Ultraviolet irradiation equipment and printing equipment

Abstract

To provide an ultraviolet irradiation device which is used in a printer for performing printing by using ultraviolet-curable ink on an outer peripheral surface of a body to be printed having a column-shaped, circular truncated cone-shaped or cone-shaped outer shape, and can quickly irradiate ink that has landed on the outer peripheral surface of the body to be printed, with ultraviolet radiation.SOLUTION: An ultraviolet irradiation device 4 comprises: a rotation mechanism 16 that holds a body 2 to be printed and rotates the body 2 to be printed about an axis of the body 2 to be printed; and an ultraviolet irradiator 17 that radiates ultraviolet radiation toward an outer peripheral surface of the body 2 to be printed to which ultraviolet-curable ink has adhered. Ink discharged from above the body 2 to be printed lands on the outer peripheral surface of the body 2 to be printed. The ultraviolet irradiator 17 is disposed on the side of the body 2 to be printed, and radiates ultraviolet radiation toward the outer peripheral surface of the body 2 to be printed from the side of the printed body 2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet irradiation device used in a printing device for printing with ultraviolet-curable ink on the outer peripheral surface of a printing medium having a cylindrical, truncated conical, or conical outer shape, and also to a printing device equipped with such an ultraviolet irradiation device. [Background technology]

[0002] Conventionally, there is known a printing device for inkjet printing on the outer peripheral surface of a cylindrical body that does not absorb ink (see, for example, Patent Document 1). The printing device described in Patent Document 1 includes a cylindrical mandrel to which the cylindrical body, which is a resin tube, is attached, a motor that rotates the mandrel around the axis of the mandrel as the center of rotation, an inkjet head that ejects ultraviolet-curable ink toward the outer peripheral surface of the cylindrical body, and an ultraviolet irradiation device that irradiates ultraviolet rays toward the outer peripheral surface of the cylindrical body with the ink adhered thereto. The inkjet head is disposed above the cylindrical body, and the ink ejected from above the cylindrical body lands on the outer peripheral surface of the cylindrical body. The ultraviolet irradiation device is disposed below the cylindrical body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-143200 Summary of the Invention [Problem to be solved by the invention]

[0004] In a printing device for printing on the outer surface of a cylindrical body using ultraviolet-curable ink, such as the printing device described in Patent Document 1, it is preferable to irradiate ultraviolet rays onto the ink that has landed on the outer surface of the cylindrical body more quickly in order to prevent the ink from bleeding.

[0005] Therefore, an object of the present invention is to provide an ultraviolet irradiation device used in a printing device for printing with ultraviolet-curable ink on the outer peripheral surface of a printing medium having a cylindrical, truncated conical, or conical outer shape, which is capable of irradiating ultraviolet rays more quickly onto ink that has landed on the outer peripheral surface of the printing medium.Another object of the present invention is to provide a printing device equipped with such an ultraviolet irradiation device. [Means for solving the problem]

[0006] In order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device used in 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, and includes a rotation mechanism that holds the printing substrate and rotates the printing substrate around its axis as the rotation center, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing substrate to which the ink is attached. a cover having an opening in which the upper end of the printing material is placed and a cover portion that covers the ultraviolet irradiator from above; Ink is ejected from above the substrate to land on the outer peripheral surface of the substrate, and the ultraviolet irradiator is disposed on the side of the substrate and irradiates ultraviolet light from the side of the substrate toward the outer peripheral surface of the substrate.

[0007] In the ultraviolet irradiation device of the present invention, the ultraviolet irradiator is disposed on the side of the substrate to irradiate ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate on which ink that has been ejected from above and landed on the substrate adheres. Therefore, in the present invention, it is possible to irradiate ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate more quickly than in the printing device described in Patent Document 1, in which the ultraviolet irradiator is disposed below the substrate.

[0008] Also, The present invention So The ultraviolet irradiation device is provided with a cover having an opening in which the upper end of the printing medium is placed and a cover portion that covers the ultraviolet irradiator from above. attitude R ForFor example, when an inkjet head disposed above a substrate ejects ink toward the outer peripheral surface of the substrate, even if an ultraviolet irradiator disposed to the side of the substrate irradiates ultraviolet rays from the side of the substrate, the cover can prevent ultraviolet rays from irradiating the nozzle surface that constitutes the underside of the inkjet head. Therefore, even if the ultraviolet irradiator is disposed to the side of the substrate, clogging of the nozzles of the inkjet head can be prevented.

[0009] In the present invention, it is preferable that the vertical position of the cover is adjustable. With this configuration, even if the outer diameter of the substrate to be printed by the printing device changes, the vertical position of the cover can be adjusted to match the outer diameter of the substrate. Furthermore, by adjusting the vertical position of the cover to match the outer diameter of the substrate, it is possible to minimize the gap between the edge of the opening of the cover and the substrate. Therefore, even if the ultraviolet irradiator is disposed to the side of the substrate and the outer diameter of the substrate changes, the cover can prevent ultraviolet light from being irradiated onto the nozzle surface of the inkjet head.

[0010] In the present invention, if the direction perpendicular to the axis of the printed material when viewed from the top and bottom is defined as the left-right direction, it is preferable that the ultraviolet irradiation device is provided with two second covers for blocking part of the opening, the left-right positions of each of the two second covers are adjustable, and one of the two second covers is capable of blocking part of the opening from one side in the left-right direction, and the other second cover is capable of blocking part of the opening from the other side in the left-right direction.

[0011] With this configuration, even if the outer diameter of the substrate to be printed on by the printing device changes, it is possible to adjust the left-right position of the second cover to match the outer diameter of the substrate. Furthermore, by adjusting the left-right position of the second cover to match the outer diameter of the substrate, it is possible to minimize the gap between the end face of the second cover and the substrate. Therefore, even if the ultraviolet irradiator is located to the side of the substrate and the outer diameter of the substrate changes, the second cover can prevent ultraviolet light from being irradiated onto the nozzle face of the inkjet head.

[0012] In the present invention, for example, an ultraviolet irradiation device includes a cover position adjustment mechanism for adjusting the left-right positions of two second covers, the second covers are held by the cover so as to be slidable left-right, the cover position adjustment mechanism includes a pressing member held by the cover so as to be slidable left-right and that contacts the second cover from the outside in the left-right direction to press the second cover inward in the left-right direction, a pressing member that presses the second cover outward in the left-right direction, and an adjustment screw rotatably held by the cover and engages with the pressing member, and the second cover slides left-right by turning the adjustment screw. In this case, the left-right position of the second cover can be adjusted by the simple task of turning the adjustment screw.

[0013] In the present invention, the cover preferably comprises an upper cover including a cover portion and a lower cover to which the upper cover is attached at its upper end, the upper cover holds the second cover and the cover position adjustment mechanism, one of the upper cover and the lower cover comprises an attraction member made of a permanent magnet, and the other of the upper cover and the lower cover comprises an attracted member made of a permanent magnet or a magnetic member and attracted to the attraction member, and the upper cover is attached to the lower cover by the magnetic attraction force generated between the attracting member and the attracted member.

[0014] With this configuration, the upper cover is attached to the lower cover by magnetic attraction, so the upper cover including the cover can be easily removed from the lower cover. Therefore, when removing a printed substrate from the rotation mechanism and attaching an unprinted substrate to the rotation mechanism (i.e., when replacing the printed substrate), the upper cover can be easily attached and detached, making it easy to replace the printed substrate.

[0015] Furthermore, with this configuration, because the upper cover holds the second cover and the cover position adjustment mechanism, it is possible to maintain the relative positional relationship between the cover part and the second cover after the removed upper cover is attached to the lower cover. Therefore, even if the upper cover is removed or attached, it is possible to suppress fluctuations in the relative position between the second cover, whose position has been adjusted in the left-right direction to match the outer diameter of the printing medium, and the printing medium. As a result, when subsequently printing on a printing medium with the same outer diameter, it is possible to avoid the hassle of readjusting the left-right position of the second cover after removing or attaching the upper cover.

[0016] In the present invention, it is preferable that the vertical position of the lower part of the cover is adjustable. With this configuration, even if the outer diameter of the substrate to be printed by the printing device changes, the vertical position of the cover can be adjusted to match the outer diameter of the substrate. Furthermore, by adjusting the vertical position of the cover to match the outer diameter of the substrate, it is possible to minimize the gap between the edge of the opening of the cover and the substrate. Therefore, even if the ultraviolet irradiator is disposed to the side of the substrate and the outer diameter of the substrate changes, the cover can prevent ultraviolet light from being irradiated onto the nozzle surface of the inkjet head.

[0017] In the present invention, if the direction of the axis of the printing medium when viewed from above is the front-to-back direction, the ultraviolet irradiation device preferably includes a third cover that blocks a portion of the opening in the front-to-back direction, and the third cover is placed on the cover portion. This configuration makes it possible to block a portion of the opening in the front-to-back direction depending on the length of the printing medium (the axial length of the printing medium). Therefore, even if the length of the printing medium to be printed by the printing device changes, it is possible to prevent ultraviolet light that has passed through the opening from being irradiated onto the nozzle surface of the inkjet head.

[0018] In addition, in order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device used in 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 characterized in that it is equipped with a rotation mechanism that holds the substrate and rotates it around its axis as the center of rotation, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the substrate to which ink is adhered, wherein ink ejected from above the substrate lands on the outer peripheral surface of the substrate, the ultraviolet irradiator is arranged to the side of the substrate and irradiates ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate, and the vertical position of the ultraviolet irradiator is adjustable. In the ultraviolet irradiation device of the present invention, the ultraviolet irradiator is disposed on the side of the substrate to irradiate ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate on which ink that has been ejected from above and landed on the substrate adheres. Therefore, in the present invention, it is possible to irradiate ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate more quickly than in the printing device described in Patent Document 1, in which the ultraviolet irradiator is disposed below the substrate. Also, The present invention So The vertical position of the UV irradiator can be adjusted. For Even if the outer shape of the substrate to be printed by the printing device changes, it becomes possible to arrange the ultraviolet irradiator in a more appropriate position for curing the ink attached to the substrate.

[0019] Furthermore, in order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device used in a printing device for printing using ultraviolet-curable ink on the outer peripheral surface of a printing substrate having a cylindrical, truncated cone-shaped, 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, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing substrate to which ink is adhered, wherein ink ejected from above the printing substrate lands on the outer peripheral surface of the printing substrate, the ultraviolet irradiator is arranged on the side of the printing substrate and irradiates ultraviolet rays from the side of the printing substrate toward the outer peripheral surface of the printing substrate, and the inclination of the rotation mechanism relative to the horizontal direction when viewed from the left-right direction is adjustable, whereby the direction perpendicular to the axis of the printing substrate when viewed from the top-bottom direction is defined as the left-right direction. In the ultraviolet irradiation device of the present invention, the ultraviolet irradiator is disposed on the side of the substrate to irradiate ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate on which ink that has been ejected from above and landed on the substrate adheres. Therefore, in the present invention, it is possible to irradiate ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate more quickly than in the printing device described in Patent Document 1, in which the ultraviolet irradiator is disposed below the substrate. Also, The present invention So If the direction perpendicular to the axis of the printing medium when viewed from the top and bottom is defined as the left-right direction, the inclination of the rotation mechanism relative to the horizontal direction when viewed from the left-right direction can be adjusted. For For example, when an inkjet head disposed above a substrate ejects ink toward the outer peripheral surface of the substrate, even if the substrate has a truncated cone or cone shape, by adjusting the inclination of the rotation mechanism, it is possible to keep the distance (gap) between the outer peripheral surface of the substrate and the nozzle face of the inkjet head constant throughout the entire axial direction of the substrate. This makes it possible to perform appropriate printing on the substrate.

[0020] In the present invention, if the direction of the axis of the printing medium when viewed from the top-bottom direction is defined as the front-to-back direction, the ultraviolet irradiation device comprises, for example, a base frame to which a rotation mechanism is connected at one end in the front-to-back direction so that the rotation mechanism can rotate about the left-to-right direction as the axis of rotation, a support frame having a stepped step portion on which a plurality of step surfaces arranged in the up-and-down direction are formed and fixed to the other end in the front-to-back direction of the base frame, an engagement member having a mounting portion to be placed on the step surface and held by the rotation mechanism so that the rotation mechanism can rotate about the left-to-right direction as the axis of rotation, and a second biasing member that biases the engagement member to one side in the rotation direction of the engagement member relative to the rotation mechanism, The rotation mechanism comprises a first rotating part that holds one end of the material to be printed and rotates together with the material to be printed, a second rotating part that holds the other end of the material to be printed and rotates together with the material to be printed, and a rotating frame to which the first rotating part and the second rotating part are rotatably attached, one front-to-rear end of the rotating frame is rotatably connected to one front-to-rear end of the base frame, the engaging member is rotatably held at the other front-to-rear end of the rotating frame, and the second biasing member biases the engaging member in a direction that moves the mounting part toward the step part, so that the mounting part is placed on the step surface due to the weight of the rotation mechanism, and when the engaging member is rotated against the biasing force of the second biasing member, the mounting part comes off the step surface.

[0021] In the present invention, the ultraviolet irradiation device preferably includes a rotation shaft that is rotatably held by a rotating frame and that serves as a rotation center of the engagement member relative to the rotating frame, and an eccentric cam fixed to the rotation shaft, the rotation shaft being rotatable relative to the engagement member, the rotating frame having a cam mounting hole in which the eccentric cam is mounted, and when the eccentric cam is rotated relative to the rotating frame, the other end of the rotating frame in the front-to-rear direction moves up and down relative to the engagement member. With this configuration, it is possible to fine-tune the inclination of the rotation mechanism relative to the horizontal when viewed from the left and right using the eccentric cam.

[0022] In the present invention, it is preferable that the eccentric cam is an eccentric disk cam formed in a disk shape, and the eccentricity, which is the distance between the center of the eccentric cam and the axis of the rotation shaft, is equal to half the step between adjacent stepped surfaces in the vertical direction. With this configuration, even when the tilt of the rotation mechanism with respect to the horizontal direction when viewed from the left and right is adjusted using the stepped portion of the support frame and the engaging member, it is possible to continuously adjust the tilt of the rotation mechanism with respect to the horizontal direction when viewed from the left and right direction.

[0023] Furthermore, in order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device used in 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 characterized in that it comprises a rotation mechanism that holds the substrate and rotates it around its axis as the center of rotation, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the substrate to which ink is adhered, wherein ink ejected from above the substrate lands on the outer peripheral surface of the substrate, the ultraviolet irradiator is positioned to the side of the substrate and irradiates ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate, and the inclination of the ultraviolet irradiator with respect to the axis of the substrate when viewed from the top and bottom is adjustable. In the ultraviolet irradiation device of the present invention, the ultraviolet irradiator is disposed on the side of the substrate to irradiate ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate on which ink that has been ejected from above and landed on the substrate adheres. Therefore, in the present invention, it is possible to irradiate ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate more quickly than in the printing device described in Patent Document 1, in which the ultraviolet irradiator is disposed below the substrate. Also, The present invention So The inclination of the ultraviolet irradiator relative to the axis of the printing material when viewed from the top and bottom is adjustable. For Even if the outer shape of the substrate is a truncated cone or a cone, by adjusting the inclination of the ultraviolet irradiator, it is possible to keep the distance between the outer surface of the substrate and the ultraviolet irradiator constant throughout the entire axial area of ​​the substrate, thereby making it possible to properly cure the ink adhered to the outer surface of the substrate.

