JP2005077348A - Discharge performance evaluation device and discharge performance evaluation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge performance evaluation device capable of evaluating accurately the discharge performance of an ionizer. <P>SOLUTION: An operation part 4 sets the potential of a metal plate 2a when a fixed time elapses after switching a switch 6 to the OFF-state and the ionizer 1 is started as a balance deviation value V1 of positive/negative ions. The operation of the ionizer 1 is stopped and the switch 6 is switched to the on-state to thereby charge an electrostatic plate 2, and then the switch 6 is switched to the off-state and the ionizer 1 is restarted. The operation part 4 determines a discharge time finish potential Ve' by using the deviation value V1 determined beforehand as a zero standard, and determines a time (discharge time) T' wherein the potential of the metal plate 2a is changed from a discharge time start potential Vs to the discharge time finish potential Ve'. Hereby, the discharge capacity of the ionizer 1 can be evaluated accurately. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a static elimination performance evaluation apparatus and a static elimination performance evaluation method for evaluating the static elimination performance of an ionizer (an apparatus that generates ions and neutralizes static electricity).

  In factories that manufacture liquid crystal display elements, films, semiconductor elements, and the like, problems such as element destruction and adhesion of foreign matter may occur due to static electricity generated by contact and friction between the product and the manufacturing apparatus / workers. For this reason, an ionizer is generally installed in the manufacturing factory for the purpose of removing static electricity.

  The ionizer is, for example, a type that generates a corona discharge by applying a high voltage to the discharge needle to generate positive and negative ions alternately or simultaneously, or soft X-ray irradiation to positively and negatively ionize the air. There is a type to be made.

  When installing an ionizer in the manufacturing plant, it is necessary to adjust and optimize the ion generation amount (static elimination capability) and the balance between positive and negative ions. Even if the ionizer was optimized at the beginning of installation, if it is used for a long period of time, the discharge capacity deteriorates and the balance between positive and negative ions is shifted due to deterioration or contamination of the discharge electrode, so that the object to be discharged can be sufficiently removed. It may not be possible to remove static electricity. Therefore, it is necessary to periodically check the charge removal performance of the ionizer and maintain the ionizer based on the check result.

  When evaluating the ionization performance of an ionizer, an electrostatic plate monitor is usually used to measure whether the surface potential of the electrostatic plate is zero and evaluate the balance between positive and negative ions. The neutralization ability (ion generation amount) is evaluated by measuring how long it takes to reach a predetermined potential from the potential.

  The configuration of a conventional electrostatic plate monitor is shown in FIG. The electrostatic plate monitor includes an electrostatic plate 2 used as a static elimination object, a static elimination performance evaluation device 20, and a recording device 8.

  The electrostatic plate 2 is a parallel plate capacitor composed of a metal plate 2a, a grounded metal plate 2b, and an insulator spacer 2c that holds the metal plates 2a and 2b in spaced facing positions. 20 pF.

  The static elimination performance evaluation apparatus 20 includes a high voltage power source 7 that outputs a high voltage, a switch 6 that switches between energization / cutoff of the metal plate 2a and the high voltage power source 7, an electrometer 3 that measures the potential of the metal plate 2a, Based on the measurement result of the electrometer 3, a timer 12 for obtaining a time until the potential metal plate 2 a changes from a predetermined potential to a predetermined potential (hereinafter referred to as static elimination time), and the static elimination time and potential obtained by the timer 12. It is comprised by the output part 5 which outputs the electric potential of the metal plate 2a which the total 3 measured. The recording device 8 records the static elimination time output from the output unit 5 and the potential of the metal plate 2a.

  The metal plate 2a is placed at a certain distance from the surface of the ionizer 1 on which the discharge electrode is provided. The potential of the metal plate 2a changes due to positive and negative ions generated from the ionizer and induction.

