Inkjet printing device, printing method thereof and inkjet printing system

Abstract

The present invention discloses an inkjet printing device, its printing method and inkjet printing system. One embodiment of the device includes: a plurality of nozzles arranged vertically, including a shell with an inner cavity and a nozzle opening located at the end of the shell, the nozzle opening facing the substrate to be printed; a gradient thermal control unit for controlling the temperature of the inner cavity so that the inner cavity forms a plurality of temperature control areas with gradually changing temperatures in the extension direction of the nozzle; a heating unit connected to the nozzle opening, for heating the nozzle opening in response to a heating signal output by the control unit; and a control unit signal output unit for outputting the heating signal and outputting a control signal for controlling the inkjet state of the nozzle opening. The inkjet printing device of the embodiment of the present invention can effectively control the supply speed of the fluid in each temperature zone and improve printing accuracy.

Description

Technical Field

[0001] The present invention relates to the field of inkjet printing, and more particularly to an inkjet printing device, a printing method thereof, and an inkjet printing system. Background Art

[0002] Electrofluidic inkjet printing is a contactless process for applying micro-droplets of ink in a conical shape. It boasts advantages such as a wide range of materials, sample conservation, and a non-contact nature. It is widely used not only in traditional inkjet printing but also in important fields such as medicine and bioengineering, 3D manufacturing, and integrated circuit board printing. Common droplet generation technologies are based on thermal, piezoelectric, and electrostatic actuation. These droplet generation technologies are also important representatives of "drop-on-demand" technologies.

[0003] Furthermore, recent years have seen significant progress in some personalized droplet generation technologies, including pneumatic droplet generation. These technologies operate by applying a driving force within the cavity that holds the ink droplet cone, pushing it out of the nozzle. The resulting droplets are typically significantly larger than the nozzle's inner diameter, hindering print resolution. Furthermore, nozzle clogging is more likely when the "fluid" contains solid particles. Summary of the Invention

[0004] An object of the present invention is to provide an inkjet printing device, a printing method thereof, and an inkjet printing system to solve at least one of the problems existing in the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A first aspect of the present invention provides an inkjet printing device, comprising:

[0007] A plurality of vertically arranged nozzles, comprising a housing having an inner cavity and a nozzle opening located at an end of the housing, the nozzle opening facing a substrate to be printed;

[0008] a gradient thermal control unit, configured to control the temperature of the inner cavity so as to form a plurality of temperature-controlled areas of gradually changing temperature in the inner cavity along the extension direction of the nozzle;

[0009] a heating unit connected to the nozzle opening, for heating the nozzle opening in response to a heating signal output by the signal output unit; and

[0010] The signal output unit is used to output the heating signal and the control signal for controlling the ink ejection state of the nozzle opening.

[0011] Furthermore, the device further includes a voltage unit for supplying power to the nozzle, and the voltage unit includes:

[0012] a first electrode connected to the nozzle orifice, and

[0013] a second electrode disposed on a side close to the substrate to be processed, the second electrode corresponding to the first electrode on a one-to-one basis, and having opposite polarities to the first electrode;

[0014] The signal output unit is further configured to output a control signal for controlling a voltage change of the voltage unit.

[0015] Furthermore, the gradient thermal control unit includes a plurality of first heaters sequentially arranged along the extension direction of the shell, wherein each of the first heaters forms a corresponding temperature control area, and the temperature of each temperature control area increases gradiently along the extension direction of the shell.

[0016] Furthermore, the heating unit includes a second heater located at the nozzle outlet, further configured to heat the temperature region corresponding to the nozzle outlet at a temperature higher than the current temperature region in response to the heating signal output by the signal output unit.

[0017] Furthermore, in the extension direction of the nozzle, the orthographic projection of the nozzle on the horizontal plane gradually decreases;

[0018] In the extension direction of the nozzle, the orthographic projection of each gradient thermal control unit on the horizontal plane gradually decreases.

[0019] Furthermore, the device further comprises a fluid storage element for filling with fluid;

[0020] The nozzle also includes a fluid connection cavity, which is located on the side of the housing away from the nozzle opening and communicates with the inner cavity.

