Printer, control method, and control program

Abstract

To provide a printer, a control method and a control program which suppress occurrence of a streak-like pattern in an ink layer, and can improve printing image quality.SOLUTION: A white clear head 52 is aligned with a color head 51 in a sub-scanning direction. A plurality of ultraviolet light-emitting diodes 614 and 624 are provided on substrates 612 and 622, and are aligned with the color head 51 and the white clear head 52 in a main scanning direction. The number of the plurality of ultraviolet light-emitting diodes 614 per area or unit area of the substrate 612 is smaller than the number of the plurality of ultraviolet light-emitting diodes 624 per area or unit area of the substrate 622. A CPU of the printer relatively moves the color head 51, the white clear head 52 and the plurality of ultraviolet light-emitting diodes 614 and 624 with respect to a platen in the main scanning direction, discharges first ink from the color head 51, and irradiates the discharged first ink with light from the plurality of ultraviolet light-emitting diodes 614.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a printer, a control method, and a control program. [Background technology]

[0002] Printers that perform gloss printing using photocurable ink are known. Gloss printing is a printing method that creates glossy prints by smoothing a layer of photocurable ink formed on a print target. For example, the printer described in Patent Document 1 has a color ink head, a clear ink head, multiple color LEDs, and multiple white / clear LEDs mounted on a carriage. The color ink head and clear ink head are aligned in the sub-scanning direction and eject photocurable color ink and photocurable clear ink, respectively, onto the print target. The multiple color LEDs are aligned in multiple rows on both sides of the color ink head in the main scanning direction and irradiate the print target with light. The multiple white / clear LEDs are aligned in multiple rows on both sides of the clear ink head in the main scanning direction and irradiate the print target with light.

[0003] During gloss printing, the printer ejects color inks from the color ink heads onto the print target and lights up multiple color LEDs while moving the carriage in the main scanning direction. The printer ejects clear ink from the clear ink head onto the print target and lights up multiple clear LEDs. The printer transports the print target in the sub-scanning direction, from the color ink heads toward the clear ink head. By repeating these operations, the printer forms a layer of color ink on the print target, and then forms a layer of clear ink on top of the color ink layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-188962 Summary of the Invention

Problems to be Solved by the Invention

[0005] When performing gloss printing, in order to ensure the time from when the layer of clear ink is formed on the object to be printed until it is smoothed, among the plurality of white / clear LEDs, only the white / clear LED located most upstream in the traveling direction of the carriage in the main scanning direction is lit.

[0006] In the above printer, for example, when a layer of clear ink is not formed on the layer of color ink, it is conceivable that gloss printing is performed by smoothing the layer of color ink. Also in this case, in order to ensure the time from when the layer of color ink is formed on the object to be printed until it is smoothed, similar to the white / clear LEDs, among the plurality of color LEDs, it is conceivable that only the color LED located most upstream in the traveling direction of the carriage in the main scanning direction is lit.

[0007] When performing these gloss printings, in the first scan, depending on how the ink in the ink layer such as clear ink and color ink cures at the boundary between the irradiated area and the non-irradiated area of the ink layer, streak-like patterns may occur in the ink layer such as clear ink and color ink. As a result, the print image quality may deteriorate.

[0008] An object of the present invention is to provide a printer, a control method, and a control program that can suppress the occurrence of streak-like patterns in the ink layer and improve the print image quality.

Means for Solving the Problems

[0009] A printer according to a first aspect of the present invention includes a platen on which a printing object is placed, a first head that ejects a photo-curable first ink onto the printing object, a second head that is aligned with the first head in a sub-scanning direction and ejects a photo-curable second ink onto the printing object, a plurality of first light sources that are aligned with the first head in a main scanning direction perpendicular to the sub-scanning direction and irradiate light onto the printing object, and a plate that faces the platen in a height direction perpendicular to the main scanning direction and the sub-scanning direction, the first plate having the plurality of first light sources provided thereon, a plurality of second light sources that are aligned with the second head in the main scanning direction and irradiate light onto the printing object, and a plate that faces the platen in the height direction, the number of the plurality of first light sources per unit area of the first plate is smaller than the number of the plurality of second light sources per unit area of the second plate, and the controller executes a movement process that moves the first head, the second head, the plurality of first light sources, and the plurality of second light sources relative to the platen in the main scanning direction; an ejection process that ejects the first ink from the first head onto the printing object while the movement process is being executed; and an irradiation process that irradiates the first ink ejected onto the printing object with light from the plurality of first light sources while the movement process is being executed.

[0010] According to the first aspect, the printer can suppress the occurrence of streaky patterns in the layer formed by the first ink, thereby improving print quality.

[0011] The control method according to the second aspect of the present invention includes a platen on which a printing object is placed, a first head that discharges a photocurable first ink onto the printing object, a second head that is arranged side by side with the first head in the sub-scanning direction and discharges a photocurable second ink onto the printing object, a plurality of first light sources that are arranged side by side with the first head in the main scanning direction orthogonal to the sub-scanning direction and irradiate the printing object with light, a first plate that faces the platen in the height direction orthogonal to the main scanning direction and the sub-scanning direction and is provided with the plurality of first light sources, a plurality of second light sources that are arranged side by side with the second head in the main scanning direction and irradiate the printing object with light, and a second plate that faces the platen in the height direction and is provided with the plurality of second light sources. The area of the first plate or the number of the plurality of first light sources per unit area is smaller than the area of the second plate or the number of the plurality of second light sources per unit area. The control method of the printer is characterized by performing a moving process of relatively moving the first head, the second head, the plurality of first light sources, and the plurality of second light sources relative to the platen in the main scanning direction, a discharging process of discharging the first ink from the first head onto the printing object during the execution of the moving process, and an irradiating process of irradiating the first ink discharged onto the printing object with light from the plurality of first light sources during the execution of the moving process.

[0012] The second aspect can achieve the same operational effects as the first aspect.

[0013] The control program according to the third aspect of the present invention includes a platen on which a printing object is placed, a first head that discharges a photocurable first ink onto the printing object, a second head that is arranged side by side with the first head in the sub-scanning direction and discharges a photocurable second ink onto the printing object, a plurality of first light sources that are arranged side by side with the first head in the main scanning direction orthogonal to the sub-scanning direction and irradiate the printing object with light, a first plate that faces the platen in the height direction orthogonal to the main scanning direction and the sub-scanning direction and is provided with the plurality of first light sources, a plurality of second light sources that are arranged side by side with the second head in the main scanning direction and irradiate the printing object with light, and a second plate that faces the platen in the height direction and is provided with the plurality of second light sources. The area of the first plate or the number of the plurality of first light sources per unit area is less than the area of the second plate or the number of the plurality of second light sources per unit area. The controller of the printer causes the first head, the second head, the plurality of first light sources, and the plurality of second light sources to move relatively to the platen in the main scanning direction, causes the first head to discharge the first ink onto the printing object during the execution of the movement process, and causes the plurality of first light sources to irradiate the first ink discharged onto the printing object with light during the execution of the movement process.

[0014] The third aspect can achieve the same operational effects as the first aspect.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0016] With reference to the drawings, the printer 1 according to an embodiment of the present invention will be described. The upper, lower, lower left, upper right, lower right, and upper left in FIG. 1 are the upper, lower, front, rear, right, and left of the printer 1, respectively.

[0017] Hereinafter, white ink will be referred to as "white ink". When collectively referring to black, cyan, yellow, and magenta inks, or when not specifying any of them, it is referred to as "color ink". Transparent or translucent ink is referred to as "clear ink". When collectively referring to white ink, color ink, and clear ink, or when not specifying any of them, it is simply referred to as "ink".

