inkjet printer

Abstract

To reduce light scattering to the outside of a case of an ultraviolet light radiation device.SOLUTION: A printer 10 includes an ultraviolet light radiation device 40 which is mounted on a carriage 20 so as to be located at one side as seen in a main scanning direction Y relative to an ink head 30 and may radiate light to a light curable ink discharged to a recording medium 5. The ultraviolet light radiation device 40 has: an LED element 43; a case 45 which houses the LED element 43 and is formed with a radiation port 45H which is open to the lower side and emits light radiated from the LED element 43 to the outside; glass 57 which closes the radiation port 45H and through which the light radiated from the LED element 43 may pass; a holding member 58 which holds the glass 57; and a light inhibition member 50 which is provided at the holding member 58 and inhibits the light reflected on both end surfaces as seen in the main scanning direction Y of the glass 57 from being emitted from the case 45.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an inkjet printer.

Background Art

[0002] Conventionally, an inkjet printer that includes an ink head having a plurality of nozzles that eject photocurable ink (hereinafter referred to as photocurable ink) and a nozzle surface on which the nozzles are formed, and a carriage that mounts the ink head and is movable in the main scanning direction, and performs predetermined printing on a recording medium by an inkjet method is known. An inkjet printer that uses photocurable ink includes, for example, a light irradiation device having an LED element that irradiates light toward the photocurable ink ejected onto the recording medium, as shown in Patent Document 1. The light irradiation device is mounted on the carriage so as to be aligned with the ink head in the main scanning direction. The photocurable ink irradiated with light quickly cures on the recording medium, and thereby a desired image is printed on the recording medium.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, the light irradiation device has a case that houses an LED element. The case has an irradiation port formed therein that emits light emitted from the LED element to the outside. Here, the light irradiation device may have a glass that covers the irradiation port. In this case, most of the light emitted from the LED element passes through the glass and is emitted to the outside, but some of the light is reflected at both ends of the glass and is emitted to the outside of the case. Since the light emitted in this way is emitted from the irradiation port of the light irradiation device at an angle that is not perpendicular to the recording medium, it is likely to diffuse outside the case and may become stray light inside the printer. For example, if stray light reaches the nozzle surface of the ink head, the photocurable ink may harden on the nozzle surface or on the nozzle, which may cause the nozzle to clog.

[0005] The present invention has been made in view of the above, and its object is to provide an inkjet printer that can reduce the light that diffuses outside the case of the light irradiation device. [Means for solving the problem]

[0006] The inkjet printer according to the present invention comprises: a mounting table on which a recording medium is placed; an ink head having a nozzle for ejecting photocurable ink onto the recording medium placed on the mounting table; a nozzle surface on which the nozzle is formed; a carriage on which the ink head is mounted and which is movable in the main scanning direction; and a light irradiation device mounted on the carriage so as to be located on one side of the ink head in the main scanning direction and capable of irradiating light toward the photocurable ink ejected onto the recording medium. The light irradiation device comprises an LED element; a case housing the LED element and having an irradiation port that opens downward and emits light emitted from the LED element to the outside; glass that blocks the irradiation port and through which light emitted from the LED element can pass; a holding member for holding the glass; and a light suppression member provided on the holding member or the glass to suppress the emission of light reflected from both end faces of the glass in the main scanning direction from the case.

[0007] According to the inkjet printer of the present invention, the light irradiation device has a light suppression member provided on a holding member or glass, and the light suppression member suppresses the emission of light reflected from both end faces of the glass in the main scanning direction from the case. With this configuration, the light suppression member suppresses the emission of a portion of the light irradiated from the LED element to the outside of the case from both end faces of the glass in the main scanning direction, thereby reducing the amount of light that diffuses outside the case. This reduces the amount of light that reaches the nozzle surface of the ink head. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an inkjet printer that can reduce the amount of light diffused outside the case of the light irradiation device. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a printer according to one embodiment. [Figure 2] This is a front view of a printer with the front cover open, according to one embodiment. [Figure 3] This is a plan view of a printer with the front cover and case removed according to one embodiment. [Figure 4] This is a schematic diagram showing the configuration of the side of the carriage facing the recording medium according to one embodiment. [Figure 5] This is a cross-sectional view of an ultraviolet irradiation device according to one embodiment. [Figure 6] This is a block diagram of a printer according to one embodiment. [Figure 7] This is a cross-sectional view of an ultraviolet irradiation device according to another embodiment. [Figure 8] This is a cross-sectional view of an ultraviolet irradiation device according to another embodiment. [Modes for carrying out the invention]

[0010] <First Embodiment> Hereinafter, an inkjet printer (hereinafter simply referred to as "printer") according to an embodiment of the present invention will be described with reference to the drawings. Naturally, the embodiments described herein are not intended to particularly limit the present invention. Furthermore, the same reference numerals are used for components and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate.

