, or the like so that rotational force can be transmitted. Further, a drive gear 29 is provided on the inner diameter portion of the flange 28 and is coupled to the inner diameter portion of the flange 28 by fitting the concave and convex portions so that rotational force can be transmitted.
A shaft portion thereof is rotatably supported by a bearing portion 18a of the casing 18. Note that the collar 30 is a member that exhibits the same effect as the collar 27 described above.

The blade 21, which is a scraping member, is in contact with the collection roll 20 assembly configured as described above over substantially the entire inner width of the casing 18. As described above, the blade 21 is for scraping off the toner on the surface of the collection roll 20, but by providing it over the entire inner width of the casing 18, the blade 21 can be used to clean the inside of the casing 18 from the conductive fur brush 23 and the collection roll. It is separated into an action section B where the toner 20 is present and a toner storage section A.

On the other hand, a sealing member 22 is positioned upstream of the blade 21 in the rotational direction of the collection roll 20 by a rib 31, and is curved approximately parallel to the axial direction of the collection roll 20 and along the rotational direction of the collection roll 20. It can be installed like this.

The sealing member 22 is usually made of polyethylene terephthalate (PET) with a thickness of 50 to 200 μm, and is provided over the entire inner width of the casing 18 like the blade 21.

To explain the operation of the cleaning device 4 configured as described above, the photoreceptor 1 holding uncopied residual toner on the surface is moved by the conductive fur brush 2.
3, the untransferred residual toner on the photoreceptor 1 is
Due to the electrical effect and the physical rubbing effect by the conductive fur brush 23, the photoreceptor 1 is moved toward the conductive fur brush 23, and the surface of the photoreceptor 1 is cleaned.

The collection roll 20 rotates in the direction of the arrow, and since a voltage of the same polarity as the power supply 24 and higher than that of the power supply 24 is applied to the collection roll 20 through the power supply 25, the conductive fur brush 20 is rotated at the contact surface with the conductive fur brush 23. The toner adhering to the toner 23 moves to the surface of the collection roll 20 due to the voltage difference, is further scraped off by the blade 21 provided in pressure contact with the collection roll 20, falls, and is accumulated inside the casing 18.

At this time, since the toner that has moved from the conductive fur brush 23 to the collection roll 20 comes into contact with the surface of the sealing member 22 in the so-called trailing direction, there is almost no scraping effect and the toner easily passes through to the next one. It is scraped off by the blade 21.

The photoreceptor 1, from which the residual toner has been removed by the cleaning device 4, further rotates in the direction of the arrow and enters the static eliminator 5, where the residual charge is removed, and is charged again by the charger 6, repeating the same cycle.

(Effects of the Invention) According to the cleaning device of the present invention, it is almost impossible for the developer once stored in the reservoir to flow back, and the working part that directly removes the developer is not exposed to unnecessary contamination for a long period of time. A stable cleaning effect can be obtained over a period of time. Also,
There is no possibility that the developer once collected will flow back onto the surface of the image carrier.

Furthermore, when the cleaning device is removed from the copier main body, it is possible to prevent the developer from overflowing even if it is tilted or shaken, making maintenance work easier and minimizing contamination of the surrounding area. be able to.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional cleaning device, FIG. 2 is a sectional view of another embodiment of the conventional cleaning device, FIG. 3 is a sectional view showing an embodiment of the present invention, and FIG. 4 is a sectional view of the present invention. FIG. 5 is an enlarged sectional view of a main part of an embodiment of the invention, and FIG. 5 is a sectional view of a main part of the present invention. 1, 41...image carrier, 2...developing device, 3...
...Transfer section, 4...Cleaning device, 5...Static neutralization section, 6...Charger, 7...Toner hopper, 8...
Developing hopper, 9... Supply roll, 10... Toner, 11... Stirring roll, 12... Developing roll,
13...Developer, 14...Exposure section, 15...Paper, 16...Power source, 17...Separation section, 18...Casing, 19...Substrate, 20...Recovery roll,
21, 44...Blade, 22...Seal member,
23... Conductive fur brush, 24, 25... Power supply, 26... Flange, 27... Color, 28...
...Flange, 29 ... Drive gear, 30 ... Collar, 31 ... Rib, 42 ... Fur brush, 43
...Collection roll, 42a... Conductive fur brush.

Claims (1)

[Scope of Claims] 1. A cleaning means for cleaning untransferred toner on an image carrier, a collection roll for collecting the toner cleaned by the cleaning means, and a collection roll for scraping the toner from the collection roll by coming into contact with the collection roll. A cleaning device that integrally includes a scraping means and a storage section for storing toner scraped off by the scraping means, further comprising: a sealing member that abuts in a trailing direction with respect to a rotating direction of the collection roll; The storage portion is shielded from the action portion where the cleaning means is placed by the collection roll, the scraping means, and the seal member to prevent the toner in the storage portion from flowing back into the action portion during the cleaning action. A cleaning device characterized by: