JP2010132007A - Inkjet printer using uv-curable ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet printer using a UV-curable ink, capable of preventing a medium mounted on a platen below a UV-radiation means from deforming by being heated to a high temperature by the UV-radiation means. <P>SOLUTION: In the UV-radiation means 100 disposed above the platen 20, a glass window provided at a lower face of a box 104 for accommodating a UV-lamp 102 is formed in a three-layer structure in which an open-air circulating space 110 is formed between two glass sheets through which ultra-violet rays can pass. The inkjet printer includes an open-air sucking fan 103 for cooling the space inside the box 104 with fresh air and an open-air circulating means 120 for circulating the cooling fresh air over inside and outside the open-air circulating space 110. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In the present invention, UV (ultraviolet ray) curing ink droplets (ink droplets that cure when irradiated with ultraviolet rays) ejected from an inkjet head and landed on the surface of a medium mounted on the platen The present invention relates to an ink jet printer using a UV curable ink of a type in which ultraviolet rays are irradiated from a UV irradiation means arranged in the head and the ink droplets are cured and fixed to a medium.

  As shown in FIG. 7, the upper side of the medium (recording medium) 50 mounted on the platen 20 is arranged on the lower surface of the inkjet head 30 that moves relatively in the XY (vertical and horizontal) directions substantially parallel to the surface of the platen 20. An ink jet printer that ejects UV curable ink droplets from a nozzle (not shown) toward the surface of the medium 50 is well known.

  In this printer, UV irradiation means 100 is disposed above the platen 20 for irradiating the ink droplets ejected from the inkjet head 30 and landing on the surface of the medium 50 with ultraviolet rays to cure the UV ink droplets. ing. Then, the UV irradiating means 100 irradiates the UV curable ink droplets which are ejected and landed by the ink jet head 30 on the surface of the medium 50 mounted on the platen, and the UV ink droplets are instantly cured. I am letting. Then, the UV ink droplet is fixed on the medium 50. Then, the UV ink droplets that have landed on the surface of the medium 50 are prevented from penetrating into the medium 50 portion around the landed portion so that a blurred ink dot having a large diameter is formed on the surface of the medium 50. Yes.

As shown in FIG. 7, the UV irradiation means 100 has a structure in which a UV lamp 102 that generates ultraviolet rays is housed in a box 104, and passes through a glass window 106 that opens on the lower surface of the box 104. Ultraviolet rays emitted from 102 are irradiated onto ink droplets that have landed on the surface of the medium 50 mounted on the platen 20 below the box 104.
The UV irradiation means 100 is integrated with the inkjet head 30 and moves above the platen 20 in the Y direction (lateral direction, the front and back direction in the drawing) substantially parallel to the surface of the platen 20, or the inkjet head Independent of 30, the upper part of the platen 20 is moved in the Y direction (lateral direction, the front and back direction in the figure) substantially parallel to the surface of the platen 20.
On the other hand, the medium 50 mounted on the platen 20 is sandwiched between a pinch roller 94 and a feed roller 92 that are disposed so as to face the upper and lower sides of the upper surface of the platen 20. Is moved in the X (vertical) direction, which corresponds to the rotation direction of the feed roller 92.
Then, the inkjet head 30 and the UV irradiation means 100 are moved in the Y direction integrally or separately from each other, or the feed roller 92 is rotated so that the medium 50 mounted on the platen 20 is moved over the platen 20 X. The inkjet head 30 and the UV irradiation means 100 can be moved relative to each other in the X-Y direction above the medium 50 mounted on the platen 20 either integrally or separately. It is configured to be able to.

According to the ink jet printer equipped with the UV irradiation means 100, the UV curable ink droplets that are ejected and landed on the surface of the medium 50 from the ink jet head 30 permeate widely into the medium 50 portion around the landed portion. Thus, on the surface of the medium 50, it is possible to print a sharp and clear picture or / and character which is composed of an array of a plurality of small-diameter ink dots and has no bleeding.
In addition, according to the ink jet printer provided with the UV irradiation means 100, pictures or / and characters are placed on the surface of various media 50 such as a plastic sheet, a metal plate, a glass plate, paper, cloth, etc. Direct printing is possible without forming an ink receiving layer.

