Curing and printing equipment

Abstract

To provide a curing device that can suppress deterioration in printing quality due to a shape of a printing medium. while suppressing cost rise.SOLUTION: A curing device 10 comprises a light emitting part 30 having a light source 31 that emits light for curing liquid on a printing medium A and a control device 60. The control device 60 controls the light source 31 so that intensities of light of the light source 31 are larger when a light source gap Gi between the light source 31 and the printing medium A is equal to a second distance larger than a first distance, in comparison with when the light source gap Gi is equal to the first distance.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a curing device and a printing device. [Background technology]

[0002] A conventional printing device is the inkjet printer described in Patent Document 1. This inkjet printer includes a head that ejects liquid onto a recording medium and an ultraviolet irradiation device that irradiates light onto the liquid ejected onto the recording medium. This ultraviolet irradiation device is movable in the vertical direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-68937 Summary of the Invention [Problem to be solved by the invention]

[0004] In the inkjet printer of Patent Document 1, an image is printed on a recording medium by ejecting liquid from a head and causing it to land on the recording medium, and then irradiating the recording medium with light from an ultraviolet irradiation device to fix the liquid on the recording medium. However, if the recording medium has a three-dimensional shape, for example, the distance between the ultraviolet irradiation device and the recording medium changes depending on the unevenness of the recording medium, and the greater the distance, the lower the illuminance of light on the recording medium.

[0005] On the other hand, if the ultraviolet irradiation device could be moved vertically according to the distance between the ultraviolet irradiation device and the recording medium, the illuminance of the light could be changed. This would make the curing state of the liquid uniform and prevent deterioration in image quality. However, this would require a mechanism to move the ultraviolet irradiation device vertically, which would increase costs.

[0006] In view of the above, an object of the present invention is to provide a curing device and a printing device that can suppress a decrease in print quality caused by the shape of the print medium while suppressing an increase in costs. [Means for solving the problem]

[0007] A curing device according to one aspect of the present invention comprises a light irradiation unit having a light source that irradiates light to cure a liquid on a printing medium, and a control device, wherein the control device controls the light source to increase the intensity of the light from the light source when the light source gap between the light source and the printing medium is a second distance that is greater than the first distance, compared to when the light source gap is a first distance.

[0008] A printing device according to one aspect of the present invention comprises a light irradiation unit having a light source that irradiates light to harden a liquid on a printing medium, a lens through which the light from the light source passes between the printing medium and the light source, and a control device, wherein the control device controls the light source to increase the intensity of the light from the light source when the light focus gap between the light focus point from the lens and the printing medium is a second distance greater than the first distance in a third direction in which the light source and the lens are aligned, compared to when the light focus gap is a first distance. [Effects of the Invention]

[0009] The present invention has the advantage of being able to provide a curing device and a printing device that can suppress deterioration in print image quality due to the shape of the printing medium while suppressing increases in costs, because the illuminance of light applied to the recording medium can be changed by controlling the light source, eliminating the need for a mechanism to move the ultraviolet irradiation device up and down.

[0010] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a perspective view of a printing device having a curing device. [Figure 2] FIG. 2 is a schematic view of the conveying device of FIG. 1 as viewed from above. [Figure 3] Fig. 3(a) is a schematic view of the conveying device of Fig. 2 as seen from the front side, and Fig. 3(b) is a schematic view of the conveying device of Fig. 2 as seen from the right side. [Figure 4] FIG. 2 is a schematic diagram of the head unit of FIG. 1 as viewed from below. [Figure 5] FIG. 2 is a functional block diagram showing the configuration of the printing device of FIG. [Figure 6] 2 is a flowchart showing an example of a control method for the printing device of FIG. 1. [Figure 7] 2 is a schematic diagram of the head and print medium of FIG. 1 as viewed from the right side. [Figure 8] 2 is a schematic diagram of the light irradiation unit and the print medium of FIG. 1 as viewed from the right side. [Figure 9] 2 is a schematic diagram of the head unit and the print medium of FIG. 1 as viewed from the front. [Figure 10] Figure 10(a) shows a light irradiation unit, lens, and printing medium with a lens gap smaller than the focal point distance, Figure 10(b) shows a light irradiation unit, lens, and printing medium with a lens gap equal to the focal point distance, and Figure 10(c) shows a light irradiation unit, lens, and printing medium with a lens gap larger than the focal point distance. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding elements will be designated by the same reference numerals throughout the drawings, and redundant description thereof will be omitted.

[0013] (Embodiment 1) <Printing device configuration> As shown in FIG. 1, a printing device 11 equipped with a curing device 10 according to the first embodiment of the present invention is, for example, an inkjet printer that ejects a liquid from a head 20 onto a print medium A (FIG. 2) and irradiates the print medium A with light from a light irradiation unit 30 to print an image. Examples of print medium A include three-dimensional objects such as balls and mugs. The liquid is a photocurable liquid, such as ink that is cured by light such as ultraviolet or infrared light.

[0014] The printing device 11 includes a curing device 10, a head 20, and a transport device 50 (FIG. 2), and the curing device 10 includes a light irradiation unit 30, a moving device 40, a housing 12, and a control device 60 (FIG. 5). The housing 12 houses the curing device 10, the head 20, and the transport device 50. For example, the head 20 and the light irradiation unit 30 are unitized as a head unit 13. The transport device 50 and the control device 60 will be described in detail below.

[0015] Furthermore, the direction in which the printing medium A and the light irradiation unit 30 are lined up is referred to as the up-down direction. A direction perpendicular to this alignment direction, in which the moving device 40 moves the printing medium A and the light irradiation unit 30 relatively, is referred to as the left-right direction. A direction perpendicular to this alignment direction and movement direction is referred to as the front-rear direction. However, the arrangement of the curing device 10 and the printing device 11 is not limited to this.

[0016] The moving device 40 has a pair of moving rails 41, a carriage 42, a drive belt 43, and a moving motor 44, and moves the head unit 13 in the left-right direction. The pair of moving rails 41 are elongated members that extend in the left-right direction, and are arranged parallel to each other so as to sandwich the head unit 13 between them in the front-rear direction.

