GB2308925A

GB2308925A - Static electricity remover

Info

Publication number: GB2308925A
Application number: GB9600245A
Authority: GB
Inventors: Toneri Ishiyama; Tomoyuki Ishiyama
Original assignee: ISHIYAMA SEISAKUSHO CO Ltd
Current assignee: ISHIYAMA SEISAKUSHO CO Ltd
Priority date: 1996-01-06
Filing date: 1996-01-06
Publication date: 1997-07-09
Anticipated expiration: 2016-01-06
Also published as: GB9600245D0; GB2308925B

Abstract

An applied voltage static electricity remover comprises a high voltage source 10 for outputting high voltages of different polarities, and an ion generating electrode 14 connected to one pole of the high voltage source 10 through a high resistor 12 and for emitting ions towards a target object 20 from which static electricity is to be removed. An operator connects the other pole of the high voltage source 10, e.g. comprising piezoelectric elements 10 a , 10 b , to a high capacity object, such as the earth, a floor or a casing, and the high voltage source 10 outputs at least once high voltages alternately of different polarities to cause ions of different polarities to be emitted from the ion generating electrode 14 for removing static electricity from the object 20. The applied voltage static electricity remover can remove static electricity in a wide area and can be used for a long time without deterioration of the ion generating electrode 14.

Description

TITLE Static electricity remover DESCRIPTION Background of the invention The present invention relates to an applied voltage static electricity remover for removing a static electrical charge from objects, and to a method for removing static electricity.

The conventional applied voltage static electricity remover includes an ion generating electrode disposed very near an opposed electrode. A high voltage is applied between the ion generating electrode and the opposed electrode to generate corona discharges, whereby charges are removed from objects by ions generated by the corona discharges.

In the conventional applied voltage static electricity remover, however, the gap between the electrodes is so small that the area where ions are generated is small, and the area in which static electricity can be removed is accordingly limited. To solve this problem, a blower is used to send the ions farther so as to widen the area in which static electricity can be removed.

The applied voltage static electricity remover using the blown air currents, however, can remove static electricity only from objects that are located downstream of the air currents, and still has the problem that the area in which static electricity can be removed is small.

If the static electricity is to be removed from light objects, such as paper, a problem is that stronger air currents for blowing the ions further could adversely blow away the objects themselves.

In the conventional applied voltage static electricity remover, sparks are generated between the ion generating electrode and the opposed electrode, and undesirably large currents flow. As a resultant problem, the tip of the ion generating electrodes deteriorates in a short time. Ion generating electrodes even of tungsten, which does not easily deteriorate, have to be replaced after about half a year.

Summary of the invention An object of the present invention is to provide an applied voltage static electricity remove and a method for removing static electricity, which can remove static electricity in a wide area.

Another object of the present invention is to provide an applied voltage static electricity remover that can be used for a long time without deterioration of ion generating electrodes.

The applied voltage static electricity remover according to the present invention comprises a high voltage source for outputting high voltages of different polarities; and an ion generating electrode connected to one pole of the high voltage source through a high resistor and for emitting ions under the high voltages output by the high voltage source towards a target object from which static electricity is to be removed.

Preferably in the above-described applied voltage static electricity remover, a plurality of the ion generating electrodes are arranged along a conveyance passage through which target objects may be moved.

Preferably in the above-described applied voltage static electricity remover, the high voltage source is a squeeze-type piezoelectric element high voltage source which outputs high voltages of different polarities upon pressure increase and pressure decrease.

Preferably in the above-described applied voltage static electricity remover, an insulating enclosure having an opening through which ions may be emitted is provided around the ion generating electrode.

The present invention also provides a method for removing static electricity from a target object by use of a high voltage source with one pole thereof connected to an ion generating electrode through a high resistor, the method comprising: connecting the other pole of the high voltage source to a high capacity object in the vicinity of the high voltage source; and outputting high voltages alternately of different polarities at least once from the high voltage source to cause ions of different polarities to be emitted from the ion generating electrode for removing static electricity from the target object.

Preferably in the above-described method for removing static electricity, a plurality of the ion generating electrodes are arranged along a conveyance passage along which the target object is moved, and ions are emitted towards the moving target object from said plurality of ion generating electrodes to remove the static electricity from the object.

Preferably in the above-described method for removing static electricity, the high voltage source is a squeeze-type piezoelectric element high voltage source which outputs high voltages of different polarities upon pressure increase and pressure decrease, and the pressure on the squeeze-type piezoelectric element high voltage source is increased and decreased at least once, whereby high voltages alternately of different polarities are output from the high voltage source.

