Printhead, printing assembly and printing equipment

Abstract

This application provides a printhead, a printing assembly, and a printing device. The printhead includes: a liquid supply main channel; and multiple ejection units, each ejection unit including a heater and a nozzle. The nozzle receives liquid to be ejected from the liquid supply main channel, and the heater heats the liquid to be ejected and generates bubbles under the action of a pulse signal with a pulse frequency of f0. The multiple ejection units include a first ejection unit and a second ejection unit. The distances between the nozzles of the first ejection unit and the liquid supply main channel are different for the nozzles of the second ejection unit and the first ejection unit. The filling frequency of the first ejection unit is f1, and the filling frequency of the second ejection unit is f2, where 0.9 ≤ f1 / f0 ≤ 1.1 and 0.9 ≤ f2 / f0 ≤ 1.1. This application can solve the problem of unsatisfactory overall printing effect of the printhead caused by the mismatch between the filling frequency and the pulse frequency of some ejection units.

Description

Technical Field

[0001] This application relates to the field of fluid inkjet printing technology, and in particular to a printhead, printing assembly, and printing equipment. Background Technology

[0002] Inkjet printers are common office equipment, providing great convenience for modern offices. As the core component of an inkjet printer, the characteristics of the inkjet printhead are usually closely related to print quality. The thermally driven printhead is a common type of inkjet printhead. A thermally driven printhead (simply referred to as a printhead) is usually composed of multiple jetting units, each of which includes a heater, chamber, ink inlet channel, and nozzles.

[0003] In current technology, due to the specific requirements of the jetting algorithm, the distance between the nozzles and the main ink supply channel of different jetting units may vary. This leads to inconsistent filling frequencies (i.e., replenishment times) among different jetting units, causing a mismatch between the filling frequency of at least some jetting units in the printhead and the pulse frequency of the pulse signal acting on the heater. When the filling frequency of a jetting unit does not match the pulse frequency, the printing effect of that jetting unit will be poor, resulting in an unsatisfactory overall printing effect of the printhead. Summary of the Invention

[0004] This application provides a printhead, a printing assembly, and a printing device that can solve the problem of unsatisfactory overall printing effect of the printhead caused by the mismatch between the filling frequency and pulse frequency of some jetting units.

[0005] In a first aspect, a printhead is provided, comprising: a liquid supply main channel; and a plurality of ejection units, each ejection unit including a heater and a nozzle, the nozzle being used to receive liquid to be ejected from the liquid supply main channel, the heater being used to heat the liquid to be ejected and generate bubbles under the action of a pulse signal, the pulse frequency of the pulse signal being f0; the plurality of ejection units including a first ejection unit and a second ejection unit, wherein the distances between the nozzles of the first ejection unit and the nozzles of the second ejection unit and the liquid supply main channel are different, the filling frequency of the first ejection unit is f1, the filling frequency of the second ejection unit is f2, 0.9≤f1 / f0≤1.1, 0.9≤f2 / f0≤1.1.

[0006] According to the printhead provided in the embodiments of this application, by structurally differentiating the different jetting units, that is, different jetting units can adopt different design schemes, so that even if the distance between the nozzle and the main liquid supply channel of two jetting units (e.g., the first jetting unit and the second jetting unit) is different, the filling frequency of the two jetting units can be matched with the pulse frequency of the pulse signal applied to the heater at the same time (e.g., the same or similar). This allows more jetting units, including the first jetting unit and the second jetting unit, to be matched with the pulse frequency at the same time, thereby reducing or even avoiding the "dry spray" phenomenon of the jetting units. Furthermore, the jetting ignition timing of more (e.g., all) jetting units can meet the downward time of the secondary oscillation, and the liquid flow direction in the nozzle will be consistent with the direction of the bubble, ensuring that more jetting units can obtain better printing results, thereby improving the overall printing effect of the printhead.

[0007] In one possible implementation, the filling frequency of any one of the plurality of injection units is fn, where 0.9 ≤ fn / f0 ≤ 1.1.

[0008] In other words, by setting the structural details of each jet unit, the filling frequency of all jet units in the printhead is matched with the pulse frequency of the pulse signal, and all satisfy the relationship 0.9≤fn / f0≤1.1. In this way, no "dry spray" phenomenon will occur in any jet unit, and the jet ignition timing of all jet units can meet the downward time of the secondary oscillation. The liquid flow direction in the nozzle will be consistent with the direction of the bubble, thereby improving the overall printing effect of the printhead to a greater extent.

[0009] In one possible implementation, 0.95 ≤ fn / f0 ≤ 1.05.

[0010] In other words, the filling frequency fn of the injection unit is closer to the pulse frequency f0 of the pulse signal, meaning that the filling frequency and pulse frequency are more well matched. This can further improve the injection effect of each injection unit, and thus improve the overall printing effect of the print head to a greater extent.

[0011] In one possible implementation, the first injection unit and the second injection unit belong to a first injection unit group, and the distance between the nozzles of the plurality of injection units in the first injection unit group and the main liquid supply channel decreases sequentially.

[0012] In one possible implementation, the injection unit further includes a chamber and a liquid supply branch channel, wherein the main liquid supply channel supplies the liquid to be injected to the nozzle via the liquid supply branch channel and the chamber in sequence.

[0013] In one possible implementation, the structure of at least one of the liquid supply branch, the chamber, or the nozzle of the first injection unit is different from that of the second injection unit.

[0014] Optionally, the chambers of the first injection unit and the second injection unit have different structures. For example, the two chambers may be different in size or shape, or their relative positions to the nozzles may differ.

[0015] Optionally, the liquid supply branch channels of the first injection unit and the second injection unit have different structures. For example, the diameters (widths) of the two liquid supply branch channels are different.

[0016] Optionally, the nozzle structures of the first injection unit and the second injection unit are different. For example, the two nozzles may be different in size or shape.

[0017] In one possible implementation, a first blocking element is provided in the liquid supply branch channel of the first injection unit and / or the second injection unit.

[0018] Optionally, the first blocking element can be a blocking block. The shape of the first blocking element can be any regular or irregular shape, such as a triangle, rectangle, trapezoid, circle, rhombus, or racetrack.

