CN211307925U

CN211307925U - Ink jet printing apparatus

Info

Publication number: CN211307925U
Application number: CN201921734184.9U
Authority: CN
Inventors: 林杰
Original assignee: Guangdong Juhua Printing Display Technology Co Ltd
Current assignee: Guangdong Juhua Printing Display Technology Co Ltd
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2020-08-21
Anticipated expiration: 2029-10-16

Abstract

The utility model relates to an ink jet printing device for to the base plate inkjet, include: the ink jet cavity is arranged opposite to the substrate and is positioned below the substrate; one side of the ink-jet cavity is provided with an opening, the opening of the ink-jet cavity faces the substrate, and the ink-jet cavity can contain ink; and an ultrasonic vibrator configured to emit ultrasonic waves that can form the ink into an ink droplet moving upward. The ink jet printing device sprays ink drops by utilizing the ultrasonic sound radiation pressure, so that a nozzle is not needed, the risk of nozzle blockage is avoided, the range of the size of the ink drops can be enlarged, the specific requirements on the viscosity, the surface tension, the density and the boiling point of the ink drops are avoided, and the application range is wide.

Description

Ink jet printing apparatus

Technical Field

The utility model relates to an ink jet printing equipment technical field especially relates to an ink jet printing device.

Background

Inkjet printing technology has been widely applied to material coating in industrial production, such as deposition of functional layers, e.g., an electron injection layer, an electron transport layer, and a light emitting layer of an Organic Light Emitting Diode (OLED) in a display panel, fabrication of an organic planarization layer of a Thin Film Encapsulation (TFE), coating of a Polyimide (PI) flexible substrate, and the like. Since inkjet printing can deposit only where film formation is required, waste of materials can be avoided. Moreover, the ink jet printing can freely pattern the film layer, is suitable for display screens with various sizes and shapes, and is particularly suitable for vehicle-mounted display screens.

Currently, common inkjet printing techniques include continuous inkjet, on-demand inkjet, and thermal inkjet, which require ink to pass through nozzles having a narrow orifice, and thus have a serious impact on inkjet printing once the nozzles are clogged. And the size of the ink drop is limited by the aperture of the nozzle, can only be changed within a small range, and cannot be freely adjusted. Meanwhile, the ink-jet printing methods have specific requirements on the viscosity, surface tension, density, boiling point and the like of ink, so that the ink is difficult to be compatible among different ink-jet printers.

SUMMERY OF THE UTILITY MODEL

In view of the above, there is a need for an inkjet printing apparatus that does not risk clogging of nozzles, has no specific requirements for viscosity, surface tension, density, and boiling point of ink, and has a wide range of applications.

An inkjet printing apparatus for ejecting ink toward a substrate, comprising:

the ink jet cavity is arranged opposite to the substrate and is positioned below the substrate; one side of the ink-jet cavity is provided with an opening, the opening of the ink-jet cavity faces the substrate, and the ink-jet cavity can contain ink; and

an ultrasonic vibrator configured to emit ultrasonic waves that can form the ink into an ink droplet moving upward.

The ink-jet printing device converts an electric signal into ultrasonic waves in a vertical upward direction through the ultrasonic vibrator, the ultrasonic waves are conducted to ink in the ink-jet cavity, the ink upwards forms ink drops under the sound radiation pressure generated by the ultrasonic waves and is upwards ejected to the substrate, and ink jet is completed. The ink jet printing device sprays ink drops by utilizing the sound radiation pressure of ultrasonic waves, so that a nozzle is not needed, the risk of nozzle blockage can be avoided, the size of the ink drops can be adjusted within a larger range by changing the frequency of the ultrasonic waves, and the size range of the ink drops is enlarged; meanwhile, the ink jet printing device has no specific requirements on the viscosity, the surface tension, the density and the boiling point of ink drops, and has wide application range.

In one embodiment, the ultrasonic vibrator is mounted on the inner wall of the ink jet cavity; each ink-jet cavity is internally provided with the ultrasonic vibrator.

