Liquid dispensing device

Abstract

This system efficiently irradiates UV-curable ink with ultraviolet light while suppressing missed spots during irradiation. [Solution] The liquid ejection device 1 comprises a head 3 for ejecting ultraviolet-curable ink, an irradiation unit 10 for irradiating ultraviolet light L, and a cleaning unit 7 for cleaning the nozzle surface 31 of the head 3. The irradiation unit 10 has an aperture defining member 15 that defines the irradiation range irradiated from the light source 11 to the printing medium P by changing the aperture width of the opening 151. The device has multiple printing modes, including a first mode selected when the aperture width is a first width B1, and a second mode selected when the aperture width is a second width B2 that is narrower than the first width B1, wherein the second mode has a longer cleaning interval or higher driving power than the first mode.

Description

Technical Field

[0001] The present invention relates to a liquid ejection device.

Background Art

[0002] Conventionally, various liquid ejection devices have been used, which include a head that ejects ultraviolet-curable ink from nozzles provided on a nozzle surface, and an irradiation unit that irradiates ultraviolet light onto the ultraviolet-curable ink landed on a printing medium. In a liquid ejection device having such a configuration, it is possible to suitably suppress bleeding and color mixing of an image formed on a printing medium. Therefore, for example, Patent Document 1 discloses an inkjet recording device including a recording head that uses an ink containing a water-soluble monomer and a photoinitiator that are cured by ultraviolet irradiation, and an ultraviolet lamp.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional liquid ejection device having such a configuration, in order to suppress a decrease in ejection performance caused by the adhesion and fixation of ultraviolet-curable ink attached to the nozzle surface, it is common to periodically clean the nozzle surface. For example, the inkjet recording device of Patent Document 1 is described as being capable of changing the irradiation conditions of ultraviolet light and performing cleaning of the nozzle surface at a predetermined cleaning interval regardless of the type of printing medium and the printing mode. However, it has been difficult to improve production efficiency with a liquid ejection device that only changes the irradiation conditions of ultraviolet light. During cleaning of the nozzle surface, printing is not performed, and cleaning of the nozzle surface causes a decrease in production efficiency. However, simply changing the irradiation conditions of ultraviolet light does not lead to an increase in the cleaning interval. [Means for solving the problem]

[0005] The liquid dispensing device of the present invention for solving the above problems comprises: a head for dispensing ultraviolet-curable ink from a nozzle provided on the nozzle surface; an irradiation unit for irradiating ultraviolet light onto the ultraviolet-curable ink that has landed on a printing medium; a moving unit capable of moving the printing medium and the irradiation unit relative to each other; a cleaning unit for cleaning the nozzle surface; and a control unit, wherein the head is arranged side by side with respect to the irradiation unit in the relative movement direction; the irradiation unit comprises a light source for irradiating ultraviolet light; and an aperture defining member having an opening and defining the irradiation range of the ultraviolet light irradiated from the light source onto the printing medium in the relative movement direction by changing the opening width of the opening; and the control unit is Multiple printing modes can be selected according to the aperture width, and the multiple printing modes include a first mode selected when the aperture width is a first width, and a second mode selected when the aperture width is a second width narrower than the first width, wherein the first mode is characterized in that the drive current of the light source is a first current and the cleaning interval of the nozzle surface by the cleaning unit is a first interval, and the second mode is characterized in that either the drive current of the light source is a first current and the cleaning interval is a second interval longer than the first interval, or the drive current of the light source is a second current greater than the first current and the cleaning interval is the first interval. [Brief explanation of the drawing]

[0006] [Figure 1] This is a schematic diagram of a liquid dispensing device according to Embodiment 1 of the present invention, showing a state in which a cover with a wide opening is attached to the irradiation section. [Figure 2] Figure 1 is a schematic diagram of the liquid dispensing device, showing a state in which a cover with a narrow opening width is attached to the irradiation section. [Figure 3] Figure 1 is a schematic diagram of the irradiation section of the liquid dispensing device, conceptually representing the direction in which reflected light propagates. [Figure 4] A schematic diagram of the liquid dispensing device according to Example 2 of the present invention. [Modes for carrying out the invention]

