JP2008159272A - Static eliminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce wear and smearing of an electrode needle and efficiently destaticize a charged body. <P>SOLUTION: The static eliminator has a destaticizing mode in which a high voltage is applied on an electrode needle 4 to generate ions and a stop mode to put the electrode needle 4 at a rest, and these can be established alternatively by selection of a user. The stop mode includes a stop period in which the high voltage is not basically applied on the electrode needle 4, and during this stop period, when a charged body approaches and self-discharge is generated, and if, accompanied with this, the absolute value of current flowing in a resistor R2 exceeds a first threshold, destaticizing operation to apply the high voltage on the electrode needle 4 to generate ions is started. Thereafter, after passing, for example, a prescribed time, the destaticizing operation is stopped, and it returns to a stop period. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a static eliminator for neutralizing a charged body charged positively or negatively.

  There is known a static eliminating device that neutralizes a charged body by generating positive and negative ions (cited documents 1 and 2). Since the static eliminator generates ions by applying a high voltage to the electrode needle and performing corona discharge, the electrode needle wears and the ion generation capacity decreases over time due to the electrode needle becoming dirty. Has the problem.

JP 2000-58290 A JP 2003-86393 A

  In order to solve this problem, Cited Document 2 applies, for example, a positive voltage on the premise of a static eliminator that alternately applies high voltages having different polarities to a common electrode needle to alternately generate positive ions and negative ions. Then, before applying the next negative voltage, an interval period in which no voltage is applied to the electrode needle is provided, and the voltage applied to the electrode needle is adjusted so that the ion balance becomes neutral immediately before entering the interval period. The invention is disclosed. According to the present invention, it is possible not only to reduce the working time of the electrode needle by inserting an interval period between applying voltages of different polarities, thereby reducing wear and contamination of the electrode needle, but also ion balance. Can be maintained properly.

  An object of the present invention is to provide a static eliminator that can reduce the wear and contamination of electrode needles and efficiently neutralize a charged body.

According to the present invention, the above technical problem is
A static elimination device that generates ions by applying a high voltage to an electrode needle,
A self-discharge detection circuit that detects self-discharge of the electrode needle when a high voltage is not applied to the electrode needle;
When the self-discharge detection circuit detects self-discharge of the electrode needle during the pause period including a pause period in which the electrode needle is paused, ions are generated by applying a high voltage to the electrode needle. This is achieved by providing a static eliminator that starts the static elimination operation and stops the static elimination operation when the neutralization of the charged body is completed and returns to the idle period.

  According to the present invention, when a charged body appears while the electrode needle is being suspended, a charge having a polarity opposite to that of the charged body is induced at the tip of the electrode needle, and self-discharge tends to occur. Further, by detecting the occurrence of self-discharge with a self-discharge detection circuit provided inside the apparatus, it is possible not only to detect the appearance of the charged body but also to start the charge eliminating operation. Therefore, the neutralization device itself can automatically detect the appearance of the charged body without relying on an external sensor, and the neutralization by the neutralization device can be executed. Therefore, a high voltage is not always applied to the electrode needle. It is possible to stand by in a resting state, thereby reducing the wear and contamination of the electrode needle and efficiently removing the charged body.

  The self-discharge detection circuit may be a circuit that detects a current value flowing through the resistor by providing a resistor between the electrode needle and the high voltage generation circuit, or between the electrode needle and the ground. It may be a circuit that provides a resistor and detects the value of the current flowing through the resistor. Not only can the self-discharge be detected based on the absolute value of the current flowing through the resistor, but also the value of the current flowing through the resistor (absolute value) decreases as the charge amount of the charged body decreases. I can know. Therefore, the charge removal operation is started when the value (absolute value) of the current flowing through the resistor exceeds the first threshold value, and the charge removal operation is stopped when it falls below the second threshold value. The static elimination operation in the sleep mode can be controlled in a manner that matches the appearance of the body. Of course, the static elimination operation may be stopped by using a timer to stop the static elimination operation after a predetermined time has elapsed after the start of the static elimination operation and return to the idle period. In order to increase the sensitivity for detecting the charged body, it is preferable to apply a high voltage of a relatively low level that does not generate ions in the electrode needle during the rest period.

  In a preferred embodiment of the present invention, in addition to a pause mode in which a static elimination operation is executed in response to the appearance of a charged body in a pause state, there is a static elimination mode in which a high voltage is applied to the electrode needle to generate ions. In addition, the static elimination mode and the pause mode can be arbitrarily set by user selection. Thereby, the user can select the operation of the static eliminator according to the application environment of the static eliminator.

  In the rest mode, it is preferable to alternately set the rest period and the ion generation period in which ions are generated by applying a high voltage to the electrode needle. According to this, it is possible to neutralize a slightly charged charged body using ions generated during the ion generation period. Of course, the time of the rest period and the time of the ion generation period may be fixed, but it is needless to say that the user can arbitrarily set the time.

  In the rest mode, it is preferable to provide a transition period between the rest period and the ion generation period or the static elimination operation. Specifically, the voltage applied to the electrode needle is gradually reduced during the transition from the static elimination operation or the ion generation period to the pause period, so that the pause period depends on the polarity of the high voltage applied at the end of the ion generation period or the static elimination operation. It is possible to avoid deviation of the ion balance in the atmosphere around the electrode needles in FIG. On the other hand, by gradually increasing the voltage applied to the electrode needle during the transition from the rest period to the ion generation period or charge removal operation, ions are suddenly generated around the electrode needle immediately after the transition to the ion generation period or charge removal operation. Thus, it is possible to avoid the occurrence of a situation in which the charged body is affected by exposure of the charged body to the ions.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a circuit diagram of the static eliminator of the embodiment. In FIG. 1, reference numeral 1 denotes a DC power source, which is composed of an external DC power source such as a secondary battery. Reference numerals 2 a and 2 b denote first and second switches provided on the output side of the DC power supply 1. The first and second switches 2 a and 2 b are controlled to be opened and closed by control signals Sa and Sb from the control unit 3. Of course, electronic switches such as transistors can be used for the first and second switches 2a and 2b.

  A positive terminal of the DC power source 1 is connected to a positive first high-voltage generating circuit 5 including a transformer 5a and a voltage doubler rectifier circuit 5b via a first switch 2a. The terminal is connected to a negative second high-voltage generating circuit 6 including a transformer 6a and a voltage doubler rectifier circuit 6b via a second switch 2b.

