Method for manufacturing board with printing layer and printing device

Abstract

The invention provides a method for manufacturing a plate with a printing layer and a printing device, which can efficiently form a printing layer on a plate with a bending part by using an ink jet method. A method for manufacturing a plate with a printed layer is a method for forming a printed layer on a main surface of a plate having a curved portion curved in a plate thickness direction using an ink jet method, in which a plurality of print heads are used, each of the plurality of print heads having at least one nozzle, and each of the plurality of print heads having a curved portion curved in a plate thickness direction. When forming a printing layer on the main surface by moving the plurality of print heads and the plate relative to each other and discharging ink from the nozzles of the plurality of print heads, the plurality of print heads and the plate are moved relative to each other such that the distance from the nozzles discharging the ink to the main surface is 20 mm or less.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a plate with a printing layer and a printing device. Background Art

[0002] A car navigation system, an audio system or other in-vehicle information device or a mobile communication device has a display device. A protective cover of a plate-shaped transparent plate is provided on the front surface of the display of the display device via an adhesive layer. A light-shielding printed layer is provided on the display side surface of the protective cover, for example, in a frame shape. The printed layer has the function of hiding the wiring on the display side to maintain the appearance, or hiding the illumination light of the backlight to prevent the illumination light from leaking from the periphery of the display.

[0003] In recent years, the cover glass of an in-vehicle display device is required to be large and have a complex shape with a curved portion. As a method for forming a printed layer on a curved surface, for example, an inkjet method described in Patent Document 1 is known.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-197850

[0005] However, in the method described in Patent Document 1, a single inkjet printing head is used. Therefore, if the printed object becomes larger, the printing head needs to be moved back and forth many times for printing, which results in a problem of low production efficiency. Summary of the invention

[0006] The present invention provides a method for manufacturing a plate with a printed layer and a printing device capable of efficiently forming a printed layer on a plate having a bent portion by using an inkjet method.

[0007] A method for manufacturing a plate with a printed layer according to one embodiment of the present invention is a method for forming a printed layer on a main surface of the plate having a bent portion bent along a thickness direction of the plate by using an inkjet method, wherein a plurality of print heads are used, each of the plurality of print heads having at least one nozzle, and when the printed layer is formed on the main surface by relatively moving the plurality of print heads and the plate and discharging ink from the nozzles of the plurality of print heads, the plurality of print heads and the plate are relatively moved in such a manner that a distance from the nozzles discharging the ink to the main surface is less than 20 mm.

[0008] A printing device in one form of the present invention is a printing device for manufacturing a plate with a printed layer by forming a printed layer on a main surface of the plate having a bent portion bent along the thickness direction of the plate using an inkjet method, wherein the printing device comprises: a plurality of print heads, each print head having at least one nozzle; a discharge control unit, which forms the printed layer on the main surface by discharging ink from the nozzles of the plurality of print heads; and a relative moving unit, which relatively moves the plurality of print heads and the plate in such a manner that the distance from the nozzles for discharging the ink to the main surface is less than 20 mm.

[0009] According to the present invention, it is possible to provide a method for manufacturing a board with a printed layer and a printing device capable of efficiently forming a printed layer on a board having a bent portion using an inkjet method. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of a plate with a printed layer according to one embodiment of the present invention, Figure 1 (A) is the top view, Figure 1 (B) is a cross-sectional view taken along the IB-IB line of (A).

[0011] Figure 2 It is a side view showing a schematic structure of the printing device in the above-mentioned embodiment.

[0012] Figure 3 It is a plan view showing a schematic structure of the printing device in the above-mentioned embodiment.

[0013] Figure 4 It is a schematic diagram showing the arrangement state of nozzles of the inkjet head in the above-mentioned one embodiment.

[0014] Figure 5 is a schematic diagram showing the positional relationship between the inkjet head and the plate when the printed layer is formed in the above-mentioned one embodiment, Figure 5 (A) shows the positional relationship when the printed layer is formed on the horizontal surface of the plate, Figure 5 (B) shows the positional relationship when the printed layer is formed on the inclined surface portion of the first plate.

[0015] Figure 6 It is a block diagram showing a schematic configuration of a control device in the above-mentioned one embodiment.

[0016] Description of Reference Numerals

[0017] 1…printing device; 21…print head; 212…nozzle; 3…water head pressure maintaining unit; 4…relative moving mechanism (relative moving unit); 552…discharge control unit; 553…print head movement control unit (relative moving unit); B1, B2, B3, B4…first boundary, second boundary, third boundary, fourth boundary; G…board; G1…first main surface; GA1, GA2…first flat portion, second flat portion; GB1, GB2…first curved portion, second curved portion; GC…inclined portion; GP…board with printing layer; GQ…printing area; GR…non-printing area; M…horizontal plane; N…ink; P…printing layer. DETAILED DESCRIPTION

[0019] The preferred embodiment of the present invention is described below. In addition, the present invention is not limited to the embodiment, and when there are multiple embodiments, embodiments formed by combining the embodiments are also included. In addition, numerical values ​​include rounded ranges.

[0020] (Board with printed layer)

[0021] First, the structure of the plate with a printed layer according to the present embodiment will be described.

[0022] Figure 1 Schematic diagram of a board with a printed layer, (A) is a top view, and (B) is a cross-sectional view along the IB-IB line of (A).

[0023] Figure 1 The printed-layer plate GP shown in (A) and (B) is a laminated body including a plate G and a printed layer P formed on the plate G and having a rectangular shape in a plan view.

[0024] The plate GP with a printed layer may be used for any purpose, but is preferably used as a cover glass for a display, preferably as a cover glass for a vehicle-mounted display. That is, in the present embodiment, it is preferred to manufacture a display device, preferably a vehicle-mounted display device, by providing the plate GP with a printed layer on the display surface side of the display (not shown). The display is preferably bonded to the printed layer P side of the plate GP with a printed layer.

[0025] In the following description, the long side direction of the printed board GP is defined as the X-axis direction, the short side direction is defined as the Y-axis direction, and the thickness direction is defined as the Z-axis direction. Figure 1 The right direction in (A) and (B) is the X1 direction, and the left direction is the X2 direction. Figure 1 The upward direction in (A) is the Y1 direction, and the downward direction is the Y2 direction. Figure 1 The upward direction in (B) is referred to as the Z1 direction, and the downward direction is referred to as the Z2 direction.

[0026] (plate)

[0027] The plate G includes: a first main surface G1 for forming a printed layer P; and a second main surface G2 located on the opposite side of the first main surface G1. The plate G includes a first flat portion GA1, a first curved portion GB1, a sloping portion GC, a second curved portion GB2, and a second flat portion GA2. In the present embodiment, the first and second flat portions GA1, GA2, and the sloping portion GC are planes with a curvature radius of 10,000 mm or more, but are not limited thereto and may also be curved surfaces. In addition, in the present application, a surface with a curvature radius of 10,000 mm or more is defined as a plane, and a surface with a curvature radius of less than 10,000 mm is defined as a curved surface. The curvature radius of the first and second curved portions GB1, GB2 is smaller than the curvature radius of the first and second flat portions GA1, GA2, and the sloping portion GC. The curvature radius of the first and second curved portions GB1, GB2 is less than 10,000 mm, for example, less than 1,000 mm, or less than 500 mm, or less than 300 mm. The curvature radius of the first and second bent portions GB1 and GB2 is preferably 10 mm or more, more preferably 50 mm or more.

[0028] The first flat portion GA1 constitutes a portion of the plate G on the X2 direction side.

[0029] The first bent portion GB1 is a portion adjacent to the X1 direction side of the first flat portion GA1 and is bent so that the first principal surface G1 becomes concave and the second principal surface G2 becomes convex. The first bent portion GB1 is bent around a bending axis parallel to the Y-axis direction. The bending axis can be said to be the central axis of the curvature circle of the portion of the second principal surface G2 that constitutes the first bent portion GB1.

[0030] The inclined portion GC is adjacent to the first bent portion GB1 in the X1 direction and is inclined at an angle θ1 relative to the first flat portion GA1. When the first flat portion GA1 is parallel to the XY plane, that is, the horizontal plane M, the inclined portion GC is inclined at an angle θ1 relative to the horizontal plane M.

[0031] The second bending portion GB2 is a portion adjacent to the X1 direction side of the inclined portion GC, and is bent in such a manner that the first principal surface G1 becomes a convex shape and the second principal surface G2 becomes a concave shape. The second bending portion GB2 is bent around a bending axis parallel to the Y-axis direction as the center, similarly to the first bending portion GB1. The bending axis can be said to be the center axis of the curvature circle of the portion of the first principal surface G1 that constitutes the second bending portion GB2.

[0032] The second flat portion GA2 is adjacent to the X1 direction side of the second bent portion GB2 and constitutes a portion on the X1 direction side of the plate G. The second flat portion GA2 is parallel to the first flat portion GA1.

[0033] The plate G is not limited to the above-mentioned shape, and may be any shape as long as it has at least one curved portion, but preferably has a curved surface that is concave on the first main surface G1 side. Examples of such a shape include a curved shape in which the first main surface G1 is a curved surface as a whole, an S-shaped shape having at least one curved portion that is concave or convex on the first main surface G1 side, and a Figure 1 The shape shown does not include the first flat portion GA1 and the first bent portion GB1. Figure 1 The shape shown does not include the second curved portion GB2 and the second flat portion GA2. As an S-shaped shape, a shape including the first flat portion GA1, the first curved portion GB1, the inclined portion GC, the second curved portion GB2 and the second flat portion GA2 as described above can be cited, and a shape in which the first flat portion GA1, the inclined portion GC and the second flat portion GA2 are replaced by a curved surface can also be cited. In addition, a shape including three or more curved portions can also be used. If such a shape is used, it is difficult to form a printed layer by other methods such as screen printing, and the printing method based on this embodiment is particularly effective. The second flat portion GA2 can also be inclined relative to the first flat portion GA1. The radius of curvature of the second curved portion GB2 can be the same as or different from the radius of curvature of the first curved portion GB1. The plate G can also include a curved portion and a flat portion at the end on the X1 direction side or the X2 direction side. The bending axis may not be parallel to the Y-axis direction.

[0034] In addition, the plate G is a rectangle in a plan view, but may be a polygon, a circle, an ellipse, or any other shape.

