JPH09226128A - Image forming device - Google Patents

Abstract

(57) An object of the present invention is to provide an image forming apparatus having a high ejection frequency and capable of forming a high density and high quality image. An inkjet printer includes a recording head 10 disposed below a platen roller 4 so as to face each other. The recording head 10 includes a rectangular plate-shaped substrate 32 having a substantially horizontal upper surface 32a. On the upper surface 32a, a plurality of ejection electrodes 34 protruding toward the platen roller 4,
A wiring pattern 36, an insulating layer 42, and an aggregating electrode 44, which are drawn from the ejection electrode 34, are formed. Also,
The recording head 10 holds the substrate 32 at a predetermined position and also supports members 47, 48 that form the ink flow path 50.
Has 49. The ink flowing through the ink flow path 50 is
The liquid surface is regulated by the regulation blades 48b and 49b, and an ink meniscus is formed at the spherical crown-shaped tip of the ejection electrode 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image by causing an electrostatic force to act on an ink in which colorant particles are dispersed in an insulating liquid carrier and causing an ink droplet to fly onto a recording medium. .

[0002]

2. Description of the Related Art In recent years, ink jet printers using an ink jet recording system have become widespread in the personal printer field. However, conventional ink jet printers have problems such as poor image storability and light fastness because dye ink is used.

On the other hand, WO 93/1186 discloses an image forming apparatus which enables the use of pigment particles as a colorant and solves the above problems of dye-based ink. This device includes a conductive ink supply tube, and a voltage is applied between the ink supply tube and a counter electrode facing the tip. As a result, the ink containing the pigment particles (hereinafter, referred to as charged toner) charged to the same polarity as the potential of the ink supply tube is supplied to the ink supply tube.

[0004] The charged toner in the ink receives an electrostatic attraction force from the counter electrode at a discharge point near the tip of the ink supply tube to form a semicircular ink meniscus. However, due to the surface tension of the solvent of the ink, the toner cannot fly from the ink meniscus and stays at the tip of the ink meniscus. In this way, a large amount of toner gathers at the tip of the ink meniscus and becomes an aggregate. When the voltage between the ink supply tube and the counter electrode is further increased, the electrostatic attraction force exceeds the surface tension of the solvent of the ink, and toner aggregates fly from the ink meniscus.

In an image forming apparatus based on the above-described flying principle, since there is no nozzle for determining a flying droplet size as in the conventional ink jet recording, pigment particles can be used. Therefore, the problems of image storability and light resistance, which are problems of the conventional inkjet printer, can be solved.

[0006]

However, the conventional image forming apparatus using the ink liquid containing the toner also has the following problems. That is, in the conventional image forming apparatus, it takes a lot of time to collect a sufficient amount of toner necessary for flight at the tip of the ink meniscus formed at the ejection point of the ink supply tube. Therefore, there is a problem that the ink cannot be ejected at a high ejection frequency. Further, when the ink ejection frequency is increased, the aggregation of the toner at the tip of the ink meniscus becomes insufficient, and the toner concentration in the flying ink decreases. This makes it impossible to achieve the desired image density,
There is a problem that a high quality image cannot be formed. The present invention has been made in view of the above points, and an object thereof is to provide an image forming apparatus having a high ejection frequency and capable of forming a high-quality image with high density.

[0007]

In order to achieve the above object, an image forming apparatus according to the present invention supplies ink formed by dispersing charged colorant particles in an insulating liquid and is supplied substantially horizontally. And an ink supply means for forming a liquid surface of the ink at a position spaced apart by a predetermined distance below the recording medium, and a protrusion provided from the liquid surface of the ink, which is ejected higher than the liquid surface due to creeping due to wetting of the ink. A guide member that guides the ink to a position, and a first electric field is formed around the guide member to aggregate the colorant particles in the ink near the vertex of the ink guided to the ejection position by the guide member. And a second electric field larger than the first electric field is formed between the guide member and the recording medium, and the colorant particles aggregated by the aggregating means are directed toward the recording medium. Comprises a jetting unit for Xiang, the.

Further, the image forming apparatus of the present invention supplies an ink in which charged colorant particles are dispersed in an insulating liquid and is positioned below a recording medium supplied substantially horizontally at a position separated by a predetermined distance. An ink supply unit that forms a liquid surface of the ink, a guide member that is provided so as to project from the liquid surface of the ink, and that guides the ink to a discharge position higher than the liquid surface by creeping up due to wetting of the ink, A first electric field is formed around the guide member, and an aggregating unit for aggregating the colorant particles in the ink near the apex of the ink guided to the ejection position by the guide member, and a larger electric field than the first electric field. Flying means for forming a second electric field between the guide member and the recording medium to fly the colorant particles aggregated by the aggregating means toward the recording medium.
And the guide member has a spherical surface protruding from the liquid surface.

Further, in the image forming apparatus of the present invention, charged colorant particles are immersed in the insulating liquid on a substantially horizontal surface which is arranged below the recording medium supplied substantially horizontally and separated by a predetermined distance. Ink supply means for supplying dispersed ink,
A tip end of a guide member that is provided on the substantially horizontal surface and guides the ink so that the liquid surface of the ink approaches the recording medium by creeping up due to wetting of the ink supplied by the ink supply means. And a liquid level regulating means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the ejection electrode, and the guide member. In the vicinity of the apex of the guide member by the aggregating means for applying a bias voltage to the ejection electrode for aggregating the colorant particles in the ink near the apex of the ink brought close to the recording medium. Flying means for applying a recording voltage higher than the bias voltage for flying the colorant particles aggregated in the recording medium toward the recording medium,
It has.

Further, in the image forming apparatus of the present invention, the charged colorant particles are dispersed in the insulating liquid on the substantially horizontal surface which is arranged below the recording medium supplied substantially horizontally with a predetermined distance. Ink supply means for supplying dispersed ink,
A tip end of a guide member that is provided on the substantially horizontal surface and guides the ink so that the liquid surface of the ink approaches the recording medium by creeping up due to wetting of the ink supplied by the ink supply means. And a liquid level regulating means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the ejection electrode, and the guide member. In the vicinity of the apex of the guide member by the aggregating means for applying a bias voltage to the ejection electrode for aggregating the colorant particles in the ink near the apex of the ink brought close to the recording medium. Flying means for applying a recording voltage higher than the bias voltage for flying the colorant particles aggregated in the recording medium toward the recording medium,
And the guide member has a spherical surface for bringing the liquid surface closer to the recording medium.

Further, in the image forming apparatus of the present invention, the charged colorant particles are dispersed in the insulating liquid on the substantially horizontal surface which is arranged below the recording medium supplied substantially horizontally at a predetermined distance. Ink supply means for supplying dispersed ink,
A tip end of a guide member that is provided on the substantially horizontal surface and guides the ink so that the liquid surface of the ink approaches the recording medium by creeping up due to wetting of the ink supplied by the ink supply means. And a liquid level regulating means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the ejection electrode, and the guide member. In the vicinity of the apex of the guide member by the aggregating means for applying a bias voltage to the ejection electrode for aggregating the colorant particles in the ink near the apex of the ink brought close to the recording medium. Flying means for applying a recording voltage higher than the bias voltage for flying the colorant particles aggregated in the recording medium toward the recording medium,
The guide member is formed of an insulating material having a spherical surface for bringing the liquid surface closer to the recording medium.

Further, in the image forming apparatus of the present invention, the charged colorant particles are dispersed in the insulating liquid on the substantially horizontal surface which is arranged below the recording medium supplied substantially horizontally with a predetermined distance. Ink supply means for supplying dispersed ink,
A tip end of a guide member that is provided on the substantially horizontal surface and guides the ink so that the liquid surface of the ink approaches the recording medium by creeping up due to wetting of the ink supplied by the ink supply means. And a liquid level control means for controlling the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the discharge electrode; In the vicinity of the ejection electrode, the aggregation electrode provided around the ejection electrode in an insulating state from the ejection electrode and the coloring material particles in the ink supplied on the substantially horizontal surface by the ink supply means are provided. A first aggregating means for applying an aggregating voltage for collecting to the aggregating electrode, and coloring material particles collected in the vicinity of the discharge electrode by the first aggregating means near the recording medium by the guide member. A second aggregation means for applying a bias voltage lower than the aggregation voltage for further agglomeration to near the top of the ink to the ejection electrodes, the first and second
And flying means for applying a recording voltage higher than the bias voltage for causing the colorant particles, which are aggregated near the apex of the guide member by the aggregating means, toward the recording medium, to the ejection electrode. .

