JP3176943B2 - Solid ion generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention]

[0001]

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

[0002]

2. Description of the Related Art Ion generation in the air used in recording technology includes corona discharge and spark discharge. The corona discharge is widely used in an electrophotographic recording type copying machine for uniformly charging a photosensitive member or transferring a toner image to transfer paper. However, in a normal corona discharge, the amount of ions generated is limited by the space charge caused by the ions generated from the corona wire, and the discharge current density is 10 μA / cm ^{2 at the} maximum. It was about. For this reason, a method of obtaining a higher corona current is to blow off a generated ion in the air which forms a space charge by blowing an air flow onto the corona wire, and 10 ³ μA / cm ² Methods for obtaining a high density ion current have been reported. However, this method has the disadvantage that compressed air is required. In addition, in the method using these corona wires, the corona wires are as thin as ~ 60 μm, the wires are cut off by the vibration of the wires generated when a high voltage is applied, and the dust particles in the air are electrostatically adsorbed. There is a drawback that must not be.

On the other hand, there is an electrostatic recording paper used in electrostatic recording and a recording method utilizing spark discharge between recording needles. This method is used for a plotter or a facsimile of an electrostatic recording system, and uses spark discharge in an air gap, and uses air discharge generated in a small air gap of 5 to 20 μm between a recording needle and the surface of an insulating recording medium. To form an electrostatic latent image. However, the charge image thus obtained is not uniform, and it has been difficult to form a uniform electrostatic latent image over a wide area.

[0004] To address these issues, Delfax has
Note that high-frequency high voltage is applied to two electrodes sandwiching an insulating layer to generate high-density ions.
The label printer was successfully commercialized in 2000. This method uses 1 MHz, 2.8 KV to generate high density ions.
High frequency high voltage of _PP and transport of ions to recording medium 6
The voltage of 00 V is switched for each electrode corresponding to the pixel, and high-speed binary recording (500 sheets / min: equivalent to A4) is performed.
Using a high-hardness alumina recording medium, large-scale printing can be performed with maintenance once per 100,000 sheets.

This method is disclosed, for example, in US Pat. S. P. 4,15
5,093. This method will be described with reference to FIG. 13. In the ion generator, electrodes 602 and 603 are provided on upper and lower surfaces of an insulating layer 601, and a lower electrode 603 is provided.
Has a groove (or hole) 604 for increasing the electric field concentration and easily generating ions.
An AC voltage 605 is applied between these electrodes 602 and 603.
Is applied, and a high AC electric field is concentrated in the groove 604 of the electrode for generating ions, whereby positive and negative ions are generated at high density. The ions generated in this manner are controlled by the control signal voltage 6 applied to the electrode 603.
Only the negative ions are selected by turning ON / OFF 06, and the ions move in the direction of the accelerating electrode as an ion flow. Further, this ion current is applied to the voltage 6 applied to the accelerating electrode 607.
At 08, it is accelerated and reaches the insulating recording medium 609, whereby an electrostatic latent image corresponding to the signal is formed. The so-called ion recording head has a large number of the above-described ion generators arranged at the image points in accordance with the number.

In order to control such a high voltage, a control IC having a high withstand voltage is required, and since a high withstand voltage IC requires a large mounting area, there is a disadvantage that a drive IC cannot be mounted on a head. Therefore, it is not suitable for high-density mounting for a high-definition head. Further, the amount of ions generated from the solid ion generator provided for each image point is easily affected by the surrounding environment, and the electrostatic latent image by the head has a disadvantage that it changes depending on the environment. For this reason, Delfax uses long-lived crystal mica, which does not change its material even with nitrate generated by ion irradiation and corona ion generation, as an insulating layer of a solid ion generator. Therefore, the production of a solid ion generator has a drawback that it is difficult to form an electrode by bonding a crystal mica to a substrate and printing a thick film on the crystal mica, and mass production of an ion generator is difficult.

[0007] In a method of reducing the control voltage except for the above-mentioned disadvantages, ions generated by the corona charger are conveyed to an air flow passage hole by a high-speed air flow, and a control electric field is generated in a vertical direction of the air flow containing the ions. There is a proposal (Japanese Unexamined Patent Publication (Kokai) No. 61-255870) for forming a latent image by controlling the amount of carrier ions reaching the recording medium by deflecting the carrier ions. This method shows that it is possible to drive the corona ion flow at a low voltage of about 30 V, but the structure is complicated because it is necessary to provide an electrode for applying a control electric field in a vertical direction in the ion flow passage hole. And there is a limit to the mounting density.
Further, the recording speed is determined by the speed of the air flow, and stable recording is difficult.

