JPS5928179A - Cleaning device - Google Patents

Abstract

PURPOSE:To heighten the efficiency of recovery of a toner and to prevent electric leakage between a recovering roll and a counter electrode by insulating electrically at least one of the recovering roll and counter electrode. CONSTITUTION:The surface of the counter electrode is covered with an insulator 13. By placing an insulator between the recovering roll 11 and counter electrode 12, the capacity of a capacitor between the recovering roll 11 and counter electrode 12 increases. Consequently, electric charge on the surface of the recovering roll 11 and counter electrode 12 increases. Accordingly, the toner 2 scraped off from a sleeve 9 by a scraper 10 and carrier 5 receives strong electric field between the recovering roll 11 and counter electrode 12, and the toner 21 is attracted electrostatically. The same result can be obtained by insulating the recovering roll side 11 instead of the counter electrode side 12, or insulating both.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for cleaning residual toner on an image bearing member. As a method for cleaning residual toner on an image bearing member, a carrier etc. formed on the peripheral surface of a rotating cylinder is used. There is a magnetic brush cleaning method in which residual [-toner] on an image carrier is attracted to a magnetic brush consisting of a magnetic brush. In this magnetic brush cleaning method, a method is known in which a voltage of opposite polarity to the toner is applied close to a magnetic brush roller forming a magnetic brush to electrically attach and collect the toner. In order to improve collection efficiency, a cleaning device has been proposed that is provided with a grounded counter electrode close to the collection roller. By providing a counter electrode, a strong electric field generated between the collecting roller causes the carriers to adhere to the collecting roller, while causing the carrier to flow down between the collecting roller and the collecting roller.

However, when using a conductive carrier such as magnetic powder as a carrier in the cleaning device described in 1-,
The nD overlapping phenomenon between the collection roller and the counter electrode is likely to occur and is dangerous, and becomes particularly noticeable when the toner concentration decreases. Furthermore, the amount of 1-ner charge in contact with the counter electrode tends to fluctuate, which adversely affects recovery efficiency.

It is an object of the present invention to provide a novel and highly useful cleaning device that eliminates the above-mentioned drawbacks.

An embodiment of the cleaning device according to the present invention will be described below with reference to the accompanying drawings. In FIG. 1, toner 2 remaining on the surface of a drum-shaped photoreceptor l, which is an example of an image carrier
is made easily peelable from the surface of the photoreceptor by a charging device (not shown), and is then attracted and carried by the ears of a magnetic brush on the circumferential surface of the sleeve 3 disposed close to the photoreceptor 1. The sleeve 3 has a magnet 4 inside, and magnetic brush ears made of the toner 2, carrier 5, etc. are formed on the circumferential surface.

The structure consisting of this sleeve 3 and magnet 4 is called a magnetic brush roller. A first transfer roller consisting of a rotating sleeve 7 and having a magnet 6 inside is disposed close to the side of the sleeve 3 remote from the photoreceptor 1. A second transfer roller consisting of a rotating sleeve 9 and also having a magnet 8 is arranged above this first transfer roller. Therefore, photoreceptor 1
The second toner 2 is attracted and carried by the magnetic brush roller, and then transferred together with the carrier 5 to the first transfer roller and the second transfer roller.

A scraper 10 is provided close to the sleeve 9 to receive the transferred toner and carrier, and a collection roller 11 is arranged at the other end of the scraper 10 with a slight spacing from the scraper. ing. Collection roller 1
A voltage of opposite polarity to the 1-ner is applied to J to attract and collect the 1-ner, and rotation is applied in the direction of the arrow.
are doing. Further, a counter electrode 12 is provided on the downstream side in the direction in which printed toner and carrier flow out from the scraper 10, facing the collection roller 1. A voltage of the same polarity as that of the toner is applied to the counter electrode 12, and its surface is coated with an insulator 13. Collection roller 11 and counter electrode 1
By inserting an insulator between the collecting roller 11 and the counter electrode 12, the capacitor capacity between the collecting roller 11 and the engraving electrode increases. will increase. Therefore, the toner and gear removed from the sleeve 9 by the scraper 10 receive a strong electric current 111 between the collecting roller and the stamping surface electrodes.
- The toner is electrostatically attracted to the surface of the collecting roller.

The 1-ner adsorbed to the collection roller 11 is scraped off by a blade l11 disposed in close contact with the collection roller and collected into the container 15. This recovered 1-ner is i13
It's great to be able to reuse it. The carrier and unrecovered 1-ner which have passed near the counter electrode are returned to the surface of the sleeve 3, and the doctor part 1.416 is placed with a slight gap from the sleeve 3 to the height of the ear of the magnetic brush. is adjusted and subjected to cleaning action again.

In the above embodiment, the first transfer roller and the second transfer roller are provided, but these transfer rollers may not be provided.
- It is also possible to collect the fuel.

The insulating material coated on the surface of the counter electrode is polyester film 11, preferably polyvinyl chloride or nylon.Also, the counter electrode side may not be insulated, the collection roller side may be insulated, or both may be insulated. . Furthermore, as a method of II@edge, in addition to insulating coating, the counter electrode and the collection roller surface are subjected to insulation treatment such as aluminium 1 treatment, Taflam treatment,
A Teflon knee may be used, and the opposing electrode may not be in the form of a roller as shown in FIG. 1, but may be in the form of a plate or a wire electrode.

FIG. 2 shows another embodiment of the present invention, in which a plurality of opposed electrode rollers 12', 12'' are provided, and an insulating belt 17 is used to wrap and pass the rollers to form a flow path for the JJu image agent. Here, the counter electrode 12'' is made movable,
By changing the distance between the collecting roller and the counter electrode depending on the claw of the flowing and falling developer, toner collecting efficiency can be increased and developer stagnation can be prevented.

According to the present invention, it is possible to improve the recovery efficiency of 1-ner and to prevent electrical leakage between the recovery roller and the counter electrode.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a magnetic brush type cleaning device according to one embodiment of the present invention, and FIG. 2 is a block diagram of main parts of a cleaning device using electrodes according to another example. 3. Sleeve, 10. Scraper. 11 ・Recovery roller, 12. 12', 12" counter electrode. Patent applicant: NE1 Co., Ltd. Liney Fig. 1 Fig. 2

Claims (1)

[Claims] A magnetic brush roller having a built-in magnet and having a magnetic carrier on its circumferential surface is rotatably held so as to rub the surface of the image carrier, and an IL provided adjacent to the magnetic brush roller. Alternatively, a scraper is provided adjacent to the magnetic brush roller and close to a transfer roller that has a built-in magnet and is rotatably held, and a voltage of opposite polarity to that of the 1-ner is applied to suck and collect the toner from the scraper. In a cleaning device for removing toner remaining on the surface of an image carrier, the cleaning device is configured to remove toner remaining on the surface of an image carrier, and a counter electrode is provided so as to be close to and opposite to the collecting roller. A cleaning device characterized in that at least one of a counter electrode and a counter electrode are electrically insulated.