JPH03297650A - Ink jet head - Google Patents

Abstract

PURPOSE:To obtain a quick response speed high functional ink jet head which can perform highly precise printing by a method wherein a pulse signal is inputted to an electrode of the ink jet head equipped with a magnetic field generator, a liquid drop is formed by jetting recording liquid from a discharge orifice by operation force to be generated in a passage, and printing is made by making the liquid drop stick to a surface to be recorded. CONSTITUTION:Conductive ink introduced into a liquid chamber with an introducing pipe 4 causes a liquid flow between electrodes 3 annexed in the liquid chamber. An electric current flows between the electrodes by input of an electric pulse. Acting force is applied to the ink by a generated violent liquid flow, the ink is discharged as an ink liquid drop 6 from an orifice 8 provided to a nozzle plate 7, and flies to stick to a recording material. A magnet 1 is, for instance, a sintered samarium cobalt magnet. Further, as the ink, the ink to which electric conductivity is given by dissolving potassium hydroxide in ordinary black ink is used. Since the ink jet head can be formed by a photolithography, densified high speed printing becomes capable of being performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention generally relates to a liquid jet printing method called an inkjet printing method, and in particular to a liquid jet printing method in which a recording liquid is ejected in the form of droplets using electromagnetic propulsion. The present invention relates to an inkjet ejection head that performs recording by adhering it to a recording surface.

[Conventional technology]

Conventional inkjet ejection devices employ the so-called ink-on-demand method, in which ink droplets are ejected only when necessary for recording.
orifice) and an ink droplet chamber with a piezoelectric element installed on the other side, and when an appropriate voltage pulse is applied to the piezoelectric element, the piezoelectric element produces electrostriction due to an inverse piezoelectric effect,
When the volume of the ink chamber decreases and the pressure inside the chamber increases instantaneously, ink droplets are ejected from the orifice.

[Problem to be solved by the invention]

However, in the inkjet jetting method using such conventional type elements, the area of the piezoelectric element required to fly the droplets is large, and there are significant restrictions on increasing the density.
Since there is also a limit to response speed, it is difficult to meet the above requirements.

Therefore, in order to solve these conventional problems, it is an object of the present invention to provide a high-performance inkjet ejection head that is capable of high-definition printing and has a fast response speed.

[Means to solve the problem]

In order to solve the above problems, an inkjet head device of the present invention is provided with an inkjet head device including an ejection orifice, a wave path filled with a recording liquid, an electrode provided along the wave path, and a magnetic field generator. A pulse signal is input into the liquid path, and the recording liquid is ejected from the ejection orifice by the action force generated in the liquid path to form droplets, and the droplets are attached to the recording surface to perform printing. Features.

[For production]

The present invention employs a method in which two electrodes facing each other are immersed in an electrolytic solution, a current is applied thereto, and a magnetic field is applied thereto to exert force on particles in the solution. It is advantageous to make the magnetic field as strong as possible.

Furthermore, the ink used is one that is imparted with electrical conductivity.

[Implementation example 1] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows one cell of an inkjet jetting device of the present invention.

The conductive ink introduced into the liquid chamber (inside the cell) through the introduction tube 4 causes a liquid flow between the electrodes 3 attached within the liquid chamber.

Note that the electrodes 3 are those in which current flows between the electrodes when an electric pulse is input.

In this way, the generated strong liquid flow exerts an acting force on the ink, and as a result, the ink is ejected as ink droplets 6 from the orifice 8 provided in the nozzle plate 7, flies, and adheres to the recording medium.

The magnet 1 used in the above experiment is a sintered samarium cobalt magnet with a BHmax of 30 MGOe.

The ink used was a regular black ink made by dissolving potassium hydroxide to give it conductivity.

Further, the electrode 3 was a platinum plate and was energized.

From the results of this experiment, the ink ejection speed is sufficiently fast and
When the orifice diameter was set to 45um, the result was 300DPI.
It has been found that printing equivalent to (dots/inch) is possible.

FIGS. 2(a) to 2(f) show other embodiments of an inkjet ejection head having a plurality of inkjet ejection chambers.

Figure 2 (a) shows a plate of sintered samarium cobalt magnet 1 coated with a polyimide face (approximately 2
The insulating layer 5 was formed by controlling the film thickness to 00 um.

Next, as shown in FIG. 2(b), a conductive film 10 (copper film) was sputtered to a thickness of 0.1 um.

Next, in Fig. 2 (C), after coating with a positive resist, it is baked at 80°C for 30 minutes, etched into a predetermined pattern by exposure to ultraviolet light, and the exposed part of the conductive film is immersed in an etching solution to perform etching. , electrode (copper) patterning 11 was performed.

Next, as shown in FIG. 2(d), electrolytic copper plating 12 was applied to the electrode patterning 11 to a thickness of about 200 um.

Next, as shown in FIG. 2(e), a protective film (gold plating) 13 having excellent corrosion resistance was applied to the electrode portion 12 to a thickness of about 3 um.

Finally, as shown in FIG. 2(f), a sintered samarium cobalt magnet 15 coated with a polyimide coating film 16 of about 200 um was adhered with an adhesive 14 to complete an inkjet ejection chamber 18.

A nozzle plate was attached to this and ink was ejected.

From the results of this experiment, the ink ejection speed is sufficiently fast and
When the orifice diameter was set to 40 um, it was found that printing corresponding to 350 DPI (dots/inch) was possible.

[Effects of the Invention] As described above, the inkjet head of the present invention can be formed by photolithography, which enables high-density printing.Moreover, since there is no mechanical drive like that using a piezo, high-speed printing is possible. It also has the effect of making it possible.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an inkjet ejection head according to the present invention. FIGS. 2(a) to 2(f) are cross-sectional views of an inkjet ejection head having a plurality of inkjet ejection chambers.・Magnet・Electrode・Introduction tube・Insulating layer・Ink droplet・Nozzle plate・Orifice・Ink・Conductive film Figure 1・Adhesive・Magnet・Orifice in insulation layer・Ejection chamber

Claims (1)

[Claims] A pulse signal is input to the electrode of the inkjet ejection head, which is equipped with a liquid path filled with a recording liquid, an electrode provided along the liquid path, and a magnetic field generator, and the pulse signal is input to the electrode of the inkjet ejection head, which is equipped with an ejection orifice and is filled with a recording liquid. An inkjet ejecting head characterized in that the recording liquid is ejected from the ejection orifice to form droplets using an acting force generated by the inkjet ejecting head, and the droplets are attached to a recording surface to perform printing.