JPH0464066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a corona discharge device used in copying machines and the like, and particularly to a corona discharge device equipped with a cleaning device for discharge wires and the like.

[Conventional technology]

Conventionally, in an electrophotographic copying machine, the surface of a photoreceptor a rotating in the direction of arrow A is charged by a corona discharger b, as shown in FIG. After forming an image and developing this latent image with toner using a developing device d to form a toner image e, this toner image e is transferred onto a sheet of paper g using a toner transfer corona discharger f, and this sheet of paper g
The toner is peeled off from the photoreceptor a using a paper-separating corona discharger h, and the toner is fixed using a fixing device i to obtain a copy.

On the other hand, the photoreceptor a after the paper g is peeled off
is configured such that it can be reused after having its static electricity removed by a static-eliminating corona discharger j as required, and the toner remaining on its surface being removed by a cleaning device k.

In this way, the corona discharge device is used as a charging or neutralizing device for the photoreceptor a, a toner image e transfer device, a paper g peeling device, etc.
As shown in FIG. 8, this corona discharge device includes a shield l whose cross section is approximately U-shaped and whose photoreceptor side is open;
It generally consists of a discharge wire m that is stretched within this shield l and generates corona ions, and in a corona discharge device for charging, the shield l is opened as necessary as shown in FIG. A grid (n) is attached to the end of the photoreceptor (a) so that the surface of the photoreceptor (a) can be uniformly charged.

However, this corona discharge device has the disadvantage that floating toner inside the copying machine and gas products accompanying discharge are likely to adhere to the shield l, the discharge wire m, or the grid n, resulting in a decline in the discharge function. .

That is, in a corona discharge device equipped with grid n, as shown in FIG.
A large number of grids to which voltages of around 1000 volts are applied are placed at ~3 mm distances.
This is because floating toner and the like are easily attracted to the grid n due to this strong electric field.

The electric field of this grid n causes the photoreceptor a to
This equalizes the excess or deficiency of the potential of the photoreceptor a.
Since it has the function of forming a uniform copy image on the photoreceptor, if it becomes contaminated, the potential of that part increases and the electric field increases, so the potential of the photoreceptor a corresponding to that part increases and As a result, the problem was that the image density locally increased.

In addition, dust such as toner powder easily adheres to the discharge wire m, and silicon-based products also adhere to it due to the adsorption phenomenon accompanying corona discharge, so the amount of corona ions generated from the discharge wire m decreases. , the discharge function was significantly deteriorated.

For this purpose, as shown in FIG. 10, a cleaning device p is provided with a cleaning pad o made of rubber, non-woven fabric, etc. within the shield l, and the discharge wire m etc. is slidably inserted through the cleaning pad o. The cleaning device p is moved along the length of the shield l, and the cleaning pad o scrapes off toner powder etc. adhering to the outer peripheral surface of the discharge wire m, etc., thereby eliminating the above-mentioned harmful effects. We are trying to prevent this.

[Problem that the invention seeks to solve]

However, in a corona discharge device equipped with this cleaning device p, since the cleaning pad o is fixed to the device p, the discharge wire m and, if necessary, the grid n are attached to the shield l. However, when replacing a cleaning pad o contaminated with toner powder or the like with a new one, the installation work is complicated and time-consuming.

That is, the discharge wire m usually has a wire diameter of
Since it is made of ultra-fine tungsten or stainless steel wire with a diameter of 50 μm to 100 μm, its shearing force is weak, and when the discharge wire m is inserted through the cleaning pad o, the wire m will not break or bend due to the pressure. However, there is a drawback that the work is complicated, and this was also the case with the above-mentioned grid n.

Also, the discharge wire m or grid n
When the cleaning pad o is inserted through the cleaning pad o and stretched within the shield l, the mounting position of the discharge wire m etc. may shift due to the repulsive force of the pad o and the distance from the photoreceptor a may change. , which caused uneven charging.

Furthermore, as shown in FIG. 11, a slight gap is created between the opening q of the cleaning pad o through which the discharge wire m, etc. is inserted, and the wire m, etc., so that the cleaning effect is reduced accordingly. The drawback was that it deteriorated.

Moreover, the above-mentioned work is time-consuming because it involves handling small parts such as the discharge wire m, the grid n, and the cleaning pad o, and the installation work of these parts is complicated and time-consuming.

