JP6725938B2 - Ion generator - Google Patents

Description

The present invention relates to an ion generator used for applications such as static elimination.

Ion generators used for applications such as static elimination generate a corona discharge from the discharge needle by alternately applying a high positive and negative voltage between the discharge needle and a counter electrode that is grounded. Generates positive and negative air ions. This type of ion generator is generally known to include a plurality of discharge needles arranged in a row (for example, see Patent Document 1).

JP, 2009-4127, A

Since the ion generator applies a high voltage between the discharge needle and the counter electrode, when the high voltage is applied, generally, a relatively large induced voltage is applied to a positive or negative air ion supply target object such as a static elimination target object. (For example, an induced voltage of several hundred V) is induced.

Then, when the positive and negative air ion supply target is an electronic component such as a semiconductor component having a low voltage resistance, for example, the induced voltage is temporarily removed during the transportation of the electronic component. Even if the induction of the electric current is completed in a short time, the electronic component may be damaged or abnormally operated.

Therefore, it is desired to suppress the induced voltage induced in the air ion supply target to a voltage as small as possible.

The present invention has been made in view of such a background, and supplies positive and negative air ions generated by corona discharge to a supply target, and suppresses an induced voltage induced in the supply target to a voltage as small as possible. It is an object of the present invention to provide an ion generator capable of performing the above.

The ion generator of the present invention, in order to achieve the above object,
A plurality of discharge needles arranged in rows,
A counter electrode which is arranged on the side of the plurality of discharge needles and grounded so that corona discharge is generated between the discharge needles when a high voltage is applied between the plurality of discharge needles. When,
A high-voltage power supply that alternately applies positive and negative high voltages between the plurality of discharge needles and the counter electrode,
An air blower that blows positive and negative air ions generated by corona discharge generated between the plurality of discharge needles and the counter electrode toward a supply target,
There is a discharge needle facing portion that is a portion facing the plurality of discharge needles at a position between the plurality of discharge needles and the supply target, and there is a space between the plurality of discharge needles and the counter electrode. And a plate-shaped conductor member that is grounded,
The plate-shaped conductor member has a plurality of holes for passing the positive and negative air ions toward the supply target, at least in a portion facing the discharge needle, and the plurality of discharge needles and the counter electrode. in a state where a high voltage is applied between it shall be the basic structure of the induced voltage to the supply object is arranged so as to suppress the induced.

According to the present invention having such a basic configuration, since the grounded plate-shaped conductor member has the discharge needle facing portion, when the high-voltage power supply is activated (a positive and negative electrode is provided between the plurality of discharge needles and the counter electrode). Induction of an induced voltage in the supply target is suppressed when the high voltage is alternately applied). Further, since a plurality of holes are formed in the portion of the plate-shaped conductor member facing the discharge needle, positive and negative air ions (positive air ions and negative air ions) generated by the corona discharge are generated by the blower. The air can pass through the plurality of holes in the portion of the plate-shaped conductor member facing the discharge needle to reach the supply target.

Therefore, according to the present invention , the positive and negative air ions generated by the corona discharge can be supplied to the supply target, and the induced voltage induced in the supply target can be suppressed to a voltage as small as possible.

In the present invention having the above basic configuration , the high-voltage power supply is configured to intermittently and alternately apply positive and negative pulsed high voltages between the plurality of discharge needles and the counter electrode. It is not preferred. Then, in this case, when the high-voltage power supply is operated in a state where the supply target charged with a predetermined charging voltage is arranged at a position at a predetermined distance from the plurality of discharge needles, the supply target is The decay time, which is the time required for the charging voltage of an object to decay to a low voltage of a predetermined value, is defined as the decay time A, and the predetermined charging voltage is applied to the position at the predetermined distance from the plurality of discharge needles. When the charged supply object is arranged and the high-voltage power supply is operated in a state where the plate-shaped conductor member is removed, the charge voltage of the supply object is attenuated to the low voltage of the predetermined value. When the decay time, which is the time required to perform, is defined as the decay time B, the pulse width of each of the positive and negative pulsed high voltages output from the high-voltage power supply, and the portion of the plate-shaped conductor member facing the discharge needle. The distance between each of the plurality of discharge needles, the size of the hole formed in the portion of the plate-shaped conductor member facing the discharge needle, and the air volume of the air blower are such that the decay time A is the decay time B. The time may be set as follows (first invention).

In the first aspect of the present invention, “to apply positive and negative pulsed high voltage intermittently and alternately” means, more specifically, a period of applying a positive pulsed high voltage and a negative polarity Between the period in which the pulsed high voltage is applied and the period in which the voltage is maintained at zero or almost zero (the pause period of voltage application), a positive pulsed high voltage and a negative polarity It means that a pulsed high voltage is alternately applied between the plurality of discharge needles and the counter electrode.

