JP2011037025A - Ultraviolet irradiation device for inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation device for an inkjet recorder which restricts adhesion of ink to a light emission surface and failure of a cooling fan. <P>SOLUTION: The ultraviolet irradiation device 1 for the inkjet recorder 20 includes a light source which is arranged adjacent to a recording head 21 for ejecting the ink to be cured by ultraviolet rays to a recording medium 30 and irradiates ultraviolet rays to cure the ink ejected to the recording medium 30, a cover member 5 which holds the light source, and cooling fans 4 which are set on the cover member 5 and cool another surface 2b opposite to one surface that emits the ultraviolet rays in the light source by sucking the air from openings 3 formed in the cover member 5. The light source is an ultraviolet LED 2, and the cover member 5 has a restricting part 6 which restricts generation of a flow of the air from the recording head 21 on the side of the light emission surface 1a that emits the ultraviolet rays from the ultraviolet LED 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation device for an ink jet recording apparatus that cures ink discharged from a recording head that discharges ink onto a recording medium by irradiation of ultraviolet rays.

  Conventionally, ink droplets are ejected from a recording head onto a recording medium made of various materials such as paper, cloth, synthetic resin such as acrylic resin and expanded polystyrene, metal, glass and wood, and characters, figures, symbols, etc. are recorded. An ink jet recording apparatus for recording on a medium is known.

  Here, if the ink jet recording apparatus can shorten the curing time of the ink ejected to the recording medium, it can prevent color mixing due to ink bleeding on the recording medium and mixing of ink droplets on the recording medium, and recording quality. Can be increased. Therefore, as an ink jet recording apparatus, ink that is cured by irradiation of ultraviolet rays is used as ink that is ejected from the recording head, and the ink on the recording medium is irradiated with ultraviolet rays from the ultraviolet irradiation apparatus provided in the ink jet recording apparatus, thereby setting the ink curing time. Some have been shortened.

  An ink jet recording apparatus equipped with this type of ultraviolet irradiation device is capable of diffusing and recording ink on a recording medium even when a recording medium in which ink penetrates deep inside or a recording medium with poor ink absorption is used. The ink can be cured in a short time before mixing between ink droplets on the medium, and a clear image can be obtained. In addition, since the time from the ink adhering to the recording medium until the ink is cured can be shortened, even when a plurality of recording media discharged with ink are stacked or rolled up, It is possible to prevent the ink from being transferred to the back surface due to the uncured ink.

  By the way, in an ink jet recording apparatus equipped with an ultraviolet irradiation device, in order to minimize the time from the ejection of ink droplets to a recording medium until the ink is cured, a recording head for ejecting ink, It is desirable to arrange the ultraviolet irradiation device for curing as close as possible.

  However, an ultraviolet irradiation device for an ink jet recording apparatus uses a low-pressure mercury lamp or the like as a light source for irradiating ultraviolet rays, and generates heat when irradiated with ultraviolet rays. The heat generated by the ultraviolet irradiation device not only deteriorates the light output characteristics of the low-pressure mercury lamp that irradiates ultraviolet rays, but also thermally deforms the recording medium irradiated with ultraviolet rays, or causes the ink in the nozzles of the adjacent recording heads. It may cause clogging.

  Therefore, the ultraviolet irradiation device 1 for the ink jet recording apparatus 20 shown in FIG. 5 is disposed adjacent to the recording head 21 that discharges the ink cured by the ultraviolet rays to the recording medium 30, and cures the ink discharged to the recording medium 30. A low-pressure mercury lamp 12 is used as a light source for irradiating ultraviolet rays. In this ultraviolet irradiation device 1, a cover member 5 that houses a low-pressure mercury lamp 12, and the other surface side of the low-pressure mercury lamp 12 provided on the cover member 5 opposite to the one surface that emits ultraviolet light from the low-pressure mercury lamp 12. Is provided with an air cooling fan 4 that cools air by sucking air from an opening 3 (not shown in FIGS. 5A and 5C) provided in the cover member 5 (for example, Patent Document 1).

  In the ink jet recording apparatus 20 shown in FIG. 5C, a main body including the recording head 21 and the ultraviolet irradiation device 1 is attached to a support base 27. Further, the recording head 21 and the ultraviolet irradiation device 1 are fixed to a carriage 24, and the carriage 24 is configured to be movable along a guide rail 25. The transport unit 26 is configured to be able to transport the recording medium 30 in a direction orthogonal to the guide rail 25. The ink stored in the ink supply tank 28 and cured by ultraviolet rays is supplied to the recording head 21 via the intermediate tank 23 and the ink supply pipe 22 shown in FIG.

  A protective member 5c that protects the low-pressure mercury lamp 12 is provided on the light emitting surface 1a side that emits ultraviolet rays from the low-pressure mercury lamp 12 shown in FIG. 5B, and a rod-like support attached to the cover member 5 is provided. It is supported by the member 5b. In addition, a plurality of first openings 3 a of the openings 3 are provided on each side wall 5 a of the cover member 5, and the second openings 3 b are formed between the cover member 5 and the support member 5 b. It is formed between. Further, an air cooling fan 4 ′ for cooling a base (not shown) of the low pressure mercury lamp 12 is separately provided in order to stabilize the light emission characteristics of the low pressure mercury lamp 12.