[0007] First, the present invention will be described in general terms. A liquid dispensing device according to a first aspect of the present invention for solving the above problems comprises: a head for dispensing ultraviolet-curable ink from a nozzle provided on the nozzle surface; an irradiation unit for irradiating ultraviolet light onto the ultraviolet-curable ink that has landed on a printing medium; a moving unit capable of moving the printing medium and the irradiation unit relative to each other; a cleaning unit for cleaning the nozzle surface; and a control unit, wherein the head is arranged in line with the irradiation unit in the relative movement direction, and the irradiation unit comprises: a light source for irradiating ultraviolet light; and an aperture defining member having an opening and defining the irradiation range of the ultraviolet light irradiated from the light source onto the printing medium in the relative movement direction by changing the opening width of the opening, and the control The unit is capable of selecting a plurality of printing modes according to the aperture width, and the plurality of printing modes include a first mode selected when the aperture width is a first width, and a second mode selected when the aperture width is a second width narrower than the first width, wherein the first mode is characterized in that the drive current of the light source is a first current and the cleaning interval of the nozzle surface by the cleaning unit is a first interval, and the second mode is characterized in that either the drive current of the light source is a first current and the cleaning interval is a second interval longer than the first interval, or the drive current of the light source is a second current greater than the first current and the cleaning interval is the first interval.

[0008] According to this embodiment, multiple printing modes are selectable, and the multiple printing modes include a first mode selected when the aperture width is a first width, and a second mode selected when the aperture width is a second width narrower than the first width. In the first mode, the drive current of the light source is a first current and the cleaning interval of the nozzle surface by the cleaning unit is a first interval, and in the second mode, the drive current of the light source is a first current and the cleaning interval is a second interval which is longer than the first interval, or the drive current of the light source is a second current which is greater than the first current and the cleaning interval is the first interval. In other words, the second mode has a longer cleaning interval or greater drive power than the first mode, and by selecting a suitable printing mode according to, for example, the type of printing medium, suitable ultraviolet irradiation and cleaning interval adjustment can be performed.Therefore, ultraviolet light can be efficiently irradiated onto ultraviolet-curable ink while suppressing irradiation misses.

[0009] A liquid dispensing device according to a second aspect of the present invention, in an aspect dependent on the first aspect, has a plurality of printing modes, the third mode being selected when the aperture width is the second width, the second mode being a second interval in which the drive current of the light source is the first current and the cleaning interval is longer than the first interval, and the third mode being a second current in which the drive current of the light source is greater than the first current and the cleaning interval is the first interval.

[0010] According to this embodiment, in addition to the first and second modes, there is a third mode that is selected when the aperture width is a second width. The second mode is when the drive current of the light source is a first current and the cleaning interval is a second interval that is longer than the first interval, and the third mode is when the drive current of the light source is a second current that is greater than the first current and the cleaning interval is a first interval. With this configuration, a suitable printing mode can be selected from a wide range of options, and particularly suitable ultraviolet irradiation and cleaning interval adjustments can be made.

[0011] A liquid dispensing device according to a third aspect of the present invention, in an aspect dependent on the first or second aspect, the opening defining member is detachably attached to the irradiation unit and comprises a first defining member having a first width and a second defining member having a second width, and the opening width can be changed to the first width or the second width by changing the opening defining member attached to the irradiation unit.

[0012] According to this embodiment, the aperture defining member is detachable from the irradiation unit and comprises a first defining member having a first width and a second defining member having a second width. By changing the aperture defining member attached to the irradiation unit, the aperture width can be changed to either the first or second width. With this configuration, the aperture width can be changed with a simple configuration of replacing the aperture defining member.

[0013] A liquid dispensing device according to a fourth aspect of the present invention, in an aspect dependent on the first or second aspect, the opening defining member has a first plate member and a second plate member stacked on top of each other, the second plate member is movable relative to the first plate member in the relative movement direction, and the opening width can be changed to a first width or a second width by changing the position of the second plate member relative to the first plate member in the relative movement direction.

[0014] According to this embodiment, the opening defining member has a first plate member and a second plate member stacked on top of each other, the second plate member is movable relative to the first plate member in the relative movement direction, and the opening width can be changed to a first width or a second width by changing the position of the second plate member relative to the first plate member in the relative movement direction. With such a configuration, for example, a configuration that automatically changes the opening width can be made, making it easy to change the opening width.

