JP2003251809A - Electrostatic inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent instability of an ink discharge amount and clogging of an ink head because of excess concentration of a solid component in ink in an electrostatic inkjet recorder which forms images onto a recording paper by discharging ink drops from the ink head with the use of the ink including the solid component charged positively or negatively. <P>SOLUTION: A cavity 105a to be an ink reservoir is formed behind ink discharge parts 102. An ink supply tube 106a and a discharge pipe 106b are set inside the cavity 105a for circulating the ink in a direction orthogonal to an ink projection direction. Discharge electrodes 103 are arranged in parallel to each other in the vicinity of each ink discharge part 102 to define a predetermined angle (for example, 90°) to the ink circulation direction respectively. The solid component is sucked by a pressure difference generated in the cavity 105a from near the ink discharge part 102 where a flow velocity is low to near a main channel where the flow velocity is high. The solid component concentrated in the vicinity of the ink discharge parts 102 is thus diluted. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an electrostatic ink jet recording apparatus which forms an electric field and ejects ink charged by Coulomb force.

[0002]

2. Description of the Related Art In an electrostatic ink jet recording apparatus, an ink head is constructed by arranging a plurality of ejection electrodes for ejecting ink droplets in the width direction of a recording sheet, and an ejection electrode and this ejection electrode. An electric field is formed between the counter electrode and the counter electrode disposed so as to face each other, and the Coulomb force of the electric field causes the charged ink to be ejected from the ink ejecting portion formed in front of each ejection electrode, thereby forming a recording sheet. The image is formed on top. Each ink ejecting part is 1
It is provided so as to correspond to each pixel, and the gradation of each pixel can be changed by controlling the amount of ink ejected from the ink ejection unit.

The ink used in such an electrostatic ink jet recording apparatus contains a solid component charged to + or-in a proportion of, for example, 3 to 10%, and the ink is well fixed on the recording paper. In order to do so, the solid component in the ink is concentrated to about 20% and ejected.

For example, in the conventional apparatus described in Japanese Patent Laid-Open No. 9-11475, the ink is circulated in the cavity formed behind the ink ejection portion in a direction parallel to the ejection direction of the ink, and the ink is circulated in the cavity. A predetermined voltage is applied to the ink concentration electrode provided, and the charged solid component is attracted to the vicinity of the ink ejection electrode to concentrate the solid component in the ink.

[0005]

By the way, not all the ink in which the solid component is concentrated is ejected in the vicinity of the ink ejection portion of the ink head, and a part of the solid component in the ink is ejected in the vicinity of the ink ejection portion. To remain. As a result of using the electrostatic ink jet recording device for a long time, the solid component in the ink is excessively concentrated and the ink ejection amount becomes unstable, or the solid component is solidified in the ink ejection part and the ink head is clogged. Had a problem of causing.

Further, the above-mentioned conventional apparatus has a problem that only the solid component in the ink is concentrated, and the excessively concentrated solid component cannot be diluted or controlled within a certain concentration range. It was

The present invention has been made in order to solve the above-mentioned problems of the conventional example, and enables the dilution of the solid component in the excessively concentrated ink in the electrostatic ink jet recording apparatus, and While stabilizing the discharge amount,
The purpose is to prevent clogging of the ink head.

[0008]

In order to achieve the above object, an electrostatic ink jet recording apparatus according to the present invention comprises a plurality of ink ejecting portions arranged at a predetermined pitch in a direction orthogonal to a protruding direction of ink. A cavity formed in the rear of the ink ejecting portion for circulating the ink, and an ink supply pipe provided in the cavity for circulating the ink in a direction orthogonal to the protruding direction of the ink, In the vicinity of the discharge pipe and each of the ink ejection portions in the cavity, ejection electrodes are provided in parallel with each other at a predetermined angle with respect to the ink circulation direction.

In the above structure, the discharge electrode has a first structure.
Is applied to concentrate the solid component in the ink in the vicinity of the ink ejection portion, and by applying a second predetermined voltage different from the first predetermined voltage, the ink in the vicinity of the ink ejection portion is applied. It is preferable to dilute the solid components therein.

Further, when a secondary electrode is provided outside the ink ejection portion and the solid component in the ink is positively charged, the second predetermined voltage is higher than the voltage applied to the secondary electrode. When a low voltage is applied and the solid component in the ink is negatively charged, it is preferable to apply a voltage higher than the voltage applied to the secondary electrode as the second predetermined voltage.

