JPS61122678A - Brush cleaning device of electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To simplify the mechanism of a toner recovery/reusing device and to improve the performance of the titled device by individually removing positively charged toner, paper powder and negatively charged toner and reusing only the positively charged toner. CONSTITUTION:Only the positively charged toner out of the toner and paper powder adhered to the surface of a photosensitive body 1 is adsorbed by the 1st cleaning brush 5 and removed from the body 1. The toner adsorbed by the 1st cleaning brush 5 is adsorbed by a dittoing roll 9, removed from the brush 5, scraped by a scraper 10, and then carried to a developing device by a carrying means 11 so as to be reused. On the other hand, the negatively charged toner and paper powder which can not be removed by the brush 5 are removed by the 2nd cleaning brush 6, carried through a dittoing roll 16, a scraper 19 and a carrying means and removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an electronic copying machine gluing device that uses a brush roll to remove untransferred toner remaining on the surface of a photoreceptor.

2. Description of the Related Art Conventional electronic copying machines have been equipped with a cleaning device that uses a cleaning brush to wipe away untransferred toner remaining on the surface of a photoreceptor after a transfer process.

However, the remaining toner removed from the photoreceptor is contaminated with foreign matter such as paper dust, and when such recovered toner is reused, it has the drawback of adversely affecting copy image quality.

In order to solve this problem, the Japanese Unexamined Patent Publication No. 5
A cyclone filter dust collector described in Japanese Patent No. 8-186781 is known. Between this cyclone filter dust collector Fi rotary pulp a and the auger b for carrying out toner, there is a scavenging roll d connected to a DC high-voltage power supply C so that only toner is adsorbed, and the scavenging roll d is adsorbed to the toner. The auger B for carrying out the toner
By providing a scraper in the cyclone filter, only the positive polarity toner is separated by the scavenging roll d and the scraper O while the toner collected in the cyclone filter is transferred from the rotary pulp a to the toner discharge auger b, and foreign matter is not mixed in. Only positive polarity toner is supplied to the developer as reused toner.

Problems to be Solved by the Invention This invention is a toner collection and reuse device that can maintain good image quality even when the collected toner is reused. Since this is necessary, the device becomes larger.

Further, there are disadvantages in that a considerable amount of noise is generated and that the cleaning brush rotates at a high speed, causing the brush and photoreceptor to wear out quickly. This invention collects paper fibers mixed into the untransferred toner, paper powder such as Merck adhering to the paper, and toner whose polarity has been reversed in the transfer process from the photoreceptor together with the positively charged toner. The purpose is to eliminate problems such as deteriorating image quality and shortening the lifespan of the developer because it is sent to the developing device and reused, and to simplify the mechanism of the toner collection and reuse device while improving performance. be.

Methods and functions for solving the problem: Positively charging untransferred toner and paper dust in front of a cleaning brush that removes untransferred toner and paper dust remaining on the surface of the photoreceptor after transfer 1 from the surface of the photoreceptor. A corona irradiation means is provided to charge the untransferred toner to a positive polarity, and the strongly negatively charged paper powder is charged to an extent that it does not change to a positive polarity, and a negative DC power is applied to the cleaning brush. Then, the negative paper powder and some of the negative toner that could not be removed by the first cleaning brush are cleaned and collected by the second cleaning brush to which a positive DC voltage is applied. Electronic copying machine plug + 7-eng device.

Practical Example One embodiment of the present invention will be described in detail with reference to the drawings. In the drawing, 1 denotes a belt-shaped (or drum-shaped) photoreceptor provided in the main body (not shown) of an electronic copying machine; 2 is a first pre-cleaning corotron that charges the untransferred toner remaining on the surface of the photoreceptor 10. By irradiating the surface of the photoreceptor 1 with a positive corona, the untransferred toner on the surface of the photoreceptor 1 (see FIG. (A) with the charge distribution shown in FIG. 3 (A) and the paper powder mixed therein (with the charge distribution shown in FIG. It has become. At this time, if the corona is too strong, the toner and paper powder will be positively charged, so if the width of the photoreceptor 1 is 400 tm, the corotron axial length is low.
Corona irradiation of about 1-2 μA is appropriate.

On the other hand, reference numeral 3 denotes the main body of this device which is provided behind the first pre-cleaning corotron 2, and inside a housing 4 whose bottom surface is open, there are two first
- Second IJ-Jung plastics 5 and 6 are accommodated.

1st IJ - fibers with a thickness of 3 to 15 denier with an outer diameter of 30 to
The brushes are planted on a roll 5α of 60m2 at a density of 20,000 to 60,000 pieces, and the brush body is bound in the direction of the arrow K to.

It is rotated at a speed of ~300 rpm, and a voltage of -200 to 40 or is applied from a DC power source 7.

