Printer and method for controlling printer

Abstract

To provide a printer which performs printing with photocurable ink on a three-dimensional printing target object and can irradiate the photocurable ink discharged to the printing target object with light neither too much nor too little, and to provide a method for controlling the printer.SOLUTION: After completing a printing operation, the printer performs an ink curing operation for continuing irradiation of a second printing target object 6 with light. The printer includes a control device. The control device acquires a final landing point P3, and an end P2 of a lighting range of a light irradiating device 70. The control device calculates a tangent point P1 of a tangent line drawn so as to come into contact with the second printing target object 6 from the end P2 of the lighting range of the light irradiating device 70. Upon rotating the second printing target object 6 until the final landing point P3 and the tangent point P1 coincide with each other, the control device causes to turn off the light irradiating device 70 to end the ink curing operation.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a printer and a method for controlling the printer.

Background Art

[0002] Conventionally, as shown in Patent Document 1, there is known a printer that performs predetermined printing on a printing object using ink (hereinafter referred to as photo-curable ink) having a property of curing when irradiated with light. The printer includes an ink head, a light irradiation device, and the like. Nozzles are formed on the lower surface of the ink head. The photo-curable ink is ejected from the nozzles toward the printing object. The light irradiation device irradiates the photo-curable ink ejected onto the printing object with light to cure the photo-curable ink.

[0003] Further, Patent Document 1 discloses a rotation mechanism that rotatably supports a three-dimensional printing object. When printing on the outer peripheral surface of a three-dimensional printing object, printing is performed while intermittently rotating the printing object by the rotation mechanism. The irradiation of light and the rotation of the printing object are also performed after the ejection of the photo-curable ink onto the printing object has ended. This is to prevent insufficient curing of the photo-curable ink ejected onto the printing object.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Some of the light irradiated from the light irradiation device may be reflected inside the printer to the ink head. The reflection of light to the ink head causes an increase in the viscosity of the ink in the ink head, which is a cause of ink head failure. When light irradiation is performed for a long time, the amount of light reflected to the ink head also increases. Therefore, in a printer using a photocurable ink, it is desirable to irradiate light without excess or deficiency. However, conventionally, for a printer that performs printing while rotating a printing object, a method of irradiating light without excess or deficiency has not been sufficiently studied.

[0006] The present invention has been made in view of this point, and an object thereof is to irradiate light without excess or deficiency to the photocurable ink discharged onto a printing object in a printer that performs printing on a three-dimensional printing object with a photocurable ink.

Means for Solving the Problems

[0007] The printer according to the present invention includes a rotation mechanism that rotatably supports a three-dimensional printed object around an axis extending in a first direction, an ink head that discharges photocurable ink onto the printed object, a light irradiation device that faces the printed object in a second direction orthogonal to the first direction and irradiates the printed object with light, and a control device that controls the rotation mechanism, the ink head, and the light irradiation device. The control device performs printing control in which an operation of rotating the printed object and an operation of discharging the photocurable ink from the ink head and irradiating the printed object with light from the light irradiation device are alternately repeated. After the completion of the printing control, the control device performs ink curing control in which an operation of rotating the printed object and an operation of not discharging the photocurable ink from the ink head but irradiating the printed object with light from the light irradiation device are alternately repeated. The control device is configured to end the ink curing control when the rotation position of the printed object reaches a predetermined rotation position between a first rotation position and a second rotation position. Here, the first rotation position is a position where the end on the downstream side in the printing direction of the printed object or the position in the third direction of the end on the downstream side in the printing direction of the lighting range of the light irradiation device and the final landing portion are the same, and the second rotation position is a position where the light irradiated from the end on the downstream side in the printing direction of the lighting range of the light irradiation device does not hit the final landing portion. Note that, among the printed object, the portion where the photocurable ink last discharged from the ink head lands is defined as the final landing portion, and the direction orthogonal to the first direction and the second direction is defined as the third direction.

[0008] According to the above printer, after the printing control is completed, ink curing control is performed. Even after the ejection of the photocurable ink from the ink head is completed, the irradiation of light by the light irradiation device is continued. Therefore, the photocurable ink ejected onto the printing material can be sufficiently irradiated with light, and insufficient curing of the photocurable ink can be prevented. By the way, when the rotational position of the printing material becomes a predetermined rotational position between the first rotational position and the second rotational position, the light irradiated from the light irradiation device toward the printing material hardly hits or does not hit at all the photocurable ink ejected onto the printing material. According to the above printer, when the printing material rotates until the photocurable ink ejected onto the printing material hardly receives light or no longer receives light at all, the ink curing control ends and the light irradiation device turns off. Therefore, unnecessary light irradiation can be suppressed. Accordingly, according to the above printer, the photocurable ink ejected onto a three-dimensional printing material can be irradiated with light without excess or deficiency.

Effects of the Invention

[0009] According to the present invention, there is provided a printer that performs printing on a three-dimensional printing material with a photocurable ink, and a printer and a printer control method capable of irradiating the photocurable ink ejected onto the printing material with light without excess or deficiency.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10A

Figure 10B

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0011] Hereinafter, with reference to the drawings, embodiments of a printer according to an embodiment of the present invention will be described. Note that the embodiments described here are not intended to particularly limit the present invention. Also, members and parts having the same function are denoted by the same reference numerals, and overlapping descriptions are omitted or simplified as appropriate.

