JP2011042061A - Ultraviolet irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation device which includes a cleaning head which cleans ink adhering to an optical emission surface which emits ultraviolet from an ultraviolet LED, and can be cleaned automatically. <P>SOLUTION: The ultraviolet irradiation device 1 includes: two or more ultraviolet LEDs 2 which cure ink on a printing object 10 by irradiating ultraviolet on the printing object 10; and the linear optical emission surface 1a on which these two or more ultraviolet LEDs 2 are put on in a line and which emits ultraviolet from the ultraviolet LEDs 2. The ultraviolet irradiation device further includes: the cleaning head 4 which cleans the optical emission surface 1a; and a single-axis robot 5 (moving means) which moves the cleaning head 4 along the linear optical emission surface 1a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation device having an ultraviolet LED as a light source for irradiating ultraviolet rays.

  In recent years, ink that has been applied to a plate and cured by irradiation with ultraviolet rays is transferred to a printing object such as paper, and then transferred from the ultraviolet irradiation device installed on the printing object conveyance path to the ink on the printing object. A printing machine that cures ink by irradiating ultraviolet rays is known (for example, see Patent Document 1). The ultraviolet irradiation device used for this type of printing machine normally uses a metal halide lamp or a mercury lamp as a light source for irradiating ultraviolet rays.

  In addition, as a light source for irradiating ultraviolet rays, ultraviolet light emitting diodes (hereinafter referred to as ultraviolet LEDs) capable of emitting ultraviolet rays with high output have been developed and put into practical use. An ultraviolet irradiation device having a line-shaped light emitting surface that emits ultraviolet rays from the light source has also been developed (see, for example, Non-Patent Document 1).

  An ultraviolet irradiation device using an ultraviolet LED as a light source has a long light source life and can suppress power consumption as compared with an ultraviolet irradiation device using a metal halide lamp as a light source. Further, the emission spectrum of the ultraviolet LED does not include ultraviolet rays having a short wavelength (for example, an emission spectrum of 200 nm or less) unnecessary for ink curing unlike a metal halide lamp. Therefore, ozone is not generated by the irradiation of ultraviolet rays from the ultraviolet LED of the ultraviolet irradiation device to the ink on the printing object, and it is not necessary to provide an exhaust device for exhausting ozone in the printing press. In addition, UV LEDs are easy to turn on and off, and can be turned on and off instantly, so there is no need for warm-up or cool-down waiting times to stabilize light emission, such as metal halide lamps. Preparation time can be shortened and printing efficiency can be increased.

JP-A-5-64878

"UV curing equipment, for printing, LED, Pana Electric Works, world's first adoption", Nikkei Sangyo Shimbun, 5th page, June 24, 2009

  By the way, the ultraviolet irradiation device tends to be disposed as close as possible to the printing object in order to efficiently irradiate the ink on the printing object with the ultraviolet light emitted from the light source. In this case, when the printing machine conveys the printing object to which uncured ink is adhered, a part of the ink of the printing object may adhere to the light emitting surface of the ultraviolet irradiation device.

  Here, the ultraviolet LED is a point light source composed of a semiconductor light emitting element, and has a narrow ultraviolet irradiation area as compared with a metal halide lamp or the like. Therefore, an ultraviolet irradiation device equipped with an ultraviolet LED has a plurality of ultraviolet LEDs arranged to form a light emission surface, but the light emission surface is compared with the light emission surface of an ultraviolet irradiation device equipped with a metal halide lamp or the like. , And tends to be easily affected by ink adhering to the light exit surface. That is, in an ultraviolet irradiation device equipped with an ultraviolet LED as a light source, when ink adheres to the line-shaped light emitting surface, not only the dirt on the light emitting surface but also the adhered and cured ink shields the ultraviolet rays and blocks the print object. The ink may not be sufficiently cured.

  When the next printing object is placed on such a printing object that is insufficiently cured, there is a back-off of the ink that is stained with uncured ink on the back surface of the overlapping printing object. The print quality may be degraded. Furthermore, the print objects may be attracted to each other by uncured ink.

  Therefore, for the ultraviolet irradiation device provided with the ultraviolet LED, maintenance for cleaning the line-shaped light emitting surface of the ultraviolet irradiation device becomes more important. In the maintenance, the operator of the printing press takes out the ultraviolet irradiation device provided with the ultraviolet LED from the inside of the printing press to the outside of the printing press, and cleans the line-shaped light emission surface of the ultraviolet irradiation device. However, since the operator takes out the ultraviolet irradiation device from the printing machine every cleaning, it is inconvenient and time-consuming. In addition, it is difficult to predict when ink adheres to the line-shaped light exit surface of the UV irradiation device. Increasing the cleaning frequency of the UV irradiation device decreases printing efficiency, and decreasing the cleaning frequency reduces the printing quality. There is a trade-off relationship that causes a decline. In particular, the ultraviolet irradiation device is often placed inside the printing press so that ultraviolet rays do not leak to the outside, so that it is difficult to maintain and it is easy to frequently clean the line-shaped light emitting surface of the ultraviolet irradiation device. It wasn't.

  The present invention has been made in view of the above-mentioned reasons, and the object thereof is to automatically arrange a plurality of ultraviolet LEDs, and automatically apply ink or the like adhering to a linear light emitting surface that emits ultraviolet rays from the ultraviolet LEDs. It is providing the ultraviolet irradiation device which can be cleaned automatically.

