An integrated printhead module for multicolor inkjet printing

Abstract

This invention relates to the field of additive manufacturing technology, specifically to an integrated printhead module for multi-color inkjet printing, composed of multiple Z-shaped printheads. Each Z-shaped printhead includes an ink distributor, a front panel, side panels, an inkjet chip, and ink tubes. The ink distributor has a Z-shaped outline. The two front panels are respectively attached to the front and rear sides of the ink distributor, and the two side panels are respectively attached to the left and right sides of the ink distributor. The inkjet chip is mounted below the ink distributor and communicates internally with it, with nozzles arrayed on the chip. The ink tubes are located above the ink distributor and supply ink to it. This invention achieves high-precision collaboration among multiple printheads by arranging the printheads in a Z-shape and optimizing the nozzle layout, thereby ensuring print quality.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, specifically to an integrated printhead module for multicolor inkjet printing. Background Technology

[0002] In the current industrial inkjet printing field, especially in the packaging industry, there is a growing demand for high-speed, high-quality printing on large substrates such as corrugated cardboard. The booming development of e-commerce has spurred a large number of personalized, small-batch packaging orders, which places higher demands on the printing area and production efficiency of digital inkjet printing technology.

[0003] However, existing individual industrial inkjet printheads, whether piezoelectric or thermal, typically have limited effective printing widths; for example, most piezoelectric printheads are no wider than 130mm. This size is far from meeting the application requirements in industrial fields, which often require printing widths of 600mm or more. Therefore, to achieve single-pass printing on large-format media such as corrugated cardboard, the industry practice is to combine multiple independent printheads into an extended print array.

[0004] When combining multiple printheads, existing technologies generally face a core technical challenge: how to ensure continuous and seamless printing coverage while maintaining extremely high printing accuracy. Currently, the mainstream solution is to use a stepped, staggered arrangement. Because traditional printheads are typically rectangular, their physical shells interfere with each other when arranged linearly end-to-end, preventing their nozzle arrays from fitting tightly together. Therefore, the printheads must be installed in a staggered manner along the media movement direction, forming a stepped physical layout.

[0005] While this staggered, stepped arrangement solves the physical interference problem, the nozzle arrays of the front and rear printheads are not actually on the same straight line in this layout. In order to print a visually continuous straight line on a moving substrate (such as corrugated cardboard), the rear printheads must perform precise inkjet delay compensation through complex software algorithms and a high-precision electronic control system. That is, the rear printhead needs to delay the ink droplet ejection by a precisely calculated time according to the speed of the substrate, so as to ensure that its ink droplets fall on the same scanning line as the ink droplets of the front printhead. This solution, which relies on software delay compensation, has an inherent defect that is difficult to overcome in actual industrial production: its printing accuracy is highly dependent on the absolute stability of the paper feed speed of the substrate. However, in practice, it is extremely difficult to achieve zero error in paper feed speed. Any slight speed fluctuation, such as speed changes caused by uneven media thickness, mechanical vibration or transmission system errors, will cause the preset delay time to be mismatched with the actual required time, which will directly manifest as visible printing defects at the splicing of the printed product, such as misalignment, breakage or overlap of lines.

[0006] To address this, an integrated printhead module for multicolor inkjet printing is proposed, which enables wide-format printing while ensuring high print quality. Summary of the Invention

[0007] The purpose of this invention is to provide an integrated printhead module for multi-color inkjet printing, which solves the problem of low print quality after multiple printheads are combined. By zig-shaped printheads and optimizing the layout of the nozzles on the printheads, high-precision collaboration of multiple printheads is achieved, thereby ensuring print quality.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An integrated printhead module for multicolor inkjet printing is composed of multiple Z-shaped printheads. Each Z-shaped printhead includes an ink distributor, a front panel, side panels, an inkjet chip, and an ink tube. The ink distributor has a Z-shaped outline. The two front panels are respectively attached to the front and rear sides of the ink distributor, and the two side panels are respectively attached to the left and right sides of the ink distributor. The inkjet chip is installed below the ink distributor and communicates internally with the ink distributor. The inkjet chip has an array of nozzles. The ink tube is located above the ink distributor and is used to supply ink to the ink distributor. The side panels of different Z-shaped printheads are attached together, and the column directions of the nozzles of two attached Z-shaped printheads coincide.

