Printing apparatus, method for setting printing medium, and method for controlling printing apparatus

Abstract

To provide a printing apparatus for performing printing on an outer peripheral surface of a printing medium having a columnar, truncated conical, or conical outer shape, the printing apparatus being capable of irradiating the ink adhering to the outer peripheral surface of the printing medium with an appropriate amount of ultraviolet rays even when the rotation speed of the printing medium changes according to the resolution of an image to be printed on the outer peripheral surface of the printing medium.SOLUTION: A printing apparatus includes a rotation mechanism 21 that rotates a printing medium 2 around an axial center of the printing medium 2 as a rotation center, inkjet heads 3 that eject ink toward an outer peripheral surface of the printing medium 2, and an ultraviolet irradiator 22 that irradiates the outer peripheral surface of the printing medium 2 to which the ink is attached with ultraviolet light, and the rotation mechanism 21 rotates the printing medium 2 during printing of the printing medium 2. A control unit of the printing apparatus controls the intensity of the ultraviolet light emitted from the ultraviolet irradiator 22 to the printing medium 2 on the basis of the rotation speed of the printing medium 2 during printing on the printing medium 2.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a printing apparatus for printing on the outer peripheral surface of a printing substrate having a cylindrical, truncated conical or conical outer shape, a method for setting a printing substrate in the printing apparatus, and a method for controlling a printing apparatus for printing on the outer peripheral surface of a printing substrate having a cylindrical, truncated conical or conical outer shape. [Background technology]

[0002] Conventionally, there has been known a printing device for printing using ultraviolet-curable ink on the outer peripheral surface of a printing medium having a cylindrical, truncated cone, or conical outer shape (see, for example, Patent Document 1). The printing device described in Patent Document 1 includes an inkjet head that ejects ink toward the outer peripheral surface of the printing medium, an ultraviolet irradiation device that cures the ink ejected onto the outer peripheral surface of the printing medium, a stage having a table on which the ultraviolet irradiation device is placed, a carriage on which the inkjet head is mounted, a carriage drive mechanism that moves the carriage in the main scanning direction, a stage drive mechanism that moves the stage in the sub-scanning direction, and a table lifting mechanism that raises and lowers the table.

[0003] In the printing device described in Patent Document 1, the ultraviolet irradiation device includes a rotation mechanism that holds the substrate and rotates it around its axis, an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the substrate to which ink is attached, and a cover that covers the ultraviolet irradiator from above. The ultraviolet irradiator includes an LED board on which multiple LED chips that emit ultraviolet rays are mounted. The cover has an opening in which the upper end of the substrate is positioned.

[0004] In the printing device described in Patent Document 1, the ultraviolet irradiation device is placed on a table so that the axis of the print medium when viewed from above coincides with the sub-scanning direction. In this printing device, the stage is stopped at a fixed position, and the print medium is rotated by a rotation mechanism, while ink is ejected from an inkjet head stopped at a fixed position to print on the outer surface of the print medium. When printing on the print medium, the ultraviolet irradiator irradiates ultraviolet light toward the outer surface of the rotating print medium. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-88834 Summary of the Invention [Problem to be solved by the invention]

[0006] In the printing device described in Patent Document 1, images of various resolutions are printed on the outer peripheral surface of a substrate. When printing a high-resolution image on the outer peripheral surface of a substrate, it is necessary to slow down the rotation speed of the substrate that rotates during printing in order to ensure the quality of the printed image. On the other hand, when printing a low-resolution image on the outer peripheral surface of a substrate, it is possible to ensure the quality of the printed image even if the rotation speed of the substrate that rotates during printing is increased. Therefore, when printing a low-resolution image on the outer peripheral surface of a substrate, it is preferable to increase the rotation speed of the substrate that rotates during printing to shorten the time required to print the substrate.

[0007] However, in the printing device described in Patent Document 1, if the rotation speed of the rotating substrate during printing is increased, the irradiation time of ultraviolet light irradiated from the ultraviolet irradiator toward the outer surface of the rotating substrate during printing is shortened, and the cumulative amount of ultraviolet light irradiated from the ultraviolet irradiator toward the outer surface of the substrate becomes less than the cumulative amount of ultraviolet light required to cure the ink attached to the outer surface of the substrate, which may result in insufficient curing of the ink attached to the outer surface of the substrate. Even if the rotation speed of the rotating substrate during printing is increased, if the intensity (illuminance) of ultraviolet light irradiated from the ultraviolet irradiator is increased, the cumulative amount of ultraviolet light irradiated from the ultraviolet irradiator toward the outer surface of the substrate increases, making it possible to prevent insufficient curing of the ink attached to the outer surface of the substrate.

[0008] However, the inventors' investigations have revealed that, in the printing device described in Patent Document 1, if the intensity of the ultraviolet light emitted from the ultraviolet irradiator is increased, an excessive amount of ultraviolet light may be irradiated onto the outer surface of the substrate when the rotation speed of the substrate slows during printing, causing the temperature of the substrate to rise excessively. If the temperature of the substrate rises excessively, problems such as deformation of the substrate may occur. Furthermore, the inventors' investigations have revealed that, depending on the type of ink, if an excessive amount of ultraviolet light is irradiated onto the outer surface of the substrate, the ink may over-cure, causing cracks in the dried ink (i.e., cracks in the image printed on the substrate).

[0009] Therefore, an object of the present invention is to provide a printing device for printing with ultraviolet-curable ink on the outer peripheral surface of a printing substrate having a cylindrical, truncated conical, or conical outer shape, which is capable of irradiating an appropriate amount of ultraviolet light onto the ink adhering to the outer peripheral surface of the printing substrate even when the rotation speed of the printing substrate changes depending on the resolution of the image to be printed on the outer peripheral surface of the printing substrate.Another object of the present invention is to provide a printing substrate setting method for setting the printing substrate in such a printing device.

