UV irradiation device, printer, and printed body setting method

Abstract

To provide a UV irradiation device used in a printer for printing on an outer peripheral surface of a printed body with a columnar, truncated-conical, or conical outer shape by using an ultraviolet curable ink that can suppress occurrence of sliding between the printed body and a rotary part which holds an end of the printed body and rotates together with the printed body.SOLUTION: In a UV irradiation device, a rotary part 23 which holds an end of a printed body 2 and rotates together with the printed body 2, comprises: a screw 35 with a head and a nut 36; a holding member 37 which comprises an annular elastic body, and of which outer peripheral surface comes into contact with an inner peripheral surface of the printed body 2; and a contact member 38 coming into contact with the holding member 37. When the nut 36 is rotated in a direction in which a head 35a of the screw 35 and the nut 36 approach each other, the holding member 37 is elastically deformed and an outer diameter of the holding member 37 expands. When the nut 36 is rotated in a direction in which the head 35a and the nut 36 are separated from each other, the holding member 37 is elastically deformed and the outer diameter of the holding member 37 narrows.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Conventionally, there has been known an ultraviolet irradiation device used in a printing apparatus for printing with ultraviolet-curable ink on the outer peripheral surface of a printing medium having a cylindrical, truncated conical, or conical outer shape (see, for example, Patent Document 1). The ultraviolet irradiation device described in Patent Document 1 includes a rotation mechanism that holds the printing medium and rotates the printing medium around its axis, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing medium to which the ink is attached.

[0003] In the ultraviolet irradiation device described in Patent Document 1, the rotation mechanism includes a first rotating unit that holds one end of the printing medium and rotates together with the printing medium, 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 to the motor, a second rotating unit that holds the other end of the printing medium and rotates together with the printing medium, and a second holding unit that rotatably holds the second rotating unit. The second holding unit is movable together with the second rotating unit toward the axis of the printing medium. In the ultraviolet irradiation device described in Patent Document 1, the positions of the second rotating unit and the second holding unit in the axis direction of the printing medium are adjusted depending on the length of the printing medium.

[0004] In a printing device that uses the ultraviolet irradiation device described in Patent Document 1, when printing on a substrate, the substrate is rotated by a rotation mechanism while ink is ejected from an inkjet head located above the substrate toward the outer surface of the substrate. In this printing device, when printing on the substrate, the timing of ink ejection from the inkjet head is controlled based on, for example, the detection result of the rotational position of the first rotating part. [Prior art documents] [Patent documents]

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

[0006] In a printing device that uses the ultraviolet irradiation device described in Patent Document 1, the timing of ink ejection from the inkjet head is controlled based on, for example, the detection results of the rotational position of the first rotating part when printing on a substrate. Therefore, in this printing device, if slippage occurs between the substrate and the first rotating part, which holds one end of the substrate and rotates together with the substrate, and the substrate no longer rotates in accordance with the rotation of the first rotating part, there is a risk that the printing accuracy of the substrate will decrease.

[0007] 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 substrate having a cylindrical, truncated conical, or conical outer shape, which can hold the edge of the printing substrate and prevent slippage between the printing substrate and a rotating part that rotates together with the printing substrate. Another object of the present invention is to provide a printing device equipped with such an ultraviolet irradiation device. A further object of the present invention is to provide a method for setting a printing substrate in such an ultraviolet irradiation device. [Means for solving the problem]

[0008] 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 medium having a cylindrical, truncated conical or conical outer shape, and is equipped with a rotation mechanism that holds the printing medium and rotates the printing medium around its axis as the center of rotation, and an ultraviolet irradiator that irradiates ultraviolet rays toward the outer peripheral surface of the printing medium to which the ink is attached, and the rotation mechanism is equipped with a rotating part that holds an end of the printing medium in the direction of the axis of the printing medium and rotates together with the printing medium, and the end of the printing medium held in the rotating part is formed in a cylindrical shape, and the rotating part is equipped with a head part and a shaft part a nut that engages with the male thread formed on the shaft; a retaining member made of an annular elastic body whose outer surface contacts the inner peripheral surface of the printed material; and an annular contact member that contacts the retaining member, wherein at least a portion of the shaft is disposed on the inner peripheral side of the retaining member, and a portion of the shaft is disposed on the inner peripheral side of the contact member, and the head, retaining member, contact member, and nut are disposed in this order in the axial direction of the shaft; when the nut is turned in a direction that brings the head and nut closer together, the retaining member elastically deforms and the outer diameter of the retaining member increases, and when the nut is turned in a direction that moves the head and nut apart, the retaining member elastically deforms and the outer diameter of the retaining member decreases.

[0009] In the ultraviolet irradiation device of the present invention, the rotating part that holds the end of the printing medium and rotates together with the printing medium includes a headed screw and nut, a holding member made of an annular elastic body whose outer surface contacts the inner surface of the printing medium, and an annular contact member that contacts the holding member. Also, in the present invention, the screw head, holding member, contact member, and nut are arranged in this order in the axial direction of the screw shaft. Furthermore, in the present invention, when the nut is turned in a direction that brings the head and nut closer together, the holding member elastically deforms, widening its outer diameter, and when the nut is turned in a direction that moves the head and nut apart, the holding member elastically deforms, narrowing its outer diameter.

[0010] Therefore, in the present invention, by turning the nut in the direction that brings the head and the nut closer together to widen the outer diameter of the holding member, it is possible to increase the contact pressure between the outer surface of the holding member that contacts the inner surface of the substrate and the inner surface of the substrate. Therefore, in the present invention, it is possible to suppress slippage between the substrate and the rotating part that holds the end of the substrate and rotates together with the substrate. Furthermore, in the present invention, it is possible to change the outer diameter of the holding member depending on the position of the nut relative to the head, so it is possible to increase the contact pressure between the outer surface of the holding member and the inner surface of the substrate even if the inner diameter of the substrate changes. Therefore, in the present invention, it is possible to suppress slippage between the rotating part and the substrate even if the inner diameter of the substrate changes.

[0011] In the present invention, if one axial side of the shaft portion is defined as the first direction side and the opposite side of the first direction side as the second direction side, the head contacts the holding member from the first direction side, the contact member contacts the holding member from the second direction side, and the head's second direction side surface preferably has a first tapered surface tapered in diameter gradually decreasing toward the second direction side, the contact member's first direction side surface preferably has a second tapered surface tapered in diameter gradually decreasing toward the first direction side, and the holding member preferably has a third tapered surface with which the first tapered surface can contact and a fourth tapered surface with which the second tapered surface can contact. This configuration allows the outer diameter of the holding member to be uniformly widened or narrowed around the entire circumferential area of ​​the holding member when the nut is turned. This allows for precise alignment of the axis of the rotating part with the axis of the printing medium.

[0012] In the present invention, for example, the holding member is made of rubber.

[0013] In the present invention, for example, if one side of the axis of the printed material is the third direction side, the rotation mechanism comprises a rotating unit that holds the end of the printed material on the third direction side, a first holding unit that rotatably holds the rotating unit, a motor for rotating the rotating unit, and a power transmission mechanism that connects the rotating unit and the motor, and the rotating unit comprises an annular ring member that contacts the end surface of the printed material on the third direction side.