[0010] Preferably, the ink dispenser includes a front part and a rear part from front to back, the length and width of the front part and the rear part are equal, and the rear side of the front part and the front side of the rear part overlap.

[0011] In the above solution, the combination of the front and rear parts allows the left and right ends of the ink dispenser to interlock, so that when multiple Z-type printheads are combined and spliced, their side plates can completely overlap and lock together to ensure the consistency of movement during collaborative operation, thereby ensuring the quality of wide-format printing. Furthermore, the standardized interface provides a basis for the standardization of Z-type printheads, thereby standardizing the production of Z-type printheads. When operating individually, they can print narrow widths, while when operating in combination, different printing widths can be accommodated by adjusting the number of combinations.

[0012] In traditional designs, inkjet chips are usually permanently encapsulated inside the printhead using methods such as bonding (for inkjet chips with higher printing precision, the density of their nozzles is correspondingly greater). However, due to the nature of ink solidifying over time, nozzle clogging or even damage often occurs, requiring the replacement of the entire expensive printhead assembly, which leads to higher operating costs and a more complex replacement process.

[0013] Preferably, the inkjet chip is configured as a split structure, the inkjet chip includes a substrate and a flexible line board, the substrate is installed below the front and rear parts, the flexible line board is electrically connected to the control circuit inside the panel, and the flexible line board is electrically connected to the substrate.

[0014] In the above solution, the monolithic inkjet chip is broken down into several smaller pieces. The number of nozzles on the smaller inkjet chip is limited. When one or more nozzles malfunction, only the inkjet chip containing the nozzle needs to be replaced. As a result, the manufacturing and replacement costs of the inkjet chip are significantly reduced. In addition, the inkjet chip installation method in this solution allows it to be installed and removed from the outside of the Z-shaped printhead, thereby improving the efficiency of inkjet chip replacement.

[0015] Preferably, the nozzles are disposed below the substrate, and the nozzles are arranged in an equidistant array of four rows and multiple columns. The four rows of nozzles are divided into Y-ports, K-ports, C-ports and M-ports. The Y-ports, K-ports, C-ports and M-ports on the front and rear upper substrates are arranged in the same order from front to back.

[0016] In the above scheme, four rows of nozzles are set on the inkjet chip. The four rows of nozzles are used to eject ink droplets of different colors. The amount of ink droplets ejected is determined by the corresponding nozzle. The combination order of ink droplets is achieved by the overall stepping of the printhead in the front and back direction. The consistent arrangement order of the nozzles on the front and rear ensures that the control logic of the front and rear is consistent.

[0017] Preferably, the plurality of substrates are equidistantly arranged below the front and rear portions, and the number of substrates in the front and rear portions is equal. The minimum horizontal distance between two nozzles on different substrates is denoted as a, and the maximum horizontal distance between two nozzles on a single substrate is denoted as b, then a≤b.

[0018] In the above scheme, by using the equal and equidistant array of substrates on the front and rear parts and the relationship of a≤b, combined with the equal length setting of the front and rear parts, the substrates on the front or rear parts are located between adjacent substrates on the rear or front parts, thereby making the substrates on the front and rear parts compensate for their respective gaps, making the inkjet area continuous, and thus ensuring the printing quality.

[0019] Preferably, the overlapping area of ​​the front substrate and the rear substrate has n sets of nozzles in the same row, and n≥1;

[0020] In the above scheme, based on the mutual compensation of the gaps between the substrates on the front and rear, the nozzles on the front and rear of the overlapping inkjet area are arranged in the same row, so that when the front and rear move in the front and rear directions, the nozzles in the overlapping inkjet area can spray ink at the same position on the substrate, thereby ensuring high printing accuracy.

[0021] Preferably, the row spacing and column spacing of the nozzle array on the substrate are denoted as d and e, respectively. The distance from the leftmost nozzle at the front and rear to the left side of the front and rear is g, and the distance from the rightmost nozzle at the front and rear to the right side of the front and rear is h. Then g + h = id. The minimum distance between the nozzles on the front substrate and the nozzles on the rear substrate is denoted as f. Then f = ke, where i and k are both positive integers.

[0022] In the above scheme, by setting g+h=id, where i is a positive integer, the nozzles of the two Z-type printheads are aligned at the docking point, thus ensuring high precision during wide-format printing; by setting f=ke, where k is a positive integer, when the Z-type printheads are rearranged to align the front or rear of the printing area, the displacement along the front-to-back direction satisfies the step relationship, thus ensuring alignment accuracy and printing quality.

