Printer

Abstract

To provide a printer which can suppress increase in the size of the whole device.SOLUTION: A printer 1 includes a head 10, and an irradiation device 50. The head 10 and the irradiation device 50 are moved in a right and left direction with respect to a printing object M. The irradiation device 50 is provided on the right side of the head 10. The irradiation device 50 is a rectangular parallelepiped, and has a light source surface 50a formed on its lower surface. The irradiation device 50 includes a first light source and a second light source. The first light source emits light of a first wavelength, and the second light source emits light of a second wavelength different from the first wavelength. The first light source and the second light source are provided on the light source surface 50a. Specifically, both the first light source and the second light source are provided on the right side of the head 10 in the right and left direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printer.

Background Art

[0002] The inkjet printer described in Patent Document 1 includes a drum, a recording head, and a plurality of light source units. The drum rotates to convey the paper. The recording head is disposed facing the outer peripheral surface of the drum. The recording head ejects ultraviolet curable ink onto the paper. The plurality of light source units are each disposed on the downstream side of the recording head in the paper conveyance direction. The plurality of light source units are arranged along the paper conveyance direction. The plurality of light source units emit ultraviolet rays having different peak wavelengths.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above inkjet printer, since the plurality of light source units are arranged along the paper conveyance direction, the entire apparatus of the inkjet printer may be enlarged.

[0005] An object of the present invention is to provide a printer capable of suppressing an increase in the size of the entire apparatus.

Means for Solving the Problems

[0006] A printer according to one aspect of the present invention includes a platen on which a printing object is placed and which moves the printing object in a first scanning direction, a head that relatively moves with respect to the printing object in a second scanning direction intersecting the first scanning direction and discharges photocurable ink onto the printing object, and an irradiation device that relatively moves with respect to the printing object in the second scanning direction and irradiates light onto the printing object to which the ink has adhered. The irradiation device includes a first light source that emits light of a predetermined first wavelength and a second light source that emits light of a second wavelength different from the first wavelength. The first light source and the second light source are provided on one side of the head in the second scanning direction.

[0007] According to this aspect, in the irradiation device, a plurality of light sources having different wavelengths are provided on one side of the head in the second scanning direction. The second scanning direction is the direction in which the head relatively moves with respect to the printing object. Therefore, the printer can effectively utilize the space on one side of the head in the second scanning direction and suppress the enlargement of the entire device.

[0008] The irradiation device is a single lamp arranged side by side with the head in the second scanning direction. The lamp includes a light source surface, and the first light source and the second light source may be provided on the light source surface.

[0009] The printer can further effectively utilize the space on one side of the head in the second scanning direction and suppress the enlargement of the entire device.

[0010] The first light source is composed of a plurality of first partial light sources. On the light source surface, a plurality of first group columns in which the plurality of first partial light sources are arranged in a row in either the first scanning direction or the second scanning direction are provided. The second light source is composed of a plurality of second partial light sources. On the light source surface, a plurality of second group columns in which the plurality of second partial light sources are arranged in a row in the either the first scanning direction or the second scanning direction are provided. The plurality of first group columns and the plurality of second group columns may be provided on the light source surface so as to be alternately arranged in the second scanning direction such that the first partial light sources and the second partial light sources are arranged in a staggered manner.

[0011] In this case, the distance between the first partial light source and the second partial light source becomes longer as compared with the case where the first group of columns and the second group of columns are arranged alternately so that the first partial light source and the second partial light source are arranged in a lattice pattern. In the first partial light source and the second partial light source, the influence of mutual heat when emitting light becomes smaller. Therefore, for example, deterioration of the first partial light source or the second partial light source due to heat can be suppressed. Also, the printer can use the irradiation device for a long time.

[0012] The irradiation device includes a first lamp and a second lamp. The first lamp includes a first light source surface, and the first light source is provided on the first light source surface. The second lamp includes a second light source surface, and the second light source is provided on the second light source surface. The second lamp may be located on the side opposite to the head with the first lamp interposed therebetween in the second scanning direction.

[0013] In this case, both the first lamp and the second lamp are arranged on one side of the head in the second scanning direction. Therefore, the printer can effectively utilize the space on one side of the head in the second scanning direction and suppress an increase in the size of the entire device.

[0014] The irradiation device may irradiate the printing object by switching one by one between the light emitted by the first light source and the light emitted by the second light source.

