JP6547473B2 - Printing method - Google Patents

Description

  The present invention relates to a printing method for printing a plurality of designs of the same shape on a printing medium while changing the relative position between the printing medium and the print head.

Heretofore, frequency selective surfaces (FSS) having transmission band selectivity (selective transmission or selective shielding) by disposing a frequency selection element on the surface of a substrate are known (e.g., for example, (See Patent Document 1 below).
Patent Document 1 below discloses an antenna having the ability to resonate in a specific frequency band by arranging a frequency selective element of the same shape on a plane.

Also, conventionally, when printing on a substrate, a technique is known in which printing is performed by three-dimensionally changing the relative position between the substrate and the print head using an articulated robot.
For example, Patent Document 2 below discloses a technique in which a multi-joint robot is provided with a print head as a tool and printing is performed on a curved surface of an object.

For example, as a method of adding a frequency selection element to a member having a curved surface shape such as an aircraft fuselage, as shown in the following Patent Document 2, a multi-joint robot holds a print head and performs printing while moving three-dimensionally The method is taken.
More specifically, a frequency selective element is formed by discharging a conductive ink such as a silver nanoparticle-containing ink into a predetermined shape and curing it using an ink jet print head.
In general, an ink jet print head has a plurality of ink ejection nozzles arranged in a direction perpendicular to the moving direction of the printing material, and ejects ink at regular intervals based on image data of a bit map which becomes a plate substitute. I have control. The print head has a predetermined width, and covering the print area with this width enables efficient printing.

U.S. Pat. No. 6,836,258 JP 2011-514234 gazette

FIG. 10 is an explanatory view showing a printing result when a defect occurs in the print head in the printing apparatus according to the prior art.
FIG. 10 shows a state in which a plurality of cross dipole type frequency selection elements (hereinafter referred to as “cross dipole type elements 82”) are printed on a planar base material 80. The print head of the printing apparatus has a width that can print two cross dipole elements 82 per scan. The cross dipole element 82 is constituted by a first dipole portion 82A which is a line segment along the scanning direction of the print head, and a second dipole portion 82B which is a line segment orthogonal to the scanning direction of the print head There is.
Here, when ink clogging occurs in a part of the ink nozzle of the print head, for example, a part of the ink nozzle for printing the element 84 on the left side of the paper surface of two cross dipole type elements printed per scanning. The printing defect F occurs in the first dipole portion 82A of the element 84, and the length in the longitudinal direction of the second dipole portion 82B is cut.
Ink jet printing has a problem that printing defects are likely to occur due to clogging of ink nozzles, and in particular, when a break such as defect F occurs in the frequency selective element, a shift occurs in the resonant frequency of the element to cause performance of the frequency selective plate. There is a problem that the
The dominant factor determining the performance of the frequency selective element is the dipole length constituting the element, and the element is elongated as compared to the influence of a break along the longitudinal direction of the element (a break in the first dipole portion 82A) A break in the direction (break in the second dipole portion 82B) has a large influence on the element performance.

  The present invention has been made in view of the problems of the prior art described above, and it is an object of the present invention to improve print quality when printing a plurality of designs of the same shape.

According to a first aspect of the present invention, there is provided a printing method according to the first aspect of the present invention, in which a plurality of designs of the same shape are printed on the print medium while changing the relative position between the print medium and the print head. A shape obtaining step of obtaining shape data of the pattern; a dividing step of dividing the pattern into a plurality of line segments each having a predetermined thickness and extending in different directions; And d) printing the line segment by linearly moving the print head or the printing medium along the extending direction, the printing step being performed on each of the plurality of line segments , And dividing the pattern so that the thickness of the line segment is equal to or less than a predetermined width smaller than the head width of the print head, and the pattern has a width larger than the predetermined width. Extend in the direction of While dividing into the first line segment group, the entire pattern is divided into the second line segment group extending in the second direction different from the first direction, and in the printing step, the first line segment group is divided into The line segments included are printed one by one along the first direction, and the line segments included in the second line segment group are superimposed on the first line segment group along the second direction. one by one to print, and wherein a call.
The printing method according to the invention of claim 2 is characterized in that, in the dividing step, when the pattern includes a portion of a curve, the portion of the curve is approximated to a polygon formed by a plurality of line segments. I assume.
In the printing method according to the invention of claim 3, the print head is an ink jet print head provided with an ink discharge port for discharging the ink forming the pattern to the print target, and in the printing step, the ink jet The printing is performed by discharging the ink from a part of the ink discharge ports provided in the print head.
The printing method according to the invention of claim 4 is characterized in that, in the printing step, printing is performed using a multi-axis robot while changing the relative position between the printing medium and the print head.
The printing method according to the invention of claim 5 is characterized in that the pattern is a frequency selection element.