[0024] In addition, in order to solve the above problems, the ultraviolet irradiation device of the present invention is an ultraviolet irradiation device used in a printing device for printing using ultraviolet-curable ink on the outer surface of a substrate having a cylindrical, truncated cone, or conical outer shape, and is equipped with a rotation mechanism that holds the substrate and rotates it around its axis as the center of rotation, an ultraviolet irradiator that irradiates ultraviolet light toward the outer surface of the substrate to which ink is attached, and a first detection mechanism for detecting that the substrate is being held by the rotation mechanism, wherein ink ejected from above the substrate lands on the outer surface of the substrate, the ultraviolet irradiator is positioned to the side of the substrate and irradiates ultraviolet light from the side of the substrate toward the outer surface of the substrate, and when the first detection mechanism detects that the substrate is being held by the rotation mechanism, it becomes possible for the ultraviolet irradiator to irradiate ultraviolet light. In the ultraviolet irradiation device of the present invention, the ultraviolet irradiator is disposed on the side of the substrate to irradiate ultraviolet rays from the side of the substrate toward the outer peripheral surface of the substrate on which ink that has been ejected from above and landed on the substrate adheres. Therefore, in the present invention, it is possible to irradiate ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate more quickly than in the printing device described in Patent Document 1, in which the ultraviolet irradiator is disposed below the substrate. Also, The present invention So The ultraviolet irradiation device includes a first detection mechanism for detecting that the printing medium is held on the rotation mechanism, and when the first detection mechanism detects that the printing medium is held on the rotation mechanism, the ultraviolet irradiator is enabled to irradiate ultraviolet light. For If the printing material is not held by the rotation mechanism, the ultraviolet irradiator will not irradiate ultraviolet light. .therefore This makes it possible to prevent the ultraviolet irradiator from irradiating ultraviolet rays in a state where an operator of the printing device can touch the ultraviolet irradiator. the result This makes it possible to improve the safety of the ultraviolet irradiation device.

[0025] In the present invention, if the direction perpendicular to the axis of the printed material when viewed from the top-bottom direction is defined as the left-right direction, the rotation mechanism, for example, comprises a first rotating unit that holds one end of the printed material, a first holding unit that rotatably holds the first rotating unit, a motor for rotating the first rotating unit, a power transmission mechanism that connects the first rotating unit and the motor, a second rotating unit that holds the other end of the printed material, the second holding unit that rotatably holds the second rotating unit, a third holding unit that rotatably holds the second holding unit so that the second holding unit can rotate around the left-right direction as the axis of rotation, and a third biasing member that biases the second holding unit relative to the third holding unit in a direction that tilts the second holding unit toward the first holding unit, and the first detection mechanism is attached to the third holding unit, and when the printed material is attached to the rotation mechanism, the second holding unit rotates relative to the third holding unit against the biasing force of the third biasing member to a position that is detected by the first detection mechanism.

[0026] In the present invention, assuming that the axis of the printing medium when viewed from above is the front-to-rear direction, the ultraviolet irradiation device preferably includes a cover having an opening for accommodating the upper end of the printing medium and a cover portion covering the ultraviolet irradiator from above, a third cover placed on the cover portion and blocking a portion of the opening in the front-to-rear direction, and a second detection mechanism for detecting that the third cover is placed on the cover portion. When the second detection mechanism detects that the third cover is placed on the cover portion, ultraviolet irradiation by the ultraviolet irradiator is enabled. With this configuration, the ultraviolet irradiator does not emit ultraviolet light unless the cover and the third cover are attached, effectively preventing ultraviolet irradiation by the ultraviolet irradiator when an operator of the printing device can touch the ultraviolet irradiator. This further enhances the safety of the ultraviolet irradiation device.

[0027] In the present invention, if the direction perpendicular to the axis of the medium to be printed when viewed from the top-bottom direction is defined as the left-right direction, then the rotation mechanism may, for example, comprise a first rotating unit that holds one end of the medium to be printed, a first holding unit that rotatably holds the first rotating unit, a motor for rotating the first rotating unit, a power transmission mechanism that connects the first rotating unit and the motor, a second rotating unit that holds the other end of the medium to be printed, a second holding unit that rotatably holds the second rotating unit, and a power transmission mechanism that rotatably holds the second holding unit so that the second holding unit can rotate about the left-right direction. The device is equipped with a third holding portion that holds the printed material, and a third biasing member that biases the second holding portion relative to the third holding portion in a direction that tilts the second holding portion toward the first holding portion, and the position of the third holding portion in the direction of the axis of the printed material is adjustable, and a detectable member having a detectable portion that is detected by the second detection mechanism is attached to the third cover, and the second detection mechanism is attached to the second holding portion, and when the third cover is placed at a predetermined position on the cover portion with the printed material held by the rotation mechanism, the detectable portion is detected by the second detection mechanism.

[0028] In this case, the position of the third holding part in the direction of the axis of the printing substrate is adjusted according to the length of the printing substrate, so the second detection mechanism attached to the second holding part can be moved and placed at a predetermined position according to the length of the printing substrate. Therefore, even when the third cover is moved according to the length of the printing substrate or the third cover is replaced according to the length of the printing substrate, the second detection mechanism can detect that the third cover is placed at an appropriate position on the cover part.

[0029] The ultraviolet irradiation device of the present invention can be used in a printing device that includes a table on which the ultraviolet irradiation device is placed and an inkjet head that is arranged above the print medium and ejects ink toward the outer peripheral surface of the print medium. In this printing device, ultraviolet rays can be irradiated more quickly onto the ink that has landed on the outer peripheral surface of the print medium. [Effects of the Invention]

[0030] As described above, the present invention enables an ultraviolet irradiation device used in 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 to more quickly irradiate ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate. Also, the printing device of the present invention enables more quickly irradiating ultraviolet rays onto the ink that has landed on the outer peripheral surface of the substrate. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a front view showing a schematic configuration of a printing apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a plan view of the ultraviolet irradiation device shown in FIG. [Figure 3] FIG. 3 is a front view for explaining the configuration of the ultraviolet irradiation device shown in FIG. [Figure 4] 4 is a side view for explaining the configuration of the rotation mechanism and its surroundings shown in FIG. 3. FIG. [Figure 5] 4 is a side view for explaining the configuration of the rotation mechanism and its surroundings shown in FIG. 3. FIG. [Figure 6] 5 is an enlarged view for explaining the configuration of part E in FIG. 4. FIG. [Figure 7] 4 is a side view for explaining the configuration of the ultraviolet irradiator and its surrounding area shown in FIG. 3. FIG. [Figure 8] 6 is a plan view for explaining the state of an ultraviolet irradiator and the like when printing is performed on the printing medium having a truncated cone or cone-shaped outer shape shown in FIG. 5. FIG. [Figure 9] 4 is a plan view of the cover, the second cover, the cover position adjusting mechanism, the third cover, etc. shown in FIG. 3. FIG. [Figure 10] 10 is a side view of the cover, the second cover, the cover position adjusting mechanism, the third cover, etc. shown in FIG. 9. [Figure 11] 10 is a front view of the cover, the second cover, the cover position adjusting mechanism, the third cover, etc. shown in FIG. 9. [Figure 12] 12 is a front view showing a state in which the upper cover and the lower cover shown in FIG. 11 are separated. FIG. [Figure 13] 10. (A) is an enlarged view for explaining the configuration of part F in FIG. 10, and (B) is an enlarged view for explaining the configuration of part G in FIG. [Figure 14] 10 is a front view for explaining the positional relationship between the cover part and the second cover shown in FIG. 9 and the printing medium. FIG. [Figure 15] 5 is a plan view for explaining the configuration of part E in FIG. 4. FIG. [Figure 16] FIG. 10 is a side view illustrating a configuration of a peripheral portion of a rotation mechanism according to another embodiment of the present invention. [Figure 17] 16(A) is a diagram for explaining the configuration of the peripheral part of the rotation mechanism as viewed from the GG direction in FIG. [Figure 18] 18 is a side view showing the support frame, the engaging members, etc., as seen from the HH direction in FIG. 17. [Figure 19] FIG. 18 is a diagram for explaining the configuration of the JJ cross section in FIG. [Figure 20] FIG. 18 is a diagram for explaining the configuration of the KK cross section of FIG. [Figure 21] FIG. 10 is a side view for explaining the configuration of the peripheral part of an ultraviolet irradiator according to another embodiment of the present invention. [Figure 22] 22 is a diagram for explaining the configuration of the periphery of the ultraviolet irradiator as viewed from the MM direction of FIG. 21. FIG. [Figure 23] FIG. 23 is a diagram for explaining the configuration of the NN cross section of FIG. 22. [Figure 24] FIG. 10 is a plan view illustrating the configuration of a cover according to another embodiment of the present invention. [Figure 25] FIG. 10 is a side view illustrating the configuration of a cover according to another embodiment of the present invention. [Figure 26] FIG. 10 is an enlarged side view illustrating the configuration of a third cover according to another embodiment of the present invention. [Figure 27] FIG. 10 is a front view for explaining the configuration of an ultraviolet irradiation device according to another embodiment of the present invention. [Figure 28] 28 is a bottom view showing a partial configuration of the ultraviolet irradiation device as seen from the PP direction in FIG. 27. FIG. [Figure 29] FIG. 10 is a plan view illustrating the configuration of a rotation mechanism according to another embodiment of the present invention. [Figure 30] FIG. 30 is a cross-sectional view of the QQ cross section of FIG. 29. [Figure 31] 30 is an enlarged plan view for explaining the configuration of the R portion of FIG. 29. FIG. [Figure 32] 30 is an enlarged plan view for explaining the configuration of the R portion of FIG. 29. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0033] (Schematic configuration of the printing device) FIG. 1 is a front view showing a schematic configuration of a printing device 1 according to an embodiment of the present invention.

[0034] The printing device 1 of this embodiment is a device for printing using ultraviolet-curable ink on the outer 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 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. For example, the outer diameter of the printing substrate 2 that can be printed by the printing device 1 is 40 to 110 (mm).

[0035] The printing device 1 includes an inkjet head 3 that ejects ultraviolet-curable ink toward the outer peripheral surface of the substrate 2, an ultraviolet irradiation device 4 for curing the ink ejected onto the outer peripheral surface of the substrate 2, a stage 6 having a table 5 on which the ultraviolet irradiation device 4 is placed, a carriage 7 on which the inkjet head 3 is mounted, a Y-bar 8 that holds the carriage 7 so that it can move in the main scanning direction, and a main frame 9 that holds the stage 6 so that it can move up and down (vertical direction) and in the sub-scanning direction perpendicular to the main scanning direction.

[0036] 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 body frame 9, and a table lifting mechanism 13 that raises and lowers the table 5. The carriage drive mechanism 11 includes, for example, a motor and a power transmission mechanism such as a belt and pulley that transmits the power of the motor to the carriage 7. The stage drive mechanism 12 includes, for example, a motor and a power transmission mechanism such as a belt and pulley that transmits the power of the motor to the stage 6. The table lifting mechanism 13 includes, for example, a motor and a power transmission mechanism such as a ball screw that transmits the power of the motor to the table 5.

[0037] The upper surface of the table 5 is a plane perpendicular to the up-down direction. The ultraviolet irradiation device 4 placed on the table 5 is arranged below the inkjet head 3. The print medium 2 is held by the ultraviolet irradiation device 4 and arranged below the inkjet head 3. In other words, the inkjet head 3 is arranged above the print medium 2. The inkjet head 3 ejects ink downward.

[0038] The ink ejected from the inkjet head 3 lands on the outer peripheral surface of the print medium 2 at the upper end of the print medium 2. That is, ink ejected from above the print medium 2 lands on the outer peripheral surface of the print medium 2. The lower surface of the inkjet head 3 is a nozzle surface on which a plurality of nozzles that eject ink are arranged. The distance (gap) between the nozzle surface of the inkjet head 3 and the upper end of the print medium 2 is, for example, 2 mm.

[0039] (Overall configuration of ultraviolet irradiation device) Fig. 2 is a plan view of the ultraviolet irradiation device 4 shown in Fig. 1. Fig. 3 is a front view for explaining the configuration of the ultraviolet irradiation device 4 shown in Fig. 2.

[0040] The ultraviolet irradiation device 4 is equipped with a rotation mechanism 16 that holds the printing substrate 2 and rotates the printing substrate 2 around the axis of the printing substrate 2 as the center of rotation. In this embodiment, when printing on a printing substrate 2 having a cylindrical outer shape, the axis of the printing substrate 2 is parallel to the horizontal. On the other hand, when printing on a printing substrate 2 having a truncated cone or conical outer shape, the axis of the printing substrate 2 is inclined relative to the horizontal. In this case, the angle of inclination of the axis of the printing substrate 2 relative to the horizontal is not very large, for example, at most about 15°.

[0041] In the following description, the direction of the axis of the substrate 2 when viewed from the top-bottom direction (X direction in Figure 2, etc.) is referred to as the front-to-back direction, and the direction perpendicular to the axis of the substrate 2 when viewed from the top-to-bottom direction (Y direction in Figure 2, etc.) is referred to as the left-to-right direction. In other words, the horizontal direction of the axis of the substrate 2 when viewed from the top-to-bottom direction is referred to as the front-to-back direction, and the horizontal direction perpendicular to the axis of the substrate 2 when viewed from the top-to-bottom direction is referred to as the left-to-right direction. In addition, in the following description, the X1 direction side in Figure 2, etc., which is one side of the front-to-back direction, is referred to as the "front" side, the X2 direction side in Figure 2, etc., which is the opposite side, is referred to as the "rear" side, the Y1 direction side in Figure 2, etc., which is one side of the left-to-right direction, is referred to as the "right" side, and the Y2 direction side in Figure 2, etc., which is the opposite side, is referred to as the "left" side.

[0042] In this embodiment, the ultraviolet irradiation device 4 is placed on the table 5 so that the left-right direction and the main scanning direction coincide (i.e., so that the front-rear direction and the sub-scanning direction coincide). In this embodiment, printing is performed on the print medium 2 while the print medium 2 is rotated by the rotation mechanism 16 with the inkjet head 3 stopped at a fixed position. In this embodiment, the length of the print medium 2 (length in the axial direction) is longer than the front-rear width of the inkjet head 3, so when printing on the print medium 2, the table 5 is moved in stages in the front-rear direction (sub-scanning direction).

[0043] The ultraviolet irradiation device 4 includes an ultraviolet irradiator 17 that irradiates ultraviolet rays toward the outer peripheral surface of the printing substrate 2 on which ink is adhered, and a cover 18 that has a cover portion 18a that covers the ultraviolet irradiator 17 from above. An opening 18b is formed in the cover portion 18a through which the upper end of the printing substrate 2 is disposed. The ultraviolet irradiator 17 is disposed to the side of the printing substrate 2. Specifically, the ultraviolet irradiator 17 is disposed on the left side of the printing substrate 2. The ultraviolet irradiator 17 irradiates ultraviolet rays onto the printing substrate 2 from the side of the printing substrate 2. In other words, the ultraviolet irradiator 17 irradiates ultraviolet rays onto the printing substrate 2 from the left side of the printing substrate 2.