[0015] In this case, at a certain timing while the irradiation device is irradiating light, only one of the light emitted by the first light source and the light emitted by the second light source is irradiated onto the printing object. In this case, melting or alteration of the printing object due to radiant heat from each light source and the heat of the curing reaction of the ink can be prevented. Also, it is possible to suppress the possibility that the polymerization proceeds too quickly due to too much light hitting the ink and the curing reaction ends before the polymerization chains of the monomers in the ink can fully extend. Thereby, quality deterioration such as the hardness of the cured ink can be prevented. For this reason, even when light is irradiated onto the printing object from a plurality of light sources having different wavelengths, the printer can reduce the influence on the printing quality due to the irradiated light.

[0016] The head discharges the ink that cures when irradiated with ultraviolet light, and the irradiation device may irradiate the ink attached to the printing object with ultraviolet light.

[0017] In this case, since the ink is cured by ultraviolet light, the printer can diversify the materials of the printing object and the like.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0019] With reference to the drawings, the printer 1 according to the first 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.

[0020] Referring to FIGS. 1 to 4, the schematic configuration of the printer 1 will be described. As shown in FIG. 1, the printer 1 includes a conveyance mechanism 6, a lifting mechanism 8, and a platen 5. The conveyance mechanism 6 is provided at the lower part of the printer 1 and includes a pair of rails 12. The pair of rails 12 extends in the front-rear direction and are arranged side by side in the left-right direction.

[0021] The lifting mechanism 8 is provided above the conveyance mechanism 6 and is supported by the pair of rails 12. The lifting mechanism 8 moves in the front-rear direction (sub-scanning direction) along the pair of rails 12. The lifting mechanism 8 expands and contracts in the vertical direction.

[0022] The platen 5 is provided above the lifting mechanism 8. The platen 5 is a plate. The platen 5 is supported by the lifting mechanism 8. The platen 5 moves in the vertical direction due to the vertical expansion and contraction of the lifting mechanism 8. The platen 5 moves in the front-rear direction due to the front-rear movement of the lifting mechanism 8. A printing object is placed on the upper surface of the platen 5.

[0023] The printer 1 includes a pair of rails 11 and a carriage 20. The pair of rails 11 is provided above the platen 5. The pair of rails 11 extends in the left-right direction and are arranged side by side 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 and is supported by the pair of rails 11. The carriage 20 moves in the left-right direction (main scanning direction) along the pair of rails 11.

[0024] The carriage 20 supports the head 10. The number of heads 10 is not limited to a specific number, but in the first embodiment, two heads 10 are mounted on the carriage 20. The two heads 10 are in the shape of a rectangular parallelepiped and are arranged in the front-rear direction. The two heads 10 are fixed to the carriage 20.

[0025] As shown in FIGS. 2 and 3, a printing object M is placed on the upper surface of the platen 5. The printing object M is, for example, plate-shaped or sheet-shaped and is made of, for example, cloth, paper, plastic, or metal. A nozzle surface 101 is formed on the lower surface of the head 10. The nozzle surface 101 is located above the platen 5 and faces the platen 5 from above. A plurality of nozzle holes 101a are formed in the nozzle surface 101. The head 10 discharges ink downward from the plurality of nozzle holes 101a (see arrow A1). As an example, the ink is a so-called ultraviolet curable ink that cures when irradiated with ultraviolet light.

[0026] Hereinafter, the distance between the nozzle surface 101 and the platen 5 in the vertical direction is referred to as "platen distance D0", and the distance between the nozzle surface 101 and the printing object M in the vertical direction is referred to as "discharge distance D1". The platen distance D0 is not limited to a specific value or a specific range, but, for example, it is displaced between about 2 mm and 15 mm by the vertical expansion and contraction of the elevating mechanism 8. The discharge distance D1 is displaced by the platen distance D0 and the thickness of the printing object M. The user adjusts the platen distance D0 by expanding and contracting the elevating mechanism 8 according to the thickness of the printing object M so that the discharge distance D1 becomes the target distance, for example.

[0027] As an example, the platen distance D0 shown in FIG. 2 is the same as the platen distance D0 shown in FIG. 3. The thickness of the printing object M shown in FIG. 2 is thicker than the thickness of the printing object M shown in FIG. 3. Therefore, the discharge distance D1 shown in FIG. 2 is smaller than the discharge distance D1 shown in FIG. 3.

[0028] As shown in FIGS. 2 and 3, an irradiation device 50 is provided on the right side of the head 10. The head 10 and the irradiation device 50 are connected by a shaft 21. The shaft 21 extends in the left-right direction. The head 10 is connected to the left end of the shaft 21. The irradiation device 50 is connected to the right end of the shaft 21. The irradiation device 50 is located above the platen 5. The number of irradiation devices 50 is not limited to a specific number, but in the first embodiment, two irradiation devices 50 are provided. That is, in the first embodiment, the printer 1 includes the same number of irradiation devices 50 as the number of heads 10.

