JPH1010947A - Toner recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover only the toner suitable for reuse out of toner eliminated from an image carrier by a cleaning device, to a developing device. SOLUTION: This device has a toner conveying path 18 where toner is conveyed from a cleaning device 17, an air flow blasting means 21 for blasting air flow to the toner conveyed in the toner conveying path 18, a plurality of classifying parts 22a, 22b into which the toner classified according to weight by air flow blasting enters, a recovered toner conveying path 23 for connecting the classifying part 22a to a developing device 15, and a waste toner conveying path 25 for connecting the other classifying part 22b to a waste tank 26. Out of the toner classified by air flow blasting from the air flow blasting means 21, only the toner entering the classifying part 22a and suitable for reuse is recovered to the developing device 15 and reused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly, to a toner collecting apparatus for collecting toner remaining on an image carrier such as a photoreceptor into a developing device for reuse.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, a toner image is formed by attaching toner to an electrostatic latent image formed on a photoreceptor, and the toner image is transferred to recording paper to form an image. It is carried out.

When a toner image is transferred onto a recording sheet, a part of the toner remains on the photosensitive member. Therefore, the remaining toner is removed by a cleaning device. There are an image forming apparatus having a structure in which the toner removed by the cleaning device is discarded as it is, and an image forming apparatus having a toner collecting device for collecting the toner in the developing device for reuse. An image forming apparatus provided with a toner collecting device is disclosed in
JP-A-08828 and JP-A-6-337589 are known.

As shown in FIG. 6, an image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 6-308828 discloses a charger 2, a developing device 3, a transfer device 4, and a cleaning device 5 around a photoreceptor 1.
And the like, and a toner transport path 6 is connected between the cleaning device 5 and the developing device 3. The toner removed by the cleaning device 5 includes light toners such as paper dust, paper chips, and fine toners, and heavy toners in which the toner aggregates to have a large diameter and the weight increases. A foreign matter collecting member 7 having a vibrating mesh structure for removing foreign matters such as toner and heavy toner is provided in the middle of the toner collecting path.

As shown in FIG. 7, an image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 6-337589 has a charger 2, a developing device 8, a transfer device 4, and a cleaning device 9 around a photoreceptor 1.
And the like, and a toner transport path 10 is connected between the cleaning device 9 and the developing device 8. The toner removed by the cleaning device 9 includes a heavy toner that has agglomerated to have a large diameter, and a mesh 11 and a mesh 11 are provided as a mechanism for grinding and refining the heavy toner. A recovery toner supply roller 12 that rotates in contact with the recovery toner supply roller 12 is provided at a recovery toner inlet of the developing device 8.

[0006]

Problems to be Solved by the Invention
In the toner collecting device disclosed in Japanese Patent Application Laid-Open No. 9-209, the mesh-like foreign matter collecting member 7 is vibrated to entangle foreign matter to form a large mass, and foreign matter smaller than the mesh of the mesh is also removed. However, the foreign matter smaller than the mesh of the mesh cannot be sufficiently removed, and the small foreign matter mixed in the toner collected in the developing device 3 deteriorates the quality of the image transferred to the recording paper.

The toner collecting device disclosed in Japanese Patent Application Laid-Open No. 6-337589 is intended to grind and agglomerate a toner having a large diameter due to agglomeration. No consideration is given to avoiding the mixing of

Accordingly, the present invention provides a toner collecting device which classifies toner removed by a cleaning device by weight, collects only toner suitable for reuse to a developing device, and removes light toner and heavy toner. The purpose is to:

[0009]

According to the first aspect of the present invention,
In a toner recovery device for recovering toner on an image carrier removed by a cleaning device to a developing device, a toner transport path through which toner is transported from the cleaning device, and a toner transport unit that transports toner in the toner transport path. Air flow blowing means for blowing an air flow against the toner conveyed through the toner conveyance path; a plurality of classifiers into which the toner classified according to the weight by blowing the air flow enters; and at least one of the classifiers And a waste toner transport path connecting the other classification unit and the waste tank. Therefore, when an air flow is blown by the air flow blowing means on the toner conveyed in the toner conveyance path,
This toner enters each classification part classified by its weight. By connecting the classifying section into which the toner of a weight suitable for reuse among the classified toner enters the developing device and the developing device via the collected toner transport path, and connecting the other classifying section and the waste tank via the waste toner transport path, Only the toner having a weight suitable for reuse can be collected in the developing device, and the quality of an image formed by the collected toner is improved.

