KR20230047306A - Method for determining print path, program for executing method for determining print path and printing method - Google Patents

Abstract

The present invention provides a method for determining print paths to be applied when discharging the ink on a substrate so that the substrate can be processed efficiently. According to the present invention, the method for determining print paths comprises: a substrate information receiving step of receiving substrate information of a substrate; a head information receiving step of receiving head information of a head ejecting the ink; and a print path determination step of determining print paths based on the substrate information and the head information. In the print path determination step, the smallest number of print paths that meet target print conditions for the substrate may be determined.

Description

Print path determination method, program for executing the print path determination method, and printing method

The present invention relates to a printing path determination method applied to an inkjet printing process, a program stored in a medium for executing the printing path determination method, and a printing method.

In recent years, display elements such as liquid crystal display elements, organic EL display elements, and the like are required to have high resolution. In order to manufacture a display device having a high resolution, more pixels per unit area must be formed on a substrate, and in a display device manufacturing process, it is important to accurately eject ink to each of the densely arranged pixels. Display device manufacturing time increases as the required level of precision in a display device manufacturing process increases. Accordingly, the number of display elements that can be manufactured per unit time is reduced.

Meanwhile, the process of discharging ink to each of the aforementioned pixels (so-called printing process) is performed by an inkjet device that discharges ink in the form of droplets. An inkjet device includes a head, and the head includes nozzles for ejecting ink. When the position of the head is determined, glass, which is an object to which ink is ejected, is moved to a lower region of the head. While ink is ejected from the nozzle of the head, the glass passes through the lower area of the head.

In addition, glass is composed of a plurality of pixels, which are printing units. Each pixel has the required amount of droplets to complete the printing process. The required amount of droplets may all be different. Accordingly, in the printing process, the head discharges ink to satisfy the amount of droplets required by each pixel while the glass passes through the lower region of the head. The amount of liquid crystal discharged by the head is smaller than or equal to the amount of liquid crystal required by the pixel. Therefore, the printing process cannot be completed by passing the glass through the lower region of the head once. When the glass passes through the lower region of the head, the position of the head is changed (that is, the printing path is continuously changed), and when the glass passes through the lower region of the head, the nozzle ejects ink to the glass several times. Repeat to complete the printing process. That is, a plurality of printing paths must be applied to complete the printing process.

In general, a printing path applied to a printing process is implemented by sequentially moving the position of a head by a specific interval. For example, when the head is positioned in the first position during the first printing, the glass passes through the lower region of the head. Thereafter, the head is moved by a set distance from the first position and positioned at the second position. The glass then passes through the lower region of the head again. Thereafter, the head moves from the second position by a set distance and is positioned at the third position. The glass then passes through the lower region of the head again. However, selecting a printing path applied to the printing process in this way may result in repeated printing operations more than necessary.

An object of the present invention is to provide a printing path determining method capable of efficiently processing a substrate, a program for executing the printing path determining method, and a printing method.

Another object of the present invention is to provide a method for determining a print path capable of effectively reducing the time required to complete a printing process, a program for executing the method for determining a print path, and a printing method.

Another object of the present invention is to provide a method for determining a print path capable of satisfying a target printing condition for a substrate through the smallest number of print paths, a program for executing the method for determining a print path, and a printing method.

The object of the present invention is not limited thereto, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

The present invention provides a method for determining the printing paths applied when ink is ejected onto a substrate. A printing path determining method may include a substrate information receiving step of receiving substrate information of the substrate; a head information receiving step of receiving head information of the head ejecting the ink; and a print path determining step of determining the print paths based on the substrate information and the head information, wherein the print path determining step determines the smallest number of print paths that satisfy a target print condition for the substrate. can

According to an embodiment, the determining of the printing path may include a virtual board generating step of generating a virtual board reflecting the target printing condition based on the board information; a print path selection step of selecting a print path having a higher priority among the print paths; a simulation step of performing virtual printing by applying the selected printing path to the virtual board; and a confirmation step of confirming whether the target printing condition is satisfied after the simulation step.

According to an embodiment, the substrate information includes information about a location of a printing unit from which the ink is ejected onto the substrate and information about a target discharged ink amount required for the printing unit, and in the printing path selection step, the printing Among the paths, a print path farther from the central portion of the print area - the print area constituted by the print units - may be preferentially selected.

According to an embodiment, in the printing path selection step, among the printing paths, a printing path overlapping less with an area to which the virtual printing is applied or an area in which the virtual printing is completed may be selected with priority.

According to an embodiment, the head information is based on at least one of the reproducibility of impact of each nozzle of the head, the number of times each nozzle is used, and the uniformity of the amount of ink ejected from each nozzle. nozzle rating information about the ratings of the nozzles; Alternatively, it may include positional information of usable nozzles among nozzles of the head, and nozzle specification information about the amount of ink ejected from each of the nozzles.

According to an embodiment, in the printing path selection step, a printing path including more high-grade nozzles among the printing paths may be preferentially selected.

According to an embodiment, in the printing path selection step, a printing path including more usable nozzles overlapping an area requiring printing may be preferentially selected among the printing paths.

According to an embodiment, the virtual substrate may be expressed in a grid form.

According to an embodiment, in the virtual substrate generating step, as many virtual substrates as the number of colors of the ink may be generated.

According to an embodiment, in the generating of the virtual substrate, a target amount of discharged ink or a target number of discharged ink droplets is not applied to the virtual substrate, and in the simulation, virtual printing is performed on the virtual substrate in an up-counting manner. can do.

According to an embodiment, in the virtual substrate generating step, a target discharged ink amount or a target discharged ink droplet number is applied to the virtual substrate, and in the simulation step, virtual printing is performed on the virtual substrate in a down-counting manner. can

In addition, the present invention may provide a program stored in a medium that executes the printing path determining method.

In addition, the present invention provides a printing method of discharging ink to a substrate using a head. The printing method may include a virtual printing step of determining printing paths applied when ink is ejected onto the substrate; and an actual printing step of discharging the ink to the substrate based on the printing paths determined in the virtual printing step, wherein in the virtual printing step, the lowest number of printing that satisfies a target printing condition for the substrate is performed. routes can be determined.

