JPH08286493A - Toner recycling device - Google Patents

Abstract

PURPOSE: To prevent a fault of an image, toner flying or the like attending lowering of charged amt. of the toner, by providing torque detecting means, and the toner empty reporting means for reporting emptiness of the fresh toner, based on the torque detecting information when the transporting torque falls below a specified threshold value. CONSTITUTION: The empty reporting means 10 of the fresh toner is composed of the torque detecting means 26 for detecting the toner transporting torque by transporting means 19 of the fresh toner, and the toner empty reporting means 27 for reporting the emptiness of the fresh toner by character display, alarm or the like, based on the torque detecting information when the transporting torque, of the fresh toner from the torque detecting means 26 falls below a specified threshold value. Then, when the fresh toner becomes empty, the transporting torque of the fresh toner by the transporting means 19 falls, it is detected by the torque detecting means 26 that the transporting torque of the toner falls below the specified threshold value, and reported by the reporting means 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner recycling apparatus equipped in an image forming apparatus such as an electrostatic photocopier and a facsimile.

[0002]

2. Description of the Related Art An image forming process by the above image forming apparatus is as follows. That is, the surface of the photosensitive drum is uniformly charged by corona discharge, an electrostatic latent image of the original image is formed on the surface of the drum by exposure, and the electrostatic latent image is developed into a toner image, and the toner image is formed. Is transferred to the recording paper, and the recording paper after the toner image transfer is separated from the drum surface to fix the toner, while the residual toner on the drum surface is collected by a cleaning device, and finally the drum surface The residual charge is removed.

The toner recycling device is a device for returning the toner collected by the cleaning device to the developing device to recycle the residual toner on the drum surface. Generally, the unused toner to be supplied to the developing device. And the toner to be recycled are mixed in advance and the toner is returned to the developing device.

More specifically, a developing device is provided with a toner concentration detecting means for a developer composed of toner and carrier particles (for example, a magnetic permeability detector utilizing the fact that the output voltage changes with the variation of the toner concentration). As for the recycled toner, the recycled toner is always conveyed to the mixing section with the unused toner, and the unused toner is conveyed to the mixing section based on the information about the toner concentration decrease from the toner concentration detecting means,
The unused toner and the recycled toner are mixed in advance and then supplied to the developing device.

[0005]

The toner density detecting means has a function of operating the toner empty notifying means on the basis of the continuous decrease information of the toner density, but the toner empty is tired. The toner in the developing device. Therefore, when the unused toner is empty, the recycled toner is used until the toner density detecting means detects the toner empty in the developing device. Only the developing device will be replenished.

However, this recycled toner is deteriorated in charging performance due to damages such as burial and separation of the surface treatment agent in the image forming process, and accordingly, only the recycled toner is supplied to the developing device. , The ratio of recycled toner in the developer is high, or the toner of the developer is only recycled toner, and the charge amount is extremely reduced, so it is said that there is an image defect or toner scattering. There was a problem.

According to the present invention, when the unused toner empty occurs, the situation is immediately notified by a rational technique utilizing the toner conveying system originally provided in the toner recycling apparatus, and only the recycled toner is used. The purpose is to eliminate the inconvenience of being supplied to the developing device.

[0008]

To achieve the above object, in the first invention, a toner recycling device for mixing toner collected by a cleaning device with unused toner and returning it to a developing device is a mixed toner. A means for conveying the unused toner to the conveying means is provided with a torque detecting means for detecting the conveying torque of the unused toner by the conveying means, and based on the torque detection information when the conveying torque falls below a predetermined threshold value. The feature is that a toner empty notifying unit for notifying the empty of the unused toner is provided.

The above-mentioned threshold value is an amount of unused toner that is determined based on the mixing ratio of recycled toner to unused toner within a range that does not cause problems such as image defects and toner scattering. It is based on the torque value.

According to the second aspect of the invention, in the toner recycling device for mixing the toner collected by the cleaning device with the unused toner and returning it to the developing device, the mixed toner is conveyed to the developing device by the conveying means. In addition to providing a torque detecting means for detecting the toner carrying torque, a toner empty notifying means for notifying the empty of the unused toner is provided based on the torque detection information that the carrying torque exceeds a predetermined threshold value. There are features.