According to a second aspect of the present invention, in the first aspect of the present invention, a classifying section in which a heavy toner out of an allowable range among the classified toners enters and a waste toner conveying path is connected, and a classified toner. At least three classifying units: a classifying unit in which light-weight toner lighter than the allowable range enters and a waste toner conveying path is connected; and a classifying unit in which toner having an intermediate weight enters and a collected toner conveying path is connected. Having. Therefore, the heavy toner that is heavier than the allowable range and the light toner that is lighter than the allowable range can be reliably removed from the toner collected in the developing device, and the quality of the image formed by the collected toner is greatly improved.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the portion from the air flow blowing portion to the classifying portion by the air flow blowing means is formed in a spiral shape. Therefore, the structure of the portion for classifying the toner becomes compact, and the toner collecting device becomes compact.

According to a fourth aspect of the present invention, in the first or second aspect, a rectifying mechanism for rectifying an air flow from the air flow blowing means is provided. Therefore, the flow of the airflow blown to the toner by the airflow blowing means is rectified and becomes substantially uniform, and the classification performance of the toner by blowing the airflow is improved.

According to a fifth aspect of the present invention, in the first or second aspect of the invention, a vibration transport mechanism for transporting the toner in the toner transport path by vibration is provided. Therefore, since the toner conveyed by the vibration has a low advancing power, the classification performance when the air flow is blown and classified by the air flow blowing means is improved.

[0014]

FIG. 1 shows a first embodiment of the present invention.
It will be described based on. A charger 14, a developing device 15, a transfer device 16, a cleaning device 17, and the like are arranged around the photoconductor 13 as an image carrier. The cleaning device 17 has a cleaning blade, and removes toner remaining on the photoconductor 13 after the transfer operation is completed.

One end of a toner transport path 18 is connected to the lower end of the cleaning device 17, and the toner transport path 1
At the other end of 8, there is formed an expanding portion 19 located below the other end and expanding. In the toner transport path 18, the cleaning device 1 is rotated and driven.
A toner transport coil 20 is provided as toner transport means for transporting the toner inside 7 toward the expanding portion 19. A toner transport path 18 is provided on the side surface of the
A fan 21 is mounted as an air flow blowing means for blowing an air flow against the toner falling from the other end of the fan.

The fan 2 is provided below the expanding portion 19.
1, two classifiers 22a and 22b are formed for classifying the toner blown by the air flow according to the weight. One end of a recovered toner transport path 23 is connected to a lower portion of one of the classification sections 22a into which heavy toner enters among the toners classified by the blowing of the air flow, and the other end of the recovered toner transport path 23 is connected to the developing device 15a. It is connected to the.
In the recovered toner transport path 23, the toner that has entered the classifying unit 22a by being driven to rotate is
5 is provided. One end of a waste toner transport path 25 is connected to a lower portion of the classifying section 22b, and the other end of the waste toner transport path 25 is connected to a waste tank 26.

In such a configuration, the toner image formed on the photoconductor 13 by the image forming operation is transferred to the recording paper, and the toner remaining on the photoconductor 13 at the time of this transfer is removed by the cleaning device 17. After the removed toner enters the cleaning device 17, the toner conveying coil 20 is rotated to drive the toner conveying path 1.
8 and falls into the expanding portion 19 from above.
An air flow is blown by the fan 21 to the toner that has fallen into the expanding portion 19, and the toner is classified according to its weight.

At the time of this classification, the heavy toner falls almost directly below without being largely affected by the air flow, and falls into the classification section 22a.
Get into it. Lightweight toner such as paper powder and fine toner is blown off by the airflow and enters the classifying unit 22b. Classification part 2
The toner entering 2a is conveyed in the collection toner conveyance path 23 by the rotation of the toner conveyance coil 24, and is collected in the developing device 15. The toner that has entered the classification section 22b falls in the waste toner transport path 25 and is stored in the waste tank 26.

Therefore, according to this toner collecting device, light toner such as paper dust and fine toner can be removed from the toner collected in the developing device 15, and the collected toner is reused to form an image. In this case, the quality of the formed image is improved.

In the present embodiment, attention is paid to the removal of the light-weight toner, and the removal of the heavy toner, which has increased in size and increased in weight due to the aggregation of the toner, is not described. And toner transport path 18
By installing a mesh in the vicinity of the connecting portion with the toner, the heavy toner can be easily removed.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. The same parts as those described in FIG. 1 are denoted by the same reference numerals (the same applies hereinafter). In the present embodiment, three classifying portions 27a, 27b, and 27c into which the toner classified according to the weight by blowing the airflow from the fan 21 enters are formed below the expanding portion 19. . The classifying section 27a receives the heavy toner of the classified toner that is heavier than the allowable range, the classifying section 27c receives the lighter toner that is lighter than the allowable range of the classified toner, and the classifying section 27b receives the intermediate weight toner. Get in.