[0029] The irradiation device 50 is in the shape of a rectangular parallelepiped. A light source surface 50a is provided on the lower surface of the irradiation device 50. In the first embodiment, the vertical position of the light source surface 50a is the same as the vertical position of the nozzle surface 101. The light source surface 50a faces the platen 5 from above.

[0030] As shown in FIG. 4, the irradiation device 50 is a single lamp and includes a plurality of light sources (a first light source 51 and a second light source 52). The first light source 51 and the second light source 52 are provided on the light source surface 50a. The first light source 51 and the second light source 52 are each an ultraviolet light emitting diode.

[0031] The first light source 51 emits ultraviolet light of a first wavelength. The first wavelength is not limited to a specific wavelength. The second wavelength is different from the first wavelength. In the first embodiment, the second wavelength is a wavelength longer than the first wavelength.

[0032] The first light source 51 is composed of a plurality of partial light sources 53. In FIG. 4, the partial light sources 53 are indicated by white circles. The number of the partial light sources 53 is not limited to a specific number. On the light source surface 50a, n (n is a natural number of 2 or more) partial light sources 53 are arranged in a row in the front-rear direction (sub-scanning direction). The plurality of partial light sources 53 arranged in a row in the front-rear direction are referred to as a first group row 51a.

[0033] The second light source 52 is composed of a plurality of partial light sources 54. In FIG. 4, the partial light sources 54 are indicated by black circles. The number of the partial light sources 54 is not limited to a specific number. On the light source surface 50a, n partial light sources 54 are arranged in a row in the front-rear direction. The plurality of partial light sources 54 arranged in a row in the front-rear direction are referred to as a second group row 52a.

[0034] In the first embodiment, on the light source surface 50a, the first group row 51a and the second group row 52a are arranged alternately in the left-right direction. On the light source surface 50a, the partial light sources 53 and the partial light sources 54 are arranged in a staggered pattern as a whole.

[0035] The first light source 51 is driven, and ultraviolet rays of the first wavelength are irradiated downward (see arrow A2) from the plurality of partial light sources 53 respectively. The second light source 52 is driven, and ultraviolet rays of the second wavelength are irradiated downward from the plurality of partial light sources 54 respectively. In the first embodiment, when the irradiation device 50 emits the first light source 51, the second light source 52 is turned off. When the irradiation device 50 emits the second light source 52, the first light source 51 is turned off.

[0036] In the printer 1, the ejection distance D1 may change depending on the thickness of the printing object M (see FIGS. 2 and 3). As shown in FIG. 5, the greater the ejection distance D1, the lower the illuminance of the ultraviolet rays irradiated onto the printing object M. Therefore, when the ejection distance D1 is relatively large, it is more difficult for the printer 1 to cure the ink adhered to the printing object M than when the ejection distance D1 is relatively small.

[0037] The ultraviolet rays of the first wavelength are more easily absorbed by the ink because, for example, they are closer to the absorption wavelength region of the ink curing initiator compared to the ultraviolet rays of the second wavelength. Therefore, the ultraviolet rays of the first wavelength are more likely to cure the upper part of the landed ink closer to the irradiation device 50 compared to the ultraviolet rays of the second wavelength. On the other hand, the ultraviolet rays of the second wavelength are less likely to be absorbed by the landed ink because, for example, they deviate from the absorption wavelength region of the ink curing initiator compared to the ultraviolet rays of the first wavelength. Furthermore, when there are particles in the ink, light scattering by the particles is less likely to occur with ultraviolet rays of longer wavelengths. Therefore, the ultraviolet rays of the second wavelength are more likely to cure the lower part of the landed ink farther from the irradiation device 50 compared to the ultraviolet rays of the first wavelength. Since the printer 1 irradiates the ultraviolet rays of the first wavelength and the ultraviolet rays of the second wavelength respectively, the ink adhered to the printing object M can be sufficiently cured even when the ejection distance D1 is relatively large. Furthermore, if an ink having a bleaching effect in which absorption at the absorption wavelength of the ink curing initiator decreases when the ink cures is used, the lower part of the landed ink farther from the irradiation device 50 can be more cured.

[0038] As a way of arranging the first group of columns 51a and the second group of columns 52a on the light source surface 50a, for example, a way can be considered in which the first group of columns 51a are arranged in order from the left end of the light source surface 50a to the right, and then the second group of columns 52a are arranged in order to the right. In the case of the arrangement of the first embodiment, the distance between the adjacent first group of columns 51a and the second group of columns 52a is farther than this arrangement. Therefore, the arrangement of the first embodiment can suppress the influence on the irradiation device 50 due to the heat generation of the first light source 51 and the second light source 52. For example, the greater the distance between the adjacent first group of columns 51a and the second group of columns 52a, the lower the temperature rise of the partial light sources 53 and 54 on the non-emitting side can be. Therefore, the thermal degradation of the partial light sources 53 and 54 can be suppressed, leading to a longer life of the device.