[0011]

DETAILED DESCRIPTION OF THE INVENTION An electrostatic ink jet recording apparatus according to an embodiment of the present invention will be described. FIG. 1 shows the configuration of an ink head in the electrostatic ink jet recording apparatus of this embodiment. Further, FIG. 2 shows a schematic configuration of an ink ejection mechanism in the electrostatic ink jet recording apparatus.

As shown in FIG. 2, in the electrostatic ink jet recording apparatus of the present embodiment, the recording paper P is shown in FIG.
It is assumed that the sheet is conveyed at a constant speed in the direction indicated by the middle arrow (for example, the vertical direction, hereinafter referred to as the “sub-scanning direction”). The ink head 10 is in a direction orthogonal to the recording surface of the recording paper P (eg, horizontal direction, hereinafter referred to as “main scanning direction”).
It is arranged so that the ink is ejected to. The counter electrode 20 is provided so as to face the ink head 10 with the recording paper P in between. A secondary electrode 30 is provided between the ink head 10 and the counter electrode 20.
It is provided so as to face 0. The counter electrode 20 and the secondary electrode 30 are substantially parallel to the recording surface of the recording paper P.

The ink head 10 is fixed and has a printing width longer than the width of the recording paper P in the main scanning direction. As an example, in the case of printing a high-quality print of a photographic quality with the electrostatic ink jet recording apparatus of the present embodiment, if the width of the recording paper P in the main scanning direction is 3.5 inches (about 89 mm), the ink The print width of the head 10 is 90 mm or more so as to be longer than that. The ink is ejected onto the recording paper P all at once from the ink ejection unit 102, which will be described later.
Is ejected toward and is printed in line units of the image.
Since only a predetermined color (1 color) of ink can be ejected from the ink head 10, it is assumed that the ink heads 10 corresponding to the respective color inks are arranged in the sub-scanning direction in the case of color printing.

As shown in FIG. 1, the ink head 10 includes
For example, the base member 101 and the cover member 105 are made of a ceramic material. At the end of the base member 101 on the ink ejection side, a plurality of ink ejection portions 102 are formed at a predetermined pitch so as to eject in the ink ejection direction. In addition, the upper surface 101 of the base member 101
In a, a plurality of ejection electrodes 103 and electric field separation electrodes 104 are formed at the above-mentioned predetermined pitch corresponding to each ink ejection portion 102.

The ink ejecting portion 102 is formed into an isosceles triangle whose tip is the apex, for example, by cutting the end surface of the base member 101, and the solid component in the ink is the apex of the ink ejecting portion 102. The solid component in the ink is concentrated by concentrating on the ink.
The resolution of this electrostatic ink jet recording device is 600d.
Assuming pi, the pitch of the ink ejection unit 102 is about 40 μm.
m.

The discharge electrode 103 is made of a highly conductive material such as gold and is laminated on the upper surface 101a of the base member 101. As shown in FIG. 2, a bias voltage source E1 for applying a bias voltage, a pulse voltage source E2 for applying a pulse voltage at the time of ink ejection, and a solid component in ink are applied to each ejection electrode 103. A reverse bias voltage source E3 for applying a reverse bias voltage for dilution is connected. The positive electrode of the pulse voltage source E2 and the negative electrode of the reverse bias voltage source E3 are switchably connected by a switch S1. The negative electrode of the bias voltage source E1 and the positive electrode of the reverse bias voltage source E3 are connected to the positive electrode of a voltage source E5 for applying a predetermined voltage (for example, 500 V) to the secondary electrode 30. The bias voltage source E1 applies a bias voltage of, for example, 1500 V to the ejection electrode 103. The pulse voltage source E2 is
A voltage (eg, 500 V) sufficient to eject ink from the ink ejecting unit 102 is applied to the ejection electrode 103. Therefore, the voltage applied to the ink ejection unit 102 when ejecting ink is 2500V. The discharge electrode 10
The upper surface 1 of the base member 101 to prevent peeling
A plurality of grooves may be formed in the groove 01a at the above-described predetermined pitch, and a highly conductive material may be laminated inside each groove to form the ejection electrode 103.