The invention of claim 1 has a plurality of ultraviolet LEDs that cure the ink on the printing object by irradiating the printing object with ultraviolet rays, and the plurality of ultraviolet LEDs are arranged side by side from the ultraviolet LED. An ultraviolet irradiation device having a line-shaped light emitting surface for emitting ultraviolet rays,
A cleaning head for cleaning the light emitting surface, and a moving means for moving the cleaning head along the line-shaped light emitting surface.

  According to the present invention, the line-shaped light emitting surface for emitting ultraviolet rays is automatically cleaned by the cleaning head that moves along the light emitting surface by the moving means. Can be cleaned. Therefore, it is possible to suppress printing defects due to adhesion of ink or the like on the light emitting surface of the ultraviolet irradiation device, and to perform higher quality printing. Further, the cleaning head for cleaning the line-shaped light emitting surface is moved by the moving means, so that the cleaning head is compared with the cleaning head provided on the entire light emitting surface. The head can also be reduced in size.

  According to a second aspect of the present invention, in the first aspect of the present invention, the cleaning head includes a rotating brush and a suction nozzle that sucks dust on the light emitting surface cleaned by the rotating brush. It is characterized by.

  According to the present invention, the line-shaped light emitting surface is cleaned with a rotating brush of the cleaning head, and the dust from the line-shaped light emitting surface is sucked by the suction nozzle, whereby dust is removed from the printing press. It can be discharged outside. Therefore, unnecessary dust is not scattered around the ultraviolet irradiation device in accordance with the cleaning of the line-shaped light emitting surface.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the moving means includes at least a single-axis robot provided with a screw shaft along the line-shaped light emitting surface. It is characterized by that.

  According to this invention, the moving means is a single-axis robot provided with a screw shaft along the line-shaped light emitting surface, so that each position corresponding to each ultraviolet LED on the light emitting surface is provided. Cleaning can be performed by moving the cleaning head.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the cleaning head includes an ultraviolet sensor that measures the illuminance of ultraviolet rays from the ultraviolet LED. And

  According to this invention, by providing the cleaning head with an ultraviolet sensor, it is possible to measure the illuminance of ultraviolet light emitted from the ultraviolet LED in which a plurality of the ultraviolet LEDs are arranged.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the position data on the line-shaped light exit surface of the ultraviolet LED measured by the ultraviolet sensor of the cleaning head moved by the moving means, An LED inspection unit that inspects the quality of each of the plurality of ultraviolet LEDs based on illuminance data obtained by measuring the illuminance of ultraviolet rays from the ultraviolet LEDs by the ultraviolet sensor in synchronization with the lighting of the ultraviolet LEDs. And

  According to this invention, the LED inspection unit can inspect the quality of each of the plurality of ultraviolet LEDs based on the position data on the line-shaped light emission surface and the illuminance data of the ultraviolet LEDs. Thereby, it becomes possible to replace only the defective ultraviolet LED or to adjust the output of the ultraviolet LED having low illuminance.

  According to a sixth aspect of the present invention, in the fourth or fifth aspect of the present invention, the illuminance data of the life characteristics of the ultraviolet LED in which the illuminance data obtained by measuring the illuminance of the ultraviolet light from the ultraviolet LED is stored in the storage means in advance. It has a calculating part which calculates the remaining life which can be used by the ultraviolet LED predicted by comparing with, and a display part which displays the remaining life based on an output from the calculating part.

  According to the present invention, the usable remaining life of the ultraviolet LED can be determined, and the ultraviolet LED can be replaced at an appropriate time.

  In the invention of claim 1, a cleaning head that arranges a plurality of ultraviolet LEDs and cleans a line-shaped light emitting surface that emits ultraviolet rays from the ultraviolet LEDs, and the cleaning head along the line-shaped light emitting surface. By providing the moving means for moving the light, it is possible to provide an ultraviolet irradiation device capable of automatically cleaning the ink or the like adhering to the light emitting surface in the line shape.

It is a principal part schematic explanatory drawing of the ultraviolet irradiation device of Embodiment 1. It is a schematic explanatory drawing of the printing machine provided with the ultraviolet irradiation device same as the above. It is a schematic explanatory drawing for driving the ultraviolet irradiation device of Embodiment 2.

(Embodiment 1)
Hereinafter, after describing the printing machine 20 including the ultraviolet irradiation device 1 based on FIG. 2, the ultraviolet irradiation device 1 of the present embodiment will be described with reference to FIG. 1.

  The printing press 20 shown in FIG. 2 provided with the ultraviolet irradiation device 1 of the present embodiment is cured with ultraviolet rays on the paper supply unit 21 for supplying a print target (for example, plain paper) 10 and the print target 10. A coating agent (for example, a varnish that is cured by irradiation of ultraviolet rays) is attached to protect the printing surface 22 of the printing object 10 to which the ink to be applied is attached and to gloss, or to remove the gloss. And a paper discharge unit 24 for discharging the print target 10 that has been subjected to printing and surface treatment.

  The paper supply unit 21 includes a storage unit 21 a that stores the printing object 10 and a supply unit 21 b that supplies the printing object 10 to the printing unit 22 side. The storage unit 21a can store a plurality of sheet-like print objects 10. The supply unit 21b pulls out the sheet-like print objects 10 stored in the storage unit 21a one by one. The printed object 10 is conveyed to the printing unit 22 side along the direction of arrow A in FIG.