In one embodiment, the inkjet printing apparatus further includes a control mechanism, and the control mechanism is connected to the ultrasonic vibrator and is used for controlling the ultrasonic vibrator to emit pulsed ultrasonic waves.

In one embodiment, a transverse partition plate is arranged in the ink-jet cavity and divides the ink-jet cavity into a cooling liquid accommodating cavity and an ink accommodating cavity, the cooling liquid accommodating cavity is located below the ink accommodating cavity, and the ultrasonic vibrator is mounted on the inner bottom wall of the cooling liquid accommodating cavity.

The ink-jet cavity is divided into a cooling liquid containing cavity and an ink containing cavity, the ultrasonic vibrator is arranged in the cooling liquid containing cavity, the ultrasonic generated by the ultrasonic vibrator is transmitted to the ink in the ink containing cavity through the cooling liquid in the cooling liquid containing cavity and the transverse division plate, on one hand, the ultrasonic vibrator is prevented from being directly contacted with the ink and being prevented from being corroded by the ink, and the ultrasonic vibrator can be protected, on the other hand, because the ultrasonic vibrator can be violently heated in the working process, the ultrasonic vibrator is directly contacted with the cooling liquid in the cooling liquid containing cavity by arranging the cooling liquid containing cavity, the cooling liquid can timely cool the ultrasonic vibrator, the working stability of the ultrasonic vibrator can be ensured, the ink can be prevented from being influenced by the working heat of the ultrasonic vibrator, and the corrosion problem of the ink to the ultrasonic vibrator and the influence problem of the heating of the ultrasonic vibrator on the ink are not, the ultrasonic vibrator and the ink can be more freely selected in material selection, so that the ink jet printing device has wider market prospect.

In one embodiment, the wall of the cooling liquid containing cavity is provided with a liquid inlet end and a liquid outlet end;

the ink jet printing device further comprises a circulating cooling mechanism, one end of the circulating cooling mechanism is communicated with the liquid inlet end, and the other end of the circulating cooling mechanism is communicated with the liquid outlet end.

So, set up cooling circulation mechanism, can be better play cooling effect.

In one embodiment, the inkjet printing device further comprises an ink supply mechanism, and the ink supply mechanism is communicated with the ink containing cavity and is used for supplying ink to the ink containing cavity.

In one embodiment, the inkjet printing apparatus further comprises a charging electrode and an auxiliary accelerating electrode;

the charging electrode is arranged on the inner wall of the ink-jet cavity and close to the opening, and the charging electrode can charge the ink drops moving upwards;

the auxiliary acceleration electrode is disposed above the substrate, and the auxiliary acceleration electrode can be charged with a charge opposite to that of the ink droplets.

Therefore, the ink drop is charged by the electrostatic induction principle of the charging electrode, the ink drop is charged with charges different from those of the charging electrode, the auxiliary accelerating electrode is arranged on the substrate or on one side of the substrate far away from the ink jet cavity, the charges of the same kind as those of the charging electrode are applied to the auxiliary accelerating electrode, and the area of the substrate or on one side of the substrate far away from the ink jet cavity is charged with charges opposite to those of the ink drop, so that the charged ink drop can be attracted, and the moving speed of the ink drop to the substrate is further improved.

In one embodiment, the charging electrode is circumferentially disposed along an inner wall of the cavity.

In one embodiment, the ink jet device further comprises a charging electrode capable of charging the upward moving ink drops, wherein the charging electrode is arranged on the inner wall of the ink jet cavity and close to the opening;

the inkjet printing device further comprises an electric field generator capable of generating an electric field that accelerates the upward movement of the ink droplets.

The charging electrode is arranged on the inner wall of the ink-jet cavity and close to the opening, so that the ink drop can be charged by the electrostatic induction principle, the ink drop is charged oppositely to the charging electrode, the charged ink drop can be accelerated to move towards the substrate under the acceleration action of an electric field of the electric field generator, and the speed of the ink drop moving towards the substrate is improved.

In one embodiment, the vertical distance between the top end of the ink-jet cavity and the substrate is 0.5 mm-1 mm, and the ultrasonic frequency of the ultrasonic vibrator is 5 MHz-300 MHz.