[0021] Wherein, the multiple fluid connecting cavities are connected to the same fluid storage element.

[0022] Furthermore, the nozzle also includes an electromagnetic shielding cover surrounding the outer surface of the shell.

[0023] Furthermore, the fluid is a material that carries electric charge.

[0024] A second aspect of the present invention provides an inkjet printing system, which includes the inkjet printing device of the first aspect of the present invention.

[0025] Furthermore, the system includes:

[0026] a fluid storage device for storing fluid;

[0027] a fluid distribution device connected to the water outlet of the fluid storage device, for distributing the fluid flowing into the fluid storage device;

[0028] A fluid buffer device is connected to the water outlet of the fluid distribution device, and the fluid buffer device is connected to the fluid storage element, and is used to conduct the fluid flowing from the fluid storage device to the fluid storage element.

[0029] A third aspect of the present invention provides a method for printing using the inkjet printing device of the first aspect of the present invention, the method comprising:

[0030] Controlling the gradient thermal control unit to control the temperature of the inner cavity of the nozzle so that the inner cavity forms a plurality of temperature control areas with gradually changing temperatures in the extending direction of the nozzle;

[0031] The signal output unit outputs a heating signal to the heating unit, so that the heating unit heats the nozzle opening according to the heating signal;

[0032] The signal output unit outputs a control signal to the nozzle head to control the ink ejection state of the nozzle opening.

[0033] The beneficial effects of the present invention are as follows:

[0034] The inkjet printing device of an embodiment of the present invention uses a gradient thermal control unit to perform hierarchical temperature control on the fluid stored in the inner cavity, so that temperature gradient changes are formed in different temperature zones. The characteristic that the fluid has different viscosities in different temperature zones is utilized to form viscosity changes along the extension direction of the nozzle. Through this setting, the supply speed of the fluid in each temperature zone can be effectively controlled, thereby improving printing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0036] Figure 1 A schematic structural diagram of an inkjet printing device according to an embodiment of the present invention is shown;

[0037] Figure 2 A schematic diagram showing electrodes of an inkjet printing device according to an embodiment of the present invention;

[0038] Figure 3a and Figure 3b Schematic diagram showing different processes implemented by the inkjet printing device according to an embodiment of the present invention;

[0039] Figure 4 A schematic diagram showing the structure of a plurality of nozzles integrated design according to an embodiment of the present invention;

[0040] Figure 5A system architecture diagram showing an inkjet printing system according to another embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the present invention, the present invention will be further described below in conjunction with the embodiments and drawings. Similar components in the drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0042] The present invention provides an inkjet printing device, a printing method thereof, and an inkjet printing system to solve the above problems.

[0043] The first embodiment of the present invention provides an inkjet printing device, such as Figure 1 As shown, an inkjet printing device 100 according to one embodiment includes:

[0044] A plurality of vertically arranged nozzles 10 include a housing 11 having an inner cavity and a nozzle opening 12 located at an end of the housing 11, wherein the nozzle opening 12 faces a substrate 200 to be printed;

[0045] A gradient thermal control unit 20 is used to control the temperature of the inner cavity so that a plurality of temperature-controlled areas with gradually changing temperatures are formed in the inner cavity along the extension direction of the nozzle 10;

[0046] a heating unit 30 connected to the nozzle opening 12, for heating the nozzle opening 12 in response to a heating signal output by a signal output unit; and

[0047] The signal output unit 40 is configured to output the heating signal and a control signal for controlling the ink ejection state of the nozzle opening 12 .

[0048] The inkjet printing device of an embodiment of the present invention uses a gradient thermal control unit to perform hierarchical temperature control on the fluid stored in the inner cavity, so that temperature gradient changes are formed in different temperature zones. The characteristic that the fluid has different viscosities in different temperature zones is utilized to form viscosity changes along the extension direction of the nozzle. Through this setting, the supply speed of the fluid in each temperature zone can be effectively controlled, thereby improving printing accuracy.

[0049] The fluid in the embodiment of the present invention is a material with a certain fluidity under a certain viscosity and can be applied to inkjet printing technology. The present invention does not limit the specific material, and those skilled in the art can select it according to actual application.

