JP2842331B2 - Electrostatic inkjet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic ink jet recording apparatus, and more particularly, to an electrostatic ink jet recording apparatus having a migration electrode for transporting toner particles in a liquid and an ejection electrode for discharging the toner particles.

[0002]

2. Description of the Related Art FIG. 6 is a schematic sectional view showing a conventional electrostatic ink jet recording apparatus of this kind. Hereinafter, description will be made based on this drawing.

[0003] An electrostatic ink jet recording apparatus 60 includes an ink 64 containing charged toner particles 62 and an ink 64.
And an ink chamber 68 having a discharge opening 66 at one end, an electrophoresis electrode 70 having a U-shaped cross section provided on the outer periphery of the ink chamber 68 so as to surround the discharge opening 66, and provided in the discharge opening 66. Single discharge electrode 7
2 and a counter electrode 74 provided to face the discharge electrode 72
And a migration voltage source 76 for applying a migration voltage to the migration electrode 70.
And an ejection voltage source 78 for applying an ejection voltage to the ejection electrode 72.
It is provided with. The recording paper 80 is in contact with the discharge electrode 72 side of the counter electrode 74.

[0004] The ink chamber 68 is made of a dielectric material,
An ink supply port 82 is provided. The migration electrode 70
An electric field is applied from the electrophoresis voltage source 76 to the toner particles 62, and the toner particles 62 are transported to the tip of the ejection electrode 72 by electrophoresis. The ejection electrode 72 applies a pulsed ejection voltage to the toner particles 62 from the ejection voltage source 78 to generate an electrostatic field between the ejection electrode 72 and the opposite electrode 74, thereby ejecting the toner particles 62 toward the opposite electrode 74. The migration electrode 70 is provided in the ink chamber 62 in such a shape that the direction of the lines of electric force generated from the migration electrode 70 is concentrated on the ejection electrode 72. The ejection electrode 72 is provided at a portion where the lines of electric force are concentrated on the ejection opening 66 so as to be insulated from the ink 64.

[0005] A constant migration voltage is applied to the migration electrode 70 so that the toner particles 62 are not discharged from the discharge opening 66. Ejection electrode 7 when no ejection voltage is applied
2 is applied with a constant bias voltage that does not hinder the conveyance of the toner particles 62 onto the discharge electrode 72 by electrophoresis. Thus, the toner particles 6 in the ink 64
2 is the discharge electrode 7 due to the electric field generated by the migration electrode 70.
It is transported so as to concentrate on zero. When an ejection voltage is applied to the ejection electrode 72, an electrostatic field is generated between the ejection electrode 72 and the counter electrode 74. As a result, the toner particles 62 supplied onto the discharge electrode 72 are discharged toward the counter electrode 74 and adhere onto the recording paper 80.

[0006]

FIG. 7 is a schematic view of the discharge port shown in FIG.
The distribution of electric lines of force E when a plurality of output electrodes 72 are provided in a line is shown. When the plurality of ejection electrodes 72 are arranged in the ink chamber 68 so as to face the opposing electrode 74 in the shape of the migrating electrode 70, the distribution of the lines of electric force E at the tip of each ejection electrode 72 varies. . As a result, the toner particles 6 concentrated on the ejection electrode 72
Since the amounts of the toner particles 2 differ from each other, there is a problem that the discharge amount of the toner particles 62 between the discharge electrodes 72 varies, and that a constant print quality cannot be obtained.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention has been made in view of such a point, and an electrostatic ink jet recording apparatus capable of making the distribution of lines of electric force between an ejection electrode and a migration electrode uniform. Is to provide.

[0008]

According to a first aspect of the present invention, there is provided an electrostatic ink jet recording apparatus, comprising: an ink containing charged toner particles; an ink chamber containing the ink and having an ejection opening at one end; A flat first electrophoretic electrode provided in the ink chamber such that an end thereof is close to the opening, and a flat first electrophoretic electrode provided in the ink chamber opposite to the first electrophoretic electrode. A second migration electrode, a plurality of discharge electrodes disposed in the discharge opening in proximity to the first migration electrode, a counter electrode provided to face the discharge electrode, and the toner particles. A migration voltage source for applying a migration voltage for moving the second migration electrode to the first migration electrode to the first and second migration electrodes, and an ejection voltage for discharging the toner particles to the ejection electrode Vomiting And a voltage source. The plurality
The discharge electrodes are all equidistant from the end of the first migration electrode
It is located in.