JP 2005-125752 A

  In recent years, high-power ultraviolet light-emitting diodes (hereinafter referred to as ultraviolet LEDs) capable of emitting light in the ultraviolet region have been developed and put into practical use as light sources for irradiating ultraviolet rays. The ultraviolet LED is a semiconductor light emitting element, and can be reduced in size as compared with the low-pressure mercury lamp 12 that irradiates the above-described ultraviolet light. Therefore, the ultraviolet LED can be disposed closer to the recording head 21.

  The emission spectrum of the ultraviolet LED is usually narrower than the range of the emission spectrum emitted by the low-pressure mercury lamp 12, and the short-wavelength ultraviolet light (for example, the emission line spectrum of 185 nm, which is unnecessary for ink curing as in the low-pressure mercury lamp 12) ) Is not included. For this reason, ozone is not generated by the short wavelength ultraviolet rays when ultraviolet rays are emitted from the ultraviolet LEDs, and it is not necessary to provide duct equipment for exhausting ozone in the inkjet device 20 or the like. Similarly, the emission spectrum irradiated from the ultraviolet LED usually does not include the infrared region. Therefore, the recording medium 30 or the like is not basically heated by the irradiation light from the ultraviolet LED, and deformation of the recording medium 30 is small.

By the way, the ink ejected from the recording head 21 may adhere to the light emitting surface 1a of the ultraviolet irradiation device 1 along with the intake of the air cooling fan 4 that air-cools the light source of the ultraviolet irradiation device 1.
In particular, when ink having a low surface tension is used, part of the ink ejected from the recording head 21 may be scattered as mist-like ink particles. Unlike the ink that is directly ejected from the recording head 21, such mist-like ink particles float in the air, so that the floating mist-like ink particles are on the light emitting surface 1 a of the ultraviolet irradiation device 1. It tends to adhere. When the low-pressure mercury lamp 12 is used as the light source of the ultraviolet irradiation device 1, the area of the light exit surface 1a is relatively large, and ink adhesion is unlikely to be a problem in a short time.

  However, when an ultraviolet LED is used instead of the low-pressure mercury lamp 12 as the light source of the ultraviolet irradiation device 1 for the ink jet recording apparatus 20, it is smaller than the light emitting surface 1a of the ultraviolet irradiation device 1 using the low-pressure mercury lamp 12. The ink tends to be easily affected by the adhered ink. That is, in the ultraviolet irradiation device 1 for the ink jet recording apparatus 20 using the ultraviolet LED, when ink adheres to the light emitting surface 1a, not only the dirt on the light emitting surface 1a but also the ink which has been adhered and cured blocks the ultraviolet light. In some cases, the ink on the recording medium 30 cannot be sufficiently cured. Therefore, there is a problem that uncured ink remains attached to the recording medium 30. The ink adheres to the light emitting surface 1a of the ultraviolet irradiation device 1 using such an ultraviolet LED, as well as being unable to irradiate the recording medium 30 with ultraviolet rays, and also uncured newly adhering to the light emitting surface 1a. The recording medium 30 may become dirty with ink.

  In particular, when the recording head 21 and the ultraviolet irradiation device 1 are arranged closer to each other, or when the suction force from the air cooling fan 4 is increased in order to enhance the cooling effect of the ultraviolet irradiation device 1, the opening portion By inhaling air from 3, the flight of ink ejected from the recording head 21 is disturbed and scattered, and ink adhesion on the light emitting surface 1a of the ultraviolet irradiation device 1 tends to become a problem. Further, the ink ejected from the recording head 21 may adhere to the air cooling fan 4, which may cause a failure of the air cooling fan 4.

  The present invention has been made in view of the above-described reasons, and an object of the present invention is for an ink jet recording apparatus that suppresses adhesion of ink to a light emitting surface that emits ultraviolet light from an ultraviolet LED and failure of an air cooling fan. The object is to provide an ultraviolet irradiation device.

  According to a first aspect of the present invention, a light source that is disposed adjacent to a recording head that discharges ink that is cured by ultraviolet rays onto a recording medium and that emits ultraviolet rays that cures the ink ejected onto the recording medium, and the light source are stored. A cover member that is provided on the cover member, and an air cooling fan that air-cools the other surface side opposite to the one surface that emits ultraviolet rays at the light source by sucking air from an opening provided on the cover member; An ultraviolet irradiation device for an inkjet recording apparatus, wherein the light source is an ultraviolet LED, and the cover member is configured to emit air from the ultraviolet LED and emit air from the recording head. It has the suppression part which suppresses that the flow of this occurs.

  According to the present invention, an ultraviolet LED is provided as a light source for curing the ink, and even when the ultraviolet LED is disposed adjacent to the recording head, the ink adheres to the light emitting surface side due to the air cooling of the ultraviolet LED or the air cooling fan. It can be set as the ultraviolet irradiation device which suppresses a failure.

  According to a second aspect of the present invention, in the first aspect of the present invention, the opening is provided on a side wall of the cover member in a direction perpendicular to the light emitting surface.

  According to the present invention, the other surface side of the ultraviolet LED can be efficiently air-cooled with a relatively simple configuration in which an opening is provided in the side wall of the cover member.

  The invention according to claim 3 is the invention according to claim 1, characterized in that the light emitting surface side is provided with a protruding portion that surrounds the one surface of the ultraviolet LED and protrudes from the light emitting surface side. To do.