[0044] In this embodiment, when printing on the substrate 2, the rotation mechanism 16 rotates the substrate 2 counterclockwise when viewed from the front. As described above, the ultraviolet irradiator 17 is disposed on the left side of the substrate 2. That is, the ultraviolet irradiator 17 is disposed to the side of the substrate 2 and downstream of the point at which ink lands on the outer peripheral surface of the substrate 2 in the direction of rotation of the substrate 2 by the rotation mechanism 16. The ultraviolet irradiator 17 also irradiates the substrate 2 with ultraviolet light from the left side of the substrate 2. Therefore, after ink lands on the upper end of the substrate 2, ultraviolet light is irradiated onto the portion of the outer peripheral surface of the substrate 2 where the ink lands, before the substrate 2 rotates 180°.

[0045] The ultraviolet irradiation device 4 also includes two second covers 20 for covering a portion of the opening 18b from the outside in the left-right direction, and a cover position adjustment mechanism 21 for adjusting the left-right position of each of the two second covers 20. That is, the left-right position of each of the two second covers 20 is adjustable. The ultraviolet irradiation device 4 of this embodiment includes four cover position adjustment mechanisms 21. The ultraviolet irradiation device 4 also includes a third cover 22 for covering a portion of the opening 18b in the front-rear direction. The third cover 22 is placed on the cover portion 18a. The ultraviolet irradiation device 4 also includes a first detection mechanism 23 (see FIG. 6) for detecting that the printing medium 2 is held by the rotation mechanism 16, and a second detection mechanism 24 (see FIG. 15, etc.) for detecting that the third cover 22 is placed on the cover portion 18a. Note that the third cover 22 is not shown in FIG. 3.

[0046] (Configuration of the rotation mechanism and its peripheral parts) Figures 4 and 5 are side views illustrating the configuration of the rotation mechanism 16 and its surroundings shown in Figure 3. Figure 6 is an enlarged view illustrating the configuration of part E in Figure 4.

[0047] The rotation mechanism 16 includes a first rotating part 27 that holds one end of the material to be printed 2, a first holding part 28 that rotatably holds the first rotating part 27, a motor 29 for rotating the first rotating part 27, a power transmission mechanism 30 that connects the first rotating part 27 and the motor 29, a second rotating part 32 that holds the other end of the material to be printed 2, a second holding part 33 that rotatably holds the second rotating part 32, a third holding part 34 that rotatably holds the second holding part 33 so that the second holding part 33 can rotate with the left-right direction as the axis of rotation, and a compression coil spring 35 (see Figure 6(A)) as a third biasing member that biases the second holding part 33 against the third holding part 34 in a direction that tilts the second holding part 33 toward the first holding part 28.

[0048] The first rotating unit 27 and the second rotating unit 32 rotate together with the printing substrate 2. The first rotating unit 27 holds the rear end of the printing substrate 2, and the second rotating unit 32 holds the front end of the printing substrate 2. The first rotating unit 27, the first holding unit 28, the motor 29, and the power transmission mechanism 30 are arranged on the rear side of the printing substrate 2. The second rotating unit 32, the second holding unit 33, the third holding unit 34, and the compression coil spring 35 are arranged on the front side of the printing substrate 2. The power transmission mechanism 30 is composed of a belt and a pulley. Note that the power transmission mechanism 30 may also be composed of a gear train.

[0049] The second holding portion 33 is rotatably connected to the upper end of the third holding portion 34. The second holding portion 33 is rotatable relative to the third holding portion 34 about a rotation center shaft 37 that is located on the rear end side of the upper end of the third holding portion 34. The compression coil spring 35 is located forward of the rotation center shaft 37. The compression coil spring 35 contacts the second holding portion 33 from below and urges the second holding portion 33 upward. In other words, the second holding portion 33 is urged by the compression coil spring 35 in the clockwise direction in FIG. 6 about the rotation center shaft 37.

[0050] When the printing material 2 is not attached to the rotation mechanism 16, the second holding part 33 is tilted toward the first holding part 28 by the biasing force of the compression coil spring 35 (see FIG. 6(C)). In other words, when the printing material 2 is not attached to the rotation mechanism 16, the axis of the second rotating part 32 is tilted with respect to the axis of the first rotating part 27. When the printing material 2 is attached to the rotation mechanism 16, the second holding part 33 rotates against the biasing force of the compression coil spring 35 to a position where the axis of the second rotating part 32 and the axis of the printing material 2 coincide.

[0051] The third holding unit 34 is movable in the direction of the axis of the substrate 2, and the position of the third holding unit 34 in the direction of the axis of the substrate 2 is adjustable. In this embodiment, the positions of the second rotating unit 32, the second holding unit 33, and the third holding unit 34 in the direction of the axis of the substrate 2 are adjusted according to the length of the substrate 2. In addition, in this embodiment, the inclination of the rotation mechanism 16 with respect to the horizontal direction when viewed from the left and right is adjustable. In other words, the inclination of the axis of the substrate 2 with respect to the horizontal direction is adjustable. In this embodiment, as shown in FIG. 5, the inclination of the rotation mechanism 16 is adjusted when printing on the outer peripheral surface of the substrate 2 having a truncated cone or conical outer shape.

[0052] The rotation mechanism 16 includes a guide rail 38 for guiding the third holding part 34 in the direction of the axis of the printing medium 2, a guide block 39 that engages with the guide rail 38 and to which the third holding part 34 is fixed, and a rotating frame 40 to which the guide rail 38 is fixed. The rotating frame 40 is formed in an elongated shape that is long and narrow in the direction of the axis of the printing medium 2. The lower end of the first holding part 28 is fixed to the rotating frame 40. In other words, the first rotating part 27 is rotatably attached to the rotating frame 40 via the first holding part 28.

[0053] The guide block 39 engages with the guide rail 38 from above. The guide block 39 is disposed below the second holding portion 33. The third holding portion 34 is fixed to the guide block 39. That is, the second rotating portion 32 is rotatably attached to the rotating frame 40 via the second holding portion 33, the third holding portion 34, the guide block 39, and the guide rail 3. The guide block 39 moves together with the third holding portion 34 in the direction of the axis of the printing medium 2.

[0054] The rotating frame 40 has an elongated screw insertion hole (not shown) formed in the direction of the axis of the printing medium 2. A fixing screw 46 (see FIG. 15) for fixing the third holding part 34 to the rotating frame 40 is inserted into the screw insertion hole. A threaded hole into which the fixing screw 46 engages is formed in the third holding part 34. When the fixing screw 46 is loosened, it becomes possible to move the second rotating part 32, the second holding part 33, and the third holding part 34 along the guide rail 38 in the direction of the axis of the printing medium 2.

[0055] The rotating frame 40 is rotatable relative to a lower frame 41 that constitutes the bottom surface of the ultraviolet irradiation device 4. Specifically, the rotating frame 40 is rotatable relative to the lower frame 41 with the left-right direction as the rotation axis direction. The rotating frame 40 is also rotatable around a rotation center shaft 42 that is disposed on the rear end side of the ultraviolet irradiation device 4. A support frame 43 is fixed to the rear end of the lower frame 41. The rotation center shaft 42 is attached to the support frame 43. The support frames 43 are disposed in two locations spaced apart in the left-right direction. Specifically, the support frames 43 are disposed on both ends of the rotating frame 40 in the left-right direction.

[0056] A guide frame 44 is fixed to the front end of the lower frame 41. The guide frame 44 has guide holes 44a formed therein for guiding the rotating frame 40 in the direction of rotation of the rotating frame 40. The guide holes 44a penetrate the guide frame 44 in the left-right direction. When viewed from the left-right direction, the guide holes 44a have an arc shape with the rotation center shaft 42 as the rotation center. The guide frames 44 are arranged in two locations spaced apart in the left-right direction. Specifically, the guide frames 44 are arranged on both left-right end sides of the rotating frame 40.

[0057] A fixing screw 45 for fixing the front end of the rotating frame 40 to the guide frame 44 is inserted into the guide hole 44a. The fixing screw 45 is a thumb screw. A screw hole into which the fixing screw 45 engages is formed in the front end of the rotating frame 40. When the fixing screw 45 is loosened, the rotating frame 40 can be rotated relative to the lower frame 41, the support frame 43, and the guide frame 44 around the rotation center shaft 42. Furthermore, by rotating the rotating frame 40, the inclination of the rotation mechanism 16 with respect to the horizontal direction can be adjusted.

[0058] In this embodiment, when printing on a printing substrate 2 having a cylindrical outer shape, the rotating frame 40 is fixed so that the direction of the axis of the printing substrate 2 coincides with the front-to-rear direction, as shown in Fig. 4. In other words, when printing on a printing substrate 2 having a cylindrical outer shape, the axis of the printing substrate 2 is positioned on a horizontal plane. Also, when printing on a printing substrate 2 having a truncated cone or cone-shaped outer shape, the inclination of the rotation mechanism 16 is adjusted and the rotating frame 40 is fixed so that the top end of the printing substrate 2 is parallel to the front-to-rear direction, as shown in Fig. 5.

[0059] (Configuration of ultraviolet irradiator and peripheral parts of ultraviolet irradiator) Fig. 7 is a side view illustrating the configuration of the ultraviolet irradiator 17 and its surrounding area shown in Fig. 3. Fig. 8 is a plan view illustrating the state of the ultraviolet irradiator 17 and other components when printing is performed on the printing medium 2 having a truncated cone or cone-shaped outer shape shown in Fig. 5.

[0060] The ultraviolet irradiator 17 includes an LED substrate 48 on which a number of LED chips that emit ultraviolet rays (ultraviolet light) are mounted. The LED substrate 48 is formed in the shape of a long, narrow rectangular plate. When viewed from the left and right, the LED substrate 48 is disposed so that the short side of the rectangular LED substrate 48 coincides with the up-down direction and the long side of the LED substrate 48 coincides with the front-to-back direction. As described above, the ultraviolet irradiator 17 is disposed on the left side of the printing substrate 2. The ultraviolet irradiator 17 emits ultraviolet rays toward the right. In this embodiment, the vertical position of the ultraviolet irradiator 17 is adjustable. Furthermore, the horizontal position of the ultraviolet irradiator 17 and the inclination of the ultraviolet irradiator 17 with respect to the axis of the printing substrate 2 when viewed from the up-down direction are adjustable.

[0061] The ultraviolet irradiator 17 is fixed to a holding portion 49. The holding portion 49 to which the ultraviolet irradiator 17 is attached is placed on a placing portion 50. The upper surface of the placing portion 50 is a plane perpendicular to the up-down direction. One end of a pair of parallel link members 51 is rotatably connected to the placing portion 50. The other end of the link members 51 is rotatably connected to a holding frame 52 fixed to the lower frame 41. The holding frame 52 is arranged below the placing portion 50.

[0062] The link member 51 is rotatable relative to the mounting portion 50 and the holding frame 52 with the left-right direction as the axis of rotation. The pair of link members 51 is arranged at two locations spaced apart in the left-right direction. Specifically, as shown in FIG. 3, the pair of link members 51 are arranged at both ends of the mounting portion 50 and the holding frame 52 in the left-right direction. In this embodiment, the mounting portion 50, the link member 51, and the holding frame 52 form a parallel link mechanism.

[0063] A guide frame 53 is fixed to the front end of the holding frame 52. The guide frame 53 has guide holes 53a formed therein for guiding the mounting portion 50 in the up-down direction. The guide holes 53a penetrate the guide frame 53 in the left-right direction. The guide holes 53a are formed in an arc shape. The guide frames 53 are arranged in two locations with a gap between them in the left-right direction. Specifically, the guide frames 53 are arranged on both left-right end sides of the mounting portion 50 and the holding frame 52.

[0064] A fixing screw 54 for fixing the front end of the mounting unit 50 to the guide frame 53 is inserted into the guide hole 53a. The fixing screw 54 is a thumb screw. A threaded hole into which the fixing screw 54 engages is formed at the front end of the mounting unit 50. Loosening the fixing screw 54 makes it possible to raise and lower the mounting unit 50 relative to the lower frame 41, the holding frame 52, and the guide frame 53. Furthermore, raising and lowering the mounting unit 50 adjusts the vertical position of the ultraviolet irradiator 17. In this embodiment, the vertical position of the ultraviolet irradiator 17 is adjusted in accordance with the outer shape of the printing medium 2 so that ultraviolet rays are irradiated to the optimal location on the outer circumferential surface of the printing medium 2.

[0065] A magnetic sheet 55, which is a sheet-shaped permanent magnet, is attached to the underside of the holding unit 49. The upper surface of the mounting unit 50 is made of a magnetic member formed from a magnetic metal material. The holding unit 49 is fixed to the upper surface of the mounting unit 50 by a magnetic attraction force generated between the magnetic sheet 55 and the upper surface of the mounting unit 50. In this embodiment, the left-right position of the ultraviolet irradiator 17 is adjusted by moving the holding unit 49, which is fixed to the upper surface of the mounting unit 50 by the magnetic attraction force, in the left-right direction. Furthermore, the inclination of the ultraviolet irradiator 17 with respect to the axis of the printing medium 2 when viewed from the top-down direction is adjusted by tilting the holding unit 49, which is fixed to the upper surface of the mounting unit 50 by the magnetic attraction force, in the horizontal plane.

[0066] In this embodiment, when printing on a printing substrate 2 having a cylindrical outer shape, the ultraviolet irradiator 17 is installed so that the ultraviolet light emission surface of the ultraviolet irradiator 17 is parallel to the front-to-rear direction. When printing on a printing substrate 2 having a truncated cone or conical outer shape, the inclination of the ultraviolet irradiator 17 is adjusted and the ultraviolet irradiator 17 is installed so that the ultraviolet light emission surface of the ultraviolet irradiator 17 is parallel to the left edge of the printing substrate 2, as shown in FIG.

[0067] (Configuration of cover, second cover, cover position adjustment mechanism, and third cover) FIG. 9 is a plan view of the cover 18, second cover 20, cover position adjustment mechanism 21, and third cover 22 shown in FIG. 3. FIG. 10 is a side view of the cover 18, second cover 20, cover position adjustment mechanism 21, and third cover 22 shown in FIG. 9. FIG. 11 is a front view of the cover 18, second cover 20, cover position adjustment mechanism 21, and third cover 22 shown in FIG. 9. FIG. 12 is a front view showing the upper cover 58 and lower cover 59 shown in FIG. 11 in a separated state. FIG. 13(A) is an enlarged view illustrating the configuration of portion F in FIG. 10, and FIG. 13(B) is an enlarged view illustrating the configuration of portion G in FIG. 10. FIG. 14 is a front view illustrating the positional relationship between the cover portion 18a and second cover 20 shown in FIG. 9 and the printing medium 2.

[0068] The cover 18 includes an upper cover 58 including a cover portion 18a, and a lower cover 59 to which the upper cover 58 is attached at its upper end. The cover 18 in this embodiment is composed of one upper cover 58 and two lower cover portions 59. The two lower cover portions 59 are arranged with a gap between them in the left-right direction. The lower cover 59 arranged on the right side supports the right end portion of the upper cover 58 from below, and the lower cover 59 arranged on the left side supports the left end portion of the upper cover 58 from below. In this embodiment, the position of the cover 18 in the up-down direction is adjustable. Specifically, the position of the lower cover 59 in the up-down direction is adjustable.