[0035] It is preferable that the plate G does not have a plurality of bending axes in different directions in one bent portion, that is, has only a bending axis in one direction.

[0036] When the plate G has a plurality of bent portions, it is preferably as follows Figure 1 As shown in (A) and (B) of FIG. 1 , the bending axes of the flexures are parallel to each other, but they do not necessarily have to be parallel to each other.

[0037] When the plate G is, for example, glass, the thickness of the plate G is not particularly limited, but in order to effectively perform the chemical strengthening treatment, it is usually preferably 5 mm or less, and more preferably 3 mm or less. In addition, in the case of a cover glass for a vehicle-mounted display device such as a car navigation, from the viewpoint of strength, the thickness of the glass is preferably 0.2 mm or more, more preferably 0.8 mm or more, and further preferably 1 mm or more. That is, the thickness of the plate G when it is glass is preferably 0.2 mm or more and 5 mm or less, more preferably 0.8 mm or more and 3 mm or less, and further preferably 1 mm or more and 3 mm or less.

[0038] The length of the plate G in the direction parallel to the bending axes of the first and second bending portions GB1 and GB2, that is, the width of the plate G is preferably not less than 100 mm and not more than 300 mm. The width here refers to the length along the first main surface G1 from one end to the other end of the plate G in the direction parallel to the bending axes of the first and second bending portions GB1 and GB2.

[0039] The length of the plate G in the direction perpendicular to the bending axes of the first and second bending portions GB1 and GB2 is preferably 350 mm or more and 1000 mm or less. The length here refers to the length along the first main surface G1 from one end to the other end of the plate G in the direction perpendicular to the bending axes of the first and second bending portions GB1 and GB2.

[0040] The sheet G having a width and a length in a direction perpendicular to the bending axes of the first and second bent portions GB1 and GB2 within the above-described preferred ranges is suitable for use as a cover glass for a vehicle-mounted display device, and the printing method of this embodiment is useful.

[0041] The material of the plate G may be any material, including glass, ceramics, resin, wood, metal, etc., but glass is preferred.

[0042] When the plate G is made of glass, the plate G is preferably tempered glass, more preferably chemically tempered glass. When the plate G is chemically tempered glass, the thickness of the DOL, i.e., the compressive stress layer of the plate G, is preferably, for example, 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. In addition, the DOL is preferably, for example, 180 μm or less, more preferably 50 μm or less.

[0043] CS, that is, the surface compressive stress of the compressive stress layer is preferably 500 MPa or more, more preferably 650 MPa or more, and further preferably 750 MPa or more. The upper limit of CS is not particularly limited, but, for example, CS is preferably 1200 MPa or less.

[0044] The method of chemically strengthening glass by chemically strengthening treatment can use a known method. As a molten salt for chemical strengthening treatment, for example, alkali metal nitrates, alkali metal sulfates, and alkali metal chloride salts such as potassium nitrate, sodium nitrate, potassium sulfate, and sodium sulfate can be cited. The above-mentioned molten salt is not limited to use alone, and can also be used in combination with a variety of, or other salts can be mixed in order to adjust the chemical strengthening characteristics. Thus, in the surface layer of plate G, alkaline ions such as Li ions or Na ions are exchanged for other alkaline ions with larger ionic radius in the molten salt, such as Na ions or K ions, and then cooled to near room temperature. Through this ion exchange, a layer, i.e., a compressive stress layer, is formed on the surface layer of plate G by high densification to generate compressive stress. In this way, plate G can be strengthened. The treatment conditions such as the temperature of the molten salt and the immersion time are set to the desired values ​​of CS and DOL.

[0045] The plate G subjected to the chemical strengthening treatment may be further subjected to an acid treatment and an alkali treatment.

[0046] The acid treatment is a treatment in which the plate G subjected to the chemical strengthening treatment is immersed in an acid solution. As a result, at least one of Na and K on the surface of the plate G subjected to the chemical strengthening treatment is replaced by H. That is, the surface layer of the compressive stress layer in the plate G subjected to the chemical strengthening treatment is altered to become a low-density layer with low density.

[0047] In addition, the alkali treatment is a treatment in which the plate G subjected to the acid treatment is immersed in an alkaline solution. In this way, a part or all of the low-density layer formed by the acid treatment is removed. In this way, cracks and hidden damage existing on the surface of the plate G can be removed together with the low-density layer.

[0048] The material of the plate G is arbitrary, and examples thereof include SiO2-Al2O3-Na2O type glass or SiO2-Al2O3-Li2O-Na2O type glass, or soda-lime glass, which are aluminosilicate glass. Among them, aluminosilicate glass is preferred from the viewpoint of strength.

[0049] Examples of the material of the plate G include: a glass material containing, expressed in mole percent on an oxide basis, 50% to 80% of SiO2, 1% to 20% of Al2O3, 6% to 20% of Na2O, 0% to 11% of K2O, 0% to 15% of MgO, 0% to 6% to 6% of CaO, and 0% to 5% of ZrO2; and a glass material containing, expressed in mole percent on an oxide basis, 50% to 80% of SiO2, 1% to 20% of Al2O3, 6% to 20% of Na2O, 0% to 11% of K2O, 0% to 15% of MgO, 0% to 6% to 6% of CaO, and 0% to 5% of ZrO2. Glass materials containing less than 0% SiO2, more than 2% and less than 25% Al2O3, more than 0.1% and less than 20% Li2O, more than 0.1% and less than 18% Na2O, more than 0% and less than 10% K2O, more than 0% and less than 15% MgO, more than 0% and less than 5% CaO, more than 0% and less than 5% P2O5, more than 0% and less than 5% B2O3, more than 0% and less than 5% Y2O3, and more than 0% and less than 5% ZrO2.

[0050] As the material of the plate G, chemically strengthened glass based on aluminosilicate glass, for example, "Dragon Trail (registered trademark)" manufactured by AGC Corporation, can also be used appropriately.

[0051] (Printing layer)

[0052] The printed layer P is formed on the first main surface G1 of the plate G. The printed layer P may be any layer made of a material different from that of the plate G, and may be, for example, a light shielding layer that shields at least one of visible light and infrared light.

[0053] The printed layer P includes a first printed layer P1 , a pair of second printed layers P2 , a third printed layer P3 , a pair of fourth printed layers P4 , and a fifth printed layer P5 .

[0054] The first printed layer P1 is formed at the end portion of the first flat portion GA1 on the X2 direction side. The first printed layer P1 is formed in a rectangular shape extending over the entire width direction of the printed-layer-attached plate GP.

[0055] The pair of second printed layers P2 are formed in a rectangular shape extending from the ends on the Y1 direction side and the Y2 direction side of the first printed layer P1 along the X1 direction to a portion near the boundary between the first flat portion GA1 and the first bent portion GB1.

[0056] The third printed layer P3 is formed from the ends of the pair of second printed layers P2 on the X1 direction side to a portion near the boundary between the second bent portion GB2 and the second flat portion GA2. The third printed layer P3 is formed in a rectangular shape extending over the entire width direction of the printed layer-attached plate GP.

[0057] The pair of fourth printed layers P4 are formed in a rectangular shape extending from the ends on the Y1 direction side and the Y2 direction side of the third printed layer P3 along the X1 direction to a portion near the edge of the second flat portion GA2 on the X1 direction side.

[0058] The fifth printed layer P5 is formed in a rectangular shape along the end edge on the X1 direction side of the second flat portion GA2 so as to connect the end edges on the X1 direction side of the pair of fourth printed layers P4 .

[0059] The area where the printed layer P is formed in the plate GP with a printed layer constitutes a printed area GQ. The area where the printed layer P is not formed in the plate GP with a printed layer constitutes a non-printing area GR. The non-printing area GR includes a first non-printing area GR1 surrounded by a first printed layer P1, a pair of second printed layers P2, and a third printed layer P3, and a second non-printing area GR2 surrounded by a third printed layer P3, a pair of fourth printed layers P4, and a fifth printed layer P5.

[0060] When the display is turned on, an image is displayed in the non-printing area GR. When the printed layer P is a light-shielding layer, the printed area GQ functions as a light-shielding area, and the non-printing area GR functions as a light-transmitting area for transmitting light. The printed area GQ plays a role in improving the appearance of the display device by hiding wiring, etc.

[0061] The printed layer P may be a single layer or a plurality of layers may be stacked.

[0062] The thickness of the printed layer P is preferably 3.0 μm to 10.0 μm, more preferably 3.5 μm to 5.0 μm, and further preferably 4.0 μm to 5.0 μm. When the thickness of the printed layer P is within this range, light leakage from the printed layer P can be suppressed.

[0063] The first boundary B1 between the first non-printing region GR1 and the first printing layer P1, the second boundary B2 between the first non-printing region GR1 and the third printing layer P3, the third boundary B3 between the second non-printing region GR2 and the third printing layer P3, and the fourth boundary B4 between the second non-printing region GR2 and the fifth printing layer P5 are formed as straight lines parallel to the Y-axis direction. The pair of fifth boundaries B5 between the first non-printing region GR1 and the pair of second printing layers P2, and the pair of sixth boundaries B6 between the second non-printing region GR2 and the pair of fourth printing layers P4 are formed as straight lines parallel to the X-axis direction.

[0064] Furthermore, at least one of the first to fourth boundaries B1 to B4 may be inclined with respect to the Y-axis direction, and at least one of the fifth and sixth boundaries B5 and B6 may be inclined with respect to the X-axis direction.

[0065] At least one of the first to sixth boundaries B1 to B6 may have a curved portion, or may have an acute or obtuse corner.

[0066] In addition, the printed layer P is not limited to Figure 1 The shape shown in (A) may not be formed in a part of the periphery of the plate G, or may be formed to provide one or more non-printing regions GR. The printed layer P may be formed at a position away from the edge of the plate G, or may be formed on the entire first main surface G1.

[0067] (Structure of printing device)

[0068] Next, a printing device for forming the printed layer P on the plate G using an inkjet method to manufacture the plate GP with a printed layer will be described.

