JP2826538B2 - Electrostatic inkjet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus in which color material particles in a pigment ink are controlled by an electrophoretic phenomenon.

[0001]

2. Description of the Related Art The non-impact recording method is excellent in that the generation of noise during recording is negligibly small, and has attracted particular interest in recent years. Among them, an ink jet recording system capable of performing high-speed recording directly on a recording medium with a simple mechanism and capable of recording on plain paper is an extremely powerful system, and various proposals have been made regarding this system. .

In an ink jet recording apparatus, a voltage is applied between a counter electrode provided on the back surface of a recording paper and a needle-shaped recording electrode facing the counter electrode, and a coloring material such as ink is applied by an electrostatic force of an electric field generated. 2. Description of the Related Art An electrostatic ink jet recording apparatus of a type that performs recording by flying is known. An example of this type of recording apparatus (conventional example 1) will be described with reference to FIGS. 13 and 14 are a perspective view and a sectional view of the recording head, and FIG. 15 is a sectional view taken along the line AA of FIG.

[0003] The substrate 1 is formed of an insulator such as glass.
A plurality of recording electrodes 2 are formed on the surface. The recording electrodes 2 are formed by patterning a conductive material such as chromium sputtered on the entire surface of the substrate by using a photolithography method, and are arranged, for example, at a pitch of 300 dpi, that is, at intervals of about 85 μm. The recording electrode 2 is connected to a driver (not shown), and selectively applies a high voltage pulse to the recording electrode 2 during recording. A meniscus forming member 18 is provided on each recording electrode 2.

The meniscus forming member 18 is obtained by processing a photosensitive polymer film laminated on the substrate 2 by a photolithography method. The meniscus forming member 18 is located at a position slightly retreated from the tip of the recording electrode 2 and at a position overlapping each recording electrode 2. Is formed. The thickness of the photosensitive polymer film is about 30 μm, for example.
The width of the meniscus forming member 18 is also about 30 μm.
On the meniscus forming member 18, the meniscus forming member 1
An upper cover (upper cover) 4 having a front edge is attached to a position further retracted from the front end of the upper cover 8. The upper cover 4 is formed of an insulating member, and has an ink supply port 5 and an ink discharge port 6 opening at the top.

A gap between the substrate 1 and the upper cover 4 forms a slit-shaped ink ejection port 7, and a meniscus forming member 18 protrudes outside the ink ejection port 7. The meniscus forming member 18 supports the upper cover 4 and also serves to form the ink flow path 16.
It continues to the lower side. When the meniscus forming member 18 is formed, at the same time, a continuous wall surface is formed on the side portion and the rear end portion of the head, and the wall surface defines the ink chamber together with the substrate 1 and the upper cover 4.

An unillustrated migration electrode is provided behind the ink flow path 16 in the ink chamber. The migrating electrode has a function of concentrating and supplying toner particles in the ink to the vicinity of the ink ejection port 7, and the toner particles are formed between the migrating electrode and a counter electrode provided on the back surface of the recording paper. Due to the electric field, it moves by the electrophoretic force and concentrates near the ink ejection port 7.

JP-B-58-153661 and JP-B-58-153662 describe another type of ink jet recording apparatus (conventional example 2). In this type of ink jet recording apparatus, a plurality of nozzles having a first electrode on the inner wall of the ink jet recording apparatus or in the vicinity thereof are two-dimensionally arranged in XY, and are driven in a matrix around the ink chamber side nozzles on the nozzle substrate surface. Two electrodes are provided, respectively, and a third electrode is provided on the recording paper side in front of the first electrode. Ink is ejected from a nozzle by an electric field formed between the electrodes to perform printing on the recording paper. The first electrode is a common electrode in the Y direction (the direction of travel of the recording paper) or the X direction (the width direction of the recording paper) of the nozzle group.

[0008]

In the electrostatic ink jet recording head of the above-mentioned prior art example 1, a voltage is applied between a counter electrode disposed on the back surface of the recording paper and a needle-like recording electrode, and an electrostatic force therebetween is used. Due to the structure in which the toner particles in the ink fly, in order to secure a sufficient distance between the counter electrode and the recording electrode, the potential difference between the recording electrode and the counter electrode is set to a high voltage of, for example, 1 KV or more. There is a need. In particular, when a thick recording medium is used, or when the recording medium floats during traveling, the distance between the recording electrode and the counter electrode changes, and the force acting on the toner particles in the ink changes. ,
There is a problem that stable flying of toner particles is hindered.

