UV-curable liquid dispensing device, and control method for UV-curable liquid dispensing device

Abstract

To provide an ultraviolet curing liquid dispensing device that can appropriately control the amount of ultraviolet light emitted when multiple light-emitting elements are used as the light source for irradiating ultraviolet light. [Solution] An ultraviolet curing liquid dispensing device comprising: a dispensing head for dispensing a liquid that hardens when irradiated with ultraviolet light; an ultraviolet light source including multiple light-emitting elements that emit ultraviolet light; an intensity adjustment mechanism for adjusting the intensity of ultraviolet light; an irradiation amount sensor for detecting the amount of ultraviolet light irradiated; and a relative position control mechanism for changing the relative position between the irradiation amount sensor and the ultraviolet light source, wherein the intensity adjustment mechanism adjusts the intensity of ultraviolet light based on the amount of ultraviolet light irradiated detected by the irradiation amount sensor during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source.

Description

Technical Field

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[0001] The present invention relates to an ultraviolet-curable liquid ejection device and a control method for an ultraviolet-curable liquid ejection device.

Background Art

[0002] Patent Document 1 discloses a liquid ejection device that ejects an ultraviolet-curable ink that cures by irradiation with ultraviolet rays onto a medium.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when using a plurality of light-emitting elements as a light source for irradiating ultraviolet rays, from the viewpoint of appropriately controlling the amount of ultraviolet light irradiated, the technology described in Patent Document 1 alone is not sufficient, and there is room for improvement.

Means for Solving the Problems

[0005] One aspect of the ultraviolet-curable liquid ejection device according to the present invention is a discharge head that discharges a liquid that cures by irradiation with ultraviolet rays, an ultraviolet light source that includes a plurality of light-emitting elements and outputs the ultraviolet rays, an intensity adjustment mechanism that adjusts the intensity of the ultraviolet rays, an irradiation amount sensor that detects the irradiation amount of the ultraviolet rays, a relative position control mechanism that changes the relative position between the irradiation amount sensor and the ultraviolet light source, and includes <000003The intensity adjustment mechanism adjusts the intensity of the ultraviolet light based on the amount of ultraviolet light detected by the irradiation amount sensor during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source.

[0006] One aspect of the control method for an ultraviolet-curable liquid dispensing device according to the present invention is: A control method for an ultraviolet-curing liquid dispensing device that dispenses a liquid that hardens upon irradiation with ultraviolet light, A relative position control step that changes the relative position of an irradiation amount sensor that detects the amount of ultraviolet irradiation and an ultraviolet light source that includes a plurality of light-emitting elements and emits the ultraviolet light, A detection step for detecting the amount of ultraviolet radiation, synchronized with the relative position control step, An adjustment step is performed to adjust the intensity of the ultraviolet light based on the amount of ultraviolet light detected in the detection step. It holds. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram illustrating the functional configuration of a liquid dispensing device. [Figure 2] This diagram illustrates the general process of forming an image on a medium. [Figure 3] This is a diagram illustrating an example of the structure of an ultraviolet irradiation device. [Figure 4] This figure shows an example of carriage placement during the period in which the strength adjustment process is performed. [Figure 5] This figure shows an example of carriage placement during the period in which the strength adjustment process is performed. [Figure 6] This diagram illustrates the irradiance distribution of ultraviolet light emitted by an ultraviolet irradiation device. [Figure 7] This is a diagram illustrating a specific example of the strength adjustment process. [Modes for carrying out the invention]

[0008] Preferred embodiments of the present invention will be described below with reference to the drawings. The drawings used are for illustrative purposes only. The embodiments described below are not intended to unduly limit the scope of the present invention as described in the claims. Furthermore, not all of the configurations described below are essential components of the present invention.

[0009] 1. Overview of the liquid dispensing device Figure 1 is a diagram illustrating the functional configuration of the liquid dispensing device 1 of this embodiment. As shown in Figure 1, the liquid dispensing device 1 receives image data signals from an external device 2, such as a computer, which define the printing specifications corresponding to the image D to be formed on the medium P. The liquid dispensing device 1 then dispenses, as an example of a liquid, an ultraviolet-curable ink that hardens when exposed to ultraviolet light, toward the medium P, and irradiates the dots formed on the medium P with ultraviolet light Ua and Ub to harden and fix the ink contained in the dots, thereby forming the image D on the medium P. This is a so-called ultraviolet-curable liquid dispensing device. Such a liquid dispensing device 1, an ultraviolet-curable liquid dispensing device, is sometimes called a UV (ultraviolet) printer.

[0010] The liquid dispensing device 1 comprises a control mechanism 10, a print head 20, ultraviolet irradiation devices 30a and 30b, a moving mechanism 40, a detection mechanism 50, a platen 60, and a carriage 70.

[0011] The image data signal output by the external device 2 is input to the control mechanism 10 of the liquid dispensing device 1. The control mechanism 10 includes a control unit 100, a dispensing control unit 200, an irradiation control unit 300, and a movement control unit 400. The control mechanism 10 generates signals to control each part of the liquid dispensing device 1, including the print head 20, ultraviolet irradiation devices 30a and 30b, and the movement mechanism 40, according to the input image data signal, and outputs them to the corresponding configuration.

[0012] The image data signal is input to the control unit 100 included in the control mechanism 10. The control unit 100 is configured to include a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), and the like. The control unit 100 performs predetermined signal processing on the input image data signal to generate various signals for controlling the ejection control unit 200, the irradiation control unit 300, and the movement control unit 400, and outputs them to the corresponding components.

[0013] The ejection control unit 200 includes an ejection control circuit 210 and a drive circuit 220. The signal output by the control unit 100 is input to the ejection control circuit 210. The ejection control circuit 210 generates a basic drive signal dC that defines the signal waveform of the drive signal COM for driving a plurality of drive elements included in the print head 20 so that ink is ejected from the print head 20 according to the signal output by the control unit 100, and outputs it to the drive circuit 220. The drive circuit 220 generates a high-voltage drive signal COM capable of driving a plurality of drive elements included in the print head 20 by amplifying the signal waveform defined by the basic drive signal dC, and outputs it to the print head 20.

[0014] In addition, the ejection control circuit 210 generates a timing control signal Tdp that controls the ejection timing and ejection amount of ink from the print head 20 according to the signal output by the control unit 100, and is a signal for controlling the supply timing of the drive signal COM to each of the plurality of drive elements included in the print head 20, and outputs it to the print head 20.

[0015] The print head 20 includes the plurality of drive elements described above and a plurality of nozzles corresponding to each of the plurality of drive elements and configured to eject ink by driving the drive elements. Then, at the timing defined by the timing control signal Tdp, the print head 20 supplies the drive signal COM to the drive elements, thereby ejecting a predetermined amount of ink droplets L from each of the plurality of nozzles toward the medium P. Here, as the drive elements included in the print head 20, for example, a piezoelectric element that is displaced by the supply of a drive signal and ejects ink by the displacement, or a heating element that generates heat by the supply of a drive signal and ejects ink by the heat generation may be used.

[0016] The irradiation control unit 300 includes an irradiation control circuit 310, a light source drive circuit 320, a shaping circuit 330, and a memory circuit 340. The signal output by the control unit 100 is input to the irradiation control circuit 310. The irradiation control circuit 310 generates an intensity designation signal Suv that defines the intensity of the ultraviolet rays Ua and Ub output by the ultraviolet irradiation devices 30a and 30b, which is the amount of light of the ultraviolet rays Ua and Ub output by the ultraviolet irradiation devices 30a and 30b, at the timing defined by the signal output by the control unit 100 according to the light amount adjustment information described later, and outputs the intensity designation signal Suv to the light source drive circuit 320. The light source drive circuit 320 generates a light source drive signal Cuv corresponding to the input intensity designation signal Suv and outputs the light source drive signal Cuv to each of the ultraviolet irradiation devices 30a and 30b.

[0017] Here, in FIG. 1, the light source drive circuit 320 is illustrated as commonly outputting one light source drive signal Cuv to the ultraviolet irradiation devices 30a and 30b. However, the light source drive circuit 320 may output different light source drive signals Cuv for the ultraviolet irradiation device 30a and the ultraviolet irradiation device 30b. At this time, the light source drive signal Cuv output toward the ultraviolet irradiation device 30a may be referred to as a light source drive signal Cuva, and the light source drive signal Cuv output toward the ultraviolet irradiation device 30b may be referred to as a light source drive signal Cuvb. Further, in the following description, the intensity of the ultraviolet rays Ua and Ub and the amount of light of the ultraviolet rays Ua and Ub are synonymous and correspond to the amount of energy that can be supplied by the ultraviolet rays Ua and Ub.

