JP5069491B2 - Ion balance adjusting electrode and static eliminator having the same - Google Patents

Description

  The present invention relates to an ion balance adjusting electrode used for a neutralizing device that irradiates a charged object with positive and negative ions to make it electrically neutral, and a neutralizing device equipped with the same.

  Conventionally, in cell production processes such as semiconductor manufacturing lines and mobile phones, static eliminators have been arranged in the vicinity of work tables, conveyors, and the like in order to prevent electrostatic damage and electrostatic adsorption due to component charging.

  In the static eliminator used at such a manufacturing site, positive or negative charges are entirely or partially excessive, and positive or negative ions are applied to static elimination objects (parts) in which the charges are not uniform. Some are neutralized by discharge (irradiation).

  As an ion balance adjusting electrode used in such a conventional static elimination device, there is one that adjusts the ion balance by changing the distance from the discharge needle (see, for example, Patent Document 1).

  Moreover, the above-mentioned static elimination apparatus is classified into several types according to the static elimination method. Hereinafter, features of each method will be briefly described.

(1) AC type A sinusoidal high voltage (frequency 50/60 Hz) is applied to one discharge needle to generate positive and negative ions alternately. Since positive and negative ions are generated from a single discharge needle, the ion balance is characterized by little deviation over time and spatial deviation.

  Here, the ion balance indicates how far the residual potential of the object to be neutralized (object to be neutralized) after ion irradiation is away from 0 volts, and the residual potential is constantly 0 volts. Is the ideal characteristic.

  And the time-dependent bias of the ion balance means that when the static eliminator is continuously operated, a difference occurs in the degree of dirt adhesion, corrosion, and wear of the positive and negative discharge needles, and the residual potential is biased. .

  Moreover, the spatial deviation of ion balance means that a difference occurs in the residual potential depending on the position of the charge removal object when the charge removal object is irradiated with ions. As will be described later, this ion balance is spatially biased by irradiating ions to a static elimination target regularly arranged at a predetermined distance from the static elimination device, and at which position the static elimination target has a residual potential. Is determined by measuring.

  Furthermore, the amplitude of ion balance described later means that the surface potential of the static elimination object irradiated with positive and negative ions periodically varies from the positive side to the negative side.

(2) DC type Positive and negative ions are steadily generated from each discharge needle by applying positive and negative high voltages to the positive discharge needle and the negative discharge needle, respectively. It is characterized in that the released positive and negative ions are less likely to recombine before reaching the object to be neutralized, and ions can be blown far as compared with the AC type.

(3) AC high frequency type A high frequency voltage having a frequency of 20 kHz to 70 kHz is applied to one discharge needle. Compared to the general AC type, the transformer is lighter and smaller.

(4) Pulse DC type Positive and negative ions are alternately generated from each discharge needle by alternately applying a positive and negative high voltage to the positive discharge needle and the negative discharge needle, respectively. The characteristic is that the deviation of the ion balance over time is improved as compared with the general DC type (for example, see Patent Document 2).

(5) Pulse AC type A high voltage of a rectangular wave is applied to one discharge needle. It is characterized in that the amount of ion generation can be increased as compared with a general AC type, and the oscillation frequency can be made variable (see, for example, Patent Document 3).
Japanese Patent Laid-Open No. 5-114496 JP 2002-43092 A JP 2000-58290 A

  However, since the above-described ion balance adjusting electrode has a part that is mechanically driven, there are problems such as lack of reliability and a complicated shape.

  Moreover, each static elimination system mentioned above has the following subjects, respectively.

(1) AC type The transformer that generates high voltage is heavy and large. This type of static eliminator is often used on a desk or suspended, and is desirably a small and lightweight static eliminator, but it is difficult to reduce the size and weight of the AC type.

  In addition, since positive and negative ions are generated alternately, the object to be neutralized is alternately charged positively and negatively, and when viewed temporally, an amplitude is generated in the ion balance. For this reason, it is difficult to keep the residual potential after ion irradiation around 0 volts.

  Furthermore, since the generation amount of positive and negative ions is smaller than that of the DC type, it is inferior to the DC type in terms of decay time characteristics. Here, the decay time characteristic refers to the time until the potential of the charge removal object reaches an allowable level after ion irradiation. Therefore, if the potential of the charged static elimination object can be lowered to an acceptable level in a short time, the decay time characteristic is excellent.

  Similarly, since the amount of positive and negative ions generated is smaller than that of the DC type, it is inferior to the DC type in terms of the static elimination range. Here, the static elimination range refers to a spatial range in which the potential of the static elimination object can be lowered to an allowable level by ion irradiation.

