Cylinder digital printing method and device based on multi-turn timing jet

Abstract

The present application relates to the field of drum digital printing, and discloses a kind of drum digital printing method and device based on multi-turn timing jet printing, and the method comprises: according to the total number of turns N required for printing of single finished product, the trigger period of feeding action and paper receiving action is set;Print medium is guided and adsorbed and fixed on the surface of the drum by automatic paper receiving mechanism;1-2 print nozzles are controlled to perform timing cycle jet printing during the multi-turn rotation of the drum;When single finished product printing is completed, the automatic paper receiving mechanism is triggered by the control module to perform connection operation.The present application can solve the problems of high equipment cost, complex nozzle calibration, high operation failure rate and insufficient overprint accuracy caused by relying on multi-nozzle parallel operation in the prior art.

Description

Technical Field

[0001] This invention relates to the field of rotary digital printing, and more particularly to a rotary digital printing method and apparatus based on multi-cycle sequential inkjet printing. Background Technology

[0002] Existing thick ink printing, multi-layer pattern overlay, and multi-color printing largely rely on multiple printheads working in parallel. This method requires a large number of printheads and complex driving, ink supply, and positioning systems, resulting in high equipment costs, difficult calibration, high failure rates, and low registration accuracy, making it unsuitable for high-quality, large-scale applications. Traditional roller printing technology only uses the roller as a media transport carrier, completing a single print run through a single rotation. It fails to utilize the multi-rotation characteristics of the roller to achieve ink layer overlay or layered printing, and cannot replace the parallel output of multiple printheads with a small number of printheads in a sequential cycle. There is a clear contradiction between the need for low cost and high-quality printing.

[0003] Furthermore, existing feeding mechanisms mostly employ a fixed-cycle, uniform-speed feeding mode, which cannot meet the requirements of multi-layer printing. The conveying methods are mostly suction belt types, resulting in very low positioning accuracy and inability to achieve high-precision registration. When printing multiple ink layers or multi-layer graphics, the rollers need to rotate multiple times to complete a single finished product. However, conventional feeding mechanisms feed material in advance at a fixed cycle, easily causing media waste, content misalignment, and chaotic finished product cutting, making them unsuitable for multi-cycle printing. Simultaneously, existing equipment lacks a dedicated automatic paper splicing mechanism, resulting in gaps in the connection between blank media and the rollers, and between finished products and subsequent media. Manual intervention is required for paper splicing and discharging, leading to production interruptions, low efficiency, and difficulty in meeting the demands of large-scale, high-efficiency production. Summary of the Invention

[0004] This invention provides a roller-type digital printing method and apparatus based on multi-cycle sequential inkjet printing, to solve the problems of high equipment cost, complex printhead calibration, high failure rate and low registration accuracy caused by the reliance on multiple printheads working in parallel in the prior art.

[0005] A rotary digital printing method based on multi-turn sequential inkjet printing includes: Based on the total number of printing cycles N required for a single finished product, set the trigger cycle for the feeding action and the paper receiving action to ensure that the feeding rhythm, the paper receiving action and the number of roller rotations are synchronized. The printing media is guided and adsorbed onto the surface of the roller through an automatic paper splicing mechanism; Controlling 1-2 printheads to perform sequential cyclic printing during the multiple rotations of the drum effectively achieves the effect of parallel output from multiple printheads; Among them, the cyclic inkjet printing adopts at least one of the following modes: Ink layer thickness stacking mode: The roller rotates multiple times, and the print head repeatedly prints the same content on the same path, achieving a thick ink protrusion effect through ink layer stacking; Layered graphic printing mode: The roller rotates multiple times, and the printing nozzles print different graphic contents sequentially on the same path to achieve a three-dimensional effect of upper and lower layers; After a single print job is completed, the control module triggers the automatic paper splicing mechanism to perform a splicing operation: the feeding component delivers a new medium and the feeding paper splicing unit splices the new medium onto the roller, while the discharging paper splicing unit guides the finished product out. The adsorption component briefly releases the finished product and re-adsorbs the new medium, entering the next print cycle.

[0006] Optionally, the control module monitors the actual number of rotations of the roller in real time, and triggers the automatic paper splicing mechanism to perform a splicing operation every N rotations.

[0007] Optionally, in the ink layer thickness stacking mode, the printhead covers the entire target graphic area in each rotation, increasing the ink layer thickness through repeated printing.

[0008] Optionally, in the layered graphic printing mode, the printhead prints the first layer of graphics in the first circle, the second layer of graphics in the second circle, and so on, until all layers are printed.

[0009] Optionally, when the automatic paper splicing mechanism adopts a flexible paper splicing roller structure, the adsorption component briefly releases the vacuum adsorption force before the finished product comes into contact with the new medium, and resumes adsorption after the new medium is fully adhered, thus achieving seamless switching of printing media; or, When the automatic paper splicing mechanism uses a toothed bar, the control module triggers the automatic paper splicing mechanism to perform splicing operations, including: the control module drives the clutch mechanism of the tooth-opening cam, so that the tooth-opening cam engages with the tooth-opening ball to complete one tooth opening and closing operation. The tooth opening and closing operation is performed once every N rotations of the roller, and the tooth-opening cam and tooth-opening ball remain separated in the remaining rotations.

[0010] A rotary digital printing apparatus based on multi-turn sequential inkjet printing includes: The roller, as the printing media carrier, can rotate multiple times around the central axis; An adsorption component, embedded in the surface of the roller, is used to firmly fix the printing medium by negative pressure or magnetic attraction; One or two printheads are arranged on the outer circumference of the roller for circumferential scanning printing or fixed-point printing on the rotating medium. The control module is communicatively connected to the roller and the print head, and is responsible for the coordinated operation of the printing components, the number of revolutions, and the position calibration. The feeding assembly, located on the feeding side, has its feeding timing and frequency precisely controlled by the control module based on the actual number of rotations of the drum. The automatic paper splicing mechanism includes a feeding splicing unit and a discharging splicing unit, which are used to achieve smooth connection between blank media and rollers, and between finished products and the discharge end.

[0011] Optionally, the control module is configured to execute the following logic: based on the number of printing cycles N required for a single finished product, set the trigger cycle for the feeding and paper receiving actions to ensure that the feeding, paper receiving, and printing rhythms are completely synchronized.

[0012] Optionally, the automatic paper splicing mechanism also includes a vacuum adsorption switching valve group disposed at both ends of the roller, which is used to briefly release the vacuum adsorption force at the finished product end when connecting a new medium; The automatic paper splicing mechanism includes a feeding paper splicing unit and a discharging paper splicing unit, both of which adopt flexible paper splicing rollers or toothed bar structures. The opening and closing of the teeth of the tooth bar is controlled by an axially disengaging tooth-opening cam; the tooth-opening cam is installed on a sliding track and can slide along the track, and is engaged or disengaged with the tooth-opening ball through a clutch mechanism; when the roller needs to perform a connecting operation, the tooth-opening cam engages with the tooth-opening ball to complete one tooth-opening and closing action, and the tooth-opening cam remains disengaged from the tooth-opening ball in the remaining rotations, so that the roller rotates N times before opening and closing the teeth once; the clutch mechanism adopts a pneumatic, electric or electromagnetic drive method.