[0015] A liquid dispensing device according to a fifth aspect of the present invention, in an aspect dependent on any one of the first to fourth aspects, is characterized in that the opening defining member has a function as a side wall covering the side surface of the irradiation portion in the relative movement direction, and has a light-shielding side wall portion that prevents ultraviolet light from leaking from the side surface.

[0016] According to this embodiment, the opening regulating member functions as a side wall covering the side of the irradiation section in the relative movement direction, and has a light-shielding side wall portion that prevents ultraviolet light from leaking from the side. With this configuration, ultraviolet light can be effectively prevented from leaking from the side, and the adhesion of ultraviolet-curable ink to the nozzle surface can be effectively suppressed. Therefore, the cleaning interval can be widened, and the decrease in production efficiency can be effectively suppressed.

[0017] A liquid dispensing device according to a sixth aspect of the present invention is characterized in that, in an embodiment dependent on any one of the first to fifth aspects, the irradiation unit has a plate-shaped transparent member disposed between the printing medium and the light source, and the opening defining member also serves as a transparent member holding unit for holding the transparent member.

[0018] According to this embodiment, the irradiation unit has a plate-shaped transparent member placed between the printing medium and the light source, and the aperture defining member also serves as a transparent member holding unit for holding the transparent member. With this configuration, it is possible to suppress contamination of the light source with, for example, ink mist, and to suppress the need to enlarge the irradiation unit by providing another member.

[0019] [Example 1] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. First, an overview of the liquid ejection device 1A of Example 1 as an example of the liquid ejection device 1 according to the present invention will be described with reference to FIGS. 1 and 2. Although not shown in FIGS. 1 and 2, the liquid ejection device 1A of the present embodiment includes a setting unit for setting a roll-shaped printing medium P and a winding unit for winding up the printing medium P conveyed from the setting unit, and is a printer capable of printing an image on a long printing medium P using ultraviolet curable ink.

[0020] The liquid ejection device 1A of the present embodiment includes a printing head 3 that ejects ultraviolet curable ink onto the printing surface P1 of the printing medium P conveyed in the conveyance direction A in the conveyance path from the setting unit to the winding unit to form an image. Further, it includes a platen (not shown) that supports the printing medium P in the image formation region where an image is formed by the printing head 3, an irradiation unit 10 that irradiates ultraviolet light L to cure the ultraviolet curable ink that has landed on the printing surface P1, and conveyance rollers 6 as moving parts of the printing medium P provided at a plurality of positions in the conveyance path of the printing medium P. However, the configuration of the moving part is not particularly limited, and there is no particular limitation as long as the printing medium P, the printing head 3, and the irradiation unit 10 can be relatively moved.

[0021] The printing head 3 is provided on the side facing the printing surface P1 of the printing medium P conveyed in the conveyance direction A, and forms an image by ejecting ultraviolet curable ink onto the printing surface P1 in a state where the support surface P2 on the opposite side of the printing surface P1 of the printing medium P is supported by a platen (not shown). Here, the configuration of the printing head 3 is not particularly limited. It may be a printing head that reciprocates in the width direction B intersecting the conveyance direction A for printing, or a printing head that reciprocates in the direction along the conveyance direction A for printing, or a so-called line head provided with nozzles for ejecting ultraviolet curable ink arranged along the width direction B across the entire width direction B of the printing medium P and printing in a state where the printing head stops.

[0022] Further, as shown in FIGS. 1 and 2, the liquid ejection device 1A of the present embodiment includes a cleaning unit 7 capable of cleaning a nozzle surface 31 on which a plurality of nozzles for ejecting ultraviolet-curable ink are formed in the print head 3. The cleaning unit of the present embodiment includes a wiper for wiping the nozzle surface 31 and a suction cap capable of sucking ultraviolet-curable ink through the nozzle, etc., but the configuration of the cleaning unit 7 is not particularly limited. Further, the liquid ejection device 1A of the present embodiment includes a control unit 8 for controlling the driving of each component member such as the print head 3, the irradiation unit 10, the conveyance roller 6, and the cleaning unit 7.