[0010] Furthermore, an object of the present invention is to provide a control method for a printing device that uses ultraviolet-curable ink to print on the outer surface of a substrate having a cylindrical, truncated cone, or conical outer shape, and that is capable of irradiating an appropriate amount of ultraviolet light onto the ink adhering to the outer surface of the substrate, even when the rotation speed of the substrate changes depending on the resolution of the image to be printed on the outer surface of the substrate. [Means for solving the problem]

[0011] In order to solve the above problems, the printing device of the present invention is a printing device for printing using ultraviolet-curable ink on the outer peripheral surface of a substrate having a cylindrical, truncated conical or conical outer shape, and is equipped with a rotation mechanism that holds the substrate and rotates the substrate around its axis as the center of rotation, an inkjet head that is positioned above the substrate and ejects ink toward the outer peripheral surface of the substrate, an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the substrate to which the ink is attached, and a control unit for controlling the printing device, wherein the rotation mechanism rotates the substrate when printing on it, and the control unit controls the intensity of the ultraviolet rays irradiated onto the substrate from the ultraviolet irradiator based on the rotation speed of the substrate when printing on it.

[0012] In the present invention, for example, printing data for printing on a substrate is input to the control unit, the printing data includes resolution data which is data on the resolution of the image to be printed on the substrate, and the rotation speed of the substrate is set based on the resolution data.

[0013] In addition, in order to solve the above-mentioned problems, the control method for a printing device of the present invention is a printing device for printing using ultraviolet-curable ink on the outer peripheral surface of a printing substrate having a cylindrical, truncated conical or conical outer shape, and is equipped with a rotation mechanism that holds the printing substrate and rotates the printing substrate around the axis of the printing substrate as the center of rotation, an inkjet head that is positioned above the printing substrate and ejects ink toward the outer peripheral surface of the printing substrate, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing substrate to which the ink is adhered, and the rotation mechanism rotates the printing substrate when printing on the printing substrate, and is characterized in that the control method for a printing device controls the intensity of ultraviolet rays irradiated onto the printing substrate from the ultraviolet irradiator based on the rotation speed of the printing substrate when printing on the printing substrate.

[0014] In the present invention, the intensity of ultraviolet light irradiated from the ultraviolet irradiator onto the substrate is controlled based on the rotation speed of the substrate when printing is performed on the substrate. Therefore, in the present invention, when the rotation speed of the substrate slows down and the irradiation time of ultraviolet light irradiated onto the outer peripheral surface of the substrate becomes longer, the intensity of ultraviolet light irradiated from the ultraviolet irradiator can be reduced, and when the rotation speed of the substrate increases and the irradiation time of ultraviolet light irradiated onto the outer peripheral surface of the substrate becomes shorter, the intensity of ultraviolet light irradiated from the ultraviolet irradiator can be increased.

[0015] That is, with the present invention, as the rotation speed of the substrate increases during printing, the intensity of the ultraviolet light irradiated onto the substrate from the ultraviolet irradiator can be increased. Therefore, with the present invention, even if the rotation speed of the substrate changes depending on the resolution of the image printed on the outer peripheral surface of the substrate, it is possible to irradiate the ink adhering to the outer peripheral surface of the substrate with an appropriate amount of ultraviolet light.

[0016] In the present invention, for example, the ultraviolet irradiator includes an LED substrate on which a plurality of light-emitting elements that emit ultraviolet light are mounted, and the control unit controls the current value of the LED substrate based on the rotation speed of the substrate when printing the substrate.

[0017] In the present invention, the inkjet head is formed with a plurality of nozzles for ejecting ink, and the lower surface of the inkjet head serves as an ink ejection surface on which the plurality of nozzles are formed. Preferably, the control unit controls the intensity of ultraviolet light irradiated from the ultraviolet irradiator onto the substrate during printing based on the ultraviolet transmittance of the substrate. This configuration makes it possible to reduce the intensity of ultraviolet light irradiated onto the substrate from the ultraviolet irradiator as the ultraviolet transmittance of the substrate increases. This makes it possible to reduce the amount of ultraviolet light that passes through the substrate and reaches the ink ejection surface of the inkjet head. As a result, it is possible to suppress hardening of the ink in the nozzles and prevent nozzle clogging.

[0018] In the present invention, if the cumulative amount of ultraviolet light irradiated from the ultraviolet irradiator toward the outer peripheral surface of the substrate during printing on the substrate is less than the cumulative amount of ultraviolet light required to cure the ink adhering to the outer peripheral surface of the substrate, it is preferable that the control unit causes the ultraviolet irradiator to irradiate additional ultraviolet light toward the outer peripheral surface of the substrate after printing on the substrate. With this configuration, since the substrate has high ultraviolet transmittance, even if the intensity of ultraviolet light irradiated from the ultraviolet irradiator to the substrate is reduced, it is possible to irradiate the outer peripheral surface of the substrate with the amount of ultraviolet light required to cure the ink adhering to the outer peripheral surface of the substrate.

[0019] In the present invention, for example, print substrate shape data, which is data on the shape of the print substrate, and ink type data, which is data on the type of ink ejected by the inkjet head, are input to the control unit, and the control unit calculates the cumulative amount of ultraviolet light required to cure the ink attached to the outer surface of the print substrate based on the input print substrate shape data and ink type data. In this case, the control unit can control the intensity of ultraviolet light irradiated from the ultraviolet irradiator to the print substrate, taking into account the calculated cumulative amount of light.

[0020] In the present invention, the rotation mechanism comprises a first holding member that contacts the substrate to hold one end of the substrate and rotates together with the substrate, and a second holding member that contacts the substrate to hold the other end of the substrate and rotates together with the substrate, and it is preferable that at least one of the first holding member and the second holding member is formed from a material that is light-blocking and thermally conductive.

[0021] With this configuration, at least one of the first and second holding members is made of a light-blocking material, which prevents ultraviolet light reflected by the first and second holding members from reaching the ink ejection surface of the inkjet head. This prevents ink from hardening in the nozzles, thereby reducing nozzle clogging. Furthermore, with this configuration, at least one of the first and second holding members is made of a thermally conductive material, which allows heat from the substrate to escape via the first and second holding members. This prevents the temperature of the substrate from rising excessively due to ultraviolet light irradiating the outer peripheral surface of the substrate.