One end of a bifurcated waste toner transport path 28 is connected to a lower portion of the classifying sections 27a and 27c, and the other end of the waste toner transport path 28 is connected to a waste tank 26. One end of the collected toner transport path 23 is connected to a lower portion of the classifying section 27b, and the collected toner transport path 23
Is connected to the developing device 15.

In such a configuration, when the airflow from the fan 21 is blown against the toner that has fallen into the expanding portion 19, the toner is classified according to its weight. At the time of this classification, the weight toner that is heavier than the allowable range, for example, the toner that has aggregated and has a large diameter, enters the classification section 27a, falls in the waste toner transport path 28, and falls into the waste tank 26.
Is stored in Lightweight toner, such as paper powder or fine toner, which is lighter than the allowable range, enters the classifying section 27c, falls in the waste toner transport path 28, and is stored in the waste tank 26. On the other hand, the toner having an intermediate weight and suitable for reuse enters the classifying section 27b, and the collected toner transport path 23
And is collected into the developing device 15.

Therefore, according to the toner collecting device, the heavy toner and the light toner such as paper powder and fine toner can be removed from the toner collected in the developing device 15, and the collected toner can be reused. When the image is formed by the above, the quality of the formed image becomes very good.

In this embodiment, three classification units 2
Although the case where 7a to 27c are formed has been described as an example,
Four or more classifiers may be formed. In such a case, a request such as what level of image quality is required of the image forming apparatus using the toner recovery apparatus or how much the ratio of the toner to be reused is desired. Is selected, the classifying unit that connects the collected toner transport path is selected.

Next, a third embodiment of the present invention will be described with reference to FIG.
It will be described based on. In the present embodiment, a helical transfer path 30 is provided in a portion extending from a position where air is blown by the fan 21 to the classifying sections 29a and 29b. The classifiers 29a and 29b are arranged vertically, and the lower classifier 2
A recovery toner transport path 23 is connected to 9b, and a waste toner transport path 25 is connected to the upper classifier 29b.

In such a configuration, the fan 21
When the air flow is blown, the toner is conveyed toward the classifying units 29a and 29b while rotating in the spiral conveying path 30.

The toner that has reached the classifying sections 29a and 29b is classified by weight, and the heavy toner enters the lower classifying section 29b, is conveyed through the collected toner conveying path 23, and is conveyed to the developing device 15. On the other hand, lightweight toner such as paper powder and fine toner enters the upper classifying section 29a, is transported in the waste toner transport path 25, and is stored in the waste tank 26.

Therefore, according to this toner collecting device, light toner such as paper dust and fine toner can be removed from the toner collected in the developing device 15, and the collected toner is reused to form an image. In this case, the quality of the formed image is improved.

In this toner collecting device, the fan 2
1. Classification parts 29a, 29b
Is provided with the spiral-shaped transport path 30 in the portion reaching
Compared with the case where the expanding portion 19 is formed and the toner is dropped as described in the first and second embodiments, the structure of the portion for classifying the toner is compact, and the toner collecting device is small. .

Next, a fourth embodiment of the present invention will be described with reference to FIG.
It will be described based on. In the present embodiment, the fan 21 is disposed in the duct 31, and the filter 32, which is the first rectifying mechanism for rectifying the air flow blown from the fan 21 to the toner, is installed in the duct 31. further,
A round portion 33 as a second rectifying mechanism is formed at a connection point between the duct 31 and the expanding portion 19.

In such a configuration, by providing the filter 32 or forming the round portion 33, the air flow from the fan 21 is prevented from generating a vortex or a partial strength, and the air flow is reduced. Are rectified and become substantially uniform.
For this reason, the performance of classifying the toner by blowing the air stream is improved, and the weight of the toner collected in the developing device 15 is stabilized. Therefore, when an image is formed by using the collected toner again, the quality of the formed image is improved.

In the present embodiment, the filter 32 and the round portion 33 have been described as examples of the rectifying mechanism. However, rectifying fins or the like may be provided in the duct 31. Further, two or more rectifying mechanisms may be provided in combination, or only one of them may be provided.