[0018] The printer 1 shown in FIG. 1 is an inkjet type UV printer, which discharges ink onto the printing object M shown in FIG. 2 and irradiates the discharged ink with ultraviolet rays to perform printing. The printing object M is not limited to a specific medium, but has, for example, a plate shape or a sheet shape and is composed of, for example, cloth, paper, plastic, metal, or ceramics. The ink has ultraviolet curability and cures when irradiated with ultraviolet rays.

[0019] White ink is used in printing to represent the white part of an image or as a base for color inks. Color inks are ejected directly onto the print target M or on top of a white ink base and are used to print color images. Clear ink has higher light transmittance than white ink and color inks. Clear ink is ejected on top of color images and is used to protect the color images.

[0020] The mechanical configuration of the printer 1 will be described with reference to Figures 1 to 3. As shown in Figure 1, the printer 1 includes a transport mechanism 6, a lifting mechanism 8, a platen 5, a pair of rails 11, and a carriage 20. The transport mechanism 6 is provided at the bottom of the printer 1 and includes a pair of rails 12. The pair of rails 12 extend in the front-to-rear direction and are aligned with each other in the left-to-right direction. In this embodiment, "one member is aligned with another member in a specific direction" means that one member is arranged so that part or all of the one member overlaps part or all of the other member when viewed from the specific direction.

[0021] The lifting mechanism 8 is provided above the transport mechanism 6 and is supported by a pair of rails 12. The lifting mechanism 8 moves in the front-to-rear direction along the pair of rails 12. The lifting mechanism 8 is configured to be extendable and retractable in the up-and-down direction.

[0022] The platen 5 is provided above the lifting mechanism 8. The platen 5 is a plate that extends in the front-to-back and left-to-right directions. The platen 5 is rectangular in plan view and is supported by the lifting mechanism 8. The printing object M shown in FIG. 2 is placed on the upper surface of the platen 5. The platen 5 moves in the front-to-back direction as the lifting mechanism 8 moves in the front-to-back direction. The platen 5 moves in the up-to-down direction as the lifting mechanism 8 expands and contracts in the up-to-down direction.

[0023] The pair of rails 11 extend in the left-right direction and are aligned with each other in the front-rear direction. The carriage 20 is provided between the pair of rails 11 in the front-rear direction. The carriage 20 is a plate that extends in the front-rear and left-right directions. The carriage 20 is supported by the pair of rails 11. The carriage 20 moves in the left-right direction along the pair of rails 11.

[0024] As shown in FIGS. 1 to 3, a color head 51, a white clear head 52, a color side lamp 61, and a white clear side lamp 62 are mounted on the carriage 20. The color head 51 and the white clear head 52 have a rectangular parallelepiped shape and are arranged in the front-rear direction with respect to each other. The color head 51 is located at the front part of the carriage 20. The white clear head 52 is located on the rear side of the color head 51.

[0025] The color side lamp 61 and the white clear side lamp 62 have a rectangular parallelepiped shape and are arranged in the front-rear direction with respect to each other. The color side lamp 61 is arranged on the right side of the color head 51. The white clear side lamp 62 is arranged on the right side of the white clear head 52. The color head 51, the white clear head 52, the color side lamp 61, and the white clear side lamp 62 move in the left-right direction by the left-right movement of the carriage 20.

[0026] As shown in FIGS. 2 and 3, a nozzle surface 511 is formed on the lower surface of the color head 51. A nozzle surface 521 is formed on the lower surface of the white clear head 52. The nozzle surfaces 511 and 521 are exposed downward from the carriage 20. As shown in FIG. 2, the nozzle surfaces 511 and 521 are located above the platen 5 and face the platen 5 in the vertical direction.

[0027] As shown in FIG. 3, nozzle rows 51Y, 51M, 51C, and 51K are formed on the nozzle surface 511. The nozzle rows 51Y, 51M, 51C, and 51K are arranged in the order of the nozzle rows 51Y, 51M, 51C, and 51K from left to right. Each of the nozzle rows 51Y, 51M, 51C, and 51K is configured by a plurality of nozzles 513 arranged in a line in the front-rear direction. The plurality of nozzles 513 discharge ink downward. In the present embodiment, the color head 51 discharges yellow ink from the nozzle row 51Y, magenta ink from the nozzle row 51M, cyan ink from the nozzle row 51C, and black ink from the nozzle row 51K.

[0028] Nozzle rows 52L and 52W are formed on the nozzle surface 521. Nozzle row 52W is aligned to the right of nozzle row 52L. Each of nozzle rows 52L and 52W is configured with a plurality of nozzles 523 lined up in a line in the front-to-rear direction. The plurality of nozzles 523 eject ink downward. In this embodiment, the white clear head 52 ejects clear ink from nozzle row 52L and white ink from nozzle row 52W.

[0029] As shown in Figures 2 and 3, the color side lamp 61 includes a housing 611, a substrate 612, and multiple ultraviolet light-emitting diodes 614. The housing 611 has a rectangular parallelepiped shape and is fixed to the carriage 20. The lower end of the housing 611 is exposed downward from the carriage 20. The substrate 612 is provided at the lower end of the housing 611. The substrate 612 has a rectangular shape when viewed from below, and extends in the front-rear and left-right directions. As shown in Figure 2, the substrate 612 is located above the platen 5 and faces the platen 5 in the up-down direction. As shown in Figure 3, the multiple ultraviolet light-emitting diodes 614 are provided in a staggered pattern on the lower surface of the substrate 612. The multiple ultraviolet light-emitting diodes 614 emit ultraviolet light when turned on.

[0030] The white clear side lamp 62 includes a housing 621, a substrate 622, and multiple ultraviolet light-emitting diodes 624. The housing 621 has a rectangular parallelepiped shape and is fixed to the carriage 20. The lower end of the housing 621 is exposed downward from the carriage 20. The substrate 622 is provided at the lower end of the housing 621. The substrate 622 is rectangular when viewed from below and extends in the front-rear and left-right directions. As shown in FIG. 2, the substrate 622 is located above the platen 5 and faces the platen 5 in the vertical direction. As shown in FIG. 3, multiple ultraviolet light-emitting diodes 624 are provided in a lattice pattern on the lower surface of the substrate 622. The multiple ultraviolet light-emitting diodes 624 emit ultraviolet light when turned on. The color side lamp 61 and the white clear side lamp 62 irradiate ultraviolet light downward by turning on the ultraviolet light-emitting diodes 614 and 624, respectively. The lower surfaces of the substrates 612 and 622 are located at the same position in the vertical direction.

[0031] Hereinafter, the area of the lower surface of each of the substrates 612 and 622 is simply referred to as the "area of the substrate 612" and the "area of the substrate 622". The area of the substrate 612 is defined by the outer peripheral edge of the substrate 612. The area of the substrate 622 is defined by the outer peripheral edge of the substrate 622. In the present embodiment, the area of the substrate 612 and the area of the substrate 622 are the same size as each other.

[0032] The number of the plurality of ultraviolet light emitting diodes 614 is not limited to a specific number, but is six in the present embodiment. The number of the plurality of ultraviolet light emitting diodes 624 is not limited to a specific number, but is twelve in the present embodiment. Therefore, in the present embodiment, the number of the plurality of ultraviolet light emitting diodes 614 is less than the number of the plurality of ultraviolet light emitting diodes 624. Thus, the number of the plurality of ultraviolet light emitting diodes 614 per unit area is less than the number of the plurality of ultraviolet light emitting diodes 624 per unit area. Further, since the area of the substrate 612 and the area of the substrate 622 are the same size as each other, in the present embodiment, the number of the plurality of ultraviolet light emitting diodes 614 per area of the substrate 612 is less than the number of the plurality of ultraviolet light emitting diodes 624 per area of the substrate 622.