[0017] The carriage 42 carries the head unit 13 and is supported so as to be movable in the left-right direction along the moving rail 41. The drive belt 43 is an endless belt that extends in the left-right direction along the moving rail 41, is connected to the carriage 42, and is linked to a moving motor 44 via a pulley. The moving motor 44 drives the drive belt 43, causing the carriage 42 to move back and forth in the left-right direction along the moving rail 41. In this way, the moving device 40 moves the printing medium A, the head 20, and the light irradiation unit 30 relatively in the left-right direction.

[0018] <Conveyor equipment> As shown in Figures 2 to 3(b), the transport device 50 has a pair of frames 51, a drive roller 52, a driven roller 53, a transport motor 54, and a pressing unit 55. The frames 51 have a flat plate shape, and the pair of frames 51 are arranged with a gap between them in the left-right direction.

[0019] The drive roller 52 and the driven roller 53 are cylindrical, with their central axes extending in the left-right direction, and are attached to a pair of frames 51 so as to be rotatable around the central axis. The drive roller 52 and the driven roller 53 are parallel to each other, spaced apart in the front-to-back direction, and arranged at the same height in the up-to-down direction. The roller spacing between the drive roller 52 and the driven roller 53 is smaller than the dimension of the printing medium A in the front-to-back direction. Therefore, the printing medium A is placed on the drive roller 52 and the driven roller 53 between the pair of frames 51.

[0020] The drive roller 52 and the driven roller 53 have anti-slip pads made of an elastic material such as rubber attached to their outer circumferential surfaces. These anti-slip pads allow the print medium A placed on the drive roller 52 and the driven roller 53 to rotate in unison with the rotating drive roller 52 and the driven roller 53.

[0021] Furthermore, the print medium A, which is placed on the drive roller 52 and the driven roller 53, is detachably attached to the housing 12 (FIG. 1) or the like so that it faces the underside of the head unit 13. This allows liquid to be ejected from the head 20 of the head unit 13 onto the print medium A, and allows light to be irradiated onto the print medium A from the light irradiation unit 30.

[0022] The transport motor 54 is disposed, for example, on the frame 51 and connected to the drive roller 52. When the transport motor 54 rotates the drive roller 52, the print medium A is rotated by the drive roller 52, and the print medium A further rotates the driven roller 53. As a result, the area of ​​the print medium A that faces the lower surface of the head unit 13 moves, for example, backward.

[0023] The pressing unit 55 has a conveying rail 56, a fixed unit 57, and a movable unit 58. The conveying rail 56 extends in the left-right direction, is disposed between the drive roller 52 and the driven roller 53 in the front-rear direction, and is bridged between and fixed to the pair of frames 51. The fixed unit 57 is fixed to the right-side frame 51 at the right end of the conveying rail 56, and the movable unit 58 is attached to the conveying rail 56 on the left side of the fixed unit 57 so as to be movable in the left-right direction.

[0024] The fixed part 57 and the movable part 58, for example, extend upward from the transport rail 56, and have rotatable balls provided on the surfaces facing each other at their upper ends. As a result, the fixed part 57 and the movable part 58 sandwich the printing medium A between them in the left-right direction, and the balls come into contact with the printing medium A. The fixed part 57 and the movable part 58 support the printing medium A rotatably with the balls.

[0025] Printing medium A is placed on driving roller 52 and driven roller 53 between fixed part 57 and movable part 58, and printing medium A is shifted to the right so that the right end of printing medium A contacts fixed part 57. Then, movable part 58 is moved to the right to contact the left end of printing medium A. As a result, printing medium A is supported in the left-right direction by fixed part 57 and movable part 58, and is rotated by driving roller 52 and driven roller 53.

[0026] <Head unit> As shown in Fig. 4, in the head unit 13, the head 20 and the light irradiation section 30 are arranged side by side in the left-right direction. The head 20 has a plurality of nozzles 21, a liquid flow path 26, a flow path formation body 24, and a plurality of drive elements 25 (Fig. 5). The plurality of nozzles 21 are arranged at equal intervals from each other in the front-rear direction to form a nozzle row. The plurality of nozzle rows are arranged at equal intervals from each other in the left-right direction.

[0027] The flow path forming body 24 has, for example, a rectangular parallelepiped shape, and has the nozzle 21 and the liquid flow path 26 formed therein. The nozzle 21 opens at a nozzle surface 24a, which is the lower surface of the flow path forming body 24. The liquid flow path 26 is connected to the liquid tank 27 ( FIG. 1 ) and the nozzle 21, and has a common flow path 23 and a plurality of individual flow paths 22. The common flow path 23 extends in the front-rear direction, and the plurality of individual flow paths 22 branch off from the common flow path 23. The upstream ends of the individual flow paths 22 are connected to the common flow path 23, and the downstream ends of the individual flow paths 22 are connected to the nozzle 21. Therefore, the liquid flows from the liquid tank 27 to the common flow path 23, and while flowing in the front-rear direction in the common flow path 23, it is diverted into the individual flow paths 22 and supplied to the nozzle 21.

[0028] The driving elements 25 are piezoelectric elements, heat generating elements, electrostatic actuators, etc., and are provided corresponding to the individual flow paths 22, and drive the individual flow paths 22 to vary the volumes of the individual flow paths 22. This applies pressure to the liquid in the individual flow paths 22 to eject the liquid from the nozzles 21.

[0029] The light irradiation unit 30 is disposed upstream of the head 20 in the direction in which the head 20 moves while ejecting liquid. In unidirectional printing, for example, the head 20 ejects liquid when it moves to the left, and does not eject liquid when it moves to the right. In this case, the light irradiation unit 30 is disposed on the right side, which is upstream of the head 20 in the direction of movement to the left during printing. The light irradiation unit 30 irradiates light onto the liquid on the printing medium A while moving in tandem with the head 20, which ejects liquid onto the printing medium A.

