JPS58186774A - Brush cleaning method of electronic copying machine - Google Patents

Abstract

PURPOSE:To prevent a toner from dropping from a flicker bar when a copying machine is stopped, by inverting the polarity of DC voltage to both fricker bars immediately before its supply is stopped. CONSTITUTION:When stopping a copying machine, immediately before the voltage supply is stopped, the polarity of voltage impressing to both flicker bars 6, 6' is inverted for about one second, and after that, the voltage supply is stopped. The supply stop time of impressed voltage to the flickers 6, 6' precedes the supply stop time of power to a vacuum source, or is the same time as the latter. During the period in which said voltage supply is inverted, the direction of an electric field between both the flickers 6, 6' is reversed, Coulomb force operates so that a toner adhering to one fricker bar 6 and a toner adhering to the other fricker bar 6' adhere to the other fricker bar and one fricker bar, respectively, and the accumulated toner layer collapses or strength of the adhering force is reduced remarkably. At the time for generating this state, the vacuum source is still operated, and the toner which collapses or reduces its adhering force by force by wind pressure of air flowing in the slit is carried in the direction of a duct 9.

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, two fur brushes are used, and each of the fur brush rolls has a pair of 7-flicker covers in contact with the fur brush rolls. The present invention relates to a brush cleaning method for an electronic copying machine in which a toner cloud scattered by a wiping action is sucked by a vacuum source.

Since direct current voltages of different polarities are constantly applied to the two 7-lit covers of the brush cleaning device during the body movement of the photocopier, charged toner particles passing between the flicker covers flicker due to Coulomb force. The air flow path between the two flick bars that tend to adhere to the bar is 25 to 3 m wide, and the cleaning tear is in the form of a slit over the entire length (400 m+), and the wind speed inside the slit is approximately 5 J.
stc. If no voltage is applied to both flicker bars, most of the toner particles will be transported through the flow path toward the cleaner duct without adhering to the side walls of the flicker covers in the slits, but if a voltage is applied, they will become positively charged. The toner which is on the other hand is attracted by the Coulomb force to the wall of the flicker cover to which a negative pressure is applied, and the toner which is on the other hand is attracted to the wall of the flicker cover where a negative pressure is applied. In this case, the adhesion and accumulation of toner cannot be suppressed at a wind speed of +5 m/sec, and furthermore, once the toner adheres and becomes entrenched, the strength of the adhesion increases over time.

On the other hand, as mentioned above, when the applied voltage to the flicker bar is stopped, the accumulated toner loses its adhesion due to Coulomb force. At times, due to vibrations or the like, this adhered toner falls onto the photoreceptor, causing smearing of the image quality.

The present invention was made with the above in mind, and the toner adhering to the flicker cover can be disintegrated and sucked out before the copying machine is stopped, especially before the vacuum source is stopped. It is an object of the present invention to provide a furan cleaning method that can prevent toner from falling.

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. Figure 1 shows an example of the frank (3) leaning mounting that is intended to be used in the present invention. This is an image carrier formed in the shape of a N-type optical semiconductor, and is wound around a tension belt 2゜2' and backup rolls 3, 3'. A pair of fur brush rolls 4 and 4' are in contact with the body 1 and are separated with their rotating shafts perpendicular to the moving direction of the image carrier 1. These fur brush rolls 4 and 4' are made of synthetic fibers all over the outer peripheral surface of the cylindrical body. 2000/- are made with other hairs,
It rotates at approximately 120 rpm.

5 is a fur brush roll 4, 4' cover housing, 6. 6'id fur brush roll 4, 4' has a role of brushing off toner particles adhering to the brush fibers of the fur brush rolls 4, 4', and imparting a desired polar charge to the brush fibers. It is a metal 7-piece cover that has the role of imparting. This flicker bar 6.6'
A suction lower is fixedly attached to the housing 5 and opens into the housing 5 between the flip covers 6 and 6'. This suction lower is connected to the duct 9 by opening the #L path 8. This duct 9 has a true (4) hose (not shown) to a device with wall temperature.
O I O, I O' which are connected through
A slit with a high air flow rate is formed between the image bearing member 1 and both portions 14i of the housing 5, and an orifice baffle is provided to prevent or prevent toner particles inside the housing 5 from leaking out of the cleaning device. This is a pre-cleaning corotron consisting of a corotron wire 13 for +2U IJ-s and a corotron shield 14.