[0012] FIG. 1 is a perspective view of a printer 10 according to the present embodiment. The printer 10 according to the present embodiment is an inkjet printer. In the following description, unless otherwise specified, when the printer 10 is viewed from the front, the direction away from the printer 10 is defined as the front, and the direction approaching the printer 10 is defined as the rear. Left, right, up, and down respectively mean left, right, up, and down when the printer 10 is viewed from the front. Also, in the drawings, reference signs F, Rr, L, R, U, and D respectively mean front, rear, left, right, up, and down. Reference sign Y in the drawings indicates the main scanning direction. Here, the main scanning direction Y is the left-right direction and is an example of the first direction. Reference sign X in the drawings indicates the sub-scanning direction. Here, the sub-scanning direction X is the front-rear direction and is an example of the third direction. Reference sign Z in the drawings indicates the up-down direction. The up-down direction Z is an example of the second direction. The main scanning direction Y, the sub-scanning direction X, and the up-down direction Z are orthogonal to each other. However, the directions described above are directions defined for convenience of explanation and do not limit the installation mode of the printer 10, nor do they limit the present invention.

[0013] As shown in FIG. 2, the printer 10 can perform printing on a first object to be printed 5 placed on a table 20 described later. The first object to be printed 5 has a plane that extends at least partially in the main scanning direction Y and the sub-scanning direction X. For example, the first object to be printed 5 is recording paper or the like. However, the first object to be printed 5 is not limited to recording paper and may be a sheet formed of a resin material, a metal plate, a glass plate, a wood plate, or the like. Also, the first object to be printed 5 may be a three-dimensional object such as a smartphone case.

[0014] As shown in FIG. 3, the printer 10 can also perform printing on the outer peripheral surface of a second object to be printed 6 while intermittently rotating the second object to be printed 6 using a rotation mechanism 90 described later. The second object to be printed 6 is a three-dimensional object, and the shape of the second object to be printed 6 includes a cylindrical shape and a tubular shape. The type of the second object to be printed 6 is not particularly limited, and for example, it may be a bottle or a cup. Also, the material of the second object to be printed 6 is not particularly limited and may be glass, resin, wood, or the like.

[0015] As shown in FIG. 1, the printer 10 is formed in a box shape. The printer 10 includes a case 11 and a front cover 12. FIGS. 2 and 3 are front views of the printer 10 with the front cover 12 open. As shown in FIGS. 2 and 3, an opening 13 is formed in the front portion of the case 11. The front cover 12 is provided so as to be able to open and close the opening 13 formed in the case 11. Here, the front cover 12 is supported by the case 11 so as to be rotatable about the rear end of the front cover 12. A window portion 12a is provided in the front cover 12. The window portion 12a is formed of, for example, a transparent acrylic plate. The user can visually recognize the inside of the case 11 through the window portion 12a.

[0016] As shown in FIGS. 2 and 3, the printer 10 includes a table 20, a table moving device 30, a carriage 40, a carriage moving device 50, an ink head 60, a light irradiation device 70, a height detection device 80, and a control device 100 (see FIG. 1).

[0017] The table 20 is a base for supporting the first printing object 5. The table 20 is a flat member and extends in the main scanning direction Y and the sub-scanning direction X. The table 20 is disposed approximately at the center in the main scanning direction Y inside the case 11.

[0018] Below the table 20, a table moving device 30 is arranged. The table moving device 30 moves the table 20 in the sub-scanning direction X and the vertical direction Z. The table 20 is supported from below by the table moving device 30. The table moving device 30 includes a sub-scanning direction moving device 30X and a vertical direction moving device 30Z. The vertical direction moving device 30Z supports the table 20 and moves it in the vertical direction Z. The sub-scanning direction moving device 30X supports the vertical direction moving device 30Z and moves it in the sub-scanning direction X. However, the configuration of the table moving device 30 is not limited to the above configuration. For example, the vertical relationship between the sub-scanning direction moving device 30X and the vertical direction moving device 30Z may be reversed. As shown in FIG. 2, when printing is performed on the first object to be printed 5 without using the rotation mechanism 90, the printer 10 ejects ink onto the first object to be printed 5 while intermittently moving the table 20 forward. However, instead of intermittently moving the table 20 forward, the printer 10 may eject ink onto the first object to be printed 5 while intermittently moving it backward to perform printing on the first object to be printed 5.

[0019] The carriage 40 is equipped with an ink head 60 and a light irradiation device 70. The carriage 40 is arranged above the table 20 and provided so as to face the table 20. The carriage 40 can be moved in the main scanning direction Y by a carriage moving device 50.

[0020] The carriage moving device 50 includes a guide rail 51, a belt 52, left and right pulleys (not shown), and a carriage motor 53 (see FIG. 6). As shown in FIGS. 2 and 3, the guide rail 51 extends in the main scanning direction Y. The carriage 40 is slidably engaged with the guide rail 51. An endless belt 52 is fixed to the carriage 40. The belt 52 is wound around pulleys (not shown) provided on the right side and the left side extending across the guide rail 51. A carriage motor 53 is attached to one of the pulleys. The carriage motor 53 is an example of a driving device that moves the carriage 40 along the guide rail 51. When the carriage motor 53 is driven, the pulley rotates and the belt 52 runs. As a result, the carriage 40 moves in the main scanning direction Y along the guide rail 51. However, the configuration of the carriage moving device 50 is not limited to this.

[0021] The ink head 60 is provided on the lower surface of the carriage 40 and faces the table 20. The light irradiation device 70 is arranged to the left of the ink head 60. However, the light irradiation device 70 may be arranged to the right of the ink head 60. Also, in the present embodiment, three ink heads 60 are provided. However, the number of ink heads 60 is not limited to this.

[0022] The ink head 60 discharges ink toward the first printed material 5 or the second printed material 6 placed on the table 20. The ink head 60 is communicated with an ink cartridge 15 (see FIG. 3) housed in the case 11 by flexible ink tubes (not shown), respectively. As shown in FIG. 4, the ink heads 60 are arranged at positions aligned in the sub-scanning direction X. However, the ink heads 60 may be arranged at positions shifted from each other in the sub-scanning direction X.

