JPH04238056A - Solid ion generator - Google Patents

Abstract

PURPOSE:To enable mass production of an ion recording head capable of recording at high speed to be performed by controlling an amount of ions by a method wherein a dielectric is composed of at least two kinds of dielectric layers for a generator of corona ion by impressing a.c. voltage between a dielectric electrode and an ion generating electrode. CONSTITUTION:A dielectric electrode 101 consisting of a sintered gold electrode is installed by a necessary length (A4) in a paper surface direction on a ceramic substrate (as not given in the figure) by thick film printing technique and sintering technique. A glass layer 102 which is electrically large in withstanding voltage and which generates deterioration phenomena by irradiation of ions is installed thereon. A polyimide layer 103 which is little in generation of deterioration phenomena by irradiation of ions and large in insulating resistance is applied onto the thick film glass layer 102 by using spinner application technique. Thereafter, in order to form an ion generation electrode with an about 100mum thick slit 104 for generation of ions in the paper surface direction, a nickel layer 105 which is intensive in joining force with polymide is provided and besides, an ion generating electrode 106 is formed thereon by plating technique.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the generation of charged particles in air, and more particularly to an ion generator that generates ions at high density.

0002

BACKGROUND OF THE INVENTION Examples of ion generation in the air used in recording technology include corona discharge and spark discharge. Corona discharge is widely used in electrophotographic copying machines to uniformly charge a photoreceptor or to transfer a toner image to transfer paper. However, in normal corona discharge, the amount of ions generated is limited by the space charge caused by ions generated from the corona wire, and the maximum discharge current density is about 10 μA/cm 2 . Therefore, the method for obtaining higher corona current is
An air flow is blown onto the corona wire to blow away the generated ions in the air that form a space charge, and the
A method for obtaining an ion current with a high density of about 2 has been reported. However, this method has the disadvantage of requiring compressed air. In addition, in methods using these corona wires, the corona wires are as thin as ~60 μm, and the wires break due to the vibrations that occur when high voltage is applied.Furthermore, they electrostatically attract floating dust in the air, so they must be cleaned frequently. There are disadvantages that cannot be avoided.

On the other hand, there is a recording method that utilizes electrostatic recording paper used in electrostatic recording and spark discharge between recording needles. This method is used in electrostatic recording plotters, facsimile machines, etc., and uses spark discharge in the air gap, which occurs in the small air gap of 5 to 20 μm between the recording needle and the surface of the insulating recording medium. It forms an electrostatic latent image. However, the charge image obtained in this way is not uniform, and it is difficult to form a uniform electrostatic latent image over a wide area.

[0004] In response to these problems, Delfax Co., Ltd.
Noting that high-density ions are generated when high-frequency, high-voltage is applied to two electrodes with an insulating layer sandwiched between them, in 1982
The company successfully commercialized a label printer in 2013. This method uses a 1MHz, 2.8KVP that generates high density ions.
-P high frequency high voltage and 600V voltage for transporting ions to the recording medium are switched for each electrode corresponding to the image point, and 2
It performs high-speed recording of values (500 sheets/minute, equivalent to A4), uses a high-hardness alumina recording medium, and can print in large quantities with maintenance required only once every 100,000 sheets.

[0005] This method is described, for example, in U.S. S. P. 4,15
5,093. To explain this method using FIG. 13, the ion generator has electrodes 602 and 603 provided on each upper and lower surface of an insulating layer 601, and a lower electrode 603.
A groove (or hole) 604 is provided in order to increase electric field concentration and easily generate ions. Also, an AC voltage 605 is applied between these electrodes 602 and 603.
is applied to concentrate a high alternating current electric field on the groove 604 of the electrode that generates ions, thereby generating positive and negative ions at a high density. The ions generated in this way are applied to the control signal voltage 603 applied to the electrode 603.
Only negative polarity ions are selected by turning on and off 06, and they become an ion stream and move toward the accelerating electrode. moreover,
This ion flow is caused by the voltage 608 applied to the accelerating electrode 607.
The signal is accelerated and reaches the insulating recording medium 609, thereby forming an electrostatic latent image in accordance with the signal. A so-called ion recording head is one in which a large number of the above-described ion generating devices are arranged at each pixel according to the number of pixels.

[0006] In order to control such a high voltage, a high voltage control IC is required, and a high voltage IC requires a large mounting area, so there is a drawback that a drive IC cannot be mounted on the head. Therefore, it is not suitable for high-density mounting for high-definition heads. Furthermore, the amount of ions generated from the solid-state ion generator provided for each picture point is easily influenced by the surrounding environment, and the electrostatic latent image produced by this head has the disadvantage that it changes depending on the environment. For this reason, Delfax uses long-life crystalline mica for the insulating layer of solid-state ion generators, which does not change in quality even with nitrates produced by ion irradiation and corona ion generation. Therefore, manufacturing a solid-state ion generator has the disadvantage that it is difficult to bond the crystalline mica to the substrate and to form electrodes by thick film printing on the crystalline mica, making it difficult to mass-produce the ion generator.