(2) DC type In the case of continuous operation, there is a difference in the degree of dirt adhesion, corrosion, and wear of the positive and negative discharge needles.

  Further, depending on the position of the discharge needle, there are places that are easily affected by positive ions or places that are easily affected by negative ions. For this reason, the static elimination object arrange | positioned in such a place will be charged positively or negatively, and the spatial deviation of ion balance will arise.

(3) AC high frequency type Since the generation interval of positive and negative ions is short, it is easy to recombine before the released positive and negative ions reach the static elimination object, and it is difficult to fly the ions far. In addition, since the amount of ions that reach is reduced, the decay time characteristics also deteriorate.

(4) Pulse DC type As in the case of DC type, when continuous operation is performed, there is a difference in the degree of dirt adhesion, corrosion, and wear on the positive and negative discharge needles. .

  In addition, there is a spatial bias in the ion balance in locations that are easily affected by positive discharge needles where dirt is likely to adhere, and locations that are susceptible to negative discharge needles where dirt is difficult to adhere. It will be negatively charged.

  Furthermore, since positive and negative ions are generated alternately, the object to be neutralized is alternately charged positively and negatively in the same manner as in the AC type, and when viewed in time, an amplitude is generated in the ion balance.

(5) Pulse AC type Since positive and negative ions are alternately generated, the static elimination target is alternately charged positively and negatively, and the amount of ions generated is larger than that of the AC type. An amplitude is generated in the ion balance.

  The present invention has been made to solve the above-described problems. In addition to being highly reliable and simple in shape, the ion balance can be adjusted without inhibiting the ion generation of the static eliminator. An object of the present invention is to provide an ion balance adjusting electrode capable of ensuring safety.

  In addition to being highly reliable and simple in shape, the present invention can adjust the ion balance without hindering the ion generation of the static eliminator, and can ensure safety. It is an object of the present invention to provide a static eliminator that includes an adjustment electrode, is small and lightweight, and has excellent decay time characteristics and ion balance characteristics.

  An ion balance adjusting electrode according to a first aspect of the present invention suitably includes a discharge electrode that generates positive or negative ions according to the polarity of an applied DC high voltage, and a front space to which the generated ions are sent. An ion balance adjusting electrode used in a static eliminator having a grounded guard electrode that is shielded by a shape, wherein an ungrounded electrode member is installed at a position that is substantially hidden by the guard electrode when viewed from the front in the direction of ion delivery. It is characterized by that.

  An ion balance adjusting electrode according to a second aspect of the present invention is the ion balance adjusting electrode according to the first aspect, wherein the discharge electrode is composed of a plurality of discharge needles arranged substantially evenly on an arbitrary plane. The electrode member is installed in a discharge region from the plurality of discharge needles to the guard electrode.

  The static eliminator according to claim 3 of the present invention is a group of 2n sets of 2n (n is a natural number) discharge needles that generate positive or negative ions according to the polarity of the applied DC high voltage. A high-voltage generation that applies a DC high voltage of opposite polarity to each other at the same time and with the polarity reversed every certain period to each discharge needle of the discharge electrode and the discharge needle of the discharge electrode A circuit, a blower that sends positive or negative ions generated by the discharge needles of the discharge electrode to the front of the apparatus, and a grounded guard electrode that blocks a front space in which the ions are sent in an appropriate shape; And an ungrounded ion balance adjusting electrode installed at a position substantially hidden by the guard electrode when viewed from the front of the ion sending direction.

  The static eliminator according to claim 4 of the present invention is the static eliminator according to claim 3, wherein the discharge electrodes are at least four discharge needles arranged one by one at the apex of a rectangle drawn on a plane. Each of the discharge needles is configured such that two discharge needles arranged on one diagonal line constitute one of the groups and another two arranged on another diagonal line. The discharge needles constitute the other group.

  The static eliminator according to claim 5 of the present invention is the static eliminator according to claim 3, wherein the high voltage generating circuit applies two high frequency high voltages obtained from one power source to one high frequency. A polarity inversion circuit is provided which converts a high voltage into two DC high voltages having different polarities and converts the other high frequency high voltage into two DC high voltages opposite to the polarity.

  The static eliminator according to claim 6 of the present invention is the static eliminator according to claim 5, wherein the alternating switching frequency of the two systems of the high frequency high voltage inputted to the polarity inversion circuit is in the range of 10 to 100 Hz. It is characterized by.