Preferably in the above-described method for removing static electricity, an insulating enclosure having an opening through which the ions may be emitted is provided around the ion generating electrode.

Brief description of the drawings FIG. 1 is a view of the applied voltage static electricity remover according to a first embodiment of the present invention.

FIG. 2 is a view of the applied voltage static electricity remover according to a second embodiment of the present invention.

FIG. 3 is a view of a protection enclosure disposed around an ion generating electrode of the applied voltage static electricity remover according to a third embodiment of the present invention.

Detailed description of the invention The applied voltage static electricity remover according to a first embodiment of the present invention is shown in FIG. 1.

The applied voltage static electricity remover according to the present embodiment uses as a high voltage source a squeeze-type piezoelectric element high voltage source 10, which outputs high voltages of different polarities corresponding to pressure increases or decreases. The squeeze-type piezoelectric element high voltage source 10 comprises two piezoelectric elements 10a,10b of different polarities, which are bonded to each other. The bonded surfaces constitute one pole for high voltage output, and the sides of the piezoelectric elements are commonly connected as the other pole for high voltage output. One pole is connected to an ion generating electrode 14 through a high resistor 12. The other pole is connected, for grounding, to an object of a large electric capacity, such as the earth, a floor, a casing or others, located in the vicinity of the squeeze-type piezoelectric element high voltage source.

The high capacity object in its vicinity functions as an opposed electrode to the ion generating electrode 14.

A shown in FIG. 1, the squeeze-type piezoelectric element high voltage source 10 outputs a high voltage, e.g. 15000 V, of different polarities in accordance with pressure increases and decreases of the sides of the piezoelectric elements 10a,10b. For example, when the both sides of the piezoelectric elements 10a,10b have an increased pressure, the ion generating electrode 14 outputs a high voltage (+15000 V) which is positive with respect to a ground voltage. When the increased pressure of the both sides of the piezoelectric elements 10a,10b is decreased, the ion generating electrode 14 outputs a high voltage (-15000 V) which is negative with respect to the ground voltage. The pressure increase and decrease are repeated, whereby a positive high voltage and a negative high voltage are alternately output by the ion generating electrode 14.

To effectively remove static electricity from a target object, it is preferred that the squeeze-type piezoelectric element high voltage source 10 is of the type which outputs a high negative voltage (-15000 V) upon the pressure increase and a high positive voltage (+15000 V) upon the pressure decrease, and emits firstly ions generated by the high negative voltage and then ions generated by the high positive voltage.

The high resistor 12 connected to one pole of the squeeze-type piezoelectric element high voltage source 10 is for the purpose of preventing, for safety, spark discharges and electric shocks when high voltages are generated. The high resistor 12 has a very high resistance value of e.g. 100 Mn. Preferably the resistance value is about 60 Mn and may be higher, e.g.

1 Tn (tera-ohm).

The ion generating electrode 14 connected to one pole of the squeeze-type piezoelectric element high voltage source 10 through the high resistor 12 is in the shape of a pointed needle. The point is preferably directed towards the target object 20 and may be spaced from the object 20 by about 50 cm.

The ion generating electrode 14 is formed of an electrically conducting material, such as copper, brass, iron or others. In the present embodiment, because substantially no sparks are discharged from the ion generating electrode 14, as are conventionally, the ion generating electrode 14 of an electrically conducting material, such as copper, brass, iron or others, can last a long time in use. It is not necessary to use a material, such as tungsten, which does not easily deteriorate.

An experiment of removing static electricity from an object by the use of the applied voltage static electricity remover according to the present embodiment was conducted.

The squeeze-type piezoelectric element high voltage source 10 which generates a high voltage of about +15000 V upon a pressure increase and generates a high voltage of about -15000 V upon a pressure decrease was used. The ion generating electrode 14 was positioned about 50 cm away from a target object 20 and the object was charged to about 10 kV. A pressure increase and a pressure decrease were applied to the squeeze-type piezoelectric element alternately, repeated twice a second. This operation was continued for 5 minutes. The result was that the charge on the target object was reduced to about 100 V residual voltage, and a good static electricity removing effect was obtained.

The applied voltage static electricity remover according to a second embodiment of the present invention is shown in FIG. 2. Common elements of the second embodiment with the applied voltage static electricity remover of FIG. 1 are represented by common reference numerals and their explanation will not be repeated.

The applied voltage static electricity remover according to the second embodiment is for removing static electricity from moving objects. A plurality of ion generating electrodes 14 are arranged along a conveyance passage of the objects 20 from which static electricity is to be removed. Each ion generating electrode 14 removes static electricity from those of the objects 20 positioned in an area extending about 50 cm radially therefrom. Each ion generating electrode 14 is located about 50 cm away from its adjacent one.

