JPS63109473A - Discharging device - Google Patents

Abstract

PURPOSE:To electrostatically charge or destaticize selectively a part of a charged body by constituting a 2nd electrode of comb-like conductors divided into plural areas, arranging respective comb teeth so as to cross a 1st electrode and electrically selecting and connecting respective comb-like conductors in accordance with necessary charging width. CONSTITUTION:Charging current flowing from a solid discharging device 1 into the charged body 20 passes a current detecting circuit 33 built in a power supply 30 through the earth and flows into a rectifier circuit 32 and a detecting signal converted into a voltage value corresponding to the charging current is sent to an output control circuit 34. The output of the circuit 34 is sent to a power driving circuit 31 to control the current supply and a DC bias voltage is also changed by the circuit 32 by operating an AC voltage value applied between the 1st and 2nd electrodes 3, 4, so that the charging current can be accurately maintained at a prescribed value. When the set value of the charging current is changed by the circuit 33 or 34 in accordance with the number of connected conductive members at the time of connecting the 2nd electrode 4 with the power supply 30 in accordance with the required charging width, the value of the charging current in each unit length is fixedly controlled at the required charging band.

Description

Detailed Description of the Invention (Technical Field) The present invention includes a dielectric, a first electrode and a second electrode for discharging disposed through the dielectric, and a method for generating ions in the vicinity of the first electrode. The present invention relates to a discharge device having means for applying an alternating current voltage between the first electrode and the second electrode. This type of discharge device can be applied to a charge removal/charging device in an electrostatic recording device such as a copying machine or a facsimile machine.

(Prior art) A plate-shaped solid-state discharge device has been put into practical use in place of the thin wire type corona discharger that was conventionally used as a charge remover and charger for electrostatic recording devices (electrophotographic devices) such as copying machines and facsimiles. It is measured.

By the way, in an electrophotographic apparatus, it is necessary to uniformly charge the surface of a photoconductive photoreceptor before exposure, but if the area outside the transfer paper area is charged, an untransferred toner image will remain on the photoreceptor.
This is undesirable because it wastes developer (toner) and increases the burden of cleaning residual toner. As a countermeasure against this, various methods have been devised in which the charging width is variably selected according to the transfer paper, but in the method of dividing the strip and connecting the divided parts according to the required width, the charging potential of the connecting part It is difficult to achieve uniformity, which hinders practical application.

Conventional examples of variably selecting the charging width include splitting the second electrode into multiple parts according to the paper size and applying AC power to each electrode, or splitting the second electrode into multiple parts according to the paper size, or dividing the second electrode into multiple parts according to the copy size. A device having electrodes and having a first electrode selectively connected to a power source according to a desired charging width is known.

However, in the former, the second electrode is formed in a step-like manner to prevent uneven charging at the divided portion, and multiple first electrodes are required to charge uniformly. Each method had its own problems, such as the need for multiple electrodes.

Further, in both of the above conventional examples, changes in the load on the source when switching the electrodes are not taken into consideration. That is, simply switching the electrodes and connecting them to a power source changes the discharge state, resulting in a drawback that a specified charging potential cannot be obtained.

(Purpose) The present invention was made based on this background,
It is an object of the present invention to provide a discharge device that can eliminate the drawbacks of the conventional examples described above and selectively charge or remove electricity from a part of a charged object (for example, depending on the paper size).

(Structure) Conventional solid-state discharge elements have a property that electrical non-uniformity in minute parts of the dielectric material causes non-uniform charging potential.As a countermeasure to this, the present invention has a comb-shaped ion generating electrode. This attempts to achieve uniformity by forcibly setting the discharge starting point at the comb-shaped Ti end. By selecting the pitch of the comb teeth and the discharge distance to the object to be charged, it is possible to create a state in which power outage unevenness that does not correspond to the pitch of the comb teeth can be ignored.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is an overall configuration diagram of a solid-state discharge device and a charged object according to an embodiment of the present invention, and FIG. 2 shows a cross section of A-AFrIA in FIG. 1 and the charged object. FIG. 3 is a diagram showing an example in which solid-state discharge devices are arranged in parallel, FIG. 4 is a diagram showing an example in which the first electrode is an overhead wire, and FIGS. 5 and 6.

7 and 8 are diagrams showing other embodiments of the discharge device, and FIG.
The figure is a sectional view taken along the line A--A in FIG.

First, explanation will be given based on FIGS. 1 and 2.

The solid state discharge device 1 consists of an insulating substrate 2, a first electrode 3 for discharge, a second electrode 4 for ion generation, and a dielectric 5, and includes a second N,
As shown in FIG. 1, the pole 4 is a comb-shaped conductor divided into a plurality of regions, and the comb teeth are provided to intersect with the first discharge electrode 3. The first electrode 3 has a continuous m-line shape with a maximum charging width of more than the entire length.