  A method for evaluating the charge removal performance of an ionizer using the electrostatic plate monitor having the above configuration will be described. First, the switch 6 is turned on to energize the metal plate 2a and the high voltage power source 7, and the electrostatic plate 2 is charged until the metal plate 2a reaches a predetermined potential V0. After charging the electrostatic plate 2, the switch 6 is turned off to cut off the metal plate 2 a and the high voltage power source 7 and start the ionizer 1. The electrostatic plate 2 is neutralized by the ionizer 1, and the potential of the metal plate 2a is attenuated. Here, the potential decay waveform of the metal plate 2a recorded by the recording device 8 is shown in FIG. The timer 12 for obtaining the time until the potential metal plate 2a changes from a predetermined potential to a predetermined potential (hereinafter referred to as static elimination time) is preliminarily determined from the static elimination time start potential Vs (in this embodiment, for example, +1000 V). The time (static elimination time) T until a predetermined potential Ve (in this embodiment, +100 V is taken as an example) is measured, and the recording device 8 records the value of the static elimination time T together with the potential decay waveform of the metal plate 2a. To do. Further, when the high voltage power supply 7 outputs a negative high voltage, the static elimination time start potential Vs and the predetermined potential Ve are set to negative values (for example, the static elimination time start potential Vs is set to −1000 V and predetermined. The applied potential Ve is set to -100V). The absolute value of the predetermined potential V0 is larger than the absolute value of the static elimination time start potential Vs.

  Then, the charge removal capability (ion generation amount) of the ionizer 1 is evaluated based on the value of the charge removal time T recorded by the recording device 8. Further, the balance between positive and negative ions is evaluated by the steady value of the potential decay waveform of the metal plate 2a recorded by the recording device 8.

The static elimination performance evaluation device may be configured not to include a timer. In such a configuration, the operator himself who performs the static elimination performance evaluation himself / herself eliminates the static elimination time T from the potential decay waveform of the metal plate 2a recorded by the recording device 8. Ask for.
JP-A-8-292220 JP 2001-124812 A

  However, the conventional static elimination performance evaluation method described above has the following two problems, and the static elimination performance of the ionizer cannot be accurately evaluated.

  The first problem is that the ionizer's ability to remove static electricity cannot be accurately evaluated when the positive and negative ions are out of balance. When the ionizer is used for a long time, when there is a metal object nearby, or when the airflow is disturbed, the balance between positive and negative ions may be off. Even after adjusting the balance of positive and negative ions, the balance of positive and negative ions is somewhat off.

  In the conventional static elimination performance evaluation method, the static elimination capability is evaluated by the time (static elimination time) from the static elimination time start potential Vs to the predetermined potential Ve even in a situation where the balance between positive and negative ions is deviated. Therefore, for example, as shown in FIG. 11, if the balance between positive and negative ions is deviated by +200 V under the condition where the static elimination time start potential Vs is +1000 V and the static elimination time end potential Ve is +100 V, the static elimination time becomes infinite. As a result, the ionizer's ability to remove static electricity could not be accurately evaluated. In addition, as shown in FIG. 12, when the balance between positive and negative ions is shifted by −200 V under the condition where the static elimination time start potential Vs is +1000 V and the static elimination time end potential Ve is +100 V, the balance between positive and negative ions is shifted. As compared with the case where the ionizer is not used (see FIG. 10), the static elimination time is shortened, and the static elimination ability of the ionizer cannot be accurately evaluated.

  The second problem is that the ability to remove static electricity cannot be accurately evaluated even when the ionizer is a type that alternately generates positive and negative ions. For example, when the ionizer 1 is a soft X-ray type or a type that simultaneously generates positive and negative ions from a pair of discharge electrodes 21 connected to high-voltage power supplies having different polarities as shown in FIG. The potential decay waveform of the metal plate 2a to be recorded is a monotonous decay curve as shown in FIG. Therefore, if the balance between positive and negative ions is not deviated, the above-described conventional static elimination performance evaluation method can accurately evaluate the static elimination capability. On the other hand, when the ionizer 1 is a pulse AC type or a pulse DC type that alternately generates positive and negative ions from the discharge electrode 21 as shown in FIG. 14, the potential decay waveform of the metal plate 2a recorded by the recording device 8 is as shown in FIG. As shown in Fig. 4, the curve is attenuated while swinging in the plus and minus directions. For this reason, in the conventional static elimination performance evaluation method described above, the static elimination time T varies depending on the timing at which positive and negative ions reach the surface of the metal plate 2a. That is, the static elimination time T differs depending on whether it swings in the positive direction when it reaches the static elimination time start potential as shown in FIG. 16 or whether it swings in the negative direction when it reaches the static elimination time start potential as shown in FIG. End up. Therefore, it was not possible to accurately evaluate the ionization capability of the ionizer.