[0019] Optionally, multiple second blocking elements are provided at intervals in the main liquid supply channel, and the second blocking elements can be circular blocking blocks.

[0020] In one possible implementation, the structures of the first blocking members disposed within the liquid supply branch channels of the first injection unit and the second injection unit are different.

[0021] In one possible implementation, the liquid supply branch channel of the first injection unit is generally Y-shaped, and the two branches of the Y-shaped structure connect the chamber.

[0022] By setting the liquid supply branch channel to a Y-shaped structure, the liquid supply branch channel can have a backflow prevention characteristic, which reduces ink backflow and can significantly reduce the liquid replenishment time, thereby enabling better adjustment and control of the filling frequency of the jetting unit.

[0023] In one possible implementation, at least one branch of the Y-shaped structure is a J-shaped hook structure.

[0024] With the above settings, the ink flowing back in the two branches can be offset as much as possible. At this time, the kinetic energy of the ink flowing back in the two branches can be fully canceled, thereby ensuring that the liquid supply branch channel has a sufficiently reliable anti-reverse characteristic.

[0025] In one possible implementation, the printhead includes a base layer, a chamber layer, and an nozzle layer stacked sequentially. The heater is located on the inner surface of the base layer to heat the liquid to be sprayed in the chamber. The chamber, the liquid supply branch channel, and the liquid supply main channel are formed in the chamber layer, and the nozzles are formed in the nozzle layer.

[0026] In a second aspect, a printing assembly is provided, including a printhead provided by any of the possible implementations of the first aspect, and a liquid storage device for providing liquid to be ejected to the printhead.

[0027] In one possible implementation, the liquid storage device includes an ink cartridge, and the printhead is disposed on the outer wall of the ink cartridge.

[0028] Thirdly, a printing apparatus is provided, comprising a printhead provided by any possible implementation of the first aspect, or a printing component provided by any possible implementation of the second aspect, and a controller for providing pulse signals to the printhead.

[0029] In one possible implementation, the printing device is an inkjet printer.

[0030] Optionally, the printing device can be, for example, a two-dimensional (2D) printer (e.g., an inkjet printer) or a three-dimensional (3D) printer. It can be a home or office printing device, used for functions such as black and white paper printing, color paper printing, paint spraying, digital inkjet printing, digital photo printing, digital printing, digital color proofing, image and artwork reproduction, advertising inkjet printing, or digital printing. The printing device can also be used in industrial applications, such as display film encapsulation, flexible printed electronics, color filter fabrication, liquid crystal display fabrication, large flat flexible flat panel device fabrication, circuit board fabrication, biomedical fields, biological tissue engineering, barcode printing, and food production.

[0031] The printing device includes a housing and a printing assembly disposed within the housing. This printing assembly, as the core component of the printing device, is used to realize the printing function. The printing assembly further includes a printhead and a liquid storage device (e.g., an ink cartridge) that provides the liquid to be sprayed onto the substrate via the printhead. This application does not limit the specific types of the liquid to be sprayed and the substrate. In conjunction with the specific types or uses of the printing devices listed above, the liquid to be sprayed can be any fluid such as ink (e.g., black or any colored ink), paint, edible fluid, industrial production fluid, biological fluid, or pharmaceuticals. The substrate can be, for example, any object requiring printing, such as paper, walls, billboards, circuit boards (e.g., rigid or flexible boards), display panels, optical sheets, etc. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the injection unit.

[0033] Figure 2 This is a schematic diagram of the injection process of the injection unit.

[0034] Figure 3 This is a schematic diagram of the structure of the injection unit group in the current technology.

[0035] Figure 4 This is a schematic diagram of the oscillation law of single-pulse jet liquid.

[0036] Figure 5 This is a schematic diagram and printed effect diagram of a frequency-matched multi-pulse continuous jet resonance.

[0037] Figure 6 This is a schematic diagram and printed effect of a multi-pulse continuous jet oscillation with mismatched frequencies.

[0038] Figure 7 This is a schematic diagram of the printing device provided in the embodiments of this application.

[0039] Figure 8 This is a schematic diagram of the installation structure of the printhead provided in the embodiments of this application.

[0040] Figure 9 This is a cross-sectional schematic diagram of the printhead provided in the embodiments of this application.

[0041] Figure 10 This is an exploded view of the printhead structure provided in the embodiments of this application.

[0042] Figure 11 This is a schematic diagram of an example structure of the first injection unit group provided in the embodiments of this application.

[0043] Figure 12This is a schematic diagram of another example of the structure of the first injection unit group provided in the embodiments of this application.

[0044] Figure 13 This is a schematic diagram of another example of the first injection unit group provided in the embodiments of this application.

[0045] Figure 14 This is a schematic diagram of another example of the first injection unit group provided in the embodiments of this application.

[0046] Figure 15 This is a schematic diagram of another example of the structure of the first injection unit group provided in the embodiments of this application.

[0047] Figure label:

[0048] 1. Chamber housing; 2. Chamber; 3. Nozzle; 4. Heater; 5. Liquid inlet channel; 6. Silicon substrate; 7. Protective layer; 9. Bubble; 10. Ink droplet;

[0049] 21. First injection unit; 22. Second injection unit; 23. Third injection unit; 24. Main channel; 25. Blocking block;

[0050] 100. Printhead; 110. Base layer; 111. Heater; 112. Liquid inlet; 120. Chamber layer; 121. Chamber; 122. Main liquid supply channel; 123. Sub-liquid supply channel; 124. First blocking element; 125. Second blocking element; 130. Nozzle layer; 131. Nozzle; 141. First jet unit; 142. Second jet unit; 143. Third jet unit;

[0051] 200. Ink cartridges;

[0052] 300. Ink bottle;

[0053] 400. Ink supply tube;

[0054] 500. Casing;

[0055] 600. Paper;

[0056] 700, Controller. Detailed Implementation

[0057] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0058] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0059] In the description of this application, it should be understood that the terms "upper", "lower", "side", "front", "rear", etc., indicate the orientation or positional relationship based on the installation orientation or positional relationship, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0060] It should also be noted that in the embodiments of this application, the same reference numerals are used to represent the same component or part. For the same part in the embodiments of this application, the reference numerals may only be used to mark one part or component as an example. It should be understood that the reference numerals are also applicable to other identical parts or components.