According to the present invention, when printing a plurality of designs of the same shape on the printing medium, the design to be printed is divided into a plurality of line segments, and the print head or printing medium is extended along the extension direction of each line segment. Since the printing is performed by linearly moving the printing head, printing can be performed without causing a break that divides the pattern in the longitudinal direction even if a defect occurs in a partial area of the print head.
According to the present invention, since the design is divided into line segments equal to or smaller than a predetermined width smaller than the head width of the print head, printing of one or more line segments can be completed by one scan of the print head.
According to the present invention, when the symbol has a width larger than the predetermined width, the entire symbol is divided into two types of line segments, and the respective line segments are superimposed and printed. Even in the case of printing a pattern having a large area when a problem occurs, printing can be performed without causing a break that divides the figure.
According to the present invention, when the pattern includes the portion of the curve, the portion of the curve is approximated to a polygon formed by a plurality of line segments, so that disconnection occurs even when the pattern includes the portion of the curve Printing can be performed.
According to the present invention, since printing is performed using only a part of the ink discharge ports provided in the inkjet print head, the ink discharge port in which the ink is clogged when the ink clogs in a part of the ink discharge ports Printing can be performed in other areas on the print head, which is advantageous in extending the usable life of the print head and reducing the printing cost.
According to the present invention, printing is performed using the multi-axis robot while changing the relative position between the printing medium and the print head, which is advantageous in improving the degree of freedom of printing on the printing medium.
According to the present invention, it is possible to print the frequency selective element without causing a break in the longitudinal direction, which is advantageous in stabilizing the performance of the frequency selective plate (FSS).

FIG. 1 is an explanatory view showing a configuration of a printing apparatus 10 according to an embodiment. 5 is an explanatory view showing a configuration example of an articulated robot 104. FIG. 5 is a flowchart showing the procedure of print processing in the printing apparatus 10; It is an example of division into the line segment of a frequency selection element. It is an example of division into the line segment of a frequency selection element. It is an example of division into the line segment of a frequency selection element. It is an example of division into the line segment of a frequency selection element. It is an example of division into the line segment of a frequency selection element. FIG. 6 is an explanatory view showing an example of a frequency selection element printed using the printing apparatus 10. FIG. 10 is an explanatory view showing a printing result when a defect occurs in the print head in the printing apparatus according to the prior art.

Hereinafter, preferred embodiments of a printing method according to the present invention will be described in detail with reference to the accompanying drawings.
In the present embodiment, the case where the printing method according to the present invention is applied to a printing apparatus that performs printing while changing the relative position between the printing medium and the print head using an articulated robot will be described as an example. .
Further, in this embodiment, a plurality of frequency selection elements are printed as a symbol of the same shape.

FIG. 1 is an explanatory view showing the configuration of a printing apparatus 10 according to the embodiment.
The printing apparatus 10 prints a wiring pattern on the surface of the substrate 20. In the present embodiment, the planar base material 20 is used as an example of the printing object (work).
The printing apparatus 10 includes a print head 102, an articulated robot 104, a print control device 108, and an ink curing unit (not shown), and prints an image on the surface of a substrate 20.

The print head 102 is supported by the articulated robot 104 so as to be movable, and is provided with a plurality of ink nozzles 102 A (ink ejection ports) for ejecting ink for forming an image to the substrate 20. By using the articulated robot 104, the moving direction of the print head 102 relative to the substrate 20 can be arbitrarily adjusted.
The print head 102 is supported downward so that, for example, the ink ejection direction from the ink nozzle 102A substantially matches the gravity direction.
The ink nozzles 102A are arranged in a line in the width direction of the print head 102. When the articulated robot 104 moves the print head 102, the orientation of the print head 102 is adjusted so that the width direction of the print head 102 is orthogonal to the movement direction of the print head 102.
The print head 102 has a width of, for example, about 3 to 4 cm, and about 500 ink nozzles 102A are disposed in this width.