[0018] Each of the ultraviolet irradiation devices 30a and 30b has a plurality of light-emitting diodes (LDs), which will be described later. As the light-emitting diodes (LDs), for example, light-emitting diodes (LEDs) that output light in the ultraviolet wavelength range are used. Each of the ultraviolet irradiation devices 30a and 30b outputs ultraviolet light Ua and Ub of an intensity corresponding to the input light source drive signal Cuv by causing the plurality of light-emitting diodes (LDs) to emit light at an intensity corresponding to the input light source drive signal Cuv. That is, the liquid dispensing device 1 of this embodiment includes an ultraviolet irradiation device 30a that outputs ultraviolet light Ua and an ultraviolet irradiation device 30b that outputs ultraviolet light Ub.

[0019] Here, the intensity of ultraviolet Ua and Ub output by the ultraviolet irradiation devices 30a and 30b is the amount of energy that can be supplied to the ink droplet L that has landed on the medium P by the ultraviolet Ua and Ub, and may be, for example, ultraviolet irradiance, which is an indicator of how much ultraviolet intensity is being irradiated to a predetermined area. In other words, the intensity of ultraviolet Ua and Ub output by the ultraviolet irradiation devices 30a and 30b includes the amount of ultraviolet Ua and Ub light output by the ultraviolet irradiation devices 30a and 30b. At this time, the light source drive circuit 320 may generate a light source drive signal Cuv with a current value defined by the intensity specification signal Suv and output it to each of the ultraviolet irradiation devices 30a and 30b. This controls the amount of light from the light-emitting element LDs of each of the ultraviolet irradiation devices 30a and 30b, which is the intensity of ultraviolet Ua and Ub output by the ultraviolet irradiation devices 30a and 30b.

[0020] For example, if the intensity of ultraviolet light Ua and Ub output by the ultraviolet irradiation devices 30a and 30b is to be increased, the light source drive circuit 320 increases the current of the output light source drive signal Cuv. If the intensity of ultraviolet light Ua and Ub output by the ultraviolet irradiation devices 30a and 30b is to be decreased, the light source drive circuit 320 decreases the current of the output light source drive signal Cuv. Alternatively, the light source drive circuit 320 may be configured to generate a light source drive signal Cuv with current and voltage values ​​corresponding to the intensity specification signal Suv, and output it to each of the ultraviolet irradiation devices 30a and 30b.

[0021] Here, both the ultraviolet irradiation devices 30a and 30b have the same configuration. Therefore, in the following description, when it is not necessary to distinguish between ultraviolet irradiation devices 30a and 30b, they may simply be referred to as ultraviolet irradiation device 30. In this case, the ultraviolet irradiation device 30 will be described as receiving a light source drive signal Cuv and outputting ultraviolet U as ultraviolet Ua and Ub. Details of such an ultraviolet irradiation device 30 will be described later.

[0022] The shaping circuit 330 receives the ultraviolet detection signal Duv output by the detection mechanism 50. The detection mechanism 50 can be configured to include a photodiode or the like that can detect the amount of light corresponding to the ultraviolet wavelength range and output an electrical signal corresponding to the detected amount of light. At a predetermined timing, the detection mechanism 50 detects the amount of ultraviolet U light output by the ultraviolet irradiation device 30 and outputs an ultraviolet detection signal Duv corresponding to the detected amount of ultraviolet U light. That is, the detection mechanism 50 generates an ultraviolet detection signal Duv which is the intensity or amount of ultraviolet U and has a voltage value corresponding to the ultraviolet irradiance of ultraviolet U, and outputs it to the shaping circuit 330.

[0023] The shaping circuit 330 removes noise components from the ultraviolet detection signal Duv input from the detection mechanism 50 and amplifies it, thereby shaping the signal waveform of the ultraviolet detection signal Duv and outputting it to the irradiation control circuit 310. Such a shaping circuit 330 can be configured to include, for example, a filter circuit that removes noise and an amplification circuit that amplifies the signal from which the noise has been removed by the filter circuit. In addition to, or instead of, the shaping circuit 330 may also be configured to include a voltage follower circuit that converts the impedance of the signal corresponding to the ultraviolet detection signal Duv, or an A / D conversion circuit that converts the signal corresponding to the ultraviolet detection signal Duv into a digital signal.

[0024] The irradiation control circuit 310 obtains the intensity of ultraviolet U output by the ultraviolet irradiation device 30 from a signal corresponding to the ultraviolet detection signal Duv input from the shaping circuit 330. The irradiation control circuit 310 then adjusts the intensity specification signal Suv, which defines the intensity of ultraviolet Ua and Ub, so that the value of the signal corresponding to the ultraviolet detection signal Duv input from the shaping circuit 330 becomes a predetermined value. This adjusts the current amount of the light source drive signal Cuv output by the light source drive circuit 320, and as a result, the intensity of ultraviolet Ua and Ub output by the ultraviolet irradiation devices 30a and 30b is adjusted. In other words, the amount of energy supplied to the ink droplet L that lands on the medium P is adjusted. The irradiation control circuit 310 then stores the value of the intensity specification signal Suv, when the value of the signal corresponding to the ultraviolet detection signal Duv input from the shaping circuit 330 is adjusted to a predetermined value, as light intensity adjustment information in the memory circuit 340. Details of how to adjust the intensity of ultraviolet Ua and Ub output by the ultraviolet irradiation devices 30a and 30b will be described later.

[0025] The memory circuit 340 is a non-volatile memory, and for example, an EEPROM or flash memory can be used. In addition to the light intensity adjustment information described above, the memory circuit 340 may also store various information relating to the operation of the irradiation control unit 300 and the ultraviolet irradiation devices 30a and 30b. Furthermore, the light intensity adjustment information stored in the memory circuit 340 may be any information used to adjust the intensity of ultraviolet Ua and Ub, and may be, for example, information on the amount of current of the light source drive signal Cuv when the value of the signal corresponding to the ultraviolet detection signal Duv input from the shaping circuit 330 is adjusted to a predetermined value, or it may be the initial setting value of the intensity specification signal Suv and the adjusted value obtained by adjusting the intensity specification signal Suv when the value of the signal corresponding to the ultraviolet detection signal Duv input from the shaping circuit 330 becomes a predetermined value, or it may be the initial setting value of the light source drive signal Cuv and the adjusted value obtained by adjusting the light source drive signal Cuv when the value of the signal corresponding to the ultraviolet detection signal Duv input from the shaping circuit 330 becomes a predetermined value.

[0026] As described above, the irradiation control unit 300 acquires the current intensity of ultraviolet U emitted by the ultraviolet irradiation device 30 and adjusts the intensity of ultraviolet U emitted by the ultraviolet irradiation device 30 to a predetermined intensity, thereby controlling the intensity of ultraviolet U emitted from the ultraviolet irradiation device 30 to be approximately constant.

[0027] Furthermore, the signals output by the control unit 100 are input to the movement control unit 400. The movement control unit 400 generates a movement control signal Cmv to control the movement of the medium P along the transport direction and the reciprocating movement of the carriage 70 along the scanning axis, and outputs it to the movement mechanism 40.

[0028] The moving mechanism 40 includes a transport motor and transport rollers for moving the medium P. The transport motor is rotationally driven in accordance with the movement control signal Cmv, and the transport rollers rotate in conjunction with the rotational drive of the transport motor while supporting or gripping the medium P. Due to the rotation of these transport rollers, the medium P moves along the transport direction. At this time, the medium P is supported by the platen 60. That is, the medium P moves along the transport direction while being supported by the platen 60, driven by the transport motor.

[0029] The moving mechanism 40 also includes a carriage motor for moving the carriage 70 and an endless belt. The carriage motor is rotationally driven in accordance with the movement control signal Cmv. A portion of the carriage 70 is fixed to the endless belt. As the endless belt rotates in accordance with the rotation of the carriage motor, the carriage 70 moves in accordance with the rotation of the endless belt. At this time, the direction of rotation of the carriage motor is switched between forward and reverse rotation in accordance with the movement control signal Cmv, thereby switching the direction of movement of the carriage 70 along the scanning axis. As a result, the carriage 70 moves back and forth along the scanning axis.