On the other hand, other methods that can be controlled with a relatively low voltage (Japanese Hardcopy '89.
9). This method always applies to the corona charger.
The ions generated by applying a voltage of 5 kV are passed through two control electrodes having an ion passage hole and controlled at a voltage of 150 V, and a high electrostatic contrast image of 400 V or more is formed using an electrostatic recording paper, Toners commonly used in copiers can be used. Further, gradation recording can be performed using a signal voltage of which pulse width is controlled for each image point, and the same image quality can be obtained at a lower resolution than a laser printer which performs gradation expression with concentrated image points. However, the disadvantage of this ion recording head is that the upper limit of the speed limit is determined by the amount of ions generated by the corona charger, and the limit is 2 sheets / min (A4). Furthermore, the control voltage is still as high as 150 V or more, and it is difficult to mount the drive IC on the head. Further, since this method uses a corona charger, it is difficult to solidify the ion recording head. There are disadvantages that are not suitable.

[0009] The above ion deposition recording method comprises:
(1) No laser optical system (light source / rotating mirror scanning) like a laser printer and a photoreceptor are required. (2) Pulse width modulation of a recording pixel is possible, equivalent to a fraction of the resolution of a laser printer. (3) Since a recording medium such as a photoconductor having a dark decay of the surface potential is not used, the holding time of the electrostatic latent image is long, and intermittent recording is possible. Furthermore, (4) there is a possibility that toner images can be sequentially formed on a recording medium in a superimposed manner, and there is a feature that high-speed one-pass color printing is expected. However, a conventional ion recording head requires a high control voltage and a driving IC with a high withstand voltage. In addition, the low voltage method required an air flow. Further, in a system in which the driving voltage is reduced by using a corona charger, the recording speed is reduced. In any of these methods, it was difficult to solidify the head.

[0010]

SUMMARY OF THE INVENTION A conventional solid ion generator for generating a high-density ion flow by applying a high-frequency high-frequency voltage between an induction electrode and an ion generation electrode disposed with a dielectric therebetween. In an ion flow head that forms each point and controls the ion flow for each image point to form an electrostatic latent image on an insulating recording medium, the solid ion generator uses solid mica for the insulating layer to form solid ions. The generator was operating stably. Therefore, there is a disadvantage that the mass productivity of the head is poor and the manufacturing cost is increased. Furthermore, a special high-voltage drive circuit is required to control the ion flow, and there is a disadvantage that the circuit scale becomes large.

On the other hand, a method in which a corona charger is used for an ion generator and an ion current can be controlled with a relatively low voltage by a control electrode having two ion passage holes has a low recording speed and uses a corona charger. There is a disadvantage that the ion flow head cannot be solidified and is not suitable for mass production.

The present invention provides a structure and a method of using a solid ion generator in which an insulating layer of the solid ion generator is formed of a material which can be mass-produced by a thick film printing technique and which can stably generate high density ions. Things. By using the solid ion generator according to the present invention, it is possible to mass-produce an ion recording head capable of performing high-speed recording by stably controlling the amount of ions. [Configuration of the Invention]

[0013]

SUMMARY OF THE INVENTION The present invention provides a solid ion generator capable of generating a large amount of ions by providing an induction electrode and an ion generation electrode with a dielectric layer interposed therebetween, at a low cost by using a thick film printing technique. An object of the present invention is to provide a solid ion generator which can be mass-produced and to provide a method of using the solid ion generator which can be used stably.

