JPH10157127A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent jamming of coloring matter particles, fluctuation of dot diameter and erroneous discharge of coloring matter particles. SOLUTION: The ink jet recorder comprises an ink chamber 1 filled with a pigment based ink 12, electrophoretic electrodes a4, b6 and c8 for concentrating the coloring matter particles in the pigment based ink 12 to an ink jet port 2 through electrophoresis, and a plurality of discharge electrodes a5, b7 and c9 for discharging the coloring matter particles concentrated to the ink jet port 2 toward a recording medium on a counter electrode 10 wherein the discharge electrodes a5, b7 and c9 are provided, respectively, with the electrophoretic electrodes a4, b6 and c8. At the time of discharging the coloring matter particles, a voltage is applied only to an electrophoretic electrode a4, b6 or c8 corresponding to a target discharge electrode a5, b7 or c9.

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 record directly on a recording medium at high speed with a simple mechanism and that can record on plain paper is an extremely powerful recording method, and various methods have been proposed so far. Have been.

In this method, a voltage is applied between a needle-like recording electrode and an electrode provided on the back of the recording paper facing the needle-like recording electrode using an ink in which toner particles are dispersed in a carrier liquid. Fly the color material in the ink by electrostatic force,
There is an electrostatic ink jet recording method for performing recording.

FIG. 3 is a schematic view of a conventional electrostatic ink jet recording apparatus disclosed in, for example, Japanese Patent Application No. 7-164307, and FIG. 4 is a waveform diagram of voltage applied to an electrophoretic electrode and a discharge electrode. .

Referring to FIG. 3, an ink jet recording apparatus utilizing the conventional electrophoretic phenomenon includes an ink chamber 21 filled with a pigment-based ink 20 and a color material particle in the pigment-based ink 20 which is electrophoretically moved. An electrophoretic electrode 23 for concentrating on the ink discharge port 22 by a phenomenon; a plurality of discharge electrodes 25 for discharging the color material particles concentrated on the ink discharge port 22 to fly on the recording medium 24;
Counter electrode 29 disposed on the back surface of the recording medium 24 facing the recording medium 24
And

[0006] The ink discharge ports 22 are partitioned by the flow path walls 28 for each discharge electrode 25 so that a convex meniscus of the pigment-based ink 20 is formed at the tip of each discharge electrode 25.

The ink chamber 21 is connected to an ink tank (not shown) by an ink supply port 26 and an ink discharge port 27 by a tube, and provides a back pressure to the ink in the ink chamber 21 and the inside of the ink chamber 21. The pigment ink 20 is forcibly circulated.

Next, the operation will be described with reference to FIG. 3 and FIG. This conventional 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, the voltage of the constant voltage V1 shown in FIG.
When an electric field is applied to the ink chamber 21 filled with the pigment-based ink 20, the color material particles in the pigment-based ink 20 move at an electrophoretic speed to the ink discharge port 22, and the convex pigment A meniscus of the system ink 20 is formed. When a voltage V2 shown in FIG. 4 and a pulse-like discharge voltage of time T2 are applied to the discharge electrode 25 for discharging the color material particles,
The coloring material particles move and concentrate on the tip of the discharge electrode 25 due to the electrostatic force. The color material particles overcome the meniscus force, the surface tension and the viscous force of the pigment ink, etc. by the electrostatic force,
At the timing synchronized with the pulsed discharge voltage, the flying particles 31 become minute flying particles 31 and fly from the tip of the discharge electrode 25 and adhere onto the recording medium 24. Color material particles are supplied, and such an operation is repeated to form an image on the recording medium 24.