[0069] Figure 2 It is a side view showing a schematic structure of a printing device. Figure 3 It is a plan view showing a schematic structure of a printing device. Figure 4 It is a schematic diagram showing the arrangement state of nozzles in an inkjet head. Figure 5 The diagram is a schematic diagram showing the positional relationship between the inkjet head and the plate when forming a printed layer. (A) shows the positional relationship when the printed layer is formed on the horizontal surface of the plate, and (B) shows the positional relationship when the printed layer is formed on the inclined surface of the first plate. Figure 6 This is a block diagram showing a schematic configuration of a control device. Figure 3 is from Figure 2 A diagram obtained by observing the printing device from the Z1 direction side, Figure 4 is from Figure 2 The figure obtained by observing the inkjet head from the Z1 direction side, Figure 5 (A) and (B) are from Figure 2 A diagram obtained by observing the inkjet head and the plate from the Y2 direction side.

[0070] Figure 2 and Figure 3 The printing device 1 shown includes a printing unit 2, a water head pressure maintaining unit 3, a relative movement mechanism 4, and a control device 5 described later. In the following description, the X1 direction is referred to as the printing direction, the X2 direction is referred to as the printing reverse direction, the X1 direction and the X2 direction are combined, that is, the X-axis direction is referred to as the printing advancing direction, and the Y-axis direction is referred to as the printing width direction.

[0071] The printing unit 2 discharges ink N by an inkjet method based on the control of the control device 5 .

[0072] The printing unit 2 includes a plurality of print heads 21 and an ink supply unit 22 .

[0073] The plurality of print heads 21 each include a rectangular parallelepiped head body 211. A nozzle plate 211A is provided on the surface on the Z2 direction side of the head body 211. The plurality of print heads 21 are provided at a position closer to the Z1 direction side, i.e., above the plate G held by the relative moving mechanism 4. The plurality of print heads 21 are arranged so that the long side direction of the surface on the Z2 direction side of the head body 211 is parallel to the printing width direction, and are arranged to form two rows parallel to the printing width direction. The plurality of print heads 21 are arranged in a state of being staggered with each other in the printing width direction, and in a state of being staggered alternately on the printing progress direction side and the printing progress opposite direction side. That is, the plurality of print heads 21 are arranged in a so-called staggered state. The plurality of print heads 21 are arranged so that, when viewed from the printing progress direction side, in the mutually adjacent print heads 21, the portion on the Y2 direction side of the print head 21 on the Y1 direction side overlaps the portion on the Y1 direction side of the print head 21 on the Y2 direction side. The length W21 of the head body 211 in each print head 21 in the printing direction is preferably 5 mm or more. The length V21 of the nozzle plate 211A in each print head 21 in the printing direction is preferably 5 mm or more.

[0074] In the following description, the row of the print heads 21 on the printing direction side is referred to as a first print head row 21A, and the row of the print heads 21 on the printing direction side is referred to as a second print head row 21B.

[0075] In addition, in this embodiment, if Figure 3 As shown in the figure, the structure in which six print heads 21 are provided in the printing device 1 is exemplified, but more than two, less than five, or more than seven print heads 21 may be provided. In addition, the plurality of print heads 21 may be arranged to form one or more than three rows parallel to the printing width direction. When three or more rows are formed, they may be arranged in a staggered manner or not. In addition, the plurality of print heads 21 may be arranged to form a row in a direction inclined relative to the X-axis direction on the XY plane.

[0076] Each print head 21 further includes: a plurality of nozzles 212 provided in a head body 211; Figure 6 The piezoelectric element 213 is shown.

[0077] The same number of piezoelectric elements 213 as the number of nozzles 212 is provided. The piezoelectric elements 213 are driven based on the control of the control device 5 to discharge the ink N supplied from the ink supply unit 22 to the nozzles 212 as droplets. In addition, the piezoelectric elements 213 impart vibration to the meniscus of each nozzle 212 based on the control of the control device 5.

[0078] The plurality of nozzles 212 are arranged inside the head main body 211 so that openings for discharging ink N are exposed from the planar lower surface of the nozzle plate 211A.

[0079] like Figure 3 and Figure 4 As shown, the plurality of nozzles 212 are arranged to form a plurality of columns in the printing width direction.

[0080] In the following instructions, Figure 4 and Figure 5 As shown in the figure, the rows of nozzles 212 in each print head 21 are called the first nozzle row 215A, the second nozzle row 215B, the third nozzle row 215C, and the fourth nozzle row 215D in order from the row on the printing direction side. The first nozzle row 215A and the second nozzle row 215B constitute a first nozzle row group 216A. The third nozzle row 215C and the fourth nozzle row 215D constitute a second nozzle row group 216B. In addition, the number of rows of nozzles 212 in each print head 21 may be 1 row, 2 rows, 3 rows, or 5 or more rows.

[0081] The nozzles 212 of the first nozzle array 215A and the nozzles 212 of the second nozzle array 215B are arranged in a state of being staggered with each other in the printing width direction, and are arranged in a state of being staggered alternately on the printing progress direction side and the printing reverse direction side. That is, the nozzles 212 constituting the first nozzle array group 216A are arranged in a so-called staggered shape. Similarly, the nozzles 212 constituting the second nozzle array group 216B are also arranged in a staggered shape. The nozzles 212 constituting the first nozzle array group 216A and the nozzles 212 constituting the second nozzle array group 216B are arranged in different positions in the printing width direction.

[0082] like Figure 4 The distance R21 from the nozzles 212 of the first nozzle array 215A to the end of the nozzle plate 211A in the printing direction and the distance R21 from the nozzles 212 of the fourth nozzle array 215D to the end of the nozzle plate 211A in the opposite printing direction are preferably 0 mm to 20 mm.

[0083] In the following instructions, Figure 4 As shown, two nozzles 212 at the end of the first nozzle array group 216A constituting the first print head array 21A may be referred to as first end nozzles 212A, and two nozzles at the end of the Y2 direction may be referred to as second end nozzles 212B. Two nozzles 212 at the end of the second nozzle array group 216B constituting the first print head array 21A may be referred to as third end nozzles 212C, and two nozzles at the end of the Y2 direction may be referred to as fourth end nozzles 212D.

[0084] Among the nozzles of the first nozzle array group 216A constituting the second print head array 21B, two nozzles at the end on the Y1 direction side may be referred to as fifth end nozzles 212E, and two nozzles at the end on the Y2 direction side may be referred to as sixth end nozzles 212F. Among the nozzles 212 of the second nozzle array group 216B constituting the second print head array 21B, two nozzles 212 at the end on the Y1 direction side may be referred to as seventh end nozzles 212G, and two nozzles at the end on the Y2 direction side may be referred to as eighth end nozzles 212H.

[0085] In each print head 21, the plurality of nozzles 212 are arranged so that the distance D (center-to-center distance) in the printing width direction between a pair of nozzles 212 with the smallest distance in the printing width direction is 5 mm or less, preferably 1 mm or less, and more preferably 0.5 mm or less. For example, the pair of nozzles 212 with the smallest distance in the printing width direction is the nozzle 212 located on the most Y1 direction side of the first nozzle array 215A and the nozzle 212 located on the most Y1 direction side of the third nozzle array 215C.

[0086] In addition, each print head 21 is configured so that when viewed from the printing direction side, the first end nozzle 212A and the sixth end nozzle 212F in the print heads 21 adjacent to each other are positioned in the same printing width direction, the second end nozzle 212B and the fifth end nozzle 212E are positioned in the same printing width direction, the third end nozzle 212C and the eighth end nozzle 212H are positioned in the same printing width direction, and the fourth end nozzle 212D and the seventh end nozzle 212G are positioned in the same printing width direction.

[0087] In addition, if Figure 3 As shown, each print head 21 is arranged so that the width WH from the nozzle 212 located most on the Y1 direction side to the nozzle 212 located most on the Y2 direction side, that is, the printing effective width WH is larger than the width WG of the plate G. With such a structure, a printed layer P of a desired shape can be formed on the plate G by moving each print head 21 only once in the printing direction.

[0088] In addition, the number of nozzles 212 provided in the print head 21 may be one. In addition, the plurality of nozzles 212 may be arranged to form one, two, three, or five or more nozzle rows parallel to the printing width direction. In the case where the plurality of nozzles 212 form a plurality of nozzle rows, the plurality of nozzles 212 may be arranged in a staggered manner or may not be arranged in a staggered manner. In addition, the plurality of nozzles 212 may be arranged to form a row parallel to the X-axis direction.

[0089] like Figure 2 and Figure 5 As shown in (A) and (B) of FIG. 1 , the ink supply unit 22 includes a first ink tank 221, a second ink tank 222, and Figure 6 The ink pressure adjustment unit 223 is shown.

[0090] The first ink tank 221 contains ink N supplied to each print head 21 of the first print head array 21A. Between each print head 21 constituting the first print head array 21A and the first ink tank 221, there are connected: a supply pipe 224 for supplying the ink N in the first ink tank 221 to each nozzle 212 of each print head 21, and a return pipe 225 for returning the ink N in each print head 21 to the first ink tank 221.

[0091] The second ink tank 222 stores ink N supplied to each print head 21 of the second print head array 21B. Supply pipes 226 and return pipes 227 having the same functions as the supply pipes 224 and return pipes 225 are also connected to each print head 21 constituting the second print head array 21B and the second ink tank 222.

[0092] The ink pressure adjustment unit 223 adjusts the pressure of the meniscus of the nozzle 212 of each print head 21 to a predetermined pressure setting value that is lower than the atmospheric pressure based on the control of the control device 5 .

[0093] The ink supply unit 22 may not include the return pipes 225 and 227. For example, the first ink tank 221 may include the same number of tanks as the print heads 21 constituting the first print head array 21A, and supply ink N from each tank to each print head 21. The second ink tank 222 is similar.

[0094] The hydraulic head pressure maintaining unit 3 includes a first printing unit holding member 31 and a second printing unit holding member 32 .

[0095] The first printing unit holding member 31 holds the print heads 21 of the first print head array 21A and the first ink tank 221. The second printing unit holding member 32 holds the print heads 21 of the second print head array 21B and the second ink tank 222.

