Light irradiation device and printing apparatus

Abstract

This light irradiation device includes a light irradiation unit and a gas supply unit. The light irradiation unit includes a light emitting element and a housing. The housing has a first outer surface having a light passage port positioned close to the first direction side as compared to the light emitting element. The gas supply unit includes a gas flow path, and a discharge unit having a first opening, a second opening, and a plurality of third openings which are all connected to said flow path. The first outer surface and the discharge unit are arranged side by side in a third direction intersecting a second direction which denotes the longitudinal direction of the light passage port. The first opening includes an opening between an end, in the second direction, of a first plate-like portion having the plurality of third openings and an end, in the first direction, of a second plate-like portion. The second opening includes an opening between an end of the first plate-like portion in a fourth direction opposite to the second direction and an end of a third plate-like portion in the first direction.

Description

Light Irradiation Device and Printing Device Cross-Reference to Related Applications

[0001] This application claims priority from Japanese Application No. 2024-189649 (filed on October 29, 2024), and the entire disclosure of the Japanese application is incorporated herein by reference for that purpose.

[0002] This disclosure relates to a light irradiation device and a printing device.

[0003] Examples of the light irradiation device include a light irradiation device including a light-emitting element, a housing, and a gas supply unit (see, for example, the descriptions in Patent Documents 1 and 2). Here, the light-emitting element is located inside the housing. The housing has a light irradiation surface provided with a light irradiation port through which light from the light-emitting element can pass. The gas supply unit has, for example, a flow path located along a region extending from a side surface of the housing to a part of the light irradiation surface. This flow path has a gas discharge port that discharges gas at an end located near the light irradiation port of this flow path. The gas discharge port has a plurality of openings.

[0004] This light irradiation device can irradiate light on an irradiated object while supplying gas to a space along the irradiated object that is moving relative to the light irradiation surface while facing the light irradiation surface.

[0005] In recent years, there has been an increasing demand for improving the light irradiation efficiency on an irradiated object and reducing the oxygen concentration in the space along the irradiated object in light irradiation devices and printing devices equipped with light irradiation devices.

[0006] International Publication No. 2019 / 151148 International Publication No. 2020 / 022424

[0007] A light irradiation device and a printing device are disclosed.

[0008] One embodiment of a light irradiation device comprises a light irradiation unit and a gas supply unit. The light irradiation unit includes a housing and a light-emitting element. The housing has an internal space in which the light-emitting element is located and a first outer surface provided with a light-passing opening through which light from the light-emitting element can pass. The light-passing opening is located on the side of the light-emitting element in a first direction. The gas supply unit includes a gas flow path and a gas discharge unit having a plurality of openings, each connected to the flow path. The first outer surface and the discharge unit are aligned in a third direction intersecting the second direction when the longitudinal direction of the light-passing opening is considered the second direction. The plurality of openings include a first opening located at the outermost end in the second direction, a second opening located at the outermost end in a fourth direction opposite to the second direction, and a plurality of third openings located between the first and second openings. The gas supply unit includes a first plate-like portion having the plurality of third openings, a second plate-like portion, and a third plate-like portion. The first plate-like portion has a first end which is the end in the second direction and a second end which is the end in the fourth direction. The first opening includes an opening in the gap between the first end and the end of the second plate-like portion in the first direction. The second opening includes an opening in the gap between the second end and the end of the third plate-like portion in the first direction.

[0009] One embodiment of a printing apparatus comprises a light irradiation device of the above embodiment, a transport unit, and a printing unit. The transport unit transports the printing medium in a direction along a fifth direction opposite to the third direction, with the medium facing the first outer surface of the light irradiation device. The printing unit is positioned facing the transport path through which the printing medium is transported by the transport unit. The transport path includes a first region and a second region located downstream of the first region. The printing unit is positioned facing the first region. The first outer surface is positioned facing the second region.

[0010] Figure 1 is a cross-sectional view showing a schematic configuration of an example of a light irradiation device according to the first embodiment. Figure 2 is a perspective view showing the external appearance of an example of a light irradiation device according to the first embodiment. Figure 3 is a plan view showing a schematic configuration of an example of a light-emitting element and substrate in a light irradiation unit according to the first embodiment. Figure 4 is a cross-sectional view showing a schematic hypothetical cross-section of a part of an example of a light-emitting element and substrate in a light irradiation unit according to the first embodiment. Figure 5 is a bottom view showing the external appearance of an example of a discharge unit according to the first embodiment. Figure 6 is a perspective view showing the external appearance of a part of an example of a gas supply unit according to the first embodiment. Figure 7 is a side view showing the external appearance of a part of an example of a gas supply unit according to the first embodiment. Figure 8 is a bottom view showing the external appearance of a discharge unit according to a reference example. Figure 9 is a schematic graph showing an example of the relationship between the position in the width direction along the second direction of the light irradiation device and the amount of nitrogen gas discharged from the discharge unit for a light irradiation device to which a discharge unit according to a reference example is applied. Figure 10 is a schematic graph showing an example of the relationship between the position in the width direction along the second direction of the light irradiation device and the amount of nitrogen gas discharged from the discharge unit for a light irradiation device according to the first embodiment. Figure 11 is a plan view showing an example of the appearance of a plate-shaped member used in the manufacture of one example of a part of the gas supply unit according to the first embodiment. Figure 12 is a perspective view showing the state in which one example of a part of the gas supply unit according to the first embodiment is being manufactured. Figure 13 is a perspective view showing an example of the appearance of a part of another example of the gas supply unit according to the first embodiment. Figure 14 is a side view showing an example of the appearance of a part of another example of the gas supply unit according to the first embodiment. Figure 15 is a plan view showing an example of the appearance of a plate-shaped member used in the manufacture of another example of a part of the gas supply unit according to the first embodiment. Figure 16 is a bottom view showing the appearance of another first example of the discharge unit according to the first embodiment. Figure 17 is a bottom view showing the appearance of another second example of the discharge unit according to the first embodiment. Figure 18 is a diagram showing a schematic configuration of an example of a printing apparatus according to the first embodiment.

[0011] A light irradiation device may include, for example, a light-emitting element, a housing, and a gas supply unit. The light-emitting element is located inside the housing. The housing has an outer surface (also called the light irradiation surface) through which light from the light-emitting element can pass. The gas supply unit has, for example, a flow path located along a region extending from the side of the housing to a part of the light irradiation surface. This flow path has a gas outlet at an end located near the light irradiation outlet that releases gas. This gas outlet has multiple openings.

[0012] This light irradiation device can, for example, irradiate an object with light while supplying gas to the space along the object that is moving relative to the light irradiation surface while facing the light irradiation surface.

[0013] Specifically, this light irradiation device can irradiate light, such as ultraviolet light emitted from a light-emitting element, through a light irradiation port onto photocurable materials, such as resins or inks, that undergo hardening (photocuring) through a chemical reaction in response to ultraviolet irradiation. Furthermore, this light irradiation device can reduce the concentration of oxygen, which can inhibit the hardening of photocurable materials by chemical reaction in response to light irradiation, in the space along the irradiated object, including the photocurable material, by using gas emitted from a gas outlet.

[0014] More specifically, this light irradiation device can be applied to a printing apparatus that uses, for example, a photocurable ink as an example of a photocurable material to print on a printing medium such as paper. In this case, the printing medium to which the photocurable ink as an example of a photocurable material is attached becomes the object to be irradiated with light by the light irradiation device. Examples of photocurable inks include ultraviolet-curable inks (UV inks) that harden when exposed to ultraviolet light. In this printing apparatus, for example, ultraviolet light is irradiated by the light irradiation device onto UV ink having a dot-like pattern formed on the printing medium by an inkjet method or the like. Also in this printing apparatus, for example, the printing medium facing the light irradiation surface of the light irradiation device moves relative to the light irradiation surface. Furthermore, in this printing apparatus, for example, the light irradiation device supplies an inert gas such as nitrogen to the space along the printing medium on which the UV ink having a dot-like pattern is formed.

[0015] Incidentally, in the light irradiation device described above, for example, the flow path of the gas supply unit has a portion (also called a protruding portion) that is located along a part of the light irradiation surface. Due to the presence of this protruding portion, the light irradiation surface must be positioned at a certain distance from the object to be irradiated, which contains the photocurable material. As a result, the amount of light irradiated onto the object to be irradiated, which contains the photocurable material, by the light irradiation device may decrease. Specifically, for example, the light irradiation surface must be positioned at a certain distance from the printing medium on which UV ink having a pattern such as dots is formed. As a result, the amount of ultraviolet light irradiated onto the printing medium on which UV ink having a pattern such as dots is formed by the light irradiation device may decrease.

[0016] To address this problem, one possible solution is to increase the amount of light irradiated onto the object being irradiated. For example, one could adopt a configuration in the light irradiation device in which a portion of the flow path of the gas supply unit is not located on the light irradiation surface. More specifically, one could adopt a configuration in which the light irradiation surface and the gas outlet are aligned in a direction along the light irradiation surface.

[0017] However, if this configuration is adopted, the phenomenon in which gas released from the gas outlet can accumulate in the space between the light irradiation port and the irradiated object due to the difference in height between the light irradiation surface and the protruding part becomes less likely to occur. Furthermore, for example, when the irradiated object is moving relative to the light irradiation surface while facing it, surrounding air can be drawn into the space between the light irradiation surface and the irradiated object from both sides in the direction perpendicular to the direction of movement of the irradiated object (also called the width direction). As a result, in the region near the light irradiation port in the space between the light irradiation surface and the irradiated object, the reduction in oxygen concentration may be insufficient on both sides in the width direction.

[0018] Therefore, there is room for improvement in light irradiation devices and printing apparatus equipped with light irradiation devices in terms of improving the efficiency of light irradiation to the object to be irradiated and reducing the insufficient decrease in oxygen concentration in the space along the object to be irradiated.

[0019] Therefore, the inventors of this disclosure have created a technology that can improve the efficiency of light irradiation to the object to be irradiated and reduce the insufficient decrease in oxygen concentration in the space along the object to be irradiated, for light irradiation devices and printing devices.

[0020] Various embodiments and examples of this will be described below with reference to the drawings. In the drawings, parts having the same or similar configuration and function are denoted by the same reference numerals. Redundant explanations have been omitted in the following description. The drawings are shown schematically.

[0021] The drawings include diagrams with right-handed XYZ coordinate systems indicated where appropriate. In the following explanation, the +Z direction is set to vertically upward (also simply called upward). The -Z direction is set to vertically downward (also simply called downward). The direction perpendicular to the +Z direction is defined as the +X direction. The direction perpendicular to both the +Z and +X directions is defined as the +Y direction. The direction opposite to the +X direction is also referred to as the -X direction. The direction opposite to the +Y direction is also referred to as the -Y direction. The direction opposite to the +Z direction is also referred to as the -Z direction.

[0022] In Figures 11 and 15, the XYZ coordinate system defines the orientation of the plate-shaped member 300 used in the fabrication of one example of a part of the gas supply unit 3 of the light irradiation device 1. In this XYZ coordinate system, one direction along the thickness direction of the plate-shaped member 300 is defined as the +X direction, one direction along the front and back surfaces of the plate-shaped member 300 is defined as the +Y direction, and the direction perpendicular to both the +X and +Y directions is defined as the +Z direction. At the stage in which one example of a part of the gas supply unit 3 of the light irradiation device 1 shown in Figures 11, 12 and 15 is fabricated, the +Z direction does not have to be upward, and the -Z direction does not have to be downward.

[0023] In this disclosure, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," or "coaxial") may be used. In these cases, unless otherwise specified, these expressions not only strictly describe the positional relationship but also describe a state that is relatively displaced with respect to angle or distance, within a tolerance or range that yields a similar level of function. In addition, expressions indicating equality (e.g., "identical," "equal," or "homogeneous") may be used. In these cases, unless otherwise specified, these expressions not only describe a state that is quantitatively exactly equal but also describe a state in which there is a tolerance or a difference that yields a similar level of function. In addition, expressions indicating shape (e.g., "quadrilateral" or "cylindrical") may be used. In these cases, unless otherwise specified, these expressions not only describe the geometrically exact shape but also describe a shape that has, for example, concavity or chamfers, within a range that yields a similar level of effect. Furthermore, in this disclosure, expressions such as “comprising a component,” “including a component,” or “having a component” may be used to describe one or more components. In these cases, these expressions are not exclusive and exclude the existence of other components. Also, in this disclosure, expressions such as “at least one of A, B, and C” may be used. In these cases, these expressions include the cases of A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0024] <1. First Embodiment> <1-1. Light Irradiation Device> Figure 1 shows a schematic cross-section of an example of a light irradiation device 1 according to the first embodiment. Figure 2 shows the external appearance of an example of a light irradiation device 1 according to the first embodiment. In Figure 1, an example of the outer edge of a printing medium 111, which is an example of an object constituting the irradiated object 110, is schematically depicted with a thin dashed line.