[0022] In the present invention, the substrate is preferably cylindrical, the rotation mechanism includes an insert member inserted into the substrate's inner periphery, and the insert member is preferably made of a material with light-blocking and thermal conductivity. With this configuration, the insert member inserted into the substrate's inner periphery is made of a material with light-blocking properties, so even if the substrate has high UV transmittance, the insert member can prevent UV rays from passing through the substrate. Therefore, even if the substrate has high UV transmittance, UV rays can be prevented from reaching the ink ejection surface of the inkjet head, thereby suppressing ink hardening in the nozzles and preventing nozzle clogging. Furthermore, with this configuration, the insert member is made of a thermally conductive material, so heat from the substrate can be dissipated through the insert member. Therefore, it is possible to prevent the temperature of the substrate from becoming excessively high due to UV rays irradiated onto the outer periphery of the substrate.

[0023] In the present invention, for example, the printing device includes a cover that covers the ultraviolet irradiator from above, and the cover has an opening formed therein in which the upper end of the printing medium is placed.

[0024] A method for setting a substrate to be printed on a rotating mechanism in a printing device of the present invention includes, for example, a substrate setting step for setting the substrate to the rotating mechanism, and an ultraviolet measurement step for irradiating ultraviolet light from an ultraviolet irradiator onto the outer peripheral surface of the substrate while rotating the substrate using the rotating mechanism after the substrate setting step and measuring the amount of ultraviolet light above the opening. In this substrate setting method, the substrate is repeatedly reset to the rotating mechanism until the amount of ultraviolet light measured in the ultraviolet measurement step falls below a predetermined reference value. Setting the substrate to the rotating mechanism using this substrate setting method reduces the amount of ultraviolet light that passes through the opening formed in the cover and reaches the ink ejection surface of the inkjet head during printing on the substrate. This reduces ink hardening in the nozzles and reduces nozzle clogging. [Effects of the Invention]

[0025] As described above, in the present invention, in a printing device for printing using ultraviolet-curable ink on the outer surface of a substrate having a cylindrical, truncated cone-shaped, or conical outer shape, it is possible to irradiate an appropriate amount of ultraviolet light onto the ink adhering to the outer surface of the substrate, even if the rotation speed of the substrate changes depending on the resolution of the image to be printed on the outer surface of the substrate. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a front view illustrating a configuration of a printing apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram illustrating the configuration of the printing apparatus shown in FIG. [Figure 3] FIG. 2A is a bottom view of the inkjet head and carriage shown in FIG. 1, and FIG. 2B is a bottom view for explaining the configuration of the inkjet head shown in FIG. [Figure 4] FIG. 2 is a front view for explaining the configuration of the ultraviolet irradiation device shown in FIG. [Figure 5] FIG. 5 is a side view for explaining the configuration of the rotation mechanism shown in FIG. [Figure 6] FIG. 5 is a side view for explaining the configuration of the rotation mechanism shown in FIG. [Figure 7] 6 is a process diagram for explaining a setting method when setting a printing medium in the rotation mechanism shown in FIG. 5. FIG. [Figure 8] 10A and 10B are diagrams for explaining a method for controlling an ultraviolet irradiator according to another embodiment of the present invention. [Figure 9] 10A and 10B are schematic diagrams illustrating the configuration of a rotation mechanism according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0028] (Overall configuration of the printing device) Fig. 1 is a front view illustrating the configuration of a printing device 1 according to an embodiment of the present invention. Fig. 2 is a block diagram illustrating the configuration of the printing device 1 shown in Fig. 1. Fig. 3(A) is a bottom view of the inkjet head 3 and carriage 7 shown in Fig. 1, and Fig. 3(B) is a bottom view illustrating the configuration of the inkjet head 3 shown in Fig. 3(A).

[0029] The printing device 1 of this embodiment is a device for printing on the outer peripheral surface of a printing substrate 2 having a cylindrical, truncated conical, or conical outer shape, and is, for example, a commercial inkjet printer. The printing device 1 prints on the outer peripheral surface of the printing substrate 2 using ultraviolet-curable ink. The printing substrate 2 is formed, for example, in a cylindrical shape. That is, the printing substrate 2 is formed in a cylindrical, truncated conical, or conical cylindrical shape. The printing substrate 2 is also formed, for example, from resin. The printing device 1 is capable of printing on multiple types of printing substrates 2 with different outer diameters and lengths.

[0030] The printing device 1 is equipped with inkjet heads 3 (hereinafter referred to as "heads 3") that eject ultraviolet-curable ink toward the outer peripheral surface of the print medium 2. The printing device 1 of this embodiment is equipped with multiple heads 3. Specifically, the printing device 1 is equipped with four heads 3. The printing device 1 also includes an ultraviolet irradiation device 4 for curing the ink ejected onto the outer peripheral surface of the print medium 2, a stage 6 having a table 5 on which the ultraviolet irradiation device 4 is placed, a carriage 7 on which the multiple heads 3 are mounted, a Y-bar 8 that holds the carriage 7 so as to allow movement in a main scanning direction perpendicular to the up-down direction (vertical direction), and a main body frame 9 that holds the stage 6 so as to allow movement in a sub-scanning direction perpendicular to the up-down direction and the main scanning direction.

[0031] The printing device 1 also includes a carriage drive mechanism 11 that moves the carriage 7 in the main scanning direction relative to the Y-bar 8, a stage drive mechanism 12 that moves the stage 6 in the sub-scanning direction relative to the main frame 9, a table lifting mechanism 13 that raises and lowers the table 5, and a control unit 14 that controls the printing device 1. The carriage drive mechanism 11 includes, for example, a motor as a drive source and a power transmission mechanism such as a belt and pulley that transmits the motor's power to the carriage 7. The stage drive mechanism 12 includes, for example, a motor as a drive source and a power transmission mechanism such as a belt and pulley that transmits the motor's power to the stage 6. The stage drive mechanism 12 moves the table 5 in the sub-scanning direction together with the stage 6. The table lifting mechanism 13 includes, for example, a motor as a drive source and a power transmission mechanism such as a ball screw that transmits the motor's power to the table 5.

[0032] In the following description, the sub-scanning direction (X direction in Fig. 1, etc.) is the front-to-rear direction, and the main scanning direction (Y direction in Fig. 1, etc.) is the left-to-right direction. In the following description, the X1 direction side in Fig. 5, etc., which is one side of the front-to-rear direction, is the "front" side, the X2 direction side in Fig. 5, etc., which is the opposite side, is the "rear" side, the Y1 direction side in Fig. 4, etc., which is one side of the left-to-right direction, is the "right" side, and the Y2 direction side in Fig. 2, etc., which is the opposite side, is the "left" side.

