JP2011031556A - Ultraviolet irradiation apparatus for printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation apparatus for printing reduced in power consumption, elongated in the service life of a light source, and improved in the printing efficiency. <P>SOLUTION: The ultraviolet irradiation apparatus is provided with an LED irradiating ultraviolet rays UV onto the printing surface 51 of printed matter 5 attached with ultraviolet-curing ink 6 of multi-colors cured by irradiation of ultraviolet rays UV, and an ultraviolet control part 12 for controlling a light amount of the LED. The printing face 51 is divided into a plurality of irradiation areas 52, and the ultraviolet control part 12 controls the light amount of the LED for every printing area 52 based on the total attached amount Q of the ultraviolet-curing ink 6 in the respective irradiation areas 52. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation apparatus for printing.

  2. Description of the Related Art Conventionally, printing apparatuses using ultraviolet curable ink that is cured by irradiation with ultraviolet rays have been proposed. In this type of printing apparatus, an ultraviolet irradiation apparatus for printing is provided adjacent to a printing unit for adhering ink to a printed matter so as to cure the ink by irradiating ultraviolet rays. The printing apparatus is often used for color printing and uses inks of four colors (cyan, magenta, yellow, black) or more, and an independent printing unit is provided for each ink.

  In addition to the use of a discharge lamp such as a xenon lamp as a light source, a printing ultraviolet irradiation apparatus has also been proposed to use an LED having an emission wavelength in the ultraviolet region as a light source (for example, Patent Document 1).

  By using the LED as the light source, the life of the light source is prolonged as compared with the conventional case where a discharge lamp is used as the light source, so that the replacement frequency of the light source is reduced and the maintenance burden can be reduced. In addition, since the power consumption is small, the electricity bill can be reduced. Further, since the LED generates little heat, it is possible to suppress the thermal influence on the printing material and the printing press. Furthermore, since the LED can be controlled to be turned on / off or dimmed instantaneously, the print preparation time is shortened, so that the printing efficiency is improved.

JP 2009-61702 A

  However, in the ultraviolet irradiation device for printing of Patent Document 1, the LED always irradiates a certain amount of ultraviolet rays regardless of the pattern or color of the printed matter. As a printing test, it is difficult to set the optimal amount of ultraviolet light for curing the ultraviolet curable ink because the printed matter is checked after printing and the amount of ultraviolet light is adjusted. For this reason, the amount of ultraviolet light to be irradiated is often set larger than the optimum amount of ultraviolet light. Therefore, the ultraviolet irradiation device for printing disclosed in Patent Document 1 consumes wasted power and shortens the life of the light source. However, in recent years, there has been a demand for an ultraviolet irradiation apparatus for printing that reduces power consumption, extends the life of a light source, and improves printing efficiency.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide an ultraviolet irradiation apparatus for printing that reduces power consumption, extends the life of a light source, and improves printing efficiency.

  The invention according to claim 1 is the light source constituted by the LED that irradiates ultraviolet rays on the printing surface of the printed matter to which the ultraviolet curable ink of a plurality of colors is attached, which is cured by irradiating ultraviolet rays. A light source control unit that controls the amount of light of the light source, the printing surface is divided into a plurality of irradiation areas, the light source control unit for each printing area based on at least the adhesion amount of ultraviolet curable ink in each irradiation area It is characterized by controlling the light amount of the light source.

  According to the present invention, the light amount of the light source is controlled for each irradiation area based on at least the amount of the ultraviolet curable ink in each irradiation area, thereby reducing power consumption and extending the life of the light source. Since a print test for adjusting the amount of light is not necessary, printing efficiency can be improved.

  According to a second aspect of the present invention, in the first aspect of the invention, the light source control unit is configured such that the light amount of the light source for each irradiation area is based on a total adhesion amount of the ultraviolet curable ink of all colors in each irradiation area. It is characterized by controlling.

  According to this invention, the light quantity of the light source in each irradiation area can be controlled easily.

  According to a third aspect of the present invention, the light source control unit according to the first aspect of the invention is configured such that the light source control unit is configured to apply the light source for each irradiation area based on an adhesion amount of the ultraviolet curable ink having the slowest curing speed in each irradiation area. The amount of light is controlled.