[0030] In bidirectional printing, the printing device 11 has a pair of light irradiation units 30 arranged to sandwich the head 20 in the left-right direction. The right light irradiation unit 30 of the pair of light irradiation units 30 irradiates light onto the liquid on the printing medium A while moving leftward, following the head 20 which moves leftward to eject liquid onto the printing medium A. The left light irradiation unit 30 of the pair of light irradiation units 30 irradiates light onto the liquid on the printing medium A while moving rightward to follow the head 20 which moves rightward to eject liquid onto the printing medium A.

[0031] The light irradiation unit 30 has a plurality of light sources 31 and a circuit board 32 on which the light sources 31 are mounted. The circuit board 32 is made of, for example, an insulating material, has a rectangular flat plate shape, and has a bottom surface on which the light sources 31 are mounted. The plurality of light sources 31 are lined up in the front-to-rear direction to form a light source row. The plurality of light source rows (for example, seven) are aligned at intervals in the left-to-right direction. The light sources 31 are, for example, light-emitting elements such as LEDs, and are driven by the control device 60 to emit light (for example, ultraviolet or infrared light) that cures the liquid ejected from the nozzles 21.

[0032] In such a head unit 13, for example, 11 nozzles 21 are arranged in the front-rear direction in each nozzle row, and 11 light sources 31 are arranged in the front-rear direction in each light source row. The 11 nozzles 21 have nozzles 21a to 21k from the front, and the 11 light sources 31 have light sources 31a to 31k from the front. Light source 31a corresponding to nozzle 21a is arranged next to nozzle 21a in the left-right direction, and irradiates light onto the liquid on the printing medium A that has been ejected from nozzle 21a. Note that, like light source 31a, light sources 31b to 31m also correspond to nozzles 21b to 21k, respectively.

[0033] <Control device> As shown in FIG. 5, the control device 60 has a calculation unit 61 and a storage unit 62. The storage unit 62 is a memory accessible by the calculation unit 61 and is composed of RAM, ROM, etc. The RAM temporarily stores various data such as print data. The ROM stores programs for performing various data processing. The control device 60 may be a single control device 60 that performs centralized control, or multiple control devices 60 that perform distributed control. The program may also be stored in a storage medium other than the storage unit 62. Furthermore, the program may be stored in a single storage medium, or may be divided and stored across multiple storage media.

[0034] The calculation unit 61 is composed of a processor such as a CPU and circuits such as integrated circuits such as ASIC. The calculation unit 61 executes a program stored in ROM to control the drive elements 25, light sources 31, movement motor 44, and transport motor 54, thereby performing printing processing. In this printing processing, the control device 60 controls the light sources 31 so that the light intensity of each of the multiple light sources 31 in the light irradiation unit 30 increases as the light source gap Gi (FIG. 8), which is the distance between the light source 31 and the printing medium A in the vertical direction, increases. Details of this control will be described later.

[0035] The control device 60 is connected to the drive element 25 via a head drive circuit 63 and controls the drive of the drive element 25. The control device 60 is connected to the light source 31 via a light source drive circuit 64 and controls the drive of the light source 31. The control device 60 is connected to the movement motor 44 via a movement drive circuit 65 and controls the drive of the movement motor 44. The control device 60 is connected to the conveyance motor 54 via a transport drive circuit 66 and controls the drive of the conveyance motor 54.

[0036] The control device 60 is connected to an external power source B, such as a commercial power source, via a power supply circuit 67. The power supply circuit 67 converts the power from the external power source B from AC to DC, and converts the voltage, frequency, etc., of the power, and supplies power to each part of the printing device 11, such as the drive element 25, light source 31, movement motor 44, and transport motor 54. This power conversion is controlled by the control device 60.

[0037] <Printing process> In such a printing device 11, the control device 60 acquires print data and executes printing processing based on the print data. The print data includes image data (e.g., raster data) that indicates an image to be printed on the printing medium A. The print data may be stored in the storage unit 62, or may be acquired from an external device such as a network, a computer, or a storage medium.

[0038] The control device 60 controls the movement motor 44 to perform a movement operation that moves the head unit 13 in the left-right direction. The control device 60 also controls the drive element 25 to perform a discharge operation that discharges liquid from the head 20. The control device 60 also controls the light source 31 to perform a light irradiation operation that irradiates light from the light source 31. The control device 60 also controls the transport motor 54 to perform a transport operation that rotates and transports the printing medium A. The printing device 11 then alternately repeats scanning, which includes the movement operation, discharge operation, and light irradiation operation, and the transport operation, to proceed with the printing process.

[0039] That is, during scanning, as shown in FIG. 3(a), the head 20 moves to the left while ejecting liquid from the nozzle surface 24a of the head 20. As a result, the liquid lands in the opposing area of ​​the printing medium A facing the nozzle surface 24a. Also, the light irradiation unit 30 moves to the left following the head 20 while irradiating light from the light source 31. As a result, the liquid on the printing medium A facing the light irradiation unit 30 is irradiated with light, and the liquid is hardened by the light and fixed to the printing medium A. As a result, an image extending in the left-right direction is printed in the opposing area of ​​the printing medium A.

[0040] 3(b), the conveying operation rotates the print medium A counterclockwise when viewed from the right, moving the area on the print medium A where the image is printed forward, and the area behind this printed area becomes the facing area. An image is then printed on this facing area by scanning. In this way, by repeating the printing of the image on the facing area by scanning and the movement of the facing area on the print medium A, images are formed sequentially in the circumferential direction of the print medium A.

[0041] <Light Intensity> 3(a), for example, a cylindrical printing medium A is placed on a drive roller 52 and a driven roller 53 so that the central axis of the printing medium A extends in the left-right direction. In this case, even if the light irradiation unit 30 is moved in the left-right direction, the light source gap Gi, which is the distance between the light source 31 of the light irradiation unit 30 and the printing medium A, remains constant.

[0042] 3(b) and 8, the printing medium A is curved in the front-to-rear direction, and therefore the light source gaps Gi of the multiple light sources 31 arranged in the front-to-rear direction in the light irradiation unit 30 are different from one another. As a result, the illuminance of light from the light irradiation unit 30 on the printing medium A decreases as the light source gap Gi increases. Therefore, the control device 60 controls the light source 31 to increase the light intensity of the light source 31 when the light source gap Gi is a second distance greater than the first distance, compared to when the light source gap Gi is a first distance. For example, the first distance is a spacing width less than a predetermined distance, and the second distance is a spacing width greater than the first distance but equal to or greater than the predetermined distance.