[0011] ← Directional explanation Figure 1 is a perspective view of the printer 10 according to this embodiment. The printer 10 prints on the recording medium 5 (see Figure 2). In the following description, when the printer 10 is viewed from the front, the direction away from the printer 10 is considered the front, and the direction towards the printer 10 is considered the rear. Left, right, up, and down refer to the left, right, up, and down directions when the printer 10 is viewed from the front, respectively. Also, the symbols F, Rr, L, R, U, and D in the drawing refer to the front, rear, left, right, up, and down directions, respectively. Also, the symbol Y in the drawing indicates the main scanning direction. Here, the main scanning direction Y is the left-right direction. The symbol X indicates the sub-scanning direction. Here, the sub-scanning direction X is the front-back direction and is perpendicular to the main scanning direction Y in a plan view. The symbol Z indicates the up-down direction. The up-down direction Z is perpendicular to the main scanning direction Y in a front view. However, the directions described above are merely defined for the sake of explanation and do not in any way limit the installation configuration of the printer 10, nor do they limit the present invention in any way.

[0012] The recording medium 5 used in this embodiment may be, for example, a flat sheet such as recording paper or transfer paper, or a three-dimensional object such as various cases such as mobile phone cases, small electronic devices, small parts such as keychains, photo frames and pens, daily necessities, or accessories. The material used to form the recording medium 5 may be paper such as plain paper or inkjet printing paper, as well as resins such as polyvinyl chloride (PVC), acrylic resin, polycarbonate, polystyrene, polyethylene, polyester, polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS) copolymer, metals such as aluminum and stainless steel, carbon, ceramics, glass, rubber, leather, wood, etc.

[0013] As shown in Figure 1, the printer 10 includes a box-shaped housing 12. The housing 12 has an internal space 12S. The housing 12 includes a case 15 and a front cover 23. An opening 28 (see Figure 2) is formed at the front of the case 15. The front cover 23 is provided so as to be able to open and close the opening 28 of the case 15. Here, the front cover 23 is supported by the case 15 so as to be able to rotate around its rear end as an axis. By rotating the front cover 23 upward, the internal space 12S and the external space of the housing 12 are connected. The internal space 12S is the space in which printing is performed on the recording medium 5 by the ink head 30 (see Figure 2), which will be described later. In this way, because the internal space 12S in which printing takes place is surrounded by the case 15 and the front cover 23, dust and dirt from the external space are less likely to enter the internal space 12S during printing, and light irradiated from the ultraviolet irradiation device 40 (see Figure 2), which will be described later, is less likely to leak into the external space.

[0014] As shown in Figure 1, windows 23A are provided on the front and top of the front cover 23. The windows 23A are formed, for example, from a transparent acrylic plate. The windows 23A are treated to prevent light from the outside (e.g., ultraviolet light) from reaching the internal space 12S. The user can see inside the housing 12 through the windows 23A.

[0015] Next, the internal configuration of the printer 10 will be described. As shown in FIG. 2, the printer 10 includes a guide rail 18, a carriage 20, an ink head 30, an ultraviolet irradiation device 40, and a control device 70. The guide rail 18, the carriage 20, the ink head 30, and the ultraviolet irradiation device 40 are provided in the internal space 12S. The guide rail 18 is disposed within the case 15. As shown in FIG. 3, the guide rail 18 is fixed to the support wall 15A of the case 15 and extends in the main scanning direction Y. A carriage 20 is provided on the guide rail 18 so as to be slidable. The carriage 20 reciprocates in the main scanning direction Y along the guide rail 18 by a carriage moving mechanism 21 (see FIG. 6). The carriage moving mechanism 21 is controlled by the control device 70. As the carriage 20 moves in the main scanning direction Y, the ink head 30 and the ultraviolet irradiation device 40 mounted on the carriage 20 move in the main scanning direction Y.