Further, the image forming apparatus of the present invention comprises a substrate having a substantially horizontal upper surface which is arranged below the recording medium supplied substantially horizontally with a predetermined distance, and an upper surface of the substrate.
An ink supply unit that supplies an ink having a predetermined thickness by dispersing charged colorant particles in an insulating liquid and flows in a predetermined direction along the upper surface, and a flow of the ink on the upper surface of the substrate. A tip end of a spherical guide member that is provided so as to project in a transverse direction and guides the ink so that the liquid surface of the ink approaches the recording medium by the creeping due to the wetting of the ink supplied by the ink supply means. A plurality of discharge electrodes, a wiring pattern formed on the upper surface of the substrate along the ink flow direction on the upstream side of each discharge electrode, and drawn from each discharge electrode, and the ink supply means. Liquid level control means for controlling the liquid level of the ink supplied on the substantially horizontal surface to a predetermined height lower than the tips of the plurality of ejection electrodes, and an insulating layer on the wiring pattern. And a comb-teeth-shaped electrode that is arranged to extend in the ink flow direction with the same pitch as the wiring pattern and a half pitch offset, and is provided on the downstream side of each ejection electrode in an insulated state from each ejection electrode. The aggregating electrode having a wavy electrode having a continuous arc portion concentric with the guide member of each ejection electrode, and coloring agent particles in the ink supplied on the substantially horizontal surface by the ink supply means. A first aggregating means for applying an aggregating voltage to the aggregating electrode to collect it in the vicinity of the respective discharge electrodes, and colorant particles collected in the vicinity of the respective discharge electrodes by the first aggregating means
Second aggregating means for applying a bias voltage lower than the aggregating voltage to the ejection electrodes for aggregating the ink closer to the recording medium by the guide member near the apex of the ink, and the first and second aggregating means. The ejection electrode selected by a recording means in accordance with an image signal has a recording voltage higher than the bias voltage for causing the colorant particles aggregated near the apex of the guide member of each ejection electrode to fly toward the recording medium. And a flight means for selectively applying to the.

Further, the image forming apparatus of the present invention comprises a substrate having a substantially horizontal upper surface which is arranged below the recording medium supplied substantially horizontally with a predetermined distance, and an upper surface of the substrate.
An ink supply unit that supplies an ink having a predetermined thickness by dispersing charged colorant particles in an insulating liquid and flows in a predetermined direction along the upper surface, and a flow of the ink on the upper surface of the substrate. A tip end of a spherical guide member that is provided so as to project in a transverse direction and guides the ink so that the liquid surface of the ink approaches the recording medium by the creeping due to the wetting of the ink supplied by the ink supply means. A plurality of discharge electrodes, a wiring pattern formed on the upper surface of the substrate along the ink flow direction on the upstream side of each discharge electrode, and drawn from each discharge electrode, and the ink supply means. Liquid level control means for controlling the liquid level of the ink supplied on the substantially horizontal surface to a predetermined height lower than the tips of the plurality of ejection electrodes, and an insulating layer on the wiring pattern. And a comb-teeth-shaped electrode that is arranged to extend in the ink flow direction with the same pitch as the wiring pattern and a half pitch offset, and is provided on the downstream side of each ejection electrode in an insulated state from each ejection electrode. The aggregating electrode having a wavy electrode having a continuous arc portion concentric with the guide member of each ejection electrode, and coloring agent particles in the ink supplied on the substantially horizontal surface by the ink supply means. A first aggregating means for applying an aggregating voltage to the aggregating electrode to collect it in the vicinity of the respective discharge electrodes, and colorant particles collected in the vicinity of the respective discharge electrodes by the first aggregating means
Second aggregating means for applying a bias voltage lower than the aggregating voltage to the ejection electrodes for aggregating the ink closer to the recording medium by the guide member near the apex of the ink, and the first and second aggregating means. The ejection electrode selected by a recording means in accordance with an image signal has a recording voltage higher than the bias voltage for causing the colorant particles aggregated near the apex of the guide member of each ejection electrode to fly toward the recording medium. And a flying means for selectively applying to the substrate. The substrate is formed with a bypass opening for diverting the insulating liquid in the ink flowing on the upper surface of the substrate from the upper surface to the lower surface of the substrate. .

In the image forming apparatus of the present invention, a dielectric film having a substantially horizontal upper surface which is arranged below the recording medium supplied substantially horizontally with a predetermined distance therebetween, and an upper surface of the dielectric film. An ink supply unit that supplies an ink formed by dispersing charged colorant particles in an insulating liquid in a predetermined thickness and flows in a predetermined direction along the upper surface, and the ink on the upper surface of the dielectric film. A tip of a guide member that is provided so as to project in a direction transverse to the flow of the ink, and that guides the ink so that the liquid surface of the ink approaches the recording medium by the creeping due to the wetting of the ink supplied by the ink supply means. A plurality of discharge electrodes,
A wiring pattern that extends along the flow direction of the ink on the lower surface of the dielectric film on the upstream side of the ejection electrodes, penetrates the dielectric film, and is connected to the ejection electrodes, and the ink supply. Disposed on the upper surface of the dielectric film, and liquid level regulating means for regulating the liquid level of the ink supplied on the upper surface of the dielectric film to a predetermined height lower than the respective tips of the plurality of ejection electrodes. A comb-teeth-shaped electrode provided on the upstream side of each of the ejection electrodes and extending in the ink flow direction at the same pitch as the wiring pattern and a half pitch, and each of the ejection electrodes on the downstream side of each of the ejection electrodes. An aggregating electrode that is provided in an insulating state and has a wavy electrode that has an edge portion that is continuous with a circular arc that is concentric with the guide member of each of the discharge electrodes; First aggregating means for applying an aggregating voltage to the aggregating electrode for aggregating the colorant particles in the supplied ink to the aforesaid respective ejecting electrodes, and the first aggregating means to aggregate in the vicinity of the respective ejecting electrodes. Second aggregating means for applying a bias voltage, which is lower than the aggregating voltage, to each of the ejection electrodes for aggregating the colorant particles near the apex of the ink brought closer to the recording medium by the guide member; A recording voltage higher than the bias voltage for causing the colorant particles aggregated near the apex of the guide member of each ejection electrode by the first and second aggregating means to fly toward the recording medium is selected according to the image signal. And a flying means for selectively applying to the ejected electrodes.

Further, the image forming apparatus of the present invention has a dielectric film having a substantially horizontal upper surface which is arranged below the recording medium supplied substantially horizontally with a predetermined distance therebetween, and an upper surface of the dielectric film. An ink supply unit that supplies an ink formed by dispersing charged colorant particles in an insulating liquid in a predetermined thickness and flows in a predetermined direction along the upper surface, and the ink on the upper surface of the dielectric film. And a spherical guide member that is provided so as to project in a direction transverse to the flow of the ink and that guides the ink so that the liquid surface of the ink approaches the recording medium due to the creep of the ink supplied by the ink supply means due to wetting. A plurality of ejection electrodes each having at its tip, and extending along the flow direction of the ink on the lower surface of the dielectric film and on the upstream side of each ejection electrode, The wiring pattern penetratingly connected to each of the ejection electrodes and the liquid surface of the ink supplied to the upper surface of the dielectric film by the ink supply unit have a predetermined height lower than the tips of the plurality of ejection electrodes. And a comb provided on the upper surface of the dielectric film and extending in the ink flow direction at the same pitch and half pitch as the wiring pattern on the upstream side of each discharge electrode. A toothed electrode, and an aggregating electrode having a wavy electrode that is provided in an insulated state with each of the ejection electrodes on the downstream side of each of the ejection electrodes, and has a wavy electrode having a continuous arc portion concentric with the guide member of each of the ejection electrodes, First aggregating means for applying an aggregating voltage to the aggregating electrodes for gathering the colorant particles in the ink supplied to the upper surface of the dielectric film by the ink supplying means to the vicinity of the discharge electrodes, A bias voltage lower than the aggregating voltage for further aggregating the colorant particles collected in the vicinity of the ejection electrodes by the first aggregating means near the apex of the ink approached to the recording medium by the guide member. Second aggregating means for applying to the ejection electrodes, and the colorant particles agglomerated by the first and second aggregating means near the apexes of the guide members of the ejection electrodes are ejected toward the recording medium. And a flying means for selectively applying a recording voltage higher than the bias voltage to the ejection electrode selected according to an image signal, and the guide member brings the liquid surface of the ink close to the recording medium. Is formed of an insulating material having a spherical surface for.