[0069] The cover portion 18a is formed in a rectangular flat plate shape. The cover portion 18a is disposed so that the thickness direction of the cover portion 18a coincides with the up-down direction. The cover portion 18a is disposed so that the long side direction of the cover portion 18a coincides with the front-rear direction. The cover portion 18a forms the upper surface of the cover 18 and also forms the upper surface of the upper cover portion 58.

[0070] The opening 18b is a through-hole that penetrates the cover portion 18a in the vertical direction. The opening 18b is formed in a rectangular shape that is elongated in the front-rear direction. The length of the opening 18b in the front-rear direction is longer than the length of the longest printing medium 2 among the printing mediums 2 to be printed by the printing device 1. A guide plate 60 for positioning the third cover 22 in the left-right direction is fixed to the upper surface of the cover portion 18a. The guide plate 60 is formed in a flat rectangular shape that is elongated in the front-rear direction. The guide plates 60 are arranged in two locations with a gap between them in the left-right direction. The two guide plates 60 are arranged so as to sandwich the opening 18b in the left-right direction.

[0071] The cover upper part 58 includes two flat side plates 58a that form the front-to-rear side surfaces of the cover upper part 58, and two flat side plates 58b that form the left-to-right side surfaces of the cover upper part 58. The side plates 58a are arranged so that the thickness direction of the side plates 58a coincides with the front-to-rear direction, and the side plates 58b are arranged so that the thickness direction of the side plates 58b coincides with the left-to-right direction. The side plates 58a are connected to both ends of the cover part 18a in the front-to-rear direction, and the side plates 58b are connected to both ends of the cover part 18a in the left-to-right direction.

[0072] The cover upper part 58 also includes an attachment part 58c to which a pressing member 68 (described later) constituting part of the cover position adjustment mechanism 21 is attached, and a holding part 58d that holds the second cover 20. The attachment part 58c is formed in the shape of a generally rectangular flat plate that is elongated in the front-rear direction. The attachment part 58c is arranged so that the thickness direction of the attachment part 58c coincides with the up-down direction. The attachment part 58c is arranged below the cover part 18a. The attachment parts 58c are also arranged in two locations, at the right and left ends of the cover upper part 58. A magnetic sheet 61, which is a sheet-like permanent magnet, is attached to the underside of the attachment part 58c. That is, the cover upper part 58 includes the magnetic sheet 61. In this embodiment, the magnetic sheet 61 is an attractive member made of a permanent magnet.

[0073] The holding portions 58d are arranged at two locations spaced apart in the left-right direction at the rear end of the cover upper portion 58, and at two locations spaced apart in the left-right direction forward of the center of the cover upper portion 58 in the front-to-rear direction. The two holding portions 58d arranged at the rear end of the cover upper portion 58 are arranged on both sides of the opening 18b in the left-to-right direction. Similarly, the two holding portions 58d arranged forward of the center of the cover upper portion 58 in the front-to-rear direction are arranged on both sides of the opening 18b in the left-to-right direction.

[0074] The holding portion 58d is composed of a flat fixing plate 62 fixed to the lower surface of the cover portion 18a, and a flat mounting plate 63 fixed to the lower surface of the fixing plate 62. The mounting plate 63 protrudes inward in the front-to-rear direction from the fixing plate 62. The upper surface of the mounting plate 63 is a flat surface that is perpendicular to the up-down direction. As shown in FIG. 13, a gap is formed between the lower surface of the cover portion 18a and the upper surface of the mounting plate 63. Both front-to-rear end portions of the second cover 20 are disposed in this gap.

[0075] The cover lower part 59 is made of a magnetic material. For example, the cover lower part 59 is made of a magnetic metal material. The cover lower part 59 is fixed to a fixed frame 64. The lower end of the fixed frame 64 is fixed to the lower frame 41. The fixed frame 64 is fixed to four locations of the lower frame 41: the right front end, right rear end, left front end, and left rear end. The cover lower part 59 includes a fixed part 59a fixed to the fixed frame 64 and a mounting part 59b on which the mounting part 58c is mounted.

[0076] The mounting portion 59b is formed in the shape of a rectangular flat plate that is elongated in the front-rear direction. The mounting portion 59b is arranged so that the thickness direction of the mounting portion 59b coincides with the up-down direction. The mounting portion 59b forms the upper surface of the lower cover 59. As described above, the lower cover 59 is formed of a magnetic material. That is, the mounting portion 59b is formed of a magnetic material. The upper cover 58 is fixed to the upper surface of the mounting portion 59b by a magnetic attraction force generated between the magnetic sheet 61 and the upper surface of the mounting portion 59b. That is, the upper cover 58 is attached to the lower cover 59 by a magnetic attraction force generated between the magnetic sheet 61 and the upper surface of the mounting portion 59b. In this embodiment, the mounting portion 59b is made of a magnetic material and serves as an attracted member that is attracted to the magnetic sheet 61, which is an attracting member.

[0077] In this embodiment, the upper cover 58 attached to the lower cover 59 is positioned horizontally relative to the lower cover 59 by the inner surfaces of the side plate portions 58b in the left-right direction and the end surfaces of the mounting portions 59b. Therefore, when the upper cover 58 is attached to the lower cover 59, the upper cover 58 is automatically positioned horizontally relative to the lower cover 59.

[0078] The fixed portions 59a are disposed at two locations, the front end and the rear end, of the cover lower portion 59. As shown in FIG. 10, the fixed portions 59a are formed with guide holes 59c for guiding the cover lower portion 59 in the up-down direction relative to the fixing frame 64. The guide holes 59c penetrate the fixed portions 59a in the left-right direction. The guide holes 59c are formed as elongated holes that are long in the up-down direction. Fixing screws 65 for fixing the cover lower portion 59 to the fixing frame 64 are inserted into the guide holes 59c. The fixing frame 64 is formed with screw holes into which the fixing screws 65 engage.

[0079] Loosening the fixing screws 65 makes it possible to raise and lower the cover lower part 59 relative to the lower frame 41 and the fixed frame 64. Furthermore, by raising and lowering the cover lower part 59, the position of the cover lower part 59 in the up and down direction can be adjusted. In other words, loosening the fixing screws 65 makes it possible to raise and lower the cover 18 relative to the lower frame 41 and the fixed frame 64, and by raising and lowering the cover 18, the position of the cover 18 in the up and down direction can be adjusted.

[0080] The second cover 20 is mainly composed of a flat plate portion formed in a generally rectangular flat plate shape that is elongated in the front-rear direction. The flat plate portion of the second cover 20 is arranged so that the thickness direction of the second cover 20 coincides with the up-down direction. The lower surface of the flat plate portion of the second cover 20 is brushed. The second cover 20 is arranged below the cover portion 18a. As described above, both ends of the second cover 20 in the front-rear direction are arranged in the gap between the lower surface of the cover portion 18a and the upper surface of the mounting plate 63, and the second cover 20 is held by the cover 18. Specifically, the second cover 20 is held by the cover upper portion 58. The second cover 20 is also held by the cover 18 so that it can slide in the left-right direction.

[0081] The length of the second cover 20 in the front-rear direction is shorter than the length of the opening 18b in the front-rear direction. In the front-rear direction, the rear end of the second cover 20 and the rear end of the opening 18b are positioned at approximately the same position. One of the two second covers 20 is positioned to the right of the center of the opening 18b in the left-right direction, so that it can cover part of the opening 18b from the right side. The other second cover 20 is positioned to the left of the center of the opening 18b in the left-right direction, so that it can cover part of the opening 18b from the left side.

[0082] The cover position adjustment mechanisms 21 are disposed at two locations on the outer left-right sides of the front ends of the two second covers 20 and two locations on the outer left-right sides of the rear ends of the two second covers 20. The cover position adjustment mechanisms 21 are held by the cover upper portion 58. The cover position adjustment mechanisms 21 include a pressing member 68 that contacts the second cover 20 from the outer left-right side and presses the second cover 20 inward in the left-right direction, a tension coil spring 69 as a pressing member that presses the second cover 20 outward in the left-right direction, and an adjustment screw 70 that is rotatably held by the cover 18 and engages with the pressing member 68.

[0083] The pressing member 68 is held by the cover 18 so as to be able to slide in the left-right direction. The pressing member 68 is placed on the mounting portion 58c of the cover upper portion 58. The pressing member 68 is disposed below the cover portion 18a. The pressing members 68 are disposed outside the two second covers 20 in the left-right direction. The pressing member 68 disposed on the right side comes into contact with the right end surface of the second cover 20 disposed on the right side and presses the second cover 20 to the left. The pressing member 68 disposed on the left side comes into contact with the left end surface of the second cover 20 disposed on the left side and presses the second cover 20 to the right.

[0084] As shown in Fig. 9, the pressing member 68 is formed with a guide hole 68a for guiding the pressing member 68 in the left-right direction. A guide screw 71 is inserted into the guide hole 68a from above. A threaded hole into which the guide screw 71 engages is formed in the mounting portion 58c. The pressing member 68 is slidable in the left-right direction along the guide screw 71. In addition, the pressing member 68 is formed with a threaded hole into which an adjustment screw 70 engages.

[0085] One end of the tension coil spring 69 engages with the second cover 20. The other end of the tension coil spring 69 engages with a spring engagement portion formed on the mounting portion 58c. The tension coil springs 69 are arranged on the outer side of the two second covers 20 in the left-right direction. The tension coil spring 69 arranged on the right side biases the second cover 20 arranged on the right side to the right, and the tension coil spring 69 arranged on the left side biases the second cover 20 arranged on the left side to the left. The adjustment screw 70 is a thumbscrew. The adjustment screw 70 is rotatably held by the side plate portion 58b. The head of the adjustment screw 70 is arranged on the outer side of the side plate portion 58b in the left-right direction.

[0086] In this embodiment, turning the adjustment screw 70 causes the second cover 20 to slide left and right. Also, in this embodiment, the cover position adjustment mechanisms 21 are disposed on the front and rear ends of the second cover 20, so that by shifting the left and right positions of the pressing member 68 disposed on the front side and the rear side, it is possible to adjust the tilt of the second cover 20 relative to the front-to-rear direction when viewed from the top and bottom, as shown in Fig. 8 .

[0087] The third cover 22 is formed in the shape of a rectangular flat plate. As described above, the third cover 22 is placed on the cover portion 18a. The third cover 22 is disposed between the two guide plates 60. The third cover 22 covers the front end portion of the opening 18b. The front end of the third cover 22 is disposed forward of the front end of the opening 18b. A detectable member 72 having a detectable portion 72a that is detected by the second detection mechanism 24 is attached to the third cover 22. The detectable member 72 is fixed to the lower surface of the third cover 22. The detectable member 72 extends downward from the lower surface of the third cover 22, and the lower end of the detectable member 72 forms the detectable portion 72a.

[0088] In this embodiment, the vertical position of the cover 18 and the horizontal position of the second cover 20 are adjusted according to the outer diameter of the material to be printed 2. Specifically, for example, when the outer diameter of the material to be printed 2 is relatively large, the vertical position of the cover 18 and the horizontal position of the second cover 20 are adjusted so that the gap G1 between the left and right edges of the opening 18b and the outer peripheral surface of the material to be printed 2 is the minimum required size, as shown in FIG. 14(A). Also, for example, when the outer diameter of the material to be printed 2 is relatively small, the vertical position of the cover 18 and the horizontal position of the second cover 20 are adjusted so that the gap G2 between the end face of the second cover 20 and the outer peripheral surface of the material to be printed 2 is the minimum required size, as shown in FIG. 14(B).

[0089] In this embodiment, when printing on a print medium 2 having a truncated cone or conical outer shape, the inclination of the second cover 20 is adjusted according to the shape of the print medium 2, as shown in FIG. 8 . Specifically, the inclination of the second cover 20 is adjusted according to the shape of the print medium 2 so that the gap G2 between the end face of the second cover 20 and the outer peripheral surface of the print medium 2 is constant throughout the entire area in the front-to-rear direction. The gaps G1 and G2 are, for example, 2 mm. When adjusting the left-to-right direction and the inclination of the second cover 20, a shim plate (for example, a shim plate with a thickness of 2 mm) is placed between the end face of the second cover 20 and the outer peripheral surface of the print medium 2, and the second cover 20 is moved to press the end face of the second cover 20 and the outer peripheral surface of the print medium 2 against the shim plate.

[0090] In this embodiment, the position of the third cover 22 in the front-to-rear direction is shifted depending on the length of the printing medium 2. If the length of the printing medium 2 is relatively short and the front end of the opening 18b cannot be covered by the third cover 22, an additional cover is placed in front of the third cover 22. However, it is also possible to prepare multiple types of third covers 22 with different lengths in the front-to-rear direction and select and attach the third cover 22 that covers the entire front end portion of the opening 18b.

[0091] (Configuration of the first detection mechanism and the second detection mechanism) FIG. 15 is a plan view for explaining the configuration of part E in FIG.

[0092] The first detection mechanism 23 is an interlock switch having a contact member that constitutes a contact portion and a lever 23a that presses the contact member (see FIG. 6). The first detection mechanism 23 is attached to the third holding portion 34. The first detection mechanism 23 is disposed below the second holding portion 33. The lever 23a is disposed above the main body of the first detection mechanism 23. When the printing medium 2 is not attached to the rotation mechanism 16, the second holding portion 33 is tilted toward the first holding portion 28 by the biasing force of the compression coil spring 35, and the lever 23a is not in contact with the contact member (see FIG. 6(C)). Therefore, the first detection mechanism 23 is in the OFF state.

[0093] In this state, when the printing medium 2 is attached to the rotation mechanism 16, the second holding portion 33 rotates against the biasing force of the compression coil spring 35 and presses the lever 23a (see FIGS. 6A and 6B). When the lever 23a, pressed by the second holding portion 33, presses the contact member, the first detection mechanism 23 turns on and the second holding portion 33 is detected by the first detection mechanism 23. In other words, when the printing medium 2 is attached to the rotation mechanism 16, the second holding portion 33 rotates relative to the third holding portion 34 against the biasing force of the compression coil spring 35 to a position where it can be detected by the first detection mechanism 23. Furthermore, when the second holding portion 33 is detected by the first detection mechanism 23, the first detection mechanism 23 detects that the printing medium 2 is being held by the rotation mechanism 16.

[0094] Similar to the first detection mechanism 23, the second detection mechanism 24 is an interlock switch having a contact member constituting a contact portion and a lever 24a that presses the contact member. The second detection mechanism 24 is fixed to a fixed member 73. The fixed member 73 is fixed to the second holding portion 33. That is, the second detection mechanism 24 is attached to the second holding portion 33 via the fixed member 73. The second detection mechanism 24 is disposed on the front side of the second rotating portion 32. The lever 24a is disposed on the front side of the main body of the second detection mechanism 24. As shown in FIG. 15 , the fixed member 73 is formed with a guide groove 73a for guiding the detected portion 72a of the detected member 72 to the lever 24a. The guide groove 73a is formed from the front end of the fixed member 73 toward the rear side.