According to the first aspect, it is possible to suppress the positive and negative air ions generated by the corona discharge from being absorbed by the plate-shaped conductor member in the process of moving toward the supply target.

Further , when the charged object to be supplied is discharged, the time required for the discharging can be set to the same time as the case where the plate-shaped conductor member is removed or a shorter time. Therefore, it is possible to suitably realize both suppression of induction of an induced voltage in the supply target and efficient removal of electricity from the supply target in a short time.

In the present invention having the above basic configuration, it is preferable that the plate-shaped conductor member is arranged so as to surround the plurality of discharge needles, the counter electrode, and the high-voltage power supply ( second invention).

According to this, induction of an induced voltage in the supply target can be effectively suppressed .
In the first invention or the second invention, the plate-shaped conductor member is preferably a member in which at least the discharge needle facing portion is formed in a mesh shape (third invention).
According to this, it is possible to appropriately realize the suppression of the induction of the induced voltage in the supply target and the suppression of the generated positive and negative air ions being absorbed by the plate-shaped conductor member. A plate-shaped conductor member can be formed.

FIG. 1A is a side view showing a part of an ion generator of one embodiment of the present invention in a cross section, and FIG. 1B is a view showing the ion generator in a cross section taken along line I-I of FIG. 1A. The figure which shows schematically the circuit structure of the ion generator of embodiment, and the arrangement structure of a plate-shaped conductor member. The figure which shows the circuit structure of the high voltage power supply with which the ion generator of embodiment is equipped. 4 is a graph illustrating an output waveform of the high voltage power supply shown in FIG. 3. 5A and 5B are diagrams schematically showing a circuit configuration and an arrangement configuration of plate-shaped conductor members of an ion generation device according to another embodiment, respectively. 6A and 6B are views showing measurement data obtained by a verification test using the ion generator of the embodiment.

One embodiment of the present invention will be described below with reference to FIGS. 1A to 4. With reference to FIG. 1A and FIG. 1B, the ion generator 1A of the present embodiment is a device that can be used as a static eliminator in a semiconductor manufacturing line or the like. This ion generator 1A includes an elongated first housing 2 in which a plurality of discharge needles 6 constituting a discharge electrode 5 and a counter electrode 7 are mounted, and an elongated second housing in which a high-voltage power supply 20 and a control unit 30 are mounted. And a housing 3.

The first housing 2 and the second housing 3 are made of an insulating material and fixed to each other. In FIG. 1A and FIG. 1B, the first housing 2 and the second housing 3 are laterally (left and right in FIG. 1A, and FIG. 1B in a state where the first housing 2 is located below the second housing 3). Then it is arranged so as to extend in the direction perpendicular to the paper surface.

On the lower surface of the first housing 2, a plurality of blowing nozzles 8 (of the same number as the discharge needles 6) made of an insulating material are arranged in a line at regular intervals in the longitudinal direction of the first housing 2. It is installed. Each blower nozzle portion 8 is formed in a bottomed tubular shape, and is projected from the lower surface portion of the first housing 2 with its open end facing downward.

Each discharge needle 6 is arranged on the axis of each blow nozzle unit 8. Each discharge needle 6 has its base end (the end opposite to the sharp tip) fixed to the center of the bottom (the upper end in FIGS. 1A and 1B) of each blow nozzle 8, and the center From the air blow nozzle portion 8 toward the open end (the lower end in FIGS. 1A and 1B). Therefore, the plurality of discharge needles 6 are arranged in a line in the longitudinal direction of the first housing 2 at regular intervals.

Further, each discharge needle 6 is electrically connected to a conductor rod 9 arranged inside the first housing 2 so as to extend in the longitudinal direction of the first housing 2 through a conducting wire. There is. The conductor rod 9 is connected to the high-voltage power supply 20 via a conducting wire, and a voltage is applied from the high-voltage power supply 20.

In addition, two counter electrodes 7, 7 extending in the longitudinal direction of the first housing 2 are mounted on the lower surface of the first housing 2. These counter electrodes 7, 7 are provided on both sides of the row of the plurality of blow nozzles 8 (both sides in the width direction of the first housing 2 (the direction perpendicular to the paper surface in FIG. 1A, the horizontal direction in FIG. 1B)). As a result, the discharge needles 6 are arranged so as to extend parallel to each other on both sides of the row. As shown in FIG. 2, the counter electrodes 7, 7 are grounded to a ground potential portion G as a high-voltage reference potential portion output from the high voltage power source 20.