[0013] Optionally, the number of printheads is one, and the entire graphic and text printing of a single finished product is completed through multi-turn reflow; and / or, The adsorption component is a microporous array structure distributed on the surface of the roller, which, together with the internal negative pressure cavity, achieves uniform adsorption of the medium.

[0014] Optionally, a position calibration unit is also included to monitor the relative position of the printhead and the roller in real time to ensure accurate overlap of the printed content over multiple passes.

[0015] The aforementioned roller-type digital printing method and apparatus based on multi-cycle sequential inkjet printing achieves the thick ink overlay and multi-layer graphic printing effects of traditional multi-head printing with only 1-2 printheads by using a roller to absorb the medium and employing a multi-cycle sequential inkjet printing method. This significantly reduces equipment costs and maintenance complexity. Based on preset linkage parameters and an automatic paper-feeding mechanism, it achieves continuous automation of the entire process from material feeding and paper feeding to printing and discharging, eliminating process interruptions caused by manual intervention and significantly improving production efficiency and finished product consistency. This invention solves the problems of high equipment costs, complex printhead calibration, high failure rates, and low registration accuracy caused by the reliance on multiple printheads working in parallel in existing technologies. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of a roller digital printing method based on multi-circle timing inkjet printing in one embodiment of the present invention; Figure 2 This is a simplified structural diagram of a roller-type digital printing device based on multi-circle sequential inkjet printing in one embodiment of the present invention; Figure 3a This is a schematic diagram of a traditional fixed-type open-tooth cam structure; Figure 3b This is a schematic diagram of the overall structure of an axially disengaging tooth-opening mechanism according to an embodiment of the present invention; Figure 3c This is a schematic cross-sectional view of the axial sliding clutch mechanism of the toothed cam in one embodiment of the present invention. Detailed Implementation

[0018] 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, not all, of the embodiments of the present invention. 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.

[0019] In one embodiment, such as Figure 1 As shown, a roller-type digital printing method based on multi-turn sequential inkjet printing is provided, including the following steps S10~S40.

[0020] S10. Based on the total number of printing cycles N required for a single finished product, set the trigger cycle for the feeding action and the paper receiving action to ensure that the feeding rhythm, the paper receiving action and the number of roller rotations are synchronized. S20. The printing media is guided and adsorbed onto the surface of the roller by an automatic paper splicing mechanism; S30: Control 1-2 printheads to perform sequential cyclic printing during the multiple rotations of the drum, which is equivalent to achieving the effect of parallel output of multiple printheads; Among them, the cyclic inkjet printing adopts at least one of the following modes: Ink layer thickness stacking mode: The roller rotates multiple times, and the print head repeatedly prints the same content on the same path, achieving a thick ink protrusion effect through ink layer stacking; Layered graphic printing mode: The roller rotates multiple times, and the printing nozzles print different graphic contents sequentially on the same path to achieve a three-dimensional effect of upper and lower layers; S40. After a single finished product is printed, the control module triggers the automatic paper splicing mechanism to perform the splicing operation: the feeding component sends out the new medium and the feeding paper splicing unit splices the new medium onto the roller, while the discharging paper splicing unit guides the finished product out. The adsorption component briefly releases the finished product and re-adsorbs the new medium, entering the next printing cycle.

[0021] Understandably, the multi-cycle sequential inkjet printing method for rotary digital printing provided in this embodiment uses multi-cycle sequential inkjet printing with a small number of printheads as its core. By pre-setting the trigger cycle for material feeding and paper splicing, it ensures that material feeding, paper splicing, and the number of rotations of the roller are completely synchronized. During the printing process, one or two printheads repeat or change the content being printed as the roller rotates multiple times, achieving the effect of overlapping ink layers or layered graphic printing, which is equivalent to replacing the traditional multi-printhead parallel output. After a single finished product is completed, the automatic paper splicing mechanism completes the connection of new media and the output of the finished product, realizing the entire process of continuous automated production from "material feeding to paper splicing to printing to output".

[0022] Specifically, the control module pre-sets the total number of rotations N (N≥1) required for the roller to complete the printing of a single finished product, based on the printing requirements of that product. On this basis, a one-to-one correspondence is established between the number of roller rotations and the feeding actions of the material conveying component and the paper receiving actions of the automatic paper receiving mechanism: if N=1, the material conveying component triggers feeding once every one rotation of the roller, and the automatic paper receiving mechanism receives paper synchronously; if N≥2, the material conveying component triggers feeding once every N rotations of the roller, and the automatic paper receiving mechanism responds synchronously. The triggering cycle here refers to the number of roller rotations from the end of one feeding / paper receiving action to the start of the next action, ensuring that the feeding rhythm, paper receiving action, and the actual number of printing rotations of the roller are completely synchronized, avoiding media waste or content misalignment caused by fixed-rhythm feeding.

[0023] The control module activates the adsorption assembly and the automatic paper feeding unit of the paper splicing mechanism. The feeding assembly delivers blank printing media, and the paper feeding unit, employing a flexible paper splicing roller structure or a gripper structure, smoothly guides and connects the blank media to the roller surface, ensuring no media deviation or jamming. Subsequently, the adsorption assembly uses negative pressure suction or magnetic attraction to flatten and securely adhere the blank printing media to the outer wall of the roller without relative displacement, allowing the media to rotate synchronously with the roller. The adsorption assembly is embedded in the roller surface, and its adsorption force can be adaptively adjusted by the control module according to the media material (such as paper, film, fabric, etc.) to ensure the media remains firmly fixed even under high-speed rotation. Specifically, for thin media such as coated paper and waterproof film, the adsorption assembly uses negative pressure suction; for media with a magnetic base or magnetic materials, it switches to magnetic adsorption to ensure that all types of media are firmly fixed.

[0024] This system controls one or two printheads to perform sequential, cyclic printing during the multiple rotations of the printing drum, effectively achieving a multi-head parallel output effect. It includes two selectable or combined modes: ink layer thickness stacking mode and layered image printing mode. In ink layer thickness stacking mode, the printing drum rotates multiple times, and the printheads strictly follow the same printing path and alignment standard as the first rotation, repeatedly printing the same basic document. Through the gradual accumulation of ink layers across multiple rotations, the physical thickness of the printed content increases, creating a thick, raised ink effect. The ink output in each rotation can be kept consistent or finely adjusted to ensure uniform ink layer stacking. In layered image printing mode, the printing drum rotates multiple times, and the printheads maintain the same printing path but print different image content sequentially. The images and text printed in each rotation are precisely aligned, creating a layered, three-dimensional image effect. The ink output, grayscale, and color of different rotations can be independently adjusted according to design requirements. Furthermore, the printing speed and accuracy of the printheads can also be flexibly adjusted by the control module according to printing needs to meet the efficiency and quality requirements of different scenarios.

[0025] In both modes described above, sequential cyclic printing refers to the printhead repeating or changing the printed content in a fixed time sequence during multiple rotations. Position calibration is monitored in real-time by a position calibration unit built into the control module, ensuring accurate overlap of the printed content across multiple rotations and preventing misalignment and ghosting. The position calibration unit automatically performs alignment calibration before each printing rotation to further eliminate accumulated errors.