The variation in the amount of ions generated in the solid ion generator is caused by a decrease in the surface resistance of the dielectric layer due to ion irradiation. The life of this ion generator is caused by dielectric breakdown of the dielectric layer. Further, in order to drive the ion generator at a low voltage, it is necessary to generate ions at a low voltage and efficiently extract the generated ions at a low voltage. Here, an object was to provide an ion generator capable of achieving 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 generation electrode, and a voltage is applied to the air space between the ion generation electrode and the dielectric. And the amount of generated ions decreases. This decrease in surface resistance is caused by the nitride or nitrate generated during ion generation adhering to the surface of the dielectric layer. For this reason, a two-layer structure including a polyimide layer whose surface is not deteriorated by these nitrides or nitrates and a high-breakdown-voltage glass layer is used to ensure the stability of the surface resistance and the breakdown voltage of the dielectric layer. Since the formed nitride or nitrate is decomposed at a temperature of about 60 ° C., an induction electrode or an ion generation electrode in contact with the dielectric layer is formed by a resistor, and a current is passed through the electrode itself to form a heater. The ion generator is stabilized by maintaining the dielectric layer at a temperature of 60 ° C. or higher.

Further, the frequency f of the AC voltage applied to the ion generator is set to a value which satisfies the following expression or more, so that stable ion generation can be performed even when the surface resistance is deteriorated. f ≧ 1 / ｛R · Co · (Lr / 2) ² ｝

Here, R is the surface resistance per unit length of the dielectric layer in the center direction 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 ion generation. The slit width (or hole) of the electrode.

This will be described below. When the resistance value of the dielectric layer surface decreases, the surface potential of the dielectric layer becomes the same as that of the ion generating electrode with a time constant determined by the resistance and the capacitance of the dielectric layer. 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. As for this time constant, the resistance value increases at the center of the slit apart from the ion generating electrode, the time constant increases, and ions are easily generated. Assuming that the surface resistance per unit length of the dielectric layer in the slit is R and the capacitance per unit area is Co, the following values are obtained at the center of the slit having the longest time constant.

Τ = (R · Lr / 2) · (Co · Lr / 2) = R · Co · (Lr / 2) ² (1) In order to generate ions at the center of this slit, the minimum frequency fo of the AC voltage needs to be higher than the frequency represented 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 the frequency fo or higher.

On the other hand, the life of the ion generator is caused by dielectric breakdown of the dielectric layer. For this reason, in the present invention, an insulating layer is provided between the ion generating electrode, the dielectric layer, and the junction where the electric field intensity is highest, and a step is provided, and the ion generating electrode is separated from the dielectric layer and the electric field intensity of the junction is provided. And to extend the service life. The present inventors have found that the region where the electric field is maximum and the region where the amount of ion generation is maximum are different from each other in the ion generating electrode, and the region where the electric field intensity is maximum is removed so that the amount of ion generation is sufficient. It is because it was obtained. In addition, ions are not generated at the step formed by the insulating layer provided in this manner, and the resistance value of the dielectric layer near the ion generating electrode does not decrease, thereby enabling stable ion generation.

In the present invention, the value obtained by dividing the thickness d of the dielectric layer by the dielectric constant .epsilon. It was smaller than the slit width (or hole diameter) Lr of the generating electrode. By doing so, the leakage electric field on the dielectric layer is increased to facilitate ion generation. Lr ≧ d / ε

Further, the leaked electric field is provided outside the slit so that the generated ions efficiently exit from the slit (or hole) in the ion generating electrode. Therefore, as shown by the following equation, the thickness Dp of the ion generating electrode is made smaller than the yt width Lr. Dp ≦ Lr

[0024]

According to the present invention, the dielectric layer has a two-layer structure of a material having a high withstand voltage such as glass and a material having a low withstand voltage but having a stable insulation resistance to ion irradiation such as polyimide. It prevents the amount of generation caused by the deterioration of the insulation resistance due to ion irradiation with time. Further, structurally, a step of an insulating layer is provided at the junction between the ion generating electrode of the ion generator and the dielectric layer, so that a strong electric field is not applied to the dielectric layer near the ion generating electrode, and the resistance of the dielectric layer is reduced. Prevention of breakdown and dielectric breakdown. Further, 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 a value obtained by dividing the thickness of the dielectric layer by the relative dielectric constant. Further, the thickness of the ion generating electrode was made smaller than the slit width so that ions easily came out of the slit, so that a leakage electric field existed outside the slit.

According to the present invention, a thick film material such as glass, which has been established for mass production and used for ordinary thermal recording heads, is used without using a special dielectric layer such as mica. By the thick film printing technology, it is possible to achieve a low-cost, long-life solid-state ion generator that generates ions stably without depending on environmental fluctuations.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. <Embodiment 1> FIGS. 1 and 2 are cross-sectional structural views of an ion generator for stabilizing and extending the life of an ion generator according to the present invention in which a dielectric layer of the ion generator has a two-layer structure. is there.