[0033] With reference to FIGS. 1 to 3, the printing operation by the printer 1 will be described. A region where the left - right movement path of the carriage 20 and the front - rear movement path of the platen 5 overlap in the vertical direction is referred to as the "printing region 10" (see FIGS. 1 and 2). The printing operation is performed in a state where the platen 5 and the carriage 20 are positioned in the printing region 10. In the printing operation, the reciprocating movement of the carriage 20 in the left - right direction and the movement of the platen 5 forward or backward by a predetermined amount are repeated.

[0034] During the movement of the carriage 20 from the right side to the left side, one or both of the color head 51 and the white clear head 52 discharge ink onto the printing object M (see FIG. 2) on the platen 5. Thereby, the ink lands on the printing object M. Hereinafter, the ink layer formed by the ink that has landed on the printing object M is simply referred to as the "ink layer 100" (see FIG. 2).

[0035] Furthermore, during the movement of the carriage 20 from right to left, one or both of the color side lamp 61 and the white clear side lamp 62 irradiate ultraviolet rays onto the object to be printed M (see FIG. 2) on the platen 5. The color side lamp 61 and the white clear side lamp 62 are respectively located on the right side (opposite to the traveling direction of the carriage 20) with respect to the color head 51 and the white clear head 52. For this reason, when the carriage 20 moves from right to left, the ultraviolet rays irradiated onto the object to be printed M are irradiated onto the ink layer 100 (see FIG. 2) formed on the object to be printed M during the movement of the carriage 20 from right to left this time. Thereby, the ink layer 100 is cured.

[0036] During the movement of the carriage 20 from left to right, both the color head 51 and the white clear head 52 stop discharging ink onto the object to be printed M on the platen 5. During the movement of the carriage 20 from left to right, one or both of the color side lamp 61 and the white clear side lamp 62 irradiate ultraviolet rays onto the object to be printed M on the platen 5.

[0037] When the carriage 20 moves from left to right, the ultraviolet rays irradiated onto the object to be printed M are irradiated onto the ink layer 100 (see FIG. 2) formed on the object to be printed M during the movement of the carriage 20 from right to left a predetermined number of times before. Thereby, the integrated amount of the ultraviolet rays irradiated onto the ink layer 100 increases. Hereinafter, the integrated amount of the ultraviolet rays irradiated per unit area of the ink layer 100 is simply referred to as the "integrated amount". The region where the object to be printed M is irradiated with ultraviolet rays by the color side lamp 61 is referred to as the "irradiation region D". Both the front and rear ends of the irradiation region D are the boundaries between the region where the ultraviolet rays hit and the region where the ultraviolet rays do not hit.

[0038] Referring to FIG. 4, the electrical configuration of the printer 1 will be described. The printer 1 includes a control board 40. The control board 40 is provided with a CPU 41, a ROM 42, a RAM 43, and a flash memory 44. The CPU 41 controls the printer 1 and is electrically connected to the ROM 42, the RAM 43, and the flash memory 44.

[0039] The ROM 42 stores control programs for the CPU 41 to control the operation of the printer 1, information required by the CPU 41 when executing various programs, etc. For example, the ROM 42 stores the rotation angles of the main scanning motor 31, sub-scanning motor 32, and lifting motor 34 (described below) in association with the left-right position of the carriage 20, the front-rear position of the platen 5, and the up-down position of the platen 5. The RAM 43 temporarily stores various data used in the control programs, etc. The flash memory 44 is non-volatile and stores print data for printing, etc.

[0040] The CPU 41 is electrically connected to the main scanning motor 31, the sub-scanning motor 32, the lift motor 34, the head drive unit 33, the plurality of ultraviolet light emitting diodes 614, the plurality of ultraviolet light emitting diodes 624, and the operation unit 37. The main scanning motor 31, the sub-scanning motor 32, the lift motor 34, the head drive unit 33, the plurality of ultraviolet light emitting diodes 614, and the plurality of ultraviolet light emitting diodes 624 are each driven under the control of the CPU 41.

[0041] The main scanning motor 31 is driven to move the carriage 20 shown in Fig. 1 in the left-right direction. The sub-scanning motor 32 is driven to move the lifting mechanism 8 shown in Fig. 1 in the front-rear direction. The lifting motor 34 is driven to extend and retract the lifting mechanism 8 shown in Fig. 1 in the up-down direction.

[0042] The main scanning motor 31, the sub-scanning motor 32, and the lift motor 34 are provided with encoders 311, 321, and 341, respectively. The encoders 311, 321, and 341 detect the rotation angles of the main scanning motor 31, the sub-scanning motor 32, and the lift motor 34, respectively, and output detection signals to the CPU 41.

[0043] The CPU 41 can identify the position of the carriage 20 in the left-right direction based on the detection signal from the encoder 311. The CPU 41 can identify the position of the platen 5 shown in FIG. 1 in the front-rear direction based on the detection signal from the encoder 321. The CPU 41 can identify the position of the platen 5 shown in FIG. 1 in the up-down direction based on the detection signal from the encoder 341.

[0044] The head driving unit 33 is composed of a piezoelectric element or a heating element, and by driving it, ink is ejected onto the color head 51 or the white clear head 52 shown in FIG. 1. The operation unit 37 is a touch panel or the like, and outputs information according to the operation by the user to the CPU 41. The user can input a print instruction or the like for starting printing by the printer 1 to the printer 1 by operating the operation unit 37. The user can set either a normal printing mode or a gloss printing mode for the printer 1 by operating the operation unit 37.

[0045] Referring to FIG. 5, the printed matter 100A will be described. The printer 1 can create the printed matter 100A by forming the ink layer 100 on the printing object M. FIG. 5 shows an example in which the white ink layer 101 and the color ink layer 102 are formed in the order of the white ink layer 101 and the color ink layer 102 from above the upper surface of the printing object M as the ink layer 100. That is, in the printed matter 100A, the color ink layer 102 becomes the outermost layer.

[0046] In the printed matter 100A, before the white ink layer 101 is smoothed or when the smoothing of the white ink layer 101 has not progressed relatively, the white ink layer 101 is cured. For this reason, the white ink layer 101 has irregularities. Further, in the printed matter 100A, the color ink layer 102 is cured in a state where the smoothing of the color ink layer 102 has progressed more than that of the white ink layer 101. For this reason, the color ink layer 102 has no irregularities or has smaller irregularities than the white ink layer 101. Since the color ink layer 102 is located on the outermost surface of the printed matter 100A, the printed matter 100A has a so-called gloss finish with gloss as a whole.

[0047] The smoothing of the ink layer 100 will be described. Hereinafter, the illuminance of the ultraviolet rays emitted by the color side lamp 61 or the white clear side lamp 62 shown in FIG. 2 will be simply referred to as "illuminance". The luminous intensity of the ultraviolet rays emitted by the color side lamp 61 or the white clear side lamp 62 shown in FIG. 2 will be simply referred to as "luminous intensity".

[0048] 2 varies depending on the illuminance etc. For example, the lower the illuminance, the slower the ink layer 100 hardens, and therefore the smoothing of the ink layer 100 progresses more easily.

[0049] Illuminance varies depending on factors such as luminous intensity. For example, the lower the luminous intensity, the lower the illuminance. In this embodiment, the number of ultraviolet light-emitting diodes 614 per unit area is smaller than the number of ultraviolet light-emitting diodes 624 per unit area. Furthermore, the number of ultraviolet light-emitting diodes 614 per area of the substrate 612 is smaller than the number of ultraviolet light-emitting diodes 624 per area of the substrate 622. Therefore, the luminous intensity of the ultraviolet light-emitting diodes 624 is smaller than the luminous intensity of the ultraviolet light-emitting diodes 614. Therefore, when ultraviolet light is irradiated onto the ink layer 100 by the color-side lamp 61, smoothing of the ink layer 100 is more likely to progress than when ultraviolet light is irradiated onto the ink layer 100 by the white-clear-side lamp 62.