[0050] The working principle of the inkjet printing device 100 according to the embodiment of the present invention is now described:

[0051] The inner cavity of the embodiment of the present invention has a conical structure, that is, in an optional embodiment, in the extension direction of the nozzle 10, the orthographic projection of the nozzle 10 on the horizontal plane gradually decreases. Through this setting, the fluidity of the fluid in the inner cavity can be ensured.

[0052] By utilizing the characteristic that fluid has different viscosities in different temperature zones, the gradient thermal control unit 20 of the embodiment of the present invention controls the temperature of the inner cavity to form a temperature control zone with a gradient temperature.

[0053] In an optional embodiment, the viscosity of the fluid on the side close to the nozzle opening 12 is less than the viscosity of the fluid on the side away from the nozzle opening 12. That is, since the gradient thermal control unit 20 forms a temperature control area with a temperature gradient change, the temperature gradient will cause the ink droplets to have different viscosities, thereby controlling the flow rate of the fluid. Having different viscosities at each position can enable the fluid to have efficient flow control capabilities, and the different viscosities of the fluids in different temperature zones and the molecular forces inside the fluid molecules can be used to control the fluid flow ability.

[0054] In an embodiment of the present invention, a heating unit 30 is disposed at the nozzle opening 12. Unlike the gradient thermal control unit 20 that forms a stable temperature control area to keep the fluid in the inner cavity in a stable viscosity state, the embodiment of the present invention utilizes the heating unit 30 to further heat the fluid at the nozzle opening 12. On the one hand, the viscosity of the aforementioned fluid changes with temperature, so that the flow rate of the fluid at the nozzle opening 12 is accelerated. On the other hand, the high heat of the heating unit 30 is utilized to squeeze out the fluid. Through this arrangement, picoliter Taylor cone-shaped ink droplets can be formed at the nozzle opening 12, thereby achieving an extremely small printing width, such as 1 to 2 um, thereby improving the inkjet printing effect.

[0055] Based on the above discussion, the embodiment of the present invention uses the gradient thermal control unit 20 to achieve a temperature control area with a gradient change in the fluid in the inner cavity. The structure of the gradient thermal control unit 20 is now described using a feasible embodiment.

[0056] like Figure 1 and Figure 2 As shown, in an optional embodiment, the gradient thermal control unit 20 includes a plurality of first heaters 21 arranged in sequence along the extension direction of the shell 11, wherein each of the first heaters 21 forms a corresponding temperature control area, and the temperature of each temperature control area increases gradiently in the extension direction of the shell 11.

[0057] In a specific example, the fluid material of an embodiment of the present invention is a quantum dot conversion material whose viscosity decreases as the temperature increases. For example, the viscosity of the quantum dot conversion material is as high as 32cp. At a temperature gradient of 5 degrees, between 35 degrees and 55 degrees, the viscosity can be reduced from 32cp to 25cp. The temperature gradient is used to form a viscosity gradient, thereby controlling the stable flow rate of the fluid.

[0058] Therefore, based on the characteristics of the fluid, this embodiment uses multiple first heaters 21 to form a temperature control area with a gradient change, such as Figure 1 As shown, four first heaters are provided in the direction from top to bottom. The first first heater can form a temperature control area of ​​35 to 40 degrees, the second first heater can form a temperature control area of ​​40 to 45 degrees, the third first heater can form a temperature control area of ​​45 to 50 degrees, and the fourth first heater can form a temperature control area of ​​50 to 55 degrees. That is to say, the temperature of the temperature control area closer to the nozzle port 12 is higher and the viscosity of the fluid is lower.

[0059] Based on the above settings, under different electrothermal gradient conditions, the fluid with high viscosity in the upper part, such as the 32cp position, has a certain tensile force, which can pull the fluid with slightly lower viscosity in the lower part. Then, as the temperature of different temperature control areas increases, the viscosity of the fluid decreases and it will be slowly supplied to the nozzle. This process can ensure the stability of the fluid.

[0060] In an optional embodiment, if Figure 1 As shown, in the extension direction of the nozzle 10, the orthographic projection of each gradient thermal control unit 20 on the horizontal plane gradually decreases, and the heating array is in a ring cone shape, thereby reducing the overall space occupancy rate.