JP2003-200244A JP 2003-127338 A

However, in the ink jet printer using the UV curable ink provided with the UV irradiation means 100, the medium 50 for printing the picture or / and the character is heat resistant such as PET resin film, polycarbonate resin film, acrylic resin film. In the case of using a medium having no property, the medium 50 is subjected to radiant heat or the like emitted from the UV irradiation means 100 and is heated to a high temperature to be deformed.
Specifically, there is only a small gap of about 10 mm between the glass window 106 on the lower surface of the box 104 in which the UV lamp 102 is accommodated and the surface of the platen 20 immediately below the glass window 106. The reason for this is that much of the ultraviolet rays emitted from the glass window 106 on the lower surface of the box 104 are efficiently and accurately irradiated onto the surface of the medium 50 mounted on the platen 20 below it without leaking outside. It is. On the other hand, the temperature of the glass window 106 on the lower surface of the box is heated to a high temperature by the UV lamp 102 that emits ultraviolet rays while emitting high heat of about 400 ° C. Further, in order to reduce the size of the UV irradiation means 100, the space in the box 104 in which the UV lamp 102 is accommodated is formed narrow, and the distance between the UV lamp 102 and the glass window 106 on the lower surface of the box 104 is small. In a short state, the glass window 106 on the lower surface of the box 104 is heated to a high temperature of about 200 to 300 ° C. by the UV lamp 102 emitting ultraviolet rays. Therefore, the medium 50 mounted on the platen 20 positioned below the glass window 106 is heated to a high temperature by the UV irradiation means 100 and deformed.
As a result, the picture or / and the character printed on the surface of the medium 50 are also displaced or distorted, and the quality of the medium 50 on which the picture or / and the character is printed is greatly reduced. .

  The present invention is a UV curable type capable of solving such problems, and preventing the media mounted on the platen below the UV irradiation means from being heated and deformed by the UV irradiation means. It is an object of the present invention to provide an ink jet printer using the above ink (hereinafter referred to as an ink jet printer).

In order to achieve the above object, a first ink jet printer of the present invention comprises:
The glass window on the lower surface of the box in which the UV lamp of the UV irradiation means arranged above the platen is housed is formed in a three-layer structure in which a vacuum layer is interposed between two upper and lower glass plates through which ultraviolet rays can pass. It is said.

  In the first ink jet printer having such a configuration, the glass window on the lower surface of the box in which the UV lamp of the UV irradiation means is accommodated emits ultraviolet rays while emitting high heat between the upper and lower glass plates through which ultraviolet rays can pass. It has a three-layer structure in which a vacuum layer is difficult to transmit radiant heat generated from the UV lamp inside. Therefore, it is possible to greatly reduce the radiant heat that leaks from the UV lamp emitting radiation to the lower side of the box through the glass window having the three-layer structure, which is blocked by the vacuum layer. Then, it is possible to prevent the media mounted on the platen below the UV irradiation means from being heated to a high temperature and deformed by radiant heat leaking down the box through the glass window.

In order to achieve the above object, the second ink jet printer of the present invention includes:
The glass window on the lower surface of the box containing the UV lamp of the UV irradiation means arranged above the platen is formed in a three-layer structure in which an outside air circulation space is provided between two upper and lower glass plates through which ultraviolet rays can pass. An outside air circulating means for circulating outside air for cooling is provided over the inside and outside of the outside air circulation space between the upper and lower glass plates.

  In the second ink jet printer having such a configuration, the glass window on the lower surface of the box in which the UV lamp of the UV irradiation means is accommodated is provided with an outside air circulation space between two upper and lower glass plates through which ultraviolet rays can pass. It has a three-layer structure, and has a structure in which the outside air for cooling is circulated by the outside air circulation means over the inside and outside of the outside air circulation space. For this purpose, using the outside air for cooling that circulates in and out of the outside air circulation space, through the glass window having the three-layer structure, ultraviolet rays are emitted from the UV lamp that emits ultraviolet rays while emitting high heat inside the box. The radiant heat that leaks out can be greatly reduced. Then, it is possible to prevent the media mounted on the platen below the UV irradiation means from being heated to a high temperature and deformed by radiant heat leaking down the box through the glass window.

  In the first and second ink jet printers of the present invention, it is preferable to use infrared cut glass for at least one of the upper and lower glass plates constituting the glass window on the lower surface of the box.

  In such a case, the infrared rays emitted from the UV lamp generating ultraviolet rays leak through the glass window on the lower surface of the box to the lower side of the box by the glass plate made of infrared cut glass constituting the glass window. Can be prevented almost perfectly. And, through the glass window, radiant heat due to infrared rays emitted from the UV lamp leaks below the box, and the media mounted on the platen below the box is heated to a high temperature by the radiant heat of the infrared rays, Deformation can be surely prevented.

  According to the first and second ink jet printers of the present invention, through the glass window on the lower surface of the box in which the UV lamp of the UV irradiating means is housed, ultraviolet rays are emitted from the UV lamp that emits ultraviolet rays while emitting high heat in the box. Leakage of radiant heat can be greatly reduced. And it can prevent reliably that the medium mounted on the platen under UV irradiation means is heated and deform | transformed by the radiant heat etc. which leaks under the box through the glass window.

