Printing method, control method of printing apparatus, and printing apparatus

Abstract

There is provided a printing method including executing a plurality of processing cycles in which a printing image is printed on a substrate, in which the printing image used in each of the processing cycles is formed of a plurality of divided images, the plurality of divided images includes a first divided image printed at a first position of the substrate and a second divided image printed at a second position of the substrate, and the first divided image and the second divided image are generated in different processing cycles.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0119206, filed with the Korean Intellectual Property Office on September 3, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a printing method, a control method for a printing apparatus, and a printing apparatus, and more specifically, to a printing method, a control method for a printing apparatus, and a printing apparatus for manufacturing a display panel by discharging ink onto a substrate. Background Technology

[0004] Manufacturing display panels involves multiple processes. Generally, display panel manufacturing includes forming various functional layers on a glass substrate and using these layers to achieve the desired electrical and optical properties. Various technologies are used in this process, such as thin-film deposition, photolithography, etching, laser processing, and inkjet printing. Each process has a significant impact on the quality and performance of the display panel, and the precision of each process is crucial, especially in the manufacture of high-resolution and large-area displays.

[0005] To manufacture display panels, ink must be applied precisely to specific locations. This requires technology to eject ink as droplets onto a glass substrate at precise locations, and inkjet equipment is widely used in this process. Inkjet equipment converts ink into tiny droplets and precisely sprays the converted ink onto designated locations on the glass substrate.

[0006] However, when inkjet equipment prints on glass substrates, it uses the printed image for the corresponding operations. The printed image includes information such as the impact location of the ink droplets ejected from the substrate, the volume of the ink droplets, the type of ink, and the nozzles involved in the printing.

[0007] Generally, inkjet equipment tests each nozzle before printing begins. Then, a printed image is generated based on the nozzle's condition, and this image is used for printing. However, because printing does not occur before the printed image is generated in this process, it can increase the overall process time. This can be a factor reducing production efficiency, especially in situations requiring large-scale production.

[0008] In recent years, as display panel substrates have become larger and the requirements for process precision have increased, the time required to generate printed images has also increased significantly. Therefore, delays in the image generation process further increase the overall process time, which is a major factor hindering productivity. Summary of the Invention

[0009] The present invention aims to provide a printing method, a control method for a printing apparatus, and a printing apparatus that can effectively perform printing on a substrate.

[0010] The present invention also aims to provide a printing method, a control method for a printing apparatus, and a printing apparatus that can minimize the reduction in the number of substrates that can be processed per unit time while minimizing the reduction in the printing quality of the substrate.

[0011] The present invention also aims to provide a printing method, a control method for a printing apparatus, and a printing apparatus that minimizes the reduction in the number of substrates that can be processed per unit time, even when the time required to generate a printed image increases.

[0012] The purpose of this disclosure is not limited thereto, and other purposes not mentioned will be clearly understood by those skilled in the art from the following description.

[0013] An exemplary embodiment of the present invention provides a printing method comprising: performing a plurality of processing cycles, wherein in each of the plurality of processing cycles a printing image is printed on a substrate, wherein the printing image used in each of the plurality of processing cycles is formed from a plurality of segmented images, the plurality of segmented images including a first segmented image printed at a first location on the substrate and a second segmented image printed at a second location on the substrate, and the first segmented image and the second segmented image may be generated in different processing cycles.

[0014] According to an exemplary embodiment of the present invention, one of the first segmented image and the second segmented image used in the Nth processing loop can be generated in the (N-1)th processing loop, and N can be a natural number greater than or equal to 2.

[0015] According to an exemplary embodiment of the present invention, the other of the first segmented image and the second segmented image used in the Nth processing loop can be generated in the (N-2)th processing loop, and N can be a natural number greater than or equal to 3.

[0016] According to an exemplary embodiment of the present invention, the other of the first segmented image and the second segmented image used in the Nth processing loop can be generated in the Nth processing loop.

[0017] According to an exemplary embodiment of the present invention, the other of the first segmented image and the second segmented image can be generated when either the first segmented image or the second segmented image is printed.

[0018] According to an exemplary embodiment of the present invention, the printed image used in the Nth processing cycle further includes a third segmented image printed at a third position different from the first and second positions on the substrate. Any one of the first, second, and third segmented images used in the Nth processing cycle is generated in the (N-3)th processing cycle, another one of the first, second, and third segmented images used in the Nth processing cycle is generated in the (N-2)th processing cycle, and the remaining one of the first, second, and third segmented images used in the Nth processing cycle is generated in the (N-1)th processing cycle, where N can be a natural number greater than or equal to 4.

[0019] According to an exemplary embodiment of the present invention, each of the plurality of processing cycles may include: a test operation that tests a head unit having a plurality of nozzles to check the state of the nozzles, the plurality of nozzles discharging ink; a print image generation operation that generates at least one of a plurality of segmented images containing information about the nozzles involved in printing based on the state of the nozzles checked in the test operation; and a print operation that performs printing on a substrate using the print images.

[0020] According to an exemplary embodiment of the present invention, in each of the plurality of processing cycles, a print image generation operation and a printing operation may be performed after a test operation.

[0021] According to an exemplary embodiment of the present invention, in each of the plurality of processing cycles, the printing image generation operation and the printing operation can be performed in parallel.

[0022] An exemplary embodiment of the present invention provides a control method for controlling a printing apparatus, the printing apparatus comprising: a printing table; a conveying unit for conveying a substrate on the printing table; and a head unit for discharging ink onto the substrate conveyed by the conveying unit, the control method comprising: performing printing on the substrate by using a printing image composed of a combination of multiple segmented images that can be generated at different times.

[0023] According to an exemplary embodiment of the present invention, some of the plurality of segmented images are generated in a preparatory loop, which may be a loop prior to printing.

[0024] According to an exemplary embodiment of the present invention, the preparation loop may include a test operation of the test head unit and a print image generation operation of generating the entire print image.

[0025] According to an exemplary embodiment of the present invention, each processing cycle of printing on a substrate is performed multiple times, and in each processing cycle, a printed image is printed on the substrate, a portion of the plurality of segmented images used in the Nth processing cycle is generated in the N-2th processing cycle, and the remainder of these segmented images used in the Nth processing cycle is generated in the N-1th processing cycle, where N can be a natural number greater than or equal to 3.

