JPH08314274A - Toner carrier device - Google Patents

Abstract

PURPOSE: To provide a toner carrier device where the flocculation of recovered waste toner in the process of carrying it is controlled and prevented and which is at low cost and whose size is very compact. CONSTITUTION: As for the toner carrier device carrying recovered toner from a cleaning device 7 recoverying remaining toner on an image carrier 1 toward a developing device 4, rotary bodies 19-22 are disposed at the end part and the corner part of a carrier route 18 formed at the inside of the carrier device, and a belt 18 provided with a recessed part and/or a projecting part is laid over the rotary bodies and the belt is driven, so that the toner is carried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner conveying device for an image forming apparatus such as a copying machine or a laser printer,
This forms a toner recycling mechanism for reusing the waste toner removed from the photoconductor by the cleaning device for development.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 9, an image forming apparatus using an electrophotographic process basically includes a charger 2 for charging the drum surface and image information around the photosensitive drum 1. An exposure device 3 for irradiating a drum with a laser beam or the like, a developing device 4 for visualizing an electrostatic latent image on the drum, a transfer charger 5 for transferring a toner image on the drum to a sheet, and a drum surface after transfer. Static eliminator 6 for eliminating static electricity and cleaning device 7 for removing and collecting residual toner on the drum
And the fixing device 8 is arranged on the downstream side of the sheet conveyance. Other functional units normally located in the electrophotographic process are omitted for simplicity of the figure.

The basic image forming operation in the image forming apparatus configured as described above is as follows. That is, first, the surface of the photoconductor 1 is uniformly charged to a high potential by the charging charger 2. When the exposure device 3 irradiates the surface of the photoconductor 1 with the reflected light of the document or the image light according to the image data, the potential of the irradiated portion decreases. Since the image light has a distribution of light amount according to white / black of the original image,
By irradiating the image light, a potential distribution corresponding to the original image, that is, an electrostatic latent image is formed on the surface of the photoconductor 1. The portion of the surface of the photoconductor on which the electrostatic latent image is formed is the developing device 4
When the toner passes through the opposite position, the toner adheres according to the level of the potential, and a toner image is formed by visualizing the electrostatic latent image. When the toner image reaches the position facing the transfer charger 5, the recording paper 1 is conveyed from the paper feeding unit (not shown) at the same timing by a registration roller (not shown).
0, and the toner image is transferred onto the recording paper 10 by the transfer charger 5. The recording paper 10 after the transfer is separated from the photoconductor 1 and reaches the fixing device 8 through the conveyance path.
After being thermally fixed by the apparatus 8, the sheet is discharged outside the apparatus. On the other hand, the surface of the photoconductor 1 after the completion of the transfer process is removed of the residual charges by the charge eliminating device 6 and the residual toner by the cleaning device 7, and is prepared for the next image forming process.

Most of the image forming apparatuses now in widespread use are
As described above, the step of removing the untransferred toner remaining on the surface of the photoconductor after the transfer processing by the cleaning device is required. The residual toner removed by the cleaning device is stored inside the image forming apparatus or in a waste toner tank or a recovery portion provided in the cleaning device. After that, normally, the waste toner tank or the collected portion is discarded when the detection means detects that it is full. In response to recent social backgrounds such as environmental problems and resource recycling, some image forming apparatuses are equipped with a toner conveying device in order to reuse the collected waste toner for printing.

The above-described toner conveying device is provided with, for example, a pipe-shaped conveying path for conveying toner from the cleaning device to the developing device, and a rotating conveying device such as a screw or a coil spring is provided inside the conveying path. A member is provided, and the waste toner collected by the cleaning process as described above is sequentially sent to the developing device.

[0006]

However, the waste toner is extremely inferior in fluidity to the fresh unused toner. Therefore, the waste toner is very likely to be aggregated during the transportation process. The degree of the aggregated particles is, for example, about 10 μm for the new toner, while it is as large as 500 μm for the aggregated toner. If such aggregated toner is reused as it is as a developing toner, density unevenness may occur, or a sharp image may not be obtained.
There are problems that image defects such as transfer defects occur, and that toner blocking occurs and jams in the transport path. For this reason, conventionally, measures such as providing a mechanism for mechanically crushing the aggregated toner and a device for classifying the aggregated toner in the downstream portion of the toner conveying path have been taken.