The second electrode 4 includes a conductor 4a corresponding to the minimum charging width, and its −
It is constructed by providing conductors 4b and 4c corresponding to each paper on the side.

At this time, the gap between 4a and 4b (6a) and the gap between 4b and 4c (6b) are set to be approximately the same as the gap between the comb teeth, and the discharge electrode 3 is made of a seamless thin wire with a diameter of at least medium, thereby reducing unevenness in the charging potential at the seam. can be ignored in practice.

In order to always keep the charging potential at a constant potential, it is preferable to use a constant voltage power source as the current is automatically controlled in response to load fluctuations caused by changing the charging width. However, when a constant current power supply having a function of correcting changes in charging current due to environmental changes is used, the charging current is not controlled by changes during charging.

The charging current flowing from the solid state discharge device 1 to the charged object 20 is
Current detection circuit 3 built into power supply 30 via ground
3 and flows to the rectifier circuit 32.

The current detection circuit 33 outputs a detection signal converted into a voltage value corresponding to the charging current, and sent to the output control circuit 34 which determines whether the detection signal is at a set value. The output of the output control circuit 34 is transmitted to the power drive circuit 3.
By controlling the amount of current supplied to the power drive circuit 31 and manipulating the AC voltage value applied between the first electric scraper 3 and the second TFI 4, the DC bias voltage is also changed by the rectifier circuit 32. Maintain charging current at a predetermined value with high precision.

Here, the second electric scraper 4 is connected to the electric A30 according to the desired charging width.
, the charging current setting value is changed in the current detection circuit 33 or the output control circuit 34 according to the number of connected conductive members, and the charging current value per unit length is determined at the desired charging width. It is controlled to be constant.

Although FIG. 1 shows an example in which the second electrode 4 is divided into three parts on one side, it may be divided into two parts or even more parts. The configuration may be such that each of the two is independently connected to the power source. In a central reference imaging system, split electrodes are provided on both ends of the bone.

Although FIG. 2 shows an example in which the solid-state discharge device 1 is arranged vertically with respect to the object to be charged 20, it may be arranged parallel to the object to be charged as shown in FIG.

Although FIGS. 1 to 3 show solid-state discharge devices in which the first electrode 3 is fixedly disposed on the dielectric 5, as shown in FIG. The discharge device 10 may also be used. Although FIG. 4 shows an example in which the discharge device 10 is arranged vertically with respect to the charged object 20, it is also possible to arrange the discharge device 10 parallel to the charged object 20. You may do so.

5 to 9 show other embodiments of the discharge device.

FIG.
This is an example in which electrode 4 is used. FIG. 6 shows an example in which band-shaped conductive members are connected at the center to form the second electrode 4, and two first electrodes 3 are provided.

FIG. 7 shows an example in which the first electrode 3 is provided outside the second electrode 4.

FIG. 8 shows an example in which the first electrode 3 is provided on the longitudinal end surface of the solid state discharge device 1.

FIG. 9 is a diagram showing a cross section along AA of the solid state discharge device 1 of FIG. 8.

In FIGS. 5 to 9, the first electrode 3 may be fixed on a dielectric material to serve as the solid state discharge device 1, or the first electrode 3 may be used as the discharge device 10 by using an overhead wire.

Also in FIGS. 5 to 9, the second electrode 4 is
It is divided according to the charging width and the power supply is selectively connected.

(Effects) The present invention is as described above, and by using the discharge device according to the present invention, a part of the charged object can be selectively removed and charged within a desired range. be able to.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a solid-state discharge device and a charged object according to an embodiment of the present invention, and FIG. 2 shows a cross section taken along line 8-A in FIG. 1 and the charged object. FIG. 3 is a diagram showing an example in which solid-state discharge devices are arranged in parallel, FIG. 4 is a diagram showing an example in which the first electrode is an overhead wire, and FIGS. 5 and 6. 7 and 8 are diagrams showing other embodiments of the discharge device, and FIG.
The figure is a sectional view taken along line A-AvA in FIG. 3... First electrode, 4... Second electrode, 5... Dielectric. Figure 1 Figure 4 Figure 5 Figure 6

Claims (3)

[Claims] (1) A dielectric and a discharge first disposed through the dielectric.
In a discharge device comprising an electrode, a second electrode, and means for applying an alternating current voltage between the first electrode and the second electrode in order to generate ions in the vicinity of the first electrode, the second electrode , is composed of a comb-shaped conductor divided into a plurality of regions, each comb-shaped conductor is arranged so as to intersect with the first electrode, and each comb-shaped conductor is electrically connected according to the required charging width. A discharge device characterized by being selectively connected. (2) The discharge device according to claim (1), wherein the charging current value is controlled according to the charging width. (3) The discharge device according to claim (1), wherein the first electrode for discharge is a seamless electrode over the maximum charging width.