[0016] As shown in FIG. 2, a plurality of ink heads 30 are mounted on the carriage 20. The ink head 30 is disposed above a table 35 described later. The ink head 30 discharges an ink having photocurability (photocurable ink) onto the recording medium 5 placed on the table 35. Each of the ink heads 30 communicates with an ink cartridge 60 accommodated in the case 15 by a flexible ink tube (not shown). The ink cartridge 60 stores the photocurable ink respectively.

[0017] As shown in Figure 4, the ink head 30 is mounted on the carriage 20. The ink heads 30 are positioned in a aligned position with respect to the sub-scanning direction X. The ink heads 30 may be positioned in a staggered position with respect to the sub-scanning direction X. That is, the ink heads 30 may be arranged in a so-called staggered configuration. The ink head 30 is formed in a shape where the length in the sub-scanning direction X is longer than the length in the main scanning direction Y. The ink head 30 comprises a plurality of left nozzles 31A aligned in the sub-scanning direction X, a plurality of right nozzles 31B aligned in the sub-scanning direction X and located to the right of the left nozzles 31A, and a nozzle surface 31C on which the left nozzles 31A and right nozzles 31B are formed. The plurality of left nozzles 31A are arranged in a row to form a left nozzle row 33A. The plurality of right nozzles 31B are arranged in a row to form a right nozzle row 33B. The left nozzles 31A and right nozzles 31B eject photocurable ink. In Figure 4, 12 nozzles are shown on the ink head 30, but in reality, many more (e.g., 180) nozzles are formed. However, the number of nozzles is not limited in any way. Also, the number of ink heads 30 is not limited to three. Furthermore, the ink head 30 has two nozzle rows, but there may be one or more nozzle rows.

[0018] Photocurable inks are inks that harden when exposed to light (e.g., ultraviolet light). Examples of photocurable inks include inks used for image formation (i.e., image quality forming inks) and inks used for forming a base layer before image formation or for surface finishing after image formation (i.e., image quality improvement inks). Image formation inks are, for example, process color inks. Examples of process color inks include cyan ink, magenta ink, yellow ink, black ink, light cyan ink, and light magenta ink. Inks used for forming a base layer before image formation are, for example, primer inks and white inks. Primer inks are tacky. Inks used for surface finishing after image formation are, for example, gloss inks.

[0019] As shown in FIG. 2, the printer 10 includes one ultraviolet irradiation device 40. The ultraviolet irradiation device 40 is an example of a light irradiation device. The ultraviolet irradiation device 40 irradiates light (typically ultraviolet light). The ultraviolet irradiation device 40 is configured to be able to irradiate light (here, ultraviolet light) onto the area where the photocurable ink has been ejected (i.e., the printing area) of the recording medium 5. The ultraviolet irradiation device 40 is configured to be able to irradiate light toward the photocurable ink ejected onto the recording medium 5. The ultraviolet irradiation device 40 is mounted on the carriage 20. The ultraviolet irradiation device 40 is disposed above the table 35 described later. As shown in FIG. 4, the ultraviolet irradiation device 40 is disposed to the right of the ink head 30. Note that the ultraviolet irradiation device 40 may be disposed to the left of the ink head 30.

[0020] FIG. 5 is a cross-sectional view of the ultraviolet irradiation device 40 according to the first embodiment. As shown in FIG. 5, the ultraviolet irradiation device 40 includes an LED element 43, a case 45 that houses the LED element 43, a printed circuit board 48, a light suppression member 50, a heat sink 55, a glass 57, and a holding member 58 that holds the glass 57.

[0021] As shown in Figure 5, the case 45 is formed in a rectangular parallelepiped shape. The case 45 includes an upper wall 45A, a front wall 45B (see Figure 4) extending downward from the front end of the upper wall 45A, a rear wall 45C (see Figure 4) extending downward from the rear end of the upper wall 45A, a left wall 45D extending downward from the left end of the upper wall 45A and connecting the front wall 45B and the rear wall 45C, and a right wall 45E extending downward from the right end of the upper wall 45A and connecting the front wall 45B and the rear wall 45C. An illumination port 45H is formed in the case 45. The illumination port 45H is formed from the front wall 45B, the rear wall 45C, the left wall 45D, and the right wall 45E. The illumination port 45H opens downward. The illumination port 45H emits light emitted from the LED element 43 to the outside. The case 45 is made of a metal material (for example, iron or aluminum). Therefore, the inner surface 45M of the case 45 reflects the light emitted from the LED element 43. The inner surface 45M may also be provided with a material that suppresses (prevents) light reflection (for example, a black coating of light reflection suppressing paint). As shown in Figure 4, the case 45 is formed in a shape in which the length in the sub-scanning direction X is longer than the length in the main scanning direction Y. The case 45 is mounted on the carriage 20 via a connecting member 22.