In the image forming apparatus of the present invention, a dielectric film having a substantially horizontal upper surface which is disposed below the recording medium supplied substantially horizontally and separated by a predetermined distance, and an upper surface of the dielectric film. An ink supply unit that supplies an ink formed by dispersing charged colorant particles in an insulating liquid in a predetermined thickness and flows in a predetermined direction along the upper surface, and the ink on the upper surface of the dielectric film. And a spherical guide member that is provided so as to project in a direction transverse to the flow of the ink and that guides the ink so that the liquid surface of the ink approaches the recording medium due to the creep of the ink supplied by the ink supply means due to wetting. A plurality of ejection electrodes each having at its tip, and extending along the flow direction of the ink on the lower surface of the dielectric film and on the upstream side of each ejection electrode, The wiring pattern penetratingly connected to each of the ejection electrodes and the liquid surface of the ink supplied to the upper surface of the dielectric film by the ink supply unit have a predetermined height lower than the tips of the plurality of ejection electrodes. And a comb provided on the upper surface of the dielectric film and extending in the ink flow direction at the same pitch and half pitch as the wiring pattern on the upstream side of each discharge electrode. A toothed electrode, and an aggregating electrode having a wavy electrode that is provided in an insulated state with each of the ejection electrodes on the downstream side of each of the ejection electrodes, and has a wavy electrode having a continuous arc portion concentric with the guide member of each of the ejection electrodes, First aggregating means for applying an aggregating voltage to the aggregating electrodes for gathering the colorant particles in the ink supplied to the upper surface of the dielectric film by the ink supplying means to the vicinity of the discharge electrodes, A bias voltage lower than the aggregating voltage for further aggregating the colorant particles collected in the vicinity of the ejection electrodes by the first aggregating means near the apex of the ink approached to the recording medium by the guide member. Second aggregating means for applying to the ejection electrodes, and the colorant particles agglomerated by the first and second aggregating means near the apexes of the guide members of the ejection electrodes are ejected toward the recording medium. A flying means for selectively applying a recording voltage higher than the bias voltage to the ejection electrodes selected according to an image signal, and the dielectric film is provided in the ink flowing on the upper surface of the dielectric film. A bypass port for diverting the insulating liquid is formed so as to penetrate from the upper surface to the lower surface of the dielectric film.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, an inkjet printer 1 as an image forming apparatus of the present invention includes a housing 2. At a predetermined position in the housing 2, a cylindrical platen roller 4 for holding the recording paper P as a recording medium and conveying it in a predetermined direction is arranged. The platen roller 4 is made of a conductive material, is grounded, or is given a predetermined potential if necessary, and acts as a counter electrode.

Below the platen roller 4, a recording head 10, which will be described later, for flying an ink on the recording paper P conveyed by the platen roller 4 to form an image is arranged oppositely at a position separated by a predetermined distance. . That is, the recording head 10 forms an image on the recording paper P by ejecting ink approximately vertically upward.

Below the recording head 10 and at the bottom of the housing 2, an ink containing portion 12 containing ink is arranged. Further, a pump 14 for pumping up the ink in the ink containing portion 12 to the recording head 10 via the ink supply pipe 11 is provided on the left bottom portion of the housing 2. The pump 14 supplies ink to the recording head 10 at a predetermined ink supply pressure and a predetermined flow rate. The ink containing portion 12, the pump 14, and the ink supply pipe 11 function as the ink supply means of the present invention.

In the recording head 10, the excess ink supplied to the recording head 10 but not used is stored in the ink container 1.
An ink recovery pipe 13 for recovery to 2 is connected. A suction device 16 is connected to the ink containing portion 12. The suction device 16 creates a negative pressure in an area above the ink surface in the ink containing portion 12. Then, by this negative pressure, the excess ink is collected in the ink containing portion 12 via the ink collecting pipe 13.

Here, the components of the above-described ink will be described. That is, the ink is configured by dispersing the toner as the charged colorant particles in the carrier liquid as the insulating liquid. The carrier liquid is, for example, a dispersion medium made of an isoparaffinic solvent (for example, Isopar G, H, L (trade name) having a DC electric resistance of 10 ¹² to 10 ¹³ ohm · cm or more when a voltage of 100 V is applied). The toner has a particle size of, for example, about 0.01 to 5 μm, and is charged to a predetermined potential (here, a positive potential),
The resin particles have at least a coloring component. This ink is basically the same as the liquid developer used in electrophotography and the like, but is required to have a higher electric resistance than the liquid developer.

The above ink is pumped up from the ink container 12 by the pump 14 and supplied to the recording head 10 through the ink supply pipe 11. Excess ink that has not been ejected by the recording head 10 is sucked through the ink recovery pipe 13 by the negative pressure of the suction device 16 and is recovered in the ink containing portion 12. In this way, the ink is circulated and used in the recording head 10.

The toner concentration of the ink collected in the ink containing section 12 is lowered due to image formation (toner flying), and it is necessary to adjust the toner concentration of the ink to an appropriate value for reuse. . Therefore, the ink containing portion 1
A detector 18 for detecting the toner concentration of the ink flowing in the pipe is provided in the bypass pipe 15 between the pump 2 and the pump 14 and in the middle of the ink supply pipe 11. Also,
An ink replenishing container 17 for replenishing the ink containing portion 12 with high-concentration ink whose toner concentration is adjusted to a predetermined value is disposed above the ink containing portion 12. Then, by supplying a predetermined amount of high-concentration ink according to the detection result of the detector 18, the ink density in the ink containing portion 12 is maintained at a predetermined value.

Since the toner in the ink has a lower specific gravity than the carrier liquid, it is necessary to stir and supply the ink in the ink containing portion 12. For this reason, a stirring device 19 for stirring the ink stored in the ink storage portion 12 is provided in the ink storage portion 12. The ink in the ink containing portion 12 is constantly stirred by the stirring device 19 so that the toner is uniformly dispersed in the ink and is pumped up by the pump 14 to be supplied to the recording head 10.

At a position adjacent to the right side of the platen roller 4 in the drawing, a recording paper accommodating cassette 21 (hereinafter, simply referred to as a paper feeding cassette 21) accommodating a plurality of recording papers P in a stacked state is arranged. ing. A paper feed roller 24 for taking out the recording paper P stored in the paper feed cassette 21 from the uppermost one is rotatably provided near the end of the paper feed cassette 21 on the platen roller 4 side. A mechanism (not shown) for pushing up the leading end of the recording paper P in the transport direction toward the paper feed roller 24 is provided in the paper feed cassette 21.

Between the front end of the paper feed cassette 21 and the platen roller 4, a paper feed roller 24 is provided between the paper feed cassette 21 and the platen roller 4.
A pair of registration rollers 26 are provided for aligning the recording paper P taken out from the platen roller 4 once and then conveying it.

On the downstream side of the platen roller 4, there is provided a paper ejection tray 28 for ejecting the recording paper P which has passed through the recording head 10 and on which an image has been formed. Further, between the platen roller 4 and the paper discharge tray 28, a pair of paper discharge rollers 27 that conveys the recording paper P that has been conveyed via the platen roller 4 toward the paper discharge tray 28 is provided. A plurality of transport guides 25 and guide rollers 29 are provided on the transport path of the recording paper P from the paper feed cassette 21 to the paper discharge tray 28.