[0039] As a way of arranging the partial light sources 53 and 54 on the light source surface 50a, for example, a way can be considered in which the partial light sources 53 and 54 are arranged in a grid pattern as a whole on the light source surface 50a. In the case of the arrangement of the first embodiment, the lateral distance between the adjacent partial light sources 53 and 54 is farther than this arrangement. Therefore, the arrangement of the first embodiment can suppress the influence on the other when either the first light source 51 or the second light source 52 generates heat.

[0040] Referring to FIG. 6, 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.

[0041] The ROM 42 stores a control program for the CPU 41 to control the operation of the printer 1, information necessary for the CPU 41 when executing various programs, and the like. The RAM 43 temporarily stores various data used in the control program. The flash memory 44 is non-volatile and stores print data and the like for performing printing.

[0042] The CPU 41 is electrically connected to the main scanning motor 31, the sub-scanning motor 32, the head driving unit 33, the lifting motor 34, the first light source 51, the second light source 52, the distance sensor 35, and the operation unit 37. The main scanning motor 31, the sub-scanning motor 32, the head driving unit 33, the lifting motor 34, the first light source 51, and the second light source 52 are driven under the control of the CPU 41. The head driving unit 33 is a piezoelectric element, a heating element, etc., and by driving it, ink is ejected from the nozzle holes 101a to the head 10.

[0043] The operation unit 37 is a touch panel or the like, and outputs information corresponding 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.

[0044] As shown in FIGS. 2 and 3, the distance sensor 35 is an optical sensor and is fixed to the carriage 20. The distance sensor 35 detects the ejection distance D1 and outputs a detection signal to the CPU 41. The CPU 41 can specify the ejection distance D1 based on the detection signal from the distance sensor 35.

[0045] Referring to FIG. 7, the main process will be described. The user places the printing object M on the platen 5. The user operates the operation unit 37 (see FIG. 6) and inputs a print instruction to the printer 1. When the print instruction is input, the CPU 41 reads out the control program from the ROM 42 and operates to execute the main process.

[0046] When the main process starts, the CPU 41 acquires the ejection distance D1 (S1). In S1, the CPU 41 performs a test scan. In the test scan, the CPU 41 drives the sub-scanning motor 32 to move the platen 5 backward to below the moving path of the carriage 20. In this state, the CPU 41 drives the main-scanning motor 31 to move the carriage 20 in the left-right direction without ejecting ink from the head 10. The distance sensor 35 detects the ejection distance D1 and outputs a detection signal to the CPU 41. The CPU 41 acquires the ejection distance D1 based on the detection signal from the distance sensor 35 at a point where the carriage 20 is arranged at a predetermined position with respect to the platen 5, and stores it in the RAM 43.

[0047] The CPU 41 performs print irradiation control based on the print data (S2). In the print irradiation control, the CPU 41 drives the sub-scanning motor 32 to move the platen 5 backward to below the moving path of the carriage 20. In the first embodiment, the CPU 41 controls so-called one-way printing.

[0048] The CPU 41 drives the main-scanning motor 31 to move the carriage 20 from the right to the left. In this case, the CPU 41 drives the head drive unit 33 and the first light source 51. Ink is ejected from the head 10 onto the printing object M on the platen 5. A plurality of partial light sources 53 emit light, and ultraviolet rays of the first wavelength are irradiated from the irradiation device 50 onto the printing object M on the platen 5 (see arrow Y1 in FIGS. 2 and 3).

[0049] The irradiation device 50 is located to the right of the head 10. Therefore, when the carriage 20 moves from the right to the left, the ultraviolet rays irradiated from the irradiation device 50 onto the printing object M (see arrow A2 in FIGS. 2 and 3) are irradiated onto the ink adhering to the printing object M in the scan of the head 10 being executed. Thereby, the ink adhering to the printing object M hardens.

[0050] The CPU 41 drives the main scanning motor 31 to move the carriage 20 from left to right. During the movement of the carriage 20, the CPU 41 drives only the first light source 51 among the head driving unit 33, the first light source 51, and the second light source 52. Therefore, no ink is ejected from the head 10. A plurality of partial light sources 53 emit light, and ultraviolet rays of the first wavelength are irradiated from the irradiation device 50 to the object M to be printed on the platen 5 (see arrow Y2 in FIGS. 2 and 3).