[0061] Inkjet printers are common office equipment, providing great convenience for modern offices. The printing process of an inkjet printer typically involves an ink container, such as an ink cartridge, providing the ink source. This ink is transported to the print head via corresponding ink supply channels. Driven by a print signal, the ink is ejected from nozzles on the print head onto a substrate such as paper to record text or graphics. As the core component of an inkjet printer, the operating characteristics of the print head are generally closely related to print quality. The print head is usually attached to the bottom surface of the ink cartridge to obtain the ink stored within and perform the printing function. Based on the ink droplet ejection mechanism, print heads can be divided into two types: piezoelectric driving type and thermal driving type.

[0062] Piezoelectric printheads use the deformation of piezoelectric materials to eject ink. A piezoelectric printhead contains one or more piezoelectric crystals within the ink chamber connected to the nozzle. Controlled by a data-modulated print signal, the piezoelectric crystals contract or expand, squeezing the ink in the nozzle and ejecting it as tiny droplets. These droplets then land on a substrate, such as paper, forming a recording point.

[0063] Thermally driven printheads utilize a heat source to generate bubbles in the ink, which are then ejected as droplets upon expansion. A heater is located within the ink chamber connected to the nozzle. A data-modulated electrical pulse signal is sent to this heater, causing it to heat up rapidly, quickly vaporizing the ink within the chamber and forming bubbles. The pressure generated by the expanding bubbles forces the ink out of the nozzle, forming tiny droplets that land on the substrate, such as paper. After the electrical pulse disappears, the ink vapor condenses, creating a negative pressure within the chamber. This negative pressure guides the ink from the ink supply pipe to flow rapidly into the ink chamber, ensuring timely ink replenishment. At this point, the ink within the nozzle is again kept flush with the nozzle's outer end due to its surface tension.

[0064] This application primarily relates to structural improvements of thermally driven printheads. Thermally driven printheads are typically composed of multiple jetting units. Figure 1 This is a schematic diagram of the injection unit, in which... Figure 1 Part (a) in the diagram is a horizontal cross-sectional view of the injection unit. Figure 1 Part (b) is a vertical cross-sectional view of the injection unit. For example... Figure 1 As shown, the spraying unit includes a heater 4, a chamber 2, a liquid inlet channel 5, and a spray nozzle 3.

[0065] Specifically, the chamber housing 1 is sealed and fitted onto the silicon substrate 6, and together with the silicon substrate 6, defines a chamber 2 for storing ink and an inlet channel 5 for supplying ink to the chamber 2. The chamber 2 is also connected to an nozzle 3 formed on the chamber housing 1. A heater 4 (e.g., a heating resistance) is disposed on the inner surface of the silicon substrate 6 to heat the ink in the chamber 2 and eject the ink through the nozzle 3 onto an external printing substrate such as paper. A protective layer 7 is provided on the surface of the heater 4 facing the nozzle 3 to protect the heater 4 and improve its durability and reliability.

[0066] Figure 2 This is a schematic diagram of the injection process of the injection unit. For example... Figure 2 As shown in part (a), in the initial state, ink fills the chamber 2 and the nozzle 3 through the inlet channel 5. The ink in the nozzle 3 maintains a flush position with the outer end of the nozzle 3 due to its own surface tension. At this time, the heater 4 is not working. Figure 2 As shown in section (b), at a certain moment, the host controller sends a pulse command (signal) to the heater 4. The heater 4 generates a momentary high temperature (e.g., exceeding 300°C), which vaporizes the ink adhering to the surface of the heater 4, generating bubbles 9 that apply pressure to the ink in the chamber 2 and the nozzle 3. This causes the ink in the nozzle 3 to be ejected from the printhead into the paper in the form of ink droplets 10, thus achieving the printing effect. Figure 2As shown in section (c), when heater 4 stops heating, the bubbles collapse, and a negative pressure is formed in chamber 2. This negative pressure guides the ink in the liquid inlet channel 5 to refill and replenish, waiting for the next injection command.

[0067] The jetting effect of the jetting unit (such as droplet volume and initial velocity) is strongly correlated with a variety of factors, including the operating frequency of the heater (i.e., pulse frequency), the shape of the chamber, the shape of the nozzle, and the flow channel structure. Any slight adjustment to these factors may significantly change the inherent fluid dynamic filling frequency of the jetting unit, causing it to mismatch with the operating frequency of the heater, resulting in problems such as reduced droplet volume and decreased initial velocity, leading to poor printing results.

[0068] A printhead is typically composed of a large number of jetting units, which can be divided into multiple jetting unit groups, each of which typically includes multiple (e.g., 3 or 4) jetting units. Figure 3 This is a schematic diagram of the structure of the injection unit assembly in current technology. For example... Figure 3 As shown, the injection unit group includes three injection units: a first injection unit 21, a second injection unit 22, and a third injection unit 23. The three injection units have obvious height differences, with the height decreasing proportionally from left to right. This height difference is required by the injection algorithm.

[0069] Specifically, such as Figure 3 As shown, each of the three injection units includes a chamber 2, an nozzle 3, and an inlet channel 5 connecting the chamber 2 and the main flow channel 24. Multiple blocking blocks 25 are spaced apart within the main flow channel 24 to slow the ink flow. The ink in the main flow channel 24 enters its corresponding chamber 2 and nozzle 3 through the inlet channel 5.

[0070] The three chambers 2 corresponding to the three jetting units described above have the same structure (e.g., the same shape and size), and the three nozzles 3 corresponding to them also have the same structure. Considering the paper movement during printing, and to improve printing quality, the distances between these three nozzles 3 and the main flow channel 24 are different. That is, from left to right, the nozzles 3 gradually approach the main flow channel 24, and the distance between the nozzles 3 and the main flow channel 24 decreases proportionally in each direction. This results in the three liquid inlet channels 5 corresponding to the three jetting units having different lengths, thus causing the three jetting units to have different heights (gradually decreasing in height from left to right).

