JPH07168492A - Cleaning device for electrophotographic device - Google Patents

Abstract

PURPOSE:To prevent the toner removed by a cleaning member from depositing around the toner transport means and interrupting the path to a toner transport means by providing an electrode around the toner transport means and impressing DC voltage having the polarity opposite to that of the toner to the electrode. CONSTITUTION:As the flowability of the toner is deteriorated after the cleaning, the toner is heaped around the toner transport screw 35 and the toner bridge is finally formed. In order to avoid this, the electrode 38 and the grounding electrode 39 are alternatively disposed on the lower side end part inside face of the toner recovering port 31. The electrode 40 and the grounding electrode 41 are alternatively disposed on the rear wall lower part inside face of the cleaning case 30 opposing across the toner transport screw 35. The electrode 38 and 40 are connected to the DC power source 43 through the lead wire 42 and the grounding electrode 39 and 41 are grounded through the lead wire 44. Then, the DC voltage having the polarity opposite to that of the toner is impressed to the electrode 38 and 40 from the DC power source 43 at the time of cleaning. Otherwire, it can be as well constituted so that the AC voltage impressed to the electrode 38 and 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus such as a laser copying machine, a laser printer or a laser facsimile which records on a sheet by using an electrophotographic process such as charging, optical writing, development, transfer and cleaning. Can be applied to. Specifically, in such an electrophotographic apparatus, the toner remaining on the photoconductor after transfer is removed by a cleaning member,
The present invention relates to a cleaning device that conveys the removed toner by a toner conveying means.

[0002]

2. Description of the Related Art Conventionally, in a cleaning device of a laser printer, for example, as shown in FIG. 7, during cleaning, toner t remaining on the photosensitive member 1 after transfer is scraped by a cleaning blade 3 as a cleaning member. In some cases, the toner t dropped and guided to the inside of the toner case 5 by the inlet seal member 4 is conveyed by the toner conveying screw 6 which is a toner conveying means in the direction orthogonal to the paper surface in the figure and is discharged to the outside.

[0003]

However, the toner t after cleaning removed from the photoconductor has poor fluidity. Therefore, in the conventional cleaning device, as shown in FIG. 8, the toner t scraped off by the cleaning blade 3 adheres and accumulates around the toner carrying screw 6, and finally, as shown in FIG. Build the bridge 7. As a result, there is a problem that it blocks the passage to the toner conveying screw 6 and makes it impossible to discharge the scraped toner t to the outside.

Therefore, an object of the present invention is to prevent the toner removed by the cleaning member from accumulating around the toner conveying means and blocking the passage to the toner conveying means.

[0005]

Therefore, what is stated in claim 1 is, for example, as shown in the following illustrated embodiment,
A cleaning device for an electrophotographic apparatus in which the toner t remaining on the photoconductor 11 after transfer is removed by a cleaning member such as a cleaning blade 34, and the removed toner t is transported by a toner transport means such as a toner transport screw 35. In FIG. 15, electrodes 38 and 40 are provided around the toner conveying means, and the toner t is attached to the electrodes 38 and 40.
It is characterized in that a DC voltage of opposite polarity is applied.

According to the second aspect of the present invention, the toner t remaining on the photoconductor 11 after transfer is removed by a cleaning member such as a cleaning blade 34 as shown in the following illustrated embodiment, and the toner t is removed. In the cleaning device 15 of the electrophotographic apparatus that conveys the toner t by the toner conveying means such as the toner conveying screw 35, electrodes 38 and 40 are provided around the toner conveying means, and AC voltage is applied to the electrodes 38 and 40. It is characterized by

[0007]

According to the first aspect of the present invention, at the time of cleaning, a DC voltage having a polarity opposite to that of the toner t is applied to the electrodes 38 and 40, the toner t removed by the cleaning member repels, and the periphery of the toner transporting means. Avoid sticking to.

