Printer and printing alignment method

Abstract

To provide a printer capable of performing printing at a position desired by a user when performing printing on a three-dimensional printed object.SOLUTION: A printer includes: an ink head 60 in which a plurality of nozzles are arranged in a sub-scanning direction; a rotation mechanism which holds a second printed object and rotates the second printed object about an axis extending in a main scanning direction; and a control device 100 which controls the ink head 60 and the rotation mechanism. The control device 100 includes: a nozzle use range acquisition unit 102 which acquires a nozzle use range which is the range of nozzles that eject ink among the plurality of nozzles; a first position acquisition unit 103 which acquires a first position which is a desired printing start position on an outer peripheral surface of the second printed object; and an alignment execution unit 106 which rotates the second printed object so that the first position of the second printed object faces the nozzles within the nozzle use range and aligns the nozzle use range with the first position.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a printer and a printing alignment method.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, a printer including an ink head and a rotating mechanism for rotating a printing medium is known. A plurality of nozzles are formed on the lower surface of the ink head. The nozzles are ejection ports for ink. The rotating mechanism rotates a three-dimensional printing medium. By ejecting ink with the ink head while rotating the printing medium by the rotating mechanism, printing can be performed on the outer peripheral surface of the printing medium.

[0003] In addition, the printer disclosed in Patent Document 1 includes a light irradiation unit that irradiates light toward the printing medium. The light irradiation unit irradiates light that serves as a mark for adjusting the rotational position around the rotation axis of the printing medium. The user can accurately adjust the rotational position around the rotation axis of the printing medium by using the light irradiated from the light irradiation unit as a mark. Thereby, the user can relatively easily adjust the position where printing is first performed on the outer peripheral surface of the printing medium (hereinafter referred to as the printing start position) to a desired position.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, when printing on a printed matter having a curved surface on its outer peripheral surface such as a cylindrical printed matter, for the purpose of suppressing deterioration in printing quality, the nozzles for ejecting ink may be restricted to only the nozzles within a predetermined range. This is because the outer peripheral surface of the printed matter is curved and the distance between the nozzle and the printed matter varies depending on the position of the nozzle. If the distance between the nozzle and the printed matter is large, ink scattering occurs and the printing quality deteriorates. Therefore, by restricting the use of the nozzles with a large distance, it is possible to suppress deterioration in printing quality.

[0006] On the other hand, when the range of use of the nozzles is changed as described above, the landing range of the ink on the printed matter changes. Therefore, even if the rotational position of the printed matter is exactly the same, the printing start position changes between the case where printing is performed with the range of use of the nozzles restricted and the case where printing is performed without restricting the range of use of the nozzles. Therefore, when printing is performed with the range of use of the nozzles restricted in order to suppress deterioration in printing quality, even if the rotational position of the printed matter is accurately adjusted, there are cases where printing cannot be performed from the printing start position desired by the user.

[0007] The present invention has been made in view of such a point, and an object thereof is to provide a printer capable of performing printing from a printing start position desired by a user while suppressing deterioration in printing quality when printing on a three-dimensional printed matter.

Means for Solving the Problems

[0008] The printer according to the present invention includes an ink head in which a plurality of nozzles for discharging ink are arranged side by side in a first direction, a rotating mechanism that holds a printing object having an outer peripheral surface and rotates the printing object around an axis extending in a second direction orthogonal to the first direction, and a control device that controls the ink head and the rotating mechanism. The control device includes a nozzle usage range acquisition unit that acquires a nozzle usage range which is a range of nozzles that discharge ink among the plurality of nozzles, a first position acquisition unit that acquires a first position which is a desired printing start position on the outer peripheral surface of the printing object, and an alignment execution unit that rotates the printing object so that the first position of the printing object faces the nozzles in the nozzle usage range and performs alignment between the nozzle usage range and the first position.

[0009] According to the above configuration, even if the nozzle usage range is restricted to suppress a decrease in printing quality, the alignment execution unit aligns the nozzle usage range with the first position. Thereby, while suppressing a decrease in printing quality, printing can be performed from a printing start position desired by the user.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a printer capable of performing printing at a position desired by a user when printing on a three-dimensional printing object.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

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Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0012] Hereinafter, a printer according to an embodiment of the present invention will be described with reference to the drawings. It should be noted 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.