[0014] In the present invention, for example, if the side opposite the third direction side is the fourth direction side, the rotation mechanism includes a second rotating unit that holds the other end of the printed material on the fourth direction side and rotates together with the printed material, and a second holding unit that rotatably holds the second rotating unit. The second holding unit is movable together with the second rotating unit toward the axis of the printed material, and the positions of the second rotating unit and the second holding unit in the axis of the printed material are adjustable. In this case, the positions of the second rotating unit and the second holding unit in the axis of the printed material are adjusted according to the length of the printed material. Also, in this case, it is possible to attach the end of the printed material to the rotating unit while moving the second rotating unit away from the rotating unit, and then move the second rotating unit and the second holding unit to attach the end of the printed material to the second rotating unit. This makes it easy to attach the printed material to the rotation mechanism.

[0015] In the present invention, if the direction perpendicular to the axis of the print medium when viewed from the top-bottom direction is defined as the left-right direction, the rotation mechanism includes a guide rail for guiding the second holding part in the direction of the axis of the print medium, a guide block that engages with the guide rail and to which the second holding part is fixed, a slide member that is held by a moving body including the second holding part and the guide block and is movable relative to the moving body in the direction of the axis of the print medium, an engaging member that is held by the slide member and is rotatable with respect to the slide member with the left-right direction as its axial direction, a restricting member for restricting movement of the slide member and the engaging member in the fourth direction, and ... engaging member in the rotational direction relative to the slide member. a first biasing member that biases the engaging member to one side of the movable body, a second biasing member that biases the movable body against the slide member, and a slide member regulating portion for regulating the range of movement of the slide member relative to the movable body in the direction of the axis of the printed material, wherein the regulating member has a saw-tooth regulating portion on which a plurality of regulating surfaces are formed that are arranged at a constant pitch in the direction of the axis of the printed material, and the regulating surfaces are inclined surfaces that slope upward as they approach the fourth direction side, and the engaging member has an engaging portion that engages with the regulating surface, and it is preferable that the first biasing member biases the engaging member in the direction in which the engaging portion faces toward the regulating surface, and the second biasing member biases the movable body in the third direction side relative to the slide member.

[0016] With this configuration, by rotating the engaging member in the direction opposite to the direction of biasing by the first biasing member, the engagement between the regulating surface of the regulating member and the engagement portion of the engaging member can be released, allowing the slide member and the engaging member to move toward the fourth direction. Therefore, the slide member and the engaging member can be moved toward the fourth direction with a simple operation. Furthermore, with this configuration, the second biasing member biases the moving body toward the third direction relative to the slide member, so the biasing force of the second biasing member can press the second rotating portion against the end of the printing medium on the fourth direction side. Therefore, it is possible to increase the holding force of the printing medium held by the first holding portion and the second holding portion.

[0017] 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 a substrate and ejects ink toward the outer peripheral surface of the substrate. In this printing device, it is possible to hold the edge of the substrate and prevent slippage between the substrate and a rotating part that rotates together with the substrate.

[0018] In a method for setting a printed material in a rotation mechanism of an ultraviolet irradiation device according to the present invention, for example, the sliding member is pushed in the third direction until the second rotating member contacts the fourth-direction end of the printed material with its third-direction end attached to the rotating member, and then the sliding member is further pushed in the third direction to set the printed material in the rotation mechanism. When the printed material is set in the rotation mechanism using this method, the biasing force of the second biasing member can increase the contact pressure between the fourth-direction end of the printed material and the second rotating member, as well as the contact pressure between the third-direction end face of the printed material and the annular member of the rotating member. This increases the holding force of the printed material held by the rotating member and the second rotating member. [Effects of the Invention]

[0019] As described above, the present invention makes it possible to suppress slippage between the printed material and a rotating part that holds the edge of the printed material and rotates together with the printed material in an ultraviolet irradiation device used in a printing device for printing with ultraviolet-curable ink on the outer surface of the printed material that has a cylindrical, truncated cone-shaped, or conical outer shape. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a front view illustrating a configuration of a printing apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a front view for explaining the configuration of the ultraviolet irradiation device shown in FIG. [Figure 3] 3 is a side view for explaining the configuration of the rotation mechanism shown in FIG. 2. FIG. [Figure 4]3 is a side view for explaining the configuration of the rotation mechanism shown in FIG. 2. FIG. [Figure 5] (A) is a side view of the second rotating part shown in Figure 3, (B) is a side view of the rotating part shown in Figure 3, and (C) and (D) are cross-sectional views of the rotating part shown in (B). [Figure 6] 3 is a plan view for explaining the configuration of the rotation mechanism shown in FIG. 2. FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along the E-E cross section of FIG. 6. [Figure 8] 7 is an enlarged plan view for explaining the configuration of part F in FIG. 6. FIG. [Figure 9] 7 is an enlarged plan view for explaining the configuration of part F in FIG. 6. FIG. [Figure 10] 4 is a diagram for explaining a method for setting a printing medium in the rotation mechanism shown in FIG. 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] (Overall configuration of the printing device) FIG. 1 is a front view illustrating the configuration of a printing device 1 according to an embodiment of the present invention.

[0023] The printing device 1 of this embodiment is a device for printing 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 device 1 prints on the outer surface of the printing substrate 2 using ultraviolet-curable ink. The printing substrate 2 is formed 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.

[0024] The printing device 1 is equipped with an inkjet head 3 (hereinafter referred to as "head 3") that ejects ultraviolet-curable ink toward the outer peripheral surface of the print medium 2. The printing device 1 of this embodiment is equipped with multiple heads 3. For example, the printing device 1 is equipped with four heads 3. The printing device 1 also includes an ultraviolet irradiation device 4 for curing the ink ejected onto the outer peripheral surface of the print medium 2, a stage 6 having a table 5 on which the ultraviolet irradiation device 4 is placed, a carriage 7 on which the multiple heads 3 are mounted, a Y-bar 8 that holds the carriage 7 so as to allow movement in a main scanning direction perpendicular to the up-down direction (vertical direction), and a main body frame 9 that holds the stage 6 so as to allow movement in a sub-scanning direction perpendicular to the up-down direction and the main scanning direction.

[0025] The printing device 1 also includes a carriage drive mechanism 11 that moves the carriage 7 in the main scanning direction relative to the Y bar 8, a stage drive mechanism 12 that moves the stage 6 in the sub-scanning direction relative to the main frame 9, and a table lifting mechanism 13 that raises and lowers the table 5. The carriage drive mechanism 11 includes, for example, a motor as a drive source and a power transmission mechanism such as a belt and pulleys that transmits the power of the motor to the carriage 7. The stage drive mechanism 12 includes, for example, a motor as a drive source and a power transmission mechanism such as a belt and pulleys that transmits the power of the motor to the stage 6. The stage drive mechanism 12 moves the table 5 in the sub-scanning direction together with the stage 6. The table lifting mechanism 13 includes, for example, a motor as a drive source and a power transmission mechanism such as a ball screw that transmits the power of the motor to the table 5.

[0026] In the following description, the sub-scanning direction (X direction in Fig. 1, etc.) is the front-to-rear direction, and the main scanning direction (Y direction in Fig. 1, etc.) is the left-to-right direction. Also, in the following description, the X1 direction side in Fig. 3, etc., which is one side of the front-to-rear direction, is referred to as the "front" side, the X2 direction side in Fig. 3, etc., which is the opposite side, is referred to as the "rear" side, the Y1 direction side in Fig. 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 Fig. 2, etc., which is the opposite side, is referred to as the "left" side.

