JPH043310Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in a corona discharger used in connection with a photosensitive drum in a copying machine or the like.

(Prior art) In a dry type copying machine, an electrostatic latent image is formed on a photosensitive drum equipped with a photoconductive layer, and then developed and transferred. After the transfer, the remaining toner is cleaned with a cleaner, and the next step is performed. Start the copying process. Therefore, dust such as toner scattered from the cleaner and developing device and paper powder from the paper used as the transfer medium floats in the air inside the machine, and it adheres to the discharge wire and corona house, causing the amount of dust attached to decrease. If this increases, uneven discharge occurs and appears as uneven copying, so cleaning is performed regularly. Furthermore, after a certain period of time has elapsed, the discharge wire and the grid wire that controls the charging of the surface of the photosensitive drum are replaced.

As shown in FIG. 3, the conventional corona discharger has shielding plates 14, at least partially conductive, arranged on both sides of the discharge wire 11, and a ceiling plate 19 on the opposite side of the opening facing the photosensitive drum. The presence of such a ceiling plate 19 prevents dust and the like from entering from the outside, and also prevents dust and the like from flowing out and adhering to other members.

(Problems to be Solved by the Invention) As described above, since the conventional corona discharger was provided with a ceiling plate, there was a problem in that it was difficult to clean and replace discharge wires and the like.

An object of the present invention is to provide a corona discharger that can prevent dust from entering from the outside and contamination of other members, and also allows easy cleaning and replacement of discharge wires and the like.

(Means for Solving the Problems) The features of the corona discharger according to the present invention include the use of a corona house 13 which is open on the opposite side of the opening facing the photosensitive drum, and which supports the corona house in a detachable manner. A rail body 17 including a base portion 17a that covers the opposite side of the opening side of the house 13
a discharge wire 11 in the base portion;
The surface facing the is made of an insulator 18.

(Function) Therefore, in this corona discharger, corona house 1
3 can be removed from the rail body 17 by sliding it in a direction perpendicular to the plane of the paper in FIG. . Since the rail body 17 covers the opening at the top of the corona house 4, dust is prevented from adhering to other members, and the rail body 17 covers the opening at the top of the corona house 4. This prevents dust, etc. from entering from the outside, and also prevents dust, etc. from flowing out and adhering to other members. Also,
In the case of a configuration using such a rail body,
When the base portion 17a of the rail body 17 is a conductor like a conventional rail body, the base portion 17a also serves as a counter electrode for corona discharge, and dust adhesion thereto can cause uneven discharge. This tendency is especially serious because the rail body is fixed to the copying machine body and is difficult to clean easily. In the present invention, by covering the surface of the base portion 17a of the rail body 17 with the insulator 18, or by making the base portion 17a itself an insulator, the base portion 17a does not act as a counter electrode. This prevents uneven discharge due to dust contamination of the base portion 17a as described above.

(Example) Next, an example of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention, in which numeral 1 is a photosensitive drum having a photoconductive layer on its surface, and a corona discharger 10 is arranged around the photosensitive drum at a distance of a predetermined distance. 11 is a discharge wire, and 12 is a grid wire; as shown in FIG. 2, the grid wire 12 may not be provided. 13 is a corona house, and both sides of the corona house 13 are constituted by shielding plates 14, at least a part of which is conductive.

In the corona discharger to which the present invention relates, the side 16 opposite the open side 15 of the corona house facing the photosensitive drum 1 is open. The corona discharger 10 includes a rail body 17 that slidably and detachably supports the corona house 13, and the rail body 17 has a base portion 17a that covers the opening 16 facing the opening side of the corona house 13. It is equipped with This rail body 17 is grounded.

In order to slidably and removably support the corona house 13, in a preferred form, the legs 17b on both sides of the base portion 17a of the rail body are provided with flange portions 17c that protrude inwardly, and each shielding plate of the corona house Edge 14a on the opposite side of the opening side 15 of 14
are bent outwards at approximately right angles, and their edges 14
a is configured to engage with the corresponding flange portion 17c. In addition, Corona House 13
2, each leg 17b of the rail body is provided with an inwardly U-shaped section 17d, in which the edge 14 of the shielding plate 14
A may be configured to fit.

Further, in this corona discharger, the surface of the base portion 17a of the rail body facing the discharge wire 11 is composed of an insulator 18, and the insulator 18 is made of a first
As shown, it may be an insulating film, such as Mylar, affixed to the base portion. Alternatively, the rail body 17 itself may be made of an insulating material such as resin, and FIG. 2 shows such a rail body 17'.
It shows.

When cleaning or replacing the corona discharger, it is only necessary to remove the corona house 13 by sliding it in the longitudinal direction against the rail body 17. When the corona house 13 is removed, its opening side 15 and the opposite side 16 are also removed. Since both are open, cleaning and replacing discharge wires etc. can be easily performed. Further, since the opening 16 of the corona house 13 on the far side from the photosensitive drum 1 is covered by the rail body 17, the intrusion of dust and the adhesion of dust to other members are prevented. And the base portion 17a of the rail body 17
Since there is an insulator 18 in the part facing the discharge wire, the base part 17a does not work as a counter electrode for corona discharge, and if the insulator 18 is not present, uneven discharge will occur if the surface of the base part 17a becomes dirty. However, the provision of such an insulator 18 prevents the occurrence of uneven discharge due to contamination of the base portion 17a as described above. Further, if the material of the rail body is iron plated with nickel or zinc, rust is likely to occur, but the insulator 18 can eliminate the influence of rust.

(Effects of the invention) As described above, according to the invention, by removing the corona house, the side opposite to the opening facing the photosensitive drum is also opened, so cleaning and replacing discharge wires, etc. It can be done easily.
In addition, when installed in a specified position, the opening on the side opposite to the opening is covered by the rail body, so there is no air flow through the opening, so there is no contamination of other components and no intrusion of dust etc. is also prevented. Furthermore, by configuring the surface of the base portion of the rail body facing the discharge wire with an insulator, occurrence of uneven discharge caused by dirt on the base portion due to dust, etc., which occurs in the case of a conductive base portion, is prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a corona discharger according to one example of the present invention, FIG. 2 is a sectional view showing another embodiment, and FIG. 3 is a sectional view of a conventional corona discharger. In the figure, 1... photosensitive drum, 10... corona discharger, 11... discharge wire, 13... corona house, 14... shielding plate, 14a... bent edge, 15...
...opening side, 16...opening on the opposite side, 17...rail body, 17a...base part, 17b...leg part,
17c...Flange part, 18...Insulator.

Claims (1)

[Claims for Utility Model Registration] (1) A corona that includes a corona discharge wire and a corona house that has shielding plates arranged on both sides of the discharge wire and is open on the opposite side of the opening facing the photosensitive drum. The discharge device further includes a rail body that detachably supports the corona house and includes a base portion that covers an opposite side of the opening side of the corona house, and the base portion of the rail body faces the discharge wire. A corona discharger characterized in that the surface is made of an insulator. (2) Utility Model Registration The corona discharger according to claim 1, wherein the insulator is an insulating film attached to the surface of the base portion of the rail body facing the discharge wire. (3) Utility Model Registration The corona discharger according to claim 1, wherein the rail body is formed of an insulating material.