A method for reducing the control voltage that eliminates the above drawbacks is to transport ions generated by a corona charger to an air flow passage hole using a high-speed air flow, and apply a control electric field in the vertical direction of the air flow containing these ions. There is a proposal (Japanese Unexamined Patent Publication No. 61-255870) in which an electrostatic latent image is formed by deflecting the transported ions and controlling the amount of transported ions that reach the recording medium. This method has been shown to be able to drive a corona ion flow with a voltage as low as 30V, but the structure is complicated as it is necessary to provide an electrode that provides a control electric field in the vertical direction within the ion flow passage hole. Therefore, there is a limit to the mounting density. Furthermore, the recording speed is determined by the speed of the airflow, making stable recording difficult.

On the other hand, there is another method (Japan Hardcopy'89..P15) that allows control with a relatively low voltage.
9). This method uses 6.
Ions generated by applying a voltage of 5 kV are passed through two control electrodes with ion passage holes, controlled at a voltage of ~150 V, and a high electrostatic contrast image of 400 V or more is created using electrostatic recording paper. You can use the toner normally used in copiers. Furthermore, gradation can be recorded using a signal voltage whose pulse width is controlled for each pixel, and the same image quality can be obtained at a lower resolution than a laser printer that expresses gradation by concentrating pixel points. However, the drawback of this ion recording head is that the upper speed limit is determined by the amount of ions generated by the corona charger.
The limit is 2 sheets/minute (A4). Furthermore, the control voltage is still high at 150V or more, making it difficult to mount a drive IC on the head.Furthermore, since this method uses a corona charger, it is difficult to solidify the ion recording head, making it difficult for mass-produced products. There are drawbacks that make it unsuitable.

The above ion deposition recording method is as follows: (
1) Like a laser printer (light source/rotating mirror scanning)
It does not require a laser optical system or a photoreceptor, (2) the recording image point can be pulse width modulated, and the same image quality can be obtained at a fraction of the resolution of a laser printer, and (3) it can print on a surface similar to a photoreceptor. Since a recording medium with potential dark decay is not used, the electrostatic latent image is held for a long time and intermittent recording is possible. moreover,
(4) There is a possibility that toner images can be sequentially formed on a recording medium, and high-speed one-pass color recording is expected. However, the conventional ion recording head requires a high voltage as a control voltage, and requires a high-voltage driving IC. Additionally, the low-voltage method required airflow. Furthermore, the recording speed decreases in a system in which a corona charger is used and the drive voltage is lowered. In any of these methods, it was difficult to solidify the head.

0010

[Problems to be Solved by the Invention] A solid-state ion generator that generates a high-density ion flow by applying a high-voltage, high-frequency voltage between an induction electrode and an ion-generating electrode arranged with a conventional dielectric in between is proposed. In an ion flow head that forms an electrostatic latent image on an insulating recording medium by controlling the ion flow point by point, crystalline mica is used in the insulating layer of the solid ion generator to generate solid ions. The generator was operating stably. Therefore, there is a drawback that mass productivity of the head is poor and manufacturing cost is high. Furthermore, controlling the ion flow requires a special high-voltage drive circuit, which has the disadvantage of increasing the circuit scale.

On the other hand, a method in which a corona charger is used as an ion generator and the ion flow can be controlled at a relatively low voltage using a control electrode having two ion passage holes has a slow recording speed and is difficult to use because it uses a corona charger. The disadvantage is that the ion flow head cannot be solidified, making it unsuitable for mass production.

[0012] The present invention provides a solid ion generator structure and usage method in which the insulating layer of the solid ion generator is formed of a material that can be mass-produced using thick film printing technology, and which is capable of stably generating high-density ions. It is something. By using the solid-state ion generator according to the present invention, it is possible to mass-produce ion recording heads that can stably control the amount of ions and perform high-speed recording. [Structure of the invention]

[0013]

[Means for Solving the Problems] This invention provides a solid-state ion generator that can generate a large amount of ions by providing an induction electrode and an ion-generating electrode with a dielectric layer in between, and uses thick film printing technology to reduce the cost. The present invention provides a solid ion generator that can be mass-produced and a method for using the solid ion generator that can be stably used.