[0025] The light irradiation device 1 is a device that can cure photocurable materials by irradiating them with light, such as ultraviolet light. This light irradiation device 1 is installed as a photocuring device in a printing device, such as an offset printing device (also called an offset printing device) or an inkjet printing device (also called an inkjet printing device). In this printing device, for example, a photocurable material such as photocurable ink attached to a printing medium 111 by the printing unit is cured by the light irradiation device 1, thereby enabling printing on the printing medium 111. For example, ultraviolet curing ink is used as the photocurable ink. For example, when the light irradiation device 1 is installed in a printing device, the printing medium 111 to which a photocurable material such as photocurable ink is attached is an example of an irradiated object 110 that is irradiated with light by the light irradiation device 1. Hereinafter, the printing medium 111 to which a photocurable material such as photocurable ink is attached will also be simply referred to as the printing medium 111.

[0026] The printing medium 111 is the object to be printed on in the printing apparatus. The printing medium 111 may be, for example, a sheet made of paper or resin, or a thin plate made of resin, semiconductor, metal, or wood.

[0027] As shown in Figures 1 and 2, the light irradiation device 1 comprises a light irradiation unit 2 and a gas supply unit 3. When the light irradiation device 1 is applied to a printing apparatus, for example, when curing a photocurable material, the gas supply unit 3 supplies gas between the light irradiation device 1 and the printing medium 111, while the light irradiation unit 2 irradiates light onto the printing medium 111. Here, for example, the gas supplied by the gas supply unit 3 is a gas that does not contain oxygen, is substantially oxygen-free, or has a lower oxygen concentration than air (also called a low-oxygen gas). For example, an inert gas such as nitrogen gas and / or a noble gas can be used as a low-oxygen gas. For example, argon gas can be used as a noble gas. This reduces the phenomenon in which radicals in the photocurable material react with oxygen in the surrounding atmosphere. As a result, the inhibition of curing of the photocurable material by oxygen can be reduced. The light irradiation device 1 can be manufactured using known methods.

[0028] <1-1-1. Light Irradiation Unit> As shown in Figure 1, the light irradiation unit 2 includes a light-emitting element 21 and a housing 22. This light irradiation unit 2 can irradiate light onto an object to be irradiated 110. For example, if a light irradiation device 1 is mounted on a printing device, the light irradiation unit 2 can irradiate light onto a printing medium 111, etc. In one example of the first embodiment, the light irradiation unit 2 includes a substrate 23, a heat dissipation member 24, a blower unit 25, and a drive substrate 26. In the examples of Figures 1 and 2, the light irradiation unit 2 includes a filter 27 and a connector 28.

[0029] The housing 22 has an internal space 221. The light-emitting element 21 is located in the internal space 221. In other words, the light-emitting element 21 is located in the internal space 221 of the housing 22. In addition to the light-emitting element 21, the housing 22 may also house, for example, a substrate 23, a heat dissipation member 24, a blower unit 25, and a drive substrate 26 in the internal space 221.

[0030] The substrate 23 is a substrate on which the light-emitting element 21 is mounted. The heat dissipation member 24 is thermally connected to the substrate 23. The thermal connection between the substrate 23 and the heat dissipation member 24 may be a direct connection between the substrate 23 and the heat dissipation member 24, or it may be an indirect connection between the substrate 23 and the heat dissipation member 24 via one or more members having excellent thermal conductivity. The heat dissipation member 24 is a member (also called a heat sink) intended for heat dissipation and heat absorption. The heat dissipation member 24 can dissipate the heat generated in the light-emitting element 21 and the substrate 23 when the light-emitting element 21 emits light. For example, the material of the heat dissipation member 24 may be a metal having excellent thermal conductivity, such as aluminum (A1) or copper (Cu). The heat dissipation member 24 includes, for example, a portion to which the substrate 23 is thermally connected (also called a base portion) and a plurality of protruding portions that protrude from the base portion. For example, a plate-shaped fin may be applied to each of the plurality of protruding portions. The air blower 25 can, for example, generate a flow of gas along the heat dissipation member 24. For example, a cooling fan may be applied to the air blower 25. The drive board 26 includes an electrical circuit (also referred to as a drive circuit) for driving the light-emitting element 21. The drive board 26 is electrically connected to the board 23, for example, via a cable or a flexible printed circuit (FPC).

[0031] Furthermore, the housing 22 has a plurality of vents 22v that allow for the supply of air from the outside of the housing 22 to the internal space 221 of the housing 22 and the exhaust of air from the internal space 221 of the housing 22 to the outside of the housing 22, for example, to enhance the heat dissipation effect of the heat dissipation member 24. In other words, the housing 22 has a plurality of vents 22v for supplying and exhausting air. In this case, the air blower 25 can, for example, generate an airflow to release the air in the internal space 221 of the housing 22, which has been heated by the heat dissipated from the heat dissipation member 24, to the outside of the housing 22. A filter 27 may be placed in some of the plurality of vents 22v. For example, a sponge or nonwoven fabric may be used for the filter 27. The presence of this filter 27 can reduce the intrusion of foreign matter such as dust and dirt from the outside of the housing 22 into the internal space 221. In addition, the presence of the filter 27 can, for example, slow down the airflow around the vent 22v in which the filter 27 is placed. Furthermore, for example, the filter 27 can absorb the operating noise of the blower unit 25 housed in the housing 22. This can reduce the noise generated by the blower unit 25 from the light irradiation device 1. Some of the multiple vents 22v may be used to electrically connect the drive board 26 and the connector 28. The drive board 26 and the connector 28 are electrically connected, for example, via wiring. For example, wiring such as cables for supplying power and control signals to the drive board 26 is attached to the connector 28.

[0032] Figure 3 shows a schematic configuration of an example of a light-emitting element 21 and substrate 23 in the light irradiation unit 2 according to the first embodiment, when viewed from above. Figure 4 shows a schematic hypothetical cross-section of a part of the example of the light-emitting element 21 and substrate 23 in the light irradiation unit 2 according to the first embodiment.

[0033] The light irradiation unit 2 has, for example, a plurality of light-emitting elements 21. The plurality of light-emitting elements 21 may be arranged in a single row on the substrate 23, or they may be arranged in a matrix-like arrangement having multiple rows.

[0034] Each of the multiple light-emitting elements 21 can emit light. The light emitted by each light-emitting element 21 includes, for example, light of a predetermined wavelength. The predetermined wavelength of light may be, for example, ultraviolet light. The light-emitting element 21 may have a configuration having, for example, multiple semiconductor layers and a pair of electrodes. Here, the multiple semiconductor layers are stacked. The multiple semiconductor layers include, for example, a p-type cladding layer, an active layer, and an n-type cladding layer. The pair of electrodes includes a first electrode and a second electrode. For example, the first electrode is connected to the p-type cladding layer and the second electrode is connected to the n-type cladding layer. For example, the first electrode may be connected to the n-type cladding layer and the second electrode may be connected to the p-type cladding layer. In this light-emitting element 21, the multiple semiconductor layers can emit light when a voltage is applied through the pair of electrodes. The materials for the multiple semiconductor layers may include, for example, gallium arsenide (GaAs) or gallium nitride (GaN). For the pair of electrodes, materials with excellent conductivity, such as silver (Ag), can be used.

[0035] The light-emitting element 21 is, for example, a laser diode (LD) or a light-emitting diode (LED). When the light emitted by the light-emitting element 21 is ultraviolet light, the wavelength at which the light spectrum shows a peak (also called the peak wavelength) is set, for example, within the range of 280 nanometers (nm) to 440 nm. The predetermined wavelength of the light emitted by the light-emitting element 21 should be any wavelength necessary for curing the photocurable material.

[0036] The substrate 23 can support the light-emitting elements 21. The outer shape of the substrate 23 is, for example, flat. The shape of the substrate 23 when viewed from above (also referred to as the planar shape) is, for example, rectangular. Multiple light-emitting elements 21 are mounted on the substrate 23.

[0037] The substrate 23 has, for example, a single insulating layer or a stack of multiple insulating layers. The material of the single insulating layer or the material of each of the multiple insulating layers may be, for example, a ceramic such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, or glass ceramics, or a resin such as epoxy resin or liquid crystal polymer. In the examples of Figures 3 and 4, the substrate 23 includes a first insulating layer 23il as a single insulating layer. The multiple insulating layers may be three or more insulating layers.

[0038] The substrate 23 further has, for example, wiring. This wiring includes, for example, a plurality of conductive layers 23cl. The plurality of conductive layers 23cl are arranged, for example, on one or more insulating layers. In the example of Figures 3 and 4, the plurality of conductive layers 23cl are arranged on a first insulating layer 23il as a single insulating layer. More specifically, the plurality of conductive layers 23cl (specifically five conductive layers 23cl) are arranged in one direction, spaced apart from each other. The material of each of the plurality of conductive layers 23cl is a material having excellent conductivity, such as gold (Au). Each of the plurality of conductive layers 23cl can be formed, for example, by plating on one or more insulating layers. The wiring may also include a portion for supplying current to at least two of the plurality of conductive layers 23cl. The material of this portion may be, for example, tungsten (W), molybdenum (Mo), manganese (Mn), or copper (Cu). In the examples shown in Figures 3 and 4, the two conductive layers 23cl are two conductive layers 23cl located at both ends in one direction among a plurality of conductive layers 23cl.

[0039] For example, each of the multiple light-emitting elements 21 has a first electrode on the substrate 23 side and a second electrode on the side opposite to the substrate 23. The first electrode of one or more light-emitting elements 21 is electrically bonded to each of some of the conductive layers 23cl among the multiple conductive layers 23cl. In the example of Figure 3, some of the conductive layers 23cl are two or more conductive layers 23cl (specifically four conductive layers 23cl) excluding the conductive layer 23cl located at the outermost edge in one direction among the multiple conductive layers 23cl (specifically five conductive layers 23cl). For bonding the first electrode to the conductive layer 23cl, for example, bonding using a silver paste containing silver powder is applied. For each of the multiple light-emitting elements 21, the second electrode is electrically connected, for example, via a bonding wire Wb1 to a second conductive layer 23cl different from the first conductive layer 23cl to which the first electrode is bonded among the multiple conductive layers 23cl. The second conductive layer 23cl may be a conductive layer 23cl located next to the first conductive layer 23cl among a plurality of conductive layers 23cl. Here, for example, for each of the plurality of light-emitting elements 21, current flows in the order of the first conductive layer 23cl, the first electrode, the plurality of semiconductor layers, the second electrode, the bonding wire Wb1, and the second conductive layer 23cl. As a result, light is emitted from the plurality of semiconductor layers (for example, the active layer) in each of the plurality of light-emitting elements 21.

[0040] The configuration of the substrate 23 and the mounting configuration of each of the multiple light-emitting elements 21 on the substrate 23 are not limited to the configuration of the example described above, but may be various other configurations.

[0041] The housing 22 has a light-emitting surface 222 as a first outer surface. The light-emitting surface 222 has an opening (also called a light-passing opening) 222o through which light from the light-emitting element 21 can pass. In other words, the light-emitting surface 222 is a surface provided with a light-passing opening 222o through which light from the light-emitting element 21 can pass.

[0042] The light-emitting surface 222 is, for example, a planar surface or plane. In the examples of Figures 1 and 2, the light-emitting surface 222 is a surface along a hypothetical horizontal plane parallel to the XY plane. In other words, the light-emitting surface 222 may be, for example, a planar surface or plane facing downwards in the -Z direction. In this case, the light-emitting surface 222 may be the bottom surface of the housing 22. The light-emitting surface 222 has, for example, a rectangular shape.

[0043] The light-passing opening 222o is located on the side of the light-emitting element 21 in the -Z direction, which is the first direction. That is, the light-passing opening 222o is located on the side of the light-emitting element 21 in the -Z direction, which is the first direction. The light-passing opening 222o has a longitudinal direction. In other words, the light-passing opening 222o has a short direction. The longitudinal direction is considered the second direction. In this case, for example, the light-passing opening 222o has a longitudinal direction along the light-emitting surface 222 and along the +Y direction, which is the second direction, orthogonal to the first direction. The light-passing opening 222o is, for example, a rectangular or strip-shaped opening. In the examples of Figures 1 and 2, the light-passing opening 222o is a rectangular opening having a longitudinal direction along the +Y direction, which is the second direction, and a short direction along the light-emitting surface 222 and along the +X direction, which is the third direction, orthogonal to the second direction. The light-passing opening 222o may be located, for example, from the end of the light-emitting surface 222 on the side in the second direction, the +Y direction, to the end on the side in the fourth direction, the -Y direction, which is opposite to the second direction. Here, for example, it is assumed that the housing 22 is viewed through from above in the direction opposite to the first direction, the -Z direction. In this case, for example, the light-passing opening 222o may be located in a form that overlaps with the region of the internal space 221 of the housing 22 that extends from the end on the side in the second direction, the +Y direction, to the end on the side in the fourth direction, the -Y direction.

[0044] A cover member made of, for example, a light-transmissive material may be disposed at the light passage opening 222o. As the light-transmissive material constituting the cover member, for example, glass or the like is applied. This light-transmissive material does not necessarily have to be light-transmissive for light of all wavelengths ranging from ultraviolet rays to infrared rays. This light-transmissive material only needs to have a light-transmissive property such that at least the light of the wavelength necessary for curing the photocurable material can pass through in the light amount necessary for curing the photocurable material. As the cover member, for example, a light-transmissive member such as a glass plate material (also referred to as a glass plate) is applied. As the material of the glass plate, for example, optical glass such as quartz glass or borosilicate crown glass (BK7) is applied. Here, for example, a form is adopted in which the cover member is fitted along the light passage opening 222o with respect to the portion constituting the light irradiation surface 222 of the housing 22. In this case, the surface of the cover member opposite to the light-emitting element 21 may be regarded as constituting the light passage opening 222o. Also, the surface of the cover member opposite to the light-emitting element 21 may be regarded as constituting a part of the light irradiation surface 222.