[0023] The ink head 60 includes a nozzle surface 60b on which a plurality of nozzles 60a are respectively formed. The nozzle surface 60b faces downward and faces the first printed material 5 or the second printed material 6 placed on the table 20. The nozzle surface 60b extends in the sub-scanning direction X. The plurality of nozzles 60a are arranged in the sub-scanning direction X to form a nozzle row. In FIG. 4, two nozzle rows are formed in one ink head 60. The nozzle 60a is a fine hole through which ink is ejected. Each nozzle 60a communicates with a pressure chamber (not shown) in which ink is stored. The ink is ejected from the nozzle 60a, for example, when the pressure chamber expands or contracts by driving a piezoelectric element. In FIG. 4, 12 nozzles 60a are formed in one nozzle row, but actually, a larger number (for example, 300) of nozzles 60a are formed. The number of nozzles 60a formed in one nozzle row is not limited. Also, the number of nozzle rows is not particularly limited.

[0024] The ink used in this embodiment is a photocurable ink that cures when irradiated with light. Here, the photocurable ink is an ultraviolet curable ink that cures when irradiated with ultraviolet rays. The components and properties of the photocurable ink are not particularly limited. Also, the color of the photocurable ink used in this embodiment is not particularly limited.

[0025] The light irradiation device 70 irradiates light onto the photocurable ink ejected onto the first printed material 5 or the second printed material 6 placed on the table 20. Here, the light irradiation device 70 is an ultraviolet irradiation device that irradiates ultraviolet rays. As shown in FIG. 4, the light irradiation device 70 includes an irradiation surface 72 facing downward and facing the table 20, and a plurality of light sources 71 provided on the irradiation surface 72. The light source 71 is, for example, an LED element or the like. In FIG. 4, 18 light sources 71 are provided in the light irradiation device, but actually, a larger number of light sources 71 (for example, 100) are provided. However, the number of light sources 71 is not particularly limited. The light irradiation device 70 is configured such that all of the plurality of light sources 71 can be turned on, or only a part of the plurality of light sources 71 can be turned on. In the present embodiment, in the front-rear direction, the rear end of the ink head 60 and the rear end of the light irradiation device 70 are aligned. However, in the front-rear direction, the rear end of the ink head 60 and the rear end of the light irradiation device 70 do not necessarily have to be aligned.

[0026] The height detection device 80 measures the height of the first printed material 5 or the second printed material 6 placed on the table 20 from the table 20. The configuration of the height detection device 80 is not particularly limited. For example, the height detection device 80 may be a laser displacement meter configured to measure the height of the first printed material 5 or the second printed material 6 from the table 20 by irradiating a laser onto the first printed material 5 or the second printed material 6.

[0027] As described above, when printing on the outer peripheral surface of the second printed material 6, a rotation mechanism 90 for rotating the second printed material 6 is used. As shown in FIG. 3, the rotation mechanism 90 is placed on the table 20 and is configured to be detachable from the table 20. The rotation mechanism 90 rotates the second printed material 6 around an axis Ax extending in the main scanning direction Y. In the present embodiment, the rotation mechanism 90 rotates the second printed material 6 forward. However, the rotation mechanism 90 may rotate the second printed material 6 backward. Also, when printing the first printed material 5, the rotation mechanism 90 is removed from the table 20.

[0028] FIG. 5 is a perspective view of the rotation mechanism 90. The rotation mechanism 90 includes a first shaft 91, a second shaft 92, a rotation motor 93, a gear set 94, and a belt 95. The first shaft 91 extends in the main scanning direction Y and can rotate around an axis Ax extending in the main scanning direction Y. The first shaft 91 is connected to the rotation motor 93 via the gear set 94. The second shaft 92 is disposed in front of the first shaft 91. Similar to the first shaft 91, the second shaft 92 extends in the main scanning direction Y and can rotate around an axis extending in the main scanning direction Y. The belt 95 is wound around the first shaft 91 and the second shaft 92. When the rotation motor 93 is driven, the first shaft 91 rotates, and the second shaft 92 also rotates together with the first shaft 91 by the belt 95. The rotation motor 93 incorporates a rotary encoder. Thereby, the rotation position of the rotation motor 93 can be grasped. However, the configuration of the rotation mechanism 90 is not limited to this. The rotation mechanism 90 may include a mechanism for gripping and rotating the second printed material 6.

[0029] FIG. 6 is a block diagram of the printer 10 according to the present embodiment. The control device 100 is electrically connected to the sub-scanning direction moving device 30X, the vertical direction moving device 30Z, the carriage motor 53 of the carriage moving device 50, the ink head 60, the light source 71 of the light irradiation device 70, the height detection device 80, and the rotation motor 93 of the rotation mechanism 90, and controls the operations thereof. The configuration of the control device 100 is not particularly limited. The control device 100 is, for example, a microcomputer or the like. In the present embodiment, the control device 100 is provided inside the printer 10. However, the control device 100 does not necessarily have to be provided inside the printer 10. For example, the control device 100 may be a computer or the like installed outside the printer 10 and communicably connected to the printer 10 via wire or wireless.

[0030] The control device 100 includes a discharge control unit 101, a rotation control unit 102, a light source control unit 103, a table movement control unit 104, a carriage movement control unit 105, a contour acquisition unit 106, a positional relationship acquisition unit 109, a final landing point acquisition unit 110, an irradiation end acquisition unit 111, and a contact point calculation unit 112. The control device 100 may include processing units other than those described above, but illustration and description thereof are omitted here.

[0031] The discharge control unit 101 controls the discharge of the photocurable ink onto the first printed material 5 or the second printed material 6 by controlling the ink head 60. When printing on the second printed material 6, the discharge control unit 101 restricts the range of the nozzles 60a to be used according to the outer diameter of the second printed material 6.