[0013] FIG. 1 is a perspective view of a printer 10 according to the present embodiment. The printer 10 according to the present embodiment is a flatbed type printer. In the following description, for convenience, the directions of the printer 10 are defined as follows. 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. The left, right, top, and bottom when the printer 10 is viewed from the front are simply expressed as left, right, top, and bottom. The reference signs F, Rr, L, R, U, and D in the drawings respectively mean front, rear, left, right, top, and bottom. The reference sign Y in the drawings indicates the main scanning direction. The main scanning direction Y is an example of the second direction. Also, the reference sign X in the drawings indicates the sub-scanning direction. The sub-scanning direction X is an example of the first direction. Here, the main scanning direction Y is the left-right direction, and the sub-scanning direction X is the front-rear direction. The main scanning direction Y and the sub-scanning direction X are orthogonal to each other. The reference sign Z in the drawings indicates the up-down direction. The up-down direction Z is orthogonal to the main scanning direction Y and the sub-scanning direction X. The directions defined here are merely for convenience and do not limit the installation state of the printer 10, nor do they limit the present invention.

[0014] 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 surface formed of 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.

[0015] As shown in FIG. 3, the printer 10 can perform printing on the outer peripheral surface of the second object to be printed 6 held by 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, a tubular shape, and the like. The second object to be printed 6 may have a surface formed of a curved surface, or may have a surface formed of a plurality of intersecting planes. The type of the second object to be printed 6 is not particularly limited, and for example, it may be a bottle, a cup, or the like. Also, the material of the second object to be printed 6 is not particularly limited, and it may be glass, resin, wood, or the like. The printer 10 performs printing on the outer peripheral surface of the second object to be printed 6 by alternately performing a rotation operation and an ink ejection operation. The rotation operation is an operation of rotating the second object to be printed 6 by the rotation mechanism 90 described later. The ink ejection operation is an operation of ejecting ink from an ink head 60 described later.

[0016] 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 part 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.

[0017] As shown in FIG. 2, inside the printer 10, a table 20, a table moving device 30, a carriage 40, a carriage moving device 50, a height detection device 75, and a control device 100 (see FIG. 1) are provided.

[0018] Table 20 is a base for supporting the first printing object 5 and the second printing object 6. Table 20 is a flat plate-shaped member and extends in the main scanning direction Y and the sub-scanning direction X. Table 20 is disposed approximately at the center in the main scanning direction Y inside the case 11.

[0019] Below the table 20, a table moving device 30 is disposed. The table moving device 30 moves the table 20 in the sub-scanning direction X and the vertical direction Z. 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. Also, the configurations of the sub-scanning direction moving device 30X and the vertical direction moving device 30Z are not particularly limited, and known moving mechanisms can be applied. As shown in FIG. 2, when printing on the first printing object 5, the printer 10 alternately performs an operation of moving the table 20 forward and an operation of discharging ink while moving the carriage 40 in the main scanning direction Y. However, the printer 10 may move the table 20 backward instead of moving it forward.

[0020] An ink head 60 and a pointer 70 are mounted on the carriage 40. The ink head 60 is provided at the lower part of the carriage 40 and faces the table 20. In this embodiment, three ink heads 60 are provided. However, the number of ink heads 60 is not limited thereto. The pointer 70 is disposed to the left of the ink head 60. Note that the pointer 70 may be disposed to the right of the ink head 60. The carriage 40 is disposed above the table 20 and is 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.

[0021] 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 FIG. 2, 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 of the guide rail 51. The carriage motor 53 is attached to one of the pulleys. The carriage motor 53 is 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.

[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. 2) housed in the case 11 by flexible ink tubes (not shown). As shown in FIG. 4, the ink heads 60 are arranged at positions aligned in the sub-scanning direction X.

[0023] As shown in FIG. 4, the ink head 60 includes a nozzle surface 60b on which a plurality of nozzles 60a are formed respectively. 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 from 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. In this embodiment, 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 is not particularly limited. Although not shown, the printer 10 may include an ultraviolet irradiation device that irradiates ultraviolet rays onto the first printed material 5 or the second printed material 6 placed on the table 20. Thereby, the curing of the ink ejected from the ink head 60 is further promoted.