The ink ejected from the print head 102 is, for example, a curable ink that is cured by energy irradiation. The pattern of the frequency selective element is drawn with a curable ink using a conductive material, and the ink is cured using the ink curing means, whereby the frequency selective element can be formed on the surface of the base 20.
The ink curing means cures the curable ink discharged on the surface of the substrate 20 by irradiating, for example, a laser, a heat source, flash light, UV light, etc., according to the type of the curable ink.
The ink curing means can improve safety by being fixed and installed on a support member or the like without being provided as a tool in the articulated robot.

The articulated robot 104 changes the relative position between the substrate 20 and the print head 102 by moving the work point while holding the print head 102 fixed to the work point.
In FIG. 1, a state in which the print head 102 is held by the articulated robot 104 is illustrated. Specifically, the articulated robot 104 is a multi-axis robot that can move in the axial direction, and is preferably a multi-axis robot that has four or more axes of movement.
In the present embodiment, an articulated robot 104 which is a six-axis articulated robot is used as the multi-axial robot.

FIG. 2 is an explanatory view showing a configuration example of the articulated robot 104. As shown in FIG.
The articulated robot 104 shown in FIG. 2 is a six-axis articulated robot, and mainly comprises a body 104A, an arm 104B, and a wrist 104C.
In the present embodiment, the print head 102 is supported by the wrist portion 104C via a jig, and is moved following the movement of the articulated robot 104.

The body portion 104A of the articulated robot 104 is rotatable around the S axis, and can be rocked back and forth around the L axis.
The arm portion 104B of the articulated robot 104 is rotatable about the R axis, and can be pivoted up and down about the U axis.
The wrist portion 104C of the articulated robot 104 is rotatable around the T axis, and can be swung up and down around the B axis.
More specifically, the moving axes (S-axis, L-axis, R-axis, U-axis, T-axis, B-axis) of each part (body part 104A, arm part 104B, wrist part 104C) of the articulated robot 104 A spindle along the shaft and a motor for rotating each spindle are provided. The amount of rotation of each motor is controlled by a print control device 108 described later.

As a coordinate system that defines the position and posture of the articulated robot 104, a base coordinate system (X, Y, Z) whose origin is the contact center of the body portion 104A and a jig supported by the work point (wrist portion 104C) There is a tool coordinate system (Xm, Ym, Zm) whose origin is at the tip end). The base coordinate system does not change as a reference of other coordinate systems, but the tool coordinate system changes due to the angle change of each axis.
In order to change the position and orientation of the articulated robot 104, movement amounts (position deviation and rotation deviation) and displacement speeds are input to each coordinate system.

  Returning to the description of FIG. 1, the print control device 108 uses the shape data of the pattern to be printed by the printing apparatus 10, the arrangement position of the pattern on the base 20, and print instruction information including print direction information indicating the print direction of the pattern. Based on the movement direction and movement amount of the articulated robot 104, the print head 102 is moved to a desired position with respect to the substrate 20 (robot controller function), and the ink ejection timing by the print head 102 and The discharge amount is controlled to control printing of a desired image on the substrate 20 (print driver function).

The print control device 108 includes, for example, a CPU, a ROM that stores and stores control programs, a RAM as an operation area of the control program, an EEPROM that rewritably holds various data, an interface unit that interfaces with peripheral circuits, and the like. It is a computer comprised.
The print control device 108 implements a main controller, a robot controller that controls the articulated robot 104, and a print driver that controls the print head 102 by the CPU executing various programs.
Note that these functions may be performed by separate processing devices.