[0045] Also, for example, the remaining portion of the housing 22 excluding the light passage opening 222o may be made of a light-shielding material. In this case, the light irradiation surface 222 has a light passage opening 222o through which the light from the light-emitting element 21 can pass, and a light-shielding portion (also referred to as a light-shielding part) that sandwiches the light passage opening 222o in the +X direction as the third direction. Depending on the specifications of the light irradiation unit 2, the light-shielding portion may surround the light passage opening 222o. In other words, the light passage opening 222o may be located inside the light irradiation surface 222. In this case, in the light irradiation surface 222, a part of the light irradiation surface 222 may be located in each of the regions on the +Y direction side of the light passage opening 222o as the second direction and the -Y direction side of the light passage opening 222o as the fourth direction.

[0046] The light-shielding portion of the light-irradiating surface 222 does not necessarily have to be light-shielding for light of all wavelengths in the wavelength range from ultraviolet light to infrared light. The material constituting the light-shielding portion in the housing 22 only needs to have a light-shielding property capable of blocking at least light of wavelengths necessary for curing the photocurable material. For the material of the remaining portion of the housing 22 excluding the portion constituting the light passage opening 222o, for example, aluminum (Al), stainless steel, or copper (Cu) is applied. The material of the remaining portion of the housing 22 excluding the portion constituting the light-irradiating surface 222 may be, for example, the same or similar material as the material constituting the light-shielding portion. Note that the material of the remaining portion of the housing 22 excluding the portion constituting the light-irradiating surface 222 may be, for example, a material different from the material constituting the light-shielding portion. A surface treatment or coating for reducing light reflection may be applied to the surface of the portion of the housing 22 excluding the light passage opening 222o. For the surface treatment, for example, anodizing treatment on the surface of an aluminum alloy is applied. For the coating, for example, application of a black paint is applied.

[0047] Here, the light-irradiating surface 222 may be, for example, a surface facing the printed medium 111 as an example of the irradiated object 110. In this case, the light-irradiating unit 2 can irradiate the printed medium 111 with light from the light-emitting element 21 housed in the housing 22 through the light passage opening 222o of the light-irradiating surface 222. Here, for example, the case where light from the light-emitting element 21 is emitted downward from the light passage opening 222o of the light-irradiating surface 222 is assumed. In this case, the length (also referred to as height) in the direction along the -Z direction as the first direction of the housing 22 (also referred to as the height direction) may be, for example, about 120 millimeters (mm) to 180 mm. The length (also referred to as width) in the direction along the +Y direction as the second direction of the housing 22 (also referred to as the width direction) may be, for example, about 60 mm to 130 mm. The length (also referred to as depth) in the direction along the +X direction as the third direction of the housing 22 (also referred to as the depth direction) may be, for example, about 80 mm to 120 mm.

[0048] The housing 22 may have various external shapes depending on the application of the light irradiation device 1. The external shape of the housing 22 may be, for example, a cube, a rectangular parallelepiped, a triangular prism, a cylinder, or a semi-cylindrical shape.

[0049] The housing 22 has, for example, a light-emitting surface 222 as a first outer surface, a plurality of side surfaces 223 as a plurality of second outer surfaces, and a top surface 224 as a third outer surface.

[0050] The multiple sides 223 include, for example, a first side 2231. The first side 2231 is, for example, the side located at the end of the housing 22 in the +X direction, which is the third direction (also referred to as the second A outer surface). In the example of Figures 1 and 2, the multiple sides 223 include four sides 223. The four sides 223 include the first side 2231, the second side 2232, the third side 2233, and the fourth side 2234. The second side 2232 is the side located at the end of the housing 22 in the -X direction, which is the fifth direction opposite to the third direction (also referred to as the second B outer surface). The third side 2233 is the side located at the end of the housing 22 in the +Y direction, which is the second direction (also referred to as the second C outer surface). The fourth side 2234 is the side located at the end of the housing 22 in the -Y direction, which is the fourth direction (also referred to as the second D outer surface). The first side surface 2231 is, for example, a planar surface or plane oriented in a direction along the +X direction as the third direction. The second side surface 2232 is, for example, a planar surface or plane oriented in a direction along the -X direction as the fifth direction. A ventilation opening 22v is located on the second side surface 2232. The third side surface 2233 is, for example, a planar surface or plane oriented in a direction along the +Y direction as the second direction. The fourth side surface 2234 is, for example, a planar surface or plane oriented in a direction along the -Y direction as the fourth direction.

[0051] The upper surface 224 includes, for example, a surface aligned with the horizontal plane (also referred to as the first upper surface) and a surface inclined with respect to the horizontal plane (also referred to as the second upper surface). For example, a vent 22v is located on the upper surface 224. A filter 27 may be placed in the vent 22v of the upper surface 224.

[0052] <1-1-2. Gas Supply Unit> Figure 5 shows an example of the appearance of the discharge unit 32 in the gas supply unit 3 according to the first embodiment. In Figure 5, the outer edge of the mounting member 34 is shown by a thin dashed line. Figures 6 and 7 each show the appearance of a part of an example of the gas supply unit 3 according to the first embodiment.

[0053] As shown in Figure 1, the gas supply unit 3 includes a gas flow path (also simply called a flow path) 31 and a gas discharge section (also called a discharge section or gas discharge section) 32. This gas supply unit 3 can supply gas (for example, low-oxygen gas) to the space between the light irradiation device 1 and the printing medium 111, which is an example of an object to be irradiated 110, when the printing device is equipped with a light irradiation device 1. The gas supply unit 3 also includes, for example, a gas introduction section (also simply called an introduction section) 30. In one example of the first embodiment, the gas supply unit 3 includes a wall section 33, a mounting member 34, and a socket 35.

[0054] The flow path 31 is located, for example, along the housing 22. In other words, the flow path 31 is located, for example, along the outer surface of the housing 22. For example, the flow path 31 is located along the side surface 223 of the housing 22. In the example in Figure 1, the flow path 31 is located along the first side surface 2231 of the housing 22. The flow path 31 is the part through which the gas flows.

[0055] The introduction section 30 is the part for introducing gas into the flow path 31. In the example shown in Figure 1, the introduction section 30 is located at the top of the gas supply section 3. The introduction section 30 has, for example, one or more inlets (also called gas inlets) 30o. Each of the one or more gas inlets 30o is connected to the flow path 31. For example, a socket 35 is fitted into each of the one or more gas inlets 30o. If a pipe for supplying a gas such as low-oxygen gas is connected to the socket 35, the gas such as low-oxygen gas can be supplied into the flow path 31 via the one or more gas inlets 30o.

[0056] The discharge section 32 is the part that releases gas from the gas supply section 3. In the example shown in Figure 1, the discharge section 32 is located at the bottom of the gas supply section 3. The light irradiation surface 222 and the discharge section 32 are aligned in a third direction that intersects the second direction, when the longitudinal direction of the light passage opening 222o is considered the second direction. In the first embodiment, the second direction and the third direction are orthogonal. Here, for example, the discharge section 32 is located on the side of the light irradiation surface 222 in the light irradiation section 2 that is in the +X direction, which is the third direction. In other words, the light irradiation surface 222 and the discharge section 32 are aligned in a direction along the +X direction, which is the third direction. This allows, for example, when the light irradiation device 1 is mounted on a printing device, the light irradiation surface 222 and the printing medium 111, which is an example of an object to be irradiated 110, to be placed close together. As a result, the light irradiation efficiency to the object to be irradiated 110 can be improved. Here, the emission unit 32 may be positioned along a virtual plane that is aligned with the light irradiation surface 222, for example. For example, the side of the emission unit 32 in the -Z direction, which is the first direction, may be positioned along a virtual plane that is aligned with the light irradiation surface 222, or it may be flush with the light irradiation surface 222.

[0057] The discharge section 32 has a plurality of openings (also called gas outlets) 32o. Each of the plurality of gas outlets 32o is connected to the flow path 31. As a result, in the gas supply section 3, the gas supplied from the introduction section 30 (for example, low-oxygen gas) flows through the flow path 31 and is discharged from the plurality of gas outlets 32o. For example, if the printing apparatus is equipped with a light irradiation device 1, the gas (for example, low-oxygen gas) discharged from the plurality of gas outlets 32o is supplied to the space between the light irradiation device 1 and the printing medium 111, which is an example of an object to be irradiated 110.

[0058] The flow path 31 is formed by, for example, a wall portion 33. In this flow path 31, for example, gas can flow in the space enclosed by the inner surface 33is of the wall portion 33. In the example of Figure 1, the flow path 31 is formed by the wall portion 33 and the mounting member 34. In this flow path 31, for example, gas can flow in the space enclosed by the inner surface 33is of the wall portion 33 and the surface of the mounting member 34 on the wall portion 33 side. For example, the material of the wall portion 33 can be a metallic material such as aluminum (Al), stainless steel, or copper (Cu).

[0059] The mounting member 34 is a member for attaching the gas supply unit 3 to the housing 22. From another perspective, the mounting member 34 is a member for attaching the wall portion 33 to the housing 22. The mounting member 34 is fixed to the housing 22. The mounting member 34 is located, for example, along the first side surface 2231 of the housing 22. The mounting member 34 is fixed to the housing 22 by means of adhesive or screw fastening, for example. Packing members may be placed where screw fastening is performed, for example.

[0060] In the example shown in Figure 1, the mounting member 34 has a flat plate-shaped portion (also referred to as a base portion) 341 and a plurality of protruding portions 342. The base portion 341 is positioned along the first side surface 2231 of the housing 22. The base portion 341 is fixed to the housing 22 by means of adhesive or screw fastening, for example. Packing members may be appropriately placed where screw fastening is performed. The plurality of protruding portions 342 each protrude from the base portion 341 on the side opposite to the housing 22. Wall portions 33 are fixed to the plurality of protruding portions 342. The wall portions 33 are fixed to the plurality of protruding portions 342 by means of adhesive or screw fastening, for example. Packing members may be appropriately placed where screw fastening is performed. Here, for example, if a packing member is placed between the base portion 341 and the wall portions 33, the airtightness of the flow path 31 can be improved.

[0061] In the gas supply unit 3, the portion composed of the wall portion 33 and the mounting member 34 has, for example, a box-like shape with a rectangular parallelepiped outer shape.

[0062] Here, the discharge unit 32 may face, for example, the printing medium 111, which is an example of the object to be irradiated 110. In this case, the discharge unit 32 can discharge the gas (for example, low-oxygen gas) flowing in the flow path 31 toward the printing medium 111 through a plurality of gas outlets 32o. Here, for example, it is assumed that the discharge unit 32 discharges the gas (for example, low-oxygen gas) flowing in the flow path 31 downward from a plurality of gas outlets 32o. In this case, the length (height) of the wall 33 in the direction along the -Z direction as the first direction (height direction) may be, for example, about 100 mm to 170 mm. The length (width) of the wall 33 in the direction along the +Y direction as the second direction (width direction) may be, for example, about 60 mm to 130 mm. The length (depth) of the wall 33 in the direction along the +X direction as the third direction (depth direction) may be, for example, about 15 mm to 30 mm. The wall portion 33 may have various external shapes depending on the application of the light irradiation device 1.

[0063] The wall portion 33 includes, for example, a plurality of plate-like portions (also referred to as plate-like portions) 331. In other words, the gas supply portion 3 includes, for example, a plurality of plate-like portions 331. The flow path 31 may be formed, for example, by a plurality of plate-like portions 331. In this flow path 31, for example, gas can flow in the space surrounded by the plurality of plate-like portions 331. In the example of Figure 1, the flow path 31 is formed by a plurality of plate-like portions 331 and a mounting member 34. In this flow path 31, for example, gas can flow in the space surrounded by the plurality of plate-like portions 331 and the mounting member 34. The material of each of the plurality of plate-like portions 331 may be, for example, a metallic material such as aluminum (Al), stainless steel, or copper (Cu).

[0064] The multiple plate-shaped portions 331 include, for example, a first plate-shaped portion 3311, a second plate-shaped portion 3312, and a third plate-shaped portion 3313. In other words, the gas supply unit 3 includes the first plate-shaped portion 3311, the second plate-shaped portion 3312, and the third plate-shaped portion 3313. In the examples of Figures 1 and 2, the multiple plate-shaped portions 331 include a fourth plate-shaped portion 3314 and a fifth plate-shaped portion 3315. Here, for example, a portion of the multiple plate-shaped portions 331 is fixed to the housing 22 via a mounting member 34. As a result, the gas supply unit 3 is fixed to the light irradiation unit 2. A portion of the multiple plate-shaped portions 331 is fixed to the housing 22 via a mounting member 34, for example, by adhesive or screw fastening. Packing members may be appropriately placed where screw fastening is performed.