[0009]

However, in the above-mentioned conventional ink jet recording apparatus, since a plurality of discharge electrodes 25 are formed for one electrophoretic electrode 23 as shown in FIG. When a voltage is applied to the electrophoretic electrode 23 to concentrate the color material particles at the tip of the target discharge electrode 25 in order to discharge the color material particles from the discharge electrode 25 for discharging the color material particles, Color material particles also concentrate at the tip of the discharge electrode 25 that does not discharge the colorant.
Therefore, the voltage V2 shown in FIG.
When a pulsed discharge voltage at time T2 is applied, the electric field generated by this voltage causes particles to be discharged from the discharge electrode 25 adjacent to the discharge electrode 25 and not discharging the color material particles. Further, a part of the color material particles that are not discharged to the tip of the discharge electrode 25 remain in a lump near the tip of the discharge electrode 25 and finally clog up, and the particles are discharged from the discharge electrode 25. Will be gone. Further, if the concentration of the coloring material particles at the end portion of the target discharge electrode 25 is insufficient, the dot diameter of the particles flying from the discharge electrode 25 becomes small, and a dropout occurs during printing.

That is, when the supply amount of the color material particles> the discharge amount of the color material particles, the particles are discharged from the plurality of discharge electrodes 25, and the excessive color material particles are aggregated near the tip of the discharge electrode 25. And eventually no particles are emitted. When the supply amount of the color material particles <the discharge amount of the color material particles, the supply amount of the color material particles becomes insufficient, so that the dot diameter becomes small and a dropout occurs during printing.

[0011]

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, and a plurality of discharge electrodes for discharging the color material particles concentrated on the ink discharge port and causing the color material particles to fly to a recording medium on a counter electrode, wherein each of the discharge electrodes Wherein the electrophoresis electrode is provided for each of them.

Further, the ink jet recording apparatus of the present invention controls so that a voltage is applied only to the target discharge electrode and the corresponding electrophoretic electrode when discharging the color material particles.

[0013]

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 and a discharge electrode according to this embodiment.

Referring to FIG. 1, an ink jet recording apparatus according to this embodiment includes an ink chamber 1 filled with a pigment-based ink 12 and a color material particle in the pigment-based ink 12 ejected by an electrophoresis phenomenon. Electrophoretic electrodes a4, b6, and c8 for concentrating on the outlet 2, and a plurality of discharge electrodes a5 for discharging the color material particles concentrated on the ink discharge port 2 and flying on the recording medium 3 on the counter electrode 10. b7, c
9, and electrophoresis electrodes a4, b6, c8 are provided for each of the discharge electrodes a5, b7, c9. Electrophoretic electrodes a4, b corresponding to target discharge electrodes a5, b7, c9 when discharging color material particles.
6, and c8 are controlled so as to apply a voltage.

Referring to FIGS. 1 and 2, the operation of this embodiment will be described. As an example, a case will be described in which the flying particle group 11 is made to fly from the ink discharge ports 2 corresponding to the respective discharge electrodes a5, c9, and b7 in the order of the discharge electrode a5, the discharge electrode c9, and the discharge electrode b7.

The control unit 14 discharges color material particles in accordance with print data and a print control signal input from a computer or the like via the input interface 13.
5. Determine the discharge electrode c9 and the discharge electrode b7 and the voltage signals to be applied to the electrophoresis electrode a4, the electrophoresis electrode c8 and the electrophoresis electrode b6 corresponding to these discharge electrodes, respectively. 15 to send a signal. When the electrophoresis electrode / discharge electrode voltage control unit 15 detects a signal from the control unit 14, the electrophoresis electrode a / discharge electrode a voltage control circuit 15a applies a constant voltage of the voltage Vepa to the electrophoresis electrode a4 to the discharge electrode a5. Is the voltage V
eja, a pulse-like discharge voltage of time Tp is applied.
At this time, the voltage applied to the electrophoresis electrode b6 and the electrophoresis electrode c8 is set to 0 V by the voltage control circuit 15b for the electrophoresis electrode b / discharge electrode b and the voltage control circuit 15c for the electrophoresis electrode c / discharge electrode. .

A pulsed discharge voltage Vej is applied to the discharge electrode a5.
After a is applied, the voltage Vep is applied to the electrophoresis electrode c8 by the electrophoresis electrode c / discharge electrode c voltage control circuit 15c.
A constant voltage of c is applied to the discharge electrode c9, and a voltage Vejc and a pulsed discharge voltage of time Tp are applied. At this time, the voltage applied to the electrophoresis electrode a4 and the electrophoresis electrode b6 is set to 0 V by the voltage control circuit 15a for the electrophoresis electrode a and the discharge electrode a and the voltage control circuit 15b for the electrophoresis electrode b and the discharge electrode b. .