Fluctuations in the amount of ions generated in the solid-state ion generator are caused by a decrease in the surface resistance of the dielectric layer due to ion irradiation. The life of this ion generator occurs due to dielectric breakdown of the dielectric layer. Furthermore, in order to drive the ion generator at a low voltage, it is necessary to generate ions at a low voltage and to efficiently extract the generated ions at a low voltage. The purpose here is to provide an ion generator that can achieve these conditions.

When the surface resistance of the dielectric layer of this ion generator decreases, the potential on the surface of the dielectric layer becomes the same as the voltage of the ion generating electrode, and a voltage is applied to the air space between the ion generating electrode and the dielectric. First, the amount of ions generated decreases. This decrease in surface resistance is caused by nitrides or nitrates produced during ion generation adhering to the surface of the dielectric layer. Therefore, we created a two-layer structure consisting of a polyimide layer whose surface is not deteriorated by these nitrides or nitrates, and a glass layer with high breakdown voltage, to ensure stability of the surface resistance and breakdown voltage of the dielectric layer. Since the formed nitride or nitrate decomposes at a temperature of about 60°C, the induction electrode or ion-generating electrode in contact with the dielectric layer is made of a resistor, and a current is passed through the electrode itself to serve as a heater. The ion generator is stabilized by maintaining the dielectric layer at a temperature of 60°C or higher.

Furthermore, the frequency f of the alternating current voltage applied to the ion generator is set to a value that satisfies the following equation or more, so that stable ion generation can be achieved even when surface resistance deteriorates. f≧1/{R・Co・(Lr/2)2 }

[0017]
Here, R is the surface resistance per unit length of the dielectric layer in the direction of the center of the slit (or hole) of the ion generating electrode, Co is the capacitance per unit area of the dielectric layer, and Lr is the slit of the ion generating electrode. width (or hole).

This point will be explained next. When the resistance value on the surface of the dielectric layer decreases, the surface potential of the dielectric layer becomes the same potential as the ion generating electrode with a time constant determined by the resistance and the capacitance of the dielectric layer, and the potential between the ion generating electrode and the dielectric surface increases. The electric field in the air decreases. Therefore, it is necessary to drive the ion generator at a frequency at which the potential rises faster than this time constant. This time constant becomes large as the resistance value increases in the center of the slit away from the ion generating electrode, and ions are easily generated. Assuming that the surface resistance per unit length of the dielectric layer in this slit is R, and the capacitance per unit area is Co, the value at the center of the slit with the longest time constant is as follows.

τ=(R・Lr/2)・(Co・Lr/2)=R・Co
-(Lr/2)2...(1) In order for ions to be generated at the center of this slit, the minimum frequency fo of the AC voltage needs to be higher than the frequency shown by the following equation (2).

fo=1/τ=1/{R・Co・(Lr/2)
2 } (2) Therefore, in order to generate ions in a wide range including the vicinity of the ion generating electrode, it is necessary to increase the frequency of the driving AC voltage to above this frequency fo.

On the other hand, the life of the ion generator is determined by dielectric breakdown of the dielectric layer. Therefore, in the present invention, an insulating layer is provided between the ion generating electrode, the dielectric layer, and the junction where the electric field strength is strongest, and a step is provided to isolate the ion generating electrode from the dielectric layer, thereby increasing the electric field strength at the junction. We aimed to weaken the power and extend the lifespan. The inventor revealed that the region where the electric field is maximum and the region where the amount of ions generated is the maximum in the ion generating electrode are different, and by removing the region where the electric field strength is maximum, the amount of ions generated is sufficient. This is so that they can be obtained. In addition, ions are not generated at the step formed by the insulating layer provided in this manner, and there is no decrease in the resistance value of the dielectric layer near the ion generating electrode, allowing stable ion generation.

In addition, in the present invention, in order to increase the electric field in the air to increase the ion generation effect, the value obtained by dividing the thickness d of the dielectric layer by the dielectric constant ε is determined by the following equation. It was made smaller than the slit width (or pore diameter) Lr of the generation electrode. By doing so, the leakage electric field on the dielectric layer is increased to facilitate ion generation. Lr≧d/ε

Furthermore, a leakage electric field is made to exist outside the slit so that the generated ions can efficiently exit from the slit (or hole) in the ion generating electrode. Therefore, the thickness Dp of the ion generating electrode was made smaller than the illit width Lr as shown by the following equation. Dp≦Lr

[0024]

[Function] In the present invention, the dielectric layer has a two-layer structure of a material with a high dielectric strength, such as glass, and a material such as polyimide, which has a low dielectric strength but has a stable insulation resistance against ion irradiation. Prevents changes in generation amount over time that occur due to deterioration of insulation resistance due to ion irradiation. Furthermore, in terms of structure, a step in the insulating layer is provided at the junction between the ion generating electrode and the dielectric layer of the ion generator, to prevent strong electric fields from being applied to the dielectric layer near the ion generating electrode, and to reduce the resistance of the dielectric layer. prevents corrosion and dielectric breakdown. Furthermore, in order to increase the leakage electric field in the air between the slits provided in the ion generation electrode and increase the ion generation efficiency, the slit width was set to be equal to or larger than the value obtained by dividing the thickness of the dielectric layer by the dielectric constant. Furthermore, so that ions can easily exit from the slit, the thickness of the ion generating electrode is made smaller than the width of the slit, so that a leakage electric field exists outside the slit.