Next, a fifth embodiment of the present invention will be described with reference to FIG.
It will be described based on. In this embodiment, the toner in the toner transport path 18 is transported by vibration. Cleaning device 17 in toner transport path 18
And a piezoelectric vibrator 3 which is a vibration conveying means.
4 is attached, and a vibration absorbing member 35 is attached to the end of the toner transport path 18 on the side of the expanded portion 19.

In such a configuration, the toner in the cleaning device 17 is transported in the toner transport path 18 by the vibration of the vibrator 34, and falls from the tip of the toner transport path 18 to the expanding portion 19. Vibration causes toner transport path 1
8 has a small advancing force, so that the expanding portion 1
At 9 falls almost directly below. For this reason, at the time of the classification in which the air flow from the fan 21 is blown in the expanding portion 19, the classification performance is improved. Therefore, when an image is formed by using the collected toner again, the quality of the formed image is improved.

[0036]

According to the first aspect of the present invention, the toner on the image carrier removed by the cleaning device is transported in the toner transport path, and an air stream is blown against the toner by the air stream blowing means. This classifies the toner by weight, and among the classified toners, the toner having a weight suitable for reuse is introduced into the classification unit connected to the developing device via the collected toner conveyance path, and the other classification units of the classified toner are By transporting the toner that has entered into the waste tank through the waste toner transport path, only toner having a weight suitable for reuse can be recovered to the developing device, and the quality of the image formed by the recovered toner can be improved. can do.

According to the second aspect of the present invention, of the classified toner, the heavy toner which is heavier than the permissible range enters, and the classifying portion to which the waste toner conveying path is connected, and the classified toner which is lighter than the permissible range. Since it has at least three classifying sections, a classifying section in which the lightweight toner enters and the waste toner conveying path is connected, and a classifying section in which the toner of intermediate weight enters and the collected toner conveying path is connected,
The heavy toner that is heavier than the permissible range and the light toner that is lighter than the permissible range can be reliably removed from the toner collected in the developing device, and the quality of the image formed by the collected toner can be greatly improved.

According to the third aspect of the present invention, the portion from the air flow blowing portion to the classification portion by the air flow blowing means is formed in a spiral shape, so that the structure of the portion for classifying the toner becomes compact, and the toner is recovered. The device can be downsized.

According to the fourth aspect of the present invention, since the rectifying mechanism for rectifying the air flow from the air flow blowing means is provided, the flow of the air flow blown to the toner by the air flow blowing means is rectified to be substantially uniform. Thus, the classification performance of the toner by blowing the air stream can be improved.

According to the fifth aspect of the present invention, since the vibration transport mechanism for transporting the toner in the toner transport path by vibration is provided, the toner transported by the vibration has a low advancing force, and the air is blown by the air blowing means. Classification performance when classifying by spraying a stream can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a main part of a fourth embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a main part of a fifth embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing a conventional example.

FIG. 7 is a schematic configuration diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 13 Image carrier 15 Developing device 17 Cleaning device 18 Toner conveyance path 20 Toner conveyance means 21 Air flow blowing means 22a, 22b, 27a, 27b, 27c Classification part 23 Collection toner conveyance path 25 Waste toner conveyance path 26 Waste tank 32, 33 Rectifying mechanism 34 Vibration transfer means

Claims (5)

[Claims] 1. A toner recovery device for recovering toner on an image carrier removed by a cleaning device to a developing device, wherein a toner transport path through which the toner is transported from the cleaning device, and toner transport within the toner transport path. A toner conveying means, an air flow blowing means for blowing an air flow against the toner conveyed through the toner conveying path, and a plurality of classifying units into which the toner classified according to the weight by blowing the air flow enters. A toner recovery apparatus comprising: a recovery toner transport path connecting at least one of the classification units and the developing device; and a waste toner transport path connecting another of the classification units and a waste tank. 2. A classifying section to which a waste toner transport path is connected by entering a heavy toner that is heavier than the permissible range of the classified toner, and a waste toner transport by entering a lighter toner that is lighter than the permissible range among the classified toners. At least three of the classifying unit connected to the path and the classifying unit connected to the collected toner conveying path through which the toner having an intermediate weight enters.
2. The toner collecting device according to claim 1, comprising two classifiers. 3. The toner collecting device according to claim 1, wherein a portion from an airflow blowing portion by the airflow blowing means to a classification portion is formed in a spiral shape. 4. A rectification mechanism for rectifying an air flow from an air flow blowing means.
The toner recovery device as described in the above. 5. The toner recovery device according to claim 1, further comprising a vibration conveyance unit configured to convey the toner in the toner conveyance path by vibration.