[0071] In other words, for these three spray units, the distance between the nozzle 3 and the main channel 24 of the first spray unit 21 is the largest, the liquid inlet channel 5 of the first spray unit 21 is the longest, and the first spray unit 21 has the highest height; the distance between the nozzle 3 and the main channel 24 of the third spray unit 23 is the smallest, the liquid inlet channel 5 of the third spray unit 23 is the shortest, and the third spray unit 23 has the lowest height; the second spray unit 22 is located between the first spray unit 21 and the third spray unit 23.

[0072] Because the distances between nozzle 3 and main channel 24 are not the same, the multiple injection units in the injection unit group have different heights (i.e., the lengths of the inlet channels 5 are not the same), which further leads to inconsistencies in the inherent hydrodynamic filling frequency (i.e., replenishment duration or replenishment cycle) of each injection unit. For example Figure 3 The filling frequencies of the three injection units from left to right are 20.5KHz, 16.5KHz and 17.9KHz, respectively, which makes it impossible for the pulse frequency of the pulse signal applied to the heater by the control system to match the filling frequencies of the three units simultaneously.

[0073] When the frequency is mismatched, a "dry spray" phenomenon will occur, that is, the ink in the chamber is not filled before the ignition and spraying occurs, which in turn disrupts the liquid oscillation in the nozzle. Figure 4 This is a schematic diagram illustrating the oscillation pattern of a single-pulse jet liquid. For example... Figure 4 As shown, after the injection is completed, the liquid surface in the nozzle will undergo periodic "contraction → overflow" oscillations. At the same time, the amplitude of the oscillation will gradually decrease until the liquid kinetic energy is completely lost due to friction. Usually, the energy of the second oscillation is not negligible, while the energy of the third and subsequent oscillations is smaller.

[0074] Figure 5 This is a schematic diagram and printed effect image of a frequency-matched multi-pulse continuous jet resonance. (Example:) Figure 5 As shown in part (a), if the filling frequency of the ejection unit matches the pulse frequency, the ejection ignition timing (i.e., the timing when the heater is powered on) will be synchronized with the downward time of the secondary oscillation. At this time (i.e., time t1 in the figure), the ink in the nozzle is exactly filled, and the liquid flow direction (i.e., the direction away from the heater) is consistent with the bubble direction, thus resonance occurs. This results in large ink droplets, few satellite points, and accurate direction of the ejected ink. Figure 5 As shown in part (b), the final printed font is clear and the lines are not rough.

[0075] Figure 6 This is a schematic diagram and printed effect image of a multi-pulse continuous jet oscillation with mismatched frequencies. For example... Figure 6As shown in part (a), if the filling frequency of the ejection unit does not match the pulse frequency, the ejection ignition timing will coincide with the upward movement time of the secondary oscillation. At this time, the ink in the nozzle is not yet fully filled, and the liquid flow direction (i.e., the direction closer to the heater) is opposite to the bubble direction. Therefore, the liquid flow is disturbed by the bubble, and the ejected ink droplets will carry multiple stray satellite ink droplets. The landing point on the paper is uncontrollable. At the same time, the volume of the ejected ink droplets will gradually decrease (and stabilize after decreasing to a constant value), ultimately causing the printed text to be very blurry, such as... Figure 6 As shown in section (b) of the diagram. In this case, the first printed drawing is relatively clear, gradually becoming blurry from the second one onwards until it stabilizes.

[0076] In summary, if the filling frequency of the jetting unit matches the pulse frequency applied to the heater, the jetting unit will not experience "dry spraying," and the liquid flow direction within the nozzle will be consistent with the bubble direction, thus creating resonance. In this case, the jetting unit will have a better jetting (printing) effect, resulting in clear text. Conversely, if the filling frequency of the jetting unit does not match the pulse frequency applied to the heater, the jetting unit will experience "dry spraying," and the liquid flow direction within the nozzle will be opposite to the bubble direction, causing the liquid flow to be disturbed by the bubbles. In this case, the jetting (printing) effect will be poor, resulting in blurry text.

[0077] Under this premise, for multiple jetting units (e.g., a group of jetting units) in a thermally driven printhead, based on jetting algorithm considerations, the distance between the nozzle and the main flow path of different jetting units may be different. This leads to inconsistent fill frequencies among different jetting units, making it impossible for the pulse frequency to match the fill frequencies of these multiple units simultaneously. This results in a mismatch between the fill frequency and pulse frequency of at least some jetting units in the printhead. When the fill frequency and pulse frequency of a jetting unit are mismatched, the printing effect of that jetting unit will be poor, leading to an unsatisfactory overall printing effect of the printhead.

[0078] In view of this, embodiments of this application provide a printhead, a printing assembly, and a printing device. By structurally differentiating the multiple jetting units of the printhead, that is, different jetting units can adopt different design schemes, even if the distance between the nozzles (i.e., the nozzles) of two jetting units and the main flow channel is different, the filling frequency of the two jetting units can be matched with the pulse frequency simultaneously (e.g., the same or similar), thereby reducing or even avoiding the "dry spray" phenomenon of the jetting units, thereby improving the overall printing effect of the printhead.

[0079] This application first provides a printing device. Figure 7 This is a schematic diagram of the printing device provided in an embodiment of this application. For example... Figure 7As shown, the printing device can be, for example, a two-dimensional (2D) printer (e.g., an inkjet printer) or a three-dimensional (3D) printer. It can be a home or office printer, used for functions such as black and white paper printing, color paper printing, paint spraying, digital inkjet printing, digital photo printing, digital printing, digital color proofing, image and artwork reproduction, advertising inkjet printing, or digital printing. The printing device can also be used in industrial applications, such as display screen thin-film encapsulation, flexible printed electronics, color filter fabrication, liquid crystal display fabrication, large flat flexible flat panel device fabrication, circuit board fabrication, biomedical fields, biological tissue engineering, barcode printing, and food production.