  An object of this invention is to provide the static elimination performance evaluation apparatus and static elimination performance evaluation method which can evaluate accurately the static elimination performance of an ionizer in view of the said problem.

  In order to achieve the above object, in the static elimination performance evaluation apparatus of the present invention, a potential measurement unit that measures the surface potential of a static elimination object, a high voltage power source that applies a high voltage to the static elimination object, and the potential measurement unit The measurement result is obtained, the balance deviation value of positive and negative ions is obtained from the steady-state surface potential of the static elimination object that has been neutralized by an ionizer, and the positive and negative ion balance deviation value is set to a predetermined value and the zero reference. An electric discharge time end potential corresponding to the positive / negative ion balance deviation value is obtained, the electric charge removal object charged by the high voltage power source is discharged by the ionizer, and the surface electric potential of the electric charge removal object from the predetermined value. A calculation unit that obtains a time until the charge removal time end potential is reached.

  According to such a configuration, considering the balance deviation value of positive and negative ions, the static elimination time (time until the surface potential of the static elimination target object reaches the static elimination end potential) is obtained by calculation processing. In the conventional static elimination performance evaluation method, it is possible to accurately evaluate the static elimination capability when the balance between the positive and negative ions, which has been obscured, is shifted.

  In order to achieve the above object, the static elimination performance evaluation apparatus of the present invention is a static elimination performance evaluation apparatus that evaluates the static elimination performance of an ionizer that alternately generates positive and negative ions, the static elimination performed by the ionizer. A potential measuring unit that measures the surface potential of the object, a high-voltage power source that applies a high voltage to the static elimination object, and a measurement result of the potential measurement unit that is input and charged by the high-voltage power source An approximate curve that is the swing center of the surface potential decay waveform of the static elimination object is obtained from the surface potential decay waveform of the static elimination object when the object is neutralized by the ionizer, and the value of the approximate curve is predetermined from a predetermined value. And a calculation unit for obtaining a time until the obtained value is reached.

  According to such a configuration, the static elimination time (time until the value of the approximate curve becomes a predetermined value from a predetermined value) is obtained by calculation processing in consideration of the swing of the potential decay waveform of the static elimination object. In this static elimination performance evaluation method, it is possible to accurately evaluate the static elimination capability when the potential decay waveform of the static elimination target that has been obscured swings.

  Further, in order to achieve the above object, the static elimination performance evaluation apparatus of the present invention is a static elimination performance evaluation apparatus that evaluates the static elimination performance of an ionizer that alternately generates positive and negative ions, and the static elimination that is eliminated by the ionizer. A potential measuring unit that measures a surface potential of an object, a high-voltage power source that applies a high voltage to the static elimination object, and a measurement result of the potential measurement unit that is input, and the static elimination object that is neutralized by the ionizer An approximate line that is the swing center of the steady-state surface potential of the object to be neutralized is obtained from the steady-state surface potential of the object, and a balance deviation value between positive and negative ions is obtained from the approximate line, and the charge-eliminated object charged by the high-voltage power source Swing center of the surface potential decay waveform of the static elimination object from the surface potential decay waveform of the static elimination target when the object is neutralized by the ionizer A certain approximate curve is obtained, a predetermined value with the positive / negative ion balance deviation value as a zero reference, and a static elimination end potential corresponding to the positive / negative ion balance deviation value are obtained, and the value of the approximate curve is the predetermined value. And a calculation unit for obtaining a time from when the static elimination time is reached to the value of the termination potential.

  According to such a configuration, the static elimination time (the value of the approximate curve is changed from the predetermined value to the value of the static elimination end potential in consideration of the balance deviation value of positive and negative ions and the swing of the potential decay waveform of the static elimination object. The time required for the static elimination performance is determined by calculation processing, and the static charge removal capability when the potential decay waveform of the static neutralization object swings while the positive / negative ion balance has been obscured in the conventional static elimination performance evaluation method Evaluation can be performed accurately.

  Further, in order to achieve the above object, in the static elimination performance evaluation method of the present invention, the step of obtaining a balance deviation value of positive and negative ions from the steady-state surface potential of the static elimination target being neutralized by the ionizer; A step of obtaining a neutralization time end potential according to a predetermined value and a positive / negative ion balance deviation value with a negative ion balance deviation value as a zero reference, and the ionization object charged by a high voltage power source is neutralized by the ionizer. And obtaining a time until the surface potential of the static elimination object reaches the static elimination end potential from the predetermined value.