It is front sectional drawing of UV irradiation means periphery of the 1st inkjet printer of this invention. It is a side view of the UV irradiation means periphery of the 1st inkjet printer of this invention. It is a bottom view of the UV irradiation means of the 1st inkjet printer of this invention. It is front sectional drawing of UV irradiation means periphery of the 2nd inkjet printer of this invention. It is a side view of the UV irradiation means periphery of the 2nd inkjet printer of this invention. It is a bottom view of the UV irradiation means of the 2nd inkjet printer of this invention. It is explanatory drawing which shows schematic structure of the inkjet printer using UV curable ink.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 show a preferred embodiment of the first ink jet printer of the present invention, FIG. 1 is a front sectional view around the UV irradiation means, FIG. 2 is a side view around the UV irradiation means, and FIG. Is a bottom view of the UV irradiation means. The first ink jet printer will be described below.

The first inkjet printer shown in the drawing is a UV that is ejected from nozzles arranged on the lower surface of the inkjet head 30 that moves relative to the XY direction above the platen 20 and landed on the surface of the medium 50 mounted on the platen 20. The curable ink droplets are also irradiated with ultraviolet rays from a UV irradiation means 100 that relatively moves in the XY direction above the platen 20, and the ink droplets are cured and fixed to the medium 50. . Then, the ink droplets fixed on the medium 50 are configured to print a picture or / and a character consisting of an array of a plurality of ink dots on the surface of the medium 50.
As shown in FIG. 1, the UV irradiation means 100 has a structure in which a UV lamp 102 that generates ultraviolet rays is housed in a box 104 having a substantially rectangular box shape, and opens on the lower surface of the box 104. Through the glass window 106, ultraviolet rays emitted from the UV lamp 102 are irradiated onto ink droplets that have landed on the surface of the medium 50 mounted on the platen 20 below the box 104.
As shown by arrows in FIG. 1, outside air is sucked into the inside of the box 104, circulated through the inside of the box 104, and then discharged to the upper side of the box 104. An outside air suction fan 103 is attached to cool the air.
A shutter mechanism 108 is built inside the box 104 near the glass window 106, and ultraviolet rays emitted from the UV lamps 102 accommodated in the box 104 are made to open and close by opening and closing the shutter mechanism 108. Through the glass window 106, ultraviolet rays emitted from the UV lamp 102 are prevented from being emitted through the glass window 106 and below the box 104.

The above configuration is the same as that of the conventional ink jet printer shown in FIG. 7. However, in the first ink jet printer shown in the figure, the UV lamp 102 of the UV irradiation means 100 disposed above the platen 20 is accommodated. Further, the glass window 106 on the lower surface of the box 104 is formed in a three-layer structure in which a vacuum layer 109 that hardly transmits radiant heat is interposed between two upper and lower glass plates 107 through which ultraviolet rays can pass.
Specifically, as shown in FIGS. 1 and 2, the glass window 106 on the lower surface of the box 104 has a side wall 105 made of a glass plate or the like around two transparent upper and lower glass plates 107 through which ultraviolet rays can pass. The inner space having the airtight chamber structure between the two upper and lower glass plates 107 is maintained in a vacuum state.

  The first ink jet printer shown in FIGS. 1 to 3 is configured as described above. In the first ink jet printer, the glass on the lower surface of the box 104 in which the UV lamp 102 of the UV irradiation means 100 is accommodated. Using the vacuum layer 109 interposed between the upper and lower two glass plates 107 through which the ultraviolet rays that constitute the window 106 can pass, the ultraviolet rays in the box 104 are emitted from the UV lamp 102 that is emitting radiation through the glass window 106. Radiant heat and the like that leak out below the box 104 can be greatly reduced. Then, it is possible to prevent the medium 50 mounted on the platen 20 below the UV irradiation unit 100 from being heated to a high temperature and deformed due to radiant heat leaking below the box 104 through the glass window 106.

  4 to 6 show a preferred embodiment of the second ink jet printer of the present invention, FIG. 4 is a front sectional view around the UV irradiation means, FIG. 5 is a side view around the UV irradiation means, and FIG. Is a bottom view of the UV irradiation means. The second ink jet printer will be described below.