[0096] The print heads 21 of the first and second print head arrays 21A and 21B and the first and second ink tanks 221 and 222 held by the first and second printing unit holding members 31 and 32 are raised and lowered by the same distance by the driving of the relative moving mechanism 4. Therefore, the change in the head pressure of the ink N caused by the raising and lowering of each print head 21 can be suppressed, and the absolute value of the pressure change of the nozzle 212 relative to the pressure setting value of the meniscus when the print layer P is formed can be maintained at 0.2 kPa or less.

[0097] The relative movement mechanism 4 relatively moves the printing unit 2 including the plurality of print heads 21 and the board G in the X-axis direction.

[0098] The relative movement mechanism 4 includes a plate holding portion 41 and a print head moving portion 42 .

[0099] The plate holding portion 41 holds the plate G from the second main surface G2 side by suction, for example, while the plate G is immobile and the first and second flat portions GA1 and GA2 are parallel to the horizontal plane M. Different plate holding portions 41 are preferably used depending on the three-dimensional shape of the plate G.

[0100] The print head moving unit 42 moves the first and second print unit holding members 31 and 32 in the X-axis direction while maintaining the lower surface of the head body 211 of each print head 21 held by the first and second print unit holding members 31 and 32 in parallel with the horizontal plane M under the control of the control device 5. That is, the print head moving unit 42 moves the first and second print unit holding members 31 and 32 in the X-axis direction while maintaining the opening surface of the nozzle 212 in parallel with the horizontal plane M.

[0101] Furthermore, the print head moving unit 42 independently raises and lowers the first and second printing unit holding members 31 and 32 in the Z-axis direction according to the shape of the first main surface G1 of the board G under the control of the control device 5 .

[0102] For example, Figure 5 As shown in (A), when the printed layer P is formed on the plate horizontal surface GH parallel to the horizontal plane M, the print head moving unit 42 moves the first and second printing unit holding components 31 and 32 along the Z-axis direction in such a way that the distance L1 from the opening surface of the nozzles 212 of all the print heads 21 constituting the first and second print head arrays 21A and 21B to the plate horizontal surface GH is less than 20 mm, preferably less than 10 mm. Figure 1 In the plate G shown in (A) and (B), the first and second flat portions GA1 and GA2 correspond to the plate horizontal surface portion GH. The lower limit of the distance L1 is not particularly limited, but is preferably 1 mm or more, for example.

[0103] like Figure 5 As shown in (B), when the printed layer P is formed on the first plate inclined surface GK1 which is inclined relative to the horizontal plane M in a manner that the X1 direction side is higher than the X2 direction side, the print head moving unit 42 moves the first and second printing unit holding components 31 and 32 along the Z-axis direction in such a manner that the distance L2 from the opening surface of the nozzle 212 of the first nozzle array group 216A located on the X1 direction side among the first and second nozzle array groups 216A and 216B of the print head 21 constituting the first and second print head arrays 21A and 21B to the first plate inclined surface GK1 is less than 20 mm, preferably less than 10 mm. Figure 1 In the plate G shown in (A) and (B), the inclined portion GC and the first and second bent portions GB1 and GB2 correspond to the first plate inclined surface portion GK1. The lower limit of the distance L2 is not particularly limited, but is preferably 1 mm or more, for example.

[0104] Although not shown, when the printed layer P is formed on the second plate inclined surface portion inclined with respect to the horizontal plane M so that the X2 direction side is higher than the X1 direction side, the print head moving unit 42 moves the first and second printing unit holding members 31 and 32 in the Z-axis direction so that the distance from the opening surface of the nozzle 212 of the second nozzle array group 216B located on the X2 direction side among the first and second nozzle array groups 216A and 216B of the print head 21 constituting the first and second print head arrays 21A and 21B to the second plate inclined surface portion is 20 mm or less, preferably 10 mm or less. In this case, the lower limit value of the distance from the opening surface of the nozzle 212 of the second nozzle array group 216B located on the X2 direction side among the first and second nozzle array groups 216A and 216B of the print head 21 constituting the first and second print head arrays 21A and 21B to the second plate inclined surface portion is not particularly limited, but is preferably 1 mm or more, for example.

[0105] In addition, as the print head moving part 42, a combination of a slider mechanism that moves the first and second printing unit holding components 31 and 32 in the X-axis direction and a piston mechanism that lifts and lowers them in the Z-axis direction, or a mechanism such as a 6-axis robot that moves the first and second printing unit holding components 31 and 32 as described above can be used.

[0106] The control device 5 controls the printing unit 2 and the relative movement mechanism 4. Figure 6 As shown, the control device 5 includes a print head position detection unit 51, an input unit 52, a display unit 53, a storage unit 54, and a control unit 55. The control unit 55 is electrically connected to the piezoelectric element 213, the ink pressure adjustment unit 223, the print head moving unit 42, the print head position detection unit 51, the input unit 52, the display unit 53, and the storage unit 54.

[0107] The print head position detection unit 51 detects the position of each print head 21 in the X-axis direction and the Z-axis direction, and outputs a signal corresponding to the detected position to the control unit 55 .

[0108] The input unit 52 is composed of, for example, a touch panel, a physical button, or a two-dimensional code reader. The input unit 52 is used to input various information, and outputs a signal corresponding to the input to the control unit 55. As information input by the input unit 52, shape determination information for determining the three-dimensional shape of the plate G and the printed layer P can be exemplified.

[0109] The display unit 53 displays various information based on the control of the control unit 55 .

[0110] The storage unit 54 is constituted by a well-known storage device such as a HDD (Hard Disk Drive). The storage unit 54 stores a print control program, candidate nozzle information, and various information required for the operation of the printing device 1. The candidate nozzle information includes first candidate information, second candidate information, and third candidate information.

[0111] like Figure 5 As shown in (B) of FIG. 1 , the first candidate information indicates the nozzles 212 that are candidates for use when forming the printed layer P on the first plate inclined surface portion GK1 that is higher on the X1 direction side than on the X2 direction side.

[0112] In the following description, the nozzle 212 that is a candidate for utilization is referred to as a candidate for utilization nozzle 212 .

[0113] The first candidate information indicates that among the nozzles 212 constituting the first and second print head arrays 21A and 21B, only the nozzles 212 of the first nozzle array group 216A are set as candidate use nozzles 212. That is, the first candidate information indicates that only the nozzles 212 that are closer to the first plate inclined surface GK1 than the second nozzle array group 216B and the nozzles 212 whose distance L2 to the first plate inclined surface GK1 can be set to 20 mm or less, preferably 10 mm or less are set as candidate use nozzles 212.

[0114] Among the nozzles 212 set as the candidate nozzles 212 based on the first candidate information, the positions of the first end nozzle 212A and the sixth end nozzle 212F in the printing width direction are the same, and the positions of the second end nozzle 212B and the fifth end nozzle 212E in the printing width direction are the same, but the positions of the other nozzles 212 in the printing width direction are different from each other. Therefore, if the first and second print head arrays 21A and 21B are moved at a constant speed and the ejection frequency of the ink N of the first, second, fifth, and sixth end nozzles 212A, 212B, 212E, and 212F is 0.5 times the ejection frequency of the other nozzles 212, the number of ink N landings per unit area becomes equal.

[0115] In addition, since two candidate nozzles 212 are arranged in the printing progress direction at the predetermined position in the printing width direction, if the discharge frequency of the candidate nozzles 212 at the same position in the printing width direction is set to 0.5 times, that is, 1 / 2 times, the discharge frequency of the other candidate nozzles 212, the number of ink N applied per unit area becomes equal. In the case where F (F is an integer greater than or equal to 3) candidate nozzles 212 are arranged in the printing progress direction at the predetermined position in the printing width direction, if the discharge frequency of the candidate nozzles 212 at the same position in the printing width direction is set to 1 / F times the discharge frequency of the other candidate nozzles 212, the number of ink N applied per unit area becomes equal.

[0116] In addition, when the distance L2 from the opening surface of the nozzle 212 of the first nozzle array group 216A to the first plate inclined surface GK1 is 20 mm or less, preferably 10 mm or less, as shown in FIG. Figure 5As shown in (B), when the distance L3 from the opening surface of the nozzle 212 of the second nozzle array group 216B to the inclined surface GK1 of the first plate is also less than 20 mm, preferably less than 10 mm, all the nozzles 212 constituting the first and second nozzle array groups 216A and 216B can also be set as candidate nozzles 212.

[0117] The second candidate information indicates the candidate nozzles 212 to be used when forming the printed layer P on the second plate inclined surface portion whose X1 direction side is lower than its X2 direction side.

[0118] The second candidate information indicates that among the nozzles 212 constituting the first and second print head arrays 21A and 21B, only the nozzles 212 of the second nozzle array group 216B are set as candidate use nozzles 212. That is, the second candidate information indicates that only the nozzles 212 that are closer to the second plate inclined surface portion than the first nozzle array group 216A and the nozzles 212 whose distance to the second plate inclined surface portion can be set to 20 mm or less, preferably 10 mm or less are set as candidate use nozzles 212.

[0119] Among the nozzles 212 set as the candidate nozzles 212 based on the second candidate information, the third end nozzle 212C and the eighth end nozzle 212H have the same position in the printing width direction, and the fourth end nozzle 212D and the seventh end nozzle 212G have the same position in the printing width direction, but the positions in the printing width direction of the other nozzles 212 are different from each other. Therefore, if the first and second print head arrays 21A and 21B are moved at a constant speed and the ejection frequency of the third, fourth, seventh, and eighth end nozzles 212C, 212D, 212G, and 212H is 0.5 times the ejection frequency of the other nozzles 212, the number of ink landings of the ink N per unit area becomes equal.

[0120] In addition, when the distance from the opening surface of the nozzle 212 of the second nozzle array 216B to the inclined surface of the second plate is less than 20 mm, preferably less than 10 mm, and when the distance L3 from the opening surface of the nozzle 212 of the first nozzle array 216A to the inclined surface of the second plate is also less than 20 mm, preferably less than 10 mm, all the nozzles 212 constituting the first and second nozzle arrays 216A and 216B can also be set as candidate nozzles 212.

[0121] The third candidate information is shown in Figure 5 The candidate nozzle 212 is used when the printed layer P is formed on the plate horizontal surface GH shown in (A).

[0122] The third candidate information has the same information as the first candidate information or the second candidate information. If the ejection frequency of the candidate nozzles 212 at the same position in the printing width direction is set to 0.5 times the ejection frequency of the other candidate nozzles 212, the number of ink landings of the ink N per unit area becomes equal.