[0026] Once the rollers have rotated to the preset total number of revolutions N required for a single printout and the current printout is complete, the control module immediately triggers the feeding assembly to deliver the next blank media to the paper feeding and splicing unit. Simultaneously, the automatic paper splicing mechanism's feeding and splicing unit smoothly connects the new media to the roller surface, while the dispensing and splicing unit smoothly guides the printed printout to the dispensing end, achieving a seamless cycle of "feeding—sponging—printing—dispensing." During dispensing, the adsorption assembly briefly releases its adsorption force on the printout to ensure smooth dispensing. The entire splicing operation requires no manual intervention. The automatic paper splicing mechanism precisely matches the roller speed and feeding speed through a flexible splicing roller structure (or gripper structure), preventing media wrinkling or tearing. The surface of the splicing roller or gripper is coated with an anti-slip and anti-scratch coating to prevent damage to the printing media and printout surface; additionally, the automatic paper splicing mechanism has a position adjustment function to adapt to printing media of different widths and thicknesses, improving equipment adaptability.

[0027] This embodiment uses a roller adsorption medium and multi-cycle sequential printing method, requiring only 1-2 printheads to achieve the thick ink stacking and multi-layer graphic printing effect of traditional multi-printhead printing, which greatly reduces equipment costs and maintenance complexity. Based on the linkage parameter preset and automatic paper receiving mechanism, it realizes the full continuous automation of material feeding, paper receiving, printing and material output, eliminating process interruptions caused by manual intervention and significantly improving production efficiency and finished product consistency.

[0028] Optionally, the control module monitors the actual number of rotations of the roller in real time, and triggers the automatic paper splicing mechanism to perform a splicing operation every N rotations.

[0029] Understandably, the control module has a built-in rotation count unit that collects and records the actual number of rotations of the roller in real time. Based on a preset total number of rotations N (N≥1) required for a single print job, the control module sets a rotation threshold – that is, when the roller accumulates N rotations, it is considered that a printing cycle for one print job is completed. At this point, the control module immediately outputs a trigger signal to activate the automatic paper splicing mechanism to perform the splicing operation. Here, the splicing operation refers to the feeding splicing unit smoothly connecting the blank new media conveyed by the feeding component to the roller surface, while the discharging splicing unit guides the printed product to the discharging end. The adsorption component briefly releases the product and re-adsorbs the new media, thus achieving a seamless switch between old and new media. This monitoring and triggering mechanism ensures precise synchronization between the feeding, splicing actions, and the number of roller print rotations, avoiding media waste or content misalignment caused by fixed-cycle feeding.

[0030] This embodiment achieves full automation and precise synchronization of the printing process by monitoring the actual number of rotations of the roller in real time and triggering the relay operation according to a preset N rotations. This eliminates the need for manual intervention and effectively prevents media waste and printing misalignment caused by mismatched rotation counts. This mechanism significantly improves the continuity and stability of the multi-rotation printing mode, providing a reliable guarantee for low-cost, high-efficiency mass production.

[0031] Optionally, in the ink layer thickness stacking mode, the printhead covers the entire target graphic area in each rotation, increasing the ink layer thickness through repeated printing.

[0032] Understandably, in the ink layer thickness stacking mode, the printhead performs a complete circumferential or pinpoint print in each rotation of the roller, covering the entire target graphic area. The target graphic area refers to the pre-defined planar range containing the graphics or text for which a thick ink effect is desired; its boundaries are determined by the control module based on the print file. The printhead strictly follows the same printing path and alignment standard as the first rotation in each revolution, repeatedly printing the same basic document content. Through multiple repeated prints, ink accumulates layer by layer in the same location, increasing the physical thickness of the ink layer and creating a thick, raised ink effect with a three-dimensional feel. During this process, the position calibration unit built into the control module monitors the relative position of the printhead and the roller in real time, ensuring precise overlap of the printed content in each rotation and avoiding misalignment or ghosting due to accumulated errors. The ink output in each rotation can be kept consistent or slightly adjusted according to the stacking requirements to ensure a uniform increase in ink layer thickness.

[0033] This embodiment achieves the thick ink layering effect that traditionally requires multiple printheads by printing the same content in each full-coverage loop, using multiple loops of one or two printheads. This significantly reduces equipment costs and printhead calibration difficulty. Because each loop has a completely consistent path and precise alignment, the ink layer thickness is uniform and controllable, and it can stably present raised images with a three-dimensional texture, meeting the special requirements of high-quality printing for ink layer thickness.

[0034] Optionally, in the layered graphic printing mode, the printhead prints the first layer of graphics in the first circle, the second layer of graphics in the second circle, and so on, until all layers are printed.

[0035] Understandably, in layered graphic printing mode, during the first rotation of the cylinder, the printhead prints the first layer of graphics and text according to a preset printing path. This constitutes the graphic, text, or color blocks that form the bottom layer or first layer of visual content in the finished product. After the first rotation, the cylinder continues to rotate for the second rotation. The printhead maintains the exact same printing path and alignment standard as the first rotation, printing the second layer of graphics and text. This second layer differs from the first layer and can be another layer of pattern or additional text information. This process continues, with each subsequent rotation corresponding to printing one independent layer of graphics and text until all layers are printed. Here, layered content refers to multiple pre-designed graphic and text layers that need to be stacked vertically. Each layer overlaps spatially but has different content, ultimately creating a three-dimensional, layered visual effect.

[0036] To ensure precise alignment of each print run, the control module's built-in position calibration unit resets to zero at the start of each run and compensates for minor offsets caused by mechanical tolerances or temperature variations by monitoring the relative position of the printhead and roller in real time. The ink output, grayscale parameters, and colors for each print run can be independently set according to layering requirements. For example, the first run can print a black background, the second run can print red text, and the third run can print a gold border, thus achieving rich color gradations and a three-dimensional effect.

[0037] This embodiment achieves the color layering printing effect that traditionally requires multiple printheads by printing different colored images and texts sequentially in different print runs, using a small number of printheads for multi-run sequence reuse. This significantly reduces equipment costs and printhead calibration complexity. Because the content of each run is independent and precisely aligned, the finished product presents a clear and stable three-dimensional effect with upper and lower layers, which can meet the application scenarios such as high-end packaging and anti-counterfeiting labels that have strict requirements for color layering and image overlay.

[0038] Optionally, when the automatic paper splicing mechanism adopts a flexible paper splicing roller structure, the adsorption component briefly releases the vacuum adsorption force before the finished product comes into contact with the new medium, and resumes adsorption after the new medium is fully adhered, thus achieving seamless switching of printing media; or, When the automatic paper splicing mechanism uses a toothed bar, the control module triggers the automatic paper splicing mechanism to perform splicing operations, including: the control module drives the clutch mechanism of the tooth-opening cam, so that the tooth-opening cam engages with the tooth-opening ball to complete one tooth opening and closing operation. The tooth opening and closing operation is performed once every N rotations of the roller, and the tooth-opening cam and tooth-opening ball remain separated in the remaining rotations.