[0025] As described above, when printing on the outer peripheral surface of the second object to be printed 6, a rotation mechanism 90 for rotating the second object to be printed 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 object to be printed 6 around the axis Ax extending in the main scanning direction Y. In the present embodiment, the rotation mechanism 90 rotates the second object to be printed 6 forward. Note that rotating the second object to be printed 6 forward means rotating the second object to be printed 6 so that the highest part of the second object to be printed 6 faces forward. However, the rotation mechanism 90 may rotate the second object to be printed 6 backward. Also, as shown in FIG. 2, when printing on the first object to be printed 5, the rotation mechanism 90 is removed from the table 20.

[0026] 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 the 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. The second shaft 92, like the first shaft 91, extends in the main scanning direction Y and can rotate around the 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 has a built-in 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 object to be printed 6.

[0027] The pointer 70 is a device that irradiates light serving as a mark for adjusting the printing start position when printing on the second printing object 6 to a position desired by the user. Here, the printing start position refers to the portion where ink is first ejected on the outer peripheral surface of the second printing object 6. As shown in FIG. 6, the pointer 70 irradiates light to the second printing object 6 placed on the rotation mechanism 90. In the present embodiment, the pointer 70 is configured to irradiate light to the highest portion of the second printing object 6. However, the location where the pointer 70 irradiates light is not limited to this. The pointer 70 is, for example, an LED marker having an LED light source. The user can adjust the rotation position of the second printing object 6 using the light irradiated from the pointer 70 as a mark. By adjusting the rotation position of the second printing object 6 so that the light irradiated from the pointer 70 hits the printing start position desired by the user, the user can specify the printing start position.

[0028] The height detection device 75 is a device that measures the height of the second printing object 6 from the table 20. Here, the height of the second printing object 6 from the table 20 refers to the distance from the upper surface of the table 20 to the highest position of the second printing object 6. The configuration of the height detection device 75 is not particularly limited, and a known device can be applied. In the present embodiment, the height detection device 75 is a contact type height detection device. The height detection device 75 measures the height of the second printing object 6 from the table 20 by measuring the vertical position Z of the table 20 at the boundary where the second printing object 6 contacts / does not contact the height detection device 75. Further, the height detection device 75 may be a laser displacement meter or the like configured to measure the height of the second printing object 6 from the table 20 by irradiating the second printing object 6 with a laser.

[0029] FIG. 7 is a block diagram of the printer 10 according to the present embodiment. The control device 100 is communicably 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 pointer 70, the height detection device 75, and the rotation motor 93 of the rotation mechanism 90, and controls the operations thereof. 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 that is installed outside the printer 10 and is communicably connected to the printer 10 via wire or wirelessly.

[0030] Functionally, the control device 100 includes a print control unit 101, a nozzle use range acquisition unit 102, a first position acquisition unit 103, a pass number acquisition unit 104, a second position acquisition unit 105, an alignment execution unit 106, and a table height adjustment unit 107. The control device 100 may include other processing units, but the description and illustration thereof are omitted here. These processing units of the control device 100 are realized by, for example, a computer program.

[0031] The print control unit 101 controls the carriage moving device 50, the ink head 60, and the rotation mechanism 90 to perform printing on the outer peripheral surface of the second printing object 6. In the present embodiment, the print control unit 101 is configured to alternately execute rotation control and ink ejection control. Here, the rotation control is control for executing a rotation operation of rotating the second printing object 6 forward by operating the rotation mechanism 90. The ink ejection control is control for executing an ink ejection operation of ejecting ink from the ink head 60 while moving the carriage 40 in the main scanning direction Y. In one ink ejection control, the carriage 40 reciprocates once in the main scanning direction Y. However, in one ink ejection control, the carriage 40 may not reciprocate in the main scanning direction Y and may move only in one direction in the main scanning direction Y.