FIG. 1 shows one embodiment. Thickness 640
On a 3 μm ceramic substrate (not shown),
electrode 101 consisting of a sintered gold electrode having a width of 200 μm
Is provided in a required length (A4) paper direction by a thick film printing technique and a sintering technique. On top of that, a glass layer 102 having a large electric breakdown voltage and causing a deterioration phenomenon with respect to ion irradiation is provided by a thick film printing technique and a sintering technique in a thickness of about 20 μm. Further, a polyimide layer 103, which is inferior in the withstand voltage at the time of applying an alternating current but has a small deterioration phenomenon due to ion irradiation and has a large insulation resistance, is uniformly coated on the thick glass layer by a spinner coating technique to a thickness of 5 μm. . Next, in order to form an ion generating electrode having a slit 104 having a width of 100 μm for ion generation in the direction of the paper, a nickel layer 105 having a strong bonding force with polyimide is provided with a thickness of several thousand angstroms and a width of 90 μm using thin film technology. . Thereafter, a non-oxidizing metal layer such as nickel or gold is provided on this nickel layer in a thickness of ２０20 μm required for ion generation in a plating step to form the ion generation electrode 106. Both ion generating electrodes on both sides of the slit are connected on both sides in the paper plane direction.

FIG. 2 shows another embodiment. A polyimide layer is uniformly coated on the gaseous dielectric layer 102 provided by the thick film technique to a thickness of about 5 μm by a spinner coating technique. Next, the etching process removes only the slit portion of the ion generating electrode. Thereafter, the ion generating electrode 106 is formed to a thickness of about 20 μm on the glass dielectric layer using the thick film technique using the thick film technique. This method has a feature that the adhesive strength of each layer is strong.

The ion generator thus manufactured has the advantages of the glass layer and the polyimide layer used for the dielectric layer. The current is stable, and the ionic current is stable after several tens of hours of use. In addition, as compared with the case of only the polyimide layer, the time required to reach the life due to dielectric breakdown was increased from several hours to several tens of hours. In this way, a stable and long-life ion generator without deterioration of the dielectric layer surface resistance can be achieved. <Example 2>

Next, another embodiment for stabilizing the ion generator will be described with reference to FIGS. The reason that the amount of ions generated by the ion generator decreases is that nitrogen ions and nitrogen oxide ions generated during ion generation react with moisture in the air to form base ions such as nitrates on the surface of the dielectric layer. This is the result. As a result, the surface resistance of the dielectric layer decreases, the potential of the dielectric layer becomes the same as the potential of the ion generating electrode, and the electric field in the air between the ion generating electrode and the dielectric layer decreases, and the amount of generated ions decreases. In the present invention, attention is paid to the fact that the generated base is easily decomposed by heat of about 60 ° C., and the ion generation electrode or the induction electrode is formed of a resistor to form a heater, and the dielectric material near the ion generation electrode is efficiently formed. This is to stabilize the ion generator by heating the layer surface to prevent the generation of a base and eliminate fluctuations in the surface resistance of the dielectric layer.

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 increases, the ionic current that has decreased is recovered, and at a temperature of about 60 ° C., the base on the dielectric layer is almost completely decomposed, and the ionic current returns to a value close to the initial state.

Next, referring to FIG.
An example in which one or the induction electrode 202 is formed of a resistor to form a heater will be described. An induction electrode 202 is formed on a ceramic substrate (not shown) by sputtering with Ta ₂ N,
W, Cr, Ni-Cr, a resistor, such as SnO ₂ 100
A thickness of 0 to 2000 angstroms is formed. A glass dielectric layer 102 having a thickness of 〜20 μm is provided on the resistor by using a thick film printing technique, and an ion generating electrode 106 of a gold electrode is formed thereon by a thickness of 〜20 μm using a thick film printing technique. On the other hand, the ion generating electrode 201 may be a resistor using a thick film technique. At this time, Pd-A
g, a resistive paste such as RuO ₂ is formed on the dielectric layer 102 by screen printing and baking. The induction electrode does not need a resistor at this time, and may be formed by a conventional thick film or thin film technique. A current is supplied to the ion generating electrode or the induction electrode composed of the resistor of the ion generator configured as described above from the power supply different from the driving AC power supply in the paper direction,
The temperature of the surface 203 of the dielectric layer is heated to 60 ° C. or higher.
Heating the surface of the thus induced electrodes 60 ° C. or higher, and changes in other substances 205 do not contribute to conduction by the decomposition of the base 204, with a base such as nitrates which has been formed on the surface ^{to 109} The resistance value, which has decreased below Ω, increases, and the ion current returns to the value before deterioration.