[0026] According to an exemplary embodiment of the present invention, each processing cycle of printing on a substrate is performed multiple times, and in each processing cycle, a printed image is printed on the substrate, a first segmented image among a plurality of segmented images is generated in even-numbered processing cycles, and a second segmented image among these segmented images is generated in odd-numbered processing cycles.

[0027] According to an exemplary embodiment of the present invention, a portion of a plurality of segmented images is generated in a processing loop in which printing can be performed.

[0028] According to an exemplary embodiment of the present invention, each of the plurality of processing cycles may include: a test operation that tests a plurality of nozzles of a head unit to check the state of the nozzles; a print image generation operation that generates at least one of a plurality of segmented images based on the state of the nozzles checked in the test operation, the segmented images containing information about the nozzles involved in printing; and a printing operation that performs printing on a substrate using the print images.

[0029] An exemplary embodiment of the present invention provides a printing apparatus comprising: a printing table; a conveying unit for conveying a substrate on the printing table; a maintenance table disposed side-by-side with the printing table; a frame configured to extend along a direction in which the printing table and the maintenance table are placed; a head unit that travels along the extension direction of the frame and has a plurality of nozzles for discharging ink onto the substrate conveyed by the conveying unit; and a controller, wherein the controller prints a printed image onto the substrate by discharging ink through the nozzles of the head unit, wherein the printed image is formed by a plurality of segmented images, each of which contains information about the nozzles involved in the printing, and a first segmented image in this segmented image is generated at a first time, and a second segmented image in these segmented images can be generated at a second time different from the first time.

[0030] According to an exemplary embodiment of the present invention, the apparatus may further include a test unit disposed on a maintenance table and allowing the nozzles of the head unit to perform test discharges, wherein the controller evaluates the state of the nozzles based on the discharge results performed by the head unit to the test unit, and can select nozzles to participate in the printing of segmented images based on the evaluation results of the nozzle states.

[0031] According to an exemplary embodiment of the present invention, the controller generates a first segmented image and a second segmented image in two cycles prior to the cycle in which the printed image can be printed.

[0032] According to an exemplary embodiment of the present invention, the two cycles preceding the loop include a preparatory loop performed before the printed image can be printed.

[0033] According to exemplary embodiments of the present invention, printing can be performed efficiently on a substrate.

[0034] Furthermore, according to exemplary embodiments of the present invention, the reduction in the number of substrates that can be processed per unit time can be minimized while minimizing the reduction in the printing quality of the substrate.

[0035] Furthermore, according to an exemplary embodiment of the present invention, even when the time required to generate a printed image increases, the reduction in the number of substrates that can be processed per unit time can be minimized.

[0036] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the specification and drawings any effects not mentioned. Attached Figure Description

[0037] Figure 1 This is a schematic diagram illustrating a printing apparatus according to an exemplary embodiment of the present invention.

[0038] Figure 2 It is viewed from below. Figure 1 A schematic diagram of the nozzle plate at the head.

[0039] Figure 3 This is a flowchart illustrating a printing method according to an exemplary embodiment of the present invention.

[0040] Figure 4 It shows the execution Figure 3 A schematic diagram of the appearance of the printing apparatus used for the test operation.

[0041] Figure 5 and Figure 6 It shows the execution Figure 3 A schematic diagram of the appearance of the printing apparatus for the printing operation.

[0042] Figure 7This is a flowchart illustrating an existing N+0 type printing method.

[0043] Figure 8 This is a flowchart illustrating an existing N+1 type printing method.

[0044] Figure 9 This is a flowchart illustrating an N+1 / 2 type printing method according to an exemplary embodiment of the present invention.

[0045] Figure 10 It is a graph showing the number of defects that appear in the substrate according to the printing method.

[0046] Figure 11 This is a flowchart illustrating an existing N+1 / 3 type printing method.

[0047] Figure 12 This is a flowchart illustrating an N+1 / 2 type printing method according to another exemplary embodiment of the present invention.

[0048] Various features and advantages of the non-limiting exemplary embodiments of this specification will become more apparent upon reading the detailed description in conjunction with the accompanying drawings. The drawings are for illustrative purposes only and should not be construed as limiting the scope of the claims. Unless explicitly stated otherwise, the drawings are not to be considered as drawn to scale. For clarity, the dimensions of the drawings may be exaggerated. Detailed Implementation

[0049] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. The exemplary embodiments provided will make this disclosure thorough and will fully convey the scope to those skilled in the art. Numerous specific details (such as examples of specific components, apparatuses, and methods) are set forth to provide a thorough understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that the exemplary embodiments may be embodied in many different forms without requiring the specific details, and that the specific details and exemplary embodiments should not be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes, well-known apparatus structures, and well-known techniques have not been described in detail.

[0050] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “the” may be intended to include the plural forms. The terms “comprises”, “comprising,” “including,” and “having” are inclusive and therefore specifically refer to the presence of that feature, integer, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. Unless expressly identified as the order of execution, the method steps, processes, and operations described herein should not be construed as necessarily having to be performed in the specific order discussed or illustrated. It should also be understood that additional or alternative steps may be employed.

[0051] When an element or layer is referred to as “on another element or layer,” “attached to another element or layer,” “connected to another element or layer,” or “coupled to another element or layer,” the element or layer may be directly on, directly attached to, directly connected to, or directly coupled to the other element or layer, or there may be intermediate elements or layers present. Conversely, when an element is referred to as “directly on another element or layer,” “directly attached to another element or layer,” “directly connected to,” or “directly coupled to another element or layer,” there may be no intermediate elements or layers. Other terms used to describe relationships between elements should be interpreted similarly (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0052] Although the terms first, second, third, etc., may be used herein to describe different elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms unless otherwise stated. These terms may be used only to distinguish one element, component, region, layer, and / or segment from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms, as used herein, do not imply order or sequence. Therefore, without departing from the teachings of the exemplary embodiments, the first element, first component, first region, first layer, or first segment discussed below may be referred to as a second element, second component, second region, second layer, or second segment.

[0053] For ease of description, spatial relative terms such as “inside,” “outside,” “below,” “below,” “above,” and “above” are used herein to describe the relationship between one element or feature shown in the figures and another element or feature. Spatial relative terms may be intended to cover different orientations of the device in use or operation other than those described in the figures. For example, if the device in the figures is flipped, an element described as “below” or “below” other elements or features will subsequently be oriented “above” other elements or features. Thus, the example term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or oriented in other orientations), and the spatial relative descriptors used herein will be interpreted accordingly.

