JPH0473876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a corona discharge device used in a copying machine or the like, and particularly to a corona discharge device equipped with a cleaning device for a discharge wire or 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 the charge is removed by a charge-eliminating corona discharger j as required, and the toner remaining on its surface is removed by a cleaning device k so that it can be reused.

As described above, the corona discharge device is used as a charging or neutralizing device for the photoreceptor a, a transfer device for the toner image e, a peeling device for the paper g, etc. This corona discharge device is shown in Fig. 10. A corona discharge device for charging is generally composed of a shield l having a substantially U-shaped cross section with the photoreceptor side open, and a discharge wire m stretched within the shield l to generate corona ions. In this case, as shown in FIG. 11, a grid n is attached to the open end side of the shield l, if necessary, 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 tend to adhere to the shield l, the discharge wire m, or the grid n, resulting in a decline in the discharge function. .

In other words, in a corona discharge device equipped with grids n, as shown in FIG. 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. 12, a cleaning device p is provided with a cleaning pad o made of rubber, non-woven fabric, etc. in the shield l, and the discharge wire m etc. is slidably inserted through the cleaning pad o. This cleaning device p
is moved along the length of the shield l, and the discharge wire m is moved by the cleaning pad o.
Toner powder and the like adhering to the outer peripheral surfaces of the rollers and the like are scraped off to prevent the above-mentioned problems.

[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 may be cut or bent due to the pressure. 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. is shifted due to the repulsive force of the pad o, and the distance from the photoreceptor a changes. This may cause uneven charging.

Furthermore, as shown in FIG. 13, 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. There was a drawback that the effect deteriorated.

Moreover, the above-mentioned work is time-consuming because small parts such as the discharge wire m, the grid n, and the cleaning pad o are handled, 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 provides a shield that is disposed near a photoreceptor and is open on the photoreceptor side, a discharge wire stretched within this shield, and a discharge wire that is attached to the open end side of the shield as necessary. and a cleaning device movably disposed within the shield along the length thereof, the cleaning device slidingly contacting at least the outer peripheral surface of the discharge wire to clean dirt therefrom. In the discharge device, the cleaning device is
By means of a fixing member comprising an insulating plate in which at least the discharge wire is sandwiched between a cleaner material from its surface side and a plurality of pins are attached thereto, and an insulating plate having a plurality of holes to engage with the pins. a cleaning pad member that clamps the cleaner material from the outside and slidably covers the outer peripheral surface of the discharge wire; and a movable member that is disposed within the shield so as to be movable along its length. and by removably attaching the cleaning pad member to this moving member,
This simplifies the installation and replacement work of the discharge wire or the cleaner material, and improves the cleaning effect by pressing the cleaner material evenly against 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 along the length 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.

Further, on one side of the yoke 2, a shaft 1 is provided loosely through 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, the corotron wire 4 has terminals 1 on both ends thereof for attaching the wire 4 to the studs 12 of the wire attachment members 5 and 6.
3 and 14, and a spring 15 that applies a certain tension to the wire 4 is detachably attached to one terminal 13, and the cleaning pad 3 slides on the wire 4. It is movably mounted.

As shown in FIG. 2, this cleaning pad 3 consists of two cleaning materials 16 and 17 that sandwich the corotron wire 4 from both sides, and a fixing member that clamps the cleaning materials 16 and 17 from both sides. It is configured to be able to slide on the corotron wire 4 along its length with a predetermined frictional force.

The fixing member is made of an insulating material such as plastic, as shown in FIG. It has four pins 20 that engage with each other, and a protrusion 21 having an approximately arrow-shaped cross section and having an outer diameter slightly larger than the inner diameter of the small hole 18 is provided at the tip end thereof.
An insulating plate 22 having 16 and 17 are attached.

Regarding the cleaner materials 16 and 17,
By making a small hole in advance in the portion through which the pin 20 is inserted, the plates 19, 2
The fixing member consisting of two parts can be easily attached.