[0050] In this embodiment, the white ink layer 101 is irradiated with ultraviolet light by the white clear side lamp 62. The color ink layer 102 is irradiated with ultraviolet light by the color side lamp 61. Therefore, the white ink layer 101 is cured before smoothing or in a state where smoothing has not progressed much. The color ink layer 102 is cured in a state where smoothing has progressed more than that of the white ink layer 101. In this way, the printed matter 100A shown in FIG. 5 is created.

[0051] Hereinafter, the difference in illuminance between the center of the irradiation area D in the front-to-back direction and both ends of the irradiation area D in the front-to-back direction in the ink layer 100 shown in FIG. 2 will be simply referred to as the "illuminance difference." If the illuminance difference is large, the curing speed of the ink layer 100 in the center of the irradiation area D in the front-to-back direction will be faster than the curing speed of the ink layer 100 at both ends of the irradiation area D in the front-to-back direction. In this case, contraction caused by the curing of the ink layer 100 may cause streaks to appear in the ink layer 100 at both ends of the irradiation area D in the front-to-back direction. Therefore, when producing the printed matter 100A shown in FIG. 5, the printer 1 needs to reduce the illuminance difference to prevent streaks from appearing, particularly in the outermost color ink layer 102.

[0052] The illuminance difference varies depending on the luminous intensity, etc. For example, as the luminous intensity decreases, the illuminance at the center and both ends of the irradiation area D in the front-to-back direction decreases. In this case, the rate of decrease in illuminance at both ends of the irradiation area D in the front-to-back direction is smaller than the rate of decrease in illuminance at both ends of the irradiation area D in the front-to-back direction. For this reason, as the luminous intensity decreases, the decrease in illuminance becomes more gradual from the center of the irradiation area D in the front-to-back direction to both ends of the irradiation area D in the front-to-back direction.

[0053] Therefore, when ultraviolet rays are irradiated by the color side lamp 61, the illuminance difference is smaller than when ultraviolet rays are irradiated by the white clear side lamp 62. Therefore, when ultraviolet rays are irradiated by the color side lamp 61, the difference in the front-to-back direction between the curing speed of the ink layer 100 at both ends of the irradiation area D and the curing speed of the ink layer 100 at the center of the irradiation area D is smaller than when ultraviolet rays are irradiated by the white clear side lamp 62. The printer 1 irradiates ultraviolet rays from the color side lamp 61 onto the color ink layer 102 by executing the main processing described below. As a result, the printer 1 can prevent streaky patterns from occurring on the color ink layer 102 at both ends of the irradiation area D in the front-to-back direction.

[0054] Referring to FIGS. 6 to 10, the main process will be described. The user places the object M to be printed on the platen 5 shown in FIG. 2. The user operates the operation unit 37 shown in FIG. 4 and inputs a printing instruction to the printer 1. When the printing instruction is input, the CPU 41 reads out the control program from the ROM 42 and operates to execute the main process.

[0055] Hereinafter, the case of creating the printed matter 100A shown in FIG. 5 will be taken as an example for explanation. At the start of the main process, it is assumed that the platen 5 is located at the set position shown in FIG. 1 and the carriage 20 is located at the standby position shown in FIG. 1. The set position is the front end of the moving range of the platen 5 in the front-rear direction and is the position of the platen 5 when the object M to be printed is set on the platen 5. The standby position is the left end of the moving range of the carriage 20 in the left-right direction.

[0056] In the main scanning process described later, setting to eject ink is referred to as "turning on the ink", and setting to stop the ejection of ink is referred to as "turning off the ink". Note that the setting to eject ink in the main scanning process means setting the ink to a state where it can be ejected so that the ink lands on a predetermined position based on the print data on the object M during the execution of the main scanning process.

[0057] In the main scanning process described later, setting to turn on the ultraviolet light emitting diode 614 is referred to as "turning on the color side lamp 61", and setting to turn off the ultraviolet light emitting diode 614 is referred to as "turning off the color side lamp 61". Setting to turn on the ultraviolet light emitting diode 624 in the main scanning process is referred to as "turning on the white clear side lamp 62", and setting to turn off the ultraviolet light emitting diode 624 is referred to as "turning off the white clear side lamp 62". Note that the setting to turn on in the main scanning process means that all the ultraviolet light emitting diodes 614 and 624 are always turned on during the execution of the main scanning process.

[0058] As shown in FIG. 6, when the main process starts, the CPU 41 acquires the print data specified by the print instruction from the flash memory 44 and stores it in the RAM 43 (S100). The CPU 41 controls the sub-scanning motor 32 based on the detection result from the encoder 321 shown in FIG. 4, and moves the platen 5 backward from the set position shown in FIG. 1 to the platen print start position (not shown) (S101). The platen print start position is the position of the platen 5 when the front end of the area (not shown) where the image is printed on the print object M shown in FIG. 2 is located behind the white clear head 52 shown in FIG. 2. The CPU 41 controls the main scanning motor 31 based on the detection result from the encoder 311 shown in FIG. 4, and moves the carriage 20 from the standby position shown in FIG. 1 to the carriage print start position to the right (S101). The carriage print start position is the position of the carriage 20 when the color head 51 and the white clear head 52 shown in FIG. 2 are located to the right of the right end of the area (not shown) where the image is printed on the print object M shown in FIG. 2.

[0059] The CPU 41 performs white printing processing (S102). In the white printing processing of S102, while the platen 5 moves forward from the platen print start position, the white ink layer 101 shown in FIG. 5 is formed on the print object M. The CPU 41 performs color printing processing (S103). In the color printing processing of S103, while the platen 5 moves backward, the color ink layer 102 shown in FIG. 5 is formed on the white ink layer 101 on the print object M. The CPU 41 ends the main process.

[0060] Referring to FIG. 7, the white printing process will be described. When the white printing process starts, the CPU 41 sets "leftward" as the main scanning direction (S141). The CPU 41 turns on the white ink (S142). The CPU 41 turns off the color ink (S143). The CPU 41 turns off the clear ink (S144). The CPU 41 turns on the white clear side lamp 62 (S145). The CPU 41 turns off the color side lamp 61 (S146).

[0061] The CPU 41 performs main scanning processing based on the settings in S141 to S146 (S147). In the main scanning processing, movement control, ejection control, and irradiation control are performed. In the main scanning processing of S147, in the movement control, the CPU 41 drives the main scanning motor 31 based on the detection result from the encoder 311 shown in FIG. 4, and moves the carriage 20 shown in FIG. 1 from the right end to the left end of the printing area 10 in the printing area 10. During the execution of the movement control, in the ejection control, the CPU 41 drives the head drive unit 33 shown in FIG. 4 based on the print data, and ejects white ink from the nozzle row 52W to the white clear head 52 shown in FIG. 3. During the execution of the movement control, in the ejection control, the CPU 41 stops the ejection of the clear ink from the nozzle row 52L to the white clear head 52 shown in FIG. 3. During the execution of the movement control, in the ejection control, the CPU 41 stops the ejection of the color ink from the nozzle rows 51Y, 51M, 51C, and 51K to the color head 51 shown in FIG. 3. During the execution of the movement control, in the irradiation control, the CPU 41 turns on the plurality of ultraviolet light emitting diodes 624 shown in FIG. 2, and irradiates ultraviolet light from the white clear side lamp 62 toward the object to be printed M. The ultraviolet light from the white clear side lamp 62 is irradiated onto the white ink layer 101 shown in FIG. 5. During the execution of the movement control, in the irradiation control, the CPU 41 turns off the plurality of ultraviolet light emitting diodes 614 shown in FIG. 2, and stops the irradiation of ultraviolet light from the color side lamp 61 to the object to be printed M.

[0062] The CPU 41 sets "rightward" as the main scanning direction (S151). The CPU 41 turns off the white ink (S152). The CPU 41 turns off the color ink (S153). The CPU 41 turns off the clear ink (S154). The CPU 41 turns on the white clear side lamp 62 (S155). The CPU 41 turns off the color side lamp 61 (S156).