  According to this invention, by providing the protruding portion protruding from the light emitting surface side, it is possible to further suppress the air flow from the recording head side on the light emitting surface side, and the protruding portion is It is possible to directly prevent the ink from adhering to the light emitting surface side. In addition, it is possible to suppress the diffusion irradiation of the ultraviolet rays emitted from the light emitting surface by the protruding portion, and to prevent the adjacent recording head from being irradiated with unnecessary ultraviolet rays due to reflection on a recording medium. Thereby, the protrusion can suppress the ultraviolet rays from entering the nozzles of the recording head, and can reduce the clogging of the nozzles due to the ink curing.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the air cooling fan is provided on a side wall of the cover member in a direction perpendicular to the light emitting surface.

  According to this invention, since the flow of air along the other surface of the ultraviolet LED can be made relatively easily, the other surface side of the ultraviolet LED can be efficiently air-cooled. Further, since the air cooling fan can be arranged in accordance with the size of the side wall of the cover member regardless of the size of the light emitting surface side, the cooling efficiency can be increased.

  According to a fifth aspect of the present invention, in the first aspect of the present invention, the air cooling fan is provided on the cover member on the side facing the light emitting surface.

  According to this invention, the other surface side of the ultraviolet LED can be air-cooled regardless of the position of the opening. Further, the air cooling fan can be disposed inside the cover member, and the ultraviolet irradiation device can be further downsized.

  The invention of claim 6 is characterized in that, in the invention of claim 1, a rectifying plate is provided for directing the air sucked from the opening to the other surface side of the ultraviolet LED.

  According to the present invention, the air sucked from the opening by the air cooling fan can be rectified by the rectifying plate so as to be directed toward the other surface side of the ultraviolet LED. The side can be efficiently air-cooled.

  In the invention according to claim 1, the air cooling fan cools the air by sucking air from the opening provided in the cover member on the other surface side opposite to the one surface emitting ultraviolet light in the ultraviolet LED, and the cover The member has a suppressing portion that suppresses the generation of the air flow from the recording head side on the light emitting surface side that emits the ultraviolet light from the ultraviolet LED, so that the ultraviolet LED is air-cooled while the ultraviolet light is being cooled. There is a remarkable effect that it is possible to provide an ultraviolet irradiation device for an ink jet recording apparatus in which adhesion of ink to the light emitting surface of the LED and failure of the air cooling fan are suppressed.

2 is a schematic explanatory diagram of an ultraviolet irradiation device for an ink jet recording apparatus according to Embodiment 1. FIG. It is a schematic explanatory drawing of the other ultraviolet irradiation device same as the above. It is a schematic explanatory drawing of the ultraviolet irradiation device for inkjet recording devices of Embodiment 2. It is a schematic explanatory drawing of the ultraviolet irradiation device for inkjet recording devices of Embodiment 3. It is a schematic explanatory drawing of the inkjet recording device provided with the conventional ultraviolet irradiation device.

(Embodiment 1)
Hereinafter, an ultraviolet irradiation apparatus for an ink jet recording apparatus according to this embodiment will be described with reference to FIG.

  The ink jet recording apparatus 20 illustrated in FIG. 1B includes a transport unit 26 including a transport belt that transports a roll-shaped recording medium 30 such as paper in one direction. The ink jet recording apparatus 20 includes an elongate support plate 9 in a direction substantially perpendicular to the conveyance direction of the recording medium 30 (the arrow direction in the drawing) so as to cover the recording medium 30 conveyed by the conveying means 26. The recording head 21 capable of ejecting ink along the longitudinal direction of the support plate 9 is provided and supported in a line shape. The recording head 21 ejects four color inks of yellow (Y), magenta (M), cyan (C), and black (BK), which are cured by ultraviolet rays, from the tip of a nozzle (not shown) to the recording medium 30. be able to. The recording head 21 is provided with an ultraviolet irradiation device 1 that irradiates the ink discharged from the recording head 21 to the recording medium 30 with ultraviolet rays on the downstream side with respect to the conveyance direction of the recording medium 30 conveyed by the conveying means 26. Adjacent and fixed.

  Here, the ultraviolet irradiation device 1 is a substantially rectangular parallelepiped that is long in a direction substantially perpendicular to the conveying direction of the recording medium 30 so as to cover the recording medium 30 conveyed by the conveying means 26, as shown in FIG. As shown in FIG. 5, the cover member 5 made of metal (for example, stainless steel) having a hollow 1b is used. One end surface side of the cover member 5 facing the recording medium 30 is a light emitting surface 1a for irradiating ultraviolet rays. Therefore, the ultraviolet irradiation device 1 has a plurality of ultraviolet LEDs 2 arranged on the one end face side of the cover member 5 along the longitudinal direction of the rectangular parallelepiped, and substantially faces the ultraviolet LEDs 2 arranged on the one end face side. On the other end face side of the rectangular parallelepiped cover member 5, a plurality of (here, four) air cooling fans (for example, fan motors) 4 are arranged along the longitudinal direction of the rectangular parallelepiped.