The internal space of the first housing 2 is a space into which air is introduced from the outside, and the air compressor 50 is installed in the pipe connection portion 2a attached to the end of the first housing 2 in the internal space. By connecting via the pipe 2b, the air pressurized to a predetermined pressure is introduced from the air compressor 50. The internal space of the first housing 2 communicates with the inside of each blow nozzle 8 through a plurality of holes 8 a formed in the bottom of each blow nozzle 8.

Therefore, the air supplied from the air compressor 50 to the internal space of the first housing 2 enters the inside of the air blowing nozzle portion 8 through the holes 8a of the air blowing nozzle portions 8 from the internal space, and further the air blowing is performed. The air is blown downward from the nozzle portion 8 (in front of the discharge needle 6 inside the air blowing nozzle portion 8).

In addition, in the present embodiment, the air compressor 50 and the blowing nozzle portion 8 are constituent elements of the blowing device of the present invention.

The high voltage power supply 20 and the control unit 30 are housed in the second housing 3. In the present embodiment, the high-voltage power supply 20 is configured to be capable of intermittently outputting a positive pulsed high voltage and a negative pulsed high voltage alternately at a constant cycle. The high voltage power supply 20 is configured as shown in FIG. 3, for example.

Specifically, the high-voltage power supply 20 includes a bridge circuit 21 having four switch elements Q1 to Q4 on each side, a DC power supply 22 that outputs a constant voltage, a transformer 23, and a secondary coil 23b of the transformer 23. And a capacitive element 24 (for example, a capacitor) connected in parallel. The capacitive element 24 may be omitted.

Each of the switch elements Q1 to Q4 is configured by a semiconductor switch element (FET in the illustrated example) such as a transistor or an FET. The bridge circuit 21 has two switch elements Q1 and Q2 connected in series and two switch elements Q3 and Q4 connected in series as a pair of output terminals 22a and 22b of the DC power supply 22. It is configured by connecting in parallel between them.

In the present embodiment, the DC power source 22 is a power source that outputs a positive constant voltage (+Vd). One of the output terminals 22a and 22b of the DC power source 22a has a positive terminal and the other output terminal 22b has a positive terminal. , A ground electrode side terminal connected to the ground potential portion G. The DC power supply 22 may be a power supply that outputs a constant negative voltage.

Both ends of the primary coil 23a of the transformer 23 are connected to a midpoint between the switch elements Q1 and Q2 and a midpoint between the switch elements Q3 and Q4, respectively.

Then, one end of the secondary coil 23b of the transformer 23 is connected to each discharge needle 6, and the other end is connected to the ground potential part G. In this case, one end of the secondary coil 23b and each discharge needle 6 are connected via the conductor rod 9.

The high-voltage power supply 20 having such a configuration keeps both the switch elements Q2 and Q3 in an off state while applying a constant voltage (+Vd) from the direct current power supply 22 to the bridge circuit 21, while turning on the switch elements Q1 and Q4. By performing the off control and the on/off control of the switch elements Q2 and Q3 while keeping both the switch elements Q1 and Q4 in the off state alternately at a constant cycle, the state shown in FIG. With a waveform pattern as illustrated, a positive pulsed high voltage and a negative pulsed high voltage are output from both ends of the secondary coil 23b of the transformer 23 (both ends of the capacitive element 24). Then, the high voltage is applied between each discharge needle 6 and the counter electrodes 7, 7 grounded to the ground potential portion G.

The control unit 30 is composed of, for example, one or more electronic circuit units including a CPU, a RAM, a ROM, an interface circuit, and the like. Then, the control unit 30 has a function of controlling start/stop of the DC power supply 22 and an ON/OFF operation of the switch elements Q1 to Q4 as functions realized by the installed hardware configuration and program (software configuration). It has a control function (and thus a function of controlling the output of the high-voltage power supply 20).

The control process of the control unit 30 relating to these functions is executed according to an operation command given by an operator, a preset schedule, or the like.

Although the control unit 30 is housed in the second housing 3 in the present embodiment, the control unit 30 is arranged outside the second housing 3 (including a location apart from the second housing 3). May be.

With reference to FIGS. 1A and 1B, and FIG. 2, the ion generator 1</b>A further includes a plate-shaped conductor member 11. The plate-shaped conductor member 11 has a portion (discharging needle facing portion) arranged in front of all the discharging needles 6 (downward in FIGS. 1A and 1B) so as to face each discharging needle 6, and at least The portion has a large number of holes (through holes) through which air ions generated as described later can pass.