  Each of the high voltage generation circuits 5 and 6 is connected to the electrode needle 4 via equivalent resistors R1 and R1 that act as current limiting impedances. The electrode needle 4 is grounded via the second resistor R2.

  The first and second switches 2a and 2b are alternately opened and closed by the control signals Sa and Sb output from the control unit 3, so that the first and second high voltage generation circuits 5 and 6 have a predetermined frequency. Then, a positive or negative pulsed high voltage is alternately supplied to the electrode needle 4, whereby positive or negative ions are alternately generated from the electrode needle 4.

  Control of the static eliminator is performed by applying a high voltage to the electrode needle 4 to generate ions to actively neutralize the charged body, that is, a voltage capable of ionizing the ambient gas around the electrode needle 4 to the electrode needle 4. Is not applied to the electrode needle 4 by stopping the application of a high voltage to the electrode needle 4, that is, no voltage is applied to the electrode needle 4, or the electrode needle 4 is not applied to the electrode needle 4 alone. There is a pause mode in which the surrounding atmosphere gas is impressed by applying a voltage that cannot be ionized, so that the electrode needle 4 is substantially in a pause state. The mode changeover switch 11 (FIG. 1) operable by the user The mode is selectively set.

  By the way, when a charged body having a potential difference between the electrode needle 4 and the electrode needle 4 capable of generating self-discharge appears when operating in the pause mode, a polarity opposite to that of the charged body is formed at the tip of the electrode needle 4. This induces a self-discharge phenomenon. This can be known from a signal generated in the internal circuit of the static eliminator as self-discharge occurs. Specifically, in order to directly or indirectly detect the current flowing through the electrode needle 4 during self-discharge, it is between the electrode needle 4 and the ground, or between the high voltage generating circuits 5 and 6 and the electrode needle 4. There may be mentioned a method in which a resistor is provided between and a current value flowing through this resistor is detected, and if the current value is equal to or greater than a threshold value, it is determined that self-discharge has occurred. Specifically, (1) A method of detecting a self-discharge detection current flowing between a high-voltage power supply and ground, and detecting a current value flowing through the resistor to detect self-discharge indirectly. (2) A method in which a resistor is interposed to detect a self-discharge detection current flowing between the counter electrode and the ground, and a self-discharge is indirectly detected by detecting a current value flowing through the resistor, (3) The combination of the above (1) and (2), that is, a resistor is interposed to detect the self-discharge detection current flowing between the high-voltage power source and the ground, and the self-discharge detection current flowing between the counter electrode and the ground is A method of detecting self-discharge by interposing a resistor R2 for detection (FIG. 1), (4) interposing a resistor R2 between the electrode needle and the high-voltage power source, and determining the self-discharge detection current value flowing through this resistor Detect and detect self-discharge directly It can be exemplified method (Figure 2).

  When the self-discharge detection circuit that detects the current value flowing between any of the above-described self-discharge detection means (1) to (3), that is, the ground, is employed, at least in the above-described static elimination mode. It can also be used as a detection means for detecting the ion balance during static elimination. Specifically, if the current value flowing through each resistor is detected and neutralization based on the currently set positive and negative duty ratios is appropriate, the total value of the current flowing through the resistor during this period will be zero. Therefore, a similar duty ratio is adopted for the subsequent period. On the other hand, if static elimination at the currently set positive and negative duty ratios is inappropriate, the total value of the current flowing through the resistor during this period becomes a value biased to either positive or negative, based on that value. In addition, during the subsequent period, a duty ratio obtained by correcting the current duty ratio is adopted, and control is performed so that more appropriate static elimination is performed. Therefore, in the circuit shown in FIG. 1, the static eliminator is controlled by the signal from the mode changeover switch 3 so that the current value data provided from the resistor R2 is properly used in the static elimination mode and the sleep mode. Of course, when a high voltage is applied to the electrode needle 4 for static elimination in the rest mode, the ion balance control may be performed using the current value flowing through the resistor R2.

  The self-discharge detection current that flows in the circuit in relation to the self-discharge passes through an amplifier 8, a low-pass filter (LPF) 9, and an analog / digital converter (A / F) 10 as illustrated in FIGS. Are supplied to the control unit 3.

  In the static elimination mode, as illustrated in FIG. 3, pulsed high voltages having different polarities are alternately applied to the electrode needle 4 continuously. 4 and 5 show modified examples of the operation in the static elimination mode. As shown in FIG. 4, the life of the electrode needle 4 is extended by inserting an interval period in which no high voltage is applied at the timing of applying a high voltage on the plus side and the next minus side, and on the minus side and the next plus side. As a further modification, as shown in FIG. 5, a high voltage is applied to the positive side to generate positive ions, and then a high voltage on the negative side is applied to the electrode needle 4 for a short time. Then, at a certain interval, a negative high voltage is applied to generate negative ions. Similarly, a high voltage is applied to the negative side to generate negative ions, and then a high voltage of reverse polarity (positive side) is applied to the electrode needle. 4 may be applied for a short time, and then a positive high voltage may be applied at intervals to generate positive ions. According to the high voltage application method of the further modification shown in FIG. 5, a high voltage application system that reaches the electrode needle 4 by applying a reverse polarity voltage to the electrode needle 4 for a short time after generating positive ions. Can be neutralized. By applying the neutralizing voltage to the electrode needle 4 in this way, the amount of dust that adheres to the electrode needle 4 over time can be reduced.

  Of course, if the balance of positive and negative ions generated by applying a high voltage to the electrode needle 4 is controlled, for example, when the ion balance is biased to the negative side, the pulse width of the positive high voltage is By adding Duty control that relatively expands, the ion balance of the atmosphere around the electrode needle 4 can be maintained constant. Regarding ion balance control, for example, since there is a detailed description in Japanese Patent Application Laid-Open No. 2003-86393, the content disclosed in this publication is incorporated herein. In this embodiment, in the static elimination mode, a high voltage with a positive polarity is used. The duty ratio for applying a high voltage of negative polarity to the electrode needle 4 is determined based on the duty ratio or the duty ratio executed immediately before.