  Further, the ultraviolet irradiation device 1 is provided with a plurality of openings 3 for taking outside air into the cover member 5 along the longitudinal direction of the rectangular parallelepiped in the cover member 5 by driving the air cooling fan 4. Further, the cover member 5 is provided with doors 10 and 10 which can cover and seal the plurality of openings 3, and the opening 3 on the side adjacent to the recording head 21 is closed by the door 10. . As a result, the air cooling fan 4 sucks air from the opening 3 provided in the vicinity of the ultraviolet LED 2 on the other surface 2b side opposite to the one surface that emits ultraviolet rays in the ultraviolet LED 2, and discharges it from the exhaust port 5d. Air-cooled with. That is, in the ultraviolet irradiation device 1 of the present embodiment, the door 10 that covers the opening 3 on the recording head 21 side serves as the suppressing unit 6 that suppresses the occurrence of air flow from the recording head 21 side on the light emitting surface 1a. Function.

  Moreover, the ultraviolet irradiation device 1 of the present embodiment includes a rectifying plate 7 that efficiently directs the air sucked from the opening 3 toward the other surface 2b side of the ultraviolet LED 2 in the cavity 1b of the ultraviolet irradiation device 1. The rectifying plate 7 includes a flat plate provided along the longitudinal direction of the ultraviolet irradiation device 1 between the other surface 2b side of the ultraviolet LED 2 and the air cooling fan 4 side, and both ends of the flat plate are on the air cooling fan 4 side. The cross-sectional shape is formed into a substantially U-shape by being bent.

  In the ultraviolet irradiation device 1, the door 10 that covers the opening 3 of the side wall 5 a of the cover member 5 that is not adjacent to the recording head 21 is fixed to the side wall 5 a of the cover member 5 and is opened outward. Further, the door 10 that covers the opening 3 of the side wall 5a of the cover member 5 adjacent to the recording head 21 is closed, and serves as a suppressing unit 6 that suppresses the occurrence of air flow from the recording head 21 side. Will work. Therefore, air is taken in by the air-cooling fan 4 from the opening 3 of the side wall 5a of the cover member 5 where the recording head 21 is not adjacent, and at least from the recording head 21 side adjacent to the light emitting surface 1a of the ultraviolet irradiation device 1. The generation of air flow can be suppressed. Therefore, the ultraviolet irradiation device 1 efficiently cools the ultraviolet LED 2 with the air cooling fan 4, while the ink ejected from the adjacent recording head 21 adheres to the light emitting surface 1 a or the air cooling fan 4 is caused by the ink. It is possible to suppress failure.

  Hereinafter, each component used for the ultraviolet irradiation apparatus 1 of this embodiment is explained in full detail.

  The ultraviolet irradiation device 1 of the present embodiment includes a substantially rectangular parallelepiped cover member 5, and includes an opening 3 for taking outside air in the vicinity of the ultraviolet LED 2 with the inside being a cavity 1 b, and is opposed to the ultraviolet LED 2 of the ultraviolet irradiation device 1. On the other end surface side, a plurality of fan motors are provided as the air cooling fan 4 along the longitudinal direction of the ultraviolet irradiation device 1.

  The ultraviolet irradiation device 1 of the present embodiment can be cured and dried instantaneously by irradiating the ink ejected onto the recording medium 30 with ultraviolet rays. Such an ultraviolet irradiation device 1 may use a spot type that irradiates a local range with ultraviolet rays or a line type that irradiates a wide range depending on the structure of the inkjet recording apparatus 20.

  The light source used in the ultraviolet irradiation apparatus 1 is an ultraviolet LED 2 that irradiates ultraviolet rays. For example, a buffer layer made of gallium nitride, an n-type gallium nitride semiconductor layer, a light emitting layer, and a p-type gallium nitride semiconductor layer are MOCVD on a sapphire substrate. It is possible to use a nitride semiconductor light emitting element made of InAlGaN or the like that can be laminated by a method or the like and can emit ultraviolet rays having a light emitting layer having a peak wavelength of about 385 nm. The ultraviolet LED 2 used in this embodiment uses a metal can package in which the nitride semiconductor element is protected, but a plurality of nitride semiconductor light emitting element bare chips are mounted on a mounting substrate. It may be a thing. In addition, the ultraviolet LED 2 may include a convex lens or a concave lens on the exit surface side for the purpose of condensing or diffusing the ultraviolet light emitted by the nitride semiconductor light emitting element.

  The light emitting surface 1 a that emits the ultraviolet rays from the ultraviolet LED 2 of the ultraviolet irradiation device 1 does not necessarily need to be smooth, so that the light emitted from the plurality of ultraviolet LEDs 2 is uniformly irradiated on the recording medium 30. An uneven lens cover may be provided on the surface.

  Furthermore, the ultraviolet LED 2 may further include a cooling fin on the other surface 2b side facing the light emitting surface 1a that emits ultraviolet rays to further improve the cooling efficiency. As a method for improving the cooling efficiency of the ultraviolet LED 2, the structure is complicated, but in addition to the air cooling by the air cooling fan 4, the outside of the ultraviolet LED 2 on the other surface 2b side, the Peltier element using the Peltier effect, the outside of the ultraviolet irradiation device 1, and the refrigerant. It is also possible to thermally connect a heat pump that circulates the gas.

