KR20110096969A - Surface acoustic wave ink-jet head - Google Patents

Abstract

The present invention provides a head main body including an injection hole for injecting ink and a discharge hole for discharging ink, a chamber formed inside the head body so as to communicate with the injection hole and the discharge hole, and containing an ink introduced from the injection hole; And an actuator installed inside the chamber and generating surface acoustic waves by an electrical signal to ionize the ink in the chamber, and a filter that filters the ink to pass only the ink ionized by the actuator, and the filter. A surface acoustic wave inkjet head comprising an electric field forming portion for forming an electric field between the filter and the discharge port so that the ink passing through the discharge port is guided to the discharge port. Of surface acoustic wave inkjet head which we can make It provides.

Description

Surface acoustic wave inkjet head {SURFACE ACOUSTIC WAVE INK-JET HEAD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave inkjet head for printing ink on a substrate by vaporizing the ink using surface acoustic waves and then spraying the ink.

In general, a display for displaying visual information is applied to a mobile phone, a mobile phone, a monitor, a digital TV, and the like. Recently, various technologies have been applied to the manufacturing process of a display in order to maintain such a display and maintain high quality.

An example of such techniques is surface acoustic wave inkjet technology. For example, an inkjet technique may be employed in the process of forming an alignment film (thin film for determining the direction of liquid crystal in a liquid crystal panel) on a glass substrate of a liquid crystal panel. When surface acoustic wave inkjet technology is used for formation of the alignment film of a liquid crystal display, the uniformity of a film thickness can be improved and the image quality of a liquid crystal panel can be improved.

In the case of the inkjet head used in the surface acoustic wave inkjet technology, the liquid ink is generally configured to be vaporized by the surface acoustic wave generator and then sprayed and deposited on the substrate. Since the vaporized ink is less dense than air, the ink is ejected from the bottom of the inkjet head upwards by the rising airflow generated thereby. That is, the ink of the inkjet head is ejected upward from the ground. Therefore, if various materials are to be stacked on the substrate or other production and processing processes must be performed continuously, the substrate must be turned over for the inkjet process. As such, the manner in which the ejection of the ink is carried out from the bottom of the inkjet head is unsuitable for such processes.

The present invention is to solve the above problems, and to provide a surface acoustic wave inkjet head having a structure capable of ejecting the vaporized ink through the discharge port from the upper portion to the lower portion of the inkjet head.

In order to achieve the above object, the present invention provides a head body having an injection hole for injecting ink and a discharge hole for discharging ink, and is formed inside the head body so as to communicate with the injection hole and the discharge hole, and flows in from the injection hole. A chamber for accommodating the ink, an actuator installed inside the chamber and generating surface acoustic waves by an electrical signal to ionize the ink in the chamber, and filtering the ink to pass only the ink ionized by the actuator. And a surface acoustic wave inkjet head including an electric field forming portion for forming an electric field between the filter and the discharge port so that ink passing through the filter is guided to the discharge port.

The discharge port is formed under the head body, and the electric field may be formed to move the ink passing through the filter in the ground direction.

The actuator may be formed of piezoelectrics that are deformed by an applied voltage.

The filter may include a plurality of through holes formed to form ink in the chamber, and the through holes may be arranged on the filter in a mesh form.

The filter is installed on the side of the actuator, it may be configured to vibrate by the operation of the actuator.

The electric field forming unit applies an anode to one of the first electrode formed on the filter, the second electrode of a conductive material mounted on one side of the discharge port, and one of the first and second electrodes, and the first and second electrodes. It may include an electrode applying unit for applying a cathode to the other one of the two electrodes.

On the other hand, the present invention is a head body having a chamber for accommodating ink, formed in the lower portion of the head body, the discharge port for discharging the ink in the chamber in the paper direction, and is installed in the chamber And an actuator for generating surface acoustic waves by an electrical signal to ionize the ink in the chamber, and an electric field forming portion for forming an electric field between the actuator and the discharge port so that the ink ionized by the actuator is guided to the discharge port. An acoustic wave inkjet head is disclosed.