[0023] As described above, the liquid ejection device 1A of the present embodiment includes a print head 3 that ejects ultraviolet-curable ink from nozzles provided on the nozzle surface 31, an irradiation unit 10 that irradiates ultraviolet light L onto the ultraviolet-curable ink landed on the print medium P, a conveyance roller 6 as a moving unit capable of relatively moving the print medium P and the irradiation unit 10, a cleaning unit 7 that cleans the nozzle surface 31, and a control unit 8. And, as shown in FIGS. 1 and 2, the print head 3 is arranged side by side in the conveyance direction A corresponding to the relative movement direction of the print medium P and the irradiation unit 10 with respect to the irradiation unit 10.

[0024] Hereinafter, the details of the irradiation unit 10, which is a main part of the liquid ejection device 1A of the present embodiment, will be described with reference to FIG. 3 in addition to FIGS. 1 and 2. As shown in FIGS. 1 to 3, the irradiation unit 10A of the liquid ejection device 1A of the present embodiment includes a light source 11 that irradiates ultraviolet light L, a copper substrate 12 on which the light source 11 is provided, a side surface portion 13 that covers the periphery of the light source 11 in the horizontal direction, a transparent protective glass 14, and a cover 15.

[0025] In this embodiment, the light source 11 is an LED (Light-Emitting Diode). However, there are no particular limitations on the type of light source 11. Furthermore, the cover 15 in this embodiment has an opening 151 and acts as an opening regulating member that defines the irradiation range of ultraviolet light L irradiated from the light source 11 onto the printing medium P in the transport direction A by changing the opening width of the opening 151. In detail, the irradiation unit 10A is configured to allow replacement of the cover 15. Figure 1 shows the state in which a cover 15A with a wide opening width B1 is attached as the cover 15, and Figure 2 shows the state in which a cover 15B with a narrow opening width B2 is attached as the cover 15. Note that the liquid dispensing device 1A in this embodiment is configured to allow three types of covers 15 with different opening widths of 2.4 mm, 1.8 mm, and 1.2 mm to be attached to the irradiation unit 10A.

[0026] For example, if a printing medium P that is prone to diffuse reflection is used, attaching a cover 15 with a wide aperture width as shown in Figure 1 may cause reflected ultraviolet light Lr diffusely reflected by the printing medium P to reach the nozzle surface 31. Therefore, when using a printing medium P that is prone to diffuse reflection, this risk can be reduced by attaching a cover 15 with a narrow aperture width as shown in Figure 2. However, if the aperture width is narrowed while keeping the intensity of ultraviolet light L irradiated from the light source 11 constant, the intensity of ultraviolet light L irradiated onto the printing medium P tends to decrease.

[0027] In other words, the wider the aperture width, the more ultraviolet L is diffused and the more ultraviolet L leaks out. Conversely, narrowing the aperture width reduces the amount of diffused ultraviolet L and the amount of leaked ultraviolet L, but also reduces the irradiation energy of the ultraviolet L irradiated onto the printing medium P. For example, as the aperture width is narrowed to 2.4 mm, 1.8 mm, and 1.2 mm, the amount of leaked ultraviolet L decreases accordingly, and the irradiation energy of the ultraviolet L irradiated onto the printing medium P also decreases. This is because narrowing the aperture width reduces the absolute amount of ultraviolet L irradiated from the irradiation unit 10.

[0028] On the other hand, if the irradiation energy of ultraviolet L is kept constant for different aperture widths, it is necessary to increase the drive current input to the light source 11 as the aperture width decreases in order to keep the irradiation energy constant. However, even if the drive current input to the light source 11 is increased, the effect of reducing the amount of ultraviolet L leaking out by reducing the aperture width is significant, and the amount of ultraviolet L leaking out does not increase significantly. This means that the amount of ultraviolet L leaking out is reduced while maintaining a high quality (high image quality) of the image formed on the printing medium P.

[0029] Furthermore, if the amount of UV light L leaking out is kept constant for different aperture widths, the irradiation energy can be increased because reducing the aperture width has a greater effect in reducing the amount of UV light L leaking out, provided that the amount of UV light L leaking out is set to an acceptable value that maintains reliability without causing problems to the print head 3. This means that the quality of the image formed on the printing medium P can be improved while maintaining a high level of reliability without causing problems to the print head 3.