[0033] The upper surface of the table 5 is a plane perpendicular to the vertical direction. The ultraviolet irradiation device 4 placed on the table 5 is arranged below the head 3. The print medium 2 is held by the ultraviolet irradiation device 4 and arranged below the head 3. In other words, the head 3 is arranged above the print medium 2. The head 3 ejects ink downward. The ink ejected by the head 3 lands on the outer peripheral surface of the print medium 2 at the upper end of the print medium 2.

[0034] The head 3 has a plurality of nozzles 3a formed therein that eject ink. Specifically, the large number of nozzles 3a are formed on the bottom surface of the head 3. The bottom surface of the head 3 is an ink ejection surface 3c on which the plurality of nozzles 3a (specifically, the large number of nozzles 3a) are formed. On the ink ejection surface 3c, a nozzle row 3b is formed from the large number of nozzles 3a that are arranged in the sub-scanning direction (front-back direction). On the ink ejection surface 3c, a plurality of nozzle rows 3b that are arranged in the main scanning direction (left-right direction) are formed. The head 3 has a plurality of piezoelectric elements (piezo elements) that cause ink to be ejected from each of the plurality of nozzles 3a.

[0035] As shown in Figure 3(A), for example, three of the four heads 3 mounted on the carriage 7 are arranged at the same position in the front-to-rear direction and are aligned in the left-to-right direction. The remaining head 3 is arranged at a position offset from the other three heads 3 in the front-to-rear direction. Three of the four heads 3 eject color inks, and the remaining head 3 ejects white ink. The viscosity of the white ink is higher than the viscosity of the color inks.

[0036] A PC (personal computer) 18 is electrically connected to the control unit 14. The PC 18 generates print data for printing on the print medium 2. When printing on the print medium 2, the print data generated by the PC 18 is sent from the PC 18 to the control unit 14. In other words, when printing on the print medium 2, the print data sent from the PC 18 is input to the control unit 14.

[0037] (Configuration of ultraviolet irradiation device) Fig. 4 is a front view for explaining the configuration of the ultraviolet irradiation device 4 shown in Fig. 1. Figs. 5 and 6 are side views for explaining the configuration of the rotation mechanism 21 shown in Fig. 4.

[0038] The ultraviolet irradiation device 4 includes a rotation mechanism 21 that holds the substrate 2 and rotates it around its axis, an ultraviolet irradiator 22 that irradiates ultraviolet rays toward the outer peripheral surface of the substrate 2 to which ink is attached, and a cover 23 that covers the rotation mechanism 21 and the ultraviolet irradiator 22 from above. The cover 23 has an opening 23a through which the upper end of the substrate 2 is positioned. The ultraviolet irradiation device 4 is placed on the table 5 so that the axis of the substrate 2 coincides with the front-to-rear direction when viewed from above. In other words, the axis of the substrate 2 coincides with the front-to-rear direction when viewed from above. The nozzle row 3b that ejects ink toward the substrate 2 during printing is positioned directly above the substrate 2.

[0039] The rotation mechanism 21 rotates the print substrate 2 when printing on the print substrate 2. In this embodiment, printing is performed on the print substrate 2 while the rotation mechanism 21 rotates the print substrate 2 with the stage 6 and carriage 7 stopped at a fixed position. When printing on the print substrate 2, the rotation mechanism 21 rotates the print substrate 2, for example, counterclockwise when viewed from the front. In this embodiment, the length of the print substrate 2 (length in the direction of the axis) is longer than the width of the head 3 in the front-to-rear direction. Therefore, when printing on the print substrate 2, the print substrate 2 is moved in stages in the front-to-rear direction (sub-scanning direction) together with the table 5 and the rotation mechanism 21, etc. Note that the length of the print substrate 2 may be equal to or shorter than the width of the head 3 in the front-to-rear direction.

[0040] The rotation mechanism 21 includes a motor 25 as a drive source and a power transmission mechanism 26 for transmitting the power of the motor 25 to the printing medium 2. The rotation mechanism 21 also includes a first rotating unit 27 that holds one end of the printing medium 2, a first holding unit 28 that rotatably holds the first rotating unit 27, a second rotating unit 29 that holds the other end of the printing medium 2, a second holding unit 30 that rotatably holds the second rotating unit 29, a rotating frame 31 to which the first holding unit 28 and the second holding unit 30 are attached, and an encoder 32 for detecting the rotational position and rotational speed of the printing medium 2. The motor 25 and the encoder 32 are electrically connected to the control unit 14. Note that the power transmission mechanism 26 and other components are not shown in FIG. 4.

[0041] The first rotating unit 27 and the second rotating unit 29 rotate together with the substrate 2. The first rotating unit 27 holds the rear end of the substrate 2, and the second rotating unit 29 holds the front end of the substrate 2. The motor 25 is located to the right of the substrate 2. The power transmission mechanism 26 connects the first rotating unit 27 and the motor 25. The power transmission mechanism 26 includes a gear train 33. The gear train 33 includes a drive gear fixed to the output shaft of the motor 25 and a driven gear fixed to the first rotating unit 27. The encoder 32 is connected to the rear end of the first rotating unit 27. The second holding unit 30 is movable in the direction of the axis of the substrate 2. In this embodiment, the positions of the second rotating unit 29 and the second holding unit 30 in the direction of the axis of the substrate 2 are adjusted depending on the length of the substrate 2. The power transmission mechanism 26 may also be configured using pulleys, belts, etc.

[0042] The rotating frame 31 is rotatable relative to a lower frame 34 that constitutes the bottom surface of the ultraviolet irradiation device 4, with the left-right direction as the axis of rotation. The rotating frame 31 is also rotatable relative to the lower frame 34, with the rear end of the rotating frame 31 as the rotation center. In this embodiment, by rotating the rotating frame 31 relative to the lower frame 34, it is possible to adjust the inclination of the rotation mechanism 21 relative to the horizontal direction when viewed from the left-right direction. In other words, by rotating the rotating frame 31 relative to the lower frame 34, it is possible to adjust the inclination of the axis of the printing medium 2 relative to the horizontal direction.