According to an embodiment, the virtual printing step may include substrate information of the substrate - the substrate information includes information about a location of a printing unit from which the ink is ejected onto the substrate and information about a target discharged ink amount required for the printing unit. a virtual board generating step of generating a virtual board reflecting the target printing condition based on; a print path selection step of selecting a print path having a higher priority among the print paths; a simulation step of performing virtual printing by applying the selected printing path to the virtual board; and a confirmation step of confirming whether the target printing condition is satisfied after the simulation step.

According to an embodiment, when the target printing condition is not satisfied in the checking step, the printing path selection step is additionally performed, and when the target printing condition is satisfied in the checking step, the target printing condition is satisfied. The actual printing step may be performed using the printing paths selected until the following.

According to an embodiment, the printing path selection step may include: a) a location of the printing path; b) the number of nozzles of the head passing over the area to be printed; and c) the grade of the nozzle.

According to an embodiment, in relation to a), among the printing paths, a printing path far from the central area of the printing area requiring printing of the substrate may have a higher priority.

According to an embodiment, in relation to b), among the printing paths, a printing path having a large number of nozzles passing through an area requiring printing may have a higher priority.

According to an embodiment, in relation to c), the grade of the nozzle may include reproducibility of the ink impact location of the nozzle, number of uses of the nozzle, uniformity of the amount of ink ejected from the nozzle, and It may be determined based on at least one of the amount of ink to be ejected.

According to an embodiment, the virtual board is expressed in a grid form, and when the moving direction of the substrate is referred to as the second direction and the moving direction of the head is referred to as the first direction, among the printing units When the arrangement of the outermost printing units is parallel to the first direction and the second direction, the virtual substrate is represented by a grid arranged in the first direction and a length in the second direction, When the arrangement of the outermost printing units among the printing units is not parallel to the first direction or the second direction, the virtual substrate may be expressed only as a grid.

According to one embodiment of the present invention, the substrate can be efficiently processed.

In addition, according to an embodiment of the present invention, the time required to complete the printing process can be effectively reduced.

In addition, according to an embodiment of the present invention, target printing conditions for a substrate can be satisfied through the smallest number of printing paths.

The effects of the present invention are not limited to the above-mentioned effects, and effects not mentioned will be clearly understood by those skilled in the art from this specification and the accompanying drawings.

1 is a diagram schematically showing an inkjet system according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing an example of an actual substrate, which is an object to be processed on which the inkjet system of FIG. 1 performs a printing process.
3 is a flow chart illustrating a printing method according to an embodiment of the present invention.
4 is a diagram schematically illustrating an inkjet device performing an ejection operation.
5 is a diagram schematically illustrating an inkjet device performing a path changing operation.
FIG. 6 is a diagram schematically illustrating an inkjet device performing an ejection operation again after the path change operation of FIG. 5 .
FIG. 7 is a flow chart showing the virtual printing steps of FIG. 3 .
FIG. 8 is a diagram showing an example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 .
FIG. 9 is a diagram showing another example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 .
FIG. 10 is a diagram schematically showing another example of an actual substrate, which is an object to be processed on which the inkjet system of FIG. 1 performs a printing process.
FIG. 11 is a diagram showing another example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 .
FIG. 12 is a diagram showing another example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 .
FIG. 13 is a diagram showing an example of printing paths that can be applied during a printing process on a virtual substrate in relation to the printing path selection step of FIG. 7 .
FIG. 14 is a diagram showing another example of print paths that can be applied during a printing process on a virtual substrate in relation to the printing path selection step of FIG. 7 .
15 to 17 are diagrams showing examples of weight functions that may be applied in relation to the printing path selection step of FIG. 7 .
FIG. 18 is a diagram for explaining the selection of a print path in consideration of a printed area or a printed area in relation to the printing path selection step of FIG. 7 .
FIG. 19 is for explaining the selection of a print path by additionally considering the number of usable nozzles of the head, in addition to considering the area to which printing has been applied or the area where printing has been completed, in relation to the printing path selection step of FIG. 7 . it is a drawing
20 is a diagram illustrating an example of a virtual board before a simulation step is performed.
FIG. 21 is a view showing a state of the virtual board of FIG. 20 after a simulation step is performed.
22 is a diagram showing another example of a virtual board before a simulation step is performed.
23 is a view showing a state of the virtual board of FIG. 22 after the simulation step is performed.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. In addition, in describing preferred embodiments of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions.

'Including' a certain component means that other components may be further included, rather than excluding other components unless otherwise stated. Specifically, terms such as "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features or It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, shapes and sizes of elements in the drawings may be exaggerated for clearer description.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms may be used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, the second element may also be termed a first element, without departing from the scope of the present invention.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, they are not interpreted in an ideal or excessively formal meaning. .

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 23 .

As an example, the substrate G, which is an object to be processed by the inkjet system 10 to be described below, is glass. The substrate G may refer to an actual substrate on which a printing process is actually performed.

1 is a diagram schematically showing an inkjet system according to an embodiment of the present invention. FIG. 1 shows a plane of the inkjet device 100 (viewing from the top to the bottom). Hereinafter, a direction parallel to the direction in which the substrate G moves is referred to as a second direction Y, and a direction perpendicular to the second direction Y when the inkjet device 100 is viewed from a plane is defined as It can be defined in one direction (X). The first direction X may be a direction parallel to the direction in which the head unit 140 moves. In addition, a direction parallel to the first direction (X) and the second direction (Y) may be defined as a third direction (Z). The third direction (Z) may be a direction perpendicular to the ground.

Referring to FIG. 1 , an inkjet system 10 according to an embodiment of the present invention may include an inkjet device 100 and a control device 200 . The inkjet device 100 may be configured to perform a printing process of discharging ink to the substrate G. The control device 200 may control driving of the inkjet device 100 .

The inkjet apparatus 100 may include a stage 110 , a moving unit 120 , a gantry unit 130 , and a head unit 140 .

The stage 110 may provide an area where a printing process for the substrate G is performed. The stage 110 may provide an area where the substrate G is loaded or unloaded. The lower surface of the substrate G may be placed in contact with the stage 110 . Unlike this, gas dispensing holes (not shown) may be formed in the stage 110 to inject gas to the lower surface of the substrate G to float the substrate G. Gas dispensing holes (not shown) that may be formed in the stage 110 may inject an inert gas such as nitrogen to the lower surface of the substrate G to lift the substrate G to a certain height.

