JPS58198074A - Cleaning device of copying machine - Google Patents

Abstract

PURPOSE:To collect and recover dispersed toner with a simple configuration by charging electrostatically a belt travelling in parallel with a cleaning blade and spacing slightly from a photoreceptor to reverse polarity against the polarity electrostatically charged to the toner. CONSTITUTION:In a toner collecting device 10 provided with both side board 11 , 12 pivotally supporting the photoreceptor, a belt 16 is extended from roll 13 to 14 and a blade 17 is contacted with one end part of the belt 16. The lower travelling surface of the belt 16 has a slight gap (g) with the surface of the photoreceptor 1 and the belt 16 charged to the reverse polarity against the polarity charged to the toner is arranged on the back of the cleaning blade 9, so that the belt 16 adsorbes the toner collected and dispersed by the blade 9 and the blade 17 flicks the toner. If the collecting device 10 is made possible to be taken out as a unit, its maintenance is simplified and the toner can be collected with the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for an electrostatic copying machine such as an electrophotographic device or an electrostatic recording device, and particularly to a cleaning device for cleaning an image support such as a photoreceptor by a cleaning blade. The accumulated toner is removed from the cleaning blade 1 during non-image formation.
The present invention relates to a cleaning device for a copying machine of a type in which a node is separated from the surface of an image support so that the image support rotates once to be transported to a developing section and recovered there.

Cleaning devices used in electrostatic copying machines are generally of the fur brush type and the blade type. In a fur brush cleaning device, residual toner on an image support, such as a photoreceptor, is removed by a rotating fur brush. Tonner attached to the fur brush is removed from the brush by the flicker bar and transferred to the air suction device.
,! :l is transported and collected by a filter.

This type of device has a problem in that the air flow rate decreases due to toner clogging of the filter. As a countermeasure against this problem, a roller or disk for electrostatically collecting toner is provided in front of the filter. Generally, this type of device requires an air suction device, which increases the size of the device and has the disadvantage of generating vibration and noise.

In contrast, the single node cleaning device has the advantage of being more compact and requiring less space for the device. This type of apparatus also requires a conveying device for conveying the toner removed by the block node to the outside of the apparatus. This is normal.

Although it is a rotating uncoordinated force or a scree, if the image support is drum-shaped, there are naturally limitations on its placement position. That is, in order for the scraped toner removed by the pump node to be conveniently conveyed by the scree, the scree must be below the blade, and the blade is preferably located near the center of the drum. By installing a toner collecting member such as a rubber roller between the blade and the scree, the grade can be placed at a higher position.

However, if the toner is placed up to the top of the drum, the toner removed by the pull node will accumulate there, making it extremely difficult to properly recover the toner.

This problem can be solved by separating the blade from the drum surface during non-image forming, so that the toner accumulated on the drum is transported by the rotation of the drum. It was resolved by this. This makes the cleaning device even more compact and eliminates the need for a toner recovery device, which is advantageous in terms of cost. However, when the blade is moved away from the drum surface, the laminar flow of air caused by the movement of the drum surface, which had been blocked by the blade's contact with the drum surface until the blade was moved away, suddenly passes between the blade and the drum surface. Therefore, a new problem arises in that the accumulated toner is scattered due to the impact when the first node is separated. This scattered toner contaminates the corona charging device, exposure optical system, quenching lamp, erase lamp, etc. that are present before the current copy is produced, making it difficult to maintain constant image forming conditions. This is one of the causes of deterioration of image quality. In order to quickly collect scattered toner in the cleaning section,
Although it is unthinkable to provide an electrode roller that electrostatically collects the toner immediately downstream of the blade, it is also possible to use a device that transports the toner collected by the electrode roller in the axial direction of the roller and collects it once. It is not a good idea as it is necessary.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning device for a copying machine equipped with a toner collecting device that can easily collect and recover toner scattered from a cleaning section using a simple mechanism.