  Further, the ultraviolet irradiation device 1 may be provided with temperature detecting means including a thermistor, a thermocouple, etc., and the temperature of the ultraviolet LED 2 may be measured to control the lighting so that the ultraviolet LED 2 does not rise excessively. When a plurality of ultraviolet LEDs 2 are arranged, the temperature tends to increase due to the heat from the adjacent ultraviolet LEDs 2, so that the lighting may be intermittently controlled while the ultraviolet LEDs 2 are air-cooled. When a plurality of ultraviolet LEDs 2 are provided, the ultraviolet irradiation amount of the ultraviolet LEDs 2 may be individually controlled, or the increase / decrease of the ultraviolet irradiation amount may be controlled simultaneously.

  The opening 3 is preferably provided in the vicinity of the ultraviolet LED 2 of the cover member 5 that protects the ultraviolet LED 2 in order to efficiently cool the ultraviolet LED 2 with air. Here, the vicinity of the ultraviolet LED 2 of the cover member 5 refers to the other surface of the ultraviolet LED 2 in which the air taken in from the opening 3 by driving of the air cooling fan 4 provided in the cover member 5 is accommodated inside the cover member 5. Any position where the 2b side can be air-cooled may be used.

  Therefore, the opening 3 may be provided not only on the side wall 5a of the cover member 5 but also on the light emitting surface 1a, as long as the air taken in from the opening 3 by the air cooling fan 4 is brought into contact with the ultraviolet LED 2. The shape of the opening 3 may be formed in various shapes such as a triangle, a rectangle, a circle, an ellipse, and a ring shape. Further, the size and number of the openings 3 may be appropriately set in consideration of the flow of air for air-cooling the ultraviolet LED 2. When the ultraviolet irradiation device 1 has a highly versatile configuration in which any side wall 5a of the cover member 5 can be attached to and detached from the recording head 21, an opening 3 is provided in each side wall 5a to provide a degree of freedom of installation of the ultraviolet irradiation device 1. It can also be increased.

  The air cooling fan 4 is provided on the cover member 5 of the ultraviolet irradiation device 1, and cools the ultraviolet LED 2 by air sucked from the opening 3 of the ultraviolet irradiation device 1. Such an air cooling fan 4 is, for example, a centrifugal fan that blows air in the centrifugal direction in addition to an axial fan that blows air in the suction direction from the axial direction. A blower such as a mixed flow fan that blows air from a different direction or a cross-flow fan that sucks air from one radial direction of the impeller and blows air from a radial direction that is vertical is appropriately provided according to the shape and structure of the ultraviolet irradiation device 1. That's fine.

  The air-cooling fan 4 of the present embodiment is provided with a substantially rectangular parallelepiped casing as an axial fan, and is provided so that the rotating blades are rotatable inside the casing. The motor is assembled into a single fan motor. In addition, the air cooling fan 4 of the present embodiment is fixedly disposed on the other end surface side of the ultraviolet irradiation device 1 facing the light emitting surface 1 a that emits ultraviolet rays of the ultraviolet irradiation device 1.

  The air cooling fan 4 may perform intake air at all times while the ultraviolet LED 2 of the ultraviolet irradiation device 1 irradiates the ink on the recording medium 30 with ultraviolet rays, and the temperature of the ultraviolet LED 2 may be the recording medium 30 or the ultraviolet LED 2. If there is no thermal adverse effect on the device itself, intake may be intermittently performed to suppress power consumption.

  In addition, the air cooling fan 4 sucks air from the outside to the inside of the ultraviolet irradiation device 1 and air from the ultraviolet irradiation device 1 to the outside in order to cool the ultraviolet LED 2 of the ultraviolet irradiation device 1 as long as ink ejection is not affected. May be alternately repeated. When air is ejected from the ultraviolet irradiation device 1 by the air cooling fan 4, the air cooling fan 4 can also promote curing of the ink ejected onto the recording medium 30. For example, when a water-soluble ultraviolet curable ink containing water, a photopolymerization initiator and a polysynthetic polymer is used as the ultraviolet curable ink, the recording medium 30 in which the ink is discharged from the air cooling fan 4 by cooling the ultraviolet LED 2 is used. The ink can be used for evaporating water in the ink and promoting the curing of the ink by increasing the contents of the apparent photopolymerization initiator and the polysynthetic polymer with respect to the water of the ink.

  The cover member 5 is configured to protect the ultraviolet LED 2 from the outside and to cool the ultraviolet LED 2 using the opening 3 provided in the cover member 5 and the air cooling fan 4. The cover member 5 of the present embodiment is formed in a long and substantially rectangular shape, but may be formed in various shapes such as a cubic shape and a cylindrical shape according to the configuration and shape of the recording head 21 of the inkjet recording apparatus 20. it can. The material of the cover member 5 may be formed using various materials as desired, such as resin as well as metal.

  The cover member 5 of the ultraviolet irradiation device 1 includes a suppression unit 6 that suppresses the occurrence of air flow from the adjacent recording head 21 side on the light emitting surface 1a. The suppression unit 6 only needs to be able to suppress the flow of air from the adjacent recording head 21 side on the light emitting surface 1a of the ultraviolet irradiation device 1 as the ultraviolet LED 2 is air-cooled. Therefore, the entire recording head 21 side adjacent to the cover member 5 of the ultraviolet irradiation device 1 may be configured as the suppressing unit 6, and the opening 3 may not be provided on the recording head 21 side adjacent to the cover member 5.