[0032] The rotation control unit 102 controls the rotation mechanism 90 to control the rotation of the second printed material 6 around the axis Ax. When printing the first printed material 5, since the rotation mechanism 90 is removed from the table 20, the rotation control unit 102 is not used.

[0033] The light source control unit 103 controls the lighting and extinguishing of the light source 71 of the light irradiation device 70. Thereby, the light source control unit 103 controls the irradiation of light on the photocurable ink discharged onto the first printed material 5 or the second printed material 6. The light source control unit 103 can turn on all of the light sources 71 or only a part of the light sources 71.

[0034] The table movement control unit 104 controls the movement of the table 20 in the sub-scanning direction X and the vertical direction Z by controlling the sub-scanning direction movement device 30X and the vertical direction movement device 30Z. The carriage movement control unit 105 controls the movement of the carriage 40 in the main scanning direction Y by controlling the carriage movement device 50. Thereby, the carriage movement control unit 105 controls the operation of the ink head 60 and the light irradiation device 70 in the main scanning direction Y.

[0035] The contour acquisition unit 106 acquires the contour of the second printed object 6. The contour acquisition unit 106 includes a diameter acquisition unit 107 and a contour estimation unit 108. The diameter acquisition unit 107 acquires the outer diameter of the second printed object 6. The contour estimation unit 108 estimates the contour of the second printed object 6 based on the outer diameter of the second printed object 6 obtained by the diameter acquisition unit 107.

[0036] The positional relationship acquisition unit 109 acquires the positional relationship between the light irradiation device 70 and the second printed object 6. The final landing point acquisition unit 110 acquires the final landing point of the photocurable ink on the second printed object 6 when viewed from the direction of the axis Ax. That is, the final landing point acquisition unit 110 acquires the portion of the second printed object 6 where the photocurable ink that was last ejected from the ink head 60 is located when viewed from the direction of the axis Ax. The irradiation end acquisition unit 111 acquires the position of the end on the downstream side in the printing direction of the lighting range of the light irradiation device 70 when viewed from the direction of the axis Ax. As described above, in this embodiment, the second printed object 6 rotates forward. Therefore, the downstream side in the printing direction in this embodiment is the front side. In the following description, unless otherwise specified, the end on the downstream side in the printing direction of the lighting range of the light irradiation device 70 when viewed from the direction of the axis Ax is referred to as the end of the lighting range of the light irradiation device 70. The contact point calculation unit 112 calculates the position of the contact point of the tangent line drawn from the end of the lighting range obtained by the irradiation end acquisition unit 111 so as to be in contact with the second printed object 6.

[0037] FIG. 7 shows an example of the contact point calculated by the contact point calculation unit 112. In FIG. 7, the portion indicated by the thick line is the range where the photocurable ink in the second printed material 6 is ejected, symbol P1 is the contact point between the tangent line G and the second printed material 6, symbol P2 is the end of the lighting range of the light irradiation device 70 acquired by the irradiation end acquisition unit 111, and symbol P3 is the final landing point acquired by the final landing point acquisition unit 110, respectively. Note that the range where the photocurable ink in the second printed material 6 shown in FIG. 7 is ejected is merely an example. FIG. 7 shows the contact point P1 when all the light sources 71 of the light irradiation device 70 are lit. When all the light sources 71 of the light irradiation device 70 are lit, the end P2 of the lighting range of the light irradiation device 70 is the lower left end of the light irradiation device 70 when viewed from the axial direction Ax (when the printer 10 is viewed from the right side). As described above, in this embodiment, the second printed material 6 rotates forward (counterclockwise in FIG. 7). The end P2 corresponds to the front end of the light source 71 located most forward among the plurality of light sources 71 arranged in the front-rear direction (see FIG. 4). The tangent line G is obtained by calculating a straight line that passes through the end P2 of the lighting range of the light irradiation device 70 and contacts the second printed material 6. Here, there may be two tangent lines that pass through the end P2 of the lighting range of the light irradiation device 70 and contact the second printed material 6. In this embodiment, among these two tangent lines, the tangent line that contacts the second printed material 6 on the front side is defined as the tangent line G. And if the tangent line G can be calculated, the contact point P1 is also calculated simultaneously. FIG. 8 shows the tangent line G when only a part of the light sources 71 of the light irradiation device 70 are lit. Also in FIG. 8, similar to FIG. 7, the portion indicated by the thick line is the range where the photocurable ink in the second printed material 6 is ejected, symbol P1 is the contact point between the tangent line G and the second printed material 6, symbol P2 is the end of the lighting range of the light irradiation device 70 acquired by the irradiation end acquisition unit 111, and symbol P3 is the final landing point acquired by the final landing point acquisition unit 110, respectively. In this case, the end P2 of the lighting range of the light irradiation device corresponds to the front end of the light source 71 located most forward among the lit light sources 71. The tangent line G in FIG. 8 can be calculated in the same manner as the tangent line G in FIG. 7 described above.

[0038] Hereinafter, the operation of the printer 10 when printing on the first printing object 5 will be described. As described above, when printing on the first printing object 5, printing is performed while intermittently moving the table 20 forward in the sub-scanning direction X. FIG. 9 shows an example of a flowchart of a method for printing on the first printing object 5. In step S01, the height of the first printing object 5 from the table 20 is measured by the height detection device 80. Based on the measurement result of the height of the first printing object 5, the table movement control unit 104 adjusts the position of the table 20 in the vertical direction Z so that it becomes a position suitable for printing. In step S02, while moving the carriage 40 in the main scanning direction Y, a photocurable ink is ejected from the nozzle 60a. At this time, simultaneously, the light irradiation device 70 is lit, and the first printing object 5 is irradiated with light. When the ejection of the photocurable ink at one position in the sub-scanning direction X is completed, the printing for one scan is completed. In step S03, the table 20 is moved forward, and the printing position is moved. Steps S02 and S03 are alternately repeated until the entire printing is completed.