The recording paper P taken out from the paper feed cassette 21 by the rotation of the paper feed roller 24 is nipped and conveyed by the registration rollers 26 and supplied between the platen roller 4 and the recording head 10. At this time, the recording paper P
Are conveyed in contact with the outer peripheral surface of the platen roller 4, and are substantially horizontal at a position facing the recording head 10. The recording paper P conveyed along the outer peripheral surface of the platen roller 4 is nipped and conveyed by the paper ejection rollers 27 and ejected onto the paper ejection tray 28.

A controller 20 for driving and controlling each mechanism of the ink jet printer 1 is provided on the upper right side of the housing 2 and above the paper feed cassette 21. The controller 20 generates an image signal for selectively driving each ejection electrode (described later) of the recording head 10.

Next, the recording head 10 according to the first embodiment of the present invention will be described in detail. As shown in FIG. 2, the recording head 10 has a rectangular plate-shaped insulating substrate 32 having a substantially horizontal upper surface 32a which is arranged below the platen roller 4 with a predetermined distance therebetween. Substrate 32
Is arranged so that its front end 32b is located substantially directly below the platen roller 4 and its rear end 32c is located away from the paper feed cassette 21 and away from it.

Then, the ink supplied through the ink supply pipe 11 arranged above the rear end 32c of the substrate 32 makes the rear end 3 of the substrate 32 move on the substantially horizontal upper surface 32a of the substrate 32.
From 2c side toward tip 32b side (in the direction of arrow A in the figure)
The ink flows and is collected via the ink collecting pipe 13 arranged below the tip 32b of the substrate 32. In this case, the flow direction of the ink flowing on the upper surface 32a of the substrate 32 is opposite to the conveying direction of the recording paper P (the arrow B direction in the drawing).

A plurality of ejection electrodes 34 arranged in a line in a direction traversing the conveyance direction of the recording paper P (or the ink flow direction) are provided on the upper surface 32a of the substrate 32 near the tip 32b, which faces the platen roller 4. (See FIGS. 3 and 4). The number of ejection electrodes 34 is provided according to the recording resolution. Each ejection electrode 34 is connected to the platen roller 4
Is provided so as to project upward toward the platen roller 4, and the distance from the tip of each ejection electrode 34 to the platen roller 4 is set to a predetermined value.

A wiring pattern 36 drawn from each ejection electrode 34 is formed on the upper surface 32a of the substrate 32, and the vicinity of the rear end 32c of the substrate 32 to the vicinity of the tip 32b (each ejection electrode) is formed along the ink flow direction. 34). An end portion of the wiring pattern 36 extending to the vicinity of the rear end 32c of the substrate 32 is connected to a power source described later via a flexible wiring board 38 made of a flexible film and an IC (not shown).

Each ejection electrode 34 has a pad 34a made of a substantially cylindrical conductive material electrically connected to the wiring pattern 36, and a substantially hemispherical tip 34b (guide member) formed on the upper surface of the pad 34a. ), And is formed in the shape of a spherical crown. The tip portion 34b is formed of a metal having a relatively large surface tension when melted, for example, solder.

The tip of the discharge electrode 34 in the shape of a spherical cap does not have a sharp shape in which the electric field is concentrated, which is opposed to the platen roller 4, and has a shape with good ink wettability.
The radius of this spherical crown portion is preferably 20 to 50 μm.
Is set to

Further, an insulating layer 42 that covers the wiring pattern 36 is provided on the upper surface 32a of the substrate 32. In this case, the ejection electrode 34 penetrates the insulating layer 42 and passes through the insulating layer 42.
It projects more upward. On the upper surface 42a of the insulating layer 42 and around the ejection electrode 34 protruding from the insulating layer 42,
The aggregation electrode 44 is provided in a non-contact state with the ejection electrode 34 and the wiring pattern 36.

The aggregating electrode 44 is composed of a comb-teeth-shaped electrode 44a provided upstream of the ejection electrode 34 in the ink flow direction and a corrugated electrode 44b provided downstream of the ejection electrode 34 in the ink flow direction. Has been done.

As shown in FIG. 8, the comb-shaped electrode 44a is
A plurality of (one more than the ejection electrode 34) needle-shaped electrodes 441 are provided between the wiring patterns 36 (and on both sides) at the same pitch as the wiring pattern 36 of the ejection electrode 34 and shifted by a half pitch. There is. These needle electrodes 441 are
It extends from the upstream side in the ink flow direction to the vicinity of the ejection electrode 34. The corrugated electrode 44b is provided on the downstream side of each ejection electrode 34 in the ink flow direction, and has a corrugated edge portion 442 having a continuous arc shape concentric with each ejection electrode 34. Incidentally, the comb-shaped electrode 44a and the wavy electrode 44
b is projected on the upper surface 42a of the insulating layer 42.

As shown in FIG. 5, the recording head 10 has a structure for holding the substrate 32 having the ejection electrode 34 and the aggregating electrode 44 at a predetermined position in the housing 2 as described above.
It comprises a support member consisting of two parts 47, 48, 49. Each of the support members 47, 48, 49 forms a flow path 50 for the ink supplied to the recording head 10 via the ink supply pipe 11 together with the substrate 32. In addition, each support member 4
7, 48, and 49 are made of an insulating material, and a material having a good ink wettability is used.

The support member includes a first support member 47 that supports the lower surface 32d side of the substrate 32, and a second support member 48 that supports the upper surface 32a side of the substrate 32 and the upstream side of the ejection electrode 34 in the ink flow direction. And a third support member 49 for supporting the upper surface 32a side of the substrate 32 and the downstream side of the ejection electrode 34 in the ink flow direction.

The first support member 47 has an upper surface in which a recess 47a for fitting the substrate 32 is formed. Recess 4
At a predetermined position of 7a, that is, at a position where the tip 32b of the substrate 32 is opposed, a rectangular groove 4 forming a part of the ink flow path 50 is formed.
7b is formed. Further, the groove 47b has a groove 47b.
47 penetrating from the lower surface of the base plate to the lower surface of the first support member 47
c is formed. The ink collecting pipe 13 for collecting the ink flowing on the upper surface 32a of the substrate 32 is connected to the hole 47c.

The second support member 48 is the upper surface 32 of the substrate 32.
It has a lower surface facing a, and a groove 48a forming a part of the ink flow path 50 is provided at a substantially central position of the lower surface. The ink supply pipe 11 penetrating from the upper surface side of the second support member 48 is connected to the groove 48a. A regulation blade 48b for regulating the liquid level of the ink supplied to the ejection electrode 34 to a predetermined height is formed at the tip of the second support member 48, that is, the end portion on the downstream side in the ink flow direction. The second support member 48 is positioned so that the regulation blade 48b is adjacent to a predetermined position on the downstream side of the ejection electrode 34, and is screwed to the first support member 47.

The third support member 49 is the first support member 4 described above.
The groove 47b of No. 7 and the groove 48a of the second support member 48 have a groove 49a in which an ink flow path 50 is formed. At the rear end of the third support member 49, that is, the end portion on the upstream side in the ink flow direction, together with the restriction blade 48b of the second support member 48, a restriction blade 49b that restricts the liquid surface height of the ink supplied to the ejection electrode 34. Are formed. The third support member 49 is positioned so that the restriction blade 49b is adjacent to a predetermined position on the upstream side of the ejection electrode 34, and is screwed to the first support member 47. The restriction blades 48b, 4
9b acts as the liquid level control means of the present invention.

Therefore, the ink supplied into the recording head 10 through the ink supply pipe 11 is the second support member 48.
Groove 48a, groove 49a of the third supporting member 47, groove 47b of the first supporting member 47, and the substrate 32 and the ink flow path 50 defined between the substrate 32 and the ink collecting pipe 13. It At this time, the heights of the regulation blades 48b and 49b are set so that the liquid level of the ink supplied to the ejection electrode 34 is slightly lower than the tip of the ejection electrode 34.