[0043] The light source gap Gi is the distance between the light source 31 and the printing medium A, for example, the distance between the light source 31 and the position of the printing medium A facing the light source 31 in a direction parallel to the optical axis of the light emitted from the light source 31. The light source gap Gi is acquired, for example, from shape information. The shape information is information indicating the shape, such as the dimensions, of the printing medium A, and may be acquired, for example, from dimensional data input from the memory unit 62 or an external device, or may be acquired from the distance measurement sensor 14 (FIG. 5).

[0044] The dimensional data includes, for example, the diameter and left-right length for a cylindrical printing medium A. The positional relationships, such as the spacing between each nozzle 21 of the head 20 and each light source 31 of the light irradiation unit 30 and the transport device 50 in the printing device 11, are determined in advance and stored in the storage unit 62. In addition, the diameters of the drive roller 52 and driven roller 53 in the transport device 50 and the spacing therebetween are determined in advance and stored in the storage unit 62.

[0045] Based on this dimensional information, the control device 60 can obtain the position of the printing medium A placed on the drive roller 52 and driven roller 53, as well as the nozzle gap Gn and light source gap Gi, which are the distances between the printing medium A and the nozzles 21. As shown in Figure 7, the nozzle gap Gn is the distance between the nozzles 21 opening in the nozzle surface 24a of the head 20 and the printing medium A facing the nozzles 21.

[0046] The distance measurement sensor 14 measures the distance to an object based on changes in the amount of light emitted by the object, and outputs the measured value to the control device 60. The distance measurement sensor 14 is disposed at a predetermined position, such as the housing 12 or the head unit 13, and measures the distance from this predetermined position to the print medium A placed on the drive roller 52 and driven roller 53. The distances from the predetermined position to each nozzle 21 and each light source 31 are stored in advance in the memory unit 62. Based on this information, the control device 60 can obtain the nozzle gap Gn and the light source gap Gi.

[0047] The light source 31 is a light-emitting element that can change the intensity of light it emits according to the power supplied, and the lower the power, the lower the light intensity. When the light-emitting element of the light source 31 is supplied with the same power as the light-emitting element of the other light sources 31, it emits light with the same intensity as the other light sources 31. For example, this control includes control to reduce the light intensity by PWM control.

[0048] The intensity of the light emitted by the light source 31 is the radiant flux emitted per unit time from a unit area of ​​the light source 31, and is expressed as, for example, the radiant emittance (mW / cm 2) on the printing medium A irradiated by the light source 31. 2 ) is the radiant flux per unit area of ​​the printing medium A of the light incident from the light source 31 per unit time. The integrated light amount is the illuminance (mW / cm 2 ) and the light irradiation time (s), and is the light energy (mJ / cm 2 ) per unit area of ​​the printing medium A of the light incident from the light irradiation unit 30. 2 )

[0049] <Printing device control method> The control method for the printing device 11 is executed by the control device 60, for example, according to the flowchart in Fig. 6. The control device 60 acquires print data (step S1) and starts printing processing based on the print data. The control device 60 also acquires shape information (step S2) and acquires the nozzle gap Gn for each nozzle 21 and the light source gap Gi for each light source 31 based on the shape information.

[0050] The control device 60 determines for each nozzle 21 whether the nozzle gap Gn is less than a predetermined third distance (step S3). For example, as shown in Fig. 7, of the 11 nozzles 21 lined up in the front-to-rear direction, the central nozzle 21f is arranged so as to overlap the central axis of the cylindrical printing medium A when viewed from above. In this case, of the nozzle gaps Gn of the 11 nozzles 21, the nozzle gap Gn of the central nozzle 21f is the smallest, and the nozzle gap Gn increases as the nozzles move away from the center in the front-to-rear direction, with the nozzle gap Gn of the end nozzles 21a, 21k being the largest.

[0051] For example, the control device 60 determines that the nozzle gap Gn between the front nozzle 21a and the rear nozzle 21k of these nozzles 21 is equal to or greater than the third distance (step S3: NO). In this case, the control device 60 does not eject liquid from the nozzles 21a, 21k having the nozzle gap Gn equal to or greater than the third distance, and does not irradiate light from the corresponding light sources 31a, 31k (step S4), and proceeds to the process of step S12.

[0052] The opposing areas of the printing medium A facing the nozzles 21a, 21k are inclined with respect to the nozzle face 24a. For this reason, if liquid is ejected from the nozzles 21a, 21k, the liquid may slide off the printing medium A. For this reason, by not ejecting liquid or irradiating light onto areas of the printing medium A where the nozzle gap Gn is large, it is possible to reduce power consumption and suppress degradation of image quality caused by the liquid.

[0053] On the other hand, the control device 60 determines that the nozzle gap Gn of the nine nozzles 21b to 21j other than the two end nozzles 21 is less than the third distance (step S3: YES). Next, the control device 60 determines whether the nozzles 21 correspond to an area of ​​the printing medium A where the angle θ with respect to the nozzle surface 24a is equal to or greater than a predetermined angle (step S5).

[0054] This angle θ is the smaller of the angles formed between the flat nozzle surface 24a, which is perpendicular to the up-down direction, and a tangent D at a position C on the printing medium A that faces the nozzles 21. At the center of the printing medium A in the front-to-back direction, the nozzle surface 24a and the tangent D are parallel. The angle θ of the tangent D to the nozzle surface 24a increases the further away from the center of the printing medium A in the front-to-back direction. For example, the angle θ formed between the tangent D at position C on the printing medium A, where the front-end nozzle 21b and the rear-end nozzle 21j of the nine nozzles 21 face, and the nozzle surface 24a is equal to or greater than a predetermined angle.

[0055] The control device 60 determines that the nozzles 21b, 21j correspond to an area of ​​the printing medium A where the angle θ with respect to the nozzle face 24a is equal to or greater than a predetermined angle (step S5: YES). In this case, the control device 60 does not eject liquid from the nozzles 21b, 21j where the angle θ is equal to or greater than the predetermined angle, and does not irradiate light from the light sources 31b, 31j corresponding to these nozzles 21 (step S4), and proceeds to the processing of step S12.

