JP2019142128A - Printer and printing method - Google Patents

Abstract

To provide a printer and a printing method for implementing high-quality printing by suppressing floating of a printing object from a table due to irradiation of a UV ray, in printing an image on a printing object extending like a belt, using UV-curable ink.SOLUTION: A table 16 supports a rear side of a partial printing section of a printing object 1 extending like a belt. A control device controls a printing head, a first moving mechanism, and a second moving mechanism, and irradiates the printing object 1 with a UV ray generated from UV light in order to cure UV-curable ink, while printing an image in the printing section of the printing object 1 supported on the table 16 by using a printing head. The table 16 includes multiple suction holes 6 for adsorbing the printing object 1, and intervals Ps and Pn of each suction hole 6 have a length that makes a floating amount of the printing object 1 from the table 16 due to irradiation of a UV ray generated from UV light, smaller than a gap between a surface of the printing object 1 before floating and the printing head.SELECTED DRAWING: Figure 3

Description

  The present invention prints an image on a part of a print section of a print object (media) extending in a belt shape by using an inkjet head that discharges UV curable ink that is cured by being irradiated with ultraviolet rays (UV). The present invention relates to a printing apparatus and a printing method. The printing object includes a thin film resin film and the like. In the present invention, the “printing section” refers to a range in the longitudinal direction of an object to be printed that can be printed by a series of scans by an inkjet head of a printing apparatus.

  An ink jet printer using an ink jet head enables high-quality printing and is widely used in various fields. In particular, sheet-fed printing that handles a sheet-like printing object is capable of quality-oriented printing due to its configuration, and is suitable for the production of a small variety of products. On the other hand, in industrial applications, there is a great demand for printing on roll films, roll papers, and the like that can be mass-produced. In this field, improvement in print quality is desired.

  In printing on a strip-shaped print object such as roll film or roll paper, the print quality can be improved with high-precision scanning technology using an inkjet head, and the print object is transported with high precision to change the print section. Conveying technology becomes a problem. Patent Document 1 discloses a work stage that sucks and holds a recording area of a long work (the “printing section” of the present invention) and a work holding means that holds a part of the work immovably. In addition to removing the recorded recording area from the work stage and feeding the unrecorded recording area to the work stage, the recording area of the long workpiece is accurately removed. A recording apparatus is disclosed. Moreover, as a work stage for sucking and holding a work, Patent Document 2 is provided with sucking holes for sucking a work, and increasing the number of suction holes per fixed area in a portion along two opposite sides of the stage. An adsorption device that ensures the flatness of a workpiece is disclosed.

Japanese Patent Laying-Open No. 2015-77811 JP 2011-230463 A

  In recent years, in various industrial fields, there is an increasing demand for printing on a thin resin film or the like using a UV curable ink that is cured by being irradiated with ultraviolet rays. When printing is performed using UV curable ink, the UV curable ink on the printing object is cured by irradiating the printed object with UV light from a UV light that generates ultraviolet light. In that case, in a printing object such as a thin resin film, the temperature of the printing object is increased by irradiation with ultraviolet rays, and the printing object is thermally expanded due to the temperature increase. In the techniques described in Patent Document 1 and Patent Document 2, thermal expansion of a printing object such as a resin film due to ultraviolet irradiation has not been considered.

  When printing using UV curable ink, UV light that generates ultraviolet light is moved with a print head equipped with an inkjet head that discharges UV curable ink, and the ultraviolet light generated from UV light is printed immediately after printing. When UV curable ink is cured immediately after printing by irradiating the object, the UV curable ink has fluidity before curing compared to the case where the UV light is disposed at the subsequent stage of the print head in the longitudinal direction of the printing object. The diffusion on the print object is reduced, and the print quality is improved. Further, as the print head is arranged closer to the surface of the printing object, the spread of the UV curable ink ejected from the inkjet head becomes smaller, and an improvement in print quality can be expected. However, if the print head is arranged at a position close to the surface of the print object, the print object may come into contact with the print head when the print object is lifted from the table due to thermal expansion.

  An object of the present invention is to perform high-quality printing by suppressing lifting of a printing object from a table due to irradiation of ultraviolet rays when printing an image on a printing object extending in a strip shape using UV curable ink. That is.

  A printing apparatus according to the present invention includes a table that supports the back surface of a part of a printing section of a print object that extends in a strip shape, and a print head that includes an inkjet head that discharges UV curable ink that is cured by irradiation with ultraviolet rays. A UV light source that generates ultraviolet light, a first moving mechanism that moves the table in the longitudinal direction of the print object, and the print head and UV light source while the print head is kept at a predetermined distance from the surface of the table. The second moving mechanism that moves in the width direction, the print head, the first moving mechanism, and the second moving mechanism are controlled, and an image is printed on the print section of the print object supported by the table by the print head. And a control device that cures the UV curable ink by irradiating the object to be printed with ultraviolet rays generated from a UV light source while the table is being printed. The spacing between the suction holes is such that the amount of lifting of the printing object from the table due to the irradiation of ultraviolet light generated from the UV light source is smaller than the gap between the surface of the printing object and the print head before lifting. It is the length which becomes.