  The static eliminator according to claim 7 of the present invention is the static eliminator according to claim 5 or 6, wherein the polarity inversion circuit has two opposite polarities obtained by converting the high frequency high voltage of each system. By outputting DC high voltage to each of the two sets of groups, the DC high voltages having opposite polarities can be applied to both groups at the same time, and the two high frequency high voltage inputs can be switched alternately. The two groups are applied by inverting the polarity of the DC high voltage every predetermined period.

  The static eliminator according to claim 8 of the present invention is the static eliminator according to any one of claims 5 to 7, wherein the high voltage generation circuit is a DC power supply circuit and a DC voltage of the DC power supply circuit is a high frequency voltage. And an output control circuit for alternately switching the high-frequency voltage to two output lines every predetermined period and outputting the high-frequency voltage, and a transformer circuit for boosting the high-frequency voltage output from the output control circuit to the high-frequency high voltage And further comprising.

  The static eliminator according to claim 9 of the present invention is the static eliminator according to claim 3, wherein the ion balance adjustment electrode is inserted between the ground terminal of the high voltage generation circuit and the ground of the guard electrode. It is connected to the ground terminal side of the ion balance adjustment circuit.

  The static eliminator according to claim 10 of the present invention is the static eliminator according to claim 9, wherein the ion balance adjustment circuit includes a variable resistor and a diode for adjusting the ion balance by the ion balance adjustment electrode toward the target. And are connected in parallel.

  As described above, according to the present invention, the discharge electrode that generates positive or negative ions according to the polarity of the applied DC high voltage and the front space where the generated ions are sent out are grounded in an appropriate shape. An ion balance adjustment electrode used in a static eliminator provided with a guard electrode, and an ungrounded electrode member is installed at a position substantially hidden by the guard electrode when viewed from the front in the direction of ion delivery. Since the ion balance adjustment electrode has no mechanically driven part, it is highly reliable and simple in shape, and in addition, the ion balance can be adjusted without hindering the ion generation of the static eliminator. Safety can also be ensured.

  Further, according to the present invention, 2n (n is a natural number) discharge needles that generate positive or negative ions according to the polarity of the applied DC high voltage are divided into two groups of n. A high voltage generating circuit for applying a DC high voltage having opposite polarities to each other to each discharge needle of the discharge electrode at the same time and with the polarity reversed every predetermined period; A blower that sends out positive or negative ions generated by each of the discharge needles to the front of the apparatus, a grounded guard electrode that shields the front space through which the ions are sent out in an appropriate shape, and a front surface in the direction of sending the ions Since it has a configuration including an ungrounded ion balance adjusting electrode installed at a position substantially hidden from the guard electrode, the ion balance adjusting electrode does not have a mechanically driven portion, so reliability But In addition to being simple in shape, the ion balance can be adjusted without hindering the ion generation of the static eliminator, and the static eliminator equipped with such an ion balance adjustment electrode is small and lightweight. Therefore, it has excellent decay time characteristics and ion balance characteristics.

  Embodiments of the present invention will be described with reference to the drawings.

1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a right side view showing an embodiment of an ion balance adjusting electrode according to the present invention. 2A is a plan view, FIG. 2B is a front view, and FIG. 2C is a right side view of the guard electrode 60 of the static eliminator 1 in which the ion balance adjusting electrode 5 is used. 3A is a plan view, FIG. 3B is a front view, and FIG. 3C is a rear view of the state in which the ion balance adjusting electrode 5 is combined with the guard electrode 60. 4 is a schematic left side view showing an ideal state of the guard electrode 60 with respect to the discharge electrode 20, FIG. 5 is a schematic left side view showing an actual state of the guard electrode 60 with respect to the discharge electrode 20, and FIG. It is a schematic left view which shows the state which inserted the balance adjustment electrode 5. FIG.
The term “non-grounded” as used in the present invention includes a configuration in which a load such as a resistor is sandwiched and a potential different from the ground potential is used.

  The relationship between the discharge electrode 20 that generates positive or negative ions according to the polarity of the applied DC high voltage and the grounded guard electrode 60 that blocks the front space to which the generated ions are sent in an appropriate shape is as follows: As shown in FIG. 4, it is ideal that the guard electrode 60 is not present in the space in front of the discharge electrode 20 (right space in the figure).

  In this case, it is because the amount of ions generated by the discharge electrode 20 and sent to the front space thereof (flying in the right direction in the figure) is large, and the neutralizing action works accordingly.

  However, if the front space of the discharge electrode 20 is completely open, an accident such as the user's (operator's) finger touching the discharge electrode 20 may occur. Thus, it is necessary to arrange the guard electrode 60 that blocks the front space of the discharge electrode 20 with an appropriate shape.