[0023] For Z-type printheads with higher printing precision, the inkjet chips are arranged more densely. Correspondingly, the Z-type printhead needs to evenly deliver the four independent inks of cyan (C), magenta (M), yellow (Y), and black (K) to all inkjet chips in a more compact space.

[0024] Preferably, the ink dispenser comprises, from top to bottom, a first ink path layer, a second ink path layer, and a base. The base is connected to a panel and a side panel. The inkjet chip is installed below the base. The first ink path layer includes a Y channel and a K channel. A barrier layer is provided between the Y channel and the K channel. The barrier layer has outlets on the side close to the Y channel and the K channel, respectively. The outlet on the Y channel side is connected to the Y port on the inkjet chip, and the outlet on the K channel side is connected to the K port on the inkjet chip. The second ink path layer includes a C channel and an M channel, and the relevant settings of the C channel and the M channel are consistent with those of the Y channel and the K channel.

[0025] In the above scheme, by extending into the vertical space, the ink distributor is divided into three layers: the upper ink channel (first ink path layer) is specifically responsible for conveying Y (yellow) and K (black) inks; the middle ink channel (second ink path layer) is specifically responsible for conveying C (cyan) and M (magenta) inks; and the lower structure (base) is not responsible for conveying inks, but provides four-color ink cavities, mounting bases, and sealing structures for all inkjet chips. By separating the color pairs (Y / K and C / M) in the vertical plane, the possibility of crossover is avoided, making the Z-type printhead more compact.

[0026] When the printhead operates at high speed for a long time, it generates a lot of heat, which affects the viscosity of the ink and the stability of electronic components (panels, inkjet chips); and industrial printing (especially corrugated paper) often uses pigment inks to obtain better water resistance and durability, but pigment particles are prone to sedimentation when stationary, which can cause nozzle clogging.

[0027] Preferably, each end of the Y channel, K channel, C channel and M channel is provided with an inlet and an outlet, and both the inlet and the outlet are connected to the ink tube;

[0028] In the above scheme, an outlet and an inlet are set at both ends of each channel and connected to the ink tube respectively, so that the ink circulates in the channel instead of being in a static state for a long time. The circulation of ink can not only promote the heat dissipation of the Z-type printhead and thus ensure the consistency of ink droplet ejection, but also effectively prevent the precipitation of pigment particles, thereby reducing the risk of nozzle clogging.

[0029] When ink enters the Y, K, C, or M channel from the inlet, it needs to be evenly distributed to all inkjet chips below the base. If the design is not proper, the ink pressure of the chip near the inlet will be too high, while the ink pressure of the chip at the end will be too low, which will result in inconsistent ink droplet size and speed, ultimately forming horizontal banding or uneven color density defects on the printed product.

[0030] Preferably, a shutter is provided on one side of the outlet that connects to the Y channel, K channel, C channel or M channel, and the height of the shutter decreases gradually along the Y channel, K channel, C channel or M channel from the inlet to the outlet.

[0031] In the above solution, the ink output of the outlet near the inlet is limited by the ink gate with progressively decreasing height. This limitation weakens as the outlet moves away from the inlet, thereby averaging the ink output of each outlet. This ensures that the inkjet chip corresponding to each outlet receives a highly consistent ink supply pressure, thus guaranteeing uniform color density and no defects within the printing width.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. This invention, by zig-shaped nozzles, enables multiple nozzles to overlap in the column direction during splicing, forming a collinear nozzle array. This eliminates the printing accuracy problems caused by software delay compensation in existing stepped misaligned splicing schemes. It shifts the splicing accuracy from dependence on easily interfered electronic control systems and paper feed speed to stable and reliable machining accuracy, thereby avoiding printing defects such as line misalignment, breakage, or overlap at the splicing point and ensuring high quality for wide-format printing.

[0034] 2. This invention employs a split inkjet chip structure, designing the core inkjet component as a substrate that can be independently disassembled and installed externally. When some nozzles are damaged, the user only needs to replace a single, low-cost substrate, without discarding the entire expensive printhead module. This reduces the user's operating and maintenance costs, significantly simplifies the replacement process, and improves printhead printing efficiency. Furthermore, through optimized nozzle layout on the inkjet chip, all nozzles maintain column alignment and uniform column spacing during both wide and narrow-width printing, thereby ensuring printing accuracy.