[0054] When the terms “same” or “identical” are used in the description of the example embodiments, it should be understood that some imprecision may exist. Therefore, when an element or value is said to be the same as another element or value, it should be understood that the element or value is the same as other elements or values ​​within the manufacturing or operational tolerance range (e.g., ±10%).

[0055] When the terms “approximately” or “substantially” are used with numerical values, it should be understood that the associated numerical value includes manufacturing or operational tolerances (e.g., ±10%) around the value. Furthermore, when the words “generally” and “substantially” are used with geometry, it should be understood that precision of the geometry is not required, but tolerance of the shape is within the scope of this disclosure.

[0056] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the example embodiments pertain. It should also be understood that terms (including those defined in common dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0057] In the following text, reference will be made to Figures 1 to 12 Exemplary embodiments of the present invention are described below.

[0058] Figure 1 This is a schematic diagram illustrating a printing apparatus according to an exemplary embodiment of the present invention.

[0059] refer to Figure 1According to an exemplary embodiment of the present invention, the printing apparatus 1 can eject ink onto a substrate G. The printing apparatus 1 can perform a film formation process by ejecting ink onto the substrate G. The printing apparatus 1 can perform printing by ejecting ink onto the substrate G. The printing apparatus 1 can be an inkjet device. The substrate G can be a glass substrate. A printed image IN (where N is an integer greater than or equal to 0), which will be described later, can be printed on the substrate G. The printing apparatus 1 can eject ink onto the substrate G to manufacture a quantum dot color filter.

[0060] The printing apparatus 1 may include a printing unit 10, a maintenance unit 20, a frame 30, a head unit 40, a controller 50, and a testing unit 60.

[0061] Printing unit 10 can be an area on substrate G where printing is performed. Printing unit 10 can include printing table 11 and transfer clamp 12 (example of a transfer unit). Substrate G can be loaded onto and / or unloaded from printing table 11. Printing table 11 can suspend substrate G by injecting air into the lower surface of substrate G. When the lower surface of substrate G is in direct contact with printing table 11, impurities such as particles may be generated due to contact. These impurities may adhere to the upper surface of substrate G, thereby degrading the quality of the manufactured display panel. To solve this problem, printing table 11 injects air into the lower surface of substrate G and separates the lower surface of substrate G from printing table 11.

[0062] The suspended substrate G can be held by a transfer gripper 12. The transfer gripper 12 can hold one side of the substrate G (and the opposite side if needed). The transfer gripper 12 can hold the lower part of the edge region of the substrate G in a vacuum adsorption method. The transfer gripper 12 can be configured to move along a second direction Y. The transfer gripper 12 can hold one side of the suspended substrate G and can move the substrate G along the second direction Y while moving along the second direction Y.

[0063] In the following text, the direction in which the substrate G is transferred via the transfer clamp 12 can be defined as the second direction Y. When viewed from above, the direction perpendicular to the second direction Y can be defined as the first direction X, and the direction perpendicular to the first direction X and the second direction Y can be defined as the third direction Z. The third direction Z can refer to the direction perpendicular to the ground.

[0064] The maintenance unit 20 can be arranged side-by-side with respect to the printing unit 10 in the first direction X. The maintenance unit 20 can perform maintenance on the head unit 40, described later, such as inspection, test discharge, purge discharge, cleaning, replacement, and repair. The maintenance unit 20 can have a structure and environment similar to the printing unit 10 as a whole. For example, the printing unit 10 and the maintenance unit 20 can be housed in the same package. An inert gas, such as nitrogen, can be supplied inside the package. That is, both the printing unit 10 and the maintenance unit 20 can be controlled using an inert gas atmosphere. In this way, the printing unit 10 and the maintenance unit 20 are controlled by the same or similar process environment because the maintenance unit 20 can perform test discharges, etc., to measure the performance of the head unit 40.

[0065] The maintenance unit 20 may include a maintenance table 21 having the same or similar shape and function as the printing table 11 described above, and a transfer plate 22 configured to be movable on the maintenance table 21. The maintenance table 21 may be arranged side by side with the printing table 11.

[0066] The conveyor plate 22 can be configured to be movable on the maintenance table 21 in a second direction Y and / or a first direction X. The conveyor plate 22 may have a mounting surface on which the test unit 60 is placed. The conveyor plate 22 can be moved in the first direction X and / or the second direction Y by an actuator (such as a motor, not shown). When the head unit 40 is positioned above the maintenance unit 20 for test discharge, the conveyor plate 22 can position the test unit 60 below the head unit 40.

[0067] The frame 30 may have a vertically extending section and a horizontally extending section. The vertically extending section may be located on the side of the printing table 11 of the printing unit 10 and on the side of the maintenance table 21 of the maintenance unit 20, respectively. The horizontally extending section may be provided above the printing table 11 and the maintenance unit 20. The horizontally extending section may extend along a first direction X along which the printing table 11 and the maintenance table 21 are located.

[0068] Additionally, the frame 30 may be equipped with a moving mechanism capable of moving the head unit 40. For example, the moving mechanism of the frame 30 may include a motor, a guide rail, a moving bracket that moves along the guide rail, etc. The head unit 40 can move along the first direction X via the moving mechanism. The head unit 40 can move between the printing unit 10 and the maintenance unit 20 via the frame 30. When the head unit 40 is above the printing unit 10, the printing process can be performed on the substrate G. Even when the head unit 40 is above the maintenance unit 20, maintenance such as inspection, test discharge, cleaning discharge, cleaning, replacement, and repair can be performed on the head unit 40.

[0069] The head unit 40 can discharge ink onto the substrate G. The head unit 40 can discharge ink onto the substrate G in the form of droplets. The ink discharged in the form of droplets can be referred to as ink droplets. The head unit 40 can discharge RGB inks such as red ink, green ink, and blue ink onto the substrate G, and alternatively, can discharge ink used to form a protective film on the substrate G.

[0070] The head unit 40 may include a housing 41, a plurality of heads 42 and a vision sensor 43.