[0032] As shown in FIG. 8, the distance between the second object to be printed 6 and the lower surface of the ink head 60 varies depending on the position in the sub-scanning direction X. That is, the distance between the second object to be printed 6 and the nozzle 60a varies depending on the position in the sub-scanning direction X. When the distance between the second object to be printed 6 and the nozzle 60a increases, the landing accuracy of the photocurable ink ejected from the nozzle 60a decreases, and the printing quality deteriorates. Therefore, when printing on the second object to be printed 6, in this embodiment, the range of the nozzles 60a that eject the photocurable ink is restricted. In the following description, the range of the nozzles 60a that eject the photocurable ink is referred to as the nozzle usage range W. The nozzle usage range acquisition unit 102 acquires the nozzle usage range W determined according to the curvature of the surface of the second object to be printed 6 as viewed from the main scanning direction Y. The nozzle usage range W is determined, for example, by an external computer connected to the printer 10. Based on the information on the shape and outer diameter of the second object to be printed 6 by the external computer, the nozzle usage range W is determined and stored in the print data. In this embodiment, only the nozzles 60a within a range where the distance between the nozzle 60a and the second object to be printed 6 is equal to or less than a predetermined value (for example, 2 mm or less) are used. The nozzle usage range acquisition unit 102 acquires the information on the nozzle usage range W included in the print data. Note that the nozzle usage range W may be determined in the nozzle usage range acquisition unit 102. That is, the nozzle usage range acquisition unit 102 may determine the nozzle usage range W based on the information on the shape and outer diameter of the second object to be printed 6 input through the operation screen of the printer 10. FIG. 8 shows an example of the nozzle usage range W. Note that the illustration of the pointer 70 is omitted in FIG. 8.

[0033] The first position acquisition unit 103 acquires the position on the surface of the second object to be printed 6 where the light of the pointer 70 is irradiated as the first position P1. In this embodiment, since the pointer 70 irradiates light on the highest portion of the second object to be printed 6, the first position acquisition unit 103 acquires the position of the highest portion of the second object to be printed 6 as the first position P1. The first position P1 is the printing start position desired by the user on the outer peripheral surface of the second object to be printed 6.

[0034] The pass number acquisition unit 104 acquires the number of printing passes. The number of passes is the number of times the ink head 60 moves while discharging ink in order to print on a predetermined area within the printing range on the outer peripheral surface of the second object to be printed 6. Here, in the present embodiment, the predetermined area is an area having a width equal to the length in the sub-scanning direction X of the nozzle usage range W in the sub-scanning direction X. In the present embodiment, in one ink discharge control, the carriage 40 moves in one direction in the main scanning direction Y. In the present embodiment, the number of passes is described as 4, but the user can set the number of passes desired. After the ink discharge is completed, the carriage 40 may be moved in the main scanning direction Y in a state where the ultraviolet irradiation device is irradiated without discharging ink, and a process of curing the ink may be performed.

[0035] The second position acquisition unit 105 acquires the second position P2. Here, the second position P2 is the position of the end on the downstream side in the rotation direction of the division range that is the most upstream side in the rotation direction among the division ranges obtained by dividing the nozzle usage range W based on the number of passes. FIG. 8 shows an example of the division range and the second position P2 acquired by the second position acquisition unit 105. The ranges indicated by reference numerals A1 to A4 in FIG. 8 are each division range. In the present embodiment, since the number of printing passes is 4, there are four division ranges A1 to A4. Each division range A1 to A4 is evenly divided. As described above, in the present embodiment, when printing on the second object to be printed 6, the second object to be printed 6 is rotated forward (see FIG. 9). Therefore, among the division ranges A1 to A4 shown in FIG. 8, the one that is the most upstream side in the rotation direction is the division range A1, and the one that is the most downstream side in the rotation direction is the division range A4. The second position P2 in the present embodiment is the position corresponding to the end point on the downstream side in the rotation direction of the division range A1 that is the most upstream side in the rotation direction. In addition, in the drawings other than FIG. 8, the division ranges are also indicated by reference numerals A1 to A4.

[0036] The alignment execution unit 106 is a processing unit that rotates the second printing object 6 by the rotation mechanism 90 to align the nozzle use range W and the first position P1 so that the first position P1 faces the nozzle 60a in the nozzle use range. In the present embodiment, the alignment execution unit 106 rotates the second printing object 6 so that the first position P1 acquired by the first position acquisition unit 103 overlaps the second position P2 acquired by the second position acquisition unit 105. Note that the alignment execution unit 106 may rotate the second printing object 6 forward or backward. FIG. 9 is a schematic view of the second printing object 6 when the first position P1 and the second position P2 overlap, as viewed from the left. Note that in FIG. 9, the pointer 70 is not shown.

