JP2011238575A - Power supply device of surface creepage discharge type ion generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface creepage discharge type positive ion generating device capable of lower power consumption, reducing the degradation of the positive ion generating element, and extending the service life due to the specification of the power supply in comparison with a conventional generating device.SOLUTION: Surface creepage discharge is caused by pulse wave 1 having negative polarity, and positive ion is emitted by direct current (DC) bias 2 having positive polarity. The specification of the power supply is configured to superimpose the two types of voltage.

Description

  The present invention relates to a high-voltage power supply waveform of a creeping discharge ion generator having a charge eliminating function, a charging function, or an environment improving function.

  In general, the creeping discharge type ion generator releases ions from an ion generating element and has a charge eliminating function, a charging function, or an environment improving function. In the ion generating element, a discharge electrode and an induction electrode are disposed on the front and back sides with a dielectric interposed therebetween, and by applying a high frequency high voltage between both electrodes, creeping discharge is caused in the discharge electrode, Release negative ions and positive ions.

  Insulators such as laminated mica, glass, and ceramic are used for the dielectric of the ion generating element, and metal foil and conductive paint are used for the discharge electrode and the induction electrode. In addition, on the surface on which the dielectric discharge electrode is formed and on the discharge electrode, an insulating resin material serving as a protective layer is provided for preventing damage due to deterioration of the dielectric and the discharge electrode and preventing oxidation and moisture absorption of the dielectric. Is coated. For the protective layer, a hard coat layer made of a glass-based or silicon-based hard coat material that is resistant to deterioration due to electric discharge or ozone is used, so that stable discharge is performed over a long period of time.

  A pulse wave is generally used for the high-frequency high-voltage power supply of the creeping discharge ion generator, the pulse width is 0.5 to 10 μsec, the number of pulses is 100 to 1000 pps, and the peak value is 1000 to 3000 Vpp. In the case of a positive ion generator, a positive pulse wave is used, and in the case of a negative ion generator, a negative pulse wave is used, and a positive and negative DC bias is superimposed on each. Its magnitude is adjusted to 30-40% of the pulse peak value. Further, when the polarity is negative, negative ions are released, and when the polarity is positive, positive ions are released.

  Here, in the case of a negative ion generator, when a negative high voltage pulse wave is applied to the discharge electrode, there are many free electrons in the metal foil or conductive paint of the discharge electrode, and the electrons are likely to jump out. Even if it is low, a large amount of plasma space can be formed around the discharge electrode, and some negative ions are released by a negative DC bias. The remaining negative ions are absorbed by the protective film of the dielectric layer.

  Conversely, in the case of a positive ion generator, when a positive high-voltage pulse wave is applied to the discharge electrode, the initial electrons at the start of discharge jump out of the dielectric layer and form a plasma space toward the discharge electrode. However, the dielectric and the protective film are insulators and have a small number of electrons. Further, since the work function for the electrons to jump out is large, a large energy is required and a high voltage needs to be applied. Some positive ions in the plasma space are ejected by a positive DC bias. The remaining positive ions are impact-absorbed by the protective film of the dielectric layer. Since positive ions have about twice the mass of negative ions, the dielectric layer is greatly damaged, and the durability life is significantly reduced compared to negative ion generators.

  The dielectric of the ion generating element gradually deteriorates due to discharge of these electrons and collision of ions. The insulator is oxidized, and voids are generated or the shape becomes irregular, or the organic bond is broken and becomes conductive. In addition, the discharge electrode is metallic, but if the conductivity decreases or the shape becomes uneven due to adhesion of oxide or nitrogen oxide, the original discharge is hindered, so that creeping discharge is less likely to occur. Will have to be raised. And even if the voltage is finally increased, no discharge occurs and the endurance life is reached.

  Creeping discharge type ion generators frequently clean the ion generating elements to remove the generated degradation products, and regularly replace them as replacement parts. In particular, the deterioration of the positive ion generator is remarkable compared to the negative ion generator, and the frequency of maintenance is increased.