  In the printing method of the present invention, the back surface of a part of the printing object extending in a strip shape is supported by a table having a plurality of suction holes, and the first moving mechanism is used to support the table in the longitudinal direction of the printing object. The print head mounted with the inkjet head that discharges the UV curable ink that is cured by being irradiated with ultraviolet rays by the second moving mechanism is maintained at a predetermined distance from the surface of the table. The UV light source that generates UV light is moved in the width direction of the object to be printed, and the UV light generated from the UV light source is printed while the image is printed on the print section of the object to be printed supported by the table. The UV curable ink is cured by irradiating the object, and the interval between the adsorption holes of the table is set to the table of the object to be printed by the irradiation of ultraviolet rays generated from the UV light source. The printing section of the printing object supported by the table while adsorbing the printing object by a plurality of suction holes so that the amount of lifting of the printing object is smaller than the gap between the surface of the printing object before the lifting and the print head An image is printed on the screen.

  The back surface of a part of the print section of the print object extending in a band shape is supported by a table having a plurality of suction holes, and the table is moved in the longitudinal direction of the print object by the first movement mechanism, and the second movement The print head and UV light source that generates ultraviolet rays are printed while the print head equipped with an inkjet head that discharges UV curable ink that is cured by irradiation with ultraviolet rays is maintained at a predetermined distance from the surface of the table. The UV curable type is irradiated with ultraviolet rays generated from a UV light source while moving in the width direction of the object and printing an image on the print section of the object to be printed supported by the table by the print head. Since the ink is cured, the UV curable ink has a fluidity before curing as compared with the case where the UV light source is disposed at the subsequent stage of the print head in the longitudinal direction of the printing object. Smaller diffusion on the printing object, the print quality is improved. The distance between the suction holes of the table is such that the amount of lifting of the printing object from the table by irradiation of ultraviolet rays generated from the UV light source is smaller than the gap between the surface of the printing object and the print head before lifting. Therefore, it is possible to reduce the spread of the UV curable ink discharged from the inkjet head by arranging the print head near the surface of the printing object. Therefore, when an image is printed on a print object extending in a strip shape using UV curable ink, lifting of the print object from the table due to irradiation of ultraviolet rays is suppressed, and high-quality printing is performed.

  Furthermore, the printing apparatus according to the present invention is configured such that the table has a plurality of suction holes in the width direction of the print object around the edge of the print object supported by the table at a shorter interval than the center of the print object. It is characterized by having. Further, in the printing method of the present invention, in the width direction of the printing object, a plurality of suction holes are provided around the edge of the printing object supported by the table at intervals shorter than the central part of the printing object. It is characterized by. In the width direction of the print object, a plurality of suction holes are provided around the edge of the print object supported by the table at intervals shorter than the center part of the print object. The amount of lifting of the print object is further reduced in the vicinity of the end of the print object that is likely to come into contact with the print head that is moved to the position.

  Furthermore, in the printing apparatus of the present invention, the table has a plurality of suction holes in the longitudinal direction of the print object on the inside of the print section of the print object supported by the table and on the outside of the print section of the print object. It is characterized by having each. Further, in the printing method of the present invention, in the longitudinal direction of the printing object, a plurality of suction holes are respectively provided inside the printing section of the printing object supported by the table and outside the printing section of the printing object. It is characterized by. In the longitudinal direction of the printing object, a plurality of suction holes are provided outside the printing area of the printing object supported by the table. Even if the heat of the ultraviolet rays irradiated from is conducted, the elongation of the print object is suppressed at that part, and wrinkles etc. occur in the part that is not supported by the table of the print object that follows that part. Is prevented.

  Furthermore, the printing apparatus of the present invention is characterized in that the diameter of each suction hole of the table is such that the amount of deformation of the print object due to suction becomes a predetermined value or less according to the suction pressure. Further, the printing method of the present invention is characterized in that the diameter of each suction hole of the table is set to a size such that the amount of deformation of the print object due to the suction is a predetermined value or less according to the suction pressure. If the print object is thin, the print object may be deformed and dented due to adsorption by the suction holes. The diameter of each suction hole of the table is set to a size that causes the deformation amount of the print object due to suction to be a predetermined value or less according to the suction pressure, so that deformation of the print object due to suction is suppressed, and higher quality printing is performed. Is done.

  According to the present invention, when printing an image on a print object extending in a strip shape using UV curable ink, high-quality printing is performed by suppressing the lifting of the print object from the table due to ultraviolet irradiation. be able to.