[0080] The printing device includes a housing 500 and a printing assembly disposed within the housing 500. This printing assembly, as the core component of the printing device, is used to realize the printing function. The printing assembly further includes a printhead 100 and a liquid storage device (e.g., an ink cartridge 200) that provides the liquid to be sprayed onto the substrate via the printhead 100. This application does not limit the specific types of the liquid to be sprayed and the substrate. In conjunction with the specific types or uses of the printing devices listed above, the liquid to be sprayed can be any fluid such as ink (e.g., black or any colored ink), paint, edible fluid, industrial production fluid, biological fluid, or pharmaceuticals. The substrate can be, for example, any object requiring printing, such as paper, walls, billboards, circuit boards (e.g., rigid or flexible boards), display panels, optical sheets, etc.

[0081] The following description uses an inkjet printer as an example to introduce the printing device provided in the embodiments of this application.

[0082] Figure 8 This is a schematic diagram of the installation structure of the printhead 100 provided in an embodiment of this application. For example... Figure 7 and Figure 8 As shown, the printing device includes an ink cartridge 200 and a print head 100 disposed on the outer wall of the ink cartridge 200. The ink cartridge 200 stores ink, and the print head 100 is tightly fitted to the bottom wall of the ink cartridge 200. A through-hole (channel) is provided on the bottom wall of the ink cartridge 200 to allow the ink cartridge 200 to communicate with the main ink supply channel inside the print head 100, thereby supplying ink to the print head 100. The print head 100 ejects ink from nozzles on the print head 100 onto the paper 600, thus recording text or graphics, i.e., realizing the printing function.

[0083] Optionally, an ink-absorbing sponge and a filter can be installed inside the ink cartridge 200. The ink-absorbing sponge can better preserve or retain the ink, which is beneficial for a stable and reliable supply of ink to the printhead 100, while the filter can filter the ink about to enter the printhead 100 and prevent impurities from clogging the nozzles.

[0084] Furthermore, such as Figure 7 As shown, the printing device also includes an ink bottle 300 and an ink supply tube 400. The ink cartridge 200, ink bottle 300, and ink supply tube 400 together constitute the aforementioned liquid storage device. By setting the ink bottle 300, more ink can be stored. When the ink in the ink cartridge 200 is insufficient, the ink bottle 300 can replenish the ink in the ink cartridge 200 in a timely manner through the ink supply tube 400.

[0085] like Figure 7 As shown, the printing device also includes a controller 700, which is communicatively connected to the printhead 100. The controller 700 is used to provide pulse signals to the printhead 100. Driven by the pulse signals, the printhead 100 ejects ink from the nozzles onto the paper 600 outside the printhead 100, thereby realizing the printing function.

[0086] Figure 9 This is a cross-sectional schematic diagram of the printhead 100 provided in an embodiment of this application. Combined with... Figure 7 and Figure 9 In this embodiment, the printhead 100 can be a thermally driven printhead, which is composed of multiple jetting units. Each jetting unit is equipped with a heater 111. The controller 700 can output a pulse signal to the heater 111. Upon receiving the pulse signal, the heater 111 rapidly heats up, causing the ink in the chamber 121 to quickly vaporize and form bubbles. The pressure generated by the expansion of the bubbles causes the ink to be ejected from the nozzle 131, forming fine ink droplets that splash onto the paper 600.

[0087] Specifically, such as Figure 9 As shown, a liquid supply main channel 122 is formed inside the printhead 100, and multiple jetting units are arranged around the liquid supply main channel 122. For example, multiple jetting units can be arranged at the edge of the liquid supply main channel 122. The liquid supply main channel 122 is connected to the ink cartridge 200 through the liquid inlet hole 112. Ink in the ink cartridge 200 can enter the interior of the liquid supply main channel 122 through the liquid inlet hole 112. The liquid supply main channel 122 is connected to the multiple jetting units to supply ink to the jetting units.

[0088] Each injection unit includes a heater 111, a chamber 121, a liquid supply branch channel 123, and an nozzle 131. The main liquid supply channel 122 supplies ink to the nozzle 131 sequentially through the liquid supply branch channel 123 and the chamber 121. The heater 111 generates instantaneous high temperature under the action of a pulse signal to heat the ink in the chamber 121 and generate bubbles. The bubbles generate extrusion pressure, causing the ink in the nozzle 131 to be ejected.

[0089] like Figure 9 As shown, the printhead 100 includes a base layer 110, a chamber layer 120, and an nozzle layer 130 stacked sequentially. An inlet port 112 is formed on the base layer 110. A heater 111 is located on the inner surface of the base layer 110 and is opposite to the nozzle 131 / chamber 121, thereby heating the ink within the chamber 121. The chamber 121, the ink supply branch channel 123, and the ink supply main channel 122 are formed in the chamber layer 120, and the nozzle 131 is formed in the nozzle layer 130.

[0090] Optionally, the substrate layer 110, the chamber layer 120, and the nozzle layer 130 can be sealed together into an integral structure by a bonding process, such as anodic bonding, direct bonding, plasma bonding, etc.

[0091] Optionally, the base layer 110 and the chamber layer 120 can be formed from a single sheet (plate) through etching or other processes (i.e., the base layer 110 and the chamber layer 120 originally constitute an integral structure), and then the nozzle layer 130 can be formed from another sheet through etching or other processes. After that, the nozzle layer 130 is sealed and covered on the side of the chamber layer 120 away from the base layer 110.

[0092] Similarly, the chamber layer 120 and the nozzle layer 130 can be formed from a single sheet through etching or other processes (i.e., the chamber layer 120 and the nozzle layer 130 originally form an integral structure). Then, the base layer 110 can be formed from another sheet through etching or other processes. After that, the base layer 110 is sealed and covered on the side of the chamber layer 120 away from the nozzle layer 130.

[0093] Optionally, the material of the aforementioned sheet may be, for example, silicon, glass, resin, or polymer. That is, the material of the aforementioned substrate layer 110, chamber layer 120, or nozzle layer 130 may include at least one of silicon, glass, resin, or polymer. For example, the substrate layer 110 may be a silicon substrate, the chamber layer 120 may be made of resin, and the nozzle layer 130 may be made of resin or glass.