A method of applying a voltage to the resistor will be described with reference to FIG. This figure shows an ion generator in which an ion generating electrode is formed of a resistor as viewed from the ion generating electrode side. An induction electrode 202 is formed on a ceramic substrate 206 to a thickness of several μm by a thick film technique, and a lead wire 208 for supplying an AC voltage 207 for ion generation is provided. The glass layer 102 is uniformly coated thereon by a thick film technique. Further, an ion generating electrode 201 made of a thick film resistor is provided thereon,
A voltage supply lead wire 209 is connected to the resistor by a thick film technique. An AC voltage 210 for ion generation is applied between the ion generation electrode and the induction electrode of the ion generator thus configured to generate ions. More ions
An ion current flows between the generating electrode and the counter electrode (not shown).
Bias voltage 211 is applied. A power supply 212 for heating the resistor is provided at both ends of the ion generating electrode.
Is connected to heat the dielectric layer to decompose the base formed on the surface of the dielectric layer to facilitate ion generation. At this time, when the temperature is detected and the power supply 212 for heating the resistor is controlled to stabilize the temperature, the generation of ions becomes stable and effective. <Example 3>

Next, a method for stabilizing the generation of ions when the surface resistance of the dielectric layer decreases will be described with reference to FIG. When an AC voltage for ion generation is applied when the surface resistance 301 of the dielectric layer 102 decreases, the potential on the surface of the dielectric layer at a point 302 away from the ion generation electrode 106 by a distance x becomes a capacitance 303 of the dielectric layer. Are sequentially charged from the vicinity of the ion generating electrode, and have the same potential as 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. 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 becomes higher before the potential between the ion generation electrode and the surface of the dielectric layer rises. No ions are generated because of the same potential as the electrodes. This time constant is given by the following equation. τ = R · Co · x ²

Here, R is the resistance per unit length of the dielectric layer surface, and Co is the capacitance per unit area of the dielectric layer. The surface resistance of the dielectric layer is set at 10 when the ion generating electrode between the slits is irradiated with ions after long-time use.
^It decreases from ¹² to about 10 ⁹ Ω. When the relative dielectric constant of the glass layer is 5, and the time constant at the center of the slit of 100 μm is calculated, it becomes １１０110 μsec. Therefore, almost 9
It is necessary to drive the ion generator with a high frequency voltage of kHz or more. As described above, the distance from the ion generation electrode at which the resistance value of the dielectric layer surface decreases and the potential of the dielectric surface becomes the same potential as the ion generation electrode is determined by a driving frequency of 30 kHz.
〜24 μm and at 150 kHz 〜１０10 μm. Therefore, when driving at a high frequency voltage of 150 kHz, Io
The potential of the region of the conduction generating electrode that is different from the vicinity of the dielectric layer is
As a result, ions are sufficiently generated.

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

This will be described in detail with reference to FIG. Induction electrode 101 provided with dielectric layer 102 interposed
When an AC voltage of 2.5 kV _PP is applied to the ion generating electrode 106 and the ion generating electrode 106, a potential distribution 401 indicated by a dotted line obtained by the boundary element method and electric fields 402 and 4 perpendicular to the potential distribution are obtained.
03 and the ion density distribution 404 on the ion generating electrode derived from the calculation are shown in the figure. When ions are generated in the air by the cosmic rays and the like, and the seeds of No. ions are accelerated by the electric field E and sequentially move in the air, they are multiplied by the multiplication coefficient α of the ions, and a large amount of ions are generated. Increases by forming secondary ions. The formation of the secondary ions requires a distance and an electric field for doubling the ions by colliding with air molecules. There is a relationship expressed by the following equation between the ion density n formed by the multiplication and the distance x and the electric field E. n = No / α ｛exp (α ・ x) -1｝ α = p ・ A ・ exp (-B ・ p / E)