[0027] The upper surface of the table 5 is a plane perpendicular to the vertical direction. The ultraviolet irradiation device 4 placed on the table 5 is arranged below the head 3. The print medium 2 is held by the ultraviolet irradiation device 4 and arranged below the head 3. In other words, the head 3 is arranged above the print medium 2. The head 3 ejects ink downward. The ink ejected from the head 3 lands on the outer circumferential surface of the print medium 2 at the upper end of the print medium 2. A large number of nozzles that eject ink are formed on the lower surface of the head 3. A nozzle row is formed on the lower surface of the head 3 by a large number of nozzles arranged in the front-to-rear direction. A plurality of nozzle rows are formed on the lower surface of the head 3 and arranged in the left-to-right direction. The head 3 is equipped with a plurality of piezoelectric elements (piezo elements) for ejecting ink from each of the large number of nozzles.

[0028] (Overall configuration of ultraviolet irradiation device) Fig. 2 is a front view for explaining the configuration of the ultraviolet irradiation device 4 shown in Fig. 1. Figs. 3 and 4 are side views for explaining the configuration of the rotation mechanism 16 shown in Fig. 2.

[0029] The ultraviolet irradiation device 4 includes a rotation mechanism 16 that holds the print medium 2 and rotates the print medium 2 around its axis, an ultraviolet irradiator 17 that irradiates ultraviolet rays toward the outer peripheral surface of the print medium 2 to which ink is attached, and a cover 18 that covers the rotation mechanism 16 and the ultraviolet irradiator 17 from above. An opening 18a is formed in the cover 18, through which the upper end of the print medium 2 is positioned.

[0030] The ultraviolet irradiation device 4 is placed on the table 5 so that the direction of the axis of the substrate 2 to be printed when viewed from above coincides with the front-to-back direction. In other words, the direction of the axis of the substrate 2 to be printed when viewed from above coincides with the front-to-back direction, and the left-to-right direction (Y direction) is perpendicular to the direction of the axis of the substrate 2 to be printed when viewed from above. The nozzle row of the head 3 that ejects ink toward the substrate 2 to be printed when printing on the substrate 2 is positioned directly above the substrate 2 to be printed. In the following description, the direction of the axis of the substrate 2 to be printed is referred to as the "axial direction of the substrate 2 to be printed."

[0031] The rotation mechanism 16 rotates the print substrate 2 when printing on the print substrate 2. In this embodiment, printing is performed on the print substrate 2 while the rotation mechanism 16 rotates the print substrate 2 with the stage 6 and carriage 7 stopped at a fixed position. When printing on the print substrate 2, the rotation mechanism 16 rotates the print substrate 2, for example, counterclockwise when viewed from the front. In this embodiment, the length (axial length) of the print substrate 2 is longer than the front-to-rear width of the head 3. Therefore, when printing on the print substrate 2, the print substrate 2 is moved in stages in the front-to-rear direction together with the table 5, the rotation mechanism 16, etc. Note that the length of the print substrate 2 may be equal to the front-to-rear width of the head 3, or may be shorter than the front-to-rear width of the head 3.

[0032] The rotation mechanism 16 includes a motor 21 as a drive source and a power transmission mechanism 22 for transmitting the power of the motor 21 to the printing medium 2. The rotation mechanism 16 also includes a first rotating unit 23 as a rotating unit that holds the rear end of the printing medium 2, a first holding unit 24 that rotatably holds the first rotating unit 23, a second rotating unit 25 that holds the front end of the printing medium 2, a second holding unit 26 that rotatably holds the second rotating unit 25, a rotating frame 27 to which the first holding unit 24 and the second holding unit 26 are attached, and an encoder 28 for detecting the rotational position and rotational speed of the printing medium 2. Note that the power transmission mechanism 22 and other components are not shown in FIG. 2.

[0033] As described above, the printing medium 2 is formed in a cylindrical shape. That is, the rear end of the printing medium 2 held by the first rotating unit 23 and the front end of the printing medium 2 held by the second rotating unit 25 are formed in a cylindrical shape. The first rotating unit 23 and the second rotating unit 25 rotate together with the printing medium 2. The motor 21 is disposed to the right of the printing medium 2. The power transmission mechanism 22 connects the first rotating unit 23 and the motor 21, and the motor 21 rotates the first rotating unit 23. The power transmission mechanism 22 includes a gear train 29. The gear train 29 includes a drive gear fixed to the output shaft of the motor 21 and a driven gear fixed to the first rotating unit 23, etc. The power transmission mechanism 22 may also be configured using a pulley, a belt, etc.

[0034] The second holding unit 26 is movable together with the second rotating unit 25 relative to the rotating frame 27 in the axial direction of the print medium 2. In this embodiment, the positions of the second rotating unit 25 and the second holding unit 26 in the axial direction of the print medium 2 can be adjusted, and the positions of the second rotating unit 25 and the second holding unit 26 in the axial direction of the print medium 2 are adjusted according to the length of the print medium 2. The encoder 28 is connected to the rear end of the first rotating unit 23. When printing on the print medium 2, the timing of ink ejection from the head 3 is controlled based on the output signal of the encoder 28.

[0035] The rotating frame 27 is rotatable with the left-right direction as the axis of rotation relative to the lower frame 30 that constitutes the bottom surface of the ultraviolet irradiation device 4. The rotating frame 27 is also rotatable with the rear end of the rotating frame 27 as the rotation center relative to the lower frame 30. In this embodiment, by rotating the rotating frame 27 relative to the lower frame 30, it is possible to adjust the inclination of the rotation mechanism 16 with respect to the horizontal direction when viewed from the left-right direction. In other words, by rotating the rotating frame 27 relative to the lower frame 30, it is possible to adjust the inclination of the axis of the printing medium 2 with respect to the horizontal direction.

[0036] In this embodiment, when printing on a substrate 2 having a cylindrical outer shape, the axial direction of the substrate 2 coincides with the front-to-rear direction (see FIG. 3). On the other hand, when printing on a substrate 2 having a truncated cone or conical outer shape, the axial direction of the substrate 2 is inclined with respect to the front-to-rear direction (see FIG. 4). In other words, the inclination of the rotation mechanism 16 is adjusted when printing on the outer peripheral surface of a substrate 2 having a truncated cone or conical outer shape. Specifically, the inclination of the rotation mechanism 16 is adjusted so that the top end of the substrate 2 is parallel to the front-to-rear direction.

[0037] If one side of the axial direction of the print medium 2 is defined as the third direction side, and the other side of the axial direction of the print medium 2 opposite the third direction side is defined as the fourth direction side, in this embodiment, when printing on a print medium 2 having a cylindrical outer shape, the third direction side coincides with the rear side, and the fourth direction side coincides with the front side. On the other hand, when printing on the outer peripheral surface of a print medium 2 having a truncated cone or cone outer shape, the third direction side does not coincide with the rear side, and the fourth direction side does not coincide with the front side.

[0038] However, when printing on the outer peripheral surface of the substrate 2 having a truncated cone or conical outer shape, the inclination of the axis of the substrate 2 relative to the front-to-rear direction is not so large, so even when printing on the outer peripheral surface of the substrate 2 having a truncated cone or conical outer shape, the third direction side generally coincides with the rear side, and the fourth direction side generally coincides with the front side. In this embodiment, the rear end of the substrate 2 is the end on the third direction side of the substrate 2, and the front end of the substrate 2 is the end on the fourth direction side of the substrate 2. A more specific configuration of the rotation mechanism 16 will be described later.