[0039] Understandably, when the automatic paper splicing mechanism adopts a flexible paper splicing roller structure, the adsorption component can use a negative pressure suction method. Through a microporous array structure embedded in the roller surface and an internal negative pressure cavity, a continuous vacuum adsorption force is generated, tightly adhering the printing media to the outer wall of the roller. When the control module detects that the roller rotation reaches a preset value N, completes the printing of a single finished product, and triggers the automatic paper splicing mechanism's splicing operation, at the moment when the finished product and the next blank new medium are about to come into contact—that is, the moment when the feeding paper splicing unit guides the new medium to the roller surface and the dispensing paper splicing unit prepares to guide the finished product away—the control module instructs the adsorption component to briefly release the vacuum adsorption force. Here, "coming into contact" refers to the point in time when the end of the finished product and the front end of the new medium meet or alternate on the roller surface. After releasing the adsorption force, the finished product can be smoothly pulled away from the roller by the dispensing paper splicing unit, while the new printing medium adheres to the roller surface with the assistance of the feeding paper splicing unit. Once the new medium is fully spread and adhered in place, the adsorption component immediately restores the vacuum adsorption force, firmly fixing the new medium and achieving seamless switching of printing media. Seamless switching refers to the continuous completion of finished product output and new media input within the same drum rotation cycle, without interruption, manual intervention, media retention or idling.

[0040] When the automatic paper splicing mechanism uses a toothed roller, the control module triggers the automatic paper splicing mechanism to perform the splicing operation as follows: the control module drives the clutch mechanism of the tooth-opening cam, causing the tooth-opening cam to engage with the tooth-opening ball to complete one tooth opening and closing action. The roller performs one tooth opening and closing action every N rotations, while the tooth-opening cam and tooth-opening ball remain separated during the remaining rotations. Specifically, the tooth-opening cam is mounted on a sliding rail and can slide along the rail, which is fixed to the wall panel. The clutch mechanism uses pneumatic, electric, or electromagnetic drive to control the engagement and disengagement of the tooth-opening cam and tooth-opening ball. When the roller completes N rotations and a splicing operation is required, the clutch mechanism pushes the tooth-opening cam to move axially along the sliding rail, causing the tooth-opening cam to engage with the tooth-opening ball, driving the toothed roller to complete one tooth opening and closing action, releasing the finished product and engaging the new media. During the remaining N-1 rotations, the clutch mechanism keeps the tooth-opening cam and tooth-opening ball separated, and the toothed roller remains in a closed state, ensuring the media is stably fixed during printing. This embodiment achieves a customized paper feeding rhythm of opening and closing the teeth only once every N rotations of the roller through an axially disengaging tooth-opening cam structure, replacing the fixed mode of opening and closing the teeth once per rotation of the traditional roller, and perfectly adapting to multi-cycle printing scenarios.

[0041] This embodiment achieves a smooth alternation of finished product and new media on the roller surface through the two optional connection methods mentioned above—vacuum adsorption switching of the adsorption component or detachable opening and closing cam control of the tooth rack. This avoids the media adhesion or tearing problems caused by continuous adsorption in traditional methods. Regardless of whether an adsorption component or a tooth rack structure is used, the stability of continuous production cycles can be guaranteed, eliminating the need for manual intervention and significantly improving the level of automation and production efficiency in multi-turn printing scenarios.

[0042] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0043] In one embodiment, such as Figure 2 As shown, a rotary digital printing apparatus based on multi-turn sequential inkjet printing is provided, comprising: Roller 01, serving as the carrier of printing medium 05, can rotate multiple times around its central axis; Adsorption component 02 is embedded in the surface of the roller 01 and is used to firmly fix the printing medium 05 by negative pressure or magnetic attraction. One or two printheads 03 are arranged on the outer circumference of the roller 01 for circumferential scanning printing or fixed-point printing on the rotating medium. The control module is communicatively connected to the roller 01 and the print head 03, and is responsible for the coordinated operation of the printing components, the number of revolutions, and the position calibration. The feeding assembly 06 is located on the feeding side, and its feeding timing and frequency are precisely controlled by the control module according to the actual number of rotations of the roller 01. The automatic paper splicing mechanism includes a feeding paper splicing unit 07 and a discharging paper splicing unit 04, which are used to achieve smooth connection between the blank medium and the roller 01, and between the finished product and the discharge end.

[0044] Understandably, the core structure of the multi-rotation sequential inkjet printing roller 01 type digital printing device provided in this embodiment includes a roller 01, an adsorption component 02, 1-2 printheads 03, a control module, a feeding component 06, and an automatic paper splicing mechanism. The roller 01, as a media carrier, can rotate multiple times around its central axis. The adsorption component 02 is embedded in the surface of the roller 01, tightly fixing the printing medium 05 through negative pressure or magnetic attraction. 1-2 printheads 03 are arranged on the outer circumference of the roller 01, performing circumferential scanning inkjet printing or fixed-point inkjet printing on the rotating medium. The control module communicates with each component, responsible for coordinated linkage, rotation counting, and position calibration. The feeding component 06 is located on the feeding side, and its feeding timing and frequency are precisely controlled by the control module based on the actual number of rotations of the roller 01. The automatic paper splicing mechanism includes a feeding paper splicing unit 07 and an output paper splicing unit 04, used to achieve smooth connection between the blank medium and the roller 01, and between the finished product and the output end. The entire device uses a small number of printheads to print in a multi-cycle, sequential manner, combined with the linkage control of material feeding and paper splicing. This enables thick ink overlay, layered graphic printing, and fully automated continuous production, significantly reducing equipment costs and maintenance difficulty while ensuring printing accuracy and production efficiency.

[0045] Specifically, roller 01, serving as the carrier of printing medium 05, is a cylinder made of metal or high-strength composite material, capable of rotating multiple times around its central axis. Its smooth surface and precise dynamic balancing ensure stable operation within a preset speed range of 10–200 r / min. The number of rotations of roller 01 is monitored in real-time by the control module and is the core benchmark for determining the printing cycle and paper feeding rhythm.

[0046] The adsorption component 02 is embedded in the surface of the roller 01 and consists of a microporous array structure and an internal negative pressure chamber. It generates a uniform vacuum adsorption force through negative pressure suction, tightly adhering the printing medium 05 to the outer wall of the roller 01. The adsorption component 02 can flexibly switch adsorption methods according to the material of the printing medium 05: for thin media such as coated paper and waterproof film, negative pressure suction adsorption is used; for media with magnetic substrates or magnetic materials, it switches to magnetic adsorption, ensuring that all types of media are firmly fixed. This component ensures that the media and roller 01 rotate synchronously without relative displacement, which is a prerequisite for accurate multi-turn printing.

[0047] One or two printheads 03 are arranged around the outer circumference of the roller 01, allowing for multiple prints along the circumference of the roller 01 or fixed-position precision printing. The printheads utilize piezoelectric inkjet technology, and their ink output, printing speed, and printing accuracy can be flexibly adjusted according to printing needs: in ink layer overlay mode, the overlay thickness can be controlled by adjusting the ink output; in layer printing mode, different colors and grayscale levels can be output layer by layer by adjusting printing parameters. Through multi-cycle sequential printing, a single printhead can perform the ink layer overlay and layered image / text functions traditionally only available with multiple printheads.