Here, A and B are experimentally determined by proportional constants in air. P is the pressure at the time of ion generation. From the above formula, 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 is shown by a curve 404 in the figure. At the junction between the ion generating electrode and the dielectric layer, the electric field intensity 403 increases, but the flying distance of the ions is short, so that the generated ion density is low. On the other hand, above the ion generating electrode, the flight distance of the ions increases but the electric field is small, so that the amount of generated ions is also small. Thus, the upper part of the ion generating electrode
The amount of generated ions is maximum at μm. At this time,
The strong electric field near the junction between the ion generation electrode and the dielectric layer does not contribute to the generation of ions, but rather determines the life of the dielectric layer of the ion generator due to dielectric breakdown. 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 described with reference to FIG. On the dielectric electrode 101 and the glass layer 102 provided on the ceramic substrate by the thick film technique, a glass layer 405 having a thickness of about 5 μm is provided by the thick film technique so that the slit 104 is obtained. Further, on the glass layer 405, an ion generating electrode 106 is formed to a thickness of about 20 μm by 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 where the amount of generated ions is maximized in the ion generating electrode, the amount of generated ions does not decrease. In addition, ions generated from the junction between the ion generating electrode and the dielectric layer reach the dielectric layer 102 at a point 40.
8 ion bombardment is not ze raw directly on the dielectric layer surface in proximity to the ion generating electrode than reduced deterioration by ion bombardment of the dielectric layer.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this example, the insulating layer 408 provided between the ion generating electrode and the dielectric layer is several μm thicker than the ion generating electrode.
By projecting from m to more than 10 μm on the slit side of the dielectric layer, the electric field near the dielectric layer and the ion generation electrode where the electric field becomes maximum is weakened, and the area where the electric field on the dielectric layer becomes the maximum is more completely removed. It was done.

FIG. 10 incorporates both the example in which the dielectric layer according to the first embodiment has a two-layer structure and the present embodiment in which the electric field near the ion generating electrode is reduced. Induction electrode 1
A glass layer 409 having a thickness of 10 μm is provided on a dielectric layer 102 formed of a glass layer having a thickness of 15 μm provided on the substrate 01 and having a thickness of 10 μm in a slit having a width of 100 μm to project from several μm to tens of μm by a thick film technique. Furthermore, ~ 5 on this slit
The polyimide layer 410 having a thickness of μm is uniformly applied by a spinner or formed by using a thin film technique such as sputtering. Next, the polyimide layer other than the slit 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 about 20 μm by a thick film technique. In the ion generator configured as described above, the electric field applied between the ion generation 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 furthermore, since the surface of the dielectric layer is formed of a polyimide layer resistant to ion irradiation, there is no decrease in surface resistance due to ion irradiation,
Stable ion generation is obtained. <Example 5>

Next, another embodiment in which ions are efficiently generated from the ion generator and the generated ions are efficiently extracted will be described with reference to FIGS. FIG.
FIG. 3 is a diagram showing a voltage arrangement for obtaining an ion current from an ion generator. The AC voltage 210 applied to the induction electrode 101 and the ion generation electrode 106 of the ion generator generates ions 501 of both positive and negative polarities. Of these ions, the positive ion 502 becomes the counter electrode 50 by the bias voltage 211.
3 to generate an ion current. The ion generator includes an induction electrode 1 provided on a ceramic substrate (not shown).
01, and a thick glass layer 102 having a thickness of 20 μm as a dielectric layer is further provided thereon, and an ion generating electrode 106 having a slit 104 having a width of 100 μm is formed to constitute an ion generator.

An ion generator for efficiently generating ions at a low AC voltage will be described with reference to FIG. Ion generation electrode 106 and induction electrode 101
In order to generate an ion discharge in the air between the ion generating electrode and the dielectric layer at a low AC voltage when an AC drive voltage for generating ions is applied to the electrode, a leakage electric field 504 for generating ions that leaks through the dielectric layer is generated. Need to be bigger. Therefore, as shown in the following formula, the thickness in air, which is the ratio of the dielectric layer thickness d to the dielectric constant ε of the dielectric layer (ε = 5), is defined as the slit width (or the diameter of the hole). 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 an ion discharge is generated 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 a leakage electric field from the induction electrode exists outside the slit of the ion generating electrode, and the generated ions are kept at a low bias. The voltage can be extracted from the ion generator. 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 electric field leaked from only the inside of the slit 104 constituted by the ion generating electrode. Therefore, to extract the generated ions, it is necessary to apply a high bias voltage so that an electric field for accelerating the ions is generated in the slit.
In the present invention, the leaked electric field generated from the induction electrode is made to reach outside the slit, and the bias voltage is only the voltage for accelerating ions to the counter electrode. For that 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 actually manufactured ion generator, the thickness Dp of the ion generating electrode is 100 μm, and the slit width Lp is 20 μm.