The toner collecting device in the present invention is located immediately downstream of the RI IJ = NGB 1 node in the direction of movement of the image support.

The cleaning belt is a belt that runs parallel to the node and slightly apart from the support, and is applied with a voltage of opposite polarity to the charged polarity of the toner or is charged with the belt. , to recover the toner electrostatically collected on this belt.

Brazed 4- provided in contact with the end of this belt Contains.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, referring to FIG. 1, an outline of a Kameko photocopying machine to which the present invention is applied will be explained. Around the photoreceptor drum 10, which is an image support, there are a charging charger 2, an exposure optical system 3, a border device 4, a transfer charger 5, a cleaning device 6 according to the present invention, and the like along the counterclockwise rotation direction thereof. A Quenten lamp 7 and the like are arranged. When the conductive surface of the photosensitive drum 10 is uniformly charged to a predetermined polarity, for example, positive, by the charging charger 2, an optical image of the original to be copied is irradiated thereon through the exposure optical system 3. As a result, the positive charge on the surface of the photoreceptor drum 1 is selectively dissipated depending on the brightness of the optical image, and an electrostatic charge a (IJ) is formed there due to the positive charge corresponding to the original image. The electrostatic latent @ is developed by supplying negatively charged toner from the developing device 4.The developed image formed by the adhesion of the negatively charged toner is: - Transfer paper 8 is overlapped under the transfer charger 5. The transfer paper 8 is transferred onto the transfer paper 8 by being positively charged by the transfer charger 5.While the transfer paper 8 is separated from the photoreceptor drum 1 and goes to the dipping device, the transfer paper 8 is transferred onto the photoreceptor drum 1. The remaining toner is removed by the blade 9 of the cleaning device 6. The cleaning blade 9 is placed near the top of the photoreceptor drum 1.
- It is provided so as to be able to approach and separate from the surface of the photoreceptor drum 1 in the IJ direction, and the residual toner scraped off by the blade 1 node 9 is transferred to the surface of the photoreceptor drum 1 and the blade that is inclined in the trailing direction relative to the surface of the photoreceptor drum 1. 1 node 9 is integrated in the horizontal part. This accumulated toner can be removed from the surface of the photoreceptor drum 1 by separating the IJ-ning blade 9 from the surface of the photoreceptor drum 1 after the quenching lamp 7 has completely eliminated the charges on the photoreceptor. Let's do it. When the blade 9 is separated from the surface of the photoreceptor 1, the movement of the surface of the photoreceptor 1, which was previously blocked by the contact of the blade 1 node 9 with the surface of the photoreceptor 1, creates a laminar flow of air, air. Since the toner rapidly passes through the space between the surface of the photoreceptor 1 and the tip of the blade 9, and due to the impact when the blade 9 separates from the surface of the photoreceptor 1, the accumulated toner tends to scatter and contaminate other members. There is. However, the toner that is about to fly away from this accumulating portion is quickly collected by the toner collecting device IO of the present invention, and is conveniently prevented from scattering to other parts.

FIG. 2 schematically shows the toner collecting device 10 of the present invention together with the photosensitive drum 1. As shown in FIG. This device 10 has a drive roller 1 running parallel to the axial direction of the photoreceptor drum 1 rotatably supported by side plates 11 and 12, and therefore parallel to the longitudinal direction of the cleaning blade 9.
3 and the driven roller 14, the belt 16 is tensioned by the tightener 15, and this belt 16
It includes a toner scraping node 17 provided in contact with the belt on one end of the drive roller 13, for example, and a menu IS for receiving the scraped toner. . The belt 16 is preferably arranged so that an air gap g of about 2 to 3 exists between its lower running surface and the surface of the photoreceptor 1 parallel to the belt. , a metal layer on a metal belt or polyester film is used,
A voltage having a polarity opposite to that of the toner is applied using a conductive brush 19 or a conductive roller as shown. What is the magnitude of this voltage?