[0123] Furthermore, when the print layer P is formed on the plate horizontal surface GH, the distance L1 from all the nozzles 212 constituting the first and second print head arrays 21A and 21B to the plate horizontal surface GH can be set to 20 mm or less, preferably 10 mm or less. Therefore, the third candidate information may also indicate that all the nozzles 212 constituting the first and second print head arrays 21A and 21B are set as candidate nozzles 212.

[0124] The ink N discharged from the nozzles 212 has wettability, so even if the ink N discharged from the adjacent nozzles 212 has ink landing positions separated, the ink N will spread to the area between the ink landing positions, forming a Figure 1 Therefore, depending on the shape of the printed layer P, for example, when the ink N is ejected only from the candidate utilization nozzles 212 of the first nozzle array group 216A constituting the first print head array 21A, a printed layer P having a width slightly wider than the distance from the candidate utilization nozzle 212 located most on the Y1 direction side to the candidate utilization nozzle 212 located most on the Y2 direction side is formed on the first main surface G1.

[0125] The control unit 55 includes, for example, a CPU (Central Processing Unit). The control unit 55 functions as a shape specifying unit 551 , a discharge control unit 552 , and a print head movement control unit 553 by the CPU executing a print control program stored in the storage unit 54 .

[0126] The shape determination unit 551 obtains the shape determination information input from the input unit 52, and determines the three-dimensional shapes of the board G and the printed layer P based on the shape determination information. For example, when the storage unit 54 stores data of a table structure that associates the type of the board GP with a printed layer with the three-dimensional shapes of the board G and the printed layer P constituting the board GP with a printed layer, the shape determination unit 551 determines the three-dimensional shapes of the board G and the printed layer P based on the shape determination information indicating the type of the board GP with a printed layer and the data of the table structure.

[0127] The discharge control unit 552 acquires information corresponding to each part of the plate G from the candidate nozzle information based on the three-dimensional shape of the printed layer P determined by the shape determination unit 551. Then, the discharge control unit 552 controls the piezoelectric element 213 based on the acquired information and the three-dimensional shape of the printed layer P, thereby controlling the discharge state of the ink N from the nozzle 212.

[0128] The print head movement control unit 553 controls the print head movement unit 42 to move the first and second print head arrays 21A and 21B based on the three-dimensional shape of the plate G determined by the shape determination unit 551. The print head movement control unit 553 and the relative movement mechanism 4 constitute a relative movement unit.

[0129] (Method for manufacturing a board with a printed layer)

[0130] Next, a method for manufacturing the plate GP with a printed layer using the printing device 1 will be described.

[0131] The following, Figure 1 The method for manufacturing the plate GP with a printed layer shown in (A) and (B) will be described below, but the plate with a printed layer can also be manufactured in the same way for plates of other three-dimensional shapes.

[0132] First, the operator inputs shape determination information using, for example, the input unit 52. The shape determination unit 551 of the control unit 55 determines the three-dimensional shapes of the plate G and the printed layer P based on the input shape determination information. Alternatively, the shape determination unit 551 may determine the three-dimensional shapes of the plate G and the printed layer P by acquiring shape determination information based on the detection results of the sensor or the photographing results of the camera.

[0133] Next, if Figure 2 As shown, an operator or a board conveying device (not shown) sets the board G on the board holding portion 41. The board holding portion 41 holds the set board G.

[0134] Furthermore, after the plate G is set in the plate holding portion 41 , the operator may input the shape specifying information.

[0135] When the three-dimensional shape of the printed layer P is determined by the shape determination unit 551, the discharge control unit 552 selects information indicating the candidate nozzles 212 for use at various locations in the X-axis direction of the plate G from the candidate nozzle information. The discharge control unit 552 selects the third candidate information as information indicating the candidate nozzles 212 for use at the first and second flat portions GA1 and GA2. The discharge control unit 552 selects the first candidate information as information indicating the candidate nozzles 212 for use at the inclined portion GC and the first and second bent portions GB1 and GB2.

[0136] The discharge control unit 552 sets the nozzle 212 to be actually used from the candidate used nozzles 212 at various locations in the X-axis direction of the plate G as the used nozzle 212 according to the planar shape of the printed layer P. That is, the discharge control unit 552 selects the candidate used nozzle 212 located vertically above the printing area GQ as the used nozzle 212, and does not select the candidate used nozzle 212 located vertically above the non-printing area GR as the used nozzle 212.

[0137] The discharge control unit 552 sets the discharge frequency of each of the two nozzles 212 at the same position in the printing width direction to 0.5 times the discharge frequency of the other nozzles 212, so that the number of ink N per unit area in the printing area GQ is equal. For example, when the nozzles 212 including the first, second, fifth, and sixth end nozzles 212A, 212B, 212E, and 212F are selected as the nozzles 212 based on the first candidate information, the discharge frequency of the first, second, fifth, and sixth end nozzles 212A, 212B, 212E, and 212F is set to 0.5 times the discharge frequency of the other nozzles 212. The discharge frequency can be adjusted by the driving state of the piezoelectric element 213.

[0138] The discharge control unit 552 controls the ink pressure adjustment unit 223 to adjust the pressure of the ink N supplied to each print head 21 to a pressure setting value.

[0139] The discharge control unit 552 controls the piezoelectric element 213 to impart vibration to the meniscus of the ink N in each nozzle 212 in the printing standby state.

[0140] If the three-dimensional shape of plate G is determined by the shape determination unit 551, the print head movement control unit 553 sets the movement trajectories of the first and second print head columns 21A and 21B at various locations in the X-axis direction of plate G so that the distances L1 and L2 from the nozzle 212 to the first main surface G1 are less than 20 mm, preferably less than 10 mm.

[0141] When the first and second print head arrays 21A and 21B move vertically above the first and second flat portions GA1 and GA2, as shown in FIG. Figure 5 As shown in (A), the print head movement control unit 553 sets the movement trajectory of the first and second print head columns 21A and 21B in such a manner that the lower surfaces of all the print heads 21 constituting the first and second print head columns 21A and 21B are located on the same plane and the distance L1 from the opening surface including all the nozzles 212 utilized to the horizontal surface GH of the plate is less than 20 mm, preferably less than 10 mm.

[0142] When the first and second print head arrays 21A and 21B move vertically above the first and second bending portions GB1 and GB2 or the inclined portion GC, as shown in FIG. Figure 5As shown in (B), the print head movement control unit 553 sets the movement trajectory of the first and second print head columns 21A and 21B in such a manner that the lower surface of the print head 21 constituting the first print head column 21A is located above the lower surface of the print head 21 constituting the second print head column 21B, and the distance L2 from the opening surface of the nozzle 212 included in the first nozzle column group 216A of the first and second print head columns 21A and 21B to the first and second bend portions GB1 and GB2 or the inclined portion GC is less than 20 mm, preferably less than 10 mm.

[0143] Then, the print head movement control unit 553 controls the print head moving unit 42 to move the first and second print head arrays 21A and 21B in the X-axis direction and the Z-axis direction along the set movement trajectory based on the detection results of the positions of each print head 21 in the X-axis direction and the Z-axis direction by the print head position detection unit 51. At this time, the print head movement control unit 553 moves the first and second print head arrays 21A and 21B in the X-axis direction at a constant speed.

[0144] On the other hand, the discharge control unit 552 controls the piezoelectric element 213 to stop applying vibration to the meniscus of the ink N.

[0145] The discharge control unit 552 controls the piezoelectric element 213 according to the positions of the first and second print head arrays 21A and 21B, and discharges the ink N from each nozzle 212 at the set discharge frequency. At this time, the discharge control unit 552 controls the piezoelectric element 213 according to the shapes of the first to fourth boundaries B1 to B4 of the printing area GQ and the non-printing area GR intersecting with the printing direction, and controls the timing of the discharge of the ink N from the nozzle 212. For example, the discharge control unit 552 stops the discharge of the ink N from the nozzle 212 of the first print head array 21A earlier than the timing of stopping the discharge of the ink N from the nozzle 212 of the second print head array 21B according to the shapes of the first and third boundaries B1 and B3. The discharge control unit 552 starts the discharge of the ink N from the nozzle 212 of the first print head array 21A earlier than the timing of starting the discharge of the ink N from the nozzle 212 of the second print head array 21B according to the shapes of the second and fourth boundaries B2 and B4.

[0146] Based on the control of the control unit 55 as described above, the ink N is discharged from the nozzle 212 with the distance L1, L2 from the printing unit 2 that moves only once in the printing direction to the first main surface G1 being 20 mm or less, preferably 10 mm or less. Figure 1As shown in (A) and (B) of FIG. 1 , a printed layer P is formed in the entire printing width direction in the printing area GQ. In addition, the first print head array 21A and the first ink tank 221 are simultaneously raised and lowered by the same distance, and the second print head array 21B and the second ink tank 222 are simultaneously raised and lowered by the same distance, so that the printed layer P is formed in a state where the absolute value of the pressure change relative to the pressure setting value of the meniscus by the nozzle 212 is maintained at 0.2 kPa or less.

[0147] (Effects of Embodiments)

[0148] When a printed layer P is formed on the first main surface G1 of a plate G having first and second bend portions GB1 and GB2 to manufacture a plate GP with a printed layer, the printing device 1 relatively moves a plurality of print heads 21 and the plate G at different positions in the printing width direction in such a manner that the distances L1 and L2 from the nozzle 212 to the first main surface G1 become less than 20 mm.

[0149] Therefore, compared with the case of using a single print head 21, the effective printing width WH can be increased, and even if the plate G is enlarged, the printed layer P can be efficiently formed. In addition, the printed layer P is formed while the distances L1 and L2 from the nozzle 212 to the first main surface G1 are maintained at 20 mm or less, so that the ink N discharged from the nozzle 212 can be suppressed from becoming mist, and the quality of the printed layer P can be suppressed from being reduced.

[0150] In particular, by relatively moving the plurality of print heads 21 and the plate G so that the distances L1 and L2 from the nozzles 212 to the first main surface G1 are 10 mm or less, the ink N can be further prevented from becoming mist, thereby further preventing the quality of the printed layer P from being degraded.