[0037] The table height adjustment unit 107 is a processing unit that sets the position in the vertical direction Z of the table 20 when printing on the second printing object 6, and moves the table 20 to the position before ink is ejected onto the second printing object 6.

[0038] Next, the operation of the printer 10 when printing on the second printing object 6 will be described. FIG. 10 is an example of a flowchart when printing on the second printing object 6. From step S11 to step S17, a setup operation is performed. From step S18 to step 20, printing is performed on the second printing object 6.

[0039] In step S11, the user places the second printing object 6 on the rotation mechanism 90. At this time, the user adjusts the rotation position of the second printing object 6 so that the light of the pointer 70 hits the desired printing start position, and places the second printing object 6.

[0040] When the placement of the second printed material 6 is completed, in step S12, based on the height of the second printed material 6 from the table 20, the table height adjustment unit 107 adjusts the position of the table 20 in the vertical direction Z. In the present embodiment, the height of the second printed material 6 from the table 20 is measured by the height detection device 75. Based on the measured height of the second printed material 6 from the table 20, the table height adjustment unit 107 adjusts the position of the table 20 in the vertical direction Z. The table height adjustment unit 107 adjusts the position of the table 20 in the vertical direction Z such that the distance between the highest part of the second printed material 6 and the ink head 60 becomes a predetermined value (for example, 1 mm) based on the height of the second printed material 6 from the table 20 measured by the height detection device 75 and the position of the ink head 60 in the vertical direction Z. Here, the position of the ink head 60 in the vertical direction Z is known. Note that the table height adjustment unit 107 may adjust the height of the table 20 based on the height of the second printed material 6 input by the user without using the height detection device 75.

[0041] In step S13, the user inputs print data from an external computer to the printer 10. In the present embodiment, the print data is input to the control device 100. Here, the input data includes information such as the nozzle use range W, the number of print passes, the image data for printing, and the print range. However, the input print data is not limited to this, and data other than this may be included. In step S14, the nozzle use range acquisition unit 102 acquires the nozzle use range W included in the print data.

[0042] In step S15, the first position acquisition unit 103 acquires the first position P1. As described above, in the present embodiment, the first position acquisition unit 103 acquires the highest part of the second printed material 6 irradiated with the light of the pointer 70 as the first position P1. Also in step S15, the pass number acquisition unit 104 acquires the number of print passes. In the present embodiment, the pass number acquisition unit 104 acquires the information on the number of passes included in the print data.

[0043] In step S16, the second position acquisition unit 105 acquires the second position P2. As described above, in this embodiment, the second position acquisition unit 105 divides the nozzle usage range W into a plurality of divided ranges A1 to A4 based on the number of passes acquired in step S15 and calculates the second position P2. Here, since the number of passes is 4, the nozzle usage range W is divided into 4 ranges. The second position acquisition unit 105 acquires, as the second position P2, the downstream end point in the rotation direction of the divided range A1, which is the most upstream in the rotation direction, among the plurality of divided ranges A1 to A4. In step S17, the alignment execution unit 106 rotates the second printing object 6 so that the first position P1 overlaps the second position P2.

[0044] When the above setup operation is completed, the printer 10 performs printing on the second printing object 6. In step S18, the print control unit 101 executes ink ejection control. Therefore, in step S18, the printer 10 performs an ink ejection operation of ejecting ink onto the second printing object 6 while moving the carriage 40 in the main scanning direction Y. In the first step S18, the print control unit 101 ejects ink only from the nozzles 60a in the divided range A1. As a result, in step S11, the printing start position (the first position P1) specified by the user becomes the downstream end point in the rotation direction of the ink landing range. Therefore, printing can be performed from the printing start position specified by the user.

[0045] When the first step S18 is completed, in step S19, the print control unit 101 determines whether or not the entire printing has been completed. If the entire printing has not been completed and printing is to be performed at other rotation positions (No in step S19), the process proceeds to step S20. When the print control unit 101 determines that not all ink ejection operations for the printing range have been completed, the process proceeds to step S20 (No in step S19).