According to the second aspect of the present invention, at the time of cleaning, the AC voltage is applied to the electrodes 38 and 40 so that the toner t removed by the cleaning member is vibrated so as not to adhere to the periphery of the toner conveying means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a laser printer provided with a cleaning device according to an embodiment of the present invention, and shows a general schematic configuration of its internal mechanism.

Reference numeral 10 in the drawing denotes a printer body. Inside the printer body 10, a drum-shaped photosensitive member 11 is provided at the substantially center. Around the photoconductor 11, a charging device 12, a developing device 13, a transfer device 14, and a cleaning device 15 according to the present invention are arranged in a driving direction indicated by an arrow in the figure. An optical writing device 16 is arranged above the charging device 12, the cleaning device 15, and the developing device 13. Then, on the right side of the apparatus main body 10 in the drawing, a paper feed cassette 17 accommodating the paper S is detachably provided.

When recording on the paper S using this laser printer, the paper feed roller 18 is rotationally driven to feed the paper S from the paper feed cassette 17 in the direction of arrow A in the figure, and the paper S Is conveyed to the lower side of the photoconductor 11 by the registration roller pair 19 at a timing.

The photoconductor 11 is rotationally driven in the clockwise direction indicated by the arrow, and at that time, the surface of the photoconductor 11 is uniformly charged by the charging device 12, and then the laser beam from the optical writing device 16 is irradiated to the photoconductor 11. Form an electrostatic latent image on top. This latent image is visualized by toner when passing through the position of the developing device 13. Then, this visible image is transferred by the transfer device 14 onto the upper surface of the sheet S conveyed to the lower side of the photoconductor 11.

After the image transfer, the sheet S is fixed to the fixing device 2
The image is conveyed to 0, and the transferred image is fixed by the fixing device 20.
After the fixing, the sheet S discharged from the fixing device 20 is conveyed to the conveyance path 21.
The sheet is conveyed through the inside, discharged by the pair of discharge rollers 22, and stacked on the discharge tray 23.

On the other hand, the cleaning device 15 removes the residual toner on the surface of the photoreceptor 11 after the image transfer.

By the way, the cleaning device 15 is
Specifically, the configuration is as shown in FIG. Reference numeral 30 in the figure
Is a cleaning case. The cleaning case 30 is formed in a horizontally long box shape, and a horizontally long toner recovery port 31 is opened on one side facing the photoconductor 11 and is provided in parallel with the photoconductor 11.

A film-like seal member 32 is provided on the lower side of the periphery of the toner recovery port 31. The film-like sealing member 32 has a base end attached to the cleaning case 30, a front end protruding obliquely upward from the toner recovery port 31, and is provided close to the peripheral surface of the photoconductor 11. The base end of the blade holder 33 is attached to the upper side of the peripheral edge of the toner recovery port 31. A cleaning blade 34 is provided at the tip of the blade holder 33. The cleaning blade 34 is formed in a horizontally long plate shape using an elastic material such as polyurethane, the base end is attached to the blade holder 33, and the tip is pressed against the surface of the photoconductor 11.

A toner carrying screw 35, which is a toner carrying means, is rotatably provided in the lower portion of the cleaning case 30.

Now, the cleaning device 1 according to the present invention
As shown in FIGS. 1 and 2, the reference numeral 5 designates two electrodes 38 on the periphery of the toner carrying screw 35 on which the scraped-off toner t easily accumulates, that is, on the inner surface of the lower edge of the toner recovery port 31. The ground electrodes 39 are alternately provided. Further, three electrodes 40 and two ground electrodes 41 are alternately provided on the inner surface of the lower portion of the rear wall of the cleaning case 30 on the side opposite to the toner recovery port 31 with the toner conveying screw 35 interposed therebetween. The electrodes 38 and 40 are lead wires 4
2 to the DC power source 43. Further, the ground electrodes 39 and 41 are grounded via the lead wire 44.

During cleaning, the photosensitive member 11 is rotated in the direction of the arrow in FIG.
Causes the electrodes 38 and 40 to have a polarity opposite to that of the toner t.
C voltage is applied.