The toner particles move from the second migration electrode to the first migration electrode in the ink chamber by the migration voltage applied to the first and second migration electrodes. The toner particles that have moved to the vicinity of the first migration electrode are ejected toward the counter electrode by the ejection voltage applied to the ejection electrode. A plurality of discharge electrodes is disposed in proximity to the first electrophoresis electrode, and position on all the ends equidistant first electrophoresis electrode
It is location.

Therefore, if a constant potential difference is applied between the ejection electrode and the first migration electrode, all lines of electric force generated between the ejection electrode and the first migration electrode become uniform. Therefore, the lines of electric force generated between the ejection electrode and the first migration electrode are suppressed in distortion and uniformly distributed.

[0011] Claim 2 electrostatic ink jet recording apparatus described, in the electrostatic ink jet recording apparatus according to claim 1, wherein the first and second electrophoresis electrode is characterized by a parallel plate electrode.

Since the first and second migration electrodes are parallel plate electrodes, the lines of electric force generated between these migration electrodes are also substantially parallel. Therefore, the lines of electric force generated between the ejection electrode and the first migration electrode are more evenly distributed. This is because the electric lines of force become vector sums and affect each other.

[0013]

1 and 2 show an embodiment of an electrostatic ink jet recording apparatus according to the present invention. FIG. 1 is an overall configuration diagram including a vertical section taken along line II in FIG.
FIG. 2 is a side view as viewed from an arrow II in FIG.

The electrostatic ink jet recording apparatus 10 includes an ink 64 containing charged toner particles 62 and an ink 64
An ink chamber 14 having a discharge opening 12 at one end, a flat electrophoretic electrode 16 provided in the ink chamber 14 such that the end is close to the discharge opening 12, and an opposing electrophoretic electrode 16. And ink chamber 14
A plate-like electrophoresis electrode 18 provided therein,
A plurality of discharge electrodes 20 arranged in the discharge opening 12 in close proximity to the discharge electrode 20, and a counter electrode 7 provided opposite the discharge electrode 20.
4 and the toner particles 62 from the migrating electrode 18 to the migrating electrode 16
And a discharge voltage source 24 for applying a discharge voltage for discharging the toner particles 62 to the discharge electrode 20.

The migration electrodes 16 and 18 are parallel plate electrodes. A plurality of ejection electrodes 20 are provided in a row corresponding to the dots, and are all located at the same distance from the end of the migration electrode 16. The ink chamber 14 includes an upper cover 141 and a lower cover 142 that are dielectrics. It is preferable to provide a partition-like flow path 26 around the ejection opening 12 at a pitch corresponding to each dot. The flow channel 26 can be formed by making the shape of the upper cover 141 uneven, and has an effect of forming a convex portion on the surface of the ink 64 at the tip of the discharge electrode 20. The discharge electrode 20 is insulated from the ink 64 in order to prevent the excessive supply of the toner particles 62 due to the endless transfer of the charge between the migration electrodes 16 and 18 and the discharge electrode 20. .

FIG. 3 shows an electrostatic ink jet recording apparatus 1.
It is a time chart of the migration voltage of 0 and an ejection voltage. Hereinafter, the operation of the electrostatic ink jet recording apparatus 10 will be described with reference to FIGS.

To the migration electrodes 16 and 18, constant migration voltages Vep1 and Vep2 are applied, respectively. Migration voltage Vep
1, Vep2 is such that Vep2> Vep1 so that an electric field is generated in the direction from the migrating electrode 18 to the migrating electrode 16, and is a value that does not cause the ejection of the toner particles 62 from the ejection opening 12. The ejection electrode 20 has a bias voltage V
b and the pulse voltage Vp are applied. Bias voltage Vb
Is always applied when the pulse voltage Vp is not applied,
Vb <Vep1. The pulse voltage Vp is applied to the ejection electrode 20 corresponding to the desired dot,
The value is such that an electric field capable of discharging the toner particles 62 can be generated between 0 and the counter electrode 74.