[0035] 3. This invention compensates for pressure loss along the ink flow by setting an ink gate with a progressively decreasing height at the outlet, ensuring that each inkjet chip receives uniform ink supply pressure, thereby avoiding defects such as horizontal stripes or uneven color density caused by uneven pressure. In addition, the "inlet" and "outlet" set for each color channel form an ink circulation loop. The continuous ink flow not only effectively prevents pigment sedimentation and reduces the risk of nozzle clogging, but also actively carries away heat to dissipate heat from the printhead, jointly ensuring high stability of operation in industrial production environments. Attached Figure Description

[0036] Figure 1 This is an isometric schematic diagram of the wide-format printing state of the present invention;

[0037] Figure 2 This is a schematic diagram of the wide-format printing state of the present invention;

[0038] Figure 3 This is a schematic diagram of the internal structure of the Z-type nozzle of the present invention;

[0039] Figure 4 This is a schematic diagram of the inkjet chip structure of the present invention;

[0040] Figure 5 For the present invention Figure 2 Enlarged schematic diagram of section L in the middle;

[0041] Figure 6 This is a front view schematic diagram of the ink dispenser of the present invention;

[0042] Figure 7 For the present invention Figure 6 A-A cross-sectional diagram;

[0043] Figure 8 For the present invention Figure 6 Schematic diagram of the B-B cross section in the image;

[0044] Figure 9 This is a bottom view schematic diagram of the ink dispenser structure of the present invention;

[0045] Figure 10 This is a schematic diagram of the first ink layer structure of the present invention.

[0046] In the diagram: 1. Z-type printhead; 2. Ink distributor; 21. Front; 22. Rear; 23. First ink path layer; 231. Y channel; 232. K channel; 24. Second ink path layer; 241. C channel; 242. M channel; 25. Base; 26. Barrier layer; 261. Outlet; 262. Ink shutter; 27. Inlet; 28. Outlet; 3. Panel; 4. Side panel; 5. Inkjet chip; 51. Substrate; 511. Nozzle; 5111. Y port; 5112. K port; 5113. C port; 5114. M port; 52. Flexible line board; 6. Ink tube. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Please see Figures 1 to 10 This invention provides an integrated printhead module for multi-color inkjet printing, the technical solution of which is as follows:

[0049] An integrated printhead module for multicolor inkjet printing is composed of multiple Z-shaped printheads 1. Each Z-shaped printhead 1 includes an ink distributor 2, a front panel 3, side panels 4, an inkjet chip 5, and ink tubes 6. The ink distributor 2 has a Z-shaped outline and serves not only as the core of ink distribution but also as the structural framework. It is typically made of materials with high dimensional stability and low coefficient of thermal expansion (such as special engineering plastics) through precision machining to ensure that the geometric accuracy of the Z-shaped splicing is maintained under various operating temperatures and mechanical loads. Two front panels 3 are respectively attached to the front and rear sides of the ink distributor 2. Various components and circuits are mounted on the front panels 3, and an interface for the inkjet chip 5 (such as...) is provided. Figure 3As shown in Figure AA, correspondingly, an interface BB is provided on the inner side of the opposite panel 3 for connecting the front inkjet chip 5; in addition, the panel 3 can also protect the internal high-frequency jet signal from external electromagnetic interference; the two side plates 4 are respectively attached to the left and right sides of the ink distributor 2, the shape of the side plates 4 is consistent with the height of the Z-shaped left and right sides of the ink distributor 2, and also has a Z-shaped cross-sectional shape, and its surface is hollowed out, which provides mechanical protection for the internal components and assists in heat dissipation; the inkjet chip 5 is installed below the ink distributor 2, and the inside of the inkjet chip 5 is connected to the ink distributor 2, and the inkjet chip 5 has an array of nozzles 511, and the ink tube 6 is located above the ink distributor 2 for supplying ink to the ink distributor 2; the side plates 4 of different Z-shaped printheads 1 are attached to each other, and the column direction of the nozzles 511 of the two Z-shaped printheads 1 after attachment coincides.

