JPH10157129A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize an image by providing electrodes for stirring coloring matter particles at the opposite ends of a plurality of discharge electrodes for discharging the coloring matter particles concentrated at an ink jet port and flying them onto a recording medium thereby preventing the coloring matter particles from being discharged from a discharge electrode for other purpose than discharging the coloring matter particles. SOLUTION: The ink jet recorder comprises an ink chamber 1 having a dielectric barrier wall 16, an electrophoretic electrode 10 for concentrating coloring matter particles 15 in a pigment based ink at an ink jet port 2, a plurality of discharge electrodes 12, 17, 18,... for discharging the coloring matter particles 15 concentrated at the ink jet port 2 and flying them onto a recording medium 4, and a counter electrode 9 arranged on the back face of the recording medium 4 at a position facing the discharge electrodes 12, 17, 18,.... In such an ink jet recorder, electrodes 5, 6 for stirring coloring matter particles are provided at the opposite ends of the plurality of discharge electrodes 12, 17, 18.... According to the arrangement, the coloring matter particles 15 can be stirred uniformly and can be prevented from being discharged from a discharge electrode for other purpose than discharging the coloring matter particles 15.

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 ink jet recording apparatus in which coloring material particles in a pigment ink are controlled by an electrophoretic phenomenon.

[0002]

2. Description of the Related Art The non-impact recording method has recently attracted attention in that noise during recording is extremely small to a negligible level. Among them, the ink jet recording method that can directly perform high-speed recording on a recording medium with a simple mechanism and that can perform recording on plain paper is an extremely powerful recording method, and various methods have been proposed so far. ing.

Conventionally, this type of ink jet recording apparatus has a voltage applied between an electrode provided on the back surface of a recording medium and a needle-shaped discharge electrode facing the electrode, as shown in, for example, Japanese Patent Application Laid-Open No. 60-228162. There is a method in which a color material such as ink is caused to fly by the electrostatic force of the applied and generated electric field to perform recording.

FIG. 6 is a schematic diagram of this conventional ink jet recording apparatus. Referring to FIG. 6, this conventional ink jet recording apparatus has an ink chamber 201 filled with a pigment-based ink 210 and a color material particle in the pigment-based ink 210 which is concentrated on an ink discharge port 202 by an electrophoretic phenomenon. Electrophoresis electrode 203 and ink ejection port 202
A plurality of discharge electrodes 205 for discharging color material particles concentrated on the recording medium 204 and causing them to fly onto the recording medium 204;
And a counter electrode 209 provided on the back surface of the recording medium 204 so as to face the recording medium 204.

[0005] The ink discharge ports 202 are separated for each discharge electrode 205 by a flow path wall 208 so that a convex meniscus of pigment-based ink 210 is formed at the tip of each discharge electrode 205. The ink chamber 201 is connected by an ink tank and a tube (not shown) at an ink supply port 206 and an ink discharge port 207, and applies a back pressure to the ink in the ink chamber 201 and the pigment-based ink 210 in the ink chamber 201. Is forcibly circulated.

FIG. 5 is a waveform diagram of a voltage applied to the electrophoresis electrode and the discharge electrode. The operation of this conventional ink jet recording apparatus will be described with reference to FIGS. This ink jet recording apparatus utilizes an electrophoresis phenomenon in which when an electric field is applied to a pigment-based ink containing charged coloring material particles, the coloring material particles move in one direction under the electric field.

That is, when a constant voltage V1 shown in FIG. 5 is applied to the electrophoretic electrode 203 and an electric field is applied to the ink chamber 201 filled with the pigment ink 210, the pigment ink 2
The color material particles in 10 move to the ink discharge port 202 at a certain electrophoretic speed, and a convex meniscus of the pigment-based ink 210 is formed at the tip of the discharge electrode 205. When a voltage V2 shown in FIG. 5 and a pulse voltage of time T2 shown in FIG. 5 are applied to the discharge electrode 205 for discharging the color material particles, the color material particles move to the tip of the discharge electrode 205 and concentrate due to the electrostatic force.

The color material particles overcome the meniscus force, the surface tension and the viscous force of the pigment-based ink by the electrostatic force,
At the timing synchronized with the pulse voltage, the flying particles become small flying particles 211 and fly from the tip of the discharge electrode 205,
It adheres on the recording medium 204. Color material particles are supplied, and such an operation is repeated to form an image on the recording medium 204.