As a result, among the toner and paper powder adhering to the surface of the photoconductor 1, only the positively charged toner (the shaded area in FIG. 4(a)) is attracted to the first cleaning plaque 5 and removed from the photoconductor 1. Then, toner and paper powder shown by diagonal lines in FIGS. 4(a) and 4(b) remain on the photoreceptor 1. Further, the toner adsorbed to the first cleaning brush 5 is adsorbed to the detoning roll 9 which has the same polarity as the plaque 5 and is applied by a DC power source 8 having a potential difference of 200 to 400 V with respect to the brush 5. The toner removed from the first cleaning plaque 5 and adsorbed on the detoning roll 9 is scraped off by a scraper 10 and then transported to a developing device (not shown) by a transporting means 11 such as an auger, where it is reused.

On the other hand, a second cleaning corotron 13 is provided between the first and second cleaning brushes 5 and 6, and irradiates the toner and paper dust not removed by the first cleaning brush 5 with a negative corona. As a result, the amount of toner and paper powder is as shown in Figure 5 (/l)! The cleaning brush 6 is negatively charged and reaches the second cleaning brush 6 as shown in FIG.

The second cleaning brush 6 and the first cleaning brush 5
It is a brush body similar to that of the first cleaning brush 5, and is rotated in the opposite direction to the first cleaning brush 5, and a voltage of +200 to 400 V with a polarity opposite to that of the first cleaning brush 5 is applied from the DC power supply 14.

As a result, toner and paper powder on the photoconductor 1 (Fig. 6H)
, (b)) are removed from the photoreceptor 1, and the photoreceptor I paste IJ-Jung is completed.

Further, the toner and paper powder adsorbed by the second cleaning brush 6 are removed by the DC power source 1 which has the same polarity as the second cleaning brush 6 and 6 and has a potential difference of 200 to 400 V with the brush 6.
After being adsorbed by the detoning roll 16 applied by the roller 5, it is scraped up by the scraper 19, and further carried out by the conveying means j8 and discarded.

In addition, Fig. 7 (a), (b) to Fig. 11 (a), (
b) is the first cleaning corotron 3. First cleaning brush5. 2nd buri cleaning corotron 13
．． This shows the cleaning process when the second cleaning brush 6 has the opposite polarity to that in the above embodiment.
As shown in Figures (A) and (B), not only is it impossible to separate the toner and paper dust, but the toner that is reframed has negative polarity, so if it is reused, it will cause background stains, a decrease in image S, and black spots. To prevent deterioration of image quality such as the occurrence of , it is preferable to set the polarity of each part as in the above embodiment.

Furthermore, in the above embodiment, toner and paper powder on the photoreceptor i were electrostatically adsorbed by the cleaning brush 5.6, but in a magnetic brush cleaning device in which the bluff 5 and the brush 6t were replaced with a magnetic brush roll. can also have a similar configuration. Furthermore, the second cleaning brush 6 may be omitted if it is acceptable that the cleaning efficiency decreases to some extent.

On the other hand, in FIG. 3, an insulating partition plate 17 is provided between the first and second cleaning brushes 5 and 60, and DC voltages of opposite polarity are applied between the first and second cleaning brushes 5 and 6. This prevents the occurrence of corona discharge and spark discharge, and in the above embodiment, a semi-cylindrical shield case 170 is provided below the partition plate 17, and inside this shield case I'M. 2nd buri cleaning corotron 1
It accommodates 3. When corona discharge occurs between the cleaning brushes 5 and 6, the charged polarity of the toner is reversed and not only is the toner not detoned, but it also adheres to the photoreceptor 1 again, resulting in poor cleaning.

In addition, if a spark discharge occurs, toner and chemical substances that are flammable may be removed.
There is a risk that the fibers of Jungplassi 5 and 6 will catch fire. Therefore, a partition plate 1 is installed between the 1st-g2 cleaning bluffs 5 and 6.
By providing the cleaning bluffs 7, these problems can be solved, and since the cleaning bluffs 5 and 6 can be brought closer to each other, the main body 3 can be made smaller.

Effects of the Invention As described in detail above, the present invention separately removes positively charged toner, paper powder, and negatively charged toner from untransferred toner remaining on the surface of the photoconductor after the transfer process, and removes the positively charged toner. Since only the toner is reused, there is no possibility of paper dust or negatively charged toner getting mixed into the developer and adversely affecting image quality.2) The configuration of the device is simplified; The noise is also very low, and the wear and tear on the cleaning brush and photoreceptor can be significantly reduced.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a cross-sectional view, FIGS. , (Figures 1 to 11 (a),
(b) is an explanatory diagram of the effect when the polarity is opposite to that of the example, the first
FIG. 2 is an explanatory diagram of another embodiment, and FIG. 13 is an explanatory diagram of the conventional method. 1 is a photoreceptor, 5 is a cleaning brush, and 7 is a DC power supply.

Claims (1)

[Claims] In a cleaning device that uses a conductive cleaning brush 5 to remove untransferred toner remaining on the surface of the photoreceptor 1 after the transfer process, a positive corona is applied to the photoreceptor between a transfer means and a cleaning means provided near the photoreceptor 1. An electronic copying machine comprising: a first cleaning brush roll 5 to which a negative voltage is applied; and a second cleaning roll 6 to which a positive voltage is applied. brush cleaning device.