  The printing unit 22 sets printing units 25, 26, 27, and 28 for each of four color inks that are cured by ultraviolet rays, for example, black (BK), cyan (C), magenta (M), and yellow (Y). They are provided in order along the transport path of the print object 10. Each printing unit 25, 26, 27, 28 is a cylindrical plate cylinder 25 a, 26 a, 27 a, 28 a that rotates in the direction of arrow M, and intermediate transfer that transfers the ink of the plate cylinder 25 a, 26 a, 27 a, 28 a. The cylindrical rubber cylinders 25b, 26b, 27b, 28b and the rubber cylinders 25b, 26b, 27b, 28b that rotate in the direction of the arrow N through the print object 10, and the directions of the arrows C, G, respectively. The cylindrical impression cylinders 30 and 31 are integrally provided. In addition, cylindrical transfer cylinders 33a, 33b, 33c, 33d, 33e, 33f, and 33g that rotate in the directions of arrows B, D, E, F, H, I, and J, respectively, provided in the printing machine 20 are printed. The object 10 is sequentially conveyed to the printing units 25, 26, 27, 28 and the surface treatment unit 29 of the surface treatment unit 23.

  In each printing unit 25, 26, 27, 28, a printing plate (not shown) is provided on the surface of the plate cylinder 25a, 26a, 27a, 28a. Is transferred to the rubber cylinders 25b, 26b, 27b, 28b. The ink transferred to the rubber cylinders 25b, 26b, 27b, and 28b is transferred to the printing object 10 that is sandwiched and conveyed by the rubber cylinders 25b, 26b, 27b, and 28b and the impression cylinders 30 and 31. The printing object 10 is conveyed from the printing unit 22 side to the surface treatment unit 23 side by transfer cylinders 33e, 33f, and 33g after each of the plates is transferred and ink is attached.

  The surface treatment unit 29 is provided with a crater-like cell (not shown) on the surface, and a cylindrical anilox roller 29a capable of accurately controlling the transfer amount of the applied material according to the size and depth of the cell, an arrow The varnish as a coating agent for surface treatment is transferred from the anilox roller 29a rotating in the direction of O, and is in contact with the cylindrical varnish cylinder 29b and the varnish cylinder 29b rotating in the direction of the arrow P through the printing object 10, and the arrow A cylindrical impression cylinder 32 that rotates in the direction K is provided.

  In the surface treatment unit 29, the varnish is supplied to the anix roller 29a, and the varnish supplied to the surface of the roller 29a is transferred to the varnish cylinder 29b. Further, the varnish transferred to the varnish cylinder 29b is applied to the printing object 10 which is held between the varnish cylinder 29b and the impression cylinder 32 and conveyed.

  In the present embodiment, the ultraviolet irradiation device 1 for irradiating the printing object 10 to which the ink or coating agent is applied with ultraviolet rays to cure the ink or coating agent on the printing object 10 is used as the surface treatment unit 29 of the printing machine 20. It is arranged so as to face the impression cylinder 32. The ultraviolet irradiation device 1 uses a plurality of ultraviolet LEDs 2 (see FIG. 1A) as light sources substantially perpendicular to the conveyance direction of the printing object 10 so that the rotating printing object 10 can be irradiated with ultraviolet light substantially uniformly. A line-shaped light emitting surface 1a (see FIG. 1A) arranged along the width of the pressure drum 32 is provided. The ultraviolet irradiation device 1 is a printing target in which ultraviolet rays from the ultraviolet LED 2 of the ultraviolet irradiation device 1 are adhered to the surface of the pressure drum 32 of the surface treatment unit 23, and each ink and varnish is adhered to the surface treatment unit 23 in the printing unit 22. By irradiating the object 10, each ink and varnish are cured. The printing object 10 irradiated with ultraviolet rays is conveyed toward the paper discharge unit 24 by the rotation of the impression cylinder 32.

  The paper discharge unit 24 includes a transport unit 24 a that transports the print object 10 from the surface processing unit 23 side in the direction of the arrow L, and a storage unit 24 b that stores the print objects 10. As a result, the paper discharge unit 24 receives and conveys the print object 10 conveyed by the impression cylinder 32 of the surface treatment unit 23 by the conveyance unit 24a, and stores it in the storage unit 24b. Further, the paper discharge unit 24 of the printing machine 20 includes an infrared lamp or the like that is disposed opposite to a conveyance surface that conveys the printing target 10 of the conveyance unit 24a and that causes the printing target 10 to be irradiated with infrared rays and dried. Dryer portions 34a and 34b are provided.

  The printing machine 20 applies the ink to the printing object 10 supplied from the paper supply unit 21 by the printing unit 22 and the varnish to the surface processing unit 23 corresponding to each plate, and then the ultraviolet rays are applied. The ink and varnish are cured by the irradiation device 1 and can be taken out from the paper discharge unit 24.

  The ultraviolet irradiation device 1 is not limited to the one arranged to face the impression cylinder 32 in the surface treatment unit 29, and a plurality of ultraviolet irradiation devices 1 may be provided in each printing unit 25, 26, 27, 28 of the printing unit 22. Good. The plurality of ultraviolet irradiation devices 1 only need to be able to cure each ink after each ink is attached to the printing object 10 in each printing unit 25, 26, 27, 28. Further, the ultraviolet irradiation apparatus 1 is installed in the impression cylinders 30 and 31 and the transfer cylinders 33b, 33c, 33d, 33e, 33f, and 33g of the printing units 25, 26, 27, and 28, and the surface treatment unit 23 itself is not provided. But you can.