  In the rest mode, basically, no voltage is applied to the electrode needle 4. Then, when the occurrence of self-discharge during the idle period in which this voltage is not applied is detected by the value of the current flowing through the second resistor R2 of the internal circuit of the static eliminator, the static elimination operation is started, and then a predetermined time has passed or When static elimination ends, it returns to the rest period. That is, in the rest mode, basically, the application of voltage to the electrode needle 4 is stopped, and the charge removal operation is executed only when it is detected that a charged body has appeared in the charge removal target area. The The intrusion of the charged body into the static elimination target area is detected by the internal circuit of the static elimination device.

  Hereinafter, the static elimination mode will be described in detail. FIGS. 6 and 7 are control examples of the pause mode, FIG. 6 (a) shows the pause mode (1) of the first example, and FIG. FIG. 7 (c) shows the third example pause mode (3), and FIG. 7 (d) shows the fourth example pause mode (4).

  In the control modes of the pause modes (1) and (2) in FIGS. 6 (a) and 6 (b), in addition to a pause period in which ions are not generated, which is a preset period, a preset period is set before and after this pause period. The period includes an ion generation period in which a high voltage is applied to the electrode needle 4 to generate ions. As a method for setting a predetermined period for the suspension period, a fixed period may be set in the static eliminator, or any method that the user arbitrarily sets based on the number of pulses or time may be adopted. Good. As a method for setting a predetermined period for the ion generation period, a fixed period may be set in the static eliminator, or any method that the user arbitrarily sets based on the number of pulses or time may be adopted. Good.

  In the control modes of the suspension modes (3) and (4) in FIGS. 7C and 7D, the suspension mode is configured only by the suspension period. Therefore, there is no predetermined period in the rest period in the control modes of the rest modes (3) and (4), and the rest period is not detected unless a charged body charged to a predetermined value or more is detected to start static elimination. Will continue. In addition, referring to FIG. 6 and FIG. 7, during the rest period, a voltage that does not generate ions may be applied to the electrode needle 4 unless a charged body charged to a predetermined value or more is present in the area to be neutralized. (Pause mode (1) in FIG. 6 (a), Pause mode (3) in FIG. 7 (c)), no voltage may be applied to electrode needle 4 (voltage application is stopped) (FIG. 6 (b) pause mode (2), Fig. 7 (d) pause mode (4)).

  When the pause modes (1) and (3) shown in FIGS. 6 (a) and 7 (c) are adopted, a high voltage lower than the voltage at which discharge starts is applied to the electrode needle 4 during the pause period. Thus, the potential difference between the electrode needle 4 and the charged body can be reduced to increase the sensitivity to the charged body slightly charged.

  When the voltage application to the electrode needle 4 is stopped during the pause period as in the pause modes (2) and (4) in FIGS. 6 (b) and 7 (d), for example, the electrode needle 4 Assuming that the voltage value that can ionize the atmosphere around the electrode needle 4 by applying a high voltage is 3 kV, the potential difference between the electrode needle 4 and the charged body during the pause period has a threshold value (for example, 3 kV). If it exceeds, self-discharge occurs from the electrode needle 4, and when this self-discharge is detected by the circuit in the above-described static elimination device (value of the current flowing through the second resistor), the static elimination operation is started. In addition, the voltage value applied to the electrode needle 4 in this static elimination operation is, for example, 5.3 kV.

  When a relatively low level high voltage (for example, 2 kV) is applied to the electrode needle 4 during the rest period, as in the rest modes (1) and (3) in FIGS. 6 (a) and 7 (c). When the potential difference between the electrode needle 4 and the charged body exceeds a threshold value (for example, 1 kV) during the rest period, self-discharge occurs from the electrode needle 4, and the value of current flowing through the second resistor R2 is self-discharge. Is detected, a high voltage (for example, 5.3 KV) capable of ionizing the surrounding atmosphere is applied to the electrode needle 4 (start of static elimination operation). This neutralization operation is substantially the same as the above-described neutralization mode operation. Thus, the sensitivity of detecting a charged body can be increased by applying a relatively low level of high voltage during the rest period. Thus, this is limited to the case where there is a charged body using the internal circuit of the static eliminator without providing an external sensor for detecting that the charged body has entered the area to be neutralized (presence / absence of charged body). The static elimination operation can be executed. In other words, when the charged body is not present, the state in which the generation of ions by the electrode needle 4 is stopped can be continued, so that wear of the electrode needle 4 and adhesion of dust can be reduced.

  Needless to say, the “threshold value” in the control based on FIGS. 6 and 7 described above is not the “threshold value” generally stored in advance in a memory or the like, but each pause mode shown in FIGS. 6 and 7. The difference between the voltage applied to the electrode needle 4 during the rest period in the mode or the potential difference between the ground and the electrode needle 4 in the non-applied state and the voltage at which the electrode needle 4 can ionize the surrounding atmosphere Of course, it is decided by. However, in a mode in which no voltage is applied to the electrode needle 4 during the pause period in the pause mode, the threshold value may be a value of 3 KV or more, and it is not necessary to stick to 3 KV. Similarly, when a relatively low level high voltage is applied during the pause period of the pause mode, for example, if the voltage value is 2 KV applied to the electrode needle 4, the threshold value is 1 KV or more. Well, there is no need to stick to 1KV. From this, the “threshold value” may be set as a “threshold value” as a “threshold value” as a fixed value for the sleep mode as a static eliminator in accordance with the above-mentioned concept. In other words, if the voltage value applied in the static elimination mode is automatically limited as the upper limit value, the user may be allowed to set any value as a “threshold value” depending on the user's setting action. .

  As described above, the “threshold value” causes the second resistor R2 (FIGS. 1 and 2) to perform switching that stops the idle period in the idle mode and starts the static elimination operation and stops the static elimination operation and returns to the idle period. ) On the basis of the value of the current i flowing (the absolute value amplified by the amplifier 7). FIG. 8 shows an example of control in which a charged body is detected during the pause period in the pause mode to perform the charge removal operation, and the charge removal operation is terminated and returned to the pause period. Referring to FIG. 8, when the absolute value | i | of the self-discharge detection current exceeds a first threshold value (for example, a current value corresponding to 3 KV), the pause period is stopped and the charge removal operation is started. Then, when the charge removal of the charged body proceeds and the absolute value | i | of the self-discharge detection current falls below a second threshold value (for example, a current value corresponding to less than 1 KV), the charge removal operation ends and pauses. Return to the period. That is, the control example in FIG. 8 is an example in which both the start of the charge removal operation and the stop of the charge removal operation in the sleep mode are performed using threshold values.