[0009]

The problem with the conventional ink jet recording apparatus described above is that the direction of the electric field due to the voltage applied to the electrophoretic electrode becomes constant and the color material particles move in a fixed direction, so that a plurality of discharges occur. That is, it is uniformly concentrated on the tip of the electrode. As a result, when a pulse voltage is applied to the discharge electrode for discharging the color material particles, the color material particles are discharged from the discharge electrode other than the target discharge electrode, which may affect the image quality.

The reason is that the coloring material particles are also concentrated on the tip of the discharging electrode which is not intended to discharge the coloring material particles.

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus which prevents discharge of color material particles from a discharge electrode not intended for discharge of color material particles and stabilizes an image.

[0012]

SUMMARY OF THE INVENTION An ink jet recording apparatus according to the present invention has an ink chamber filled with a pigment-based ink and a color material particle in the pigment-based ink which is concentrated at an ink discharge port by an electrophoretic phenomenon. An electrophoretic electrode, a plurality of discharge electrodes for discharging the color material particles concentrated on the ink discharge ports and causing them to fly on a recording medium, and a plurality of discharge electrodes disposed on the back surface of the recording medium at a position facing the discharge electrode. In the ink jet recording apparatus provided with the provided counter electrode,
A stirring electrode for stirring the color material particles is provided at both ends of the plurality of discharge electrodes.

Further, in the ink jet recording apparatus of the present invention, after applying the voltage to the electrophoretic electrode to concentrate the coloring material particles on the tip of the discharge electrode, the applied voltage is applied to the stirring electrode. After the coloring material particles at the tip of the discharging electrode flow, a voltage is applied to the discharging electrode to discharge the coloring material particles from the discharging electrode.

Further, the ink jet recording apparatus according to the present invention is characterized in that the electrophoretic electrodes are provided for each of the discharge electrodes.

Further, in the ink jet recording apparatus of the present invention, after applying the voltage to a predetermined electrophoretic electrode corresponding to a predetermined discharge electrode, the coloring material particles are concentrated on the tip of the predetermined discharge electrode. After applying the applied voltage to the stirring electrode to cause the color material particles at the predetermined discharge electrode tip to flow, the voltage is applied to the predetermined discharge electrode to cause the color material particles to flow from the predetermined discharge electrode. Is discharged.

Further, the ink jet recording apparatus according to the present invention is characterized in that the coloring material particles concentrated on the ink discharge port are stirred by periodically changing the voltage applied to the stirring electrode.

[0017]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a simple basic structure of an ink jet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing waveforms of voltages applied to an electrophoretic electrode, a stirring electrode, and a discharge electrode according to this embodiment.

Referring to FIG. 1 and FIG. 2, an ink jet recording apparatus according to this embodiment includes an ink chamber 1 filled with a pigment-based ink composed of a dielectric partition 16 and color material particles in the pigment-based ink. An electrophoresis electrode 10 for concentrating 15 on the ink ejection port 2 by an electrophoresis phenomenon;
A plurality of discharge electrodes 12, 1 for discharging the color material particles 15 concentrated on the ink discharge port 2 to fly on the recording medium 4
7, 18 and the like, a counter electrode 9 disposed on the back surface of the recording medium 4 at a position facing the plurality of discharge electrodes 12, 17, 18 and the like, and both ends of the plurality of discharge electrodes 12, 17, 18 and the like. The color material particles 15 are provided with stirring electrodes 5 and 6 for stirring. In addition, in the ink jet recording apparatus of this embodiment, the color material particles 15 are concentrated on the leading end portions of the discharge electrodes 12, 17, 18 by applying a voltage to the electrophoretic electrode 10, and then the stirring is performed on the stirring electrodes 5, 6. By applying the applied voltage, the coloring material particles 15 at the tip portions such as the discharge electrodes 12, 17, 18
After the flowing, the color material particles 15 are discharged from the discharge electrodes 12, 17, 18 and the like by applying a voltage to the discharge electrodes 12, 17, 18 and the like. Further, the ink jet recording apparatus according to the present embodiment periodically changes the voltage applied to the stirring electrodes 5 and 6,
It is characterized in that the coloring material particles 15 concentrated on the ink discharge ports 2 are stirred.

In this embodiment, print data and a print control signal input from a computer or the like via an input interface 13 discharge color material particles 15 from a discharge electrode a12 and a discharge electrode c18, and a discharge electrode b1.
7 will be described with reference to FIGS. 1 and 2 when the signal does not discharge the color material particles 15.