[0065] The first plate-like portion 3311 is located, for example, at the end of the gas supply unit 3 on the side in the -Z direction, which is the first direction. The first plate-like portion 3311 has an end (also referred to as the first end) Ed1 located on the side in the +Y direction, which is the second direction, and an end (also referred to as the second end) Ed2 located on the side in the -Y direction, which is the fourth direction. In other words, the first plate-like portion 3311 has a first end Ed1 which is the end in the second direction, and a second end Ed2 which is the end in the fourth direction. The first end Ed1 may be, for example, the end face of the first plate-like portion 3311 located on the side in the +Y direction, which is the second direction. The second end Ed2 may be, for example, the end face of the first plate-like portion 3311 located on the side in the -Y direction, which is the fourth direction.

[0066] In the examples of Figures 1 and 2, the first plate-like portion 3311 is located below the gas supply unit 3. The shape of the first plate-like portion 3311 may be, for example, a flat plate. In the examples of Figures 1 and 2, the shape of the first plate-like portion 3311 is a flat plate along a hypothetical plane parallel to the XY plane perpendicular to the -Z direction as the first direction. More specifically, in the examples of Figures 1 and 2, the first plate-like portion 3311 has a rectangular surface (also referred to as the first A surface) located on the side of the -Z direction as the first direction, and a rectangular surface (also referred to as the first B surface) located on the side of the +Z direction as the sixth direction opposite to the first direction. Each of the first A surface and the first B surface is, for example, a rectangular surface having a longitudinal direction along the +Y direction as the second direction and a short direction along the +X direction as the third direction.

[0067] The first plate-like portion 3311 is located, for example, on the side of the light-emitting surface 222 in the housing 22 of the light-emitting unit 2 in the +X direction, which is the third direction. In other words, for example, the light-emitting surface 222 and the first plate-like portion 3311 are aligned in a direction along the +X direction, which is the third direction. Here, for example, the first plate-like portion 3311 may be located along a virtual plane that is aligned with the light-emitting surface 222. For example, the side of the first plate-like portion 3311 in the -Z direction, which is the first direction (first A surface) may be located along a virtual plane that is aligned with the light-emitting surface 222, or it may be flush with the light-emitting surface 222.

[0068] The second plate-shaped portion 3312 is located, for example, at the end of the gas supply unit 3 on the side in the second direction, the +Y direction. The second plate-shaped portion 3312 has, for example, a corner portion (also referred to as the first corner portion) Cn1 located on the side in the first direction, the -Z direction, on the side in the fourth direction, the -Y direction. The first corner portion Cn1 may be, for example, the corner portion formed by the surface (also referred to as the main surface) located on the side in the fourth direction, the -Y direction, of the second plate-shaped portion 3312 and the end surface located on the side in the first direction, the -Z direction.

[0069] In the examples of Figures 1 and 2, the second plate-like portion 3312 constitutes the side surface of the gas supply unit 3 on the side in the second direction, the +Y direction. The shape of the second plate-like portion 3312 may be, for example, a flat plate. In the examples of Figures 1 and 2, the shape of the second plate-like portion 3312 is a flat plate along a hypothetical plane parallel to the XZ plane perpendicular to the second direction, the +Y direction. More specifically, in the examples of Figures 1 and 2, the second plate-like portion 3312 has a rectangular surface located on the side in the second direction, the +Y direction (also referred to as the second A surface) and a rectangular surface located on the side in the fourth direction, the -Y direction (also referred to as the second B surface). Each of the second A surface and the second B surface is, for example, a rectangular surface having a longitudinal direction along the first direction, the -Z direction and a short direction along the third direction, the +X direction.

[0070] The second plate-like portion 3312 is located, for example, on the side of the third surface 2233 of the housing 22 of the light-emitting unit 2 in the +X direction, which is the third direction. In other words, for example, the third surface 2233 and the second plate-like portion 3312 are aligned in a direction along the +X direction, which is the third direction. Here, for example, the second plate-like portion 3312 may be located along a virtual plane that is aligned with the third surface 2233. For example, the side of the second plate-like portion 3312 in the +Y direction, which is the second direction (second A surface), may be located along a virtual plane that is aligned with the third surface 2233, or it may be flush with the third surface 2233.

[0071] The third plate-like portion 3313 is located, for example, at the end of the gas supply unit 3 on the side in the -Y direction, which is the fourth direction. The third plate-like portion 3313 has, for example, a corner portion (also referred to as the second corner portion) Cn2 located on the side in the +Y direction, which is the second direction, on the side in the -Z direction, which is the first direction. The second corner portion Cn2 may be, for example, the corner portion formed by the surface (also referred to as the main surface) located on the side in the +Y direction, which is the second direction, of the third plate-like portion 3313 and the end surface located on the side in the -Z direction, which is the first direction.

[0072] In the examples of Figures 1 and 2, the third plate-like portion 3313 constitutes the side surface of the gas supply unit 3 on the side in the -Y direction, which is the fourth direction. The shape of the third plate-like portion 3313 may be, for example, a flat plate. In the examples of Figures 1 and 2, the shape of the third plate-like portion 3313 is a flat plate along a hypothetical plane parallel to the XZ plane perpendicular to the -Y direction, which is the fourth direction. More specifically, in the examples of Figures 1 and 2, the third plate-like portion 3313 has a rectangular surface located on the side in the -Y direction, which is the fourth direction (also referred to as the third A surface) and a rectangular surface located on the side in the +Y direction, which is the second direction (also referred to as the third B surface). Each of the third A surface and the third B surface is, for example, a rectangular surface having a longitudinal direction along the -Z direction, which is the first direction, and a short direction along the +X direction, which is the third direction.

[0073] The third plate-like portion 3313 is located, for example, on the side of the fourth side surface 2234 of the housing 22 of the light-emitting unit 2 in the +X direction, which is the third direction. In other words, for example, the fourth side surface 2234 and the third plate-like portion 3313 are aligned in a direction along the +X direction, which is the third direction. Here, for example, the third plate-like portion 3313 may be located along a virtual plane that is aligned with the fourth side surface 2234. For example, the side of the third plate-like portion 3313 in the -Y direction, which is the fourth direction (third A surface) may be located along a virtual plane that is aligned with the fourth side surface 2234, or it may be flush with the fourth side surface 2234.

[0074] The fourth plate-shaped portion 3314 is located, for example, at the end of the gas supply unit 3 on the side in the +X direction, which is the third direction. The fourth plate-shaped portion 3314 may be connected to the first plate-shaped portion 3311 at the end in the -Z direction, which is the first direction. The fourth plate-shaped portion 3314 may be connected to the second plate-shaped portion 3312 at the end in the +Y direction, which is the second direction. The fourth plate-shaped portion 3314 may be connected to the third plate-shaped portion 3313 at the end in the -Y direction, which is the fourth direction. The fourth plate-shaped portion 3314 may be connected to the fifth plate-shaped portion 3315 at the end in the +Z direction, which is the sixth direction.

[0075] In the examples of Figures 1 and 2, the fourth plate-like portion 3314 constitutes the side surface of the gas supply unit 3 on the side in the third direction, the +X direction. The shape of the fourth plate-like portion 3314 may be, for example, a flat plate. In the examples of Figures 1 and 2, the shape of the fourth plate-like portion 3314 is a flat plate along a hypothetical plane parallel to the YZ plane perpendicular to the third direction, the +X direction. More specifically, in the examples of Figures 1 and 2, the fourth plate-like portion 3314 has a rectangular surface located on the side in the third direction, the +X direction (also referred to as the fourth A surface) and a rectangular surface located on the side in the fifth direction, the -X direction (also referred to as the fourth B surface). Each of the fourth A surface and the fourth B surface is, for example, a rectangular surface having a longitudinal direction along the first direction, the -Z direction, and a short direction along the second direction, the +Y direction.

[0076] The fifth plate-like portion 3315 is located at the end of the gas supply unit 3 on the side in the sixth direction, the +Z direction. In the examples of Figures 1 and 2, the fifth plate-like portion 3315 is located on the upper part of the gas supply unit 3. The shape of the fifth plate-like portion 3315 may be, for example, a flat plate. In the examples of Figures 1 and 2, the shape of the fifth plate-like portion 3315 is a flat plate along a hypothetical plane parallel to the XY plane perpendicular to the sixth direction, the +Z direction. More specifically, in the examples of Figures 1 and 2, the fifth plate-like portion 3315 has a rectangular surface located on the side in the sixth direction, the +Z direction (also referred to as the fifth A surface) and a rectangular surface located on the side in the first direction, the -Z direction (also referred to as the fifth B surface). Each of the fifth A surface and the fifth B surface is, for example, a rectangular surface having a longitudinal direction along the second direction, the +Y direction and a short direction along the third direction, the +X direction.

[0077] As shown in Figures 2 and 5 to 7, the discharge section 32 of the gas supply section 3 includes a plurality of gas outlets 32o, a first opening 32o1, a second opening 32o2, and a plurality of third openings 32o3. The first opening 32o1 is located at the very end of the plurality of gas outlets 32o in the +Y direction, which is the second direction. This first opening 32o1 includes an opening in the gap between the first end Ed1 of the first plate-like portion 3311 and the end of the second plate-like portion 3312 in the -Z direction, which is the first direction. In other words, this first opening 32o1 includes, for example, a slit-shaped opening along the +X direction, which is the third direction, in the gap between the first end Ed1 of the first plate-like portion 3311 and the first corner Cn1 of the second plate-like portion 3312. The second opening 32o2 is located at the very end of the plurality of gas outlets 32o in the -Y direction, which is the fourth direction. The second opening 32o2 includes an opening in the gap between the second end Ed2 of the first plate-like portion 3311 and the end of the third plate-like portion 3313 in the -Z direction as the first direction. From another point of view, the second opening 32o2 includes, for example, a slit-shaped opening along the +X direction as the third direction in the gap between the second end Ed2 of the first plate-like portion 3311 and the second corner Cn2 of the third plate-like portion 3313. The plurality of third openings 32o3 are located between the first opening 32o1 and the second opening 32o2. The plurality of third openings 32o3 are located in the first plate-like portion 3311. In other words, the first plate-like portion 3311 has the plurality of third openings 32o3. Each of the plurality of third openings 32o3 may be an opening on the opposite side of the flow path 31 of a through hole penetrating the first plate-like portion 3311. This through-hole may penetrate the first plate-like portion 3311 along the direction of the thickness of the first plate-like portion 3311. The direction of the thickness of the first plate-like portion 3311 may be, for example, along the -Z direction as the first direction.

[0078] In the discharge section 32 of the gas supply section 3 having this configuration, for example, there is a first opening 32o1 that utilizes the gap between the first plate-shaped portion 3311 and the second plate-shaped portion 3312, and a second opening 32o2 that utilizes the gap between the first plate-shaped portion 3311 and the third plate-shaped portion 3313. For this reason, in the gas supply section 3, multiple gas outlets 32o can be arranged in a wider range in the width direction along the second direction, the +Y direction. More specifically, in the gas supply section 3, in the width direction along the second direction, the +Y direction, the first opening 32o1 can be positioned closer to the end in the second direction, the +Y direction, and the second opening 32o2 can be positioned closer to the end in the fourth direction, the -Y direction. As a result, for example, if the printing apparatus is equipped with a light irradiation device 1, the amount of gas (e.g., low-oxygen gas) supplied to reduce the oxygen concentration can be increased on both sides in the width direction along the second direction, +Y, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110. As a result, the deficiency in reducing the oxygen concentration can be reduced on both sides in the width direction along the second direction, +Y, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110. Thus, it is possible to improve the light irradiation efficiency to the printing medium 111, which is an example of the irradiated object 110, and to reduce the deficiency in reducing the oxygen concentration in the space along the printing medium 111, which is an example of the irradiated object 110.

[0079] In the examples shown in Figures 2 and 5 to 7, the surface of the first plate-like portion 3311 opposite to the flow path 31 (first A surface) and the first corner Cn1 of the second plate-like portion 3312 are aligned in the width direction along the second direction, the +Y direction. The surface of the first plate-like portion 3311 opposite to the flow path 31 (first A surface) and the second corner Cn2 of the third plate-like portion 3313 are aligned in the width direction along the fourth direction, the -Y direction.

[0080] Here, for example, the first end Ed1 of the first plate-like portion 3311 and the first corner Cn1 of the second plate-like portion 3312 may be aligned in the width direction along the second direction, the +Y direction. For example, the second end Ed2 of the first plate-like portion 3311 and the second corner Cn2 of the third plate-like portion 3313 may be aligned in the width direction along the fourth direction, the -Y direction.

[0081] Figure 8 shows the appearance of an example of a gas discharge section (discharge section) 32z in a gas supply section 3z according to one reference example. In Figure 8, as in Figure 5, the outer edge of the mounting member 34 is shown by a thin dashed line. The discharge section 32z in the gas supply section 3z according to one reference example is based on the discharge section 32 in the gas supply section 3 according to the first embodiment described above, and has a configuration in which the first opening 32o1 and the second opening 32o2 have been removed.