[0094] Figure 10 This is an exploded view of the structure of the printhead 100 provided in an embodiment of this application. Figure 10Part (a) in the diagram is a bottom view of the base layer 110. Figure 10 Part (b) is a top view of chamber 120. Figure 10 Part (c) is a bottom view of the nozzle layer 130.

[0095] like Figure 10 As shown in part (a), the printhead 100 includes multiple ejection units, each of which includes a heater 111, a chamber 121, a liquid supply channel 123, and an nozzle 131. Multiple heaters 111, corresponding to each ejection unit, are disposed on the inner surface of the substrate layer 110 and correspond to the positions of the chambers 121, i.e., the multiple heaters 111 face each chamber 121 to heat the ink within the corresponding chamber 121. A liquid inlet 112 is formed on the substrate layer 110, for example, located in the middle of the substrate layer 110, to allow the ink cartridge 200 to communicate with the main liquid supply channel 122, thereby supplying ink to the main liquid supply channel 122.

[0096] like Figure 10 As shown in part (b), chamber 121, liquid supply branch channel 123, and liquid supply main channel 122 are formed in chamber layer 120. The liquid supply main channel 122 is located inside chamber layer 120 and extends from one edge to the other. Multiple chambers 121 are sequentially spaced along both edges of the liquid supply main channel 122. Each chamber 121 is connected to the liquid supply main channel 122 via a corresponding liquid supply branch channel 123. That is, ink in the liquid supply main channel 122 enters the corresponding chamber 121 through the liquid supply branch channel 123, and then enters the corresponding nozzle 131. The nozzle described in this application can also be understood or replaced as a nozzle.

[0097] like Figure 10 As shown in section (c), a plurality of nozzles 131 are arranged on the nozzle layer 130 and communicate with corresponding chambers 121, for example, the edges of the chambers 121 surround the nozzles 131. Figure 9 as well as Figure 10 In part (b), the heater 111, chamber 121, and nozzles 131 are stacked sequentially, with the nozzles 131 arranged in an alternating pattern, and their distances from the main liquid supply channel 122 are not entirely the same. For example, some nozzles 131 are closer to the main liquid supply channel 122, while others are farther away. Furthermore, because the distances between the multiple nozzles 131 and the main liquid supply channel 122 are not entirely the same, the lengths of the multiple liquid supply branch channels 123 are also not entirely the same; that is, some liquid supply branch channels 123 are longer, and some are shorter.

[0098] like Figure 9 and Figure 10 As shown, the printhead 100 is composed of a large number of jetting units, which can be divided into multiple jetting unit groups. Each jetting unit group typically includes multiple (e.g., 3) jetting units. Due to the requirements of the jetting algorithm, the distances between the multiple jetting units within a given jetting unit group and the main liquid supply channel 122 are not the same. For example, along... Figure 10 From left to right, the three nozzles 131 corresponding to the three nozzles in the same injection unit group gradually approach the liquid supply main channel 122, and the distance between the nozzles 131 and the liquid supply main channel 122 decreases proportionally in turn.

[0099] The printhead 100 includes multiple jetting unit groups, which may include a first jetting unit group. Figure 11 This is a schematic diagram of an example structure of the first injection unit group provided in an embodiment of this application. Figure 11 As shown, the first injection unit group includes a first injection unit 141 and a second injection unit 142. The distances between the nozzle 131 of the first injection unit 141 and the nozzle 131 of the second injection unit 142 and the main liquid supply channel 122 are different. For example, the nozzle 131 of the second injection unit 142 is closer to the main liquid supply channel 122.

[0100] In this embodiment, the first jetting unit 141 and the second jetting unit 142 are designed with structural differences. That is, the two jetting units can adopt different design schemes so that even if the distance between the nozzles of the two jetting units and the liquid supply main channel 122 is different, the filling frequency of the two jetting units can be matched with the pulse frequency of the pulse signal applied to the heater (e.g., the same or similar). This can reduce or even avoid the "dry spray" phenomenon of the jetting units and improve the overall printing effect of the printhead 100.

[0101] Specifically, heater 111 heats the ink and generates bubbles under the action of a pulse signal. The pulse frequency of this pulse signal can be denoted as f0. The filling frequency of the first jetting unit 141 is denoted as f1, and the filling frequency of the second jetting unit 142 is denoted as f2. By setting the structure of the first jetting unit 141 and the second jetting unit 142, f1 and f2 are made to satisfy the following relationship: 0.9 ≤ f1 / f0 ≤ 1.1, and 0.9 ≤ f2 / f0 ≤ 1.1. For example, f1 = f2 = f0, or f1 and f2 are approximately equal to (close to) f0. That is, the filling frequency of the first jetting unit 141 matches the pulse frequency of the pulse signal applied to heater 111, and the filling frequency of the second jetting unit 142 also matches the pulse frequency of the pulse signal applied to heater 111. Here, "matching" means being the same or similar (e.g., approximately equal).

[0102] According to the printhead 100 provided in the embodiments of this application, by structurally differentiating the different jetting units, that is, different jetting units can adopt different design schemes, so that even if the distance between the nozzle 131 of two jetting units (e.g., the first jetting unit 141 and the second jetting unit 142) and the liquid supply main channel 122 is different, the filling frequency of the two jetting units can be matched (e.g., the same or similar) with the pulse frequency of the pulse signal applied to the heater 111. This allows more jetting units, including the first jetting unit 141 and the second jetting unit 142, to be matched with the pulse frequency at the same time, thereby reducing or even avoiding the "dry spray" phenomenon of the jetting units. Furthermore, the jetting ignition timing of more (e.g., all) jetting units can meet the downward time of the secondary oscillation, and the liquid flow direction in the nozzle 131 will be consistent with the direction of the bubble, ensuring that more jetting units can obtain better printing results, thereby improving the overall printing effect of the printhead 100.

[0103] Optionally, 0 < f0 ≤ 30 kHz, or 5 kHz ≤ f0 ≤ 25 kHz, or 10 kHz ≤ f0 ≤ 20 kHz, or 15 kHz ≤ f0 ≤ 19 kHz. For example, the value of f0 can be 3 kHz, 8 kHz, 12 kHz, 17 kHz, 19 kHz, or 25 kHz, etc.