Next, the structure for ejecting ink and the ink ejecting operation in the recording head 10 constructed as described above will be described in detail with reference to FIGS. 6 and 7.

As shown in FIG. 6, to the wiring pattern 36 of the ejection electrodes 34, a recording voltage Vej for ejecting ink in response to an image signal from the controller 20 is selectively applied to each ejection electrode 34. Power source 62 (aggregating means [second aggregating means] or flying means) is connected through an IC (not shown). Further, the power source 62 applies a bias voltage Vb for forming Taylor cones (described later) having high ink density to the tips of all the ejection electrodes 34. A power supply 64 for applying an aggregation voltage Vep for aggregating the toner in the ink supplied to the ejection electrode 34 near the ejection electrode 34 to the aggregation electrodes 44a and 44b.
(Aggregating means [first aggregating means]) is connected. In the present embodiment, the bias voltage Vb <the aggregation voltage Ve
It was set to p <recording voltage Vej.

The ink drawn up from the ink container 12 by the pump 14 is supplied into the ink flow path 50 through the ink supply pipe 11 with a predetermined supply pressure. The ink 51 supplied into the ink flow path 50 is the substrate 32.
It flows over the (insulating layer 42 and the aggregating electrode 44) in the direction of arrow A in the figure, flows through the tip 32b of the substrate 32 into the flow path on the lower surface 32d side of the substrate 32, and passes through the ink recovery tube 13 and the ink containing portion 12. Be recovered to.

In this case, the regulating blade 48b of the second supporting member 48 and the regulating blade 49b of the third supporting member 49.
Thus, the liquid level of the ink 51 supplied to the ejection electrode 34 is regulated to a predetermined value. The liquid level of the ink 51 is set at a position lower than the tip of the ejection electrode 34, preferably 5 to 30 μm. The liquid surface height of the ink 51 is determined by the wettability between the ink 51 and the ejection electrode 34, the viscosity of the ink 51, and the tip shape of the ejection electrode 34. A thin layer of the ink 51 is formed at the ejection position near the tip of the ejection electrode 34. Is set to a value capable of forming the ink meniscus 52 consisting of.

As described above, by lowering the liquid surface of the ink 51 from the tip of the ejection electrode 34, the toner concentration in the Taylor cone formed at the tip of the ejection electrode 34 can be increased, and high density printing can be performed. . However, when the liquid surface of the ink 51 is located at a position higher than the tip of the ejection electrode 34, that is, when the tip of the ejection electrode 34 does not protrude from the ink surface, the dominance of the carrier liquid in the Taylor cone becomes high, and the ink The voltage value required to fly 51 becomes high, the proportion of the carrier liquid flying becomes high, the toner concentration of the flying ink 51 drops, and a good image cannot be obtained. Therefore, in the present embodiment, the liquid surface of the ink 51 is set at a position lower than the tip of the ejection electrode 34.

When the ink 51 is supplied and the ink meniscus 52 is formed at the tip of the ejection electrode 34 as described above, the bias voltage Vb is applied to all the ejection electrodes 34 via the power supply 62. When the bias voltage Vb is applied to each ejection electrode 34, a first electric field is formed in the direction indicated by the arrow E in the figure between the ejection electrode 34 and the platen roller 4 as a counter electrode which is grounded.

Due to the electric field E and the surface tension of the ink 51, the toner 53 in the ink 51 is transferred to the ink meniscus 5.
2 centrally (see FIG. 7). When the toner 53 is collected in the center of the ink meniscus 52, a strong electrostatic force due to the electric field E acts on the collected toner aggregates 55,
A tailor cone 56 protruding toward the platen roller 4 is formed at the center of the ink meniscus 52. In this case, the bias voltage Vb is set so that the ink drop 57 including the toner aggregates 55 does not fly due to the electrostatic force generated by the electric field E.

When the recording voltage Vej higher than the bias voltage Vb is applied to the ejection electrode 34 by the power source 62 with the tailor cone 56 thus formed, a second electric field larger than the first electric field is formed. The electrostatic force acting on the toner aggregate 55 due to the electric field of 2 overcomes the surface tension of the ink 51, and the ink droplet 5 containing the toner aggregate 55.
7 flies from the tip of the tailor cone 56 toward the platen roller 4.

Next, the operation of the above-mentioned aggregating electrode 44 (comb-shaped electrode 44a and corrugated electrode 44b) will be described with reference to FIG. As described above, in the state where the bias voltage Vb is applied to all the ejection electrodes 34 (before the recording voltage Vej is applied), the recording voltage Vb is higher than the bias voltage Vb.
When the aggregation voltage Vep lower than ej is applied to the comb-teeth electrode 44a and the corrugated electrode 44b, the aggregation electrodes 44a, 44 are formed.
b (or wiring pattern 3)
An electric field is formed toward 6). That is, the comb-shaped electrode 44
The electric field (electric field crossing the ink flow direction) from each needle-shaped electrode 441 of a toward the wiring pattern 36, and the wavy electrode 4
An electric field (an electric field running counter to the ink flow direction) is formed from the edge portion 442 of 4b toward the ejection electrode 34. Then, the positively charged toner 53 is moved by the influence of these electric fields.

More specifically, the toner 53 in the ink 51 flowing from the upper surface 42a of the insulating layer 42 toward the ejection electrode 34 is
The wiring pattern 3 is formed from the comb-shaped electrodes 44a arranged alternately.
6 is moved toward the ejection electrode 34 while being gathered on the wiring pattern 36 under the influence of the electric field directed toward 6. The toner 53 in the ink 51 that has passed through the ejection electrode 34 is affected by the electric field directed from the wavy electrode 44 b toward the ejection electrode 34, and is collected at the ejection electrode 34. In this way, the insulating layer 4
Toner 53 in the ink 51 flowing on the substrate 2 (substrate 32)
Are aggregated on the ejection electrode 34 by the action of the comb-shaped electrode 44a and the corrugated electrode 44b.

As described above, according to the recording head 10 of the first embodiment of the present invention, since the tip shape of the ejection electrode 34 is spherical, the wettability of the ink 51 is good and the ink meniscus 52 is formed. It can be easily formed. Further, since the ejection electrode 34 has a spherical crown shape, the electric field strength formed on the ejection electrode 34 does not change rapidly, and the recording characteristics can be stabilized.

Further, as in the present embodiment, the spherical cap-shaped ejection electrode 34 is formed on a substantially horizontal surface, and the ink 51 is caused to flow substantially horizontally on this surface, so that the flow path resistance of the ink 51 is reduced. It can be reduced and ink clogging does not occur.

Further, since the ejection electrode 34 has a spherical crown shape and the liquid level of the ink supplied to the ejection electrode 34 is lower than the tip of the ejection electrode 34, the ink supplied to the ink meniscus 52 at the tip of the ejection electrode 34. The control rate of the carrier liquid 54 in the 51 can be lowered, the toner can be quickly and highly efficiently collected in the Taylor cone 56 formed in the center of the ink meniscus 52, and a high-quality image without blurring can be obtained. And a high ejection frequency can be achieved.

Furthermore, as in the present embodiment, by providing the aggregation electrode 44, the toner 53 is discharged from the discharge electrode 34.
With this, it is possible to rapidly and highly efficiently aggregate, form a higher quality image, and achieve a higher protruding frequency.

Since the ejection electrode 34 can be formed by the photolithography technique and the semiconductor technique, the variation in shape can be reduced and the multi-channel electrode can be easily formed. Next, a recording head 70 according to a second embodiment of the present invention will be described with reference to FIGS. 9 to 13. The recording head 70 of the present embodiment is
The discharge electrode and the aggregating electrode are formed on the dielectric film, and the tip portion of the discharge electrode is formed of an insulating material. The other basic structure is substantially the same as that of the first embodiment. Therefore, the same parts as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted, and only the parts different from the first embodiment will be described. In addition, in the first embodiment, the tip of the ejection electrode can be formed of an insulating material.