FIG. 3 is a flowchart showing the procedure of the printing process in the printing apparatus 10.
The printing apparatus 10 first acquires a pattern to be printed this time, that is, shape data of the frequency selection element and position information indicating the arrangement position of each frequency selection element on the base 20 (step S300).
The acquisition of the shape data is performed, for example, by the operator selecting the shape and size of the frequency selection element to be printed this time on the monitor of the print control device 108.
Alternatively, shape data may be input to the print control device 108 from an external device.
The frequency selection element to be specified is not limited to one type (the same shape and size), and plural types of frequency selection elements may be periodically arranged.
In order to obtain position information, for example, the operator inputs the arrangement pattern of the frequency selection elements and the interval between the elements on the monitor of the print control device 108, and the print control device 108 selects each frequency on the substrate 20 It is performed by calculating the arrangement position of the element. As an arrangement pattern of the frequency selection elements, for example, there is a square arrangement, an equilateral triangle arrangement or the like.

Next, the print control device 108 divides the designated frequency selection element into a plurality of line segments each having a predetermined thickness and extending in different directions (step S302). The division process may be performed by the operator operating the print control device 108.
At this time, the symbol is divided such that the thickness of the divided line segment is equal to or less than a predetermined width smaller than the head width of the print head 102.
The predetermined width is, for example, a width that can be printed by a predetermined number of adjacent ink nozzles 102A of the print head 102. That is, the width is a printable width using only a part of the ink nozzles 102A included in the print head 102.
4 to 8 show examples of division of the frequency selection element into line segments.
Note that the size (width) of each frequency selection element shown in FIGS. 4 to 8 is smaller than the head width of the print head 102, and the width of the line constituting each frequency selection element shown in FIGS. Is smaller than the above-mentioned predetermined width.

FIG. 4A shows a cross dipole type frequency selection element 50.
In this case, the frequency selection element 50 is divided into a first line segment 50A extending in the direction D1 as shown in FIG. 4B and a second line segment extending in the direction D2 orthogonal to the direction D1 as shown in FIG. 4C. Divide into 50B. Further, the thickness of each line segment is set to the size of the frequency selection element 50 designated in step S300.

FIG. 5A shows a tripole frequency selection element 52.
In this case, as shown in FIG. 5D, the frequency selection element 52 includes a first line segment 52A extending in the direction D3 as shown in FIG. 5B and a second line segment 52B extending in the direction D4 as shown in FIG. 5C. And a third line segment 52C extending in the normal direction D5. Further, the thickness of each line segment is set to the size of the frequency selection element 52 designated in step S300.

FIG. 6A is a circular loop type frequency selective element 54, which includes the points of the curve.
In this case, first, as shown in FIG. 6B, the circular portion (the entire portion of the frequency selection element 54) is approximated to a polygon formed by a plurality of line segments. In FIG. 6B, the circular frequency selective element 54 is approximated to an octagonal loop element 56.
Then, the octagonal loop element 56 is divided into straight lines 56A to 56H extending in the directions D6 to D13, respectively.

FIG. 7A shows a square patch frequency selection element 58 whose width is larger than the predetermined width.
In this case, first, as shown in FIG. 7B, the entire symbol of the frequency selection element 58 is divided into a first line segment group 58A extending in the direction D14 (first direction). Next, as shown in FIG. 7C, the entire symbol of the frequency selection element 58 is divided into a second line segment group 58B extending in a direction D15 (second direction) different from the direction D14 (first direction).
The thickness W of each of the line segments constituting the first line segment group 58A and the second line segment group 58B is equal to or less than the predetermined width. Moreover, the thickness W of each line segment may not be constant. The direction D14 and the direction D15 may be different directions, and may not be orthogonal to each other. Alternatively, the frequency selection element 58 may be divided into three or more line segment groups, and printing may be performed by being superimposed from three or more directions.

FIG. 8A is a frequency selective element 60 of a circular patch, the width of which is greater than the predetermined width and includes the location of the curve.
In this case, first, as shown in FIG. 8B, the circular portion (the entire portion of the frequency selection element 60) is approximated to a polygon formed by a plurality of line segments. In FIG. 8B, the circular frequency selective element 60 is approximated to an octagonal patch element 62.
Thereafter, the entire pattern of patch element 62 is divided into first line segment group 62A extending in direction D16 (first direction), and the entire pattern of patch element 62 is different from direction D16 (first direction) It is divided into a second line segment group 62B extending in D17 (second direction).
As in the case of the square patch shown in FIG. 7, the thickness W of each of the line segments constituting the first line segment group 62A and the second line segment group 62B is equal to or less than the predetermined width, and the thickness W of each line segment is constant. It does not have to be. The direction D16 and the direction D17 may be different directions, and may not be orthogonal to each other. Also, the frequency selection element 62 may be divided into three or more line segment groups, and printing may be performed by being superimposed from three or more directions.
In the case of planar patches as shown in FIG. 7 and FIG. 8, the shape may be printed a plurality of times with the printing direction being made different, without being divided into a plurality of line segments.