The electric field separation electrode 104 is the discharge electrode 103.
Like the above, it is formed of a material having high conductivity, and is laminated on the upper surface 101a of the base member 101. A voltage source E4 is connected to each electric field separation electrode 104, and a predetermined voltage (for example, 1000 V) is applied. The electric field separation electrode 104 is located approximately in the middle of two adjacent ejection electrodes 103 and has a function of electrically shielding (screening) each ejection electrode 103. That is, assuming that the electric field separation electrode 104 does not exist, an electric field may be generated due to the potential difference between the adjacent ejection electrodes 103, and the ink may be ejected obliquely to the original ejection direction. Further, in a standby state in which ink is not ejected, the electric field generated by the potential difference between the adjacent ejection electrodes 103 may cause the ink to be ejected by mistake.
On the other hand, by arranging the electric field separation electrode 104 between the adjacent ejection electrodes 103, the electric field generated between the adjacent ejection electrodes 103 becomes small, and the ink is ejected obliquely or by mistake. Discharge can be prevented.

Discharge electrode 103 and electric field separation electrode 104
Are arranged in a direction substantially orthogonal to the ink circulation direction shown by the arrow in FIG. 1, but the arrangement is not necessarily limited to this, and solid components in the ink are likely to accumulate near the ink ejection portion 102. In order to do so, it may be formed to form a predetermined angle (for example, about 80 degrees) with respect to the ink circulation direction.

An elongated single slit 105b parallel to the main scanning direction, that is, the arrangement direction of the ink ejection portions 102 is formed at the end of the cover member 105 on the ink ejection side. Behind the slit 105b and the cover member 10
A cavity 105a that functions as an ink storage portion is formed inside the ink container 5. Further, an ink supply pipe 106a and an ink discharge pipe 106b are provided on both sides 105c of the cover member 105, respectively, and ink flows in the direction indicated by the arrow in FIG. 1 (ink circulation direction).

Ink supply pipe 106a and ink discharge pipe 1
06b is connected to an ink tank and a pump (not shown), respectively, and is connected to the ink tank and the cavity 105a.
The ink is configured to circulate at a predetermined flow rate between and. The cross-sectional area of the cavity 105a is the ink supply pipe 1
Since it is larger than the cross-sectional area of 06a, the cavity 105a
Inside the ink supply pipe 106a and the ink discharge pipe 10
There is a phenomenon in which the flow velocity in the vicinity of the main flow path connecting to 6b is the highest, and the flow velocity in the vicinity of the ink ejection portion 102 and in the vicinity on the opposite side to the main flow path becomes slow. Thus, the cavity 1
When a flow velocity difference occurs inside 05a, a negative pressure is generated so as to be sucked from a portion having a low flow velocity to a portion having a high flow velocity.

In the present embodiment, a bias voltage is applied to the ejection electrode 103 to forcibly collect, for example, the solid component charged to + in the vicinity of the ink ejection portion 102, and a predetermined concentration (for example, about 20%). Discharge electrode 1 after concentrated to
Ink is applied by applying a pulse voltage to 03.
On the other hand, when the solid component in the ink is excessively concentrated or when it is necessary to adjust the concentration of the solid component in the other ink, the bias voltage applied to the ejection voltage 103 is turned off, and The solid component in the ink that has accumulated in the vicinity of the ejection portion 102 is sucked into the main flow path side, and the concentration of the solid component in the ink near the ink ejection portion 102 can be lowered (diluted).

The counter electrode 20 is grounded and functions as an electrode facing the discharge electrode 103. Counter electrode 20
Is formed in a flat plate shape by a conductor such as copper, and the recording paper P slides on it. The secondary electrode 30 is
It is provided to strengthen the electric field in the vicinity of the ink ejection unit 102, and a predetermined voltage (500 V) is applied by the voltage source E5 in order to increase the potential gradient between the ink head 10 and the secondary electrode 30. . The secondary electrode 30 is also formed in a flat plate shape with a conductor such as copper. The ink head 10 is provided near the center of the secondary electrode 30.
Slits 31 are formed in parallel with the width direction (main scanning direction) of the recording paper P for passing the ink ejected from the ink ejecting unit 102.

The ink ejection control unit 40 switches the switch S1 to the pulse voltage source E2 side when the main switch of the apparatus is turned on or when a print start signal is received, and the ejection electrode 10 is discharged.
A bias voltage is applied to 3 to concentrate the solid components in the ink near the ink ejection portion 102. Further, when printing of one image of the apparatus is completed, the switch S1 is switched to the reverse bias voltage source E3 side, and the reverse bias voltage is applied to the ejection electrode 103 to remove the solid components in the ink in the vicinity of the ink ejection portion 102. Dilute. Also, during printing, for example, 256
The pulse voltage source E2 is controlled based on a gradation image signal or the like, and a signal having a pulse width corresponding to the gradation of each pixel signal is applied to the corresponding ejection electrode 103.