[0095] When the third cover 22 is placed at a predetermined position on the cover unit 18a with the medium to be printed 2 held by the rotation mechanism 16, the detectable portion 72a presses the lever 24a. When the lever 24a, pressed by the detectable portion 72a, presses the contact member, the second detection mechanism 24 is turned on, and the detectable portion 72a is detected by the second detection mechanism 24. In other words, when the third cover 22 is placed at a predetermined position on the cover unit 18a with the medium to be printed 2 held by the rotation mechanism 16, the detectable portion 72a is detected by the second detection mechanism 24. Furthermore, when the detectable portion 72a is detected by the second detection mechanism 24, the second detection mechanism 24 detects that the third cover 22 is placed on the cover unit 18a.

[0096] In this embodiment, when the first detection mechanism 23 detects that the printing medium 2 is held by the rotation mechanism 16, irradiation of ultraviolet light by the ultraviolet irradiator 17 becomes possible. More specifically, when the first detection mechanism 23 detects that the printing medium 2 is held by the rotation mechanism 16 and the second detection mechanism 24 detects that the third cover 22 is placed on the cover portion 18a, irradiation of ultraviolet light by the ultraviolet irradiator 17 becomes possible.

[0097] (Main effect of this form) As described above, in this embodiment, the ultraviolet irradiator 17 is disposed to the side of the substrate 2, and irradiates ultraviolet light from the side of the substrate 2 toward the outer peripheral surface of the substrate 2 on which the ink that has landed at the upper end of the substrate 2 is attached. Specifically, the ultraviolet irradiator 17 irradiates ultraviolet light onto the portion of the outer peripheral surface of the substrate 2 on which the ink has landed, after the ink has landed on the upper end of the substrate 2 and before the substrate 2 rotates 180°. Therefore, in this embodiment, it is possible to irradiate ultraviolet light onto the ink that has landed on the outer peripheral surface of the substrate 2 more quickly than in the printing device described in Patent Document 1, where the ultraviolet irradiator 17 is disposed below the substrate 2.

[0098] In this embodiment, the ultraviolet irradiator 17 is covered from above by the cover portion 18a. Therefore, in this embodiment, even when the ultraviolet irradiator 17 arranged to the side of the print medium 2 irradiates ultraviolet rays from the side of the print medium 2, the cover portion 18a can prevent ultraviolet rays from being irradiated onto the nozzle surface (lower surface) of the inkjet head 3 arranged above the print medium 2. Therefore, in this embodiment, even when the ultraviolet irradiator 17 is arranged to the side of the print medium 2, it is possible to prevent the nozzles of the inkjet head 3 from becoming clogged.

[0099] In this embodiment, the vertical position of the cover 18 is adjustable, and the left-right position of the second cover 20 is adjustable. Furthermore, in this embodiment, the vertical position of the cover 18 and the left-right position of the second cover 20 are adjusted according to the outer diameter of the material to be printed 2 so that the gap G1 between the left-right edges of the opening 18b and the outer peripheral surface of the material to be printed 2 and the gap G2 between the end face of the second cover 20 and the outer peripheral surface of the material to be printed 2 are kept to the minimum necessary sizes. Therefore, in this embodiment, even if the ultraviolet irradiator 17 is disposed to the side of the material to be printed 2 and the outer diameter of the material to be printed 2 changes, it is possible for the cover portion 18a and the second cover 20 to suppress irradiation of ultraviolet light onto the nozzle surface of the inkjet head 3.

[0100] In this embodiment, the cover position adjustment mechanism 21 includes a pressing member 68 that contacts the second cover 20 from the outside in the left-right direction and presses the second cover 20 inward in the left-right direction, a tension coil spring 69 that urges the second cover 20 outward in the left-right direction, and an adjustment screw 70 that is rotatably held by the cover 18 and engages with the pressing member 68, and turning the adjustment screw 70 causes the second cover 20 to slide in the left-right direction. Therefore, in this embodiment, the left-right position of the second cover 20 can be adjusted by the simple task of turning the adjustment screw 70.

[0101] In this embodiment, the upper cover 58 is attached to the lower cover 59 by a magnetic attraction force generated between the magnet sheet 61 and the upper surface of the mounting portion 59b. Therefore, in this embodiment, the upper cover 58 including the cover portion 18a can be easily removed from the lower cover 59. Therefore, in this embodiment, when removing the printed substrate 2 from the rotation mechanism 16 and attaching the unprinted substrate 2 to the rotation mechanism 16 (i.e., when replacing the substrate 2), the upper cover 58 can be easily attached and detached, and as a result, the replacement of the substrate 2 can be easily performed.

[0102] Furthermore, in this embodiment, because the upper cover 58 holds the second cover 20 and the cover position adjustment mechanism 21, it is possible to maintain the relative positioning of the cover portion 18a and the second cover 20 after the once-removed upper cover 58 is attached to the lower cover 59. Furthermore, in this embodiment, because the attachment portion 58c of the upper cover 58 is placed on the placement portion 59b of the lower cover 59, it is possible to maintain the vertical positions of the cover 18a and the second cover 20 after the once-removed upper cover 58 is attached to the lower cover 59. Furthermore, in this embodiment, when the upper cover 58 is attached to the lower cover 59, the upper cover 58 is automatically positioned horizontally relative to the lower cover 59.

[0103] Therefore, in this embodiment, even if the cover upper part 58 is attached or detached, it is possible to suppress fluctuations in the relative position between the second cover 20, whose position has been adjusted in the left-right direction to match the outer diameter of the print medium 2, and the print medium 2, and it is also possible to suppress fluctuations in the relative position between the cover 18, whose position has been adjusted in the up-down direction to match the outer diameter of the print medium 2, and the print medium 2. As a result, in this embodiment, when subsequently printing on a print medium 2 with the same outer diameter, it is possible to avoid the hassle of readjusting the left-right position of the second cover 20 after attaching or detaching the cover upper part 58, and it is also possible to avoid the hassle of readjusting the up-down position of the cover 18.

[0104] In this embodiment, the third cover 22 covers the front end portion of the opening 18b. Therefore, in this embodiment, by arranging the third cover 22 in an appropriate position depending on the length of the printing medium 2, it is possible to prevent ultraviolet light that has passed through the front end portion of the opening 18b from irradiating the nozzle surface of the inkjet head 3, even if the length of the printing medium 2 to be printed by the printing device 1 changes.

[0105] In this embodiment, the vertical position of the ultraviolet irradiator 17 is adjustable, and the vertical position of the ultraviolet irradiator 17 is adjusted according to the outer shape of the substrate 2 so that ultraviolet light is irradiated to the optimal location on the outer circumferential surface of the substrate 2. Therefore, in this embodiment, even if the outer shape of the substrate 2 to be printed by the printing device 1 changes, it is possible to arrange the ultraviolet irradiator 17 in a more appropriate position for curing the ink attached to the substrate 2.

[0106] In this embodiment, the inclination of the rotation mechanism 16 relative to the horizontal when viewed from the left and right is adjustable, and when printing on a print substrate 2 having a truncated cone or conical outer shape, the inclination of the rotation mechanism 16 is adjusted so that the upper end of the print substrate 2 is parallel to the front-to-rear direction. Therefore, in this embodiment, even when printing on a print substrate 2 having a truncated cone or conical outer shape, it is possible to keep the distance between the outer surface of the print substrate 2 and the nozzle face of the inkjet head 3 constant throughout the axial direction of the print substrate 2. Therefore, in this embodiment, appropriate printing on the print substrate 2 is possible.

[0107] In this embodiment, the inclination of the ultraviolet irradiator 17 with respect to the axis of the substrate 2 when viewed from the top and bottom is adjustable, and when printing on a substrate 2 having a truncated cone or conical outer shape, the inclination of the ultraviolet irradiator 17 is adjusted so that the ultraviolet light emission surface of the ultraviolet irradiator 17 is parallel to the left end of the substrate 2. Therefore, in this embodiment, even if the outer shape of the substrate 2 is truncated cone or conical, it is possible to keep the distance between the outer surface of the substrate 2 and the ultraviolet irradiator 17 constant throughout the axial direction of the substrate 2. Therefore, in this embodiment, it is possible to appropriately cure the ink adhered to the outer surface of the substrate 2.

[0108] In this embodiment, when the first detection mechanism 23 detects that the printing medium 2 is held by the rotation mechanism 16, the ultraviolet irradiator 17 is able to irradiate ultraviolet light. That is, in this embodiment, if the printing medium 2 is not held by the rotation mechanism 16, the ultraviolet irradiator 17 does not irradiate ultraviolet light. Therefore, in this embodiment, it is possible to prevent the ultraviolet irradiator 17 from irradiating ultraviolet light in a state where the operator of the printing device 1 can touch the ultraviolet irradiator 17. Therefore, in this embodiment, it is possible to improve the safety of the ultraviolet irradiator 4.

[0109] Furthermore, in this embodiment, when the second detection mechanism 24 detects that the third cover 22 is placed on the cover portion 18a, the ultraviolet irradiator 17 is enabled to irradiate ultraviolet rays, and therefore the ultraviolet irradiator 17 does not irradiate ultraviolet rays unless the cover 18 and the third cover 22 are attached. Therefore, in this embodiment, it is possible to effectively prevent the ultraviolet irradiator 17 from irradiating ultraviolet rays in a state where the operator of the printing device 1 can touch the ultraviolet irradiator 17, and as a result, it is possible to further improve the safety of the ultraviolet irradiator 4.

[0110] In particular, in this embodiment, when the first detection mechanism 23 detects that the printing material 2 is being held by the rotating mechanism 16 and the second detection mechanism 24 detects that the third cover 22 is being placed on the cover portion 18a, it becomes possible for the ultraviolet irradiator 17 to irradiate ultraviolet rays, which makes it possible to more effectively prevent the ultraviolet irradiator 17 from irradiating ultraviolet rays in a state where the operator of the printing device 1 can touch the ultraviolet irradiator 17.Therefore, in this embodiment, it is possible to further increase the safety of the ultraviolet irradiation device 14.

[0111] In this embodiment, the second detection mechanism 24 is attached to the second holding part 33, whose position is adjusted in the direction of the axis of the printing medium 2 according to the length of the printing medium 2. Therefore, in this embodiment, even when the third cover 22 is moved according to the length of the printing medium 2, for example, the second detection mechanism 24 can detect that the third cover 22 has been placed in an appropriate position on the cover part 18a.

[0112] (Example of modification to the peripheral part of the rotation mechanism) Fig. 16 is a side view illustrating the configuration of the peripheral part of a rotation mechanism 16 according to another embodiment of the present invention. Fig. 17 is a view illustrating the configuration of the peripheral part of the rotation mechanism 16 from the direction GG in Fig. 16(A). Fig. 18 is a side view showing a support frame 80, an engaging member 81, etc. from the direction HH in Fig. 17. Fig. 19 is a view illustrating the configuration of a JJ cross section in Fig. 17. Fig. 20 is a view illustrating the configuration of a KK cross section in Fig. 17. In Figs. 16 to 20, the same reference numerals are used to designate the same components as those in the above-described embodiment.

[0113] In the embodiment described above, two guide frames 44 are fixed to the front end of the lower frame 41 with a gap between them in the left-right direction, but in this modified example, a support frame 80 is fixed to the front end of the lower frame 41 instead of one of the two guide frames 44. In this modified example, the ultraviolet irradiation device 4 includes an engaging member 81 held by the rotation mechanism 16 (specifically, held by the rotating frame 40) so as to be rotatable about the left-right direction as the axis of rotation, a tension coil spring 82 as a second biasing member that biases the engaging member 81 to one side in the rotation direction of the engaging member 81 relative to the rotation mechanism 16, a rotation shaft 83 that is the rotation center of the engaging member 81 relative to the rotating frame 40, and an eccentric cam 84 fixed to the rotation shaft 83.

[0114] As described above, the rotating frame 40 is rotatable relative to the lower frame 41 with the left-right direction as the rotation axis. The support frame 43 is fixed to the rear end of the lower frame 41, and the rotation center shaft 42, which serves as the rotation center of the rotating frame 40, is attached to the support frame 43. That is, the rotating frame 40 is connected to the support frame 43 so as to enable the rotating frame 40 to rotate with the left-right direction as the rotation axis. In this modified example, the lower frame 41 and the support frame 43 form a base frame 85 to which the rotation mechanism 16 is connected at its rear end, which is one end in the front-rear direction, so as to enable the rotation mechanism 16 to rotate with the left-right direction as the rotation axis. The rear end of the rotating frame 40 is rotatably connected to the rear end of the base frame 85. Note that the support frame 43 is not shown in FIG. 16 .

[0115] The support frame 80 is fixed to the front end of the lower frame 41. That is, the support frame 80 is fixed to the front end, which is the other end in the front-rear direction, of the base frame 85. The guide frame 44 is disposed on the right side of the rotating frame 40, and the support frame 80 is disposed on the left side of the rotating frame 40. The support frame 80 is formed with guide holes 80a corresponding to the guide holes 44a of the guide frame 44. The support frame 80 is also formed with a vertically elongated through hole 80b that penetrates the support frame 80 in the left-right direction. The through hole 80b is formed in front of the guide hole 80a.

[0116] The front side surface of the through hole 80b is a stepped portion 80d in which a plurality of step surfaces 80c arranged in the vertical direction are formed. That is, the support frame 80 is provided with a stepped portion 80d. When viewed from the left-right direction, the plurality of step surfaces 80c are arranged on an arc with the rotation central axis 42 as the center of curvature. The plurality of step surfaces 80c face upward. A step S (see FIG. 18) between adjacent step surfaces 80c in the vertical direction is constant. Specifically, the step S is constant in the circumferential direction around the rotation central axis 42.

[0117] A scale plate 87 having a scale 86 marking it that indicates the angle of the rotating frame 40 relative to the front-to-rear direction when viewed from the left-to-right direction is fixed to the guide frame 44 or the support frame 80. That is, a scale plate 87 having a scale 86 marking it that indicates the angle of the rotation mechanism 16 relative to the horizontal direction when viewed from the left-to-right direction is fixed to the guide frame 44 or the support frame 80.

[0118] The rotating shaft 83 is arranged so that its axial direction coincides with the left-right direction. The eccentric cam 84 is an eccentric disk cam formed in a disk shape. The eccentric cams 84 are fixed to both ends of the rotating shaft 83, and the two eccentric cams 84 are rotatable together with the rotating shaft 83. The centers of the eccentric cams 84 are offset from the axis of the rotating shaft 83. The eccentricity D (see Figure 20(A)), which is the distance between the center of the eccentric cam 84 and the axis of the rotating shaft 83, is equal to half the step S between adjacent step surfaces 80c in the vertical direction.

[0119] The rotating frame 40 is formed with a cam mounting hole 40a in which an eccentric cam 84 is mounted (see FIG. 20). Specifically, the cam mounting hole 40a is formed in the front end of a side surface portion 40b that constitutes the left and right side surface of the rotating frame 40. The cam mounting hole 40a is formed in an elongated hole shape. The eccentric cam 84 is rotatably held by the side surface portion 40b. That is, a rotating shaft 83 to which the eccentric cam 84 is fixed is rotatably held by the rotating frame 40 via the eccentric cam 84. Specifically, both ends of the rotating shaft 83 are rotatably held by the front end of the rotating frame 40 via the eccentric cam 84. The rotating shaft 83 and the eccentric cam 84 are rotatable relative to the rotating frame 40, with the left and right direction being the rotation axis direction.