[0104] For example, if f0 = 20kHz, then 18kHz ≤ f1 ≤ 22kHz, and 18kHz ≤ f2 ≤ 22kHz. For example, f1 = f2 = f0 = 20kHz; or f1 = f2 = 19.5kHz, or f1 = 19.8kHz, f2 = 20.3kHz.

[0105] Optionally, the filling frequency of any one of the multiple ejection units in the printhead 100 is fn, where 0.9 ≤ fn / f0 ≤ 1.1. In other words, by setting the structural details of each ejection unit, the filling frequency of all ejection units in the printhead 100 is matched with the pulse frequency of the pulse signal, satisfying the relationship 0.9 ≤ fn / f0 ≤ 1.1. This ensures that no "dry spraying" occurs in any of the ejection units, and that the ejection ignition timing of all ejection units coincides with the downward movement time of the secondary oscillation. The liquid flow direction within the nozzle 131 will be consistent with the bubble direction, thereby significantly improving the overall printing effect of the printhead 100.

[0106] Furthermore, 0.95 ≤ fn / f0 ≤ 1.05. In other words, the filling frequency fn of the jetting unit is closer to the pulse frequency f0 of the pulse signal, meaning the matching degree between the filling frequency and the pulse frequency is higher. This can further improve the jetting effect of each jetting unit, and thus improve the overall printing effect of the printhead 100 to a greater extent.

[0107] For example, if f0 = 20kHz, then 19kHz ≤ fn ≤ 21kHz, that is, 19kHz ≤ f1 ≤ 21kHz, 19kHz ≤ f2 ≤ 21kHz. For example, f1 = f2 = 19.8kHz, or f1 = 19.9kHz, f2 = 20.1kHz.

[0108] like Figure 10 As shown, the first injection unit group includes a first injection unit 141, a second injection unit 142, and a third injection unit 143. The three injection units have obvious height differences, and their heights decrease proportionally from left to right. This height difference is required by the injection algorithm.

[0109] Specifically, considering the paper movement during printing, in order to improve printing quality, the three nozzles 131 corresponding to the three jetting units are gradually moved closer to the main liquid supply channel 122. This further results in the three liquid supply branch channels 123 corresponding to the three jetting units having different lengths, thus causing the three jetting units to have different heights (gradually decreasing in height from left to right).

[0110] In other words, for the three injection units, the distance between the nozzle 131 of the first injection unit 141 and the main liquid supply channel 122 is the largest, the liquid supply branch channel 123 of the first injection unit 141 is the longest, and the first injection unit 141 has the highest height; the distance between the nozzle 131 of the third injection unit 143 and the main liquid supply channel 122 is the smallest, the liquid supply branch channel 123 of the third injection unit 143 is the shortest, and the third injection unit 143 has the lowest height; the second injection unit 142 is located between the first injection unit 141 and the third injection unit 143.

[0111] like Figure 11 As shown in the embodiments of this application, the structures of at least one of the liquid supply branch channel 123, chamber 121, or nozzle 131 of the first injection unit 141 and the second injection unit 142 are different. That is, given that the distances between the nozzle 131 and the main liquid supply channel 122 of the two units are different, the two injection units are structurally differentiated, that is, different injection units can adopt different design schemes, thereby enabling the filling frequency of both injection units to match the pulse frequency.

[0112] Optionally, the structures of the chambers 121 of the first injection unit 141 and the second injection unit 142 are different. For example, the two chambers 121 may be different in size or shape, or their relative positions to the nozzles 131 may be different.

[0113] Optionally, the liquid supply branch channels 123 of the first injection unit 141 and the second injection unit 142 have different structures. For example, the diameters (widths) of the two liquid supply branch channels 123 are different.

[0114] Optionally, the structures of the nozzles 131 of the first injection unit 141 and the second injection unit 142 are different. For example, the two nozzles 131 may be different in size or shape.

[0115] like Figure 11 As shown in the embodiment of this application, each of the three liquid supply branch channels 123 corresponding to the first jetting unit 141, the second jetting unit 142, and the third jetting unit 143 is provided with a first blocking member 125. At this time, the first blocking member 125 divides the liquid supply branch channel 123 into two channels (dual channels). The three first blocking members 125 have different shapes and / or sizes. By setting the first blocking member 125, the ink flow rate is controlled. At this time, there is no need to differentiate the design of the chamber 121 or the nozzle 131, and the filling frequency of the three jetting units can be close to or equal, that is, they can be matched with the pulse frequency at the same time.

[0116] For example, by setting a first blocking element 125 in each of the liquid supply branch channels 123, the filling frequencies of the first jet unit 141, the second jet unit 142, and the third jet unit 143 are 20KHz / 20.2KHz / 19.6KHz respectively, which accurately match the pulse frequency of 20KHz, and the frequency error is within ±0.5KHz. This effectively improves the problems of initial jetting speed, droplet volume, and satellite points of the jetting unit, and improves the overall printing effect of the printhead 100.

[0117] Optionally, the first blocking member 125 can be a blocking block. The shape of the first blocking member 125 can be any regular or irregular shape such as triangle, rectangle, trapezoid, circle, rhombus, racetrack, etc.

[0118] Optionally, a plurality of second blocking elements 125 are provided at intervals within the main liquid supply channel 122, and the second blocking elements 125 can be circular blocking blocks.

[0119] Figure 12 This is a schematic diagram of another example of the first injection unit group provided in the embodiments of this application. For example... Figure 12 As shown, relative to the aforementioned Figure 11In the embodiment shown, the first blocking member 125 is not provided in the liquid supply branch channel 123. By designing the size and / or shape of the chamber 121 and the width of the liquid supply branch channel 123 differently, the filling frequencies of the first injection unit 141, the second injection unit 142, and the third injection unit 143 can be close to or equal, that is, they can be matched with the pulse frequency simultaneously.