[0048] The control module, as the central hub of the entire system, establishes electrical connections with the drive motor of roller 01, the valve of suction component 02, the drive board of printhead 03, the servo motor of feeding component 06, and the actuator of the automatic paper-receiving mechanism. Its built-in rotation count unit collects the actual number of rotations of roller 01 in real time, ensuring precise timing of the actions of feeding component 06 and the automatic paper-receiving mechanism, preventing premature or delayed feeding. The position calibration unit monitors the relative position of the printhead and roller 01 through encoders and photoelectric sensors, and automatically performs alignment calibration before each printing rotation to avoid defects such as misalignment and ghosting during multiple printing rotations. Based on preset linkage parameters, the control module triggers the feeding and paper-receiving actions every N rotations.

[0049] The feeding assembly 06 is located on the feeding side of the roller 01 and employs a swing-type, roller-type, or belt-type feeding structure. Its feeding timing and frequency are precisely controlled by the control module based on the actual number of rotations of the roller 01—feeding only begins after the required number of rotations for a single finished product has been completed, avoiding media waste caused by a fixed cycle. The feeding length and speed can also be dynamically adjusted according to the media material and printing speed. The actions of the feeding assembly 06 and the automatic paper splicing mechanism are strictly triggered by the control module based on the actual number of rotations of the roller 01. The paper splicing speed is precisely matched with the roller 01's rotation speed and feeding speed, ensuring complete synchronization of feeding, paper splicing, and printing rhythms, avoiding media waste, splicing, and printing misalignment.

[0050] The automatic paper splicing mechanism includes an infeed splicing unit 07 and an outfeed splicing unit 04, both employing flexible splicing rollers or toothed rollers with anti-slip and anti-scratch coatings to prevent damage to the printing media 05 and the finished product surface. They also feature position adjustment to accommodate printing media 05 of varying widths and thicknesses, enhancing equipment adaptability. The infeed splicing unit 07 smoothly guides the blank media conveyed by the feeding assembly 06 onto the surface of the roller 01, ensuring no deviation or jamming. The outfeed splicing unit 04 smoothly connects the printed finished product to the outfeed end, simultaneously coordinating with the brief release of the adsorption assembly 02 to achieve seamless switching between the finished product and new media. The two units work synchronously, with the splicing speed precisely matched to the roller 01's rotation speed and the feeding speed, preventing media wrinkling or tearing.

[0051] This embodiment achieves the thick ink overlay and layered graphic printing effects that traditionally require multiple printheads by using the coordinated operation of roller 01, adsorption component 02, printhead 03, control module, material feeding component 06, and automatic paper splicing mechanism. It achieves these effects through the multi-revolution timing reuse of 1-2 printheads, significantly reducing equipment costs and maintenance complexity. Based on the linkage control of the revolution count and the automatic paper splicing mechanism, it realizes the continuous automation of the entire process of material feeding, paper splicing, printing, and material output, eliminating process interruptions caused by manual intervention and significantly improving production efficiency and finished product consistency.

[0052] Optionally, the control module is configured to execute the following logic: based on the number of printing cycles N required for a single finished product, set the trigger cycle for the feeding and paper receiving actions to ensure that the feeding, paper receiving, and printing rhythms are completely synchronized.

[0053] Understandably, the control module is configured to execute the core logic: First, based on the printing requirements of a single finished product, obtain the number of printing revolutions N (N≥1) required for that single finished product. The number of printing revolutions required for a single finished product refers to the total number of revolutions that roller 01 must complete to finish a complete printed item (such as a label or a pattern), which determines the number of ink layer stacks or the number of layers to be printed. Based on this, the control module calculates and sets the trigger cycle for the feeding and paper receiving actions. This trigger cycle is defined as the number of revolutions that roller 01 should complete between two adjacent feeding actions (or paper receiving actions), and its value is equal to N. In other words, the built-in revolution counting unit of the control module monitors the actual number of revolutions of roller 01 in real time. Whenever the cumulative rotation reaches N revolutions, it is determined that a finished product has been printed, and simultaneously, the feeding component 06 is triggered to deliver new media, and the automatic paper receiving mechanism performs the feeding and discharging paper connection operations. In this way, the feeding and paper receiving actions are strictly linked with the printing process, ensuring that the rhythm of the three is completely synchronized—that is, the start time of feeding and the execution time of paper receiving coincide with the moment when roller 01 completes the Nth rotation, without any time deviation or fixed rhythm interference.

[0054] This embodiment, through this logical configuration, enables the control module to achieve precise matching of feeding, paper receiving, and printing rhythm, fundamentally solving the problems of media waste and content misalignment caused by mismatched cycle counts in traditional fixed-cycle feeding modes. This mechanism ensures the continuity and stability of the multi-cycle printing process, automatically completing the media switching for each finished product without manual intervention, significantly improving the equipment's production efficiency and automation level.

[0055] Optionally, the automatic paper splicing mechanism also includes a vacuum adsorption switching valve group disposed at both ends of the roller 01, which is used to briefly release the vacuum adsorption force at the finished product end when connecting a new medium; The automatic paper receiving mechanism includes a feeding paper receiving unit 07 and a discharging paper receiving unit 04, both of which adopt flexible paper receiving rollers or toothed bar structures. The opening and closing of the teeth of the tooth bar is controlled by an axially disengaging tooth-opening cam 012; the tooth-opening cam 012 is mounted on the sliding rail 014 and can slide along the axis of the roller 01, and is engaged or disengaged with the tooth-opening ball 011 through the clutch mechanism 013; when the roller 01 needs to perform a connecting operation, the tooth-opening cam 012 engages with the tooth-opening ball 011 to complete one tooth-opening and closing action, and in the remaining rotations, the tooth-opening cam 012 and the tooth-opening ball 011 remain disengaged, so that the roller 01 rotates N times before opening and closing the teeth once; the clutch mechanism 013 adopts a pneumatic, electric or electromagnetic drive method.

[0056] Understandably, the automatic paper splicing mechanism includes a feeding paper splicing unit 07 and a discharging paper splicing unit 04, both of which adopt flexible paper splicing rollers or toothed bar structures.

[0057] When the automatic paper splicing mechanism adopts a flexible paper splicing roller structure, it also includes a vacuum adsorption switching valve group located at both ends of the roller 01. This valve group consists of a set of solenoid valves and corresponding air passages, connected to microporous adsorption holes in different areas of the roller 01 surface. When the control module detects that the roller 01 has rotated to a preset value N and triggers the splicing operation, the vacuum adsorption switching valve group receives a control command and momentarily shuts off the adsorption channel corresponding to the area on the roller 01 carrying the finished product, thus briefly releasing the vacuum adsorption force at the finished product end. The finished product end refers to the local area on the roller 01 surface currently adsorbed with the printed finished product; the brief release refers to a very short release time (usually 0.1–0.5 seconds), just enough for the paper splicing unit 04 to smoothly pull the finished product off the roller 01 surface. Simultaneously, the area on the roller 01 carrying the new media maintains normal adsorption force, ensuring that the new media quickly adheres under the guidance of the feeding paper splicing unit 07. After the finished product is completely detached, the valve group reopens the air passage at the finished product end, restoring the vacuum adsorption force in that area, preparing for the fixation of the next piece of media.