The electric field forming unit applies an anode to any one of the first electrode formed on the actuator, the second electrode of a conductive material provided on one side of the discharge port, and the first and second electrodes, and the first and second electrodes. It may include an electrode applying unit for applying a cathode to the other one of the two electrodes.

According to the present invention having the above configuration, the ink vaporized (ionized) by the actuator can be guided to the lower direction of the inkjet head by using the electric field formed by the electric field forming unit, so that the ink vaporized in the paper direction It is possible to provide a structure that can be sprayed.

According to the configuration of the surface acoustic wave inkjet head as described above, the inkjet head of the present invention enables efficient process performance even when various materials are laminated on a substrate or various processes must be continuously performed.

In addition, the present invention can provide an integrated inkjet head by simultaneously configuring an actuator, which is a surface acoustic wave generator, and a filter, which is a device capable of supplying a high voltage, in the head body.

1 is a perspective view showing a surface acoustic wave inkjet head according to an embodiment of the present invention.
FIG. 2 is a cross-sectional perspective view showing an internal configuration of the surface acoustic wave inkjet head shown in FIG. 1. FIG.
3 is a plan view of the filter shown in FIG.
4 is a cross-sectional view of a surface acoustic wave ink jet head showing an operating state of the surface acoustic wave ink jet head according to an embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, the inkjet head which concerns on this invention is demonstrated in detail with reference to drawings.

1 is a perspective view showing a surface acoustic wave inkjet head according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional perspective view showing an internal configuration of the surface acoustic wave inkjet head shown in FIG. 1.

1 and 2, a surface acoustic wave inkjet head according to an embodiment of the present invention includes a head body 110, a chamber 120, an actuator 130, and a filter 140.

The head body 110 forms an appearance of the inkjet head and functions to provide a space for temporarily receiving ink supplied from the outside. The head body 110 may be formed of a material such as a synthetic resin as an insulating material. As the ink applied to the present invention, various kinds of inks such as conductive inks and organic compound inks may be used.

The head body 110 is provided with an injection hole 111 for injecting ink and a discharge hole 112 for discharging ink. The injection hole 111 may be connected to the ink supply device through a tube, and the discharge hole 112 is formed at the lower portion (eg, the bottom) of the head body 110. Ink inside the head body 110 is discharged from the bottom of the head body 110 in the ground direction.

Although the embodiment illustrates that the injection hole 111 is formed on the side of the head body 110, the injection hole 111 may be formed on the upper surface of the head body 110.

The chamber 120 refers to a space for temporarily receiving the ink injected from the injection hole 111. The chamber 120 is formed inside the head body 110 and is formed to communicate with the injection hole 111 and the discharge hole 112.

The actuator 130 vibrates by an electrical signal to generate a surface acoustic wave. The ink in the chamber 120 vibrates and ionizes by the surface acoustic waves, and the liquid ink phase changes into gas as it is ionized.

The actuator 130 may be formed of piezoelectrics that are deformed by a voltage applied from the outside. Representative examples of such piezoelectric materials include piezoelectric ceramics.

The actuator 130 may be installed on the inner wall of the chamber 120, and is configured to repeatedly deform in a vertical direction when a voltage is applied from the outside. The actuator 130 is repeatedly deformed at a constant frequency, and thus surface acoustic waves having a mechanical wavelength are generated around the surface of the actuator 130. According to the present embodiment, the actuators 130 are mounted in pairs on both inner walls of the chamber 120 and used several megahertz (Mhz) as the vibration frequency of the actuators 130.

The filter 140 is for filtering the ink in the chamber 120. Only the ink having ionization completed from the ink above the filter 140 passes through the filter 140 below the filter 140. The filter 140 may be mounted on the side of the actuator 130, and the filter 140 also vibrates as the actuator 130 operates and vibrates. This embodiment illustrates that filter 140 is mounted between a pair of actuators 130.

Hereinafter, the configuration of the filter 140 will be described in detail with reference to FIG. 3. 3 is a plan view of the filter illustrated in FIG. 2.

As shown in FIG. 3, the filter 140 may have a plate shape in which a plurality of through holes 141 are formed. The through holes 141 may be arranged to have a predetermined distance from each other in a mesh form. These through holes 141 are formed to allow the ink in the chamber 120 to form.