Therefore, the vertical distance between the top end of the ink-jet cavity and the substrate is 0.5 mm-1 mm, the liquid level of the ink is slightly lower than the top end of the ink-jet cavity, the distance between the substrate and the liquid level of the ink can be 1 mm-2 mm during operation, and the ultrasonic waves with the frequency of 5 MHz-300 MHz are generated by the ultrasonic vibrator, so that the ink drops with the ink drop diameter of 5 micrometers-200 micrometers can be generated and move upwards to the substrate.

Drawings

Fig. 1 is a schematic structural diagram of an inkjet printing apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic view of a portion of the ink jet printing apparatus of FIG. 1 according to the present invention;

fig. 3 is a schematic structural view of an inkjet printing apparatus according to another embodiment of the present invention;

fig. 4 is a schematic structural diagram of an inkjet printing apparatus according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an inkjet printing apparatus according to an embodiment of the present invention.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, an inkjet printing apparatus 100 according to an embodiment of the present invention is used for jetting ink to a substrate 10, and includes at least one inkjet chamber 120 and an ultrasonic vibrator 130.

The ink-jet cavity 120 is disposed opposite to the substrate 10 and below the substrate 10. The ink-jet chamber 120 is open at one side, and the opening of the ink-jet chamber 120 faces the substrate 10, and can be used for containing ink. The ultrasonic vibrator 130 is configured to emit ultrasonic waves that can cause ink to form an ink droplet moving upward. Specifically, the transmission direction of the ultrasonic wave emitted by the ultrasonic vibrator may be vertically upward.

It is understood that the substrate 10 may be placed on a carrier table 110 for carrying the substrate.

In operation, the substrate 10 is placed on the carrier table 110 upside down (that is, the opening of the pixel pit on the substrate 10 is downward, which means that the direction of the opening is the same as the direction of gravity), the ultrasonic vibrator 130 converts an electrical signal into a vertical ultrasonic wave, the ultrasonic wave is conducted to the ink contained in the ink jet cavity 120, and can generate vibration in the vertical direction, the liquid surface of the ink generates deformation and swelling under the acoustic radiation pressure generated by the ultrasonic wave, when the acoustic radiation pressure is greater than the surface tension of the ink, the swelling forms an ink droplet and emits upward, the ink droplet moves to the substrate 10 on the carrier table 110 and contacts with the substrate 10, and due to the small mass of the ink droplet formed by the ultrasonic radiation, the ink droplet cannot freely fall down and remains in the pixel pit under the action of the surface tension of the ink droplet and the intermolecular attraction, and can be deposited on the surface of the substrate 10.

It is understood that the number of the ink-jet chambers 120 may be one or more.

In this embodiment, the ultrasonic vibrator 130 is installed on the inner wall of the ink-jet cavity 120, and the ultrasonic vibrator 130 is disposed in each ink-jet cavity 120. In other embodiments, the ultrasonic vibrator 130 may be mounted outside the bottom wall of the ink jet chamber 120, and the ultrasonic waves are conducted to the ink inside the chamber through the chamber wall of the ink jet chamber 120.

It can be understood that the ultrasonic vibrator 130 is mounted on the inner wall of the ink-jet cavity 120, and may be partially fixed on the inner wall of the ink-jet cavity 120 and partially protrude from the ink-jet cavity, or may be integrally mounted on the inner wall of the ink-jet cavity 120.

In this embodiment, as shown in fig. 2, the ultrasonic vibrator 130 includes an ultrasonic horn 131 and an ultrasonic transducer 132, the ultrasonic horn 131 is fixed on the inner side of the bottom wall of the ink jet chamber 120, and the ultrasonic transducer 132 is disposed on the outer side of the bottom wall of the ink jet chamber 120. Therefore, the ultrasonic transducer 132 converts the electrical energy into mechanical energy to generate vibration, and the vibration is input to the ultrasonic horn 131, and the ultrasonic horn 131 changes the vibration amplitude and then transmits the vibration amplitude to the ink in the ink jet chamber 120.