  In this case, a part of the ions that are generated by the discharge electrode 20 and are sent to the front space (flight in the right direction in the figure) are collected by the guard electrode 60, so that they are sent beyond the guard electrode 60. The amount of ions generated (going to the right from the guard electrode 60 in the figure) is reduced compared to FIG.

  Therefore, as shown in FIG. 6, the ion balance adjusting electrode 5 according to the present invention uses a wire material that is not thicker than the wire material of the guard electrode 60 (thickness of the same degree or less), When viewed from the front of the ion delivery direction (as viewed from the right side to the left side of the guard electrode 60 in the figure), the ion electrode is disposed at a position substantially hidden by the guard electrode 60.

  Thereby, by installing the ion balance adjusting electrode 5, the amount of a part of the ions that are sent from the discharge electrode 20 to the front space (going to the right in the figure) and collected is the guard electrode 60. Compared to just the case, it hardly increases. Therefore, it is possible to ensure safety without disturbing the generation amount of ions that are sent over the guard electrode 60 (going to the right from the guard electrode in the figure).

  As shown in FIG. 1, the ion balance adjusting electrode 5 has a simple shape in which electrode members (wires) 5a and 5b are formed in a substantially U shape. In addition, as shown in FIG. 3 (particularly, (c)), the ion balance adjusting electrode 5 is installed at a position substantially hidden by the guard electrode when viewed from the front in the ion sending direction.

  The ion balance adjusting electrode 5 is installed in a discharge region from the discharge electrode 20 to the guard electrode 60. FIG. 6 shows the positional relationship. That is, as shown in FIG. 6, the discharge electrode 20, the ion balance adjustment electrode 5, and the guard electrode 60 are arranged in order.

  As described above, the ion balance adjusting electrode 5 has high reliability because there is no mechanically driven portion. Further, the shape is not limited to a U-shape, but in any case, it is a very simple shape. Furthermore, the ion balance can be adjusted without hindering the ion generation of the static eliminator, and safety can be ensured.

  FIG. 7 is an overall configuration diagram showing an embodiment of a static eliminator according to the present invention, FIG. 8 is an explanatory diagram showing a configuration of a discharge electrode, and FIG. 9 is a block diagram showing a configuration of a high voltage generating circuit.

  As shown in FIG. 7, the static eliminator 1 includes a high voltage generation circuit 10, a discharge electrode 20, a blower 30, a streamer corona pulse detection electrode 40, a streamer corona pulse signal detection device 50, and a guard electrode 60, and further includes an ion A balance adjustment electrode 5 is provided. Reference numeral 70 denotes a static elimination object.

  The high voltage generation circuit 10 is a circuit that simultaneously applies DC high voltages having different polarities to the discharge electrode 20 alternately at regular intervals. The configuration of the high voltage generation circuit 10 will be described later.

  The discharge electrode 20 is composed of 2n (n is a natural number) discharge needles that generate positive or negative ions according to the polarity of the applied DC high voltage divided into two groups of n. It is.

  That is, as shown in FIG. 8, the discharge electrode 20 is composed of at least four discharge needles 20a, 20b, 20c, and 20d arranged one by one at the vertices of a rectangle (for example, a square) drawn substantially on a plane. Is done. In each discharge needle 20a to 20d, two discharge needles 20a and 20c arranged facing one diagonal line constitute one group, and another discharge needle 20a to 20d arranged opposite to another diagonal line. The two discharge needles 20b and 20d constitute the other group.

  Each of the discharge needles 20a to 20d outputs positive ions when a positive DC high voltage is applied, and outputs negative ions when a negative DC high voltage is applied. When a DC high voltage supplied from the high voltage generation circuit 10 is applied to the discharge needles 20a to 20d, corona discharge is generated between the discharge needles 20a to 20d and the guard electrode 60, and positive ions and negative ions are generated. Is output. The discharge electrode 20 is supplied with a DC high voltage having different polarities alternately from the high voltage generation circuit 10 every predetermined period.

  As shown in FIG. 8, each of the discharge needles 20a to 20d is arranged at four locations so that the tip is directed toward the center. Among these, the discharge needles whose tips are opposed to each other form an electrode pair (group) that outputs ions of the same polarity. That is, the discharge needles 20a and 20c are in the first group, and the discharge needles 20b and 20d are in the second group. While one group outputs positive ions, the other group outputs negative ions simultaneously, and while one group outputs negative ions, the other group outputs positive ions simultaneously.