  Further, in the width direction of the printing object, by providing a plurality of suction holes around the edge of the printing object supported by the table at intervals shorter than the central part of the printing object, in particular, the printing object. The amount of lifting of the printing object can be further reduced around the edge of the printing object that is likely to come into contact with the print head moved in the width direction.

  Furthermore, in the longitudinal direction of the printing object, a plurality of suction holes are provided outside the printing area of the printing object supported by the table, so that the area outside the printing area of the printing object is not printed. Even if the heat of the ultraviolet light irradiated from the UV light source is conducted, it is possible to suppress the elongation of the print object at that portion, and to wrinkle the portion not supported by the table of the print object following that portion. And the like can be prevented.

  Furthermore, by setting the diameter of each suction hole of the table to a size that causes the amount of deformation of the print object due to suction to be a predetermined value or less according to the suction pressure, the deformation of the print object due to suction is further suppressed. High quality printing can be performed.

1A and 1B are diagrams illustrating a schematic configuration of a printing apparatus according to an embodiment of the present invention, in which FIG. 1A is a top view and FIG. 1B is a side view. It is the front view which looked at the movement stage and the gate from the collection reel side. 3A is a top view of the table, and FIG. 3B is a cross-sectional view taken along the line AA of the table of FIG. It is a figure explaining the amount of lifting of a printing subject. 1 is a block diagram of a detection device and a control device of a printing apparatus according to an embodiment of the present invention. 4 is a flowchart illustrating an operation of the printing apparatus according to the embodiment of the present invention. It is a figure explaining printing operation of one printing section. It is a figure which shows the printed image and the positioning mark for one printing section. It is a figure explaining the change operation of a printing section. It is a figure explaining the change operation of a printing section. It is a figure explaining the detection operation of the position of the mark for positioning. It is a figure explaining the detection operation of the position of the mark for positioning It is a figure which shows the image and positioning mark which were printed for two printing sections.

[Embodiment]
Hereinafter, a printing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the embodiment described below, the printing object 1 is made of a resin film such as PBT (polybutylene terephthalate) or PET (polyethylene terephthalate). In the drawings used below, in order to facilitate understanding of the operation of the printing apparatus, the distance between the surface of the table 16 and the print head 10 is made larger than that of the actual apparatus.

(Configuration of printing device)
1A and 1B are diagrams illustrating a schematic configuration of a printing apparatus according to an embodiment of the present invention, in which FIG. 1A is a top view and FIG. 1B is a side view. The printing apparatus 100 according to the present embodiment includes a print head 10, a base 11, a gate 12, a guide 13, a moving stage 14, a θ stage 15, a table 16, a first moving mechanism, a second moving mechanism, a UV light 20, A supply reel 21, dancer rollers 22 and 25, guide rollers 23 and 24, a recovery reel 26, an upper roller 27, and a detection device 30 and a control device 40 described later are configured.

  In the present embodiment, a supply reel 21 is used as a supply mechanism for supplying the printing object 1 before printing. However, the supply mechanism of the printing object 1 is not limited to a reel, and any mechanism that supports the printing object 1 wound in a roll shape so as to be rotatable can be used. In the present embodiment, the collection reel 26 is used as a collection mechanism for collecting the printed object 1 after printing. However, the collection mechanism for the print target 1 is not limited to a reel, and any mechanism that can store the print target 1 in a space-saving manner may be used.

  A drive motor (not shown) is attached to the supply reel 21 and the recovery reel 26. The print target 1 extending in a belt shape is fed out from the supply reel 21, and is wound around the collection reel 26 via the dancer roller 22, the guide rollers 23 and 24, and the dancer roller 25. In FIG. 1A, the width direction of the print object 1 is the X direction, and the longitudinal direction of the print object 1 is the Y direction. The supply reel 21 may be configured to rotate according to the movement of the print target 1 without attaching a driving motor.

  Each of the dancer roller 22 and the dancer roller 25 is configured to be movable up and down, and is urged downward in the drawing of FIG. Thereby, tension is applied to the printing object 1 in the longitudinal direction, and unnecessary positional deviation of the printing object 1 is suppressed.

  The print head 10 is equipped with a plurality of inkjet heads. In the case of a color printing apparatus, for example, an inkjet head for each color of cyan (C), magenta (M), yellow (Y), and black (K) is mounted, or a plurality of sets of inkjet heads for each color are installed. It is installed. Each inkjet head discharges a UV curable ink that is cured by being irradiated with ultraviolet rays.

  In FIG. 1B, a guide 13 is installed on the upper surface of the base 11, and a moving stage 14 is mounted on the guide 13. The moving stage 14 moves in the Y direction along the guide 13. A θ stage 15 is mounted on the moving stage 14, and a table 16 is mounted on the θ stage 15. The θ stage 15 rotates the table 16 in the θ direction. The table 16 supports the back surface of a part of the printing section of the printing object 1 extending in a strip shape. The surface of the table 16 is provided with suction holes to be described later, and the table 16 vacuum-sucks the back surface of the printing section of the print object 1 with the suction holes during printing, so that the print object 1 is placed on the table 16. Secure to.