In other embodiments, the ultrasonic horn and the ultrasonic transducer may be fixed together as a whole on the inner side of the bottom wall of the ink jet chamber, i.e. the ultrasonic vibrator is fixed on the inner side of the bottom wall of the ink jet chamber as a whole.

With continued reference to fig. 1, the inkjet printing apparatus 100 further includes a control mechanism 140, and the control mechanism 140 is connected to the ultrasonic vibrator 130 for controlling the ultrasonic vibrator 130 to emit the pulse-type ultrasonic wave.

In this embodiment, the control mechanism 140 is electrically connected to the ultrasonic transducer 132, and controls the operation of the ultrasonic transducer 132, drives the ultrasonic horn 131 to convert the electrical signal into the vertically upward ultrasonic wave, and controls the operating frequency, the operating time, and the like of the ultrasonic vibrator 130.

In this embodiment, a transverse partition plate 122 is disposed inside the ink jet cavity 120, the transverse partition plate 122 partitions the ink jet cavity 120 into an ink accommodating cavity 121 and a cooling liquid accommodating cavity 123, the cooling liquid accommodating cavity 123 is located below the ink accommodating cavity 121, and the ultrasonic vibrator is mounted on an inner bottom wall of the cooling liquid accommodating cavity 123.

The ink accommodating chamber 121 is located on the cooling liquid accommodating chamber 123 and is used for accommodating ink, and the cooling liquid accommodating chamber 123 is used for accommodating cooling liquid. Specifically, the cooling liquid may be cooling water.

By arranging the cooling liquid accommodating cavity 123 to accommodate the cooling liquid, when the ultrasonic vibrator 130 is in operation, the cooling liquid is in direct contact with the ultrasonic vibrator 130, and the generated ultrasonic waves are transmitted to the ink through the cooling liquid and the transverse partition plate 122, so that on one hand, the ink can be prevented from being in direct contact with the ultrasonic vibrator 130, and thus the ultrasonic vibrator 130 can be prevented from being corroded by the ink, the ultrasonic vibrator 130 is protected, on the other hand, the cooling liquid can cool the ultrasonic vibrator 130 in operation, so as to avoid the severe temperature rise of the ultrasonic vibrator 130 in the operation process, thereby ensuring the operation stability of the ultrasonic vibrator 130, meanwhile, adverse effects of the ink caused by the severe temperature rise of the ultrasonic vibrator 130 can be avoided, for example, the properties of the ink may be changed due to the high temperature generated in the working process of the ultrasonic vibrator, the viscosity and the surface tension of the ink are affected, and even the material is deformed or thermally cured.

With continued reference to fig. 1 and fig. 2, in the present embodiment, a liquid inlet end (not shown) and a liquid outlet end (not shown) are disposed on the cavity wall of the cooling liquid accommodating cavity 123; the inkjet printing apparatus 100 further includes a circulating cooling mechanism 150, wherein one end of the circulating cooling mechanism 150 is communicated with the liquid inlet end, and the other end is communicated with the liquid outlet end.

So, hold the chamber 123 through circulative cooling mechanism 150 and coolant liquid and be linked together, can realize the circulation backward flow of coolant liquid, guarantee the cooling effect of coolant liquid to ultrasonic vibrator 130.

In the present embodiment, the inkjet printing apparatus 100 further includes an ink supply mechanism 160, and the ink supply mechanism 160 is communicated with the ink containing chamber 121 for supplying ink to the ink containing chamber 121.

Because the ink-jet cavity (the cavity wall of the ink containing cavity) and the transverse separation plate need to be in contact with ink, the materials of the ink-jet cavity and the transverse separation plate need to be resistant to solvents in various inks, and therefore, materials resistant to corrosion of ink organic solvents are selected as the materials of the ink-jet cavity and the transverse separation plate.

In this embodiment, the inkjet cavity 120 may be a glass inkjet cavity or a teflon inkjet cavity, and the transverse partition plate 121 may be a glass partition plate or a teflon partition plate.

In the present embodiment, the thickness of the lateral partition plate 121 is 0.8mm to 1.2 mm.

In this embodiment, the vertical distance between the top end of the ink-jet chamber 120 and the substrate 10 is 0.5mm to 1mm, and the ultrasonic frequency of the ultrasonic vibrator 130 is 5MHz to 300 MHz.