[0056] As a result, even if the nozzle gap Gn is less than the third distance, if the inclination of the printing medium A is large, the liquid may drip down onto the printing medium A even if it is ejected. Therefore, by not ejecting liquid or irradiating light onto such areas of the printing medium A, it is possible to reduce power consumption and suppress degradation of image quality caused by adhering liquid.

[0057] On the other hand, for the seven nozzles 21c-21i of the nine nozzles 21, other than nozzles 21b and 21j, the angle θ formed between the tangent D at position C on the printing medium A facing the nozzle 21 and the nozzle surface 24a is less than the predetermined angle. Therefore, the control device 60 determines that the nozzles 21c-21i do not correspond to an area on the printing medium A where the angle θ with respect to the nozzle surface 24a is equal to or greater than the predetermined angle (step S5: NO). Next, the control device 60 ejects liquid from the nozzles 21c-21i while moving the head 20 to the left based on the print data (step S6). As a result, the liquid ejected from the nozzles 21c-21i lands on the printing medium A.

[0058] Next, the control device 60 determines whether the light source gap Gi is the second distance (step S7). In the example of Fig. 8, the control device 60 acquires the light source gap Gi for each of the light sources 31c to 31i. Then, for the light sources 31e to 31g whose light source gap Gi is less than a predetermined distance, the control device 60 determines that the light source gap Gi is the first distance (step S7: NO). For example, the predetermined value is 10 mm.

[0059] When the light source gap Gi is small, the control device 60 causes the light sources 31e to 31g, whose light source gap Gi is the first distance, to emit light of a predetermined first intensity (step S8). As a result, the liquid is irradiated with light, and the liquid is fixed on the print medium A.

[0060] On the other hand, for the light sources 31c-31d and 31h-31i whose light source gap Gi is equal to or greater than the predetermined distance, the control device 60 determines that the light source gap Gi is the second distance (step S7: YES). Subsequently, the control device 60 determines whether the difference in the light source gap Gi for the light sources 31c-31d and 31h-31i whose light source gap Gi is the second distance is equal to or greater than a predetermined value (step S9).

[0061] The difference in the light source gap Gi is the difference between the first light source gap and the second light source gap. The first light source gap Gi is the light source gap Gi between the first light source and the printing medium A, and the second light source gap Gi is the light source gap Gi between the second light source and the printing medium A. The first light source and the second light source are different light sources 31 and are, for example, lined up in the front-to-back direction. In the example of FIG. 8, the first light source and the second light source are any of the light sources 31a to 31k. For example, the first light source is light source 31f, and the second light sources are light sources 31c to 31d and 31h to 31i. In this case, the control device 60 calculates the difference between the second light source gap Gi, which is the light source gap Gi, for each of the light sources 31c to 31d and 31h to 31i, and the first light source gap Gi, which is the light source gap Gi of the light source 31f. Note that, for example, the light source 31 closest to the second light source among the light sources 31e to 31g at the first distance may be set as the first light source.

[0062] For example, when the control device 60 determines that the difference in light source gap Gi between the light sources 31d and 31h is less than a predetermined value (step S9: NO), it causes the light sources 31d and 31h to emit light of a first intensity (step S8). In this way, even if the second light source gap of the light sources 31d and 31h, which are the second light sources, is large, if the difference with the first light source gap of the first light source is small, the intensity of the light from the light sources 31d and 31h is made equal to the intensity of the light from the first light source. This makes it possible to homogenize the state of the liquid cured by light.

[0063] On the other hand, when the control device 60 determines that the difference in the light source gap Gi between the light sources 31c and 31i is equal to or greater than a predetermined value (step S9: YES), it causes the light sources 31c and 31i to emit light of a second intensity greater than the first intensity (step S10). In this way, when the difference between the second light source gap of the light sources 31c and 31i (which are the second light sources) and the first light source gap of the first light source is large, the intensity of the light from the light sources 31c and 31i is made greater than the intensity of the light from the first light source. This allows the liquid to harden.

[0064] Then, the control device 60 determines whether the printing process based on the print data has been completed (step S11). If the printing process remains (step S11: NO), the control device 60 returns to the process of step S3 and repeats the subsequent processes. On the other hand, if the printing process has been completed, the control device 60 ends the printing.

[0065] <Actions and Effects> The curing device 10 includes a light irradiation unit 30 having a light source 31 that emits light to cure the liquid on the print medium A, and a control device 60. The control device 60 controls the light source 31 so that the intensity of the light from the light source 31 is increased when the light source gap Gi between the light source 31 and the print medium A is a second distance that is greater than the first distance, compared to when the light source gap Gi is a first distance.

[0066] According to this, when the light intensity of the light source 31 is constant, the larger the light source gap Gi, the lower the illuminance of light on the printing medium A. In response to this, the light intensity is made higher when the light source gap Gi is large at the second distance than when the light source gap Gi is small at the first distance. This makes the illuminance of light on the printing medium A uniform, uniformly curing the liquid on the printing medium A by light, and suppresses degradation of print image quality caused by the shape of the printing medium A.

[0067] Furthermore, by controlling the light intensity, the illuminance of the light on the print medium A is adjusted. As a result, the curing device 10 does not have to include a mechanism for moving the light irradiation unit 30 in the vertical direction, and an increase in the cost of the curing device 10 can be suppressed.

[0068] In this curing device 10, the light source 31 has a first light source and a second light source different from the first light source. The control device 60 controls the light source 31 while moving the printing medium A and the light irradiation unit 30 relatively in the movement direction so that when the first light source gap Gi between the first light source and the printing medium A is a first distance and the second light source gap Gi between the second light source and the printing medium A is a second distance, the control device 60 controls the light source 31 so that the light intensity of the second light source is greater than the light intensity of the first light source.