In the present embodiment, most of the plate-shaped conductor member 11 is a member formed by a plurality of linear conductors 11a made of a conductor such as metal into a mesh shape. Further, in the present embodiment, the plate-shaped conductor member 11 is arranged so as to surround most of the periphery of the first housing 2 and the second housing 3 including all the discharge needles 6 and the counter electrodes 7, 7. Has been done.

Specifically, as shown in FIG. 1B, the plate-shaped conductor member 11 has each discharge needle 6 in a state in which there is a gap with the lower end of each blow nozzle portion 8 (and thus in a gap with the tip of each discharge needle 6). 11A (hereinafter referred to as the lower flat portion 11A) located in front (downward) of the first housing 2 and the second housing 3 are spaced from each other by the side surface (therefore, each discharge needle 6). And the flat portions 11B and 11B (hereinafter referred to as "spaces with the counter electrodes 7 and 7") which are erected from both sides (both sides in the width direction of the first casing 2 and the second casing 3) of the lower flat portion 11A. , Lateral flat portions 11B) and upper portions 11C and 11C extending from the respective upper ends of the lateral flat portions 11B and 11B to the upper surface side of the second housing 3, the upper portion 11C. , 11C are fixed to the upper surface of the second housing 3. The lower flat portion 11A and the side flat portions 11B, 11B are portions formed in a mesh shape. The upper portions 11C and 11C may also be formed in a mesh shape. Moreover, the plate-shaped conductor member 11 covers both longitudinal ends of the first housing 2 and the second housing 3 in addition to the lower flat portion 11A, the lateral flat portions 11B and 11B, and the upper portions 11C and 11C. You may further provide a part.

As described above, the plate-shaped conductor member 11 is formed in a mesh shape below and on both sides of the first casing 2 and the second casing 3, including all the discharge needles 6 and the counter electrodes 7, 7. It is arranged so as to be surrounded by the lower flat portion 11A and the side flat portions 11B, 11B. The plate-shaped conductor member 11 is grounded to the ground potential portion G as shown in FIG.

Therefore, in the present embodiment, as conceptually shown in FIG. 2, the discharge needle 6, the counter electrodes 7 and 7, and the high-voltage power supply 20 are entirely surrounded by the plate-shaped conductor member 11 which is grounded.

The positional relationship between the plate-shaped conductor member 11 and the tip of each discharge needle 6 (the distance d between the lower flat portion 11A of the plate-shaped conductor member 11 and the tip of each discharge needle 6) and the plate The size and the like of each mesh of the linear conductor member 11 (a rectangular void portion surrounded by two linear conductors 11a, 11a adjacent in the vertical direction and two linear conductors 11a, 11a adjacent in the horizontal direction) As will be described later, when the air ions are generated, the induced voltage induced in the static elimination target W is suppressed to a sufficiently small voltage, and the static elimination target W can be efficiently discharged in a short time as much as possible. , Preset.

In the present embodiment, the lower flat portion 11A of the plate-shaped conductor member 11 corresponds to the discharge needle facing portion of the present invention. Further, each mesh of the lower flat portion 11A and the side flat portions 11B, 11B of the plate-shaped conductor member 11 corresponds to the holes of the plate-shaped conductor member 11.

Supplementally, in the ion generator 1A shown in FIGS. 1A and 1B, as described above, the discharge needle 6, the counter electrodes 7 and 7, and the high-voltage power supply 20 are all surrounded by the mesh-shaped plate-shaped conductor member 11. Is configured.

However, in the ion generator according to the embodiment of the present invention, as shown in FIG. 5A, for example, the ion generator has a configuration in which the mesh-shaped plate-shaped conductor member 12 is arranged only in front of (below) the discharge needle 6. It may be the device 1B. In other words, the ion generator 1B has a configuration in which a portion other than the lower flat portion 11A of the plate-shaped conductor member 11 of the ion generator 1A is removed.

Alternatively, the ion generator according to the embodiment of the present invention is formed in a mesh shape in front of (below) the discharge needle 6 and on the side of the discharge needle 6 and the counter electrodes 7, 7 as shown in FIG. 5B, for example. The ion generator 1C may be configured to have the plate-shaped conductor member 13 arranged therein. In other words, the ion generator 1B includes a portion of the plate-shaped conductor member 11 of the ion generator 1A, which is located above the first housing 2 of the flat side portions 11B and 11B and above the upper portion 11C and 11C. It has a configuration in which and are removed.

The configurations of the ion generators 1B and 1C other than the plate-shaped conductor members 12 and 13 may be the same as those of the ion generator 1A.