A pulsed discharge voltage Vej is applied to the discharge electrode c9.
After the voltage c is applied, the voltage Vep is applied to the electrophoresis electrode b6 by the electrophoresis electrode b / discharge electrode b voltage control circuit 15b.
A constant voltage of b is applied to the discharge electrode b7, and a voltage Vejb and a pulsed discharge voltage of time Tp are applied. At this time, the voltage applied to the electrophoresis electrode a4 and the electrophoresis electrode c8 is set to 0 V by the voltage control circuit 15a for the electrophoresis electrode a and the discharge electrode a and the voltage control circuit 15c for the electrophoresis electrode c and the discharge electrode c8. .

As described above, since a constant voltage of Vepa, Vepb or Vepc is applied only to the electrophoretic electrode corresponding to the discharge electrode for discharging the flying particle group 11, a required dot diameter is formed. For this purpose, only a necessary amount of the color material particles move at a target electrophoresis speed to the target ink discharge port 2, and a convex meniscus of the pigment-based ink 12 is formed only at the target discharge electrode tip. On the other hand, since the voltage applied to the electrophoretic electrode corresponding to the discharge electrode that is not intended to discharge the flying particle group 11 is set to 0 V, it is possible to discharge the flying particle group 11 close to the discharge electrode intended to discharge the flying particle group 11. The concentration of the coloring material particles hardly occurs at the tip of the discharge electrode.

When a pulsed discharge voltage of time Tp is applied to the target discharge electrode, the particles overcome the meniscus force, the surface tension and the viscous force of the pigment-based ink 12 by electrostatic force, and these pulse-like discharge voltages are applied. At the timing synchronized with the discharge voltage of the discharge electrode a
5, flying from the tip of the ink discharge port 2 corresponding to each discharge electrode in the order of the discharge electrode c9 and the discharge electrode b7,
It adheres on the recording medium 3. Replenishment of color material particles is performed, and such an operation is repeated to form an image on the recording medium 3.

[0022]

As described above, according to the present invention, an electrophoretic electrode is provided for each discharge electrode, and when discharging color material particles, a voltage is applied only to the electrophoretic electrode corresponding to the target discharge electrode. Is controlled so that the supply amount of the color material particles and the discharge amount of the color material particles can be made substantially the same,
Non-discharge of particles, change in dot diameter, and discharge of particles from a discharge electrode that does not discharge particles can be prevented, and an image can be stabilized.

[Brief description of the drawings]

FIG. 1 is a simple 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 and a discharge electrode according to the embodiment.

FIG. 3 is a schematic view of a conventional electrostatic ink jet recording apparatus.

FIG. 4 is a waveform diagram of a voltage applied to a conventional example of an electrophoretic electrode and a discharge electrode.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ink chamber 2 ink discharge port 3 recording medium 4 electrophoresis electrode a 5 discharge electrode a 6 electrophoresis electrode b 7 discharge electrode b 8 electrophoresis electrode c 9 discharge electrode c 10 counter electrode 11 flying particle group 12 pigment ink 13 input Interface 14 Control unit 15 Electrophoresis electrode / discharge electrode voltage control unit 15a Electrophoresis electrode a / discharge electrode a voltage control circuit 15b Electrophoresis electrode b / discharge electrode b voltage control circuit 15c Electrophoresis electrode c / discharge electrode c voltage control circuit

 ──────────────────────────────────────────────────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 (2)

[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. A plurality of discharge electrodes for discharging the color material particles and causing the color material particles to fly onto a recording medium on a counter electrode, wherein the electrophoretic electrode is provided for each of the discharge electrodes. Inkjet recording apparatus. 2. The method according to claim 1, wherein when discharging the color material particles, control is performed such that a voltage is applied only to the target discharge electrode and the corresponding electrophoretic electrode. Ink jet recording device.