[0051] When the carriage 20 moves from left to right, the ultraviolet rays irradiated from the irradiation device 50 to the object M to be printed (see arrow A2 in FIGS. 2 and 3) are irradiated to the ink adhering to the object M in the previous scan of the head 10. As a result, the integrated light amount of the ultraviolet rays irradiated to the ink on the object M to be printed increases.

[0052] When one round-trip scan of the head 10 in the left-right direction ends a predetermined number of times, the CPU 41 drives the sub-scanning motor 32 to move the platen 5 forward by a predetermined amount. The CPU 41 controls the printing on the object M to be printed on the platen 5 by repeating a predetermined number of scans of the head 10 in the left-right direction and a predetermined amount of forward movement of the platen 5. The predetermined number of times may be once or two or more times.

[0053] The CPU 41 determines whether or not the printing irradiation control has been completed based on the printing data (S3). The relationship between the size of the printing data and the processing time of the printing irradiation control is stored in the ROM 42. If the printing irradiation control has not been completed (S3: NO), the CPU 41 returns the process to S3. If the printing irradiation control has been completed (S3: YES), the CPU 41 shifts the process to S4.

[0054] The CPU 41 determines whether or not the obtained ejection distance D1 is greater than the threshold value (S4). The threshold value is stored in the ROM 42. The threshold value is not limited to a specific value. For example, it is greater than the lower limit of the platen distance D0 and smaller than the upper limit of the platen distance D0.

[0055] When the ejection distance D1 is less than or equal to the threshold value (S4: NO), the CPU 41 ends the main process. When the ejection distance D1 is greater than the threshold value (S4: YES), the CPU 41 performs irradiation control (S6). In the irradiation control, the CPU 41 drives the sub-scanning motor 32 to move the platen 5 backward until below the moving path of the carriage 20. The CPU 41 drives the main-scanning motor 31 to move the carriage 20 from right to left. During the movement of the carriage 20, the CPU 41 drives only the second light source 52 among the head driving unit 33, the first light source 51, and the second light source 52. Accordingly, ink is not ejected from the nozzle surface 101. A plurality of partial light sources 54 emit light, and ultraviolet light of the second wavelength is irradiated from the irradiation device 50 onto the printing object M on the platen 5. When the scanning of the irradiation device 50 to the left ends, the CPU 41 drives the sub-scanning motor 32 to move the platen 5 forward by a predetermined amount.

[0056] The CPU 41 drives the main-scanning motor 31 to move the carriage 20 from left to right. The CPU 41 drives only the second light source 52 among the head driving unit 33, the first light source 51, and the second light source 52, does not eject ink from the nozzle surface 101 to the head 10, and irradiates ultraviolet light from the light source surface 50a onto the printing object M on the platen 5. When the scanning of the irradiation device 50 to the right ends, the CPU 41 drives the sub-scanning motor 32 to move the platen 5 forward by a predetermined amount. In the first embodiment, when the scanning of the irradiation device 50 to the left or right ends, the CPU 41 moves the platen 5 forward by a predetermined amount. In contrast, the CPU 41 may move the platen 5 forward by a predetermined amount, for example, when a predetermined number of reciprocating scans of the irradiation device 50 in the left-right direction end.

[0057] The CPU 41 determines whether the irradiation control is completed based on the print data (S7). The relationship between the size of the print data and the processing time of the irradiation control is stored in the ROM 42. When the print irradiation control is not completed (S7: NO), the CPU 41 returns the process to S7. When the print irradiation control is completed (S7: YES), the CPU 41 ends the main process.

[0058] As described above, in the first embodiment, the printer 1 includes a head 10, a first light source 51, and a second light source 52. The head 10 moves in the left-right direction (main scanning direction) with respect to the printing object M. Both the first light source 51 and the second light source 52 are provided on the right side of the head 10 in the left-right direction. Therefore, the printer 1 can effectively utilize the space on the right side of the head 10 in the left-right direction and suppress the enlargement of the entire apparatus.

[0059] The first light source 51 and the second light source 52 are provided on the light source surface 50a. Thereby, the printer 1 can further effectively utilize the space on the right side of the head 10 in the left-right direction and suppress the enlargement of the entire apparatus.

[0060] The first light source 51 is composed of a plurality of partial light sources 53. The partial light sources 53 are arranged in n in the front-rear direction to form a first group row 51a. A plurality of first group rows 51a are provided on the light source surface 50a. The second light source 52 is composed of a plurality of partial light sources 54. The partial light sources 54 are arranged in n in the front-rear direction to form a second group row 52a. A plurality of second group rows 52a are provided on the light source surface 50a. On the light source surface 50a, the plurality of first group rows 51a and the plurality of second group rows 52a are arranged alternately in the left-right direction. Further, the plurality of partial light sources 53 and the plurality of partial light sources 54 are arranged in a staggered pattern as a whole. In this case, the distance between adjacent partial light sources 53 and partial light sources 54 becomes longer, for example, compared with the case where the partial light sources 53 and the partial light sources 54 are arranged in a grid pattern as a whole on the light source surface 50a. Therefore, when the partial light sources 53 and the partial light sources 54 are arranged in a staggered pattern, the influence on the other when either the first light source 51 or the second light source 52 generates heat is small. Therefore, the printer 1 can use the irradiation device 50 for a long time.