Although it varies depending on various circumstances, about IKV 8 degrees is preferable. When forming the belt 16 by providing a metal layer on a resin film, it is not a uniform metal layer over the entire surface, but a continuous pattern such as vertical stripes or a mesh, so that an electric field can be applied to the edge of the pattern. Since the toner can be concentrated, scattered toner can be collected effectively. Further, instead of applying a voltage directly to the conductive belt 16, the dielectric belt or the dielectric belt with a conductive layer can be charged with a corona charger, and the toner can be scraped off and rubbed by the bull node 17. It can also be electrically charged. In the latter case, the materials of the blade 17 and the belt 16 are selected such that the belt 16 is charged with a polarity opposite to that of the toner.
Of course, the method should be selected from among the triboelectrification series, but this has the advantage of not requiring a special electric source.

In this way, since the belt 16 to which a voltage of opposite polarity to the toner is applied or charged is provided close to the surface of the photoreceptor drum 10 immediately after the cleaning blade 9,
The toner scattered from the toner accumulated and scattered by grade 9 is quickly adsorbed to the surface of the belt 16 and is not carried out to the outside of the cleaning device 6, and contamination of other members by the scattered toner is effectively prevented. . The toner adhering to the belt 16 is scraped off from the belt 16 by a scraping blade 17, which is usually preferably a polyester film with a thickness of about 0.2 tnm, and collected in a hopper 18 below. to snatch The collected toner is stored in this hopper 18 or guided into the current iron device 4 from this hopper 18. If such a toner collecting device 10 is made into a unit so that it can be taken out parallel to the drum axis, maintenance of the belt, brush, blade, etc. will be facilitated.

As described above, since the present invention uses a belt to collect scattered toner, the effective electric field area for toner collection can be made wider than that of the roller type, and moreover, the electric field area can be completely covered by the photoreceptor drum. Can be placed close to the surface. It's a moat, because this belt Y is moved parallel to the photoconductor drum axis.

The number of layers of toner adhering to the belt surface does not increase beyond a certain amount, so the collection electric field strength does not weaken, and toner can be collected efficiently. Since the toner collected on the belt is conveyed by the belt and scraped off by the blade, no special toner conveying means is required.

The present invention is particularly suitable for application to a type of copying machine that utilizes a multi-sheet transfer process in which an electrostatic image once created is used multiple times to repeat visual image and transfer operations.

In such a copying machine, it is impossible to keep the cleaning blade in constant contact with the surface of the photoreceptor.

This is undesirable because the surface of the photoreceptor is charged and the contrast of the latent image potential is lowered, and the cleaning blade is normally brought into contact with the surface of the photoreceptor only after the transfer is completed. The present invention can be applied to copying machines in which the image support uses not only a photoreceptor but also a dielectric, and the image support may be not only drum-shaped but also belt-shaped. In addition, various modifications of this invention (A, all modifications within the scope of the spirit of this invention as set forth in the claims) are included in this invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an electrophotographic copying machine to which the present invention is applied, and FIG. 2 is a diagram schematically showing a toner collecting device in the present invention. 1... Photosensitive drum, 6... Cleaning device, 9... Cleaning blade, IO...
- Toner collection device, 16... belt. 17...Scraping blade.

Claims (1)

[Scope of Claims] Toner removed from and accumulated on the image support is transferred to the cleaning blade by moving the blade away from the surface of the image support during non-image formation. In a cleaning device for a copying machine in which the image support is transported to a developing section and collected there. A device for collecting and recovering the toner scattered when the blade is separated from the image support, the device being installed parallel to the blade immediately downstream of the B1 node in the moving direction of the F-image support. a belt to which a voltage having a polarity opposite to that of the toner is applied or charged, the belt running at a slight distance from the image support; a cleaning device for a copying machine, comprising a toner collecting device including a blade provided in contact with an end of the belt to collect toner;