[0030] The carriage 70 is equipped with a print head 20 and ultraviolet irradiation devices 30a and 30b. At this time, ultraviolet irradiation device 30a is located at one end of the carriage 70 along the scanning axis, ultraviolet irradiation device 30b is located at the other end of the carriage 70 along the scanning axis, and the print head 20 is located between ultraviolet irradiation devices 30a and 30b along the scanning axis. Then, in response to the movement control signal Cmv, the carriage 70 moves back and forth along the scanning axis, and the print head 20 and ultraviolet irradiation devices 30a and 30b mounted on the carriage 70 also move back and forth along the scanning axis.

[0031] An example of the operation when an image D is formed on a medium P by the liquid ejection device 1 configured as described above will now be explained. Figure 2 is a schematic diagram showing the operation in which an image D is formed on a medium P by the liquid ejection device 1 according to this embodiment. Here, in Figure 2, the explanation assumes that the carriage 70 on which the print head 20 is mounted moves in the direction of the arrow. Figure 2(a) shows the state in which ink droplets L are ejected from the print head 20 and dots Dw are formed on the medium P before curing, and Figure 2(b) shows the state in which, after dots Dw have been formed on the medium P, ultraviolet light Ua is irradiated, causing the ink contained in dots Dw to harden and fix, and dots Dd are formed on the medium P.

[0032] As shown in Figure 2(a), the medium P moves to a predetermined position on the platen 60 under the control of the moving mechanism 40. At the same time, the carriage 70, which is equipped with the print head 20 and ultraviolet irradiation devices 30a and 30b, moves along the scanning axis in the direction of the arrow shown in the figure, under the control of the moving mechanism 40. Then, under the control of the ejection control unit 200, ink droplets L are ejected from the print head 20 in synchronization with the movement of the carriage 70. When these ink droplets L ejected from the print head 20 land on the medium P, dots Dw are formed on the medium P.

[0033] Subsequently, as shown in Figure 2(b), the carriage 70 continues to move along the arrow. As a result, ultraviolet light Ua emitted from the ultraviolet irradiation device 30a, which is located behind the print head 20, is irradiated onto the dot Dw in the direction of movement of the carriage 70. This initiates and progresses the polymerization of the ultraviolet-curable ink contained in the dot Dw. Consequently, the ultraviolet-curable ink hardens and fixes in the medium P, and a dot Dd is formed in the medium P.

[0034] Although not shown in the diagram, even when the carriage 70 moves in the opposite direction to the arrow shown in Figure 2, a similar action will form dots Dd on the medium P.

[0035] Specifically, under the control of the moving mechanism 40, the medium P moves to a predetermined position on the platen 60, and then under the control of the moving mechanism 40, the carriage 70, equipped with the print head 20 and ultraviolet irradiation devices 30a and 30b, moves along the scanning axis in the direction opposite to the arrows shown in the figure. Then, under the control of the ejection control unit 200, ink droplets L are ejected from the print head 20 in sync with the movement of the carriage 70, forming dots Dw on the medium P. Subsequently, as the carriage 70 continues to move along the direction opposite to the arrows shown in the figure, ultraviolet light Ub emitted from the ultraviolet irradiation device 30b, which is located behind the print head 20 in that direction of movement, is irradiated onto the dots Dw, initiating and progressing the polymerization of the ultraviolet-curable ink contained in the dots Dw, and forming dots Dd on the medium P.

[0036] In the liquid ejection device 1 of this embodiment, the transport of the medium P along the transport direction, the ejection of ink droplets L from the print head 20, and the curing and fixing of the ink are repeatedly performed, so that dots Dd are sequentially formed at desired positions on the medium P, and as a result an image D corresponding to the image data signal is formed on the medium P.

[0037] In other words, in the liquid ejection device 1 of this embodiment, in response to the image data signal, the movement control unit 400 controls the reciprocating movement of the carriage 70 along the scanning axis and the transport of the medium P along the transport direction, under the control of the control unit 100. The ejection control unit 200 ejects ink droplets L from the print head 20 at a timing linked to the reciprocating movement of the carriage 70 along the scanning axis and the transport of the medium P along the transport direction. As a result, the ink droplets L land at the desired position on the medium P, and dots Dw are formed at the desired position on the medium P. Subsequently, under the control of the control unit 100, the irradiation control unit 300 irradiates the dots Dw with ultraviolet rays Ua and Ub using ultraviolet irradiation devices 30a and 30b, so that the ink contained in the dots Dw hardens and fixes, and dots Dd are formed on the medium P. In the liquid ejection device 1 of this embodiment, the ejection of ink and the hardening and fixing of the ejected ink are repeatedly performed to form the desired image D on the medium P.

[0038] In other words, the liquid ejection device 1 of this embodiment includes a print head 20 that ejects UV-curable ink that hardens when irradiated with ultraviolet U, a UV irradiation device 30 that includes a plurality of light-emitting elements LD and outputs UV U, an irradiation control circuit 310 that adjusts the intensity of UV U, a detection mechanism 50 that detects the amount of UV U irradiation, which is the intensity or amount of UV U, and a moving mechanism 40 that changes the relative position between the detection mechanism 50 and the UV irradiation device 30 by moving a carriage 70 on which the UV irradiation device 30 is mounted.

[0039] Here, if the carriage 70 is moving in the direction of the arrow shown in Figure 2, and the ink contained in the dots Dw formed on the medium P is cured and fixed by ultraviolet Ua, the ultraviolet irradiation device 30b may stop outputting ultraviolet Ub. If the carriage 70 is moving in the direction opposite to the arrow shown in Figure 2, and the ink contained in the dots Dw formed on the medium P is cured and fixed by ultraviolet Ub, the ultraviolet irradiation device 30a may stop outputting ultraviolet Ua.

[0040] 2. Adjustment of UV intensity As described above, in the liquid dispensing device 1 of this embodiment, the ultraviolet irradiation device 30 irradiates ultraviolet U onto the dots Dw formed on the medium P by ultraviolet-curable ink, thereby curing and fixing the ink contained in the dots Dw and forming dots Dd on the medium P. In such a liquid dispensing device 1, if there is an excess or deficiency in the amount of ultraviolet U energy irradiated onto the ink contained in the dots Dw, variations in the degree of curing and fixing of the ink may occur, potentially degrading the image quality formed on the medium P. In the liquid dispensing device 1 of this embodiment, the irradiation control unit 300 performs an intensity adjustment process to adjust the intensity of the ultraviolet U output by the ultraviolet irradiation device 30 to be approximately constant. This makes it possible to control the intensity or amount of ultraviolet U irradiated onto the ink contained in the dots Dw by the irradiation of ultraviolet U to be approximately constant, thereby controlling the amount of energy supplied to the dots Dw by the irradiation of ultraviolet U to be approximately constant. As a result, the risk of an excess or deficiency in the amount of ultraviolet U energy irradiated onto the ink contained in the dots Dw is reduced.

[0041] Before explaining the details of the intensity adjustment process for adjusting the intensity of ultraviolet U emitted by the ultraviolet irradiation device 30 to be approximately constant, we will first describe an example of the structure of the ultraviolet irradiation device 30 that emits ultraviolet U. Figure 3 is a diagram illustrating an example of the structure of the ultraviolet irradiation device 30. As shown in Figure 3, the ultraviolet irradiation device 30 has a base member 31, a plurality of light-emitting elements LD, and a heat sink 32.

[0042] The base member 31 is a wiring board on which multiple wiring patterns are formed, and multiple light-emitting elements (LDs) are mounted in a matrix on one side of the base member 31. The light source drive signal Cuv input to the ultraviolet irradiation device 30 propagates through the wiring patterns formed on the base member 31 and is supplied to the multiple light-emitting elements (LDs). As a result, each of the multiple light-emitting elements (LDs) emits light in response to the light source drive signal Cuv, and ultraviolet light U is output from the ultraviolet irradiation device 30 due to the light emission from the multiple light-emitting elements (LDs).