Also, 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 9 of the yoke 2 at a predetermined position.

Therefore, in the corona discharge device of the present invention, the cleaning pad 3 and the yoke 2 are configured to be detachable, so when replacing the old corotron wire 4 with a new wire 4, the following procedure is required. It can be done easily.

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 a cleaning pad 3 has been attached in advance to the stud 12 of the wire attachment members 5 and 6, using the spring 15 for one terminal 13 and directly 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 and the wire 4 insertion position of the pad 3 to be aligned in a straight line, the pad 3 is fixed to the yoke 2 by appropriate means, and the corotron wire 4 is replaced.

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

Further, in the corona discharge device of the present invention, the cleaning material 16, 17 of the cleaning pad 3 is
As shown in FIG. 5, the cleaning materials 16 and 17 are firmly fitted by plates 19 and 22, which are fixing members, so that the cleaner materials 16 and 17 are applied evenly to the outer peripheral surface of the corotron wire 4 and even with sufficient pressing force. Since the wires 4 come into contact with each other, the wire 4 can be cleaned thoroughly and evenly.

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. A cleaner material 24 is formed between the recesses 23 and the bottom surface 7 of the shield 1.
24, the bottom surface 7 side of the shield 1 can also be cleaned.

Although some of the corona discharge devices of the above embodiments do not have a grid on the open end side of the shield 1, the present invention can also be applied to corona discharge devices equipped with a grid.

That is, as shown in FIG. 7, the grid 25 is sandwiched between two cleaning materials 26 and 27 from both sides, and is held by a fixing member consisting of plates 28 and 29 to form a cleaning pad 30.
This pad 30 may be fitted into a second yoke 31 which is detachably attached to the upper surface of the yoke 2.

The cleaning pad 30 is thin because the cleaning materials 26 and 27 constituting it are firmly clamped by plates 28 and 29, which are fixing members, as shown in FIG. The pad 30 can be placed without contacting the surface of a photoreceptor (not shown).

Therefore, when operating the yoke 2 to clean the corotron wire 4, grid 25, etc., the cleaning pad 30 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, the cleaner material is sandwiched by a fixed member, and a movable member,
In addition, since the pad is detachably attached to the movable member, the work of attaching and replacing the discharge wire or the cleaner image is simplified, and
The cleaner material has the effect of uniformly pressing against the outer circumferential surface of the discharge wire to improve its cleaning effect, and its practical effects are great.

[Brief explanation of the drawing]

1 to 8 show embodiments of the present invention. FIG. 1 is a perspective view of the corona discharge device of the present invention with the corotron wire 4 attached, and FIG. 2 is a perspective view of the cleaning pad 3. 3 and 4 are perspective views of the plates 19 and 22 constituting the fixing member, FIG. 5 is a sectional view of the cleaning pad 3, and FIG. 6 is a corona discharge device according to another embodiment. FIG. 7 is also a partial perspective view of a corona discharge device according to another embodiment, FIG. 8 is a cross-sectional view of the cleaning pad 30, and FIG. 9 is a conventional electrophotographic copying device. Machine configuration explanatory diagram, Figure 10~
FIG. 12 is a perspective view of a conventional corona discharge device, and FIG. 13 is a sectional view of its cleaning pad o. Description of symbols, 1... Shield, 2, 31... Yoke, 3, 30... 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, 24, 26, 27...Cleaner material, 18
...Small hole, 19,22,28,29...Plate, 20...Pin, 21...Protrusion, 23...Recess, 25...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 at least an insulating plate in which the discharge wire is sandwiched between cleaner materials on both sides thereof and a plurality of pins are attached thereto, and an insulating plate having a plurality of holes that engage with the pins. a cleaning pad member which clamps the cleaner material from the outside with a fixing member and slidably covers the outer circumferential surface of the discharge wire; and a cleaning pad member disposed within the shield so as to be movable along its length. What is claimed is: 1. A corona discharge device comprising a movable member, and the cleaning pad member is removably attached to the movable member.