Further, when there is no recording medium between the counter electrode and the recording electrode, an ink bridge occurs between the recording electrode and the counter electrode for some reason, and a voltage is applied to the recording electrode at that time. Then, a large current flows between the recording electrode and the counter electrode, and there is also a problem that the recording electrode and the counter electrode are damaged.

In addition, in addition to the problems of the conventional example 1, the electrostatic ink jet recording apparatus of the above-mentioned conventional example 2 causes the charged ink to fly, so that bleeding or bleeding of the print occurs and the print quality is deteriorated. There are also problems. Further, since the second electrode for performing matrix driving is in contact with the ink, the potential in the ink becomes unstable, and there is a problem that stable ejection is difficult.

In view of the above, it is an object of the present invention to provide an ink jet recording apparatus which stabilizes the flight of ink toner and has a good recording quality, and in particular, a gate disposed between a recording electrode and a counter electrode. The above object is achieved based on the electrode structure and the driving method.

[0012]

In order to achieve the above object, an electrostatic ink jet recording apparatus according to the present invention comprises: a migration electrode; a counter electrode disposed opposite to the migration electrode; And a plurality of recording electrodes disposed between the counter electrode and the recording electrode to which a recording voltage pulse is applied, wherein a group of toner particles contained in the pigment ink flies from the ink chamber in accordance with an electrostatic field from the migrating electrode to the counter electrode. In the electrostatic ink jet recording apparatus of the present invention, a gate electrode is provided between the recording electrode and the counter electrode, the gate electrode being at least opened at a position aligned with the recording electrode, and the surface of the gate electrode is covered with an insulating material. Features.

In the electrostatic ink jet recording apparatus of the present invention, it is preferable that at least a portion of the recording electrode facing the gate electrode is covered with an insulating material.

The gate electrode is made of an insulating material and has a separate orifice at a position aligned with each of the recording electrodes; and a separate conductive thin film pattern formed on the substrate adjacent to each of the orifices. And an insulating film covering the conductive thin film pattern. In this case, the manufacture is facilitated, and the matrix drive of the gate electrode is enabled.

Instead of the above, a gate electrode is made of an insulating material and has a common slit-shaped opening at a position corresponding to the plurality of recording electrodes; And a conductive thin film pattern common to the plurality of recording electrodes and an insulating film covering the conductive thin film pattern.

The conductive thin film pattern can be formed from a lead frame formed on a TAB tape, and in this case, the manufacturing cost can be reduced.

Further, instead of the above, the gate electrode may include a conductive substrate having an individual orifice at a position corresponding to each of the recording electrodes, and an insulating fill covering the conductive substrate. A gate electrode which is structurally rigid can be easily obtained, and the gate electrode can be driven in a matrix.

Further, instead of the above, the gate electrode is
A conductive substrate having a slit-shaped opening common to the plurality of recording electrodes, and an insulating film covering the conductive substrate may be provided.

It is preferable that the opening of the gate electrode is formed in a tapered shape in which the opening on the recording electrode side is larger than that on the counter electrode side. In this case, good flight of the toner particle group can be obtained.

The voltage applied to the gate electrode and the voltage applied to the counter electrode can be set to the same potential.
In this case, after passing through the gate electrode, the toner particle group moves toward the counter electrode by inertia.

Alternatively, the voltage applied to the counter electrode may be lower than the voltage applied to the gate electrode. In this case, the flying of the toner particle group is more stable.

[0022] The conductive thin film pattern may be arranged so that a part thereof protrudes into the slit-shaped opening. In this case, a good electric field shape is obtained.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail based on embodiments of the present invention with reference to the drawings. FIG.
FIG. 2 is a perspective view of a recording head in the electrostatic inkjet recording apparatus according to the first embodiment of the present invention. The substrate 1 is made of an insulator such as plastic and supports the base film 10 from the back side. The base film 10 is made of an insulator such as polyimide, has a thickness of about 50 μm, and has a plurality of recording electrodes 2 formed on its surface as a thin film pattern.

