JPS5930576A - Toner recovering device of electrophotographic copying machine or the like - Google Patents

Abstract

PURPOSE:To prevent toner blocking and to stabilize toner recovering by disposing freely movably a spherical body of a specified size in the region formed with the toner discharging port of a rotary valve and the introducing part of an auger for discharging the toner. CONSTITUTION:The tightness of a cyclone filter 1 is maintained by the rotating effect of a rotary valve 2 disposed in the lower part of the cyclone filter 1 and the settled toner is discharged into a lower space A. A steel ball 4 having an outside diameter D satisfying the conditions of the equation 1 are disposed in the space A. The ball 4 is positioned always in the space A without moving to below the revolving shaft 3a of an auger and without being meshed between the auger 3 and the outside cyliner thereof; said ball is vibrated and oscillated by the rotation of the auger 3. Therefore the toner blocking in the space A is prevented and the toner is conveyed and recovered into a toner box by the rotating auger 3. The recovery of the toner is thus stably accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention cleans and collects toner remaining on the surface of a photoreceptor in a machine that uses an electrophotographic process, such as an electrophotographic copying machine or a facsimile machine, without being transferred to recording paper. , concerning the improvement of reusable equipment.

In a copying method using an electrophotographic process, first, in a dark place, a uniform charge is applied to the surface of a photoreceptor, which is a photoconductive insulating film placed on a conductive support. This charge is normally provided by corona discharge. Next, the original image to be reproduced is projected onto the surface of the photoreceptor through a lens system to form an electrostatic latent image. In other words, only the part of the photoconductive insulating film that has been exposed to light becomes conductive, and the charge in the exposed part is lost to the conductive support side, leaving only the charge for one original image disturbance, and the electrostatic charge A latent image is obtained.

Although there are various methods for developing this electrostatic latent image, a cascade development method is generally used. According to this method,
A developer having toner particles attached to the surface of carrier beads by triboelectric charging is used, and this developer is cascaded onto the surface of the photoreceptor. During this time, the electrostatic force of the original image overcomes the bonding force between the carrier and the torch, and the toner adheres to the original image area.

The most widely used method for transferring the thus obtained toner image onto paper is electrostatic transfer using corona discharge. That is, paper is stacked on a photoreceptor having a toner image, the paper is charged with a corona discharger (corotron), and then the paper is peeled off from the photoreceptor, so that the toner on the photoreceptor is transferred to the paper. In addition, the electric field created by the charge on the paper causes the drum to be the toner? Corona discharge must be performed so that it is larger than the electric field that attracts it, and the stronger the electric field on the paper, the higher the transfer rate, but if it is too strong, dielectric breakdown will occur in the paper and the photoreceptor on the drum. Normally, complete transfer is not performed, so cleaning must be performed in preparation for the next copy.

There are various methods for fixing as the final step, but the most common method is to melt the toner by heating.

The copying method using the electrophotographic process has been briefly described above, and the present invention relates to a technique related to the post-transfer cleaning step.

In a typical electrophotographic copying machine, a rotating drum is used as the photoreceptor, and in order to perform repeated copying, it is necessary to clean toner remaining on the photoreceptor drum due to insufficient transfer.

As this cleaning means, there is a method using a brush. In this brush cleaning device, a rotating brush is brought into contact with the surface of a rotating photoreceptor drum, and the toner remaining on the photoreceptor drum is scraped off with the bristles of the brush and pulled out by an air flow.

The drawn toner is collected by a cyclone filter dust collector, and while the cyclone filter is in operation, the collected toner 2 is automatically and continuously carried out and transferred to the toner box of the developing device.
It was not possible to supply it as recycled toner. The reason is that the dust inside the cyclone filter is 100 to 300.
The negative pressure is about mmAq, and if we provide an ejection path 2 to automatically and continuously collect the collected toner from the dust collection section, air will flow into the dust collection section through the circulation section, which will reduce the separation efficiency of the cyclone filter. This is because there is a significant decrease in

In order to solve this problem, a method of taking out the collected toner using a rotary valve has already been proposed (see, for example, Japanese Patent Laid-Open No. 56-93624).