[0071] The housing 41 can be coupled to a moving mechanism of the frame 30. The housing 41 can be a main body into which a head 42 is inserted and fixed. Multiple heads 42 can be inserted into and fixed to the housing 41. Each of the multiple heads 42 can have, for example... Figure 2 The nozzle plate NP is shown. Multiple nozzles N can be formed on each nozzle plate NP. Each nozzle N can discharge ink in the form of droplets. Each head 42 can be provided with a droplet discharge device, such as a piezoelectric element, to adjust the volume of a unit of ink in droplet form. The amount of ink discharged onto the substrate G can be adjusted by the current intensity applied to the piezoelectric element, the time period of the current applied to the piezoelectric element, etc.

[0072] Although Figure 2 The invention is shown to have 24 nozzles N formed in the nozzle plate NP, but it is not limited to this. For example, the number of nozzles N formed on each nozzle plate NP can be varied from tens to thousands.

[0073] review Figure 1 The vision sensor 43 can be mounted on one side of the housing 41. The vision sensor 43 can be a camera including illumination. The vision sensor 43 can acquire images of ink discharged onto the substrate G. The ink discharged onto the substrate G can be ink that is applied to the surface of the substrate G in droplet form or ink that falls to apply to the surface of the substrate G. The vision sensor 43 can acquire images that can examine the location and volume of the ink droplets discharged onto the substrate G. Additionally, the vision sensor 43 can collect images of ink discharged into the test unit 60, which will be described later. Therefore, the controller 50, described later, can check whether any of the nozzles N of the head unit 40 corresponds to a faulty nozzle.

[0074] The controller 50 controls the operation of the printing apparatus 1. The controller 50 can generate control signals for controlling the operation of the printing apparatus 1. The controller 50 may include: a process controller, which is composed of a microprocessor (computer) that executes the control of the printing apparatus 1; a user interface, which is composed of a keyboard, on which the operator performs command input operations to manage the printing apparatus 1; a display for visualizing and displaying the operating status of the printing apparatus 1; and a storage unit that stores control programs for executing processes performed in the printing apparatus 1 under the control of the process controller, or stores programs (i.e., processing schemes) for executing processes in various components according to various data and processing conditions. Additionally, the controller 50 may include a storage medium for storing programs for enabling the printing apparatus 1 to implement the printing method described later. The storage medium may be a portable disk such as a hard disk, CD-ROM, or DVD, or a semiconductor memory such as flash memory.

[0075] Test unit 60 can be provided on maintenance table 21. Test unit 60 can be mounted on maintenance table 21. Test unit 60 can provide test components. Test components can be test films or test substrates on which head unit 40 can perform test discharge. For example, test unit 60 can be configured to remove and retrieve test films using a roll-to-roll method. When head unit 40 is positioned above test unit 60, head unit 40 discharges ink in droplet form onto the test component provided by test unit 60. In addition, the state of each nozzle N of head unit 40 can be evaluated by the discharge results occurring on the test component (such as the presence or absence of ink, the location of ink application, and the volume of ink applied).

[0076] Figure 3 This is a flowchart illustrating a printing method according to an exemplary embodiment of the present invention. The printing method described below can be implemented by printing apparatus 1. Alternatively, the printing method described below can also be implemented by a control method for controlling printing apparatus 1. Furthermore, in order to implement the printing method described below, controller 50 can control components of printing apparatus 1.

[0077] For example, the controller 50 can control the components of the printing unit 10, maintenance unit 20, frame 30, and head unit 40 of the printing apparatus 1. Furthermore, in order to implement the printing method described below, the controller 50 can receive and analyze images of the ink discharge test component from the vision device 43, etc., to determine the test discharge result discharged to the test unit 60.

[0078] refer to Figure 3The printing method according to an exemplary embodiment of the present invention may include a preparatory cycle S00 and a plurality of processing cycles SN0 (N is a natural number greater than or equal to 1). The preparatory cycle S00 and the plurality of processing cycles SN0 may be executed sequentially.

[0079] The preparatory cycle S00 can be a cycle before the execution of the first processing cycle S10. Alternatively, the preparatory cycle S00 can be a cycle after the printing apparatus 1 is set up and before the execution of the first processing cycle S10.

[0080] Alternatively, the user may temporarily stop the operation of the printing apparatus 1 to process a preset number of substrates G, and then provide a pause time for the printing apparatus 1. The preparation cycle S00 may refer to the cycle after the pause time of the printing apparatus 1 and before the first processing cycle S10 is executed again.

[0081] Alternatively, the preparatory cycle S00 can also refer to a cycle executed after the processing scheme of the substrate G changes, prior to the first processing cycle S10 (which is the first processing cycle). For example, the change in the processing scheme of the substrate G may be due to a change in the type of substrate G to be printed on by the printing apparatus 1, a change in the printed image to be printed on the substrate G, a change in the type of ink discharged to the substrate G, or a change in the type of processing performed on the substrate G.

[0082] Processing cycle SN0 may include printing on substrate G. In each processing cycle SN0, printing can be completed on one substrate G. For example, the first substrate G can be printed in the first processing cycle S10, the second substrate G can be printed in the second processing cycle S20, and the Nth substrate G can be printed in the Nth processing cycle SN0. The first substrate G, the second substrate G, and the Nth substrate G may all refer to different substrates G.

[0083] Since each processing cycle SN0 contains printing operation SN4 (N is a natural number greater than or equal to 1), and the preparatory cycle S00 is the cycle that precedes the execution of processing cycle SN0, the possible difference is that the preparatory cycle S00 does not contain printing operation SN4 for substrate G.

[0084] Each of the preparatory loop S00 and the multiple processing loops SN0 may include a test operation SN1 (N is an integer greater than or equal to 0), a print path calculation operation SN2 (N is an integer greater than or equal to 0), and a print image generation operation SN3 (N is an integer greater than or equal to 0).

[0085] Figure 4 Is to show execution Figure 3 A schematic diagram of the appearance of the printing apparatus used for the test operation.

[0086] refer to Figure 3 and Figure 4 In test operation SN1, the head unit 40 can be moved in the first direction X via a moving mechanism disposed in the frame 30 and positioned above the maintenance unit 20. Subsequently, the conveyor plate 22 can move the test unit 60 below the head unit 40. In this operation, the head unit 40 can discharge test ink into the test unit 60 in the form of droplets. The test unit 60 provides a test component, which can be formed from a test film supplied and recovered in roll-to-roll form. The ink may affect the test component.