[0022] As shown in Figure 4, the ultraviolet irradiation device 40 has a plurality of LED elements 43 arranged in the sub-scanning direction X. The plurality of LED elements 43 are arranged in a row to form a light source row 44. The LED elements 43 irradiate the photocurable ink ejected onto the recording medium 5 with light (in this case, ultraviolet light). The LED elements 43 are located in the light irradiation chamber 46 (see Figure 5), which will be described later, of the case 45. The light source row 44 is located to the side (in this case, to the right) of the ink head 30. The length of the light source row 44 in the sub-scanning direction X is longer than the length of the left nozzle row 33A and the right nozzle row 33B of the ink head 30 in the sub-scanning direction X. Although 18 LED elements 43 are shown in each row in Figure 4, in reality, many more (for example, 30) light sources are provided.

[0023] As shown in Figure 5, the printed circuit board 48 is housed in a case 45. The printed circuit board 48 is held in the case 45. Multiple LED elements 43 are mounted on the printed circuit board 48. Together with the case 45, the printed circuit board 48 partitions a light irradiation chamber 46 and a component placement chamber 47. The light irradiation chamber 46 includes an irradiation port 45H. The component placement chamber 47 is located above the light irradiation chamber 46. On the lower surface 48A of the printed circuit board 48, which faces the light irradiation chamber 46, a light-reflecting member is provided to promote light reflection. The light-reflecting member is, for example, a white coating of light-reflecting paint (e.g., "white paint such as titanium dioxide").

[0024] As shown in Figure 5, the heat sink 55 is placed in the component placement chamber 47. The heat sink 55 is in contact with the printed circuit board 48. The heat sink 55 is placed on top of the printed circuit board 48. The heat sink 55 is a component used for the purpose of dissipating heat from the printed circuit board 48.

[0025] As shown in Figure 5, the glass 57 is placed in the light irradiation chamber 46. The glass 57 is held in the case 45. More specifically, the glass 57 is held in the holding member 58. The glass 57 is provided to cover the irradiation opening 45H. The glass 57 is configured to allow light irradiated from the LED element 43 to pass through. The glass 57 is transparent. The glass 57 is a component that prevents foreign matter (e.g., ink mist, dust, etc.) from entering the case 45 from the outside and protects the LED element 43.

[0026] As shown in Figure 5, the retaining member 58 is integrally formed with the case 45. Here, the retaining member 58 is provided at the lower ends of the front wall 45B, rear wall 45C, left wall 45D, and right wall 45E of the case 45. The retaining member 58 holds the glass 57 by surrounding it from all four sides. Note that the retaining member 58 may be a separate component from the case 45.

[0027] As shown in Figure 5, the light suppression member 50 is provided on the holding member 58. The light suppression member 50 suppresses the emission of light reflected from both end faces (here, the left end face 57L and the right end face 57R) of the glass 57 in the main scanning direction Y from the case 45. The light suppression member 50 cuts out light incident on both end faces of the glass 57 in the main scanning direction Y. The light suppression member 50 is located above the glass 57. The light suppression member 50 includes a right-side light suppression member 50R extending from the right inner surface 45R of the case 45 toward the center of the main scanning direction Y of the case 45 (i.e., to the left), and a left-side light suppression member 50L extending from the left inner surface 45L of the case 45 toward the center of the main scanning direction Y of the case 45 (i.e., to the right). Here, when H is the length of the light suppression member 50 in the main scanning direction Y, t is the thickness of the glass 57, A is the vertical distance Z from the LED element 43 to the glass 57, and B is the distance in the main scanning direction Y from the center 43C of the LED element 43 to the left inner surface 45L and the right inner surface 45R of the case 45, H is set to ≥ Bt / (A+t). Here, as shown in Figure 5, in order to set H so that light is not reflected at the right end surface 57R of the glass 57, for example, the light emitted from the LED element 43 toward the right end surface 57R of the glass 57 must be blocked by the light suppression member 50. To achieve this, the angle θ2 between the line LY passing through the center 43C of the LED element 43 and the center line passing through the center 43C of the LED element 43 must be set to be smaller than the angle θ1 between the line LX connecting the center 43C of the LED element 43 and the lower end of the right end surface 57R of the glass 57 and the center line passing through the center 43C of the LED element 43. That is, θ1 = (A+t) / B, θ2 = A / (BH), and A / (BH) ≤ (A+t) / B are set. As described above, by satisfying H ≥ Bt / (A+t), the reflection of light at both end faces of the glass 57, which causes stray light, can be suppressed.

