JP2000132035A - Electrophotographic device and toner replenishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue image-forming without a difficulty even when toner gets less or is depleted in a toner hopper by feeding the recovered toner in a recovery container and carrying the toner to a developing device when the amount of the toner in the recovery container exceeds the specified one. SOLUTION: This device is provided with a cleaning device 29 incorporating a cleaning blade 29A in order to remove the toner remaining on a photoreceptor drum 10 after transfer. Furthermore it is provided with a toner recycling device 30 incorporating a screw 301 between the device 29 and a toner replenishing container 213 in order to restore the removed toner to a developing device 21. Then, a branching tube 31 for supplying the toner to the recovery container 34 arranged under the device 29 is connected to one part of the device 30. By such constitution, the toner for reserve is always prepared, so that the image- forming is continued even when the toner is used up and depleted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus for forming an electrostatic latent image on an image forming body and developing the formed electrostatic latent image with toner to form an image. The present invention relates to an improvement in toner supply for supplying toner.

[0002] The electrophotographic apparatus according to the present invention is used for copying machines, facsimile machines, printers and the like.

[0003]

2. Description of the Related Art In an electrophotographic apparatus, toner is replenished to a developing device at a controlled rate from a toner hopper in response to consumption by image formation, so that proper development is always performed and a predetermined image quality is maintained. . Then, when the toner in the toner hopper runs out, a warning display indicating that toner supply from the outside is necessary is performed or together with the warning display,
The operation of the device stops.

A conventional electrophotographic apparatus has the above-described toner replenishing device, which ensures a good image formation as long as the toner is in the toner hopper. It is designed so that no serious inconvenience or burden is imposed on the user.

[0005]

However, in the actual use of the electrophotographic apparatus, there may be situations where the average use is deviated and the design is unexpected. In other words, an example is that there is no spare toner to be supplied to the toner hopper. In such a case, it is impossible to form an image due to lack of toner, or the image forming operation has to be carried out with patience even for an image of low quality due to reduced image density.

As a countermeasure against such inconvenience, there is an electrophotographic apparatus in which even when toner remains in the toner hopper, a preliminary warning of toner replenishment is issued when the amount of toner drops below a predetermined amount. There are limits to the measures, and the inconveniences described above cannot be completely eliminated.

That is, when the amount of residual toner at the preliminary warning stage is small, the effect of the preliminary warning system is small, and when the amount of residual toner at the preliminary warning stage is increased, the capacity of the toner hopper becomes large. Not desirable.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problem relating to toner replenishment of an electrophotographic apparatus, and it is possible to continue image formation without any trouble even when the toner in a toner hopper is reduced or exhausted. To provide an electrophotographic apparatus.

[0009]

The object of the present invention is as follows.
(1) In an electrophotographic apparatus in which toner collected by a cleaning device is returned to a developing device and reused, the toner collected by the cleaning device is sent to a collection container, and the amount of toner in the collection container is reduced to a predetermined amount. And (2) returning the toner collected by the cleaning device to the developing device and reusing the toner to the developing device. In the toner supply method, the toner is transported from the cleaning device to the developing device, the toner is transported from the cleaning device to a collecting container, the toner is stored in the collecting container, and new toner is supplied to the developing device. When the toner is substantially depleted in the toner supply unit, the toner is transferred from the collection container to the developing device. Toner supply method and supplying is accomplished by.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a copying apparatus according to an embodiment of the present invention will be described. FIG. 1 is a sectional view of the copying apparatus, and FIG. 2 shows a collection container for storing the cleaned toner of the copying apparatus shown in FIG. 1 and a switching mechanism for recycling the toner to the developing apparatus. FIG. 3 is a perspective view of the switching mechanism and the collection container of FIG.

In a copying apparatus, a cylindrical photosensitive drum 1 having an OPC photosensitive member (organic photosensitive member) formed on a drum base is provided.
0, and is driven clockwise by a drive source (not shown) to rotate. Reference numeral 11 denotes a charger, which applies a constant charging potential to the photosensitive drum 10 by corona discharge using a grid and a corona discharge wire that are maintained at a constant voltage on the peripheral surface of the photosensitive drum 10. Prior to charging by the charger 11, exposure is performed by a pre-charging static eliminator (PCL) 12 using a light emitting diode or the like in order to eliminate the history of the photoconductor up to the previous print.