[0043] In this embodiment, when printing on a printing substrate 2 having a cylindrical outer shape, the direction of the axis of the printing substrate 2 coincides with the front-to-rear direction (see FIG. 5). On the other hand, when printing on a printing substrate 2 having a truncated cone or conical outer shape, the direction of the axis of the printing substrate 2 is inclined with respect to the front-to-rear direction (see FIG. 6). In other words, the inclination of the rotation mechanism 21 is adjusted when printing on the outer peripheral surface of a printing substrate 2 having a truncated cone or conical outer shape. Specifically, the inclination of the rotation mechanism 21 is adjusted so that the top end of the printing substrate 2 is parallel to the front-to-rear direction.

[0044] The ultraviolet irradiator 22 includes an LED substrate 36 on which a plurality of light-emitting elements (specifically, a large number of light-emitting elements) that emit ultraviolet rays (ultraviolet light) are mounted. The light-emitting elements are LED chips (UV LED chips). The LED substrate 36 is formed in the shape of a long, narrow rectangular plate. The LED substrate 36 is arranged so that the thickness direction of the LED substrate 36 coincides with the left-right direction. Furthermore, the LED substrate 36 is arranged so that the direction of the short side of the rectangular LED substrate 36 coincides with the up-down direction when viewed from the left-right direction, and so that the direction of the long side of the LED substrate 36 coincides with the front-to-back direction. The ultraviolet ray emission surface of the LED substrate 36 faces rightward.

[0045] The ultraviolet irradiator 22 is disposed on the left side of the substrate 2. The ultraviolet irradiator 22 irradiates the substrate 2 with ultraviolet light from the left side immediately after ink has landed thereon. In this embodiment, the vertical position of the ultraviolet irradiator 22 is adjustable. In addition, the horizontal position of the ultraviolet irradiator 22 and the inclination of the ultraviolet irradiator 22 with respect to the axis of the substrate 2 when viewed from the vertical direction are adjustable. In this embodiment, when printing on a substrate 2 having a cylindrical outer shape, the ultraviolet irradiator 22 is installed so that the ultraviolet light emission surface of the ultraviolet irradiator 22 (i.e., the ultraviolet light emission surface of the LED substrate 36) is parallel to the front-to-rear direction. In addition, when printing on a substrate 2 having a truncated cone or conical outer shape, the inclination of the ultraviolet irradiator 22 is adjusted so that the ultraviolet light emission surface of the ultraviolet irradiator 22 is parallel to the left edge of the substrate 2.

[0046] The LED substrate 36 is divided into a plurality of blocks in the front-rear direction and is composed of a plurality of divided irradiation units divided in the front-rear direction. For example, the LED substrate 36 is composed of 12 divided irradiation units. The LED substrate 36 is electrically connected to the control unit 14. Specifically, each of the divided irradiation units is electrically connected to the control unit 14. Each of the divided irradiation units is current-controlled by the control unit 14. That is, the LED substrate 36 is current-controlled by the control unit 14.

[0047] In this embodiment, by controlling the current flowing through the LED substrate 36, it is possible to control the intensity (illuminance) of the ultraviolet light irradiated from the LED substrate 36. That is, the control unit 14 is able to control the intensity of the ultraviolet light irradiated from the ultraviolet irradiator 22. Specifically, the control unit 14 is able to individually control the current of each of the multiple divided irradiation units, and by individually turning on and off each of the multiple divided irradiation units and individually adjusting the intensity of the ultraviolet light irradiated from each of the multiple divided irradiation units, it is possible to control the intensity of the ultraviolet light irradiated from the ultraviolet irradiator 22.

[0048] (Method for controlling ultraviolet irradiators) As described above, when printing on the substrate 2, print data transmitted from the PC 18 is input to the control unit 14. The control unit 14 prints on the substrate 2 based on the input print data. The print data includes resolution data, which is data on the resolution of the image to be printed on the substrate 2. The control unit 14 sets the rotation speed of the substrate 2 during printing on the substrate 2 based on the resolution data. That is, the rotation speed of the substrate 2 is set based on the resolution data. Specifically, as the resolution of the image to be printed on the substrate 2 increases, the rotation speed of the substrate 2 during printing decreases, and as the resolution of the image to be printed on the substrate 2 decreases, the rotation speed of the substrate 2 during printing increases. That is, as the resolution of the image to be printed on the substrate 2 decreases, the rotation speed of the substrate 2 during printing increases.

[0049] When printing on the substrate 2, the ultraviolet irradiator 22 irradiates the substrate 2 with ultraviolet light. Specifically, when printing on the substrate 2, the LED board 36 irradiates the substrate 2 with ultraviolet light. When printing on the substrate 2, the control unit 14 controls the intensity of the ultraviolet light irradiated from the ultraviolet irradiator 22 to the substrate 2 based on the rotation speed of the substrate 2. In other words, when printing on the substrate 2, the control unit 14 controls the current value of the LED board 36 based on the rotation speed of the substrate 2 (according to the rotation speed of the substrate 2).

[0050] Specifically, when the rotation speed of the substrate 2 during printing, which is set based on the resolution data, is slower and the irradiation time of ultraviolet light irradiated onto the outer peripheral surface of the substrate 2 is longer, the control unit 14 reduces the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22. On the other hand, when the rotation speed of the substrate 2 during printing is faster and the irradiation time of ultraviolet light irradiated onto the outer peripheral surface of the substrate 2 is shorter, the control unit 14 increases the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22. In other words, when printing the substrate 2, the control unit 14 increases the intensity of ultraviolet light irradiated onto the substrate 2 from the ultraviolet irradiator 22 as the rotation speed of the substrate 2 increases.

[0051] (How to set the printing material) FIG. 7 is a process diagram for explaining a setting method when setting the printing medium 2 on the rotation mechanism 21 shown in FIG.

[0052] When setting the printing material 2 in the rotation mechanism 21, first, the type and shape of the printing material 2 are selected (steps ST1 and ST2). In steps ST1 and ST2, for example, an operator selects the type and shape of the printing material 2 on an operation panel of the printing device 1. Also, for example, in step ST1, the operator selects whether the printing material 2 is transparent or opaque, and in step ST2, the operator selects whether the shape of the printing material 2 is cylindrical, truncated conical, or conical.