  The specific charge removal control of the charge removal operation executed in the sleep mode is performed in the charge removal mode from various specific examples of the voltage application method performed in the charge removal mode illustrated with reference to FIGS. The same voltage application method as the voltage application method employed may be adopted. Of course, a method different from the voltage application method adopted in the static elimination mode may be adopted in the static elimination operation during the pause mode.

  In the sleep mode, the timer may be used to stop the charge removal operation after stopping the discharge period by using the “threshold” to start the charge removal operation. Specific examples thereof are shown in FIGS. In FIG. 9, the set time t of the timer is constant, and this set time t may be a fixed value set at the time of factory shipment or may be arbitrarily set by the user.

  FIG. 10 shows an example in which the timer time t is adjusted by the magnitude of the peak value of the absolute value of the self-discharge detection current, and FIG. 11 shows an example in which the timer time t is adjusted by the magnitude of the slope at which the self-discharge detection current value decreases. Indicates.

  The adjustment of the timer time t by the “peak value” illustrated in FIG. 10 is adjusted so that the timer time t becomes long when the “peak value” is large, that is, when the charge amount of the charged body is large. When the “value” is small, that is, when the charge amount of the charged body is small, it is preferable to adjust the timer time t to be short.

  The adjustment of the timer time t by the “tilt” shown in FIG. 11 is adjusted so that the timer time t becomes long when the “tilt” is small, that is, when the charge amount of the charged body is gradually decreased. When the “tilt” is large, that is, when the charge amount of the charged body is greatly reduced, it is preferable to adjust the timer time t to be short.

  8 to 11 show an example in which no voltage is applied to the electrode needle 4 (pause mode (4) in FIG. 7) as the pause mode. The pause mode (1) and pause mode (3) are illustrated. It goes without saying that other control modes (FIGS. 13 and 14) described later and other control modes described later may be adopted. FIG. 12 shows a case where a charged body is detected during the rest mode (1) of FIG. 6 (a) or the rest mode (3) of FIG. 7 (c) in which a relatively low voltage is applied to the electrode needle 4 during the rest period. The example of starting the static elimination operation and controlling both using the “threshold value” in order to end the static elimination operation is shown, but the termination of the static elimination operation is a timer as in FIGS. Needless to say, it can be controlled.

  As described above, when a charged body is detected in the rest period in the internal circuit of the static eliminator, a static elimination operation is performed in which a high voltage is applied to the electrode needle 4 to actively generate ions. Moreover, as illustrated in FIGS. 6A and 7C, an ion generation period in which a high voltage is applied to the electrode needle 4 intermittently and periodically during the pause mode to generate ions is included. Therefore, it is possible to thoroughly eliminate the charge of the weakly charged charged body. Here, in the control modes (1) and (3) of the pause mode exemplified in FIGS. 6 (a) and 7 (c), the length of the ion generation period and the length of the pause period may be arbitrarily set. . Moreover, the time of the single cycle which consists of the combination of an ion generation period and the subsequent rest period, and the ratio of the ion generation period and rest period in this single cycle can be set arbitrarily. For example, the time of a single cycle may be set to a time corresponding to the work tact time of the work when, for example, the static eliminator is disposed on the transport conveyor on which the work (electric charge removal object) flows.

  A transition period is added between the ion generation period in which a high voltage is applied to the electrode needle 4 or when the ionization operation is stopped and the rest period when an ion generation period is provided in the pause mode or when the charge removal operation is performed during the pause period. It is good to do. That is, when the ion generation period (or the charge removal operation) is immediately switched to the pause period, the high voltage polarity applied to the electrode needle 4 immediately before switching to the pause period, that is, at the end of the ion generation period is the initial charge removal target area of the pause period. This may affect the ion balance and cause deviation in the ion balance. In addition, the remaining charge accumulated in the circuit during the ion generation period (or the charge removal operation) is applied to the electrode needle 4 during the rest period, which may continue to generate ions even during the rest period. In order to cope with this, as illustrated in FIG. 13, a pre-stage transition period is inserted before switching from the ion generation period (or static elimination operation) to the rest period, and the absolute value of the voltage is gradually increased in the pre-stage transition period. Is preferably applied to the electrode needle 4. FIG. 13A shows an example of control in a pause mode in which no voltage is applied to the electrode needle 4 during the pause period. FIG. 13B shows a pause mode in which a low level voltage is applied to the electrode needle 4 during the pause period. An example of control is shown.

  Similarly, it is preferable to add a transition period when shifting from the pause period to the ion generation period or the charge removal operation. That is, if the ion generation period (or the charge removal operation) is immediately switched from the rest period to the charge removal object, the charge removal object suddenly receives ions to charge the charge removal object, so that, for example, the semiconductor is the charge removal object. For example, the memory may disappear due to a sudden charge, which may cause unexpected damage to the target object. In order to cope with this, as illustrated in FIG. 14, a rear transition period is inserted before switching from the rest period to the ion generation period (or the charge removal operation), and the absolute value gradually increases in the rear transition period. Is preferably applied to the electrode needle 4. FIG. 14A shows an example of control in a pause mode in which no voltage is applied to the electrode needle 4 during the pause period, and FIG. 14B shows a pause mode in which a low level voltage is applied to the electrode needle 4 during the pause period. An example of control is shown.

  FIG. 15 shows a preferable control example in the case where an ion generation period is provided in the pause mode, and a transition period from the previous stage is inserted immediately before switching from the ion generation period (or charge removal operation) to the pause period. An example is shown in which a post-stage transition period is inserted immediately before switching to (or static elimination operation). FIG. 15A shows an example of control in a pause mode in which no voltage is applied to the electrode needle 4 during the pause period. FIG. 15B shows a pause mode in which a low level voltage is applied to the electrode needle 4 during the pause period. An example of control is shown.

  In general, in the static elimination apparatus, air is blown in order to efficiently convey ions generated by applying a high voltage to the electrode needle 4 toward the static elimination body (charged body). FIG. 16 shows the static eliminator 100. In the static eliminator 100, a plurality of electrode units 12 including the electrode needles 4 described above are arranged at intervals, and the static eliminator 100 is supplied with an inert gas such as filtered compressed air or nitrogen through an external pipe 13. Then, the compressed air and the inert gas that have entered the static eliminator 100 are discharged through each electrode unit 12.

