JPH03266398A - Ion balance control device of static electricity eliminator - Google Patents

Abstract

PURPOSE:To control ion balance with high accuracy by directly detecting an ion current with a current detection electrode provided between a positive electrode and a negative electrode to adjust voltage of the electrodes and pulse width basing polarity and an ion quantity. CONSTITUTION:A current detection electrode 9 is arranged between a positive electrode 1 and a negative electrode 2 to directly detect an ion current flowing between the electrodes 1 and 2. The ion current shows positive polarity in case of more positive ions while showing negative polarity in case of more negative ions according to a difference of ion quantity. Accordingly, the difference in detected polarity and ion quantity of the ion current is measured by a control device 8 to adjust voltage and pulse width to be impressed on one electrode of the electrodes 1 and 2 in accordance with a measured value. Thereby, even if the ion current is changed by an external factor due to contamination of the electrode or the like, ion balance is directly measured to enable highly accurate balance control to be performed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention is an ion balance control device for generating equal amounts of positive and negative ions in a static eliminator that generates positive and negative ions by applying positive and negative high voltages to a positive electrode and a negative electrode, respectively. Regarding.

[Conventional technology]

A conventional ion balance device of this type, as disclosed in Japanese Patent Application Laid-Open No. 61-290699, includes a voltage dividing resistor connected to a voltage storage resistor connected to the output of a plus/minus voltage generator. Connect these resistors to form a voltage divider, and take advantage of the fact that the current flowing through the voltage dividing resistor changes when the voltage of the picture sho voltage generator becomes unbalanced. Those that detect balance are known.

[Problem to be solved by the invention]

However, this only detects output fluctuations of the plus and minus voltage generators, and cannot detect changes in the ion current due to external factors such as the plus and minus electrodes becoming dirty. Therefore, it is not possible to directly detect whether the amounts of plus and minus ions currently being generated are balanced, and highly accurate ion balance control cannot be performed. The purpose of the present invention is to accurately detect changes in ion current caused by external factors such as soiling of the positive and negative electrodes.
The objective is to enable highly accurate ion balance control.

[Means for Solving the Problems] An ion balance control device according to the present invention includes a current detection electrode disposed between a positive electrode and a negative electrode, and an ion current for measuring an ion current detected by the current detection electrode. The device includes a measuring circuit and an adjusting circuit that adjusts the voltage or pulse width applied to at least one of the positive electrode and the negative electrode according to the measured value. Furthermore, this ion balance control device is equipped with a pulse voltage application circuit that alternately applies a positive pulse voltage to the positive electrode and a negative pulse voltage to the negative electrode, and the ion current measuring circuit is a pulse voltage application circuit. The ionic current can be configured to be measured when a positive pulse voltage is applied and when a negative pulse voltage is applied. In this case, it is possible to further include an alarm circuit that issues an alarm when the ion current measured by the ion current measurement circuit is below a predetermined value.

[For production]