[0039] The ultraviolet irradiator 17 includes an LED substrate 31 on which a plurality of light-emitting elements (specifically, a large number of light-emitting elements) that emit ultraviolet rays (ultraviolet light) are mounted. The light-emitting elements are LED chips (UV LED chips). The LED substrate 31 is formed in the shape of a long, narrow rectangular plate. The LED substrate 31 is arranged so that the thickness direction of the LED substrate 31 coincides with the left-right direction. When viewed from the left-right direction, the LED substrate 31 is arranged so that the direction of the short side of the rectangular LED substrate 31 coincides with the up-down direction and the direction of the long side of the LED substrate 31 coincides with the front-to-back direction. The ultraviolet ray emission surface of the LED substrate 31 faces rightward.

[0040] The ultraviolet irradiator 17 is disposed on the left side of the substrate 2. The ultraviolet irradiator 17 irradiates the substrate 2 with ultraviolet light from the left side immediately after ink has landed thereon. In this embodiment, the vertical position of the ultraviolet irradiator 17 is adjustable. In addition, the horizontal position of the ultraviolet irradiator 17 and the inclination of the ultraviolet irradiator 17 relative to the axis of the substrate 2 when viewed from the vertical direction are adjustable. In this embodiment, when printing on a substrate 2 having a cylindrical outer shape, the ultraviolet irradiator 17 is installed so that the ultraviolet light emission surface of the ultraviolet irradiator 17 (i.e., the ultraviolet light emission surface of the LED substrate 31) is parallel to the front-to-rear direction. In addition, when printing on a substrate 2 having a truncated cone or conical outer shape, the inclination of the ultraviolet irradiator 17 is adjusted so that the ultraviolet light emission surface of the ultraviolet irradiator 17 is parallel to the left edge of the substrate 2.

[0041] (Configuration of the first rotating part and the second rotating part) Figure 5(A) is a side view of the second rotating part 25 shown in Figure 3, Figure 5(B) is a side view of the first rotating part 23 shown in Figure 3, and Figures 5(C) and (D) are cross-sectional views of the first rotating part 23 shown in Figure 5(B).

[0042] As described above, the rotation mechanism 16 includes a first rotating unit 23 that holds the rear end of the substrate 2 (more specifically, the end of the substrate 2 on the third direction side), and a second rotating unit 25 that holds the front end of the substrate 2 (more specifically, the end of the substrate 2 on the fourth direction side). The first rotating unit 23 includes a headed screw 35 having a head 35a and a shaft 35b, a nut 36 that engages with the male thread formed on the shaft 35b, a holding member 37 made of an annular elastic body and whose outer surface contacts the inner circumferential surface of the substrate 2, a contact member 38 that contacts the holding member 37, and an annular member 39 that contacts the end surface of the substrate 2. The head 35a, holding member 37, contact member 38, annular member 39, and nut 36 are arranged in this order in the axial direction of the shaft 35b.

[0043] When the printing material 2 is correctly attached to the rotation mechanism 16, the axial direction of the shaft portion 35b of the screw 35 coincides with the axial direction of the printing material 2. If one side of the axial direction of the shaft portion 35b, that is, the V1 direction side in Fig. 5, is defined as the first direction side, and the other side of the axial direction of the shaft portion 35b opposite the first direction side (the V2 direction side in Fig. 5) is defined as the second direction side, when the printing material 2 is correctly attached to the rotation mechanism 16, the first direction side coincides with the above-mentioned fourth direction side, and the second direction side coincides with the above-mentioned third direction side.

[0044] The holding member 37 is a chuck that contacts the print medium 2 and holds the end of the print medium 2 on the third direction side. The holding member 37 is arranged on the inner peripheral side of the print medium 2. As described above, the holding member 37 is made of an elastic body. Specifically, the holding member 37 is formed of a highly elastic material that adheres closely to the print medium 2. The holding member 37 in this embodiment is made of rubber. The holding member 37 is formed in an annular shape. Furthermore, the holding member 37 is formed in a cylindrical shape with the axial length of the shaft portion 35b being relatively short. This makes it possible for the outer peripheral surface of the holding member 37 to be in surface contact with the inner peripheral surface of the print medium 2.

[0045] A portion of the shaft portion 35b is disposed on the inner circumferential side of the holding member 37. A portion of the head portion 35a may also be disposed on the inner circumferential side of the holding member 37. That is, at least a portion of the shaft portion 35b is disposed on the inner circumferential side of the holding member 37. The inner diameter of the holding member 37 is larger than the outer diameter of the shaft portion 35b. A substantially uniform gap is formed between the inner circumferential surface of the holding member 37 and the outer circumferential surface of the shaft portion 35b over the entire circumferential area of ​​the holding member 37.

[0046] The surface of the holding member 37 on the first direction side is formed with a tapered surface 37a whose outer diameter gradually decreases toward the second direction side. The tapered surface 37a is formed between a radially intermediate position of the end surface of the holding member 37 on the first direction side and the inner circumferential surface of the holding member 37. The surface of the holding member 37 on the second direction side is formed with a tapered surface 37b whose outer diameter gradually decreases toward the first direction side. The tapered surface 37b is formed between a radially intermediate position of the end surface of the holding member 37 on the second direction side and the inner circumferential surface of the holding member 37. The inclination angle of the tapered surface 37a and the inclination angle of the tapered surface 37b are equal. However, the inclination angle of the tapered surface 37a and the inclination angle of the tapered surface 37b may be different.

[0047] The head 35a constitutes the end of the screw 35 on the first direction side. The outer diameter of the head 35a is smaller than the inner diameter of the material to be printed 2. The head 35a is arranged on the inner periphery of the material to be printed 2. The outer diameter of the head 35a is larger than the inner diameter of the holding member 37. The end of the shaft 35b on the second direction side is connected to a rotating shaft 40 (see Figures 3 and 4). The rotating shaft 40 is rotatably held by the first holding part 24. The axis of the screw 35 coincides with the axis of the rotating shaft 40.

[0048] The screw 35 is a flat head screw. The head 35a has a truncated conical seat. That is, the surface of the head 35a on the second direction side has a tapered surface 35c whose outer diameter gradually decreases toward the second direction side. The inclination angle of the tapered surface 35c is equal to the inclination angle of the tapered surface 37a. The head 35a contacts the holding member 37 from the first direction side. The tapered surface 35c is capable of contacting the tapered surface 37a of the holding member 37. The tapered surface 35c in this embodiment is a first tapered surface. The tapered surface 37a is a third tapered surface that is capable of contacting the first tapered surface, tapered surface 35c.

[0049] The annular member 39 is formed in a circular, flat plate shape. The annular member 39 is arranged so that the thickness direction of the annular member 39 coincides with the axial direction of the shaft portion 35b. A portion of the shaft portion 35b is arranged on the inner circumferential side of the annular member 39. The outer diameter of the annular member 39 is larger than the inner diameter of the material to be printed 2. The outer diameter of the annular member 39 is also smaller than the outer diameter of the end portion of the material to be printed 2 on the third direction side. The annular member 39 is in contact with the end face of the material to be printed 2 on the third direction side.

[0050] The contact member 38 is formed, for example, from resin. The contact member 38 is formed in an annular shape. The contact member 38 is also formed in a generally cylindrical shape with the axial length of the shaft portion 35b being relatively short. The outer diameter of the contact member 38 is smaller than the inner diameter of the medium to be printed 2. A portion of the shaft portion 35b is disposed on the inner circumferential side of the contact member 38. The inner diameter of the contact member 38 is substantially equal to the outer diameter of the shaft portion 35b. The contact member 38 is movable relative to the shaft portion 35b in the axial direction of the shaft portion 35b. The contact member 38 is composed of a fixed portion 38a fixed to the inner circumferential surface of the annular member 39 and a tapered portion 38b disposed on the first direction side of the annular member 39. The tapered portion 38b is disposed on the inner circumferential side of the medium to be printed 2.