  According to this invention, the light quantity of the light source in each irradiation area can be controlled easily.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the light source control unit is configured so that each color attached to the irradiation area corresponds to a total adhesion amount of the ultraviolet curable ink of all the colors in the irradiation area. The light amount of the light source is controlled for each irradiation area based on the ratio of the adhesion amount of the ultraviolet curable ink.

  According to this invention, the ink of each color can be reliably cured.

  As described above, the present invention has the effects of reducing power consumption, extending the life of the light source, and improving printing efficiency.

It is a figure which shows schematic structure of a printing machine. It is a figure which shows schematic structure of Embodiment 1 of this invention. It is a figure which shows a printing process. It is a figure which shows the relationship of the light quantity with respect to irradiation time. It is a figure which shows schematic structure of Embodiment 2 of this invention. It is a figure which shows schematic structure of Embodiment 3 same as the above.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a schematic configuration diagram of the printing press, and FIG. 2 shows a schematic configuration diagram of the first embodiment.

  The ultraviolet irradiation device 3 of the present invention is provided in an offset printing machine described below. In the offset printing machine, a printing unit 2 is provided along the conveyance direction X of the printed material 5 with respect to the printed material 5 such as paper conveyed in one direction (the arrow X direction in FIG. 1) by the conveyance mechanism 4. . Further, an ultraviolet irradiation device 3 is provided on the downstream side of the printing unit 2 in the conveyance direction X of the printed matter 5. The operations of the printing unit 2, the ultraviolet irradiation device 3, and the transport mechanism 4 are controlled by the control unit 1.

  The printing unit 2 uses an ink roller 6a to which ultraviolet curable ink 6 (hereinafter referred to as ink 6) is attached, to uniformly attach the ink 6 to the plate 21 attached to the outer periphery of the plate cylinder 21a, and thereby the blanket cylinder. The ink 6 is transferred to the printing surface 51 of the printed matter 5 through the blanket 22 attached to the outer periphery of 22a. Further, the printing unit 2 of the present embodiment is configured with four colors of black, cyan, magenta, and yellow. It is also possible to use inks 6 of other colors or inks 6 of five colors or more.

  The ultraviolet irradiation device 3 includes an LED as a light source for irradiating ultraviolet UV. A plurality of LEDs are arranged in a direction perpendicular to the conveyance direction X of the printed matter 5, and irradiates the printing surface 51 of the printed matter 5 with ultraviolet rays UV. And the ink 6 adhering to the printing surface 51 is hardened | cured with the ultraviolet-ray UV which LED irradiates. Further, the ultraviolet irradiation device 3 has a length dimension capable of irradiating the ultraviolet UV over substantially the entire length of the width W of the printed matter 5 orthogonal to the transport direction X.

  The printing surface 51 of the printed matter 5 is irradiated with ultraviolet rays UV from the LEDs of the ultraviolet irradiation device 3 after the ink 6 is attached by the printing unit 2. As shown in FIG. 2, the printing surface 51 is divided in a direction orthogonal to the transport direction X to form a plurality of irradiation areas 52. The size of the irradiation area 52 is equivalent to the range in which the LED of the ultraviolet irradiation device 3 irradiates the ultraviolet light UV, and the irradiation area 52 is configured in order from the end of the printing surface 51 in the transport direction X. In addition, the four irradiation areas 52a-52d are comprised in the printing surface 51 of the printed matter 5 of this embodiment.

  The control unit 1 includes a print control unit 11 that controls the operation of the printing unit 2, an ultraviolet control unit 12 that controls the operation of the ultraviolet irradiation device 3, and a conveyance control unit 13 that controls the operation of the conveyance mechanism 4. ing. The print controller 11 controls the operations of the ink roller 6a, the plate cylinder 21a, and the blanket cylinder 22a of the printing unit 2. The ultraviolet light control unit 12 controls turning on / off and dimming of the LED of the ultraviolet irradiation device 3. Further, the ultraviolet light control unit 12 controls the amount of ultraviolet light UV radiated by the LED of the ultraviolet light irradiation device 3 based on the amount of ink 6 attached to the printing surface 51. The conveyance control unit 13 controls the printing speed and print quality by controlling the speed of the conveyance mechanism 4 that conveys the printed material 5.