First, in the case of the sequence a in FIG.
Reference numeral 4 detects print data and a print control signal input from a computer or the like via the input interface 13. The control unit 14 sends a signal to the electrophoresis electrode voltage control circuit 8. The electrophoresis electrode voltage control circuit 8 includes a control unit 14
A voltage V1 is applied to the electrophoretic electrode 10 for a time T1 in response to the signal sent from the printer, and an electric field is applied to the ink chamber 1 filled with the pigment ink. Since the color material particles 15 in the pigment-based ink move at a certain electrophoretic speed to the ink discharge port 2, the color material particles 5 are concentrated at the tips of the discharge electrodes a12, b17, and c18.

Next, in the case of the sequence b in FIG.
4 sends a signal to the electrophoresis electrode voltage control circuit 8 and the stirring electrode voltage control circuit 7. The electrophoresis electrode voltage control circuit 8 turns off the voltage to the electrophoresis electrode 10 in response to the signal sent from the control unit 14. In addition, the stirring electrode voltage control circuit 7 responds to the signal sent from the control unit 14 so that the voltages applied to the stirring electrode a5 and the stirring electrode b6 are in opposite phases to each other for a certain period of the period Tab (FIG. 2).
Then, 3/2 Tab) is changed.

When the voltage applied to the electrophoretic electrode 10 is turned off, the color material particles 15 that have been moving toward the ink discharge port 2 stop. Further, since the voltages applied to the stirring electrode a5 and the stirring electrode b6 change in the cycle Tab so that the phases are opposite to each other, the direction of the electric field changes in the cycle Tab / 2, and the ink chamber 1, the discharge electrode a12, and the discharge electrode b1 are changed.
The coloring material particles 15 near the tip of the discharge electrode 7 and the discharge electrode c18 move and change the direction between the stirring electrodes a5 and b6 at a cycle of Tab / 2 and are stirred. For this reason, the coloring material particles 15 uniformly move near the tip of the discharge electrode a12, the discharge electrode b17, and the discharge electrode c18.

Next, in the case of the sequence c in FIG.
4 sends a signal to the stirring electrode voltage control circuit 7 and the discharge electrode voltage control circuit 3. The stirring electrode voltage control circuit 7 turns off the voltage applied to the stirring electrode a5 and the stirring electrode b6 in response to the signal sent from the control unit 14. When the voltage applied to the stirring electrode a5 and the stirring electrode b6 is turned off, the coloring material particles 15 stop. The coloring material particles 15 are the discharge electrode a1.
2. In the state of being uniformly distributed near the tip of the discharge electrode b17 and the discharge electrode c18.

At this time, the discharge electrode voltage control circuit 3 responds to the signal sent from the
A pulse voltage of voltage V2 and time T2 is applied to the discharge electrode c18. When a voltage V2 and a pulse voltage of time T2 are applied to the discharge electrode a12 and the discharge electrode c18, the coloring material particles 15 uniformly distributed near the tip of the discharge electrode a12 and the discharge electrode c18 are discharged by the discharge electrode a1 by electrostatic force.
2 and move to the tip of the discharge electrode c18 to concentrate. The coloring material particles 15 overcome the meniscus force, the surface tension and the viscous force of the pigment-based ink by the electrostatic force, and become a small flying particle group 11 at a timing synchronized with the pulse voltage, and form the discharge electrode a12 and the discharge electrode c18. Flies from the leading end of the recording medium 4 and adheres to the recording medium 4. Since the color material particles 15 are not concentrated near the tip of the discharge electrode b17 which is not intended to discharge the color material particles 15, the color material particles 15 are not affected by the pulse voltage applied to the discharge electrode a12 and the discharge electrode c18. There is no discharge from the discharge electrode b17.

Next, when there is a request to discharge the color material particles 15 from the discharge electrode a12 and the discharge electrode c18, the control unit 14 sends a signal to the electrophoresis electrode voltage control circuit 8.
The electrophoresis electrode voltage control circuit 8 applies the voltage V1 to the electrophoresis electrode 10 again for a time T1 in response to the signal sent from the control unit 14, and applies an electric field to the ink chamber 1 filled with the pigment ink. Add. Color material particles 1 in pigment-based ink
5 moves to the ink discharge port 2 at a certain electrophoretic speed, so that the discharge electrode a12, the discharge electrode b17, and the discharge electrode c
Concentration of the coloring material particles 15 occurs again at the tip end of 18.