The moving unit 120 may move the substrate G. When a gas dispensing hole is formed in the stage 110 to inject gas to the lower surface of the substrate G, the moving unit 120 may grip the substrate G. The moving unit 120 may grip the substrate G to position the substrate G at a certain height. Also, the moving unit 120 may include a gripping hand gripping the substrate G and a traveling rail (not shown) moving the gripping hand along the second direction Y. The moving unit 120 may be configured to move the substrate G along the second direction Y while gripping one side and the other side of the lower surface of the substrate G. The moving unit 120 may move the substrate G forward or backward along the second direction Y.

In the above example, the moving unit 120 includes a grip hand and a travel rail, and the grip hand grips one side and the other side of the lower surface of the substrate G as an example, but is not limited thereto. For example, the moving unit 120 may include a support plate having a seating surface on which the substrate G can be placed, and a running rail for moving the support plate.

The gantry unit 130 may provide a movement path along which the head unit 140, which will be described later, moves. The gantry unit 130 may include a body and a driving member (eg, a motor, not shown) that changes the position of the head unit 140 . The body may have a shape extending from both sides of the stage 110 along the third direction (Z) and extending across the stage 110 along the first direction (X).

The head unit 140 may discharge ink to the substrate G to perform a printing process. The head unit 140 may include a frame 141 and a head 142 . The frame 141 of the head unit 140 is installed on the body of the gantry unit 130 and can move along the first direction X. In addition, a plurality of insertion spaces into which the head 142 can be inserted may be formed in the frame 141 .

A plurality of heads 142 may be provided. Each head 142 may be formed with a plurality of nozzles 143 that discharge ink in the form of droplets. The plurality of nozzles 143 may eject ink of different volumes. For example, the nozzles 143 belonging to a first group of nozzles 143 are configured to eject ink of a first volume, and the nozzles 143 belonging to a second group different from the first group of nozzles 143 ) may be configured to eject ink of a second volume different from the first volume. Expressions of different volumes, different amounts of ink, or different diameters of ink in the form of droplets may be used in the same or similar meaning.

1 shows an example in which three insertion spaces are formed in the frame 141, three heads 142 are provided, and six nozzles 143 are formed in each head 142, but this is a simple example. This is just one example, and the number of insertion spaces formed in the frame 141, the number of heads 142, and the number of nozzles 143 formed in the head 142 may be variously modified according to the user's needs. there is.

The control device 200 may control the operation of the inkjet device 100 . The control device 200 may generate a control signal to control the operation of the inkjet device 100 . The control device 200 may be configured to perform a virtual printing step (S10) to be described later. Also, the control device 200 may generate a control signal so that the inkjet device 100 may actually perform the printing step (S20). In addition, the control device 200 includes a process controller composed of a microprocessor (computer) that controls the inkjet device 100, a keyboard through which an operator inputs commands to manage the inkjet device 100, and the like, and an inkjet device. A user interface consisting of a display that visualizes and displays the operation status of the device 100, a control program for executing the actual printing step (S20) performed by the inkjet device 100 under the control of a process controller, various data and A storage unit may be provided in which a program for executing processing in each component unit according to processing conditions is stored. In addition, the control device 200 may include a storage medium storing a program for performing a virtual printing step (S10) to be described later. The storage medium may be a hard disk, or may be a portable disk such as a CD-ROM or DVD, or a semiconductor memory such as a flash memory.

FIG. 2 is a diagram schematically showing an example of an actual substrate, which is an object to be processed on which the inkjet system of FIG. 1 performs a printing process.

Referring to FIG. 2 , a substrate G, which is an object to be processed on which the inkjet system 10 according to an embodiment of the present invention performs a printing process, may be glass having a substantially rectangular shape. The substrate G may be an actual substrate that is an object to be processed in the actual printing step (S20).

The substrate G may include a printing area SP, which is an area where ink is ejected, and a non-printing area NP, which is an area other than the printing area SP and an area in which ink is not ejected. Also, the print area SP included in the substrate G may include a plurality of print areas SP1 , SP2 , SP3 , and SP4 . For example, the print area SP may include a first print area SP1, a second print area SP2, a third print area SP3, and a fourth print area SP4. The print area SP may include a plurality of print units. The printing unit may be one pixel formed on the substrate G. One print unit may include a plurality of auxiliary print units. A sub-printing unit may be a sub-pixel included in one pixel. One print unit may include red, green, and blue elements. One sub-printing unit may include any one of red, green and blue elements. The shape, size, position, and target discharged ink amount (which can also be referred to as target volume) of the above-described printing unit may vary depending on the type of substrate G, which is an object to be processed, or the specification of a display device to be manufactured. . In addition, as at least one ejection operation through the nozzle 143 of the head unit 140 or a plurality of ejection operations through one nozzle is performed on the printing unit, the above-described target discharged ink amount may be satisfied.

Hereinafter, a printing method according to an embodiment of the present invention will be described in detail. 3 is a flow chart illustrating a printing method according to an embodiment of the present invention.

Referring to FIG. 3 , the printing method according to an embodiment of the present invention may include a virtual printing step ( S10 ) and an actual printing step ( S20 ). The virtual printing step (S10) may be a step for determining printing paths applied when ink is ejected onto the substrate G through simulation, that is, virtual printing. The actual printing step (S20) may be a step of performing actual printing by discharging ink to the substrate (G) based on the printing paths determined in the virtual printing step (S20). In the printing method according to an embodiment of the present invention, the virtual printing step (S10) and the actual printing step (S20) may be sequentially performed. After the virtual printing step (S10) is performed, the actual printing step (S20) may be performed.

Apart from the fact that the actual printing step (S20) is performed after the virtual printing step (S10), the actual printing step (S20) will first be described below for convenience of description.