[0061] In an optional embodiment, the heating unit 30 includes a second heater 31 located at the nozzle opening 12 , further configured to heat the nozzle opening 12 at a temperature higher than a current temperature range in response to the heating signal output by the signal output unit.

[0062] In a specific example, Figure 1 As shown, the second heaters 31 corresponding to different nozzle openings 12 are connected to the same signal receiving unit for receiving a heating signal.

[0063] Based on the above example, the first heater 21 is distributed in the shell 11 corresponding to the entire inner cavity, and the second heater 31 is located at the position of the nozzle opening 12. The heating temperature of the second heater 31 is higher than the temperature of the first heater 21 on the side closest to the nozzle opening 12. Through this setting, on the basis of the above-mentioned use of the first heater 21 to make the fluid have a gradient change, the second heater 31 is used to heat the fluid at the nozzle opening 12. The second heater 31 will squeeze the ink droplets from the nozzle opening 12 out of the nozzle 10, thereby forming a Taylor cone. As the electrothermal fluid inkjet prints, ink droplet cones continuously leave the Taylor cone surface of the nozzle opening, causing the fluid volume in the Taylor cone surface of the nozzle opening to gradually decrease. This process can ensure the stability and consistency of electrothermal fluid inkjet printing.

[0064] The inkjet printing device of the present invention is a structural design proposed based on electrohydrodynamics (EHD). Different from the related art that uses the driving force of "pushing", electrothermal fluid inkjet printing uses electric field drive to produce droplets in a "drawing" manner. The basic principle is: a high voltage is applied between the metal nozzle and the collecting electrode to generate a strong electric field near the nozzle. The strong electric field will cause the accumulation of charges on the Taylor cone surface of the nozzle mouth, forcing the Taylor cone surface of the nozzle mouth to become sharper, so that the surface tension increases to balance the electric field force. The Taylor cone surface of this conical nozzle mouth is also called a Taylor cone. When the electric field force at the end of the Taylor cone surface of the nozzle mouth exceeds the surface tension, a small part of the ink droplet cone at the top of the cone will overcome the effect of the surface tension and break open, thereby producing a droplet.

[0065] Therefore, the inkjet printing device based on the above structure combined with the EHD method in this embodiment can produce droplets smaller than the inner diameter of the nozzle opening 12, which not only improves the printing resolution but also greatly reduces the risk of nozzle clogging.

[0066] like Figure 2 As shown, in an optional embodiment, the device further includes a voltage unit 50 for supplying power to the nozzle 10, and the voltage unit 50 includes:

[0067] a first electrode 51 connected to the nozzle opening 12, and

[0068] A second electrode 52 is provided on a side close to the substrate 200 to be processed, wherein the second electrode 52 corresponds to the first electrode 51 one-to-one, and the polarity of the second electrode 52 is opposite to that of the first electrode 51. Exemplarily, the second electrode 52 corresponds to the first electrode 51 point-to-point.

[0069] The signal output unit 40 is further configured to output a control signal for controlling the voltage change of the voltage unit 50 .

[0070] Based on the above principles, the embodiment of the present invention designs the positions of the first electrode 51 and the second electrode 52, and sets the first electrode 51 at the nozzle opening 12, and sets the second electrode 52 on the side of the substrate 200 to be printed, thereby forming a vertical point electric field between the nozzle 10 and the substrate 200 to be printed. In a specific example, the first electrode 51 has a voltage signal higher than that of the second electrode 52. For example, the second electrode 52 is a ground electrode, and the voltage signal output by the first electrode 51 to the nozzle opening 12 is generated according to the control signal output by the signal output unit. Through this setting, an electric current pulling force is formed between the nozzle 10 and the substrate 200, and the tip of the picoliter ink droplet formed by the heating unit 30 is formed into a femtoliter ink droplet downward, and the electric field between the nozzle 10 and the substrate 200 is used to draw the ink droplet, forming an ink droplet to be ejected onto the substrate 200. This setting can further improve the level of the ink droplet, thereby improving the printing accuracy.