A current detection electrode placed between the plus electrode and the minus electrode directly detects the ionic current flowing between the plus electrode and the minus electrode. The ion TL flow becomes positive when there are many positive ions, and becomes negative when there are many negative ions, and corresponds to the difference in the amount of positive and negative ions. Therefore, by measuring this detected ion current with an ion current measuring circuit, it is possible to detect the difference in polarity and ion amount, and depending on the measured value, the voltage is applied to at least one of the positive electrode and the negative electrode. By automatically adjusting the voltage or pulse width using an adjustment circuit, positive and negative ion balance can be achieved automatically.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. In Fig. 1, the static eliminator itself has a needle-shaped positive electrode 1 and a negative electrode 2 which are arranged facing each other at a predetermined interval, and the positive high voltage generated in the positive and negative high voltage generating circuits 3.4 and the negative This is a known structure in which a high voltage is rectified by each rectifier circuit 5 and 6 and applied to the positive electrode 1 and the negative electrode 2, respectively, to generate positive ions and negative ions to neutralize the charged object. In such a static eliminator, the ion balance control device 8 according to the present invention arranges a current detection electrode 9 in the form of two needles between the positive electrode 1 and the negative electrode 2, and detects an ion current with the current detection electrode 9. Digitally measured by a microcomputer, and a high voltage generating circuit of plus or minus according to the measured value 3.4
This ion balance control device 8 is specifically shown in FIG. 2. In FIG. 2, the ion current detected by the current detection electrode 9 is amplified by two stages of amplifier circuits 10 and 11.
At point a on the output side of No. 1, a third
A voltage with the characteristics shown in the figure is generated. That is, when the positive ions and negative ions between the positive and negative electrodes 1.2 are the same, the line is a solid line, when there are many positive ions, the line is a dashed-dotted line, and when there are many negative ions, the line is a dotted line. The output of the amplifier circuit 11 is level-shifted by a level shift circuit 12 as shown in FIG. 4 for the next analog-to-digital conversion, and then converted into numerical data by an A-D converter circuit 14 via a sample/hold circuit 13. converted. The numerical data of the 0 point after A-D conversion is the maximum value when there are many positive ions, for example FFH (hexadecimal), 80H when positive ions and negative ions are at the same time, and the minimum value when there are many negative ions. It is determined to be OOH. A
The D-converted numerical data is input to the microcomputer through the input terminal of I10 port 15, and the CP
Under the control of U16, the data is stored in RAM 17 as described below, and the polarity and numerical value of the ion current detected by current detection electrode 9 are finally measured by CPU 16. Then, the control amount of the plus/minus high voltage generation circuits 3 and 4 is calculated from the measured value, and the numerical data is outputted from the output terminal D2 of the I10 port 15. In addition, code 1
8 is a ROM. The control amount (numerical data) output from the output terminal Dz is D
- Converted to an analog voltage by the A conversion circuit 19,
After being amplified by the amplifier circuit 20, the level is shifted by the level shift circuit 21. Now, the numerical data at point d before D-A conversion is FFH as the control amount for the maximum value when there are many positive ions, 808 as the control amount when positive ions and negative ions are the same, and 808 when there are many negative ions. If OOH is the control amount for the minimum value, the voltages at point e amplified by the amplification circuit 820 in three cases are, for example, IOV, 5■, and 0■, respectively, and the level-shifted voltages at point f are IIV and 16V, respectively. ,
It becomes 21■. The positive and negative high voltage generating circuits 3 and 4 are adjusted by the corresponding voltage regulators 22 and 23 to determine the voltage value to be applied to each electrode 1.2, but in this example, the voltage value applied to the negative electrode The voltage applied to electrode 2 is kept constant, and the voltage applied to only positive electrode 1 is varied to achieve ion balance. Therefore, the output of level shift circuit 21 is input to voltage regulator 22 on the positive side, but the voltage on the negative side is It is not input to the regulator 23. The output of the voltage regulator 22 on the positive side changes in the range of, for example, 15V to 24V according to the voltage from the level shift circuit 21, but the voltage regulator 23 on the negative side is constant (eg, 18V). By the way, in this ion balance control device, there is a DC static elimination mode in which positive and negative DC high voltages are applied to the positive and negative electrodes 1.2, respectively, as shown in Figure 5, and a positive electrode 1.2 as shown in Part 6. Apply a positive pulse voltage to electrode 1, and apply a negative pulse voltage to negative electrode 2.
Pulse static electricity removal mode in which negative voltage is applied alternately is
It can be switched by the pulse static elimination changeover switch 24, and in the case of the pulse static elimination mode, both chamber pressure regulators 22 and 23 alternate between OV and the above voltage value. The on/off signal of the switch 24 is I
/○ is input to the CPU 16 through the input terminal D3 of the eye 5. In the above configuration, if, for example, dust or the like adheres to the positive or negative electrode 1.2, the amount of change in the positive ion current and the amount of change in the negative ion current will be different, causing the positive and negative ions to become unbalanced. Therefore, a voltage with the characteristics described above is generated at point a, which is converted into numerical data and taken into the microcomputer. For example, the numerical data is 85, which is higher than the balance point of 80H.