[0063] The CPU 41 performs main scanning processing based on the settings in S151 to S156 (S157). In the main scanning processing of S157, in movement control, the CPU 41 drives the main scanning motor 31 based on the detection result from the encoder 311 shown in FIG. 4, and moves the carriage 20 shown in FIG. 1 from the left end to the right end of the printing area 10 in the printing area 10. During the execution of movement control, in ejection control, the CPU 41 stops the ejection of white ink from the nozzle row 52W of the white clear head 52 shown in FIG. 3. During the execution of movement control, in ejection control, the CPU 41 stops the ejection of clear ink from the nozzle row 52L of the white clear head 52 shown in FIG. 3. During the execution of movement control, in ejection control, the CPU 41 stops the ejection of color ink from the nozzle rows 51Y, 51M, 51C, 51K of the color head 51 shown in FIG. 3. During the execution of movement control, in irradiation control, the CPU 41 turns on the plurality of ultraviolet light emitting diodes 624 shown in FIG. 2, and irradiates ultraviolet light from the white clear side lamp 62 toward the printing object M. The ultraviolet light from the white clear side lamp 62 is irradiated onto the white ink layer 101 shown in FIG. 5. During the execution of movement control, in irradiation control, the CPU 41 turns off the plurality of ultraviolet light emitting diodes 614 shown in FIG. 2, and stops the irradiation of ultraviolet light from the color side lamp 61 to the printing object M.

[0064] The CPU 41 determines whether the formation of the white ink layer 101 over the entire area where the image is to be printed on the printing object M shown in FIG. 5 is completed based on the print data (S158). If the formation of the white ink layer 101 over the entire area where the image is to be printed on the printing object M shown in FIG. 5 is in progress (S158: NO), the CPU 41 sets "forward" as the sub-scanning direction (S161). The CPU 41 performs sub-scanning processing based on the setting in S161 (S162). In the sub-scanning processing of S162, the CPU 41 controls the sub-scanning motor 32 based on the detection result from the encoder 321 shown in FIG. 4, and moves the platen 5 shown in FIG. 2 forward. When the platen 5 shown in FIG. 2 moves forward by a predetermined amount, the CPU 41 stops the sub-scanning motor 32 shown in FIG. 4. The CPU 41 shifts the process to S141.

[0065] Until the formation of the white ink layer 101 over the entire area where the image is to be printed on the print target M shown in FIG. 5 is completed, the CPU 41 repeatedly performs main scanning processing (S147, S157) and sub-scanning processing (S162). When the formation of the white ink layer 101 over the entire area where the image is to be printed on the print target M shown in FIG. 5 is completed (S158: YES), the CPU 41 returns the process to the main process shown in FIG. 6.

[0066] Referring to FIG. 8, the formation mode of the white ink layer 101 in the white printing process will be described. Hereinafter, "N" and "K" are natural numbers. In FIG. 8, the white ink layer 101 is indicated by hatching. FIG. 8 shows the positional relationship in the front-rear direction between the carriage 20 and the print target M when the main scanning process of the Nth S157 shown in FIG. 7 is completed.

[0067] In the main scanning process of the Nth S147 shown in FIG. 7, the white ink layer 101(N) is formed on the print target M by discharging white ink from the white clear head 52. In the main scanning process of S147 shown in FIG. 7, the carriage 20 moves from right to left, and the white clear side lamp 62 is located on the right side of the white clear head 52, that is, in the direction opposite to the moving direction of the carriage 20. For this reason, the white ink layer 101(N) is irradiated with ultraviolet rays emitted from the white clear side lamp 62 during the main scanning process of the Nth S147 shown in FIG. 7. Since the luminous intensity of the white clear side lamp 62 is relatively large, the white ink layer 101(N) cures in a state where it is not smoothed or with relatively little smoothing progress.

[0068] The white ink layer 101(N) is further irradiated with ultraviolet rays emitted from the white clear side lamp 62 during the main scanning process of the Nth S157 shown in FIG. 7. As a result, since the integrated amount on the white ink layer 101(N) increases, the printer 1 can surely cure the white ink layer 101(N). As described above, the white ink layer 101 is formed on the print target M.

[0069] Referring to FIG. 9, the color printing process will be described. When the color printing process is started, the CPU 41 sets "leftward" as the main scanning direction (S201). The CPU 41 turns off the white ink (S202). The CPU 41 turns on the color ink (S203). The CPU 41 turns off the clear ink (S204). The CPU 41 turns off the white clear side lamp 62 (S205). The CPU 41 turns on the color side lamp 61 (S206).

[0070] Based on the settings in S201 to S206, the CPU 41 performs the main scanning process (S207). In the main scanning process of S207, in terms of movement control, the CPU 41 drives the main scanning motor 31 based on the detection result from the encoder 311 shown in FIG. 4, and moves the carriage 20 shown in FIG. 1 from the right end to the left end of the printing area 10 in the leftward direction. During the execution of the movement control, in terms of ejection control, the CPU 41 stops the ejection of white ink from the nozzle row 52W of the white clear head 52 shown in FIG. 3. During the execution of the movement control, in terms of ejection control, the CPU 41 stops the ejection of clear ink from the nozzle row 52L of the white clear head 52 shown in FIG. 3. During the execution of the movement control, in terms of ejection control, the CPU 41 drives the head drive unit 33 shown in FIG. 4 based on the print data, and ejects color ink from the nozzle rows 51Y, 51M, 51C, and 51K of the color head 51 shown in FIG. 3. During the execution of the movement control, in terms of irradiation control, the CPU 41 turns off the plurality of ultraviolet light emitting diodes 624 shown in FIG. 2, and stops the irradiation of ultraviolet light from the white clear side lamp 62 onto the printing object M. During the execution of the movement control, in terms of irradiation control, the CPU 41 turns on the plurality of ultraviolet light emitting diodes 614 shown in FIG. 2, and irradiates ultraviolet light from the color side lamp 61 toward the printing object M. The ultraviolet light from the color side lamp 61 is irradiated onto the color ink layer 102 shown in FIG. 5.

[0071] The CPU 41 sets "rightward" as the main scanning direction (S211). The CPU 41 turns off the white ink (S212). The CPU 41 turns off the color ink (S213). The CPU 41 turns off the clear ink (S214). The CPU 41 turns off the white clear side lamp 62 (S215). The CPU 41 turns on the color side lamp 61 (S216).

[0072] Based on the settings in S211 to S216, the CPU 41 performs the main scanning process (S217). In the main scanning process of S217, in terms of movement control, based on the detection result from the encoder 311 shown in FIG. 4, the CPU 41 drives the main scanning motor 31 to move the carriage 20 shown in FIG. 1 from the left end to the right end of the printing area 10 in the printing area 10. During the execution of the movement control, in terms of ejection control, the CPU 41 stops the ejection of white ink from the nozzle row 52W of the white clear head 52 shown in FIG. 3. During the execution of the movement control, in terms of ejection control, the CPU 41 stops the ejection of clear ink from the nozzle row 52L of the white clear head 52 shown in FIG. 3. During the execution of the movement control, in terms of ejection control, the CPU 41 stops the ejection of color ink from the nozzle rows 51Y, 51M, 51C, and 51K of the color head 51 shown in FIG. 3. During the execution of the movement control, in terms of irradiation control, the CPU 41 turns off the plurality of ultraviolet light emitting diodes 624 shown in FIG. 2 to stop the irradiation of ultraviolet light from the white clear side lamp 62 to the printing object M. During the execution of the movement control, in terms of irradiation control, the CPU 41 turns on the plurality of ultraviolet light emitting diodes 614 shown in FIG. 2 to irradiate ultraviolet light from the color side lamp 61 toward the printing object M. The ultraviolet light from the color side lamp 61 is irradiated onto the color ink layer 102 shown in FIG. 5.