[0051] A tapered surface 38c having a tapered shape in which the outer diameter gradually decreases toward the first direction side is formed on the surface of the tapered portion 38b on the first direction side. That is, the tapered surface 38c is formed on the surface on the first direction side of the contact member 38. The inclination angle of the tapered surface 38c is equal to the inclination angle of the tapered surface 37b. The contact member 38 contacts the holding member 37 from the second direction side. Furthermore, the tapered surface 38c is capable of contacting the tapered surface 37b of the holding member 37. The tapered surface 38c in this embodiment is a second tapered surface. Furthermore, the tapered surface 37b is a fourth tapered surface with which the tapered surface 38c, which is the second tapered surface, can come into contact.

[0052] In this embodiment, tapered surface 35c is formed on head 35a, tapered surface 38c is formed on contact member 38, and tapered surface 37a that contacts tapered surface 35c and tapered surface 37b that contacts tapered surface 38c are formed on retaining member 37. Therefore, even if the inner diameter of retaining member 37 is larger than the outer diameter of shank 35b, the axis of retaining member 37, which is formed in an annular shape, substantially coincides with the axis of screw 35. Nut 36 is disposed on the second direction side relative to contact member 38 and annular member 39. A washer 41 is disposed between nut 36 and annular member 39.

[0053] In this embodiment, when the nut 36 is turned in a direction in which the head 35a and the nut 36 move closer to each other (i.e., when the nut 36 is tightened relative to the screw 35), the contact member 38 and the annular member 39 move relative to the head 35a in the direction in which the head 35a and the contact member 38 move closer to each other. When the contact member 38 moves relative to the head 35a in the direction in which the head 35a and the contact member 38 move closer to each other, the retaining member 37 elastically deforms, and the outer diameter of the retaining member 37 expands (see FIG. 5(C)). That is, the retaining member 37 expands radially outward, increasing the outer diameter of the retaining member 37. At this time, the tapered surface 37a of the retaining member 37 contacts the tapered surface 35c of the head 35a, and the tapered surface 37b of the retaining member 37 contacts the tapered surface 38c of the contact member 38.

[0054] On the other hand, when the nut 36 is turned in a direction that separates the head 35a from the nut 36 (i.e., when the nut 36 is loosened from the screw 35), the contact member 38 and the annular member 39 move relative to the head 35a in a direction that separates the head 35a from the contact member 38. When the contact member 38 moves relative to the head 35a in a direction that separates the head 35a from the contact member 38, the retaining member 37 elastically deforms, and the outer diameter of the retaining member 37 narrows (see FIG. 5(D)). That is, the retaining member 37 contracts radially inward, and the outer diameter of the retaining member 37 becomes smaller.

[0055] The second rotating unit 25 includes a holding member 44 that contacts the end of the printing medium 2 on the fourth direction side, a fixed member 45 to which the holding member 44 is fixed, and a rotating shaft 46 to which the fixed member 45 is attached. The fixed member 45 is formed, for example, in the shape of a stepped cylinder. The end of the rotating shaft 46 on the second direction side is inserted into the inner periphery of the fixed member 45. The rotating shaft 46 is rotatably held by the second holding unit 26.

[0056] The holding member 44 is a chuck that contacts the end of the print medium 2 on the fourth direction side and holds the end of the print medium 2 on the fourth direction side. The holding member 44 is made of an elastic material similar to the holding member 37. That is, the holding member 44 is made of rubber. The holding member 44 is also formed in an annular shape. The holding member 44 is composed of a disk-shaped small-diameter portion 44a arranged on the inner periphery of the print medium 2 and a tapered portion 44c with a tapered surface 44b that contacts the end of the print medium 2 on the fourth direction side. The outer diameter of the small-diameter portion 44a is approximately equal to the inner diameter of the print medium 2. The tapered surface 44b is formed in a tapered shape such that the outer diameter gradually decreases toward the second direction side. The axis of the small-diameter portion 44a and the axis of the tapered portion 44c coincide with the axis of the rotation shaft 46.

[0057] (Configuration of the peripheral parts of the second rotating part and the second holding part) Fig. 6 is a plan view for explaining the configuration of the rotation mechanism 16 shown in Fig. 2. Fig. 7 is a cross-sectional view of the E-E cross section of Fig. 6. Figs. 8 and 9 are enlarged plan views for explaining the configuration of part F of Fig. 6. Note that Figs. 3 and 4 omit illustration of the configuration described below.

[0058] In addition to the above-described configuration, the rotation mechanism 16 includes a guide rail 50 for guiding the second holding part 26 in the axial direction of the printing medium 2, and a guide block 51 (see FIG. 7) that engages with the guide rail 50 and to which the second holding part 26 is fixed. The guide rail 50 is fixed to the rotating frame 27. The guide block 51 engages with the guide rail 50 from above. The guide block 51 is disposed below the second holding part 26. The guide block 51 moves in the axial direction of the printing medium 2 together with the second rotating part 25 and the second holding part 26.

[0059] The rotation mechanism 16 also includes a fixed member 52 fixed to the guide block 51, a slide member 53 held by the fixed member 52 and movable relative to the fixed member 52 in the axial direction of the medium 2 to be printed, an engagement member 54 held by the slide member 53 and rotatable relative to the slide member 53 in the left-right direction as the axial direction of the rotation, a restriction member 55 for restricting movement of the slide member 53 and the engagement member 54 in the fourth direction, and a rotation member 56 held by the fixed member 52 and rotatable relative to the fixed member 52 in the up-down direction as the axial direction of the rotation. In this embodiment, the second rotating unit 25, the second holding unit 26, the guide block 51, the fixed member 52, the rotation member 56, etc. form a moving body 57. The slide member 53 is held by the moving body 57 and is movable relative to the moving body 57 in the axial direction of the medium 2 to be printed.

[0060] Furthermore, the rotation mechanism 16 includes a torsion coil spring 59 (see Figure 7) as a first biasing member that biases the engaging member 54 to one side in the rotation direction of the engaging member 54 relative to the slide member 53, a fixed shaft 60 fixed to the slide member 53, a compression coil spring 61 as a second biasing member that biases the moving body 57 relative to the slide member 53, a tension coil spring 62 that biases the rotating member 56 to one side in the rotation direction of the rotating member 56 relative to the fixed member 52, and a detection mechanism 63 for detecting that the printing material 2 is correctly attached to the rotation mechanism 16.

[0061] The slide member 53 is formed with a guide hole 53a for guiding the slide member 53 relative to the fixed member 52 in the axial direction of the print medium 2 and for restricting the range of movement of the slide member 53 relative to the fixed member 52 in the axial direction of the print medium 2 (see FIG. 7). The guide hole 53a is an elongated hole that is long in the axial direction of the print medium 2. A part of a guide screw 65 that is fixed to the fixed member 52 is disposed in the guide hole 53a. In this embodiment, the guide hole 53a and the guide screw 65 form a slide member restricting portion 66 that restricts the range of movement of the slide member 53 relative to the movable body 57 in the axial direction of the print medium 2 (see FIG. 7). The slide member 53 is equipped with a rotation restricting portion 53b that restricts rotation of the rotating member 56 to one side in the rotation direction of the rotating member 56 relative to the fixed member 52, and a spring engaging portion 53c with which one end of the torsion coil spring 59 comes into contact.