  The external pipe 12 is provided with an electromagnetic on-off valve or an electric opening degree adjusting valve 14, and the opening degree of the on-off valve or opening degree adjusting valve 14 is controlled by an output signal Sc from the static eliminator 100. . An example of control of the on-off valve or the opening adjustment valve 14 will be described with reference to FIG. In the control illustrated in FIG. 17, as can be seen from FIG. 17, the application of voltage to the electrode needle 4 is stopped during the pause period. When the absolute value of the self-discharge detection current i becomes larger than the first threshold value, the operation is switched to the charge removal operation, and application of a high voltage to the electrode needle 4 is started. At the same time, when the absolute value of the self-discharge detection current i becomes larger than the first threshold value, the output signal Sc is output from the static eliminator 100 and the electromagnetic on-off valve 14 is opened. Thereby, supply of compressed air or an inert gas is started with respect to the static elimination apparatus 100 in synchronization with switching to static elimination mode. On the other hand, when the absolute value of the self-discharge detection current i falls below the second threshold value, the static elimination operation is completed and the rest period is resumed. In synchronization with this, the on-off valve 14 is closed and the static elimination device 100 is compressed. The supply of air or inert gas is stopped.

  As described above, the trigger signal for performing the switching control between the ion generation period in the pause mode or the charge removal operation and the pause period based on the absolute value of the self-discharge detection current i or the control signal based on the trigger signal is output to the outside. For example, by controlling the flow rate of the gas supplied to the static eliminator 100 based on the output signal Sc, the consumption of the compressed air or the inert gas can be made rational. When a low level voltage is applied to the electrode needle 4 during the rest period, the opening degree of the opening degree adjustment valve 14 is narrowed down by the output signal Sc in synchronization with the transition to the rest period, and compression with respect to the static eliminator 100 is performed. The supply amount of air or inert gas should be reduced.

  Further, when the pause mode described in FIG. 6 and the like includes an ion generation period and a pause period, it is generated inside the static eliminator 100 to switch from the ion generation period to the pause period and from the pause period to the ion generation period. A signal or a control signal based on the signal may be supplied from the static eliminator 100 to the on-off valve or the opening adjustment valve 14 as the output signal Sc. Even in this case, as shown in FIGS. 6B and 7D, when no voltage is applied to the electrode needle 4 during the resting period, the on-off valve 14 is closed and the static eliminator 100 is compressed. It is preferable to stop the supply of air or inert gas. When a low level voltage is applied to the electrode needle 4 during the pause period as illustrated in FIG. A signal for narrowing the degree is preferably supplied from the static eliminator 100. The output signal Sc from the static eliminator 100 may be used to display the current operating state of the static eliminator 100. That is, the static eliminator 100 is provided in or near the static eliminator 100 so that the operation during the ion generation period, the operation during the rest period, or the operation in the static elimination mode is currently performed. In the case of displaying with an indicator lamp (not shown), the blinking of the indicator lamp may be controlled by the output signal Sc based on the internal signal used in the control of the static eliminator 100.

  A specific control example will be described based on the flowcharts illustrated in FIGS. FIG. 18 is a flowchart relating to the control of the static elimination operation during the sleep mode based on the “threshold value” of FIG. 8 described above. Referring to the flowchart of FIG. 18, it is determined in step S1 whether or not the sleep mode is set. If YES (the sleep mode is set), the process proceeds to step S2 and the self-discharge detection current i is measured. Then, it is determined whether or not the absolute value of the measured self-discharge detection current i is larger than the first threshold value (step S3). If YES, the process proceeds to the next step S4 and the charge removal operation is started. The In step S5, the self-discharge detection current i is measured, and the static elimination operation is continued until the absolute value of the self-discharge detection current i is smaller than the second threshold value. If it becomes smaller than 2 threshold values, the static elimination operation is stopped in step S6. As a result, the static eliminator returns to the pause period in the pause mode, and the monitoring of the appearance of the charged body, that is, the occurrence of self-discharge, is continued, and the static eliminator can be put on standby in the pause state.

  The flowchart in FIG. 19 corresponds to the control for terminating the static elimination operation described with reference to FIG. 9 by a timer. Referring to the flowchart of FIG. 19, it is determined in step S10 whether or not the sleep mode is set. If YES (the sleep mode is set), the self-discharge detection current i is measured in step S11. It is determined whether or not the absolute value of the measured self-discharge detection current i is larger than the first threshold value (step S12). If YES, the process proceeds to the next step S13, and the charge removal operation is started. In S14, the timer is operated, and when the timer time t reaches a predetermined time t0, the process proceeds to step S15 and the static elimination operation is stopped. As a result, the static eliminator returns to the pause period in the pause mode. As a result, the static eliminator returns to the rest period in the rest mode, and the appearance of the charged body, that is, the occurrence of self-discharge is continuously monitored.

  The flowchart in FIG. 20 corresponds to the control for changing the timer time described in FIG. With reference to the flowchart of FIG. 20, it is determined whether or not the sleep mode is set in step S20. If YES (the sleep mode is set), the self-discharge detection current i is measured in step S21. It is determined whether or not the absolute value of the measured self-discharge detection current i is larger than the first threshold value (step S22). If YES, the process proceeds to the next step S23 and the charge removal operation is started. In step S24, the self-discharge detection current i is measured, the peak value of the ground current is detected from the self-discharge detection current value i (step S25), and the timer time t0 corresponding to the peak value is obtained from the data table. (Step S26). Subsequently, the timer is set to the timer time t0 obtained from the data table to start the timer t (step S27). When the timer t reaches the set timer time t0 (step S28), the static elimination operation is stopped (step S28). S29). As a result, the static eliminator returns to the pause period in the pause mode. As a result, the static eliminator returns to the rest period in the rest mode, and the appearance of the charged body, that is, the occurrence of self-discharge is continuously monitored.