[0061] The irradiation device 50 irradiates the printing object M by switching between the lights emitted by the first light source 51 and the second light source 52 one by one. When both the light emitted by the first light source 51 and the light emitted by the second light source 52 irradiate the printing object M, the ink attached to the printing object M is irradiated with ultraviolet rays of excessive energy, so the printing quality may deteriorate. For example, the printing object may melt or deteriorate due to the radiant heat from the light source and the heat of the ink curing reaction, or the polymerization may proceed too fast due to excessive light exposure, and the curing reaction may end before the polymerization chains of the monomers in the ink can fully extend, resulting in quality deterioration such as the hardness of the cured ink. Since the irradiation device 50 irradiates the printing object M by switching between the lights emitted by the first light source 51 and the second light source 52 one by one, the printer 1 can reduce the possibility of deterioration of the printing quality.

[0062] The head 10 discharges the ink that cures when irradiated with ultraviolet rays from the nozzle surface 101. The irradiation device 50 irradiates the ink discharged from the nozzle surface 101 and attached to the printing object M with ultraviolet rays. Since the ink is cured by the ultraviolet rays, the printer 1 can diversify the materials of the printing object M. That is, the printer 1 can print on the printing object M on which the ink is relatively difficult to adhere.

[0063] The printer 1 according to the second embodiment of the present invention will be described. The printer 1 of the second embodiment is different from the printer 1 of the first embodiment in that two lamps are provided for the head 10. Hereinafter, the components having the same functions as those of the printer 1 of the first embodiment are denoted by the same reference numerals as those of the printer 1 of the first embodiment, and the description is omitted or simplified.

[0064] As shown in FIG. 8, the irradiation device 50 is provided on the right side of the head 10. The irradiation device 50 is located above the platen 5. The irradiation device 50 includes a first lamp 61 and a second lamp 62. The first lamp 61 and the second lamp 62 are located above the platen 5. The first lamp 61 is provided on the right side of the head 10. The head 10 and the first lamp 61 are connected by a shaft 21.

[0065] The second lamp 62 is provided on the right side of the first lamp 61. That is, in the left - right direction, the second lamp 62 is provided on the side opposite to the head 10 with the first lamp 61 in between. The first lamp 61 and the second lamp 62 are connected by a shaft 22. The shaft 22 extends in the left - right direction. The first lamp 61 is connected to the left end of the shaft 22. The second lamp 62 is connected to the right end of the shaft 22.

[0066] The first lamp 61 and the second lamp 62 are in the shape of a rectangular parallelepiped. The first lamp 61 has a first light - source surface 61a. The first light - source surface 61a forms the lower surface of the first lamp 61. In the second embodiment, the vertical position of the first light - source surface 61a is the same as the vertical position of the nozzle surface 101. The first light - source surface 61a faces the platen 5 from above.

[0067] The first lamp 61 includes a first light source 51. The first light source 51 is provided on the first light - source surface 61a. As shown in Fig. 9(a), the first light source 51 is composed of a plurality of partial light sources 53. The partial light sources 53 are arranged in the front - rear direction and the left - right direction on the first light - source surface 61a. The first light source 51 emits ultraviolet rays of a first wavelength.

[0068] The second lamp 62 has a second light - source surface 62a. The second light - source surface 62a forms the lower surface of the second lamp 62. In the second embodiment, the vertical position of the second light - source surface 62a is the same as the vertical positions of the nozzle surface 101 and the first light - source surface 61a. The second light - source surface 62a faces the platen 5 from above.

[0069] The second lamp 62 includes a second light source 52. The second light source 52 is provided on the second light - source surface 62a. As shown in Fig. 9(b), the second light source 52 is composed of a plurality of partial light sources 54. The partial light sources 54 are arranged in the front - rear direction and the left - right direction on the second light - source surface 62a. The second light source 52 emits ultraviolet rays of a second wavelength. The second wavelength is different from the first wavelength.