  The rectifying plate 7 only needs to be able to direct the air sucked from the opening 3 toward the other surface 2b of the ultraviolet LED 2, and does not necessarily need to be a flat plate. Therefore, the rectifying plate 7 may be provided with unevenness on the surface facing the other surface 2 b side of the ultraviolet LED 2.

  The recording head 21 disposed adjacent to the ultraviolet irradiation device 1 only needs to be able to eject ink that is cured by ultraviolet rays onto the recording medium 30. As an ink jet method, for example, a piezoelectric element is disposed at the tip of a nozzle, to the piezoelectric element. A piezoelectric jet that discharges ink by applying pressure to the ink in the nozzle, and a thermal jet that discharges the ink in the nozzle by generating bubbles caused by resistance heating using the resistance provided at the tip of the nozzle There are methods, etc., which may be used as appropriate according to the application.

  The ink cured by the ultraviolet rays from the ultraviolet irradiation device 1 of the present embodiment includes, for example, a polymerizable compound such as a radical polymerizable compound or a cationic polymerizable compound as a main component, a photopolymerization initiator, a dye or a pigment, and the like. Ink containing a coloring material can be used. Further, the color and number of ink used in the inkjet recording apparatus 20 may be appropriately used as desired. For example, only black (BK) may be used, or yellow (Y), magenta (M), and cyan (C 4) and inks of four or more colors can be used.

  The recording medium 30 recorded by the inkjet recording apparatus 20 includes various papers such as plain paper, recycled paper and glossy paper, various fabrics and various non-woven fabrics, synthetic resins such as acrylic resin and expanded polystyrene, metal, glass, A recording medium 30 made of a material such as wood can be used. Moreover, since the inkjet recording apparatus 20 provided with the ultraviolet irradiation apparatus 1 of the present embodiment can be downsized, the recording medium 30 is not limited to a planar shape such as a roll shape, a cut sheet shape, or a plate shape. In addition, various three-dimensional shapes such as a rectangular parallelepiped shape and a cylindrical shape can be used.

  In the inkjet recording apparatus 20 including the ultraviolet irradiation device 1 according to the present embodiment, the recording medium 30 is moved relative to the line-shaped recording head 21 and the ultraviolet irradiation device 1 by the conveying unit 26. Another configuration may be used as long as the ink can be discharged and cured on the recording medium 30. For example, similarly to the conventional example shown in FIG. 5, the recording head 21 and the ultraviolet irradiation device 1 are each spot-shaped fixed to the carriage 24, and the carriage 24 runs along the guide rail 25 in a direction orthogonal to the conveyance direction of the recording medium 30. May be moved and printed continuously in combination with the conveyance of the recording medium 30. When color printing is performed by the ink jet recording apparatus 20, the recording head 21 and the ultraviolet irradiation apparatus 1 including a set of ink tanks of yellow (Y), magenta (M), cyan (C), and black (BK) are used. What is necessary is just to mount in the carriage 24 which can be attached or detached.

  In particular, since the ultraviolet irradiation device 1 of the present embodiment cools the ultraviolet LED 2 only by air cooling by the air cooling fan 4, for example, the structure is simpler than that in which the ultraviolet LED 2 is cooled by circulation of the refrigerant. Since it can be configured, it can be usefully applied when the above-described ultraviolet irradiation device 1 is mounted on the carriage 24 and moved.

  Next, the process of recording ink on the recording medium 30 using the inkjet apparatus 20 provided with the ultraviolet irradiation apparatus 1 of the present embodiment will be described.

  In the inkjet recording apparatus 20, for example, based on print data to be recorded on the recording medium 30, a control device (not shown) including a computer having an appropriate program controls lighting of the ultraviolet LED 2 of the ultraviolet irradiation device 1. An ultraviolet LED control circuit (not shown), a recording head control circuit (not shown) for controlling the ejection of ink from the recording head 21, and an air cooling fan control circuit (not shown) for controlling the air cooling fan 4 of the ultraviolet irradiation device 1. And a transport control circuit (not shown) for controlling the transport means 26 for transporting the recording medium 30.

  The ink jet recording apparatus 20 causes ink to be ejected from the recording head 21 to the recording medium 30 in response to a command from the control apparatus. Next, after the ink is ejected, the recording medium 30 is transported from the recording head 21 side to the ultraviolet irradiation device 1 side by the transport means 26 in accordance with a command from the control device. Subsequently, a desired image or the like can be formed by irradiating the recording medium 30 on which the ink has been ejected with ultraviolet rays from the ultraviolet LED 2 of the ultraviolet irradiation device 1 to cure the ink.

  The ultraviolet LED control circuit may control lighting and extinguishing of the ultraviolet LED 2 of the ultraviolet irradiation device 1 according to the amount of ink ejected from the recording head 21 and the ejection position. As a result, the power consumption can be reduced without irradiating the recording medium 30 with unnecessary ultraviolet rays, and the ink on the recording medium 30 can be cured. The UV LED 2 can be controlled not only by turning on and off the UV LED 2 but also by viewing the UV LED 2 to control the UV irradiation amount.

