JPS6217824Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a corona discharger that is applied to an image forming apparatus such as an electrophotographic copying machine using an electrophotographic method. More specifically, the present invention relates to a cleaning member for a corona discharger that cleans the grid wire and corona wire of the corona discharger.

2. Description of the Related Art In recent years, efforts have been made to improve the image quality of images copied by, for example, copying machines. For this purpose, it is important to control the surface potential of a latent image carrier such as a photoreceptor to a predetermined potential. Therefore, in discharge vessels as well, grid wires for controlling the discharge potential are increasingly being provided in addition to the conventional corona wires.

Furthermore, when these dischargers are used in a copying machine, developing toner, dust, and other contaminants floating in the copying machine tend to adhere to grid wires, corona wires, and the like. If these contaminants adhere, the discharge efficiency will decrease and discharge unevenness will occur, resulting in a decrease in image quality. Therefore, in order to prevent these phenomena, it is necessary to properly clean the grid wire.

Conventionally, when cleaning a grid, for example, a wiper member such as felt or moltplane was applied to the side of the grid facing the corona wire, and the wiper member was slid to remove toner particles and dirt on the grid. Toner particles and dirt are removed by sandwiching the grid between wires and sliding it in the longitudinal direction of the grid wire, or by wiping off the dirt using a solvent.

However, in machines that generate a large amount of corona discharge, such as high-speed copying machines, uneven discharge tends to occur due to not only contamination such as toner particles but also adhesion of corona products and oxidation of wires and grids. Well, I can't take it.

The purpose of the present invention is to actively polish the surface of the grid or corona wire to completely remove dirt and oxides from the surface, in order to solve the above-mentioned conventional drawbacks.

The present invention that achieves this object is a cleaning device for a corona discharger that has a cleaning member that cleans the grid or corona wire by rubbing against the grid or corona wire of the corona discharger, wherein the cleaning member is made of a flexible material; A cleaning member fixedly supporting an abrasive material for removing deposits adhering to a grid or corona wire, the holding member holding the cleaning member so that the abrasive material of the cleaning member contacts the grid or corona wire. and guide means for guiding the holding means so that the abrasive material of the cleaning member slides relative to the grid or corona wire without separating from the grid or corona wire. It is something to do.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a partial perspective view of a corona discharger according to the present invention, in which 1 is a conductive shield case, 2 is a corona wire, 3 is a grid, and 4 is a cleaning member sandwiching the grid in a sandwich-like manner.

FIG. 2 is an enlarged perspective view of the cleaning member. In the figure, a polishing member 5 is provided on the portion of the cleaning member facing the wire so as to sandwich a grid wire 3 made of a tungsten wire having a diameter of about 100 μm. This polishing member has, for example, #800~
Use cloth or paper coated with an abrasive agent, such as #1000 sandpaper, or paper, cloth, or felt coated with cerium oxide. In order to press this polishing member against the grid wire, use #6 to
Provide a flexible material 6, such as #120 polyurethane foam. Using this polyurethane foam 6, the polishing member 5 is evenly pressed against the grid wire 3. A support member 7 for sandwiching and fixing the polishing member 5 and the flexible material 6 from both sides of the grid 3 is made of an insulator such as polycarbonate. By moving this supporting member 7 along the longitudinal direction of the shield case (in the direction of the arrow in FIG. 1), both sides of the grid can be cleaned.

In the conventional method, since the wire surface is not polished, uneven discharge occurs immediately after the wire is cleaned, often resulting in image deterioration such as fogging. This is because corona products, oxide films, etc. are formed on the wire surface, and the surface becomes insulated, which changes the discharge conditions there and causes uneven charging. These oxides cannot be removed simply by rubbing with something like a sponge as in the conventional method, resulting in uneven charging. Furthermore, since these oxides are not soluble in solvents, the effect is not sufficient just by using a solvent.

Therefore, by sliding the cleaning member of the present invention, which has the above-mentioned configuration, along the grid two to three times, dirt and grime that could not be removed by conventional methods can be removed.
The oxide will be removed cleanly and a new surface of the grid will appear. In this state, no charging unevenness is observed, and the charging state is the same as when using a new grid. Of course, the grid is no longer insulated.

As a method of polishing wires, in order to clean a large number of wires at once, such as a grid, sandpaper is used to sandwich both sides of the grid, as shown in Fig. Press it against the wire using a soft object such as Since this kind of cleaning member is slid, it cleans both sides of each grid wire.
Can be polished uniformly at once. Grids polished in this way have a new, polished surface that takes longer to oxidize and is more durable. In the conventional method, charging unevenness appeared again immediately after cleaning or after several thousand copies were made, but with the method of the present invention, charging unevenness did not appear even after 200,000 to 400,000 copies were made.

In the above example, an example was shown in which both sides of the grid were polished, but since dirt on the grid and uneven charging due to oxidation are related to dirt on the side of the grid facing the corona wire on the hands, it is recommended to clean only this side. You can also do this. Needless to say, it is preferable to uniformly polish both sides of the grid.