[0039] Next, the operation of the printer 10 when printing on the outer peripheral surface of the second printing object 6 will be described. When printing on the outer peripheral surface of the second printing object 6, the rotation of the second printing object 6 by the rotation mechanism 90 and the ejection of the photocurable ink are alternately repeated. The ejection of the photocurable ink is performed while moving the carriage 40 in the main scanning direction Y. FIGS. 10A and 10B show an example of a flowchart of a method for printing on the second printing object 6. Here, the operation of the printer 10 when printing on the second printing object 6 will be described by dividing it into a setup operation S10, a printing operation S20, and an ink curing operation S30.

[0040] The setup operation S10 includes the processes from step S11 to step S18 shown in FIG. 10A. In step S11, the height of the second object to be printed 6 from the table 20 is measured by the height detection device 80. Based on the measurement result of the height of the second object to be printed 6, the table movement control unit 104 adjusts the position of the table 20 in the vertical direction Z to a position suitable for printing.

[0041] In step S12, the diameter acquisition unit 107 calculates the outer diameter of the second object to be printed 6. Here, the control device 100 calculates the outer diameter of the second object to be printed by subtracting the height of the rotating mechanism 90 from the table 20 from the height of the second object to be printed 6 from the table 20 obtained in step S11. Here, the dimensions of the rotating mechanism 90 are known. In step S13, the contour estimation unit 108 simply estimates the contour of the second object to be printed 6. Here, the contour estimation unit 108 estimates that the second object to be printed 6 has a cylindrical shape with the outer diameter calculated in step S12.

[0042] When the distance between the nozzle 60a and the second printing object 6 is large, the landing position of the photocurable ink is likely to shift when the photocurable ink is ejected. In particular, in the case of a cylindrical printing object, the distance between the nozzle and the printing object varies depending on the position in the sub-scanning direction X. Therefore, when printing on a cylindrical printing object, the use range of the nozzle may be restricted. In step S14, the control device 100 determines the use range of the nozzle 60a from the outer diameter of the second printing object 6 acquired in step S12, the contour of the second printing object 6 estimated in step S13, and the vertical position Z of the table 20 adjusted in step S11. Here, only the nozzles 60a within the range where the distance H between the nozzle surface 60b and the second printing object 6 shown in FIG. 7 is equal to or less than a predetermined value (for example, 2 mm or less) are used. Also, in step S14, the lighting range of the light irradiation device 70 is determined. The method for determining the lighting range of the light irradiation device 70 is not particularly limited. In all cases, all of the light sources 71 of the light irradiation device 70 may be lit. Also, the lighting range of the light irradiation device 70 may be determined according to the outer diameter of the second printing object 6 acquired in step S12 and the contour of the second printing object 6 estimated in step S13. However, in the present embodiment, the lighting range of the light irradiation device 70 is determined such that the end P2 of the lighting range of the light irradiation device 70 is at the same position as the front end of the second printing object 6 or on the front side of the second printing object 6.

[0043] In step S15, the positional relationship acquisition unit 109 acquires the positional relationship between the lighting range of the light irradiation device 70 and the second printing object 6. The positional relationship between the lighting range of the light irradiation device 70 and the second printing object 6 can be calculated from the vertical position Z of the table 20 adjusted in step S11, the contour of the second printing object 6 estimated in step S13, and the lighting range of the light irradiation device 70 determined in step S14. In step S16, the final landing point acquisition unit 110 acquires the final landing point P3 of the photocurable ink on the second printing object 6. Here, for example, the result of predicting the final landing point P3 from the print data input by the user is acquired.

[0044] In step S17, the irradiation end acquisition unit 111 acquires the position of the end P2 on the downstream side in the printing direction of the lighting range of the light irradiation device 70 obtained in step S14. As described above, in this embodiment, the second printing object 6 rotates forward during printing. The downstream side in the printing direction of the lighting range corresponds to the front side of the lighting range. The front end of the lighting range becomes the end P2 of the lighting range of the light irradiation device 70. In step S18, as shown in FIG. 7, the contact point calculation unit 112 calculates the position of the contact point P1 of the tangent line G drawn from the end P2 of the lighting range of the light irradiation device 70 obtained in step S17 so as to be in contact with the second printing object 6.

[0045] The printing operation S20 includes the processes from step S21 to step S24 shown in FIG. 10B. In step S21, the light source control unit 103 turns on the light irradiation device 70. In step S22, while the carriage movement control unit 105 moves the carriage 40 in the main scanning direction Y, the discharge control unit 101 discharges the photocurable ink from the nozzles 60a toward the second printing object 6. At this time, since the light irradiation device 70 is turned on, light is being irradiated toward the second printing object 6. When the discharge of the photocurable ink at one rotational position (printing for one scan) is completed, in step S23, the control device 100 checks whether the entire printing is completed. If the entire printing is not completed and the discharge of the photocurable ink is also to be performed at other rotational positions (No in step S23), the process proceeds to step S24. In step S24, the rotation control unit 102 rotates the second printing object 6 to change the rotational position of the second printing object 6. Returning to step S22 again, the discharge control unit 101 discharges the photocurable ink. Until the entire printing is completed, steps S22 to S24 are repeatedly performed. When the entire printing is completed, the printing operation S20 is completed.

