JPS58211768A - Corona discharger - Google Patents

Abstract

PURPOSE:To prevent the generation of arc discharge when a corona wire is broken by grounding a receiving terminal electrically forcibly when the corona wire is broken. CONSTITUTION:While a corona wire remains without breakage, the wire insertion hole 12 of an elastic member 10 is positioned in the central part of a case 1 and corona is kept discharged. When the wire is broken, the force that holds an arm 11 in the central part of the case is lost and the arm tries to return to the position where the own elastic force is made zero. Consequently, the forward end of the arm 11 contacts with the inside surface of the case 1 and a high voltage terminal is conducted electrically to the case 1 and is thus grounded, whereby the arc discharge is prohibited. The example in which the energizing force of the elastic member on the corona wire is applied in the lateral direction of the case 1 is shown, but the energizing force may be in the bottom direction of the case 1, and may after all be in any direction as far as part of the member 10 contacts with the case 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corona discharger that prevents the occurrence of arc discharge due to wire cutting accidents.

As a conventional corona discharger, for example, there is one shown in FIG.
A pair of insulating blocks 2 fixedly installed in grooves at both ends and formed of an insulating material, and a wire-shaped tungsten or the like fixed to the exposed surface of the insulating blocks 2 and stretched between the two insulating blocks. The corona wire 3 is constructed using a corona wire 3. To attach the corona wire 3, as shown in FIG. This is done by tightening while pulling.

In the above configuration, a high voltage of several thousand volts supplied from the high voltage terminal 4 is applied to the corona wire 3, and this high voltage exerts a certain effect on the discharge target. For example, when applied to an electrophotographic copying machine, the metal case 1 has functions such as accelerating discharge and preventing excessive charging, and has functions such as conducting spatial ions, stabilizing discharge, and diffusing ions. are doing.

An example of an electrophotographic copying machine constructed using such a corona discharger is shown in FIG. 3. A series of processes such as charging, exposure, development, transfer, and cleaning are performed on the surface of the machine as the rotation progresses. a charging section 32 that applies a high voltage to charge the surface of the photosensitive drum 31 with a charge, an exposing section 33 that optically exposes the contents of the original onto the charged drum surface; A developing section 34 applies toner to the completed drum surface for development, a transfer section 35 performs corona discharge to copy paper that is in contact with the drum surface after development and moves in synchronization, and a transfer section 35 performs the process of transferring to the drawing paper. The cleaning section 36 performs pretreatment by irradiating the finished drum surface with corona and then cleaning it with a magnetic brush.

In the configuration shown in FIG. 3, the photosensitive drum 31 rotates with the start of copying, and when the drum surface charged by the band v14; section 32 reaches the exposure section 33, the drum surface is charged according to the brightness and darkness of the copy document. The state is changed, and then the latent image portion on the drum surface is developed by the developing section 34 by electrically attracting fine particles called toner. In this case, the toner adheres only to the charged portions of the drum surface.

Next, the copy paper is passed through the transfer section 35 with the toner-printed surface stacked on top of the copy paper, and the paper is loaded and loaded so that the toner is transferred from the drum surface to the copy paper. Most of the toner on the drum surface is removed by transfer, but the remaining toner is electromagnetically removed by the cleaning section 36.

In this configuration, the corona discharger shown in FIGS. 1 and 2 is used in each of the charging section 32, the transfer section 33, and the cleaning section 36 to generate a /Fr'N corona discharge.

However, in conventional corona dischargers, if the corona wire deteriorates or is cut due to external mechanical force, leaving a length that consists of the power supply side, the broken high voltage power supply side Arc discharge occurs between the wire and the surroundings, which may generate heat or electrical noise.

The present invention has been made in view of the above, and provides a corona discharger in which the power-receiving side after cutting is forcibly brought into contact with the case in order to prevent the occurrence of arc discharge when cutting the corona wire. It provides:

Hereinafter, the corona discharger according to the present invention will be explained in detail.

FIG. 4 shows an embodiment of the present invention, in which a perspective view of the main parts is shown, and the same reference numerals are used for the same parts as in FIGS. 1 and 2. With the corona wire 3 inserted into the wire through hole 12 provided at the tip of the arm 11 on the high voltage terminal 5 side, an elastic member 10 made of a conductive material as shown in FIG. 5 fixes the wire with the fixing screw 6. It is fixedly installed on the top of the board 4.

The arm 11 has a required elastic force and is mounted at a position such that it always applies a constant force in the side direction of the case 1 to the wire inserted into the wire through hole 12. Naturally, since the corona wire 3 is a thin wire, the urging force is selected to be an appropriate value for the wire so that the corona wire 3 is not cut by the elastic force of the elastic member 10.

In the above configuration, under normal conditions, that is, when the corona wire is uncut, the wire through hole 12 of the elastic member 10 is located at the center of the metal case 1, as shown in FIG. 4, and corona discharge is not performed. ing. However, if the corona wire 3 is cut, the arm 11 as shown in FIG.
The force holding the arm 11 in the center of the case disappears, and the arm 11 attempts to return to the position where its own elastic force becomes zero. Therefore, the tip of the arm 11 contacts the inner surface of the metal case 1, and the high voltage terminal is electrically connected to the metal case 1 and grounded, so that no arc discharge occurs.

In the above embodiments, the biasing force of the elastic member against the corona wire is applied in the side direction of the case 1, but this biasing force may also be applied in the bottom direction of the case 1. As long as 1 and a part of the elastic member 10 are in contact with each other, the direction does not matter.

Furthermore, the present invention is applicable to any type of discharge device that aims to perform corona discharge using a wire. Further, when grounding due to cutting of the corona wire is detected, application of high voltage is stopped or other necessary control is performed.

As explained above, according to the corona discharger of the present invention, since the power receiving terminal is electrically forcibly grounded during disconnection, arc discharge can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional corona discharger, Fig. 2 is a side view showing the terminal section of the corona discharger shown in Fig. 1, and Fig. 3 is a principle diagram of an electrophotographic copying machine using the corona discharger. , FIG. 4 is a perspective view of a main part showing an embodiment of the present invention, FIG. 5 is a perspective view showing an elastic member 10 according to the present invention, and FIG. 6 is a diagram showing an operating mode when cutting a corona wire in the present invention. FIG. 1... Metal case, 2... Corona wire, 3...
Insulating block, 4... Wire fixing plate, 5... High voltage terminal, 6... Fixing screw, 10... Elastic member, 11...
...Arm, 12...Wire through hole.

Claims (1)

[Claims] Insulating blocks are placed at both ends of a case that has the required width and length and is open on at least one longitudinal side, and a wire to which a high voltage is applied for corona discharge is placed between the insulating blocks. In the stretched corona discharger, a predetermined urging force is applied toward the case to the wire installed in the insulating block on the high voltage receiver πL side, and when the wire is cut, the urging force is released and the A corona discharger characterized in that a conductive elastic member is provided, a part of which contacts a case.