JP3861980B2 - Charging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a corona charging device having a discharge wire and a grid.
[0002]
[Prior art]
As a charging device used in an image forming apparatus, those using corona discharge are generally widely used. In particular, in order to charge the photoconductor, an apparatus called a scorotron having a discharge wire and a grid for controlling the potential of the photoconductor surface is used. In this apparatus, as the image is formed, the image may be disturbed due to the deterioration of the discharge wire or the adhering matter. As means for improving this, there has been proposed a method in which cleaning is performed by bringing a cleaning member into contact with a wire and sliding the wire (Japanese Patent Publication No. 4-64066). In addition, it has been proposed to clean both the grid and the wire (Japanese Utility Model Publication No. 63-24561).
[0003]
[Problems to be solved by the invention]
By the way, it is generally performed that the corona charging device is disposed above the photosensitive member and is charged. This is to prevent floating toner or the like from falling and contaminating the corona charging device. As a result, products that are heavier than air, such as ozone and nitrogen oxides generated by corona discharge, stay near the surface of the photoconductor when the fan is stopped, such as when the device is stopped. Was the cause. On the other hand, it is possible to protect the photosensitive layer from ozone and nitrogen oxide by disposing the corona charging device below the photosensitive member.
[0004]
However, when the corona charging device is placed below the photoconductor, the discharge wire is positioned below the grid, so the cleaning member is in contact with the discharge wire, and if it slides, remove the cartridge and clean it. When the cartridge is installed in the apparatus, foreign matters such as toner adhered to the grid fall on the wire, and the cleaning effect becomes insufficient.
[0005]
Further, when both the grid and the wire are cleaned, the arrangement direction of the charging device and the positional relationship between the grid cleaning member and the wire cleaning member are not clear. For this reason, for example, if the grid and the wire are cleaned at the same time, foreign matters such as toner fall from the grid cleaning member to the wire, and the wire cleaning effect cannot be sufficiently obtained. When charging is performed, there is a problem that an image defect occurs immediately after cleaning.
[0006]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and is intended to obtain a good image by sufficiently enhancing the cleaning effect of the charging device when charging is performed from below the photoreceptor.
Therefore, the present invention has a discharge wire and a grid, and a charging device that is disposed below the photoreceptor and performs corona charging, has a wire cleaning member that contacts the discharge wire and a grid cleaning member that contacts the grid, A cleaning member support member provided with cleaning means for cleaning by sliding along the extending direction of the discharge wire and the grid, the cleaning means being fixed to the grid cleaning member and rotatably attached to the wire cleaning member And moving the cleaning member support member along the stretching direction of the discharge wire and the grid so that the grid cleaning member precedes the wire cleaning member in the sliding direction of the cleaning means. It is characterized by cleaning.
Further, in the present invention, the cleaning means is configured such that the grid cleaning member precedes the wire cleaning member in the traveling direction at least in the return path of the reciprocating sliding along the stretching direction of the discharge wire and the grid. Features.
Further, the present invention is characterized in that the common part of the wire cleaning range and the grid cleaning range is at least wider than the effective image range.
Further, the present invention is characterized in that the grid cleaning member is made of a material that does not leave a residue on the grid.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a cleaning member of a charging device according to the present invention, and FIG. 2 is a diagram illustrating a cleaning mechanism of the charging device.
The charging device of the present invention is housed in the case 8 and disposed below the photosensitive member 11, and the cartridge can be removed by opening the rotating cover 10 of the case during cleaning. The rotary cover 10 is provided with a position restricting opening 9 into which the cleaning member knob 7 is fitted at the standby position. On the other hand, the bottom surface of the house 1 of the charging device is opened along the extending direction of the discharge wire and the grid, and the cleaning member knob 7 is connected to the cleaning member support member 4 through the opening. Therefore, when the rotary cover 10 is opened while the cleaning member knob 7 is in its standby position, the cleaning member knob 7 can be manually moved in the direction of the photosensitive member axis. The cleaning member support member 4 is provided with a grid cleaning member 6 and a wire cleaning member 5 that come into contact with the grid, and the cleaning member support member 4 can be cleaned with the discharge wire and the grid by holding the cleaning member knob 7. The ozone generated by the charging device is exhausted in the exhaust direction indicated by the arrow 12 by providing an exhaust pump (not shown) on the side opposite to the cleaning member knob standby position restricting opening 9. 9 makes it difficult for floating toner or the like to enter.