[0050] As one embodiment of the present invention, refer to Figure 1 and Figure 2 The ink dispenser 2 consists of a front part 21 and a rear part 22 from front to back. The length and width of the front part 21 and the rear part 22 are equal, and the rear side of the front part 21 and the front side of the rear part 22 partially overlap. The ink dispenser 2 is made of engineering plastic by casting and CNC precision machining to ensure that the reference surface on the ink dispenser 2 used to install the inkjet chip 5, as well as the interlocking meshing surface of the Z-shaped part itself, have extremely high coplanarity and positional accuracy.

[0051] As one embodiment of the present invention, refer to Figure 3 and Figure 4 The inkjet chip 5 preferably adopts a split structure to facilitate maintenance and reduce costs. The inkjet chip 5 includes a substrate 51 and a flexible line plate 52. The substrate 51 is installed below the front part 21 and the rear part 22. The flexible line plate 52 is electrically connected to the control circuit inside the panel 3, and the flexible line plate 52 is electrically connected to the substrate 51.

[0052] The Z-type printhead 1 consists of 10 inkjet chips 5, each 0.92 inches wide, assembled using a precision splicing process to achieve an inkjet width of 220mm. The splicing process is carried out by the printhead manufacturer in a cleanroom using tooling fixtures. The Z-type printhead 1 adopts a modular design, integrating the inkjet chip 5, ink distributor 2, and ink tube 6 together. After receiving the Z-type printhead 1, the printer manufacturer only needs to perform simple installation, connect the data cable / power cable, and connect the ink supply line before it can be used, which greatly simplifies the design of the printer manufacturer's inkjet carriage structure and piping.

[0053] Before installing the inkjet chip 5, the internal installation of the Z-type printhead 1 is performed first, followed by connecting the flexible line board 52 to the interface on the panel 3 (such as...). Figure 3After (as shown in AA), the Z-shaped printhead 1 is sealed, and then the substrate 51 is installed below the ink distributor 2 (fixed with bolts). Finally, the connection between the flexible line plate 52 and the substrate 51 is completed. The electrical connection between the flexible line plate 52 and the substrate 51 can be achieved by anisotropic conductive film (ACF) thermoforming or micro connectors, which ensures reliable transmission of high-density signals while also allowing for disassembly and maintenance. When the inkjet chip 5 needs to be replaced, it is usually because the nozzle 511 on the substrate 51 is blocked or damaged. In this case, it is only necessary to disconnect the connection between the flexible line plate 52 and the substrate 51 first, and then remove the substrate 51 from the ink distributor 2.

[0054] As one embodiment of the present invention, refer to Figure 5 The nozzles 511 are located below the substrate 51, and the nozzles 511 are arranged in an equidistant array of four rows and multiple columns. The four rows of nozzles 511 are divided into Y nozzles 5111, K nozzles 5112, C nozzles 5113 and M nozzles 5114. The Y nozzles 5111, K nozzles 5112, C nozzles 5113 and M nozzles 5114 on the substrate 51 on the front part 21 and the rear part 22 are arranged in the same order from front to back.

[0055] In the field of multicolor inkjet printing, the most commonly used color mode is CMYK, which uses four colors of ink: cyan, magenta, yellow, and key / black. Its working principle is as follows: The printhead is equipped with an independent ink channel and nozzle array for each color. When printing a color image, the image processing system first decomposes the image into the four CMYK color channels. Then, the print controller instructs thousands of tiny nozzles 511 on the printhead to spray these four colors of tiny ink droplets onto the same location on the paper in a specific ratio and order. That is, the final color at a point is formed by multiple inkjet steps. The ink color, ink volume, and the order of each step all affect the final color. For example, theoretically, green is a mixture of cyan (C) and yellow (Y), but different spraying sequences will produce significant differences.

[0056] 1) Spray cyan (C) first, then yellow (Y): When cyan ink droplets fall onto the paper first, and then yellow ink droplets are superimposed on top, since yellow ink is usually more transparent than cyan ink, light will penetrate the yellow ink layer, be reflected by the cyan ink layer below, and then pass through the yellow ink layer into the human eye. In this case, the cyan at the bottom layer has a greater impact on the final green hue, resulting in a cooler green.

[0057] 2) Spray yellow (Y) first, then cyan (C): When yellow ink droplets fall onto the paper first, and then cyan ink droplets are superimposed on top, the situation is reversed. The cyan ink layer with relatively high opacity will cover the yellow ink layer and dominate most of the light reflection. In this case, the final result is a warm green.