[0070] In the second embodiment, the irradiation device 50 includes a first lamp 61 and a second lamp 62. In the left-right direction (main scanning direction), the second lamp 62 is provided on the side opposite to the head 10 with the first lamp 61 interposed therebetween. The first lamp 61 and the second lamp 62 are both arranged on the right side of the head 10. Therefore, the printer 1 can effectively utilize the space on the right side of the head 10 in the left-right direction and suppress the enlargement of the entire device.

[0071] In the above embodiment, the print object M corresponds to the "print object" of the present invention. The front-rear direction in the printer 1 corresponds to the "first scanning direction" of the present invention. The left-right direction in the printer 1 corresponds to the "second scanning direction" of the present invention. The partial light source 53 corresponds to the "first partial light source" of the present invention. The partial light source 54 corresponds to the "second partial light source" of the present invention.

[0072] The present invention can be variously modified from the above embodiment. Each of the various modification examples described below can be combined with each other as long as there is no contradiction. In the above embodiment, the head 10 moves in the left-right direction. In contrast, the head 10 may be a line head. In this case, the head 10 moves relative to the platen 5 in the front-rear direction by the movement of the platen 5.

[0073] In the above embodiment, when the carriage 20 moves from left to right, the irradiation device 50 scans from left to right while irradiating ultraviolet rays. In contrast, when the carriage 20 moves from left to right, the irradiation device 50 may scan from left to right without irradiating ultraviolet rays.

[0074] In the above embodiment, the printer 1 employs ultraviolet curable ink. In contrast, as long as the ink is cured by irradiation with light, for example, the printer 1 may employ ink that is cured by irradiation with visible light or infrared light. In this case, the irradiation device 50 emits visible light or infrared light.

[0075] In the above embodiment, the vertical positions of the light source surface 50a, the first light source surface 61a, and the second light source surface 62a are all the same as the vertical position of the nozzle surface 101. In contrast, at least one of the vertical positions of the light source surface 50a, the first light source surface 61a, and the second light source surface 62a may be above or below the vertical position of the nozzle surface 101.

[0076] In the above embodiment, the platen 5 and the nozzle surface 101 face each other in the vertical direction. In contrast, the platen 5 and the nozzle surface 101 may face each other in the left - right direction or in the front - rear direction. For example, when the platen 5 and the nozzle surface 101 face each other in the left - right direction or the front - rear direction, the head 10 may move relative to the platen 5 in the vertical direction.

[0077] In the above embodiment, in the printing irradiation control and the irradiation control, the carriage 20 and the irradiation device 50 both move in the left - right direction. However, the irradiation device 50 may move in the left - right direction with respect to the carriage 20. For example, in the irradiation control, the carriage 20 may be stationary and only the irradiation device 50 may move in the left - right direction. In this case, the printer 1 may be provided with a drive mechanism for the irradiation device 50 to move in the left - right direction with respect to the carriage 20.

[0078] The irradiation device 50 of the first embodiment and the first lamp 61 and the second lamp 62 of the second embodiment are rectangular parallelepipeds, but they may be polyhedrons different from rectangular parallelepipeds. For example, the irradiation device 50 of the first embodiment may be a pentahedron that is triangular in side view.

[0079] In the irradiation device 50 of the first embodiment, the first group of columns 51a is formed by arranging a plurality of partial light sources 53 in the front - rear direction. However, a plurality of partial light sources 53 may be arranged in the left - right direction. In this case, the second group of columns 52a is formed by arranging a plurality of partial light sources 54 in the left - right direction. The first group of columns 51a and the second group of columns 52a are arranged alternately in the front - rear direction. Further, the plurality of partial light sources 53 and the plurality of partial light sources 54 are arranged in a staggered pattern. In this case, the same effects as those of the first embodiment are also achieved.

[0080] In the above embodiment, the first light source 51 is composed of a plurality of partial light sources 53. In contrast, the first light source 51 may be composed of a single partial light source 53. In the above embodiment, the second light source 52 is composed of a plurality of partial light sources 54. In contrast, the second light source 52 may be composed of a single partial light source 54.

[0081] In the first light source surface 61a and the second light source surface 62a of the second embodiment, the plurality of partial light sources 53 and 54 are arranged in a lattice pattern, but the arrangement method is not limited to this. For example, the plurality of partial light sources 53 and 54 may be arranged in a staggered manner.

[0082] In the above embodiment, the CPU 41 obtains the ejection distance D1 in S1. In contrast, the CPU 41 may obtain the platen distance D0. For example, the distance sensor 35 may detect the platen distance D0. The platen distance D0 may be the distance between any one of the light source surface 50a, the first light source surface 61a, and the second light source surface 62a and the platen 5 in the vertical direction. The ejection distance D1 may be the distance between any one of the light source surface 50a, the first light source surface 61a, and the second light source surface 62a and the printing object M in the vertical direction.