[0151] When manufacturing the board GP with a printed layer, the printing device 1 keeps the board G stationary and moves the plurality of print heads 21 in the printing direction by raising or lowering them according to the shape of the first main surface G1.

[0152] In this way, by adopting a structure in which the print head 21 which is smaller than the plate G is moved, it is possible to achieve miniaturization of the mechanism for relatively moving the plate G and the print head 21.

[0153] Each print head 21 includes a first nozzle array group 216A and a second nozzle array group 216B having nozzles 212 at different positions in the printing direction. When the printed layer P is formed on the first and second bent portions GB1 and GB2 or the inclined portion GC, the printing device 1 moves each print head 21 in the printing direction so that the distances L1 and L2 from the first nozzle array group 216A of each print head 21 to the first main surface G1 are 20 mm or less, while maintaining the state in which the opening surface of each nozzle 212 is parallel to the horizontal plane M, and discharges ink N from the nozzles 212 constituting the first nozzle array group 216A.

[0154] Therefore, by making the plurality of print heads 21 rise or fall according to the shape of the first and second bending portions GB1, GB2 or the inclined portion GC without rotating, the printed layer P can be formed, so that the structure of the print head moving portion 42 can be simplified and the control of the print head moving portion 42 can be prevented from becoming complicated.

[0155] The plurality of print heads 21 are arranged so that the Y2 direction side portions of the print heads 21 adjacent to each other on the Y1 direction side overlap with the Y1 direction side portions of the print heads 21 on the Y2 direction side when viewed from the printing direction side.

[0156] Therefore, the joints between the printed layers P formed by the respective print heads 21 can be made invisible.

[0157] The plurality of print heads 21 are arranged in a state where they are shifted from each other in the printing width direction and are shifted alternately in the printing progress direction side and the printing reverse direction side.

[0158] Therefore, the length of the print head group composed of the plurality of print heads 21 in the printing progress direction can be shortened.

[0159] The printing device 1 controls the discharge state of the ink N from the nozzles 212 of the first and second print head arrays 21A and 21B so that the number of landings of the ink N per unit area in the print region GQ of the first main surface G1 is equal.

[0160] Therefore, the thickness of the printed layer P in the printed area GQ can be made uniform, and the quality of the printed layer P can be improved.

[0161] The printing device 1 controls the timing of discharging the ink N from the nozzles 212 according to the shapes of the first to fourth boundaries B1 to B4 intersecting the printing progress direction.

[0162] Therefore, the first to sixth boundaries B1 to B6 of the printed layer P can be made into desired shapes, and the quality of the printed layer P can be improved.

[0163] The plurality of print heads 21 are arranged so that the effective printing width WH is larger than the width WG of the plate G, and are configured to form the printed layer P in the entire printing width direction of the printing area GQ by one movement in the printing direction.

[0164] Therefore, the productivity of the board GP with a printed layer is improved.

[0165] The printing device 1 forms the printed layer P while maintaining the absolute value of the pressure fluctuation with respect to the pressure setting value of the meniscus by the nozzle 212 at 0.2 kPa or less.

[0166] Therefore, the ink N can be discharged from each utilization nozzle 212 in a stable state, and the quality reduction of the printed layer P can be suppressed.

[0167] In particular, for example, by simply applying a simple structure in which each print head 21 of the first print head array 21A and the first ink tank 221 are held by the first print unit holding member 31 , it is possible to suppress degradation of the quality of the printed layer P.

[0168] [Modifications]

[0169] Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the embodiments, and various improvements and design changes that do not depart from the gist of the present invention are also included in the present invention.

[0170] For example, a plurality of print heads 21 each having a plurality of nozzles 212 arranged in the printing width direction may be arranged to form a row along the printing direction and not to be misaligned with each other in the printing width direction.

[0171] With such a configuration, a thicker print layer P can be formed compared to the case of using a single print head 21, and a print layer P having a desired thickness can be efficiently formed. In addition, the print layer P is formed while maintaining the distances L1 and L2 from the nozzle 212 to the first main surface G1 at 20 mm or less, so that the quality of the print layer P can be suppressed from being degraded.

[0172] It is also possible to move each print head 21 along the X-axis and Z-axis directions while maintaining the lower surface of the head body 211 on the same plane, and rotate around a rotation axis parallel to the Y-axis direction, so that the distances L1 and L2 from the nozzle 212 to the first main surface G1 are less than 20 mm.

[0173] Each print head 21 can also be fixed in a manner such that the lower surface of the head body 211 is parallel to the horizontal plane M, and the plate G can be moved in the X-axis direction and the Z-axis direction, for example by a robot arm, and rotated around a rotation axis parallel to the Y-axis direction, so that the distances L1 and L2 from the nozzle 212 to the first main surface G1 are less than 20 mm.

[0174] At least one of the printing unit 2 and the plate G may be moved in the X-axis direction and the Z-axis direction and rotated about a rotation axis parallel to the Y-axis direction so that the distances L1 and L2 from the nozzle 212 to the first main surface G1 are 20 mm or less.

[0175] As a method of controlling the discharge state of the ink N from the nozzles 212 so that the number of landings of the ink N per unit area in the printing area GQ is equal, the following method may be applied.

[0176] For example, as the candidate nozzles 212 for forming the print layer P on the first plate inclined surface GK1, only one nozzle 212 of the nozzles 212 of the first nozzle array group 216A constituting the first and second print head arrays 21A and 21B, each of which has a different position in the printing width direction, is set as the candidate nozzle 212. Therefore, only the first end nozzle 212A of the first end nozzle 212A and the sixth end nozzle 212F, which have the same position in the printing width direction, is set as the candidate nozzle 212, and only the second end nozzle 212B of the second end nozzle 212B and the fifth end nozzle 212E, which have the same position in the printing width direction, is set as the candidate nozzle 212.

[0177] Furthermore, the number of ink N landings per unit area in the printing area GQ can be made equal by moving the first and second print head columns 21A and 21B at a constant speed and discharging ink N from nozzles 212 at different positions in the printing width direction at the same discharge frequency.

[0178] The timing of discharging the ink N from the nozzle 212 is controlled based on the shapes of the first to fourth boundaries B1 to B4 intersecting the printing progress direction, but such control may not be performed.

[0179] It is also possible to form a printed layer P as a whole in the printing width direction within the printing area GQ by configuring multiple print heads 21 so that the effective printing width WH is smaller than the width WG of the plate G, and moving the print heads 21 in the printing width direction multiple times at different positions, or by reciprocating at least once.

[0180] For example, as a water head pressure maintaining unit 3 for controlling the variation of the water head pressure of the ink N caused by the lifting and lowering of each print head 21 of the first and second print head columns 21A and 21B, the first and second printing unit holding components 31 and 32 are used, but the first and second printing unit holding components 31 and 32 can be replaced so that the ink pressure adjusting unit 223 can function as the water head pressure maintaining unit 3, and the first and second ink tanks 221 and 222 can be used to suppress the variation of the water head pressure of the ink N caused by the lifting and lowering of each print head 21 of the first and second print head columns 21A and 21B, and the pressure of the ink N can be adjusted by the ink pressure adjusting unit 223.

[0181] Furthermore, the hydraulic head pressure maintaining unit 3 may not be provided in the printing device 1 . For example, the first and second ink tanks 221 and 222 may be fixed to raise and lower the print heads 21 of the first and second print head arrays 21A and 21B.

[0182] The plate G may also be shaped such that a plurality of bending axes in different directions exist in one bending portion. In this case, the print head moving section 42 is configured so as to generate a step difference between the print heads 21 adjacent to each other in the printing width direction of each print head array 21A, 21B, and the ink supply section 22 is configured so as to be able to supply ink N from each tank to each print head 21. Furthermore, the print heads 21 adjacent to each other in the printing width direction may be raised or lowered to different heights according to the shape of the first main surface G1 so that the distances L1, L2 from the nozzle 212 to the first main surface G1 are 20 mm or less, and may be moved in the printing direction.

[0183] Example

[0184] Next, examples of the present invention will be described. Examples 2 to 6 are examples, and Examples 1 and 7 are comparative examples. In addition, the present invention is not limited to the examples.

[0185] (Manufacturing method and manufacturing results of a board with a printed layer)

[0186] <Example 1>

[0187] As the plate of Example 1, "Doragon Trail (registered trademark)" produced by AGC Corporation was used. Figure 1 The plate G shown in (A) and (B) is similarly formed by heat forming to have first and second flat portions GA1, GA2, first and second bent portions GB1, GB2, and a sloped portion GC. The length LG of the plate of Example 1 is 700 mm, and the width WG is 180 mm. The sloped portion GC has an inclination angle θ1 relative to the horizontal plane M of 10°.

[0188] In addition, as a printing device of Example 1, a device having the same structure as the printing device 1 of the above-mentioned embodiment is prepared. The printing device of Example 1 includes a printing head. Figure 4 The length L21 in the printing width direction is shown to be 150 mm.

[0189] The print head of Example 1 includes first and second nozzle array groups similar to the first and second nozzle array groups 216A and 216B of the print head 21 of the above-described embodiment. The first and second nozzle array groups are configured as follows: Figure 3 The effective printing width WH shown is 50 mm. The first and second nozzle array groups are configured so that the number of printed pixels in the Y-axis direction, i.e., the printing width direction, i.e., the number of ink strokes, is 600 dpi. The nozzles of the first nozzle array constituting the first nozzle array group are located at the end of the print head in the printing direction. Figure 4 The distance R21 shown in the figure and the distance from the nozzle of the fourth nozzle row to the end of the printing head in the opposite direction of printing are Figure 4 The distance R21 shown is 6 mm.

[0190] By using the printing apparatus of Example 1 having the above-described structure, a printed layer was formed entirely on the first main surface of the board of Example 1, thereby manufacturing a board with a printed layer of Example 1.