  In FIG. 1A, a gate 12 is provided above the table 16 over a length that is equal to or greater than the width of the print target 1. FIG. 2 is a front view of the moving stage and the gate as viewed from the collection reel side. In the present embodiment, the first moving mechanism that moves the table 16 in the longitudinal direction of the printing object 1 is constituted by a linear motor, and the linear motor of the first moving mechanism has a built-in magnet. It consists of a plate-like stator 17a and a plate-like mover 17b with a built-in coil. The stator 17 a extends in the depth direction of FIG. 2 and is embedded in the upper surface of the base 11. The mover 17 b is attached to the lower surface of the moving stage 14. The stator 17a and the mover 17b are installed so as not to contact each other with a slight gap. When a current is passed through the coil of the mover 17b, the framing is determined from the coil current and the magnetic field of the magnet of the stator 17a. In accordance with the left hand rule, a propulsive force (Lorentz force) acts on the mover 17b, and the moving stage 14 is moved in the drawing front direction or the drawing depth direction in FIG.

  Similarly, the second moving mechanism that moves the print head 10 in the width direction of the print object 1 is configured by a linear motor 18. The linear motor 18 is attached to the side surface of the gate 12. In the case of the linear motion motor 18, a guide in the X direction, a stator made of a magnet, and a mover made of a coil are housed. The operating principle of the linear motion motor 18 is the same as that of the linear motion motor of the first moving mechanism, and the print head 10 is moved in the X direction by the linear motion motor 18. At this time, the distance between the surface of the table 16 and the print head 10 is kept constant, and the second moving mechanism keeps the print head 10 at a predetermined distance from the surface of the table 16 while keeping the print head 10 at a predetermined distance. Move in the width direction of 1.

  A camera unit 31 constituting a detection device 30 described later is attached to one side surface of the print head 10. The camera unit 31 includes a light source 32, a lens 33, and a camera 34. The illumination light generated from the light source 32 is reflected by the half mirror in the lens 33 and is irradiated onto the surface of the printing object 1 supported by the table 16. The camera 34 has a two-dimensional image sensor such as a CCD, acquires a mark image of a positioning mark 3 to be described later via a lens 33, and outputs an image signal.

  A UV light 20 that generates ultraviolet rays is attached to the other side surface of the print head 10. The UV light 20 is composed of an ultraviolet lamp, a light emitting diode (LED), or the like, and irradiates the surface of the printing object 1 supported by the table 16 with ultraviolet rays, so that the surface of the printing object 1 from each inkjet head of the printing head 10. The UV curable ink discharged to is cured.

(Table structure)
3A is a top view of the table, and FIG. 3B is a cross-sectional view taken along the line AA of the table of FIG. 3A, the table 16 has a support base 16a that supports the back surface of a part of the printing section of the printing object 1, and a plurality of suction holes 6 are provided on the surface of the support base 16a. Yes. As shown in FIG. 3B, the decompression space 7 is formed inside the table 16, and each suction hole 6 penetrates the support base 16 a from the surface of the support base 16 a to the decompression space 7. Communicates. The inside of the decompression space 7 is decompressed by the vacuum pump 5, whereby each suction hole 6 vacuum-sucks the back surface of the printing object 1 supported by the support base 16 a. The suction force of each suction hole 6 is larger than the force that expands when the printing object 1 is thermally expanded by irradiation with ultraviolet rays generated from the UV light 20.

  In FIG. 3A, each suction hole 6 has an interval (pitch) Ps at the center of the printing object 1 supported by the table 16 in the width direction of the printing object 1, and the end of the printing object 1. In the periphery, it is formed on the support 16a with a spacing Pn. Further, in the longitudinal direction of the printing object 1, the intervals between the suction holes 6 are all Ps. The intervals Ps and Pn between the suction holes 6 are such that the amount of lifting of the printing object 1 from the table 16 due to the irradiation of ultraviolet rays generated from the UV light 20 is the surface of the printing object 1 before the lifting and the print head 10. The length is smaller than the gap.

  FIG. 4 is a diagram for explaining the amount of lifting of the print object. FIG. 4A shows a state in which the printing object 1 is lifted from the table 16 due to thermal expansion due to irradiation of ultraviolet rays generated from the UV light 20. When the interval between the suction holes 6 is Ps, the linear expansion coefficient of the print object 1 is α, and the rising temperature of the print object 1 due to the irradiation of ultraviolet rays generated from the UV light 20 is ΔT. The elongation amount ΔPs due to thermal expansion of the printing object 1 is expressed by the equation (1). In FIG. 4B, a right triangle DEF is hypothesized as shown in FIG. 4B with respect to the surface of the printed object 1 lifted by a broken line. Then, when the length of the hypotenuse DE of the right triangle DEF is approximated to (Ps + ΔPs) / 2, which is half of the sum of the interval Ps between the suction holes 6 and the extension amount ΔPs, Holds. Therefore, the expression (3) is obtained from the expression (2), and the lifting amount δ of the printing object 1 can be calculated by the expression (3). In the present embodiment, equations (1) and (3) are used so that the lift amount δ calculated by equation (3) is smaller than the gap H between the surface of the printing object 1 and the print head 10 before the lift. From this, the interval Ps is determined. Further, the interval Pn is determined as Pn = Ps / x (x ≧ 2).