The recording electrode 2 is formed by pattern-plating a conductive material such as copper to a thickness of 20 to 30 μm on a base film 10 at a pitch of, for example, 300 dpi.
They are arranged approximately parallel to each other at intervals of about 85 μm. Each recording electrode 2 has a base film
0 protrudes from the end face by about 80 to 500 μm. The surface of the tip of the recording electrode 2 is uniformly covered with an insulating coating member having a thickness of 10 μm or less. In the recording apparatus of this embodiment, the base film 10
A head on a tape on which the recording electrodes 2 are integrally formed is employed. More specifically, TAB (Tape Automated B
onding) technology using TAB tape,
An insulating coating member 17 is formed by chemical vapor deposition of a parylene resin on a copper thin film pattern forming a lead frame.

The upper cover 4 and the lower cover 3 are arranged so as to sandwich the recording electrode 2 protruding from the base film 10 except for the protruding portion. The upper cover 4 is formed of an insulating member.
The space defined by the base film 10 and the base film 10 constitutes an upper ink chamber. The upper ink chamber is open upward at an ink supply port 5 formed in the upper cover, and the ink is
The ink is filled from the ink supply port 5 to fill the inside of the ink chamber.

A gap between the upper cover 4 and the base film 10 at the leading end of the recording head forms a slit-shaped ink ejection port 7, and near the ink ejection port 7, an ink meniscus is formed as described later. Is formed. The lower cover 3 is made of an insulating member, and has an ink discharge port (not shown) opened downward. The space defined by the lower cover 3 and the base film 10 constitutes a lower ink chamber, and ink passes from the upper ink chamber to between the recording electrodes 2, and from the vicinity of the ink ejection port 7 to the lower ink chamber. enter,
The toner is forcibly discharged from the ink discharge port together with excess toner particles via the lower ink chamber.

The ink jet head shown in FIG. 1 is connected to an ink tank via a tube (not shown), and a negative pressure of about 1 cmH ₂ O is applied to the ink chamber to forcibly circulate the ink. . The ink is a dispersion of colored thermoplastic resin fine particles, so-called toner particles, together with a charge control agent, in a petroleum organic solvent (isoparaffin). Each toner particle has an apparent positive charge due to the zeta potential. ing.

On the inside of the rear end of the upper cover 4, an electrophoresis electrode 11 that comes into contact with ink is provided. Electrophoresis electrode 1
1, a voltage having the same polarity as the toner potential is applied.
The toner particles in the ink supplied from the ink supply port 5 follow the electric field between the migrating electrode 11 and the counter electrode 23,
The recording electrode 2 is moved to the vicinity of the tip portion by the electrophoresis phenomenon. In addition to the supply of the toner particles by forcible ink circulation by the pump, the movement of the toner particles due to the electrophoretic phenomenon causes the concentration of the toner particles in the vicinity of the ink ejection port 7 to be relatively higher than that in the upstream side of the ink chamber. Become higher.

FIGS. 2 and 3 are an enlarged plan view of the vicinity of the ink ejection port 7 as viewed from above and a sectional view taken along the line AA, respectively, in a state where ink is supplied to the recording head of FIG. . The gate electrode 22 is made of a conductive substrate material manufactured by electroforming (electroforming) or the like.
It is arranged between the recording electrode 2 and the counter electrode 23 (FIG. 12). The gate electrode 22 is located at a position facing each element of the recording electrode 2, and the orifice 21 is individually separated.
have. Here, assuming that the diameter of each individual orifice 21 of the gate electrode 22 is D and the distance between the gate electrode 22 and the recording electrode 2 is L, an arrangement and a diameter that satisfy the relationship of L / 2 <D <L are desirable. The gate electrode 22 has a connection pad (not shown) for externally controlling the potential of the gate electrode 22, and the surface of the gate electrode 22 is covered with the insulating coating member 17. This prevents a short-circuit bridge due to toner particles between the recording electrode 2 and the gate electrode 22.

The counter electrode is disposed in front of the gate electrode 22 so as to face the recording head, and is maintained at the same potential as the gate electrode 22 or at a lower potential. The ink is
Due to the surface tension, an ink meniscus 8 is formed near the ink ejection port 7. Since a negative pressure is applied to the ink chamber, and the recording electrode 2 projects from the base film 10, the upper cover 4, and the lower cover 3 to the gate electrode side 22, the ink meniscus 8 is viewed from the side. The upper ink chamber has a concave shape obliquely downward, and the lower ink chamber has a symmetrical shape. Further, since each recording electrode 2 protrudes outward from the ink ejection port 7, the tip of the ink meniscus 8 is separated for each recording electrode 2.