Next, in the case of the second sequence b in FIG. 2, the control section 14 sends signals to the electrophoresis electrode voltage control circuit 8 and the stirring electrode voltage control circuit 7. The electrophoresis electrode voltage control circuit 8 turns off the voltage to the electrophoresis electrode 10 in response to the signal sent from the control unit 14. Also,
The stirring electrode voltage control circuit 7 responds to the signal sent from the control unit 14 so that the voltages applied to the stirring electrode a5 and the stirring electrode b6 are in opposite phases to each other for a certain period of time Tab (3/3 in FIG. 2). 2Tab) change.

When the voltage applied to the electrophoretic electrode 3 is turned off, the color material particles 15 that have been moving toward the ink ejection port 2 are stopped. Further, since the voltage applied to the stirring electrode a5 and the stirring electrode b6 change in the cycle Tab so that the phases are opposite to each other, the direction of the electric field changes in the cycle Tab / 2, and the color near the ink ejection port 2 of the ink chamber 1 is changed. Material particle 1
5 moves between the stirring electrodes a5 and b6 while changing the direction at a cycle of Tab / 2, and is stirred. For this reason, the coloring material particles 15 uniformly move near the tip of the discharge electrode a12, the discharge electrode b17, and the discharge electrode c18.

Next, in the case of the sequence d in FIG.
4 sends a signal to the stirring electrode voltage control circuit 7 and the discharge electrode voltage control circuit 3. The stirring electrode voltage control circuit 7 turns off the voltage applied to the stirring electrode a5 and the stirring electrode b6 in response to the signal sent from the control unit 14. When the voltage applied to the stirring electrode a5 and the stirring electrode b6 is turned off, the coloring material particles 15 stop. The coloring material particles 15 are the discharge electrode a1.
2. In the state of being uniformly distributed near the tip of the discharge electrode b17 and the discharge electrode c18.

At this time, the discharge electrode voltage control circuit 3 responds to the signal sent from the control unit 14 to
A pulse voltage of voltage V2 and time T2 is applied to the discharge electrode c18. When a voltage V2 and a pulse voltage of time T2 are applied to the discharge electrode a12 and the discharge electrode c18, the coloring material particles 15 uniformly distributed near the tip of the discharge electrode a12 and the discharge electrode c18 are discharged by the discharge electrode a1 by electrostatic force.
2 and move to the tip of the discharge electrode c18 to concentrate. The coloring material particles 15 overcome the meniscus force, the surface tension and the viscous force of the pigment-based ink by the electrostatic force, and become a small flying particle group 11 at a timing synchronized with the pulse voltage, and form the discharge electrode a12 and the discharge electrode c18. Flies from the leading end of the recording medium 4 and adheres to the recording medium 4. Since the color material particles 15 are not concentrated near the tip of the discharge electrode b17 which is not intended to discharge the color material particles 15, the color material particles 15 are not affected by the pulse voltage applied to the discharge electrode a12 and the discharge electrode c18. There is no discharge from the discharge electrode b17.

The controller 14 sends a signal to the electrophoresis electrode voltage control circuit 8 when there is no request to discharge the next color material particle 15 from any of the discharge electrodes a12, b17 and c18. . The electrophoresis electrode voltage control circuit 8 turns off the voltage applied to the electrophoresis electrode 10 in response to the signal sent from the control unit 14.

FIG. 3 is a diagram showing a simple basic structure of an ink jet recording apparatus according to another embodiment of the present invention, and FIG. 4 is a diagram showing voltage waveforms applied to an electrophoretic electrode, a stirring electrode, and a discharge electrode according to this embodiment. .