[0030] In this way, by adjusting the aperture width, it is possible to control the irradiation energy and the amount of ultraviolet light L that leaks out. However, if the drive current input to the light source 11 is increased too much, the amount of heat generated in the irradiation unit 10 will increase significantly, which may affect the performance of the irradiation unit 10. In order to maintain the performance of the irradiation unit 10 at a high level, it is necessary to provide a cooling time for the irradiation unit 10 to cool down, and printing operations cannot be performed during the cooling time, which may reduce productivity.

[0031] Therefore, the liquid ejection device 1A of this embodiment has five printing modes (first reliability improvement mode, second reliability improvement mode, normal mode, second high-quality mode, and first high-quality mode) as shown in Table 1 below, taking these factors into consideration. Note that the TCL interval in Table 1 is an abbreviation for timer cleaning interval, and represents the interval at which the print head 3 is cleaned by the cleaning unit 7, which is automatically and periodically performed to suppress the generation of foreign matter due to the curing of UV-curable ink on the nozzle surface 31 by leaking ultraviolet light L. A wider TCL interval results in higher productivity. Here, the TCL interval in the table is a reference value.

[0032] [Table 1]

[0033] In the first reliability-enhancing mode, compared to the default normal mode, the ultraviolet light L directed towards the print head 3 can be suppressed, and productivity can be improved by shortening the TCL interval while maintaining the transport speed of the transport rollers 6. In the second reliability-enhancing mode, although not to the same extent as the first reliability-enhancing mode, productivity can be improved by suppressing the ultraviolet light L directed towards the print head 3 compared to the default normal mode, and by shortening the TCL interval while maintaining the transport speed of the transport rollers 6. In the second high-image-quality mode, image quality, which is the quality of the image formed on the printing medium P, can be improved compared to the default normal mode. In the first high-image-quality mode, image quality can be improved even further than in the second high-image-quality mode compared to the default normal mode.

[0034] Thus, in the liquid dispensing device 1A of this embodiment, multiple printing modes can be selected. To explain in more detail from another perspective, in the liquid dispensing device 1A of this embodiment, the control unit 8 can select multiple printing modes according to the aperture width, and the multiple printing modes can be described as having a first mode (e.g., normal mode) selected when the aperture width is a first width (e.g., 2.4 mm), and a second mode (e.g., first reliability improvement mode or first high image quality mode) selected when the aperture width is a second width narrower than the first width (e.g., 1.2 mm).

[0035] In the first mode (for example, the normal mode), the drive current of the light source 11 is the first current (for example, 151 mA), and the cleaning interval of the nozzle surface 31 by the cleaning unit 7 is the first interval (for example, 40 min). In the second mode (for example, the first reliability improvement mode), the drive current of the light source 11 is the first current, and the cleaning interval is a second interval (for example, 60 min) which is longer than the first interval, or in the second mode (for example, the first high image quality mode), the drive current of the light source 11 is a second current (for example, 318 mA) which is greater than the first current, and the cleaning interval is the first interval.

[0036] In other words, in the liquid dispensing device 1A of this embodiment, the second mode has a longer cleaning interval or higher driving power than the first mode. Therefore, by selecting a suitable printing mode according to, for example, the type of printing medium P, it is possible to adjust the irradiation of ultraviolet L and the cleaning interval appropriately. Accordingly, the liquid dispensing device 1A of this embodiment can efficiently irradiate the ultraviolet-curable ink on the printing surface P1 of the printing medium P with ultraviolet L while suppressing irradiation leakage of ultraviolet L.

[0037] To explain from another perspective, the liquid ejection device 1A of this embodiment has multiple printing modes, including a third mode (e.g., a first high-quality mode) that is selected when the aperture width is a second width (e.g., 1.2 mm). The second mode (e.g., a first reliability improvement mode) has a drive current of the light source 11 that is a first current (e.g., 151 mA) and a cleaning interval that is longer than the first interval (e.g., 40 min), which is a second interval (e.g., 60 min). The third mode has a drive current of the light source 11 that is greater than the first current, which is a second current (e.g., 318 mA) and a cleaning interval that is the first interval (e.g., 40 min). With this configuration, the liquid ejection device 1A of this embodiment can select a suitable printing mode from a wide range of options, and can adjust the irradiation of ultraviolet L and the cleaning interval to be particularly suitable.