[0087] While the test is in progress, the vision device 43 acquires an image by photographing the ink applied to the test component. This image can be transmitted to the controller 50. The controller 50 can analyze the image transmitted by the vision device 43 to evaluate the state of each nozzle N included in the head unit 40. The state of each nozzle N can be graded according to specific criteria and managed by the controller 50.

[0088] For example, nozzles N that excel in all metrics, such as the presence or absence of ink, ink application location, and ink volume, can be managed as Grade A. Nozzles N excelling in two metrics can be managed as Grade B, those excelling in one metric as Grade C, and those with poor performance in all metrics as Grade D. This grading system can be crucial for systematically monitoring the status of each nozzle N and maintaining optimal print quality in subsequent printing processes. However, this grading is just one example, and grading criteria can vary considerably.

[0089] review Figure 3 After test operation SN1 is completed, printing path calculation operation SN2 can be executed. In printing path calculation operation SN2, the position, number, and application order of the printing path that can meet the user's requirements when the head unit 40 is printed on the substrate G can be calculated.

[0090] The length of the head unit 40 in the first direction X is less than the length of the substrate G in the first direction X. Therefore, multiple printing operations are required to complete printing on a substrate G using the head unit 40. The position of the head unit 40 changes each time printing is performed. Depending on the position of the head unit 40, the printing path on the substrate G changes. In other words, multiple printing operations using different printing paths are required to complete printing on a single substrate G. In the printing path calculation operation SN2, the number of printing paths required to complete printing on the substrate G, the positions of the printing paths, and the order in which the printing paths are applied are calculated.

[0091] Simultaneously, the position of the printing path can correspond to the printing position of the head unit 40. The position of the printing path can be determined based on the user-preset change in the unit position of the head unit 40. For example, when the user moves the position of the head unit 40 by a set unit distance, the value calculated by dividing the length of the substrate G in the first direction X by the set unit distance can be the maximum number of usable printing paths, and the positions of the corresponding printing paths spaced apart by the set unit distance can be the positions of the printing paths that can be applied in printing operation SN4.

[0092] Typically, the application sequence of the printing paths can be from one side of the substrate G to the other. The application sequence can also be from one edge of the substrate G to the other along the first direction X. However, the present invention is not limited to this. For example, considering that the relative edges of the substrate G have a relatively low chance of contributing to the printing of the head unit 40, and the central portion of the substrate G has a relatively high chance of contributing to the printing of the head unit 40, the application sequence of the printing paths can be determined by first applying the printing paths from the relative edges of the substrate G, and then applying the printing paths to the central portion of the substrate G.

[0093] The print path calculation operation SN2 can be implemented by a program stored in the recording medium of the controller 50. This program is an important software component for optimizing the print paths to be applied in the print operation SN4, and may include algorithms capable of calculating the number of print paths, the position of the print paths, and the order in which the print paths are applied. This program can be implemented by computer software and can calculate the print paths while considering various variables and conditions.

[0094] If necessary, the user can set the number of printing paths required for printing on the substrate G, the position of the printing paths, and the application order of the printing paths in the controller 50, and can omit the printing path calculation operation SN2.

[0095] In the printing image generation operation SN3, a printing image to be used in the printing operation SN4 can be generated. The printing apparatus 1 can print the printing image onto the substrate G.

[0096] As described above, printing on a substrate G can be performed multiple times. The sheet-like region of the substrate G printed on it through each printing path can be called a swath, and a printed image corresponding to each swath can be generated in the printed image generation operation SN3.

[0097] In the printing operation SN4 described later, a printed image can be printed onto the substrate G, which can be formed from multiple segmented images. Each of the multiple segmented images can correspond to a cross-section and a printing path as described above. In each cycle of the printed image generation operation SN3, at least one or more of the multiple segmented images can be generated.

[0098] The print image generation operation SN3 can be implemented by a program stored in the controller 50, and the process of generating the print image can be referred to as drawing. The segmented image generated in the print image generation operation SN3 may include information about the location of the ejected ink, the amount of ejected ink, the type of ejected ink, and the nozzles N involved in printing the corresponding print image. In this case, the information about the nozzles N involved in printing can be generated based on the status information of each nozzle N checked (evaluated) in the aforementioned test operation SN1.

[0099] For example, in test operation SN1, each nozzle N is classified into four levels, A, B, C, and D, based on criteria such as the presence or absence of ink, the location of ink application, and the volume of ink applied. Among the many nozzles N that can be used to print segmented images at various printing positions, nozzles N with higher levels can be preferentially selected and used for printing.

[0100] In some cases, parts requiring high print quality may only use Class A nozzle N, while parts requiring lower quality may use Class B or Class C nozzle N.

[0101] The segmented image generated in the print image generation operation SN3 includes recent state information about the nozzle N. More specifically, state information about the nozzle N tested in the test operation SN1 can be reflected in the segmented image generated in the print image generation operation SN3. For example, the segmented image generated in the print image generation operation S13 of the first cycle can reflect the state information of the nozzle N tested in the test operation S11 of the first cycle.

[0102] Figure 5 and Figure 6 It shows the execution Figure 3 A schematic diagram of the appearance of the printing apparatus for the printing operation.

[0103] refer to Figure 5 and Figure 6 In printing operation SN4 of the present invention, printing can be performed on the substrate G through at least one printing path. For example, printing can be performed through multiple printing paths in printing operation SN4. Figure 5 The diagram shows the printing apparatus 1 performing printing on the substrate G via a first printing path, and... Figure 6 The illustration shows the printing apparatus 1 performing printing on the substrate G via a second printing path. Printing can be achieved using the printing image generated in the aforementioned printing image generation operation SN3. Each corresponding segmented image can be used when printing is performed for each printing path.

[0104] Printing operation SN4 can be performed in printing unit 10, and during printing operation SN4, head unit 40 can be located above printing unit 10.

[0105] In printing operation SN4, when the head unit 40 performs printing via the first printing path, the head unit 40 can be positioned at the first printing position. In this case, the substrate G can pass through the area below the head unit 40 located at the first printing position and is conveyed by the transfer holder 12. As the substrate G passes through the area below the head unit 40, the nozzle N provided by the head unit 40 discharges ink onto the substrate G. When the head unit 40 performs printing via the second printing path, the head unit 40 can be positioned at the second printing position. The second printing position can be a position different from the first printing position, and at this position, the substrate G can also pass through the area below the head unit 40. At this time, the substrate G is also conveyed by the transfer holder 12, and as the substrate G passes through the area below the head unit 40, the nozzle N of the head unit 40 discharges ink.