The utility model discloses an ink jet printing device adopts acoustic radiation pressure to initiate the inkjet to do not need the nozzle, consequently also do not have the restriction to the size of ultrasonic vibrator 130 and inkjet cavity 120 and the ink droplet size that produces. The size of the ejected ink droplets depends on the ultrasonic frequency of the ultrasonic vibrator 130, and the size of the ink droplets decreases linearly as the ultrasonic frequency of the ultrasonic vibrator increases. The ultrasonic vibrator with ultrasonic frequency of 5 MHz-300 MHz is adopted, and the size (diameter) of the formed ink drop is 5-200 μm. However, the ultrasonic vibrator vibrates for 5-20 mus at the frequency to generate an ink drop, the ink drop moves upwards for 1-2 mm to reach the substrate after being generated, the liquid level of the ink can be recovered to be stable during the time when the ink drop reaches the substrate, and the next ink drop is convenient to form, so that the deviation of the volume of the ink drop is avoided.

As shown in fig. 3, in another embodiment of the present invention, the inkjet printing apparatus 200 includes a charging electrode 270 and an auxiliary accelerating electrode 280 in addition to at least one inkjet chamber 220 and the ultrasonic vibrator 230.

The charging electrode 270 is disposed on an inner wall of the ink-jet chamber 220 and near the opening, and the charging electrode 270 charges the ink droplets moving upward. An auxiliary acceleration electrode 280 is provided above the substrate 20, the auxiliary acceleration electrode being capable of being charged opposite to the charge of the ink droplets.

It is understood that the auxiliary accelerating electrode 280 is disposed above the substrate 20, that is, the auxiliary accelerating electrode 280 is disposed on a side of the substrate 20 away from the ink-jet chamber 220, and may be disposed directly on the substrate 20 or may have a gap with the substrate 20.

The charging electrode 270 is disposed on the inner wall of the ink-jet cavity 220 and near the opening, and charges the generated ink drop by electrostatic induction, so that the ink drop has charges opposite to the charging electrode 270, and the auxiliary accelerating electrode 280 above the substrate 20 has charges different from the charges of the ink drop, so that the ink drop with charges can be accelerated to move toward the substrate by coulomb force, and the speed of the ink drop moving toward the substrate is increased. For example, the charging electrode has a positive charge, and the ink droplets can be charged by the electrostatic induction principle, so that the ink droplets are negatively charged, and the auxiliary accelerating electrode 280 on the substrate or on the side of the substrate away from the ink-jet cavity is positively charged, so that the attraction of the negatively charged ink droplets can be realized, and the speed of the ink droplets moving to the substrate can be increased.

Specifically, the auxiliary acceleration electrode 280 and the charging electrode 270 are respectively connected to a power supply, the auxiliary acceleration electrode 280 and the charging electrode 270 are charged by the power supply, and after the auxiliary acceleration electrode 280 and the charging electrode 270 are charged with the same kind of charges.

In the present embodiment, the auxiliary accelerating electrode 280 is a metal electrode.

In this particular embodiment, the charging electrode 270 is circumferentially disposed along an inner wall of the ink ejection chamber 220. Thus, a ring-shaped charging electrode is formed around one circle. In other embodiments, the charging electrode may be a pair of charging electrodes oppositely disposed on the inner side walls of the opening of the ink-jet chamber 220.

In another embodiment, as shown in fig. 4, the inkjet printing device 300 further includes a charging electrode 370 and an electric field generator (not shown).

The charging electrode 370 is disposed on an inner wall of the ink-jet chamber 320 and near the opening, and the charging electrode 370 can charge the ink droplet moving upward. The electric field generator is capable of generating an electric field that accelerates the ink droplets upward.

The charging electrode 370 is arranged on the inner wall of the ink-jet cavity 320 and close to the opening, so that the generated ink drop can be charged by the electrostatic induction principle, the ink drop is charged oppositely to the charging electrode 370, the charged ink drop can generate upward force under the action of an electric field, and the ink drop can accelerate to move towards the substrate under the action of the force, so that the speed of the ink drop moving towards the substrate is improved.