Returning to the description of FIG. 3, the printing apparatus 10 linearly moves the print head 102 along the extension direction of each line segment divided in step S302 to print the line segment, for each of the plurality of line segments. Do.
That is, one of the line segments divided in step S302 is selected, the print head 102 is linearly moved along the extension direction of the line segment, and the line segment is printed on the substrate 20 (step S304). Until all line segments constituting the frequency selection element are printed (step S306: No), the moving direction of the print head 102 is changed (step S308), and the process returns to step S304 to repeat printing of the remaining line segments. return.
Then, when all the line segments constituting the frequency selection element are printed (step S306: Yes), the processing according to this flowchart ends.

  When the frequency selection element is a patch type (see FIGS. 7 and 8), the line segments included in the first line segment group are printed one by one along the first direction, and the first line segment group is printed. And print the line segments included in the second line segment group one by one along the second direction. That is, printing is performed overlapping from two directions.

In step S304, if the print head 102 has a width capable of printing a plurality of frequency selection elements per scan, the plurality of frequency selection elements are printed per scan.
In the case where the frequency selective elements are printed in the same arrangement as in FIG. 10 as an example, first, the print head 102 is scanned a plurality of times along the extending direction of the first dipole portion 82A to Print all the dipole parts 82A. At this time, two first dipole portions 82A are printed two by two in the width direction for one scan.
Next, the moving direction of the print head 102 is changed to the extending direction of the second dipole portion 82B, and scanning is performed a plurality of times along the extending direction of the second dipole portion 82B. Print all the dipole parts 82B.

FIG. 9 is an explanatory view showing an example of the frequency selection element printed using the printing apparatus 10. As shown in FIG.
FIG. 9 shows a state in which the cross dipole type frequency selection element 64 is printed, and the frequency selection element 64 is orthogonal to the first dipole portion 64A extending in the first direction D18 and the first direction D18. The second dipole portion 64B extends in the second direction D19.
Here, it is assumed that a defect occurs in part of the ink nozzle 102A and a defect F occurs in the first dipole portion 64A.
Conventionally, the frequency selection element 64 is printed by one scan, and the ink nozzle 102A printed the first dipole portion 64A also at the intersection region C of the first dipole portion 64A and the second dipole portion 64B. As a result of the printing in the above, a break occurs in the frequency selection element 64 (see FIG. 10).
On the other hand, when printing is performed using the printing apparatus 10, two scans are performed for printing of the frequency selection element 64. That is, scanning along the first direction D18 and scanning along the second direction D19. In this case, the possibility that the ink nozzle 102A having a defect at the second scan may print the second dipole portion 64B is very small.
For this reason, as shown in FIG. 9, the disconnection due to the defect F is complemented in the intersection area C, and conduction can be obtained.

Furthermore, in the printing apparatus 10, since only a part of the ink nozzles 102A is used at the time of printing, the usable period of the print head 102 can be extended to reduce the printing cost.
That is, when defects occur in some of the ink nozzles 102A, printing can be performed using only the ink nozzles 102A in which no defects occur by adjusting the printing position.
In inkjet printing, nozzle clogging is a major problem in print quality. When printing using the full width of the print head 102, if any ink nozzle 102A clogs the ink, the entire print head 102 needs to be replaced immediately, but in general the print head 102 is expensive and printing The cost goes up.
In the printing apparatus 10, it is possible to continue to use only the good ink nozzles 102A free from ink clogging, and the life of the print head 102 can be substantially extended substantially.

