JPS60179773A - Device for removing foreign matter from recovered toner - Google Patents

Abstract

PURPOSE:To remove reversely polarized toner and foreign matters from recovered toner so that only positively polarized toner can be recirculated to a developer, by connecting a conductive pipe to the midway of the auger pipe of an auger which feeds the recovered toner through insulating members and impressing a bias voltage upon the conductive pipe. CONSTITUTION:A conductive pipe 50 of aluminium, etc., is connected with the midway in the direction of length of the auger pipe 4 of an auger 3 through a pair of annular insulating members 51 and 51' and an opening 52 is provided at the bottom of the conductive pipe 50. The conductive pipe 50 is connected with a bias power source 53 and a bias voltage of a polarity opposite to that of positively polarized toner is impressed upon the pipe 50. When recovered toner carried by the auger 3 passes through the conductive pipe 50, upon which the negatively polarized bias voltage is impressed, only positively polarized toner of the recovered toner is electrostatically attracted to the inner surface of the conductive pipe 50 and carried to the toner box 21 of a developer 20 without falling down through the opening 52.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a toner collection and reuse device that collects toner remaining on a photoreceptor of an electrophotographic copying machine and conveys it to a developing device for reuse. This invention relates to a device for removing foreign matter.

Prior Art Conventional electrophotographic copying machines use a rotating drum as the photoreceptor, but in order to make repeated copies, the toner remaining on the photoreceptor drum due to insufficient transfer must be cleaned. No.

As a cleaning method, there is one that uses a brush. In this brush cleaning device, a rotating brush is brought into contact with the surface of a rotating photoreceptor drum, and the toner remaining on the photoreceptor drum is scraped off with the bristles of the brush and carried out by an air flow. The drawn toner is collected by the cyclone filter dust collector, but it is not possible to automatically and continuously carry out the collected toner while the cyclone filter is in operation and supply it to the developer toner box as recycled toner. Ta. The reason is that the inside of the cyclone filter dust collection part is 100~! If a negative pressure of about 100IIIA (L) is created and an ejection path is provided to automatically and continuously collect the collected toner from the dust collection section, air will flow into the dust collection section through the circulating section, and the cyclone filter will This is because the separation efficiency decreases significantly.

In order to solve this problem, a method has already been proposed that uses a rotary valve to take out the collected toner (for example, see Japanese Patent Application Laid-Open No. 1983-95624). A rotary valve with multiple blades is installed in the cyclone filter, and as the valve rotates, the toner collected in the cyclone filter is taken out one by one, and is continuously supplied to the toner box of the developing device by an auger, which is a conveyor with a set of screws. It is something to do.

However, the toner collected as described above contains foreign matter such as reverse polarity toner, coarse particles of toner, paper dust, and brush fibers, and if the collected toner is transported to a developing device and reused, it will not be possible to develop the toner. This has the problem of causing problems such as poor image quality of copies.

OBJECT OF THE INVENTION It is an object of the invention to remove toner of opposite polarity and foreign matter from collected toner so that only toner of positive polarity can be conveyed to a developing device.

Structure of the Invention A conductive pipe is connected through an insulating material to the auger vibe of an auger that conveys collected toner, and a bias voltage is applied to this conductive pipe.

Embodiment FIG. 1 is a schematic explanatory diagram of a toner collection and reuse device.A charging device, an exposure system, a developing device 20, a transfer device, and a cleaning device 3 are arranged around the photosensitive drum 10 in a normal layout.
0 is placed. The toner image formed on the photoreceptor drum 10 is transferred to paper in a transfer process, but residual toner adheres to the surface of the photoreceptor after the transfer. This residual toner is removed by a cleaning device 301C.

An AC voltage (*c6xv, Do-2Kv) on which a negative bias voltage is superimposed is applied to the entrance side of the cleaning device 30.
) is applied to the static eliminating corotron 31 and the static eliminating rung 3.
2 are arranged. In the cleaning device 30, the first and second brush rolls 33 and 34 equipped with brushes made of insulating fiber form a nip (nIp) with respect to the photoreceptor drum 10 at a depth of approximately 1.5 mm. )l and are arranged so as to be in sliding contact with each other. Moreover, both rolls are 35.5
4 is rotated at 120 rpm in the opposite direction and the same direction with respect to the 100 rotations of the photoreceptor drum.

Additionally, both rolls ss, g<, first and second flicker bars (flokar bar"> 35,
56 are in sliding contact, and the first and second flicker bars are connected to a DC high voltage power source 37 (DC+4KV) and a DC high voltage power source 38, respectively.
(DO-4Kv).