Specifically, the electric field generator can generate a uniform electric field in a vertical direction, and the plummer 310 is located in the uniform electric field generated by the electric field generator.

In this particular embodiment, the charging electrode 370 is circumferentially disposed along an inner wall of the ink ejection chamber 320. Further, in operation, the charging electrode 370 is charged with positive electricity, and charges the ink drop to negative electricity by the electrostatic induction principle; the electric field generator provides a uniform electric field vertically upwards, and the negatively charged ink drops can accelerate to move upwards under the action of the electric field.

As shown in fig. 5, the number of the ink jet cavities 420 of the ink jet printing apparatus 400 according to another embodiment of the present invention is plural, and the plural ink jet cavities 420 are arranged in a row.

Therefore, the plurality of ink jet cavities 420 are arranged to form the printing head with the plurality of ink jet cavities 420, so that large-area ink jet printing can be performed, and the printing efficiency is improved.

Further, an ultrasonic vibrator 430 is arranged in each ink jet cavity 420, and the plurality of ultrasonic vibrators 430 are connected with the control mechanism 440 in parallel, that is, each ultrasonic vibrator 430 is independently and electrically connected with the control mechanism 4400; the multiple ink jet cavities 420 are connected in series with the circulating cooling mechanism 450 to form a circulating cooling reflux system, that is, cooling liquid accommodating cavities of the multiple ink jet cavities 420 are connected in series with the circulating cooling mechanism 450; the plurality of ink jet chambers 420 are connected in parallel with the ink supply mechanism 460, that is, the ink containing chamber of each ink jet chamber 420 is independently communicated with the ink supply mechanism 460, and the ink supply mechanism 460 can independently supply ink to each ink containing chamber.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An inkjet printing apparatus for ejecting ink toward a substrate, comprising:

2. The inkjet printing apparatus according to claim 1, wherein the ultrasonic vibrator is mounted on an inner wall of the inkjet chamber; each ink-jet cavity is internally provided with the ultrasonic vibrator.

3. The inkjet printing apparatus according to claim 1, further comprising a control mechanism connected to the ultrasonic vibrator for controlling the ultrasonic vibrator to emit pulsed ultrasonic waves.

4. The inkjet printing device according to claim 1, wherein a transverse partition plate is arranged inside the inkjet cavity, the transverse partition plate divides the inkjet cavity into a cooling liquid accommodating cavity and an ink accommodating cavity, the cooling liquid accommodating cavity is located below the ink accommodating cavity, and the ultrasonic vibrator is mounted on the inner bottom wall of the cooling liquid accommodating cavity.

5. The inkjet printing apparatus according to claim 4, wherein a liquid inlet end and a liquid outlet end are provided on a wall of the cooling liquid accommodating chamber;

6. The inkjet printing apparatus according to claim 4 further comprising an ink supply mechanism in communication with the ink receiving chamber for supplying ink to the ink receiving chamber.

7. The inkjet printing apparatus according to any one of claims 1 to 6, further comprising a charging electrode and an auxiliary accelerating electrode, wherein the charging electrode is disposed on an inner wall of the inkjet chamber and near the opening, the charging electrode is capable of charging the upward moving ink droplets, the auxiliary accelerating electrode is disposed above the substrate, and the auxiliary accelerating electrode is capable of charging an opposite charge to that of the ink droplets; or

The ink jet printing device further comprises a charging electrode which can enable the ink drops moving upwards to carry charges, the charging electrode is arranged on the inner wall of the ink jet cavity and close to the position of the opening, and the ink jet printing device further comprises an electric field generator which can generate an electric field which enables the ink drops to move upwards in an accelerating mode.

8. The inkjet printing apparatus according to claim 7, wherein the charging electrode is disposed circumferentially along an inner wall of the inkjet chamber.

9. The inkjet printing apparatus according to claim 8, wherein a vertical distance between a top end of the inkjet chamber and the substrate is 0.5mm to 1mm, and an ultrasonic frequency of the ultrasonic vibrator is 5MHz to 300 MHz.