[0046] After the completion of the printing operation S20, an ink curing operation S30 is performed to prevent insufficient curing of the photocurable ink ejected in the printing operation S20 (Yes in step S23). In the ink curing operation S30, the rotation of the second printing object 6 and the irradiation of light on the second printing object 6 are alternately performed. In the ink curing operation S30, while moving the carriage 40 in the main scanning direction Y, only light irradiation is performed without ejecting the photocurable ink. On the other hand, when the second printing object 6 rotates by a predetermined angle or more from the rotation position at the end of the printing operation S20, almost no light hits the photocurable ink ejected onto the second printing object 6, or no light hits it at all. Therefore, the control device 100 ends the ink curing operation S30 when the second printing object 6 rotates by a predetermined angle from the rotation position at the end of the printing operation S20 to reach a predetermined rotation position. In the present embodiment, this predetermined rotation position is the rotation position of the second printing object 6 when the final landing point P3 acquired in step S16 and the contact point P1 acquired in step S18 coincide when viewed from the main scanning direction Y.

[0047] As shown in FIG. 10B, the ink curing operation S30 includes processes from step S31 to step S34. In step S31, the rotation control unit 102 rotates the second printing material 6. In step S32, during the rotation in step S31, as shown in FIG. 11, it is determined whether the final landing point P3 obtained in step S16 and the contact point P1 obtained in step S18 match. Also in FIG. 11, similar to FIG. 7, the portion shown by the thick line is the range where the photocurable ink is discharged on the second printing material 6, the symbol P1 is the contact point between the tangent line G and the second printing material 6, the symbol P2 is the end of the lighting range of the light irradiation device 70 acquired by the irradiation end acquisition unit 111, and the symbol P3 is the final landing point acquired by the final landing point acquisition unit 110, respectively. Step S32 makes a determination during the rotation operation in step S31. If the final landing point P3 and the contact point P1 do not match (No in step S32), the process proceeds to step S33. In step S33, the carriage movement control unit 105 moves the carriage 40 in the main scanning direction. In step S33, the photocurable ink is not discharged, and only light irradiation is performed. When step S33 ends, the process returns to step S31 again, and the rotation control unit 102 rotates the second printing material 6. Steps S31 to S33 are repeated until the final landing point P3 and the contact point P1 match. As shown in FIG. 11, when the final landing point P3 and the contact point P1 match, the light of the light irradiation device 70 hardly hits the photocurable ink discharged on the second printing material 6. Therefore, if the final landing point P3 and the contact point P1 match, even if more light is irradiated, the effect of curing the photocurable ink is small. Therefore, the process proceeds from step S32 to step S34 (Yes in step S32). In step S34, the light source control unit 103 turns off the light irradiation device 70. By turning off the light irradiation device 70, the ink curing operation S30 is completed.

[0048] The printer 10 according to this embodiment performs an ink curing operation S30 after the completion of the printing operation S20. In the ink curing operation S30, the irradiation of light onto the second printing material 6 is continuously performed. In the ink curing operation S30, when the second printing material 6 rotates to such an extent that the light irradiated from the light irradiation device 70 hardly hits the photocurable ink ejected onto the second printing material 6, the light irradiation device 70 is turned off. By continuously turning on the light irradiation device 70 even after the completion of the printing operation S20, sufficient light can be irradiated onto the photocurable ink ejected onto the second printing material 6. Thereby, insufficient curing of the photocurable ink can be prevented. And when the light hardly hits the photocurable ink ejected onto the second printing material 6, the light irradiation device 70 is turned off. Thereby, wasteful light irradiation can be suppressed. Therefore, the photocurable ink ejected onto the second printing material 6 can be irradiated with light without excess or deficiency.

[0049] The control device 100 includes a contour acquisition unit 106, a positional relationship acquisition unit 109, a final landing point acquisition unit 110, an irradiation end acquisition unit 111, and a contact point calculation unit 112. By the control device 100 including these processing units, the printer 10 can calculate the rotational position of the second printing material 6 when the light irradiated from the light irradiation device 70 no longer hits the photocurable ink ejected onto the second printing material 6. Also, the final landing point P3, the range where the second printing material 6 is irradiated with light, etc. vary depending on various conditions such as the outer diameter of the second printing material 6. Accordingly, the timing at which the light irradiation device 70 should be turned off also differs. Therefore, it is a complicated task for the user to manually set the timing of turning off the light irradiation device 70. However, in this embodiment, since the control device 100 calculates the timing of turning off the light irradiation device 70, there is no need for the user to perform complicated settings.

[0050] The light irradiation device 70 includes a plurality of light sources 71. The light source control unit 103 of the control device 100 can light only a part of the light sources 71. As a result, the light sources 71 that do not irradiate light onto the photocurable ink ejected onto the second printing material 6 remain turned off, and only the light sources 71 that can irradiate light onto the photocurable ink ejected onto the second printing material 6 can be turned on. Thereby, wasteful light irradiation can be suppressed.

[0051] The contour acquisition unit 106 of the control device 100 includes a diameter acquisition unit 107 and a contour estimation unit 108. Thereby, the contour of the second printing material 6 can be easily estimated.

[0052] As described above, one embodiment of the present invention has been described, but the above embodiment is merely an example. Various other embodiments are possible.

[0053] In the above embodiment, the contact point calculation unit 112 of the control device 100 calculated the position of the contact point P1 of the tangent line G drawn so as to contact the second printing material 6 from the end P2 of the lighting range obtained by the irradiation end acquisition unit 111. However, the method for calculating the position of the contact point P1 is not limited to this. For example, as shown in FIG. 12, when viewed in the direction of the axis Ax, the position of the contact point P1 of the tangent line G that is orthogonal to the irradiation surface 72 of the light irradiation device 70 and is drawn so as to contact the second printing material 6 may be calculated as the contact point P1 by the contact point calculation unit 112. In FIG. 12 as well, similar to FIG. 7, the portion indicated by the thick line is the range where the photocurable ink is ejected on the second printing material 6, the symbol P1 is the contact point between the tangent line G and the second printing material 6, the symbol P2 is the end of the lighting range of the light irradiation device 70 acquired by the irradiation end acquisition unit 111, and the symbol P3 is the final landing point acquired by the final landing point acquisition unit 110. At this time, with respect to the sub-scanning direction X, if the end P2 of the lighting range of the light irradiation device 70 is at a position equal to the end on the downstream side in the printing direction of the second printing material 6 or at a position on the downstream side in the printing direction from the second printing material 6, all the light sources 71 of the light irradiation device 70 may be lit, or only a part of them may be lit. Further, when an arbitrary point located between two different contact points P1 calculated by two different methods coincides with the final landing point P3, the control device 100 may be configured to end the ink curing operation S30.