[0043] The heat sink 32 is attached to the other side of the base member 31. In the ultraviolet irradiation device 30, multiple light-emitting elements LDs are densely arranged on one side of the base member 31. This widens the range of ultraviolet U intensity that the ultraviolet irradiation device 30 can output, thereby increasing the versatility of the ultraviolet irradiation device 30. On the other hand, because multiple light-emitting elements LDs are densely arranged on one side of the base member 31, the amount of heat generated by the multiple light-emitting elements LDs increases, causing the temperature of the multiple light-emitting elements LDs to rise. This temperature rise of the multiple light-emitting elements LDs contributes to the characteristics of the light emitted by the light-emitting elements LDs. The heat sink 32 is thermally connected to the multiple light-emitting elements LDs via the base member 31, allowing the heat generated by the multiple light-emitting elements LDs to be efficiently released. As a result, even when multiple light-emitting elements LDs are densely arranged in the ultraviolet irradiation device 30, the risk of changes in the characteristics of the light-emitting elements LDs is reduced, and the risk of changes in the characteristics of the ultraviolet U emitted by the ultraviolet irradiation device 30 is also reduced.

[0044] In other words, the ultraviolet irradiation device 30a includes multiple light-emitting elements LDs, and outputs ultraviolet light Ua when the multiple light-emitting elements LDs emit light, while the ultraviolet irradiation device 30b includes multiple light-emitting elements LDs, and outputs ultraviolet light Ub when the multiple light-emitting elements LDs emit light.

[0045] Next, the arrangement of the carriage 70, which is equipped with the print head 20 and ultraviolet irradiation devices 30a and 30b, during the period in which the intensity adjustment process is performed will be described. Figures 4 and 5 show examples of the arrangement of the carriage 70 during the period in which the intensity adjustment process is performed. Here, Figure 4 shows an example of the arrangement of the carriage 70 when the intensity adjustment process is performed on ultraviolet light Ua output by ultraviolet irradiation device 30a, and Figure 5 shows an example of the arrangement of the carriage 70 when the intensity adjustment process is performed on ultraviolet light Ub output by ultraviolet irradiation device 30b.

[0046] As shown in Figures 4 and 5, the detection mechanism 50, which outputs an ultraviolet detection signal Duv corresponding to the intensity of ultraviolet Ua and Ub light, is located in a region outside the transport area where the medium P is transported. Here, Figures 4 and 5 illustrate the case where the detection mechanism 50 is configured separately from the platen 60, but the detection mechanism 50 may also be configured integrally with the platen 60.

[0047] Then, when an intensity adjustment process is performed to adjust the intensity of ultraviolet light Ua, as shown in Figure 4, the moving mechanism 40 moves the carriage 70 so that the ultraviolet irradiation device 30a is in a position facing the detection mechanism 50, in accordance with the movement control signal Cmv output by the movement control unit 400. As a result, the detection mechanism 50 detects the amount of ultraviolet light Ua output by the ultraviolet irradiation device 30a.

[0048] Similarly, when an intensity adjustment process is performed to adjust the intensity of ultraviolet light Ub, as shown in Figure 5, the moving mechanism 40 moves the carriage 70 so that the ultraviolet irradiation device 30b is in a position facing the detection mechanism 50, in accordance with the movement control signal Cmv output by the movement control unit 400. As a result, the detection mechanism 50 detects the amount of ultraviolet light Ub output by the ultraviolet irradiation device 30b.

[0049] Furthermore, during the period in which the detection mechanism 50 detects the intensity of ultraviolet Ua output by the ultraviolet irradiation device 30a, the ultraviolet irradiation device 30b may stop outputting ultraviolet Ub, and during the period in which the detection mechanism 50 detects the intensity of ultraviolet Ub output by the ultraviolet irradiation device 30b, the ultraviolet irradiation device 30a may stop outputting ultraviolet Ua.

[0050] Here, we will explain the distribution of ultraviolet U light output by the ultraviolet irradiation device 30, specifically the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30. Figure 6 is a diagram illustrating the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30. In addition to the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30, Figure 6 also shows the structure of the ultraviolet irradiation device 30.

[0051] As shown in Figure 6, the amount of ultraviolet U light output by the ultraviolet irradiation device 30, specifically the illuminance of ultraviolet U light output by the ultraviolet irradiation device 30, is approximately maximum at the central part xc of the ultraviolet irradiation device 30 and decreases toward the ends x0 and x1 of the ultraviolet irradiation device 30. In other words, the illuminance of ultraviolet U light output by the ultraviolet irradiation device 30 changes even in the area facing the ultraviolet irradiation device 30 if the detection position within that area is slightly shifted. Therefore, as shown in Figures 4 and 5, even when the detection mechanism 50 is positioned facing the ultraviolet irradiation device 30 and the detection mechanism 50 detects the amount of ultraviolet Ua light output by the ultraviolet irradiation device 30, slight shifts in the relative position between the ultraviolet irradiation device 30 and the detection mechanism 50 cause variations in the amount of ultraviolet U light detected by the detection mechanism 50. Furthermore, if there is variation in the amount of light detected by the detection mechanism 50, and an intensity adjustment process is performed to adjust the intensity of ultraviolet U output by the detection mechanism 50, even after the intensity adjustment process is performed, there may still be variation in the amount of ultraviolet U output by the ultraviolet irradiation device 30, which could result in a decrease in the image quality formed on the medium P.

[0052] To address this problem, for example, by improving the control accuracy of the scanning position of the carriage 70 in the moving mechanism 40, it is possible to reduce the risk of misalignment between the relative position of the ultraviolet irradiation device 30 and the detection mechanism 50, and thereby reduce the risk of variations in the amount of ultraviolet U detected by the detection mechanism 50. However, as shown in the liquid discharge device 1 of this embodiment, when the ultraviolet irradiation device 30 is configured to output the combined light of multiple light-emitting elements LD as ultraviolet U, if there is a slight misalignment in the optical axis of each of the multiple light-emitting elements LD due to mounting variations of the multiple light-emitting elements LD mounted on the base member 31, or if there is a variation in the amount of light from each of the multiple light-emitting elements LD due to variations in the characteristics of each of the multiple light-emitting elements LD, the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30 changes.

[0053] In particular, this problem becomes more pronounced when highly directional light-emitting diodes (LEDs) are used as multiple light-emitting elements (LDs). Therefore, even if the control accuracy of the scanning position of the carriage 70 in the moving mechanism 40 is improved and the risk of misalignment between the relative position of the ultraviolet irradiation device 30 and the detection mechanism 50 is reduced, it is difficult to sufficiently reduce the variation in the amount of light detected by the detection mechanism 50. Consequently, even after performing the intensity adjustment process, there is a risk of variation in the amount of light, which is the intensity of ultraviolet U output by the ultraviolet irradiation device 30.

[0054] To address the aforementioned problem, the liquid dispensing device 1 of this embodiment has a distinctive configuration in which, during the period in which an intensity adjustment process is performed to adjust the intensity of ultraviolet U output by the ultraviolet irradiation device 30 to be approximately constant, the relative position between the ultraviolet irradiation device 30 and the detection mechanism 50 is changed, and during the period in which the relative position between the ultraviolet irradiation device 30 and the detection mechanism 50 changes, the light intensity of the ultraviolet irradiation device 30 is adjusted based on the light quantity, which is the intensity of ultraviolet U detected by the detection mechanism 50. A specific example of such an intensity adjustment process will be described.

[0055] Figure 7 is a diagram illustrating a specific example of the intensity adjustment process in the liquid dispensing device 1 of this embodiment. Hereinafter, in the following description, the ultraviolet irradiation device 30 is described as being mounted on the carriage 70 such that the ends x0 and x1 described above are positioned along the scanning axis.

[0056] When the intensity adjustment process is executed, the irradiation control circuit 310 performs an initial setting, setting the variable n to "1" (step S1). After the initial setting is complete, the moving mechanism 40 moves the carriage 70 so that the end x0 of the ultraviolet irradiation device 30 is positioned along the detection axis of the detection mechanism 50 (step S2). The detection mechanism 50 then acquires the amount of ultraviolet U light output by the ultraviolet irradiation device 30 and outputs an ultraviolet detection signal Duv corresponding to the acquired light amount to the shaping circuit 330 (step S3). The ultraviolet detection signal Duv output by the detection mechanism 50 is shaped in the shaping circuit 330 and then input to the irradiation control circuit 310. The irradiation control circuit 310 associates the signal corresponding to the ultraviolet detection signal Duv input via the shaping circuit 330 with the information of the scanning position along the scanning axis of the ultraviolet irradiation device 30 or carriage 70 when the ultraviolet detection signal Duv was acquired, and stores it in the storage circuit 340 as acquired intensity information Guv[n] (step S4). Subsequently, the moving mechanism 40 moves the carriage 70 by a predetermined amount in the direction from end x1 to end x0 of the ultraviolet irradiation device 30 along the scanning axis (step S5). Here, the "determined amount" is a distance that is sufficiently shorter than the distance between end x0 and end x1 in the direction along the scanning axis, and may be defined, for example, based on a signal output by an encoder (not shown) that detects the scanning position of the carriage 70 in the direction along the scanning axis, or it may be defined by the rotation angle of the carriage motor that controls the movement of the carriage 70.