Next, the operation of the electrostatic ink jet recording apparatus of this embodiment will be described with reference to FIG.
First, as ink, the solid component charged to + is 3-1.
A pigment-based ink containing 0% is used.

The switch S1 is switched to the pulse voltage source E2 side by turning on the main switch of the apparatus or receiving a print start signal, and a predetermined bias voltage is applied to each ejection electrode 103 by the bias voltage source E1. As a result, an electric field is generated near the ink ejection portion 102 in the ink ejection direction, and the concentration of the solid component in the ink is concentrated to about 20% near the ink ejection portion 102.

Next, when a predetermined signal voltage is applied to each ejection electrode 103 by the pulse voltage source E2, the electric field in the vicinity of the ink ejection portion 102 becomes stronger, and the Coulomb force due to this electric field is received to concentrate the electric field. Ink droplets are ejected from the ink ejection unit 102 toward the recording paper P.

The ejected ink droplet is accelerated by the Coulomb force due to the electric field formed between the secondary electrode 30 and the ejection electrode 103, and passes through the slit 31 of the secondary electrode 30. The ink droplets that have passed through the slits 31 are the secondary electrodes 3
0, the Coulomb force is generated by the electric field formed between the counter electrode 20 and the counter electrode 20, and further advances forward, and eventually reaches the recording paper P. As a result, printing for one line in the sub-scanning direction is completed. Next, the recording paper P is conveyed by one line in the sub-scanning direction, and the next line is printed. An image is formed on the recording sheet P by repeating these operations.

Next, changes in the voltage applied to the ejection electrode 103 will be described with reference to FIG. In FIG. 3, the vertical axis represents voltage and the horizontal axis represents time.

In FIG. 3, "concentration 1" indicates a period during which the solid component in the ink is concentrated after the main switch of the apparatus is turned on or the print start signal is received. During this period, the ink ejection control unit 40 switches the switch S1 to the pulse voltage source E2 side, applies a bias voltage from the bias voltage source E1 to the ejection electrode 103, and removes solid components in the ink in the vicinity of the ink ejection unit 102. Concentrate. In addition, this "concentration 1"
During the period, the pulse voltage source E2 is turned off by the ink ejection control unit 40.

"Discharge 1" indicates a period during which, for example, one image is printed. During this period, the ink ejection control unit 40
Turns on the pulse voltage source E2 and applies a pulse signal for a predetermined time to each ejection electrode 103 according to the image signal.

When a pulse voltage is applied to the ejection electrode 103, a Coulomb force in the ejection direction is applied to the ink in the vicinity of the ink ejection portion 102, and as shown in FIG.
And inflate. When the ink droplet K grows, the ink droplet K is eventually cut by the Coulomb force and the surface tension, and is ejected from the ink ejection unit 102 to the recording paper P side. In the present embodiment, PWM control is performed, and for example, by changing the pulse width (application time) of the pulse signal applied to the ejection electrode 103 in 256 steps by increasing the pulse width as the gradation degree increases. It represents 256 gradations. That is, the amount of ink adhered on the recording paper P depends on the pulse width of the pulse signal.

The "reverse bias" indicates a waiting period after the printing of one image is completed and before the next print start signal is received. During the “reverse bias” period, the ink ejection control unit 4
When 0, the switch S1 is switched to the reverse bias voltage source E3 side, and the reverse bias voltage is applied to the ejection electrode 103 to dilute the solid component in the ink in the vicinity of the ink ejection portion 102. That is, as shown in FIG. 4, since an electric field is generated in the direction opposite to the ink ejection direction, the solid component charged to + in the ink in the vicinity of the ink ejection portion 102 is attracted in the direction of the electric field, and the ink ejection is performed. Part 102 to cavity 10
Move to the 5a side. Further, due to the negative pressure due to the flow velocity difference in the cavity 105a, the solid component in the ink in the vicinity of the ink ejection unit 102 is sucked to the ink main flow path side of the cavity 105a and collected in the tank. As a result, the concentration of the solid component in the ink in the vicinity of the ink ejecting unit 102 decreases, and the slit 10 of the cover member 105 is reduced.
The solid component does not precipitate or coagulate at the portion 5b, and the ink head 10 can be prevented from clogging.