[0046] In step S20, the print control unit 101 executes rotation control. Accordingly, the printer 10 performs a rotation operation to rotate the second printing medium 6. Here, the rotation amount of the second printing medium 6 is calculated by the print control unit 101 based on the nozzle usage range W acquired by the nozzle usage range acquisition unit in step S14 and the number of passes acquired by the pass number acquisition unit 104 in step S15. In the present embodiment, the second printing medium 6 is rotated by the length of each divided range. Note that the rotation amount may be corrected based on the outer diameter of the second printing medium 6. By rotating the second printing medium 6 by the length of each divided range, as shown in FIG. 11, the first position P1 moves forward and becomes equal to the end point on the downstream side in the rotation direction of the divided range A2. Note that the thick line portion in FIG. 11 indicates the range where the ink has landed on the outer peripheral surface of the second printing medium 6 when the first step S18 and step S20 are completed.

[0047] When step S20 ends, the process returns to step S18. In the second step S18, the print control unit 101 executes ink ejection control again. When performing the second step S18, as shown in FIG. 11, the first position P1 is at a position equal to the end point on the downstream side in the rotation direction of the divided range A2. Therefore, in the second step S18, the print control unit 101 ejects ink from the nozzles 60a in the divided ranges A1 and A2 that are upstream of the first position P1 in the rotation direction. Similarly, in the third step S18, since the first position P1 is at a position equal to the end point on the downstream side in the rotation direction of the divided range A3, the print control unit 101 ejects ink from the nozzles 60a in the divided ranges A1, A2, and A3. When performing the fourth step S18, the first position P1 is at a position equal to the end point on the downstream side in the rotation direction of the divided range A4, and the entire nozzle usage range W overlaps with the printing range. Therefore, in the fourth step S18, the print control unit 101 ejects ink from all the nozzles 60a within the nozzle usage range W.

[0048] Also in step S18 and subsequent steps, as shown in FIG. 12, since the entire nozzle usage range W overlaps with the printing range, the print control unit 101 causes ink to be ejected from all the nozzles 60a within the nozzle usage range W. The thick line portion in FIG. 12 indicates the range where the ink has landed on the outer peripheral surface of the second object to be printed 6 when the fourth step S18 and step S20 are completed. Also, reference numeral P3 in FIG. 12 indicates the printing end position. The printing end position P3 is the end on the side opposite to the printing start position of the printing range (i.e., the first position P1).

[0049] As shown in FIG. 13, when, viewed from above, the printing end position P3 of the printing range reaches a position overlapping with the nozzle usage range W, the print control unit 101 causes ink to be ejected only from the nozzles 60a of the nozzle usage range W at positions overlapping with the printing range. In order not to land ink at positions outside the printing range, the print control unit 101 does not cause ink to be ejected from the nozzles 60a of the nozzle usage range W at positions not overlapping with the printing range. The thick line portion in FIG. 13 indicates the range where the ink has landed on the outer peripheral surface of the second object to be printed 6.

[0050] Until the entire printing is completed, the printer 10 repeats the operations from step S18 to step S20. When the print control unit 101 has performed all the printing of the print data, the printer 10 ends the operation (Yes in step S19).

[0051] According to this embodiment, the printer 10 includes an ink head 60 in which a plurality of nozzles 60a that eject ink are arranged side by side in the sub-scanning direction X, a rotation mechanism 90 that holds the second printing material 6 and rotates the second printing material 6 around an axis Ax extending in the main scanning direction Y, and a control device 100 that controls the ink head 60 and the rotation mechanism 90. The control device 100 includes a nozzle usage range acquisition unit 102 that acquires a nozzle usage range W that is the range of the nozzles 60a that eject ink among the nozzles 60a, a first position acquisition unit 103 that acquires a first position P1 that is a desired printing start position on the outer peripheral surface of the second printing material 6, and an alignment execution unit 106 that rotates the second printing material 6 to align the nozzle usage range W and the first position P1 so that the first position P1 of the second printing material 6 faces the nozzles 60a of the nozzle usage range W. Even if the nozzle usage range W is restricted to suppress a deterioration in printing quality, the alignment execution unit 106 aligns the nozzle usage range W and the first position P1. Thereby, printing can be performed from a printing start position desired by the user while suppressing a deterioration in printing quality.