If it is H, it is determined that there are many positive ions, and numerical data larger than 80H is output to the DA conversion circuit 19. As a result, the voltage at point f changes to a lower value, and the output voltage of the voltage regulator 22 decreases. When this decreases, the voltage of the positive high voltage generating circuit 3 also decreases accordingly. At this time, since the voltage of the negative high voltage generating circuit 4 is constant, ion balance can be maintained. By the way, in the case of DC static elimination, a high voltage is always applied to the positive electrode 1 and negative electrode 2 as described above, so the difference between the initial ionic current when these electrodes are clean and the ionic current when these electrodes are contaminated is It is not possible to determine the amount of change. Therefore, with only the above configuration, ion balance can be achieved, but a decreasing trend in the amount of ions cannot be detected in the DC static elimination mode. Therefore, in this ion balance control device, even in the DC static elimination mode, changes in the amount of ions can be detected by the following configuration, which will be explained next. At point g in FIG. 2, a clock pulse of a constant period as shown in FIG. 7(A) output from the oscillator 25 is counted by a counter 26, and two types of frequency-divided pulses are output be done. That is, a pulse as shown in FIG. 7(B) is output from one point h, and this pulse is input to the sample ho 4) circuit 13 as a sample/hold control signal, and is also used to confirm the sample/hold. For I10 port 5 input terminal D
It is also input to the CPU 16 through 6. Note that the signal is input to the sample hold circuit 13 after being inverted by a NOT circuit 27 . The other point outputs a pulse as shown in FIG. The signal is inverted by the knot circuit 28 and becomes a pulse at point j as shown in FIG. 3D, which is similarly input as an on/off signal. Further, the pulse from one point is input to the CPU 16 through the input terminal D7 of the I10th board 5 as a signal for determining whether the measured ion current is positive or negative. The pulses of (C) and (D) in the figure are input to the voltage regulator 22.23 via the gate circuit 29.30, respectively, and the voltage regulator 22.23 due to these pulses is input to the voltage regulator 22.23 through the gate circuit 29.30.
is turned on and off only when the pulse neutralization control signal (signal at point k) shown in FIG. In addition, these voltage regulators 22 and 23 are both forcibly turned off when the high voltage stop signal (one point signal) shown in FIG. Application of high voltage to both negative electrodes 1 and 2 is stopped. I10 boat 15
A buzzer 31 for warning of deterioration of static electricity removal performance is connected to the output terminal D11 of the
A cleaning alarm lamp 32 is connected to the output terminal. In addition, the output terminal D4 of the I/○ boat 15
Signals from D, D, , D, are also obtained from the CPU 16. In order to measure the ion current detected by the current detection electrode 9 at regular intervals, the 7th V (E) pulse neutralization control signal (k
Point signal) is a constant cycle! iJ] (For example, output at intervals of one hour or several minutes. When this becomes HIGH,
The pulses in (C) and (D) in the same figure are the voltage regulator 22.
．． 23, and the positive and negative high voltages applied to the positive and negative electrodes 1.2 are alternately turned on and off to perform pulse static elimination. In this case, the CPU 16 confirms the inversion of the pulse shown in FIG. 4B, takes in the numerical data (ion current) from the A-D conversion circuit 14 when it is HIGH, and stores it in the RAM 17. In addition, the pulse shown in the same figure (C) is also taken in, and it becomes HI.
A-D conversion circuit 14 depending on whether it is GH or LOW.
It is determined whether the numerical data (ion current) from 2 is the one when a positive high voltage is applied or the one when a negative high voltage is applied. Then, the CPU 16 compares the numerical data with the balance point of 808, and adjusts the control according to the difference.
The amount is outputted to the DA conversion circuit 19 as described above, and ion balance control is performed. As the ion current decreases due to dirt on the positive and negative electrodes 1.2, the numerical data from the A-D conversion circuit 14 gradually moves away from the balance point of 80H, so the percentage decrease from the initial value changes over time. can be judged. For example, as shown in Figure 8, the balance point of positive and negative ion currents is
The maximum value of B is the negative ion at the beginning of FFH1.The maximum value of KB is 00H, and when the positive ion current is COH and the negative ion current is 40H (50% 11 less than the maximum value), the cleaning alarm point is the positive ion. If the current is AOH and the negative ion current reaches 60H (70% decrease from the maximum value) as the forced stop point, a cleaning alarm signal will be output from the output terminal of I10 port 15 when the current decreases below the cleaning alarm point. When the voltage decreases below the forced stop point, a stop signal is output from the output terminal D4, a performance deterioration alarm signal is output from the output terminal Dq, and the high voltage application to the positive and negative electrodes 1.2 is stopped. At the same time, the buzzer 31 can be sounded. Next, the flow of the above-mentioned control performed by the CPU 164 will be explained with reference to the flowcharts shown in FIGS. 9 to 13. In FIG. 9 (main routine), in step 50 I
After initializing the 10th port 5, in step 51, the balance value 80H is output from the output terminal D2 to the D-A conversion circuit 19, and it is transferred to the first port of the RAM 17.
It is stored in the memory, and in the next step 52 the output terminal D4 is
After setting the output of the HIGH1 output terminals Ds, Da, and LOW to LOW, step 53 takes in the input of the input terminal D3, and step 54 determines whether it is LOW or HIGH2.