  In particular, when a creeping discharge ion generator is used as a static eliminator, it is necessary to operate a positive ion generator and a negative ion generator at the same time, and the positive ion generator must be replaced earlier than the negative ion generator. As a result, it is necessary to manage the replacement timing, which significantly impedes productivity.

  An object of the present invention is to provide a high voltage power supply specification for a positive ion generator having a long durability life.

  The high-voltage power supply specification of the positive ion generator of the present invention is to emit positive ions by superimposing a positive DC bias on a negative pulse wave.

  According to this, a negative high voltage pulse wave is applied to the discharge electrode, and electrons are emitted from it. Since the discharge electrode is a metal system, there are many free electrons and electrons are ejected at a low voltage, resulting in creeping discharge and high density. A plasma space is formed in the space around the discharge electrode. Then, positive ions are released to the outside by a positive DC bias applied to the discharge electrode. Since this positive DC bias is direct current, it does not contribute to the occurrence of creeping discharge. The dielectric electrode collides with the dielectric protective film because the induction electrode is relatively positive compared to the discharge electrode, and thus is a negative ion, and is less damaged than the positive ion. Accordingly, it is possible to provide a positive ion generating element having a long durability life.

  The high-voltage power supply specification preferably has a pulse width of 0.5 to 10 μsec, a pulse peak value of 1000 to 3000 Vpp having a negative polarity, and a DC bias of +300 to 1200 V.

  According to the high voltage power supply specification for the positive ion generating element of the present invention, electrons can be easily ejected from a metal-based discharge electrode with many free electrons to form a high-density plasma space, and damage to the discharge electrode and oxidation deterioration can be prevented. . Moreover, deterioration of the dielectric near the discharge electrode can be prevented. Thus, a positive ion generating element with a low applied voltage and a long durability life can be provided.

It is a power supply specification for plus ion generators concerning the present invention. It is the conventional power supply specification for an ion generator, (a) is for a positive ion generator, (b) is the power supply specification for a negative ion generator. It is a graph which shows the relationship between an applied voltage and static elimination time. It is a graph which shows the result of a durability test.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a specification of a high voltage power supply for a positive ion generator according to the present invention, which is a waveform obtained by folding a pulse wave 1 and a DC bias 2.

  The pulse wave 1 is negative and has a peak value of −1800 Vpp. This is preferably −1000 to −3000 Vpp. Many negative discharges occur near this peak.

  The pulse width is 1 μsec and the frequency is 300 pps. The pulse width is preferably 0.5 to 10 μsec and the frequency is preferably 100 to 1000 pps. The discharge is generated in this cycle. The shorter the pulse width, the better the efficiency.

  The DC bias 2 is positive and is + 630V. This is preferably 30 to 40% of the pulse peak value. This DC bias releases positive ions to the outside.

  FIG. 2 shows power supply specifications of a conventional plus ion generator and a minus ion generator, which are shown as a comparative example. The power source of the positive ion generator is a combination of a positive pulse wave and a positive DC bias, and the power source of the negative ion generator is a combination of a negative pulse wave and a negative DC bias.

  Next, specific examples are shown in FIGS. 3 and 4 together with comparative examples. FIG. 3 is a graph showing the relationship between the applied voltage and the static elimination time. The vertical axis represents the static elimination time, and the horizontal axis represents the applied voltage. FIG. 4 is a graph showing the results of the durability test, where the vertical axis represents the applied voltage and the horizontal axis represents the durability time. The static elimination time refers to the time required for ions discharged from the ion generating element to discharge the potential of the plate to 100 V after placing a 15 cm square plate charged to 1000 V at a position 5 cm away from the ion generating element. is there.