[0106] Furthermore, the transport direction of the substrate G when printing via the first printing path and the transport direction of the substrate G when printing via the second printing path can be opposite to each other. For example, when printing via the first printing path, the substrate G moves forward along the second direction Y, and when printing via the second printing path, the substrate G can move backward along the second direction Y. This method accurately forms the desired pattern on the substrate G using various printing paths and can help improve the flexibility and accuracy of the printing process.

[0107] Figure 7 This is a flowchart illustrating an existing N+0 type printing method.

[0108] refer to Figure 7In the N+0 type printing method, the head unit 40 is tested, and a printed image IM of the entire area of ​​the substrate is generated by drawing based on the state of the nozzle N obtained from the test. In this case, the printed image IM is formed by multiple segmented images. Then, the printed image IM generated in the corresponding processing cycle is printed onto the substrate G.

[0109] In the N+0 type printing method, a printed image IM for the entire area of ​​the substrate G is generated based on the test results of the head unit 40, and the generated printed image IM is directly printed onto the substrate G. In other words, the N+0 type printing method is most advantageous in ensuring a high level of print quality because the latest status information of the nozzle N can be reflected in the printed image IM. However, since printing cannot be performed on the substrate G after the test of the head unit 40 is completed until the printed image IM is drawn, it is very disadvantageous in terms of the number of substrates that can be processed per unit time.

[0110] To solve the above problems, the N+1 type printing method can be considered.

[0111] Figure 8 This is a flowchart illustrating an existing N+1 type printing method.

[0112] refer to Figure 8 In the N+0 type printing method, a printed image IMN (where N is an integer greater than or equal to 0) of the entire area of ​​the substrate G is generated by drawing based on the state of the nozzle N obtained through corresponding tests. In this case, the printed image IMN is formed by multiple segmented images, and a printed image IMN for printing in the next processing cycle is generated. Then, the generated printed image IMN is printed on the substrate G in the next processing cycle. Printing is performed on the substrate G simultaneously with the generation of the printed image IMN.

[0113] For example, in the preparatory operation, the head unit 40 is tested, and a printing image IM0 is drawn by reflecting the state of the nozzle N through the test. Thus, the printing image IM0 is generated.

[0114] Subsequently, in the first processing cycle, the head unit 40 is tested, and a printed image IM1 is drawn by testing the state of the nozzle N. While drawing the printed image IM1, the head unit 40 prints the printed image IM0 generated in the preparatory cycle onto the substrate G.

[0115] Subsequently, in the second processing cycle, the head unit 40 is tested, and a printed image IM2 is drawn by testing the state of the nozzle N. While drawing the printed image IM2, the head unit 40 prints the printed image IM1 generated in the first processing cycle onto the substrate G.

[0116] Compared to the N+0 type printing method, the N+1 type printing method uses a printed image IMN that already reflects the state information of nozzle N in the previous cycle. This N+1 type printing method has some drawbacks in ensuring print quality. However, although it prints a printed image IMN that already reflects the state information of nozzle N in past cycles, it also prints a printed image IMN that reflects the state information of nozzle N immediately following the previous cycle, so the print quality may not decrease significantly. Furthermore, it has an advantage in terms of the number of substrates that can be processed per unit time because the drawing of the printed image IMN and the printing of the printed image IMN on the substrate G can be performed in parallel. In other words, the advantage of the N+1 type printing method is that it minimizes the reduction in the number of substrates that can be processed per unit time without significantly reducing print quality.

[0117] However, due to the large area of ​​the substrate G and the high resolution of the printed image required for high-level printing quality, the time required to generate the printed image increases significantly. In other words, because the time required to draw the printed image increases dramatically, printing on the substrate G must be stopped until the drawing is complete, even when using the N+1 type printing method. For example, a second processing cycle of printing may be required, but the drawing of the printed image at the beginning of the first processing cycle may not yet be complete.

[0118] The present invention provides a printing method, a control method for a printing apparatus, and a printing apparatus for solving the problems that may occur when applying the above-mentioned N+0 and N+1 type printing methods.

[0119] Figure 9 This is a flowchart illustrating an N+1 / 2 type printing method according to an exemplary embodiment of the present invention.

[0120] refer to Figure 9 In the N+1 / 2 type printing method, the region of the substrate G is divided into 1 / 2 sections. Furthermore, in each processing loop SN0, the printing image is drawn only for the divided region. The description of the printing path calculation operation SN2 will be omitted below.

[0121] In the preparation cycle S00, the test operation S01 and the print image generation operation S03 are performed to generate a pre-printed image I0. The pre-printed image I0 can be a print image for the entire area of ​​the substrate G, and can be formed by multiple segmented images.

[0122] In the first processing loop S10, the test operation S11 and the printed image generation operation S13 are performed. In the printed image generation operation S13, a first segmented image I1 can be generated (drawn), which is a printed image corresponding to the division of the first region of the substrate G by 1 / 2.

[0123] The first segmented image I1 can be an image printed at a first position (also called an odd position) on the substrate G. In this case, in parallel with the printing image generation operation S13, the pre-printed image I0 can be printed on the substrate G in the printing operation S14.

[0124] In the second processing loop S20, the test operation S21 and the printed image generation operation S23 are performed. In the printed image generation operation S23, a second segmented image I2 can be generated (drawn). This second segmented image I2 is a printed image corresponding to a second region, which is another region divided into 1 / 2 of the substrate G. The second segmented image I2 can be an image printed at a second position (also referred to as an even-numbered position) different from the first position on the substrate G.

[0125] In this case, in parallel with the printing image generation operation S23, in the printing operation S24, a portion of the pre-printed image I0 generated in the preparatory operation S00 and the printed image composed of the first segmented image I1 can be printed on the substrate G.

[0126] In the third processing loop S30, the test operation S31 and the printed image generation operation S33 are performed. In the printed image generation operation S33, a third segmented image I3 can be generated (drawn). This third segmented image I3 is a printed image corresponding to the first region, which is another region divided into 1 / 2 of the substrate G. The third segmented image I3 can be an image printed at a first position (also referred to as an odd position) on the substrate G. Except for information about the nozzles N involved in printing, the third segmented image I3 can be the same as the first segmented image I1 described above. In some cases, the third segmented image I3 can also be referred to as the first segmented image.