[0062] The fixed shaft 60 is arranged so that its axial direction coincides with the axial direction of the printing medium 2. The fourth direction side end of the fixed shaft 60 is fixed to the slide member 53. A through hole is formed in the second holding portion 26, in which a part of the fixed shaft 60 is arranged. A part of the fixed shaft 60 is arranged on the inner circumferential side of the compression coil spring 61. The fourth direction side end of the compression coil spring 61 is in contact with the slide member 53. The third direction side end of the compression coil spring 61 is in contact with the second holding portion 26. The compression coil spring 61 biases the moving body 57 in the third direction relative to the slide member 53.

[0063] The regulating member 55 is formed in an elongated shape that is long and narrow in the axial direction of the print medium 2. The regulating member 55 is fixed to the rotating frame 27. The regulating member 55 has a saw-tooth regulating portion 55b on which a plurality of regulating surfaces 55a (specifically, a large number of regulating surfaces 55a) are formed that are arranged at a constant pitch in the axial direction of the print medium 2 (see FIG. 7). The regulating portion 55b is formed on the upper surface of the regulating member 55. The regulating surface 55a is an inclined surface that slopes upward as it approaches the fourth direction side.

[0064] The engagement member 54 is rotatable relative to the slide member 53 around a rotation center shaft 67 (see FIG. 7) fixed to the end of the slide member 53 on the third direction side. The rotation center shaft 67 is arranged so that the axial direction of the rotation center shaft 67 coincides with the left-right direction. The rotation center shaft 67 is arranged below the spring engagement portion 53c. An insertion hole through which the rotation center shaft 67 is inserted is formed in the end of the engagement member 54 on the third direction side. The engagement member 54 has an engagement portion 54a that engages with the restriction surface 55a (see FIG. 7). The engagement portion 54a forms the lower end of the engagement member 54. When the printing medium 2 is correctly attached to the rotation mechanism 16, the end face on the fourth direction side of the engagement portion 54a contacts the restriction surface 55a with a predetermined contact pressure.

[0065] The engaging member 54 has a guide hole 54b formed therein for guiding the engaging member 54 in the direction in which the engaging member 54 rotates relative to the slide member 53 and for restricting the range of rotation of the engaging member 54 relative to the slide member 53 (see FIG. 7). The guide hole 54b is disposed on the fourth direction side of the rotation center shaft 67. The guide hole 54b is also disposed above the rotation center shaft 67. When viewed from the left-right direction, the shape of the guide hole 54b is formed in an arc shape with the axis of the rotation center shaft 67 as the center of curvature. A guide screw 68 that is fixed to the slide member 53 is inserted into the guide hole 54b.

[0066] A part of the rotation center shaft 67 is disposed on the inner peripheral side of the torsion coil spring 59. One end of the torsion coil spring 59 contacts the spring engaging portion 53c of the slide member 53. The other end of the torsion coil spring 59 contacts the engaging member 54. When viewed from the right side, the torsion coil spring 59 biases the engaging member 54 in a counterclockwise direction (counterclockwise direction in FIG. 7) around the rotation center shaft 67. The engaging portion 54a constituting the lower end of the engaging member 54 is disposed above the restricting portion 55b. The torsion coil spring 59 biases the engaging member 54 in a direction in which the engaging portion 54a faces the restricting portion 55b.

[0067] When engaging member 54 is rotated against the biasing force of torsion coil spring 59 (i.e., when engaging member 54 is rotated clockwise as viewed from the right side so that engaging portion 54a moves away from restricting portion 55b), engaging portion 54a disengages from restricting surface 55a, as shown by the two-dot chain line in Figure 7. Therefore, when engaging member 54 is rotated against the biasing force of torsion coil spring 59, it becomes possible to move slide member 53 and engaging member 54 in the fourth direction. Note that a finger hook 54c is formed on the upper end of engaging member 54 on the fourth direction side.

[0068] When the printing material 2 is properly attached to the rotation mechanism 16, the movement of the slide member 53 and the engagement member 54 in the fourth direction is restricted by the restriction surface 55a and the engagement portion 54a in contact with the restriction surface 55a. Furthermore, when the printing material 2 is properly attached to the rotation mechanism 16, the compression coil spring 61 is compressed by a predetermined amount, and the biasing force of the compression coil spring 61 biases the moving body 57 in the third direction relative to the slide member 53. Therefore, when the printing material 2 is properly attached to the rotation mechanism 16, the end of the printing material 2 on the fourth direction side contacts the tapered surface 44b of the holding member 44 with a predetermined contact pressure, and the end face of the printing material 2 on the third direction side contacts the annular member 39 with a predetermined contact pressure.

[0069] The rotating member 56 is rotatable relative to the fixed member 52 around a rotation center shaft fixed to the end of the fixed member 52 on the third direction side. This rotation center shaft is arranged so that the axial direction of the rotation center shaft and the up-and-down direction generally coincide. The rotating member 56 includes a restricted portion 56a arranged on the fourth direction side of the rotation restricting portion 53b, and a spring engaging portion 56b with which the end of the tension coil spring 62 on the fourth direction side engages. The restricted portion 56a is arranged at the left end of the rotating member 56 on the fourth direction side. The spring engaging portion 56b is arranged on the third direction side of the restricted portion 56a.

[0070] The detection mechanism 63 is an interlock switch having a contact member that forms a contact portion and a lever 63a that presses the contact member. The detection mechanism 63 is arranged on the third direction side of the rotating member 56. The detection mechanism 63 is attached to the fixed member 52 so that the lever 63a is arranged on the fourth direction side of the main body of the detection mechanism 63. The end of the rotating member 56 on the third direction side can come into contact with the lever 63a from the fourth direction side.

[0071] The end of the tension coil spring 62 on the third direction side is engaged with the second holding portion 26. The end of the tension coil spring 62 on the fourth direction side is engaged with the spring engaging portion 56b of the rotating member 56, as described above. When viewed from above, the tension coil spring 62 biases the rotating member 56 in a clockwise direction (clockwise direction in FIGS. 8 and 9) around the rotation center of the rotating member 56. Rotation of the rotating member 56 in the clockwise direction in FIGS. 8 and 9 is restricted by the rotation restricting portion 53b arranged on the third direction side of the restricted portion 56a.

[0072] When the printing medium 2 is correctly attached to the rotation mechanism 16, the compression coil spring 61 is compressed by a predetermined amount, the slide member 53 moves relatively in the third direction with respect to the movable body 57, and the rotation restricting portion 53b moves in the third direction. At this time, as shown in Fig. 9, the rotating member 56 rotates in the clockwise direction in Fig. 9, and the end portion of the rotating member 56 on the third direction side presses the lever 63a in the third direction. Specifically, the end portion of the rotating member 56 on the third direction side presses the lever 63a in the third direction to a position where the lever 63a presses the contact member of the detection mechanism 63.

[0073] Therefore, the detection mechanism 63 detects that the printing medium 2 is correctly attached to the rotation mechanism 16. On the other hand, for example, when the printing medium 2 is not attached to the rotation mechanism 16, the compression coil spring 61 is not compressed, and the end of the rotating member 56 on the third direction side is separated from the lever 63a (see FIG. 8). At this time, the lever 63a is not in contact with the contact member of the detection mechanism 63. Therefore, the detection mechanism 63 is in the OFF state.

[0074] (How to set the printing material) FIG. 10 is a diagram for explaining a setting method when setting the printing medium 2 on the rotation mechanism 16 shown in FIG.

[0075] When setting the printed material 2 in the rotation mechanism 16, the operator first moves the movable body 57 together with the slide member 53 and the engaging member 54 in the fourth direction to a position where the printed material 2 can be placed between the first rotating part 23 and the second rotating part 25, and then attaches the end of the printed material 2 on the third direction side to the first rotating part 23.