The above-mentioned threshold value is a carrying torque of the mixed toner calculated based on the mixing ratio of the recycled toner to the unused toner within a range that does not cause problems such as image defects and toner scattering. It is based on value.

[0012]

Here, the fact that the toner carrying torque by the means for carrying the unused toner has decreased means that the unused toner has become empty. In view of this point, in the first invention, the empty toner is notified based on the torque detection information when the toner carrying torque of the unused toner carrying means falls below a predetermined threshold value. is there.

On the other hand, the amount of recycled toner collected by the cleaning device is very small, and most of the mixed toner carried by the mixed toner carrying means is unused toner. The decrease in the toner carrying torque by the means means that the unused toner has become empty.

In view of this point, in the second invention, the empty toner is notified based on the torque detection information when the toner carrying torque of the carrying means for the mixed toner falls below a predetermined threshold value. Is there.

Therefore, in both the first and second aspects of the invention, the empty toner empty is immediately notified based on the torque detection information when it falls below a predetermined threshold value. By replenishing the unused toner based on the above, it is possible to effectively prevent image defects and toner scattering due to the reduction of the charge amount of the toner, which is caused by supplying only the recycled toner.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an image forming means equipped in the image forming apparatus. A photosensitive drum 1 horizontally mounted on the apparatus main body is provided with a corona discharger 2 for charging the drum surface and an electrostatic charge formed on the drum surface. A developing device 3 for developing a latent image into a toner image, a corona discharger 4 for transferring a toner image onto recording paper, and a corona discharger 5 for separating recording paper from the drum surface.
A cleaning device 6 for collecting residual toner on the drum surface and a corona discharger 7 for removing residual charge on the drum surface are arranged in that order, and as shown in FIGS. A supply device 8 for the used toner, a recycling device 9 that uses the toner collected by the cleaning device 6 as recycled toner, mixes this toner with the unused toner and returns it to the developing device 3, and an empty toner empty notification device 10. And are provided.

In the developing device 3 in this, the mixed toner carrying means 11 provided in the toner recycling device 9 is connected to a developing housing 12 which is disposed so as to face the photosensitive drum 1, and the developing housing 12 is provided. A developer stirring means 13 and 14 composed of toner and carrier particles, and a developing roller 15 for forming a magnetic brush for developing an electrostatic latent image on the surface of the drum are disposed on the magnetic disk. The cutting board 16 for limiting the height of the spikes is continuously provided, and further,
For example, the toner concentration detecting means 17 such as a magnetic permeability detector that utilizes the fact that the output voltage changes in accordance with the variation of the toner concentration is arranged.

The unused toner supply device 8 comprises a conveying means 19 for sending the unused toner to the mixing portion 18 for mixing the recycled toner with a hopper 20 for replenishing the unused toner, while the cleaning device 6 is used. Is a cleaning blade 21 for scraping off the residual toner on the drum surface,
The cleaning housing 24 is provided with a cleaning roller 23 that sends the scraped toner to the toner take-out means 22.

The toner recycle device 9 mixes the recycle toner and the unused toner with the conveying means 25 for feeding the recycle toner into the mixing section 18, and the developing device 3
And a transporting means 11 for feeding the collected toner to the recycle toner transporting means 25.
Are continuously driven to continuously stock the recycled toner in the mixing section 18, and the unused toner conveying means 19 and the mixed toner conveying means 11 are provided with the toner concentration decrease information from the toner concentration detecting means 17. Based on the driving, the unused toner and the recycled toner are mixed in advance, and the toner is supplied to the developing device 3.

In the present embodiment, the mixed toner conveying means 11, the unused toner conveying means 19 and the recycled toner conveying means 25 are a toner conveying spiral and a toner conveying cylinder containing the spiral. Consists of.

Unused toner empty notification device 10
Is based on the torque detection means 26 for detecting the toner carrying torque of the unused toner carrying means 19 and the torque detection information when the unused toner carrying torque from the torque detecting means 26 falls below a predetermined threshold value. And a toner empty notifying means 27 for notifying the empty of the unused toner by a character display or an alarm.

The above-mentioned threshold value of the unused toner is determined based on the mixing ratio of the recycled toner to the unused toner within a range that does not cause problems such as image defects and toner scattering. This is based on the transport torque value.