[0058] like Figure 3a , 3b As shown in Figure 3c, when the automatic paper splicing mechanism adopts a toothed bar structure, the opening and closing of the toothed bar is controlled by the toothed bar opening cam 012, which can be axially disengaged. Figure 3a The illustration depicts a traditional fixed-position tooth-opening cam structure, where the tooth-opening cam is fixedly installed, and the opening and closing action is performed once for each rotation of the roller. In contrast, the tooth-opening cam 012 in this embodiment adopts a disengageable design, such as... Figure 3b and Figure 3cAs shown. The tooth-opening cam 012 is mounted on the sliding rail 014 and can slide along the axial direction of the roller 01. The sliding rail 014 is fixed to the wall plate 015. The tooth-opening cam 012 engages or disengages with the tooth-opening ball 011 through the clutch mechanism 013. The clutch mechanism 013 is pneumatically, electrically, or electromagnetically driven. When the roller 01 needs to perform a connection operation, the control module drives the clutch mechanism 013, causing the tooth-opening cam 012 to move axially along the sliding rail 014 and engage with the tooth-opening ball 011 to complete one tooth-opening and closing action, releasing the finished product and engaging the new medium. In the remaining rotations, the tooth-opening cam 012 remains separated from the tooth-opening ball 011, and the tooth row remains in a closed state, so that the roller 01 rotates N times before opening and closing the teeth once, replacing the fixed mode of the traditional roller 01 opening and closing the teeth once per rotation.

[0059] This embodiment achieves smooth alternation of finished product and new media on the surface of roller 01 through the two optional connection methods mentioned above—vacuum adsorption switching valve group or detachable opening cam 012. This avoids the problems of finished product sticking or tearing caused by continuous adsorption, as well as the stability problems caused by excessive opening and closing frequency in traditional opening methods. Regardless of whether the flexible paper receiving roller is used in conjunction with the adsorption component 02 or the tooth bar is used in conjunction with the detachable opening cam 012, the stability of continuous production cycle can be guaranteed, eliminating the need for manual peeling or intervention, and further improving the automation level and operational reliability in multi-turn printing scenarios.

[0060] Optionally, the number of printheads 03 is one, and the entire graphic and text printing of a single finished product is completed through multi-turn reflow; and / or, The adsorption component 02 is a microporous array structure distributed on the surface of the roller 01, which, together with the internal negative pressure cavity, achieves uniform adsorption of the medium.

[0061] Understandably, there can be only one printhead 03, arranged around the outer perimeter of roller 01. This single printhead completes the printing of all text and images for a single product through multi-return printing. Multi-return printing refers to the roller 01 rotating multiple times, with the printhead scanning and printing along the same fixed printing path in each revolution, replacing the parallel output of traditional multi-printhead printing through multi-return sequential cycles. In ink layer thickness stacking mode, the printhead repeatedly prints the same content in each revolution, achieving a gradual increase in ink layer thickness; in layered text and image printing mode, the printhead sequentially prints different text and image content in each revolution, achieving layered stacking of colors or patterns. The position calibration unit built into the control module ensures precise overlap of the printed content in each revolution, avoiding misalignment or ghosting.

[0062] Meanwhile, the adsorption component 02 is a microporous array structure distributed on the surface of the roller 01, which, together with the negative pressure cavity inside the roller 01, achieves uniform adsorption of the media. The microporous array structure refers to the regularly arranged micro-holes (typically with a diameter of 0.1–0.5 mm) on the surface of the roller 01. These microholes are connected to the negative pressure cavity inside the roller 01; the negative pressure cavity can be a sealed cavity structure inside the roller 01, maintaining a stable negative pressure environment through an external air extraction device. When the negative pressure cavity is working, airflow flows into the cavity through the microholes, forming a uniform adsorption force field on the surface of the roller 01, which flattens the printing media 05 against the outer wall of the roller 01 without relative displacement. This structure can adjust the negative pressure intensity according to the media material (such as paper, film, cloth, etc.) to adapt to different types of printing needs.

[0063] This embodiment achieves the thick ink overlay and layered graphic printing effects that traditionally require multiple printheads by using a single printhead with a multi-return printing strategy, significantly reducing equipment costs and printhead calibration difficulty. The adsorption structure combining the micropore array and the negative pressure chamber ensures the stable fixation of the medium during high-speed multi-return rotation, avoiding printing deviations and misregistration caused by medium displacement, and providing a reliable guarantee for high-quality and continuous production.

[0064] Optionally, a position calibration unit is also included to monitor the relative position of the printhead and roller 01 in real time to ensure accurate overlap of the printed content over multiple passes.

[0065] Understandably, the printing apparatus also includes a position calibration unit, which is integrated into the control module or communicates with the control module as a separate sensing component. The position calibration unit monitors the relative position of the printhead and roller 01 in real time. This relative position includes the spatial relationship in three dimensions: axial coordinates, circumferential angle, and vertical spacing between the printhead nozzle and the surface of roller 01, ensuring precise overlap of printed content across multiple rotations. Here, real-time monitoring refers to continuously acquiring position data at millisecond-level frequencies during the rotation of roller 01, rather than performing a single calibration at startup. The position calibration unit can employ a high-resolution rotary encoder mounted on the roller 01 shaft to provide real-time feedback on the angular displacement and angular velocity of roller 01; simultaneously, it works in conjunction with photoelectric sensors or linear encoders mounted on the printhead support to monitor the movement of the media along the circumference of roller 01. The control module fuses and calculates the above position data to generate the start trigger signal for each printing rotation, thereby eliminating accumulated errors caused by mechanical tolerances, temperature variations, or long-term wear.

[0066] This embodiment introduces a position calibration unit to achieve closed-loop control of the printhead and roller positions during multi-turn printing, ensuring that the printed content in each turn strictly overlaps in space, fundamentally avoiding quality problems such as misalignment and ghosting. This mechanism enables multi-turn sequential cyclic printing with a small number of printheads to achieve positioning accuracy far exceeding that of traditional multi-printhead parallel printing, providing a reliable guarantee for the high-quality realization of thick ink overlay and layered graphic printing.

[0067] Example 1: Ink layer thickness superposition mode (single printhead, 4 circles to print one finished product, material feeding and paper splicing are synchronized) This embodiment employs an inkjet roller printer, equipped with one printhead, a negative pressure suction roller, a roller feed assembly, an automatic paper receiving mechanism with a flexible paper receiving roller structure, and a control module. Coated paper is used as the printing medium to create thick, raised logo patterns, meeting the needs for high-efficiency, batch printing of advertising signs.

[0068] Linkage parameter preset: The control module is set to require the roller to rotate 4 times to complete the printing of a single finished product. The feeding component triggers a feeding action once every 4 rotations. The feeding and discharging units of the automatic paper receiving mechanism are linked synchronously, and the paper receiving speed is precisely matched with the roller speed (30r / min) and the feeding speed. At the same time, the printing accuracy of the print head is set to 600dpi to ensure printing clarity and thickness uniformity.

[0069] Media splicing and adsorption positioning: The control module activates the negative pressure adsorption component and the automatic paper splicing mechanism. The feeding component delivers the first blank coated paper to the feeding and splicing unit, which smoothly guides the coated paper onto the roller surface. Subsequently, the negative pressure adsorption component adsorbs and fixes it flat and without offset to the outer wall of the roller, ensuring that the coated paper rotates synchronously with the roller without relative slippage or positional displacement. The automatic paper splicing mechanism monitors the media status in real time to prevent jamming.