[0038] Furthermore, as described above, the liquid dispensing device 1A of this embodiment has a cover 15 as an opening defusing member, which is detachable from the irradiation unit 10A. It has a cover 15A as a first defusing member having a first width (e.g., 2.4 mm) and a cover 15B as a second defusing member having a second width (e.g., 1.2 mm). By changing the cover 15 attached to the irradiation unit 10A, the opening width can be changed to either the first width or the second width. With this configuration, the liquid dispensing device 1A of this embodiment can change the opening width with a simple configuration of replacing the cover 15.

[0039] In this embodiment, the liquid dispensing device 1A, the cover 15, as an opening regulating member, functions together with the side portion 13 as a side wall covering the side of the irradiation unit 10A in the transport direction A. The cover 15 also acts as a light-shielding side wall to prevent ultraviolet light L from leaking from the side of the irradiation unit 10A. With this configuration, the liquid dispensing device 1A of this embodiment can effectively prevent ultraviolet light L from leaking from the side and heading toward the print head 3, and effectively suppress the hardening of ultraviolet-curable ink that adheres to the nozzle surface 31. Therefore, the liquid dispensing device 1A of this embodiment can widen the cleaning interval and effectively suppress the decrease in production efficiency.

[0040] Furthermore, as described above, in the liquid dispensing device 1A of this embodiment, the irradiation unit 10A has a protective glass 14, which is a plate-shaped transparent member placed between the printing medium P and the light source 11. The cover 15 also serves as a transparent member holder that holds the protective glass 14. With this configuration, the liquid dispensing device 1A of this embodiment can suppress contamination of the light source 11 by, for example, ink mist, and can also suppress the need to increase the size of the irradiation unit 10 by providing another member.

[0041] Furthermore, in the liquid dispensing device 1A of this embodiment, as shown in Figure 3, the opening 151 is configured to widen as it moves away from the light source 11. With this configuration, even if the ultraviolet light L irradiated from the light source 11 is diffusely reflected, as shown by the dashed line trajectory of the ultraviolet light L in Figure 3, the ultraviolet light L will remain within the opposing region between the irradiation unit 10A and the printing medium P, thereby suppressing the ultraviolet light L from heading towards the print head 3 due to diffuse reflection.

[0042] Furthermore, in the liquid dispensing device 1A of this embodiment, as shown in Figure 2, in the transport direction A, the width B2 of the narrow opening of the cover 15B is narrower than the width B3 of the light source 11. This configuration effectively suppresses ultraviolet light L from being directed towards the print head 3 due to diffuse reflection, etc.

[0043] [Example 2] Next, the liquid dispensing device 1B of Example 2 will be described using Figure 4. Figure 4 corresponds to Figure 2 in the liquid dispensing device 1A of Example 1. In Figure 4, components common to Example 1 are indicated by the same reference numerals, and detailed explanations will be omitted. Here, the liquid dispensing device 1B of this example has the same configuration as the liquid dispensing device 1A of Example 1, except for the configuration of the irradiation unit 10 (irradiation unit 10B). Therefore, with respect to parts other than those described below, the liquid dispensing device 1B of this example has the same characteristics as the liquid dispensing device 1A of Example 1.

[0044] As described above, the liquid dispensing device 1A of Example 1 was equipped with a replaceable cover 15 for the irradiation unit 10A as an opening regulating member. On the other hand, in the liquid dispensing device 1B of this embodiment, the cover 15C as an opening regulating member is not intended to be replaced and is fixed to the irradiation unit 10B.

[0045] As shown in Figure 4, in the liquid dispensing device 1B of this embodiment, the cover 15C, which serves as the opening regulating member, has a shutter structure 152 consisting of plate members (first plate member 152A and second plate member 152B) that are stacked on top of each other and movable in a direction intersecting the stacking direction. In other words, the cover 15C has a first plate member 152A and a second plate member 152B that are stacked on top of each other, and the second plate member 152B is movable relative to the first plate member 152A in the transport direction A, and by changing the position of the second plate member 152B relative to the first plate member 152A in the transport direction A, it is possible to change the opening width to a first width (e.g., 2.4 mm) or a second width (e.g., 1.2 mm).