  Furthermore, after printing one side in the printing unit 22, the printing object 10 is reversed by a reversing device (not shown) for reversing the printing object 10, and then the printing object is provided by a separately provided printing unit (not shown). Double-sided printing can also be performed by printing the other 10 sides. Further, the printing unit 22 of the printing machine 20 may be configured by only the printing unit 25 that prints black (BK), for example.

  The ink used in this embodiment has a property of being cured by irradiation with ultraviolet rays. As the main component of such an ink, for example, an ink containing a polymerizable compound such as a radical polymerizable compound or a cationic polymerizable compound, a photopolymerization initiator, and a coloring material such as a dye or a pigment may be used.

  Similarly, a varnish serving as a coating agent for surface treatment has a property of being cured by irradiation with ultraviolet rays. As the main component of the varnish, for example, a resin composition containing a polymerizable compound such as a radical polymerizable compound or a cationic polymerizable compound and a photopolymerization initiator can be used.

  Next, the ultraviolet irradiation apparatus 1 of this embodiment is demonstrated. FIG. 1A shows a schematic perspective view of the ultraviolet irradiation device 1, and FIG. 1B shows a schematic perspective view of the cleaning head 4 on the side in contact with the light emitting surface 1 a of the ultraviolet irradiation device 1. ing. FIG. 1C is an explanatory diagram of the operation of the cleaning head 4.

  As described above, the ultraviolet irradiation device 1 is disposed to face the impression cylinder 32 inside the surface treatment unit 23 of the printing machine 20. The ultraviolet irradiation device 1 shown in FIG. 1A includes a line-shaped light emitting surface 1a for arranging a plurality of (here, 14) ultraviolet LEDs 2 in a straight line and emitting ultraviolet rays from the ultraviolet LEDs 2. Further, the ultraviolet irradiation device 1 is provided with a cleaning unit 3 that removes ink, varnish, and the like attached to the line-shaped light emission surface 1a. The cleaning unit 3 includes a cleaning head 4 that cleans the line-shaped light emitting surface 1a, and a single-axis robot 5 that is a moving unit that moves the cleaning head 4 along the surface of the line-shaped light emitting surface 1a. I have.

  The cleaning unit 3 includes a suction hose 7 connected to the cleaning head 4, a suction exhaust device 8 connected to the suction hose 7 and discharging dust to an external dust box (not shown) of the printing machine 20, And an exhaust hose 9 connected to the dust box from the suction exhaust device 8.

  Here, as shown in FIGS. 1B and 1C, the cleaning head 4 includes a rotating brush 4 a that removes at least the ink and varnish adhered and cured on the surface of the light emitting surface 1 a of the ultraviolet irradiation device 1, and a rotating brush. A suction nozzle 4b for sucking the dust dropped in 4a is provided.

  When cleaning the light emitting surface 1a of the ultraviolet irradiation device 1, the above-described printing machine 20 first turns on the ultraviolet LED 2 of the ultraviolet irradiation device 1. When uncured ink adheres to the light emitting surface 1 a of the ultraviolet irradiation device 1, the ultraviolet irradiation device 1 can cure the ink on the light emitting surface 1 a by turning on the ultraviolet LED 2.

  Subsequently, the rotary brush 4a is brought into contact with the light emitting surface 1a while the rotary brush 4a of the cleaning head 4 is rotated while the suction / exhaust device 8 is operated and negative pressure is generated from the suction nozzle 4b of the cleaning head 4. Let The cleaning head 4 in this state is moved by the single-axis robot 5 along the line-shaped light emission surface 1a. The ultraviolet irradiation device 1 can remove the ink cured on the light emitting surface 1a.

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

  The ultraviolet irradiation device 1 according to the present embodiment is a substantially rectangular parallelepiped metal that is long in a direction substantially perpendicular to the conveyance direction of the printing object 10 and has a hollow inside so as to cover the impression cylinder 32 to which the printing object 10 is conveyed. A cover member 1b made of (for example, stainless steel) is provided. In the ultraviolet irradiation device 1, a plurality of ultraviolet LEDs 2 are arranged side by side along the long longitudinal direction on one end surface side of the cover member 1 b facing the printing object 10. On the one end face side of the ultraviolet irradiation device 1, there is provided an ultraviolet transmitting member 1 c made of quartz glass or the like that protects each ultraviolet LED 2 and transmits ultraviolet rays from each ultraviolet LED 2, and the surface of the ultraviolet transmitting member 1 c is The line-shaped light emission surface 1a for emitting the ultraviolet rays from the ultraviolet LED 2 is formed.

  Inside the ultraviolet irradiation device 1, a pipe (not shown) for circulating a refrigerant is arranged on the other surface side opposite to one surface of the ultraviolet LED 2 that irradiates ultraviolet rays, and the ultraviolet LED 2 and the pipe are thermally connected. The ultraviolet LED 2 can be cooled.