Therefore, the residual toner after the transfer is electrostatically strongly adhered to the surface of the photoreceptor drum 10, and reaches the position of the cleaning device 30 as the photoreceptor drum rotates. Before entering the gap, first, the surface of the photoreceptor drum 1o and the residual toner are neutralized by the action of the AO discharge of the static elimination corotron 31 and the static elimination lamp 52, and the -DO discharge of the static elimination corotron 31 also causes the photosensitive drum 1o to be neutralized. The surface of the body drum 100 and the remaining toner are electrically charged. Therefore, the residual toner adheres to the surface of the photoreceptor 100 in an extremely unstable state, enters the cleaning device 50, and comes into sliding contact with the first brush swirl 33.

(g) When the first brush roll 33 comes into contact with the charged residual toner that is unstablely attached to the surface of the photoreceptor drum, approximately 90% of the residual toner is removed by electrostatic absorption and mechanical wiping action. It is removed from the surface of the photoreceptor drum 100.

Then, approximately 10% of the residual toner that has adhered to the surface of the photoreceptor drum 10 in an unstable state comes into sliding contact with the second brush roll 54.

The second brush roll 54 is (→ charged, so it is 0
The charged residual toner is electrostatically repelled and subjected to mechanical wiping action to completely remove and clean the residual toner from the surface of the photoreceptor drum 100.

Further, the toner removed from the surface of the photoreceptor drum 10 by the action of the first and second brush rolls 5g and 54 is
The brush fibers of each brush roll 53, 34 are brushed off by the action of the second flicker bar 55, 56, and transported to the cyclone filter 1 along with the air flow through the cleaner duct 39 and the connecting duct 40 by the suction force of the blower. be done.

In the cyclone filter 1, the toner is separated from the air stream and settles downward.

A rotary valve 2 is disposed at the bottom of the cyclone filter 1, and a rotating rotary pulp 2 is installed at the bottom of the cyclone filter 1.
Due to this action, the settled toner is carried out to the lower space A without breaking the airtightness of the cyclone filter 1. The discharged toner is conveyed by the rotating auger 3 and collected as recycled toner into the toner box 21 of the developing device 20.

a longitudinally intermediate portion of the auger pipe 4 of the auger 3;
A pair of annular insulating materials 51 are provided in the intermediate path of the tab.
, 51', a conductive pipe 50 made of aluminum or the like is connected, and the lower end of the conductive pipe 50 has an opening 52, and is connected to a bias power supply 53 to supply toner of positive polarity and toner of opposite polarity. Bias voltage is applied.

In the embodiment, a bias voltage of about -500 to 1000 V is applied.

A toner box 54 for storing waste toner is provided below the opening 52 of the conductive pipe 50.

Thus, the recovered toner conveyed by the auger 3 is transferred to the conductive pipe 50 to which a negative bias voltage is applied.
When the toner is applied, only the positive donor in the recovered toner is electrostatically attracted to the wall surface of the conductive pipe 50 and transported by the auger 3 to the toner box 21 of the developing device 20 without falling through the opening 52. Ru.

However, due to electrostatic repulsion, negative toner (reverse polarity toner) in the collected toner falls away from the wall surface of the conductive pipe 50 and falls into the city box 54 through the opening 52. Foreign matter such as paper powder and brush fibers fall into the seat box 54 through the opening 52.

For this reason, only the positive donor (positive polarity toner) is transported into the toner box 21 of the developing device 20, so even if the collected toner is reused, image quality defects will not occur.

Effects of the invention Since the reverse polarity toner and foreign matter in the recovered toner are removed and only the positive polarity toner is transported to the developing device, there is no problem with development and there is no possibility of poor image quality in copies. .

[Brief explanation of drawings]

The drawings show an embodiment of the present invention. Stripe 1 is a schematic explanatory diagram of a toner collection and reuse device, FIG. ■Line, ff-ff
FIG. 3 is an auger, 4 is an auger pipe, 10 is a photoreceptor, 50 is a conductive pipe, and 51.51' is an insulating material. Applicant Fuji Xerox Co., Ltd. Agent Patent Attorney Tadashi Yonehara / Patent Attorney Kazumoto Tadashi Hama Figure 1

Claims (1)

[Claims] The toner remaining on the photoreceptor 10 is collected and conveyed to the developing device 20 by the auger 3, and a conductive pipe 50 is installed in the middle of the auger pipe 4 of the auger 3 through insulating materials 51 and 51'. A device for removing foreign matter from collected toner, characterized in that a bias voltage is applied to the conductive pipe 50.