[0025] According to the present invention, a thick film material such as glass, which is used in ordinary heat-sensitive recording heads and has established mass production technology, can be used without using a special dielectric layer such as mica. Thick-film printing technology makes it possible to achieve a solid-state ion generator that stably generates ions without depending on environmental fluctuations, is inexpensive, and has a long life.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. <Example 1> Figures 1 and 2 are cross-sectional structural diagrams of an ion generator with the purpose of stabilizing and extending the life of the ion generator according to the present invention, in which the dielectric layer of the ion generator has a two-layer structure. be.

FIG. 1 shows one example of this. Thickness 640
3-4 μm thick on a μm ceramic substrate (not shown)
Induction electrode 101 made of a sintered gold electrode with a width of 200 μm
The required length (A4) is provided in the direction of the paper using thick film printing technology and sintering technology. On top of that, a glass layer 102 having a high electrical withstand voltage and deteriorating when exposed to ion irradiation is provided to a thickness of about 20 μm using thick film printing technology and sintering technology. Further, on this thick film glass layer, a polyimide layer 103 having a low breakdown voltage when applied with alternating current but little deterioration phenomenon when exposed to ion irradiation and high insulation resistance is uniformly applied to a thickness of ~5 μm using a spinner coating technique. . Next, in order to form an ion generating electrode having a 100 μm wide slit 104 for ion generation in the direction of the paper, a nickel layer 105 with a thickness of several thousand angstroms and a width of 90 μm is formed using thin film technology, including a nickel layer 105 that has a strong bonding force with polyimide. . Thereafter, a non-oxidizing metal layer such as nickel or gold is provided on the nickel layer in a plating process to a thickness of ~20 μm necessary for ion generation to form the ion generation electrode 106. Both ion generating electrodes on both sides of this slit are connected on both sides in the direction of the paper.

FIG. 2 shows another embodiment. A polyimide layer is uniformly applied to a thickness of ˜5 μm using a spinner coating technique on top of the gas laminated dielectric layer 102 provided using a thick film technique. Then, the ion generating electrode is removed by an etching process, leaving only the slit portion. Thereafter, the ion generating electrode 106 is formed to a thickness of ~20 μm using a thick film technique on the glass dielectric layer. This method is characterized by strong adhesion between each layer.

The ion generator manufactured in this way has the advantages of the glass layer and polyimide layer used for the dielectric layer, and the ion generator can be used for a long period of time compared to when the dielectric layer is made of only a glass layer. The current is stable, and the ion current remains stable even after several tens of hours of use. Moreover, compared to the case of only a polyimide layer, the time required to reach the end of life due to dielectric breakdown was extended from several hours to several tens of hours. In this way, a stable, long-life ion generator without deterioration of the dielectric layer surface resistance can be achieved. <Example 2>

Next, another embodiment for achieving stabilization of the ion generator will be described using FIGS. 3 to 5. The amount of ions generated by the ion generator decreases because nitrogen ions, nitrogen oxide ions, etc. generated during ion generation react with moisture in the air and base ions such as nitrates are formed on the surface of the dielectric layer. This is the result. Therefore, the surface resistance of the dielectric layer decreases, the dielectric layer potential becomes the same as the ion generation electrode potential, the electric field in the air between the ion generation electrode and the dielectric layer decreases, and the amount of ions generated decreases. In this invention, we focused on the fact that the generated base is easily decomposed by heat of about 60 degrees Celsius, and by constructing the ion generating electrode or the induction electrode with a resistor and using it as a heater, we can efficiently remove the dielectric near the ion generating electrode. The ion generator is stabilized by heating the layer surface to prevent base generation and eliminate fluctuations in the dielectric layer surface resistance.

FIG. 3 shows the relationship between the heating temperature of the dielectric layer and the generated ion current. As the temperature of the dielectric layer rises, the ionic current that had been decreasing recovers, and at a temperature of approximately 60° C., the base on the dielectric layer is almost completely decomposed and the ionic current returns to a value close to its initial state.