  At this time, the intervals Ps and Pn between the respective suction holes 6 are made as long as possible in a range where the amount of lifting δ of the printing object 1 is smaller than the gap H between the surface of the printing object 1 and the printing head 10 before lifting. Since the number of the suction holes 6 is small, the printing object 1 can be fixed efficiently. Further, as the distances Ps and Pn between the suction holes 6 are shortened, the floating amount δ of the print object 1 is reduced, and the print quality is improved.

  The back surface of a part of the printing section of the printing object 1 extending in a band shape is supported by a table 16 having a plurality of suction holes 6, and the table 16 is moved in the longitudinal direction of the printing object 1 by the first moving mechanism. The print head 10 and the ultraviolet rays are held while the print head 10 mounted with the inkjet head for discharging the UV curable ink that is cured by being irradiated with ultraviolet rays by the second moving mechanism is kept at a predetermined distance from the surface of the table 16. The UV light 20 is generated in the width direction of the print object 1 and is generated from the UV light 20 while the print head 10 prints an image on the print section of the print object 1 supported by the table 16. Since the UV curable ink is cured by irradiating the printed object 1 with the UV light, the UV light source is placed downstream of the print head 10 in the longitudinal direction of the print object 1. Compared with the case of location, diffusion on the printing object 1 UV curable ink having fluidity before curing becomes small, the printing quality is improved. The distance Ps and Pn between the suction holes 6 of the table 16 is set so that the amount of lifting of the printing object 1 from the table 16 due to the irradiation of ultraviolet rays generated from the UV light 20 is the same as the surface of the printing object 1 before lifting. Since the length is smaller than the gap H between the head 10 and the print head 10, the spread of the UV curable ink ejected from the inkjet head can be reduced by disposing the print head 10 near the surface of the printing object 1. Become. Therefore, when an image is printed on the print object 1 extending in a strip shape using the UV curable ink, lifting of the print object 1 from the table 16 due to irradiation of ultraviolet rays is suppressed, and high-quality printing is performed.

  Further, in FIG. 3A, in the table 16 of the present embodiment, in the width direction of the print object 1, the interval Pn between the suction holes 6 around the edge of the print object 1 supported by the table 16. However, it is shorter than the interval Ps between the suction holes 6 at the center of the printing object 1. As a result, the amount of lifting of the printing object 1 is further reduced particularly in the vicinity of the end of the printing object 1 that is likely to come into contact with the print head 10 that is moved in the width direction of the printing object 1. Moreover, it can respond also to the printing target object from which the dimension of the width direction differs a little.

  Furthermore, in the table 16 of the present embodiment, a plurality of print objects 1 are arranged inside the print section of the print object 1 supported by the table 16 and outside the print section of the print object 1 in the longitudinal direction of the print object 1. Adsorption holes 6 are respectively provided. The suction holes 6 inside the print section of the print object 1 suck the back surface of the print section of the print object 1. A printing area on the printing object 1 by the printing apparatus 100 according to the present embodiment is a range indicated by a broken line in FIG. The suction holes 6 outside the printing section of the printing object 1 form a non-printing suction section, and suck the back surface of the section where printing is not performed outside the printing section in the longitudinal direction of the printing object 1.

  Since a plurality of suction holes 6 are provided outside the print section of the print object 1 supported by the table 16 in the longitudinal direction of the print object 1, printing is performed outside the print section of the print object 1. Even if the heat of the ultraviolet light irradiated from the UV light 20 is conducted to a non-compartment, it is suppressed that the print object 1 is stretched at that portion, and is supported by the table 16 of the print object 1 following that portion. It is possible to prevent wrinkles and the like from being generated in the unfinished portion.

  Furthermore, in the table 16 of the present embodiment, the diameter of each suction hole 6 is a predetermined value in which the deformation amount of the print object 1 due to suction is determined in advance according to the suction pressure, that is, the pressure of air in the decompression space 7. The size is as follows. Thereby, the deformation | transformation of the printing target 1 by adsorption | suction is suppressed and still higher quality printing is performed. In addition, although the diameter of the suction hole 6 is about several mm, in FIG.3 and FIG.4, the suction hole 6 is shown larger than actual so that it may be easy to see.