FIG. 3 is a perspective view of a cleaning member showing another embodiment of the present invention. As shown in the figure, a polishing member 5 is provided on half of the portion of the cleaning member 8 in contact with the grid 3, and the other half is provided with an abrasive member 5. A flexible, wear-resistant material 6, such as a sponge-like foam, felt or expanded polymer, which supports the abrasive member, is arranged in direct contact with the grid 3. In this way, dirt etc. from polishing can be removed with the sponge 6, increasing the effectiveness of cleaning.

Furthermore, FIG. 4 shows an example of the configuration of a corona discharger for implementing the present invention. In this embodiment, the corona wire can be cleaned as well as the grid. The discharger 9 includes two corona wires 10, insulating blocks 11 and 12 for stretching the corona wires 10, a first frame 13 for connecting and supporting both blocks 11 and 12, and a grid wire 14. Blocks 15 and 16 for tensioning the grid wire 14 and both blocks 15 and 16
It is composed of second frames 17 and 18 for connecting and supporting. Then, the discharger 9 is inserted into the copying machine main body by moving the guide 19 of the first frame 13 on a lever (not shown) on the main body side in the direction shown by arrow A. Further, the block 11 has a connector 20 for supplying high voltage to the corona wire 10, and the block 15 has a connector 20 for grounding the grid wire 14 or for supplying a bias voltage of about 0 to 1 [KV]. Connectors 21 are attached, and each is connected to a connector (not shown) on the copying machine main body side. In addition, the first frame 13 and the second frame
The frames 17 and 18 have a U-shaped cross section and also serve as a shield. Furthermore, the second frame 1
7 and 18 have a concave portion 18a that engages with a convex portion 19a provided at the upper end of the first frame 13,
It is designed to be able to move using the engaging portion as a guide.

Here, the cleaning member 22 for removing the deposits on the corona wire 10 by rubbing has a polishing member 5 in contact with the wire and a soft material 6 such as a sponge, as in the above-described embodiment, and its support 23 It is fixed to the grid fixing block 15 via. Further, a cleaning member 24 also has a polishing member 5 and a soft material 6 to remove deposits from the grid wire 14 by rubbing, and is fixed to the corona wire fixing block 12 via a support 25 thereof. Of course cleaning member 2
2 and 24 may have the shape shown in FIG.

Therefore, when the grip portion 26 provided on the grid fixing block 16 is pulled out in the direction of arrow B, the second frame 1 which supports the blocks 15 and 16 in communication with each other opens.
7 and 18 slide in the direction of arrow B along the first frame 13, and the deposits on the grid wire 14 are rubbed off by the cleaning member 24 when they pass through the fixed cleaning member 24. . At the same time,
The cleaning member 22 fixed to the block 15 is
The corona wire 10 is moved while being rubbed to remove deposits. Therefore, the corona wire 10 and the grid wire 14 can be cleaned at the same time by pulling out the knob 26. Moreover,
Even if the photosensitive drum is close to the grid wire when the discharger is loaded into the copying machine main body, the grid wire can be cleaned while the discharger is loaded.

In all of the dischargers described above, it is difficult to stretch the corona wire when the grid is stretched, but a window that can be opened and closed is provided in the connecting support member of the block that holds both ends of the corona wire. The corona wire may be stretched from below the grid. Alternatively, each cleaning member may be detachably attached to the discharger, and the corona wire may be stretched after the grid wire is extracted.

In this embodiment, even if there are objects in the vicinity of the grid wire, the grid wire and corona wire can be cleaned in that state. Therefore, the wire can be cleaned while the discharger is fixed, so there is no risk of the wire breaking. Moreover, since the corona wire and the grid wire can be cleaned at the same time, the wire can be cleaned quickly. Additionally, the corona wire and grid wire cleaning elements can be mounted on separate supports, so
The height of each wire can be easily adjusted.

As described above, in the present invention, since the polishing member is provided on the surface of the cleaning member that comes into contact with the grid wire or the corona wire, the wire can be used stably for a long period of time with one cleaning.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a corona discharger according to the present invention, FIG. 2 is an enlarged perspective view of a cleaning member, and FIG. 3 is a perspective view of a cleaning member showing another embodiment of the present invention.
FIG. 4 is a perspective view of a configuration example of a corona discharger for implementing the present invention. In the figure, 1... conductive shield case, 2
...Corona wire, 3... Grid, 4/8...
Cleaning member, 5... Polishing member, 6... Flexible substance,
7...represents a support member.

Claims (1)

[Claims for Utility Model Registration] A cleaning device for a corona discharger that has a cleaning member that cleans the grid or corona wire by rubbing against the grid or corona wire of the corona discharger, the cleaning member comprising a flexible material and the grid or corona wire. A cleaning member fixedly supporting an abrasive material for removing deposits adhering to a corona wire, and holding means for holding the cleaning member so that the abrasive material of the cleaning member contacts the grid or the corona wire. ,
a guide means for guiding the holding means so that the abrasive material of the cleaning member slides relative to the grid or the corona wire without separating from the grid or the corona wire; Cleaning device for discharge vessel.