  According to such a method, the static elimination time (time until the surface potential of the static elimination target object reaches the static elimination end potential) is calculated in consideration of the balance deviation value between positive and negative ions. In the evaluation method, it is possible to accurately perform the static elimination ability evaluation when the balance between the positive and negative ions, which has been obscured, is shifted. In addition, it is not always necessary to use the above-described static elimination performance evaluation apparatus, and the operator himself who performs the static elimination performance evaluation may perform all or part of the steps.

  Further, in order to achieve the above object, the static elimination performance evaluation method of the present invention is a static elimination performance evaluation method for evaluating the static elimination performance of an ionizer that alternately generates positive and negative ions, which is charged by a high voltage power source. Obtaining an approximate curve that is a swing center of the surface potential attenuation waveform of the static elimination object from the surface potential attenuation waveform of the static elimination object when the static elimination object is neutralized by the ionizer; and a value of the approximate curve is predetermined. Obtaining a time from the value until a predetermined value is reached.

  According to such a method, the static elimination time (time until the value of the approximate curve becomes a predetermined value from a predetermined value) is obtained in consideration of the swing of the potential decay waveform of the static elimination object. In the method, it is possible to accurately evaluate the static elimination ability when the potential decay waveform of the static elimination target that has been obscured swings. In addition, it is not always necessary to use the above-described static elimination performance evaluation apparatus, and the operator himself who performs the static elimination performance evaluation may perform all or part of the steps.

  In addition, in order to achieve the above object, the static elimination performance evaluation method of the present invention is a static elimination performance evaluation method for evaluating the static elimination performance of an ionizer that alternately generates positive and negative ions, and is neutralized by the ionizer. A step of obtaining an approximate line that is a swing center of the steady state surface potential of the static elimination object from the steady state surface potential of the static elimination object, a step of obtaining a balance deviation value of positive and negative ions from the approximate line, and a high voltage power source Obtaining an approximate curve that is the swing center of the surface potential attenuation waveform of the static elimination object from the surface potential attenuation waveform of the static elimination object when the charged static elimination object is neutralized by the ionizer; With the negative ion balance deviation value as the zero reference, the charge removal time according to the predetermined value and the positive / negative ion balance deviation value is over. A determining a potential, and a step of obtaining the time from the values predetermined value of the approximate curve to a value of the discharge time ends potential.

  According to such a method, the static elimination time (the value of the approximate curve is changed from the predetermined value to the value of the static elimination end potential in consideration of the balance deviation value of positive and negative ions and the swing of the potential decay waveform of the static elimination object. Therefore, it is possible to accurately evaluate the static elimination performance when the balance between positive and negative ion balances, which has been obscured by the conventional static elimination performance evaluation method, is shifted and the potential decay waveform of the static elimination target swings. It can be carried out. In addition, it is not always necessary to use the above-described static elimination performance evaluation apparatus, and the operator himself who performs the static elimination performance evaluation may perform all or part of the steps.

  According to the present invention, since the static elimination time is obtained in consideration of the positive / negative ion balance deviation value, the neutralization ability evaluation when the positive / negative ion balance has been obscured in the conventional static elimination performance evaluation method. Can be done accurately. In addition, according to the present invention, since the static elimination time is obtained in consideration of the swing of the potential decay waveform of the static elimination object, the potential decay waveform of the static elimination object that has been obscured by the conventional static elimination performance evaluation method swings. It is possible to accurately evaluate the charge removal capability. In addition, according to the present invention, since the static elimination time is calculated in consideration of the balance deviation value of positive and negative ions and the swing of the potential decay waveform of the static elimination object, the positive and negative characteristics that have been obscured in the conventional static elimination performance evaluation method. It is possible to accurately perform the charge removal capability evaluation when the ion balance is shifted and the potential decay waveform of the charge removal object swings. Therefore, according to the present invention, it is possible to accurately evaluate the static elimination performance regardless of any type of ionizer or any type of manufacturing apparatus or process.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an electrostatic plate monitor used in the static elimination performance evaluation method according to the present invention. In FIG. 1, the same parts as those in FIG. 9 are denoted by the same reference numerals. The electrostatic plate monitor used in the static elimination performance evaluation method according to the present invention includes the electrostatic plate 2 used as the static elimination target, the static elimination performance evaluation device 9, and the recording device 8.