Below, control of the light quantity of the ultraviolet-ray UV which LED of the ultraviolet irradiation device 3 irradiates by the ultraviolet-ray control part 12 is demonstrated concretely.
FIG. 3 shows a schematic configuration diagram of the printing process.

  The printed product 5 is transported to the printing unit 2 by the transport mechanism 4. Then, the printing control unit 11 rotates the ink roller 6a, the plate cylinder 21a, and the blanket cylinder 22a of the printing unit 2 based on the conveyance speed signal PS output from the conveyance control unit 13. As a result, the ink 6 adhered to the plate 21 is once adhered to the blanket 22, and the blanket 22 contacts the printing surface 51 of the printed matter 5, whereby the ink 6 is transferred to the printing surface 51 according to the pattern of the plate 21. Is done. Note that the printing unit 2 of the present embodiment is composed of four printing units, and the printed matter is in the order of the printing unit (black) K, the printing unit (cyan) C, the printing unit (magenta) M, and the printing unit (yellow) Y. 5 is conveyed, and the ink 6 is attached to the printing surface 51. The order in which the ink 6 is attached is merely an example, and the present invention is not limited to this.

  Then, after the ink 6 of each color is attached to the printing surface 51, the printed material 5 is conveyed to the ultraviolet irradiation device 3 by the conveyance mechanism 4. Further, the ultraviolet light control unit 12 controls the amount of ultraviolet light UV irradiated by the LED of the ultraviolet light irradiation device 3 based on the amount of ink 6 attached to the printing surface 51. Below, control of the light quantity of ultraviolet-ray UV is demonstrated using FIG.

  The ultraviolet light control unit 12 stores the total adhesion amount Q of the ink 6 of all colors in each irradiation area 52 configured on the printing surface 51 based on the pattern of the plate 21 provided in the printing unit 2 of each color. 12a. In addition, the UV light amount N (hereinafter referred to as unit light amount N) that is optimal for curing the unit amount of the ink 6 is calculated in advance by a test and stored in the storage unit 12b. Then, the calculation unit 12c multiplies the total adhesion amount Q of the ink 6 stored in the storage unit 12a by using the unit light quantity N stored in the storage unit 12b as a coefficient, so that the ink 6 in each irradiation area 52 is cured. A light amount QN (hereinafter referred to as an optimal light amount QN) of the ultraviolet ray UV that is optimal for the calculation is calculated for each irradiation area 52.

  Moreover, the optical sensor 7 is provided in the upstream of the conveyance direction X in the irradiation range of LED. When the printed product 5 is conveyed and the optical sensor 7 senses the front end of the printed product 5, the ultraviolet light control unit 12 turns on the LED of the ultraviolet irradiation device 3, and the optimal amount of UV UV QN corresponding to each irradiation area 52. Irradiate. Below, the relationship between the irradiation time of ultraviolet-ray UV and the optimal light quantity QN is demonstrated using FIG.

  The ultraviolet light control unit 12 determines that the front end of the irradiation area 52a of the printing surface 51 enters the LED irradiation range based on the conveyance speed signal PS of the conveyance control unit 13 and the length L of the irradiation area 52 in the conveyance direction X. The time Ta until the rear end of the irradiation area 52a comes out of the LED irradiation range is calculated. Then, during the time Ta after the optical sensor 7 senses the front end of the printed matter 5, the LED irradiates the optimal amount QN (a) of ultraviolet UV corresponding to the irradiation area 52a.

  Next, at the same time as the rear end of the irradiation area 52a comes out of the LED irradiation range, the rear end of the irradiation area 52b enters the LED irradiation range. Therefore, the time Tb from the time when the rear end of the irradiation area 52b enters the LED irradiation range to the time when the rear end of the irradiation area 52b comes out of the LED irradiation range is calculated, and during the time Tb, the LED enters the irradiation area 52b. Irradiate the corresponding ultraviolet light UV with the optimum light quantity QN (b). Also for the irradiation area 52c, the time Tc is calculated in the same manner as the irradiation area 52b, and during the time Tc, the LED irradiates the optimal amount of UV UV light QN (c) corresponding to the irradiation area 52c.