As described above, in the printing method according to the embodiment, when printing a plurality of frequency selective elements of the same shape on the base material 20, the frequency selective elements to be printed are divided into a plurality of line segments. Since printing is performed by linearly moving the print head 102 along the extending direction, printing can be performed without causing a break that divides the frequency selection element in the longitudinal direction even when a failure occurs in a partial area of the print head 102. It can be carried out.
In addition, since the printing method according to the embodiment divides the frequency selection element into line segments smaller than a predetermined width smaller than the head width of the print head 102, one scan of the print head 102 performs one or more line segments. The printing can be completed.
In the printing method according to the embodiment, when the frequency selection element has a width larger than the predetermined width, the entire frequency selection element is divided into two types of line segment groups, and the respective line segment groups are superimposed and printed. Even when printing a frequency selective element having a large area when a defect occurs in a partial area of the print head 102, printing can be performed without causing disconnection for dividing the frequency selective element.
Further, in the printing method according to the embodiment, when the frequency selection element includes the portion of the curve, the portion of the curve is approximated to a polygon formed by a plurality of line segments. Even in the case of including, printing can be performed without causing disconnection.
In the printing method according to the embodiment, since printing is performed using only a part of the ink nozzles 102A included in the ink jet print head 102, the ink is clogged in some of the ink nozzles 102A. Printing can be performed in other areas on the print head 102 by avoiding the clogged ink nozzles 102 A, which is advantageous in extending the usable period of the print head 102 and reducing the printing cost.
In the printing method according to the embodiment, printing is performed while changing the relative position between the substrate 20 and the print head 102 using the articulated robot 104 which is a multi-axis robot. It is advantageous in improving the degree of freedom.
Further, the printing method according to the embodiment can print the frequency selective element without causing a break in the longitudinal direction, which is advantageous in stabilizing the performance of the frequency selective plate (FSS).

In the present embodiment, the frequency selection element is described as an example of the pattern to be printed. However, the present invention is not limited to this, and the present invention can be widely applied to printing a plurality of patterns having the same shape.
Further, in the present embodiment, the base material 20 is flat, but for example, a base material having a curved surface such as a hemispherical base may be used.
When the flat substrate 20 is used, instead of using the articulated robot 104, for example, the print head 102 can be moved in one direction, and the substrate 20 can be rotated in any direction by 360 degrees. The angle of the moving direction of the print head 102 with respect to the substrate 20 may be arbitrarily adjustable by placing it on a rotary table.
For example, while fixing the print head 102, printing may be performed by moving the substrate 20 by setting the substrate 20 on a movable table or the like.

  10: printing apparatus 102: print head 102A: ink nozzle 104: articulated robot 108: printing control device 20: base material 50, 52, 54, 56, 58, 60, 62, 64 ... frequency selective element, F ... defective.

Claims (5)

A printing method for printing a plurality of designs of the same shape on the print medium while changing the relative position between the print medium and the print head,
A shape acquisition step of acquiring shape data of the pattern;
A dividing step of dividing the pattern into a plurality of line segments each having a predetermined thickness and extending in different directions;
Performing a step of linearly moving the print head or the printing medium along the extending direction of the line segment and printing the line segment on each of the plurality of line segments ;
In the dividing step, the symbol is divided such that the thickness of the line segment is equal to or less than a predetermined width smaller than the head width of the print head, and the symbol has a width larger than the predetermined width. The whole is divided into a first line segment group extending in a first direction, and the whole design is divided into a second line segment group extending in a second direction different from the first direction,
In the printing step, line segments included in the first line segment group are printed one by one along the first direction, and are included in the second line segment group so as to be superimposed on the first line segment group. Printing the line segments one by one along the second direction,
Printing wherein a call. In the dividing step, when the pattern includes a portion of a curve, the portion of the curve is approximated to a polygon formed by a plurality of line segments,
The printing method according to claim 1, wherein a. The print head is an ink jet print head provided with an ink discharge port for discharging the ink forming the pattern to the printing material,
In the printing step, printing is performed by discharging the ink from a part of the ink discharge ports provided in the ink jet print head.
The printing method according to claim 1 or 2 , characterized in that: In the printing step, printing is performed using a multi-axis robot while changing the relative position between the printing medium and the print head.
The printing method according to any one of claims 1 to 3 , characterized in that: The symbol is a frequency selection element,
The printing method according to any one of claims 1 to 4 , characterized in that:

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