[0069] According to this, when light is emitted from the multiple light sources 31 of the light irradiation unit 30 while the light irradiation unit 30 is moving, the intensity of light from the light source 31 whose light source gap is the second distance is made greater than the intensity of light from the light source 31 whose light source gap is the first distance. In this way, by controlling the light intensity of the multiple light sources 31 in the light irradiation operation according to the light source gap Gi, it is possible to suppress a decrease in print image quality caused by the shape of the print medium A while suppressing an increase in costs.

[0070] In this curing device 10, the moving device 40 has a carriage 42 that carries the light irradiation unit 30 and moves in a moving direction (e.g., left-right direction), and the first light source and the second light source are aligned in an orthogonal direction (e.g., front-rear direction) that is perpendicular to the moving direction. Even when multiple light sources 31 are aligned in the front-rear direction in this way, it is possible to suppress a decrease in print image quality due to the shape of the print medium A while suppressing an increase in costs.

[0071] In this curing device 10, when the difference between the first light source gap and the second light source gap is equal to or greater than a predetermined value, the control device 60 increases the light intensity of the other light source 31, of the first and second light sources, whose light source gap Gi is a second distance, compared to the other light source 31, whose light source gap Gi is a first distance; when the difference between the first light source gap and the second light source gap is less than a predetermined value, the control device 60 controls the light source 31 so that the light intensity of the first light source and the light intensity of the second light source are equal to each other.

[0072] For example, even if the first light source gap is a first distance and the second light source gap is a second distance, the first light source gap and the second light source gap may be close to a predetermined distance that is a threshold between the first and second distances, and the difference between the first light source gap and the second light source gap may be small. In this case, by making the light intensity of the first light source and the light intensity of the second light source equal to each other, the state of the liquid cured by light can be made uniform.

[0073] The printing device 11 includes a curing device 10 and a head 20 having a plurality of nozzles 21 capable of ejecting liquid onto a printing medium A. When a nozzle gap Gn between the nozzle 21 and the printing medium A is less than a third distance, the control device 60 causes the nozzle 21 to eject liquid and causes the light source 31 to irradiate light onto the printing medium A, and when the nozzle gap Gn is equal to or greater than the third distance, the control device 60 does not cause the nozzle 21 to eject liquid and does not cause the light source 31 to irradiate light onto the printing medium A.

[0074] For example, the nozzle gap Gn is very large at the edge of the curved print medium A, so if liquid is ejected in such an area, the liquid may drip. For this reason, by not ejecting liquid in such an area and not irradiating it with light, it is possible to reduce power consumption and prevent degradation of image quality caused by adhering liquid.

[0075] In the printing device 11, the head 20 has a nozzle surface 24a in which the nozzles 21 are open. When the nozzle gap Gn is less than the third distance, the control device 60 does not eject liquid from the nozzles 21 corresponding to an area of ​​the printing medium A where the angle θ with respect to the nozzle surface 24a is equal to or greater than a predetermined angle, and does not irradiate light onto the printing medium A from the light source 31 corresponding to the area.

[0076] Even if the nozzle gap Gn is less than the third distance, the liquid may drip when ejected if the print medium A is significantly tilted. For this reason, by not ejecting liquid onto such areas and not irradiating them with light, it is possible to reduce power consumption and prevent degradation of image quality caused by adhering liquid.

[0077] <Variation 1> In the printing device 11 according to the first modification, the third distance is set based on the printing medium A. For example, the ease with which the liquid adheres to the printing medium A and the illuminance at which the liquid on the printing medium A hardens differ depending on the type of material and color of the printing medium A, and the third distance changes accordingly.

[0078] For this reason, the correspondence relationship between the type of printing medium A and the third distance is stored in advance in the memory unit 62. The control device 60 acquires the type of printing medium A from the memory unit 62 or an external device, and acquires the third distance corresponding to the type of printing medium A based on the predetermined correspondence relationship. Then, in step S3 of Fig. 6, the control device 60 determines for each nozzle 21 whether the nozzle gap Gn is less than the acquired third distance.

[0079] <Variation 2> The curing device 10 according to the second modification includes a movement device 40 that moves the print medium A and the light irradiation unit 30 relatively in a movement direction perpendicular to the direction in which the print medium A and the light irradiation unit 30 are aligned. The control device 60 controls the light source 31 so that the intensity of light from the light source 31 is greater when the light source gap Gi is a second distance compared to when the light source gap Gi is a first distance, while moving the print medium A and the light irradiation unit 30 relatively in the movement direction.

[0080] 9, if the print medium A has unevenness in the left-right direction, when the head unit 13 is moved left-right by the movement device 40, the light source gap Gi, which is the distance between the light source 31 and the print medium A, changes in accordance with the unevenness. In such a case, while moving the head unit 13 left-right, the control device 60 controls the light source 31 so that the intensity of the light from the light source 31 is increased when the light source gap Gi is a second distance greater than the first distance, compared to when the light source gap Gi is a first distance. This makes it possible to suppress deterioration in print quality due to the shape of the print medium A while suppressing increases in costs.

[0081] (Embodiment 2) As shown in Figures 10(a) to 10(c), a printing device 11 according to a second embodiment includes a curing device 10 and a head 20 (Figure 1) capable of ejecting a liquid onto a printing medium A. The curing device 10 includes a light irradiation unit 30 having a light source 31 that irradiates light to cure the liquid on the printing medium A, a lens 33 through which the light from the light source 31 passes between the printing medium A and the light source 31, and a control device 60 (Figure 5). The control device 60 controls the light source 31 to increase the intensity of light from the light source 31 when the light focus gap Gf between the focusing point F of the light from the lens 33 and the printing medium A is a second gap larger than the first gap in a third direction in which the light source 31 and the lens 33 are aligned, compared to when the light focus gap Gf is a first gap.

[0082] A lens 33 is provided between the light irradiation unit 30 and the print medium A so as to cover multiple (e.g., all) light sources 31 of the light irradiation unit 30. The lens 33 is, for example, a convex lens, and its axis extends in the vertical direction, for example, parallel to the optical axis of the light emitted from the light source 31. Note that one lens 33 may be provided for each of the multiple light sources 31 of the light irradiation unit 30. Alternatively, multiple lenses 33 may be provided for the light irradiation unit 30, with one lens 33 arranged for each of the multiple light sources 31 of the light irradiation unit 30.