[0053] Thereafter, the printing material 2 is set on the rotation mechanism 21 (printing material setting step, step ST3). In step ST3, the printing material 2 is held by the first rotating unit 27 and the second rotating unit 29, thereby attaching the printing material 2 to the rotation mechanism 21. Also, in step ST3, adjustments are made, as necessary, to the positions of the second rotating unit 29 and the second holding unit 30 in the direction of the axis of the printing material 2, and the inclination of the rotation mechanism 21 relative to the horizontal direction. Also, in step ST3, the cover 23 is set while adjusting its position so that the upper end of the printing material 2 is positioned in the opening 23a of the cover 23.

[0054] Thereafter, while rotating the printing medium 2 using the rotation mechanism 21, ultraviolet light is irradiated onto the outer peripheral surface of the printing medium 2 from the ultraviolet irradiator 22, and the amount of ultraviolet light above the opening 23a is measured (ultraviolet light measurement step, step ST4). That is, in step ST4, the amount of stray ultraviolet light leaking from the opening 23a is measured. In step ST4, an illuminance meter is used to measure the amount of ultraviolet light above the opening 23a. At this time, the carriage 7 is not positioned above the ultraviolet irradiation device 4. Also, in step ST4, the irradiation range of the LED substrate 36 is changed (i.e., the number of divided irradiation units that are turned on is changed) and the illuminance of the LED substrate 36 is changed, and the amount of ultraviolet light above the opening 23a is measured.

[0055] If the amount of ultraviolet light measured in step ST4 (i.e., the amount of stray light) is equal to or less than a predetermined reference value, the operator determines that resetting of the printing substrate 2 is not necessary and completes the setting of the printing substrate 2 on the rotation mechanism 21. On the other hand, if the amount of ultraviolet light measured in step ST4 exceeds the reference value, the operator determines that resetting of the printing substrate 2 is necessary. In this case, for example, the amount of ultraviolet light measured in step ST4 (i.e., the amount of stray light) is stored in the control unit 14 (step ST5). Also, the process returns to step ST3, and the printing substrate 2 is set again on the rotation mechanism 21. That is, the resetting of the printing substrate 2 on the rotation mechanism 21 is repeated until the amount of ultraviolet light measured in step ST4 becomes equal to or less than the reference value.

[0056] (Main effect of this form) As described above, in this embodiment, the control unit 14 controls the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22 onto the print substrate 2 based on the rotational speed of the print substrate 2 during printing on the print substrate 2. Specifically, when the rotational speed of the print substrate 2 during printing is slow and the irradiation time of ultraviolet light irradiated onto the outer peripheral surface of the print substrate 2 is long, the control unit 14 reduces the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22, and when the rotational speed of the print substrate 2 during printing is fast and the irradiation time of ultraviolet light irradiated onto the outer peripheral surface of the print substrate 2 is short, the control unit 14 increases the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22. Therefore, in this embodiment, even if the rotational speed of the print substrate 2 changes depending on the resolution of the image printed on the outer peripheral surface of the print substrate 2, it is possible to irradiate an appropriate amount of ultraviolet light onto the ink attached to the outer peripheral surface of the print substrate 2.

[0057] In this embodiment, when the printing substrate 2 is set on the rotation mechanism 21, ultraviolet light is irradiated from the ultraviolet irradiator 22 onto the outer peripheral surface of the printing substrate 2 while the printing substrate 2 is rotated by the rotation mechanism 21, and the amount of ultraviolet light above the opening 23a is measured in step ST4. The printing substrate 2 is repeatedly reset on the rotation mechanism 21 until the amount of ultraviolet light measured falls below a reference value. Therefore, in this embodiment, it is possible to reduce the amount of ultraviolet light that passes through the opening 23a and reaches the ink ejection surface 3c of the head 3 during printing on the printing substrate 2. Therefore, in this embodiment, it is possible to suppress hardening of the ink in the nozzles 3a and prevent the nozzles 3a from clogging.

[0058] (Example of change in UV irradiator control method) FIG. 8 is a diagram for explaining a method of controlling the ultraviolet irradiator 22 according to another embodiment of the present invention.

[0059] In the above-described embodiment, the substrate 2 may be formed of a material that easily transmits ultraviolet light (for example, a transparent material), or may be formed of a material that does not easily transmit ultraviolet light (for example, an opaque material). For example, when the substrate 2 is formed of a material that transmits ultraviolet light, as shown in FIG. 8(A), ultraviolet light irradiated from the ultraviolet irradiator 22 passes through the substrate 2 and easily reaches the ink ejection surface 3c of the head 3. That is, in this case, the amount of ultraviolet light that is irradiated from the ultraviolet irradiator 22 toward the substrate 2, passes through the substrate 2, and reaches the ink ejection surface 3c increases.

[0060] On the other hand, if the printing substrate 2 is made of a material that does not transmit ultraviolet light, as shown in Figure 8(B), the ultraviolet light irradiated from the ultraviolet irradiator 22 does not penetrate the printing substrate 2, and therefore does not reach the ink ejection surface 3c. If the amount of ultraviolet light that is irradiated from the ultraviolet irradiator 22 toward the printing substrate 2 and then penetrates the printing substrate 2 to reach the ink ejection surface 3c becomes large, there is a risk that the ink will harden inside the nozzles 3a during printing on the printing substrate 2, causing the nozzles 3a to become clogged.

[0061] In this modified example, in order to prevent the nozzles 3a from becoming clogged due to ultraviolet light that passes through the print substrate 2 and reaches the ink ejection surface 3c, the control unit 14 controls the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22 onto the print substrate 2 based on the ultraviolet light transmittance of the print substrate 2 during printing on the print substrate 2. Specifically, the control unit 14 decreases the intensity of ultraviolet light irradiated from the ultraviolet irradiator 22 onto the print substrate 2 as the ultraviolet light transmittance of the print substrate 2 increases. Therefore, in this modified example, it is possible to reduce the amount of ultraviolet light that passes through the print substrate 2 and reaches the ink ejection surface 3c, which in turn makes it possible to prevent the ink from hardening in the nozzles 3a and prevent the nozzles 3a from becoming clogged.