(Configuration of detection device and control device)
FIG. 5 is a block diagram of a detection apparatus and a control apparatus of the printing apparatus according to an embodiment of the present invention. The detection device 30 includes a camera unit 31 and an image processing device 35 that processes an image signal of a mark image output from the camera unit 31. The control device 40 includes a CPU 41, a main scanning control unit 42, a sub-scanning control unit 43, a printing control unit 44, a θ stage drive control unit 45, a supply reel drive control unit 47, and a collection reel drive control unit 48. ing. The CPU 41 commands the operations of the main scanning control unit 42, the sub scanning control unit 43, the θ stage drive control unit 45, the supply reel drive control unit 47, and the collection reel drive control unit 48.

  The main scanning control unit 42 performs drive control of the print head 10 via the print control unit 44, and also performs drive control of the linear motion motor 18 that constitutes the second moving mechanism, so that the print head for the print target 1 is printed. 10 main scans are controlled. The sub-scanning control unit 43 controls the sub-scanning of the print head 10 with respect to the print target 1 by performing drive control of the mover 17b of the linear motion motor constituting the first moving mechanism. The θ stage drive control unit 45 performs drive control of the θ stage 15. The supply reel drive control unit 47 controls the drive motor of the supply reel 21 to send out the print target 1 from the supply reel 21. The collection reel drive control unit 48 controls the drive of the drive motor for the collection reel 26 to wind the print target 1 around the collection reel 26.

(Printing operation of one printing section)
FIG. 6 is a flowchart showing the operation of the printing apparatus according to the embodiment of the present invention. The printing apparatus 100 first prints one printing section (step 101). FIG. 7 is a diagram for explaining a printing operation in one printing section. In the printing apparatus 100 of the present embodiment, the width direction (X direction) of the print object 1 is the main scanning direction, and the longitudinal direction (Y direction) of the print object 1 is the sub-scanning direction. The main scanning control unit 42 in FIG. 5 first performs drive control of the linear motion motor 18 to move the print head 10 to the movement start position in the width direction (X direction) of the print target 1.

  Next, the main scanning control unit 42 performs drive control of the linear motion motor 18 to move the print head 10 in the drawing depth direction of FIG. Drive control is performed, and printing for one scanning width is performed on the printing object 1. At this time, the UV curable ink ejected from each inkjet head of the print head 10 to the surface of the printing object 1 is cured immediately after printing by the ultraviolet rays irradiated from the UV light 20. Subsequently, the sub-scanning control unit 43 in FIG. 5 performs drive control of the mover 17b of the linear motion motor, moves the moving stage 14 in the Y direction, and print object 1 that is sucked and fixed on the table 16. Is moved in the Y direction by one scanning width. In the meantime, the main scanning control unit 42 controls the drive of the linear motor 18 and returns the print head 10 to the movement start position. These operations are repeated to print the entire print section. FIG. 7A shows the position of the moving stage 14 in the Y direction at the start of printing, and FIG. 7B shows the position of the moving stage 14 in the Y direction when printing for one printing section is completed. ing.

  When the moving stage 14 is moved in the Y direction, the dancer roller 22 moves upward in the drawing shown by the arrow in FIG. 7A against the biasing force, and the dancer roller 25 is attached thereto. Due to the force, it moves downward in the figure as indicated by the arrow in FIG. Therefore, it is not necessary to drive the supply reel 21 and the recovery reel 26 every time the moving stage 14 is moved in the Y direction. The drive reels 22 and 25 can move up and down by driving the supply reel 21 and the recovery reel 26. You can do this when you are approaching the limits of the range.

  The print control unit 44 stores image data to be printed on the print object 1 and positioning mark data. The print head 10 prints an image and a positioning mark on the print section of the print object 1. To do. FIG. 8 is a diagram showing a printed image and positioning marks for one printing section. The positioning mark 3 has a shape that allows easy image recognition, such as a cross shape, for example, and two or more positioning marks 3 are printed at the corners in the width direction of the print object 1 for each printing section. .

  In the printing apparatus 100 of the present embodiment, printing is performed when the print head 10 is moved in the same direction. However, printing may be performed while the print head 10 is moved in the direction opposite to the previous scan. Good. In that case, UV light sources that generate ultraviolet rays are provided on both sides of the print head 10 in the scanning direction.

(Print section change operation)
In FIG. 6, when printing for one printing section is completed, the CPU 41 in FIG. 5 determines whether printing of all printing sections has been completed (step 102). If printing of all print sections has not been completed, the printing apparatus 100 changes the print section (step 103). 9 and 10 are diagrams for explaining the operation of changing the print section. In the present embodiment, the linear motion motors (stator 17a and mover 17b) as the first moving mechanism also serve as a printing section changing mechanism that changes the printing section of the printing object 1 supported by the table 16. Yes. Further, the guide rollers 23 and 24 and the upper roller 27 constitute a holding mechanism that holds the printing object 1 and lifts it from the table 16.

