JPH03144686A - Cleaner for image forming device - Google Patents

Abstract

PURPOSE:To reuse carriers by recovering toner removed from a image carrying body by a scraper and recovering carriers which are beaten off from an image carrier by a brush roller. CONSTITUTION:Residual toner T on a photosensitive body 6 is scraped off with the brush fur 11 of a brush roller 1 applied with a bias voltage and also attracted electrically to the brush fur 11. The toner T attracted to the brush fur 11 is recovered onto the recovery roller 2 applied with the bias voltage and the toner on the roller is scraped off by the scraper 3 to fall on a conveyance device 4, so that the toner is recovered by the rotation of a conveyance coil 41. Carriers C sticking on the photosensitive body 6, on the other hand, are beaten off the photosensitive body 6 as the brush roller 1 rotates to fall on the conveyance device 5 provided in a carrier scatter area on the downstream side in the rotating direction of the brush roller 1. The carriers are carried out of the cleaning device by a rotating conveyance coil 51, returned to a developing device 27, and reused. Consequently, the carriers can be reused.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaner unit for an image forming apparatus such as a copying machine or a printer.

[Conventional technology]

In electrophotographic image forming apparatuses such as copying machines and printers, an image carrier having a photoconductive photosensitive layer on the surface is used, and image information is exposed onto the surface of the image carrier to form an electrostatic latent image. This latent image is developed by a developing device to form a toner image, and this toner image is transferred to a transfer material and fixed.

However, when transferring the toner image from the image carrier to the transfer material,
Some toner remains on the image carrier.

Therefore, in order to clean this residual toner from the image carrier and prepare for the next operation, a cleaning device is provided for cleaning the residual toner.

There are several types of cleaning devices, one of which uses a brush roller.

A cleaning device using a brush roller, for example, has a second brush roller.
As shown in the figure, a bias voltage (not shown) is applied to the brush roller 8 that rubs the image bearing member (photoreceptor drum in the illustrated example) 6 to remove residual toner on the photoreceptor 6 onto the brush roller 8. Furthermore, a bias voltage (not shown) is applied to a collection roller 9 in contact with the brush roller 8 to collect toner from the brush roller onto the collection roller 9.

The principle of removing residual toner from the image carrier 4 by the brush roller 8 is as shown in FIG.

That is, for example, if the toner T is charged to a positive polarity, the brush bristles 81 constituting the brush roller 8 are charged to a negative polarity, and as the brush bristles rub the surface of the image carrier 4, the toner T is charged. It is scraped off by the brush bristles 81 and is electrically attracted and removed.

The toner captured by the collection roller 9 is scraped off by a scraper IO, and the toner is removed from the toner collection path 10 below the collection roller.
0, and is collected into a toner collection bottle (not shown) by a rotary conveyance means such as a coil or screw provided there.

In addition to the conventional cleaning device mentioned above, there is also a
As disclosed in Japanese Patent No. 22678, a brush roller type cleaning device has also been proposed that separately removes positively charged toner and collects only the positively charged toner so that it can be reused.

Further, Japanese Patent Application Laid-Open No. 14328/1983 discloses a method of collecting and reusing only toner having a polarity suitable for development.

[Problem to be solved by the invention]

However, as shown in FIG. 3, after the toner image is transferred to the transfer material, not only the toner T but also some carrier C remains on the image carrier 6. This carrier C is negatively charged in the example shown in FIG. The particles are thrown off from the image carrier 4 and deposited on the bottom plate of the housing h of the cleaning device.

When the carrier C is gradually removed from the developer in this way, the amount of developer in the developing device decreases, causing poor development.

In addition, the carrier C deposited on the housing bottom plate in this way
There is also the problem that the toner spills out of the cleaning device, contaminates the inside of the image forming apparatus, and falls onto the transfer material passing below, causing image disturbance.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a brush roller type cleaning device that collects and reuses carriers that have been brushed off from an image bearing member by a brush roller without spilling out of the cleaning device. An object of the present invention is to provide a cleaning device that can prevent contamination within the transfer material and disturbance of the image on the transfer material.

[Means to solve the problem]

In accordance with the above object, the present invention applies a bias voltage to a brush roller that rubs an image carrier to remove residual toner on the image carrier onto the brush roller, and applies a bias voltage to a collection roller in contact with the brush roller. In a cleaning device for an image forming apparatus, the toner is collected from the brush roller onto the collection roller by applying a pressure to the collection roller, and the toner on the collection roller is scraped off by a scraper, in which the toner removed from the collection roller by the scraper is collected. The present invention provides a cleaning device comprising: a first conveyance means for removing the carrier; and a second conveyance means for recovering the carrier brushed off from the image bearing member by the brush roller.

It is preferable that the second transport means is capable of returning the recovered carrier to the developing device.

[For production]

According to the cleaning device of the present invention, the toner remaining on the image carrier is removed onto the brush roller, and the toner on the brush roller is collected onto the collection roller in contact with the brush roller. The toner on the collection roller is scraped off from the roller by a scraper, and is transported to a toner collection bottle by the first transport means.