That is, it is determined whether the DC/pulse static elimination switch 24 is on the DC static elimination side or the pulse static elimination side. In the case of pulse static elimination, the routine goes to the pulse static elimination routine shown in FIG. 10, and in the case of DC static elimination, the routine goes to the DC static elimination routine shown in FIG. 11. In the case of the pulse static elimination shown in FIG. 10, in step 60, HIGH is output from the output terminal to set the pulse static elimination mode, and then in step 61, the test subroutine shown in FIG. 13 is called. That is, the magnitude of the ion current when the DC/rO-less static elimination changeover switch 24 is switched is checked as described below. After setting a timer (for example, 30 minutes) in the next step 62, the measurement subroutine shown in FIG. 12 is called in step 63. When this is called, in FIG. 12, first in step 80 it is determined whether the input to the input terminal is H[; , that is, the numerical data from the A-D conversion circuit 14,
Store it in the second memory. Next, in step 82, whether the input of input terminal D7 is LOW,
In other words, it is determined whether the positive high voltage is being applied, and if the positive high voltage is being applied, it is determined again in step 83 whether it is the sample hold period, and if it is the sample hold period, the signal from the AD conversion circuit 14 is determined in step 84. The numerical data is taken in again and stored separately in a third memory. After this, in step 85, the input of input terminal D7 becomes HI.
GH, that is, whether or not a negative high voltage is being applied, and if it is a negative high voltage being applied, step 86
Next, the deviation from the balance point for both the positive and negative poles, that is, the calculation of subtracting the balance point 80H from the contents of the second memory, and the calculation of subtracting the contents of the third memory from 80H are calculated. Now (contents of second memory)
-80H=A, 80H-(contents of third memory)=B. In the next step 871, it is determined whether A=B, and A=B
If so, return, otherwise stay. Determine whether A>B or A<B at step 87□, and then
If B, the contents of the first memory are counted down in step 88 and the process returns; if A<B, the contents of the first memory are counted up in step 89 and the process returns. In this way, after going through the measurement subroutine, the process proceeds from step 63 in FIG. 10 to Step 4, where the contents of the first memory
That is, the control amount is outputted from the output terminal D2 to the DA conversion circuit 19 to control the voltage regulator 22 as described above. Next, in step 65, it is determined whether A=B, and A=B
If so, that is, if the deviation from the balance point is equal to plus or minus, the inspection subroutine of FIG. 13 is called, the process returns to step 62, and steps 63 to 66 are repeated at the time period set by the timer. When the inspection subroutine shown in FIG. 13 is called, the output of the output terminal is set to HIGH in step 90 to set the pulse charge removal mode, and then the measurement subroutine shown in FIG. Numerical data of the negative ion current is stored in a second memory and a third memory, respectively. Next, in step 92, it is determined whether the DC/pulse static elimination switch 24 is on the DC static elimination side or the pulse static elimination side, and if it is on the DC static elimination side, the output terminal is switched on in step 93.
After setting the output to LOW and returning to the DC static elimination mode, step 94 determines whether the contents of the second memory are below COH. At step 95, it is determined whether the contents of the third memory have decreased to 40H or more, that is, whether the positive and negative ion currents have decreased to the point where they exceed the cleaning alarm point. If it has not decreased, it returns as is, but if it has, then in step 96 it checks whether the contents of the second memory are less than AOH, and in step 97 it checks whether the contents of the third memory are more than 60H, that is, plus or minus. Determine whether the ionic current of has decreased to a point beyond the forced stop point. When the cleaning alarm point is exceeded, the output of the output terminal is set to H in step 98.
When the forced stop point is exceeded, the output of the output terminal D4 is set to LOW to stop the high voltage application, and at step 100, the output of the output terminal is set to HIGH and the buzzer 31 is activated. Make it ring. In the case of DC static elimination in FIG. 11, after setting the output of the output terminal D5 to LOW in step 70 and setting the DC static elimination mode,
In step 71, the test subroutine is called to test the ion current when the DC/pulse static elimination switch 24 is switched as described above, and in step 72, the timer is set. After this, in step 73, the output of the output terminal RI is set to HIGH.
Temporarily switch to pulse neutralization mode, call the measurement subroutine, measure the positive and negative ion currents in the same way as above, and find the deviation from the balance point.
In step 74, the content of the first memory, that is, the control amount, is outputted from the output terminal D2 to the DA conversion circuit 19 to control the voltage regulator 22 in the same manner as described above. Next, step 7
In Step 5, judge whether A=B, and if A=B, that is, if the deviation from the balance point is the same plus or minus, then in Step 7B, set the output of the output terminal LOW to LOW and return to DC static elimination mode. After that, the test subroutine is called in step 77, and the process returns to step 72, and steps 73 to 77 are repeated at the time period set by the timer. In addition, in the above example, ion balance was achieved by adjusting only the voltage applied to one of the positive and negative electrodes (the positive electrode), but it is also possible to adjust both electrodes, and the voltage can also be adjusted. Ion balance can also be achieved by adjusting the Hals width instead.