[0071] In a specific example, the control signal output by the signal output unit includes a DC control signal and an AC control signal, for example, Figure 3a As shown, when the signal output unit outputs an AC control signal, such as a periodic pulse control signal to the voltage unit 50, the voltage unit 50 outputs an AC voltage to the first electrode 51 according to the AC control signal, so that the vertical electric field force between the nozzle 10 and the substrate 200 to be printed changes, and the ink droplets are cut off at the period of the AC control signal, completing the dot spraying process of the inkjet printing process, and further realizing the inkjet printing application of the embodiment of the present invention on the basis of forming stable femtoliter-level ink droplets.

[0072] In another specific example, Figure 3b As shown, when the signal output unit outputs a DC control signal, for example, a stable DC control signal to the voltage unit 50, the voltage unit 50 outputs an AC voltage to the first electrode 51 according to the DC control signal, so that the vertical electric field force between the nozzle 10 and the substrate 200 to be printed remains stable, completing the spinning direct writing process of the inkjet printing process, and further realizing the inkjet printing application of the embodiment of the present invention on the basis of forming stable femtoliter ink droplets. Figure 1 and Figure 4 As shown, in an optional embodiment, the inkjet printing device 100 further includes a fluid storage member 60 for filling the fluid;

[0073] The nozzle 10 further includes a fluid connection cavity 13, which is located on the side of the housing 11 away from the nozzle opening 12 and communicates with the inner cavity.

[0074] The multiple fluid connection chambers 13 are connected to the same fluid storage element 60 .

[0075] For example, Figure 4As shown, the nozzle 10 is arranged on a side of the fixing platform 80 facing the substrate 200 to be printed.

[0076] Although current inkjet printing technology has high printing accuracy and resolution, the biggest challenging problem it currently faces is the use of a single nozzle. This is because both high-voltage pulse electrothermal fluid dynamic jet printing and electric field driven jet deposition micro-nano inkjet printing require the printing nozzle to be connected to a high-voltage power supply. Therefore, these printing technologies have serious electric field crosstalk problems between multiple nozzles, making it difficult to achieve a tightly integrated arrangement of multiple nozzles. Therefore, existing commercial dot-jet printing devices and electric field driven jet micro-nano inkjet printing devices all use a single nozzle, and their application in industry is also greatly limited, resulting in low production efficiency and unable to meet the high-efficiency manufacturing requirements of large-size OLED or QLED devices.

[0077] The inkjet printing device 100 of the embodiment of the present invention designs the dot matrix electric field on one side of the substrate 200 to be processed. By setting a second electrode 52 with a dot array distribution on one side of the substrate 200 to be processed, the second electrode 52 with a dot array distribution forms a dot electric field with the first electrode 51 with a similar dot array distribution. This arrangement can avoid the problem caused by adjacent electric field crosstalk. Therefore, the embodiment of the present invention can form a large-scale array nozzle, and connect multiple nozzles to the same fluid storage element 60, sharing the fluid filled in the same fluid storage element 60, so as to perform inkjet printing on large-scale substrates. For example, the inkjet printing device of the embodiment of the present invention can be used for large-scale inkjet printing of 24 inches or more, thereby improving inkjet printing efficiency.

[0078] In an optional embodiment, the nozzle further includes an electromagnetic shielding cover 70 surrounding the outer surface of the shell 11 .

[0079] Based on the above embodiment, in order to avoid crosstalk between the electric fields formed at various points on the nozzle 10 and the substrate 200 to be printed, the embodiment of the present invention further provides an electromagnetic shielding cover 70 on the nozzle 10 to further improve the electric field crosstalk.

[0080] Furthermore, the first electrode 51 of the embodiment of the present invention is connected to the nozzle port 12. Therefore, the electromagnetic shielding cover 70 of the embodiment of the present invention is arranged at the edge area of ​​the shell 11 corresponding to the nozzle port 12. This arrangement avoids structural interference between the gradient thermal control unit 20 and the electromagnetic shielding cover 70, and only shields the nozzle where the first electrode 51 is provided, thereby simplifying the structural design.

[0081] In an optional embodiment, the viscosity of the fluid is 20 cp to 10,000 cp. For example, the fluid in the embodiment of the present invention may be ink, and for another example, the fluid in another embodiment may be colloid, both of which can be applied to the inkjet printing device of the embodiment of the present invention. Therefore, the inkjet printing device of the embodiment of the present invention has broad application prospects.