[0070] Basic pattern printing: The control module drives the roller to rotate at a constant speed of 30r / min for one revolution, while simultaneously controlling the print head to scan and print along a preset fixed path, completing the basic printing of the LOGO pattern (file 1) and ensuring that the underlying pattern is clear and complete. The automatic paper feeding mechanism remains in standby monitoring mode.

[0071] Multi-layer ink stacking: The roller continues to rotate at the same constant speed for the 2nd, 3rd, and 4th revolutions. The print head strictly follows the same printing path and alignment standard as the first revolution, repeatedly printing the LOGO pattern (File 1). Through the gradual stacking of 4 ink layers, the LOGO pattern forms a distinct thick ink raised effect, meeting the design requirements. The automatic paper splicing mechanism continuously monitors the media adhesion status to ensure no misalignment.

[0072] Material feeding and paper splicing linkage control: After the roller has rotated a total of 4 revolutions and completed the printing of a single finished product, the control module immediately triggers the material feeding component to deliver the next blank coated paper to the feeding and splicing unit. At the same time, the feeding and splicing unit smoothly connects the new blank coated paper to the roller surface, and the discharging and splicing unit smoothly guides the printed thick ink LOGO finished product to the discharging end, achieving continuous connection.

[0073] Continuous finished product output and cyclic operation: The adsorption component briefly releases its grip on the finished product, and the paper feeding unit smoothly conveys the finished product to the output end. The adsorption component then restarts, securing the new blank coated paper conveyed by the paper feeding unit, and the next finished product is printed. Repeating these steps enables continuous batch printing without process interruption, significantly improving production efficiency.

[0074] Example 2: Layered graphic printing mode (single printhead, 3 circles for printing one finished product, material feeding and paper splicing are synchronized) This embodiment uses an industrial digital roller printer, equipped with one printhead, a magnetic adsorption roller, a belt conveyor assembly, an automatic paper receiving mechanism with a flexible paper receiving roller structure, and a control module. The printing medium is PVC soft film, used for printing three-layer graphics (bottom layer pattern, middle layer text, and top layer logo), suitable for the high-efficiency batch printing needs of industrial signage.

[0075] Linkage parameter preset: The control module is set to require the roller to rotate 3 times to complete the printing of a single finished product. The feeding component triggers a feeding action once every 3 rotations. The automatic paper receiving mechanism is linked synchronously. The paper receiving speed is precisely matched with the roller speed (20r / min) to ensure that the feeding, paper receiving and printing rhythms are completely synchronized.

[0076] Media splicing and adsorption positioning: The feeding assembly delivers blank PVC film to the feeding splicing unit, which smoothly guides the film onto the roller surface. The control module activates the magnetic adsorption assembly to firmly adsorb and fix the PVC film onto the outer wall of the roller, adapting to the material characteristics of the film to prevent displacement during rotation. The automatic splicing mechanism monitors the splicing status in real time to ensure no jamming.

[0077] First printing cycle: The roller rotates at a constant speed of 20r / min for the first cycle, and the print head prints the underlying pattern (file 1) along the preset path, ensuring that the outline of the underlying pattern is clear and the position is accurate.

[0078] Second printing cycle: The roller continues to rotate at a constant speed for the second cycle. The print head maintains the same printing path and alignment standard as the first cycle, printing the middle layer text (Document 2), ensuring that the middle layer text is precisely aligned with the bottom layer pattern to form a preliminary layered effect. The automatic paper splicing mechanism continuously monitors the media adhesion status.

[0079] Third printing: The roller continues to rotate at a constant speed for the third time. The print head uses the same printing path and alignment standard to print the top layer logo (file 3), so that the bottom layer pattern, the middle layer text, and the top layer logo are precisely aligned to form a layered graphic effect with distinct layers and a strong three-dimensional effect.

[0080] Material feeding, paper splicing, and continuous finished product output: After the roller completes three rotations and a single finished product is printed, the control module triggers the material feeding assembly to deliver the next blank PVC film to the paper splicing unit. Simultaneously, the paper splicing unit smoothly attaches the new film to the roller surface, and the paper splicing unit smoothly guides the printed layered graphic product to the output end. The magnetic adsorption assembly briefly releases its adsorption force on the finished product; after the product detaches, it re-adsorbs a new film, entering the next printing cycle. Repeating these steps achieves continuous and efficient production without process interruption.

[0081] Example 3: Hybrid printing mode (two circles to print one finished product, thickened bottom layer + graphic top layer, material feeding and paper splicing are synchronized) This embodiment uses an outdoor sign inkjet roller printing device, equipped with one printhead, a negative pressure suction roller, a roller feed assembly, an automatic paper receiving mechanism with a flexible paper receiving roller structure, and a control module. The printing medium is a waterproof film, used to create composite outdoor signs with a "thick base + surface graphics" design. These signs are waterproof, wear-resistant, and have a strong three-dimensional effect, meeting the needs of high-efficiency mass production.

[0082] Linkage parameter preset: The control module is set to require the roller to rotate 2 revolutions to complete the printing of a single finished product. The feeding component triggers a feeding action every 2 revolutions. The automatic paper receiving mechanism is linked synchronously to ensure that the paper receiving, feeding and printing rhythm are completely consistent.

[0083] First printing cycle: The feeding and paper receiving unit smoothly connects the blank waterproof film conveyed by the feeding component to the surface of the roller. After the adsorption component fixes it, the roller rotates at a constant speed for the first cycle, and the printing nozzle prints the bottom layer pattern (file 1) along the preset path, completing the bottom layer printing.

[0084] Second round of mixed printing: The roller continues to rotate at a constant speed for the second round. The print head first repeats the printing of the bottom layer pattern (file 1) along the same path to thicken the bottom ink layer; then the printing content is switched and the top layer text (file 2) is printed along the same path to ensure that the top layer text is precisely aligned with the thickened bottom layer pattern, forming a composite three-dimensional effect of "thick bottom + surface graphics".

[0085] Material feeding, paper splicing, and finished product output are linked: After the roller completes two rotations, the control module triggers the material feeding assembly to deliver the next blank waterproof film to the feeding and splicing unit. The automatic paper splicing mechanism simultaneously completes the new film splicing and finished product output: the feeding and splicing unit smoothly splices the new film onto the roller surface, and the output splicing unit guides the printed composite label to the output end. The adsorption assembly briefly releases its adsorption force on the finished product; after the finished product detaches, it re-adsorbs the new film, entering the next printing cycle, achieving continuous and efficient production.

[0086] Example 4: Dual printhead extended application (printing one finished product in 2 rotations, with material feeding and paper splicing synchronized). This embodiment employs a multi-color roller printing device, equipped with two printheads of different colors, a negative pressure suction roller, a roller-type feeding assembly, an automatic paper-splitting mechanism with a flexible paper-splitting roller structure, and a control module. Colored cardstock is used as the printing medium to create multi-color layered graphics, enhancing the color gradation and visual effect of the graphics while achieving efficient continuous production.