[0057] After moving the carriage 70 by a predetermined amount along the scanning axis in the direction from end x1 to end x0 of the ultraviolet irradiation device 30, the control unit 100 or the irradiation control circuit 310 determines whether the detection axis of the detection mechanism 50 is located between end x0 and end x1 of the ultraviolet irradiation device 30 (step S6). If the control unit 100 or the irradiation control circuit 310 determines that the detection axis of the detection mechanism 50 is located between end x0 and end x1 of the ultraviolet irradiation device 30 (Y in step S6), the irradiation control circuit 310 adds "1" to the variable n (step S7) and repeats steps S3 to S6 described above. In other words, the irradiation control circuit 310 moves the carriage 70 by a predetermined amount at intervals while the detection axis of the detection mechanism 50 is located between the ends x0 and x1 of the ultraviolet irradiation device 30. Each time the carriage 70 moves, it acquires a signal corresponding to the ultraviolet detection signal Duv input via the shaping circuit 330. The acquired signal corresponding to the ultraviolet detection signal Duv is associated with the position information along the scanning axis of the ultraviolet irradiation device 30 or carriage 70 at the time the signal corresponding to the ultraviolet detection signal Duv was acquired, and stored in the memory circuit 340.

[0058] Then, if the control unit 100 or the irradiation control circuit 310 determines that the detection axis of the detection mechanism 50 is not located between the ends x0 and x1 of the ultraviolet irradiation device 30 (N in step S6), the irradiation control circuit 310 reads the acquired intensity information Guuv[1] to Guuv[n] from the memory circuit 340 and selects the acquired intensity information Guuv[m] from among the read acquired intensity information Guuv[1] to Guuv[n] that has the maximum amount of ultraviolet U light detected by the detection mechanism 50 (step S8). Then, the movement mechanism 40 moves the ultraviolet irradiation device 30 or carriage 70 to the scanning position associated with the acquired intensity information Guuv[m] (step S9). After that, when the ultraviolet irradiation device 30 or carriage 70 reaches the scanning position associated with the acquired intensity information Guuv[m], the irradiation control circuit 310 adjusts the intensity designation signal Suv so that the signal corresponding to the ultraviolet detection signal Duv input via the shaping circuit 330 becomes a predetermined value (step S10). As a result, the maximum amount of ultraviolet U light output by the ultraviolet irradiation device 30, which is the maximum value of the ultraviolet U intensity, is adjusted to a predetermined value. That is, during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30, the irradiation control circuit 310 adjusts the intensity of ultraviolet U, which is the maximum value of the ultraviolet U intensity and light amount detected by the detection mechanism 50, so that it becomes a predetermined value.

[0059] Then, the irradiation control circuit 310 stores the intensity specification signal Suv, which corresponds to the ultraviolet detection signal Duv input via the shaping circuit 330, as light intensity adjustment information in the memory circuit 340 (step S11).

[0060] As described above, in the liquid dispensing device 1 of this embodiment, the irradiation control circuit 310 adjusts the intensity and light quantity of ultraviolet U, which is the amount of ultraviolet U irradiation, based on the intensity and light quantity of ultraviolet U detected by the detection mechanism 50, during the period in which the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30. In other words, the control method for a liquid dispensing device 1 that dispenses ink that hardens by irradiation with ultraviolet U as shown in this embodiment, wherein in the intensity adjustment process in which the liquid dispensing device 1 adjusts the intensity of ultraviolet U output by the ultraviolet irradiation device 30 to be substantially constant, the moving mechanism 40 has steps S2 and S5 in which it changes the relative position between the moving mechanism 40 and a detection mechanism 50 that detects the amount of ultraviolet U irradiation and the ultraviolet irradiation device 30 which includes a plurality of light-emitting elements LD and outputs ultraviolet U, and steps S3 in which the detection mechanism 50 detects the amount of ultraviolet U irradiation in synchronization with the change in the relative position between the detection mechanism 50 that detects the amount of ultraviolet U irradiation by the moving mechanism 40 in steps S2 and S5 and the ultraviolet irradiation device 30 which includes a plurality of light-emitting elements LD and outputs ultraviolet U, and steps S10 in which it adjusts the intensity of ultraviolet U based on the amount of ultraviolet U irradiation detected by the detection mechanism 50 in step S3, and the irradiation control circuit 310 adjusts the intensity of ultraviolet U in step S10 so that the maximum value of the amount of ultraviolet U irradiation detected in step S3 becomes a predetermined value.

[0061] In this embodiment, the liquid dispensing device 1 includes an ultraviolet irradiation device 30a and an ultraviolet irradiation device 30b as the ultraviolet irradiation device 30. Therefore, the intensity adjustment process in the liquid dispensing device 1 of this embodiment is performed individually for each of the ultraviolet irradiation devices 30a and 30b. That is, the irradiation control circuit 310 adjusts the intensity of ultraviolet Ua according to the amount of ultraviolet Ua detected by the detection mechanism 50 during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a, and adjusts the intensity of ultraviolet Ub according to the amount of ultraviolet Ub detected by the detection mechanism 50 during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30b. In other words, step S3, in which the detection mechanism 50 detects the amount of ultraviolet U irradiation in synchronization with the change in relative position with the ultraviolet irradiation device 30 which includes a plurality of light-emitting elements LDs as shown in Figure 7 and emits ultraviolet U, includes a step of detecting the amount of ultraviolet Ua irradiation and a step of detecting the amount of ultraviolet Ub irradiation, and step S10, in which the intensity of ultraviolet U is adjusted based on the amount of ultraviolet U irradiation detected by the detection mechanism 50, includes a step of adjusting the intensity of ultraviolet Ua based on the amount of ultraviolet Ua irradiation detected in the step of detecting the amount of ultraviolet Ua irradiation in step S3, and a step of adjusting the intensity of ultraviolet Ub based on the amount of ultraviolet Ub irradiation detected in the step of detecting the amount of ultraviolet Ub irradiation in step S3.

[0062] Here, the liquid ejection device 1 that ejects UV-curable ink that hardens when exposed to ultraviolet light corresponds to the UV-curable liquid ejection device, and the control method for the liquid ejection device 1 that ejects UV-curable ink that hardens when exposed to ultraviolet light, including the intensity adjustment process method described above, corresponds to the control method for the UV-curable liquid ejection device. The print head 20 is an example of an ejection head, the UV irradiation device 30 is an example of an ultraviolet light source, the moving mechanism 40 is an example of a relative position control mechanism, the detection mechanism 50 is an example of an irradiation amount sensor, and the irradiation control circuit 310 is an example of an intensity adjustment mechanism. Furthermore, among the UV irradiation devices 30, the UV irradiation device 30a is an example of a first UV light source, the multiple light-emitting element LDs in the UV irradiation device 30a are an example of multiple first light-emitting elements, and the ultraviolet light Ua output by the UV irradiation device 30a is an example of first ultraviolet light. Among the UV irradiation devices 30, the UV irradiation device 30b is an example of a second UV light source, the multiple light-emitting element LDs in the UV irradiation device 30b are an example of multiple second light-emitting elements, and the ultraviolet light Ub output by the UV irradiation device 30b is an example of second ultraviolet light. Furthermore, steps S2 and S5 in the intensity adjustment process are examples of relative position control processes, step S3 is an example of a detection process, and step S10 is an example of an adjustment process. Additionally, step S3 performed on the ultraviolet irradiation device 30a is an example of a first detection process, step S3 performed on the ultraviolet irradiation device 30b is an example of a second detection process, step S10 performed on the ultraviolet irradiation device 30a is an example of a first adjustment process, and step S10 performed on the ultraviolet irradiation device 30b is an example of a second adjustment process.