Specifically, as shown in FIG. 1, there are a plurality of blades at the bottom of the cyclone filter 01. The toner collected in the cyclone filter 01 is sequentially taken out by rotating the rotary valve 02, and the toner collected in the cyclone filter 01 is sequentially taken out by an auger O' which is a screw set conveyor.
3, the toner is continuously supplied to the toner box of the developing device.

However, in this case, there is a problem in that the toner causes blocking in the space A, which is the communication path from the rotary valve 02 to the auger 03, resulting in clogging.

The present invention has been achieved in view of the above-mentioned circumstances, and provides a specific size in the area formed by the toner discharge port of the rotary pulp and the introduction portion of the toner conveying auger that communicates with the toner discharge port. The spherical bodies are arranged so that they can move freely.

An object of the present invention is to continuously take out collected toner from an operating cyclone filter without causing toner blocking, and to collect it as recycled toner into a developing device.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 2, a normal layout is shown around the photosensitive drum 10, including a charger, an exposure system, a developer, and a transfer device. , a cleaning device 30 is provided.

The toner image formed on the photoreceptor drum 10 is transferred to paper in a transfer process, but residual toner adheres to the surface of the photoreceptor after the transfer. This residual toner is removed by a cleaning device 30.

On the inlet side of the cleaning device I, an alternating current voltage (AC6KV, DC!-) with negative Iasumi pressure superimposed is applied.
A static eliminating corotron 31 and a static eliminating lamp 32 to which a voltage of 2 KV) is applied are provided. In the cleaning device 30, first and second brush rolls 33 and 34 each having an insulating fiber brush are mounted on the photoreceptor drum 10.
Nip L at a depth of about 1.5 mm
.

It is arranged so that it makes sliding contact. Moreover, both mouths - rule 3
3.34 is rotated at 1200 rpm in opposite directions and in the same direction as the photosensitive drum rotates 100 times.

Furthermore, both rolls 33.34 have first and second flicker bars 35.36.
are in sliding contact with each other, and the first and second flicker bars are respectively connected to DC high voltage power supplies 37 (Do +4KV) and 38 (Do +4KV).
DC-4KV).

Therefore, the residual toner after transfer is removed from the photosensitive drum 100.
It is strongly electrostatically attached to the surface and reaches the cleaning device 30 fifK as the photoreceptor drum rotates. Before entering the rotating section, first, the AC of the static eliminating corotron 31 is
1 photosensitive drum 1 due to the action of the discharge and static elimination lamp 32
00 surface and residual toner are removed, and the photoreceptor drum 1 is also
00 surface and the residual toner are charged to (→. Therefore, the residual toner is extremely unstable as it approaches the photoreceptor 100.
It adheres to the surface, enters the cleaning device 30, and comes into sliding contact with the first brush roll 33.

The first brush roll 33 is charged (→) and is sensitive to electricity.
When the photosensitive drum 1o comes into contact with the toner, approximately 90% of the remaining toner is removed from the surface of the photosensitive drum 1o by electrostatic adsorption and mechanical wiping action.

Then, in an even more unstable state, the residual toner particles remaining about 10% of the remaining toner adhering to the surface of the photosensitive drum 1o come into sliding contact with the second brush roll 34.

Since the second brush roll 34 is charged (→), (
→The charged residual toner is electrostatically repelled and subjected to mechanical wiping action to completely remove and clean the residual toner from the surface of the photoreceptor drum]0.

Further, the toner removed from the surface of the photoreceptor drum 10 by the action of the first and second brush rolls 33 and 34 is
The brush fibers of each brush roll 33, 34 are brushed off by the action of the second flicker bar 35, 360, and the cleaner duct 39, the connecting duct 4 are cleaned by the suction force of the blower.
0 to the cyclone filter 1 along with the air flow.

In the cyclone filter 1, the toner is separated from the air flow and settles downward (see Figures 3 and 4 below). A rotary valve 2 is disposed at the bottom of the cyclone filter 1, and the rotary valve 2 rotates.
The settled toner is carried out to the lower space A without breaking the airtightness of the cyclone filter 1 due to the zero action. The discharged toner is conveyed by the rotating auger 3 and collected as recycled toner into the toner box 21 of the developing device 20.