When the gate electrode 22 is set to, for example, zero potential and a high voltage pulse is applied to an arbitrary recording electrode 2, an electric field concentrates on the tip of the ink meniscus in contact with the protruding tip of the recording electrode 2. The charged toner particles in the ink are guided by this electric field generated between the gate electrode 22 and the recording electrode 2, and are drawn out from the protruding tip of the ink meniscus. The toner particles collectively form the toner group 9, pass through the individual orifices 21 of the gate electrode 22, and fly in the direction of the counter electrode, that is, in the direction of the recording medium. The toner that has adhered to the recording medium and formed the recording dots is heated by a heater and fixed.

FIG. 4 is a schematic plan view of a TAB tape used for manufacturing the recording head of FIG. Less than,
A method for manufacturing the TAB tape 12 will be described. First, flash plating is performed on a tape-like base film 10 such as polyimide having sprocket holes 15 at both ends. Next, a dry film is laminated, and a pattern is formed by exposure and development. Next, after pattern plating with copper or the like, the base film is etched to form the through holes 14. Further, the resist film is removed and finish plating is performed. After that, an insulating coating member is chemically vapor-deposited on a necessary portion to obtain a recording head. In this process, the inner lead portion 13 projecting from the portion where the base film has been removed by etching becomes the recording electrode 2.

FIGS. 5 and 6 are views similar to FIGS. 1 and 2 of a recording head in an electrostatic ink jet recording apparatus according to a second embodiment of the present invention. This embodiment has the same configuration as that of the first embodiment except for the configuration of the gate electrode. The gate electrode 22 </ b> A is formed of an insulating base material, and has an individual orifice 21 at a position corresponding to each recording electrode 2. A conductive material is applied around the orifices 21 around the orifices 21 by sputtering or the like, and individual gates 19 are formed corresponding to the recording electrodes 2. The upper surface of the individual gate electrode 19 is coated with an insulating coating member 17 covering the whole.

FIG. 7 is a timing chart of signals for driving the recording electrodes and the individual gate electrodes in the second embodiment. A drive voltage pulse train P1 having a predetermined pulse width and a peak value is applied to the group A of the recording electrodes that fly the toner group, and the groups B1, B2, and B3 of the corresponding individual gate electrodes 22 are sequentially gate-driven. Voltage pulses P2, P3 and P4 are applied. By applying such a drive voltage to the group of the recording electrodes 2 and each group of the individual gate electrodes 19, the toner particles fly from the desired recording electrode group. That is, discharge from each recording electrode 2 can be controlled by matrix drive of the gate electrode.

The gate electrode 22A in the present embodiment example
Can be configured by a manufacturing method using a TAB tape similar to the recording electrode 2, that is, a forming method in which the electrode portion does not protrude when the through hole 14 is formed.

FIG. 8 is a perspective view of a recording head in an electrostatic ink jet recording apparatus according to a third embodiment of the present invention. The configuration of the third embodiment is the same as the configuration of the first and second embodiments except for the configuration of the gate electrode. The gate electrode 22B is made of a single conductive substrate material manufactured by electroforming or the like.
And a counter electrode (not shown). The gate electrode 22B is configured as a common gate electrode provided at a position facing the entire element of the recording electrode 2, and
It has a single slit-shaped opening 20. In the third embodiment, unlike the gate electrodes 22 and 22A having the individual orifices 21 as in the first and second embodiments, the alignment between the gate electrode 22B and the recording electrode 2 is facilitated. .

FIG. 9 is a perspective view of a recording head in an electrostatic ink jet recording apparatus according to a fourth embodiment of the present invention. The configuration of this embodiment is the same as the configuration of each of the above embodiments except for the configuration of the gate electrode. The gate electrode 22C is made of an insulating base material and has a recording electrode 2C.
A single slit opening 20 is provided at a position facing the entire element. A conductive material is applied to the slit opening 20 at a position corresponding to each recording electrode 2 to form an individual gate electrode 19. The surface of the gate electrode is covered with an insulating coating member 17. The gate electrode 22C can be manufactured by adopting a manufacturing method using the same TAB tape as the recording electrode 2.
That is, it is possible to use the inner lead portion of the two-layer or three-layer TAB tape as the individual gate electrode 19. The formation of the single slit-shaped opening 20 facilitates the alignment between the gate electrode 22C and the recording electrode 2.