  The ultraviolet irradiation device 1 may be air-cooled by an air cooling fan such as a fan motor in addition to the forced water cooling method as a method for increasing the cooling efficiency of the ultraviolet LED 2. Moreover, in order to improve cooling efficiency, the ultraviolet LED 2 may include a cooling fin on the other surface side.

  Here, the line shape of the light emitting surface 1a in the ultraviolet irradiation device 1 does not necessarily need to be a continuous straight line, and corresponds to a plurality of ultraviolet LEDs 2, and a plurality of light emitting surfaces 1a are formed in a linear manner. May be provided. Further, the plurality of ultraviolet LEDs 2 are not necessarily limited to those in which the ultraviolet LEDs 2 are arranged on the same straight line, but may be arranged in a staggered pattern, for example. In any case, the ultraviolet irradiation device 1 only needs to irradiate the printing object 10 with ultraviolet rays by relatively moving the ultraviolet irradiation device 1 and the printing object 10.

  Further, the surface of the ultraviolet transmitting member 1c may be formed in a convex shape or a concave shape having a lens effect so that the ultraviolet rays irradiated from the plurality of ultraviolet LEDs 2 are uniformly irradiated on the printing object 10. Or simply a smooth plane.

  The ultraviolet LED 2 is, for example, an ultraviolet light in which a buffer layer made of gallium nitride, an n-type gallium nitride layer, a light emitting layer, and a p-type gallium nitride layer are stacked on a sapphire substrate by MOCVD or the like, and the light emitting layer has a peak wavelength of about 385 nm. A nitride semiconductor light emitting device made of InAlGaN or the like that can emit light can be used.

  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 one surface side of the ultraviolet LED 2 for the purpose of condensing or diffusing the ultraviolet light emitted by the nitride semiconductor light emitting element.

  The ultraviolet irradiation device 1 may individually control each ultraviolet LED 2 in the plurality of ultraviolet LEDs 2 to adjust the illuminance of ultraviolet rays, or may control the increase and decrease of the illuminance of ultraviolet rays simultaneously. For example, in the ultraviolet irradiation device 1 provided with the line-shaped light emission surface 1a, the illuminance of the ultraviolet LED 2 disposed on both ends of the line is more than the illuminance of the ultraviolet LED 2 disposed on the center side of the line. By increasing the value, uniform illuminance can be obtained in a line shape.

  The cleaning head 4 of the present embodiment cleans the line-shaped light emitting surface 1a of the ultraviolet irradiation device 1, and sucks dust on the light emitting surface 1a to be cleaned by the rotating brush 4a that contacts the light emitting surface 1a. A suction nozzle 4b is provided. The rotating brush 4a of the cleaning head 4 has, for example, a twisted shape obtained by twisting a thin plate shown in FIG. 1B, and gears (not shown) are provided at both ends in the longitudinal direction of the rotating brush 4a. ing. The shaft of the gear is rotatably held by a bearing 4c of the cleaning head 4, and the rotation of a motor (not shown) built in the cleaning head 4 is transmitted. In addition, the rotating brush 4a may decenter the rotating shaft. The rotating brush 4a having an eccentric rotating shaft can vibrate by rotating the force of the rotating brush 4a that strikes the light exit surface 1a to make it easier to drop ink or the like. Moreover, what is necessary is just to comprise suitably the shape of the rotating brush 4a, such as a brush shape using not only a twist shape but a strand wire. Similarly, the shape of the opening of the suction nozzle 4b may be an appropriate shape such as a triangle or an ellipse in addition to a rectangle.

  The moving means only needs to be able to move at least the cleaning head 4 along the line-shaped light exit surface FIG. 1a, not only one single-axis robot 5, but also two axes obtained by orthogonally combining a plurality of single-axis robots 5. A robot or a three-axis robot may be used. Therefore, the single-axis robot 5 in the present application is interpreted in a broad sense including those constituting a part of a multi-axis robot such as a 2-axis robot or a 3-axis robot. A single-axis robot 5 serving as a moving means shown in FIG. 1A includes a servo motor 5d, and a screw shaft 5a is provided along the line-shaped light emitting surface 1a of the ultraviolet irradiation device 1. The servo motor 5d of the single-axis robot 5 is capable of reciprocating the cleaning head 4 along the line-shaped light exit surface 1a, and can also be stopped with good controllability while reciprocating the cleaning head 4. Here, the motor of the single-axis robot 5 is not limited to the servo motor 5d, and may be configured using various motors such as a stepping motor. In such a single-axis robot 5, for example, a ball is disposed between a screw shaft 5a provided parallel to the light emitting surface 1a and a nut (not shown) attached to the outer periphery of the screw shaft 5a. A ball screw that uses rotation to move the nut along the screw shaft 5a; a servomotor 5d that incorporates a rotation detector (not shown) and feedback-controls rotation based on data from the rotation detector; A linear guide 5b that supports the slider 5c fixed to the nut and performs linear motion using rolling of a ball that circulates between the slider 5c and a rail provided parallel to the light emitting surface 1a. Can be configured. The cleaning head 4 is attached and fixed to the slider 5 c of the single-axis robot 5.

  The screw shaft 5a of the single-axis robot 5 is rotated by a servo motor 5d, and the rotational speed, rotation speed, and the like are controlled, so that the position at which the cleaning head 4 attached to the slider 5c stops and the moving speed can be freely adjusted. be able to. In the ultraviolet irradiation device 1 of the present embodiment, a synchronous motor that maintains a constant speed in synchronization with the AC frequency of the commercial power supply is used as the servo motor 5d.