[0191] When forming all the printing layers, all the nozzles constituting the first and second nozzle array groups are used as the used nozzles. That is, the nozzle array group of the print head used in the inclined portion GC is set to the first nozzle array group located on the printing progress direction side and the second nozzle array group located on the printing progress direction side. With such a setting, the number of printed pixels in the printing progress direction when forming the printing layer is 600 dpi. With the maximum distance from the opening surface of the used nozzle to the plate, i.e. Figure 5 The maximum value of the distances L1 and L2 shown in (A) and (B) is 1.6 mm, and the print head is moved and raised in the printing direction at a printing speed of 100 mm / sec while maintaining the state that the opening surface of the nozzle is parallel to the horizontal plane. In addition, the ink is discharged from the nozzle at a discharge frequency of 600 dpi, that is, the number of printed pixels in the printing direction, that is, the number of ink landings. That is, the ink is discharged from the nozzle under the condition that the number of printed pixels in the printing width direction and the printing direction is 600 dpi.

[0192] Furthermore, the effective printing width WH is about 27% of the width WG of the plate in Example 1, so the print head is moved back and forth twice, and the position in the printing width direction when moving in the printing direction or the reverse direction of the printing direction is changed, and the printed layer is formed on the first main surface as a whole. That is, the number of printing passes is 4. The printing time is 28 seconds. In addition, the printing time only includes the time for discharging ink, and does not include the time when the ink is not discharged, such as the time when the print head moves.

[0193] The surface of the printed layer of the plate with a printed layer of Example 1 was observed with an optical microscope to evaluate the printing quality, and a high-quality printed layer was formed without missing or uneven printing, and without ink adhesion to other than the intended ink discharge position. In the following description, such a high-quality printed layer is referred to as a printed layer with a printing quality of "A".

[0194] <Example 2>

[0195] As a plate of Example 2, a plate having the same shape as that of the plate of Example 1 was prepared.

[0196] In addition, as a printing device of Example 2, a device having the same structure as the printing device of Example 1 was prepared. The printing device of Example 2 includes three print heads of Example 2. The print head of Example 2 includes first and second nozzle array groups as the print head of Example 1. The print head of Example 2 has the same structure as the print head of Example 1 except that the distance R21 from the nozzles of the first nozzle array to the end portion of the print head on the printing direction side is 18 mm.

[0197] The three print heads of Example 2 are arranged in a staggered manner along the printing width direction so that the effective printing width WH is 150 mm and the number of printed pixels in the printing width direction within the entire area of ​​the effective printing width WH is 600 dpi. The first print head column of Example 2 is composed of one print head, and the second print head column is composed of two print heads. The print heads of Example 2 are arranged in the same manner as the printing device 1 of the above-mentioned embodiment, so that the positions of the nozzles located at the end of the printing width direction included in the first print head column and the positions of the nozzles located at the end of the printing width direction included in the second print head column are the same in the printing width direction.

[0198] By using the printing apparatus of Example 2 having the above-described structure, a printed layer was formed entirely on the first main surface of the board of Example 2, thereby manufacturing a board with a printed layer of Example 2.

[0199] When forming all the printed layers, the nozzle array groups of each print head used in the inclined portion GC are set to the first and second nozzle array groups in the same manner as in Example 1. Each print head is moved in the same conditions as in Example 1, except that the maximum distance from the opening surface of the nozzle to the plate is 3.7 mm. Ink is discharged from the nozzle under the condition that the number of printed pixels in the printing width direction and the printing advancing direction is 600 dpi. Moreover, the effective printing width WH is about 83% of the width WG of the plate in Example 2, so by making the print head go back and forth once, changing the position in the printing width direction when moving in the printing forward direction or the reverse direction of the printing forward direction, a printed layer is formed on the first main surface as a whole. That is, the number of printing passes is two. In addition, the printing time is 14 seconds.

[0200] The printing quality of the plate with a printed layer of Example 2 was evaluated in the same manner as in Example 1, and a printed layer having a printing quality of "A" was formed.

[0201] <Example 3>

[0202] As a plate of Example 3, a plate having the same shape as that of the plate of Example 1 was prepared.

[0203] In addition, as a printing device of Example 3, a device having the same structure as the printing device of Example 2 was prepared. The printing device of Example 3 includes six print heads of Example 3. The print heads of Example 3 have the same structure as the print heads of Example 2.

[0204] The six print heads of Example 3 are arranged in a staggered manner along the printing width direction so that the effective printing width WH is 300 mm and the number of printed pixels in the printing width direction within the entire area of ​​the effective printing width WH is 600 dpi. The first and second print head arrays of Example 3 are similar to the printing device 1 of the above-mentioned embodiment, and each is composed of three print heads. The print heads of Example 3 are similar to the print heads of Example 2, and are arranged so that the positions of the nozzles located at the ends of the printing width direction included in the first print head array and the positions of the nozzles located at the ends of the printing width direction included in the second print head array are the same in the printing width direction.

[0205] By using the printing apparatus of Example 3 having the above-described structure, a printed layer was formed entirely on the first main surface of the board of Example 3, thereby manufacturing a board with a printed layer of Example 3.

[0206] When forming all the printed layers, the nozzle array groups of each print head 21 used in the inclined portion GC are set to the first and second nozzle array groups in the same manner as in Examples 1 and 2. In addition, each print head is moved under the same conditions as in Example 2, and ink is discharged from the used nozzles under the condition that the number of printed pixels in the printing width direction and the printing advancing direction is 600 dpi. Moreover, since the printing effective width WH is larger than the width WG of the plate of ratio 3, the printed layer is formed on the entire first main surface by moving the print head once in the printing advancing direction. That is, the number of printing passes is one pass. In addition, the printing time is 7 seconds.

[0207] The printing quality of the plate with a printed layer of Example 3 was evaluated in the same manner as in Example 1, and a printed layer having a printing quality of "A" was formed.

[0208] <Example 4>

[0209] As a plate of Example 4, a plate having the same structure as that of the plate of Example 1 was prepared except that the inclination angle θ1 of the inclined portion GC with respect to the horizontal plane M was 32°.

[0210] In addition, as a printing device of Example 4, a device having the same structure as the printing device of Example 3 was prepared. The printing device of Example 4 includes six print heads of Example 4. The print heads of Example 4 have the same structure as the print heads of Example 1.

[0211] The six print heads of Example 4 are arranged in a staggered manner in the same manner as in Example 3.

[0212] By using the printing apparatus of Example 4 having the above-described structure, a printed layer was formed entirely on the first main surface of the board of Example 4, thereby manufacturing a board with a printed layer of Example 4.

[0213] When forming all the printing layers, the nozzles constituting only the first nozzle array group of each print head are used as the utilized nozzles. That is, the nozzle array group of each print head used in the inclined portion GC is set only to the first nozzle array group located on the printing direction side. With such a setting, the number of printed pixels in the printing direction when the printing layer is formed is 300 dpi. Except for moving each print head in such a manner that the maximum distance from the opening surface of the utilized nozzle to the plate is 4.2 mm, each print head is moved under the same conditions as in Examples 1 to 3, and ink is discharged from the utilized nozzle at a discharge frequency of 1200 dpi for the number of printed pixels in the printing direction. That is, ink is discharged from the utilized nozzle under the conditions that the number of printed pixels in the printing width direction and the printing direction are 300 dpi and 1200 dpi, respectively. As in Example 3, the number of printing passes is one pass, and the printing time is 7 seconds.

[0214] The printing quality of the plate with a printed layer of Example 4 was evaluated in the same manner as in Example 1, and a printed layer having a printing quality of "A" was formed.

[0215] In addition, if the nozzle array group of each print head used in the inclined portion GC and the first and second bent portions GB1 and GB2 is set to only the first nozzle array group, and the nozzle array group of each print head used in the first and second flat portions GA1 and GA2 is set to the first nozzle array group and the second nozzle array group, a printed layer with a printing quality of "A" can be formed in a shorter time than in the above-mentioned Example 4.

[0216] <Example 5>

[0217] As a plate of Example 5, a plate having the same shape as that of the plate of Example 4 was prepared.

[0218] In addition, as the printing apparatus of Example 5, the printing apparatus of Example 3 was prepared.

[0219] By using the printing apparatus of Example 5, a printed layer was formed on the entire first main surface of the plate of Example 5, thereby manufacturing a plate with a printed layer of Example 5.

[0220] When forming all the printed layers, the nozzle array groups of each print head used in the inclined portion GC were set to the first and second nozzle array groups in the same manner as in Examples 1 to 3. Each print head was moved in the same conditions as in Examples 1 to 4 except that the maximum distance from the opening surface of the used nozzle to the plate was 11.7 mm, and ink was discharged from the used nozzles under the condition that the number of printed pixels in the printing width direction and the printing advancing direction was 600 dpi. As in Examples 3 and 4, the number of printing passes was one pass, and the printing time was 7 seconds.

[0221] In addition, although a printed layer is formed on a plate of the same shape in Examples 4 and 5, the maximum distance from the opening surface using the nozzles to the plate in Example 5 is larger than that in Example 4. This is because in the inclined portion, if the print head is moved in a manner that does not contact the plate, the distance from the opening surface using the nozzles of the second nozzle array group to the plate becomes longer than the distance from the opening surface using the nozzles of the first nozzle array group to the plate.

[0222] The printing quality of the plate with a printed layer of Example 5 was evaluated in the same manner as in Example 1, and a printed layer of a grade that had no problem as a product but had a little printing unevenness was formed. In the following description, a printed layer of a grade that had a little printing unevenness but had no problem as a product is referred to as a printed layer of printing quality "B".

[0223] <Example 6>

[0224] As a plate of Example 6, a plate having the same structure as that of the plate of Example 1 was prepared except that the inclination angle θ1 of the inclined portion GC with respect to the horizontal plane M was 60°.

[0225] In addition, as the printing device of Example 6, the printing device of Example 4 was prepared.

[0226] By using the printing device of Example 6, a printed layer was formed on the entire first main surface of the plate of Example 6, thereby manufacturing a plate with a printed layer of Example 6.

[0227] When forming all the printed layers, the nozzle array group of each print head used in the inclined portion GC was set as the first nozzle array group in the same manner as in Example 4. Each print head was moved in the same conditions as in Examples 1 to 5 except that the maximum distance from the opening surface of the used nozzle to the plate was 10.9 mm, and ink was discharged from the used nozzle under the conditions that the number of printed pixels in the printing width direction and the printing forward direction were 300 dpi and 1200 dpi, respectively. As in Examples 3 to 5, the number of printing passes was one pass, and the printing time was 7 seconds.