Next, using FIG. 4, the ion generating electrode 20
An example in which the induction electrode 1 or the induction electrode 202 is formed of a resistor and used as a heater will be shown. The induction electrode 202 is connected to a ceramic substrate (
(not shown) by sputtering on Ta2N,W
, Cr, Ni-Cr, SnO2, etc.
Form a thickness of ~2000 angstroms. A glass dielectric layer 102 is formed on the resistor using thick film printing technology.
A thickness of 20 μm is provided, and an ion generating electrode 106 of a gold electrode is formed thereon to a thickness of ~20 μm using a thick film printing technique. On the other hand, the ion generating electrode 201 may be made into a resistor using thick film technology. At this time, Pd-Ag
, RuO2, or the like is screen printed on the dielectric layer 102 and fired. The inductive electrode may then be formed by conventional thick film or thin film techniques without the need for a resistor. A current is applied in the direction of the paper from a power source different from the driving AC power source to the ion generating electrode or the induction electrode configured with the resistor of the ion generator configured in this way, and the temperature of the surface 203 of the dielectric layer is increased to 60° C. or higher. Heat to. When the surface of the induction electrode is heated above 60°C in this way, the base 204 decomposes into other substances 205 that do not contribute to conduction, and the base such as nitrate formed on the surface causes a resistance of ~109 Ω or less. The resistance value, which had been decreasing during the process, increases, and the ion current returns to the value before deterioration.

A method of applying voltage to this resistor will be explained using FIG. 5. This figure shows an ion generator in which the ion generating electrode is formed of a resistor, viewed from the ion generating electrode side. An induction electrode 202 with a thickness of several μm is formed on a ceramic substrate 206 by thick film technology, and an AC voltage 2 for ion generation is applied.
A lead wire 208 is provided to supply 07. A glass layer 102 is uniformly coated thereon using thick film technology. Furthermore, an ion generating electrode 201 made of a thick film resistor is provided thereon, and a lead wire 209 for voltage supply is connected to the resistor by thick film technology. An alternating current voltage 210 for ion generation is applied between the ion generation electrode and the induction electrode of the ion generator configured in this way to generate ions. Furthermore, the ion generating electrode has a counter electrode (not shown) that exists in the direction of the page.
A bias voltage 211 is applied to cause an ion current to flow. A power source 212 for heating the resistor is connected to both ends of this ion generating electrode to heat the dielectric layer and decompose the base formed on the surface of the dielectric layer to facilitate ion generation. At this time, the temperature is detected and the power supply 2 for heating the resistor is
Controlling 12 and stabilizing the temperature stabilizes ion generation and is effective. <Example 3>

Next, a method for stabilizing the generation of ions when the surface resistance of the dielectric layer decreases will be explained with reference to FIG. Dielectric layer 1
When the surface resistance 301 of 02 decreases and an AC voltage for ion generation is applied, the distance x from the ion generation electrode 106 increases.
The potential on the surface of the dielectric layer at a distant point 302 becomes the same potential as the ion generating electrode as the electrostatic capacitance 303 of the dielectric layer is sequentially charged starting from the vicinity of the ion generating electrode. Therefore, no electric field is applied to the air between the ion generating electrode and the dielectric layer, and no ions are generated. In this way, if the frequency of the AC voltage for ion generation is lower than the frequency given by the time constant, the potential on the surface of the dielectric layer increases before the potential between the ion generation electrode and the surface of the dielectric layer increases. It has the same potential as the generation electrode and no ions are generated. This constant is as follows. τ=R・Co・x2

Here, R is the resistance value per unit length of the surface of the dielectric layer, and Co is the capacitance per unit area of the dielectric layer. The surface resistance of the dielectric layer has a resistance value of 10 at the ion generating electrode between the slits due to ion irradiation after long-term use.
It decreases from 12 to about 109 Ω. Assuming that the dielectric constant of the glass layer is 5, the time constant at the center of the 100 μm slit is calculated to be ~110 μsec. Therefore, it is necessary to drive the ion generator with a high frequency voltage of approximately 9 kHz or higher. In this way, the distance from the ion generation electrode for the resistance value of the dielectric layer surface to decrease and the potential of the dielectric surface to be the same as that of the ion generation electrode is determined by a drive frequency of 30k.
It is ~24 μm at Hz and ~10 μm at 150 kHz. Therefore, when driven with a high frequency voltage of 150kHz,
The potential of the following region of the ion generating electrode different from the vicinity of the dielectric layer of the ion generating electrode increases, and ions are sufficiently generated. <Example 4>

Next, an embodiment for achieving a longer life of the ion generator will be described with reference to FIGS. 7 to 10. The life of an ion generator is determined by dielectric breakdown of the dielectric layer at the junction between the ion generating electrode and the dielectric layer where the electric field is maximum. However, the region where the amount of ions generated is maximum is different from the region where the electric field is maximum. Therefore, an insulating layer is provided below the ion generating electrode to float the ion generating electrode from the dielectric layer to prevent a strong electric field from forming near the ion generating electrode. In this way, the electric field on the ion generating electrode where the amount of ions generated is maximum is the same, and dielectric breakdown does not occur in the dielectric layer.