  The flowchart in FIG. 21 corresponds to the control in FIG. With reference to the flowchart of FIG. 21, it is determined whether or not the sleep mode is set in step S30. If YES (the sleep mode is set), the self-discharge detection current i is measured in step S31. It is determined whether or not the absolute value of the measured self-discharge detection current i is larger than the first threshold value (step S32). If YES, the process proceeds to the next step S33 to start the static elimination operation. In step S34, the self-discharge detection current i is measured, and the peak value of the ground current is detected from the current value i (step S35). When the peak value is detected, the process proceeds to step S36, where the self-discharge detection current i is measured, and the slope is obtained from the differential value of the current value i (step S37). Then, the timer time t0 corresponding to the obtained inclination is obtained from the data table (step S38). Subsequently, the timer is set at the timer time t0 obtained from the data table to start the timer t (step S39). When the timer t reaches the set timer time t0 (step S40), the static elimination operation is stopped (step S40). Step S41). As a result, the static eliminator returns to the pause period in the pause mode. As a result, the static eliminator returns to the rest period in the rest mode, and the appearance of the charged body, that is, the occurrence of self-discharge is continuously monitored.

  In the static eliminator 100 described above, when the ion balance in the static elimination target area is biased during the operation in the pause mode, for example, control to keep the ion balance properly as shown in FIGS. 22 and 23 may be performed. . The ion balance control illustrated in FIG. 22 is control (Duty ratio control) in which the pulse width of a pulsed high voltage applied to the electrode needle 4 is changed, and FIG. 22 (a) shows the ion balance around the electrode needle 4. Shows control when the is biased to the plus side, and in this case, the pulse width for applying the plus high voltage is controlled to be small. On the other hand, FIG. 22 (b) shows control when the ion balance around the electrode needle 4 is biased to the minus side, and in this case, control is performed so that the pulse width for applying a positive high voltage is expanded. Is done.

  The control example in FIG. 22 is a control example in which the ion balance is appropriately maintained by changing the pulse width of the high voltage. However, the voltage value of the plus / minus high voltage applied to the electrode needle 4 is changed. Also good. Further, as shown in FIG. 23, an average value of plus / minus high voltage values corresponding to the degree of deviation of the ion balance may be used. Of course, digital averaging may be performed. When such ion balance control is performed even in the pause mode, it is necessary to appropriately sample the plus / minus high voltage applied to the electrode needle 4, and preferably ion balance using an appropriate averaging method. Control should be performed appropriately.

  Specifically, the ion balance control is performed on the positive side applied to the electrode needle 4 so that the plus / minus ion balance around the electrode needle 4 is appropriate for neutralizing the charge of the charged body. In this ion balance control, for example, when ion balance control is performed with a duty ratio of plus / minus high voltage, for example, a positively charged object is subject to charge removal. When entering the area, this charged state is detected and a high voltage adjusted to increase the duty ratio to the negative side is applied to the electrode needle 4. In order to properly execute this control, at least the currently executed duty ratio and the resulting ion balance state of the static elimination target area are reflected in the next determination of the high voltage duty ratio to be applied to the electrode needle 4. Is preferred.

  As described above, the pause mode includes a pause period in which ions are not generated by the electrode needle 4, and when the transition from the pause period to the ion generation period or the transition from the pause period to the charge removal operation, the currently executed duty ratio Therefore, reflecting the duty ratio of the rest period to the ion balance control immediately after the transition to the ion generation period or the charge removal operation is effective for the ion balance control immediately after the transition to the ion generation period or the charge removal operation. Prone to cause inappropriateness.

  Further, when a method in which a high voltage for ionization is not applied to the electrode needle 4 in the pause period of the pause mode is used, in order to optimize the ion balance control data including the pause period, some data before or before It is also appropriate to average the stored data, but it is inappropriate to include the data during the pause period in this data and to average the ion balance control immediately after shifting to the ion generation period or static elimination operation. It is easy to cause. Specifically, in the static eliminator, normally, the duty ratio for applying a positive high voltage and a negative high voltage to the electrode needle 4 is the single or plural duty ratios that were performed immediately before that. However, when this is adopted in the sleep mode including the pause period, there is a possibility that an appropriate duty ratio cannot be set. In order to avoid this, as shown in the flowchart of FIG. 24, the sampling of the data during the pause period is stopped, and the electrode to be started from now is based on the latest data in the past ion generation period or static elimination operation. It is preferable to reflect this in the control of high voltage application to the needle 4. Furthermore, it is preferable to average past data in order to optimize the ion balance control in this high voltage application.

  FIG. 24 is a flowchart executed in association with the pause modes (1) and (2) including the pause period and the ion generation period described in FIGS. 6 (a) and 6 (b). First, in step S50, the high voltage power supply is turned on, and in the next step S51, it is determined whether or not it is an ion generation period. If YES, that is, if a high voltage is applied to the electrode needle 4 and ions are generated, the process proceeds to step S52, and sampling of, for example, the duty ratio on the positive side and the negative side of the high voltage applied to the electrode needle 4 is performed. And stored in the memory as shown in FIG. Next, in step S53, the average value is calculated based on a predetermined number of sampling data, the average value is stored in the memory, and ion balance control is executed based on the average value.

  When the ion generation period is switched to the pause period, the process proceeds from step S51 to step 54 to turn off the high-voltage power supply, and then to the electrode needle 4 to be executed next based on the average value stored in the memory in step S55. The voltage value or duty ratio of the high voltage to be applied is determined, and this value is stored in the memory. When the pause period ends, a high voltage is supplied from the high voltage power source to the electrode needle 4 based on the voltage value or duty ratio determined during the pause period. That is, for example, the sampling of the duty ratio is not performed during the suspension period. FIG. 25 shows an example of digital processing, and data transfer to the memory may be prohibited during the suspension period.

  To optimize the ion balance control immediately after the transition from the pause period to the ion generation period, the ion balance of the static elimination target area during the pause period is detected and stored in memory, and this is constantly updated during the pause period. Taking into account the ion balance data of the static elimination target area at the end of the rest period, adding a correction to the voltage value or duty ratio determined during the above-described rest period, the corrected voltage value or duty ratio immediately after that You may make it perform control of voltage application.

  In this way, it is possible to determine a duty ratio and a high voltage value suitable for ion balance control immediately after the transition from the pause period to the ion generation period. In the pause mode that does not include the ion generation period (Fig. 7 (c) and (d)), the latest data of the duty ratio or high voltage value as a result of ion balance control executed during the static elimination operation is sequentially sampled. Immediately before starting the static elimination operation, the data saved during the most recent previous static elimination operation is averaged to determine the voltage value or duty ratio of the high voltage to be applied to the electrode needle 4 to be executed next. It is good to do. Thereby, averaging including zero applied voltage during the rest period can be avoided. In addition, the ion balance of the static elimination target area during the pause period is detected and stored in the memory, and this is constantly updated during the pause period, based on the data immediately before entering the static elimination operation described above. You may make it correct | amend the value determined as the voltage value or Duty ratio of the high voltage which should be applied to the needle | hook 4. FIG.