  The electrostatic plate 2 is a parallel plate capacitor composed of a metal plate 2a, a grounded metal plate 2b, and a spacer 2c that holds the metal plates 2a and 2b in spaced-apart positions, and the capacitance is, for example, 20 pF. is there.

  The static elimination performance evaluation device 9 includes a high voltage power source 7 that outputs a high voltage, a switch 6 that switches between energization / cutoff of the metal plate 2a and the high voltage power source 7, an electrometer 3 that measures the potential of the metal plate 2a, An arithmetic unit 4 that performs arithmetic processing for obtaining a static elimination time and the like in consideration of a balance deviation value of positive and negative ions and / or a swing of a potential decay waveform of the metal plate 2a based on a measurement result of the electrometer 3; 4 and an output unit 5 for outputting the calculation result of 4 to the outside. The recording unit 8 records the calculation result of the calculation unit 4 such as the balance deviation value of positive / negative ions and the static elimination time.

  The metal plate 2a is placed at a certain distance from the surface of the ionizer 1 on which the discharge electrode is provided. The potential of the metal plate 2a changes due to positive and negative ions generated from the ionizer and induction.

  A method for evaluating the charge removal performance of the ionizer using the electrostatic plate monitor having the above configuration will be described below.

  First, the case where the ionizer 1 is a soft X-ray type or a type in which positive and negative ions are generated simultaneously from a pair of discharge electrodes 21 connected to high-voltage power supplies having different polarities as shown in FIG.

  First, the ionizer 1 is started in a state where the switch 6 is turned off and the metal plate 2a and the high voltage power source 7 are disconnected. When a certain time elapses after the ionizer 1 is started, the potential of the metal plate 2a settles to a substantially constant value as shown in FIG. The calculation unit 4 sets the potential settled at the substantially constant value as the balance deviation value V1 between positive and negative ions.

  After the calculation unit 4 obtains the positive / negative ion balance deviation value V1, the switch 6 is turned on to energize the metal plate 2a and the high voltage power source 7 in order to apply a predetermined potential V0 to the metal plate 2a, and the ionizer 1 operation is stopped. After the electrostatic plate 2 is charged until the metal plate 2a reaches a predetermined potential V0, the switch 6 is turned off to cut off the metal plate 2a and the high voltage power source 7, and the ionizer 1 is started again. The electrostatic plate 2 is neutralized by the ionizer 1, and the potential of the metal plate 2a is attenuated. The computing unit 4 obtains the static elimination time end potential Ve ′ by the following equation (1) using the positive / negative ion balance deviation value V1 obtained earlier as a zero reference.

Ve ′ = (Vs−V1) / N + V1 (1)
Here, Vs is a static elimination time start potential (in this embodiment, +1000 V as an example), N is an arbitrary constant (in this embodiment, 10 as an example), and V1 is a balance deviation value of positive and negative ions obtained earlier.

  The calculation unit 4 has a timer function, and the time (static elimination time) T ′ until the potential of the metal plate 2a reaches the static elimination time end potential Ve ′ obtained by the above equation (1) from the static elimination time start potential Vs. Ask for. This makes it possible to accurately evaluate the neutralization ability of the soft X-ray type or the type of ionizer that simultaneously generates positive and negative ions from a pair of discharge electrodes 21 connected to high-voltage power supplies having different polarities as shown in FIG. be able to. For example, in the conventional static elimination performance evaluation method, the static elimination time T becomes infinite when the balance between positive and negative ions is shifted by +200 V under the condition that the static elimination time start potential Vs is +1000 V and the static elimination time end potential Ve is +100 V. However, the ionization capability of the ionizer could not be accurately evaluated. However, in the method for evaluating the neutralization performance according to the present invention, the balance between positive and negative ions is shifted by +200 V under the condition of the static elimination time start potential Vs of +1000 V. In this case, the neutralization time end potential Ve ′ is +280 V with the positive / negative ion balance deviation value as the zero reference, so the static elimination time T ′ does not become infinite (see FIG. 3).