[0063] 3. Effects In the liquid dispensing device 1 of this embodiment, configured as described above, the irradiation control circuit 310 adjusts the intensity of ultraviolet U, which is the amount of light, and the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30. During the period in which the relative position between the detection mechanism 50, which detects the amount of ultraviolet U irradiation, and the ultraviolet irradiation device 30, which includes a plurality of light-emitting elements LD and outputs ultraviolet U, is changed, the irradiation control circuit 310 adjusts the intensity of ultraviolet U, which is the amount of light, based on the intensity of ultraviolet U, which is the amount of ultraviolet U irradiation, detected by the detection mechanism 50. As a result, the irradiation control circuit 310 can adjust the intensity of ultraviolet U at the optimal relative position between the detection mechanism 50 and the ultraviolet irradiation device 30 according to the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30. In other words, in the liquid dispensing device 1 of this embodiment, the intensity of ultraviolet U can be optimally adjusted regardless of the illuminance distribution of ultraviolet U. Therefore, in the liquid dispensing device 1 of this embodiment, the optimal amount of ultraviolet U energy can be irradiated onto the ink contained in the dot Dw. Thus, the risk of variations in the degree of ink curing and fixing is reduced, and the risk of a decrease in the image quality formed on the medium P is reduced.

[0064] In particular, when the ultraviolet irradiation device 30 that outputs ultraviolet U includes multiple light-emitting elements LDs and outputs ultraviolet U through the emission of light from multiple light-emitting elements LDs, the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30 varies greatly from one liquid to another in the liquid dispensing device 1. Even in such cases, the liquid dispensing device 1 of this embodiment can optimally adjust the intensity of ultraviolet U regardless of the illuminance distribution of ultraviolet U, so that the ink contained in the dot Dw can be irradiated with the optimal amount of ultraviolet U energy. As a result, the risk of variations in the degree of ink curing and fixing is reduced, and the risk of deterioration in the image quality formed on the medium P is reduced. In other words, even when multiple light-emitting elements LDs are used as the light source for irradiating ultraviolet U, the amount of ultraviolet U light irradiated onto the ink can be appropriately controlled.

[0065] Furthermore, in the liquid dispensing device 1 of this embodiment, even if the ultraviolet irradiation device 30 includes ultraviolet irradiation devices 30a and 30b, the irradiation control circuit 310 adjusts the intensity of ultraviolet Ua according to the amount of ultraviolet Ua detected by the detection mechanism 50 during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a, and adjusts the intensity of ultraviolet Ub according to the amount of ultraviolet Ub detected by the detection mechanism 50 during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30b. This allows for optimal adjustment of the intensity of ultraviolet Ua and Ub, regardless of the respective illuminance distributions of ultraviolet Ua and Ub. Therefore, the ink contained in the dot Dw can be irradiated with an optimal amount of ultraviolet Ua and Ub, and as a result, the risk of variations in the degree of ink curing and fixing is reduced, and the risk of a decrease in the image quality formed on the medium P is reduced.

[0066] In the control method for the liquid dispensing device 1 of this embodiment described above, the intensity adjustment process for adjusting the intensity of ultraviolet U includes steps S2 and S5 to change the relative position of a detection mechanism 50 that detects the amount of ultraviolet U irradiation and an ultraviolet irradiation device 30 that includes a plurality of light-emitting elements LD and outputs ultraviolet U, step S3 to detect the amount of ultraviolet U irradiation in synchronization with the change in relative position in steps S2 and S5, and step S10 to adjust the intensity of ultraviolet U based on the amount of ultraviolet U irradiation detected in step S3. This allows the intensity of ultraviolet U to be adjusted at the optimal relative position between the detection mechanism 50 and the ultraviolet irradiation device 30 according to the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30. In other words, the control method for the liquid dispensing device 1 of this embodiment can optimally adjust the intensity of ultraviolet U regardless of the illuminance distribution of ultraviolet U. Therefore, the liquid dispensing device 1 of this embodiment can irradiate the ink contained in the dot Dw with an optimal amount of ultraviolet U energy. Thus, the risk of variations in the degree of ink curing and fixing is reduced, and the risk of a decrease in the image quality formed on the medium P is reduced.

[0067] In particular, when the ultraviolet irradiation device 30 that outputs ultraviolet U includes multiple light-emitting elements LDs and outputs ultraviolet U through the emission of light from multiple light-emitting elements LDs, the illuminance distribution of ultraviolet U output by the ultraviolet irradiation device 30 varies greatly from one liquid ejection device 1 to another. Even in such cases, the control method of the liquid ejection device 1 of this embodiment can optimally adjust the intensity of ultraviolet U regardless of the illuminance distribution of ultraviolet U, so that the ink contained in the dot Dw can be irradiated with the optimal amount of ultraviolet U energy. As a result, the risk of variations in the degree of ink curing and fixing is reduced, and the risk of deterioration in the image quality formed on the medium P is reduced. In other words, even when multiple light-emitting elements LDs are used as the light source for irradiating ultraviolet U, the amount of ultraviolet U light irradiated onto the ink can be appropriately controlled.

[0068] Furthermore, in the control method for the liquid dispensing device 1 of this embodiment, even if the ultraviolet irradiation device 30 includes an ultraviolet irradiation device 30a and an ultraviolet irradiation device 30b, the method includes a step of adjusting the intensity of ultraviolet Ua according to the amount of ultraviolet Ua irradiation detected by the detection mechanism 50 during the period in which the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a is changed, and a step of adjusting the intensity of ultraviolet Ub according to the amount of ultraviolet Ub irradiation detected by the detection mechanism 50 during the period in which the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30b is changed. This allows for optimal adjustment of the intensity of ultraviolet Ua and Ub regardless of the respective illuminance distributions of ultraviolet Ua and Ub. Therefore, the ink contained in the dot Dw can be irradiated with an optimal amount of ultraviolet Ua and Ub, and as a result, the risk of variations in the degree of ink curing and fixing is reduced, and the risk of a decrease in the image quality formed on the medium P is reduced.

[0069] 4. Variations In the liquid dispensing device 1 of this embodiment described above, the irradiation control circuit 310 was described as adjusting the intensity of ultraviolet U so that the maximum value of the ultraviolet U irradiation amount, which is the intensity and light quantity of ultraviolet U detected by the detection mechanism 50, becomes a predetermined value during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30. However, the irradiation control circuit 310 may also adjust the intensity of ultraviolet U so that the integral value of the ultraviolet U irradiation amount, which is the intensity and light quantity of ultraviolet U detected by the detection mechanism 50, becomes a predetermined value during the period when the moving mechanism 40 changes the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30. In other words, the irradiation control circuit 310 may adjust the intensity of ultraviolet U so that the integral value of the ultraviolet U irradiation amount detected in step S3 becomes a predetermined value.

[0070] Specifically, in step S8 shown in Figure 7, the irradiation control circuit 310 may adjust the intensity designation signal Suv such that the sum of the light quantities of ultraviolet U in each of the acquired intensity information Guv[1] to Guv[n] read from the memory circuit 340 is a predetermined value. Even in this case, the same effects and advantages as in the embodiments described above can be achieved.

[0071] Furthermore, the ultraviolet irradiation device 30 may have a mirror that focuses the light emitted by multiple light-emitting diodes (LDs).

[0072] If the ultraviolet irradiation device 30 has a mirror that focuses the light emitted by multiple light-emitting elements LDs, it becomes possible to efficiently irradiate the ink contained in the dot Dw with ultraviolet U emitted by the ultraviolet irradiation device 30, thereby efficiently curing and fixing the ink contained in the dot Dw. However, on the other hand, the illuminance distribution of ultraviolet U emitted by the ultraviolet irradiation device 30 changes greatly depending on the angle of the mirror, so the illuminance distribution becomes more complicated.

[0073] In the liquid dispensing device 1 of this embodiment, the intensity of ultraviolet U can be optimally adjusted regardless of the illuminance distribution of ultraviolet U. Therefore, even when the ultraviolet irradiation device 30 has a mirror that focuses the light emitted by multiple light-emitting elements LD, the intensity of ultraviolet U can be optimally adjusted, and the ink contained in the dot Dw can be irradiated with an optimal amount of ultraviolet U energy. Accordingly, the same effects and advantages as in the embodiments described above can be achieved.