[Means and actions for solving problems]

The present invention has been made in view of the above circumstances, and is based on the premise of a corona discharge device equipped with a cleaning device. It is an object of the present invention to provide a corona discharge device that simplifies the replacement work and improves the cleaning effect.

That is, the present invention includes a shield disposed near a photoconductor and open on the photoconductor side, a discharge wire stretched within this shield, and a discharge wire attached to the open end side of the shield as necessary. and a cleaning device disposed within the shield so as to be movable along the length of the shield, the cleaning device slidingly contacting at least the outer circumferential surface of the discharge wire to clean dirt therefrom. In the corona discharge device, the cleaning device includes a movable member disposed within the shield so as to be movable along the length thereof, and at least the discharge wire is sandwiched between a cleaner material from both sides thereof, and the cleaner material and a cleaning pad member sewn with an insulating wire to slidably cover the outer peripheral surface of the discharge wire, and the cleaning pad member is removably attached to the movable member, thereby removing the discharge wire. Alternatively, the work of attaching or replacing the cleaner material is simplified, and the cleaning effect is improved by bringing the cleaner material into even contact with the outer peripheral surface of the discharge wire.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. The cleaning pad 3 is attached to the shield 1, and the corotron wire 4 is stretched within the shield 1.

First, the shield 1 is made of a conductive material formed into a substantially U-shaped cross section, and wire attachment members 5 and 6 made of an insulating material are attached to both ends of the shield 1.
A guide 8 for guiding the yoke 2 is provided on the bottom surface 7 of the shield 1 in parallel along the length direction of the shield 1. In FIG. 1, one side of the shield 1 is omitted from illustration in order to facilitate understanding of the present invention.

Further, the yoke 2 has a concave groove 9 formed on its upper surface side parallel to the width direction of the shield 1, into which the cleaning pad 3 is fitted, and a concave groove 9 formed parallel to the length direction of the shield 1. It is composed of a rectangular parallelepiped-shaped insulating storage body having a concave groove 10 through which the corotron wire 4 is passed, and a protrusion (not shown) provided on the outside of the bottom surface is connected to the shield 1
The guide 8 is loosely fitted into the guide 8.

Furthermore, a shaft 1 is provided on one side of the yoke 2 and is loosely fitted into the wire attachment member 5.
1 is attached to the shield 1, and by sliding this shaft 11, the yoke 2 is moved along the length direction of the shield 1.

On the other hand, as shown in FIG. 1, the corotron wire 4 is provided with terminals 13 and 14 on both ends thereof for attaching the wire 4 to the studs 12 of the wire attachment members 5 and 6. A spring 15 for applying a certain tension to the wire 4 is detachably attached to one terminal 13, and a cleaning pad 3 is slidably attached to the wire 4.

This cleaning pad 3 is composed of two cleaning materials 16 and 17, as shown in FIG. The contact surfaces of the cleaner materials 16 and 17 are sewn with an insulating wire material 18 such as nylon thread so that they can slide on the corotron wire 4 along its length with a predetermined frictional force. is formed.

In addition, instead of using two pieces of cleaner material, one
Of course, it is also possible to use two sheets of cleaner material, bend them, and sandwich the wire between them.

The corona discharge device of the present invention is constructed by fitting the cleaning pad 3 into the groove of the yoke 2 at a predetermined position.

Therefore, in the corona discharge device of the present invention,
Since the cleaning pad 3 and the yoke 2 are configured to be detachable, when replacing the old corotron wire 4 with a new wire 4, it can be easily done as follows.

First, the spring 1 of the corotron wire 4
5 from the stud 12 of the wire attachment member 5, and the wire 4 is removed from the shield 1 while pulling the wire 4 upward to take out the cleaning pad 3 from the yoke 2.

Next, attach a new corotron wire 4 to which the cleaning pad 3 has been attached in advance to the spring 15 for one terminal 13, and to the stud 12 of the wire attachment members 5, 6 for the other terminal 14. It is engaged and installed inside the shield 1.

Then, the cleaning pad 3 is fitted into the groove 9 of the yoke 2, and while the pad 3 is moved vertically, the corotron wire 4 is removed.
After adjusting the pad 3 so that the wire 4 insertion position is aligned with the pad 3, the pad 3 is fixed to the yoke 2 by appropriate means, and the corotron wire 4 is replaced.

By setting in advance the positional relationship between the cleaning pad 3 and the corotron wire 4 with respect to the mounting position of the groove 9, the work of replacing the wire 4 can be further simplified.