After the photosensitive drum 10 is uniformly charged by the charger 11, image exposure is performed by the image exposure device 13.
The image exposure apparatus 13 has a scanning unit including an exposure lamp 16 for exposing a document 15 placed on a document table 14 provided above the copying apparatus A, and a mirror 17 moving integrally with the exposure lamp 16. A scanning unit consisting of two V-mirrors 18 which move at half the speed of the mirror 17 and are formed in a V-shape;
And a mirror 20 for irradiating the photosensitive drum 10 with exposure light of the original 15.

A developing device 21 having a developing sleeve 211 is provided to face the photosensitive drum 10.
A toner replenishing container 212 for replenishing the developing device 21 with toner and storing unused new toner, and a toner replenishing container 213 for storing recycled toner are provided above the printer. Further, a toner density sensor 214 is provided below the developing device 21.

On the other hand, a two-stage paper cassette 22 containing recording papers P of different sizes is provided at the lower part of the copying apparatus. A registration roller pair 23 is provided to convey the recording paper P to a transfer position after the recording paper P is temporarily stopped.

A transfer unit 24 for toner images and a separator 25 for recording paper P are provided below the photosensitive drum 10, and a recording paper for transporting the recording paper P to a heat fixing unit 27. A transport device 26 is provided. Reference numeral 28 denotes a paper discharge unit that discharges the recording paper P on which fixing has been completed.

In order to clean the toner remaining on the photosensitive drum 10 after the transfer, a cleaning device 29 having a built-in cleaning blade 29A is provided.
A toner recycle device 30 incorporating a screw 301 is provided between the cleaning device 29 and the toner replenishing container 213 in order to return to the state shown in FIG.

A collection container 34 made of a transparent material and containing the toner collected by the cleaning device 29 is provided below the cleaning device 29. A branch pipe 31 for supplying the toner to the collection container 34 is connected to a part of the toner recycling device 30, and a part of the branch pipe 31 has a shutter 32 (described in detail in FIGS. 2 and 3). Are provided movably.

A connecting member 33 for detachably connecting the collection container 34 and the branch pipe 31 is provided so as to be movable with respect to the branch pipe 31.

Further, a light emitting portion L and a toner amount sensor TS including a light receiving element S are provided to face the toner inlet position of the collection container 34.

Next, the operation of the copying apparatus will be described.

By pressing a copy start button (not shown), a copying process is started and a pre-charging static eliminator (PC) is started.
L) An electrostatic latent image is formed on the photoconductive drum 10 by charging the surface of the photoconductive drum 10 having been neutralized by 12 and exposing it by the image exposure device 13. The formed electrostatic latent image is developed by the developing device 21, and a toner image is formed on the peripheral surface of the photosensitive drum 10.

The toner image on the photosensitive drum 10 is transferred onto a recording paper P supplied by a pair of registration rollers 23 by a transfer device 2.
4 is transferred.

Next, the recording paper P on which the toner image has been transferred is
The recording paper P is separated from the photosensitive drum 10 by the separator 25, conveyed to the heat fixing device 27 by the recording paper conveying device 26, subjected to a fixing process, and discharged from the paper discharge unit 28.

When the toner in the developing device 21 runs short due to the consumption of toner due to the image formation, and a toner supply signal is output from the toner density sensor 214, the toner supply container 21
The toner is supplied at a rate controlled from 2, 213.

The toner image is transferred onto the recording paper P by the transfer unit 24, but the residual toner adheres to the photosensitive drum 10 and is cleaned by the cleaning blade 29 A of the cleaning device 29. The toner collected in the cleaning device 29 in this manner is supplied to the screw 301
Is discharged to the outside of the cleaning device 29, and is discharged to the collection container 34 through the branch pipe 31.

In the present embodiment, the cleaning device 29
Is discharged to the developing device 21 via the collection container 34 and the toner supply container 213. Hereinafter, such conveyance of the toner will be described.

As shown in FIGS. 2 and 3, a shutter 32 is provided above the branch pipe 31. The shutter 32 has an opening 321 through which toner passes, and is pulled rightward by a spring 36. The shutter 32 is engaged with the cam 38 by a lever 39 at the other end with respect to the end provided with the opening 321. The cam 38 is connected to the motor 35 via the gear 37.
Driven by

When the toner amount sensor TS outputs a signal indicating that a predetermined amount of toner has been stored in the collection container 34, the motor 35 rotates the cam 38 by 180 °. The rotation of the cam 38 causes the shutter 32 to move in one direction.