[0082] Figure 9 is a schematic graph illustrating an example of the relationship between the position in the width direction along the second direction (+Y) of the light irradiation device and the amount of nitrogen gas, an example of gas, emitted from the emission unit 32z, for a light irradiation device to which the emission unit 32z according to one reference example is applied. The light irradiation device to which the emission unit 32z according to one reference example is applied is based on the light irradiation device 1 according to the first embodiment, and has a configuration in which the emission unit 32 is replaced with the emission unit 32z. In Figure 9, an example of the relationship between the position in the width direction along the second direction (+Y) of the light irradiation device and the amount of nitrogen gas blown onto the irradiated object 110 from the emission unit 32z is schematically shown by a curve drawn with a thick solid line.

[0083] Figure 10 is a schematic graph illustrating an example of the relationship between the position of the light irradiation device 1 in the width direction along the second direction, the +Y direction, and the amount of nitrogen gas, an example of gas, emitted from the discharge unit 32, for a light irradiation device 1 according to the first embodiment. In Figure 10, an example of the relationship between the position of the light irradiation device 1 in the width direction along the second direction, the +Y direction, and the amount of nitrogen gas blown from the discharge unit 32 onto the object to be irradiated 110 is schematically shown by a curve drawn with a thick solid line. In Figure 10, for comparison, a curve corresponding to the curve drawn in Figure 9 is shown with a thin dashed line.

[0084] In the light irradiation device 1 according to the first embodiment, the emission section 32 further includes a first opening 32o1 and a second opening 32o2 compared to the emission section 32z according to one reference example. More specifically, the emission section 32 of the gas supply section 3 further includes a first opening 32o1 utilizing the gap between the first plate-shaped portion 3311 and the second plate-shaped portion 3312, and a second opening 32o2 utilizing the gap between the first plate-shaped portion 3311 and the third plate-shaped portion 3313, compared to the emission section 32z according to one reference example. As a result, in the emission section 32 of the gas supply section 3, a plurality of gas outlets 32o can be arranged over a wider range in the width direction along the second direction, the +Y direction. This allows, for example, as shown in Figures 9 and 10, the amount of nitrogen gas supplied as an example of a gas for reducing oxygen concentration to increase on both sides in the width direction along the second direction, the +Y direction. Therefore, when the printing apparatus is equipped with a light irradiation device 1, the amount of gas supplied to reduce the oxygen concentration can be increased on both sides in the width direction along the second direction, the +Y direction, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110. As a result, the insufficient reduction of oxygen concentration can be reduced on both sides in the width direction along the second direction, the +Y direction, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110.

[0085] In this case, for example, the gas inlet 30o may be located in the fifth plate-shaped portion 3315. In other words, for example, the fifth plate-shaped portion 3315 may have a gas inlet 30o. The gas inlet 30o may be the opening on the side opposite to the flow path 31 of the through hole that penetrates the fifth plate-shaped portion 3315. This through hole may penetrate the fifth plate-shaped portion 3315 along the direction of the thickness of the fifth plate-shaped portion 3315.

[0086] <1-1-3. Method for Manufacturing the Gas Supply Unit> The multiple third openings 32o3 of the discharge unit 32 of the gas supply unit 3 having the above configuration can be formed, for example, by punching holes in a plate material. The first opening 32o1 and the second opening 32o2 can be formed, for example, by bending a plate-shaped member (also referred to as a plate-shaped member). In this way, the first opening 32o1 and the second opening 32o2 can be easily manufactured.

[0087] Here, a method for manufacturing an example of a wall portion 33, which is part of the gas supply unit 3 according to the first embodiment, will be described.

[0088] Figure 11 shows an example of the appearance of a plate-shaped member 300 used in the fabrication of an example of a wall portion 33, which is part of the gas supply unit 3 according to the first embodiment. Figure 12 shows the state in which an example of a wall portion 33, which is part of the gas supply unit 3 according to the first embodiment, is fabricated. In Figure 11, during the bending process of the plate-shaped member 300, thin dashed lines are drawn along the outer edges of each of the four regions (also called bending regions) Bd1 that the plate-shaped member 300 is to be bent.

[0089] Here, first, a plate-shaped member 300 is prepared, and then the plate-shaped member 300 is bent.

[0090] <<<Preparation of Plate-Shaped Member>>> For example, a plate-shaped member 300 as shown in Figure 11 is prepared. The plate-shaped member 300 can be manufactured, for example, by processing a metal plate. For processing the plate, one or more of the following types of processing may be applied: punching, hole punching, and cutting.

[0091] The plate-shaped member 300 includes a plurality of portions 331p that become a plurality of plate-shaped portions 331 after bending. The plurality of portions 331p include a first plate-shaped portion 3311p, a second plate-shaped portion 3312p, a third plate-shaped portion 3313p, a fourth plate-shaped portion 3314p, and a fifth plate-shaped portion 3315p.

[0092] The first portion 3311p is the portion that becomes the first plate-shaped portion 3311 after bending the plate-shaped member 300. The second portion 3312p is the portion that becomes the second plate-shaped portion 3312 after bending the plate-shaped member 300. The third portion 3313p is the portion that becomes the third plate-shaped portion 3313 after bending the plate-shaped member 300. The fourth portion 3314p is the portion that becomes the fourth plate-shaped portion 3314 after bending the plate-shaped member 300. The fifth portion 3315p is the portion that becomes the fifth plate-shaped portion 3315 after bending the plate-shaped member 300. In the plate-shaped member 300, the first portion 3311p is connected to the fourth portion 3314p, the second portion 3312p is connected to the fourth portion 3314p, the third portion 3313p is connected to the fourth portion 3314p, and the fifth portion 3315p is connected to the fourth portion 3314p.

[0093] The fourth portion 3314p has a rectangular front surface and a rectangular back surface. In the example of Figure 11, in the fourth portion 3314p, each of the rectangular front surface and the rectangular back surface has a longitudinal direction along the +Z direction and a short direction along the +Y direction.

[0094] The first portion 3311p has a rectangular surface and a rectangular back surface. In the example of Figure 11, the rectangular surface and the rectangular back surface of the first portion 3311p each have a short direction along the +Z direction and a long direction along the +Y direction. The portion of the first portion 3311p located at the +Z end is connected to the portion of the fourth portion 3314p located at the -Z end. The first portion 3311p has a plurality of through holes, each having an opening 32o3p that becomes a third opening 32o3 after the plate-shaped member 300 is bent. The first portion 3311p has a portion Ed1p that becomes a first end Ed1 (also referred to as the first end portion) after the plate-shaped member 300 is bent, and a portion Ed2p that becomes a second end Ed2 (also referred to as the second end portion) after the plate-shaped member 300 is bent. In the example shown in Figure 11, the first end portion Ed1p is the end face located at the +Y direction end of the first portion 3311p. The second end portion Ed2p is the end face located at the -Y direction end of the first portion 3311p.

[0095] The second part 3312p has a main body part (also referred to as the first main body part) B1 and a part (also referred to as the first protruding part) P1 that protrudes in the -Z direction from a part of the first main body part B1 that is away from the fourth part 3314p. The first main body part B1 has a rectangular surface and a rectangular back surface. In the example of Figure 11, in the first main body part B1, each of the rectangular surface and the rectangular back surface has a longitudinal direction along the +Z direction and a short direction along the +Y direction. The part of the first main body part B1 located at the -Y end is connected to the part of the fourth part 3314p located at the +Y end. The first protruding part P1 has a rectangular surface and a rectangular back surface. In the example of Figure 11, in the first protruding part P1, each of the rectangular surface and the rectangular back surface has a longitudinal direction along the +Y direction and a short direction along the +Z direction. The first protruding portion P1 has a corner portion Cn1p that becomes the first corner portion Cn1 after the plate-shaped member 300 is bent. In the example shown in Figure 11, the corner portion Cn1p is the corner portion located at both the -Z direction end and the -X direction end of the first protruding portion P1.

[0096] The third part 3313p has a main body part (also referred to as the second main body part) B2 and a part (also referred to as the second protruding part) P2 that protrudes in the -Z direction from the part of the second main body part B2 that is away from the fourth part 3314p. The second main body part B2 has a rectangular surface and a rectangular back surface. In the example of Figure 11, in the second main body part B2, each of the rectangular surface and the rectangular back surface has a longitudinal direction along the +Z direction and a short direction along the +Y direction. The part of the second main body part B2 located at the +Y end is connected to the part of the fourth part 3314p located at the -Y end. The second protruding part P2 has a rectangular surface and a rectangular back surface. In the example of Figure 11, in the second protruding part P2, each of the rectangular surface and the rectangular back surface has a longitudinal direction along the +Y direction and a short direction along the +Z direction. The second protruding portion P2 has a corner portion Cn2p which becomes the second corner portion Cn2 after the plate-shaped member 300 is bent. In the example shown in Figure 11, the corner portion Cn2p is the corner portion of the second protruding portion P2 that is located at both the -Z direction end and the -X direction end.

[0097] The fifth portion 3315p has a rectangular surface and a rectangular back surface. In the example of Figure 11, in the fifth portion 3315p, the rectangular surface and the rectangular back surface each have a short direction along the +Z direction and a long direction along the +Y direction. The portion of the fifth portion 3315p located at the -Z end is connected to the portion of the fourth portion 3314p located at the +Z end. The fifth portion 3315p has a through hole with an opening 30op that becomes a gas inlet 30o after the plate-shaped member 300 is bent.

[0098] <<<Bending of plate-shaped member>>> Next, for example, the plate-shaped member 300 exemplified in Figure 11 is bent into the form shown in Figure 12. Here, for example, the plate-shaped member 300 is bent in each of the four bending regions Bd1, each indicated by a dashed line with a thin outer edge in Figure 11.

[0099] More specifically, the plate-shaped member 300 is bent in such a way that, for example, in a bending region Bd1 along the +Y direction between the fourth portion 3314p and the first portion 3311p, the first portion 3311p is substantially perpendicular to the fourth portion 3314p. The plate-shaped member 300 is bent in such a way that, for example, in a bending region Bd1 along the +Z direction between the fourth portion 3314p and the second portion 3312p, the second portion 3312p is substantially perpendicular to the fourth portion 3314p. The plate-shaped member 300 is bent in such a way that, for example, in a bending region Bd1 along the +Z direction between the fourth portion 3314p and the third portion 3313p, the third portion 3313p is substantially perpendicular to the fourth portion 3314p. The plate-shaped member 300 is bent in such a way that, for example, in the bending region Bd1 along the +Y direction between the fourth portion 3314p and the fifth portion 3315p, the fifth portion 3315p is substantially perpendicular to the fourth portion 3314p.

[0100] As a result, for example, the first portion 3311p becomes the first plate-like portion 3311, the second portion 3312p becomes the second plate-like portion 3312, the third portion 3313p becomes the third plate-like portion 3313, the fourth portion 3314p becomes the fourth plate-like portion 3314, and the fifth portion 3315p becomes the fifth plate-like portion 3315. Also, for example, the multiple openings 32o3p become the multiple third openings 32o3, the first end portion Ed1p becomes the first end portion Ed1, and the second end portion Ed2p becomes the second end portion Ed2. Also, for example, the corner Cn1p of the first protruding portion P1 becomes the first corner portion Cn1, and the corner Cn2p of the second protruding portion P2 becomes the second corner portion Cn2. Also, the opening 30op becomes the gas inlet 30o.

[0101] Furthermore, for example, a first opening 32o1 is formed, which includes a slit-shaped opening along the +X direction as a third direction in the gap between the first end Ed1 of the first plate-like portion 3311 and the first corner Cn1 of the second plate-like portion 3312. For example, a second opening 32o2 is formed, which includes a slit-shaped opening along the +X direction as a third direction in the gap between the second end Ed2 of the first plate-like portion 3311 and the second corner Cn2 of the third plate-like portion 3313. In this way, each of the first opening 32o1 and the second opening 32o2 can be formed, for example, by bending the plate-like member 300. As a result, the first opening 32o1 and the second opening 32o2 can be easily manufactured.

[0102] Here, for example, in the portion where the second plate-shaped portion 3312 and the fifth plate-shaped portion 3315 are in close proximity, the second plate-shaped portion 3312 and the fifth plate-shaped portion 3315 may be joined by welding or the like. For example, in the portion where the third plate-shaped portion 3313 and the fifth plate-shaped portion 3315 are in close proximity, the third plate-shaped portion 3313 and the fifth plate-shaped portion 3315 may be joined by welding or the like. This allows the wall portion 33 to be created.

[0103] <1-1-4. Various Variations in the Configuration of the Discharge Section> The size, shape, and arrangement of the multiple third openings 32o3 can be set in various ways, for example, by considering the distribution of gas discharge from the discharge section 32.

[0104] For example, as shown in Figures 2, 5, and 6, each of the multiple third openings 32o3 may be an opening whose length in the third direction, +X, is greater than its length in the second direction, +Y. More specifically, each of the multiple third openings 32o3 may have an elongated shape with a longitudinal direction along the third direction, +X. In other words, for each of the multiple third openings 32o3, the through hole in the first plate-like portion 3311 having the third opening 32o3 may be an elongated hole with a longitudinal direction along the third direction, +X. Furthermore, the multiple third openings 32o3 may be aligned in the second direction, +Y. From another point of view, the multiple third openings 32o3 may be aligned in a direction along the second direction, +Y. If this configuration is adopted, the proportion of the area occupied by the multiple third openings 32o3 on the side of the gas supply unit 3 facing the first direction, -Z (for example, the bottom surface), can be easily increased.