[0062] The ultraviolet transmittance of the substrate 2 is input by an operator, for example, on the operation panel of the printing device 1. The ultraviolet transmittance of the substrate 2 input on the operation panel of the printing device 1 is input to the control unit 14 as ultraviolet transmittance data. When printing on the substrate 2, the control unit 14 controls the intensity of ultraviolet light irradiated onto the substrate 2 from the ultraviolet irradiator 22 based on the input ultraviolet transmittance data. Note that instead of the ultraviolet transmittance of the substrate 2, the operator may input whether the substrate 2 is transparent or opaque on the operation panel of the printing device 1.

[0063] In this modified example, as a result of reducing the intensity of the ultraviolet light irradiated from the ultraviolet irradiator 22 onto the substrate 2, it may occur that the cumulative amount of ultraviolet light irradiated from the ultraviolet irradiator 22 toward the outer peripheral surface of the substrate 2 during printing on the substrate 2 is less than the cumulative amount of ultraviolet light required to cure the ink adhered to the outer peripheral surface of the substrate 2. In this case, the control unit 14 causes the ultraviolet irradiator 22 to irradiate additional ultraviolet light toward the outer peripheral surface of the substrate 2 after printing on the substrate 2.

[0064] Specifically, the control unit 14 pre-stores the cumulative amount of ultraviolet light required to cure the ink adhering to the outer peripheral surface of the substrate 2. The control unit 14 also calculates the cumulative amount of ultraviolet light to be irradiated from the ultraviolet irradiator 22 toward the outer peripheral surface of the substrate 2 when printing on the substrate 2. The control unit 14 compares the calculated cumulative amount of light with the cumulative amount of ultraviolet light required to cure the ink adhering to the outer peripheral surface of the substrate 2, and if the cumulative amount of ultraviolet light irradiated onto the outer peripheral surface of the substrate 2 is insufficient, the control unit 14 causes the ultraviolet irradiator 22 to irradiate additional ultraviolet light toward the outer peripheral surface of the substrate 2 after printing on the substrate 2 to make up for the shortfall. In this modified example, because the substrate 2 has a high ultraviolet transmittance, even if the intensity of the ultraviolet light irradiated onto the substrate 2 from the ultraviolet irradiator 22 is reduced, it is possible to irradiate the outer peripheral surface of the substrate 2 with the amount of ultraviolet light required to cure the ink adhering to the outer peripheral surface of the substrate 2.

[0065] (Example of a modified rotation mechanism) FIG. 9 is a schematic diagram for explaining the configuration of a rotation mechanism 21 according to another embodiment of the present invention.

[0066] In the embodiment described above, the first rotating unit 27 includes a holding member 41 as a first holding member that contacts the material to be printed 2 and holds one end of the material to be printed 2, and the second rotating unit 29 includes a holding member 42 as a second holding member that contacts the material to be printed 2 and holds the other end of the material to be printed 2. In other words, the rotation mechanism 21 includes the holding member 41 that contacts the material to be printed 2 and holds one end of the material to be printed 2 and rotates together with the material to be printed 2, and the holding member 42 that contacts the material to be printed 2 and holds the other end of the material to be printed 2 and rotates together with the material to be printed 2.

[0067] The holding member 41 is in contact with, for example, the inner circumferential surface of the print medium 2. The holding member 42 is in contact with, for example, the inner circumferential surface of the print medium 2 and the front end of the print medium 2. The holding members 41, 42 are formed of a highly elastic material that adheres closely to the print medium 2. In this modified example, the holding members 41, 42 are formed of a material that is light-blocking and thermally conductive. For example, the holding members 41, 42 are formed of black rubber containing a thermally conductive carbon filler.

[0068] In this modified example, the holding members 41 and 42 are formed from a light-blocking material, which prevents ultraviolet light reflected by the holding members 41 and 42 from reaching the ink ejection surface 3c of the head 3. This prevents the ink from hardening in the nozzles 3a, thereby preventing the nozzles 3a from becoming clogged. In addition, in this modified example, the holding members 41 and 42 are formed from a thermally conductive material, which allows heat from the substrate 2 to escape via the holding members 41 and 42. This prevents the temperature of the substrate 2 from becoming excessively high due to ultraviolet light irradiated onto the outer peripheral surface of the substrate 2. Note that either the first holding member 41 or the second holding member 42 does not have to be formed from a material that is light-blocking and thermally conductive.

[0069] In the above-described embodiment, the rotation mechanism 21 may also include an insertion member 43 that is inserted into the inner periphery of the printing medium 2. In this case, the insertion member 43 is made of a material that is light-blocking and thermally conductive. For example, the insertion member 43 is made of black rubber containing a thermally conductive carbon filler.

[0070] In this case, because the insert member 43 is formed of a light-blocking material, even if the substrate 2 has high UV transmittance, the insert member 43 can prevent UV rays from passing through the substrate 2. Therefore, even if the substrate 2 has high UV transmittance, UV rays can be prevented from reaching the ink ejection surface 3c. As a result, hardening of the ink in the nozzles 3a can be suppressed, and clogging of the nozzles 3a can be suppressed. In addition, in this case, because the insert member 43 is formed of a thermally conductive material, heat from the substrate 2 can be dissipated through the insert member 43. Therefore, it is possible to prevent the temperature of the substrate 2 from becoming excessively high due to UV rays irradiated onto the outer peripheral surface of the substrate 2.

[0071] (Other embodiments) The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications can be made without departing from the spirit of the present invention.

[0072] In the above-described embodiment, when printing on the print substrate 2, print substrate shape data, which is data on the shape of the print substrate 2, and ink type data, which is data on the type of ink ejected by the head 3, may be input to the control unit 14. In this case, for example, the shape of the print substrate 2 input by an operator on the operation panel of the printing device 1 is input to the control unit 14 as print substrate shape data. Also, for example, the ink type data is included in the print data, and the ink type data is input to the control unit 14 from the PC 18.

[0073] In this case, the control unit 14 calculates the cumulative amount of ultraviolet light required to cure the ink attached to the outer peripheral surface of the print substrate 2 based on the input print substrate shape data and ink type data. In this case, the control unit 14 is able to control the intensity of the ultraviolet light irradiated from the ultraviolet irradiator 22 to the print substrate 2, taking into account the calculated cumulative amount of light. The shape of the print substrate 2 may also be input via the PC 18. In this case, for example, print substrate shape data is included in the printing data, and the print substrate shape data is input from the PC 18 to the control unit 14. The type of ink may also be input via the operation panel of the printing device 1. In this case, the type of ink input via the operation panel of the printing device 1 is input to the control unit 14 as ink type data.