In the actual printing step ( S20 ), a printing process may be performed on the substrate G placed on the stage 110 . The printing process may be performed through an ejection operation and a path change operation. In the discharge operation, the substrate G passes through the lower area of the head unit 140 located at the set position at a constant speed, and the head unit 140 passes through the lower area of the head unit 140. At least one of the nozzles 143 of ) may be an operation of discharging ink to the substrate (G). The path changing operation may be an operation of moving the location of the head unit 140 along the first direction X in order to change the printing path of the head unit 140 performing the ejection operation.

4 is a diagram schematically illustrating an inkjet device performing an ejection operation.

Referring to FIG. 4 , the head unit 140 may be located in a first position. The substrate G may pass through an area below the head unit 140 located at the first position at a constant speed. The moving unit 120 may move the substrate G at a constant speed. The moving unit 120 may move the substrate G along the second direction Y. The nozzles 143 of the head unit 140 may eject ink to the substrate G passing through the lower area of the head unit 140 . At this time, a printing path applied when ink is ejected to the substrate G may be referred to as a first path.

5 is a diagram schematically illustrating an inkjet device performing a path changing operation.

Referring to FIG. 5 , the location of the head unit 140 may be changed. When the position of the head unit 140 is changed, a printing path applied in an ejection operation performed later may be changed. For example, the position of the head unit 140 may be changed along the first direction X along the gantry unit 130 . For example, the head unit 140 may move to a second position different from the above-described first position.

FIG. 6 is a diagram schematically illustrating an inkjet device performing an ejection operation again after the path change operation of FIG. 5 .

Referring to FIG. 6 , the change of the location of the head unit 140 from the first location to the second location may be completed through the above-described path changing operation. That is, the head unit 140 may be located in the second position. The substrate G may pass through an area below the head unit 140 located at the second position at a constant speed. The moving unit 120 may move the substrate G at a constant speed. The moving unit 120 may move the substrate G along the second direction Y. The nozzles 143 of the head unit 140 may eject ink to the substrate G passing through the lower area of the head unit 140 . At this time, a printing path applied when ink is ejected to the substrate G may be referred to as a second path.

The actual printing step (S20) may be performed by repeating the above-described ejection operation and path changing operation. When the actual printing step ( S20 ) is completed, target printing conditions for the substrate G may be satisfied. The target print condition may be the above-described print unit, more specifically, a target volume for each sub print unit. Also, target volumes for each of the print units may be the same or different from each other. Target volumes of some of the print units may be the same, and target volumes of other parts of the print units may be different from each other.

Hereinafter, the virtual printing step (S10) according to an embodiment of the present invention will be described in detail. FIG. 7 is a flow chart showing the virtual printing steps of FIG. 3 .

Referring to FIG. 7 , unlike the actual printing step (S20) performed by actually ejecting ink on the substrate G, which is an actual substrate, the virtual printing step (S10) is a simulation implemented through a program stored in the control device 200. It can be an algorithm. In the virtual printing step ( S10 ), print paths that can be applied in the actual printing step ( S20 ) may be determined. In the virtual printing step ( S10 ), it is possible to derive the smallest number of printing paths that satisfy the above-described target printing condition for the substrate (G).

The virtual printing step ( S10 ) may include a board information receiving step ( S11 ), a head information receiving step ( S12 ), and a print path determining step ( S12 ).

In the substrate information receiving step (S11), information on the substrate G to be processed may be received. An operator may input information about the substrate G to be processed into the control device 200 . The substrate information, which is information about the substrate G, includes the type of the substrate G, the size of the substrate G, the position of a printing unit formed on the substrate G and from which ink is ejected, and an auxiliary printing unit included in the printing unit. position, the target amount of ejected ink required for the printing unit (target volume), the target amount of ejected ink required for the sub printing unit (target volume), and the elements to be included in the sub printing unit (which of R, G, and B elements are selected) whether to be included), location information of the above-described printing area SP and non-printing area NP, and the like.

The head information receiving step ( S12 ) may include information about the heads 142 included in the head unit 140 , more specifically, nozzles 143 formed on the heads 142 . As described above, the head unit 140 may have a plurality of nozzles 143 . The quality of each nozzle 143 may be slightly different due to a shape, an installation location, and various other reasons. For example, the nozzles 143 may differ from each other in reproducibility of impact (when ink is ejected several times, the position where the ejected ink is impacted is the same) and the uniformity of the amount of ejected ink. In addition, some of the nozzles of the head 142 may be usable, and other nozzles may not be usable because the reproducibility of impact and the uniformity of the amount of ejected ink are very poor, or the ejection is not properly performed. . Also, the amount of ink (ejection volume) ejected from the nozzles 143 may be different from each other.

In the head information receiving step ( S12 ), head information that may be information about the nozzles 143 may be received. Head information may be input to the control device 200 by an operator.

The head information is each nozzle based on at least one of the reproducibility of impact of the nozzles 143 of the head 142, the number of times each nozzle 143 is used, and the uniformity of the amount of ink ejected from each nozzle 143. (143) may include nozzle class information about the class. As the reproducibility of the nozzles 143 and the uniformity of the amount of ejected ink are excellent, and the number of times of use of the nozzles 143 is reduced, the higher grade can be classified.

Also, the head information may include positional information of usable nozzles among the nozzles 143 and nozzle specification information regarding the amount of ink ejected from each of the nozzles 143 .

The head information receiving step ( S12 ) may be performed simultaneously with the board information receiving step ( S11 ). Alternatively, the head information receiving step ( S12 ) may be performed after the board information receiving step ( S11 ) or may be performed before the board information receiving step ( S11 ).

In the printing path determining step ( S13 ), the smallest number of printing paths that satisfy target printing conditions for the substrate G processed in the actual printing step ( S10 ) may be determined.

The printing path determining step ( S13 ) may include a virtual board generating step ( S131 ), a printing path selecting step ( S132 ), a simulation step ( S133 ), and a confirmation step ( S134 ).

In the virtual board generating step ( S131 ), a virtual board reflecting target printing conditions may be generated based on the board information on the substrate G to be actually processed received in the above-described board information receiving step ( S11 ). The generated virtual board may be a virtual board (IG) on a program in which virtual printing is performed in a simulation step (S133) to be described later.

FIG. 8 is a diagram showing an example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 . FIG. 8 shows an example of a virtual substrate IGA according to the first embodiment among virtual substrates IG based on the substrate information about the substrate G of FIG. 2 .