However, in the conventional toner conveying device as described above, the toner is a very small particle, and there is a limit to mechanically pulverizing or classifying it, and it is as good as a new toner. There was a problem that it was difficult to obtain a good image. Further, by installing these devices, it is necessary to secure an installation space for them, which makes the entire image forming apparatus large and increases the cost of parts, which is an economical problem.

The present invention has been made in view of such a background, and it is possible to suppress and prevent the aggregation of the collected waste toner in the conveying process, and at the same time, at a low cost, the toner conveying device is suppressed to a very compact size. The challenge is to provide.

[0009]

In order to solve the above-mentioned problems, according to the present invention, in a toner carrying device for carrying the collected toner from a cleaning device for collecting the residual toner on the image carrier to a developing device, A rotating body is arranged at the end and the corner of a conveying path formed in the conveying device, and a belt having a concave portion and / or a convex portion is hung on the rotating body, and the toner is conveyed by driving the belt. To do so. It is preferred if the belt has a U-shaped cross section.

In a toner carrying device for carrying the collected toner from a cleaning device for collecting the residual toner on the image carrier to the developing device, a rotating body is provided at the end and the corner of a carrying path formed in the carrying device. The above problem can also be solved by arranging the magnetic member and wrapping it around the rotating member and driving the belt to convey the toner.

By the way, the toner scraped off the photosensitive member by the cleaning blade often contains foreign matter such as paper dust. Such foreign matter is likely to serve as a nucleus when the toner aggregates, and even if the toner does not serve as a nucleus of the aggregated toner, if the collected toner containing the foreign matter is used for development, it adversely affects the image. Therefore, it is still effective if a mechanism for applying vibration to the belt is additionally provided.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 schematically shows the periphery of the photoconductor centering on the toner conveying device according to the present invention. Other devices and configurations required for image recording are not essential for understanding the toner transport device according to the present invention, and are therefore omitted for simplification of description.

A developing roller 13 is provided on the side of the photosensitive drum 1.
And a photoconductor drum 1.
Counter type cleaning blade 15
A cleaning device 7 including is disposed. One end of each of the developing device 4 and the cleaning device 7 is connected by a side surface conveyance path 16 for conveying the collected toner, and the collected toner conveyed through the conveyance path 16 to the end portion of the developing device 4 is By the carrying member 17 arranged in the longitudinal direction of the developing device 4, it is taken into the developing device. Instead of directly transporting the recovered toner from the transport path 16 to the developing device 4 by the transport member 17, the recovered toner may be temporarily housed in the toner hopper or the toner cartridge from the transport path, and then the toner may be supplied to the developing device. Of course it's good.

The toner is conveyed to the end portion of the developing device 4 by a single conveying belt 18 that is stretched over the conveying path 16 and the entire cleaning device 7 in the longitudinal direction. Two rollers 1 which are vertically arranged at the connecting portion between the cleaning device 7 and the side transport path 16 and which are rotatable about a vertical axis.
9, 20 and driving rollers 21, which are arranged near the ends on the opposite side in the longitudinal direction of the cleaning device 7 and are rotatable around a horizontal axis,
The belt 18 is stretched over by a driven roller 22 which is arranged at a connecting portion between the developing device 4 and the side surface transport path 16 and is rotatable around the longitudinal axis of the developing device. It is natural that the number and arrangement of the rollers are not limited to this as long as they do not hinder the belt driving. When the driving roller 21 is driven by a driving device (not shown), the conveyor belt 18 rotates as shown by an arrow. The collected toner captured by the belt 18 is conveyed to the developing device 4, is taken over by the conveying device 17 and is sent into the developing device, and toner recycling is realized.

In order to recycle the toner, it is necessary that the conveyor belt 18 has a structure for capturing the toner, and for example, a concave portion or a protruding portion such as a hole or a groove is formed on the belt surface. That is, as shown in FIG. 2, the round belt 181 has lateral V grooves 182 formed at intervals (FIG. 2A), and the round belt 183 has round holes 184 formed at intervals. (Fig. 2 (b)), square belt 185
It is conceivable that the plate-like projections 186 are formed on the upper surface of the sheet at intervals (FIG. 2 (c)), and the holes and the projections are not limited to these shapes as long as they can capture and convey the toner. It is of course possible to form both the groove and the groove. The holes and protrusions need not be evenly spaced. Further, the cross-sectional shape of the belt is not limited as long as it does not hinder driving, and therefore many combinations of holes / grooves and belt cross-sectional shape are conceivable. It is desirable that the holes and grooves formed in the belt be upward during the forward movement of the belt, but in the case of protrusions, it is also possible to move the belt while sliding it against the inner wall of the cleaning device or the conveyance path. As long as there are obstacles due to rollers in each place, there is no directional limitation.