[0076] In this case, for example, the outer diameter of the holding member 37 is narrowed to a position where the outer peripheral surface of the holding member 37 does not contact the inner peripheral surface of the print medium 2 (see FIG. 5(D)), and then the holding member 37 etc. is placed on the inner peripheral side of the print medium 2, and the nut 36 is turned in the direction in which the head 35a and the nut 36 move closer to each other, thereby widening the outer diameter of the holding member 37 until the outer peripheral surface of the holding member 37 contacts the inner peripheral surface of the print medium 2 with a predetermined contact pressure (see FIG. 5(C)). Alternatively, the print medium 2 is press-fitted into the holding member 37 whose outer diameter has been widened in advance until the outer peripheral surface of the holding member 37 contacts the inner peripheral surface of the print medium 2 with a predetermined contact pressure.

[0077] Thereafter, the operator pushes the slide member 53 in the third direction until the second rotating part 25 contacts the end of the fourth direction of the print medium 2, the end of which is attached to the first rotating part 23 at the third direction (see FIG. 10(A)). That is, the operator pushes the slide member 53 in the third direction until the tapered surface 44b of the holding member 44 contacts the end of the print medium 2 at the fourth direction. Thereafter, the operator further pushes the slide member 53 in the third direction to set the print medium 2 in the rotation mechanism 16 (see FIG. 10(B)). That is, the slide member 53 and the engaging member 54 are moved in the third direction until the compression coil spring 61 is compressed by a predetermined amount, thereby setting the print medium 2 in the rotation mechanism 16. For example, the slide member 53 is pushed in the third direction by two to four restriction surfaces 55a.

[0078] When the slide member 53 and the engaging member 54 move in the third direction, the movable body 57 is also pushed by the compression coil spring 61 and moves in the third direction. Furthermore, when the slide member 53 and the engaging member 54 are moved in the third direction until the compression coil spring 61 is compressed by a predetermined amount, the end of the print medium 2 on the fourth direction side comes into contact with the tapered surface 44b of the holding member 44 at a predetermined contact pressure, and the end face of the print medium 2 on the third direction side comes into contact with the annular member 39 at a predetermined contact pressure. When the print medium 2 is to be removed from the rotation mechanism 16, the engaging member 54 is rotated against the biasing force of the torsion coil spring 59, and the slide member 53 and the engaging member 54 are moved in the fourth direction to a position where the print medium 2 can be removed from between the first rotating part 23 and the second rotating part 25.

[0079] (Main effect of this form) As described above, in this embodiment, the first rotating part 23, which holds the end of the print medium 2 on the third direction side and rotates together with the print medium 2, is provided with a holding member 37 made of an annular elastic body and whose outer surface contacts the inner surface of the print medium 2. Also, in this embodiment, when the nut 36 is turned in a direction that brings the head 35a of the screw 35 and the nut 36 closer to each other, the holding member 37 elastically deforms and the outer diameter of the holding member 37 increases, and when the nut 36 is turned in a direction that moves the head 35a and the nut 36 away from each other, the holding member 37 elastically deforms and the outer diameter of the holding member 37 decreases.

[0080] Therefore, in this embodiment, by turning the nut 36 in the direction in which the head 35a and the nut 36 approach each other to increase the outer diameter of the holding member 37, it is possible to increase the contact pressure between the outer surface of the holding member 37 that contacts the inner surface of the substrate 2 and the inner surface of the substrate 2. Therefore, in this embodiment, it is possible to suppress slippage between the first rotating part 23 and the substrate 2. Furthermore, in this embodiment, it is possible to change the size of the outer diameter of the holding member 37 depending on the position of the nut 36 relative to the head 35a. Therefore, it is possible to increase the contact pressure between the outer surface of the holding member 37 and the inner surface of the substrate 2 even if the size of the inner diameter of the substrate 2 changes. Therefore, in this embodiment, it is possible to suppress slippage between the first rotating part 23 and the substrate 2 even if the size of the inner diameter of the substrate 2 changes.

[0081] In this embodiment, a tapered surface 35c is formed on the second-direction side surface of the head 35a of the screw 35, and a second tapered surface 38c is formed on the first-direction side surface of the contact member 38. Furthermore, in this embodiment, the retaining member 37 is formed with a tapered surface 37a that can contact the tapered surface 35c and a tapered surface 37b that can contact the tapered surface 38c. Therefore, in this embodiment, when the nut 36 is turned, the outer diameter of the retaining member 37 can be uniformly widened or narrowed over the entire circumferential area of ​​the retaining member 37. Therefore, in this embodiment, the axis of the first rotating part 23 and the axis of the printing medium 2 can be precisely aligned.

[0082] In this embodiment, the position of the movable body 57 in the axial direction of the print medium 2 can be adjusted, and when setting the print medium 2 in the rotation mechanism 16, the movable body 57 is moved in the fourth direction together with the slide member 53 and the engaging member 54 to a position where the print medium 2 can be placed between the first rotating unit 23 and the second rotating unit 25, and the end of the print medium 2 on the third direction side is attached to the first rotating unit 23. In this embodiment, the movable body 57 is then moved in the third direction together with the slide member 53 and the engaging member 54, and the end of the print medium 2 on the fourth direction side is attached to the second rotating unit 25. Therefore, in this embodiment, the print medium 2 can be easily attached to the rotation mechanism 16.

[0083] In this embodiment, by rotating engaging member 54 in the direction opposite to the direction of bias by torsion coil spring 59, the engagement state between restricting surface 55a of restricting member 55 and engaging portion 54a of engaging member 54 is released, and sliding member 53 and engaging member 54 can be moved in the fourth direction. Therefore, in this embodiment, sliding member 53 and engaging member 54 can be moved in the fourth direction with a simple operation.

[0084] In this embodiment, the slide member 53 is pushed in the third direction until the second rotating part 25 contacts the end of the fourth direction of the print medium 2, whose end on the third direction is attached to the first rotating part 23. Then, the slide member 53 is further pushed in the third direction to set the print medium 2 in the rotation mechanism 16. Therefore, in this embodiment, the biasing force of the compression coil spring 61 can increase the contact pressure between the end of the print medium 2 on the fourth direction side and the second rotating part 25 (specifically, the contact pressure between the end of the print medium 2 on the fourth direction side and the tapered surface 44b of the holding member 44) and the contact pressure between the end face of the print medium 2 on the third direction side and the annular member 39 of the first rotating part 23. Therefore, in this embodiment, the holding force of the print medium 2 held by the first rotating part 23 and the second rotating part 25 can be increased.

[0085] (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.

[0086] In the above-described embodiment, the screw 35 does not have to be a flat head screw. That is, the tapered surface 35c does not have to be formed on the head 35a. In this case, the tapered surface 37a does not have to be formed on the retaining member 37. Also, in the above-described embodiment, the tapered surface 38c does not have to be formed on the contact member 38. In this case, the tapered surface 37b does not have to be formed on the retaining member 37. If the tapered surfaces 35c, 37a, 37b, and 38c are not formed, it is preferable that the inner diameter of the retaining member 37 is approximately equal to the outer diameter of the shank 35b. In this case, even if the tapered surfaces 35c, 37a, 37b, and 38c are not formed, as long as the inner diameter of the retaining member 37 is approximately equal to the outer diameter of the shank 35b, it is possible to uniformly widen or narrow the outer diameter of the retaining member 37 throughout the entire circumferential direction of the retaining member 37 when the nut 36 is turned.