[0028] As shown in Figure 2, the printer 10 is a so-called flatbed type printer. The printer 10 includes a table 35 located below the carriage 20, a first table movement mechanism 36, and a second table movement mechanism 37. The table 35, the first table movement mechanism 36, and the second table movement mechanism 37 are located in the internal space 12S. The table 35 is an example of a mounting platform. A recording medium 5 is placed on the table 35. The table 35 is a platform that supports the recording medium 5. The table 35 is configured to be movable in the sub-scanning direction X by the first table movement mechanism 36. The table 35 is configured to be movable in the vertical direction Z by the second table movement mechanism 37.

[0029] As shown in Figure 2, the first table moving mechanism 36 comprises slide rails 36a and 36b, a transport member 36c, a ball screw 36d, and a first motor 39A (see also Figure 6). The slide rails 36a and 36b extend in the sub-scanning direction X. The transport member 36c is slidably mounted relative to the slide rails 36a and 36b. Above the transport member 36c, the table 35 is supported via other members. The transport member 36c is connected to the ball screw 36d. The ball screw 36d extends in the sub-scanning direction X. The first motor 39A is connected to the ball screw 36d via a gear (not shown). The first motor 39A rotates the ball screw 36d. The first motor 39A is electrically connected to and controlled by the control device 70. When the first motor 39A is driven, the transport member 39c moves in the sub-scanning direction X along the slide rails 36a and 36b due to the rotation of the ball screw 36d. As a result, the table 35 moves in the sub-scanning direction X.

[0030] As shown in Figure 2, the second table movement mechanism 37 comprises a height adjustment member 37a and a second motor 39B (see Figure 6). The height adjustment member 37a is located on the underside of the table 35. The height adjustment member 37a is connected to the second motor 39B. The second motor 39B is electrically connected to the control device 70 and controlled by the control device 70. When the second motor 39B is driven, the height of the height adjustment member 37a changes, and the height of the table 35 is adjusted. That is, the table 35 moves in the vertical direction Z.

[0031] As shown in Figure 6, the control device 70 is a device that controls printing to the recording medium 5. The configuration of the control device 70 is not particularly limited. The control device 70 is, for example, a microcomputer. The control device 70 is communicatively connected to and controls the carriage movement mechanism 21, the ink head 30, the ultraviolet irradiation device 40, the first motor 39A of the first table movement mechanism 36 (see Figure 2), and the second motor 39B of the second table movement mechanism 37 (see Figure 2).

[0032] As shown in Figure 6, the control device 70 comprises a print control unit 71, a light source control unit 72, and a movement control unit 73. The functions of each part of the control device 70 are realized by a program. The print control unit 71 is the part that forms an image on the recording medium 5. The print control unit 71 controls the carriage movement mechanism 21 and the ink head 30. The light source control unit 72 controls the LED element 43 of the ultraviolet irradiation device 40. The light source control unit 72 is the part that irradiates light from the LED element 43 onto the photocurable ink ejected onto the recording medium 5 to cure the photocurable ink. The movement control unit 73 is the part that moves the recording medium 5 in the sub-scanning direction X. The movement control unit 73 controls the first motor 39A.

[0033] As described above, according to the printer 10 of this embodiment, the ultraviolet irradiation device 40 has a light suppression member 50 provided on the holding member 58, and the light suppression member 50 suppresses the emission of light reflected from both end faces of the glass 57 in the main scanning direction Y (for example, the left end face and the right end face of the glass 57) from the case 45. With this configuration, the light suppression member 50 suppresses the emission of a portion of the light irradiated from the LED element 43 from both end faces of the glass 57 in the main scanning direction Y to the outside of the case 45, thereby reducing the light that diffuses outside the case 45 (light directed diagonally outward from the case 45). As a result, the amount of light reaching the nozzle surface 31C of the ink head 30 can be reduced.

[0034] In the printer 10 of this embodiment, the light suppression member 50 is located above the glass 57 and is provided on the holding member 58 so as to extend from the left inner surface 45L and the right inner surface 45R of the case 45 toward the center of the case 45 in the main scanning direction Y. With this configuration, since the light incident on both end faces of the glass 57 in the main scanning direction Y is blocked by the light suppression member 50, the emission of some of the light irradiated from the LED element 43 out of the case 45 from both end faces of the glass 57 in the main scanning direction Y is further suppressed.