As shown in FIGS. 9 and 10, the recording head 70 has a polyimide film 71 as a dielectric film. This polyimide film 71 has a wide rear portion and a tapered front portion with a tapered portion interposed therebetween, and has the functions of both the substrate 32 and the insulating layer 42 in the recording head 10 according to the first embodiment described above. doing.
The polyimide film 71 holds the ejection electrode and the aggregating electrode on one surface (upper surface), and holds the wiring pattern of the ejection electrode on the other surface (lower surface).

The polyimide film 71 having the discharge electrode and the aggregating electrode is supported by the supporting member 75 as in the first embodiment. In this case, the support member 75 forms the ink flow path 50 together with the polyimide film 71. Then, the polyimide film 71 supported by the support member 75 has the tip of the discharge electrode at the platen roller 4
Is positioned at a predetermined position so as to face the.

FIG. 11 shows the upper surface 71a of the polyimide film 71 facing the platen roller 4, and FIG.
The lower surface 71b of the polyimide film 71 is shown. On the upper surface 71a of the polyimide film 71, as shown in detail in FIG. 13, a plurality of ejection electrodes 72 arranged in a line in a direction transverse to the ink flow direction are provided. Further, on the upper surface 71a and around the ejection electrode 72, the aggregating electrode 44 including the comb-shaped electrode 44a and the corrugated electrode 44b is formed. Then, the lead 44c connected to the aggregating electrode 44 is drawn out to the rear end of the polyimide film 71. Further, the upper surface 71a of the polyimide film 71 other than the tip portion X1 exposing the ejection electrode 72 and the aggregating electrode 44 and the rear end portion X2 exposing the lead 44c of the aggregating electrode 44 is made of polyimide or the like which substantially conforms to the shape of the upper surface 71a. Insulating film 7 made of insulating film
It is covered by 3.

On the other hand, the lower surface 71 of the polyimide film 71
On b, a wiring pattern 74 is provided corresponding to the ejection electrode 72 provided on the upper surface 71a and extending substantially along the ink flow direction. The wiring pattern 74 is
According to the shape of the polyimide film 71, it converges toward the tip of the film. At the end of the wiring pattern 74 extending to the rear end of the polyimide film 71, the connection terminal 7
4a are formed. The lower surface 71b of the polyimide film 71 excluding the rear end portion X2 where the connection terminals 74a of the wiring pattern 74 are exposed is formed of an insulating film 7 made of an insulating film such as polyimide that substantially conforms to the shape of the lower surface 71a.
6.

Each of the ejection electrodes 72 has a pad 72a penetrating the polyimide film 71 and connected to each wiring pattern 74, and a tip portion 72b made of a substantially hemispherical insulating material provided on the pad 72a. Have For the tip portion 72a, for example, a resin material having a large surface tension when melted and having a good ink wettability is used.

When ink is ejected using the recording head 70 having the above-described structure, first, the ink flow path 50 is formed.
Ink is made to flow into the recording head 70 via the. The ink flowing in the ink flow path 50 flows on the upper surface 71a of the polyimide film 71, the height of the liquid surface is regulated by the action of the regulation blades 48b, 49b, and the ink meniscus 52 is formed at the tip of each ejection electrode 72. .

With the ink meniscus 52 thus formed, the predetermined bias voltage Vb and aggregation voltage Vep are applied to the ejection electrode 72 and the aggregation electrode 44. As a result, an electric field E directed from the pad 72a of each ejection electrode 72 to the platen roller 3 and an electric field directed from the aggregation electrode 44 to the ejection electrode 72 are formed, and a Taylor cone 56 having a high toner concentration is formed at the top of the ink meniscus 52. Is formed. Then, the recording voltage Vej is applied to the ejection electrode 72 selected according to the image signal to eject the ink.

As described above, according to the recording head 70 of the present embodiment, the same effect as that of the first embodiment described above can be obtained, and the tip portion 72a of the ejection electrode 72 is made of an insulating material. Since it is formed, the injection of charges into the carrier liquid in the ink can be reduced.

Next, a recording head 80 according to a third embodiment of the present invention will be described with reference to FIGS. 14 and 15. Incidentally, the basic configuration is the above-mentioned first and second
The recording head is substantially the same as the recording head of the above embodiment, and only different portions will be described in detail.

As shown in FIG. 14, the recording head 80 is
Upper surface 32a with ejection electrode 34 and aggregating electrode 44
And a lower surface 32d having a wiring pattern 36 connected to the ejection electrode 34, and a substrate 32 having the lower surface 32d. Board 3
2 is arranged at a predetermined position by the support member 81. Then, the ink flow path 50 is formed between the support member 81 and the upper surface 32 a of the substrate 32, the tip 32 b of the substrate 32, and the lower surface 32 d of the substrate 32.

The recording head 80 penetrates from the ink flow path 50 upstream of the ejection electrode 34 to the ink flow path 50 downstream of the ejection electrode 34 from the upper surface 32a side to the lower surface 32d side of the substrate 32. It has a bypass port 82. The bypass port 82 is provided for each needle-shaped electrode 4 of the comb-shaped electrode 44a.
The carrier liquid 54 of the ink 51, which is provided between the nozzles 41 and flows toward the ejection electrode 34, is diverted.

That is, the ink 51 supplied into the ink flow path 50 through the ink supply pipe 11 flows toward the ejection electrode 34 along the upper surface 32a of the substrate 32. On this occasion,
The toner 53 in the ink 51 is moved toward the ejection electrode 34 without being directed to the bypass port 82 due to the influence of the electric field formed by the wiring pattern 36 of the ejection electrode 34. On the other hand, since the carrier liquid 54 in the ink 51 is not charged, it is not affected by the electric field, and the bypass port 8
It is diverted to 2.

As described above, according to the recording head 80 of this embodiment, it is possible to obtain the same effects as those of the first and second embodiments described above, and the ink 5 is used.
Since the carrier liquid 54 in 1 can be diverted, the toner concentration of the ink flowing to the ejection electrode 34 can be increased, and the aggregation efficiency of the toner 53 can be further increased.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, the tip shape of the ejection electrode is not limited to the spherical crown shape, and may be any shape that is suitable for guiding the ink surface toward the recording paper.

[0075]

As described above, since the image forming apparatus of the present invention has the above-described structure and operation, the toner in the ink can be quickly aggregated and the ejection frequency can be increased. It is possible to form a high-quality image with high density and without blurring.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an ink jet printer as an image forming apparatus of the present invention.

2 is a cross-sectional view showing a recording head according to a first embodiment incorporated in the inkjet printer of FIG.

3 is a cross-sectional view showing a main part of the recording head of FIG.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

5 is an exploded perspective view of the recording head of FIG.

6 is a diagram for explaining a recording operation in the recording head of FIG.

FIG. 7 is a diagram showing a flying state of ink.

8 is a plan view for explaining the action of the aggregating electrode in the recording head of FIG.

FIG. 9 is a plan view showing a recording head according to a second embodiment of the invention.

FIG. 10 is a side view showing the recording head of FIG. 9.

FIG. 11 is a top view of the recording head of FIG. 9.

FIG. 12 is a bottom view of the recording head of FIG.

13 is a diagram for explaining a recording operation in the recording head of FIG.

FIG. 14 is a plan view and a sectional view showing a recording head according to a third embodiment of the invention.

15 is a diagram showing the flow of ink in the recording head of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 2 ... Housing, 4 ... Platen roller, 10 ... Recording head, 11 ... Ink supply pipe, 12 ... Ink storage part, 13 ... Ink collection pipe, 21 ... Paper feed cassette, 32 ... Substrate, 32a ... Top surface , 34 ... Ejection electrode, 34a ... Pad, 34b ... Tip part, 36 ... Wiring pattern, 42 ... Insulating layer, 44 ... Aggregation electrode, 44a ... Comb-shaped electrode, 44b ... Wavy electrode, 47, 48, 49 ... First Thru | or 3rd support member, 48b, 49b ... regulation blade, 50 ... ink flow path, 52 ... ink meniscus, 62, 64 ... power supply.