Next, the operation of the ion generator 1A will be described. The ion generator 1A is used, for example, as a static eliminator. In this case, as shown in FIG. 2, the discharge target object W as the supply target of the air ions is in a state where the lower flat portion 11A of the plate-shaped conductor member 11 is positioned between the discharge needles 6 and the discharge needles. It is arranged in front of (below) 6.

In this state, the compressed air is supplied from the air compressor 50 to the inner space of the first housing 2 to blow air from the blower nozzle portions 8 to the front of the discharge needles 6, and the high-voltage power supply 20 is activated. By doing so, positive and negative pulsed high voltages are alternately and intermittently output from the high-voltage power supply 20 in a constant cycle.

At this time, each discharge needle 6 is divided into a period in which a high voltage of positive polarity is applied from the high-voltage power supply 20 and a period in which a high voltage of negative polarity is applied between each discharge needle 6 and the counter electrodes 7, 7. A corona discharge is generated between the counter electrode 7 and the counter electrode 7, and air ions are generated around each discharge needle 6 by this corona discharge. In this case, positive air ions are generated and negative polarity is generated during a period in which a positive high voltage is applied between each discharge needle 6 and the counter electrodes 7, 7 (hereinafter referred to as a positive high voltage application period). During the period when the high voltage is applied (hereinafter referred to as the negative electrode high voltage application period), negative air ions are generated.

Therefore, by positively and negatively pulsed high voltage is intermittently output from the high-voltage power supply 20 in a constant cycle, positive air ions and negative air ions are alternately generated in a constant cycle. The amount of positive air ions (charge amount) generated during the positive electrode high voltage application period and the amount of negative air ions generated during the negative electrode high voltage application period (charge amount) are approximately the same. Further, since the plate-shaped conductor member 11 is farther from each discharge needle 6 than the counter electrodes 7, 7, corona discharge does not occur between each discharge needle 6 and the plate-shaped conductor member 11.

Further, in the present embodiment, all the discharge needles 6, the counter electrodes 7, 7 and the high-voltage power supply 20 are surrounded by the grounded plate-shaped conductor member 11, so that the plate-shaped conductor member 11 is so-called Faraday. Functions as a cage. Therefore, during the positive electrode high voltage application period and the negative electrode high voltage application period, the high voltage applied from the high-voltage power supply 20 between each discharge needle 6 and the counter electrodes 7, 7 induces the static elimination target W. Induction of voltage is suppressed. Although the details will be described later, the induced voltage can be suppressed to a magnitude of 10 V or less (peak to peak magnitude), for example.

As described above, the positive air ions and the negative air ions generated by the corona discharge during the positive electrode high voltage application period and the negative electrode high voltage application period are forward of each discharge needle 6 by the air blow from each air blow nozzle unit 8. Moves toward the static elimination target W. Then, the positive and negative air ions that have reached the static elimination target W neutralize the charge of the static elimination target W, and the static elimination target W is discharged.

In this case, some of the positive and negative polar air ions generated by the corona discharge between the discharge needles 6 and the counter electrodes 7, 7 move toward the static elimination target W in the process of moving toward the static elimination target W. It can be absorbed by the lower flat portion 11A of the plate-shaped conductor member 11 existing between the object W and the discharge needle 6.

However, in the ion generator 1A of the present embodiment, the distance from the tip of each discharge needle 6 to the lower flat portion 11A of the plate-shaped conductor member 11, the mesh size of the plate-shaped conductor member 11, the pressure of the blown air (air By appropriately setting the pressure of the air supplied from the compressor 50 to the internal space of the first housing 2) or the like, the amount of air ions absorbed in the lower flat portion 11A of the plate-shaped conductor member 11 can be minimized. By reducing the number, most of the generated air ions of each polarity can reach the static elimination target W. Consequently, the static elimination of the static elimination target W can be efficiently performed in a short time. For example, the static elimination of the object W to be eliminated (attenuation of the charging potential) can be achieved in the same time as when the plate-shaped conductor member 11 is removed.

As described above, according to the ion generator 1A, it is possible to efficiently perform static elimination of the static elimination target W in a short time while suppressing the induced voltage that can be induced in the static elimination target W to a sufficiently small voltage. is there. Such an effect is not limited to the ion generator 1A having the structure shown in FIGS. 1A and 1B, but can be similarly exerted in the ion generators 1B and 1C having the configuration shown in FIG. 5A or 5B.

However, in order to reduce the induced voltage as much as possible, it is preferable to dispose the plate-shaped conductor member 11 so as to surround all the discharge needles 6, the counter electrodes 7, 7, and the high-voltage power source 20 as in the ion generator 1A. That is, the ion generator 1A can make the induced voltage smaller than the ion generators 1B and 1C. When the ion generators 1B and 1C are compared with each other, the ion generator 1C can make the induced voltage smaller than that of the ion generator 1B.