[0035] In the printer 10 of this embodiment, when the length of the light suppression member 50 in the main scanning direction Y is H, the thickness of the glass 57 is t, the distance in the vertical direction Z from the LED element 43 to the glass 57 is A, and the distances in the main scanning direction Y from the center 43C of the LED element 43 to the left inner surface 45L and the right inner surface 45R of the case 45 in the main scanning direction Y are B, then H is set to ≥ Bt / (A+t). With this configuration, it is possible to reduce the amount of light that diffuses to the outside of the case 45.

[0036] <Second Embodiment> Figure 7 is a cross-sectional view of the ultraviolet irradiation device 140 according to the second embodiment. As shown in Figure 7, the ultraviolet irradiation device 140 includes an LED element 43, a case 45 housing the LED element 43, a printed circuit board 48, a light suppression member 150, a heat sink 55, a glass 57, and a holding member 158 for holding the glass 57.

[0037] As shown in Figure 7, the retaining member 158 is integrally formed with the case 45. Here, the retaining member 158 is provided at the lower ends of the front wall 45B, rear wall 45C, left wall 45D, and right wall 45E of the case 45. The retaining member 158 holds the glass 57 by surrounding it from all four sides. The retaining member 158 clamps the glass 57 in the vertical direction Z.

[0038] As shown in Figure 7, the light suppression member 150 is provided on the holding member 158. The light suppression member 150 suppresses the emission of light reflected from both end faces (here, the left end face 57L and the right end face 57R) of the glass 57 in the main scanning direction Y from the case 45. The light suppression member 150 cuts out light incident on both end faces of the glass 57 in the main scanning direction Y. The light suppression member 150 suppresses the emission of light reflected from both end faces of the glass 57 in the main scanning direction Y from the case 45. The light suppression member 150 includes a first light suppression member 151 located above the glass 57 and a second light suppression member 152 located below the glass 57. The first light suppression member 151 includes a right-side first light suppression member 151R extending from the right-side inner surface 45R of the case 45 toward the center of the main scanning direction Y of the case 45 (i.e., to the left), and a left-side first light suppression member 151L extending from the left-side inner surface 45L of the case 45 toward the center of the main scanning direction Y of the case 45 (i.e., to the right). The second light suppression member 152 includes a right-side second light suppression member 152R extending from the right-side inner surface 45R of the case 45 toward the center of the main scanning direction Y of the case 45 (i.e., to the left), and a left-side second light suppression member 152L extending from the left-side inner surface 45L of the case 45 toward the center of the main scanning direction Y of the case 45 (i.e., to the right). Here, when M is the length of the second light suppression member 152 in the main scanning direction Y, N is the length of the first light suppression member 151 in the main scanning direction Y, t is the thickness of the glass 57, A is the vertical distance Z from the LED element 43 to the glass 57, and B is the distance in the main scanning direction Y from the center 43C of the LED element 43 in the main scanning direction Y to the left inner surface 45L and the right inner surface 45R of the case 45, then M≧t and N≧Bt / (A+t) are set. In this embodiment, length N is shorter than length M, but length N may be the same as length M, or length N may be longer than length M.

[0039] In the printer 10 of this embodiment, the light suppression member 150 includes a left first light suppression member 151L and a right first light suppression member 151R, which are located above the glass 57 and extend from the left inner surface 45L and the right inner surface 45R of the case 45 toward the center of the main scanning direction Y of the case 45, respectively, and a left second light suppression member 152L and a right second light suppression member 152R, which are located below the glass 57 and extend from the left inner surface 45L and the right inner surface 45R of the case 45 toward the center of the main scanning direction Y of the case 45, respectively. When M is the length of the left second light suppression member 152L and the right second light suppression member 152R in the main scanning direction Y, N is the length of the left first light suppression member 151L and the right first light suppression member 151R in the main scanning direction, t is the thickness of the glass 57, A is the vertical distance Z from the LED element 43 to the glass 57, and B is the distance in the main scanning direction Y from the center 43C of the LED element 43 to the left inner surface 45L and the right inner surface 45R of the case 47, then M≧t and N≧Bt / (A+t) are set. With this configuration, it is possible to reduce the amount of light that diffuses to the outside of the case 45.