[0054] In the above embodiment, as shown in FIGS. 7 and 8, the downstream end P2 in the printing direction of the lighting range of the light irradiation device 70 was at the same position as the downstream end in the printing direction of the second printing material 6 or was located downstream in the printing direction of the second printing material 6 in the sub-scanning direction X. However, as shown in FIGS. 13 and 14, the downstream end P2 in the printing direction of the lighting range of the light irradiation device 70 may be upstream in the printing direction from the position equal to the downstream end in the printing direction of the second printing material 6 in the sub-scanning direction X. That is, when viewed from above, the position of the end P2 of the lighting range of the light irradiation device 70 may be a position overlapping the second printing material 6. At this time, as shown in FIG. 13, the contact point P1 of the tangent line G passing through the end P2 of the lighting range of the light irradiation device 70 and contacting the second printing material 6 is calculated, and the control device 100 may be configured to end the ink curing operation S30 when the second printing material 6 rotates until the contact point P1 and the final landing point P3 coincide. As shown in FIG. 14, the intersection point P4 of the straight line M orthogonal to the irradiation surface 72 and passing through the end P2 of the lighting range of the light irradiation device 70 and the second printing material 6 is calculated, and the control device 100 may be configured to end the ink curing operation S30 when the second printing material 6 rotates until the intersection point P4 and the final landing point P3 coincide. When calculating the intersection point P4 and ending the ink curing operation S30, the contact point calculation unit 112 of the control device 100 calculates the intersection point P4 of the straight line M and the second printing material 6. Further, both the contact point P1 and the intersection point P4 may be calculated, and the control device 100 may be configured to end the ink curing operation S30 when an arbitrary point located between the contact point P1 and the intersection point P4 coincides with the final landing point P3.

[0055] In the above embodiment, the light irradiation device 70 was turned off when the second printed material 6 rotated until the final landing point P3 and the contact point P1 coincided. However, the condition for turning off the light irradiation device 70 is not limited to this. When the second printed material 6 rotates by a predetermined angle from the rotation position of the second printed material 6 at the end of the printing operation S20 (the rotation position before the start of the ink curing operation S30) to a predetermined rotation position, the light irradiated from the light irradiation device 70 may hardly hit the photocurable ink ejected onto the second printed material 6. Therefore, the control device 100 may be configured to turn off the light irradiation device 70 when the second printed material 6 reaches a predetermined rotation position after the end of the printing operation S20 without calculating the contact point P1. In this case, the control device 100 has a memory for storing this predetermined rotation position. This predetermined rotation position may be determined in advance for each size of the outer diameter of the second printed material 6, or the control device 100 may be configured to select an appropriate predetermined rotation position according to the outer diameter acquired by the diameter acquisition unit 107. Further, this predetermined rotation position may be determined in advance by the user. At this time, it is not necessary to calculate the contact point P1, and it is not necessary to provide the contact point calculation unit 112 in the control device 100. Therefore, compared with the case where the contact point calculation unit 112 is provided in the control device 100, the configuration of the control device 100 becomes simpler.

[0056] In the above embodiment, the drive source of the rotation mechanism 90 was the rotation motor 93, but the configuration of the rotation mechanism 90 is not limited to this. For example, the printer 10 may be provided with a rack and pinion mechanism that can convert linear motion into rotational motion. A rack may be provided on the table 20, a pinion may be provided on the rotation mechanism 90, and the rotation mechanism 90 may be configured so that the linear motion of the table 20 moving in the sub-scanning direction X can be converted into the rotational motion of the second printed material 6 rotating.

[0057] The configuration and operation of the control device 100 are not limited to the above embodiment. For example, in the above embodiment, the diameter acquisition unit 107 of the control device 100 calculated the outer diameter of the second printed material 6. However, the control device 100 may be configured so that the control device 100 can acquire the outer diameter of the second printed material 6 by the user inputting the outer diameter of the second printed material 6.

[0058] In the above embodiment, the light irradiation device 70 was lit even while the second printing object 6 was being rotated in step S24 and step S31. However, the light irradiation device 70 does not necessarily need to be lit during the rotation of the second printing object 6. The control device 100 may be configured such that the light irradiation device 70 is turned off during the rotation of the second printing object 6, and the light irradiation device 70 is lit only when the carriage 40 is moved in the main scanning direction Y in step S22 and step S33. Even when the control device 100 is configured in this way, the end condition of the ink curing operation S30 may be the same as the condition described above.