[0105] From another perspective, for example, the first opening 32o1, the multiple third openings 32o3, and the second opening 32o2 may be arranged in a direction along the -Y direction, which is the fourth direction. This allows the multiple gas outlets 32o to be arranged in a manner that broadly corresponds to the region of the light passage opening 222o extending from the end in the +Y direction, which is the second direction, to the end in the -Y direction, which is the fourth direction, in the width direction along the +Y direction, which is the second direction.

[0106] Here, the discharge section 32 may have a symmetrical shape in the direction along the second direction, the +Y direction (width direction). In other words, for example, consider the case where the discharge section 32 is viewed from above in the direction of the sixth direction, the -Z direction. In this case, it may have a line-symmetrical shape with respect to a virtual line (not shown) along the third direction, the +X direction. This virtual line may be a virtual line passing through the center of the discharge section 32 in the width direction along the second direction, the +Y direction.

[0107] Thus, if the discharge unit 32 has a symmetrical shape in the width direction, for example, the occurrence of uneven distribution of the amount of gas (e.g., low-oxygen gas) supplied from the discharge unit 32 to the space in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, can be reduced. As a result, for example, in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, the decrease in oxygen concentration in the space along the printing medium 111 can become more uniform. Therefore, for example, uneven curing of photocurable materials such as photocurable ink attached to the printing medium 111, which is an example of the irradiated object 110, can be reduced.

[0108] Each of the multiple third openings 32o3 may be, for example, a rectangular opening with a longitudinal direction along the +X direction as the third direction, or an elliptical opening with a longitudinal direction along the +X direction as the third direction. One or more of the four corners of the rectangular opening may have a rounded shape.

[0109] In the space between the light-irradiating surface 222 and the printing medium 111, which is an example of the irradiated object 110, the gas emitted from the plurality of gas outlets 32o can diffuse outward in the region near the light-passing opening 222o on both sides in the width direction along the second direction, the +Y direction. In contrast, for example, each of the first opening 32o1 and the second opening 32o2 may have a longitudinal length along the third direction, the +X direction, which is larger than each of the plurality of third openings 32o3, and an area larger than each of the plurality of third openings 32o3. In other words, for example, each of the first opening 32o1 and the second opening 32o2 may have a length in the third direction, the +X direction, which is larger than each of the plurality of third openings 32o3, and an area larger than each of the plurality of third openings 32o3. In this case, the amount of gas released from the first opening 32o1 and the second opening 32o2, located on both sides in the width direction along the second direction, the +Y direction, among the multiple gas outlets 32o, may be greater than the amount of gas released from each of the multiple third openings 32o3. As a result, for example, in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, the concentration of low-oxygen gas in the space along the printing medium 111 may approach uniformity. Consequently, for example, in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, the decrease in oxygen concentration in the space along the printing medium 111 may approach uniformity. Therefore, for example, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, the deficiency in the decrease in oxygen concentration may be reduced on both sides in the width direction along the second direction, the +Y direction, in the region near the light passage opening 222o.

[0110] Here, for example, as described above, a first opening 32o1 and a second opening 32o2, each containing a slit-shaped opening, can be formed by bending the sheet material. This makes it easy to increase the longitudinal length of each of the first opening 32o1 and the second opening 32o2 along the third direction, the +X direction.

[0111] The multiple third openings 32o3 may, for example, have the same or substantially the same shape, or they may have the same or substantially the same size. The spacing between the multiple third openings 32o3 in the second direction, the +Y direction, can be set appropriately according to, for example, the shape and size of each of the multiple third openings 32o3.

[0112] Here, for example, each of the multiple third openings 32o3 may have the same length (also referred to as width) in the direction along the second direction, the +Y direction. In other words, for example, each of the multiple third openings 32o3 may have the same length in the second direction, the +Y direction. Furthermore, for example, the multiple third openings 32o3 may be arranged at a constant interval (also referred to as the opening distance or opening pitch) in the direction along the second direction, the +Y direction (width direction). In other words, for example, the multiple third openings 32o3 may be arranged at a constant interval in the second direction, the +Y direction. In this case, for example, the occurrence of an uneven distribution of the amount of gas (e.g., low-oxygen gas) supplied from the discharge unit 32 to the space in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, can be reduced. As a result, for example, in the gap between the light-irradiated surface 222 and the printing medium 111, which is an example of the irradiated object 110, the decrease in oxygen concentration in the space along the printing medium 111 can become more uniform. The aperture distance (aperture pitch) may be, for example, the distance between the centers of any two adjacent third apertures 32o3 among a plurality of third apertures 32o3 in the direction along the +Y direction as a second direction (width direction). The center of the third aperture 32o3 is the center of the third aperture 32o3 in the direction along the +Y direction as a second direction (width direction). The distance between the centers of two adjacent third apertures 32o3 is the distance between the center of one of these two adjacent third apertures 32o3 and the center of the other of these two adjacent third apertures 32o3. From another perspective, the distance between openings (opening pitch) may be, for example, the distance between the widthwise ends of any two adjacent third openings 32o3 among a plurality of third openings 32o3 in the direction along the +Y direction as a second direction (widthwise direction). The distance between the widthwise ends of two adjacent third openings 32o3 may be the distance between the widthwise end of one of the two adjacent third openings 32o3 and the widthwise end of the other of the two adjacent third openings 32o3.

[0113] In this case, for example, in the direction along the +Y direction as the second direction (width direction), the distance between the third opening 32o3 closest to the first opening 32o1 and the first opening 32o1 may or may not be the same as the distance between two adjacent third openings 32o3. For example, in the direction along the +Y direction as the second direction (width direction), the distance between the third opening 32o3 closest to the second opening 32o2 and the second opening 32o2 may or may not be the same as the distance between two adjacent third openings 32o3.

[0114] Furthermore, for example, each of the multiple third openings 32o3 may have the same length in the +X direction as the third direction. More specifically, for example, each of the multiple third openings 32o3 may have the same length in the longitudinal direction along the +X direction as the third direction. In this case, for example, the occurrence of an uneven distribution in the amount of gas (e.g., low-oxygen gas) supplied from the discharge unit 32 to the space in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, can be further reduced. As a result, for example, the decrease in oxygen concentration in the space along the printing medium 111 in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, can be made more uniform.

[0115] Here, for example, when the discharge section 32 is viewed from above in the -Z direction as the sixth direction, each of the multiple third openings 32o3 may have a width of about 1 mm to 3 mm and a longitudinal length of about 10 mm to 15 mm. In this case, the spacing (opening pitch) between the multiple third openings 32o3 aligned in the direction along the +Y direction as the second direction may be about 2 mm to 6 mm. For example, when the discharge section 32 is viewed from above in the -Z direction as the sixth direction, each of the first opening 32o1 and the second opening 32o2 may have a width of about 1 mm to 3 mm and a longitudinal length of about 13 mm to 28 mm.

[0116] Here, for example, a porous material may be placed in the flow path 31. More specifically, for example, in the gas supply unit 3, a porous material may be placed on the discharge unit 32 side of the flow path 31. This can reduce the unevenness of the gas flow just before it reaches the discharge unit 32 from the flow path 31. As a result, gas can be discharged from the discharge unit 32 in a more uniform flow. The porous material can be, for example, a material that can correct the unevenness of the gas flow by creating a certain resistance to the passage of gas. More specifically, the porous material can be a mesh-like material such as a metal mesh having many holes finer than the plurality of third openings 32o3, a hard porous material such as pumice or porous ceramics, or a fibrous porous material such as woven or nonwoven fabric or steel wool. The porous material can be a breathable urethane foam or sponge. Various materials can be used for the porous material, for example, depending on the specifications required for the discharge of gas from the discharge unit 32. The porous member may have a size and thickness, etc., depending on the material of the porous member. The porous member may be composed of one material, or of two or more materials.

[0117] Figures 13 and 14 show the external appearance of a part of another example of the gas supply unit 3 according to the first embodiment. Here, for example, as shown in Figures 13 and 14, the first end Ed1 of the first plate-like portion 3311 is located on the side of the first direction -Z direction more than the end of the second plate-like portion 3312 in the first direction -Z direction, and the second end Ed2 of the first plate-like portion 3311 is located on the side of the first direction -Z direction more than the end of the third plate-like portion 3313 in the first direction -Z direction. Here, for example, the first end Ed1 of the first plate-like portion 3311 is located on the side of the first direction -Z direction more than the first corner Cn1 of the second plate-like portion 3312, and the second end Ed2 of the first plate-like portion 3311 is located on the side of the first direction -Z direction more than the second corner Cn2 of the third plate-like portion 3313. In other words, for example, the first corner Cn1 of the second plate-like portion 3312 may be located on the side of the sixth direction, the +Z direction, more than the first end Ed1 of the first plate-like portion 3311, and the second corner Cn2 of the third plate-like portion 3313 may be located on the side of the sixth direction, the +Z direction, more than the second end Ed2 of the first plate-like portion 3311. From another point of view, when the gas supply unit 3 is viewed from above in the fourth direction, the -Y direction, the first opening 32o1 is located between the first plate-like portion 3311 and the second plate-like portion 3312, and when the gas supply unit 3 is viewed from above in the second direction, the +Y direction, the second opening 32o2 may be located between the first plate-like portion 3311 and the third plate-like portion 3313.

[0118] In this case, for example, the areas of the first opening 32o1 and the second opening 32o2 may increase. Also, gas can be released from the first opening 32o1 in a wider area in the second direction, the +Y direction, and gas can be released from the second opening 32o2 in a wider area in the fourth direction, the -Y direction. As a result, for example, in the space between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, the area in which gas to reduce the oxygen concentration (e.g., low-oxygen gas) is supplied can be expanded on both sides in the width direction along the second direction, the +Y direction, in the area near the light passage opening 222o. As a result, for example, in the gap between the light irradiation surface 222 and the printing medium 111, which is an example of the irradiated object 110, and in the wider space around it, the concentration of low-oxygen gas in the space along the printing medium 111 can become more uniform. As a result, for example, in the gap between the light-irradiated surface 222 and the printing medium 111 and in the wider space surrounding it, the decrease in oxygen concentration in the space along the printing medium 111 can become more uniform. In other words, for example, in the gap between the light-irradiated surface 222 and the printing medium 111 as an example of the irradiated object 110, the entrainment of oxygen from both sides in the width direction along the second direction, the +Y direction, can be reduced. Therefore, for example, in the region near the light-passing opening 222o in the space between the light-irradiated surface 222 and the printing medium 111 as an example of the irradiated object 110, the deficiency in the decrease in oxygen concentration can be reduced on both sides in the width direction along the second direction, the +Y direction.

[0119] Figure 15 shows an example of the appearance of a plate-shaped member 300 used in the manufacture of another example of a wall portion 33, which is part of the gas supply unit 3 according to the first embodiment. The plate-shaped member 300 illustrated in Figure 15 is based on the plate-shaped member 300 illustrated in Figure 11, and has a configuration in which the first protruding portion P1 of the second portion 3312p corresponding to the second plate-shaped portion 3312 and the second protruding portion P2 of the third portion 3313p corresponding to the third plate-shaped portion 3313 are removed. Here, the corner Cn1p corresponding to the first corner Cn1 is the corner located at the -Z direction end and the -X direction end of the second portion 3312p corresponding to the second plate-shaped portion 3312. Also, the corner Cn2p corresponding to the second corner Cn2 is the corner located at the -Z direction end and the -X direction end of the third portion 3313p corresponding to the third plate-shaped portion 3313. In Figure 15, as in Figure 11, a thin dashed line is drawn along the outer edge of each of the four regions (bending regions) Bd1 that are targeted to be bent during the bending process of the plate-shaped member 300.

[0120] In the plate-shaped member 300 illustrated in Figure 15, the end of the second portion 3312p corresponding to the second plate-shaped portion 3312 on the -Z direction is located in the +Z direction more than the first portion 3311p corresponding to the first plate-shaped portion 3311. In other words, the plate-shaped member 300 illustrated in Figure 15 has a configuration in which the end of the second portion 3312p corresponding to the second plate-shaped portion 3312 on the -Z direction is recessed in the +Z direction, compared to the plate-shaped member 300 illustrated in Figure 11.

[0121] Furthermore, in the plate-shaped member 300 illustrated in Figure 15, the end of the third portion 3313p corresponding to the third plate-shaped portion 3313 on the -Z direction is located in the +Z direction more than the first portion 3311p corresponding to the first plate-shaped portion 3311. In other words, the plate-shaped member 300 illustrated in Figure 15 has a configuration in which the end of the third portion 3313p corresponding to the third plate-shaped portion 3313 on the -Z direction is recessed in the +Z direction, compared to the plate-shaped member 300 illustrated in Figure 11.

[0122] The plate-shaped member 300 shown in Figure 15 can be bent at each of the four bending regions Bd1, each indicated by a thin dashed line on its outer edge, thereby forming the first opening 32o1 and the second opening 32o2, respectively, which have the shapes shown in Figures 13 and 14.