According to the above construction, when the unused toner becomes empty, the transport torque of the unused toner by the transport means 19 decreases, and the torque detection means 26 indicates that the toner transport torque has fallen below the predetermined threshold value. When it is detected, the empty toner empty is immediately notified based on the torque detection information. By reusing the unused toner in the hopper 20 based on the toner empty notification information, only the recycled toner is regenerated. However, it is possible to effectively prevent image defects and toner scattering due to the decrease in the toner charge amount.

In the above-mentioned embodiment, the empty of the unused toner is notified based on the toner carrying torque by the unused toner carrying means 19, but FIG.
As indicated by a phantom line, the torque detecting means 26 detects the mixed toner carrying torque of the mixed toner carrying means 11, and the mixed toner carrying torque from the torque detecting means 26 falls below a predetermined threshold value. It is also possible to notify the empty of the unused toner by the toner empty notification means 27 based on the detected torque information.

That is, the amount of recycled toner collected by the cleaning device 6 is very small, and most of the mixed toner carried by the mixed toner carrying means 11 is unused toner. The fact that the toner carrying torque by the carrying means 11 has decreased means that the unused toner has become empty.

Therefore, based on the fact that the torque detecting means 26 detects that the toner carrying torque of the mixed toner carrying means 11 has decreased and the toner carrying torque has fallen below a predetermined threshold value, the torque is detected. The empty toner empty can be immediately notified based on the information. By supplying the unused toner to the hopper 20 based on the notification information of the toner empty, only the recycled toner is supplied. Image defects and toner scattering due to the decrease in the toner charge amount are effectively prevented.

It should be noted that the above threshold value is calculated based on the mixing ratio of the recycled toner to the unused toner within a range that does not cause problems such as image defects and toner scattering. It is based on the carrier torque value of.

[0028]

As described above, the present invention is made by utilizing the toner conveying system originally included in the toner recycling apparatus. In the first invention, when unused toner becomes empty, Paying attention to the fact that the toner carrying torque of the used toner carrying means is lowered, based on the torque detection information when the toner carrying torque falls below a predetermined threshold, the empty toner empty is notified. There is.

On the other hand, the amount of recycled toner collected by the cleaning device is very small, and most of the mixed toner conveyed by the mixed toner conveying means is unused toner. The decrease in the toner transport torque means that the unused toner is empty. Focusing on this point, in the second invention, the empty of the unused toner is notified based on the torque detection information when the toner carrying torque by the carrying means for the mixed toner falls below a predetermined threshold value. is there.

In any of the first and second aspects of the invention, therefore, the toner conveying system originally provided in the toner recycling device is utilized, and the torque detecting means for activating the toner empty notifying means is simply provided. With the technology, it is possible to accurately notify the empty toner empty, and by supplementing the unused toner based on this, it is possible to reduce the charge amount of the toner by supplying only recycled toner. Therefore, it has become possible to effectively prevent the accompanying image defects and toner scattering.

[Brief description of drawings]

FIG. 1 is a principle diagram of an image forming unit.

FIG. 2 is a plan view in which a main part of an image forming unit is cut away.

FIG. 3 is an explanatory diagram of a toner recycling device shown together with a means for transporting unused toner.

[Explanation of symbols]

3 ... Developing device, 6 ... Cleaning device, 11 ... Mixed toner conveying means, 19 ... Unused toner conveying means, 26 ...
Torque detecting means, 27 ... Toner empty notifying means.

Claims (2)

[Claims] 1. A toner recycling device that mixes toner collected by a cleaning device with unused toner and returns it to a developing device, wherein the unused toner is conveyed to a mixed toner conveying means by the conveying means. In addition to providing a torque detecting means for detecting the carrying torque of the unused toner, and providing a toner empty notifying means for notifying the empty of the unused toner based on the torque detection information when the carrying torque falls below a predetermined threshold value. A toner recycling device characterized in that there is. 2. A toner recycling device that mixes toner collected by a cleaning device with unused toner and returns the mixed toner to a developing device, wherein the means for conveying the mixed toner to the developing device conveys the mixed toner by the conveying means. In addition to providing a torque detecting means for detecting the carrying torque, a toner empty notifying means for notifying the empty of the unused toner is provided based on the torque detection information indicating that the carrying torque exceeds a predetermined threshold value. Toner recycling device.