  FIG. 9A shows a state where printing for one printing section is completed. First, the printing apparatus 100 lowers the upper roller 27 located above the guide rollers 23 and 24 from the state shown in FIG. 9A, and as shown in FIG. The printing object 1 is held between the rollers 23 and 24. Then, after releasing the vacuum suction of the printing object 1 by the table 16, the printing apparatus 100 raises the upper roller 27 and the guide roller 23 sandwiching the printing object 1 together, and also moves the printing object 1 The upper roller 27 and the guide roller 24 sandwiched are raised together, and the printing object 1 is lifted from the table 16 as shown in FIG. Then, the sub-scan control unit 43 in FIG. 5 performs drive control of the movable element 17b of the linear motion motor, moves the moving stage 14 in the opposite direction to that during printing, and prints the printing section where the printing of the table 16 has been completed. Return to where it was at the start.

  FIG. 10A shows a state where the table 16 is returned to the original location. From the state shown in FIG. 10A, the printing apparatus 100 lowers the upper roller 27 and the guide roller 23 that sandwich the printing object 1 together, and the upper roller 27 that sandwiches the printing object 1 and The guide roller 24 is lowered together, and the printing object 1 is mounted on the table 16 as shown in FIG. Then, the printing apparatus 100 lifts the upper roller 27 to the original position as shown in FIG. Through the above series of operations, the printing section of the printing object 1 supported by the table 16 is changed.

  While the first moving mechanism also serves as the print section changing mechanism and the holding mechanism holds the print target 1, the table 16 is returned to the place where the printing started in the print section where printing was completed, and the table Since the printing section of the printing object 1 supported by the printer 16 is changed, it is not necessary to separately provide a printing section changing mechanism, and the configuration is simple. Further, since it is not necessary to separately perform the operation of returning the table 16 to the original place, the tact time is shortened.

  Further, since the printing object 1 is held by the holding mechanism and lifted from the table 16, the table 16 is returned to the place where the printing started in the printing section where printing was completed, and the printing object 1 supported by the table 16. When the printing section is changed, the printing object 1 is not displaced due to friction with the table 16.

(Detection operation of positioning mark position)
In FIG. 6, when the change of the printing section is completed, the printing apparatus 100 detects the position of the positioning mark (step 104). 11 and 12 are diagrams for explaining the operation of detecting the position of the positioning mark. The main scanning control unit 42 in FIG. 5 first performs drive control of the linear motion motor 18 to move the camera unit 31 attached to the print head 10 to the position of the two positioning marks 3 as shown in FIG. Move one of the above to the sky. The camera unit 31 acquires a mark image of the positioning mark 3, and the image processing device 35 in FIG. 5 processes the image signal of the mark image output from the camera unit 31 to print the positioning mark 3 print object. The position in the longitudinal direction of 1 and the position in the width direction are detected. Subsequently, the main scanning control unit 42 performs drive control of the linear motion motor 18 so that the camera unit 31 attached to the print head 10 is replaced with one of the two positioning marks 3 as shown in FIG. Move to one sky. The camera unit 31 acquires the mark image of the positioning mark 3, and the image processing device 35 processes the image signal of the mark image output from the camera unit 31, and the length of the printing object 1 of the positioning mark 3 The position in the direction and the position in the width direction are detected.

(Determination of correction amount)
In FIG. 6, the printing apparatus 100 next determines a correction amount for the position in the longitudinal direction of the print object 1 and a correction amount for the print start position in the width direction (step 105). At this time, the sub-scanning control unit 43 in FIG. 5 determines the correction amount of the position in the longitudinal direction of the printing object 1 from the position in the longitudinal direction of the printing object 1 of each positioning mark 3 detected in step 104. . 5 determines the correction amount of the print start position in the width direction of the print object 1 from the position in the width direction of the print object 1 of each positioning mark 3 detected in step 104. The print control unit 44 in FIG. .

(Longitudinal position correction operation)
In FIG. 6, next, the printing apparatus 100 corrects the position of the print object 1 in the longitudinal direction (step 106). The sub-scanning control unit 43 in FIG. 5 performs drive control of the mover 17b of the linear motion motor that constitutes the first moving mechanism, based on the correction amount of the position in the longitudinal direction of the print target 1 determined in step 105. Thus, the moving stage 14 is moved in the Y direction, and the position in the longitudinal direction of the printing object 1 supported by the table 16 is corrected.

  A correction amount of the position of the printing object 1 in the longitudinal direction is determined from the position of each positioning mark 3 in the longitudinal direction of the printing object 1 (step 105). Based on the determined correction amount, the first moving mechanism determines the correction amount. Since the table 16 is moved and the position in the longitudinal direction of the printing object 1 supported by the table 16 is corrected (step 106), the influence of the expansion and contraction in the longitudinal direction due to the temperature change of the printing object 1 is suppressed. Complex image processing for correcting the expansion and contraction in the longitudinal direction of the printing object 1 is not necessary.

