JPS6337251Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a charge amount control type inkjet printer that can improve printing quality.

Such an inkjet printer will be explained with reference to FIG. The ink particles 10 ejected from the nozzle 1 in the horizontal direction are charged ink particles 10a that are charged with electric charges according to print information by the charging electrode 2.
and uncharged ink particles 10b, which are uncharged and collected by the gutter 5. When the charged ink particles 10a pass through a pair of deflection electrodes consisting of a low-voltage deflection electrode 3 and a high-voltage deflection electrode 4, which are at ground potential, for example, they are deflected according to their charges and reach the paper 9 to form characters. . Reference numeral 6 denotes a print head on which the nozzle 1, charging electrodes 2, deflection electrodes 3, 4, gutter 5, etc. are mounted, and it reciprocates along a pair of guide shafts 7 in a direction perpendicular to the plane of the paper. Further, 8 is a feeder for feeding the paper 9.

In the printer configured as described above, a horizontal component E _cd of an electric field from the high voltage deflection electrode 4 toward the charged electrode 2 is generated between the charged electrode 2 and the high voltage deflection electrode 4, and the charged ink particles 10a are Horizontal component E _cd
Since the ink particles are decelerated by the ink particles, there is a problem that the ink particles merge with the following uncharged ink particles 10b. This merging of ink particles 10 is more likely to occur as the amount of charge of the ink particles 10a is larger and as the generation period of the ink particles 10 is shorter. When merging of ink particles 10 occurs, the deflection force received from the deflection electrodes 3 and 4 changes and the flight trajectory is disturbed, resulting in a decrease in print quality. In FIG. 2, the center line indicates the flight trajectory of the uncharged ink particles 10b, and a and b indicate the flight trajectory and the high-voltage deflection electrode 4.
and the distance between the low voltage deflection electrodes 3.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to prevent ink particles from merging with a simple structure, and to thereby improve printing quality.

The present invention focuses on the fact that charged ink particles are decelerated by the horizontal component of the electric field directed from the high-voltage deflection electrode toward the charged electrodes, causing merging of ink particles, and reduces the electric field directed from the high-voltage deflection electrode toward the charged electrodes. The arrangement of the deflection electrodes has been devised. The present invention will be described below with reference to the drawings.

The low-voltage deflection electrode 30 and the high-voltage deflection electrode 40 each approach the flight trajectory of the uncharged ink particle 10b on the inlet side of the ink particle 10 (distance d).
It is tilted along the vertical direction so as to move away from (distance c) and to move away from (distance b) and approach (distance a, a<c) the flight trajectory on the exit side.

Therefore, the electric field directed from the high-voltage deflection electrode 40 toward the charged electrode 2 becomes very small, and the charged ink particles 1
0a is no longer decelerated, and ink particle 1
Merging of zeros does not occur. As a result, the flight trajectory is not disturbed, and printing quality can be improved. Furthermore, since the merging can be prevented and the amount of charge on the charged ink particles 10a can be increased, the deflection width can be increased.

As described above, according to the present invention, it is possible to reduce the electric field that decelerates charged ink particles.
Merging of ink particles is prevented, and disturbances in the flight trajectory of ink particles can be reduced, thereby improving print quality.

[Brief explanation of drawings]

FIG. 1 is a side view showing an example of an inkjet printer, and FIGS. 2 and 3 are side views for explaining the operation of the conventional printer and the printer of the present invention. In the figure, 1
2 is a nozzle, 2 is a charging electrode, 3 and 30 are low voltage deflection electrodes, and 4 and 40 are high voltage deflection electrodes.

Claims (1)

[Claims for Utility Model Registration] A nozzle that ejects ink particles and an opening through which the ink particles pass, and is installed in front of the nozzle and charges the ink particles with an electric charge corresponding to printed information and records the information. It is composed of a charging electrode that does not charge non-contributing ink particles, and a high-voltage deflection electrode and a low-voltage deflection electrode that face each other, and generates a deflection electric field that deflects the charged ink particles from the high-voltage deflection electrode toward the low-voltage deflection electrode. An inkjet printer comprising a pair of deflection electrodes, wherein a low voltage deflection electrode and a high voltage deflection electrode are connected to the flight trajectory of uncharged ink particles at the inlet side of the deflection electrode and the outlet side of the deflection electrode of the ink particles, respectively. An inkjet printer in which the nozzles are inclined in a direction perpendicular to the axial direction of the nozzles so as to approach each other.