[0120] Both ends of the rotating shaft 83 protrude outward in the left-right direction beyond the rotating frame 40. The right end of the rotating shaft 83 is inserted into the guide hole 44a of the guide frame 44, and the left end of the rotating shaft 83 is inserted into the guide hole 80a of the support frame 80. The right end of the rotating shaft 83 protrudes to the right beyond the guide frame 44, and the left end of the rotating shaft 83 protrudes to the left beyond the support frame 80. A clamp lever 88 with an eccentric cam is attached to the right end of the rotating shaft 83 that protrudes to the right beyond the guide frame 44.

[0121] The engagement member 81 is disposed between the two side surface portions 40b in the left-right direction. The engagement member 81 is disposed adjacent to the right side of the side surface portion 40b disposed on the left side. An insertion hole through which the rotation shaft 83 is inserted is formed in the engagement member 81. The engagement member 81 is rotatably held at the front end of the rotating frame 40 via the rotation shaft 83 and an eccentric cam 84. The rotation shaft 83 is rotatable relative to the engagement member 81. The engagement member 81 has a mounting portion 81a that is placed on the stepped surface 80c (see FIGS. 17 and 18). The mounting portion 81a is disposed at the front lower end of the engagement member 81, and is disposed forward and below the rotation shaft 83. The mounting portion 81a is disposed at the left end of the engagement member 81.

[0122] One end of the tension coil spring 82 engages with the rear upper end of the engaging member 81. The other end of the tension coil spring 82 engages with the spring engaging portion 40c arranged at the front end of the rotating frame 40. The spring engaging portion 40c is arranged behind the engaging member 81. When viewed from the right side, the tension coil spring 82 biases the engaging member 81 in a clockwise direction (clockwise direction in Figure 19) around the rotating shaft 83. The mounting portion 81a arranged at the front lower end of the engaging member 81 is arranged behind the stepped portion 80d. The tension coil spring 82 biases the engaging member 81 in a direction in which the mounting portion 81a faces the stepped portion 80d.

[0123] The mounting portion 81a is placed on the step surface 80c by the weight of the rotation mechanism 16. Furthermore, since the engaging member 81 is biased in a direction in which the mounting portion 81a moves toward the step portion 80d, when the rotating frame 40 is rotated relative to the base frame 85 so that the front end portion of the rotating frame 40 rises, the mounting portion 81a is automatically placed on the step surface 80c that corresponds to the angle of the rotating frame 40 with respect to the horizontal direction.

[0124] When the engaging member 81 is rotated against the biasing force of the tension coil spring 82 (i.e., when the engaging member 81 is rotated counterclockwise as viewed from the right side so that the mounting portion 81a moves away from the stepped portion 80d), the mounting portion 81a comes off the stepped surface 80c. Therefore, when the engaging member 81 is rotated against the biasing force of the tension coil spring 82, it becomes possible to rotate the rotating frame 40 relative to the base frame 85 so that the front end of the rotating frame 40 moves downward. A finger hook 81b is formed on the front upper end of the engaging member 81 for rotating the engaging member 81 against the biasing force of the tension coil spring 82.

[0125] In this modified example, when the eccentric cam 88a of the clamp lever 88 is positioned as shown by the two-dot chain line in Fig. 17, it becomes possible to rotate the rotating frame 40 relative to the base frame 85. On the other hand, when the clamp lever 88 is rotated with the front-to-rear direction as the axis of rotation so that the eccentric cam 88a is positioned as shown by the solid line in Fig. 17, the front end of the rotating frame 40 becomes fixed to the guide frame 44 and the support frame 80, and it becomes impossible to rotate the rotating frame 40 relative to the base frame 85.

[0126] On the left side of the support frame 80, the rotating shaft 83 is inserted into a washer 89, and the washer 89 is fixed to the rotating shaft 83. On the right side of the guide frame 44 and to the left of the clamp lever 88, the rotating shaft 83 is inserted into a washer 89, and the washer 89 is movable in the left-right direction relative to the rotating shaft 83. Therefore, when the clamp lever 88 is rotated so that the eccentric cam 88a is positioned as shown by the solid line in FIG. 17 , the guide frame 44, the support frame 80, and the rotating frame 40 are sandwiched between the two washers 89, and the front end of the rotating frame 40 is fixed to the guide frame 44 and the support frame 80.

[0127] In this modified example, the tilt of the rotation mechanism 16 with respect to the horizontal direction is adjusted by moving the eccentric cam 88a of the clamp lever 88 to the position shown by the two-dot chain line in Figure 17 and rotating the rotating frame 40 with respect to the base frame 85. To adjust the tilt of the rotation mechanism 16 with respect to the horizontal direction, the operator of the printing apparatus 1 first manually rotates the rotating frame 40 with respect to the base frame 85 so that the front end of the rotating frame 40 rises. When the rotating frame 40 is rotated in this manner, the mounting portion 81a is automatically placed on a step surface 80c that corresponds to the angle of the rotating frame 40 with respect to the horizontal direction. In this modified example, the tilt of the rotation mechanism 16 with respect to the horizontal direction can be changed in increments of, for example, 0.5° using multiple step surfaces 80c.

[0128] Thereafter, the operator rotates the clamp lever 88 with the left-right direction as the rotation axis direction to rotate the eccentric cam 84. The eccentric cam 84 rotates relative to the rotating frame 40 and the engaging member 81 around the rotation shaft 83 as the rotation center, so when the eccentric cam 84 is rotated, the front end of the rotating frame 40 moves up and down relative to the engaging member 81. In other words, the rotating frame 40 rotates relative to the base frame 85. In this way, when the eccentric cam 84 is rotated, the front end of the rotating frame 40 moves up and down relative to the engaging member 81 and the rotating frame 40 rotates relative to the base frame 85. Therefore, in this modified example, the eccentric cam 84 can be used to fine-tune the inclination of the rotation mechanism 16 with respect to the horizontal direction.

[0129] Furthermore, in this modified example, the eccentricity D, which is the distance between the center of the eccentric cam 84 and the axis of the pivot shaft 83, is equal to half the step S between adjacent step surfaces 80c in the vertical direction. Therefore, even when adjusting the inclination of the rotation mechanism 16 relative to the horizontal direction using the step portion 80d of the support frame 80 and the engaging member 81, it is possible to continuously adjust the inclination of the rotation mechanism 16 relative to the horizontal direction.

[0130] The amount of eccentricity D does not have to be equal to half the step S. Furthermore, the ultraviolet irradiation device 4 does not have to include the eccentric cam 84. Furthermore, the rotating frame 40 may be rotated relative to the base frame 85 by moving the front end of the rotating frame 40 up and down using a screw member. In this case, an operator may rotate the screw member manually, or the ultraviolet irradiation device 4 may be provided with a motor that rotates the screw member.

[0131] (Example of modification to the surrounding area of ​​the ultraviolet irradiator) Fig. 21 is a side view illustrating the configuration of the peripheral part of an ultraviolet irradiator 17 according to another embodiment of the present invention. Fig. 22 is a view illustrating the configuration of the peripheral part of the ultraviolet irradiator 17 from the MM direction in Fig. 21. Fig. 23 is a view illustrating the configuration of the NN cross section in Fig. 22. In Figs. 21 to 23, the same reference numerals are used to denote the same components as those in the above-described embodiment.

[0132] In the embodiment described above, two guide frames 53 are arranged at a left-right distance apart on the front end side of the lower frame 41, but in this modified example, a support frame 90 formed substantially similarly to the support frame 80 is arranged on the front end side of the lower frame 41 in place of one of the two guide frames 53. In this modified example, the ultraviolet irradiation device 4 includes an engaging member 91 held on the mounting portion 50 so as to be rotatable about the left-right direction as the axis of rotation, a tension coil spring 92 that biases the engaging member 91 to one side in the rotation direction of the engaging member 91 relative to the mounting portion 50, a rotation shaft 93 that serves as the rotation center of the engaging member 91 relative to the mounting portion 50, and an eccentric cam 94 fixed to the rotation shaft 93.

[0133] The mounting portion 50 has a link connection portion 50a to which one end of the link member 51 is connected. As shown in FIG. 21 , a compression coil spring 98 is disposed between the link connection portion 50a and the holding frame 52 to bias the mounting portion 50 in a direction to lift the ultraviolet irradiator 17. The upper end of the compression coil spring 98 is engaged with the link connection portion 50a near the connection between the link member 51 disposed on the rear side and the link connection portion 50a. The compression coil spring 98 biases the link connection portion 50a to one side in the circumferential direction about the center of rotation of the link member 51 disposed on the rear side relative to the holding frame 52. The compression coil spring 98 functions as an assist spring.

[0134] The support frame 90 is fixed to the front end of the lower frame 41. The guide frame 53 is disposed to the right of the link connecting portion 50a, and the support frame 90 is disposed to the left of the link connecting portion 50a. The support frame 90 is formed with guide holes 90a corresponding to the guide holes 53a of the guide frame 53. The support frame 90 is also formed with vertically elongated through holes 90b that penetrate the support frame 90 in the left-right direction. The through holes 90b are formed in front of the guide holes 90a. Note that the through holes 90b are not shown in FIG. 21, and the guide holes 90a are not shown in FIG. 23.

[0135] Similar to the support frame 80, the front side of the through-hole 90b is a stepped portion 90d with a plurality of step surfaces 90c arranged in the vertical direction. The step between adjacent step surfaces 90c in the vertical direction is constant. A scale plate 97 with markings 96 indicating the height of the ultraviolet irradiator 17 is fixed to the guide frame 53 or the support frame 90.

[0136] The rotating shaft 93 is arranged so that its axial direction coincides with the left-right direction. The eccentric cam 94 is an eccentric disk cam formed in a disk shape. The eccentric cams 94 are fixed to both ends of the rotating shaft 93, and the two eccentric cams 94 are rotatable together with the rotating shaft 93. The centers of the eccentric cams 94 are offset from the axis of the rotating shaft 93. The amount of eccentricity, which is the distance between the center of the eccentric cam 94 and the axis of the rotating shaft 93, is equal to half the step between adjacent step surfaces 90c in the vertical direction.

[0137] A cam mounting hole in which an eccentric cam 94 is mounted is formed in the front end of the side surface portion 50b that constitutes the left-right side surface of the link connecting portion 50a. The eccentric cam 94 is rotatably held by the side surface portion 50b. That is, a rotation shaft 93 to which the eccentric cam 94 is fixed is rotatably held by the mounting portion 50 via the eccentric cam 94. Specifically, both ends of the rotation shaft 93 are rotatably held by the front end of the mounting portion 50 via the eccentric cam 94. The rotation shaft 93 and the eccentric cam 94 are rotatable relative to the mounting portion 50, with the left-right direction being the rotation axis direction.

[0138] Both ends of the rotating shaft 93 protrude outward in the left-right direction beyond the link connecting portion 50a. The right end of the rotating shaft 93 is inserted into the guide hole 53a of the guide frame 53, and the left end of the rotating shaft 93 is inserted into the guide hole 90a of the support frame 90. The right end of the rotating shaft 93 protrudes to the right beyond the guide frame 53, and the left end of the rotating shaft 93 protrudes to the left beyond the support frame 90. A clamp lever 88 is attached to the left end of the rotating shaft 93 that protrudes to the left beyond the support frame 90.

[0139] The engagement member 91 is disposed between the two side surface portions 50b in the left-right direction. The engagement member 91 is disposed adjacent to the right side of the side surface portion 50b disposed on the left side. An insertion hole through which a rotation shaft 93 is inserted is formed in the engagement member 91. The engagement member 91 is rotatably held at the front end of the link connecting portion 50a via the rotation shaft 93 and an eccentric cam 94. The rotation shaft 93 is rotatable relative to the engagement member 91. The engagement member 91 has a mounting portion 91a that is placed on the stepped surface 90c (see FIG. 22). The mounting portion 91a is disposed at the front lower end of the engagement member 91, and is disposed forward and below the rotation shaft 93. The mounting portion 91a is disposed at the left end of the engagement member 91.

[0140] One end of the tension coil spring 92 engages with the rear upper end of the engaging member 91. The other end of the tension coil spring 92 engages with a spring engaging portion 50c arranged at the front end of the link connecting portion 50a. The spring engaging portion 50c is arranged behind the engaging member 91. When viewed from the right side, the tension coil spring 92 biases the engaging member 91 in a clockwise direction (clockwise direction in Figure 23) around the rotation shaft 93. A mounting portion 91a arranged at the front lower end of the engaging member 91 is arranged behind the stepped portion 90d. The tension coil spring 92 biases the engaging member 91 in a direction in which the mounting portion 91a faces the stepped portion 90d.

[0141] The mounting portion 91a is placed on the stepped surface 90c by the weight of the ultraviolet irradiator 17 and the like. Furthermore, because the engaging member 91 is biased in a direction in which the mounting portion 91a moves toward the stepped portion 90d, when the ultraviolet irradiator 17 is lifted together with the mounting portion 50, the mounting portion 91a is automatically placed on the stepped surface 90c corresponding to the height of the ultraviolet irradiator 17. When the engaging member 91 is rotated against the biasing force of the tension coil spring 92 (i.e., when the engaging member 91 is rotated counterclockwise as viewed from the right side so that the mounting portion 91a moves away from the stepped portion 90d), the mounting portion 91a is released from the stepped surface 90c, and the ultraviolet irradiator 17 can be lowered together with the mounting portion 50. A finger hook 91b is formed at the front upper end of the engaging member 91 for rotating the engaging member 91 against the biasing force of the tension coil spring 92.

[0142] In this modified example, when the eccentric cam 88a of the clamp lever 88 is positioned at the position shown by the two-dot chain line in Fig. 22, it becomes possible to raise and lower the ultraviolet irradiator 17 together with the mounting unit 50. On the other hand, when the clamp lever 88 is rotated with the front-to-rear direction as the axial direction of rotation so that the eccentric cam 88a is positioned at the position shown by the solid line in Fig. 22, the front end of the link connecting portion 50a becomes fixed to the guide frame 53 and the support frame 90, and it becomes impossible to raise and lower the ultraviolet irradiator 17 together with the mounting unit 50.

[0143] On the right side of the guide frame 53, the rotary shaft 93 is inserted into a washer 89, and the washer 89 is fixed to the rotary shaft 93. On the left side of the support frame 90 and to the right of the clamp lever 88, the rotary shaft 93 is inserted into a washer 89, and the washer 89 is movable in the left-right direction relative to the rotary shaft 93. Therefore, when the clamp lever 88 is rotated so that the eccentric cam 88a is positioned as shown by the solid line in FIG. 22 , the guide frame 53, the support frame 90, and the link connecting portion 50a are sandwiched between the two washers 89, and the front end of the link connecting portion 50a is fixed to the guide frame 53 and the support frame 90.

[0144] In this modified example, the height (vertical position) of the ultraviolet irradiator 17 is adjusted by moving the eccentric cam 88a of the clamp lever 88 to the position shown by the two-dot chain line in Figure 22. When adjusting the height of the ultraviolet irradiator 17, the operator of the printing apparatus 1 first manually lifts the link connection part 50a. When the link connection part 50a is lifted, the mounting part 91a is automatically placed on a step surface 90c that corresponds to the height of the link connection part 50a.