"Concentrate 2" means that after printing one image,
The period during which the solid components in the ink are concentrated after the next print start signal is received is shown. The operation is the same as in the case of "concentration 1". Further, "ejection 2" indicates a period during which the second and subsequent images are printed, and is the same as the case of "ejection 1".

"Voltage source off" indicates a state after the main switch of the apparatus is turned off. When the main switch is turned off, all the voltage sources E1 to E5 are turned off, and the voltage of the ejection electrode 103 becomes 0V. In the present embodiment, each voltage source E1 to E
By driving a pump that circulates the ink for a certain period of time even after 5 is turned off, the negative pressure due to the difference in the flow velocity in the cavity 105a causes the solid component in the ink near the ink ejection unit 102 to move to the ink in the cavity 105a. It is sucked into the main flow path and collected in the tank. As a result, the ink ejection unit 102 is turned off after the main switch of the apparatus is turned off.
Even if the ink in the vicinity of the cover is fitted and the concentration of the solid component therein increases, the slit 1 of the cover member 105
It is difficult for the solid component to coagulate at the portion 05b, and clogging of the ink head 10 can be prevented.

In the above embodiment, the ink ejecting section 1
The shape of the recording paper P from the end surface of the base member 101
Although it is formed in the shape of an isosceles triangle protruding to the side, the present invention is not limited to this, and as shown in FIG. 5, for example, a comb tooth shape protruding from the end surface of the base member 101 to the recording paper P side. You may form. In that case, by forming a convex portion 120 shorter than the ink ejection portion 102 between two adjacent ink ejection portions 102, the ink ejection portion 1
The ink has a meniscus shape due to the surface tension between 02 and the convex portion 120.

Further, in the above embodiment, the ink ejecting section 1
The isosceles triangular portion of 02 is the upper surface 1 of the base member 101.
However, the present invention is not limited to this, and is configured to be perpendicular to the upper surface 101a of the base member 101 as shown in FIG. 6, for example. You may. In that case, a slit 130 may be provided for each ink ejection unit 102, and the ink may be supplied to the ink ejection unit 102 through the slit 130 by utilizing a capillary phenomenon.

Further, in the above embodiment, the reverse bias voltage source E3 is provided, and when the solid component in the ink in the vicinity of the ink ejecting portion 102 is diluted, the bias voltage is turned off and the reverse bias voltage is ejected instead. Although the voltage is applied to the electrode 103, the present invention is not limited to this, and the bias voltage is simply turned off as shown in FIG. 7 (the voltage of the secondary electrode 30 ( The same effect can be obtained only by applying, for example, 500 V). Alternatively, as shown in FIG. 8, the voltage source E5 applied to the secondary electrode 30 may be turned off so that the voltage of the ejection electrode 103 becomes 0V.

In the above embodiment, the case where the solid component in the ink is positively charged has been described. However, when the solid component is negatively charged, the discharge electrode 103 and the secondary electrode 30 are charged. The solid component in the ink may be diluted by applying a voltage higher than the applied voltage.

[0039]

As described above, in the electrostatic ink jet recording apparatus of the present invention, a plurality of ink ejection portions arranged at a predetermined pitch in the direction orthogonal to the ink ejection direction, and the ink ejection portion. A cavity for circulating ink, which is formed on the rear side of the ink supply chamber, and an ink supply pipe and a discharge pipe provided in the cavity so as to circulate the ink in a direction orthogonal to the protruding direction of the ink; In the vicinity of each of the ink ejection portions in the cavity, since the ejection electrodes are provided in parallel with each other at a predetermined angle to the ink circulation direction, the ink supply pipe and the ejection electrode are provided in the cavity. The flow velocity of ink in the vicinity of the main flow path of the ink connecting the pipes is high, while the flow velocity of the ink in the vicinity of the ink ejection portion is low. Therefore, a pressure difference occurs due to the difference in the flow velocity of the ink in the cavity, and a negative pressure acts so that the solid component is sucked from the vicinity of the ink discharge portion having the slow flow velocity toward the vicinity of the main flow passage having the fast flow velocity. That is, it becomes possible to dilute the concentrated solid component in the vicinity of the ink ejection portion.
Therefore, by appropriately controlling the voltage applied to the ejection electrode, the application time thereof, the flow velocity of the ink, and the like, it is possible to prevent the excessive concentration of the solid component in the ink or to control the concentration of the solid component within a certain range. Stabilize the ink discharge amount,
It is possible to prevent clogging of the ink head.