[0074] In the above-described embodiment, if only printing on a substrate 2 having a fixed outer diameter is performed by the printing device 1, the vertical position of the ultraviolet irradiator 22 does not have to be adjustable. Also, in the above-described embodiment, if only printing on a substrate 2 having a cylindrical outer shape is performed by the printing device 1, the inclination of the rotation mechanism 21 relative to the horizontal when viewed from the left and right does not have to be adjustable, and the inclination of the ultraviolet irradiator 22 relative to the axis of the substrate 2 when viewed from the top and bottom does not have to be adjustable.

[0075] In the above-described embodiment, the ultraviolet irradiation device 4 may be placed on the table 5 so that the direction of the axis of the print medium 2 when viewed from the top-bottom direction coincides with the left-right direction. Also, in the above-described embodiment, the ultraviolet irradiator 22 may be disposed below the print medium 2 or to the right of the print medium 2. Furthermore, in the above-described embodiment, the printing device 1 may be provided with a Y-bar drive mechanism that moves the Y-bar 8 in the sub-scanning direction together with the head 3 and carriage 7, instead of the stage drive mechanism 12. Also, in the above-described embodiment, the printing device 1 may have only one head 3. [Explanation of symbols]

[0076] 1 Printing device 2 Printing material 3 heads (inkjet heads) 3a nozzle 3c Ink ejection surface 14 Control Unit 21 Rotation mechanism 22 Ultraviolet irradiator 23 Cover 23a opening 36 LED boards 41 holding member (first holding member) 42 holding member (second holding member) 43 Insertion member ST3 Printing substrate setting process ST4 UV measurement process

Claims

1. A printing device for printing with ultraviolet-curable ink on the outer peripheral surface of a printing object having a cylindrical, truncated conical, or conical outer shape, a rotation mechanism that holds the substrate and rotates the substrate around the axis of the substrate, an inkjet head that is disposed above the substrate and ejects ink toward the outer peripheral surface of the substrate, an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the substrate to which the ink is attached, and a control unit that controls the printing device; the rotation mechanism rotates the printing medium when printing is performed on the printing medium; A printing device characterized in that the control unit controls the intensity of ultraviolet light irradiated from the ultraviolet irradiator onto the substrate based on the rotation speed of the substrate when printing on the substrate.

2. The control unit receives print data for printing on the print medium, the print data includes resolution data that is data on the resolution of an image to be printed on the printing medium; 2. The printing apparatus according to claim 1, wherein the rotation speed of the printing medium is set based on the resolution data.

3. the ultraviolet irradiator includes an LED substrate on which a plurality of light emitting elements that emit ultraviolet light are mounted, 3. The printing device according to claim 1, wherein the control unit controls a current value of the LED board based on a rotation speed of the printing medium during printing on the printing medium.

4. The inkjet head has a plurality of nozzles formed therein for ejecting ink, a lower surface of the inkjet head serving as an ink ejection surface on which a plurality of the nozzles are formed; The printing device according to claim 1 or 2, characterized in that the control unit controls the intensity of the ultraviolet light irradiated from the ultraviolet irradiator onto the substrate based on the ultraviolet transmittance of the substrate when printing on the substrate.

5. The printing device according to claim 4, characterized in that, if the cumulative amount of ultraviolet light irradiated from the ultraviolet irradiator toward the outer peripheral surface of the substrate during printing on the substrate is less than the cumulative amount of ultraviolet light required to harden the ink adhering to the outer peripheral surface of the substrate, the control unit causes the ultraviolet irradiator to irradiate additional ultraviolet light toward the outer peripheral surface of the substrate after printing on the substrate.

6. Printing medium shape data, which is data on the shape of the printing medium, and ink type data, which is data on the type of ink ejected by the inkjet head, are input to the control unit, 3. The printing device according to claim 1, wherein the control unit calculates the cumulative amount of ultraviolet light required to cure the ink adhered to the outer peripheral surface of the printing medium based on the input printing medium shape data and the input ink type data.

7. the rotation mechanism includes a first holding member that contacts the medium to be printed, holds one end of the medium, and rotates together with the medium, and a second holding member that contacts the medium to be printed, holds the other end of the medium, and rotates together with the medium, 3. The printing apparatus according to claim 1, wherein at least one of the first holding member and the second holding member is made of a material that is light-blocking and thermally conductive.

8. The printing medium is formed into a cylindrical shape, the rotation mechanism includes an insertion member that is inserted into the inner circumferential side of the printing medium, 3. The printing device according to claim 1, wherein the insert member is made of a material having light-blocking and heat-conductive properties.

9. a cover that covers the ultraviolet irradiator from above, 3. The printing device according to claim 1, wherein the cover has an opening through which an upper end of the medium to be printed is placed.

10. 10. A method for setting the printing medium on the rotation mechanism in the printing device according to claim 9, comprising: a printing medium setting step of setting the printing medium on the rotation mechanism; and an ultraviolet light measuring step of irradiating ultraviolet light from the ultraviolet irradiator onto the outer peripheral surface of the printing medium while rotating the printing medium by the rotation mechanism after the printing medium setting step, and measuring the amount of ultraviolet light above the opening, A method for setting a printing medium, characterized in that the printing medium is repeatedly reset to the rotation mechanism until the amount of ultraviolet light measured in the ultraviolet light measurement process becomes equal to or less than a predetermined reference value.

11. A printing device for printing with ultraviolet-curable ink on the outer peripheral surface of a substrate having a cylindrical, truncated conical or conical outer shape, the printing device comprising: a rotation mechanism for holding the substrate and rotating the substrate around its axis as the center of rotation; an inkjet head disposed above the substrate and ejecting ink toward the outer peripheral surface of the substrate; and an ultraviolet irradiator for irradiating ultraviolet rays toward the outer peripheral surface of the substrate to which the ink has adhered, the rotation mechanism rotating the substrate when printing on the substrate, the method comprising: A method for controlling a printing device, comprising controlling the intensity of ultraviolet light irradiated from the ultraviolet irradiator onto the printing medium based on the rotation speed of the printing medium during printing on the printing medium.

Images