  Specifically, if the amount of ink ejected from the recording head 21 is large, the ultraviolet LED 2 can be controlled to light for a longer time or to increase the light output than when the amount of ink is smaller. Further, the ultraviolet irradiation device 1 can also suppress the light output of the ultraviolet LED 2 corresponding to the portion of the recording medium 30 where the ink is not ejected. The air cooling fan 4 of the ultraviolet irradiating device 1 is driven and controlled by the air cooling fan control circuit while the ultraviolet LED 2 is lit, while suppressing the flow of air from the recording head 21 side on the light emitting surface 1a side. The ultraviolet LED 2 is air-cooled. The ultraviolet irradiation device 1 may control the air cooling fan 4 while detecting the temperature by a temperature detection means (not shown) so that the temperature of the ultraviolet LED 2 does not exceed the operating temperature.

  FIG. 2 shows an example of another ultraviolet irradiation device 1 of this embodiment.

  In the ultraviolet irradiation device 1 shown in FIG. 2A, the suppressing unit 6 is configured using the entire recording head 21 side adjacent to the cover member 5, and an opening is formed on the recording head 21 side adjacent to the cover member 5. 3 is not provided. Here, the air cooling fan 4 is arranged in the vicinity of the ultraviolet LED 2 inside the cover member 5.

Further, in the ultraviolet irradiation device 1 shown in FIG. 2B, all the openings provided in the cover member 5 provided on the side wall 5 a of the cover member 5 with the suppressing portion 6 in contact with the cover member 5 and one end. 3 is configured using a door 10 that closes 3. When the ultraviolet LED 2 is air-cooled by the air-cooling fan 4 of the ultraviolet irradiation unit 1, the adjacent door 10 on the recording head 21 side may block the opening 3 to be the suppressing unit 6 and open the other doors 10. Here, the opening direction of the door 10 is a hinged door that opens to the light emitting surface 1a side so as to take in air from the light emitting surface 1a side. In addition,
The air cooling fan 4 is disposed on the other end surface side of the cover member 5 facing the light emitting surface 1 a inside the cover member 5.

  In the ultraviolet irradiation device 1 shown in FIG. 2C, the opening direction of the door 10 is made to take in air from the air cooling fan 4 side facing the light emitting surface 1a, and the influence of the air flow on the light emitting surface 1a side is affected. Less.

  In any configuration of the ultraviolet irradiation device 1, the ultraviolet irradiation device 1 for the ink jet recording apparatus 20 that suppresses the adhesion of ink to the light emitting surface 1 a of the ultraviolet LED 2 or the failure of the air cooling fan 4 while cooling the ultraviolet LED 2 with air. It can be.

(Embodiment 2)
Since the basic configuration of the ultraviolet irradiation device 1 for the inkjet recording apparatus 20 of the present embodiment is the same as that of the first embodiment, the characteristic parts will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The ultraviolet irradiation device 1 of the present embodiment is a substantially rectangular parallelepiped cover member instead of providing the air cooling fan 4 on the other end surface side of the ultraviolet irradiation device 1 substantially parallel to the other surface 2b side of the ultraviolet LED 2 as in the first embodiment. 5 is different in that the air cooling fan 4 is arranged on the side wall 5a.

  The ultraviolet irradiation device 1 of the present embodiment is configured by using a substantially rectangular parallelepiped cover member 5 having a hollow 1b inside, and one end surface side of the substantially rectangular parallelepiped cover member 5 emits ultraviolet light from the ultraviolet LED 2. The light exit surface 1a is used. In the ultraviolet irradiation device 1, the other end surface side of the rectangular parallelepiped cover member 5 facing the ultraviolet LED 2 disposed on the one end surface side forms a discharge port 5 d for discharging air from the air cooling fan 4 to the outside.

  Further, the ultraviolet irradiation device 1 includes an air cooling fan 4 in the vicinity of the side surface 5a of the cover member 5 in the direction perpendicular to the light emitting surface 1a and on the other surface 2b side of the ultraviolet LED 2. That is, the air cooling fan 4 is provided so as to cover the opening 3 provided in the side wall 5a of the cover member 5, and the air is sucked into the cover member 5 by rotating the wings of the air cooling fan 4, so that the cover By discharging from the discharge port 5d of the member 5, the other surface 2b side of the ultraviolet LED 2 is air-cooled.

  The cavity 1b inside the ultraviolet irradiation device 1 is provided with a rectifying plate 7 for efficiently directing the air sucked by the air cooling fan 4 to the other surface 2b side of the ultraviolet LED 2 toward the other surface 2b side of the ultraviolet LED 2. Yes.

  The ultraviolet irradiation device 1 of the present embodiment suppresses the air flow from at least the adjacent recording head 21 side on the light emitting surface 1a, so that there is no opening 3 on the adjacent recording head 21 side and the cover member 5. The side wall 5a is closed to form a restraining portion 6, and the air cooling fan 4 is not provided. In the ultraviolet irradiation device 1, air is taken in by the air-cooling fan 4 from the opening 3 of the side wall 5 a of the cover member 5 not adjacent to the recording head 21, and at least the recording head adjacent to the light emitting surface 1 a of the ultraviolet irradiation device 1. The occurrence of the air flow from the 21 side can be suppressed. Therefore, the ultraviolet irradiation device 1 allows the other surface 2b side of the ultraviolet LED 2 to be efficiently air-cooled by the air cooling fan 4, while the ink ejected from the adjacent recording head 21 adheres to the light emitting surface 1a or the air cooling fan. 4 can be prevented from being damaged by ink.