  For example, as shown in FIG. 8A, in period A, the first group of discharge needles 20a, 20c outputs positive ions, and the second group of discharge needles 20b, 20d outputs negative ions. Further, as shown in FIG. 8B, in the next period B, the first group of discharge needles 20a, 20c outputs negative ions, and the second group of discharge needles 20b, 20d outputs positive ions. Similarly, each group repeats the output of period A and the output of period B alternately at regular intervals.

  As shown in FIGS. 8A and 8B, the ion balance characteristics can be improved by always applying a voltage of the same polarity to the opposing discharge needles. However, a voltage of a different polarity may always be applied to the opposing discharge needle. Further, the number of discharge needles is not limited to four, and may be 2n (n is a natural number).

  Further, as shown in FIG. 7, the discharge needles 20 a to 20 d are arranged substantially perpendicular to the blowing direction of the blower 30 (from left to right in the figure). The interpolar distance K between the different polarity discharge needles is determined by the spatial ion balance performance and the distance L between the apparatus main body and the static elimination object 70 in use. As an example, in the range of L = 150 mm to 600 mm, K = 40 mm to 120 mm is a preferable range.

  The blower 30 is disposed on the windward side of the discharge electrode 20 and blows air by rotating a fan (not shown) with a motor. By this blowing, positive ions and negative ions output from the discharge electrode 20 are transported toward the static elimination object 70.

  The streamer corona pulse detection electrode 40 is disposed between the blower 30 and the discharge electrode 20, detects a discharge current due to corona discharge of the discharge electrode 20, and outputs a pulse signal (detection signal) corresponding to the detected discharge current. To do.

  The streamer corona pulse signal detection device 50 determines whether or not the discharge state of the corona discharge is normal based on the pulse signal output from the streamer corona pulse detection electrode 40. That is, when a streamer corona pulse discharge is occurring, the discharge current due to the corona discharge changes greatly in a short time (changes very steeply), so that the pulse signal corresponding to the detected discharge current has a predetermined level. When it exceeds, it can be determined that the corona discharge is abnormal.

  In general, it is known that the frequency of occurrence of abnormal corona discharge increases due to contamination of the discharge needle. For this reason, by providing a device for detecting an abnormality of corona discharge, it is possible to accurately know the cleaning time of the discharge needle, so that maintenance can be reliably performed.

  The guard electrode 60 is for preventing an operator's finger or the like from touching the discharge needle to which a high voltage is applied, and is disposed between the discharge electrode 20 and the static elimination object 70. The guard electrode 60 is connected to the ground potential, and also functions as a counter electrode for the discharge needles 20a to 20d. The guard electrode 60 is desirably formed of a conductor such as metal in order to reduce voltage fluctuation of the static elimination object 70 due to induction.

  The guard electrode 60 has a structure in which ring-shaped metal electrodes are arranged concentrically. However, the guard electrode 60 is not limited to this example. It suffices if an interval that makes it easy is secured.

  The shape of the ion balance adjusting electrode 5 is also determined according to the structure and shape of the guard electrode 60. That is, the ion balance adjusting electrode 5 has a shape that is substantially hidden by the guard electrode 60 when viewed from the front in the direction of ion delivery, and is installed at a position that is substantially hidden.

  Furthermore, it is desirable that the guard electrode 60 be disposed so that the distance M between the discharge needle and the discharge needle is less than the distance K between the electrodes. When corona discharge starts at the discharge electrode 20, the potential difference between the guard electrode and the discharge needle is larger than the potential difference between the discharge needles 20a to 20d, and thus the generated positive and negative ions fly toward the guard electrode 60. At this time, if the guard electrode 60 is present, positive and negative ions are captured, so that the decay time characteristic slightly decreases. However, by providing the guard electrode 60, the ion balance amplitude can be greatly reduced.

  Next, the configuration of the high voltage generation circuit 10 will be described. In other words, the high voltage generation circuit 10 applies to the discharge needles 20a to 20d of the discharge electrode 20 a DC high voltage of opposite polarity to each other at the same time and with the polarity reversed at regular intervals. .

  As shown in FIG. 9, the high voltage generation circuit 10 includes a DC power supply circuit 11, an output control circuit 12, a transformer circuit 13, and a polarity inversion circuit 14.

  The DC power supply circuit 11 is a circuit that is connected to an AC power supply (AC 100 V) (not shown), converts an AC voltage into a DC voltage (DC 12 V), and outputs the DC voltage.

  The output control circuit 12 converts the DC voltage output from the DC power supply circuit 11 into a high-frequency voltage (20 kHz to) higher than the audible frequency, and alternately switches the high-frequency voltage to two output lines at regular intervals. Output.