This point will be explained in detail using FIG. 7. Induction electrode 101 provided with dielectric layer 102 in between
When an AC voltage of 2.5 kVP-P is applied to the ion generating electrode 106, a potential distribution 401 shown by a dotted line obtained by the boundary element method, an electric field 402 perpendicular to this potential distribution,
403 and the ion density distribution 404 on the ion generating electrode derived from calculation are shown in the figure. Ion generation occurs when No. 1 ion species, which are naturally generated in the air by cosmic rays, are accelerated by an electric field E and sequentially move through the air, and are multiplied by the ion multiplication coefficient α, producing a large amount of Increases by forming secondary ions. Formation of this secondary ion requires a distance and an electric field for the ion to collide with air molecules and multiply. Ion density n and distance x formed by this multiplication
and the electric field E, there is a relationship shown by the following equation. n=No/α・{exp(α・x)−1}α=p・A・
exp(-B・p/E)

Here, A and B are proportional constants in air and are determined experimentally. Moreover, p is the atmospheric pressure at the time of ion generation. From the above equation, based on the potential distribution 401 obtained by the boundary element method when the thickness of the insulating layer is 20 μm, the slit width between the ion generating electrodes is 100 μm, and the thickness of the ion generating electrode is ~20 μm, The ion generation density distribution n was calculated and shown as a curve 404 in the figure. At the junction between the ion generating electrode and the dielectric layer, the electric field strength 403 increases, but the flight distance of the ions is short, so the generated ion density is low. On the other hand, above the ion generating electrode, the flight distance of the ions increases, but since the electric field is small, the amount of ions generated is similarly small. In this way, above the ion generating electrode ~ 15
The amount of ions generated is maximum at μm. At this time,
A strong electric field near the junction between the ion generating electrode and the dielectric layer does not contribute to ion generation, but rather becomes a cause of dielectric breakdown that determines the life of the dielectric layer of the ion generator. In the present invention, an insulating layer is provided below the ion generating electrode, and the ion generating electrode is floated from the dielectric layer 102 to prevent a strong electric field from being applied to the dielectric layer, thereby extending the life of the ion generator.

This embodiment will be explained using FIG. 8. A glass layer 405 having a thickness of ~5 μm is provided using a thick film technique on the induction electrode 101 and the glass layer 102, which are provided on a ceramic substrate using a thick film technique, so as to form a slit 104. Furthermore, the ion generating electrode 106 is formed on the glass layer 405 to a thickness of ~20 μm using a thick film technique. The electric field at the interface 406 with the dielectric layer 102 in the vicinity of the ion generating electrode 106 manufactured in this way is reduced, dielectric breakdown of the dielectric layer is prevented, and the life of the ion generator can be extended. At this time, since a sufficient electric field is applied to the region of the ion generating electrode where the amount of ions generated is maximum, the amount of ions generated does not decrease. Further, ions generated from the junction between the ion generating electrode and the dielectric layer take a trajectory as indicated by an arrow 407 and reach the dielectric layer. Therefore, the ions are transferred to the dielectric layer 1.
Direct ion bombardment does not occur on the dielectric layer surface closer to the ion generating electrode than point 408 leading to point 02, and deterioration of the dielectric layer due to ion bombardment is reduced.

Next, another embodiment according to the present invention is shown in FIG.
Explain using. In this example, the insulating layer 408 provided between the ion generating electrode and the dielectric layer is several meters from the ion generating electrode.
By extending from m to tens of mm to the slit side of the dielectric layer, the electric field near the dielectric layer and ion generation electrode where the electric field is maximum is weakened, and the area where the electric field is maximum on the surface of the dielectric layer is more completely removed. This is what I did.