[0008]
In the example shown in FIG. 2, the grid 3 has a configuration in which a large number of holes are opened obliquely in a rectangular plate extending in the direction of the photoreceptor axis, and a wire 2 is stretched below the grid 3. In the cleaning means of the present invention, a grid cleaning member 6 that contacts the lower surface of the grid 3 and a wire cleaning member 5 that sandwiches the wire 2 from both sides are attached to the cleaning member support member 4. As described above, the cleaning member knob 7 is attached to the cleaning member support member 4, and the cleaning member knob 7 extends out of the case 8 through an opening formed along the axial direction on the bottom surface of the house 1 of the charging device. The grid and wires are cleaned by gripping the cleaning member knob 7 and reciprocating it in the photosensitive member axial direction.
[0009]
The grid cleaning member 6 is fixed to the cleaning member support member 4, while the wire cleaning member 5 is rotatably attached to the cleaning member support member 4, so that the wire cleaning direction is held with the cleaning member knob 7. When the wire cleaning member 5 is reciprocated along the wire 2, the wire cleaning member 5 is delayed with respect to the grid cleaning member 6 due to friction with the wire 2. For this reason, the grid cleaning member precedes the wire cleaning member, and even if foreign matter falls from the grid to the wire side by the grid cleaning member, the dirt is removed by the wire cleaning member that arrives later.
[0010]
As described above, since the grid cleaning member always precedes the wire cleaning member in the moving direction of the cleaning member, foreign matters dropped on the wire by the grid cleaning can be removed. In this case, the grid cleaning is performed in the forward path of the photosensitive member. Even when the foreign matter dropped on the wire cannot be sufficiently removed by the wire cleaning member, it can be removed by wire cleaning in the return path, and the cleaning effect can be further enhanced.
[0011]
Further, the moving range is set so that both the wire and the grid cleaning member can clean a wider range than the effective image width. Thereby, both the wire and the grid can be cleaned with respect to the effective image width.
[0012]
Further, if hair such as felt or brush remains on the grid, abnormal discharge may occur and the image may be disturbed. Therefore, a member that does not leave any residue such as hair loss on the grid, such as synthetic leather, is used for the grid cleaning member. As a result, abnormal discharge can be prevented.
[0013]
【The invention's effect】
As described above, according to the present invention, the grid cleaning member precedes the wire cleaning member in the traveling direction of the cleaning member. Can be removed. Further, even when the falling object cannot be sufficiently removed in the forward path, it can be removed by cleaning the wire in the backward path, and a good image can be obtained with more enhanced cleaning effects. Further, by setting the movement range of the wire and grid cleaning members wider than the effective image width, the effective image width can be cleaned, and similarly good images can be obtained. Further, by using a member that does not leave any residue on the grid as the grid cleaning member, abnormal discharge can be prevented and a good image can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a cleaning member of a charging device used in an image forming apparatus of the present invention.
FIG. 2 is a diagram illustrating a cleaning mechanism of the charging device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... House, 2 ... Wire, 3 ... Grid, 4 ... Cleaning member support member, 5 ... Wire cleaning member, 6 ... Grid cleaning member, 7 ... Cleaning member knob, 8 ... Case, 9 ... Cleaning member knob standby position regulation Opening, 10 ... rotating cover, 11 ... photoconductor.

Claims (4)

A charging device that includes a discharge wire and a grid, and is disposed below the photosensitive member and performs corona charging, includes a wire cleaning member that contacts the discharge wire and a grid cleaning member that contacts the grid, and the tension of the discharge wire and the grid. The cleaning unit includes a cleaning unit that performs cleaning by sliding along a racking direction. The cleaning unit includes a cleaning member support member to which a grid cleaning member is fixed and a wire cleaning member is rotatably attached. by moving the support member discharge wire and along the stretched direction of the grid, characterized in that for cleaning cleaning brush in the sliding time of the traveling direction of said cleaning means so as to precede the wire cleaning member The charging device.   The cleaning means is configured such that the grid cleaning member precedes the wire cleaning member in the advancing direction at least in the return path of reciprocating sliding along the extending direction of the discharge wire and the grid. The charging device described. 3. The charging device according to claim 1, wherein a common portion of the wire cleaning range and the grid cleaning range is at least wider than the effective image range. 3. The charging device according to claim 1, wherein the grid cleaning member is made of a material that does not leave a residue on the grid.

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