[0058] In this method, when printing a complete image, a partial image is first printed by instructing the front part 21, and the remaining image is printed by instructing the rear part 22. The nozzles 511 on the substrate 51 of the front part 21 and the rear part 22 are arranged in the order of K nozzle 5112, Y nozzle 5111, C nozzle 5113, and M nozzle 5114 from front to back. The printer control system can use a unified color management and color separation algorithm without distinguishing which nozzle 511 is currently performing the printing task, thereby ensuring a high degree of consistency and predictability of color performance throughout the entire printing width.

[0059] As one embodiment of the present invention, refer to Figure 5 Multiple substrates 51 are equidistantly arrayed below the front portion 21 and the rear portion 22, with the number of substrates 51 in the front portion 21 and the rear portion 22 being equal. The minimum horizontal distance between two nozzles 511 on different substrates 51 is denoted as 'a', and the maximum horizontal distance between two nozzles 511 on a single substrate 51 is denoted as 'b', where a ≤ b. The overlapping area of ​​the front portion 21 substrate 51 and the rear portion 22 substrate 51 contains n sets of nozzles 511 in the same column, where n ≥ 1. The nozzles 511 are arrayed on the substrates 51. The row spacing and column spacing are denoted as d and e, respectively. The distance from the leftmost nozzle 511 of the front part 21 and the left side of the rear part 22 to the left side of the front part 21 and the rear part 22 is g. The distance from the rightmost nozzle 511 of the front part 21 and the right side of the rear part 22 to the right side of the front part 21 and the rear part 22 is h. Then g + h = id. The minimum distance between the nozzle 511 of the front part 21 substrate 51 and the nozzle 511 of the rear part 22 substrate 51 is denoted as f. Then f = ke, where i and k are both positive integers.

[0060] During operation, the Z-type printhead 1 is fixed on a crossbeam and driven by a stepper motor, with a step unit of e. Taking the printing of a certain point area on the substrate as an example, this point area needs to use either the nozzle 511 on the front part 21 or the nozzle 511 on the rear part 22 during the printing process. These two scenarios are used as the basis for analysis: 1) If the point area is located in the area of ​​the nozzle 511 on the front part 21, then the front part 21 is used for printing. Initially, the point area is aligned with the K-port 5112 on the front part 21. If cyan inkjet printing is required, the Z-type printhead 1 will move forward by a distance of 3e, which is three step units; 2) If the point is located at the break point of the nozzle 511 of the front 21, the printing of the area of ​​the point will be carried out after the printing work of the front 21 is completed. After the front 21 is set up, the M port 5114 of the front 21 is aligned with the coloring area. Then the Z-type printhead 1 needs to move forward by ke first so that the K port 5112 of the rear 22 is aligned with the point, and then the Z-type printhead 1 will step according to the printing steps.

[0061] As one embodiment of the present invention, refer to Figures 6-9 The ink dispenser 2 comprises, from top to bottom, a first ink path layer 23, a second ink path layer 24, and a base 25. The base 25 connects to the panel 3 and the side panel 4. The inkjet chip 5 is mounted below the base 25. The first ink path layer 23 includes a Y channel 231 and a K channel 232. A barrier layer 26 is provided between the Y channel 231 and the K channel 232. The barrier layer 26 has outlets 261 on the side of the barrier layer 26 closest to the Y channel 231 and the K channel 232, respectively. The outlet 261 on the Y channel 231 side connects to the Y port 5111 on the inkjet chip 5. The outlet 261 on side 232 is connected to the K port 5112 on the inkjet chip 5. The second ink path layer 24 includes a C channel 241 and an M channel 242, and the relevant settings of the C channel 241 and the M channel 242 are consistent with those of the Y channel 231 and the K channel 232. The first ink path layer 23, the second ink path layer 24 and the base 25 are respectively precision injection molded, and then laminated and bonded with an adhesive with excellent chemical resistance. O-rings or liquid sealant are set between the layers to ensure absolute sealing between each color channel and prevent color mixing.