FIG. 10 incorporates both the example in which the dielectric layer has a two-layer structure according to Example 1 and the present example in which the electric field near the ion generating electrode is reduced. Induction electrode 1
On the dielectric layer 102 made of a glass layer with a thickness of 15 μm provided on the dielectric layer 102, a glass layer 409 with a thickness of 10 μm is provided by thick film technology in a slit with a width of 100 μm and protrudes by several μm to more than ten μm. Furthermore, ~5 on this slit
A polyimide layer 410 with a thickness of μm is uniformly applied using a spinner or formed using a thin film technique such as sputtering. Then, the polyimide layer other than the slits is removed by etching. On the other hand, an ion generating electrode 106 having a slit width of 100 μm is formed on the glass insulating layer 409 to a thickness of ~20 μm using a thick film technique. In the ion generator configured in this manner, the electric field applied between the ion generating electrode and the dielectric layer is reduced, so that the life of the ion generator due to dielectric breakdown can be extended. In addition, the dielectric layer near the ion generating electrode between the slits is not irradiated with ions, and the surface of the dielectric layer is made of a polyimide layer that is resistant to ion irradiation, so there is no decrease in surface resistance due to ion irradiation.
Stable ion generation can be obtained. <Example 5>

Next, another embodiment in which ions are efficiently generated from the ion generator and the generated ions are efficiently taken out will be described with reference to FIGS. 11 and 12. Figure 11
FIG. 2 is a diagram showing a voltage arrangement for obtaining an ion current from an ion generator. Ions 501 of both positive and negative polarities are generated by the AC voltage 210 applied to the induction electrode 101 and the ion generation electrode 106 of the ion generator. Among these ions, positive polarity ions 502 are transferred to the counter electrode 50 by the bias voltage 211.
3 to generate an ionic current. This ion generator has an induction electrode 1 provided on a ceramic substrate (not shown).
01, and a thick film glass layer 102 with a thickness of ~20 μm as a dielectric layer is provided thereon, and an ion generating electrode 106 having a slit 104 with a width of 100 μm is formed to constitute an ion generator.

An ion generator that efficiently generates ions at a low AC voltage will be described with reference to FIG. 12. Ion generation electrode 106 and induction electrode 101
When an AC drive voltage for ion generation is applied to the ion generation electrode, in order to generate ion discharge in the air between the ion generation electrode and the dielectric layer with a low AC voltage, the leakage electric field 504 for ion generation leaking through the dielectric layer must be reduced. It needs to be bigger. Therefore, as shown in the following formula, the slit width (or diameter of the hole) is the thickness equivalent to air, which is the ratio of the dielectric layer thickness d to the relative dielectric constant ε of the dielectric layer (Gasler layer ε = 5). It is necessary to make it smaller than Lr so that the electric field from the induction electrode can sufficiently leak from the dielectric layer. d/ε<Lr

In this embodiment, d/ε is set to 4 μm, which is sufficiently smaller than the slit width of 100 μm, to obtain a sufficient leakage electric field so that ion discharge occurs between the ion generating electrode and the dielectric layer.

On the other hand, the thickness Dp of the ion generating electrode 106 is made smaller than the slit width (or hole diameter) Lr so that the leakage electric field from the induction electrode exists outside the slit of the ion generating electrode, and the generated ions are kept under a low bias. Make it possible to extract it from the ion generator even with voltage. This leakage electric field 50
4 reaches the height of the ion generating electrode 505 which is the same as the slit width. At this time, the thickness D of the ion generating electrode 505
When p is larger than the slit width Lr, the induction electrode 101
The leakage electric field from the ion generating electrode is only within the slit 104 made up of the ion generating electrode. Therefore, in order to extract the generated ions, it is necessary to apply a high bias voltage to generate an electric field that accelerates the ions within the slit. In the present invention, the leakage electric field generated from the induction electrode is made to reach outside the slit, and the bias voltage is set only to the voltage that accelerates ions to the counter electrode. For this purpose, the thickness Dp of the ion generating electrode is made smaller than the slit width Lr as shown by the following equation. Dp<Lr In the ion generator that was actually prototyped, the thickness Dp of the ion generation electrode was 100 μm, and the slit width Lp was 20 μm.

In the ion generator thus formed, sufficient ions can be generated with an applied AC voltage of 2.5 kVP-P, and the bias voltage can be set at a distance of 250 mm between the ion generator and the opposing electrode. At about 250 V, a sufficient ion current of ~3×10 −6 A/cm can be obtained.

[0047]

[Effects of the Invention] Unlike conventional ion generators, the ion generator according to the present invention does not require a complicated structure in which electrodes are pasted on a special dielectric layer such as mica. This provides a structure that can be manufactured using thick film printing technology or thin film technology.