In the ion generator formed in this manner, sufficient ions are generated at an applied AC voltage of 2.5 kV _PP , and the bias voltage is set such that the distance between the ion generator and the counter electrode is 250 mm. At this time, if the voltage is about 250 V, a sufficient ion current of about 3 × 10 ⁻⁶ A / cm can be obtained.

[0047]

According to the present invention, the ion generator according to the present invention does not have a complicated structure in which electrodes are attached on a special dielectric layer such as mica as in a conventional ion generator. To provide a structure that can be manufactured by thick film printing technology or thin film technology.

In this ion generator, the surface of the dielectric layer is made of a material having a small chemical material variation by ion irradiation.
The dielectric layer itself has a two-layer structure using a material having a high electric breakdown voltage, thereby achieving a stable and long-life ion generator. Furthermore, the lower limit frequency of the AC voltage at which ions can be generated even when the surface resistance of the dielectric layer is deteriorated is clarified. By driving at or above that frequency, the ion generation is stabilized even when the ion generator is deteriorated. Is given. Regarding the life of the ion generator, an insulating layer for weakening the electric field was provided between the ion generating electrode and the dielectric layer to prevent dielectric breakdown of the dielectric layer and extend the life. Further, at this time, the thickness of the dielectric layer converted into the dielectric constant in the air is made smaller than the slit width, and the leakage electric field in the slit space is increased to lower the AC voltage for driving, thereby reducing the AC drive power supply. It is possible to set the price by applying voltage. Furthermore, the thickness of the ion generating electrode is made smaller than the slit width so that the generated ions can be taken out with a low bias voltage, and the ions are ejected out of the slit by a leakage electric field. Ions can be extracted from the ion generator. This makes it possible to reduce the cost of the bias power supply. According to the above invention, a stable and long-life ion generator that can be mass-produced can be supplied at a low price.

[Brief description of the drawings]

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

FIG. 2 is a schematic cross-sectional view of another embodiment of the solid ion generator of the present invention having a two-layer dielectric layer.

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

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

FIG. 5 is a view for explaining a method of applying a 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 decrease in potential 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 the electric field intensity at the junction between the ion generating electrode and the dielectric layer according to 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 view showing another example of FIG. 8;

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

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

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

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 ... Induction electrode 102 ... Glass layer 103 ... Polyimide layer 104 ... Slit 105 ... Nickel layer 106 ... Ion generation electrode

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shuzo Hirahara 1 Kosuka Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside Toshiba Research Institute, Inc. Address Toshiba Research Institute, Inc. (56) References JP-A-54-53537 (JP, A) JP-A-62-181161 (JP, A) JP-A-61-286162 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B41J 2/415

Claims (3)

(57) [Claims] 1. A AC voltage between the dielectric interposed therebetween arrayed induction electrode and the ion generating electrode is applied, the ion generator for generating corona ions, the dielectric, the induction
Two or more types including a first dielectric layer formed on the conductive electrode side and a second dielectric layer formed on the ion generation electrode side and having less deterioration due to ion irradiation than the first dielectric layer. solid ion generator, characterized in that it comprises a dielectric layer. Wherein an AC voltage between the dielectric interposed therebetween arranged been induction electrode and the ion generating electrode is applied, the ion generator for generating corona ions, the dielectric, the induction
A glass layer formed on the conductive electrode side, two or more induction and a polyimide layer formed on the ion generating electrode side
A solid ion generator comprising an electric layer . Wherein an AC voltage is applied between induction disposed to sandwich a dielectric waveguide electrode and the ion generating electrode, the ion generator for generating ions in air from around the ion generating electrode, the induction electrode said dielectric body surface or ion generating electrode
A solid ion generator comprising a resistor for heating a surface .