[0073] Based on the print data, the CPU 41 determines whether the formation of the color ink layer 102 over the entire area where the image is to be printed on the print object M shown in FIG. 5 has been completed (S218). If the formation of the color ink layer 102 over the entire area where the image is to be printed on the print object M shown in FIG. 5 is in progress (S218: NO), the CPU 41 sets "backward" as the sub-scanning direction (S221). Based on the setting in S221, the CPU 41 performs sub-scanning processing (S222). In the sub-scanning processing of S222, the CPU 41 controls the sub-scanning motor 32 based on the detection result from the encoder 321 shown in FIG. 4, and moves the platen 5 shown in FIG. 2 backward. When the platen 5 has moved backward by a predetermined amount, the CPU 41 stops the sub-scanning motor 32 shown in FIG. 4. The CPU 41 transfers the process to S201.

[0074] Until the formation of the color ink layer 102 over the entire area where the image is to be printed on the print object M shown in FIG. 5 is completed, the CPU 41 repeatedly performs main scanning processing (S207, S217) and sub-scanning processing (S222). When the formation of the color ink layer 102 over the entire area where the image is to be printed on the print object M shown in FIG. 5 is completed (S218: YES), the CPU 41 returns the process to the main process shown in FIG. 6.

[0075] Referring to FIG. 10, the formation mode of the color ink layer 102 in the color printing process will be described. In FIG. 10, the white ink layer 101 is indicated by oblique lines, and the color ink layer 102 is indicated by vertical lines. FIG. 10 shows the positional relationship in the front-rear direction between the carriage 20 and the print object M when the main scanning process of the Nth S217 shown in FIG. 9 is completed.

[0076] In the N-th main scanning process of S207 shown in FIG. 9, by discharging color ink from the color head 51, a color ink layer 102(N) is formed on the white ink layer 101 on the printing object M. In the main scanning process of S207 shown in FIG. 9, the carriage 20 moves from right to left, and the color side lamp 61 is located on the right side of the color head 51, that is, in the direction opposite to the moving direction of the carriage 20. Therefore, the color ink layer 102(N) is irradiated with ultraviolet rays emitted from the color side lamp 61 during the N-th main scanning process of S207 shown in FIG. 9. Since the luminous intensity of the color side lamp 61 is relatively small, the color ink layer 102(N) cures while being relatively smoothed.

[0077] The color ink layer 102(N) is further irradiated with ultraviolet rays emitted from the color side lamp 61 during the N-th main scanning process of S217 shown in FIG. 9. As a result, since the integrated amount on the color ink layer 102(N) increases, the printer 1 can surely cure the color ink layer 102(N). As described above, the white ink layer 101 and the color ink layer 102 are formed as the ink layer 100 in the order of the white ink layer 101 and the color ink layer 102 from the upper surface of the printing object M upward. Thereby, the printed matter 100A shown in FIG. 5 is created.

[0078] As described above, in the above embodiment, the number of a plurality of ultraviolet light emitting diodes 614 per unit area of the substrate 612 is smaller than the number of a plurality of ultraviolet light emitting diodes 624 per unit area of the substrate 622. Therefore, the luminous intensity of a plurality of ultraviolet light emitting diodes 614 per unit area of the substrate 612 is smaller than the luminous intensity of a plurality of ultraviolet light emitting diodes 624 per unit area of the substrate 622. Further, the number of a plurality of ultraviolet light emitting diodes 614 per unit area is smaller than the number of a plurality of ultraviolet light emitting diodes 624 per unit area. Therefore, the luminous intensity of a plurality of ultraviolet light emitting diodes 614 per unit area is smaller than the luminous intensity of a plurality of ultraviolet light emitting diodes 624 per unit area. For this reason, the illuminance of ultraviolet light irradiated on the ink layer 100 by the plurality of ultraviolet light emitting diodes 614 is smaller than the illuminance of ultraviolet light irradiated on the ink layer 100 by the plurality of ultraviolet light emitting diodes 624. Thus, the printer 1 can reduce the illuminance of ultraviolet light irradiated on the ink layer 100 by the plurality of ultraviolet light emitting diodes 614 without, for example, controlling the displacement of the distance from the plurality of ultraviolet light emitting diodes 614 to the ink layer 100. The printer 1 can reduce the illuminance of ultraviolet light irradiated on the ink layer 100 by the plurality of ultraviolet light emitting diodes 614 without, for example, controlling the lighting, extinguishing, wavelength, luminous intensity, etc. of the plurality of ultraviolet light emitting diodes 614. That is, the printer 1 can reduce the illuminance of ultraviolet light irradiated on the ink layer 100 by the plurality of ultraviolet light emitting diodes 614 while suppressing the complication of control. The color ink layer 102 is irradiated with ultraviolet light from the plurality of ultraviolet light emitting diodes 614. For this reason, the printer 1 can suppress the occurrence of streak-like patterns in the color ink layer 102 as compared with the case where ultraviolet light is irradiated from the plurality of ultraviolet light emitting diodes 624. Therefore, the printer 1 can improve the printing image quality while suppressing the complication of control.

[0079] The direction from right to left is the direction from the color side lamp 61 towards the color head 51. In the main scanning process of S207, when the carriage 20 moves from right to left by movement control, color ink is ejected from the color head 51 by ejection control. In the main scanning process of S207, when the carriage 20 moves from right to left by movement control, ultraviolet rays are irradiated from the color side lamp 61 to the color ink layer 102 by irradiation control. Thereby, the printer 1 can execute both the formation of the color ink layer 102 and the curing of the formed color ink layer 102 during one movement of the carriage 20 from right to left. For this reason, the printer 1 can shorten the processing time required for printing while suppressing the occurrence of streak-like patterns in the color ink layer 102.

[0080] Ink adheres less easily to a printing object M such as plastic, metal, or ceramic than to a general printing object M such as cloth or paper. In the above embodiment, since the ink has ultraviolet curability, the printer 1 can print on a printing object M to which ink adheres relatively less easily. Therefore, the printer 1 can diversify the material and the like of the printing object M.

[0081] The color head 51 ejects color ink. The white clear head 52 ejects white ink as a base for the color ink layer 102. For this reason, the printer 1 can improve the color development of the color ink.

[0082] The white clear head 52 further ejects clear ink. For this reason, the printer 1 can protect the printed image and improve the glossiness of the printed image by, for example, ejecting clear ink onto the color ink layer 102.

[0083] In the above embodiment, the platen 5 corresponds to the "platen" of the present invention. The color head 51 corresponds to the "first head" of the present invention. The white clear head 52 corresponds to the "second head" of the present invention. The plurality of ultraviolet light emitting diodes 614 correspond to the "plurality of first light sources" of the present invention. The vertical direction corresponds to the "height direction" of the present invention. The substrate 612 corresponds to the "first plate" of the present invention. The plurality of ultraviolet light emitting diodes 624 correspond to the "plurality of second light sources" of the present invention. The substrate 622 corresponds to the "second plate" of the present invention. The CPU 41 corresponds to the "controller" of the present invention.

[0084] In each main scanning process of the main scanning processes of S207 and S217, the movement control process performed corresponds to the "movement process" of the present invention. In each main scanning process of the main scanning processes of S207 and S217, the ejection control process performed corresponds to the "ejection process" of the present invention. In each main scanning process of the main scanning processes of S207 and S217, the irradiation control process performed corresponds to the "irradiation process" of the present invention. In each main scanning process of the main scanning process of S207, the movement control process performed corresponds to the "first movement process" of the present invention.

[0085] The present invention can be variously modified from the above embodiment. The following various modification examples can be combined with each other as long as there is no contradiction. For example, the printer 1 may be provided with a lamp 60 shown in FIG. 11 instead of the color side lamp 61 and the white clear side lamp 62. In FIG. 11, for members having the same functions as those in the above embodiment in the modification example, the same reference numerals as those in the above embodiment are given, and the description is omitted or simplified.