[0048] In this ion generator, a material whose chemical properties are less likely to change by ion irradiation is used on the surface of the dielectric layer,
In addition, the dielectric layer itself has a two-layer structure using a material with high electrical withstand voltage, thereby achieving a stable and long-life ion generator. Furthermore, we clarified the lower limit frequency of the AC voltage that allows ion generation even when the surface resistance of the dielectric layer deteriorates, and by driving at a frequency higher than that frequency, ion generation can be stabilized even when the ion generator deteriorates. It provides instructions on how to use it. Regarding the lifespan of the ion generator, an insulating layer was provided between the ion generating electrode and the dielectric layer to weaken the electric field to prevent dielectric breakdown of the dielectric layer, thereby increasing the lifespan of the ion generator. Furthermore, at this time, the thickness of the dielectric layer calculated as a dielectric constant in air is made smaller than the slit width, and the leakage electric field in the slit space is increased, thereby lowering the driving AC voltage and reducing the AC drive power supply. The voltage conversion makes it possible to reduce the price to a fixed price. Furthermore, the thickness of the ion generation electrode is made smaller than the slit width so that the generated ions can be extracted with a low bias voltage, and the ions are ejected outside the slit by the leakage electric field. Ions can be extracted from the ion generator. By doing so, it becomes possible to reduce the cost of the bias power supply. The invention described above makes it possible to supply a stable, long-life ion generator that can be mass-produced at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an embodiment of a solid-state ion generator of the present invention in which the dielectric layer has a two-layer structure.

FIG. 2 is a schematic cross-sectional view of another embodiment of the solid-state ion generator of the present invention in which the dielectric layer has a two-layer structure.

FIG. 3 is a diagram showing the relationship between the heating temperature of the dielectric layer and the generated ion current in the solid-state generator of the present invention.

FIG. 4 is a diagram showing an example in which the ion generation electrode or dielectric electrode in the solid-state ion generator of the present invention is formed of a resistor.

FIG. 5 is a diagram for explaining a method of applying voltage to a resistor in the solid-state ion generator of the present invention.

FIG. 6 is an explanatory diagram of a time constant showing a potential drop on the surface of the dielectric layer when the surface resistance of the dielectric layer in the present invention is reduced by the generated base.

FIG. 7 is a schematic cross-sectional view of an ion generator for reducing the electric field distribution and electric field strength at the junction between the ion generating electrode and the dielectric layer in the present invention.

FIG. 8 is a diagram showing an example of extending the life of the ion generator in the present invention.

FIG. 9 is a diagram showing another example of FIG. 8.

FIG. 10 is a diagram showing a modification of FIG. 1.

FIG. 11 is a voltage layout diagram for obtaining ion current from the ion generator of the present invention.

FIG. 12 is a schematic cross-sectional view of the ion generator showing the leakage electric field within the ion generating electrode of the present invention.

FIG. 13 is a diagram for explaining a conventional example.

[Explanation of symbols]

101... Induction electrode 102... Glass layer 103... Polyimide layer 104... Slit 105... Nickel layer 106...
ion generating electrode

Claims (6)

[Claims] Claim 1: In an ion generator that generates corona ions by applying an alternating current voltage between an induction electrode and an ion generation electrode arranged with a dielectric interposed therebetween, the dielectric is formed of two or more types of dielectric layers. A solid-state ion generator characterized by: [Claim 2] Applying an alternating current voltage between an induction electrode and an ion generation electrode for ion generation disposed with a dielectric material in between,
A solid ion generator that generates ions into the air from around an ion generating electrode, characterized in that an induction electrode or an ion generating electrode is formed of a resistor, and the electrode is heated with a heater. 3. In an ion generator that generates corona ions by applying an alternating current voltage between an induction electrode disposed with a dielectric material in between and an ion generation electrode having a slit (or hole) for ion generation. , the capacitance per unit area of the slit (or hole) of the dielectric layer is Co, the surface resistance per unit length of the dielectric layer is R, and the slit width (or diameter of the hole) is Lr. AC voltage frequency f
A solid ion generator characterized in that f≧1/{R・Co・(Lr/2)2 }. 4. An insulating layer that isolates the ion generating electrode from the dielectric in an ion generator that generates corona ions by applying an alternating current voltage between an induction electrode and an ion generating electrode disposed with a dielectric interposed therebetween. A solid-state ion generator characterized in that an ion-generating electrode section is provided with: 5. In an ion generator that generates corona ions by applying an alternating current voltage between an induction electrode disposed with a dielectric material in between and an ion generation electrode having a slit (or hole) for ion generation. , when the thickness of the dielectric layer is d, the dielectric constant of the dielectric layer is ε, and the diameter of the slit width (or hole) is Lr, the thickness d of the dielectric layer is the inequality d≦ε・Lr. A solid-state ion generator characterized in that the value is less than or equal to the indicated value. 6. In an ion generator that generates corona ions by applying an alternating current voltage between an induction electrode disposed with a dielectric material in between and an ion generation electrode having a slit (or hole) for ion generation. , where the thickness of the ion generating electrode is Dp and the diameter of the slit width (or hole) is Lr, the thickness Dp of the ion generating electrode is less than or equal to the value expressed by the inequality Dp≦Lr. ion generator.