This pre-cleaning corotron 12mm 400M1.
0.09-0.23 p#sgc/(4 of 1ft(:
Coarse irradiation and plus D C:lu irradiation of 0.046 pA-sec/ctd are performed, thereby processing the residual toner image on the image carrier 1 so that it can be easily cleaned. There is. Of the pair of 7-flip covers 6.6', the upstream flicker 6 that contacts the 7g-brush rule 4 located 1° upstream in the moving direction of the image carrier 1 is supplied with a voltage of -3 KV. Eleven pressures of plus three pressures are applied to each of the seven pressure covers 6' on the downstream side. In addition, the pole I of both applied currents! + means the above image carrier 1
The reverse is true when the semiconductor is made of a Pm optical semiconductor.

The untransferred toner image remaining on the image carrier 1 is removed by the pre-cleaning corotron 1.
After being subjected to corona irradiation from Step 2 and processed into a state where it can be easily cleaned, it enters the cleaning device. Then, the transferred toner image is removed by the cleaning iron scrap film by the wiping action of the rotating fur flag rolls 4, 4' and the electric suction force, that is, by the pre-cleaning corotron 12, the toner charged with a positive voltage is cleaned. The toner of opposite polarity that is removed by the first negatively charged cleaning brush is removed by the second cleaning brush, which is electrically charged. The removed toner is scattered in the air, passes through the suction lower, the flow path 8, the duct 9, and the hose at the X air source, and reaches the finishing device, where the toner and air are separated.

At this time, voltage is applied to the flicker bar 6.6'.
), toner is deposited on both side walls of the suction lower 0.

Therefore, in the present invention, when the rJ, ++, 1 copying machine is stopped, the polarity of the voltage applied to the flicker covers 6.6', 11C, and the flicker covers 6.6' is approximately Rotate in reverse for 1 second, then stop power supply. The voltage supply time chart)Vi to this flicker bar 6+6' becomes K as shown in FIG. The timing of stopping the voltage supply to the flicker bar 6.6' preceded the timing of stopping the power supply to the vacuum source (blower), and the voltage supply to the flicker bar 6.6' was reversed at the same time. During this period, the direction of the electric field between the two flicker covers 6 and 6' is reversed, and the toner adhering to one of the flicker covers 6 and 6' is transferred to another force, while the toner adhering to the other flicker cover 6' is transferred to one force. Coulomb force acts on each layer, causing one layer of accumulated toner to collapse or the strength of the layering force (7) to decrease significantly. V at the time when this state occurs
i) The vacuum source (blower) is also in operation, and the toner that has collapsed or has reduced its printing force due to the force of the wind pressure of the air flowing in the slit is conveyed in the duct 17 direction.

If the slit between the two flicker bars 6.6' is narrow, spark discharge is likely to occur between the two flicker bars 6.6', and the electric field strength between the flicker bars 6.6' becomes large, so that the toner cannot be plowed. Coulomb force also increases, promoting adhesion and deposition.

Therefore, as shown in Figure 3, the width of the slit is 25~3 +t
By providing m II (insulating plate 15 and l 5' on the opposite sides of the slits of both flip bars 6 and 6'), it becomes possible to solve the two problems.

Since the present invention is as described above, the toner that has adhered and accumulated between the covers 6 and 6' while the copying machine is in operation weakens its adhesion and collapses just before the copying machine is stopped, and the toner is disintegrated in the direction of the duct 9. It is possible to prevent the toner from falling onto the photoreceptor while the copying machine is stopped.

(8)

[Brief explanation of the drawing]

FIG. 1I is a side view of a cleaning device to which the present invention is applied, FIG. 2 is a timing chart, and FIG. 3 is a sectional view showing a modification of the flicker bar. 4.4'ld fur brush roll, 5 is housing, 6
, 6' is a flicker bar. Applicant Fuji Xerox Co., Ltd. Representative Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto

Claims (1)

[Claims] In a brush cleaning device for an electronic copying machine configured to allow toner-containing air to pass between a pair of flicker bars each interfering with a fur brush roll and to which DC voltages of different polarities are applied, both seven flicker covers are used. +m[immediately before the voltage supply is stopped, the polarity of the DC voltage is reversed, and after the polarity is reversed, the passage of toner-containing air between the flicker bars is stopped. Brush cleaning method.