  As shown in FIG. 3, in the conventional negative ion generator, since the discharge electrode is a metal, electrons are easily emitted, and since the negative ions are light, they are easily released to the outside, and the time for static elimination is the shortest. In the conventional positive ion generator, electrons are ejected from the dielectric material of the insulator, but the obstacles are large and difficult to eject, and the positive ions are heavy and difficult to be released to the outside. The positive ion generator according to the present invention forms a plasma space with a negative pulse wave in the same discharge form as the negative ion generator and emits positive ions with a positive DC bias, resulting in a conventional positive ion generator. And the negative charging time between the negative ion generator.

  Next, the durability test will be described with reference to FIG. This shows the transition of the applied voltage when feedback control is performed so that the static elimination time is 1 second. When the applied voltage becomes 3 kVpp or more, it is determined that the endurance life of the ion generating element has been reached.

  As shown in FIG. 4, the lifetime of the positive ion generator is short, about 2000 hours, whereas the negative ion generator has a low initial voltage and a lifetime of 5000 hours or more. The lifetime of the positive ion generator according to the present invention is in the middle of 4000 hours or more.

  Thus, in the power supply specification of the present invention, it is possible to generate positive ions at a lower voltage than the conventional product, and there is less damage deterioration of the dielectric, and the durability life is extended.

  The results of FIGS. 3 and 4 are summarized in Table 1. The static elimination voltage in Table 1 is the static elimination time when a 15 cm square plate charged to 1000 V is placed at a position 5 cm away from the ion generating element, and then the ions discharged from the element bring the potential of this plate to 100 V. It is the drive voltage of the ion generating element which shows 1 second. The endurance time is the time until the applied voltage becomes 3 kVpp or more when feedback control is performed so that the charge removal time is 1 second.

  In the conventional positive ion generator, it is difficult for electrons to jump out, so the voltage for generating the plasma space has to be increased, and since the positive ions are heavy, the driving voltage has to be increased in order to release them. Therefore, the initial slow voltage is as high as 1.9 kVpp.

  On the other hand, in the conventional negative ion generator, electrons are likely to jump out, so that the plasma space density becomes high and the voltage may be low. In addition, since negative ions are light, the driving voltage may be low. As low as 5 kVpp.

  The positive ion generator according to the present invention is a discharge driving voltage of a negative ion generator in which electrons are likely to jump out. However, since positive ions are released by positive DC bias driving, the initial slow voltage is intermediate between the above. It was 1.8 kVpp.

  Further, the conventional plus ion generator has a durability time of about 3000 hours, because heavy plus ions collide with the dielectric material, so that the dielectric material is greatly deteriorated and damaged and it is difficult for electric discharge to occur early.

  In the conventional negative ion generator, since the light negative ions collide with the dielectric, the deterioration and damage of the dielectric are small, and the discharge occurs continuously for a long time, and the durability time is 5000 hours or more.

  Table 2 shows an example of ionic species of air generated by discharge and its relative mass. Looking at the average value of the relative mass at which several types of ions are generated, the mass of positive ions is about twice that of negative ions. For this reason, positive ions are difficult to be emitted even by an electric field of DC bias, and when they collide with a dielectric, they cause great damage and damage.

  Even in the positive ion generator using the high voltage power supply for the positive ion generator according to the present invention, in order to release the positive ions, it is necessary to increase the voltage as compared with the negative ion emission. The deterioration damage given is small, so the deterioration damage on the discharge surface is smaller than that of the conventional product and the durability time is 4000 hours or more.

1 Pulse wave 2 DC bias

Claims (4)

  A creeping discharge positive ion generator comprising a dielectric, a discharge electrode formed on the front and back of the dielectric, and an induction electrode, wherein a negative discharge voltage and a positive DC bias voltage are superimposed. .   2. The power supply device according to claim 1, wherein the negative discharge voltage is a negative pulse wave and has a peak value of 1000 to 3000 Vpp.   The power supply apparatus according to claim 1, wherein the DC bias voltage is 30 to 40% of a discharge voltage.   The power supply device according to claim 2, wherein the pulse wave of the negative discharge voltage has a width of 0.5 to 10 µsec.

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