[0052] According to this embodiment, the nozzle usage range acquisition unit 102 acquires the nozzle usage range W based on the curvature of the outer peripheral surface of the second printing material 6. For example, the nozzle usage range acquisition unit 102 sets the nozzle usage range W to be smaller as the curvature of the outer peripheral surface of the second printing material 6 is larger, and sets the nozzle usage range W to be larger as the curvature of the outer peripheral surface of the second printing material 6 is smaller. By performing printing using only the nozzles 60a in a range suitable for the shape of the second printing material 6, a deterioration in printing quality can be suppressed.

[0053] According to this embodiment, the control device 100 further includes a pass number acquisition unit 104 that acquires the number of printing passes, and a second position acquisition unit 105 that acquires a second position P2 which is the position of the downstream end in the rotation direction of the division range that is the most upstream in the rotation direction among the division ranges obtained by dividing the nozzle usage range W based on the number of passes. The alignment execution unit 106 rotates the second printing object 6 so that the first position P1 and the second position P2 coincide. Thereby, alignment between the nozzle usage range W and the first position P1 can be performed in consideration of the number of printing passes. Therefore, printing can be performed starting from the printing start position desired by the user while suppressing deterioration in printing quality. Note that in this embodiment, the number of passes was 4, but the number of passes is not particularly limited. The number of passes may be 1, 2, or 3, or may be 5 or more.

[0054] According to this embodiment, the printer 10 includes a pointer 70 that irradiates light toward the second printing object 6. The first position acquisition unit 103 acquires, as the first position P1, the position on the outer peripheral surface of the second printing object 6 where the light of the pointer 70 is irradiated. Thereby, the user can easily set the printing start position of the second printing object 6 using the light of the pointer 70 as a mark.

[0055] 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.

[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 include 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 printing object 6 rotating.

Description of Reference Numerals

[0057] 6 Second printing object (printing object) 10 Printer 40 Carriage 60 Ink head 60a Nozzle 70 Pointer 90 Rotation mechanism 100 Control device 102 Nozzle usage range acquisition unit 103 First position acquisition unit 104 Number of passes acquisition unit 105 Second position acquisition unit 106 Alignment execution unit

Claims

1. An ink head in which a plurality of nozzles for discharging ink are arranged side by side in a first direction, a rotating mechanism that holds a printed object having an outer peripheral surface and rotates the printed object around an axis extending in a second direction orthogonal to the first direction, a control device that controls the ink head and the rotating mechanism, and the control device includes: a nozzle usage range acquisition unit that acquires a nozzle usage range that is a range of nozzles that discharge ink among the plurality of nozzles; a first position acquisition unit that acquires a first position that is a desired printing start position on the outer peripheral surface of the printed object; an alignment execution unit that rotates the printed object so that the first position of the printed object faces the nozzles in the nozzle usage range, and performs alignment between the nozzle usage range and the first position. A printer.

2. The printer according to claim 1, wherein the nozzle usage range acquisition unit acquires the nozzle usage range based on the curvature of the outer peripheral surface of the printed object.

3. A carriage that moves the ink head in the second direction is provided, and the control device includes: a pass number acquisition unit that acquires a pass number that is the number of times the ink head moves in the second direction over a predetermined area on the outer peripheral surface of the printed object; a second position acquisition unit that acquires a second position that is the position of the downstream end in the rotation direction of the divided range that is the most upstream in the rotation direction among the divided ranges obtained by dividing the nozzle usage range based on the pass number, and further includes: The printer according to claim 1, wherein the alignment execution unit rotates the printed object so that the first position and the second position coincide with each other.

4. A pointer that irradiates light toward the printed object is provided, The printer according to claim 1, wherein the first position acquisition unit acquires, as the first position, a position on the outer peripheral surface of the printed object where the light of the pointer is irradiated.

5. A printing alignment method for a printer including an ink head in which a plurality of nozzles for discharging ink are arranged side by side in a first direction, and a rotating mechanism that holds a printed object having an outer peripheral surface and rotates the printed object around an axis extending in a second direction orthogonal to the first direction, a nozzle usage range acquisition step of acquiring a nozzle usage range that is a range of nozzles that discharge ink among the plurality of nozzles; a first position acquisition step of acquiring a first position that is a desired printing start position on the outer peripheral surface of the printed object; An alignment step of rotating the object to be printed so that the first position of the object to be printed faces the nozzles in the nozzle usage range, and performing alignment between the nozzle usage range and the first position, a printing alignment method including this.

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