  Next, for the irradiation area 52d located at the tail end of the printing surface 51, the time Td is calculated in the same manner as the irradiation areas 52b and 52c, and during the time Td, the LED is optimal for the ultraviolet UV corresponding to the irradiation area 52d. Irradiate light quantity QN (d). Then, when the time Td elapses, the ultraviolet light control unit 13 turns off the LED of the ultraviolet illumination device 3. In addition, the size of each irradiation area 52 of the present embodiment is configured to be the same, and the time Tb, Tc, and Td is from when the rear ends of the irradiation areas 52b, 52c, and 52d enter the irradiation range of the LED until they exit. Therefore, the times Tb, Tc, and Td are the same. The time Ta is the time from when the front end of the irradiation area 52a enters the LED irradiation range until the rear end of the irradiation area 52a comes out of the LED irradiation range, so the time Ta is twice the time Tb, Tc, and Td. It will be time.

  That is, the optical sensor 7 senses the printed matter 5, and the ultraviolet light control unit 12 irradiates the ultraviolet light UV with the optimum light quantity QN corresponding to each irradiation area 52 according to the elapsed time (Ta to Td) after turning on the LED. To do.

  As described above, the optimal amount of UV UV light for curing the ink 6 in each irradiation area 52 by changing the amount of UV UV light emitted by the LED for each irradiation area 52 formed on the printing surface 51. Can be irradiated. For example, in the irradiation area 52 where the total adhesion amount Q of the ink 6 is small, it is possible to reduce the amount of ultraviolet light UV irradiated by the LED. As a result, unlike the conventional ultraviolet irradiation device, the ultraviolet ray UV is not irradiated more than necessary. Therefore, power consumption can be reduced and the lifetime of the LED can be kept long. Furthermore, the heat generation of the LED is also suppressed, and the LED can be mounted at a higher density than in the past. Moreover, since the light source of the ultraviolet irradiation device 3 can be configured as a surface light source or a line light source by mounting LEDs at high density, unevenness of curing of the ink 6 can be suppressed. Furthermore, since the maximum amount of ultraviolet light UV increases, the time for curing the ink 6 can be shortened, and the printing efficiency can be improved.

  Further, since the amount of ultraviolet UV light is controlled based on the pattern of the plate 21 of the printing unit 2, it is necessary to confirm the quality of the printed matter 5 after printing by a printing test and adjust the amount of ultraviolet UV light as in the past. Therefore, the print adjustment time can be shortened and the printing efficiency can be improved.

  Moreover, in this embodiment, when there is no printed matter 5 in the irradiation range of the LED, the LED is automatically turned off, so that the power consumption can be further reduced.

(Embodiment 2)
FIG. 5 shows a schematic configuration diagram of the second embodiment of the present invention.

  The basic configuration of the printing press is the same as that of the first embodiment, and the same reference numerals are given and description thereof is omitted. The difference from the first embodiment is a method of controlling the light amount of the LED of the ultraviolet irradiation device 3 by the ultraviolet control unit 12.

  The ultraviolet light control unit 12 of this embodiment irradiates the LED for each irradiation area 52 based on the data of the plate 21 provided in the printing unit 2 of the color A (hereinafter referred to as “color A”) having the slowest curing speed. The amount of ultraviolet light UV is changed.

  The UV curable ink 6 has a different curing speed depending on the color, and generally black has the slowest curing speed. This is because the carbon used in the black ink has a characteristic of absorbing light. For this reason, the carbon absorbs most of the ultraviolet rays UV, and the ultraviolet rays UV do not sufficiently reach the catalyst for curing by the ultraviolet rays UV, so that the curing time of the black ultraviolet curable ink 6 is delayed.

  Therefore, in the present embodiment, the light amount of the ultraviolet ray UV is controlled based on the amount of the color A ink 6 having the slowest curing speed. Below, control of the light quantity of ultraviolet-ray UV is demonstrated using FIG.