Referring to FIGS. 3 and 4, the ink jet recording apparatus according to the present embodiment comprises an ink chamber 1 filled with a pigment ink composed of a dielectric partition 16 and color material particles in the pigment ink. Electrophoretic electrodes 19 and 2 for concentrating 15 on the ink discharge port 2 by an electrophoretic phenomenon
0, 21 and the like, and coloring material particles 15 concentrated on the ink ejection port 2
And a plurality of discharge electrodes 12, 17, 18 and the like for discharging the recording medium 4 to fly the recording medium 4.
A counter electrode 9 disposed on the back surface of the recording medium 4 at a position facing the recording medium 4;
Electrophoresis electrodes 19, 20, 21, etc. provided for every 8
It is composed of stirring electrodes 5 and 6 for stirring the color material particles 15 provided at both ends of the plurality of discharge electrodes 12, 17, 18 and the like. In addition, the inkjet recording apparatus according to this embodiment provides a predetermined discharge electrode, for example, a discharge electrode by applying a voltage to a predetermined discharge electrode, for example, a predetermined electrophoretic electrode corresponding to the discharge electrode b17, for example, the electrophoretic electrode b20. After the coloring material particles 15 are concentrated at the tip of the b17, a predetermined discharge electrode, for example, the coloring material particles 15 at the tip of the discharging electrode b17 are caused to flow by applying an applied voltage to the stirring electrodes 5 and 6,
The color material particles 15 are discharged from a predetermined discharge electrode, for example, the discharge electrode b17 by applying a voltage to a predetermined discharge electrode, for example, the discharge electrode b17. Further, the ink jet recording apparatus of this embodiment is characterized in that the color material particles 15 concentrated on the ink ejection port 2 are stirred by periodically changing the voltage applied to the stirring electrodes 5 and 6.

Next, in this embodiment, print data and a print control signal input from a computer or the like via the input interface 13 are transmitted to the discharge electrode a12.
The operation when the signal is such that the color material particles 15 are discharged from the discharge electrode b17 and the color material particles 15 are not discharged from the discharge electrode c18 will be described with reference to FIGS.

First, in the case of the sequence a in FIG.
Reference numeral 4 detects print data and a print control signal input from a computer or the like via the input interface 13. The control unit 14 sends a signal to the electrophoresis electrode voltage control circuit 8. The electrophoresis electrode voltage control circuit 8 includes a control unit 14
A voltage V1 is applied to the electrophoretic electrode b20 for a time T1 in response to the signal sent from the printer, and an electric field is applied to the ink chamber 1 filled with the pigment-based ink. Since the color material particles 15 in the pigment-based ink move at the electrophoretic speed to the ink ejection port 2, the color material particles 15 mainly concentrate at the tip of the discharge electrode b17, and the discharge electrode a12 and the discharge electrode c18.
The coloring material particles 15 are slightly concentrated also at the front end portion.

Next, in the case of the sequence b in FIG.
4 sends a signal to the electrophoresis electrode voltage control circuit 8 and the stirring electrode voltage control circuit 7. The electrophoresis electrode voltage control circuit 8 turns off the voltage to the electrophoresis electrode b20 in response to the signal sent from the control unit 14. Further, the stirring electrode voltage control circuit 7 responds to the signal sent from the control unit 14 so that the voltages applied to the stirring electrode a5 and the stirring electrode b6 are in opposite phases to each other for a certain period of time Tab (FIG. 4). 3/2 Tab).

The voltage applied to the electrophoresis electrode b20 is turned off.
, The color material particles 15 that have been moving toward the ink ejection port 2 stop. Further, since the voltages applied to the stirring electrode a5 and the stirring electrode b6 change in the cycle Tab so that the phases are opposite to each other, the direction of the electric field changes in the cycle Tab / 2, and the ink chamber 1 and the discharge electrode a12 and the discharge electrode b
The color material particles 15 near the tip of the discharge electrode 17 and the discharge electrode c18 move while being turned between the stirring electrodes a5 and b6 at a cycle of Tab / 2, and are stirred. For this reason, the coloring material particles 15 uniformly move near the tip of the discharge electrode a12, the discharge electrode b17, and the discharge electrode c18.

Next, in the case of the sequence c in FIG.
4 is a stirring electrode voltage control circuit 7 and a discharge electrode voltage control circuit 3
Send a signal to The stirring electrode voltage control circuit 7 includes the control unit 1
The voltage applied to the stirring electrodes a5 and b6 is turned off in response to the signal sent from the step No. 4. Stirring electrode a5
When the voltage applied to the stirring electrode b6 is turned off, the color material particles 15 stop. The color material particles 15 are discharged from the discharge electrode a12,
It is in a state of being uniformly distributed near the tip of the discharge electrode b17 and discharge electrode c18.