Next, a verification test regarding the effect of being able to efficiently perform static elimination while suppressing the induced voltage induced in the static elimination target to a small voltage by the ion generator of the present invention will be described.

The inventors of the present application use, for example, the ion generator 1A among the ion generators 1A to 1C described above to measure the induced voltage that can be induced at the position of the object W to be neutralized and the time required for the neutralization. A verification test was conducted.

In this verification test, two kinds of plate-shaped conductor members 11 having different mesh sizes are used as the mesh-shaped plate-shaped conductor member 11, and the air compressor 50 supplies them to the internal space of the first housing 2. The pressure of the air to be used (hereinafter referred to as the air input pressure) is set to a plurality of values. The air input pressure regulates the air volume of the air blown from each air blowing nozzle unit 8. The higher the air input pressure, the larger the air volume.

In the ion generator 1A used for the verification test, the pulse widths of the positive and negative high voltages output from the high-voltage power supply 20 (the respective time widths of the positive electrode high voltage application period and the negative electrode high voltage application period) are 1 ms, the pitch of the discharge needles 6 is 50 mm, and the distance d from the tip of each discharge needle 6 to the lower flat portion 11A of the plate-shaped conductor member 11 in front thereof is 20 mm. The peak value (peak value) of the positive and negative high voltages is 10 kV, and the output cycle of the high voltage of each polarity is 4 ms (equivalent to 250 Hz).

The results of the verification test are shown in FIGS. 6A and 6B. 6A and 6B, the measurement data of Example 1 shows that the size of each mesh (specifically, the inner dimension between the linear conductors adjacent in the vertical direction and the horizontal direction) is 11.5 mm×11.5 mm. As the measurement data of the case where the plate-shaped conductor member 11 formed in a mesh shape with the linear conductor having the line diameter of 0.7φ (0.7 mm) is used, the measurement data of Example 2 shows that the size of each mesh is 5 The measurement data in the case of using the plate-shaped conductor member 11 formed into a mesh shape with the linear conductor of 1.2φ (1.2 mm) as the wire diameter of 0.65 mm×5.65 mm, the measurement data of the comparative example are It is measurement data in the state where plate-like conductor member 11 was removed from generator 1A.

Then, in each of Examples 1 and 2 and Comparative Example, the air injection pressure was set to 5 types of 0 Mpa, 0.05 Mpa, 0.1 Mpa, 0.2 Mpa, and 0.3 Mpa, and measurement was performed. The state in which the air input pressure is 0 MPa is a state in which air is not supplied from the air compressor 50 to the internal space of the first housing 2.

FIG. 6A shows a square-shaped metal plate of a predetermined size (150 mm×150 mm) as a pseudo static electricity removal target, which is a predetermined distance (100 mm distance) from the lower flat portion 11A of the plate-shaped conductor member 11 of the ion generator 1A. ), the high-voltage power supply 20 causes positive and negative pulsed high voltages to be alternately output at a constant cycle, and is induced on the surface of the metal plate. The measurement data obtained by measuring the induced voltage (peak-to-peak voltage value) are shown.

As shown in the figure, in the comparative example in which the plate-shaped conductor member 11 is removed, an induced voltage of 300 V or more is generated, but in Examples 1 and 2 including the plate-shaped conductor member 11, the generated induced voltage is significantly small. It can be seen that the voltage is suppressed (about 10 V at most).

In particular, when the air is blown from the air blowing nozzle unit 8 (when the air input pressure is not 0 Mpa), in the second embodiment in which the mesh size is smaller than that in the first embodiment, the induced voltage is set to a voltage lower than 10V. It turns out that it can be suppressed.

As described above, in the ion generator 1B including the plate-shaped conductor member 11 in front (downward) of the discharge needle 6, an object such as an object to be neutralized disposed below the lower flat portion 11A of the plate-shaped conductor member 11 can be used. The induced voltage induced can be significantly reduced as compared with the case where the plate-shaped conductor member 11 is not provided. This applies not only to the ion generator 1A but also to the ion generators 1B and 1C.

Supplementally, according to the experiments performed by the inventors of the present application, for example, even an ion generator configured to alternately output a positive high voltage and a negative high voltage from a high-voltage power supply for each half-cycle period, When the plate-shaped conductor member 11 is provided, the induced voltage becomes smaller than when the plate-shaped conductor member 11 is not provided, but even when the plate-shaped conductor member 11 is provided, an induced voltage of several tens of V or more can be induced. Was confirmed.