[0040] <Third Embodiment> Figure 8 is a cross-sectional view of an ultraviolet irradiation device 240 according to the third embodiment. As shown in Figure 8, the ultraviolet irradiation device 240 includes an LED element 43, a case 45 housing the LED element 43, a printed circuit board 48, a light suppression member 250, a heat sink 55, a glass 257, and a holding member 258 for holding the glass 257.

[0041] As shown in Figure 8, the glass 257 is placed in the light irradiation chamber 46. The glass 257 is held in the case 45. More specifically, the glass 257 is held in the holding member 258. The glass 257 is provided to cover the irradiation opening 45H. The glass 257 is configured to allow light irradiated from the LED element 43 to pass through. The glass 257 has a plurality of glass bodies 257A arranged in the main scanning direction Y. The glass bodies 257A in this embodiment are formed in the same shape, but they may be different. The upper surface 257C of the glass body 257A is formed in a convex shape (i.e., a shape that protrudes upward). The upper surface 257C of the glass body 257A may be flat or concave (i.e., a shape that is recessed downward).

[0042] As shown in Figure 8, the retaining member 258 is integrally formed with the case 45. Here, the retaining member 258 is provided at the lower ends of the front wall 45B, rear wall 45C, left wall 45D, and right wall 45E of the case 45. The retaining member 258 holds the glass 57 by surrounding it from all four sides.

[0043] As shown in Figure 8, the light suppression member 250 is provided on the glass 257. More specifically, the light suppression member 250 is provided between the glass 257 and the case 45 (i.e., the left inner surface 45L and the right inner surface 45R of the case 45). The light suppression member 250 is further provided between adjacent glass bodies 257A. The light suppression member 250 is provided, for example, on the side surface of the glass body 257A (the surface intersecting the main scanning direction Y). It is sufficient that the light suppression member 250 is provided on at least one of the opposing side surfaces of adjacent glass bodies 257A. The light suppression member 250 is, for example, a member that suppresses (prevents) light reflection (e.g., a black coating of light reflection suppressing paint). The light suppression member 250 suppresses the emission of light reflected from both end faces of the glass 257 in the main scanning direction Y (i.e., the right end face and the left end face of the glass body 257A) from being emitted from the case 45. The light suppression member 250 suppresses the reflection of light at both end faces of the glass 257 in the main scanning direction Y (i.e., the right end face and left end face of the glass body 257A).

[0044] In the printer 10 of this embodiment, the light suppression member 250 is provided between the case 45 and the glass 257. With this configuration, it is possible to reduce the light that diffuses to the outside of the case 45 without providing a separate structure such as a grid.

[0045] In the printer 10 of this embodiment, the glass 257 has a plurality of glass bodies 257A arranged in the main scanning direction Y, and the light suppression member 250 is further provided between the case 45 and the glass bodies 257A. With this configuration, it is possible to reduce the light that diffuses to the outside of the case 45 without attenuating the straight-traveling light irradiated from the LED element 43.

[0046] In the printer 10 of this embodiment, the upper surface 257C of the glass body 257A is formed in a convex shape. With this configuration, the amount of light diffused to the outside of the case 45 can be reduced.

[0047] Preferred embodiments of the present invention have been described above. However, the embodiments described above are merely illustrative, and the present invention can be implemented in various other forms.

[0048] In the embodiment described above, the printer 10 was equipped with a first table moving mechanism 36 as a moving device that moves the recording medium 5 relative to the carriage 20 in the sub-scanning direction X by moving the table 35 on which the recording medium 5 is placed relative to the carriage 20 in the sub-scanning direction X, but is not limited to this. For example, the printer may be equipped with a moving device that fixes the table 35 to the housing 12 and moves the carriage 20 relative to the table 35 in the sub-scanning direction X, thereby moving the recording medium 5 relative to the carriage 20 in the sub-scanning direction X.