Then, the toner t remaining on the photoconductor 11 after the transfer is scraped off by the tip of the cleaning blade 34, and the scraped toner t is guided to the toner carrying screw 35 side by the seal member 32, By the rotation of the toner transport screw 35, the toner is transported to the back or front of the paper in the drawing and discharged to the outside of the cleaning case 30.

During the cleaning, the electrodes 38 and 40 are
At the portion, the toner t repels as shown in FIG. 3 showing the electrode 40. Therefore, the scraped-off toner t does not adhere to the seal member 32, slides on the inclined surface thereof, and smoothly moves to the toner carrying screw 35 side. Further, the toner t scraped up by the toner carrying screw 35 does not adhere to the inner surface of the rear wall of the cleaning case 30 and falls by gravity and returns to the toner carrying screw 35 side again, as shown in the figure.

In the illustrated embodiment described above, the electrodes 38 and 40 are provided around the toner conveying screw 35, and a DC voltage having the opposite polarity to the toner t is applied to the electrodes 38 and 40. However, as shown in FIG. 5, the electrodes 38 and 40 are provided around the toner conveying screw 35, and the electrodes 38 and 40 are
The AC voltage may be applied to 0.

However, during cleaning, the AC power supply 45
When an AC voltage is applied to the electrodes 38 and 40,
The toner t between and the toner t between the electrodes 40 shown in FIG. 6 vibrate and are moved in the AC electric field. Therefore, the toner t scraped off does not adhere to the seal member 32, slides on the inclined surface thereof, and smoothly moves to the toner conveying screw 35 side. Further, the toner t scraped up by the toner carrying screw 35 does not adhere to the inner surface of the rear wall of the cleaning case 30 and falls by gravity and returns to the toner carrying screw 35 side again.

[0024]

As described above, according to the first aspect of the present invention, when cleaning, the electrode having a polarity opposite to that of the toner is used.
Since the C voltage is applied to prevent the toner removed by the cleaning member from repelling and adhering to the periphery of the toner conveying means, it is possible to prevent the toner from accumulating and blocking the passage to the toner conveying means. .

According to the second aspect of the present invention, at the time of cleaning, the AC voltage is applied to the electrodes so that the toner removed by the cleaning member is vibrated so as not to adhere to the periphery of the toner conveying means. It is possible to prevent the accumulation and blocking of the path to the toner conveying means.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a cleaning device that is an embodiment of the invention described in claim 1.

FIG. 2 is a perspective view of a part thereof.

FIG. 3 is an explanatory diagram showing a state in which toner repels and does not adhere to an electrode portion during the cleaning.

FIG. 4 is a schematic configuration diagram of an entire internal mechanism of a laser printer including the cleaning device.

FIG. 5 is a schematic configuration diagram of a cleaning device according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a state in which toner vibrates and does not adhere between electrodes during cleaning.

FIG. 7 is a state explanatory view showing a state where the cleaning blade of the conventional cleaning device scrapes off the residual toner on the photosensitive member.

FIG. 8 is a state explanatory view showing a state in which the scraped off toner is accumulated around the toner conveying means.

FIG. 9 is a state explanatory view showing a state in which the accumulated toner is used to block the passage to the toner conveying unit.

[Description of Reference Signs] 11 Photoreceptor 15 Cleaning Device 34 Cleaning Blade (Cleaning Member) 35 Toner Conveying Screw (Toner Conveying Means) 38/40 Electrode t Toner

Claims (2)

[Claims] 1. A cleaning device for an electrophotographic apparatus in which toner remaining on a photoconductor after transfer is removed by a cleaning member, and the removed toner is transported by a toner transport means, and an electrode is provided around the toner transport means. And a DC voltage having a polarity opposite to that of the toner is applied to the electrode,
Cleaning device for electrophotographic device. 2. A cleaning device for an electrophotographic apparatus, wherein a cleaning member removes toner remaining on a photoconductor after transfer, and the removed toner is conveyed by a toner conveying means. An electrode is provided around the toner conveying means. A cleaning device for an electrophotographic apparatus, which is provided and applies an AC voltage to its electrode.