【Effect of the invention】

As described above, the present invention directly detects the ionic current flowing between the positive electrode and the negative electrode with a current detection electrode placed between the positive electrode and the negative electrode, and uses the ionic current measurement circuit to measure the value. Measure and according to that measurement,
An adjustment circuit automatically adjusts the voltage or pulse width applied to at least one of the positive electrode and the negative electrode. Therefore, even if the ion current changes due to external factors such as the positive and negative electrodes becoming dirty, it is possible to directly detect whether or not the currently generated positive and negative ions are harassing. Ion balance control can be performed. According to the second aspect, it is possible to detect a change in the ion current over time, and according to the third aspect, an alarm can be issued when the ion current decreases to a predetermined value or less. A block diagram of an example of a balance control device. Fig. 3 is a graph showing the output voltage at point a in Fig. 2, Fig. 4 is a graph showing the output voltage at point b, and Fig. 5 is a graph showing the output voltage at point b in Fig. 2. Fig. 5 is a graph showing the output voltage at point b in Fig. 2. A waveform diagram of the voltage applied to the positive and negative electrodes, Figure 6 is a waveform diagram of the applied voltage during positive charge removal, and Figures 7 (A) to (F) are output waveform diagrams at points g-E in Figure 2. , FIG. 8 is a graph showing the dark values of each control with respect to the measured value of the ion current, and FIGS. 9 to 13 are flowcharts showing the flow of control by the CPU. 1...Positive electrode, 2...Minus electrode, 9...Current detection electrode, 16...CP
L, ', 2223・old・voltage regulator, 25・・
...Oscillator, 26...Counter, 31...
...Buzzer for warning of deterioration of static electricity removal performance, 32.Old...Lamp for cleaning warning.

[Brief explanation of drawings]

111i4 is a conceptual diagram showing the relationship between the ion balance control device and the static eliminator according to the present invention. Voltage diagram (A) Figure (79) Figure CD> Figure CE) Chrysanthemum diagram CF)

Claims (1)

[Claims] 1. In a static eliminator that generates positive and negative ions by applying positive and negative high voltages to a positive electrode and a negative electrode, respectively, a static eliminator disposed between the positive electrode and the negative electrode. a current detection electrode, an ion current measurement circuit that measures the ion current detected by the current detection electrode, and a voltage or pulse that is applied to at least one of the positive electrode and the negative electrode according to the measured value. An ion balance control device for a static eliminator, comprising an adjustment circuit for adjusting width. 2. A pulse voltage application circuit that alternately applies a positive pulse voltage to the positive electrode and a negative pulse voltage to the negative electrode, and the ion current measurement circuit applies a positive pulse voltage by the pulse voltage application circuit. 2. The ion balance control device for a static eliminator according to claim 1, wherein the ion current is measured both when applying the negative pulse voltage and when applying the negative pulse voltage. 3. The ion balance control device for a static eliminator according to claim 2, further comprising an alarm circuit that issues an alarm when the ion current measured by the ion current measurement circuit is below a predetermined value.