For this reason, for example, the following reason can be considered. That is, in the ion generator, since the positive electrode high voltage application period and the negative electrode high voltage application period are longer than those of the ion generators 1A to 1C of the above-described embodiment, the ion generation is performed in the positive electrode high voltage application period and the negative electrode high voltage application period, respectively. The amount of positive air ions and negative air ions is increased, which facilitates induction of higher induced voltage. As a result, even when the plate-shaped conductor member 11 is provided, an induced voltage of several tens of volts or more is considered to be induced.

FIG. 6B shows that a square-shaped metal plate of a predetermined size (150 mm×150 mm), which is arranged at a position 100 mm below the lower flat portion 11A of the plate-shaped conductor member 11 of the ion generator 1A, is charged with a predetermined charge. When the high voltage power source 20 alternately outputs positive and negative pulsed high voltages at a constant cycle after charging to a voltage (±1000 V), the charging voltage of the metal plate is a predetermined value from the initial value. The measurement data obtained by measuring the time required to decay to a value (±100 V) (hereinafter referred to as the decay time) is shown.

In this case, the measured value of the decay time shown in FIG. 6B is, more specifically, an average value of the measured values of the decay time from +1000V to +100V and the measured values of the decay time from −1000V to −100V.

The decay time according to Examples 1 and 2 corresponds to the decay time A in the present invention, and the decay time according to the comparative example corresponds to the decay time B in the present invention.

As shown in the figure, in Examples 1 and 2 including the plate-shaped conductor member 11, it is understood that the same decay time as that of the comparative example not including the plate-shaped conductor member 11 can be achieved. In particular, it was confirmed that when the air injection pressure was 0.2 MPa or more, the damping time was shorter in Examples 1 and 2 than in the comparative example not including the plate-shaped conductor member 11.

From this, in the ion generator 1A of the embodiment, most of the positive and negative air ions generated around the respective discharge needles 6 by the corona discharge are not absorbed so much by the plate-shaped conductor member 11, and the pseudo charge removal is performed. It can be seen that the metal plate as the object W can be reached, and that the effect becomes more remarkable especially by the air blow from the air blow nozzle unit 8.

For this reason, for example, the following reason can be considered. That is, although a force is generated that causes the air ions of each polarity to be attracted to the plate-shaped conductor member 11 by the lines of electric force generated between the generated air ions of each polarity and the plate-shaped conductor member 11, In the ion generator 1</b>A of the embodiment, since the positive electrode high voltage application period and the negative electrode high voltage application period in one cycle of the output of the high voltage power supply 20 are relatively short, positive air ions are generated and negative air ions are generated. And the amount of positive air ions and negative air ions generated is relatively small (more specifically, the positive electrode high voltage application period and the negative electrode high voltage application period are each reduced to half). It is less than the period of the cycle).

Therefore, the lines of electric force generated between the air ions of each polarity and the plate-shaped conductor member 11 are relatively weak, and by blowing air at a certain level or more of air pressure, the polarity of each polarity is reduced. The absorption of air ions by the plate-shaped conductor member 11 is effectively suppressed. As a result, most of the generated air ions of each polarity can pass through the mesh (holes) of the plate-shaped conductor member 11 and reach the metal plate (pseudo static elimination object W).

As described above, in the ion generating device 1A including the plate-shaped conductor member 12, the plate-shaped conductor member 11 is prevented from absorbing air ions as much as possible, and passes through the mesh (holes) of the plate-shaped conductor member 11. It is possible to sufficiently secure the amount of air ions of each polarity that can be generated. This applies not only to the ion generator 1A but also to the ion generators 1B and 1C.

Supplementally, according to experiments by the inventors of the present application, for example, in an ion generator configured to alternately output a positive high voltage and a negative high voltage from a high-voltage power source for each half-cycle period, It has been confirmed that when the plate-shaped conductor member 12 is arranged in front of the discharge needle, the decay time becomes longer than when the plate-shaped conductor member 11 is not provided.

For this reason, for example, the following reason can be considered. That is, in the ion generating apparatus, as described above, since the amounts of positive air ions and negative air ions generated during the positive electrode high voltage application period and the negative electrode high voltage application period increase, the plate-shaped conductor member 11 is When provided, the lines of electric force generated between the air ions of each polarity and the plate-shaped conductor member 11 are likely to be relatively strong. As a result, the generated air ions of each polarity are easily absorbed by the plate-shaped conductor member 11 and can pass through the mesh (holes) of the plate-shaped conductor member 11 (as the pseudo static elimination target W). It is considered that the number of air ions that can reach the metal plate in (1) decreases.