  Based on the pattern of the plate 21 provided in the color A printing unit 2, the adhesion amount Qa of the color A ink 6 in each irradiation area 52 formed on the printing surface 51 is stored in the storage unit 12 a in the ultraviolet light control unit 12. Stored in In addition, a UV light amount Na (hereinafter referred to as a unit light amount Na) optimum for curing the unit amount of the ink 6 of color A is calculated in advance by a test, and the storage unit 12b in the UV control unit 12 is used. Stored in Then, the calculation unit 12c multiplies the unit light quantity Na stored in the storage unit 12b as a coefficient by the adhesion amount Qa of the ink 6 of the color A stored in the storage unit 12a, so that the color A of each irradiation area 52 is obtained. A UV light amount QNa (hereinafter referred to as an optimal light amount QNa) that is optimal for the ink 6 to be cured is calculated for each irradiation area 52.

  As in the first embodiment, the optical sensor 7 senses the printed matter 5, and the ultraviolet light control unit 12 performs ultraviolet light corresponding to each irradiation area 52 according to the elapsed time (Ta to Td) after turning on the LED. Irradiate the optimum light quantity QNa of UV.

  As described above, the optimum ultraviolet ray for curing the ink 6 of the color A in each irradiation area 52 by changing the amount of the ultraviolet ray UV irradiated by the LED for each irradiation area 52 configured on the printing surface 51. The amount of UV light can be irradiated. For example, in the irradiation area 52 where the adhesion amount of the color A ink 6 is small, it is possible to reduce the amount of ultraviolet light UV irradiated by the LED. As a result, unlike the conventional ultraviolet irradiation device, the ultraviolet ray UV is not irradiated more than necessary. Therefore, power consumption can be reduced and the lifetime of the LED can be kept long. Furthermore, the heat generation of the LED is also suppressed, and the LED can be mounted at a higher density than in the past. Moreover, since the light source of the ultraviolet irradiation device 3 can be configured as a surface light source or a line light source by mounting LEDs at high density, unevenness of curing of the ink 6 can be suppressed. Furthermore, since the maximum amount of ultraviolet light UV increases, the time for curing the ink 6 can be shortened, and the printing efficiency can be improved.

  Further, since the amount of ultraviolet UV light is controlled based on the pattern of the plate 21 of the printing unit 2, it is necessary to confirm the quality of the printed matter 5 after printing by a printing test and adjust the amount of ultraviolet UV light as in the past. Therefore, the print adjustment time can be shortened and the printing efficiency can be improved.

  Moreover, in this embodiment, when there is no printed matter 5 in the irradiation range of the LED, the LED is automatically turned off, so that the power consumption can be further reduced.

(Embodiment 3)
FIG. 6 shows a schematic configuration diagram of the third embodiment of the present invention.

  The basic configuration of the printing press is the same as that of the first embodiment, and the same reference numerals are given and description thereof is omitted. The difference from the first embodiment is a method of controlling the light amount of the LED of the ultraviolet irradiation device 3 by the ultraviolet control unit 12.

  The ultraviolet light control unit 12 of the present embodiment changes the amount of ultraviolet light UV irradiated by the LED for each irradiation area 52 based on the ratio of the adhesion area of each color ink 6 to the area of each irradiation area 52 on the printing surface 51. . Below, control of the light quantity of ultraviolet-ray UV is demonstrated using FIG.

  Based on the pattern of the plate 21 provided in the printing unit 2 of each color, the ratio of the adhesion area of the ink 6 of each color to the area of each irradiation area 52 formed on the printing surface 51 is a storage unit in the ultraviolet light control unit 12. 12a. Note that this embodiment is configured by a four-color printing unit 2 as in the first embodiment, and the ratio of the adhesion area of the ink 6 of each color (K, C, M, Y) to the area of the irradiation area 52 is as follows. The ratio is A: B: C: D, and is 1 when A to D are added.

  In addition, an optimum dimming ratio (hereinafter referred to as a color dimming ratio) for curing the ink 6 of each color (K, C, M, Y) with a rated light amount of 100% is calculated in advance by a test. The color dimming ratios of the respective colors (K, C, M, and Y) are a%, b%, c%, and d%, and are stored in the storage unit 12b in the ultraviolet light control unit 12.