Explanation of Signs

[0059] 6 Second printing object (printing object) 10 Printer 40 Carriage 60 Ink head 70 Light irradiation device 71 Light source 72 Irradiation surface 90 Rotation mechanism 100 Control device 106 Contour acquisition unit 107 Diameter acquisition unit 108 Contour estimation unit 109 Position relationship acquisition unit 110 Final landing point acquisition unit 111 Irradiation end acquisition unit 112 Contact point calculation unit

Claims

1. A rotating mechanism for rotatably supporting a three-dimensional printed object around an axis extending in a first direction, an ink head for discharging photocurable ink onto the printed object, a light irradiation device facing the printed object in a second direction orthogonal to the first direction and irradiating light toward the printed object, a control device for controlling the rotating mechanism, the ink head, and the light irradiation device, comprising: The control device: Performs printing control that alternately repeats an operation of rotating the printed object and an operation of discharging the photocurable ink from the ink head and irradiating light from the light irradiation device; After completion of the printing control, performs ink curing control that alternately repeats an operation of rotating the printed object and an operation of not discharging the photocurable ink from the ink head and irradiating light from the light irradiation device; Is configured to end the ink curing control when the rotational position of the printed object reaches a predetermined rotational position between a first rotational position and a second rotational position; Of the printed object, a portion where the photocurable ink last discharged from the ink head lands is defined as a final landing portion; When a direction orthogonal to the first direction and the second direction is defined as a third direction, The first rotational position is a position where the end on the downstream side in the printing direction of the printed object, or the position in the third direction of the end on the downstream side in the printing direction of the lighting range of the light irradiation device and the final landing portion are the same; The second rotational position is a position where the light irradiated from the end on the downstream side in the printing direction of the lighting range of the light irradiation device no longer hits the final landing portion. A printer.

2. The predetermined rotational position is a rotational position when, as viewed from the first direction, the final landing portion coincides with the contact point of a tangent line drawn so as to contact the contour of the printed object from the end on the downstream side in the printing direction of the lighting range of the light irradiation device. The printer according to claim 1.

3. The control device: A contour acquisition unit for acquiring the contour of the printed object; A positional relationship acquisition unit for acquiring the positional relationship between the lighting range of the light irradiation device and the contour of the printed object; A final landing point acquisition unit for acquiring the final landing portion; An irradiation end acquisition unit for acquiring the end on the downstream side in the printing direction of the lighting range of the light irradiation device; The printer according to claim 2, further comprising a contact point calculation unit for calculating the position of the contact point of a tangent line drawn so as to contact the contour of the printed object from the end on the downstream side in the printing direction of the lighting range of the light irradiation device.

4. The light irradiation device has an irradiation surface facing the object to be printed, the end on the downstream side in the printing direction of the lighting range of the light irradiation device is, in the third direction, at the same position as the end on the downstream side in the printing direction of the object to be printed or at a position downstream in the printing direction from the object to be printed, the predetermined rotational position is, when viewed from the first direction, the rotational position when the final landing portion coincides with the contact point of the tangent line drawn so as to be orthogonal to the irradiation surface and in contact with the contour of the object to be printed, the printer according to claim 1.

5. The control device includes a contour acquisition unit that acquires the contour of the object to be printed, a positional relationship acquisition unit that acquires the positional relationship between the lighting range of the light irradiation device and the contour of the object to be printed, a final landing point acquisition unit that acquires the final landing portion, an irradiation end acquisition unit that acquires the end on the downstream side in the printing direction of the lighting range of the light irradiation device, and a contact point calculation unit that calculates the position of the contact point of the tangent line drawn so as to be orthogonal to the irradiation surface of the light irradiation device and in contact with the object to be printed, the printer according to claim 4.

6. The light irradiation device has an irradiation surface facing the object to be printed, the end on the downstream side in the printing direction of the lighting range of the light irradiation device is, when viewed from the second direction, at a position overlapping the object to be printed, the predetermined rotational position is, when viewed from the first direction, the rotational position when the final landing portion coincides with the intersection point of the straight line drawn so as to be orthogonal to the irradiation surface from the end on the downstream side in the printing direction of the lighting range of the light irradiation device and the contour of the object to be printed, the printer according to claim 1.

7. The control device includes a contour acquisition unit that acquires the contour of the object to be printed, a positional relationship acquisition unit that acquires the positional relationship between the lighting range of the light irradiation device and the contour of the object to be printed, a final landing point acquisition unit that acquires the final landing portion, an irradiation end acquisition unit that acquires the end on the downstream side in the printing direction of the lighting range of the light irradiation device, and a contact point calculation unit that calculates the position of the intersection point of the straight line drawn so as to be orthogonal to the irradiation surface from the end on the downstream side in the printing direction of the lighting range of the light irradiation device and the contour of the object to be printed, the printer according to claim 6.

8. The light irradiation device includes a plurality of light sources arranged in the third direction, the control device is configured to be able to turn on all or part of the light sources, the printer according to claim 1.

9. The contour acquisition unit includes a diameter acquisition unit that acquires the outer diameter of the object to be printed, A printer according to claim 3, 5 or 7, comprising a contour estimation unit that estimates the contour of the printed object based on the outer diameter of the printed object.

10. The control device has a memory that stores the predetermined rotational position, The printer according to claim 1, wherein after the completion of the printing control, when the rotational position of the printed object reaches the predetermined rotational position, the ink curing control is terminated.

11. A rotation mechanism that rotatably supports a three-dimensional printed object around an axis extending in a first direction, An ink head that discharges photocurable ink onto the printed object, A control method for a printer, comprising: a light irradiation device that faces the printed object in a second direction orthogonal to the first direction and irradiates light, A printing step of alternately repeating an operation of rotating the printed object and an operation of discharging the photocurable ink from the ink head and irradiating light from the light irradiation device, After the completion of the printing step, an ink curing step of alternately repeating an operation of rotating the printed object and an operation of not discharging the photocurable ink from the ink head and irradiating light from the light irradiation device, The ink curing step is configured to end when the rotational position of the printed object reaches a predetermined rotational position between a first rotational position and a second rotational position, Among the printed object, a portion where the photocurable ink last discharged from the ink head lands is defined as a final landing portion, When a direction orthogonal to the first direction and the second direction is defined as a third direction, The first rotational position is a position where the end on the downstream side in the printing direction of the printed object or the position in the third direction of the end on the downstream side in the printing direction of the lighting range of the light irradiation device and the final landing portion are the same, The second rotational position is a position where the light irradiated from the end on the downstream side in the printing direction of the lighting range of the light irradiation device no longer hits the final landing portion.

Images