  In addition, the static elimination performance evaluation apparatus 9 is equipped with the control part (not shown). The control unit controls the electrometer 3, the calculation unit 4, the output unit 5, the switch 6, and the high voltage power source 7, and is also connected to the external ionizer 1 to control the start and stop of the ionizer. Thereby, the series of operations described above can be automatically processed.

  Next, the case where the ionizer 1 is a pulse AC type or a pulse DC type in which positive and negative ions are alternately generated from the discharge electrode 21 as shown in FIG. 14 will be described.

  First, the ionizer 1 is started in a state where the switch 6 is turned off and the metal plate 2a and the high voltage power source 7 are disconnected. FIG. 4 shows a potential waveform 10 of the metal plate 2a after a predetermined time has elapsed since the ionizer 1 was started. The calculation unit 4 obtains the approximate line 11 by, for example, a method of obtaining an average value from the maximum value and the minimum value of the potential waveform 10, a method of obtaining a linear approximation or a polynomial approximate curve of the potential waveform 10, and the value of the approximate line 11 is obtained. The balance deviation value V1 between positive and negative ions is set. The approximate line 11 is a line passing through the swing center of the potential waveform 10 which is a swing waveform.

  After the calculation unit 4 obtains the positive / negative ion balance deviation value V1, the switch 6 is turned on to energize the metal plate 2a and the high voltage power source 7 in order to apply a predetermined potential V0 to the metal plate 2a, and the ionizer 1 operation is stopped. After the electrostatic plate 2 is charged until the metal plate 2a reaches a predetermined potential V0, the switch 6 is turned off to cut off the metal plate 2a and the high voltage power source 7, and the ionizer 1 is started again. The electrostatic plate 2 is neutralized by the ionizer 1, and the potential of the metal plate 2a is attenuated. The calculation unit 4 temporarily stores the potential decay waveform 12 of the metal plate 2a shown in FIG. 5 in association with the elapsed time since the switch 6 is turned off, and obtains the approximate curve 13 of the potential decay waveform 12.

  Here, as a method for calculating the approximate curve 13 of the potential decay waveform 12 by the calculation unit 4, for example, as shown in FIG. 6, an upper limit comprehensive line 14 and a lower limit comprehensive line 15 of the potential decay waveform 12 are obtained, and an average line of these is 13 is a method.

  In addition, for example, there is a method of obtaining an exponential approximate curve by using an approximate expression such as the following formula (2) and setting the exponential approximate curve as the approximate curve 13 (see FIG. 7).

V = f (t) = (Vs−V1) exp {(− at) + V1} (2)
Here, a is a constant, t is the time elapsed since the switch 6 was turned off, Vs is the static elimination time start potential, and V1 is the balance deviation value of positive and negative ions obtained earlier.

  Further, there is a method of obtaining a polynomial approximation or moving average of the potential decay waveform 12 and using the obtained curve as the approximate curve 13. The average interval at this time may be, for example, an interval for one period of the potential waveform 10 shown in FIG.

  Then, the calculation unit 4 obtains the static elimination time end potential Ve ′ by the above-described equation (1) with the positive / negative ion balance deviation value V1 obtained as the zero reference, and the value of the approximate curve 13 is the static elimination time start potential. A time (static elimination time) T ′ from the value of Vs until reaching the value of the static elimination time end potential Ve ′ obtained by the above-described equation (1) is obtained by arithmetic processing. As described above, since the static elimination time is obtained based on the value of the approximate curve 14, the static elimination time T 'does not vary depending on the timing at which positive and negative ions reach the surface of the metal plate 2a. Further, since the neutralization time end potential Ve ′ is obtained with the positive / negative ion balance deviation value V1 as a zero reference, the static elimination time becomes infinite or the positive / negative ion balance is not deviated. Compared to this, the static elimination time is not shortened. As a result, as shown in FIG. 14, the ability of the pulse AC type or pulse DC type ionizer that alternately generates positive and negative ions from the discharge electrode 21 can be accurately evaluated.