  The alternate switching frequency of the two systems of outputs is in the range of 10 to 100 Hz. For example, when the alternate switching frequency of the output is 50 Hz, one cycle is 0.02 s, so 0.01 s that is a half cycle is the above-described fixed period.

  Thus, by setting the alternate switching frequency when the high-frequency voltage is alternately output to the two output lines by the output control circuit 12 in the range of 10 to 100 Hz, the positive and negative ions output from the discharge needles of each group The polarity is also reversed at regular intervals defined by this alternating switching frequency.

  As a result, the generation interval of positive and negative ions can be increased, so that compared to the AC high frequency static eliminator, the released positive and negative ions are less likely to recombine before reaching the static elimination target, and the ions are blown far away. Can do.

  The transformer circuit 13 is composed of a high-frequency winding transformer or a piezoelectric transformer corresponding to an oscillation frequency higher than the audible frequency (20 kHz to), and boosts the high-frequency voltage output from the output control circuit 12 and outputs it as a high-frequency high voltage. It is.

  The transformer circuit 13 includes transformers L1 and L2, and high-frequency voltages are alternately output from the transformers L1 and L2 at regular intervals. The output side of the transformer circuit 13 is connected to the polarity inversion circuit 14 through two output lines, and the high-frequency high voltage output from the transformers L1 and L2 is alternately output to the polarity inversion circuit 14 from each output line.

  Since the transformer circuit 13 is composed of a high-frequency winding transformer or a piezoelectric transformer corresponding to an oscillation frequency exceeding the audible frequency (20 kHz to), the device can be made smaller and lighter than an AC type static eliminator.

  The polarity inversion circuit 14 converts the high-frequency high voltage alternately output from the transformer circuit 13 at regular intervals into two direct-current high voltages of rectangular waves having different polarities in the same period, and the two direct-current high voltages Are reversed at regular intervals and output to both groups of discharge electrodes 20.

  That is, when a positive DC high voltage is output to the first group of discharge electrodes 20, a negative DC high voltage is simultaneously output to the second group of discharge electrodes 20, and a negative DC high voltage is output. Is output to the second group of discharge electrodes 20 at the same time.

  By applying two DC high voltages of rectangular waves with different polarities to the first and second groups of the discharge electrodes 20, the amount of positive and negative ions generated can be increased as compared with the AC type static eliminator. For this reason, the electric potential of the charged static elimination object can be lowered to an allowable level in a short time, and the decay time characteristic can be improved. In addition, the static elimination range can be expanded as compared with an AC static elimination device that generates less positive and negative ions.

Next, the configuration and operation of the polarity inverting circuit 14 will be described. FIG. 10 is a circuit diagram showing a configuration of the polarity inversion circuit. As shown in FIG. 10, the polarity inversion circuit 14 is configured by a rectifier circuit including capacitors C1 to C8, resistors R1 to R4, and diodes D1 to D8. The rectifier circuit is alternately supplied with high-frequency high voltages as indicated by inputs A and B from the transformers L1 and L2 every predetermined time. In the rectifier circuit, the input high frequency high voltage is rectified into a DC high voltage, and outputs indicated by output A and output B are output from the output terminal.

  When the input A is supplied from the transformer L1 (the input B is zero during this period), the input A is rectified by the rectifier circuit, and then the output A has a positive voltage and the output B has a negative polarity. Each voltage is output. In the next period, when the input B is supplied from the transformer L2 (in this period, the input A is zero), the input B is rectified by a rectifier circuit, and then a negative voltage is output to the output A. A positive voltage is output to B.

  As described above, when the high frequency high voltages of the inputs A and B are alternately supplied from the transformers L1 and L2 at regular intervals, the polarity inversion circuit 14 rectifies and smoothes the input high frequency high voltage. The polarity is inverted every period and output to outputs A and B. Since the discharge needles 20a and 20c of the first group are connected to the output A and the discharge needles 20b and 20d of the second group are connected to the output B, the polarity of ions output from each group is constant. It will be reversed every period.

  That is, as shown in FIG. 8A, in the period A, positive ions are output from the first group of discharge needles 20a and 20c, and simultaneously, negative ions are output from the second group of discharge needles 20b and 20d. Is done. Further, as shown in FIG. 8B, in the next period B, negative ions are output from the first group of discharge needles 20a and 20c, and simultaneously, positive ions are output from the second group of discharge needles 20b and 20d. Is output. And since the polarity of the ion output from each group is reversed for every fixed period, the ion of a different polarity is output for every fixed period from the discharge needle of each group.