[0074] In the liquid dispensing device 1 of this embodiment described above, the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a was explained as changing by the movement of the carriage 70 equipped with the ultraviolet irradiation device 30. However, the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a may change as the detection mechanism 50 moves, or as both the ultraviolet irradiation device 30 and the detection mechanism 50 move, thereby changing the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a. Furthermore, the relative position between the detection mechanism 50 and the ultraviolet irradiation device 30a is not limited to changing in the direction along the scanning axis, but may also change along the transport direction of the medium P, or along the dispensing direction in which the ink is dispensed. Naturally, it may also be configured by several combinations of changes along the scanning axis, changes along the transport direction, and changes along the dispensing direction.

[0075] Although embodiments and modifications have been described above, the present invention is not limited to these embodiments and can be implemented in various forms without departing from its spirit. For example, the above embodiments can be combined as appropriate.

[0076] The present invention includes configurations that are substantially identical to those described in the embodiments (for example, configurations with the same function, method, and result, or configurations with the same purpose and effect). Furthermore, the present invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as those described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configurations described in the embodiments.

[0077] The following conclusions can be drawn from the embodiments described above.

[0078] One embodiment of an ultraviolet curing liquid dispensing apparatus is: A dispensing head that dispenses a liquid that hardens when exposed to ultraviolet light, A UV light source that includes multiple light-emitting elements and emits ultraviolet light, An intensity adjustment mechanism for adjusting the intensity of the ultraviolet light, An irradiation amount sensor for detecting the amount of ultraviolet radiation, A relative position control mechanism that changes the relative position between the irradiation amount sensor and the ultraviolet light source, Equipped with, The intensity adjustment mechanism adjusts the intensity of the ultraviolet light based on the amount of ultraviolet light detected by the irradiation amount sensor during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source.

[0079] In this ultraviolet curing liquid dispensing device, the intensity adjustment mechanism, which adjusts the intensity of ultraviolet light, and the relative position control mechanism, which changes the relative position between the irradiation amount sensor and the ultraviolet light source, adjust the intensity of ultraviolet light based on the amount of ultraviolet light detected by the irradiation amount sensor during the period in which the relative position between the irradiation amount sensor, which detects the amount of ultraviolet light, and the ultraviolet light source, which includes multiple light-emitting elements and emits ultraviolet light, is changed. As a result, the intensity adjustment mechanism can adjust the intensity of ultraviolet light at the optimal relative position between the irradiation amount sensor and the ultraviolet light source according to the illuminance distribution of ultraviolet light emitted by the ultraviolet light source. In other words, the intensity of ultraviolet light can be optimally adjusted regardless of the illuminance distribution of ultraviolet light. Therefore, the optimal amount of ultraviolet energy can be irradiated onto the liquid. Thus, the risk of variations in the degree of curing and fixing of the liquid is reduced, and the risk of a decrease in the image quality formed on the medium is reduced.

[0080] In particular, when an ultraviolet light source that emits ultraviolet light includes multiple light-emitting elements and emits ultraviolet light through the emission of light from multiple light-emitting elements, the illuminance distribution of the ultraviolet light emitted by the ultraviolet light source varies greatly from one ultraviolet curing liquid dispensing device to another. Even in such cases, because the intensity of the ultraviolet light can be optimally adjusted regardless of the illuminance distribution of the ultraviolet light, the optimal amount of ultraviolet energy can be irradiated onto the liquid, reducing the risk of variations in the degree of curing and fixing of the liquid, and reducing the risk of deterioration in the image quality formed on the medium. In other words, even when multiple light-emitting elements are used as the light source that irradiates ultraviolet light, the amount of ultraviolet light irradiated onto the liquid can be appropriately controlled.

[0081] One embodiment of the UV-curing liquid dispensing apparatus, The ultraviolet light source may have a mirror for focusing the ultraviolet light.

[0082] In this UV-curing liquid dispensing device, if the UV light source has a mirror, the illuminance distribution of the UV light emitted by the UV light source becomes more complex. However, because the intensity of the UV light can be optimally adjusted regardless of the illuminance distribution, the optimal amount of UV energy can be irradiated onto the liquid, reducing the risk of variations in the degree of curing and fixing of the liquid, and reducing the risk of a decrease in the image quality formed on the medium.

[0083] One embodiment of the UV-curing liquid dispensing apparatus, The ultraviolet light source comprises a first ultraviolet light source and a second ultraviolet light source. The first ultraviolet light source includes a plurality of first light-emitting elements among the plurality of light-emitting elements, and outputs first ultraviolet light as the ultraviolet light, The second ultraviolet light source includes a plurality of second light-emitting elements among the plurality of light-emitting elements, and outputs second ultraviolet light as the ultraviolet light, The aforementioned strength adjustment mechanism is During the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the first ultraviolet light source, the intensity of the first ultraviolet light is adjusted according to the irradiation amount of the first ultraviolet light detected by the irradiation amount sensor. During the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the second ultraviolet light source, the intensity of the second ultraviolet light may be adjusted according to the irradiation amount of the second ultraviolet light detected by the irradiation amount sensor.

[0084] In this UV-curing liquid dispensing device, even when the UV light source includes both a first UV light source and a second UV light source, the intensity adjustment mechanism adjusts the intensity of the first UV light according to the amount of first UV light detected by the irradiation amount sensor during the period when the relative position control mechanism changes the relative position between the irradiation amount sensor and the first UV light source, and adjusts the intensity of the second UV light according to the amount of second UV light detected by the irradiation amount sensor during the period when the relative position control mechanism changes the relative position between the irradiation amount sensor and the second UV light source. This allows for optimal adjustment of the intensity of both the first and second UV light sources, regardless of their respective illuminance distributions. As a result, the liquid can be irradiated with the optimal amount of energy from both the first and second UV light sources, reducing the risk of variations in the degree of curing and fixing of the liquid, and reducing the risk of a decrease in the image quality formed on the medium.

[0085] One embodiment of the UV-curing liquid dispensing apparatus, The intensity adjustment mechanism may adjust the intensity of the ultraviolet light so that the maximum value of the ultraviolet light irradiation amount detected by the irradiation amount sensor becomes a predetermined value during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source.

[0086] One embodiment of the UV-curing liquid dispensing apparatus, The intensity adjustment mechanism may adjust the intensity of the ultraviolet light so that the integral value of the ultraviolet light irradiation amount detected by the irradiation amount sensor becomes a predetermined value during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source.

[0087] One aspect of a control method for an ultraviolet-curing liquid dispensing device is: A control method for an ultraviolet-curing liquid dispensing device that dispenses a liquid that hardens upon irradiation with ultraviolet light, A relative position control step that changes the relative position of an irradiation amount sensor that detects the amount of ultraviolet irradiation and an ultraviolet light source that includes a plurality of light-emitting elements and emits the ultraviolet light, A detection step for detecting the amount of ultraviolet radiation, synchronized with the relative position control step, An adjustment step is performed to adjust the intensity of the ultraviolet light based on the amount of ultraviolet light detected in the detection step. It holds.

[0088] This control method for an ultraviolet curing liquid dispensing device includes a relative position control step that changes the relative position of an irradiation amount sensor that detects the amount of ultraviolet irradiation and an ultraviolet light source that includes multiple light-emitting elements and emits ultraviolet light; a detection step that detects the amount of ultraviolet irradiation in synchronization with the change in relative position in the relative position control step; and an adjustment step that adjusts the intensity of ultraviolet light based on the amount of ultraviolet irradiation detected in the detection step. This allows the intensity of ultraviolet light to be adjusted at the optimal relative position between the irradiation amount sensor and the ultraviolet light source according to the illuminance distribution of ultraviolet light emitted by the ultraviolet light source. In other words, the intensity of ultraviolet light can be optimally adjusted regardless of the illuminance distribution of ultraviolet light. Therefore, the optimal amount of ultraviolet energy can be irradiated onto the liquid, reducing the risk of variations in the degree of curing and fixing of the liquid, and reducing the risk of deterioration in the image quality formed on the medium.

[0089] In particular, when an ultraviolet light source that emits ultraviolet light includes multiple light-emitting elements and emits ultraviolet light through the emission of light from multiple light-emitting elements, the irradiance distribution of ultraviolet light emitted by the ultraviolet light source varies greatly from one ultraviolet curing liquid dispensing device to another. However, this control method for ultraviolet curing liquid dispensing devices allows for optimal adjustment of the ultraviolet intensity regardless of the irradiance distribution of ultraviolet light. As a result, the optimal amount of ultraviolet energy can be irradiated onto the liquid, reducing the risk of variations in the degree of curing and fixing of the liquid, and reducing the risk of deterioration in the image quality formed on the medium. In other words, even when multiple light-emitting elements are used as the light source that irradiates ultraviolet light, the amount of ultraviolet light irradiated onto the liquid can be appropriately controlled.