[0049] The technology disclosed herein can be applied to various types of printers. In addition to the flatbed type printer 10 shown in the embodiments described above, it can also be similarly applied to a so-called roll-to-roll type printer 10 that transports a roll-shaped recording medium 5 in the sub-scanning direction X. [Explanation of symbols]

[0050] 5. Recording media 10. Printer (inkjet printer) 20 Carriage 30 Inkheads 31C Nozzle surface 35 Table (Platform) 40 Ultraviolet irradiation device (light irradiation device) 43 LED elements 45 cases 45H irradiation port 50 Light suppression member 57 Glass 58 Retaining member

Claims

1. A mounting platform on which the recording medium is placed, An ink head having a nozzle for ejecting photocurable ink onto the recording medium placed on the mounting base, and a nozzle surface on which the nozzle is formed, A carriage equipped with the aforementioned ink head and movable in the main scanning direction, The carriage is mounted such that it is located on one side of the main scanning direction from the ink head, and includes a light irradiation device capable of irradiating light toward the photocurable ink ejected onto the recording medium, The aforementioned light irradiation device is LED elements and A case that houses the LED element and has an illumination port that opens downward and emits light emitted from the LED element to the outside, A glass held in the case, which blocks the irradiation opening and allows light irradiated from the LED element to pass through, The case includes a light suppression member that blocks light emitted from the LED element and incident on both end faces of the glass in the main scanning direction, An inkjet printer wherein the light suppression member is located above the glass and extends from the inner surfaces of one and the other side of the case in the main scanning direction toward the center of the case in the main scanning direction, so as to block light emitted from the LED element and incident on the lower ends of both end faces of the glass in the main scanning direction.

2. The inkjet printer according to claim 1, wherein the light suppression member extends from the inner surfaces of one and the other side of the case in the direction toward the center

3. A mounting platform on which a recording medium is placed, An ink head having a nozzle for ejecting photocurable ink onto the recording medium placed on the mounting base, and a nozzle surface on which the nozzle is formed, A carriage equipped with the aforementioned ink head and movable in the main scanning direction, The carriage is mounted such that it is located on one side of the main scanning direction from the ink head, and includes a light irradiation device capable of irradiating light toward the photocurable ink ejected onto the recording medium, The aforementioned light irradiation device is LED elements and A case that houses the LED element and has an illumination port that opens downward and emits light emitted from the LED element to the outside, A glass held in the case, which blocks the irradiation opening and allows light irradiated from the LED element to pass through, The case includes a light suppression member that blocks light emitted from the LED element and incident on both end faces of the glass in the main scanning direction, When the length of the light suppression member in the main scanning direction is H, the thickness of the glass is t, the vertical distance from the LED element to the glass is A, and the distances in the main scanning direction from the center of the LED element in the main scanning direction to the inner surfaces of one side and the other side of the case in the main scanning direction are B, H≧Bt / (A+t) An inkjet printer that is set to [this setting].

4. A mounting platform on which a recording medium is placed, An ink head having a nozzle for ejecting photocurable ink onto the recording medium placed on the mounting base, and a nozzle surface on which the nozzle is formed, A carriage equipped with the aforementioned ink head and movable in the main scanning direction, The carriage is mounted such that it is located on one side of the main scanning direction from the ink head, and includes a light irradiation device capable of irradiating light toward the photocurable ink ejected onto the recording medium, The aforementioned light irradiation device is LED elements and A case that houses the LED element and has an illumination port that opens downward and emits light emitted from the LED element to the outside, A glass held in the case, which blocks the irradiation opening and allows light irradiated from the LED element to pass through, The case includes a light suppression member provided in the case, which suppresses the emission of light reflected from both end faces of the glass in the main scanning direction from the case, An inkjet printer in which the light suppression member is located below the glass and extends from the inner surfaces of one and the other sides of the case in the main scanning direction toward the center of the case in the main scanning direction.

5. A mounting platform on which a recording medium is placed, An ink head having a nozzle for ejecting photocurable ink onto the recording medium placed on the mounting base, and a nozzle surface on which the nozzle is formed, A carriage equipped with the aforementioned ink head and movable in the main scanning direction, The carriage is mounted such that it is located on one side of the main scanning direction from the ink head, and includes a light irradiation device capable of irradiating light toward the photocurable ink ejected onto the recording medium, The aforementioned light irradiation device is LED elements and A case that houses the LED element and has an illumination port that opens downward and emits light emitted from the LED element to the outside, A glass held in the case, which blocks the irradiation opening and allows light irradiated from the LED element to pass through, The case includes a light suppression member provided in the case, which suppresses the emission of light reflected from both end faces of the glass in the main scanning direction from the case, The light-suppressing member is provided between the inner surface of the case and the glass in an inkjet printer.

6. The glass has a plurality of glass bodies arranged in the main scanning direction, The inkjet printer according to claim 5, wherein the light-suppressing member is further provided between adjacent glass bodies.

7. The inkjet printer according to claim 6, wherein the upper surface of the glass body is formed in a convex shape.

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