  In addition, the static elimination performance evaluation apparatus 9 is equipped with the control part (not shown). The control unit controls the electrometer 3, the calculation unit 4, the output unit 5, the switch 6, and the high voltage power source 7, and is also connected to the external ionizer 1 to control the start and stop of the ionizer. Thereby, the series of operations described above can be automatically processed. When there is no need to consider the positive / negative ion balance deviation, the calculation unit 4 does not obtain the positive / negative ion balance deviation value V1, and the value of the approximate curve 13 is determined in advance from the static elimination start voltage Vs. It is advisable to find the time to reach the desired value.

  In the above-described embodiment, the static elimination performance evaluation apparatus includes the arithmetic unit. However, the static elimination performance evaluation apparatus may include no arithmetic unit. In the case of such a configuration, the operator who performs the static elimination performance evaluation obtains the positive / negative ion balance deviation value V1 and the approximate curve 13 from the potential decay waveform of the metal plate 2a recorded by the recording device 8, and uses them. The static elimination time T ′ and the like may be obtained.

  In the above-described embodiment, the electrostatic plate 2 having a predetermined electrostatic capacity is used as the static elimination object. However, as shown in FIG. Even if 16 or the like is used, the static elimination performance evaluation method according to the present invention can be applied. In FIG. 8, the same parts as those in FIG.

  The electrostatic capacity of the static elimination object is determined by the distance between the member 17 in contact with the glass substrate provided in the manufacturing apparatus and the grounded portion 11 of the manufacturing apparatus. In the electrostatic plate monitor shown in FIG. 8, in order to measure the surface potential of the surface of the glass substrate 16 facing the ionizer 1 and perform the charge removal performance evaluation, the charge removal performance evaluation apparatus 19 including the surface potential meter 3a is used. . The surface potential sensor 3b externally connected to the static elimination performance evaluation device 19 detects the surface potential of the surface of the glass substrate 16 facing the ionizer 1, and the surface potential meter 3a is based on the detection result of the surface potential sensor 3b. The surface potential of the surface facing the ionizer 1 is measured. Based on the measurement result of the surface potential meter 3a, the calculation unit 4 performs a calculation process for obtaining a static elimination time and the like in consideration of the balance deviation value of positive and negative ions and / or the swing of the surface potential decay waveform of the glass substrate 16. .

These are figures which show the structure of the electrostatic plate monitor used for the static elimination performance evaluation method which concerns on this invention. These are figures which show the steady state of a metal plate electric potential when the ionizer of FIG. 13 is starting. These are figures which show the electric potential attenuation waveform of a metal plate at the time of static elimination with the ionizer of FIG. These are figures which show the steady state of a metal plate electric potential when the ionizer of FIG. 14 is starting. These are figures which show the electric potential attenuation | damping waveform of a metal plate at the time of static elimination with the ionizer of FIG. These are the figures which show the approximated curve calculated | required from the upper limit comprehensive line and the lower limit comprehensive line of the electric potential attenuation waveform of the metal plate at the time of static elimination with the ionizer of FIG. These are figures which show the exponential approximation curve of the electric potential decay waveform of a metal plate at the time of static elimination with the ionizer of FIG. These are figures which show the other structure of the electrostatic plate monitor used for the static elimination performance evaluation method which concerns on this invention. These are figures which show the structure of the electrostatic plate monitor used for the conventional static elimination performance evaluation method. These are figures which show the electric potential attenuation waveform of a metal plate at the time of static elimination with the ionizer of FIG. These are figures which show the electric potential attenuation waveform of a metal plate in case the balance of positive / negative ion has shifted | deviated + 200V. These are figures which show the electric potential decay waveform of a metal plate in case the balance of positive / negative ion has shifted | deviated -200V. FIG. 3 is a schematic diagram of an ionizer that simultaneously generates positive and negative ions. FIG. 3 is a schematic diagram of an ionizer that alternately generates positive and negative ions. These are figures which show the electric potential attenuation | damping waveform of a metal plate at the time of static elimination with the ionizer of FIG. These are figures which show the electric potential attenuation | damping waveform which is swinging to the plus direction when it becomes the static elimination time start electric potential. These are figures which show the electric potential attenuation | damping waveform which is swung to a negative | minus direction when it becomes static elimination time start electric potential.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ionizer 2 Electrostatic plate 3 Electrometer 3a Surface potential meter 3b Surface potential sensor 4 Calculation part 5 Output part 6 Switch 7 High voltage power supply 8 Recording device 9, 19 Static elimination performance evaluation apparatus 16 Glass substrate