  The ultraviolet irradiation device 1 of this embodiment forms an air flow along the other surface 2b side of the ultraviolet LED 2 to easily cool the ultraviolet LED 2 and improve the cooling efficiency.

  The air cooling fan 4 in the ultraviolet irradiation device 1 of the present embodiment has the air cooling fan 4 attached to the outside of the side wall 5a of the cover member 5. However, if the air cooling fan 4 is small and the other surface 2b side of the ultraviolet LED 2 can be air cooled, the ultraviolet light is cooled. You may arrange | position inside the irradiation apparatus 1. FIG.

(Embodiment 3)
Since the basic configuration of the ultraviolet irradiation apparatus 1 for the inkjet recording apparatus 20 of the present embodiment is the same as that of the first embodiment, the characteristic parts will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The ultraviolet irradiation device 1 of the present embodiment is different from the first embodiment in that the opening 3 is provided on the side wall 5a of the cover member 5 in the vicinity of the other surface 2b side of the ultraviolet LED 2, instead of providing the opening 3 on the light emitting surface 1a side of the ultraviolet irradiation device 1. The light emitting surface 1a is different from the light emitting surface 1a in that the light emitting surface 1a includes a protruding portion 8 that surrounds one surface of the ultraviolet LED 2 and protrudes from the light emitting surface 1a.

  The ultraviolet irradiation device 1 of this embodiment is provided with openings 3 and 3 between the end of the ultraviolet irradiation device 1 and the ultraviolet LED 2 when the light emission surface 1a is viewed from the front.

  The other end surface side of the substantially rectangular parallelepiped cover member 5 facing the ultraviolet LED 2 is provided with an air cooling fan 4, and air is sucked from the opening 3 on the light emitting surface 1a side to the other end surface side by the air cooling fan 4. To do. Further, the opening 3 provided on the light emitting surface 1a side of the ultraviolet irradiation device 1 suppresses the flow of air from at least the adjacent recording head 21 side on the light emitting surface 1a. The door 10 covering the opening 3 is closed to form the restraining portion 6. Therefore, in the ultraviolet irradiation device 1, outside air is taken in by the air cooling fan 4 from the opening 3 in the light emitting surface 1 a where the recording head 21 is not adjacent.

  In particular, the ultraviolet irradiation device 1 according to the present embodiment includes a protruding portion 8 that surrounds the one surface of the ultraviolet LED 2 and protrudes from the light emitting surface 1a side on the light emitting surface 1a side. Further, the occurrence of the air flow from at least the adjacent recording head 21 side on the emission surface 1a is further suppressed. Therefore, in the ultraviolet irradiation device 1, while the ultraviolet LED 2 is efficiently air-cooled by the air cooling fan 4, the ink discharged from the adjacent recording head 21 adheres to the light emitting surface 1a or the air cooling fan 4 is caused by the ink. It is possible to suppress failure.

  Such a protrusion 8 only needs to be able to prevent the ink from adhering to the light emitting surface 1a of the ultraviolet irradiation device 1, and is not necessarily formed in a plate shape. Further, the material of the protruding portion 8 may be formed of metal, synthetic resin, glass, or a porous sponge that can absorb ink so that unnecessary ink can be easily attached. Note that the height of the protruding portion 8 may be appropriately set in consideration of the suction force of the air cooling fan 4 and the distance from the recording medium 30.

DESCRIPTION OF SYMBOLS 1 Ultraviolet irradiation device 1a Light emission surface 2 Ultraviolet LED
2b Other surface 3 Opening portion 4 Air cooling fan 5 Cover member 5a Side wall 6 Suppressing portion 7 Current plate 8 Protruding portion 20 Inkjet recording device 21 Recording head 30 Recording medium

Claims (6)

A light source that is disposed adjacent to a recording head that discharges ink that is cured by ultraviolet rays to a recording medium and that irradiates ultraviolet rays that cures the ink discharged to the recording medium, a cover member that houses the light source, and the cover For an inkjet recording apparatus, comprising: an air cooling fan provided on a member for air cooling by sucking air from an opening provided on the cover member on the other surface opposite to the one surface that emits ultraviolet rays in the light source An ultraviolet irradiation device of
The light source is an ultraviolet LED, and the cover member includes a suppressing unit that suppresses the occurrence of the air flow from the recording head side on a light emitting surface side that emits ultraviolet rays from the ultraviolet LED. An ultraviolet irradiation device for an ink jet recording apparatus.   The ultraviolet irradiation device for an ink jet recording apparatus according to claim 1, wherein the opening is provided on a side wall of the cover member in a direction perpendicular to the light emitting surface.   The ultraviolet irradiation device for an ink jet recording apparatus according to claim 1, further comprising a protruding portion that surrounds the one surface of the ultraviolet LED on the light emitting surface side and protrudes from the light emitting surface side.   The ultraviolet irradiation device for an ink jet recording apparatus according to claim 1, wherein the air cooling fan is provided on a side wall of the cover member in a direction perpendicular to the light emitting surface.   The ultraviolet irradiation device for an ink jet recording apparatus according to claim 1, wherein the air cooling fan is provided in the cover member on a surface side facing the light emitting surface. 6. The ultraviolet irradiating device for an ink jet recording apparatus according to claim 4, further comprising a rectifying plate for directing the air sucked from the opening to the other surface side of the ultraviolet LED.

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