FIG. 4 is a schematic diagram showing electric lines of force in FIG. 1, and FIG. 5 is a schematic diagram showing lines of electric force in a cross section taken along line VV in FIG. Hereinafter, description will be made with reference to FIGS.

Electrophoresis voltages Vep1 and Vep2 are applied to the electrophoresis electrodes 16 and 18, respectively. Electrophoresis electrode 16,1
8 is a parallel plate electrode, so that the migration electrodes 16, 1
It is substantially parallel to the electrical field lines E ₁ generated between 8 (Figure 4). Therefore, the toner particles 62 are
To the electrophoresis electrode 16. Further, a bias voltage Vb or a pulse voltage Vp is applied to the ejection electrode 20. Since the migration electrode 16 has a uniform potential,
Electric flux lines E ₂ between the electrophoresis electrode 16 and the discharge electrode 20 becomes parallel (Figure 5). Therefore, the toner particles 62 are uniformly discharged from the discharge electrode 20.

[0020]

According to the first aspect of the present invention, the toner particles are moved from the second migration electrode to the first migration electrode, and the toner particles are moved to the vicinity of the first migration electrode. causes discharged from the discharge electrode, a plurality
Of the first swimming electrode
By all being located at the same distance from the end of the moving electrode ,
The electric lines of force generated between the discharge electrode and the first electrophoresis electrode, can be distributed uniformly by suppressing the distortion. As a result, it is possible to suppress variations in the discharge amount of the toner particles between the discharge electrodes, thereby improving the print quality.

According to an electrostatic ink jet recording apparatus according to claim 2, by which the first and second electrophoresis electrodes parallel plate electrodes, substantially parallel to the electric lines of force generated between these migration electrode Therefore, the lines of electric force generated between the ejection electrode and the first migration electrode can be more evenly distributed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of an electrostatic ink jet recording apparatus according to the present invention, including a vertical cross section taken along a line II in FIG. 2;

FIG. 2 is a side view as viewed from an arrow II in FIG.

FIG. 3 is a time chart of a migration voltage and a discharge voltage of the electrostatic ink jet recording apparatus of FIG. 1; FIG. 3 [1] shows a migration voltage applied to a second migration electrode;
Is the electrophoresis voltage applied to the first electrophoresis electrode, and FIG.
[3] is the discharge voltage applied to the discharge electrode.

FIG. 4 is a schematic diagram showing electric lines of force in FIG. 1;

FIG. 5 is a schematic diagram showing lines of electric force in a cross section taken along line VV in FIG. 2;

FIG. 6 is a schematic sectional configuration diagram showing a conventional electrostatic ink jet recording apparatus.

FIG. 7 is a schematic diagram showing lines of electric force when a plurality of the migration electrodes of FIG. 6 are provided in a line.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 electrostatic ink jet recording device 12 discharge opening 14 ink chamber 16 first migration electrode 18 second migration electrode 20 discharge electrode 22 migration voltage source 24 discharge voltage source 62 toner particles 64 ink 74 counter electrode

Continuation of the front page (72) Inventor Hitoshi Minemoto 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Yoshihiro Hagiwara 7-1-1 Shiba, Minato-ku, Tokyo NEC Corporation (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/06

Claims (2)

(57) [Claims] 1. An ink chamber containing charged toner particles, an ink chamber containing the ink and having an ejection opening at one end, and an ink chamber provided in the ink chamber such that the end is close to the ejection opening. A flat first electrophoretic electrode, a flat second electrophoretic electrode provided in the ink chamber opposite to the first electrophoretic electrode, and A plurality of discharge electrodes disposed in the discharge opening, a counter electrode provided to face the discharge electrode, and migration for moving the toner particles from the second migration electrode to the first migration electrode. comprises a migration voltage source for applying a voltage to the first and second electrophoresis electrodes, and a discharge voltage source for applying a discharge voltage for discharging the toner particles to the discharge electrode, said plurality of ejection electrodes, the first End of one electrophoresis electrode From the department
An electrostatic ink jet recording device , all located at the same distance . Wherein said first and second electrophoresis electrodes, electrostatic ink jet recording apparatus according to claim 1, wherein the parallel plate electrodes.