[0123] Here, for example, the size of the multiple third openings 32o3 may change in steps in the width direction along the second direction, the +Y direction. For example, as shown in Figure 16, when each of the multiple third openings 32o3 has a longitudinal direction along the third direction, the +X direction, the size of the multiple third openings 32o3 may change in steps in the width direction along the second direction, the +Y direction. Figure 16 shows the appearance of another first example of the discharge section 32 in the gas supply section 3 according to the first embodiment. Figure 16 shows the appearance of another first example of the discharge section 32 when viewed from above toward the sixth direction, the -Z direction.

[0124] In the example shown in Figure 16, the central part of the discharge section 32 in the direction along the second direction, the +Y direction (width direction), is used as a reference point. The third opening 32o3 becomes larger as you move towards the direction along the second direction, the +Y direction, and the third opening 32o3 becomes larger as you move towards the direction along the fourth direction, the -Y direction. More specifically, in the discharge section 32, the central part of the discharge section 32 in the direction along the second direction, the +Y direction (width direction), is used as a reference point. The longitudinal length and width of the third opening 32o3 become larger as you move towards the direction along the second direction, the +Y direction, and the longitudinal length and width of the third opening 32o3 become larger as you move towards the direction along the fourth direction, the -Y direction.

[0125] Here, for example, each of the multiple third openings 32o3 is not limited to an elongated shape having a longitudinal direction along the +X direction as the third direction. For example, as shown in Figure 17, each of the multiple third openings 32o3 may be a circular opening, and the multiple third openings 32o3 may be arranged planarly between the first opening 32o1 and the second opening 32o2. Figure 17 shows the appearance of another second example of the discharge section 32 in the gas supply section 3 according to the first embodiment. Figure 17 shows the appearance of another second example of the discharge section 32 when viewed in plan toward the -Z direction as the sixth direction. Here, the arrangement of the multiple third openings 32o3 may be set in various ways, for example, taking into consideration the distribution of gas discharge from the discharge section 32. The multiple third openings 32o3 can be efficiently formed, for example, by punching or other processes.

[0126] <1-2. Schematic Configuration of the Printing Apparatus> Figure 18 shows a schematic configuration of an example of the printing apparatus 100 according to the first embodiment.

[0127] As shown in Figure 18, the printing apparatus 100 comprises the light irradiation device 1 described above, a transport unit 120, and a printing unit 130. The transport unit 120 can transport the printing medium 111, which is an example of the object to be irradiated 110, in a direction along the -X direction, which is a fifth direction opposite to the third direction, with the medium facing the light irradiation surface 222 of the light irradiation device 1. The printing unit 130 is positioned facing the path (also called the transport path) 120p through which the printing medium 111 is transported by the transport unit 120. The transport path 120p includes a first region A1 and a second region A2 located downstream of the first region A1 in the transport path 120p. The printing unit 130 is positioned facing the first region A1. The light irradiation surface 222 of the light irradiation device 1 is positioned facing the second region A2.

[0128] This printing apparatus 100 can transport the printing medium 111 by the transport unit 120, apply a photocurable ink 112 (an example of a photocurable material) to the printing medium 111 by the printing unit 130, and cure the photocurable ink 112 applied to the printing medium 111 by the light irradiation unit 1. This allows predetermined printing to be performed on the printing medium 111. Furthermore, this printing apparatus 100 can, for example, supply low-oxygen gas to the space between the light irradiation unit 1 and the printing medium 111 by the gas supply unit 3 of the light irradiation unit 1, and irradiate the printing medium 111 to which the photocurable ink 112 is applied by the light irradiation unit 2 of the light irradiation unit 1. In Figure 18, the outer edge of the area through which light passes from the light passage opening 222o of the light irradiation unit 2 toward the printing medium 111 is shown by a thin dashed line. Also in Figure 18, the direction in which gas is released from the discharge unit 32 of the gas supply unit 3 is shown by an arrow drawn below the gas supply unit 3.

[0129] In this printing apparatus 100, the configuration of the light irradiation device 1 described above allows for a close arrangement of the light irradiation surface 222 and the printing medium 111. As a result, the light irradiation efficiency to the printing medium 111, which is an example of an irradiated object 110, can be improved. In addition, the amount of low-oxygen gas supplied can be increased on both sides in the width direction along the second direction, +Y direction, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111. As a result, the insufficient reduction in oxygen concentration can be reduced on both sides in the width direction along the second direction, +Y direction, in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111. Thus, both an improvement in the light irradiation efficiency to the printing medium 111 and a reduction in the insufficient reduction in oxygen concentration in the space along the printing medium 111, which is an example of an irradiated object 110, can be achieved. Therefore, the inhibition of curing by oxygen in response to light irradiation of the photocurable ink 112 adhering to the printing medium 111 can be reduced. In other words, the printing performance of the printing apparatus 100 can be improved.

[0130] In the example shown in Figure 18, the printing apparatus 100 comprises a light irradiation device 1, a transport unit 120, a printing unit 130, and a control unit (also called a controller) 140.

[0131] The transport unit 120 can transport the printing medium 111 in the order described above, passing it through the region facing the printing unit 130 (more specifically, the first region A1) and the region facing the light irradiation device 1 (more specifically, the second region A2). Here, for example, the transport unit 120 can transport the printing medium 111 in a predetermined direction (also referred to as the transport direction) with the printing medium 111 facing the light irradiation surface 222 of the light irradiation device 1. Here, the light irradiation surface 222 of the light irradiation device 1 and the surface of the printing medium 111 passing through the second region A2 are arranged, for example, parallel or substantially parallel. In Figure 18, the transport direction is indicated by a thin solid arrow. The transport direction may be the direction along the -X direction as the fifth direction. Here, the side along the -X direction as the fifth direction is the downstream side of the transport direction, and the side along the +X direction as the third direction opposite to the fifth direction is the upstream side of the transport direction.

[0132] In the example shown in Figure 18, the transport unit 120 transports the printing medium 111, which is located along a virtual plane parallel to the horizontal plane, in a direction along the -X direction, which is the fifth direction. Here, the width direction of the printing medium 111 is along the +Y direction, which is the second direction perpendicular to the fifth direction. The thickness direction of the printing medium 111 is along the -Z direction, which is the first direction. Above the transport path 120p through which the printing medium 111 is transported by the transport unit 120, the printing unit 130 and the light irradiation device 1 are arranged in the order described above in the transport direction along the -X direction, which is the fifth direction.

[0133] As shown in Figure 18, the transport unit 120 includes, for example, a pair of transport rollers 121 located upstream of the printing device 100 and a pair of transport rollers 122 located downstream of the printing device 100. Each of the transport rollers 121 and 122 can hold the printing medium 111 by sandwiching it from above and below. The printing medium 111 can be transported in the transport direction by the rotation of the downstream transport rollers 122 and the upstream transport rollers 121. The rotation of each of the transport rollers 121 can be achieved by a drive such as an electric motor. The rotation of each of the transport rollers 122 can be achieved by a drive such as an electric motor.

[0134] The transport unit 120 may have a support section that supports the printing medium 111 from below, for example, between a pair of upstream transport rollers 121 and a pair of downstream transport rollers 122. For example, a plurality of cylindrical or columnar rollers (also referred to as support rollers) may be applied to this support section. The plurality of support rollers may be arranged in the transport direction, and each of the plurality of support rollers may have an axial direction along a direction perpendicular to the transport direction. For example, a platform on which the printing medium 111 is placed (also referred to as a mounting platform) may be applied to the support section. In this case, the printing medium 111 can be moved by sliding against the mounting platform while it is placed on the mounting platform.

[0135] The printing unit 130 can deposit a photocurable ink 112, as an example of a photocurable material, onto the printing medium 111 being transported by the transport unit 120. The printing unit 130 is fitted with, for example, an inkjet (IJ) head that ejects the photocurable ink 112. The photocurable ink 112 is, for example, an ultraviolet-curable ink (UV ink) that hardens (photocures) in response to irradiation with ultraviolet light, which is light in a specific wavelength range.

[0136] The printing unit 130 can, for example, adhere the photocurable ink 112 to the upper surface of the printing medium 111 being transported by the transport unit 120. Here, the IJ head of the printing unit 130 can adhere droplets of the photocurable ink 112 to the upper surface of the printing medium 111 being transported by the transport unit 120. Here, the printing unit 130 can, for example, adhere the photocurable ink 112 to the upper surface of the printing medium 111 in a desired pattern. The printing unit 130 may, for example, adhere the photocurable ink 112 to substantially the entire upper surface of the printing medium 111, or it may adhere the photocurable ink 112 to a part of the upper surface of the printing medium 111.

[0137] Here, for example, a line-type IJ head is applied to the IJ head of the printing unit 130. The line-type IJ head has a plurality of ink ejection holes arranged in a line (linear) shape. The line-type IJ head can eject light-curing ink 112 from each of the plurality of ink ejection holes. The direction in which the plurality of ink ejection holes are arranged (also referred to as the arrangement direction) is, for example, a direction that is perpendicular to the direction in which the medium to be printed 111 is transported by the transport unit 120 and is also parallel to the upper surface of the medium to be printed 111 being transported by the transport unit 120. In other words, the arrangement direction of the plurality of ink ejection holes is, for example, a direction that is perpendicular to the width direction of the medium to be printed 111 being transported by the transport unit 120. In the example of Figure 18, the arrangement direction of the plurality of ink ejection holes is a direction that is parallel to the +Y direction as a second direction. With this configuration, photocurable ink 112 is ejected from multiple ink ejection holes of the line-type IJ head onto the printing medium 111 being transported in the transport direction by the transport unit 120, thereby allowing the photocurable ink 112 to adhere to the upper surface of the printing medium 111. As a result, the printing unit 130 can adhere the photocurable ink 112 to the upper surface of the printing medium 111 in a desired pattern.

[0138] The IJ head used as the printing unit 130 may be of a different type, such as a serial IJ head, which is different from a line-type IJ head. The serial IJ head can move along the width direction of the printing medium 111. In this case, for example, the discharge of photocurable ink 112 onto the upper surface of the printing medium 111 while the serial IJ head is moving along the width direction of the printing medium 111 and the movement of the printing medium 111 in the transport direction by the transport unit 120 are performed alternately. This allows the printing unit 130 to adhere the photocurable ink 112 to the upper surface of the printing medium 111 in a desired pattern.

[0139] In an example of the printing apparatus 100 according to the first embodiment, the gas supply unit 3 of the light irradiation device 1 is located between the light irradiation unit 2 and the printing unit 130 of the light irradiation device 1. This reduces the incidence of light emitted from the light passage port 222o of the light irradiation unit 2 onto the printing unit 130. For this reason, for example, the hardening of the photocurable ink 112 in the ink ejection holes of the printing unit 130 by the light emitted from the light passage port 222o of the light irradiation unit 2 can be reduced. As a result, for example, the occurrence of clogging of the ink ejection holes in the printing unit 130 can be reduced.

[0140] The control unit 140 can control the operation of each part of the printing device 100. The control unit 140 has various electrical circuits, such as a processor and memory. The control unit 140 is electrically connected to each part of the printing device 100, for example, using cables. For example, the control unit 140 may be electrically connected to the connector 28 of the light irradiation device 1 via cables. The control unit 140 may be electrically connected to the transport unit 120 and the printing unit 130, for example, via cables.

[0141] The control unit 140 can, for example, control the transport of the printing medium 111 by the transport unit 120. The control unit 140 can, for example, control the ejection of the photocurable ink 112 by the IJ head of the printing unit 130. The control unit 140 can, for example, control the light emission of the plurality of light-emitting elements 21 in the light irradiation unit 2 of the light irradiation device 1 and the release of gas by the gas supply unit 3. The control unit 140 has, for example, an internal memory. This memory may store, for example, information indicating the characteristics of light that enable relatively good photocuring of the photocurable ink 112 ejected from the IJ head of the printing unit 130. Specific examples of this information include the characteristics of the wavelength distribution of light suitable for causing photocuring of droplets of photocurable ink 112 ejected from the IJ head, and numerical values ​​representing the light intensity (emission intensity in each wavelength range). In the printing device 100, for example, the control unit 140 may adjust the magnitude of the drive current input to the plurality of light-emitting elements 21 in the light irradiation unit 2 of the light irradiation device 1 based on the information in the memory. As a result, for example, multiple light-emitting elements 21 in the light irradiation section 2 of the light irradiation device 1 emit light with an appropriate amount of light according to the characteristics of the light-curable ink 112 being used, and the light-curable ink 112 can be cured with relatively low-energy light.

[0142] <1-3. Summary of the First Embodiment> In the light irradiation device 1 according to the first embodiment, the light irradiation surface 222 of the light irradiation unit 2 and the discharge unit 32 of the gas supply unit 3 are aligned in a direction along the +X direction, which is a third direction along the light irradiation surface 222. This makes it possible to arrange the light irradiation surface 222 and the object to be irradiated 110 in close proximity. As a result, the light irradiation efficiency to the object to be irradiated 110 can be improved.