Referring to FIG. 8 , the substrate G of FIG. 2 includes a plurality of print areas SP1 , SP2 , SP3 , and SP4 . In the virtual board generating step S131 , the plurality of print areas SP1 and SP2 , SP3 , SP4 ), a plurality of virtual substrates IGA1 , IGA2 , IGA3 , and IGA4 may be generated. Each of the virtual substrates IGA1 , IGA2 , IGA3 , and IGA4 may be expressed in a grid form, and the print areas SP1 , SP2 , SP3 , and SP4 may be expressed in a plurality of grids GA. Also, each grid may correspond to the above-described printing unit. For example, each grid may correspond to the above-described auxiliary printing unit.

FIG. 9 is a diagram showing another example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 . 9 shows an example of a virtual board IGB according to the second embodiment among virtual boards IG based on board information about the board G.

In the above-described example, in the virtual board generating step S131, the plurality of virtual boards IGA1, IGA2, IGA3, and IGA4 are generated corresponding to the plurality of print areas SP1, SP2, SP3, and SP4, respectively. Although described, a virtual substrate may be created otherwise. The virtual board IGB may be represented by a plurality of grids GB. The grid GB may include a printed grid SGB and a non-printed grid NGB.

For example, in the virtual board generation step S131, the virtual board IGB corresponding to the board G is expressed in a grid form, and the printing areas SP1, SP2, SP3, and SP4 are printed grid SGB. ), the non-printing area NP can be expressed as a non-printing grid NGB. The printed grid (SGB) and the non-printed grid (NGB) can be distinguished in various ways, but for example, the printed grid (SGB) and the non-printed grid (NGB) can be distinguished from each other by varying the shading. . As shown in FIG. 9 , the first virtual print area IP1 to the fourth virtual print area IP4 corresponding to the first print area SP1 to the fourth print area SP4 are collected by the printing grids SGB. ) can be implemented respectively.

FIG. 10 is a diagram schematically showing another example of an actual substrate, which is an object to be processed on which the inkjet system of FIG. 1 performs a printing process. As in the example of the substrate G' shown in FIG. 10 , depending on the substrate G', the printed areas SP1', SP2', SP3', and SP4' may have different shapes. For example, the first print area SP1' and the second print area SP2' may have the same shape, and the third print area SP3' may have a shape inclined with respect to the second direction Y (eg, , parallelogram shape), and the fourth print area SP4' is a rectangular shape shorter in length in the second direction Y than the first print area SP1' and the second print area SP2'. can have a shape.

FIG. 11 is a diagram showing another example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 . 11 shows an example of a virtual substrate IGB' according to a third embodiment among virtual substrates IG based on substrate information about the substrate G'.

As shown in FIG. 11 , even if the shapes of the printed areas SP1', SP2', SP3', and SP4' are deformed, the virtual substrate IGB' has a printed grid SGB' and a non-printed grid NGB'. ), the virtual print areas IP1', IP2', IP3', and IP4' may be expressed through the grid GB' including.

FIG. 12 is a diagram showing another example of a virtual substrate generated in the virtual substrate generating step of FIG. 7 . 12 shows an example of a virtual board IGC according to the fourth embodiment among virtual boards IG.

As shown in FIG. 12 , when the information on the printing area SP, which may be included in the substrate information on the substrate G, satisfies a specific condition, the virtual substrate IGC can be simplified and expressed. For example, when the arrangement of the outermost printing units among the printing units constituting the printing area SP is parallel to the first direction X and the second direction Y and/or the second direction Y When the target ink volume between the printing units of the substrate G arranged along the substrate G is equal to each other, the virtual substrate IGB, as shown in FIG. It can be expressed as a length in (Y, Y direction). That is, in the case of the rectangular printing area SP disposed horizontally or vertically to the printing direction, data is stored as the length of the second direction (Y) in the movement direction during the ejection operation on the substrate (G), and data is stored in the first direction (X). ) is expressed as an array or list data structure. Such an expression method not only reduces memory usage, but also simplifies the process of matching the printing area SP and the nozzles 143 to be corresponded to, thereby speeding up the algorithm (that is, the speed at which the virtual printing step S10 is performed). has the advantage of improving

In addition, when the arrangement of the outermost printing units among the printing units is not parallel to the first direction (X) or the second direction (Y), it is expressed only in the grids (GA, GB) as in the previous example, Substrates (IGA, IGB) can be created.

The virtual board (IG) may have a different appearance from the actual board (G) depending on the format in which it is expressed, but since the virtual board (IG) is generated based on the board information of the real board (G), the virtual board (IG) ) It can be seen that the simulation result for the actual substrate (G) is substantially the same as the actual printing result.

Referring back to FIG. 7 , in the printing path selection step S132 according to an embodiment of the present invention, printing paths for performing virtual printing on the virtual substrates IGA, IGB, and IGB may be selected. The position of the head unit 140 may be variously modified at intervals of the minimum moving distance. For example, the position of the head unit 140 is a first position, a second position, a third position... . It can be changed to the nth position. Correspondingly, the printing path is a first path, a second path, a third path... . The nth path and the like may exist. Multiple print paths may exist depending on where the head unit 140 can be changed. Information on print paths that may exist according to the changeable position of the head unit 140 may be previously stored in the control device 200 .

In the case of performing printing on the substrate G, there may be various types of print path sets (also referred to as “swath set”) composed of print paths to satisfy specific target print conditions. According to an embodiment of the present invention, in the print path determining step (S13), a print path set consisting of the smallest number of print paths is derived from among various print path sets, and the corresponding print path set is actually printed (S20). make it applicable to In the print path selection step (S132), a print path having the highest priority among print paths is searched for and selected.

In the simulation step (S133), virtual printing may be performed by applying the print path selected in the print path selection step (S132) to the virtual substrate IG.

In the confirmation step (S134), as a result of the virtual printing performed in the simulation step (S133), it may be determined whether target printing conditions are satisfied. When the target print condition is satisfied, the print path determining step (S13) is terminated, and the print path set derived in the print path determining step (S13) (that is, the print paths selected until the target print condition is satisfied) is actually printed. Apply to step S20 to perform a printing process on the substrate (G).