As a result of the above configuration, the photosensitive drum 1
The residual toner scraped off by the cleaning blade 15 from the above is caught by the forward portion of the belt in the cleaning device (the area A in FIG. 1 and the cross-sectional portion of the upper belt in FIG. 3), and the developing device 4 and the side transport path. As shown in FIG. 3, when the belt 18 makes a U-turn (area B), the toner is dropped to the end portion (area C) of the developing device 4 by the natural fall due to its own weight. , Developing device 4
The sheet is conveyed to the inside of the developing device 4 by another conveying device 17 provided in the above and is reused for the development. As compared with the conventional screw and coil spring, the belt conveyor type conveyance as described above can limit the stress on the toner during the conveyance process. If the collected toner is put in a recycling process early or is conveyed at a high speed, aggregation of the toner can be suppressed or prevented.
In the example of FIG. 3, the partition between the forward and backward movements of the belt is partitioned by the partition 23. However, holes or grooves are formed in the belt, and the toner captured during the forward movement may fall downward during transportation. If the number is small, the partition 23 is not necessary.

Furthermore, in the embodiment shown in FIGS. 1 and 3,
The plane formed by the loops of the belt is arranged so as to form a vertical plane, but it can also be arranged so as to be a horizontal plane unless space is restricted. In that case, drive roller 2
It is also necessary to arrange 1 and the driven roller 22 so that the rotation axis is vertical and to provide a partition between the forward and backward movements of the belt.

FIG. 4 shows one modification. Components common to those of the embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted for simplification. As shown in FIG. 5, the conveyor belt 38 that conveys the collected toner to the developing device 4 has a U-shaped cross section with an upward opening, and has teeth on its bottom bottom surface. The U-shaped belt 38 is stretched over the entire length of the side transport path 16 and the cleaning device 7 so that the opening side faces upward in the forward movement range shown by D in FIG. Similar to the embodiment shown in FIG. 1, the transfer is provided with two rollers 19 and 20 which are vertically arranged at the connecting portion between the cleaning device 7 and the side surface conveyance path 16 and are rotatable around the vertical axis, and the opposite ends of the cleaning device 7 in the longitudinal direction. A driving roller 40 disposed near the portion and rotatable about a horizontal axis, and a driven roller 41 disposed at a connection portion between the developing device 4 and the side surface transport path 16 and rotatable about a longitudinal axis of the developing device. Since the conveyor belt 38 is configured with teeth in order to ensure the driving, the driving roller 40 and the driven roller 41 are provided with teeth that engage with the tooth portions 39 thereof. On the other hand, since the rollers 19 and 20 arranged at the connecting portion between the cleaning device 7 and the side surface transport path 16 contact the flat portion of the belt 38, they are not toothed.

As shown in FIG. 6, the open portion of the U-shaped belt 38 is located immediately below the contact portion (E portion in FIG. 6) between the cleaning blade 15 and the photosensitive drum 1. It is desirable that the toner scraped off by the cleaning blade 15 is naturally dropped to fall into the belt opening. However, if such arrangement is difficult due to the relationship between the members, a guide or the like is provided. Alternatively, the toner may be guided into the belt opening.

With the above-mentioned structure, the collected toner enters the belt opening and is conveyed to the developing device 4, so that no stress is caused by the conveyance and aggregation can be prevented. Further, if the toner is continuously conveyed at a high speed, the belt is small, and therefore, even if the inside of the belt has a large capacity, it is possible to follow a considerable toner recovery amount, and the apparatus can be made very small. Become.

If the conveyor belt is made of a magnetic material,
When the magnetic toner is used, the magnetic toner can be attracted to the belt surface and conveyed. When the toner is conveyed by the magnetic force as described above, as shown in FIG. 7, the scraping member 45 is disposed in contact with the belt in the U-turn region of the belt so that the toner attached and conveyed to the belt is conveyed. Scraping is done at the end of the developing device 4. In the magnetic transfer, it is necessary to separate the toner from the belt in the vicinity of the developing device, and thus a round belt or a square belt having a simple shape is used, a U-shaped belt shown in FIG. 5 is used, or It is preferable that a mechanism for releasing the magnetism of the belt is provided near the developing device to facilitate the scraping by the scraping member 45.