[0087] In the above-described embodiment, the second rotating part 25 may be configured similarly to the first rotating part 23. In this case, the second rotating part 25 corresponds to the rotating part of the present invention. Also, in the above-described embodiment, for example, if the screw 35 is not a flat head screw, a contact member configured similarly to the contact member 38 may be disposed between the head 35a and the holding member 37. Furthermore, in the above-described embodiment, the axial intermediate portion of the printing medium 2, excluding the end on the third direction side of the printing medium 2 held by the first rotating part 23 and the end on the fourth direction side of the printing medium 2 held by the second rotating part 25, does not have to be formed in a cylindrical shape.

[0088] In the above-described embodiment, the contact member 38 and the annular member 39 may be integrally formed. The nut 36 and the annular member 39 may be integrally formed, or the nut 36, the contact member 38, and the annular member 39 may be integrally formed. In the above-described embodiment, the holding member 37 may be made of an elastic material other than rubber. Furthermore, in the above-described embodiment, the rotation mechanism 16 may be provided with a spring member other than the torsion coil spring 59 in place of the torsion coil spring 59, or a spring member other than the compression coil spring 61 in place of the compression coil spring 61.

[0089] In the above-described embodiment, if only printing on a substrate 2 having a fixed outer diameter is performed by the printing device 1, the vertical position of the ultraviolet irradiator 17 does not have to be adjustable. Also, in the above-described embodiment, if only printing on a substrate 2 having a cylindrical outer shape is performed by the printing device 1, the inclination of the rotation mechanism 16 relative to the horizontal when viewed from the left and right does not have to be adjustable, and the inclination of the ultraviolet irradiator 17 relative to the axis of the substrate 2 when viewed from the top and bottom does not have to be adjustable.

[0090] In the above-described embodiment, the ultraviolet irradiation device 4 may be placed on the table 5 so that the axial direction of the print medium 2 coincides with the left-right direction when viewed from the top-bottom direction. Also, in the above-described embodiment, the ultraviolet irradiator 17 may be disposed below the print medium 2 or to the right of the print medium 2. Furthermore, in the above-described embodiment, the printing apparatus 1 may be provided with a Y-bar drive mechanism, instead of the stage drive mechanism 12, that moves the Y-bar 8 in the sub-scanning direction together with the head 3 and carriage 7. [Explanation of symbols]

[0091] 1 Printing device 2 Printing material 3 heads (inkjet heads) 4 Ultraviolet irradiation device 5 tables 16 Rotation mechanism 17 Ultraviolet irradiator 21 Motor 22 Power transmission mechanism 23 First rotating part (rotating part) 24 1st holding part 25 Second Rotating Section 26 Second holding part 35 screws 35a head 35b Shaft 35c Tapered surface (first tapered surface) 36 Nut 37 Retaining member 37a Tapered surface (third tapered surface) 37b Tapered surface (fourth tapered surface) 38 Contact member 38c Tapered surface (second tapered surface) 39 Annular member 50 guide rail 51 Guide Block 53 Slide member 54 Engagement member 54a Engagement part 55 Regulatory components 55a Regulatory aspects 55b Regulatory Department 57 Mobile 59 Torsion coil spring (first biasing member) 61 compression coil spring (second biasing member) 66 Slide member restricting portion V1 1st direction side V2 2nd direction side 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 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 ink is attached, the rotation mechanism includes a rotating part that holds an end of the printing medium in a direction of an axial center of the printing medium and rotates together with the printing medium; The end of the printing medium held by the rotating part is formed in a cylindrical shape, the rotating part includes a headed screw having a head and a shaft, a nut that engages with the male thread formed on the shaft, a holding member made of an annular elastic body and whose outer surface contacts the inner circumferential surface of the printing medium, and an annular contact member that contacts the holding member; At least a portion of the shaft portion is disposed on the inner peripheral side of the holding member, a part of the shaft portion is disposed on the inner peripheral side of the contact member, the head, the holding member, the contact member, and the nut are arranged in this order in the axial direction of the shaft portion, When the nut is turned in a direction that brings the head and the nut closer together, the retaining member elastically deforms and the outer diameter of the retaining member expands, and when the nut is turned in a direction that moves the head and the nut apart, the retaining member elastically deforms and the outer diameter of the retaining member narrows.

2. When one side in the axial direction of the shaft portion is defined as a first direction side and the side opposite to the first direction side is defined as a second direction side, the head portion contacts the holding member from the first direction side, the contact member contacts the holding member from the second direction side, a first tapered surface having an outer diameter that gradually decreases toward the second direction is formed on a surface of the head on the second direction side; a second tapered surface having an outer diameter that gradually decreases toward the first direction side is formed on a surface of the contact member on the first direction side; 2. The ultraviolet irradiation device according to claim 1, wherein the holding member is formed with a third tapered surface with which the first tapered surface can come into contact and a fourth tapered surface with which the second tapered surface can come into contact.

3. 3. The ultraviolet irradiation device according to claim 1, wherein the holding member is made of rubber.

4. If one side of the axis of the printing medium is defined as a third direction side, the rotation mechanism includes the rotating unit that holds the end of the printing medium on the third direction side, a first holding unit that rotatably holds the rotating unit, a motor that rotates the rotating unit, and a power transmission mechanism that connects the rotating unit and the motor, 3. The ultraviolet irradiation device according to claim 1, wherein the rotating portion includes an annular member that contacts an end surface of the printing medium on the third direction side.

5. If the side opposite to the third direction side is defined as a fourth direction side, the rotation mechanism includes a second rotating unit that holds the other end of the printing medium on the fourth direction side and rotates together with the printing medium, and a second holding unit that rotatably holds the second rotating unit, the second holding portion is movable together with the second rotating portion in the direction of the axis of the printing medium, 5. The ultraviolet irradiation device according to claim 4, wherein the positions of the second rotating part and the second holding part in the axial direction of the printing medium are adjustable.

6. 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 guide rail for guiding the second holding part in the direction of the axis of the medium to be printed, a guide block that engages with the guide rail and to which the second holding part is fixed, a slide member that is held by a moving body including the second holding part and the guide block and that is movable relative to the moving body in the direction of the axis of the medium to be printed, an engaging member that is held by the slide member and that is rotatable relative to the slide member with the left-right direction as its axial direction, a restricting member that restricts movement of the slide member and the engaging member in the fourth direction, a first biasing member that biases the engaging member to one side in the rotation direction of the engaging member relative to the slide member, a second biasing member that biases the moving body against the slide member, and a slide member restricting part that restricts the movement range of the slide member in the direction of the axis of the medium to be printed relative to the moving body, the regulating member includes a sawtooth-shaped regulating portion having a plurality of regulating surfaces arranged at a constant pitch in the axial direction of the printing medium, The restriction surface is an inclined surface that is inclined upward as it approaches the fourth direction side, the engaging member includes an engaging portion that engages with the restriction surface, the first biasing member biases the engaging member in a direction in which the engaging portion faces the restriction surface, 6. The ultraviolet irradiation device according to claim 5, wherein the second biasing member biases the moving body in the third direction relative to the sliding member.

7. 3. 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.

8. 7. A method for setting the printing medium on the rotation mechanism in the ultraviolet irradiation device according to claim 6, comprising: A method for setting a printed material, characterized in that the sliding member is pushed in the third direction until the second rotating member contacts the fourth direction end of the printed material with the third direction end attached to the rotating member, and then the sliding member is further pushed in the third direction to set the printed material in the rotating mechanism.

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