[0087] Preset linkage parameters: The control module is set to require two rotations of the roller to complete printing for each finished product. The feeding component triggers a feeding action every two rotations, and the automatic paper receiving mechanism works in sync, with the paper receiving speed precisely matched to the roller speed (25r / min). Two printheads correspond to different colors for multi-color overlay printing.

[0088] First printing cycle: The paper feeding unit smoothly connects the blank color card paper conveyed by the feeding component to the surface of the roller. After the adsorption component fixes it, the roller rotates at a constant speed for the first cycle, and the first nozzle is controlled to print the bottom color pattern (file 1) along the preset path, completing the basic printing of the bottom color.

[0089] Second print: The roller continues to rotate at a constant speed for the second revolution, controlling the second printhead to print the top layer of colored text along the same path (File 2). The two printheads work together to achieve multi-color layered graphic effects, effectively replacing the multi-color parallel printing function of traditional multi-printhead printing.

[0090] Material feeding, paper splicing, and finished product output: After the roller completes two rotations, the control module triggers the material feeding assembly to deliver the next blank color cardstock to the paper splicing unit. The automatic paper splicing mechanism simultaneously completes the connection of the new cardstock and the output of the finished product: the paper splicing unit smoothly connects the new cardstock to the roller surface, and the paper splicing unit guides the printed multi-color layered graphic product to the output end. The adsorption assembly briefly releases its adsorption force on the finished product, and after the finished product detaches, it re-adsorbs the new cardstock, entering the next printing cycle. This embodiment further enriches the color layers of the graphics by using the time-series reuse of two printheads, while ensuring continuous production with the help of the automatic paper splicing mechanism, balancing print quality and production efficiency.

[0091] The modules in the aforementioned multi-turn sequential inkjet printing rotary digital printing device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0092] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0093] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A rotary digital printing method based on multi-turn sequential inkjet printing, characterized in that, include: Based on the total number of printing cycles N required for a single finished product, set the trigger cycle for the feeding action and the paper receiving action to ensure that the feeding rhythm, the paper receiving action and the number of roller rotations are synchronized. The printing media is guided and adsorbed onto the surface of the roller through an automatic paper splicing mechanism; Controlling 1-2 printheads to perform sequential cyclic printing during the multiple rotations of the drum effectively achieves the effect of parallel output from multiple printheads; Among them, the cyclic inkjet printing adopts at least one of the following modes: Ink layer thickness stacking mode: The roller rotates multiple times, and the print head repeatedly prints the same content on the same path, achieving a thick ink protrusion effect through ink layer stacking; Layered graphic printing mode: The roller rotates multiple times, and the printing nozzles print different graphic contents sequentially on the same path to achieve a three-dimensional effect of upper and lower layers; After a single print job is completed, the control module triggers the automatic paper splicing mechanism to perform a splicing operation: the feeding component delivers a new medium and the feeding paper splicing unit splices the new medium onto the roller, while the discharging paper splicing unit guides the finished product out. The adsorption component briefly releases the finished product and re-adsorbs the new medium, entering the next print cycle.

2. The roller-type digital printing method based on multi-turn sequential inkjet printing according to claim 1, characterized in that, The control module monitors the actual number of rotations of the roller in real time, and triggers an automatic paper splicing operation every N rotations.

3. The roller-type digital printing method based on multi-turn sequential inkjet printing according to claim 1, characterized in that, In the ink layer thickness superposition mode, the printhead covers the entire target graphic area in each rotation, increasing the ink layer thickness through repeated printing.

4. The roller digital printing method based on multi-turn sequential inkjet printing according to claim 1, characterized in that, In the layered graphic printing mode, the printhead prints the first layer of graphic in the first circle, the second layer of graphic in the second circle, and so on, until all layers are printed.

5. The roller-type digital printing method based on multi-turn sequential inkjet printing according to claim 1, characterized in that, When the automatic paper splicing mechanism adopts a flexible paper splicing roller structure, the adsorption component briefly releases the vacuum adsorption force before the finished product and the new medium come into contact, and resumes adsorption after the new medium is fully attached, thus achieving seamless switching of printing media. or, When the automatic paper splicing mechanism uses a toothed bar, the control module triggers the automatic paper splicing mechanism to perform splicing operations, including: the control module drives the clutch mechanism of the tooth-opening cam, so that the tooth-opening cam engages with the tooth-opening ball to complete one tooth opening and closing operation. The tooth opening and closing operation is performed once every N rotations of the roller, and the tooth-opening cam and tooth-opening ball remain separated in the remaining rotations.

6. A rotary digital printing apparatus based on multi-turn sequential inkjet printing, characterized in that, include: The roller, as the printing media carrier, can rotate multiple times around the central axis; An adsorption component, embedded in the surface of the roller, is used to firmly fix the printing medium by negative pressure or magnetic attraction; One or two printheads are arranged on the outer circumference of the roller for circumferential scanning printing or fixed-point printing on the rotating medium. The control module is communicatively connected to the roller and the print head, and is responsible for the coordinated operation of the printing components, the number of revolutions, and the position calibration. The feeding assembly, located on the feeding side, has its feeding timing and frequency precisely controlled by the control module based on the actual number of rotations of the drum. The automatic paper splicing mechanism includes a feeding splicing unit and a discharging splicing unit, which are used to achieve smooth connection between blank media and rollers, and between finished products and the discharge end.

7. The rotary digital printing apparatus based on multi-turn sequential inkjet printing according to claim 6, characterized in that, The control module is configured to execute the following logic: based on the number of printing cycles N required for a single finished product, set the trigger cycle for feeding and receiving paper actions to ensure that feeding, receiving, and printing rhythms are completely synchronized.

8. The rotary digital printing apparatus based on multi-turn sequential inkjet printing according to claim 6, characterized in that, The automatic paper splicing mechanism also includes a vacuum adsorption switching valve group located at both ends of the roller, which is used to briefly release the vacuum adsorption force at the finished product end when connecting a new medium. The automatic paper splicing mechanism includes a feeding paper splicing unit and a discharging paper splicing unit, both of which adopt flexible paper splicing rollers or toothed bar structures. The opening and closing of the teeth of the tooth bar is controlled by an axially disengaging tooth-opening cam; the tooth-opening cam is installed on a sliding track and can slide along the track, and is engaged or disengaged with the tooth-opening ball through a clutch mechanism; when the roller needs to perform a connecting operation, the tooth-opening cam engages with the tooth-opening ball to complete one tooth-opening and closing action, and the tooth-opening cam remains disengaged from the tooth-opening ball in the remaining rotations, so that the roller rotates N times before opening and closing the teeth once; the clutch mechanism adopts a pneumatic, electric or electromagnetic drive method.

9. The rotary digital printing apparatus based on multi-turn sequential inkjet printing according to claim 6, characterized in that, The number of printheads is one, and the entire graphic and text printing of a single finished product is completed through multi-turn reflow; and / or, The adsorption component is a microporous array structure distributed on the surface of the roller, which, together with the internal negative pressure cavity, achieves uniform adsorption of the medium.

10. The rotary digital printing apparatus based on multi-turn sequential inkjet printing according to claim 9, characterized in that, It also includes a position calibration unit, which monitors the relative position of the printhead and the roller in real time to ensure accurate overlap of the printed content over multiple passes.

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