The carrier attached to the image carrier along with the residual toner is brushed off from the image carrier by the rotation of the brush roller, and the dropped carrier is collected by the second conveying means. When the second transport means is capable of returning the recovered carrier to the developing device, the second transport means returns the carrier to the developing device.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The cleaning device A shown in FIG. 1 is installed in a printer, and is provided with a brush roller 1 and a collection roller 2 in a housing H, and the brush roller 1 has conductive bristles 11. This is in contact with the photoreceptor 6, and both rollers are rotated in the direction of the arrow in the figure by a driving means (not shown).

A bias voltage V is applied to the brush roller 1 to capture the toner T on the photoreceptor 6, and a bias voltage Vbz is applied to the collection roller 2 to collect the toner from the roller 1 onto the roller 2. ing.

A scraper 3 is in contact with the lower surface of the collection roller 2.

The scraper 3 is attached to a scraper holding member 31 rotatably supported by the housing H.
is applied a force to the spring 32, which causes the scraper 3 to
is in contact with the collection roller 2.

Two conveying devices 4 and 5 are provided below the brush roller 1. , the R feeding device 4 conveys the toner scraped off from the collection roller 2 by the scraper 3 to a toner collection bottle (not shown) by rotation of a conveyance coil 41. The conveying device 5 collects carriers knocked off the photoreceptor 6 by the brush roller 1 using a rotating conveying coil 51. Although not shown in the drawings, one end of a conveying means such as a tube-shaped body having a built-in rotating coil for conveying the carrier is connected to the device 5, and the other end is connected to the developing device 72, and the recovered carrier is connected to the device 5. may be directly returned to the developing device 72.

Note that the photoreceptor 6 is driven in the direction of the arrow in the figure by a drive means (not shown), and a charger 71 is provided around the photoreceptor 6.
Developing device 72, transfer charger 73, separation charger 74
, the cleaning device A, and the eraser 75 are arranged in this order.

An electrostatic latent image is formed on the photoreceptor 6 by exposure from the direction indicated by the arrow in the figure according to the image information. The toner image is transferred to a transfer material (not shown), which is separated from the photoreceptor 6 by a separation charger 74, and then the toner image on the transfer material is fixed by a fixing device (not shown). After the toner image is transferred to the transfer material, the toner T remaining on the photoconductor 6 and the carrier C attached to the photoconductor 6 together with the toner are removed from the photoconductor 6 by a cleaning device A.

That is, the residual toner T on the photoreceptor 6 is scraped off by the bristles 11 of the brush roller 1 to which a bias voltage is applied, and is electrically attracted to the bristles. The toner T attracted to the brush bristles 11 is collected on a collection roller 2 to which a bias voltage is applied, and the toner on the roller is scraped off by a scraper 3 and falls onto a conveying device 4 . The toner that has fallen onto the conveyance device 4 is collected by the rotation of the conveyance coil 41 into a toner collection bottle (not shown).

On the other hand, the carrier C adhering to the photoreceptor 6 is brushed off from the photoreceptor 6 as the brush roller 1 rotates.
The carrier falls onto a conveying device 5 provided in a carrier scattering area on the downstream side in the rotating direction of the brush roller 1, is carried out of the cleaning device by a rotating conveying coil 5, and is returned to the developing device 72 for reuse.

According to the embodiment, the carrier C recovered by the conveying device 5 is a normal carrier that has not been rubbed by the scraper 3, and therefore can be returned to the developing device 72 and reused. Further, the toner T that may be mixed into this carrier C is not rubbed by the scraper 3,
Therefore, since there is no risk of deterioration in quality due to rubbing, there is no problem in returning it to the developing carrier 72 together with the carrier C.

Incidentally, it goes without saying that the present invention can also be applied to an apparatus using a -component developer. In other words,
Since the toner that has received a transfer charge during transfer and the toner that has not received a transfer charge have different polarities, it is possible to collect and transport both toners through separate routes.

〔Effect of the invention〕

The cleaning device of the present invention has the following advantages.

■ Normal developer (mainly carrier) that has not been deteriorated by being rubbed with a scraper can be collected and reused, which prevents the amount of developer (mainly carrier) from decreasing and ensures stable images. .

(2) There is no carrier scattering from the cleaning device, and contamination within the image forming device and disturbance of the image on the transfer material are reduced accordingly.

■ No magnet is required to collect the carrier or separate the carrier from the toner, which can reduce costs accordingly.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention together with a photoreceptor, etc., FIG. 2 is an explanatory diagram of a conventional example, and FIG. 3 is an explanation of a state in which toner and carrier are removed from an image carrier using brush bristles. It is a diagram. l... Brush roller 2... Recovery roller ■, Vb2... Bias voltage 3... Scraper 4... Toner transport device 5... Carrier transport device 6... Photoreceptor T... Toner C...Carrier applicant 5 Norta Camera Co., Ltd.

Claims (2)

[Claims] (1) Applying a bias voltage to a brush roller that rubs the image carrier to remove residual toner on the image carrier onto the brush roller, and applying a bias voltage to a collection roller in contact with the brush roller. In a cleaning device for an image forming apparatus that collects toner from the brush roller onto the collection roller and scrapes off the toner on the collection roller with a scraper, a first cleaning device for collecting the toner removed from the collection roller by the scraper; A cleaning device comprising: a conveying means; and a second conveying means for recovering the carrier knocked off the image carrier by the brush roller. (2) The cleaning device according to claim 1, wherein the second transport means is capable of returning the collected carrier to the developing device.