JPS58217372A - Particle formation stabilizing device of ink jet printer - Google Patents

Abstract

PURPOSE:To obtain the titled device, which is suitable for multiple nozzle formation, by which surrounding parts are not contaminated due to satellites, and wherein a deflecting electrode on the ground side is used to perform a function of an electric charge detecting electrode, and the deflecting electrode and the detecting electrode are functionally combined. CONSTITUTION:When the presence or absence of the yield of a satellite is detected, the polarity of one of the outputs of a high voltage power source 6 and an electric charge voltage generator 4 is made reverse in comparison with the polarity when printing is made. The satellite is made to hit an grounding side electrode 9. The charge of the satellite is discharged through a resistor 8, and the generated potential difference is amplified by an amplifier 7 and applied to a controller 5. The controller 5 changes an exciting voltage of an exciting voltage generator 3 and detects the presence or absence of the satellite. Then the optimum particle forming region is obtained and set in the optimum exciting voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stabilizing device for xs:r in a charged deflection type inkjet printer, in which the lower full K arrangement of the two deflection electrodes is connected through a resistor. The ink droplets are deflected toward the ground electrode when detecting atomization, the state of atomization is detected by detecting the deflection of the ground side deflection electrode, and the excitation voltage is controlled to prevent the generation of satellites. This is an attempt to set an optimal excitation voltage.

In inkjet printers that eject ink from a nozzle and turn the ink into particles by exciting them with πI, φ cylinders, etc., small particles called satellites are generated separately from the basic particles, which can disrupt printing. be. The generation of satellites depends on various factors such as ink pressure, ink viscosity, ink turbidity, and excitation pressure.For this reason, even if you initially set the excitation voltage to a region where satellites do not occur, Satellites may occur due to changes in other factors.Conventionally, particle formation has been indirectly detected by detecting changes in charging characteristics based on the relationship between the excitation voltage ψ〕 and changes in the particle formation phase. However, in order to detect particle formation indirectly, the i
It was difficult to judge the detection of t”i childization.

Invention 1: In view of such an oil condition /+a), the purpose is to accurately detect the generation of searchlights and find the optimum excitation voltage that does not generate satellites to perform printing. be.

? lr, 1 figure d1, ink droplet separates from ink column -,
FIG. 3 is a diagram showing a state of particle formation when satellites S are generated in a superculm where basic particles R are generated. If a load or voltage is applied during this particle formation, the ink droplets will be charged,
When an ink droplet separates from a satellite, a larger specific charge Q/m will be placed on the satellite. This is the load
This is because the output amount is separated according to the surface area ratio of the main cylinder and the satellite. Therefore, when traveling through the same electric field strength, a droplet with a smaller radius will be deflected more than a droplet in the main cylinder. Therefore, it is possible to detect the generation of satellites by applying the same electric field as during printing to greatly deflect the satellites and detecting this, but this may greatly contaminate the deflection section and its surroundings.

, @2 Fig. 11, Toy 1 for explaining the detection of particulate abnormality according to the present invention, when detecting the particulate state, the GND side deflection 'lfwL9, which is placed on the lower side, is in the opposite direction to that when printing.
The satellite S is deflected toward the deflection electrode 9.
By connecting hI to a charge amount detection circuit, the amount of charge of the satellite can be detected, and thereby it is possible to detect the presence or absence of the occurrence of a sprite. Then, whether or not satellites occur can be fed back to the excitation voltage control device, and while changing the excitation voltage, a region where satellites do not occur can be found, and the optimum lj1υ oscillation voltage and total voltage can be set.

FIG. 3 shows a line 1 showing an embodiment according to the present invention, and 711.1 driven by the excitation voltage generation circuit 3. Distortion vibration 11;
One child ejects ink from head 2. The ejected ink column is charged by the charging type Wi 12 to which a voltage is applied from the charging voltage generation circuit 24, and the ink flies in a 4×1 ink column. Printing is performed by receiving the corresponding deflection, and unnecessary ink droplets are collected by the gutter 11. Next, the controller 5 controls the high-voltage power supply 6 to determine the time and date for detecting the presence or absence of satellite occurrence.
In addition, by setting one of the outputs of the output circuit □4 to the jφ polarity during printing, the satellite is grounded (Ill j%j%, g).As a result, The electric charge of the satellite is discharged through the resistor 8.Then, by amplifying the potential difference generated when the electric current flows through the resistor 8, the electric charge of the satellite is
'; Detects the load and informs the controller 5.

The controller 5 changes the excitation voltage of the vibration pressure generating circuit 3 and detects the presence or absence of the satellite from the force.

Then, the optimum rs/childization region is determined and set to an appropriate excitation voltage. Normally, Ji city granulation area, as shown in Figure 4,
λ/I) (+): nozzle diameter, λ: interparticle distance) changes as shown in the shaded area when the excitation voltage Vp is set as the excitation voltage Vp. For example, when λ/D=5, the appropriate value falls within the range of ■ in the detailed area diagram. As the excitation voltage Vp is varied, the detection circuit detects a particulate abnormality (satellite) outside the proper particulate area. In this way, the appropriate particle formation area (2) is determined. In the control circuit 5 shown in FIG. 3, by setting the excitation box and the river near the midpoint of the region (2), an optimal particle state can always be obtained.

As described above, according to the present invention, the grounding 11i118 direction electrode has the function of an electro-hydraulic f(. :j;5
．． (There is no need to provide L(1), making it suitable for multi-nozzle configuration, and since the satellite is deflected downward to perform detection L(1), there is no possibility that the group 1 side will be contaminated by the satellite.

[Brief explanation of the drawing]

Figure 1 shows 1','/ (fine 1,
FIG. 2 is a diagram for explaining the satellite detection method according to the present invention, FIG. 3 is a diagram showing an actual Mti example according to the present invention, and FIG. 4 is a diagram for explaining the satellite detection method according to the present invention. It is a graph showing the amount of land N-4°. R. Ink drop, S. Satellite, 1-? l+:
′? T≦Jkgth−r. 2. Head, 3. Excitation 1 (, pressure generation fil path, 4. Charge voltage generation circuit, 5. Controller, 6. (+r+
i direction'Fh pressure generation l1iJ path, 7 amplifier, 9.10-
111 poles for 4jiff, 11 gutter. Patent Applicant: Ricoh Co., Ltd. 7th Representative: Ken Akira Takashi,': ,+-(1,
- '(-1/ Figure 1 Figure 2 Figure 3 Figure 4 Figure 42

Claims (1)

[Claims] A means for pressurizing the ink to eject it from a nozzle, a means for applying excitation to the ink to make it into particles, a means for charging the ink droplets when they are made into particles, and a means for applying a deflection electric field to deflect the ink droplets according to the amount of charge on the ink droplets. A deflection electrode consisting of two deflection plates, the electrode arranged at the bottom being grounded through a resistor, a means for deflecting the ink to the grounded electrode through the resistor when detecting atomization, and detecting the potential of the grounded electrode. means to determine the particle state using the detected potential as input,
A particulate stabilization device in an inkjet printer consisting of a control circuit that controls excitation to ink.