[0046] The liquid dispensing device 1B of this embodiment has the following configuration, which allows the opening width to be automatically changed by the control unit 8, making it easy to change the opening width. In Figure 4, the state in which the opening width is set to width B2 is shown, but in the liquid dispensing device 1B of this embodiment, the opening width can be set to width B1 by moving the second plate member 152B relative to the first plate member 152A in the transport direction A. The first plate member 152A may also be configured to be movable in the transport direction, and the shutter structure 152 may be configured to be moved manually.

[0047] The present invention is not limited to the embodiments described above, and can be realized in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each embodiment described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of symbols]

[0048] 1…Liquid ejection device, 1A…Liquid ejection device, 1B…Liquid ejection device, 3…Print head, 6…Transport roller (transport section), 7…Cleaning section, 8…Control section, 10…Irradiation section, 10A…Irradiation section, 10B…Irradiation section, 11…Light source, 12…Copper substrate, 13…Side section, 14…Protective glass (transparent member), 15…Cover (opening regulating member, light-shielding side wall section), 15A…Cover (first regulating member), 15B…Cover (second regulating member), 15C…Cover (opening regulating member), 31…Nozzle surface, 151…Opening, 152…Shutter structure, 152A…First plate member, 152B…Second plate member, B1…Width, B2…Width, L…Ultraviolet light, Lr…Reflected ultraviolet light, P…Printing medium, P1…Printing surface, P2…Support surface

Claims

1. A head that dispenses UV-curable ink from a nozzle on the nozzle surface, An irradiation unit that irradiates ultraviolet light onto the ultraviolet-curable ink that has landed on the printing medium, A movable unit capable of moving the printing medium and the irradiation unit relative to each other, A cleaning unit for cleaning the nozzle surface, Control unit and Equipped with, The heads are arranged side by side with respect to the irradiation section in the relative movement direction, The irradiation unit comprises a light source that emits ultraviolet light, and an aperture defining member that has an aperture and defines the irradiation range of the ultraviolet light emitted from the light source onto the printing medium in the relative movement direction by changing the aperture width of the aperture. The control unit can select from a plurality of printing modes corresponding to the aperture width. The plurality of printing modes include a first mode selected when the aperture width is a first width, and a second mode selected when the aperture width is a second width narrower than the first width. In the first mode, the driving current of the light source is a first current, and the cleaning interval of the nozzle surface by the cleaning unit is a first interval. The second mode is a liquid dispensing device characterized in that the driving current of the light source is the first current and the cleaning interval is a second interval that is longer than the first interval, or the driving current of the light source is a second current that is greater than the first current and the cleaning interval is a first interval.

2. In the liquid dispensing device described in claim 1, The plurality of printing modes include a third mode that is selected when the aperture width is the second width, The second mode is characterized in that the driving current of the light source is the first current and the cleaning interval is a second interval that is longer than the first interval. The third mode is a liquid dispensing device characterized in that the driving current of the light source is a second current which is greater than the first current, and the cleaning interval is a first interval.

3. In the liquid dispensing device described in claim 1 or 2, The opening defining member is detachable from the irradiation section and comprises a first defining member having the first width and a second defining member having the second width. A liquid dispensing device characterized in that the opening width can be changed to a first width or a second width by changing the opening defining member attached to the irradiation unit.

4. In the liquid dispensing device described in claim 1 or 2, The opening defining member has a first plate member and a second plate member stacked on top of each other, The second plate member is movable relative to the first plate member in the relative movement direction, A liquid dispensing device characterized in that the opening width can be changed to a first width or a second width by changing the position of the second plate member relative to the first plate member in the relative movement direction.

5. In the liquid dispensing device described in claim 1 or 2, The liquid dispensing device is characterized in that the opening defining member functions as a side wall covering the side surface of the irradiation portion in the relative movement direction, and has a light-shielding side wall portion that prevents ultraviolet light from leaking from the side surface.

6. In the liquid dispensing device described in claim 1 or 2, The irradiation unit has a plate-shaped transparent member that is placed between the printing medium and the light source. The liquid dispensing device is characterized in that the opening defining member also serves as a transparent member holding portion for holding the transparent member.

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