From the verification test described above, according to the ion generators 1A to 1C of the embodiment, the static elimination of the static elimination target W can be performed for a short time while suppressing the induced voltage that can be induced in the static elimination target W to a sufficiently small voltage. It turns out that can be done efficiently with.

Regarding the distance d between each discharge needle 6 and the plate-shaped conductor member 11 (or the flat portion of the plate-shaped conductor member 12 or 13 located in front of the discharge needle 6), the static elimination target W It has been confirmed by experiments by the inventors of the present application that the distance d is preferably set within a range of 10 to 30 mm in order to efficiently perform the static elimination in a short time.

Supplementally, in the above-described embodiment, the high-voltage power supply 20 exemplifies a pulsed high voltage having a positive polarity and a negative polarity which are alternately output at a constant cycle. However, in order to suppress the induced voltage, the high voltage power supply 20 may be configured to alternately output a positive high voltage and a negative high voltage for each half cycle period.

Further, the plate-shaped conductor members 11 to 13 are not limited to those formed in a mesh shape. For example, the plate-shaped conductor member may have a structure in which a plurality of holes are punched in a thin conductor plate such as a metal plate.

1A, 1B, 1C... Ion generator, 6... Discharge needle, 7... Counter electrode, 11, 12, 13... Plate-shaped conductor member, 8... Blow nozzle part (blower), 50... Air compressor (blower), W... Target of static elimination (target of supply).

Claims (3)

A plurality of discharge needles arranged in rows,
When a high voltage is applied between the plurality of discharge needles, the plurality of discharge needles are arranged laterally of the discharge needles so that corona discharge is generated between the discharge needles, and a grounded counter electrode is provided. ,
A high voltage power source for intermittently and alternately applying positive and negative pulsed high voltages between the plurality of discharge needles and the counter electrode,
An air blower that blows positive and negative air ions generated by corona discharge generated between the plurality of discharge needles and the counter electrode toward a supply target,
There is a discharge needle facing portion that is a portion facing the plurality of discharge needles at a position between the plurality of discharge needles and the supply target, and there is a space between the plurality of discharge needles and the counter electrode. And a plate-shaped conductor member that is grounded,
The plate-shaped conductor member has a plurality of holes for passing the positive and negative air ions toward the supply target, at least in a portion facing the discharge needle, and the plurality of discharge needles and the counter electrode. In a state where a high voltage is applied between, it is arranged to suppress the induction voltage induced in the supply target ,
When the high-voltage power supply is operated in a state in which the supply target charged with a predetermined charging voltage is arranged at a position at a predetermined distance from the plurality of discharge needles, the charging voltage of the supply target is The decay time, which is the time required to decay to a low voltage of a predetermined value, is defined as a decay time A, and the supply is charged at the predetermined charging voltage to a position at the predetermined distance from the plurality of discharge needles. Time required for the charging voltage of the supply target to decay to the low voltage of the predetermined value when the high-voltage power supply is operated with the target placed and the plate-shaped conductor member removed. When the decay time is defined as the decay time B, each pulse width of the positive and negative pulsed high voltages output from the high-voltage power supply, the discharge needle facing portion of the plate-shaped conductor member, and the plurality of discharge needles. With respect to each of the above, the size of the hole formed in the portion of the plate-shaped conductor member facing the discharge needle, and the air volume of the blower, the decay time A is a time equal to or shorter than the decay time B. Ion generator characterized by being set as follows . A plurality of discharge needles arranged in rows,
When a high voltage is applied between the plurality of discharge needles, the plurality of discharge needles are arranged laterally of the discharge needles so that corona discharge is generated between the discharge needles, and a grounded counter electrode is provided. ,
A high-voltage power supply that alternately applies positive and negative high voltages between the plurality of discharge needles and the counter electrode,
An air blower that blows positive and negative air ions generated by corona discharge generated between the plurality of discharge needles and the counter electrode toward a supply target,
There is a discharge needle facing portion that is a portion facing the plurality of discharge needles at a position between the plurality of discharge needles and the supply target, and there is a space between the plurality of discharge needles and the counter electrode. And a plate-shaped conductor member that is grounded,
The plate-shaped conductor member has a plurality of holes for passing the positive and negative air ions toward the supply target, at least in a portion facing the discharge needle, and the plurality of discharge needles and the counter electrode. In a state where a high voltage is applied between them, it is arranged to suppress induction of an induced voltage in the supply target , and further, the plurality of discharge needles, the counter electrode, and the high-voltage power supply. An ion generator characterized in that it is arranged so as to surround the . The ion generator according to claim 1 or 2 ,
The ion generating device, wherein the plate-shaped conductor member is a member in which at least the discharge needle facing portion is formed in a mesh shape.