[0228] In addition, although only the first nozzle array group is used in Examples 4 and 6, the maximum distance from the opening surface of the nozzles used to the plate in Example 6 is larger than that in Example 4. This is because the inclination angle of the inclined portion of Example 6 is larger than that in Example 4. Therefore, if the print head is moved in a manner that does not contact the plate, the distance from the opening surface of the nozzles used to the plate in Example 6 is longer than that in Example 4.

[0229] The printing quality of the plate with a printed layer of Example 6 was evaluated in the same manner as in Example 1, and a printed layer having a printing quality of "B" was formed.

[0230] <Example 7>

[0231] As the plate of Example 7, a plate having the same shape as that of the plate of Example 6 was prepared.

[0232] In addition, as the printing device of Example 7, the printing device of Example 5 was prepared.

[0233] By using the printing apparatus of Example 7, a printed layer was formed on the entire first main surface of the plate of Example 7, thereby manufacturing a plate with a printed layer of Example 7.

[0234] When forming all the printed layers, the nozzle array groups of each print head used in the inclined portion GC were set to the first and second nozzle array groups in the same manner as in Examples 1 to 3 and 5. Each print head was moved in the same conditions as in Examples 1 to 6 except that the maximum distance from the opening surface of the used nozzle to the plate was 31.7 mm, and ink was discharged from the used nozzles under the condition that the number of printed pixels in the printing width direction and the printing advancing direction was 600 dpi. As in Examples 3 to 6, the number of printing passes was one pass, and the printing time was 7 seconds.

[0235] In addition, although a printed layer is formed on a plate of the same shape in Examples 6 and 7, the maximum distance from the opening surface using the nozzle to the plate in Example 7 is larger than that in Example 6, for the same reason as the reason why the maximum distance from the opening surface using the nozzle to the plate in Example 5 is larger than that in Example 4.

[0236] The printing quality of the plate with a printed layer of Example 7 was evaluated in the same manner as in Example 1, and the printed layer had a high level of uneven printing, and it was observed that the ink did not land at the specified position, which was a level that the product had problems. In the following description, such a printed layer with a level that the product had problems is referred to as a printed layer with a printing quality of "C".

[0237] (Inspection)

[0238] The manufacturing methods and manufacturing results of the plates with printed layers of Examples 1 to 7 are shown in Table 1 below.

[0239]

Table 1

[0240]

[0241] <About the number of print heads>

[0242] When using plates of the same shape to manufacture plates with printed layers, the number of printing passes is 4 when using the printing device of Example 1 with one print head. In contrast, the number of printing passes is less than 2 when using the printing devices of Examples 2 to 7 with multiple print heads.

[0243] This shows that the use of a plurality of print heads at different positions in the printing width direction allows the printed layer to be formed more efficiently than when a single print head is used.

[0244] <About the maximum distance from the opening surface of the nozzle to the plate>

[0245] The printing quality of the board with a printed layer in Example 7 where the maximum distance from the opening surface of the nozzle to the board exceeds 20 mm is "C", the printing quality of the boards with a printed layer in Examples 5 and 6 where the maximum distance from the opening surface of the nozzle to the board is greater than 10 mm and less than 20 mm is "B", and the printing quality of the boards with a printed layer in Examples 1 to 4 where the maximum distance is less than 10 mm is "A".

[0246] As the maximum distance from the opening surface of the nozzle to the plate increases, the printing quality decreases. This is probably because the ink tends to become mist more easily before landing on the plate as the nozzle moves away from the plate.

[0247] Thus, it was confirmed that by forming the printed layer in a state where the maximum distance from the opening surface of the nozzle to the plate is 20 mm or less, the reduction in printing quality of the printed layer can be suppressed, and by forming the printed layer in a state where the maximum distance is 10 mm or less, a high-quality printed layer can be formed.

[0248] This application is based on Japanese patent application No. 2023-094025 filed on June 7, 2023, the contents of which are incorporated into this specification as a reference.

Claims

1. A method for manufacturing a plate with a printed layer, wherein the printed layer is formed on a main surface of the plate having a curved portion curved in the plate thickness direction by an inkjet method, wherein: Using a plurality of print heads, each of the plurality of print heads has at least one nozzle, When forming a printed layer on the main surface by relatively moving the plurality of print heads and the plate and discharging ink from the nozzles of the plurality of print heads, the plurality of print heads and the plate are relatively moved in such a manner that a distance from the nozzles for discharging the ink to the main surface is less than 20 mm.

2. The method for manufacturing a board with a printed layer according to claim 1, wherein: As a process for relatively moving the plurality of print heads and the plate, a process is performed in which the plate is kept stationary and the plurality of print heads are moved in a printing direction by ascending or descending according to the shape of the bent portion of the main surface.

3. The method for manufacturing a board with a printed layer according to claim 2, wherein: Each of the plurality of print heads includes a plurality of nozzles at different positions in the printing direction. The multiple print heads are moved while maintaining the opening surfaces of the multiple nozzles parallel to the horizontal plane. According to the inclination of the main surface, the ink is discharged only from the nozzles on the printing direction side or the side opposite to the printing direction side whose distance to the main surface is less than 20 mm among the multiple nozzles with different positions in the printing direction.

4. The method for manufacturing a board with a printed layer according to claim 3, wherein: The ink is discharged from the nozzles at a distance of 10 mm or less from the main surface.

5. The method for manufacturing a board with a printed layer according to claim 2, wherein: The multiple print heads are composed of two or more print heads with different positions in the printing direction, and have a plurality of nozzles arranged in a printing width direction orthogonal to the printing direction, and are arranged so that when viewed from the printing direction side, a portion of the print head on one end side of the printing width direction of one of the adjacent print heads overlaps with a portion of the other end side of the printing width direction of the other print head.

6. The method for manufacturing a board with a printed layer according to claim 5, wherein: The plurality of print heads are composed of three or more print heads arranged in a state of being shifted from one another in the printing width direction.

7. The method for manufacturing a board with a printed layer according to claim 5 or 6, characterized in that: The nozzles are respectively arranged at overlapping portions of the adjacent print heads when viewed from the printing direction side. The discharge state of the ink from the nozzles is controlled so that the number of landings of the ink per unit area in the printing area of ​​the main surface is equal.

8. The method for manufacturing a board with a printed layer according to claim 5 or 6, characterized in that: The plate with a printed layer comprises: a printed area where the printed layer is formed; and a non-printed area where the printed layer is not formed. The nozzles are respectively arranged at overlapping portions of the adjacent print heads when viewed from the printing direction side. The timing of discharging the ink from the nozzle is controlled based on the shape of the boundary between the printing area and the non-printing area, the boundary intersecting the printing progress direction.

9. The method for producing a board with a printed layer according to any one of claims 1 to 6, wherein: The plurality of print heads are arranged so as to be able to form the printed layer over the entire printing width direction of the printing region of the main surface by a single movement in the printing direction.

10. The method for producing a board with a printed layer according to any one of claims 2 to 6, wherein: The ink is discharged while maintaining an absolute value of a pressure fluctuation of the nozzle relative to a pressure setting value of the meniscus at 0.2 kPa or less during formation of the printed layer.

11. The method for producing a board with a printed layer according to any one of claims 1 to 6, wherein: The flexure portion flexes around a bending axis.

12. The method for manufacturing a board with a printed layer according to claim 11, wherein: The curvature radius of the bent portion is greater than or equal to 10 mm and less than 10,000 mm.

13. A printing device for producing a plate with a printed layer by forming a printed layer on a main surface of a plate having a curved portion curved in a plate thickness direction using an inkjet method, characterized in that: have: A plurality of print heads, each print head having at least one nozzle; a discharge control unit configured to form the printed layer on the main surface by discharging ink from the nozzles of the plurality of print heads; as well as The relative moving unit relatively moves the plurality of print heads and the plate so that a distance from the nozzles that discharge the ink to the main surface is 20 mm or less.

14. The printing device according to claim 13, wherein: The relative moving portion comprises: a plate holding portion for holding the plate in a state where the plate is immobile; a print head moving unit that moves the plurality of print heads; and The print head movement control unit controls the print head movement unit so that the plurality of print heads are moved in a printing direction by ascending or descending according to the shape of the bent portion of the main surface.

15. The printing device according to claim 14, characterized in that Each of the plurality of print heads includes a plurality of nozzles at different positions in the printing direction. The print head movement control unit controls the print head movement unit so as to move the plurality of print heads while maintaining the state in which the opening planes of the plurality of nozzles are parallel to the horizontal plane. The discharge control unit discharges the ink from the nozzles whose distance from the main surface is 20 mm or less among the plurality of nozzles at different positions in the printing progress direction, according to the inclination of the main surface.

16. The printing device according to claim 14, wherein: The multiple print heads have multiple nozzles arranged in a printing width direction orthogonal to the printing direction, and are arranged so that: when viewed from the printing direction side, the portion of the print head on one end side of the printing width direction of one of the adjacent print heads overlaps with the portion of the other end side of the printing width direction of the other print head.

17. The printing device according to claim 16, wherein The plurality of print heads are composed of three or more print heads arranged in a state of being shifted from one another in the printing width direction.

18. The printing device according to claim 16 or 17, characterized in that The nozzles are respectively arranged at overlapping portions of the adjacent print heads when viewed from the printing direction side. The discharge control unit controls a discharge state of the ink from the nozzles so that the number of landings of the ink per unit area in the printing region of the main surface is equal.

19. The printing device according to claim 16 or 17, characterized in that The plate with a printed layer comprises: a printed area where the printed layer is formed; and a non-printed area where the printed layer is not formed. The nozzles are respectively arranged at overlapping portions of the adjacent print heads when viewed from the printing direction side. The discharge control unit controls the timing of discharging the ink from the nozzles according to the shape of the boundary between the printing area and the non-printing area, the boundary intersecting the printing progress direction.

20. The printing device according to any one of claims 14 to 17, wherein: The plurality of print heads are arranged so as to be able to form the printed layer over the entire printing width direction of the printing region of the main surface by a single movement in the printing direction.

21. The printing device according to any one of claims 14 to 17, wherein: A hydraulic head pressure maintaining unit is provided for maintaining an absolute value of a pressure fluctuation of the nozzle relative to a pressure setting value of a meniscus at 0.2 kPa or less during formation of the printed layer.

Images