  The ion balance control during the ion generation period is based on the voltage value or duty ratio determined at the beginning of the ion generation period, for example, the voltage applied to the positive and negative electrode needles 4 in the first time during the pause period. In the next ion balance control, the voltage value or Duty ratio of the voltage to be applied to the positive and negative electrode needles 4 based on the current value flowing in the internal circuit, that is, the current value flowing in the internal circuit is applied in the next ion balance control. The ion balance control may be performed based on the feedback control. That is, at the beginning of the ion generation period, it is preferable to perform the ion balance control in a prospective manner based on the data determined during the pause period, and to perform the ion balance control by switching to the feedback control in the subsequent ion balance control. As a modified example, the ion generation period is initially controlled in a predictive manner based on the data determined during the pause period, and then determined during the pause period based on the current value flowing through the internal circuit. Ion balance control may be performed while correcting data.

  In the rest mode that does not include the ion generation period ((c) and (d) in FIG. 7), the value of the current flowing in the internal circuit related to the ion balance and the ion balance data related to the direction during the static elimination operation performed during the rest period. Is stored in a memory, for example, the ion balance data obtained as a result of applying a high voltage to the electrode needle 4 at the very end of the static elimination operation is used to execute the initial ion balance control in the next static elimination operation, and the subsequent ions The balance control may be switched to the feedback control described above, or the initial ion balance control of the subsequent neutralization operation is performed in a prospective manner using the ion balance data stored during the previous neutralization operation, and thereafter, You may make it perform ion balance control (for example, Duty ratio control), correct | amending based on the electric current value which flows into an internal circuit.

  The embodiment has been described above by alternately applying high voltages having different polarities to the common electrode needle 4 to alternately generate positive / negative ions. The present invention is also applied to a static eliminator that generates positive ions and negative ions by applying positive and negative high voltages to the electrode needles that are paired with a positive electrode and a negative electrode, which are described as an embodiment in FIG. It goes without saying that the same applies. Specifically, a self-discharge detection circuit is provided between the electrode needle of each of the positive electrode and the negative electrode and the ground, and when self-discharge is detected in one of the electrode needles, a high voltage similar to that in the static elimination mode is applied to the electrode needle. The static elimination operation may be executed by applying the voltage to the voltage. Of course, it is needless to say that a voltage that does not generate ions, that is, a voltage (for example, 2 kV) for increasing the sensitivity of detecting the charged body may be applied to the electrode needle during the pause period in the pause mode.

It is a circuit diagram contained in the static elimination apparatus of an Example. It is a figure which shows the modification of the circuit diagram contained in the static elimination apparatus of an Example. It is a figure for demonstrating an example of the system of the high voltage application in the static elimination mode in the static elimination apparatus which can selectively set static elimination mode and dormant mode. FIG. 10 is a diagram for explaining another example of a high voltage application method in a static elimination mode in a static elimination apparatus that can selectively set a static elimination mode and a pause mode. FIG. 10 is a diagram for explaining still another example of a high voltage application method in a static elimination mode in a static elimination apparatus capable of selectively setting a static elimination mode and a pause mode. It is a figure for demonstrating the example of the control aspect in a dormant mode including a dormant period and an ion generation period, (a) is a low level voltage which does not generate | occur | produce an ion in the dormant period in an idle mode. (B) shows an example in which no voltage is applied to the electrode needle during the pause period in the pause mode. It is a figure for demonstrating the example of the control aspect in the idle mode comprised only by the idle period which does not include an ion generation period, (c) is a low level of the grade which does not generate | occur | produce ion in an idle mode (interval period) An example in which voltage is applied to the electrode needle is shown, and (D) shows an example in which no voltage is applied to the electrode needle in the rest mode (rest period). It is a figure for demonstrating an example of the control which performs a static elimination operation by applying a high voltage to an electrode needle substantially in the same manner as the static elimination mode when a charged body is detected by the internal circuit of the static elimination device during the pause mode. An example of starting and stopping the static elimination operation using a threshold value will be described. It is a figure for demonstrating the other example which performs static elimination operation when a charged body appears during the idle period in idle mode, and shows the example where static elimination operation is stopped using a timer. It is a figure for demonstrating the further another example which performs static elimination operation when a charged body appears in the pause period in pause mode, and shows an example in which variable control of the timer time for stopping static elimination operation is performed. It is a figure for demonstrating the further another example which performs static elimination operation when a charged body appears during the idle period in idle mode, and shows the other example which performs variable control of the timer time which stops static elimination operation. FIG. 5 is a diagram for explaining an example in which a low-level voltage that does not generate ions is continuously applied to an electrode needle during a pause period in control for performing a static elimination operation during a pause period due to the appearance of a charged body. For explaining an example in which a pre-stage transition period is provided when the ion generation period or the static elimination operation ends and the transition to the rest period is performed, and in this pre-stage transition period, the voltage applied to the electrode needle is gradually decreased. (B) shows an example in which no voltage is applied to the electrode needle during the pause period, and (b) shows an example in which a low level voltage that does not generate ions is applied to the electrode needle during the pause period. Show. It is a diagram for explaining an example in which a transition period is provided when transitioning from an idle period to an ion generation period or a static elimination operation, and in this latter transition period, control is performed to gradually increase the voltage applied to the electrode needle. (A) shows an example in which no voltage is applied to the electrode needle during the pause period, and (B) shows an example in which a low level voltage that does not generate ions is applied to the electrode needle during the pause period. It is a figure for demonstrating the example which provides a front stage transition period when changing to the rest period from the end of an ion generation period or static elimination operation, and provides a back stage transition period when changing to an ion generation period or static elimination operation from a rest period. Yes, (a) shows an example in which no voltage is applied to the electrode needle during the pause period, and (b) shows an example in which a low level voltage that does not generate ions is applied to the electrode needle during the pause period. An external valve that supplies compressed air to the static eliminator of the embodiment is provided with an on-off valve or an opening adjustment valve, and an output signal generated by an internal signal used for controlling the static eliminator is supplied to the on-off valve or the opening adjustment valve. It is a figure for demonstrating the example which controls compressed air supplied to a static elimination apparatus. It is a figure explaining that an internal signal is produced | generated inside a static elimination apparatus synchronizing with this, in order to start and complete | finish static elimination operation | movement during an idle period by the appearance of a charging body. FIG. 8 is a control example in which a static elimination operation is performed when a charged body is detected by an internal circuit of the static elimination device during a pause period in a pause mode, and the static elimination operation is started and terminated using a threshold value. It is a flowchart of. FIG. 9 shows an example of control in which a static elimination operation is performed when a charged body is detected by an internal circuit of the static elimination device during a pause period of a pause mode, and the static elimination operation is started using a threshold value and terminated using a timer. It is a flowchart of the example of control. This is a control example in which the static elimination operation is performed when a charged body is detected by the internal circuit of the static eliminator during the pause period of the pause mode. The static elimination operation is started using a threshold value, and the timer is used to end the timer. It is a flowchart of the example of control of FIG. 10 which adjusts time. This is a control example in which the static elimination operation is performed when a charged body is detected by the internal circuit of the static eliminator during the pause period of the pause mode. The static elimination operation is started using a threshold value, and the timer is used to end the timer. It is a flowchart of the example of control of FIG. 11 which adjusts time. It is a figure for demonstrating the specific method of the ion balance control contained in the static elimination apparatus of an Example, (a) is an example of control when ion balance is biased to the plus side, (b) is ion balance It is an example of control when is biased to the minus side. It is a figure for demonstrating the specific method of the ion balance control contained in the static elimination apparatus of an Example, and shows the control example which changes the average value of plus / minus high voltage with the value equivalent to the deviation of ion balance. FIG. FIG. In the ion balance control of the static elimination apparatus which performs an idle mode including an ion generation period and an idle period, it is a flowchart which shows an example of the control example which stops sampling of the voltage value applied to an electrode needle during an idle period. FIG. 25 is a diagram for explaining that when data sampled during an ion generation period in FIG. 24 is stored in a memory, transfer to the memory may be canceled during a pause period by digital processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC power supply 2a switch 2b switch 3 Control unit 4 Electrode needle 5 Positive high voltage generation circuit 5a Transformer 5b Double voltage rectification circuit 6 Negative high voltage generation circuit 6a Transformer 6b Double voltage rectification circuit 7 Amplifier 8 Analog / digital converter 9 Low-pass filter 100 Static elimination device 12 Electrode unit 13 External piping 14 Valve R2 Second resistance