If the target printing condition is not satisfied in the confirmation step (S134), the target printing condition is additionally performed in the print path selection step (S132), and in the additionally performed printing path selection step (S132), the second step Searches for and selects a print path with priority.

This process is repeatedly performed until target printing conditions are satisfied.

That is, in the printing path determining step (S13) of the present invention, printing paths are sequentially selected in order of priority from a higher priority printing path, and the lowest number that satisfies the target printing condition for the virtual board (IG) is selected. Derives a print path set consisting of print paths.

Hereinafter, an example of a print path having a higher priority when selecting a print path in the print path selection step (S132) will be described.

FIG. 13 is a diagram showing an example of printing paths that can be applied during a printing process on a virtual substrate in relation to the printing path selection step of FIG. 7 .

FIG. 13 shows an example of performing printing on the virtual board IG by sequentially moving the head unit 140 by a predetermined distance without considering the priority of the printing paths. As shown in FIG. 13 , in order to complete the printing process on the virtual substrate IG, the print path set may include the first to tenth print paths SW1 to SW10 . Each of the print paths SW1 to SW10 may be implemented as the position of the head unit 140 in the first direction X is changed. Printing areas of the virtual substrate IG in which each of the printing paths SW1 to SW10 perform printing may partially overlap. This is because there is an advantage in minimizing deterioration in printing uniformity due to quality deviation of the nozzles 143 when printing on a specific area is completed by ejecting ink multiple times rather than by ejecting ink once.

Meanwhile, the printing area of the virtual substrate IG may include edge portions A and central portions B arranged along the first direction X. As shown in FIG. 13, the central portion (B) has many opportunities for printing to be performed. For example, all of the first to tenth printing paths SW1 to SW10 may contribute to the printing of the central portion B. That is, in the case of the central portion (B), although there are many opportunities for printing to be performed, since a large number of printing paths are arranged, printing efficiency may be reduced.

FIG. 14 is a diagram showing another example of print paths that can be applied during a printing process on a virtual substrate in relation to the printing path selection step of FIG. 7 .

14 shows an example of performing printing on the virtual substrate IG by considering the priority of the printing paths. As shown in FIG. 14 , in completing the printing process for the virtual substrate IG, it may be sufficient for the print path set to include the first to seventh print paths SW7 . Each of the print paths SW1 to SW7 may be implemented as the position of the head unit 140 in the first direction X is changed.

As described above, the printing area of the virtual board IG may include edge portions A and a central portion B arranged along the first direction X, and the central portion B is printed. While there are many opportunities to be printed, the edge portion (A) may have relatively few opportunities to be printed.

Therefore, in the printing path selection step (S132) according to an embodiment of the present invention, the printing path for printing the edge portion A of the virtual board IG with relatively few opportunities for printing is given priority. you can choose by

That is, in the printing path selection step (S132), in selecting a printing path for performing virtual printing on the virtual board (IG), a printing path for performing virtual printing on the edge portion (A) of the virtual board (IG) is selected. You can choose first.

For example, in the print selection step (S132), the first print path (SW1), the second print path (SW2), the third print path (SW3), the fourth print path (SW4), and the fifth print path shown in FIG. The path (SW5), the sixth print path (SW6), and the seventh print path (SW7) can be sequentially selected.

When viewing the virtual substrate IG from a plane, the first and second printing paths SW1 and SW2 are the distance from the central portion B of the virtual substrate IG, for example, in the second direction (Y). ) and may have the same distance from an imaginary line passing through the center of the substrate (G).

Priorities between the first and second printing paths SW1 and SW2 may be determined by other factors described below, in addition to the distance from the central portion of the substrate G.

Similarly, the third and fourth print paths SW3 and SW4 may have the same distance from the central portion B of the virtual board IG. Also, the fifth and sixth print paths SW5 and SW6 may have the same distance from the central portion B of the virtual board IG. Priorities between the third print path SW3 and the fourth print path SW4, and the priorities of the fifth print path SW5 and the sixth print path SW6 may also be determined by other factors described below. there is.

15 to 17 are diagrams showing examples of a weight function W(x) that may be applied in relation to the printing path selection step of FIG. 7 .

As in the above example, when it is desired to preferentially select a printing path passing through the edge portion (A) of the virtual board (IG) rather than the central portion (B), a weight function W(x) as shown in FIG. 15 is applied. . For example, FIG. 15 shows a weight function W(x) in which a weight changes according to a distance from the center of the virtual substrate IG. In this case, since the weight applied when selecting a printing path increases as the distance from the center of the virtual substrate IG increases, a printing path farther than the central portion B of the virtual substrate IG is selected with priority.

In the above example, the selection of the printing path passing through the edge portion A of the virtual substrate IG rather than the central portion B has been described as an example, but if necessary, the edge portion of the virtual substrate IG ( It may be necessary to preferentially select a print path passing through the central portion (B) rather than A). In this case, as shown in FIG. 16, the closer the weight function W(x) is to the center of the virtual board IG, the larger the weight applied when selecting the printing path, so that the central portion of the virtual board IG ( A print path closer to B) is preferentially selected.

Also, if necessary, as shown in FIG. 17 , the virtual substrate IG may include a first region C and a second region D different from the first region C. A boundary between the first region C and the second region D may be eccentric with respect to the center of the virtual substrate IG. The first area C and the second area D may have different required ink volumes. For example, when it is necessary to discharge relatively less ink to the second area (D) than to the first area (C), the printing path can be selected by applying a weight function W(x) biased towards the second area (D). there is. In this case, in the graph of the weight function W(x), since the area of the portion corresponding to the second area D is smaller than the area of the portion corresponding to the first area C, the first area C is relatively More printing paths passing through can be selected.

Hereinafter, among the factors determining the priority of the printing path, other factors, except for the factor related to the distance from the central portion of the printing path and the substrate G, will be described.

FIG. 18 is a diagram for explaining the selection of a print path in consideration of a printed area or a printed area in relation to the printing path selection step of FIG. 7 .