[0127] In this case, in parallel with the printing image generation operation S33, the printing image formed by the first segmented image I1 and the second segmented image I2 can be printed on the substrate G in the printing operation S34.

[0128] In the fourth processing cycle S40, the test operation S41 and the printed image generation operation S43 are performed. In the printed image generation operation S43, a fourth segmented image I4 can be generated (drawn). This fourth segmented image I4 is a printed image corresponding to the second region, which is another region divided into 1 / 2 of the substrate G. The fourth segmented image I4 can be an image printed at a second position (also referred to as an even-numbered position) on the substrate G. Except for information about the nozzles N involved in printing, the fourth segmented image I4 can be the same as the second segmented image I2 described above. In some cases, the fourth segmented image I4 can also be referred to as the second segmented image.

[0129] In this case, in parallel with the printing image generation operation S43, the printing image formed by the second segmented image I2 and the third segmented image I3 can be printed on the substrate G in the printing operation S44.

[0130] The N+1 / 2 type printing method repeats the above process. When the area of ​​the substrate G is divided into 1 / 2, the segmented images corresponding to the first and second positions appear alternately in odd and even numbers, which has the technical advantage of solving the problem of smudges in the printing results.

[0131] In this invention, the printed image used in the printing operation is formed from multiple segmented images. Further, the multiple segmented images include a first segmented image, a second segmented image, a third segmented image, a fourth segmented image, and so on, and each of the multiple segmented images can be generated at different times (different cycles, where the cycles include not only the processing cycle S00 but also the preparation cycle S00). For example, the first segmented image can be generated in the first processing cycle S10, the second segmented image can be generated in the second processing cycle S20, and the third segmented image can be generated in the third processing cycle S30.

[0132] In other words, at least some of the segmented images used in the Nth processing loop, which are included in the printed image, can be generated in other loops.

[0133] As in the exemplary embodiment of the present invention, since the area of ​​the substrate G is divided into 5 / 6 segments, and the segmented image corresponding to 5 / 6 of the substrate G is drawn only in each processing loop SN0, the time required to generate the image can be significantly reduced. Therefore, the problem of not being able to start the printing operation SN4 while drawing the image can be effectively solved. This method can effectively address the increased drawing time caused by the large area of ​​the substrate G and the high resolution of the printed image.

[0134] Furthermore, in the N+1 / 2 type printing method of the present invention, a printing image is formed by combining the segmented image generated by the previous cycle with the preceding cycle of the previous cycle, and printing is performed on the substrate G based on the formed printing image. In this way, it is confirmed that even when using the segmented image generated by the preceding cycle of the previous cycle, the printing quality of the substrate G does not significantly decrease.

[0135] Figure 10 It is a chart showing the number of defects that appear in the substrate depending on the printing method.

[0136] Figure 10This diagram illustrates the number of defects appearing on substrate G during the generation and printing of a printed image onto substrate G, depending on the number of substrates G processed. The number of defects can be interpreted in various ways, such as the number of particles, spots, irregularities, incorrect ink placement, and the number of ink droplets on substrate G with sizes differing from the set values.

[0137] refer to Figure 10 When printing is performed using the N+0 type printing method, that is, when printing is performed using the printed image generated in the current cycle, the N+0 type printing method exhibits the lowest defect level.

[0138] When printing is performed using the N+1 type printing method, that is, printing using the printed image generated by the loop prior to the first loop, the N+1 type printing method exhibits a relatively high defect level compared to the N+0 type printing method, but shows a stable overall defect level.

[0139] When printing is performed using the N+2 type printing method, that is, printing using the printing images generated two cycles prior, the N+2 type printing method exhibits a relatively high level of defects compared to the N+0 and N+1 type printing methods, but exhibits a stable overall level of defects.

[0140] When printing is performed using the N+3 type printing method, that is, printing using the printing images generated three cycles prior, the N+3 type printing method exhibits a relatively high level of defects compared to the N+0, N+1, and N+2 type printing methods.

[0141] In summary, considering the overall tact time and defect patterns, stable inking was observed up to the images generated in the loops preceding the second loop.

[0142] Therefore, according to an exemplary embodiment of the present invention, the first segmented image that can be used in the Nth processing loop SN0 can be generated in the (N-2)th loop, and the second segmented image can be generated in the (N-1)th loop. Here, N is an integer greater than or equal to 3.

[0143] In other words, the present invention segments the substrate G region and draws the printed image only for each segmented region in each processing loop SN0. Therefore, the time required to draw the printed image in each processing loop SN0 can be significantly reduced. Furthermore, even if the controller 50 does not use a GPU or similar device to perform high-speed drawing operations, it can efficiently generate the printed image within a certain cycle time.

[0144] Furthermore, the present invention can even minimize the degradation of the printing quality of the substrate G by using an image generated in a cycle prior to the second cycle when printing is performed on the substrate G.

[0145] Additionally, when a segmented image is reused multiple times, the old segmented image may not reflect the latest state of the nozzle N. However, the present invention solves the problem of excessively long usage time of images corresponding to specific regions by segmenting the area of ​​the substrate G and generating segmented images printed in the segmented areas in sequence.

[0146] In the above example, an N+1 / 2 type printing method for dividing the region of substrate G into 1 / 2 sections was described, but the present invention is not limited thereto.

[0147] For example, such as Figure 11 As shown, an N+1 / 3 type printing method in which the area of ​​substrate G is divided into 1 / 3 sections can also be considered.

[0148] In this case, the printed image used in the Nth processing cycle SN0 may include a first segmented image printed at a first position on the substrate G, a second segmented image printed at a second position, and a third segmented image printed at a third position.

[0149] The first segmented image can be generated in the (N-3)th processing loop, the second segmented image can be generated in the (N-2)th processing loop, and the third segmented image can be generated in the (N-1)th processing loop. Here, N is an integer greater than or equal to 4.

[0150] In addition, not only are cases of dividing the region of substrate G into 1 / 2, 1 / 3, etc., considered, but cases of dividing the region of substrate G into 1 / N (N is a natural number greater than 2) can also be considered.