[0083] Light from the light source 31 passes through the lens 33 and is focused at a focusing point F. The distance (mm) from the lens 33 in the vertical direction is z, the focusing point distance (mm) is z0, and the illuminance (mW / cm) of the light at the focusing point F is 2 ) is I0, the illuminance I(z) at a position at a distance z is expressed by the following equation: In the following equation, k(i) and n(i) are predetermined coefficients. I(z)=I0×(1-Σk(i)*|z-z0|^n(i))

[0084] As shown in the above formula, the illuminance of light is greatest at the focal point F of lens 33, and the larger the focal point gap Gf between focal point F of lens 33 and print medium A in the vertical direction, the smaller the illuminance of light on print medium A. In the example of FIG. 10(b), the focal point F of light is on the surface of print medium A, and the lens gap, which is the distance z between lens 33 and print medium A, is equal to the focal point distance z0, so the focal point gap Gf, which is the difference between lens gap z and focal point distance z0, is 0. Here, for example, if the illuminance on print medium A with lens gap z=10 (mm) is 5 (mW / cm 2 )

[0085] In the example of FIG. 10(a), the surface of the printing medium A is above the light condensing point F, and the lens gap z is smaller than the condensing point distance z0. Here, for example, when the light intensity of the light source 31 is the same as in the case of FIG. 10(b), the illuminance on the printing medium A with a lens gap z=8 (mm) is 4.6 (mW / cm 2 )

[0086] In the example of FIG. 10(c), the surface of the printing medium A is below the light condensing point F, and the lens gap z is greater than the condensing point distance z0. Here, for example, when the light intensity of the light source 31 is the same as in the case of FIG. 10(b), the illuminance on the printing medium A with a lens gap z=16 (mm) is 1.4 (mW / cm 2 )

[0087] In this case, the light-focus gap Gf in the example of FIG. 10(a) is 2 mm, e.g., a first gap less than the predetermined gap. In contrast, the light-focus gap Gf in the example of FIG. 10(c) is 6 mm, e.g., a second gap greater than the predetermined gap. The control device 60 controls the light source 31 to increase the light intensity of the light source 31 when the light-focus gap F in FIG. 10(c) is a second gap greater than the first gap, compared to when the light-focus gap Gf in FIG. 10(a) is the first gap. This uniformizes the illuminance of light on the printing medium A, uniformly curing the liquid on the printing medium A by light, and reduces degradation of print quality due to the shape of the printing medium A. Furthermore, controlling the light source 31 helps prevent increases in costs.

[0088] <Other variations> In all of the above embodiments and modified examples, the area on the printing medium A where the light is irradiated from the light irradiation unit 30 may be larger than the area where the liquid ejected from the head 20 lands on the printing medium A. That is, in the center of the irradiation area on the printing medium A, the light from the multiple light sources 31 overlaps, resulting in high light illuminance, while at the edges of the irradiation area on the printing medium A, there is little or no overlap of the light from the light sources 31, resulting in low light illuminance. In contrast, by making the light irradiation area on the printing medium A larger than the area where the liquid lands, the edges of the irradiation area of ​​the light with low illuminance are positioned outside the edges of the liquid landing area, making it possible to uniform the light illuminance in the area of ​​the light irradiation area that overlaps with the liquid landing area.

[0089] For example, the arrangement range of the nozzles 21 in the head 20 may be wider than the arrangement range of the light sources 31 in the light irradiation unit 30. In this case, as shown in FIG. 4 , the arrangement range of the multiple nozzles 21 lined up in the front-rear direction and the arrangement range of the multiple light sources 31 lined up in the front-rear direction are equal to each other, i.e., range C. In contrast, the arrangement range of the light sources 31 in the front-rear direction may be wider than the arrangement range of the nozzles 21. In this case, the number of light sources 31 lined up in the front-rear direction may be greater than the number of nozzles 21 lined up in the front-rear direction. As a result, on the printing medium A, the irradiation range where light is irradiated from the multiple light sources 31 is wider in the front-rear direction than the landing range where liquid is landed from the multiple nozzles 21. For this reason, the edge of the irradiation range is positioned outside the edge of the landing range in the front-rear direction, and the illuminance of the light is made uniform in the range of the light irradiation range that overlaps with the landing range of the liquid.

[0090] Furthermore, when liquid is ejected from some of the nozzles 21 of the multiple nozzles 21 in the head 20, the control device 60 may irradiate light from the light source 31 corresponding to that nozzle 21 and one or more light sources 31 arranged around that light source 31. As a result, the light irradiation range on the printing medium A overlaps with the liquid landing range and is larger than the liquid landing range, thereby achieving uniform illuminance of light in the range of light irradiation that overlaps with the liquid landing range.

[0091] Furthermore, when the light source gap Gi, which is the distance between the light source 31 and the printing medium A, is a second distance, the control device 60 may control the light source 31 so that the light irradiation range on the printing medium A is larger than the light landing range of the nozzle 21 corresponding to that light source 31. In this case, when the light source gap Gi is large, that is, the second distance, the control device 60 causes light to be emitted from the light source 31 corresponding to the nozzle 21 and one or more light sources 31 arranged around that light source 31. Even in such a case, the light irradiation range on the printing medium A overlaps with and is larger than the liquid landing range, so that sufficient light can be irradiated to harden the liquid.

[0092] In all of the above embodiments and modifications, the moving device 40 moves the head 20 in the left-right direction relative to the printing medium A without moving the printing medium A. In contrast, the moving device 40 may move the transport device 50 in the left-right direction so as to move the printing medium A relative to the head 20 without moving the head 20 in the left-right direction.

[0093] In the first embodiment and its modifications, the control device 60 determines whether the light source gap Gi is the first distance or the second distance based on one predetermined distance. However, the threshold distance for determining the light source gap Gi is not limited to one, and may be two or more.

[0094] For example, the control device 60 may determine the light source gap Gi as a first distance if the light source gap Gi is less than a first predetermined distance, determine the light source gap Gi as a second distance greater than the first distance if the light source gap Gi is equal to or greater than the first predetermined distance and less than a second predetermined distance greater than the first predetermined distance, and determine the light source gap Gi as a third distance greater than the second distance if the light source gap Gi is equal to or greater than the second predetermined distance.