[0145] Thereafter, the operator rotates the clamp lever 88 with the left-right direction as the rotation axis direction, thereby rotating the eccentric cam 94. The eccentric cam 94 rotates relative to the link connection part 50a and the engaging member 91 around the rotation shaft 93, so that when the eccentric cam 94 is rotated, the link connection part 50a moves up and down relative to the engaging member 91. In this way, when the eccentric cam 94 is rotated, the link connection part 50a moves up and down relative to the engaging member 91, so in this modified example, the eccentric cam 94 can be used to fine-tune the height of the ultraviolet irradiator 17.

[0146] The link connection part 50a may be moved up and down using a screw member. In this case, the operator may manually rotate the screw member, or the ultraviolet irradiation device 4 may be provided with a motor that rotates the screw member.

[0147] (Examples of cover modifications, examples of modifications to the periphery of the cover) Fig. 24 is a plan view illustrating the configuration of a cover portion 18a according to another embodiment of the present invention. Fig. 25 is a side view illustrating the configuration of a cover 18 according to another embodiment of the present invention. Fig. 26 is an enlarged side view illustrating the configuration of a third cover 22 according to another embodiment of the present invention. Fig. 27 is a front view illustrating the configuration of an ultraviolet irradiation device 4 according to another embodiment of the present invention. Fig. 28 is a bottom view showing the configuration of a part of the ultraviolet irradiation device 4 as seen from the PP direction in Fig. 27. In Figs. 24 to 28, the same reference numerals are used to denote the same components as those in the above-described embodiment.

[0148] In the embodiment described above, the ultraviolet irradiation device 4 is provided with the cover position adjustment mechanism 21, but in this modified example, the ultraviolet irradiation device 4 is not provided with the cover position adjustment mechanism 21. In this modified example, a plurality of through holes 18c are formed in the cover portion 18a so that an operator can directly touch the upper surface of the second cover 20 to adjust the left-right position and inclination of the second cover 20 (see FIG. 24). The through holes 18c are formed on both left-right sides of the opening 18b. Furthermore, the through holes 18c are formed in, for example, three locations on each of the left-right sides of the opening 18b.

[0149] Furthermore, in the embodiment described above, the upper cover 58 is removed from the lower cover 59 when replacing the printing medium 2, but in this modified example, the upper cover 58 can be rotated relative to the lower cover 59 so that the upper cover 58 opens relative to the lower cover 59 to a position where the printing medium 2 can be replaced when replacing the printing medium 2 (see FIG. 25). Also, in this modified example, when the upper cover 58 is opened while the third cover 22 is placed on the cover portion 18a, the detectable member 72 attached to the third cover 22 can be folded (see the dashed line and the two-dot chain line in FIG. 25). Furthermore, in this modified example, the ultraviolet irradiation device 4 is provided with a cover lifting mechanism 105 that raises and lowers the lower cover 59 relative to the lower frame 41 (see FIG. 27).

[0150] In this modified example, as shown in FIG. 25 , the rear end of the upper cover 58 is rotatably connected to the upper rear end of the lower cover 59. The upper cover 58 is rotatable relative to the lower cover 59 with the left-right direction as the rotation axis. In this modified example, when replacing the printing medium 2, the operator opens the upper cover 58 by rotating the upper cover 58 relative to the lower cover 59 to a position where the printing medium 2 can be replaced. A support member 106 is attached to the lower cover 59 to support the upper cover 58 in the open state from below. One end of the support member 106 is rotatably attached to the upper front end of the lower cover 59. The other end of the support member 106 is engageable with the upper cover 58 from below. The support member 106 is receivable inside the lower cover 59.

[0151] In this modified example, the detectable member 72 is rotatable relative to the third cover 22 with the left-right direction as the axial direction of the rotation. As shown in Fig. 26, the detectable member 72 is rotatable relative to the third cover 22 around a rotation center shaft 107 disposed on the underside of the third cover 22. A shaft holding member 108 to which the rotation center shaft 107 is attached is fixed to the underside of the third cover 22. The detectable member 72 is rotatable relative to the third cover 22 between a detectable position (position indicated by the two-dot chain line in Fig. 25) in which the detectable member 72 extends downward from the cover upper portion 58, and a storage position (position indicated by the dashed line in Fig. 25) in which the detectable member 72 is stored inside the cover upper portion 58.

[0152] A leaf spring 109 for holding the detectable member 72 is fixed to the underside of the third cover 22. The leaf spring 109 has a first engagement portion 109a for holding the detectable member 72 at the detectable position and a second engagement portion 109b for holding the detectable member 72 at the storage position. The detectable member 72 is formed with a first engagement hole 72b with which the first engagement portion 109a engages and a second engagement hole 72c with which the second engagement portion 109b engages. When printing on the printing medium 2, the detectable member 72 is positioned at the detectable position (see FIG. 26(A)). Furthermore, when the cover upper portion 58 is opened to replace the printing medium 2, the operator rotates the detectable member 72 from the detectable position to the storage position so as not to interfere with the replacement of the printing medium 2 (see FIG. 26(B)).

[0153] The cover lifting mechanism 105 includes a screw member 112 that is held by the lower frame 41 so as to be rotatable about the vertical direction as the axis of rotation, and a nut member 113 that threads onto the screw member 112 and is fixed to the cover lower part 59. The screw members 112 and the nut members 113 are disposed near each of the four corners of the ultraviolet irradiation device 4. That is, the cover lifting mechanism 105 includes four screw members 112 and four nut members 113. The nut members 113 are fixed to the lower ends of the cover lower parts 59.

[0154] Pulleys 114 are fixed to the lower ends of the screw members 112. As shown in Fig. 28, a belt 115 is stretched across the four pulleys 114. The cover lifting mechanism 105 also includes an idle pulley 116 for adjusting the tension of the belt 115. A lever 117 for rotating one of the four screw members 112 is detachably attached to the upper end of the screw member 112.

[0155] In this modified example, when adjusting the height of the cover 18 by adjusting the height of the cover lower part 59, the operator attaches lever 117 to one screw member 112 and rotates lever 117. When lever 117 is rotated, the four screw members 112 rotate together, and the cover lower part 59 moves up and down relative to the lower frame 41. When the cover lower part 59 moves up and down, the four screw members 112 rotate in sync, so that the cover part 18a remains horizontal. When adjustment of the height of cover 18 is complete, lever 117 is removed.

[0156] The ultraviolet irradiation device 4 is provided with a scale plate 119 on which a scale 118 indicating the height of the cover 18 is marked. The scale plate 119 is fixed to a fixing member 120 which is fixed to the lower frame 41. The cover lifting mechanism 105 may also be provided with a motor which rotates the screw member 112.

[0157] (Example of a modified rotation mechanism) Fig. 29 is a plan view illustrating the configuration of a rotation mechanism 16 according to another embodiment of the present invention. Fig. 30 is a cross-sectional view of the QQ section of Fig. 29. Figs. 31 and 32 are enlarged plan views illustrating the configuration of the R portion of Fig. 29. In Figs. 29 to 32, the same reference numerals are used to designate the same components as those in the above-described embodiment.

[0158] In the embodiment described above, the rotation mechanism 16 includes the third holding portion 34 and the compression coil spring 35, but the rotation mechanism 16 of this modified example does not include the third holding portion 34 or the compression coil spring 35. In this modified example, the second holding portion 33 is fixed to the guide block 39. Also, in this modified example, the rotation mechanism 16 includes a fixed member 124 fixed to the guide block 39, a slide member 125 held by the fixed member 124 so as to be movable in the front-rear direction relative to the fixed member 124, an engaging member 126 held by the slide member 125 so as to be rotatable about the left-right direction relative to the slide member 125, and a restricting member 127 for restricting the forward movement of the slide member 125 and the engaging member 126.

[0159] The rotation mechanism 16 also includes a torsion coil spring 128 (see Figure 30) that biases the engagement member 126 toward one side in the rotation direction of the engagement member 126 relative to the slide member 125, a fixed shaft 129 fixed to the slide member 125, a compression coil spring 130 through which the fixed shaft 129 is inserted, a rotating member 131 held by the fixed member 124 so as to be able to rotate with the vertical direction relative to the fixed member 124 as the axis of rotation, and a tension coil spring 132 that biases the rotating member 131 toward one side in the rotation direction of the rotating member 131 relative to the fixed member 124.

[0160] The slide member 125 is formed with a guide hole 125a for guiding the slide member 125 in the front-rear direction relative to the fixed member 124 and for restricting the range of movement of the slide member 125 in the front-rear direction relative to the fixed member 124 (see FIG. 30). The guide hole 125a is an elongated hole that is long in the front-rear direction. A guide screw 135 that is fixed to the fixed member 124 is inserted into the guide hole 125a. The slide member 125 is equipped with a rotation restricting portion 125b that restricts rotation of the rotating member 131 to one side in the rotation direction of the rotating member 131 relative to the fixed member 124, and a spring engaging portion 125c with which one end of the torsion coil spring 128 comes into contact.

[0161] The fixed shaft 129 is disposed such that its axial direction coincides with the front-rear direction. The front end of the fixed shaft 129 is fixed to the slide member 125. A through-hole through which the fixed shaft 129 is inserted is formed in the second holding portion 33. As described above, the fixed shaft 129 is inserted into the inner periphery of the compression coil spring 130. The front end of the compression coil spring 130 contacts the slide member 125. The rear end of the compression coil spring 130 contacts the second holding portion 33. The compression coil spring 130 biases the second holding portion 33 rearward with respect to the slide member 125. In other words, the compression coil spring 130 biases the second rotating portion 32, the second holding portion 33, the guide block 39, and the fixed member 124 rearward with respect to the slide member 125.

[0162] The restricting member 127 is formed in an elongated shape that is long and narrow in the front-rear direction. The restricting member 127 is fixed to the rotating frame 40. The restricting member 127 is provided with a saw-tooth-shaped restricting portion 127b on which a plurality of restricting surfaces 127a arranged in the front-rear direction are formed (see FIG. 30). The restricting portion 127b is formed on the upper end surface of the restricting member 127. The restricting surface 127a is an inclined surface that slopes upward toward the front. The pitch (pitch in the front-rear direction) of the plurality of restricting surfaces 127a is constant.

[0163] The engagement member 126 is rotatable relative to the slide member 125 around a rotation center shaft 136 (see Figure 30) fixed to the rear end of the slide member 125. The rotation center shaft 136 is arranged so that the axial direction of the rotation center shaft 136 coincides with the left-right direction. The rotation center shaft 136 is arranged below the spring engagement portion 125c. An insertion hole through which the rotation center shaft 136 is inserted is formed in the rear end of the engagement member 126. The engagement member 126 has an engagement portion 126a that engages with the restriction surface 127a (see Figure 30). The engagement portion 126a is arranged at the lower end of the engagement member 126. When the printing medium 2 is correctly attached to the rotation mechanism 16, the front end surface of the engagement portion 126a contacts the restriction surface 127a with a predetermined contact pressure.

[0164] The engaging member 126 is formed with a guide hole 126b for guiding the engaging member 126 in the direction of rotation of the engaging member 126 relative to the slide member 125 and for regulating the range of rotation of the engaging member 126 relative to the slide member 125 (see FIG. 30). The guide hole 126b is disposed in front of the rotation center shaft 136. The guide hole 126b is also disposed above the rotation center shaft 136. When viewed from the left-right direction, the shape of the guide hole 126b is formed in an arc shape with the axis of the rotation center shaft 136 as the center of curvature. A guide screw 137 that is fixed to the slide member 125 is inserted into the guide hole 126b.

[0165] The rotation center shaft 136 is inserted through the torsion coil spring 128. One end of the torsion coil spring 128 is in contact with the spring engagement portion 125c of the slide member 125. The other end of the torsion coil spring 128 is in contact with the engagement member 126. When viewed from the right side, the torsion coil spring 128 biases the engagement member 126 in a counterclockwise direction (counterclockwise direction in FIG. 30) around the rotation center shaft 136. The engagement portion 126a, which is arranged at the lower end of the engagement member 126, is arranged above the restriction portion 127b. The torsion coil spring 128 biases the engagement member 126 in a direction in which the engagement portion 126a faces the restriction portion 127b.

[0166] When engaging member 126 is rotated against the biasing force of torsion coil spring 128 (i.e., when engaging member 126 is rotated clockwise as viewed from the right side so that engaging portion 126a moves away from restricting portion 127b), engaging portion 126a disengages from restricting surface 127a, as shown by the two-dot chain line in Figure 30. Therefore, when engaging member 126 is rotated against the biasing force of torsion coil spring 128, it becomes possible to move slide member 125 and engaging member 126 forward. A finger hook 126c is formed at the front upper end of engaging member 126 for rotating engaging member 126 against the biasing force of torsion coil spring 128.

[0167] In this modified example, when the printing medium 2 is properly attached to the rotation mechanism 16, the forward movement of the slide member 125 and the engaging member 126 is restricted by the restricting surface 127a and the engaging portion 126a that contacts the restricting surface 127a. When the printing medium 2 is properly attached to the rotation mechanism 16, the compression coil spring 130 is compressed by a predetermined amount (for example, by approximately 5 mm), and the biasing force of the compression coil spring 130 biases the second rotating portion 32, the second holding portion 33, the guide block 39, and the fixed member 124 rearward relative to the slide member 125. Therefore, when the printing medium 2 is properly attached to the rotation mechanism 16, the front end surface of the printing medium 2 contacts the second rotating portion 32 with a predetermined contact pressure, and the rear end surface of the printing medium 2 contacts the first rotating portion 27 with a predetermined contact pressure.

[0168] The rotating member 131 is rotatable relative to the fixed member 124 around a rotation center shaft fixed to the front end of the fixed member 124. This rotation center shaft is arranged so that the axial direction of the rotation center shaft coincides with the up-down direction. The rotating member 131 includes a regulated portion 131a arranged in front of the rotation regulating portion 125b, and a spring engaging portion 131b with which the front end of the tension coil spring 132 engages. The regulated portion 131a is arranged at the left front end of the rotating member 131. The spring engaging portion 131b is arranged behind the regulated portion 131a.

[0169] The first detection mechanism 23 is disposed behind the rotating member 131. The first detection mechanism 23 is attached to the fixed member 124 so that the lever 23a is disposed in front of the main body of the first detection mechanism 23. The rear end of the rotating member 131 is capable of contacting the lever 23a from the front. The rear end of the tension coil spring 132 is engaged with the second holding portion 33. The front end of the tension coil spring 132 is engaged with the spring engaging portion 131b of the rotating member 131, as described above. When viewed from above, the tension coil spring 132 biases the rotating member 131 in a clockwise direction (clockwise direction in FIGS. 31 and 32) around the rotation center of the rotating member 131. The rotation of the rotating member 131 in the clockwise direction in FIGS. 31 and 32 is restricted by a rotation restricting portion 125b disposed behind the restricted portion 131a.

[0170] In this modified example, when attaching the medium to be printed 2 to the rotation mechanism 16, the medium to be printed 2 is placed between the first rotating part 27 and the second rotating part 32, and then the slide member 125 and the engaging member 126 are moved rearward until the compression coil spring 130 is compressed by a predetermined amount. When the slide member 125 and the engaging member 126 are moved rearward, the second rotating part 32, the second holding part 33, the guide block 39, and the fixing member 124 are also pushed rearward by the compression coil spring 130. Furthermore, when the slide member 125 and the engaging member 126 are moved rearward until the compression coil spring 130 is compressed by a predetermined amount, the front end surface of the medium to be printed 2 comes into contact with the second rotating part 32 with a predetermined contact pressure, and the rear end surface of the medium to be printed 2 comes into contact with the first rotating part 27 with a predetermined contact pressure, and the medium to be printed 2 is properly set in the rotation mechanism 16.