Claims (11)

[Claims] 1. An ink in which charged colorant particles are dispersed in an insulating liquid is supplied to form a liquid surface of the ink at a position separated by a predetermined distance below a recording medium supplied substantially horizontally. An ink supply unit, a guide member provided so as to project from the liquid surface of the ink, and guiding the ink to a discharge position higher than the liquid surface by the creeping due to the wetting of the ink, and a first member around the guide member. Aggregating means for forming an electric field and aggregating the colorant particles in the ink near the apex of the ink guided to the ejection position by the guide member, and a second electric field larger than the first electric field in the guide member. And a recording medium, and a flying unit configured to fly the colorant particles aggregated by the aggregating unit toward the recording medium, the image forming apparatus. 2. An ink formed by dispersing charged colorant particles in an insulating liquid is supplied to form a liquid surface of the ink at a position separated by a predetermined distance below a recording medium supplied substantially horizontally. An ink supply unit, a guide member provided so as to project from the liquid surface of the ink, and guiding the ink to a discharge position higher than the liquid surface by the creeping due to the wetting of the ink, and a first member around the guide member. Aggregating means for forming an electric field and aggregating the colorant particles in the ink near the apex of the ink guided to the ejection position by the guide member, and a second electric field larger than the first electric field in the guide member. And a recording medium formed between the recording medium and the recording medium, and flying means for flying the colorant particles aggregated by the aggregating means toward the recording medium, the guide member protruding from the liquid surface. Image forming apparatus characterized by having a spherical surface. 3. An ink in which charged colorant particles are dispersed in an insulating liquid is supplied onto a substantially horizontal surface which is disposed below a recording medium supplied substantially horizontally and is separated by a predetermined distance. A guide that is provided so as to project from the ink supply means on the substantially horizontal surface, and that guides the ink so that the liquid surface of the ink approaches the recording medium due to creeping up due to wetting of the ink supplied by the ink supply means. A discharge electrode having a member at its tip, and a liquid level regulation means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the discharge electrode. An aggregating means for applying a bias voltage to the ejection electrode to agglomerate the colorant particles in the ink near the apex of the ink that is brought close to the recording medium by the guide member; And a flying means for applying a recording voltage higher than the bias voltage to the ejection electrode for flying the colorant particles aggregated near the apex of the guide member toward the recording medium. A characteristic image forming apparatus. 4. An ink in which charged colorant particles are dispersed in an insulating liquid is supplied onto a substantially horizontal surface which is arranged below a recording medium supplied substantially horizontally and at a predetermined distance. A guide that is provided so as to project from the ink supply means on the substantially horizontal surface, and that guides the ink so that the liquid surface of the ink approaches the recording medium due to creeping up due to wetting of the ink supplied by the ink supply means. A discharge electrode having a member at its tip, and a liquid level regulation means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the discharge electrode. An aggregating means for applying a bias voltage to the ejection electrode to agglomerate the colorant particles in the ink near the apex of the ink that is brought close to the recording medium by the guide member; And a flying means for applying a recording voltage higher than the bias voltage to the ejection electrode for flying the colorant particles aggregated near the apex of the guide member toward the recording medium. Is an image forming apparatus having a spherical surface for bringing the liquid surface closer to the recording medium. 5. An ink in which charged colorant particles are dispersed in an insulating liquid is supplied onto a substantially horizontal surface which is disposed below a recording medium supplied substantially horizontally and is separated by a predetermined distance. A guide that is provided so as to project from the ink supply means on the substantially horizontal surface, and that guides the ink so that the liquid surface of the ink approaches the recording medium due to creeping up due to wetting of the ink supplied by the ink supply means. A discharge electrode having a member at its tip, and a liquid level regulation means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the discharge electrode. An aggregating means for applying a bias voltage to the ejection electrode to agglomerate the colorant particles in the ink near the apex of the ink that is brought close to the recording medium by the guide member; And a flying means for applying a recording voltage higher than the bias voltage to the ejection electrode for flying the colorant particles aggregated near the apex of the guide member toward the recording medium. Is formed of an insulating material having a spherical surface for bringing the liquid surface closer to the recording medium. 6. An ink in which charged colorant particles are dispersed in an insulating liquid is supplied onto a substantially horizontal surface which is disposed below a recording medium supplied substantially horizontally and is separated by a predetermined distance. A guide that is provided so as to project from the ink supply means on the substantially horizontal surface, and that guides the ink so that the liquid surface of the ink approaches the recording medium due to creeping up due to wetting of the ink supplied by the ink supply means. A discharge electrode having a member at its tip, and a liquid level regulation means for regulating the liquid level of the ink supplied on the substantially horizontal surface by the ink supply means to a predetermined height lower than the tip of the discharge electrode. And an aggregating electrode in the ink around the ejection electrode in an insulated state from the ejection electrode, and colorant particles in the ink supplied on the substantially horizontal surface by the ink supply means. The above A first aggregating means for applying an aggregating voltage to the aforesaid aggregating electrode to collect it in the vicinity of the discharge electrode, and coloring material particles gathered in the vicinity of the discharge electrode by the aforesaid first aggregating means by the guide member to the recording medium. Second aggregating means for applying a bias voltage lower than the aggregating voltage to the ejection electrode for further aggregating the ink near the apex of the ink, and near the apex of the guide member by the first and second aggregating means. An image forming apparatus comprising: a flying unit that applies a recording voltage, which is higher than the bias voltage, for flying the colorant particles aggregated in the recording medium toward the recording medium. 7. A substrate having a substantially horizontal upper surface arranged below a recording medium supplied substantially horizontally with a predetermined distance therebetween, and charged colorant particles in an insulating liquid on the upper surface of the substrate. An ink supply means for supplying the dispersed ink in a predetermined thickness and flowing in a predetermined direction along the upper surface, and an ink supply means projecting on the upper surface of the substrate side by side in a direction crossing the ink flow. A plurality of ejection electrodes having a spherical guide member at the tip thereof for guiding the ink so that the liquid surface of the ink approaches the recording medium due to the creeping due to the wetting of the ink supplied by the supply means; The wiring pattern formed on the upper surface of the substrate on the upstream side of the electrode along the flow direction of the ink and led out from each of the ejection electrodes and the ink supply means are provided on the substantially horizontal surface. Liquid level regulating means for regulating the liquid level of the formed ink to a predetermined height lower than the respective tips of the plurality of ejection electrodes, and an insulating layer provided on the wiring pattern via an insulating layer and having the same pitch as the wiring pattern. A comb tooth-shaped electrode that is displaced by a half pitch and extends in the ink flow direction, and is provided on the downstream side of each ejection electrode in an insulated state from each ejection electrode, and is concentric with the guide member of each ejection electrode. An aggregating electrode having a wavy electrode having a continuous arc portion, and an aggregating voltage for collecting the colorant particles in the ink supplied on the substantially horizontal surface by the ink supply means to the vicinity of the respective ejection electrodes. To the aggregating electrode, and the colorant particles collected in the vicinity of the ejection electrodes by the first aggregating means near the apex of the ink brought close to the recording medium by the guide member. To The second aggregating means for applying a bias voltage lower than the aggregating voltage for further aggregating to each of the ejection electrodes, and the first and second aggregating means aggregated near the apex of the guide member of each of the ejection electrodes. And a flying means for selectively applying a recording voltage higher than the bias voltage for flying the colorant particles toward the recording medium to the ejection electrode selected according to an image signal. Image forming apparatus. 