[0082] In a specific example, for example, thermoplastic materials, liquid metals, resin materials, ABS glue, quantum dot conversion materials, etc., different materials are selected according to different processes, which will not be described in detail here.

[0083] Based on the description of the above embodiment, the inkjet printing device 100 of the embodiment of the present invention forms a gradient-graded temperature control area through the gradient thermal control unit 20, thereby effectively controlling the layered control of the high-viscosity fluid. After the thermal gradient control is formed, the fluid viscosity will gradually decrease from top to bottom, thereby controlling the fluid flow rate in the inner cavity.

[0084] Furthermore, the nozzle opening 12 is heated by the heating unit 30 at the nozzle opening 12 . The temperature of the heating unit 30 is higher than that of the gradient thermal control unit 20 , which can squeeze out the fluid and form picoliter Taylor cone-shaped ink droplets at the nozzle opening 12 .

[0085] Furthermore, the embodiment of the present invention utilizes the voltage unit 50 to form a point electric field between the nozzle 10 and the substrate 200 to be printed to form a current pull, so that the tip of the picoliter ink droplet is formed into a stable femtoliter ink droplet pointing downward. The point array electric field can improve the mutual interference between the multi-array printing nozzles 10, and can form stable ink droplets on the substrate 200, thereby improving printing accuracy.

[0086] Based on the above settings, the inkjet printing device of the embodiment of the present invention can reduce the volume of ink droplets and improve the landing accuracy, which can greatly improve the printing ability of the device, thereby improving the resolution of the printed product, thereby increasing the wider application scenarios of the device.

[0087] Another embodiment of the present invention provides an inkjet printing system 400 , which includes the inkjet printing device 100 of the above embodiment.

[0088] In an optional embodiment, if Figure 4 As shown, the system 400 includes:

[0089] A fluid storage device 401, for storing fluid;

[0090] a fluid distribution device 402 connected to the water outlet of the fluid storage device 401, for distributing the fluid flowing into the fluid storage device 401;

[0091] A fluid buffer device 403 connected to the water outlet of the fluid distribution device 402 , wherein the fluid buffer device 403 is connected to the fluid storage element 60 and is used to conduct the fluid flowing from the fluid storage device 401 to the fluid storage element 60 .

[0092] In a specific example, Figure 5 As shown,

[0093] The fluid storage device 401 includes a nitrogen source 4011 , a filter 4012 connected to the nitrogen source 4011 , and a fluid storage bottle 4013 connected to the filter 4012 .

[0094] The fluid dispensing device 402 includes a vacuum source 4021 , a vacuum buffer 4022 connected to the vacuum source 4021 , and an ink supply control unit 4023 connected to the vacuum buffer 4022 .

[0095] The ink supply control unit 4023 includes a first inlet connected to the water outlet of the fluid storage bottle 4013 and a second inlet connected to the vacuum buffer 4022 .

[0096] In this example, the nitrogen source 4011 is injected into the fluid storage bottle 4013 after removing gas impurities through the filter 4012. By changing the internal air pressure of the fluid storage bottle 4013, the fluid in the fluid storage bottle 4013 is introduced into the organic ink supply control unit 4023. The vacuum source 4021 and the vacuum buffer 4022 change the air pressure in the organic ink supply control unit 4023 to achieve the first distribution of the ink.

[0097] Illustratively, the ink supply control unit 4023 includes a plurality of dispensing bottles, and the volume of the fluid storage bottle 4013 is larger than that of the dispensing bottles, so that the first dispensing is achieved in the ink supply control unit 4023 .

[0098] Furthermore, the water outlet of the dispensing bottle is connected to the fluid buffer device 403, and the ink supply control unit 4023 distributes the fluid for the first time and then introduces it into the fluid buffer device 403 for the second distribution. Under the pressure of the fluid dispensing device 402, the fluid is further conducted to the fluid storage element 60, and finally flows through the fluid connecting cavity 13 to the inner cavity of each nozzle 10 for inkjet printing.