By applying a first predetermined voltage to the ejection electrode, the solid component in the ink in the vicinity of the ink ejection portion is concentrated, and a second predetermined voltage different from the first predetermined voltage is applied. Is applied to dilute the solid component in the ink in the vicinity of the ink ejecting portion, so that the solid component contained in the ink to be used is applied to the ejection electrode according to the charging characteristic (+ or −). By appropriately switching the voltage between the first predetermined voltage and the second predetermined voltage, the concentration and dilution of the solid component in the ink in the vicinity of the ink ejection portion can be controlled, and the solid content in the ink can be more efficiently achieved. It is possible to prevent excessive concentration of components, more accurately control the concentration of solid components within a certain range to stabilize the ink ejection amount, and prevent clogging of the ink head. It made.

Further, when a secondary electrode is provided outside the ink ejecting section and the solid component in the ink is positively charged, the second predetermined voltage is higher than the voltage applied to the secondary electrode. When a low voltage is applied and the solid component in the ink is negatively charged, by applying a voltage higher than the voltage applied to the secondary electrode as the second predetermined voltage, the ink used It is possible to control the concentration and dilution of the solid component in the ink in the vicinity of the ink ejection portion according to the charging characteristics (+ or −) of the solid component contained in the ink, and prevent the excessive concentration of the solid component in the ink. ,
It is possible to control the concentration of the solid component within a certain range to stabilize the ink ejection amount and prevent clogging of the ink head.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a schematic configuration of an ink ejection mechanism in the electrostatic ink jet recording apparatus.

FIG. 3 is a diagram showing a change in voltage applied to an ejection electrode in the above embodiment.

FIG. 4 is a diagram showing how ink droplets are ejected from an ink head in the above embodiment.

FIG. 5 is a perspective view showing another configuration example of the ink head of the electrostatic ink jet recording apparatus according to the embodiment of the invention.

FIG. 6 is a perspective view showing still another configuration example of the ink head of the electrostatic ink jet recording apparatus according to the embodiment of the present invention.

FIG. 7 is a diagram showing a modified example of a voltage change applied to the ejection electrode in the above embodiment.

FIG. 8 is a diagram showing another modification of the voltage applied to the ejection electrode in the above embodiment.

[Explanation of symbols]

K: Ink drop P: Recording paper S1: Switch E1: Bias voltage source E2: Pulse voltage source E3: Reverse bias voltage source E4: Voltage source (for electric field separation electrode) E5: (for secondary electrode) voltage source 10: Ink head 20: Counter electrode 30: Secondary electrode 40: Ink ejection control unit 101: Base member 102: Ink ejection section 103: discharge electrode 104: electric field separation electrode 105: cover member 105a: cavity 105b: slit 106a: Ink supply pipe 106b: ink discharge tube

Claims (3)

[Claims] 1. A plurality of ink ejecting portions arranged at a predetermined pitch in a direction orthogonal to a protruding direction of ink, a cavity formed behind the ink ejecting portion, for circulating ink, and the cavity. Inside, an ink supply pipe and a discharge pipe provided so as to circulate ink in a direction orthogonal to the protruding direction of the ink, and an ink circulation direction in the vicinity of each of the ink ejecting portions in the cavity. An electrostatic ink jet recording apparatus, characterized in that it is provided with ejection electrodes that are arranged in parallel with each other at a predetermined angle with respect to. 2. A second predetermined voltage different from the first predetermined voltage is applied by applying a first predetermined voltage to the ejection electrode to concentrate the solid component in the ink in the vicinity of the ink ejection portion. The electrostatic ink jet recording apparatus according to claim 1, wherein the solid component in the ink in the vicinity of the ink ejection portion is diluted by applying a voltage. 3. When a secondary electrode is provided outside the ink ejection portion and the solid component in the ink is positively charged, the second predetermined voltage is lower than the voltage applied to the secondary electrode. A low voltage is applied, and when the solid component in the ink is negatively charged, a voltage higher than the voltage applied to the secondary electrode is applied as the second predetermined voltage. 2. The electrostatic inkjet recording device according to 2.