In the fourth embodiment, as in the second embodiment, the recording electrode 2 and the individual gate electrode 19 are connected to each other as shown in FIG.
By applying the drive voltage pulses P1 to P4 shown in the above, toner is discharged from each recording electrode 2. That is, the discharge of the toner can be controlled by the matrix drive of the gate electrode. In this embodiment, the tip of the individual gate electrode 19 protrudes into the slit-shaped opening. In this case, as shown in FIG. 10 as viewed in the direction of arrows AA in FIG. 9, the individual gate electrodes 19 are aligned with the respective recording electrodes 2, or as shown in FIG. However, a configuration in which the recording electrodes 2 are aligned at an intermediate position between two adjacent recording electrodes 2 may be used.

FIG. 12 illustrates a cross section of a recording head section in the electrostatic ink jet recording apparatus of each of the above embodiments of the present invention, taking the first embodiment as an example. The same potential (or a lower potential) as the potential of the gate electrode 22 is applied to the counter electrode 23. When the opposite electrode 23 has the same potential as the gate electrode 22 as described above, the toner group 9 is guided by the electric field generated between the gate electrode 22 and the recording electrode 2, and the protruding tip of the ink meniscus. Drawn from. The toner group 9 flies through the orifice 21 of the gate electrode 22, and
From 2 to the opposing electrode 23, it flies only by its inertial force. Further, when the counter electrode 23 is maintained at a lower potential than the gate electrode 22, the toner group 9 keeps the contact between the counter electrode 23 and the gate electrode 22 while flying between the counter electrode 23 and the gate electrode 22. It flies by being accelerated by the electric field formed therebetween. Therefore, the flight is more stable than the previous example.

Although the present invention has been described based on the preferred embodiment, the electrostatic ink jet recording apparatus of the present invention is not limited to the configuration of the above-described embodiment. An inkjet recording apparatus in which various modifications and changes have been made from the configuration of the example is also included in the scope of the present invention. For example, the configuration of the recording electrode 2 is not limited to the configuration of the above embodiment, and the recording electrode 2 is formed in a slit-like opening on the base film 10 in a bridge shape,
The recording electrode may be formed by bending the recording electrode at the opening.

[0041]

As described above, the electrostatic ink jet recording head of the present invention employs a structure in which the gate electrode whose surface is coated is provided between the recording electrode and the counter electrode, so that the toner particles No short-circuit bridge is formed, and a highly reliable electrostatic ink jet recording apparatus can be obtained.

If individual gate electrodes corresponding to the respective recording electrodes are employed as the gate electrodes, the ejection of toner particles can be controlled by matrix driving. Alternatively, when a slit-shaped opening is formed in the gate electrode, alignment between the gate electrode and the recording electrode becomes easy.

[Brief description of the drawings]

FIG. 1 is a perspective view of a recording head of an electrostatic ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a detailed plan view showing the vicinity of an ink ejection port of the recording head of FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a view showing a stage of a manufacturing process of the recording head of FIG. 1;
The top view of a B tape.

FIG. 5 is a perspective view of a recording head of an electrostatic inkjet recording apparatus according to a second embodiment of the present invention.

FIG. 6 is a plan view of the vicinity of an ink ejection port of the recording head of FIG. 5;

FIG. 7 is a timing chart showing driving voltage pulses of the recording head of FIG. 5;

FIG. 8 is a perspective view of a recording head of an electrostatic inkjet recording apparatus according to a third embodiment of the present invention.

FIG. 9 is a perspective view of a recording head of an electrostatic inkjet recording apparatus according to a fourth embodiment of the present invention.

FIG. 10 is a front view showing an example of a gate electrode in the recording head of FIG. 9;

FIG. 11 is a front view showing another example of the gate electrode in the recording head of FIG. 9;

FIG. 12 is a cross-sectional view illustrating the configuration of a recording head unit of the electrostatic ink jet recording apparatus of the present invention.