Claims (16)

A static elimination device that generates ions by applying a high voltage to an electrode needle,
A self-discharge detection circuit that detects self-discharge of the electrode needle when a high voltage is not applied to the electrode needle;
When the self-discharge detection circuit detects self-discharge of the electrode needle during the pause period including a pause period in which the electrode needle is paused, ions are generated by applying a high voltage to the electrode needle. A static eliminator which starts a static elimination operation and stops the static elimination operation when the neutralization of a charged body is completed, and returns to the idle period.   The static eliminator according to claim 1, wherein the self-discharge detection circuit includes a circuit that detects a value of a current flowing through the resistor by providing a resistor between the electrode needle and the high voltage generation circuit.   2. The static eliminator according to claim 1, wherein the self-discharge detection circuit includes a circuit that detects a value of a current flowing through the resistor by providing a resistor between the electrode needle and the ground.   The static elimination apparatus according to claim 2 or 3, wherein the static elimination operation is started when an absolute value of a current value flowing through the resistor exceeds a first threshold value.   The static elimination operation is stopped when the absolute value flowing through the resistor falls below a second threshold value, and returns to the pause period in which the electrode needle is paused. The static elimination apparatus of description.   The static elimination apparatus according to any one of claims 1 to 5, wherein the static elimination operation is stopped after a predetermined time has elapsed since the static elimination operation is started, and returns to the pause period in which the electrode needle is paused. A peak value detecting means for detecting a peak value of the current flowing through the resistor;
The predetermined time is adjusted by the magnitude of the absolute value of the peak value detected by the peak value detecting means,
The predetermined time is extended when the absolute value of the peak value is large compared to when it is small, and the predetermined time is shortened when the absolute value of the peak value is small compared to when it is large. Static eliminator. A peak value detecting means for detecting a peak value of an absolute value of a current flowing through the resistor;
Current value reduction speed detection means for detecting the speed at which the current flowing through the resistor decreases when the absolute value of the peak value decreases,
The predetermined time is adjusted according to the decrease rate of the absolute value of the current detected by the current value decrease rate detection means,
The predetermined time is extended when the rate of decrease of the absolute value of the current is small compared to when it is large, and the predetermined time is shortened when the rate of decrease of the absolute value of the current is large compared to when it is small. The static eliminator described in 1.   The static eliminator according to any one of claims 1 to 8, wherein a high voltage is not applied to the electrode needle during the pause period.   9. The static eliminator according to claim 1, wherein a voltage having a value that does not generate ions around the electrode needle is applied to the electrode needle during the pause period.   The value of the voltage applied to the electrode needle is gradually reduced when returning to the pause period after the static elimination operation for applying a high voltage to the electrode needle is performed in the pause mode. The static elimination apparatus as described in any one of Claims.   The value of the voltage applied to the electrode needle is gradually increased when performing a static elimination operation for applying a high voltage to the electrode needle from the pause period in the pause mode. The static eliminator described in the paragraph.   The pause mode includes the pause period and an ion generation period in which ions are generated by applying a high voltage to the electrode needle, the ion generation period being set at a predetermined interval, and the electrode in the pause period The cycle of claim 1-12, wherein a needle is paused, and then a high voltage is applied to the electrode needle during an ion generation period to generate ions, and then the electrode needle is paused during a pause period. The static elimination apparatus as described in any one of Claims.   14. The static eliminator according to claim 13, wherein in the pause mode, a value of a voltage applied to the electrode needle is gradually decreased when the ion generation period shifts to the pause period.   15. The static eliminator according to claim 13 or 14, wherein in the pause mode, a value of a voltage applied to the electrode needle is gradually increased when shifting from the pause period to the ion generation period.   In addition to the pause mode, there is a static elimination mode in which a high voltage is applied to the electrode needle to generate ions, and the static elimination mode and the pause mode can be selectively set. The static elimination apparatus as described in any one of.

Images