  FIG. 10 shows the ion balance adjustment circuit 6. The ion balance adjustment circuit 6 is inserted between the ground terminal of the high voltage generation circuit 10 and the ground of the guard electrode 60. The ion balance adjustment electrode 5 is connected to the ground terminal side of the high voltage generation circuit 10 of the ion balance adjustment circuit 6.

  The ion balance adjusting circuit 6 is a circuit in which a variable resistor VR and a resistor R and a diode D are connected in parallel, and is for adjusting the ion balance by the ion balance adjusting electrode 5 toward a target.

  That is, if the resistance value of VR + R is increased by adjusting the variable resistance VR, the ion balance becomes positive, and if the resistance value of VR + R is reduced, the ion balance becomes negative.

  Therefore, by designing the ion balance to be negative with the variable resistance VR minimized, by adjusting the variable resistance VR, the ion balance can be arbitrarily adjusted to plus or minus. it can. Therefore, it is of course possible to adjust the ion balance to zero.

  As described above, the static eliminator 1 has a transformer circuit configured by a high-frequency winding transformer or a piezoelectric transformer corresponding to an oscillation frequency that is higher than the audible frequency (20 kHz to), so that the apparatus is smaller and lighter than the AC static eliminator. Can be.

  Further, since two DC high voltages of rectangular waves having different polarities are applied to the first and second groups of the discharge electrodes 20, the amount of positive and negative ions generated can be increased as compared with the AC type static eliminator. The decay time characteristic can be improved. For the same reason, the static elimination range can be expanded as compared with the AC static elimination device.

  In addition, the static eliminator 1 simultaneously generates positive and negative ions from the discharge needles divided into two groups in the same period, and reverses the polarity of ions output from each group every predetermined period. In addition, the polarity of the positive and negative ions is reversed every predetermined period, and the position where ions are emitted is also switched every predetermined period.

  As a result, positive and negative ions are generated at the same time in the same period, so that the amount of positive and negative ions on the charged plate surface is substantially the same. Accordingly, neutralization of the potential is promoted, and the residual potential on the charged plate surface can be reduced. As a result, the amplitude of the ion balance can be brought close to zero and the amplitude deviation can be reduced.

  Moreover, since the polarity of the positive / negative ion discharge | released reverses every fixed period and the position which discharge | releases ion switches for every fixed period, the static elimination apparatus 1 changes either positive or negative ion according to the position of the static elimination object. Thus, positive and negative ions can be irradiated almost uniformly on all the charged plates. Therefore, the spatial bias of ion balance can be reduced.

  In addition, since the static eliminator 1 reverses the polarity of positive and negative ions emitted from the discharge needles of each group at regular intervals, even when continuously operated, the degree of dirt adhesion, corrosion, and wear of each discharge needle is almost the same. It will be equal. For this reason, there is no bias in the residual potential for each discharge needle, and the bias in ion balance over time can be reduced.

  Moreover, since the static elimination apparatus 1 sets the alternating switching frequency when alternately outputting the high frequency voltage to the two lines of output lines in the range of 10 to 100 Hz, the generation interval of positive and negative ions can be increased. For this reason, it becomes difficult to recombine until the positive and negative ions that have been released reach the object to be neutralized, compared with the AC high-frequency type static eliminator, and ions can be blown far away.

  Further, the static eliminator 1 is provided with a streamer corona pulse detection electrode 40 and a streamer corona pulse signal detection device 50 as a streamer pulse detection means for detecting a pulse signal due to corona discharge between the blower 30 and the discharge electrode 20. Therefore, it becomes possible to know the cleaning timing of the discharge needle accurately, and the maintenance can be performed reliably.

  Moreover, since the static elimination apparatus 1 has provided the guard electrode 60 between the discharge electrode 20 and the static elimination object 70, the amplitude of ion balance can be reduced significantly.

  Further, the static eliminator 1 is provided with an ion balance adjustment electrode 5 between the discharge electrode 20 and the guard electrode 60 (on the back side of the guard electrode 60). The ion balance adjustment electrode 5 is a variable of the ion balance adjustment circuit 6. By adjusting the resistance VR, the ion balance can be arbitrarily adjusted to plus or minus.