Further, in the corona discharge device of the present invention, the cleaner material 1 constituting the cleaning pad 3 is
6 and 17 are insulating wire rods 18 as shown in FIG.
Cleaner material 1
Since the wires 6 and 17 contact the outer peripheral surface of the corotron wire 4 evenly and with sufficient pressing force, the wire 4 can be cleaned evenly and sufficiently.

As the cleaner materials 16 and 17, materials with excellent ozone resistance are selected from nonwoven fabrics made of fibers such as wool, rayon, nylon, and acrylic, and rubber materials such as SBR, silicone, and nylon. Furthermore, the cleaning effect can be further enhanced by dispersing and adhering an abrasive material such as a glass beam or metal powder to the portions of the cleaner materials 16 and 17 that contact the corotron wire 4.

Further, in the above embodiment, only the corotron wire 4 is cleaned, but as shown in FIG. The notch-shaped recesses 19, 19 are formed, and the recesses 19, 19 are
Cleaner material 2 is placed between the bottom surface 7 of the shield 1 and
0 and 20, the bottom surface 7 side of the shield 1 can also be cleaned.

Although the corona discharge device of the above embodiment is of a type without a grid on the open end side of the shield 1, the present invention can also be applied to a corona discharge device equipped with a grid.

That is, as shown in FIG. 5, the grid 21 is sandwiched between two cleaner materials 22 and 23 from both sides, and the contact surfaces of the cleaner materials 22 and 23 are sewn with an insulating wire 24 to form a cleaning pad. 25, and the pad 25 may be fitted into a second yoke 26 which is detachably attached to the upper part of the yoke 2.

The cleaning pad 25 is thin because the cleaner materials 22 and 23 constituting it are firmly sewn together with an insulating wire 24 as shown in FIG. (Not shown) The pad 25 can be placed without contacting the surface.

Therefore, when operating the yoke 2 to clean the corotron wire 4, grid 21, etc., the cleaning pad 25 will not damage the photoreceptor.

〔Effect of the invention〕

As described above, the present invention provides a corona discharge device for a copying machine, which includes a shield, a discharge wire, and a grid attached as necessary, and a cleaning device for cleaning at least the discharge wire. The cleaning device comprises a cleaning pad in which at least the discharge wire is sandwiched between a cleaner material and the cleaner material is sewn with an insulating wire, and a moving member,
In addition, since the pad is detachably attached to the movable member, the work of attaching and replacing the discharge wire or cleaner material is simplified, and
The cleaner material has the effect of improving the cleaning effect by uniformly contacting the outer circumferential surface of the discharge wire, and its practical effects are great.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention. FIG. 1 is a perspective view of the corona discharge device of the present invention with a corotron wire 4 attached, and FIG. 2 is a perspective view of the cleaning pad 3. 3 is a sectional view thereof, FIG. 4 is a partial sectional view of a corona discharge device according to another embodiment, FIG. 5 is a partial perspective view of a corona discharge device according to another embodiment, and FIG. shows a sectional view of the cleaning pad 25, and the seventh
1 is an explanatory diagram of the configuration of a conventional electrophotographic copying machine, FIGS. 8 to 10 are perspective views of a conventional corona discharge device, and FIG. 11 is a sectional view of the cleaning pad o thereof. Description of symbols, 1... Shield, 2, 26... Yoke, 3, 25... Cleaning pad, 4... Corotron wire, 5, 6... Wire mounting member, 7... Bottom, 8... Guide, 9, 10... Concave groove, 11... Shaft, 12... Stud, 1
3, 14...terminal, 15...spring, 16,
17, 20, 22, 23...Cleaner material, 1
8, 24... Insulating wire, 19... Recess, 21...
...Grid.

Claims (1)

[Claims] 1. A shield disposed near the photoreceptor and open on the photoreceptor side, a discharge wire stretched within the shield, and a grid attached to the open end side of the shield as necessary. A corona discharge device for a copying machine, further comprising: a cleaning device movably disposed within the shield along the length thereof and slidingly contacting at least the outer circumferential surface of the discharge wire to clean dirt therefrom; The cleaning device includes a movable member disposed within the shield so as to be movable along the length thereof, and at least the discharge wire is sandwiched between a cleaner material from both sides thereof, and the cleaner material is inserted into an insulating wire. 1. A corona discharge device comprising a cleaning pad member which is sewn to cover the outer peripheral surface of a discharge wire in a slidable manner, and the cleaning pad member is detachably attached to the movable member.