Referring to FIG. 18, in the printing path selection step (S132), a printing-applied area, more specifically, a print path that overlaps less with a virtual printing-applied area or a virtual-printed area in the simulation step (S133) is preferentially selected. can For example, as shown in FIG. 18 , if the simulation step ( S133 ) is performed at least one time, the virtual printing result may be partially applied to the virtual substrate IG. When an area where printing has been performed at least once or an area where printing has been completed is referred to as a printing applied area (E), and an area that is not printed is referred to as a non-printing area (F), printing that overlaps less with the printing applied area (E) You can choose a route in preference. For example, taking the case that the printing application area E is completely printed, the first printing path SW1 has an efficiency of about 60%, and the second printing path SW2 has an efficiency of about 60%. It has an efficiency of about 80%, and in the case of the third print path (SW3), it may have an efficiency of about 100%. In this case, the second print path SW2 may be selected with priority over the first print path SW1, and the third print path SW3 may be selected with priority over the second print path SW2. That is, by preferentially selecting a print path that overlaps less with the print application area E, it is possible to further reduce the number of print paths that satisfy the target print condition.

FIG. 19 is for explaining the selection of a print path by additionally considering the number of usable nozzles of the head, in addition to considering the area to which printing has been applied or the area where printing has been completed, in relation to the printing path selection step of FIG. 7 . it is a drawing

Referring to FIG. 19, the head information input to the control device 200 as described above includes the reproducibility of impact of each nozzle 143 of the head 142, the number of times each nozzle 143 is used, and each nozzle ( 143) as well as nozzle information about the grade of each nozzle 143 based on at least one of the uniformity of the amount of ink ejected from the head 142, positional information of available nozzles 143 that the head 142 has, and each It may include nozzle specification information about the amount of ink ejected from the nozzles 143 .

Some of the nozzles 143 of the head 142 may have very low ink ejection quality or may be nozzles 143 that cannot eject ink. For example, the head unit 140 may include a non-usable nozzle NN and a usable nozzle PN. If the position of the usable nozzle PN of the head unit 140 is additionally considered, the result may be different when determining the printing path priority considering the printing area E and the non-printing area F.

For example, as shown in FIG. 19, considering the number and position of the non-usable nozzles NN of the head unit 140, the first and third printing paths SW1 and SW3 achieve 60% efficiency. , the second print path SW2 has an efficiency of 40%. In this case, the first print path SW1 and the third print path SW3 may be selected prior to the second print path SW3.

In addition to the factors that affect the priority of printing path selection as described above, nozzle grade information may be additionally considered. For example, when the same rank printing path occurs even though all of the above factors are considered, nozzle grade information may be additionally considered. For example, when printing paths of the same rank occur, a printing path including more nozzles of a higher rank among the printing paths may be preferentially selected. For a printing path that includes more nozzles of a higher grade, for example, a score is assigned to each grade of the nozzle, and the scores corresponding to the grade of each nozzle participating in printing are summed up so that the score is higher. You can select the print path with priority.

In the above example, when the same priority printing path occurs, the nozzle class information is additionally considered as an example, but it is not limited thereto, and the nozzle class information may be considered together with the priority consideration factors described above. .

Hereinafter, a specific example in which the simulation step (S133) is performed will be described. Hereinafter, an example in which the simulation step S133 is performed using the virtual board IGC according to the fourth embodiment among the virtual boards IG described above will be described.

20 is a diagram illustrating an example of a virtual board before a simulation step is performed.

As shown in FIG. 20 , in the virtual substrate generation step ( S131 ), virtual substrates IGCs corresponding to each color of the ink used may be generated. That is, a virtual board IGC may be generated corresponding to each auxiliary printing unit. Each virtual board IGC may have an initial value set to 0. That is, the target discharged ink amount or the target discharged ink droplet number may not be applied to the virtual substrate IGC.

FIG. 21 is a diagram showing a state of the virtual board of FIG. 20 after a simulation step is performed. As shown in FIG. 21 , when virtual printing is performed on the virtual board IGC, the virtual printing result may be reflected on the virtual board IGC in an up-counting manner. For example, after the virtual printing result to which one of the printing paths is applied is reflected on the virtual board IGC, it is checked whether the reflected virtual printing result satisfies the target printing condition in step S134. Whether or not the target printing condition is satisfied may be determined based on whether the up-counted number meets the target printing condition. When the target print condition is satisfied, it is determined that the print path set is completed and the virtual print step (S10) is terminated. When the target print condition is not satisfied, it is determined that the print path set is not completed and the print path selection step (S132 ) is performed again.

In the above example, the initial value of the virtual board IGC is 0 and the virtual printing result is reflected on the virtual board IGC in an up-counting manner, but is not limited thereto.

For example, as shown in FIG. 22 , in the virtual board generating step ( S131 ), the virtual board IGC reflecting target printing conditions pre-input into the control device 200 may be generated. In this case, a target discharged ink amount or a target discharged ink droplet number may be applied to the virtual substrate IGC.

FIG. 23 is a view showing a state of the virtual board of FIG. 22 after a simulation step is performed. As shown in FIG. 23 , when virtual printing is performed on the virtual board IGC, the virtual printing result may be reflected on the virtual board IGC in a down-counting manner. For example, after the virtual printing result to which one of the printing paths is applied is reflected on the virtual substrate IGC, it is checked whether the reflected virtual printing result satisfies the target printing condition in step S134. Whether or not the target printing condition is satisfied may be determined by whether or not the down-counted number reaches zero. When the target print condition is satisfied, it is determined that the print path set is completed and the virtual print step (S10) is terminated. When the target print condition is not satisfied, it is determined that the print path set is not completed and the print path selection step (S132 ) is performed again.

When the actual printing step (S20) is performed using the set of printing paths determined in the virtual printing step (S10), the number of printing paths required to meet the printing conditions for the actual substrate (G) can be minimized, so that the actual substrate (G) can be minimized. The time required to perform the printing process of (G) can be more reliably shortened. In addition, when the printing path is selected, since the printing path is selected in consideration of the nozzle grade information of the nozzle 143, the print quality of the actual substrate G can also be improved. In addition, a printing result may be predicted through the virtual substrate printing step (S10). Accordingly, when it is determined that the printing quality is not as good as expected or that printing takes a lot of time, the user can take other measures in addition to the above-described method, so that the printing process can be operated more efficiently. In addition, the method of determining the above-described printing paths and the printing method may be implemented through a program stored in a recording medium.