[0062] As one embodiment of the present invention, refer to Figure 7 and Figure 8 The Y channel 231, K channel 232, C channel 241 and M channel 242 are all equipped with inlet 27 and outlet 28 at both ends, and both inlet 27 and outlet 28 are connected to ink tube 6;

[0063] In the printer system, each inlet 27 is connected to the output of the ink supply pump via an ink tube 6, while each outlet 28 is connected to the return port of the main ink cartridge or an intermediate buffer tank, thus forming a complete closed-loop circulation system. This continuous ink circulation brings several key benefits: First, it effectively prevents high-density particles in pigment-based inks (such as white, metallic, or ceramic inks commonly used in industrial applications) from settling due to gravity, ensuring that the ink remains in a uniform suspension state throughout the flow path, thereby fundamentally avoiding nozzle clogging caused by pigment sedimentation. Second, the circulation can actively carry away tiny air bubbles generated in the ink path due to temperature changes or negative pressure fluctuations from the printhead and return them to the main ink tank for unified processing, greatly improving the reliability of inkjet printing and preventing print line breaks caused by air bubbles entering the nozzle. Finally, the circulating ink acts as an active coolant, continuously carrying away the heat generated by the inkjet chip 5 and the drive circuit during high-speed operation, maintaining the stability of the internal temperature of the printhead, and thus ensuring the consistency of fluid properties such as ink viscosity.

[0064] As one embodiment of the present invention, refer to Figure 10 A shutter 262 is provided on one side of the outlet 261 that connects to the Y channel 231, K channel 232, C channel 241 or M channel 242. The height of the shutter 262 decreases step by step along the Y channel 231, K channel 232, C channel 241 or M channel 242 from the inlet 27 to the outlet 28.

[0065] Based on the fundamental principle of fluid flow in a pipeline, pressure naturally decreases along the flow direction due to friction and diversion. The pressure is higher near the inlet 27, so a higher ink gate 262 is set to increase flow resistance and limit the amount of ink flowing out from this outlet 261. Conversely, the pressure in the main channel is lower closer to the outlet 28, so a lower ink gate 262 is set to reduce flow resistance and increase the amount of ink flowing out from this outlet 261. This compensates for the pressure loss along the main channel, ensuring that the flow rate at each outlet 261 is basically equal, thereby ensuring equal ink supply pressure for each inkjet chip 5, eliminating horizontal banding defects and ensuring uniform color density.

[0066] Working Principle: To address the issue of decreased print quality caused by splicing accuracy problems when combining multiple printheads in existing technologies, this invention achieves high-precision physical coordination of multiple printheads by arranging the printheads in a Z-shape and optimizing the layout of the internal nozzles 511, thereby ensuring the quality of wide-format printing. First, the Z-shaped structure ensures that the nozzles 511 of adjacent printheads are physically aligned directly on the same straight line, eliminating the reliance on software delay compensation and avoiding printing defects caused by fluctuations in substrate speed. Simultaneously, to support this compact external structure, a three-layer three-dimensional ink path distributor is used internally, integrating pressure equalization and ink circulation functions, ensuring high-precision splicing while maintaining the high reliability and color consistency required for industrial applications.

[0067] To achieve high-precision, seamless wide-format printing, the specific method is to design the ink dispenser 2 of each Z-type printhead 1 with a Z-shaped profile, such as... Figure 1 and Figure 2 As shown, this complementary geometry allows the rightmost nozzle 511 of one nozzle to directly overlap with the leftmost nozzle 511 of the adjacent nozzle when the side plates 4 of multiple Z-type nozzles 1 are fitted together, forming a physically collinear nozzle array. Furthermore, by constraining the distance from the nozzle 511 to the side using the mathematical relationship g+h=id, it is ensured that the physical gap at the splice is exactly an integer multiple of the row spacing (d) of the nozzle 511, thereby achieving compensation at the image data level and ensuring that the printed image has no visual breaks or overlaps at the splice.

[0068] To achieve uniform, non-overlapping four-color ink supply to multiple inkjet chips 5 within the compact internal space provided by the Z-shaped structure, a three-layer ink distributor 2 consisting of a first ink path layer 23, a second ink path layer 24, and a base 25 is employed; for example... Figures 6 to 9 As shown, this design physically separates the ink channels of different color pairs by extending into the vertical space: the first ink path layer 23 is responsible for conveying ink from the Y channel 231 and the K channel 232, while the second ink path layer 24 is responsible for conveying ink from the C channel 241 and the M channel 242.