[0171] When the printing material 2 is correctly attached to the rotation mechanism 16, the compression coil spring 130 is compressed by a predetermined amount, the slide member 125 moves rearward relative to the second holding portion 33, and the rotation restriction portion 125b moves rearward. At this time, as shown in FIG. 32, the rotating member 131 rotates clockwise in FIG. 32, and the rear end portion of the rotating member 131 pushes the lever 23a rearward. Specifically, the rear end portion of the rotating member 131 pushes the lever 23a rearward to a position where the lever 23a presses the contact member of the first detection mechanism 23. Therefore, the first detection mechanism 23 detects that the printing material 2 is correctly attached to the rotation mechanism 16.

[0172] When removing the printed material 2 from the rotation mechanism 16, the engaging member 126 is rotated against the biasing force of the torsion coil spring 128, and the slide member 125 and the engaging member 126 are moved forward to a position where the printed material 2 can be removed from between the first rotating part 27 and the second rotating part 32.

[0173] (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.

[0174] In the embodiment described above, the upper cover 58 and the lower cover 59 are formed as separate bodies and are separable from each other, but the upper cover 58 and the lower cover 59 may also be formed as a single body. Also, in the embodiment described above, the second cover 20 may be disposed above the cover 18. Furthermore, in the embodiment described above, the second detection mechanism 24 may be attached to the rotating frame 40, for example.

[0175] In the above-described embodiment, the first detection mechanism 23 may be an optical sensor. Similarly, the second detection mechanism 24 may be an optical sensor. Furthermore, in the above-described embodiment, the third biasing member that biases the second holding portion 33 against the third holding portion 34 may be a spring member other than the compression coil spring 35. Furthermore, the biasing member that biases the second cover 20 outward in the left-right direction may be a spring member other than the tension coil spring 69.

[0176] In the embodiment described above, the magnetic sheet 61 may be attached to the upper surface of the mounting portion 59b. That is, the cover lower portion 59 may be provided with the magnetic sheet 61. In this case, the cover upper portion 58 is formed of a magnetic material, and the attachment portion 58c serves as the member to be attracted. Alternatively, the magnetic sheet 61 may be attached to the lower surface of the attachment portion 58c, and a magnetic sheet may be attached to the upper surface of the mounting portion 59b. In this case, the magnetic sheet attached to the upper surface of the mounting portion 59b serves as the member to be attracted.

[0177] In the above-described embodiment, if printing is performed in the printing device 1 only on print substrates 2 having a fixed outer diameter, the vertical position of the cover 18 does not have to be adjustable. Also, if printing is performed in the printing device 1 only on print substrates 2 having a fixed outer diameter, the ultraviolet irradiation device 4 does not have to be equipped with the second cover 20 and the cover position adjustment mechanism 21. Also, if printing is performed in the printing device 1 only on print substrates 2 having a fixed outer diameter, the vertical position of the ultraviolet irradiator 17 does not have to be adjustable.

[0178] In the above-described embodiment, if printing is performed in the printing device 1 only on a printing substrate 2 of a certain length, the ultraviolet irradiation device 4 does not need to be equipped with the third cover 22. Also, in the above-described embodiment, if printing is performed in the printing device 1 only on a printing substrate 2 having a cylindrical outer shape, the tilt of the rotation mechanism 16 with respect to the horizontal direction when viewed from the left and right does not need to be adjustable. Also, if printing is performed in the printing device 1 only on a printing substrate 2 having a cylindrical outer shape, the tilt of the ultraviolet irradiator 17 with respect to the axis of the printing substrate 2 when viewed from the top and bottom does not need to be adjustable.

[0179] In the above-described embodiment, the ultraviolet irradiation device 4 may be placed on the table 5 so that the front-to-rear direction (X direction) and the main scanning direction coincide (i.e., so that the left-to-right direction and the sub-scanning direction coincide). Also, 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, instead of the stage drive mechanism 12. Note that in the above-described embodiment, the ultraviolet irradiator 17 may also be disposed below the printing medium 2. [Explanation of symbols]

[0180] 1 Printing device 2 Printing material 3 Inkjet head 4 Ultraviolet irradiation device 5 tables 16 Rotation mechanism 17 Ultraviolet irradiator 18 Cover 18a Cover part 18b opening 20 Second Cover 21 Cover position adjustment mechanism 22 Third Cover 23 First detection mechanism 24 Second detection mechanism 27 First Rotating Section 28 1st holding part 29 Motor 30 Power transmission mechanism 32 Second Rotating Section 33 Second holding part 34 Third holding part 35 compression coil spring (third biasing member) 40 Rotating Frame 40a Cam placement hole 58 Top of cover 59 Lower cover 59b Placement section (attached member) 61 Magnetic sheet (adsorption material) 68 Pressing member 69 Tension coil spring (biasing member) 70 Adjustment screw 72 Detectable member 72a Detected part 80 Support Frame 80c step surface 80d step 81 Engagement member 81a Placement section 82 tension coil spring (second biasing member) 83 Rotating shaft 84 Eccentric Cam 85 base frame D Eccentricity S step X: The direction of the axis of the printing material when viewed from the front-to-back and top-to-bottom directions Y left / right direction

Claims

1. An ultraviolet irradiation device used in 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 ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the substrate to which the ink is attached; and a cover that has an opening in which an upper end of the substrate is positioned and a cover part that covers the ultraviolet irradiator from above, The ink ejected from above the printing medium lands on the outer peripheral surface of the printing medium, The ultraviolet irradiation device is characterized in that the ultraviolet irradiator is arranged on the side of the printing medium and irradiates ultraviolet rays from the side of the printing medium toward the outer peripheral surface of the printing medium.

2. 2. The ultraviolet irradiation device according to claim 1, wherein the position of the cover in the vertical direction is adjustable.

3. If the direction perpendicular to the axis of the printing medium when viewed from the top and bottom is defined as the left and right direction, two second covers for covering a part of the opening; 2. The ultraviolet irradiation device according to claim 1, wherein the left-right positions of the two second covers are adjustable, and one of the two second covers is capable of blocking a portion of the opening from one side in the left-right direction, and the other second cover is capable of blocking a portion of the opening from the other side in the left-right direction.

4. a cover position adjustment mechanism for adjusting the left-right positions of the two second covers, the second cover is held by the cover so as to be slidable in the left-right direction; the cover position adjustment mechanism includes a pressing member that is held by the cover so as to be slidable in the left-right direction and that contacts the second cover from the outside in the left-right direction to press the second cover inward in the left-right direction, a biasing member that biases the second cover outward in the left-right direction, and an adjustment screw that is rotatably held by the cover and engages with the pressing member, 4. The ultraviolet irradiation device according to claim 3, wherein the second cover slides left and right when the adjustment screw is turned.

5. the cover includes an upper cover portion including the cover portion and a lower cover portion to which the upper cover portion is attached at an upper end side; the cover upper portion holds the second cover and the cover position adjustment mechanism; one of the upper cover and the lower cover is provided with an attraction member made of a permanent magnet; the other of the upper cover and the lower cover is made of a permanent magnet or a magnetic member and is provided with an attracted member that is attracted to the attracting member, 5. The ultraviolet irradiation device according to claim 4, wherein the upper cover is attached to the lower cover by a magnetic attraction force generated between the attracting member and the attracted member.

6. 6. The ultraviolet irradiation device according to claim 5, wherein the position of the lower part of the cover is adjustable in the vertical direction.

7. If the direction of the axis of the printing medium when viewed from the top and bottom is defined as the front-to-back direction, a third cover that closes a portion of the opening in the front-rear direction; 7. The ultraviolet irradiation device according to claim 1, wherein the third cover is placed on the cover portion.

8. An ultraviolet irradiation device used in 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, comprising: a rotation mechanism that holds the printing medium and rotates the printing medium around an axis of the printing medium as a rotation center, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing medium on which the ink is attached, The ink ejected from above the printing medium lands on the outer peripheral surface of the printing medium, the ultraviolet irradiator is disposed on a side of the printing medium and irradiates ultraviolet light from the side of the printing medium toward an outer peripheral surface of the printing medium; An ultraviolet irradiation device characterized in that the position of the ultraviolet irradiator in the vertical direction is adjustable.

9. An ultraviolet irradiation device used in 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, comprising: a rotation mechanism that holds the printing medium and rotates the printing medium around an axis of the printing medium as a rotation center, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing medium on which the ink is attached, The ink ejected from above the printing medium lands on the outer peripheral surface of the printing medium, the ultraviolet irradiator is disposed on a side of the printing medium and irradiates ultraviolet light from the side of the printing medium toward an outer peripheral surface of the printing medium; If the direction perpendicular to the axis of the printing medium when viewed from the top and bottom is defined as the left and right direction, An ultraviolet irradiation device characterized in that the tilt of the rotation mechanism relative to the horizontal direction when viewed from the left and right is adjustable.

10. If the direction of the axis of the printing medium when viewed from the top and bottom is defined as the front-to-back direction, a base frame to which the rotation mechanism is connected at one end in the front-rear direction so as to enable rotation of the rotation mechanism about the left-right direction as an axial direction of rotation; a support frame having a stepped portion formed with a plurality of step surfaces arranged in the up-down direction and fixed to the other end in the front-rear direction of the base frame; an engaging member having a mounting portion to be placed on the step surface and held by the rotation mechanism so as to enable rotation about the left-right direction as an axial direction of rotation; and a second biasing member that biases the engaging member to one side in the rotation direction of the engaging member relative to the rotation mechanism, the rotation mechanism includes a first rotating part that holds one end of the medium to be printed and rotates together with the medium to be printed, a second rotating part that holds the other end of the medium to be printed and rotates together with the medium to be printed, and a rotating frame to which the first rotating part and the second rotating part are rotatably attached; One end of the pivot frame in the front-rear direction is pivotably connected to one end of the base frame in the front-rear direction, the engaging member is rotatably held at the other end of the rotating frame in the front-rear direction, the second biasing member biases the engaging member in a direction in which the placement portion moves toward the step portion, the placement portion is placed on the step surface by the weight of the rotation mechanism, 10. The ultraviolet irradiation device according to claim 9, wherein when the engaging member is rotated against the biasing force of the second biasing member, the placement portion is released from the stepped surface.

11. a rotation shaft that is rotatably held by the rotation frame and serves as a rotation center of the engagement member relative to the rotation frame; and an eccentric cam that is fixed to the rotation shaft, The rotation shaft is rotatable relative to the engagement member, a cam arrangement hole in which the eccentric cam is arranged is formed in the rotating frame; 11. The ultraviolet irradiation device according to claim 10, wherein when the eccentric cam is rotated relative to the rotating frame, the other end of the rotating frame in the front-rear direction moves up and down relative to the engaging member.

12. the eccentric cam is an eccentric disk cam formed in a disk shape, 12. The ultraviolet irradiation device according to claim 11, wherein the eccentricity, which is the distance between the center of the eccentric cam and the axis of the rotary shaft, is equal to half the step between the step surfaces adjacent in the vertical direction.

13. An ultraviolet irradiation device used in 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, comprising: a rotation mechanism that holds the printing medium and rotates the printing medium around an axis of the printing medium as a rotation center, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing medium on which the ink is attached, The ink ejected from above the printing medium lands on the outer peripheral surface of the printing medium, the ultraviolet irradiator is disposed on a side of the printing medium and irradiates ultraviolet light from the side of the printing medium toward an outer peripheral surface of the printing medium; An ultraviolet irradiation device characterized in that the inclination of the ultraviolet irradiator with respect to the axis of the printing medium when viewed from above and below is adjustable.

14. An ultraviolet irradiation device used in 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, comprising: a rotation mechanism that holds the substrate and rotates the substrate around the axis 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 first detection mechanism that detects that the substrate is being held by the rotation mechanism, The ink ejected from above the printing medium lands on the outer peripheral surface of the printing medium, the ultraviolet irradiator is disposed on a side of the printing medium and irradiates ultraviolet light from the side of the printing medium toward an outer peripheral surface of the printing medium; When the first detection mechanism detects that the printing medium is being held by the rotation mechanism, the ultraviolet irradiator is enabled to irradiate ultraviolet light.

15. If the direction perpendicular to the axis of the printing medium when viewed from the top and bottom is defined as the left and right direction, the rotation mechanism includes a first rotating unit that holds one end of the medium to be printed, a first holding unit that rotatably holds the first rotating unit, a motor for rotating the first rotating unit, a power transmission mechanism that connects the first rotating unit and the motor, a second rotating unit that holds the other end of the medium to be printed, a second holding unit that rotatably holds the second rotating unit, a third holding unit that rotatably holds the second holding unit so that the second holding unit can rotate about an axis of rotation in the left-right direction, and a third biasing member that biases the second holding unit against the third holding unit in a direction that tilts the second holding unit toward the first holding unit, the first detection mechanism is attached to the third holding portion, The ultraviolet irradiation device according to claim 14, characterized in that when the printing medium is attached to the rotation mechanism, the second holding portion rotates relative to the third holding portion against the biasing force of the third biasing member to a position detected by the first detection mechanism.

16. If the direction of the axis of the printing medium when viewed from the top and bottom is defined as the front-to-back direction, a cover having an opening in which an upper end of the printing medium is placed and a cover portion that covers the ultraviolet irradiator from above; a third cover that is placed on the cover portion and that closes a part of the opening in the front-rear direction; and a second detection mechanism that detects that the third cover is placed on the cover portion; 15. The ultraviolet irradiation device according to claim 14, wherein when the second detection mechanism detects that the third cover is placed on the cover portion, the ultraviolet irradiator is enabled to irradiate ultraviolet light.

17. If the direction perpendicular to the axis of the printing medium when viewed from the top and bottom is defined as the left and right direction, the rotation mechanism includes a first rotating unit that holds one end of the medium to be printed, a first holding unit that rotatably holds the first rotating unit, a motor for rotating the first rotating unit, a power transmission mechanism that connects the first rotating unit and the motor, a second rotating unit that holds the other end of the medium to be printed, a second holding unit that rotatably holds the second rotating unit, a third holding unit that rotatably holds the second holding unit so that the second holding unit can rotate about an axis of rotation in the left-right direction, and a third biasing member that biases the second holding unit against the third holding unit in a direction that tilts the second holding unit toward the first holding unit, The position of the third holding part in the direction of the axis of the printing medium is adjustable, a detection member having a detection portion that is detected by the second detection mechanism is attached to the third cover; the second detection mechanism is attached to the second holding portion, The ultraviolet irradiation device according to claim 16, characterized in that when the third cover is placed at a predetermined position on the cover portion while the printing medium is held by the rotation mechanism, the detected portion is detected by the second detection mechanism.

18. 18. A printing device comprising: the ultraviolet irradiation device according to claim 1; a table on which the ultraviolet irradiation device is placed; and an inkjet head disposed above the medium to be printed and configured to eject the ink toward the outer peripheral surface of the medium to be printed.

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