[0095] In this case, the control device 60 increases the light intensity of the light source 31 when the light source gap Gi is the second distance compared to when the light source gap Gi is the first distance. Also, the control device 60 controls the light source 31 so as to increase the light intensity of the light source 31 when the light source gap Gi is the third distance compared to when the light source gap Gi is the second distance.

[0096] In this way, the greater the threshold value of the light source gap Gi, the smaller the difference in light intensity according to the light source gap Gi, and the more uniform the illuminance of light on the printing medium A. Therefore, the hardness, glossiness, and other curing properties of the liquid cured by light on the printing medium A can be made more uniform.

[0097] In the first embodiment and its variations, the control device 60 may continuously determine the relationship between the light source gap Gi and the light intensity of the light source 31. In this case, for example, the light source 31 may be a light-emitting element that can change the intensity of the light it emits depending on the power supplied, such that the light intensity decreases as the power decreases. Here, the control device 60 controls the light source 31 so that the light intensity increases as the light source gap Gi increases. This further reduces the difference in light intensity depending on the light source gap Gi, further uniforming the illuminance of light on the printing medium A and making the curing property of the liquid cured by light on the printing medium A even more uniform.

[0098] It should be noted that all of the above embodiments may be combined with one another as long as they do not exclude one another. Furthermore, many improvements and other embodiments of the present invention will be apparent to those skilled in the art from the above description. Therefore, the above description should be construed as merely illustrative and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure and / or function of the present invention may be substantially changed without departing from the spirit of the present invention. [Industrial Applicability]

[0099] The curing device and printing device according to the present invention are useful as curing devices and printing devices that can suppress deterioration in print quality due to the shape of the print medium while suppressing increases in costs. [Explanation of symbols]

[0100] 10:Curing equipment 11:Printing device 20: Head 21: Nozzle 30: Light irradiation unit 31:Light source 40: Mobile device 42: Carriage 60: Control device 311: 1st light source 312:Second light source

Claims

1. a curing device including a light irradiation unit having a light source that irradiates a print medium having a curved surface with light that cures a liquid on the curved surface, and a control device; a head having a plurality of nozzles capable of ejecting the liquid onto the printing medium and a nozzle surface in which the nozzles open; a support mechanism that supports the print medium so that the curved surface faces the nozzle surface, the curved surface of the printing medium is the outer surface of a cylinder, cup, or ball, and forms a convex surface facing the head; The control device an apparatus for controlling a light source so as to increase the intensity of light from the light source when a light source gap between the light source and the printing medium is a first distance, the second distance being larger than the first distance; When a nozzle gap between the nozzle and the printing medium is less than a third distance, the liquid is ejected from the nozzle, and light is irradiated from the light source onto the printing medium; When the nozzle gap is equal to or greater than the third distance, the liquid is not ejected from the nozzles and the light source is not irradiated onto the printing medium.

2. a curing device including a light irradiation unit having a light source that irradiates light to cure the liquid on the print medium, and a control device; a head having a plurality of nozzles capable of ejecting the liquid onto the print medium and a nozzle surface in which the nozzles open; The control device an apparatus for controlling a light source so as to increase the intensity of light from the light source when a light source gap between the light source and the printing medium is a first distance, the second distance being larger than the first distance; When a nozzle gap between the nozzle and the printing medium is less than a third distance, the liquid is ejected from the nozzle, and light is irradiated from the light source onto the printing medium; When the nozzle gap is equal to or greater than the third distance, the liquid is not ejected from the nozzle, and light is not irradiated from the light source onto the printing medium; A printing device that, when the nozzle gap is less than the third distance, does not eject the liquid from the nozzles corresponding to areas of the printing medium that are angled at a predetermined angle or greater with respect to the nozzle face, and does not irradiate light onto the printing medium from the light source corresponding to those areas.

3. The curing device is a moving device that moves the print medium and the light irradiation unit relatively in a moving direction perpendicular to a direction in which the print medium and the light irradiation unit are arranged, 3. The printing device according to claim 1, wherein the control device controls the light source so that the intensity of the light from the light source is increased when the light source gap is the second distance compared to when the light source gap is the first distance while moving the printing medium and the light irradiation unit relative to each other in the movement direction.

4. the light source includes a first light source and a second light source different from the first light source; 4. The printing device according to claim 3, wherein the control device controls the light source to make the light intensity of the second light source greater than the light intensity of the first light source when a first light source gap, which is the light source gap between the first light source and the printing medium, is the first distance and a second light source gap, which is the light source gap between the second light source and the printing medium, is the second distance while moving the printing medium and the light irradiation unit relative to each other in the movement direction.

5. the moving device has a carriage that carries the light irradiation unit and moves in the moving direction, The printing device according to claim 4 , wherein the first light source and the second light source are aligned in a direction perpendicular to the movement direction.

6. The control device When a difference between the first light source gap and the second light source gap is equal to or greater than a predetermined value, the light source having the light source gap at the second distance from the first light source and the second light source has a higher light intensity than the light source having the light source gap at the first distance from the other light source, 6. A printing device according to claim 4, wherein when the difference between the first light source gap and the second light source gap is less than the predetermined value, the light source is controlled so that the light intensity of the first light source and the light intensity of the second light source are equal to each other.

7. 7. The printing apparatus according to claim 6, wherein the predetermined value is 10 mm.

8. 8. The printing device according to claim 1, wherein the control device controls the light source based on shape information of the printing medium.

9. The printing device according to any one of claims 1 to 8, wherein the third distance is set based on the printing medium.

10. a light irradiation unit having a light source that irradiates light to harden the liquid on the printing medium; a lens between the print medium and the light source through which the light from the light source passes; a control device; The control device controls the light source to increase the intensity of light from the light source when the focal point gap between the focal point of light from the lens and the printing medium is a second distance larger than the first distance in a third direction in which the light source and the lens are aligned, compared to when the focal point gap is a first distance.

11. A curing device according to claim 10; a head capable of ejecting the liquid onto the printing medium.

Images