However, a steel ball 4 having an outer diameter that satisfies the following conditions is disposed in the space A.

"o') D% P) D) R-r (However, Po...Pitch of auger 3, P... Distance between auger rotation axis center and the lowest end of rotary valve 2, R...
・Inner wall radius of auger outer cylinder, r...Auger rotation axis 3
radius of a) Note that instead of the steel ball 40, a spherical body with a smooth surface may be used instead of a perfect sphere, and the material is not limited to steel, but has a higher specific gravity than the toner and has abrasion resistance. Any material may be used as long as it has corrosion resistance and toner resistance.

By setting the outer diameter of the steel ball 4 to satisfy the above conditional expression, the steel ball 4 can be prevented from moving below the auger rotation shaft 3a or being caught between the auger 3 and its outer cylinder. It is always located in the space AVA and vibrates and swings as the auger 3 rotates. As a result, blocking of toner in the space is reliably prevented,
Toner collection is always performed in a stable state.

In addition, as shown in FIGS. 5 and 6, the auger rotation shaft 3
It is even more effective if a plurality of protruding members 5 smaller than the auger outer diameter are provided in a, so that the steel balls 4 are periodically moved by the protrusions mR5 as the auger 3 rotates. The shape of the protruding member may be any shape (for example, a pin shape) that allows the steel ball 4 to move, and it is effective to use an elastic material such as urethane rubber as the material.

As is clear from the above description of the S embodiment, in the present invention,
In a toner recovery device, a spherical ball of a specific size is installed in the area formed by the toner outlet of the rotary knob attached to the lower part of the cyclone filter and the introduction part of the toner conveying auger that communicates with the toner outlet. Since the body is disposed in a freely movable manner, the spherical body vibrates and swings as the auger rotates, thereby effectively preventing toner blocking in the area. Therefore, the collected toner can be constantly taken out in a stable state from the cyclone filter during operation and fed to the developing device as recycled toner.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of main parts of a known toner recovery device, and FIG.
The figure is an explanatory diagram of the main parts of an electrophotographic copying machine equipped with a toner collection device according to an embodiment of the present invention, FIG. 3 is an explanatory text of the main parts of the toner collection device, and FIG. FIG. 5 is a diagram illustrating the main parts of a toner recovery device according to another embodiment, and FIG. 6 is a section diagram taken along the line VI-Vl in FIG. 5. DESCRIPTION OF SYMBOLS 1... Cyclone filter, 2... Rotary valve, 3... Auger, 4... Steel ball, 5... Projection member 110... Photosensitive drum, 20... Developing device, 21...・・Toner box, 30・
... Cleaning device, 31 ... Static elimination corotron, 3
2... Static elimination run *A3. ．． ．． First brush roll, 34
...Second Brosillol, 35...First flicker bar, 36...Second flicker bar, 37.38...
DC high voltage power supply, 39...Cleaner duct, 40...
connection duct. Agent Patent Attorney Nozomi Ehara 1 name Fan 1 Zuko 2 Zuken 5 Kan Fan 6 Procedural amendments February 14, 1981 Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the case Special edition WR No. 1988 141.546 No. 3, the amended person's case. Related: Patent applicant 4 will replace Figures 2 and 4 of the drawings originally filed by his agent with attached drawings. 2nd prisoner 4th ward

Claims (1)

[Claims] A cleaning device that cleans toner remaining on the surface of a photoreceptor in an electrophotographic copying machine, etc.; a cyclone filter that separates the toner from an air flow; In a toner recovery device having a rotary bell for carrying out the toner in the dust section and an auger for carrying the toner discharged from the rotary valve, a toner discharge port of the rotary valve and a toner discharge port of the rotary valve are provided. An electrophotographic copying machine, etc., characterized in that a spherical body capable of coming into contact with the rotating shaft of the toner conveying auger is movably disposed in a region formed by an inlet portion of the toner conveying auger that communicates with the inlet portion of the toner conveying auger. Toner collection device.