[0099] Another embodiment of the present invention provides a method for printing using the inkjet printing device of the above embodiment, the method comprising:

[0100] The control gradient thermal control unit 20 controls the temperature of the inner cavity of the nozzle 10 so that the inner cavity forms a plurality of temperature control areas with gradually changing temperatures in the extending direction of the nozzle 10;

[0101] The signal output unit 40 outputs a heating signal to the heating unit 30, so that the heating unit 30 heats the nozzle opening 12 according to the heating signal;

[0102] The signal output unit 40 outputs a control signal to the nozzle 10 to control the inkjet state of the nozzle opening 12. Figure 3a and Figure 3b As shown, the control signal can be a DC control signal or an AC control signal, thereby achieving different inkjet printing requirements.

[0103] It is worth noting that the specific embodiment of the inkjet printing method of the embodiment of the present invention can be found in the inkjet printing device of the aforementioned embodiment, which will not be described in detail here.

[0104] In the description of the present invention, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0105] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in this field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. An inkjet printing device, characterized in that: The device comprises: A plurality of vertically arranged nozzles, comprising a housing having an inner cavity and a nozzle opening located at an end of the housing, the nozzle opening facing a substrate to be printed; a gradient thermal control unit, configured to control the temperature of the inner cavity so as to form a plurality of temperature-controlled areas of gradually changing temperature in the inner cavity along the extension direction of the nozzle; a heating unit connected to the nozzle opening, for heating the nozzle opening in response to a heating signal output by a control unit; and a signal output unit, configured to output the heating signal and a control signal for controlling the ink ejection state of the nozzle opening; The gradient thermal control unit includes a plurality of first heaters sequentially arranged along the extension direction of the housing, wherein each of the first heaters forms a corresponding temperature control zone, and the temperature of each temperature control zone increases in a gradient manner along the extension direction of the housing; The heating unit includes a second heater located at the nozzle outlet, further configured to heat the nozzle outlet at a temperature higher than a current temperature range in response to a heating signal output by the signal output unit.

2. The device according to claim 1, characterized in that The device further comprises a voltage unit for supplying power to the nozzle, the voltage unit comprising: a first electrode connected to the nozzle orifice, and a second electrode disposed on a side close to the substrate to be printed, the second electrode corresponding to the first electrode in a one-to-one manner, and having opposite polarities to the first electrode; The signal output unit is further configured to output a control signal for controlling a voltage change of the voltage unit.

3. The device according to claim 1, characterized in that In the extension direction of the nozzle, the orthographic projection of the nozzle on the horizontal plane gradually decreases; In the extension direction of the nozzle, the orthographic projection of each gradient thermal control unit on the horizontal plane gradually decreases.

4. The device according to claim 1, characterized in that The device further comprises a fluid storage element for filling with a fluid; The nozzle also includes a fluid connection cavity, which is located on the side of the housing away from the nozzle opening and communicates with the inner cavity. Wherein, the multiple fluid connecting cavities are connected to the same fluid storage element.

5. The device according to claim 4, characterized in that The nozzle further includes an electromagnetic shielding cover surrounding the outer surface of the shell.

6. The device according to claim 4, characterized in that The viscosity of the fluid is 20 cp to 10,000 cp.

7. An inkjet printing system, characterized in that: The system comprises the inkjet printing device according to any one of claims 1 to 6.

8. The system according to claim 7, characterized in that The system comprises: a fluid storage device for storing fluid; a fluid distribution device connected to the water outlet of the fluid storage device, for distributing the fluid flowing into the fluid storage device; A fluid buffer device is connected to the water outlet of the fluid distribution device, and the fluid buffer device is connected to the fluid storage element, and is used to conduct the fluid flowing from the fluid storage device to the fluid storage element.

9. A method for printing using the inkjet printing device according to any one of claims 1 to 6, characterized in that: The method comprises: Controlling the gradient thermal control unit to control the temperature of the inner cavity of the nozzle so that the inner cavity forms a plurality of temperature control areas with gradually changing temperatures in the extending direction of the nozzle; The signal output unit outputs a heating signal to the heating unit, so that the heating unit heats the nozzle opening according to the heating signal; The signal output unit outputs a control signal to the nozzle head to control the ink ejection state of the nozzle opening.

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