The ink on the upper side of the filter 140 is in contact with the upper surface of the filter 140, and some of the ink is formed in the through hole 141 by capillary action. The ink above the filter 140 may not pass through the through hole 141 due to its surface tension.

The size of the through hole 141 is determined according to the characteristics of the ink, and the through hole 141 may have a size of several micrometers (μm) to several nanometers (nm). The filter 140 having the through holes 141 may also be referred to as a 'micro mesh' or 'nano mesh'.

The filter 140 may be formed of a conductive material, for example, a metal material so as to apply a voltage as described below.

4 is a cross-sectional view of a surface acoustic wave inkjet head showing an operating state of the surface acoustic wave inkjet head according to an embodiment of the present invention.

Referring to FIG. 4, the surface acoustic wave inkjet head has an electric field forming unit for forming an electric field E in a space between the filter 140 and the discharge port 112 (or between the actuator 130 and the discharge port 112). And 150. The electric field forming unit 150 forms the electric field E to guide the ionized ink passing through the filter 140 to the discharge port 112. That is, the ionized ink is moved to the discharge port 112 by the electric force of the electric field (E).

This electric field E is formed to move the ionized ink passing through the filter 140 in the downward direction (ie, the ground direction). For example, when the ionized ink has a positive polarity as shown in Fig. 4, the electric field E is formed to face downward. If the ionized ink has a negative polarity, the electric field E would have to be formed in the opposite direction. The polarity of the ionized ink varies depending on the type of the ink, and thus the polarization of the ionized ink may be set to vary the direction in which the electric field E is formed.

The electric field forming unit 150 is electrically connected to the first electrode 151 formed on the filter 140, the second electrode 152 mounted on one side of the discharge port 112, and the first and second electrodes 151 and 152. It may include an electrode applying unit 153 connected to.

The first electrode 151 is formed on the filter 140. In FIG. 4, 151, which is a reference numeral of the first electrode, is written together on the parenthesis 140 of the filter. The filter 140 is formed of a conductive material so as to function as an electrode.

The second electrode 152 may have a plate or ring shape of a conductive material and may be mounted under the head body 110. The second electrodes 152 may be formed in a pair, and the discharge holes 112 may be formed by the space therebetween. Here, the injection amount of the ionized ink can be adjusted by adjusting the size of the discharge port 112.

The electrode applying unit 153 applies an anode to one of the first and second electrodes 151 and 152 and a cathode to the other of the first and second electrodes 151 and 512. For example, when the direction of the electric field E is formed downward as shown in FIG. 4, the electrode applying unit 153 applies an anode to the first electrode 151 and a cathode to the second electrode 152. It is composed. On the contrary, when the direction of the electric field E is formed upward, the electrode applying unit 153 is configured to apply the cathode to the first electrode 151 and to apply the anode to the second electrode 152 as opposed to the case of FIG. 4. do.

The electrode applying unit 153 is electrically connected to the first and second electrodes 152 by a wire or the like. Since the filter 140 and the actuator 130 are electrically connected, FIG. 4 illustrates that the electrode applying unit 153 is connected to the actuator 130. In this case, the actuator 130 is also formed of a conductive material. do. However, the electrode applying unit 153 may be directly connected to the filter 140.

Hereinafter, the operation state of the surface acoustic wave inkjet head will be described based on the above description of the structure of the surface acoustic wave inkjet head.

First, the ink supply device connected to the injection hole 111 is operated to inject liquid ink 115 (hereinafter, 'ink liquid') into the chamber 120. Accordingly, the ink liquid 115 is filled in the chamber 120. Here, the ink liquid 115 is only filled up to the upper side based on the filter 140. As described above, the through-holes 141 of the filter 140 have a size that the ink liquid 115 can form, and the ink liquid 115 does not pass through the through-hole 141 and is the through-hole 141. It is concluded.

Next, the actuator 130 is operated to cause the actuator 130 and the filter 140 to repeatedly vibrate in the vertical direction. As a result, the ink liquid 115 formed in the through hole 141 is ionized by vibration and is converted into the gas state.