[0083] In the above embodiment, the distance sensor 35 is an optical sensor. In contrast, the distance sensor 35 may be an image sensor, a switch sensor, etc. For example, an encoder may be provided on the lifting motor 34. The CPU 41 may determine the vertical position of the platen 5 based on the detection signal from the encoder, and specify the distance between the platen 5 and the nozzle surface 101, or the distance between the platen 5 and the first light source surface 61a or the second light source surface 62a in the vertical direction.

[0084] In the above embodiment, the distance sensor 35 is provided on the carriage 20. In contrast, the distance sensor 35 may be provided on the head 10, on the irradiation device 50, or on the platen 5. That is, as long as the distance sensor 35 can detect the ejection distance D1, it may be provided at any position.

[0085] In the above embodiment, the method for obtaining the ejection distance D1 by the CPU 41 can be changed as appropriate. For example, the user may operate the operation unit 37 to manually input the ejection distance D1 to the printer 1. In this case, the CPU 41 obtains the ejection distance D1 via the operation unit 37. The user may also operate an external device to manually input the ejection distance D1 to the external device. In this case, the user operates the external device or the operation unit 37 to cause the printer 1 and the external device to communicate with each other. The CPU 41 obtains the ejection distance D1 from the external device through communication. When the CPU 41 obtains the manually input ejection distance D1, the printer 1 may omit the distance sensor 35.

[0086] In the first embodiment, the threshold value in the main process was stored in the ROM 42. In contrast, the threshold value may be stored in the flash memory 44 and may be changeable by the user. The CPU 41 may obtain the threshold value from an external device and store it in the RAM 43.

[0087] In the first embodiment, the relationship between the size of the print data and the processing time of the print irradiation control or the irradiation control in the main process was stored in the ROM 42. In contrast, the relationship between the size of the print data and the processing time of the print irradiation control or the irradiation control may be stored in the flash memory 44 and may be changeable by the user. The CPU 41 may obtain the relationship between the size of the print data and the processing time of the print irradiation control or the irradiation control from an external device and store it in the RAM 43.

Explanation of Reference Numerals

[0088] 1 Printer 5 Platen 10 Head 50 Irradiation device 50a Light source surface 51 First light source 51a First group array 52 Second light source 52a Second group array 53, 54 Partial light sources 61 First lamp 61a First light source surface 62 Second lamp 62a second light source surface M object to be printed

Claims

1. A platen on which a printing object is placed and which moves the printing object in a first scanning direction, A head that relatively moves with respect to the printing object in a second scanning direction intersecting the first scanning direction and discharges photocurable ink onto the printing object, An irradiation device that relatively moves with respect to the printing object in the second scanning direction and irradiates light onto the printing object to which the ink has adhered, and The irradiation device includes A first light source that emits light of a predetermined first wavelength, A second light source that emits light of a second wavelength different from the first wavelength, and A distance sensor that detects any one of the distance between the head and the printing object, the distance between the head and the platen, the distance between the irradiation device and the printing object, and the distance between the irradiation device and the platen, The first light source and the second light source are provided on one side of the head in the second scanning direction, A printer characterized in that either the first light source or the second light source is caused to emit light based on the distance detected by the distance sensor.

2. The irradiation device is a single lamp arranged side by side with the head in the second scanning direction, The lamp includes a light source surface, The printer according to claim 1, wherein the first light source and the second light source are provided on the light source surface.

3. The first light source is composed of a plurality of first partial light sources, A plurality of first group columns in which a plurality of the first partial light sources are arranged in a row in either the first scanning direction or the second scanning direction are provided on the light source surface, The second light source is composed of a plurality of second partial light sources, A plurality of second group columns in which a plurality of the second partial light sources are arranged in a row in the one of the first scanning direction and the second scanning direction are provided on the light source surface, The printer according to claim 2, wherein the plurality of first group columns and the plurality of second group columns are provided on the light source surface such that the first partial light source and the second partial light source are arranged alternately in the second scanning direction in a staggered manner.

4. The irradiation device includes a first lamp and a second lamp. The first lamp includes a first light source surface. The first light source is provided on the first light source surface. The second lamp includes a second light source surface. The second light source is provided on the second light source surface. The printer according to claim 1, wherein the second lamp is located on the side opposite to the head with the first lamp interposed therebetween in the second scanning direction.

5. The printer according to any one of claims 1 to 4, wherein the irradiation device irradiates the printing object by switching one by one the light emitted by the first light source and the light emitted by the second light source.

6. The head discharges the ink that is cured by being irradiated with ultraviolet rays. The printer according to any one of claims 1 to 5, wherein the irradiation device irradiates the ink attached to the printing object with ultraviolet rays.

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