[0069] To further ensure uniform printing color and reliability for industrial applications, the specific approach is to integrate pressure equalization and ink circulation functions within the ink distributor. Firstly, to guarantee uniform and flawless color density across the entire print width, such as... Figure 10As shown, an ink gate 262 is installed at each outlet 261, and the height of the ink gate 262 decreases gradually along the ink flow direction to actively adjust the flow resistance of each outlet 261, effectively compensating for the pressure loss along the main channels (Y channel 231, K channel 232, C channel 241 and M channel 242), ensuring that each inkjet chip 5 can obtain a highly consistent ink supply pressure; secondly, in order to improve the stability of long-term operation, such as Figure 7 and Figure 8 As shown, each color channel is equipped with an inlet 27 and an outlet 28 at both ends to form an ink circulation loop. The continuous ink circulation not only effectively prevents pigment particles from settling and reduces the risk of nozzle 511 clogging, but also actively removes the heat generated by the Z-type printhead 1, thus playing a heat dissipation role. This ensures that the Z-type printhead 1 can operate stably and reliably for a long time in high-speed, high-load industrial production environments.

[0070] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated printhead module for multi-color inkjet printing, composed of multiple Z-shaped printheads, characterized in that: The Z-type printhead includes an ink distributor, a front panel, side panels, an inkjet chip, and an ink tube. The ink distributor has a Z-shaped outline. The two front panels are respectively attached to the front and rear sides of the ink distributor, and the two side panels are respectively attached to the left and right sides of the ink distributor. The inkjet chip is installed below the ink distributor and communicates internally with the ink distributor. The inkjet chip has an array of nozzles. The ink tube is located above the ink distributor and is used to supply ink to the ink distributor. The side panels of different Z-type printheads are attached to each other, and the column directions of the nozzles of the two attached Z-type printheads coincide. The ink dispenser consists of a front part and a rear part from front to back. The length and width of the front part and the rear part are equal, and the rear side of the front part and the front side of the rear part overlap. By combining the front and rear sections, the left and right ends of the ink dispenser can be interlocked, allowing the side plates of multiple Z-type printheads to completely overlap and lock together when they are assembled. The inkjet chip is configured as a split structure, the inkjet chip includes a substrate and a flexible line board, the substrate is installed below the front and rear, the flexible line board is electrically connected to the control circuit inside the panel, and the flexible line board is electrically connected to the substrate. The nozzles are located below the substrate, and the nozzles are arranged in an equidistant array of four rows and multiple columns. The four rows of nozzles are divided into Y-ports, K-ports, C-ports and M-ports. The Y-ports, K-ports, C-ports and M-ports on the front and rear upper substrates are arranged in the same order from front to back. The ink dispenser comprises, from top to bottom, a first ink path layer, a second ink path layer, and a base. The base is connected to a panel and a side panel. The inkjet chip is mounted below the base. The first ink path layer includes a Y channel and a K channel. A barrier layer is provided between the Y channel and the K channel. The barrier layer has outlets on the side close to the Y channel and the K channel, respectively. The outlet on the Y channel side is connected to the Y port on the inkjet chip, and the outlet on the K channel side is connected to the K port on the inkjet chip. The second ink path layer includes a C channel and an M channel, and the relevant settings of the C channel and the M channel are the same as those of the Y channel and the K channel. The Y-channel, K-channel, C-channel and M-channel are each provided with an inlet and an outlet at both ends, and the inlet and outlet are both connected to the ink tube; A shutter is provided on one side of the outlet that connects to the Y-channel, K-channel, C-channel, or M-channel, and the height of the shutter decreases gradually along the Y-channel, K-channel, C-channel, or M-channel from the inlet to the outlet.

2. The integrated printhead module for multi-color inkjet printing according to claim 1, characterized in that: Multiple substrates are equidistantly arranged below the front and rear portions, and the number of substrates in the front and rear portions is equal. The minimum horizontal distance between two nozzles on different substrates is denoted as a, and the maximum horizontal distance between two nozzles on a single substrate is denoted as b. Then a≤b.

3. An integrated printhead module for multi-color inkjet printing according to claim 2, characterized in that: The overlapping area of ​​the front substrate and the rear substrate has n sets of nozzles in the same row, and n≥1.

4. An integrated printhead module for multi-color inkjet printing according to claim 2, characterized in that: The row spacing and column spacing of the nozzle array on the substrate are denoted as d and e, respectively. The distance from the leftmost nozzle at the front and rear to the left side of the front and rear is g, and the distance from the rightmost nozzle at the front and rear to the right side of the front and rear is h. Then g + h = id. The minimum distance between the nozzles on the front substrate and the nozzles on the rear substrate is denoted as f, then f = ke, where i and k are both positive integers.

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