[0151] In the above example, the present invention is described based on the case that the printed image used in the Nth processing loop SN0 is formed only by segmented images generated in the loops preceding the current loop (such as the N-1th loop and the N-2th loop, etc.), but the present invention is not limited thereto.

[0152] For example, such as Figure 12 As shown, the printed image used in the Nth processing loop SN0 can be formed from the segmented images generated by the (N-1)th loop and the Nth loop (the current loop).

[0153] It should be understood that the embodiments disclosed herein are exemplary and other variations are possible. Individual elements or features of a particular exemplary embodiment are generally not limited to that particular exemplary embodiment, but are interchangeable and may be used in selected exemplary embodiments where applicable, even if not specifically described or illustrated. These modifications should not be considered as departing from the spirit and scope of the invention, and all modifications that are obvious to those skilled in the art are intended to be included within the scope of the appended claims.

Claims

1. A printing method, the printing method comprising: performing a plurality of processing cycles, wherein a print image is printed on a substrate in each of the plurality of processing cycles, wherein the print image used in each of the plurality of processing cycles is formed from a plurality of split images, the plurality of split images include a first split image printed at a first location of the substrate and a second split image printed at a second location of the substrate, and the first split image and the second split image are generated in different processing cycles.

2. The printing method according to claim 1, wherein, one of the first split image and the second split image used in an Nth processing cycle is generated in an (N-1)th processing cycle, and N is a natural number greater than or equal to 2.

3. The printing method according to claim 2, wherein, the other of the first split image and the second split image used in the Nth processing cycle is generated in an (N-2)th processing cycle, and N is a natural number greater than or equal to 3.

4. The printing method according to claim 2, wherein, the other of the first split image and the second split image used in the Nth processing cycle is generated in the Nth processing cycle.

5. The printing method according to claim 4, wherein, the other of the first split image and the second split image is generated while any one of the first split image and the second split image is printed.

6. The printing method according to claim 1, wherein, the print image used in the Nth processing cycle further includes a third split image printed at a third location different from the first location and the second location of the substrate, any one of the first split image, the second split image, and the third split image used in the Nth processing cycle is generated in an (N-3)th processing cycle, the other of the first split image, the second split image, and the third split image used in the Nth processing cycle is generated in an (N-2)th processing cycle, and the remaining one of the first split image, the second split image, and the third split image used in the Nth processing cycle is generated in an (N-1)th processing cycle, where N is a natural number greater than or equal to 4.

7. The printing method according to claim 1, wherein, each of the plurality of processing cycles includes: a test operation of testing a head unit having a plurality of nozzles to check a state of the plurality of nozzles, the plurality of nozzles discharging ink; a print image generation operation of generating a print image of at least one of a plurality of split images based on the state of the plurality of nozzles checked in the test operation, the plurality of split patterns containing information on nozzles involved in printing; and a print operation of performing printing on the substrate by using the print image.

8. The printing method according to claim 7, wherein, in each of the plurality of processing cycles, the print image generation operation and the print operation are performed after the test operation.

9. The printing method according to claim 8, wherein, in each of the plurality of processing cycles, the print image generation operation and the print operation are performed in parallel.

10. A control method of a printing apparatus, the printing apparatus includes: a printing stage; a conveyance unit for conveying a substrate on the printing stage; and a head unit for discharging ink to the substrate conveyed by the conveyance unit, ​ The control method includes performing printing on the substrate by using a print image that is combined from a plurality of divided images generated at different times.

11. The control method according to claim 10, wherein Some of the plurality of divided images are generated in a preparatory cycle that is a cycle before the printing is performed.

12. The control method according to claim 11, wherein The preparatory cycle includes a test operation of testing the head unit and a print image generation operation of generating an entire print image.

13. The control method according to claim 10, wherein Each of a plurality of processing cycles in which the printing on the substrate is performed is executed, and in each of the processing cycles, a print image is printed onto the substrate, A part of the plurality of divided images used in an Nth processing cycle is generated in an N-2th processing cycle, The rest of the plurality of divided images used in the Nth processing cycle is generated in an N-1th processing cycle, where N is a natural number that is greater than or equal to 3.

14. The control method according to claim 10, wherein Each of a plurality of processing cycles in which the printing on the substrate is performed is executed, and in each of the processing cycles, a print image is printed onto the substrate, In an even-numbered processing cycle, a first divided image of a plurality of divided images is generated, and In an odd-numbered processing cycle, a second divided image of the plurality of divided images is generated.

15. The control method according to claim 10, wherein A part of the plurality of divided images is generated in a processing cycle in which the printing is performed.

16. The control method according to claim 13, wherein Each of the plurality of processing cycles includes: a test operation of testing a plurality of nozzles of the head unit to check a state of the plurality of nozzles; a print image generation operation of generating at least one of a plurality of divided images based on the state of the plurality of nozzles checked in the test operation, the divided image containing information on nozzles involved in printing; and a printing operation of performing printing on the substrate by using a print image.

17. A printing apparatus, the printing apparatus comprising: a printing stage; a conveyance unit for conveying a substrate on the printing stage; and a maintenance stage disposed side by side with the printing stage; a rack configured to extend in a direction in which the printing stage and the maintenance stage are disposed; a head unit that travels in a direction in which the rack extends and has a plurality of nozzles that discharge ink to the substrate conveyed by the conveyance unit; and a controller, wherein the controller is configured to print a print image onto the substrate by the nozzles of the head unit discharging ink, wherein the print image is formed from a plurality of divided images, each of the plurality of divided images contains information on nozzles involved in printing, and a first divided image of the plurality of divided images is generated at a first time, and a second divided image of the plurality of divided images is generated at a second time different from the first time. The printing apparatus further comprises:

18. The printing device of claim 17, wherein, a test unit disposed on the maintenance stage and allowing the plurality of nozzles of the head unit to perform a test discharge, ​ The controller is configured to evaluate states of the plurality of nozzles based on a result of the discharge to the test unit performed by the head unit, and to select a nozzle to participate in printing of the divided image based on a result of the evaluation of the states of the plurality of nozzles.

19. The printing device of claim 17, wherein, The controller is configured to generate the first divided image and the second divided image within two cycles before a cycle in which the print image is printed.

20. The printing device of claim 19, wherein, The two cycles before the cycle include a preparatory cycle performed before the print image is printed.

Images