  The cleaning head 4 attached to the ultraviolet irradiation device 1 is, for example, every day in advance by the calendar function of a control device composed of a computer connected to the printing machine 20 or once a predetermined week when the printing machine 20 is started. Alternatively, the ink or the like attached to the light emitting surface 1a can be cleaned by automatically moving the cleaning head 4 back and forth by the single-axis robot 5 along the linear light emitting surface 1a of the ultraviolet irradiation device 1 after the printing is completed. .

  That is, when the printing press 20 is started up or after printing is finished, the suction / exhaust device 8 of the cleaning unit 3 is started to operate, and the cleaning head 4 located at one end in the longitudinal direction on the one end face side of the ultraviolet irradiation device 1. Is moved along the linear light emitting surface 1a together with the slider 5c by the servo motor 5d of the single-axis robot 5. The cleaning head 4 sucks from the suction nozzle 4b while scraping at least the ink adhered and cured on the light emitting surface 1a with the rotating brush 4a, and sucks and exhausts the ink attached to the light emitting surface 1a from the suction hose 7 as dust. Aspirate with 8. The sucked dust is discharged from the exhaust hose 9 to the dust box installed outside the printing press 20 through the suction exhaust device 8.

  Here, the cleaning head 4 of the cleaning unit 3 is held and moved along the holding rail 6 by the slider 5c of the single-axis robot 5 from the one end side in the longitudinal direction of the ultraviolet irradiating device 1 to the opposite other end side. When the limit switch 6a is hit, the servo motor 5d of the single-axis robot 5 is stopped. Next, by rotating the servo motor 5d in the reverse direction and driving the servo motor 5d of the single-axis robot 5 until the cleaning head 4 fixed to the slider 5c hits the other limit switch 6b, the single-axis robot 5 is moved to the cleaning head. 4 can be returned to the initial position. Thereby, the cleaning unit 3 can automatically clean the light emitting surface 1a of the ultraviolet irradiation device 1. In addition, cleaning of the light emission surface 1a of the ultraviolet irradiation device 1 is not only automatically performed, but may be arbitrarily performed by manually operating the cleaning unit 3 by operating the control device.

  The holding rail 6 can prevent the cleaning head 4 from falling off and stabilize the movement of the cleaning head 4. Moreover, the ink adhered to the light emitting surface 1a can be scraped off by bringing the rotating brush 4a of the cleaning head 4 into close contact with the light emitting surface 1a. In order to clean the light emitting surface 1a in the cleaning head 4, not only the rotating brush 4a but also a sponge containing a solution for melting ink may be brought into contact with the light emitting surface 1a to wipe off the ink.

  Further, in order to completely cure the uncured ink attached to the light emitting surface 1 a of the ultraviolet irradiation device 1, ultraviolet light may be irradiated from the cleaning head 4 side to the light emitting surface 1 a side of the ultraviolet irradiation device 1. In this case, an ultraviolet LED that can irradiate the cleaning head 4 with ultraviolet rays for curing the ink may be separately provided.

  In FIG. 1A, the suction / exhaust device 8 of the cleaning unit 3 is provided in parallel with the light emitting surface 1 a of the ultraviolet irradiation device 1, but depending on the structure of the printing machine 20, the light emitting surface of the ultraviolet irradiation device 1. You may provide in the other end surface side which opposes 1a, and you may provide in the exterior of the printing machine 20.

  Further, the ultraviolet irradiation device 1 can efficiently irradiate ultraviolet rays when the light emitting surface 1a of the ultraviolet irradiation device 1 is as close as possible to the printing object 10. However, if the distance between the light emitting surface 1 a of the ultraviolet irradiation device 1 and the printing object 10 is too narrow, the cleaning head 4 is moved between the light emitting surface 1 a of the ultraviolet irradiation device 1 and the printing object 10. It becomes difficult. Therefore, at the time of cleaning by the cleaning head 4 of the cleaning unit 3, the distance between the light emitting surface 1 a of the ultraviolet irradiation device 1 and the printing object 10 is wider than the surface of the impression cylinder 32 that conveys the printing object 10. Thus, the cleaning head 4 can be moved by the single-axis robot 5 after the entire ultraviolet irradiation device 1 is tilted. In this case, it is only necessary to provide a separation mechanism (not shown) that inclines and separates the ultraviolet irradiation device 1 from the impression cylinder 32 when cleaning the light emitting surface 1a of the ultraviolet irradiation device 1.

  The cleaning unit 3 provided in the ultraviolet irradiation device 1 may be configured to be detachable from the ultraviolet irradiation device 1. In this case, a positioning pin (not shown) provided in the cleaning unit 3 is fitted into a recess (not shown) of the ultraviolet irradiation device 1 and, for example, two screws (in the longitudinal direction of the ultraviolet irradiation device 1) ( A structure that can be fixed and installed relatively easily by screwing with a screw (not shown). Thereby, when there are a plurality of printing machines 20 or when one printing machine 20 has a plurality of ultraviolet irradiation apparatuses 1, the cleaning unit 3 can be fixedly installed on the ultraviolet irradiation apparatus 1 of the printing machine 20. The cleaning unit 3 can be easily moved and attached to the ultraviolet irradiation device 1 of the printing machine 20 to be cleaned.