FIG. 13 is a perspective view of a recording head of a conventional electrostatic ink jet recording apparatus.

FIG. 14 is a plan view showing the vicinity of an ink ejection port of the recording head of FIG. 13;

FIG. 15 is a sectional view of the vicinity of an ink ejection port of the recording head of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Recording electrode 3 Lower cover 4 Upper cover 5 Ink supply hole 6 Ink discharge hole 7 Ink ejection opening 8 Ink meniscus 9 Toner group 10 Base film 11 Migration electrode 12 TAB tape 13 Inner lead part 14 Through hole 15 Sprocket hole 16 Ink flow Path 17 Insulating coating member 18 Meniscus forming member 19 Individual gate electrode 20 Slit opening 21 Orifice 22 Gate electrode 23 Counter electrode 24 Recording medium

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitoshi Minemoto 7546 Yasuda, Kashiwazaki-shi, Niigata Niigata Nippon Electric Co., Ltd. (72) Inventor Hitoshi Takemoto 7546 Yasuda, Kashiwazaki-shi, Niigata Within (72) Inventor Yoshihiro Hagiwara 7546 Yasuda, Kashiwazaki-shi, Niigata Prefecture Within Niigata Nippon Electric Co., Ltd. References JP-A-10-808 (JP, A) JP-A-10-44428 (JP, A) JP-A-10-67107 (JP, A) JP-A-10-86380 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) B41J 2/06

Claims (12)

(57) [Claims] 1. An electrophoretic electrode comprising: an electrophoretic electrode; an opposing electrode disposed opposite to the electrophoretic electrode; and a plurality of recording electrodes disposed between the electrophoretic electrode and the opposing electrode to which a recording voltage pulse is applied. According to the electrostatic field from the electrophoresis electrode to the counter electrode,
An electrostatic ink jet recording apparatus of a type in which a group of toner particles contained in pigment ink flies from an ink chamber, comprising a gate electrode that is at least opened at a position aligned with the recording electrode between the recording electrode and a counter electrode. An electrostatic ink jet recording apparatus, wherein the surface of the gate electrode is covered with an insulating material. 2. The electrostatic ink jet recording apparatus according to claim 1, wherein at least a portion of the recording electrode facing the gate electrode is covered with an insulating material. 3. A substrate, wherein said gate electrode is made of an insulating material and has an individual orifice at a position aligned with each of said recording electrodes, and an individual conductive material formed on said substrate adjacent to each of said orifices. 2. The semiconductor device according to claim 1, comprising a thin film pattern and an insulating film covering the conductive thin film pattern.
Or the electrostatic ink jet recording apparatus according to 2. 4. A substrate made of an insulating material and having a common slit-like opening at a position corresponding to the plurality of recording electrodes, and formed on the substrate adjacent to the slit-like opening. 3. The electrostatic ink jet recording apparatus according to claim 1, further comprising a conductive thin film pattern common to the plurality of recording electrodes, and an insulating film covering the conductive thin film pattern. 5. The electrostatic ink jet recording apparatus according to claim 3, wherein the conductive thin film pattern is configured as a lead frame. 6. A conductive substrate, wherein the gate electrode has an individual orifice at a position corresponding to each of the recording electrodes;
The electrostatic ink jet recording apparatus according to claim 1, further comprising: an insulating film that covers the conductive substrate. 7. The gate electrode includes: a conductive substrate having a slit-shaped opening common to the plurality of recording electrodes; and an insulating film covering the conductive substrate.
Or the electrostatic ink jet recording apparatus according to 2. 8. The electrostatic ink jet recording apparatus according to claim 1, wherein the gate electrode has a tapered opening at a surface portion on the recording electrode side larger than a surface portion on the counter electrode side. . 9. The electrostatic ink jet recording apparatus according to claim 1, wherein a voltage applied to said gate electrode and a voltage applied to said counter electrode have the same potential. 10. The electrostatic ink jet recording apparatus according to claim 1, wherein a voltage applied to said counter electrode is lower than a voltage applied to said gate electrode. 11. The electrostatic ink jet recording apparatus according to claim 3, wherein the gate electrode is driven in a matrix. 12. The electrostatic ink jet recording apparatus according to claim 4, wherein a part of the conductive thin film pattern is disposed so as to protrude from the slit-shaped opening. [0001]