[0120] Figure 13 This is a schematic diagram of another example of the structure of the first injection unit group provided in the embodiments of this application. Figure 13 The embodiments shown can be considered as described above. Figure 11 and Figure 12 The connection of the illustrated embodiment. Specifically, as Figure 13 As shown, in the three injection units 141, 142, and 143, the first injection unit 141 has a first blocking member 125 in its liquid supply branch channel 123, while the other two injection units do not. The three chambers 121 of the three injection units are of different sizes and / or shapes, and the widths of the three liquid supply branch channels 123 are also different. Through this irregular design, the filling frequencies of the three injection units can be close to or equal, i.e., simultaneously matched with the pulse frequency.

[0121] Figure 14 This is a schematic diagram of another example of the structure of the first injection unit group provided in the embodiments of this application. Figure 15 This is a schematic diagram of another example of the structure of the first injection unit group provided in the embodiments of this application. Figure 14 and Figure 15 The main difference in the first injection unit group shown is that, Figure 14 The chamber 121 in the middle is circular in shape, while Figure 15 The chamber 121 in the middle is rectangular (e.g., square). Figure 14 and Figure 15 As shown, the liquid supply branch channel 123 can be arranged in a Y-shape. This Y-shape includes a main channel and two branches. The front end of the main channel is connected to the main liquid supply channel 122, and the rear end of the main channel is connected to the front ends of the two branches. The rear ends of the two branches are connected to the chamber 121. By setting the liquid supply branch channel 123 in a Y-shape, it can have a backflow prevention characteristic, reducing ink backflow and significantly reducing the replenishment time, thereby enabling better adjustment and control of the filling frequency of the jetting unit.

[0122] Specifically, such as Figure 14As shown, during the replenishment phase, ink enters the main branch of the supply branch channel 123 from the main supply channel 122, and then enters the chamber 121 through two branches. During the ejection phase, ink flows back from the chamber 121 towards the two branches. At this time, the ink flowing back from the two branches will collide and interfere with each other at the confluence point of the main branch, and the kinetic energy of the backflow will be canceled out. This results in the ink in the entire supply branch channel 123 not being able to flow back smoothly, or the amount of ink flowing back is relatively small. Reducing the ink backflow can significantly reduce the replenishment time.

[0123] Optionally, the included angle between the two branches can be an obtuse angle, in which case the kinetic energy of the ink flowing back from the two branches can be more fully canceled, thereby ensuring that the liquid supply branch channel 123 has a sufficiently reliable anti-reverse characteristic.

[0124] Optionally, the liquid supply branch channel 123 can be configured into a Y-shaped structure by providing a first blocking element 125 inside the liquid supply branch channel 123.

[0125] Furthermore, such as Figure 14 and Figure 15 As shown, one branch of the Y-shaped structure (i.e., the liquid supply branch channel 123) has a J-shaped hook structure. Through the above arrangement, the ink flowing back in the two branches can be offset as much as possible. At this time, the kinetic energy of the ink flowing back in the two branches can be relatively fully canceled, thereby ensuring that the liquid supply branch channel 123 has a sufficiently reliable anti-reverse characteristic.

[0126] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A printhead, characterized in that, include: Main fluid supply channel; Multiple injection units, each injection unit including a heater and a nozzle, the nozzle being used to receive the liquid to be injected from the main liquid supply channel, the heater being used to heat the liquid to be injected and generate bubbles under the action of a pulse signal, the pulse frequency of the pulse signal being f0; The plurality of injection units include a first injection unit and a second injection unit. The distances between the nozzle of the first injection unit and the nozzle of the second injection unit and the main liquid supply channel are different. The filling frequency of the first injection unit is f1, and the filling frequency of the second injection unit is f2, 0.9≤f1 / f0≤1.1, 0.9≤f2 / f0≤1.

1.

2. The printhead according to claim 1, characterized in that, The filling frequency of any one of the plurality of injection units is fn, where 0.9 ≤ fn / f0 ≤ 1.

1.

3. The printhead according to claim 2, characterized in that, 0.95≤fn / f0≤1.

05.

4. The printhead according to any one of claims 1-3, characterized in that, The first injection unit and the second injection unit belong to a first injection unit group, and the distance between the nozzle of the plurality of injection units in the first injection unit group and the main liquid supply channel decreases sequentially.

5. The printhead according to any one of claims 1-3, characterized in that, The injection unit further includes a chamber and a liquid supply branch channel, wherein the main liquid supply channel supplies the liquid to be sprayed to the nozzle through the liquid supply branch channel and the chamber in sequence.

6. The printhead according to claim 5, characterized in that, The structure of at least one of the liquid supply branch channel, the chamber, or the nozzle of the first injection unit and the second injection unit is different.

7. The printhead according to claim 5, characterized in that, A first blocking element is provided in the liquid supply branch channel of the first injection unit and / or the second injection unit.

8. The printhead according to claim 7, characterized in that, The structures of the first blocking members installed in the liquid supply branch channels of the first injection unit and the second injection unit are different.

9. The printhead according to claim 5, characterized in that, The liquid supply branch channel of the first injection unit has an overall Y-shaped structure, and the two branches of the Y-shaped structure connect the chamber.

10. The printhead according to claim 9, characterized in that, At least one branch of the Y-shaped structure has a J-shaped hook structure.

11. The printhead according to claim 5, characterized in that, The printhead includes a base layer, a chamber layer, and an nozzle layer stacked sequentially. The heater is located on the inner surface of the base layer to heat the liquid to be sprayed in the chamber. The chamber, the liquid supply branch channel, and the liquid supply main channel are formed in the chamber layer, and the nozzles are formed in the nozzle layer.

12. A printing component, characterized in that, It includes a printhead as described in any one of claims 1-11, and a liquid storage device for providing the printhead with the liquid to be sprayed.

13. The printing component as claimed in claim 12, characterized in that, The liquid storage device includes an ink cartridge, and the printhead is disposed on the outer wall of the ink cartridge.

14. A printing device, characterized in that, include: The printhead as described in any one of claims 1-11, or the printing assembly as described in claim 12 or 13; as well as, A controller is used to provide pulse signals to the printhead.

15. The printing apparatus according to claim 14, characterized in that, The printing device is an inkjet printer.

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