At this time, the discharge electrode voltage control circuit 3 responds to the signal sent from the
And a pulse voltage of time T2. When a voltage V2 and a pulse voltage of time T2 are applied to the discharge electrode b17, the coloring material particles 15 uniformly distributed near the front end of the discharge electrode b17 move and concentrate on the front end of the discharge electrode b17 due to electrostatic force. . The coloring material particles 15 overcome the meniscus force, the surface tension and the viscous force of the pigment-based ink by the electrostatic force, and become fine flying particles 11 at a timing synchronized with the pulse voltage, from the tip of the discharge electrode b17. It flies and adheres on the recording medium 4. Since the color material particles 15 are not concentrated near the distal ends of the discharge electrode a12 and the discharge electrode c18 which are not intended to discharge the color material particles 15, the color material particles 15 are not affected by the pulse voltage applied to the discharge electrode b17. Is not discharged from the discharge electrode a12 and the discharge electrode c18.

Next, when there is a request to discharge the color material particles 15 from the discharge electrode a12 and the discharge electrode b17, the control unit 14 sends a signal to the electrophoresis electrode voltage control circuit 8.
The electrophoresis electrode voltage control circuit 8 applies the voltage V1 again to the electrophoresis electrode a19 and the electrophoresis electrode b20 for the time T1 in response to the signal sent from the control unit 14, and the ink filled with the pigment-based ink. An electric field is applied to chamber 1.
Since the coloring material particles 15 in the pigment-based ink move at a certain electrophoretic speed to the ink discharge port 2, the coloring material particles 15 mainly concentrate at the tip of the discharge electrode a12 and the discharge electrode b17, and the discharge electrode c18 A slight concentration of the coloring material particles 15 also occurs at the tip.

Next, in the case of the second sequence b in FIG. 4, the control section 14 sends signals to the electrophoresis electrode voltage control circuit 8 and the stirring electrode voltage control circuit 7. The electrophoresis electrode voltage control circuit 8 turns off the voltage to the electrophoresis electrode a19 and the electrophoresis electrode b20 in response to the signal sent from the control unit 14. In addition, the stir electrode voltage control circuit 7 responds to the signal sent from the control unit 14 to
And the voltage applied to the stirring electrode b6 is changed for a period of time (3/2 Tab in FIG. 4) which is the period Tab so as to have opposite phases.

Electrophoresis electrode a19 and electrophoresis electrode b
When the voltage applied to 20 is turned off, the color material particles 15 that have been moving toward the ink ejection port 2 are stopped. Further, since the voltage applied to the stirring electrode a5 and the stirring electrode b6 change in the cycle Tab so that the phases are opposite to each other, the direction of the electric field changes in the cycle Tab / 2, and the color near the ink ejection port 2 of the ink chamber 1 is changed. The material particles 15 move between the stirring electrodes a5 and b6 while changing their directions at a cycle of Tab / 2, and are stirred. For this reason, the coloring material particles 15 uniformly move near the tip of the discharge electrode a12, the discharge electrode b17, and the discharge electrode c18.

Next, in the case of the sequence d in FIG.
4 is a stirring electrode voltage control circuit 7 and a discharge electrode voltage control circuit 3
Send a signal to The stirring electrode voltage control circuit 7 includes the control unit 1
The voltage applied to the stirring electrodes a5 and b6 is turned off in response to the signal sent from the step No. 4. Stirring electrode a5
When the voltage applied to the stirring electrode b6 is turned off, the color material particles 15 stop. The color material particles 15 are in a state of being uniformly distributed near the tip of the discharge electrode a12, the discharge electrode b17, and the discharge electrode c18.

At this time, the discharge electrode voltage control circuit 3 responds to the signal sent from the
Further, a pulse voltage of voltage V2 and time T2 is applied to the discharge electrode b17. When a pulse voltage of voltage V2 and time T2 is applied to the discharge electrode a12 and the discharge electrode b17, the coloring material particles 15 uniformly distributed near the tip of the discharge electrode a12 and the discharge electrode b17 are discharged by the discharge electrode a1 by electrostatic force.
2 and move to the tip of the discharge electrode b17 and concentrate. The coloring material particles 15 overcome the meniscus force, the surface tension and the viscous force of the pigment-based ink by the electrostatic force, become minute flying particles 11 at a timing synchronized with the pulsed discharge voltage, and form the discharge electrodes a12 and It flies from the tip of the discharge electrode b17 and adheres on the recording medium 4.

Since the coloring material particles 15 are not concentrated near the tip of the discharging electrode c18 which is not intended to discharge the coloring material particles 15, the coloring material is affected by the pulse voltage applied to the discharging electrodes a12 and b17. Particles 15 are discharge electrodes c
There is no discharge from 18.