[0090] In one embodiment of the control method for the ultraviolet curing liquid dispensing apparatus, The ultraviolet light source may have a mirror for focusing the ultraviolet light.

[0091] In this control method for UV-curing liquid dispensing devices, although the illuminance distribution of UV light emitted by the UV light source becomes more complex when the UV light source has a mirror, the intensity of UV light can be optimally adjusted regardless of the illuminance distribution. Therefore, the optimal amount of UV energy can be irradiated onto the liquid, reducing the risk of variations in the degree of curing and fixing of the liquid, and reducing the risk of deterioration in the image quality formed on the medium.

[0092] In one embodiment of the control method for the ultraviolet curing liquid dispensing apparatus, The ultraviolet light source comprises a first ultraviolet light source that includes a plurality of first light-emitting elements among the plurality of light-emitting elements and outputs first ultraviolet light as the ultraviolet light, and a second ultraviolet light source that includes a plurality of second light-emitting elements among the plurality of light-emitting elements and outputs second ultraviolet light as the ultraviolet light, The detection step includes a first detection step for detecting the irradiation amount of the first ultraviolet light in the relative position control step, and a second detection step for detecting the irradiation amount of the second ultraviolet light in the relative position control step. The adjustment step may include a first adjustment step of adjusting the intensity of the first ultraviolet light based on the amount of first ultraviolet light detected in the first detection step, and a second adjustment step of adjusting the intensity of the second ultraviolet light based on the amount of second ultraviolet light detected in the second detection step.

[0093] In this control method for an ultraviolet curing liquid dispensing device, even when the ultraviolet light source includes a first ultraviolet light source and a second ultraviolet light source, the detection step includes a first detection step for detecting the irradiation amount of the first ultraviolet light in the relative position control step, and a second detection step for detecting the irradiation amount of the second ultraviolet light in the relative position control step. The adjustment step includes a first adjustment step for adjusting the intensity of the first ultraviolet light based on the irradiation amount of the first ultraviolet light detected in the first detection step, and a second adjustment step for adjusting the intensity of the second ultraviolet light based on the irradiation amount of the second ultraviolet light detected in the second detection step. As a result, the intensity of the first ultraviolet light and the second ultraviolet light can be optimally adjusted regardless of the respective illuminance distributions of the first and second ultraviolet light. Therefore, the liquid can be irradiated with the first and second ultraviolet light with the optimal amount of energy, which reduces the risk of variations in the degree of curing and fixing of the liquid, and reduces the risk of deterioration in the image quality formed on the medium.

[0094] In one embodiment of the control method for the ultraviolet curing liquid dispensing apparatus, In the adjustment step, the intensity of the ultraviolet light may be adjusted so that the maximum value of the ultraviolet light irradiation amount detected in the detection step becomes a predetermined value.

[0095] In one embodiment of the control method for the ultraviolet curing liquid dispensing apparatus, In the adjustment step, the intensity of the ultraviolet light may be adjusted so that the integral value of the ultraviolet light irradiation amount detected in the detection step becomes a predetermined value. [Explanation of Symbols]

[0096] 1…Liquid ejection device, 2…External equipment, 10…Control mechanism, 20…Print head, 30, 30a, 30b…Ultraviolet irradiation device, 31…Base component, 32…Heat sink, 40…Movement mechanism, 50…Detection mechanism, 60…Platen, 70…Carriage, 100…Control unit, 200…Ejection control unit, 210…Ejection control circuit, 220…Drive circuit, 300…Irradiation control unit, 310…Irradiation control circuit, 320…Light source drive circuit, 330…Shaping circuit, 340…Memory circuit, 400…Movement control unit, D…Image, Dd, Dw…Dot, L…Ink droplet, LD…Light-emitting element, P…Medium, U, Ua, Ub…Ultraviolet light

Claims

1. A dispensing head that dispenses a liquid that hardens when exposed to ultraviolet light, A UV light source that includes multiple light-emitting elements and emits ultraviolet light, An intensity adjustment mechanism for adjusting the intensity of the ultraviolet light, An irradiation amount sensor for detecting the amount of ultraviolet radiation, A relative position control mechanism that changes the relative position between the irradiation amount sensor and the ultraviolet light source, Equipped with, The intensity adjustment mechanism adjusts the intensity of the ultraviolet light based on the amount of ultraviolet light detected by the irradiation sensor during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source. A UV-curing liquid dispensing device characterized by the following features.

2. The ultraviolet light source has a mirror that concentrates the ultraviolet light. The ultraviolet curing liquid dispensing apparatus according to feature 1.

3. The ultraviolet light source comprises a first ultraviolet light source and a second ultraviolet light source. The first ultraviolet light source includes a plurality of first light-emitting elements among the plurality of light-emitting elements, and outputs first ultraviolet light as the ultraviolet light. The second ultraviolet light source includes a plurality of second light-emitting elements among the plurality of light-emitting elements, and outputs second ultraviolet light as the ultraviolet light. The aforementioned strength adjustment mechanism is During the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the first ultraviolet light source, the intensity of the first ultraviolet light is adjusted according to the irradiation amount of the first ultraviolet light detected by the irradiation amount sensor. During the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the second ultraviolet light source, the intensity of the second ultraviolet light is adjusted according to the irradiation amount of the second ultraviolet light detected by the irradiation amount sensor. The ultraviolet curing liquid dispensing apparatus according to feature 1.

4. The intensity adjustment mechanism adjusts the intensity of the ultraviolet light so that the maximum value of the ultraviolet light irradiation amount detected by the irradiation amount sensor becomes a predetermined value during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source. The ultraviolet curing liquid dispensing apparatus according to any one of claims 1 to 3.

5. The intensity adjustment mechanism adjusts the intensity of the ultraviolet light so that the integral value of the ultraviolet light irradiation amount detected by the irradiation amount sensor becomes a predetermined value during the period in which the relative position control mechanism changes the relative position between the irradiation amount sensor and the ultraviolet light source. The ultraviolet curing liquid dispensing apparatus according to any one of claims 1 to 3.

6. A control method for an ultraviolet-curing liquid dispensing device that dispenses a liquid that hardens upon irradiation with ultraviolet light, A relative position control step that changes the relative position of an irradiation amount sensor that detects the amount of ultraviolet irradiation and an ultraviolet light source that includes a plurality of light-emitting elements and emits the ultraviolet light, A detection step for detecting the amount of ultraviolet radiation, synchronized with the relative position control step, An adjustment step is performed to adjust the intensity of the ultraviolet light based on the amount of ultraviolet light detected in the detection step. Having, A control method for an ultraviolet-curable liquid dispensing device, characterized by the following features.

7. The ultraviolet light source has a mirror that concentrates the ultraviolet light. A control method for an ultraviolet-curable liquid dispensing apparatus according to feature 6.

8. The ultraviolet light source comprises a first ultraviolet light source that includes a plurality of first light-emitting elements among the plurality of light-emitting elements and outputs first ultraviolet light as the ultraviolet light, and a second ultraviolet light source that includes a plurality of second light-emitting elements among the plurality of light-emitting elements and outputs second ultraviolet light as the ultraviolet light, The detection step includes a first detection step for detecting the irradiation amount of the first ultraviolet light in the relative position control step, and a second detection step for detecting the irradiation amount of the second ultraviolet light in the relative position control step. The adjustment step includes a first adjustment step of adjusting the intensity of the first ultraviolet light based on the amount of first ultraviolet light detected in the first detection step, and a second adjustment step of adjusting the intensity of the second ultraviolet light based on the amount of second ultraviolet light detected in the second detection step. A control method for an ultraviolet-curable liquid dispensing apparatus according to feature 6.

9. In the adjustment step, the intensity of the ultraviolet light is adjusted so that the maximum value of the ultraviolet light irradiation amount detected in the detection step becomes a predetermined value. A control method for an ultraviolet-curable liquid dispensing apparatus according to any one of claims 6 to 8.

10. In the adjustment step, the intensity of the ultraviolet light is adjusted so that the integral value of the ultraviolet light irradiation amount detected in the detection step becomes a predetermined value. A control method for an ultraviolet-curable liquid dispensing apparatus according to any one of claims 6 to 8.

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