Claims (6)

A potential measuring unit for measuring the surface potential of the static elimination object;
A high voltage power supply for applying a high voltage to the static elimination object;
The measurement result of the potential measuring unit is input, and the balance deviation value of positive and negative ions is obtained from the steady state surface potential of the static elimination object that has been neutralized by an ionizer, and the balance deviation value of the positive and negative ions is based on zero. As a predetermined value and the positive / negative ion balance deviation value, a static elimination time end potential is obtained, and the static elimination object charged by the high voltage power source is neutralized by the ionizer so that the surface potential of the static elimination object is A calculation unit for obtaining a time from the predetermined value to the electric discharge time end potential;
A static elimination performance evaluation apparatus comprising: A static elimination performance evaluation device for evaluating the static elimination performance of an ionizer that alternately generates positive and negative ions,
An electric potential measuring unit for measuring a surface electric potential of a static elimination object to be eliminated by the ionizer;
A high voltage power supply for applying a high voltage to the static elimination object;
The measurement result of the potential measurement unit is input, and the surface potential attenuation of the static elimination object is calculated from the surface potential attenuation waveform of the static elimination object when the static elimination object charged by the high voltage power source is neutralized by the ionizer. An approximate curve that is a swing center of the waveform, and a calculation unit that calculates a time until the value of the approximate curve reaches a predetermined value from a predetermined value;
A static elimination performance evaluation apparatus comprising: A static elimination performance evaluation device for evaluating the static elimination performance of an ionizer that alternately generates positive and negative ions,
An electric potential measuring unit for measuring a surface electric potential of a static elimination object to be eliminated by the ionizer;
A high voltage power supply for applying a high voltage to the static elimination object;
Input the measurement result of the potential measurement unit, obtain an approximate line that is the swing center of the steady-state surface potential of the static elimination object from the steady-state surface potential of the static elimination object that has been neutralized by the ionizer, and from the approximate line A surface potential attenuation of the static elimination object is obtained from a surface potential decay waveform of the static elimination object when the static elimination object charged by the high voltage power source is neutralized by the ionizer. Obtain an approximate curve that is the center of the swing of the waveform, obtain a predetermined value and a positive / negative ion balance deviation value based on the positive / negative ion balance deviation value as a zero reference, and determine the approximate curve of the approximate curve A calculation unit for obtaining a time from the predetermined value to the value of the static elimination end potential;
A static elimination performance evaluation apparatus comprising: Obtaining a balance deviation value of positive and negative ions from the steady-state surface potential of a static elimination object that has been eliminated by an ionizer;
Obtaining a predetermined value and a positive / negative ion balance deviation value according to the positive / negative ion balance deviation value based on the positive / negative ion balance deviation value; and
Obtaining a time from when the static elimination object charged by a high voltage power source is neutralized by the ionizer until the surface potential of the static elimination object reaches the static elimination end potential from the predetermined value;
A method for evaluating static elimination performance, comprising: A static elimination performance evaluation method for evaluating the static elimination performance of an ionizer that alternately generates positive and negative ions,
Obtaining an approximate curve that is the swing center of the surface potential attenuation waveform of the static elimination object from the surface potential attenuation waveform of the static elimination object when the static elimination object charged by the high voltage power source is neutralized by the ionizer;
Obtaining a time until the value of the approximate curve becomes a predetermined value from a predetermined value;
A method for evaluating static elimination performance, comprising: A static elimination performance evaluation method for evaluating the static elimination performance of an ionizer that alternately generates positive and negative ions,
Obtaining an approximate line that is the swing center of the steady state surface potential of the static elimination object from the steady state surface potential of the static elimination object that has been neutralized by the ionizer;
Obtaining a balance deviation value of positive and negative ions from the approximate line;
Obtaining an approximate curve that is the swing center of the surface potential attenuation waveform of the static elimination object from the surface potential attenuation waveform of the static elimination object when the static elimination object charged by a high voltage power source is neutralized by the ionizer; ,
Obtaining a predetermined value and a positive / negative ion balance deviation value according to the positive / negative ion balance deviation value based on the positive / negative ion balance deviation value; and
Obtaining a time until the value of the approximate curve reaches the value of the static elimination end potential from the predetermined value;
A method for evaluating static elimination performance, comprising:

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