  The ultraviolet irradiation device 1 of the present embodiment is not only used in the printing machine 20 that transfers the ink applied to the plate, but also used in the inkjet printing machine 20 that discharges ink from the ink head. (Not shown). For example, the ultraviolet irradiation device 1 is provided with a long ink head capable of ejecting ink in a direction substantially perpendicular to the conveyance direction of the print object 10 so as to cover the print object 10 to be conveyed, Ink curable by ultraviolet rays is ejected from the tip of the nozzle of the ink head to the printing object 10. Further, the ultraviolet irradiation device 1 for irradiating the ultraviolet rays that cure the ink ejected to the printing object 10 is fixedly disposed adjacent to the ink head on the downstream side with respect to the conveyance direction of the printing object 10. Good.

  In particular, in the case of the ink jet printer 20 using an ink having a low surface tension, a part of the ink ejected from the ink head may be scattered as mist-like ink particles. Unlike the ink ejected directly from the ink head, such mist-like ink particles float in the air, so that the floating mist-like ink particles adhere to the light emitting surface 1 a of the ultraviolet irradiation device 1. It tends to be easy to do. Therefore, the ultraviolet irradiation device 1 in the inkjet printer 20 also requires maintenance for periodically cleaning the light emitting surface 1a of the ultraviolet irradiation device 1, and the ultraviolet irradiation device provided with the cleaning unit 3 of the present embodiment. 1 can be suitably used.

(Embodiment 2)
Since the basic configuration of the ultraviolet irradiation device 1 of the present embodiment is the same as that of the first embodiment, the characteristic portions 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 in that the cleaning head 4 provided in the ultraviolet irradiation device 1 of the first embodiment includes an ultraviolet sensor 4d that individually measures the illuminance of ultraviolet rays from each ultraviolet LED 2. .

  The cleaning head 4 of the ultraviolet irradiation device 1 is the moving means described above in the direction of the two-dot chain line in FIG. 3 based on the movement control signal transmitted from the control device 12 that controls the ultraviolet irradiation device 1 via the control line 12d. It is moved by the single axis robot 5. The control device 12 controls lighting of the plurality of ultraviolet LEDs 2 of the ultraviolet irradiation device 1 by a lighting control signal transmitted via the control line 12c. Further, the ultraviolet sensor 4d of the cleaning head 4 measures the illuminance of each ultraviolet LED 2 in synchronization with the lighting of the ultraviolet LED 2 by the control device 12. The ultraviolet sensor 4d transmits the measured illuminance data of ultraviolet rays from the ultraviolet LED 2 to the control device 12 side through the control line 12d.

  Here, the control device 12 inspects whether the ultraviolet rays emitted from each ultraviolet LED 2 are sufficient to cure ink or the like based on the illuminance data measured by the ultraviolet sensor 4d in synchronization with the lighting of the ultraviolet LED 2. An LED inspection unit 12a is provided. The LED inspection unit 12a uses the position data on the line-shaped light exit surface 1a of the ultraviolet LED 2 measured by the ultraviolet sensor 4d of the cleaning head 4 moved by the single-axis robot 5 and the illuminance data of each of the plurality of ultraviolet LEDs 2. Based on this, the quality of each of the plurality of ultraviolet LEDs 2 is inspected, and if there is a defective ultraviolet LED 2, it is displayed on the display unit 12b of the control device 12.

  That is, if the LED inspection unit 12a of the control device 12 determines that the illuminance of the ultraviolet LED 2 is insufficient to cure the ink or the like, the insufficient ultraviolet LED 2 is identified in the display unit 12b serving as the monitor of the control device 12. To display.

  In addition, the ultraviolet irradiation device 1 arrange | positions the pipe (not shown) which circulates a refrigerant | coolant on the other surface side facing one surface which irradiates the ultraviolet-ray of ultraviolet LED2, and ultraviolet-ray LED2 and the said pipe are heat-connected. . The refrigerant is taken out of the ultraviolet irradiation device 1 through the pipe 11a, cooled by the refrigerant circulation device 11 provided outside the printing machine 20, and again through the other pipe 11b in the ultraviolet LED 2 of the ultraviolet irradiation device 1. The surface side is cooled.

  As the ultraviolet sensor 4d of this embodiment, for example, an ultraviolet sensor 4d formed of a photoconductive type using a Si material, a GaAsP material, a ZnO material or a gallium nitride material, a pn junction type, or a Schottky contact type may be used. .

  Moreover, the control apparatus 12 can be comprised with the computer etc. into which appropriate software was introduced. The display unit 12b of the control device 12 may be a monitor of the computer, or may be constituted by a display lamp using a separate LED that emits visible light.

  In the ultraviolet irradiation device 1 of the present embodiment, only the defective ultraviolet LED 2 can be individually taken out from the ultraviolet irradiation device 1 and replaced. Further, the control device 12 can adjust the output of the ultraviolet LED 2 having low illuminance.

  Next, as another ultraviolet irradiation device 1 of the present embodiment, storage means (not shown) in which the control device 12 stores the illuminance with respect to the cumulative lighting time of the ultraviolet LED 2 as illuminance data of life characteristics, and the illuminance data, The ultraviolet irradiating device 1 that further includes a calculation unit (not shown) that compares the illuminance data of the lifetime characteristics and calculates the remaining lifetime that the ultraviolet LED 2 can use will be described.