An experiment of removing static electricity from objects by the applied voltage static electricity remover according to the second embodiment was conducted.

A squeeze-type piezoelectric element high voltage source 10 which generates a high voltage of about +15000 V upon pressure increase and a high voltage of about -15000 V upon pressure decrease was used. As shown in FIG 2, four ion generating electrodes 14 were arranged along a conveyance passage at a distance of about 50 cm from the passage. A pressure increase and a pressure decrease were alternately applied twice per second to the squeeze-type piezoelectric element voltage source 10 while objects charged to about 10 kV were moved through the conveyance passage. This operation was continued for 5 minutes. The result was that the charge was reduced to about 100 V residual voltage, and a good static electricity removing effect was obtained.

The applied voltage static electricity remover according to a third embodiment of the present invention is shown in FIG. 3.

In the applied voltage static electricity remover according to the present invention, the ion generating electrodes 14 are so pointed that, very dangerously, they are broken when other objects violently contact the ion generating electrodes 14, and operators may be injured when touch the ion generating electrodes 14. For the purpose of avoiding such dangers and for determining an emitting direction of the ions, as shown in FIG. 3 a funnel-shaped protection enclosure 30 of an insulating material is provided around an ion generating electrode 14. The larger mouth of the funnel shape is an ion emitting opening 32 through which ions generated by the ion generating electrode 14 are emitted.

The protection enclosure 30 functions to keep the ion generating electrode 14 from breakage, to protect operators from contacting the ion generating electrode 14 and being injured, and to emit the ions in a prescribed direction.

It is possible that the protection enclosures 30 may be provided around respective ion generating electrodes 14 of the second embodiment.

The present invention is not limited to the abovedescribed embodiments and can cover other variations and modifications within the scope of the present invention as defined in the claims.

For example, squeeze-type piezoelectric element high voltage sources are used in the above-described embodiments but other high voltage sources may be used as long as they output high voltages of different polarities.

The ion generating electrodes are not necessarily needle-shaped and may have any shape as long as the shape can generate ions between the ion generating electrodes and an opposed electrode such as the earth, a floor of a room, a casing of an apparatus or others.

The protection enclosures for the ion generating electrodes do not necessarily have the funnel shape of the above-described embodiment and may have any shape as long as the shape encloses the ion generating electrode and allows the emission of ions generated by the ion generating electrode towards an object from which static electricity is to be removed.

Claims

1. An applied voltage static electricity remover comprising: a high voltage source for outputting high voltages of different polarities; and an ion generating electrode connected to one pole of the high voltage source through a high resistor and for emitting ions under the high voltages output by the high voltage source towards a target object from which static electricity is to be removed.

2. An applied voltage static electricity remover according to claim 1, wherein a plurality of the ion generating electrodes are arranged along a conveyance passage, through which a target object may be moved.

3. An applied voltage static electricity remover according to claim 1 or 2, wherein the high voltage source is a squeeze-type piezoelectric element high voltage source which outputs high voltages of different polarities upon pressure increase and pressure decrease.

4. An applied voltage static electricity remover according to any of claims 1 to 3, wherein an insulating enclosure having an opening through which ions may be emitted is provided around the ion generating electrode.

5. A method for removing static electricity from a target object by use of a high voltage source with one pole thereof connected to an ion generating electrode through a high resistor, the method comprising: connecting the other pole of the high voltage source to a high capacity object in the vicinity of the high voltage source; and outputting high voltages alternately of different polarities at least once from the high voltage source to cause ions of different polarities to be emitted from the ion generating electrode for removing static electricity from the target object.

6. A method for removing static electricity according to claim 5, wherein a plurality of the ion generating electrodes are arranged along a conveyance passage along which the target object is moved, and ions are emitted towards the moving target object from said plurality of ion generating electrodes to remove the static electricity from the object.

7. A method for removing static electricity according to claim 5 or claim 6, wherein the high voltage source is a squeeze-type piezoelectric element high voltage source which outputs high voltages of different polarities upon pressure increase and pressure decrease, and the pressure on the squeeze-type piezoelectric element high voltage source is increased and decreased at least once, whereby high voltages alternately of different polarities are output from the high voltage source.

8. A method for removing static electricity according to any of claims 5 to 7, wherein an insulating enclosure having an opening through which the ions may be emitted is provided around the ion generating electrode.

9. An applied voltage static electricity remover substantially as described herein with reference to the drawings.