8. A substrate having a substantially horizontal upper surface arranged below a recording medium supplied substantially horizontally with a predetermined distance, and charged colorant particles in an insulating liquid on the upper surface of the substrate. An ink supply means for supplying the dispersed ink in a predetermined thickness and flowing in a predetermined direction along the upper surface, and an ink supply means projecting on the upper surface of the substrate side by side in a direction crossing the ink flow. A plurality of ejection electrodes having a spherical guide member at the tip thereof for guiding the ink so that the liquid surface of the ink approaches the recording medium due to the creeping due to the wetting of the ink supplied by the supply means; The wiring pattern formed on the upper surface of the substrate on the upstream side of the electrode along the flow direction of the ink and led out from each of the ejection electrodes and the ink supply means are provided on the substantially horizontal surface. Liquid level regulating means for regulating the liquid level of the formed ink to a predetermined height lower than the respective tips of the plurality of ejection electrodes, and an insulating layer provided on the wiring pattern via an insulating layer and having the same pitch as the wiring pattern. A comb tooth-shaped electrode that is displaced by a half pitch and extends in the ink flow direction, and is provided on the downstream side of each ejection electrode in an insulated state from each ejection electrode, and is concentric with the guide member of each ejection electrode. An aggregating electrode having a wavy electrode having a continuous arc portion, and an aggregating voltage for collecting the colorant particles in the ink supplied on the substantially horizontal surface by the ink supply means to the vicinity of the respective ejection electrodes. To the aggregating electrode, and the colorant particles collected in the vicinity of the ejection electrodes by the first aggregating means near the apex of the ink brought close to the recording medium by the guide member. To The second aggregating means for applying a bias voltage lower than the aggregating voltage for further aggregating to each of the ejection electrodes, and the first and second aggregating means aggregated near the apex of the guide member of each of the ejection electrodes. The flying means for selectively applying a recording voltage higher than the bias voltage for flying the colorant particles toward the recording medium to the ejection electrode selected according to an image signal, the substrate, An image forming apparatus characterized in that a bypass port for diverting the insulating liquid in the ink flowing on the upper surface of the substrate is formed so as to penetrate from the upper surface to the lower surface of the substrate. 9. A dielectric film having a substantially horizontal upper surface which is arranged below a recording medium supplied substantially horizontally with a predetermined distance therebetween, and electrically charged colorant particles are insulated on the upper surface of the dielectric film. Ink supplying means for supplying an ink dispersed in an ionic liquid in a predetermined thickness and flowing in a predetermined direction along the upper surface, and an ink supply means arranged on the upper surface of the dielectric film in a direction crossing the ink flow. And a plurality of ejection electrodes having a guide member for guiding the ink so as to bring the liquid surface of the ink closer to the recording medium by creeping up due to wetting of the ink supplied by the ink supply means, An arrangement that extends along the ink flow direction on the lower surface of the dielectric film on the upstream side of each ejection electrode, penetrates the dielectric film, and is connected to each ejection electrode. Line patterns, liquid level control means for controlling the liquid level of the ink supplied to the upper surface of the dielectric film by the ink supply means to a predetermined height lower than the tips of the plurality of ejection electrodes, and the dielectric Of the comb-teeth-shaped electrode provided on the upper surface of the conductive film and extending in the ink flow direction at the same pitch and half pitch as the wiring pattern on the upstream side of each ejection electrode, and the downstream of each ejection electrode. The aggregating electrode having a corrugated electrode which is provided in a state of being insulated from each of the ejection electrodes on the side and has an edge portion in which a circular arc concentric with the guide member of each of the ejection electrodes is continuous; First aggregating means for applying an aggregating voltage to the aggregating electrode for collecting the colorant particles in the ink supplied to the upper surface to the vicinity of the aforesaid respective ejecting electrodes; The second agglomeration in which a bias voltage lower than the agglomeration voltage for further agglomerating the colorant particles collected in the vicinity in the vicinity of the apex of the ink which is brought close to the recording medium by the guide member is applied to the ejection electrodes. And a recording voltage higher than the bias voltage for causing the colorant particles aggregated near the apex of the guide member of each ejection electrode by the first and second aggregation units to fly toward the recording medium. An image forming apparatus comprising: a flying unit that selectively applies the discharge electrodes selected according to a signal. 10. A dielectric film having a substantially horizontal upper surface which is arranged below a recording medium supplied substantially horizontally with a predetermined distance therebetween, and electrically charged colorant particles are insulated on the upper surface of the dielectric film. Ink supplying means for supplying an ink dispersed in an ionic liquid in a predetermined thickness and flowing in a predetermined direction along the upper surface, and an ink supply means arranged on the upper surface of the dielectric film in a direction crossing the ink flow. A plurality of ejections having a spherical guide member at the tip of the spherical guide member, which is projected and guides the ink so as to bring the liquid surface of the ink closer to the recording medium due to the rising of the ink supplied by the ink supply means due to wetting of the ink. An electrode and a lower surface of the dielectric film, which extends along the ink flow direction on the upstream side of each ejection electrode, penetrates the dielectric film, and contacts each ejection electrode. A continuous wiring pattern, and liquid level control means for controlling the liquid level of the ink supplied to the upper surface of the dielectric film by the ink supply means to a predetermined height lower than the tips of the plurality of ejection electrodes. A comb-teeth electrode disposed on the upper surface of the dielectric film and extending in the ink flow direction on the upstream side of each of the discharge electrodes with the same pitch and a half pitch offset from the wiring pattern, and each of the discharges. An aggregating electrode having a corrugated electrode provided on the downstream side of the electrode in an insulated state from each of the ejection electrodes and having an edge portion continuous with an arc concentric with the guide member of each of the ejection electrodes; First aggregating means for applying an aggregating voltage to the aggregating electrodes to collect the colorant particles in the ink supplied to the upper surface of the conductive film to the vicinity of the discharge electrodes, and A bias voltage lower than the aggregation voltage for further aggregating the colorant particles collected in the vicinity of each ejection electrode near the apex of the ink which is brought close to the recording medium by the guide member is applied to each ejection electrode. A second aggregating unit, and a recording voltage higher than the bias voltage for causing the colorant particles aggregated near the apex of the guide member of each ejection electrode by the first and second aggregating units to fly toward the recording medium. A flight means for selectively applying a voltage to the ejection electrode selected according to an image signal, and the guide member is formed of an insulating material having a spherical surface for bringing the liquid surface of the ink close to the recording medium. An image forming apparatus characterized by being formed. 11. A dielectric film having a substantially horizontal upper surface which is arranged below a recording medium supplied substantially horizontally with a predetermined distance, and electrically charged colorant particles are insulated on the upper surface of the dielectric film. Ink supplying means for supplying an ink dispersed in an ionic liquid in a predetermined thickness and flowing in a predetermined direction along the upper surface, and an ink supply means arranged on the upper surface of the dielectric film in a direction crossing the ink flow. A plurality of ejections having a spherical guide member at the tip of the spherical guide member, which is projected and guides the ink so as to bring the liquid surface of the ink closer to the recording medium due to the rising of the ink supplied by the ink supply means due to wetting of the ink. An electrode and a lower surface of the dielectric film, which extends along the ink flow direction on the upstream side of each ejection electrode, penetrates the dielectric film, and contacts each ejection electrode. A continuous wiring pattern, and liquid level control means for controlling the liquid level of the ink supplied to the upper surface of the dielectric film by the ink supply means to a predetermined height lower than the tips of the plurality of ejection electrodes. A comb-teeth electrode disposed on the upper surface of the dielectric film and extending in the ink flow direction on the upstream side of each of the discharge electrodes with the same pitch and a half pitch offset from the wiring pattern, and each of the discharges. An aggregating electrode having a corrugated electrode provided on the downstream side of the electrode in an insulated state from each of the ejection electrodes and having an edge portion continuous with an arc concentric with the guide member of each of the ejection electrodes; First aggregating means for applying an aggregating voltage to the aggregating electrodes to collect the colorant particles in the ink supplied to the upper surface of the conductive film to the vicinity of the discharge electrodes, and A bias voltage lower than the aggregation voltage for further aggregating the colorant particles collected in the vicinity of each ejection electrode near the apex of the ink that is brought close to the recording medium by the guide member is applied to each ejection electrode. A second aggregating unit, and a recording voltage higher than the bias voltage for causing the colorant particles aggregated near the apex of the guide member of each ejection electrode by the first and second aggregating units to fly toward the recording medium. A flight means for selectively applying a voltage to the ejection electrode selected according to an image signal, and the dielectric film divides the insulating liquid in the ink flowing on the upper surface of the dielectric film. The image forming apparatus is characterized in that the bypass opening is formed so as to penetrate from the upper surface to the lower surface of the dielectric film.