  In the ultraviolet irradiation device 1, the calculation unit of the control device 12 has the illuminance data detected by the ultraviolet sensor 4 d of the cleaning head 4 and the illuminance of the lifetime characteristic of the ultraviolet LED 2 stored in advance in the storage unit of the control device 12. The remaining lifetime that can be used by the predicted ultraviolet LED 2 is calculated by comparing with the data. The display unit 12b of the control device 12 displays the remaining life predicted based on the output from the calculation unit.

  Since the ultraviolet LED 2 serving as the light source of the ultraviolet irradiation device 1 is a semiconductor light emitting element, it does not become unlit by disconnection of the filament like a mercury lamp. However, the ultraviolet LED 2 has a life characteristic (change with time) in which the illuminance gradually decreases as the lighting time elapses (cumulative lighting time). If the predetermined illuminance cannot be obtained, the ink and the coating agent are cured. Can not do. Further, the illuminance of the ultraviolet LED 2 with respect to the cumulative lighting time tends to change depending on the current value for driving the ultraviolet LED 2.

  For example, in the ultraviolet irradiation apparatus 1 in which a plurality of ultraviolet LEDs 2 are arranged and provided with a line-shaped light emitting surface 1a, the amount of current of the ultraviolet LEDs 2 arranged at both ends of the line is increased, so By relatively reducing the current amount of the ultraviolet LED 2 on the side, the ultraviolet light emitted from the light emitting surface 1a of the ultraviolet irradiation device 1 may be uniformly irradiated in a line shape. Although the ultraviolet irradiation device 1 can suppress uneven curing of the ink printed on the print object 10, the lifetimes of the plurality of ultraviolet LEDs 2 in the ultraviolet irradiation device 1 tend to be different from each other.

  In such a case, the control device 12 may store illuminance data of a plurality of life characteristics according to the current value for driving the ultraviolet LED 2 in the storage unit, or the storage unit stores the illuminance data. You may correct | amend by adding an appropriate correction coefficient with respect to the illumination data of a lifetime characteristic.

  Here, the lifetime of the ultraviolet LED 2 in the present embodiment is set as the lifetime until the illuminance of the ultraviolet light emitted from the ultraviolet LED 2 is reduced to 70% of the initial value. Depending on the initial value, it may be determined that the time until the value falls to a value set appropriately, such as 50%, as the lifetime.

  Note that the storage means of the control device 12 may use in advance a nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) for the life characteristic data of the ultraviolet LED 2.

  In addition, the calculation unit of the control device 12 may be configured by the computer into which appropriate software is introduced, or includes a comparator that compares the illuminance data measured by the ultraviolet sensor 4d with the illuminance data of the life characteristics. A comparison circuit or the like can also be used.

  Since the ultraviolet irradiation device 1 judges and displays the remaining life of each individual ultraviolet LED 2, the operator of the printing press 20 may take out the ultraviolet LED 2 from the ultraviolet irradiation device 1 and replace it at an appropriate time. It is also possible to replace the ultraviolet irradiating device 1 itself by judging the lifetime of the entire ultraviolet irradiating device 1 according to the ultraviolet LED 2 that comes first.

DESCRIPTION OF SYMBOLS 1 Ultraviolet irradiation device 1a Light emission surface 2 Ultraviolet LED
4 Cleaning head 4a Rotating brush 4b Suction nozzle 4d Ultraviolet sensor 5 Single axis robot (moving means)
5a Screw shaft 10 Print object 12a LED inspection part 12b Display part

Claims (6)

It has a plurality of ultraviolet LEDs that cure the ink on the printing object by irradiating the printing object with ultraviolet rays, and arranges the plurality of ultraviolet LEDs to emit ultraviolet rays from the ultraviolet LEDs. An ultraviolet irradiation device having a light exit surface,
An ultraviolet irradiation apparatus comprising: a cleaning head that cleans the light emitting surface; and a moving unit that moves the cleaning head along the light emitting surface in the line shape.   2. The ultraviolet irradiation device according to claim 1, wherein the cleaning head includes a rotating brush and a suction nozzle that sucks dust on the light emitting surface cleaned by the rotating brush.   The ultraviolet irradiation apparatus according to claim 1, wherein the moving unit includes at least a single-axis robot provided with a screw shaft along the line-shaped light emission surface.   4. The ultraviolet irradiation device according to claim 1, wherein the cleaning head includes an ultraviolet sensor that measures an illuminance of ultraviolet rays from the ultraviolet LED. 5.   Position data on the light emitting surface of the line-shaped UV LED measured by the UV sensor of the cleaning head moved by the moving means and the UV LED from the UV LED in synchronization with lighting of the UV LED. The ultraviolet irradiation apparatus according to claim 4, further comprising an LED inspection unit that inspects the quality of each of the plurality of ultraviolet LEDs based on illuminance data obtained by measuring the illuminance of the ultraviolet rays. The remaining lifetime that can be used by the ultraviolet LED is calculated by comparing the illuminance data obtained by measuring the illuminance of the ultraviolet ray from the ultraviolet LED with the illuminance data of the lifetime characteristic of the ultraviolet LED stored in the storage unit in advance. The ultraviolet irradiation apparatus according to claim 4, further comprising: a calculation unit; and a display unit that displays the remaining life predicted based on an output from the calculation unit.

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