  And based on the ratios A to D of the adhesion area of the ink 6 of each color for each irradiation area 52 stored in the storage unit 12a and the color light amount ratios a% to d% of each color stored in the storage unit 12b. The calculation unit 12c calculates the ultraviolet light UV dimming ratio S (hereinafter referred to as the optimal dimming ratio S) optimal for curing the ink 6 in each irradiation area 52 for each irradiation area 52. The optimum dimming ratio S indicates the ratio of the light amount of the ultraviolet ray UV, where the rated light amount is 100. Hereinafter, the optimum dimming ratio S will be described.

  For each irradiation area 52, the calculation unit 12c multiplies the adhering area ratios A to D of the ink 6 of each color by using the color tonal ratio a% to d% as a coefficient. Then, the optimum dimming ratio S is calculated for each irradiation area 52 by adding all the multiplication results of the respective colors. Formula (1) shows a derivation formula for the optimum dimming ratio S.

S = Aa + Bb + Cc + Dd (1)
As in the first embodiment, the optical sensor 7 senses the printed matter 5, and the ultraviolet light control unit 12 is optimal for each irradiation area 52 according to the elapsed time (Ta to Td) after the LED is turned on. Irradiate ultraviolet rays UV having a dimming ratio S.

  As described above, the ink 6 of each color (K, C, M, Y) in each irradiation area 52 is changed by changing the amount of ultraviolet light UV irradiated by the LED for each irradiation area 52 configured on the printing surface 51. It is possible to irradiate with an amount of ultraviolet light UV that is optimal for curing. For example, in the irradiation area 52 where the adhesion area of the ink 6 having a color with a low color tone ratio is large, the amount of ultraviolet UV irradiated by the LED can be reduced. As a result, unlike the conventional ultraviolet irradiation device, the ultraviolet ray UV is not irradiated more than necessary. Therefore, power consumption can be reduced and the lifetime of the LED can be kept long. Furthermore, the heat generation of the LED is also suppressed, and the LED can be mounted at a higher density than in the past. Moreover, since the light source of the ultraviolet irradiation device 3 can be configured as a surface light source or a line light source by mounting LEDs at high density, unevenness of curing of the ink 6 can be suppressed. Furthermore, since the maximum amount of ultraviolet light UV increases, the time for curing the ink 6 can be shortened, and the printing efficiency can be improved.

  Further, since the amount of ultraviolet UV light is controlled based on the pattern of the plate 21 of the printing unit 2, it is necessary to confirm the quality of the printed matter 5 after printing by a printing test and adjust the amount of ultraviolet UV light as in the past. Therefore, the print adjustment time can be shortened and the printing efficiency can be improved.

  Moreover, in this embodiment, when there is no printed matter 5 in the irradiation range of the LED, the LED is automatically turned off, so that the power consumption can be further reduced.

DESCRIPTION OF SYMBOLS 1 Control part 2 Printing unit 3 Ultraviolet irradiation apparatus 4 Conveyance mechanism 5 Printed matter 6 Ultraviolet curable ink 7 Optical sensor 11 Print control part 12 Ultraviolet control part 13 Conveyance control part 21 Plate 22 Blanket

Claims (4)

Provided with a light source composed of LEDs that irradiate ultraviolet rays and a light source control unit that controls the amount of light of the light source on the printed surface of a printed matter that is cured by irradiating ultraviolet rays and has a plurality of colors of ultraviolet curable ink attached thereto ,
The printing surface is divided into a plurality of irradiation areas, and the light source control unit controls the light amount of the light source for each printing area based on at least the adhesion amount of the ultraviolet curable ink in each irradiation area. UV irradiation device.   2. The printing according to claim 1, wherein the light source control unit controls the light amount of the light source for each irradiation area based on a total adhesion amount of the ultraviolet curable ink of all colors in each irradiation area. UV irradiation equipment.   The light source control unit controls the light amount of the light source for each irradiation area based on the amount of the ultraviolet curable ink having the slowest curing speed in each irradiation area. UV irradiation equipment for printing. The light source control unit performs irradiation based on a ratio of the adhesion amount of the ultraviolet curable ink of each color adhering to the irradiation area to the total adhesion amount of the ultraviolet curable ink of all colors in the irradiation area. The ultraviolet irradiation device for printing according to claim 1, wherein the light quantity of the light source is controlled for each area.

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