FIGS. 2A and 3 show a state in which the shutter 32 moves to the right and closes the branch pipe 31. This state is when a predetermined amount of toner is stored in the collection container 34. It is a state of. In the state shown in FIG. 3, the toner is transported by the toner recycling device 30 to the toner supply container 213 as indicated by an arrow. FIG. 3 shows a state in which the connection member 33 is separated from the collection container 34. In this state, the collection container 34 can be taken out of the copying apparatus main body, and the toner can be put into the toner supply containers 212 and 213. The empty collection container 34 is mounted as shown in FIGS. 1 and 2, and when the copying apparatus is reset, a reset signal
The motor 35 rotates, the cam 38 rotates by 180 °, the shutter 32 is moved to the left, the opening 321 is aligned with the branch pipe 31, and the toner from the cleaning device 29 is sent into the collection container 34 again. Become like

The toner supply container 213 always contains a certain amount of toner, and the developing device 21 is supplied with toner at a controlled rate from the toner supply containers 212 and 213 to perform development.

When the amount of toner in the collection container 34 is low or runs out in the toner supply container 212 containing new toner, the user supplies the toner to the toner supply container 21.
2 or 213 or both 212 and 213 are used for development. As described above, the toner stored in the collection container 34 is always prepared in a state where the collection container 34 is full as spare toner in case the toner is completely consumed.

Therefore, even when the toner runs out, the copying operation can be continued by using the toner in the collection container 34. Therefore, it is difficult to perform the copying operation or to perform the copying operation with the density lowered. It will not be done.

It should be noted that the toner supply container 2
12 is provided with a toner conveying device for conveying the toner to the developing device 21, and when the amount of toner in the toner replenishing container 212 becomes equal to or less than a predetermined amount, the toner is automatically replenished from the collecting container 34. You can also.

The toner replenishment warning signal output when the amount of toner in the toner replenishment container 212 becomes small is set to two or more stages, and a preliminary warning of toner replenishment is performed in the first stage, and toner consumption further proceeds. In the second stage, the collection container 3
Or a warning to prompt toner supply from
4, the toner can be automatically supplied.

[0035]

As described above, even when the toner is used up, a spare toner is always prepared and the image forming operation cannot be performed due to the lack of the toner, or the image having a low density and only a poor quality image can be formed. This inconvenience is eliminated, and image formation can be continued. Since new toner can be obtained while forming an image using the toner collected by the cleaning device and stored in the collection container, image formation can be performed without any trouble.

[Brief description of the drawings]

FIG. 1 is a sectional view of a copying apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a toner collecting unit of the copying apparatus shown in FIG.

FIG. 3 is a diagram illustrating a switching unit of a toner conveyance path of the copying apparatus illustrated in FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoreceptor drum 11 charger 12 pre-charging static eliminator (PCL) 13 image exposure device 14 original mounting table 21 developing device 29 cleaning device 30 toner recycling device 32 shutter 34 collection container 212, 213 toner supply container TS toner amount sensor

Claims (4)

[Claims] 1. An electrophotographic apparatus in which toner collected by a cleaning device is returned to a developing device for reuse, wherein the toner collected by the cleaning device is sent to a collection container and the amount of toner in the collection container is adjusted. An electrophotographic apparatus, wherein the toner is conveyed to the developing device when the amount exceeds a fixed amount. 2. The apparatus according to claim 1, further comprising detecting means for detecting an amount of toner in said collecting container, wherein a toner conveying path from said collecting container to said developing device is switched by a signal from said detecting means. 2. The electrophotographic apparatus according to 1. 3. A toner supply unit for supplying new toner to the developing device, wherein when the toner supply unit runs out of toner, toner is supplied from the collection container to the developing device. The electrophotographic apparatus according to claim 1 or 2. 4. A method of replenishing toner to the developing device of an electrophotographic apparatus, wherein toner collected by a cleaning device is returned to the developing device for reuse, wherein the toner is conveyed from the cleaning device to the developing device, Transfer the toner from the cleaning device to the collection container,
Storing the toner in the collection container and supplying toner to the development device from the collection container when the toner supply unit that supplies new toner to the development device is substantially depleted of toner; How to replenish.