It is (a) top view, (b) front view, and (c) right side view showing one embodiment of an ion balance adjusting electrode according to the present invention. It is (a) top view, (b) front view, (c) right view of the guard electrode of the static elimination apparatus in which the ion balance adjustment electrode of FIG. 1 is used. 3A is a plan view, FIG. 3B is a front view, and FIG. 3C is a rear view in a state where the ion balance adjusting electrode of FIG. 1 is combined with the guard electrode of FIG. 2. It is a schematic left view which shows the ideal state of the guard electrode with respect to a discharge electrode. It is a schematic left view which shows the actual state of the guard electrode with respect to a discharge electrode. It is a schematic left view which shows the state which inserted the ion balance adjustment electrode. 1 is an overall configuration diagram showing an embodiment of a static eliminator according to the present invention. It is explanatory drawing which shows the structure of a discharge electrode. It is a block diagram which shows the structure of a high voltage generation circuit. It is a circuit diagram which shows the structure of a polarity inversion circuit.

Explanation of symbols

1 Static eliminator
5 ion balance adjustment electrode
5a, 5b electrode member (wire)
6 Ion balance adjustment circuit 10 High voltage generation circuit 11 DC power supply circuit 12 Output control circuit 13 Transformer circuit 14 Polarity inversion circuit 20 Discharge electrode 20a, 20b, 20c, 20d Discharge needle 30 Blower 40 Streamer corona pulse detection electrode 50 Streamer corona pulse signal Detection device 60 Guard electrode 70 Target for static elimination L1, L2 Transformer

Claims (10)

A static eliminator comprising a discharge electrode that generates positive or negative ions according to the polarity of the applied DC high voltage, and a grounded guard electrode that blocks the front space to which the generated ions are sent out in an appropriate shape An ion balance adjusting electrode used for
An ion balance adjusting electrode, wherein an ungrounded electrode member is installed at a position substantially hidden by the guard electrode when viewed from the front of the ion delivery direction.   The discharge electrode is composed of a plurality of discharge needles arranged substantially evenly on an arbitrary plane, and the electrode member is installed in a discharge region extending from the plurality of discharge needles to the guard electrode. The ion balance adjusting electrode according to claim 1. Discharge electrodes in which 2n (n is a natural number) discharge needles that generate positive or negative ions according to the polarity of an applied DC high voltage are divided into two groups of n pieces each;
A high voltage generating circuit that applies a DC high voltage having opposite polarities to each other at the same time and inverts the polarity every predetermined period to each discharge needle of the discharge electrode;
A blower that sends positive or negative ions generated by the discharge needles of the discharge electrode to the front of the device;
A grounded guard electrode that blocks the front space in which the ions are sent out in an appropriate shape;
A non-grounded ion balance adjusting electrode installed at a position substantially hidden by the guard electrode when viewed from the front of the ion sending direction;
A static eliminator characterized by comprising: The discharge electrode is composed of at least four discharge needles arranged one by one at a vertex of a rectangle drawn substantially on a plane,
In each of the discharge needles, two discharge needles arranged on one diagonal line constitute one of the groups, and another two discharges arranged on another diagonal line. The static eliminator according to claim 3, wherein the needle constitutes the other group.   The high voltage generation circuit converts a high frequency high voltage, which is alternately input from two power sources obtained from one power source, into one high frequency high voltage and two direct current high voltages having different polarities, and the other high frequency high voltage. 4. The static eliminator according to claim 3, further comprising a polarity inversion circuit for converting a voltage into two DC high voltages opposite to the polarity.   6. The static eliminator according to claim 5, wherein an alternating switching frequency of the two systems of the high frequency and high voltage inputted to the polarity inversion circuit is in a range of 10 to 100 Hz.   The polarity inversion circuit outputs two DC high-voltages having opposite polarities obtained by converting the high-frequency high voltage of each system to the two sets of groups, so that the two groups have a DC polarity opposite to each other. A high voltage is applied at the same time, and the high frequency high voltage input of the two systems is alternately switched, so that the polarity of the DC high voltage is reversed and applied between the two groups at regular intervals. The static elimination apparatus of Claim 5 or Claim 6. The high voltage generation circuit includes:
A DC power supply circuit;
An output control circuit that converts the DC voltage of the DC power supply circuit into a high-frequency voltage, and alternately switches the high-frequency voltage to output lines of two systems every predetermined period;
A transformer circuit that boosts the high-frequency voltage output from the output control circuit to the high-frequency high voltage;
The static eliminator according to claim 5, further comprising:   4. The ion balance adjustment electrode is connected to the ground terminal side of an ion balance adjustment circuit inserted between a ground terminal of the high voltage generation circuit and a ground of the guard electrode. The static elimination apparatus of description.   The static eliminator according to claim 9, wherein a variable resistor and a diode are connected in parallel to the ion balance adjustment circuit in order to adjust the ion balance by the ion balance adjustment electrode toward a target.

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