The control section 14 sends a signal to the electrophoretic electrode voltage control circuit 8 when there is no request to discharge the next color material particles 15 from any of the discharge electrodes a12, b17 and c18. . The electrophoresis electrode voltage control circuit 8 responds to the signal sent from the control unit 14 to control the electrophoresis electrode a19, the electrophoresis electrode b20 and the electrophoresis electrode c.
The voltage applied to 21 is turned off.

[0047]

As described above, the effect of the present invention is as follows.
Since the color material particles can be uniformly stirred and the color material particles are prevented from being concentrated at the tip of the discharge electrode which is not intended to discharge the color material particles, the discharge is performed for the purpose of discharging the color material particles. This means that an unintended discharge of the color material particles from the discharge electrode can be prevented by the influence of the voltage applied to the electrode, so that the image can be stabilized.

The reason is that stirring electrodes for stirring color material particles are provided at both ends of the plurality of discharge electrodes, and the voltage applied to the stirring electrodes is controlled.

[Brief description of the drawings]

FIG. 1 is a basic structural diagram of an ink jet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a waveform diagram of a voltage applied to an electrophoresis electrode, a stirring electrode, and a discharge electrode according to the embodiment of FIG.

FIG. 3 is a basic structural diagram of an ink jet recording apparatus according to another embodiment of the present invention.

FIG. 4 is a waveform diagram of voltage applied to the electrophoresis electrode, the stirring electrode, and the discharge electrode of the embodiment of FIG.

FIG. 5 is a waveform diagram of a voltage applied to a conventional example of an electrophoretic electrode and a discharge electrode.

FIG. 6 is a schematic diagram of a conventional ink jet recording apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ink chamber 2 ink discharge port 3 discharge electrode voltage control circuit 4 recording medium 5 stirring electrode a 6 stirring electrode b 7 stirring electrode voltage control circuit 8 electrophoresis electrode voltage control circuit 9 counter electrode 10 electrophoresis electrode 11 flying particle group 12 discharge Electrode a 13 Input interface 14 Control unit 15 Color material particles 16 Dielectric partition wall 17 Discharge electrode b 18 Discharge electrode c 19 Electrophoresis electrode a 20 Electrophoresis electrode b 21 Electrophoresis electrode c

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Mizoguchi 7546 Yasuda, Niigata Prefecture Kashiwazaki-shi Niigata Nippon Electric Co., Ltd. (72) Inventor Kazuo Shima 7546 Yasuda, Kashiwazaki-shi, Niigata Prefecture Niigata Nippon Electric Co., Ltd.

Claims (5)

[Claims] 1. An ink chamber filled with a pigment-based ink, an electrophoretic electrode for concentrating coloring material particles in the pigment-based ink to an ink discharge port by an electrophoretic phenomenon, and a concentration in the ink discharge port. An ink jet recording apparatus comprising: a plurality of discharge electrodes for discharging the colored material particles to fly on a recording medium; and a counter electrode disposed on a back surface of the recording medium at a position facing the discharge electrode. ,
An ink jet recording apparatus, wherein a stirring electrode for stirring the color material particles is provided at both ends of the plurality of discharge electrodes. 2. After the coloring material particles are concentrated on the discharge electrode tip by applying a voltage to the electrophoresis electrode, the applied voltage is applied to the stirring electrode, and the discharge electrode tip is 2. The ink jet recording apparatus according to claim 1, wherein after the color material particles flow, the color material particles are discharged from the discharge electrode by applying a voltage to the discharge electrode. 3. An ink jet recording apparatus according to claim 1, wherein said electrophoretic electrode is provided for each of said discharge electrodes. 4. A method in which a voltage is applied to a predetermined electrophoresis electrode corresponding to a predetermined discharge electrode so that the color material particles are concentrated on the end of the predetermined discharge electrode, and then an applied voltage is applied to the stirring electrode. After flowing the coloring material particles at the end of the predetermined discharging electrode, the coloring material particles are discharged from the predetermined discharging electrode by applying a voltage to the predetermined discharging electrode. The inkjet recording apparatus according to claim 3. 5. A color material particle concentrated on an ink discharge port is agitated by periodically changing a voltage applied to said agitation electrode.
The inkjet recording apparatus according to any one of the preceding claims.