[0086] As shown in FIG. 11, the lamp 60 includes a housing 601, a substrate 602, a plurality of ultraviolet light emitting diodes 614, and a plurality of ultraviolet light emitting diodes 624. The housing 601 is arranged on the right side of the color head 51 and the white clear head 52 and is fixed to the carriage 20. The housing 601 has a rectangular parallelepiped shape. The lower end of the housing 601 is exposed downward from the carriage 20. The substrate 602 is provided at the lower end of the housing 601. The substrate 602 extends from the front end portion of the color head 51 to the rear end portion of the white clear head 52.

[0087] A plurality of ultraviolet light emitting diodes 614, 624 are provided on the lower surface of the substrate 602. The plurality of ultraviolet light emitting diodes 614 are located in a region of the substrate 602 that aligns with the color head 51 in the left - right direction. The plurality of ultraviolet light emitting diodes 624 are located in a region of the substrate 602 that aligns with the white clear head 52 in the left - right direction.

[0088] The area of the lower surface of the substrate 602 is simply referred to as "the area of the substrate 602". The number of the plurality of ultraviolet light emitting diodes 614 per unit area is less than the number of the plurality of ultraviolet light emitting diodes 624 per unit area. The number of the plurality of ultraviolet light emitting diodes 614 per area of the substrate 602 is less than the number of the plurality of ultraviolet light emitting diodes 624 per area of the substrate 602.

[0089] In the case of the above - mentioned modification, in the main scanning process, the lamp 60 turns on the ultraviolet light emitting diodes 614 when the color - side lamp 61 is "ON" in the above - mentioned embodiment, and turns off the ultraviolet light emitting diodes 614 when the color - side lamp 61 is "OFF" in the above - mentioned embodiment. In the main scanning process, the lamp 60 turns on the ultraviolet light emitting diodes 624 when the white clear - side lamp 62 is "ON" in the above - mentioned embodiment, and turns off the ultraviolet light emitting diodes 624 when the white clear - side lamp 62 is "OFF" in the above - mentioned embodiment.

[0090] According to the above - mentioned modification, the plurality of ultraviolet light emitting diodes 614 and the plurality of ultraviolet light emitting diodes 624 are provided on one substrate 602. That is, both the plurality of ultraviolet light emitting diodes 614 and the plurality of ultraviolet light emitting diodes 624 are fixed to one housing 601. Therefore, compared with the case where the plurality of ultraviolet light emitting diodes 614 and the plurality of ultraviolet light emitting diodes 624 are fixed to different housings, the printer 1 can more easily keep the distance from the plurality of ultraviolet light emitting diodes 614 to the platen 5 equal to the distance from the plurality of ultraviolet light emitting diodes 624 to the platen 5 in the vertical direction. Thus, the printer 1 can more easily stabilize the illuminance of the light by the plurality of ultraviolet light emitting diodes 614 and the illuminance of the light by the plurality of ultraviolet light emitting diodes 624.

[0091] In the above-described modification, the housing 601 corresponds to the "housing" of the present invention. The substrate 602 corresponds to the "first plate" and the "second plate" of the present invention. That is, the "first plate" and the "second plate" of the present invention may be a single common plate. Note that the lamp 60 may include a plurality of substrates instead of the substrate 602. In this case, the plurality of substrates are fixed to the lower end of the housing 601 and are arranged side by side in the front-rear direction. The plurality of ultraviolet light-emitting diodes 614 and the plurality of ultraviolet light-emitting diodes 624 are provided on different substrates.

[0092] The mechanism for moving the platen 5 in the front-rear direction and the mechanism for moving the carriage 20 in the left-right direction are not limited to the above-described embodiment. For example, the printer 1 may move various members such as the platen 5 and the carriage 20 by a cylinder or the like instead of a motor. The printer 1 may move the platen 5 in the left-right direction with respect to the carriage 20.

[0093] In the above-described embodiment, the color side lamp 61 may be provided to the left of the color head 51. The printer 1 may include a plurality of color side lamps 61. For example, the plurality of color side lamps 61 may be provided on both the right and left sides of the color head 51. The white clear side lamp 62 can also be changed in the same manner as the color side lamp 61.

[0094] When a plurality of color side lamps 61 and a plurality of white clear side lamps 62 are provided, so-called bidirectional printing may be performed. That is, the CPU 41 may control the color head 51 and the white clear head 52 to discharge ink even when the carriage 20 moves from right to left. For example, the CPU 41 turns on the white ink in S152 and turns on the color ink in S213. In this case, after S147, the CPU 41 may move the platen 5 forward by a predetermined amount when the formation of the white ink layer 101 is not completed. After S207, the CPU 41 may move the platen 5 backward by a predetermined amount when the formation of the color ink layer 102 is not completed.

[0095] The printer 1 may eject clear ink from the white clear head 52 onto the color ink layer 102. That is, the color ink layer 102 does not necessarily form the outermost layer on the printed matter 100A. In this case, the CPU 41 may turn on the clear ink, for example, in S204. The CPU 41 may omit the white printing process. In this case, the color ink layer 102 is directly formed on the object M to be printed.

[0096] The color head 51 and the white clear head 52 may be line heads. In this case, the carriage 20 is fixed so as not to move. The color head 51 and the white clear head 52 are arranged in the front-rear direction. The nozzle rows 51Y, 51M, 51C, 51K are configured by arranging a plurality of nozzles 513 in a line in the left-right direction. The nozzle rows 52L, 52W are configured by arranging a plurality of nozzles 523 in a line in the left-right direction. The printer 1 may be provided with either the color side lamp 61 or the white clear side lamp 62. In the printer 1, either the color side lamp 61 or the white clear side lamp 62 is arranged on one or both of the rear and the front of the color head 51 and the white clear head 52. The color head 51 and the white clear head 52 move relative to the platen 5 in the front-rear direction by the movement of the platen 5 in the front-rear direction.

[0097] If the printer 1 uses ink that cures when irradiated with light, for example, ink that cures when irradiated with visible light or infrared rays may be employed. In this case, the color side lamp 61 and the white clear side lamp 62 emit visible light or infrared rays. The color side lamp 61 and the white clear side lamp 62 may be incandescent lamps, mercury lamps, fluorescent lamps, or the like.

[0098] In the above embodiment, in the white printing process, the CPU 41 may turn on the white clear side lamp 62 when setting at least one of "leftward" and "rightward" as the main scanning direction. In the color printing process, the CPU 41 may turn on the color side lamp 61 when setting at least one of "leftward" and "rightward" as the main scanning direction.

[0099] In the above-described embodiment, the printer 1 may form the white ink layer 101 while moving the platen 5 backward. The printer 1 may form the color ink layer 102 while moving the platen 5 forward.

[0100] In the above-described embodiment, the printer 1 may appropriately change the types and the number of types of the colors of the inks ejected by the color head 51 and the white clear head 52. For example, the color head 51 may eject white ink or clear ink instead of or in addition to the color ink. The white clear head 52 may eject color ink instead of or in addition to one or both of the white ink and the clear ink. For example, the printer 1 may include three or more heads such as a head that ejects color ink, a head that ejects white ink, and a head that ejects clear ink. For example, the color head 51 may eject clear ink to form a clear ink layer on the color ink layer 102. In this case, the printer 1 irradiates the clear ink layer with ultraviolet rays from the color-side lamp 61. Since the luminous intensity of the color-side lamp 61 is relatively small, the printer 1 can cure the clear ink layer while suppressing the occurrence of streak-like patterns in the clear ink layer and smoothing the clear ink layer.