Next, the electrode applying unit 153 is operated to apply an anode and a cathode to the first electrode 151 and the second electrode 152, respectively. Accordingly, the electric field E in the downward direction is formed between the filter 140 and the discharge port 112.

Since the ionized ink has a low density gas state, it has a property of moving to the upper region of the chamber 120. The electric field E formed by the electric field forming unit 150 forcibly moves the ionized ink to the lower region of the chamber 120. Accordingly, the ionized ink is guided to the discharge port 112.

This embodiment illustrates a case where the ionized ink has a positive polarity, and accordingly, an anode and a cathode are applied to the first and second electrodes 151 and 152 so that the direction of the electric field is downward. If the ionized ink has a negative polarity, the cathode and the anode may be applied to the first and second electrodes 151 and 152 so that the direction of the electric field is reversed.

The ink guided to the discharge hole 112 is injected downward through the discharge hole 112 (that is, the paper direction), and is deposited on the print object (eg, the substrate).

In the above description, the filter is used to filter ink and the electric field is formed between the filter 140 and the discharge port, but the filter 140 may not be used. In this case, the ink liquid 115 should be ionized as soon as the ink liquid 115 reaches the actuator 130 while continuously injecting the ink liquid 115 in a small amount. In addition, the electric field E is formed in the space between the actuator 130 and the discharge port 112 by forming the first electrode 151 on the actuator 130.

The surface acoustic wave inkjet head described above is not limited to the configuration and method of the embodiments described above, but the embodiments may be configured by selectively combining all or some of the embodiments so that various modifications can be made.

Claims (12)

A head body having an injection hole for injecting ink and a discharge hole for discharging the ink;
A chamber formed inside the head main body so as to communicate with the injection hole and the discharge hole, and containing the ink flowing from the injection hole;
An actuator installed inside the chamber, the actuator generating surface acoustic waves by an electrical signal to ionize ink in the chamber;
A filter for filtering the ink to pass only the ink ionized by the actuator; And
Surface acoustic wave inkjet head including an electric field forming portion for forming an electric field between the filter and the discharge port so that the ink passing through the filter is guided to the discharge port. The method of claim 1,
The discharge port is formed in the lower portion of the head body,
The electric field is a surface acoustic wave inkjet head, characterized in that formed to move the ink passing through the filter to the ground direction. The method of claim 1, wherein the filter,
A surface acoustic wave inkjet head arranged in a mesh form and having a plurality of through holes formed to allow ink in the chamber to form. The method of claim 1,
The filter is installed on the side of the actuator, the surface acoustic wave inkjet head, characterized in that vibrating by the operation of the actuator. The method of claim 1, wherein the electric field forming unit,
A first electrode formed on the filter;
A second electrode made of a conductive material mounted on one side of the discharge port; And
And an electrode applying unit for applying an anode to one of the first and second electrodes and a cathode to the other of the first and second electrodes. The method of claim 5,
The actuator and the filter are formed of a conductive material and electrically connected to each other,
The surface acoustic wave inkjet head of the electrode applying unit is connected to the actuator. A head body having a chamber for receiving ink;
A discharge port formed under the head body and configured to discharge ink inside the chamber in a paper direction;
An actuator installed inside the chamber, the actuator generating surface acoustic waves by an electrical signal to ionize ink in the chamber; And
And an electric field forming portion for forming an electric field between the actuator and the discharge port so that the ink ionized by the actuator is guided to the discharge port. 8. The method of claim 1 or 7,
The actuator is a surface acoustic wave inkjet head, characterized in that formed of a piezoelectric element deformed by the applied voltage. The method of claim 8,
And the piezoelectric body is configured to repeatedly vibrate at a predetermined frequency to generate surface acoustic waves. The method of claim 7, wherein the electric field forming unit,
A first electrode formed on the actuator;
A second electrode made of a conductive material provided on one side of the discharge port; And
And an electrode applying unit for applying an anode to one of the first and second electrodes and a cathode to the other of the first and second electrodes. The method of claim 7, wherein
And a filter for filtering the ink to pass only the ionized ink on the side of the actuator. The method of claim 11, wherein the filter,
A surface acoustic wave inkjet head arranged in a mesh form and having a plurality of through holes formed to allow ink in the chamber to form.

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