In the second ink jet printer shown in the drawing, the glass window 106 on the lower surface of the box 104 in which the UV lamp 102 of the UV irradiation means 100 disposed above the platen 20 is accommodated, as shown in FIGS. Is formed in a three-layer structure in which an outside air circulation space 110 is provided between two upper and lower glass plates 107 through which air can pass. At the same time, an outside air circulating means 120 for circulating outside air for cooling over the inside and outside of the outside air circulation space 110 between the upper and lower glass plates 107 is provided.
Specifically, as indicated by arrows in FIG. 4, the outside air for cooling is circulated on the upper surface of the box 104 between the upper and lower glass plates 107 constituting the glass window 106 on the lower surface of the box 104. After being sucked into the outside air circulation space 110 from one open end 112 of the space 110 and circulated inside the outside air circulation space 110, the other opening end 114 of the outside air circulation space 110 is moved above the box 104. An outside air exhaust fan 122 is attached for discharge. The periphery of the outside air exhaust fan 122 and the other open end 114 of the outside air circulation space 110 between the two upper and lower glass plates 107 are connected by a duct 116. A structure in which the outside air circulated inside the outside air circulation space 110 between the two upper and lower glass plates 107 through the inside of the duct 116 is discharged to the upper side of the box 104 from the other opening end 114 of the outside air circulation space 110. I am doing.
The other parts of the second ink jet printer shown in FIGS. 4 to 6 are configured in the same manner as the first ink jet printer shown in FIGS.

  The second ink jet printer shown in FIGS. 4 to 6 is configured as described above. In the second ink jet printer, the glass on the lower surface of the box 104 in which the UV lamp 102 of the UV irradiation means 100 is accommodated. The outside air for cooling that is circulated by the outside air circulation means 120 through the inside and outside of the outside air circulation space 110 provided between the upper and lower glass plates 107 constituting the window 106 is used to pass through the glass window 106. Further, it is possible to greatly reduce the radiant heat and the like that leaks from the UV lamp 102 that emits ultraviolet rays to the lower side of the box 104 while emitting high heat stored in the box 104. Then, it is possible to prevent the medium 50 mounted on the platen 20 below the UV irradiation unit 100 from being heated to a high temperature and deformed due to radiant heat leaking below the box 104 through the glass window 106.

In the first ink jet printer shown in FIGS. 1 to 3 and the second ink jet printer shown in FIGS. 4 to 6, at least one of the upper and lower glass plates 107 constituting the glass window 106 is used. An infrared cut glass is preferably used for the glass plate 107.
In such a case, the infrared rays emitted from the UV lamp 102 that emits ultraviolet rays while emitting high heat leak through the glass window 106 on the lower surface of the box 104 to the lower side of the box 104 to constitute the glass window 106. It is possible to prevent the glass plate 107 made of infrared cut glass from being nearly 100%. Through the glass window 106, the radiant heat generated by the infrared rays emitted from the UV lamp 102 leaks out below the box 104, and the medium 50 mounted on the platen 20 below the box 104 is caused by the infrared radiant heat. It can be surely prevented from being deformed by being heated to a high temperature.

In the first and second ink jet printers of the present invention, UV curable ink droplets ejected from an ink jet head and landed on the surface of a medium mounted on the platen, from UV irradiation means disposed above the platen, The present invention can be widely used in ink jet printers that irradiate ultraviolet rays through a glass window on the lower surface of the means to cure the ink droplets and fix them on a medium.
The first and second ink jet printers of the present invention are so-called flat beds in which a medium is mounted on a flat bed and the ink jet head is moved in the X and Y directions above the medium mounted on the bed. It can also be used for types of ink jet printers.

20 Platen 30 Inkjet head 50 Media 100 Irradiation means 102 UV lamp 103 Outside air suction fan 104 Box 106 Glass window 107 Glass plate 108 Shutter mechanism 109 Vacuum layer 110 Outside air circulation space 120 Outside air circulation means 122 Outside air discharge fan

Claims (2)

Ultraviolet rays generated from a UV lamp housed in a box of UV irradiation means arranged above the platen pass through a glass window provided on the lower surface of the box, and ink jet on the surface of the media mounted on the platen located below the box In an ink jet printer that irradiates a UV curable ink droplet ejected from a head and lands, and cures the ink droplet to fix it on a medium.
The glass window on the lower surface of the box is formed in a three-layer structure in which an outside air circulation space is provided between two upper and lower glass plates through which ultraviolet rays can pass.
The inkjet printer is
An outside air suction fan for cooling the box inner space with outside air;
An outside air circulation means for circulating outside air for cooling over the inside and outside of the outside air circulation space,
The outside air suction fan sucks outside air inside the box, circulates through the inside space of the box, and then discharges it above the box.
The outside air circulation means includes
An outside air exhaust fan provided adjacent to the box above the box;
A duct communicating the periphery of the outside air discharge fan and the other open end of the outside air circulation space;
After the outside air discharge fan sucks the outside air for cooling from the one open end of the outside air circulation space into the outside air circulation space and circulates the inside of the outside air circulation space, the other opening end of the outside air circulation space The ink jet printer is characterized in that it is discharged above the box through a duct communicating with the open end.   2. The ink jet printer according to claim 1, wherein the duct has a shape in which a cross-sectional area of a horizontal cross section increases as it goes upward.

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