[0143] Furthermore, in the discharge section 32 of the gas supply section 3, there is a first opening 32o1 that utilizes the gap between the first plate-shaped portion 3311 and the second plate-shaped portion 3312, which have a plurality of third openings 32o3, and a second opening 32o2 that utilizes the gap between the first plate-shaped portion 3311 and the third plate-shaped portion 3313. For this reason, in the gas supply section 3, a plurality of gas discharge ports 32o can be arranged over a wider range in the width direction along the second direction, the +Y direction. More specifically, in the gas supply section 3, in the width direction along the second direction, the +Y direction, the first opening 32o1 can be positioned closer to the end in the second direction, the +Y direction, and the second opening 32o2 can be positioned closer to the end in the fourth direction, the -Y direction. As a result, for example, the amount of gas (e.g., low-oxygen gas) supplied to reduce the oxygen concentration can be increased in the region near the light passage 222o in the space between the light irradiation surface 222 and the object to be irradiated 110, on both sides in the width direction along the second direction, the +Y direction. Consequently, the insufficient reduction of oxygen concentration can be reduced in the region near the light passage 222o in the space between the light irradiation surface 222 and the object to be irradiated 110, on both sides in the width direction along the second direction, the +Y direction.

[0144] Therefore, it is possible to improve the efficiency of light irradiation to the irradiated object 110 and reduce the insufficient decrease in oxygen concentration in the space along the irradiated object 110.

[0145] <2. Other Embodiments> This disclosure is not limited to the first embodiment described above, and various modifications and improvements are possible without departing from the gist of this disclosure.

[0146] In the first embodiment described above, for example, the gas supply unit 3 does not need to include a mounting member 34. In this case, for example, the gas supply unit 3 may be attached to the light irradiation unit 2 by fixing the wall portion 33 to the housing 22 by adhesive or screw fastening. For example, a packing member may be appropriately placed where screw fastening is performed. Here, for example, the flow path 31 may be formed by the wall portion 33 and the housing 22. In this flow path 31, for example, gas can flow in the space enclosed by the inner surface 33is of the wall portion 33 and the first side surface 2231 of the housing 22. As a result, for example, the gas supplied to the flow path 31 can flow in a manner that is in contact with the first side surface 2231 of the housing 22. As a result, the heat dissipation of the housing 22 can be improved by the gas flowing through the flow path 31.

[0147] In the first embodiment described above, for example, the printing unit 130 is not limited to a configuration having an IJ head, but may have other configurations different from an IJ head. For example, the printing unit 130 may be an offset printing apparatus, a flexographic printing apparatus, a gravure printing apparatus, or a screen printing apparatus that uses a photocurable ink 112. Also, for example, the printing unit 130 may be fitted with an electrostatic head. The electrostatic head may be a type of head that charges the printing medium 111 and adheres the developer (toner) by the electrostatic force due to the static electricity of the printing medium 111. The printing unit 130 may be fitted with a configuration that transports the developer (toner) with a brush, roller, etc. Here, for example, the developer may be an ultraviolet-curable toner that hardens in response to irradiation with ultraviolet light.

[0148] In the first embodiment described above, for example, the photocurable ink 112 may be changed to a photosensitive resist or a photocurable resin as a photosensitive material.

[0149] In the first embodiment described above, for example, a plurality of light irradiation devices 1 arranged in the width direction along the +Y direction as the second direction of the light irradiation device 1 may be used in a state in which they are integrally connected. In this case, the width of the gas supply unit 3 in the width direction along the +Y direction as the second direction should be the same as or approximately the same as the width of the light irradiation unit 2. Here, for example, it is assumed that a plurality of integrally connected light irradiation devices 1 are mounted on a printing device. In this case, the amount of gas (e.g., low-oxygen gas) supplied to reduce the oxygen concentration can be increased in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of an object to be irradiated 110, near the portion where two adjacent light irradiation devices 1 are connected. As a result, the deficiency in reducing the oxygen concentration can be reduced in the region near the light passage opening 222o in the space between the light irradiation surface 222 and the printing medium 111, which is an example of an object to be irradiated 110, near the portion where two adjacent light irradiation devices 1 are connected.

[0150] In the first embodiment described above, for example, the light irradiation device 1 may be applied to a field other than the printing field, such as a printing device 100.

[0151] For example, the light irradiation device 1 may be applied to various devices that have the function of irradiating ultraviolet light onto materials that undergo a chemical reaction in response to ultraviolet irradiation. This chemical reaction may be one in which the reaction can be inhibited by oxygen in the atmosphere. Examples of the various devices include devices for curing photocurable materials such as ultraviolet curing resins (also called UV curing resins) or UV inks. Examples of the devices include manufacturing devices for producing elements or components including various electrical circuits, or three-dimensional molding devices. Examples of the various electrical circuits include substrates (also called wiring boards) or integrated circuits (ICs) with various wiring. Examples of the manufacturing devices include devices in which a paste containing a photosensitive resin such as photoresist as a photocurable material is applied to the surface of an object such as a substrate by spin coating or screen printing, and then the photosensitive resin is cured by irradiation with light from the light irradiation device 1. For example, a three-dimensional modeling apparatus can be used that forms a three-dimensional object by repeatedly performing the formation of a layer of UV-curable resin, which is an example of a photocurable material, and curing the UV-curable resin by irradiation with ultraviolet light.

[0152] In the first embodiment described above, for example, the second A surface on the side of the second plate-shaped portion 3312 in the gas supply unit 3 in the +Y direction (as the second direction) was located along a virtual plane along the third side surface 2233 of the housing 22 in the light irradiation unit 2, but is not limited to this. For example, the second A surface on the side of the second plate-shaped portion 3312 in the gas supply unit 3 in the +Y direction (as the second direction) may be located on the side of the second direction (as the second direction) +Y than the third side surface 2233 of the housing 22 in the light irradiation unit 2. In the first embodiment described above, for example, the third A surface on the side of the third plate-shaped portion 3313 in the gas supply unit 3 in the -Y direction (as the fourth direction) was located along a virtual plane along the fourth side surface 2234 of the housing 22 in the light irradiation unit 2, but is not limited to this. For example, the third A surface of the third plate-shaped portion 3313 in the gas supply unit 3 on the side in the fourth direction (-Y direction) may be located on the side in the fourth direction (-Y direction) of the fourth side surface 2234 of the housing 22 in the light irradiation unit 2.

[0153] In the first embodiment described above, for example, the plurality of plate-shaped portions 331 in the gas supply unit 3 may have a configuration in which two or more portions are connected to each other by welding or the like. For example, the fifth plate-shaped portion 3315 may be connected to the fourth plate-shaped portion 3314 by welding or the like.

[0154] In the first embodiment described above, the first direction and the second direction were orthogonal, but this is not limited to this. For example, the first direction and the second direction may intersect. For example, the angle between the first direction and the second direction may be, for example, 70 to 110 degrees, 80 to 100 degrees, or 85 to 95 degrees.

[0155] In the first embodiment described above, the second direction and the third direction were orthogonal, but this is not limited to this. For example, the second direction and the third direction may intersect. For example, the angle between the second direction and the third direction may be, for example, 70 to 110 degrees, 80 to 100 degrees, or 85 to 95 degrees.

[0156] As described above, the light irradiation apparatus and printing apparatus have been described in detail, but the above description is illustrative in all respects, and this disclosure is not limited thereto. Furthermore, the various examples described above can be applied in combination, as long as they do not contradict each other. And countless examples not illustrated can be conceived without falling outside the scope of this disclosure.

[0157] This disclosure includes the following:

[0158] In one embodiment, (1) the light irradiation device comprises a light irradiation unit and a gas supply unit, the light irradiation unit includes a housing and a light-emitting element, the housing has an internal space in which the light-emitting element is located and a first outer surface provided with a light-passing opening through which light from the light-emitting element can pass, the light-passing opening is located on the side of the light-emitting element in a first direction and has a longitudinal direction along the first outer surface and a second direction perpendicular to the first direction, the gas supply unit includes a gas flow path located along the housing and a gas discharge unit having a plurality of openings connected to the flow path, the first outer surface and the discharge unit are aligned in a direction along the first outer surface and a third direction perpendicular to the second direction, the plurality of openings include a first opening located at the outermost end in the second direction and an opening opposite to the second direction The gas supply unit includes a second opening located at the outermost end in the fourth direction and a plurality of third openings located between the first and second openings, the gas supply unit includes a first plate-like portion having the plurality of third openings, a second plate-like portion, and a third plate-like portion, the first plate-like portion having a first end located on the side in the second direction and a second end located on the side in the fourth direction, the second plate-like portion having a first corner located on the side in the first direction and the side in the fourth direction, the third plate-like portion having a second corner located on the side in the first direction and the side in the second direction, the first opening includes a slit-shaped opening along the third direction in the gap between the first end and the first corner, and the second opening includes a slit-shaped opening along the third direction in the gap between the second end and the second corner.

[0159] (2) In the light irradiation device described in (1) above, the first end may be located on the side of the first direction that is closer to the first corner, and the second end may be located on the side of the first direction that is closer to the second corner.

[0160] (3) In the light irradiation device of (1) or (2) above, each of the plurality of third apertures has an elongated shape with a longitudinal direction along the third direction, and the plurality of third apertures may be arranged in a direction along the second direction.

[0161] (4) In the light irradiation device described in (3) above, each of the first aperture and the second aperture may have a length along the third direction that is greater than each of the plurality of third apertures, and an area that is greater than each of the plurality of third apertures.

[0162] (5) In the light irradiation device of (3) or (4) above, each of the plurality of third apertures has the same width in the direction along the second direction, and the plurality of third apertures may be arranged at regular intervals in the direction along the second direction.

[0163] (6) In the light irradiation device described in (5) above, each of the plurality of third apertures may have the same length in the longitudinal direction along the third direction.

[0164] In one embodiment, (7) the printing apparatus comprises a light irradiation device one of (1) to (6) above, a transport unit that transports a medium to be printed in a direction along a fifth direction opposite to the third direction with the medium facing the first outer surface of the light irradiation device, and a printing unit positioned opposite to the transport path through which the medium to be printed is transported by the transport unit, wherein the transport path includes a first region and a second region located downstream of the transport path from the first region, the printing unit is positioned opposite to the first region, and the first outer surface is positioned opposite to the second region.

[0165] 1 Light irradiation device 2 Light irradiation section 3, 3z Gas supply section 21 Light-emitting element 22 Housing 31 Flow path 32 Discharge section 32o Gas discharge port (opening) 32o1 First opening 32o2 Second opening 32o3 Third opening 100 Printing device 111 Printing medium 120 Transport section 120p Transport path 130 Printing section 221 Internal space 222 Light irradiation surface (first outer surface) 222o Light passage opening 3311 First plate-shaped section 3312 Second plate-shaped section 3313 Third plate-shaped section A1 First region A2 Second region Cn1 First corner Cn2 Second corner Ed1 First end Ed2 Second end

Claims

1. The device comprises a light irradiation unit and a gas supply unit, the light irradiation unit includes a housing and a light-emitting element, the housing has an internal space in which the light-emitting element is located and a first outer surface provided with a light-passing opening through which light from the light-emitting element can pass, the light-passing opening is located on the side of the light-emitting element in a first direction, the gas supply unit includes a gas flow path and a gas discharge unit having a plurality of openings connected to the flow path, the first outer surface and the discharge unit are aligned in a third direction intersecting the second direction when the longitudinal direction of the light-passing opening is the second direction, the plurality of openings include a first opening located at the outermost end in the second direction, a second opening located at the outermost end in a fourth direction opposite to the second direction, and a plurality of third openings located between the first and second openings, the gas supply unit includes a first plate-shaped portion having the plurality of third openings, a second plate-shaped portion, and a third plate-shaped portion, A light irradiation device wherein the first plate-like portion has a first end which is the end in the second direction and a second end which is the end in the fourth direction, the first opening includes an opening in the gap between the first end and the end of the second plate-like portion in the first direction, and the second opening includes an opening in the gap between the second end and the end of the third plate-like portion in the first direction.

2. A light irradiation device according to claim 1, wherein the first end is located on the side in the first direction of the second plate-shaped portion that is further to the first direction than the end of the second plate-shaped portion that is further to the first direction than the end of the third plate-shaped portion that is further to the first direction.

3. A light irradiation device according to claim 1 or claim 2, wherein each of the plurality of third apertures has a length in the third direction greater than the length in the second direction, and the plurality of third apertures are arranged in the second direction.

4. A light irradiation device according to claim 3, wherein each of the first aperture and the second aperture has a length in the third direction that is greater than each of the plurality of third apertures, and an area that is greater than each of the plurality of third apertures.

5. A light irradiation device according to claim 3 or claim 4, wherein each of the plurality of third apertures has the same length in the second direction, and the plurality of third apertures are arranged at regular intervals in the second direction.

6. A light irradiation device according to claim 5, wherein each of the plurality of third apertures has the same length in the third direction.

7. A printing apparatus comprising: a light irradiation device according to any one of claims 1 to 6; a transport unit for transporting a medium to be printed in a direction along a fifth direction opposite to the third direction, with the medium facing the first outer surface of the light irradiation device; and a printing unit positioned opposite to a transport path through which the medium to be printed is transported by the transport unit, wherein the transport path includes a first region and a second region located downstream of the transport path from the first region, the printing unit is positioned opposite to the first region, and the first outer surface is positioned opposite to the second region.

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