The above detailed description is illustrative of the present invention. In addition, the foregoing is intended to illustrate and describe preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications are possible within the scope of the concept of the invention disclosed in this specification, within the scope equivalent to the written disclosure and / or within the scope of skill or knowledge in the art. The written embodiment describes the best state for implementing the technical idea of the present invention, and various changes required in the specific application field and use of the present invention are also possible. Therefore, the above detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to cover other embodiments as well.

Inkjet system: 10
Substrate: G
Non-printing area: NP
Print Area: SP
1st direction : X
2nd direction : Y
3rd direction : Z
Inkjet device: 100
Stage: 110
Mobile units: 120
Gantry units: 130
Head unit: 140
Frames: 141
Pack: 142
Nozzle: 143
Control unit: 200
Virtual print step: S10
Actual printing step: S20
Substrate information reception step: S21
Head information reception step: S22
Printing route determination step: S23
Virtual board creation step: S231
Printing path selection step: S232
Simulation step: S233
Confirmation step: S234
Virtual boards: IG, IGA, IGB, IGC
Print Grid: SGB
Non-printing grid: NGB

Claims (20)

A method for determining printing paths applied when ink is ejected on a substrate,
a substrate information receiving step of receiving substrate information of the substrate;
a head information receiving step of receiving head information of the head ejecting the ink; and
A printing path determining step of determining the printing paths based on the substrate information and the head information,
In the step of determining the printing path,
determining the smallest number of print paths that satisfy a target print condition for the substrate. According to claim 1,
In the step of determining the printing path,
a virtual board generating step of generating a virtual board reflecting the target printing condition based on the board information;
a print path selection step of selecting a print path having a higher priority among the print paths;
a simulation step of performing virtual printing by applying the selected printing path to the virtual substrate; and
and a confirmation step of confirming whether or not the target printing condition is met after the simulation step. According to claim 2,
The substrate information includes information about a location of a printing unit from which the ink is ejected on the substrate and a target amount of ink ejected required for the printing unit,
In the printing path selection step,
and preferentially selecting a print path distant from a central portion of a print area, wherein the print area is constituted by the print units, among the print paths. According to claim 3,
In the printing path selection step,
The method of claim 1 , wherein among the print paths, a print path that overlaps less with an area to which the virtual printing is applied or an area in which the virtual printing is completed is preferentially selected. According to claim 4,
The head information is a nozzle grade related to a grade of each nozzle based on at least one of the reproducibility of impact of each nozzle of the head, the number of times each nozzle is used, and the uniformity of the amount of ink ejected from each nozzle. information; or,
The method includes position information of usable nozzles among nozzles of the head, and nozzle specification information about an amount of the ink ejected from each of the nozzles. According to claim 5,
In the printing path selection step,
A method of selecting a print path containing more high-ranking nozzles from among the print paths with priority. According to claim 5,
In the printing path selection step,
The method of claim 1 , wherein among the print paths, a print path including a larger number of the usable nozzles overlapping an area to be printed is preferentially selected. According to claim 2,
The method of claim 1 , wherein the virtual substrate is expressed in a grid form. According to claim 8,
In the generating of the virtual substrate, as many virtual substrates as the number of colors of the ink are generated. According to claim 8,
In the virtual substrate generating step, a target discharged ink amount or a target discharged ink droplet number is not applied to the virtual substrate;
In the simulation step, virtual printing is performed in an up-counting manner with respect to the virtual substrate. According to claim 8,
In the virtual substrate generating step, a target discharged ink amount or a target discharged ink droplet number is applied to the virtual substrate;
In the simulation step, virtual printing is performed in a down-counting manner with respect to the virtual substrate. A program stored in a medium that executes the printing path determination method according to any one of claims 1 to 11. In the printing method of discharging ink on a substrate using a head,
a virtual printing step for determining printing paths applied when ink is ejected onto the substrate; and
An actual printing step of discharging the ink to the substrate based on the printing paths determined in the virtual printing step,
In the virtual printing step, the printing method of determining the smallest number of printing paths that satisfy a target printing condition for the substrate. According to claim 13,
The virtual printing step,
The target printing condition is reflected based on the substrate information of the substrate - the substrate information includes information about the location of the printing unit from which the ink is ejected on the substrate and the target discharged ink amount required for the printing unit. a virtual substrate generating step of generating a virtual substrate;
a print path selection step of selecting a print path having a higher priority among the print paths;
a simulation step of performing virtual printing by applying the selected printing path to the virtual board; and
After the simulation step, a confirmation step of confirming whether or not the target printing condition is satisfied, the printing method. According to claim 14,
When the target printing condition is not satisfied in the checking step, the printing path selection step is additionally performed;
When the target printing condition is satisfied in the checking step, the actual printing step is performed using selected printing paths until the target printing condition is satisfied. According to claim 15,
In the printing path selection step,
a) the location of the print path;
b) the number of nozzles of the head passing over the area to be printed; and
c) the grade of the nozzle;
and selecting the printing path according to the priority based on at least one of the following. According to claim 16,
Regarding a), among the printing paths, a printing path having a distance from a central area of a printing area requiring printing of the substrate has a higher priority. According to claim 16,
In relation to b), a printing path having a large number of nozzles passing through an area requiring printing among the printing paths has a higher priority. According to claim 16,
In relation to c), the grade of the nozzle is determined among the reproducibility of the ink impact location of the nozzle, the number of times the nozzle is used, the uniformity of the amount of ink ejected from the nozzle, and the amount of ink ejected from the nozzle. The printing method determined based on at least one or more. According to any one of claims 13 to 18,
The virtual substrate is expressed in the form of a grid,
When the moving direction of the substrate is referred to as the second direction and the moving direction of the head is referred to as the first direction,
When the arrangement of the outermost printing units among the printing units is parallel to the first direction and the second direction, the virtual substrate has a grid arranged in the first direction and a length in the second direction. is expressed as
If the arrangement of the outermost printing units among the printing units is not parallel to the first direction or the second direction, the virtual substrate is expressed only as a grid.

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