FIG. 8 shows an example of a structure for giving a minute vibration to the belt. The configuration and arrangement are basically the same as those of the embodiment according to FIG. 1, and constituent members common to the embodiment of FIG. Cleaning device 7
A roller 49, which is installed at the connection portion of the side transport path 16 and the forward side (F) of the transport belt 48, has a prismatic shape. As a result, when the roller 49 is rotated by the conveyor belt 48, the belt 49 rotates while changing the tension of the belt in an amplitude manner, so that a minute vibration can be applied to the belt 48. By vibrating the belt, foreign matter such as non-magnetic paper powder mixed in the toner can be shaken off while the toner is being conveyed.

[0023]

According to the first aspect of the invention, in the toner conveying device for conveying the collected toner from the cleaning device for collecting the residual toner on the image carrier to the developing device, the toner conveying device is formed in the conveying device. A rotary body is arranged at the end and corner of the transport path, and a belt having a concave portion and / or a convex portion is hung around the rotary body, and the toner is transported by driving the belt. Therefore, the stress applied to the toner with respect to the conveying speed is much smaller than that of the conventional method, and the aggregation of the toner can be suppressed or prevented. Moreover, since the number of parts can be suppressed and the conveying member can be made small, it is possible to provide a compact and low-cost conveying device.

According to the second aspect of the invention, since the conveyor belt has a U-shaped cross section, the collected toner can be continuously conveyed, and a large amount of collected toner can be conveyed even in a relatively short time. Even if the amount of collected toner is very large, the conveyance can be easily followed, which is more effective.

According to the third aspect of the invention, in the toner conveying device for conveying the collected toner from the cleaning device for collecting the residual toner on the image carrier to the developing device, the conveying device formed in the conveying device. Rotating bodies are arranged at the end and corner of the road, and a belt made of a magnetic material is hung on the rotating body, and the toner is conveyed by driving the belt, so there is no stress on the toner and the toner agglomerates. Can be prevented. High-speed conveyance is possible, and the followability of conveyance is high. As a result, parts can be made smaller and the device can be made smaller. Further, since the magnetic force of the belt is used for transportation, it is not necessary to make the belt into a special shape.

According to the invention described in claim 4, since a mechanism for imparting vibration to the belt is additionally provided, in addition to the effect of claim 3, the conveyed toner is cleaned before reaching the developing device. The amount of foreign matter can be reduced as compared with the state immediately after that, and therefore image defects due to foreign matter can be prevented or reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an arrangement of a toner conveying device according to the present invention.

FIG. 2 is a partial schematic view of a conveyor belt, in which (a)-
(C) is an example.

FIG. 3 is a schematic end view corresponding to FIG.

FIG. 4 is a perspective view showing an arrangement of a toner conveying device having another structure.

FIG. 5 is a partial schematic perspective view of a conveyor belt.

FIG. 6 is a schematic end view corresponding to FIG.

FIG. 7 is a diagram for explaining how to scrape off the toner magnetically attached to the belt.

FIG. 8 is a perspective view showing the arrangement of a toner conveying device having a belt vibrating mechanism.

FIG. 9 is a schematic conceptual diagram of a general image forming apparatus using an electrophotographic process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 4 Developing device 7 Cleaning device 13 Developing roller 15 Cleaning blade 16 Side transfer path 17 Transfer device 21 Drive roller 22 Driven roller

Claims (4)

[Claims] 1. A toner transport device for transporting recovered toner from a cleaning device for recovering residual toner on an image bearing member to a developing device, wherein the toner is rotated at an end and a corner of a transport path formed in the transport device. An apparatus, in which a body is disposed, a belt having a concave portion and / or a convex portion is hung on the rotating body, and the toner is conveyed by driving the belt. 2. The apparatus of claim 1, wherein the belt has a U-shaped cross section. 3. A toner transport device for transporting recovered toner from a cleaning device for recovering residual toner on an image bearing member to a developing device, wherein the toner is rotated at an end and a corner of a transport path formed in the transport device. An apparatus, in which a body is disposed, a belt made of a magnetic material is hung on the rotating body, and the toner is conveyed by driving the belt. 4. The apparatus according to claim 3, wherein a mechanism for imparting vibration to the belt is additionally provided.