[0101] In the above-described embodiment, the housing 611 of the color-side lamp 61 may be omitted. The housing 621 of the white clear-side lamp 62 may also be omitted. That is, the substrates 612 and 622 may be exposed in the vertical direction, the horizontal direction, and the front-rear direction.

[0102] In the above-described embodiment, the white clear head 52 may be arranged side by side with the color head 51 on the front side. The white clear head 52 may be located at a position shifted to the left or right with respect to the color head 51 on the front side or the rear side of the color head 51.

[0103] The setting to turn on in the main scanning process may mean that all of the plurality of ultraviolet light-emitting diodes 614 or all of the plurality of ultraviolet light-emitting diodes 624 are turned on at a predetermined timing during the main scanning process.

[0104] In the above embodiment, if the printer 1 satisfies the first condition that the number of a plurality of ultraviolet light-emitting diodes 614 per unit area of the substrate 612 is smaller than the number of a plurality of ultraviolet light-emitting diodes 624 per unit area of the substrate 622, the number of a plurality of ultraviolet light-emitting diodes 614 per unit area may be the same as, or larger than, the number of a plurality of ultraviolet light-emitting diodes 624 per unit area.

[0105] In the above embodiment, if the printer 1 satisfies the second condition that the number of a plurality of ultraviolet light-emitting diodes 614 per unit area is smaller than the number of a plurality of ultraviolet light-emitting diodes 624 per unit area, the number of a plurality of ultraviolet light-emitting diodes 614 per unit area of the substrate 612 may be the same as, or larger than, the number of a plurality of ultraviolet light-emitting diodes 624 per unit area of the substrate 622.

[0106] If the printer 1 satisfies at least one of the first condition and the second condition, for example, the area of the substrate 612 may be larger or smaller than the area of the substrate 622. If the printer 1 satisfies at least one of the first condition and the second condition, for example, the number of a plurality of ultraviolet light-emitting diodes 614 may be larger or the same as the number of a plurality of ultraviolet light-emitting diodes 624.

[0107] The arrangement modes of the plurality of ultraviolet light-emitting diodes 614 and the plurality of ultraviolet light-emitting diodes 624 are not limited to the above embodiment. For example, both the plurality of ultraviolet light-emitting diodes 614 and the plurality of ultraviolet light-emitting diodes 624 may be arranged in a staggered pattern or in a grid pattern. The plurality of ultraviolet light-emitting diodes 614 may be arranged in a row in the front-rear direction or the left-right direction. Similarly, the plurality of ultraviolet light-emitting diodes 624 may also be arranged in a row.

Explanation of reference numerals

[0108] 1 Printer 5 Platen 41 CPU 51 Color head 52 White clear head 60 Lamp 61 Color side lamp 62 White clear side lamp 601, 611, 621 Housing 602, 612, 622 Substrate 614, 624 Ultraviolet light emitting diode

Claims

1. A platen on which a printing object is placed, a first head that discharges a color ink as a photocurable first ink onto the printing object, a second head that is arranged side by side with the first head in the sub-scanning direction and discharges a white ink as a photocurable second ink and as an undercoat for the color ink onto the printing object, a plurality of first light sources that are arranged side by side with the first head in the main scanning direction orthogonal to the sub-scanning direction and irradiate the printing object with light, a first plate that is a plate facing the platen in the height direction orthogonal to the main scanning direction and the sub-scanning direction, and on which the plurality of first light sources are provided, a plurality of second light sources that are arranged side by side with the second head in the main scanning direction and irradiate the printing object with light, a second plate that is a plate facing the platen in the height direction and on which the plurality of second light sources are provided, a controller and comprising the number of the plurality of first light sources per area or per unit area of the first plate is less than the number of the plurality of second light sources per area or per unit area of the second plate, the controller in the main scanning direction, performs a movement process of relatively moving the first head, the second head, the plurality of first light sources, and the plurality of second light sources with respect to the platen, during execution of the movement process, performs a discharge process of discharging the first ink from the first head onto the printing object, and during execution of the movement process, performs an irradiation process of irradiating the first ink discharged onto the printing object with light from the plurality of first light sources. A printer characterized by this.

2. The printer according to claim 1, characterized in that the illuminance of the light irradiated by the plurality of first light sources is smaller than the illuminance of the light irradiated by the plurality of second light sources.

3. the controller in the movement process, in the direction from the plurality of first light sources toward the first head in the main scanning direction, performs a first movement process of relatively moving the first head, the second head, the plurality of first light sources, and the plurality of second light sources with respect to the platen, and performs the discharge process and the irradiation process during execution of the first movement process. The printer according to claim 1 or 2, characterized by this.

4. A printer according to any one of claims 1 to 3, comprising a housing including the first light source and the second light source, the housing having both the first plate and the second plate.

5. The first head discharges the first ultraviolet-curable ink. The second head discharges the second ultraviolet-curable ink. A printer according to any one of claims 1 to 4, wherein the first light source and the second light source irradiate ultraviolet light.

6. A printer according to any one of claims 1 to 5, wherein the second head further discharges a clear ink having higher light transmittance than the color ink and the white ink as a third ink.

7. A platen on which a printing object is placed, A first head that discharges a color ink as a first photo-curable ink onto the printing object, A second head that is arranged side by side with the first head in the sub-scanning direction and discharges a white ink as a second photo-curable ink and as an undercoat for the color ink onto the printing object, A plurality of first light sources that are arranged side by side with the first head in the main scanning direction orthogonal to the sub-scanning direction and irradiate light onto the printing object, A first plate that is a plate facing the platen in the height direction orthogonal to the main scanning direction and the sub-scanning direction, the first plate being provided with the plurality of first light sources, A plurality of second light sources that are arranged side by side with the second head in the main scanning direction and irradiate light onto the printing object, A second plate that is a plate facing the platen in the height direction and is provided with the plurality of second light sources, Comprising, A control method for a printer, wherein the number of the plurality of first light sources per area or per unit area of the first plate is less than the number of the plurality of second light sources per area or per unit area of the second plate, A moving process of relatively moving the first head, the second head, the plurality of first light sources, and the plurality of second light sources relative to the platen in the main scanning direction, A discharging process of discharging the first ink from the first head onto the printing object during the execution of the moving process, A control method characterized by performing an irradiation process of irradiating light from the plurality of first light sources onto the first ink discharged onto the printing object during the execution of the moving process.

8. The control method according to claim 7, wherein the illuminance of the light irradiated by the plurality of first light sources is smaller than the illuminance of the light irradiated by the plurality of second light sources.

9. A platen on which a printing object is placed, A first head that discharges color ink as a photocurable first ink onto the printing object, A second head that is arranged side by side with the first head in the sub-scanning direction and discharges white ink as a photocurable second ink and as an undercoat for the color ink onto the printing object, A plurality of first light sources that are arranged side by side with the first head in the main scanning direction orthogonal to the sub-scanning direction and irradiate the printing object with light, A first plate that is a plate facing the platen in the height direction orthogonal to the main scanning direction and the sub-scanning direction, and on which the plurality of first light sources are provided, A plurality of second light sources that are arranged side by side with the second head in the main scanning direction and irradiate the printing object with light, A second plate that is a plate facing the platen in the height direction and on which the plurality of second light sources are provided comprising: In a controller of a printer, the number of the plurality of first light sources per area or per unit area of the first plate is smaller than the number of the plurality of second light sources per area or per unit area of the second plate, In the main scanning direction, a moving process of relatively moving the first head, the second head, the plurality of first light sources, and the plurality of second light sources with respect to the platen, During the execution of the moving process, a discharging process of discharging the first ink from the first head onto the printing object, A control program characterized in that during the execution of the moving process, an irradiation process of irradiating the first ink discharged onto the printing object with light from the plurality of first light sources is executed.

10. The control program according to claim 9, wherein the illuminance of the light irradiated by the plurality of first light sources is smaller than the illuminance of the light irradiated by the plurality of second light sources.

Images