(Correction of misalignment in the θ direction)
In FIG. 6, the printing apparatus 100 further corrects the positional deviation of the print object 1 in the θ direction (step 107). The image processing device 35 in FIG. 5 detects the amount of positional deviation in the θ direction of the printing object 1 from the position in the longitudinal direction and the position in the width direction of the printing object 1 of each positioning mark 3 detected in step 104. . Then, the θ stage drive control unit 45 in FIG. 5 rotates the table 16 in the θ direction by the θ stage 15 based on the positional deviation amount of the print object 1 detected by the image processing device 35 in the θ direction. The positional deviation in the θ direction of the printing object 1 supported on the head is corrected.

  A plurality of positioning marks 3 are printed for each printing section of the printing object 1, and the position of the positioning marks 3 is detected by the detection device 30. Can be detected. Then, based on the detection result, the table 16 is rotated in the θ direction by the θ stage 15 to correct the positional deviation in the θ direction of the print object 1 supported by the table 16, so that the print object 1 in the θ direction is corrected. The positional deviation is eliminated, and the image 2 is printed with higher accuracy.

(Change operation of print start position)
In FIG. 6, when the correction of the positional deviation in the θ direction of the print object 1 is completed, the printing apparatus 100 returns to Step 101 and prints the image 2 and the positioning mark 3 in a new print section. At the time of printing, the print control unit 44 in FIG. 5 controls the print head 10 based on the correction amount of the print start position in the width direction of the print object 1 determined in step 105, and controls the print object 1 in the width direction. Change the print start position.

  From the position of each positioning mark 3 in the width direction of the print object 1, the correction amount of the print start position in the width direction of the print object 1 is determined (step 105), and the print head 10 is moved based on the determined correction amount. Since the print start position in the width direction of the print object 1 is changed by control, the influence of expansion and contraction in the width direction due to the temperature change of the print object 1 is suppressed by a simple process. FIG. 13 is a diagram showing a printed image and positioning marks for two printing sections.

[Effect of the embodiment]
According to the embodiment described above, the following effects can be obtained.
(1) When printing an image on a print object 1 extending in a strip shape using UV curable ink, high-quality printing is performed by suppressing lifting of the print object 1 from the table 16 due to irradiation of ultraviolet rays. be able to.

(2) Further, in the width direction of the print object 1, a plurality of suction holes 6 are provided around the end of the print object 1 supported by the table 16 at intervals shorter than the central part of the print object 1. In particular, the amount of lifting of the print object 1 can be further reduced in the vicinity of the end of the print object 1 that is highly likely to come into contact with the print head 10 moved in the width direction of the print object 1. .

(3) Furthermore, by providing a plurality of suction holes 6 outside the printing section of the printing object 1 supported by the table 16 in the longitudinal direction of the printing object 1, the printing section of the printing object 1 is provided. Even if the heat of the ultraviolet light irradiated from the UV light 20 is conducted to the outside section where printing is not performed, the print object 1 is restrained from being stretched at that part, and the print object following the part is suppressed. It is possible to prevent wrinkles and the like from occurring in a portion that is not supported by one table 16.

(4) Further, by setting the diameter of each suction hole 6 of the table 16 to a size that causes the deformation amount of the print object 1 by suction to be a predetermined value or less according to the suction pressure, the print object 1 by suction is reduced. Deformation can be suppressed and higher quality printing can be performed.

  In the embodiment described above, linear motion motors are used as the first movement mechanism and the second movement mechanism, but other movement mechanisms such as a ball screw may be used.

  In the embodiment described above, the holding mechanism for holding the printing object 1 is constituted by the guide rollers 23 and 24 and the upper roller 27. However, the upper roller 27 is not limited to the roller, and is a guide roller. Any structure that can clamp the printing object 1 with 23 or 24 is acceptable.

  Furthermore, in the embodiment described above, two positioning marks 3 are printed for each printing section. However, three or more positioning marks 3 may be printed for each printing section.

  In the embodiment described above, the camera unit 31 is attached to the print head 10 and the camera unit 31 is moved together with the print head 10, but the camera unit 31 may be fixedly installed.

  In the embodiment described above, the camera unit 31 includes the light source 32, the lens 33, and the camera 34, and the illumination light generated from the light source 32 is reflected by the half mirror in the lens 33 to print the object 1. However, ring illumination or other illumination methods may be used as long as the illumination light can be irradiated onto the surface of the printing object.

DESCRIPTION OF SYMBOLS 1 Print target 2 Image 3 Positioning mark 5 Vacuum pump 6 Suction hole 7 Depressurized space 10 Print head 11 Base 12 Gate 13 Guide 14 Moving stage 15 θ stage 16 Table 16a Support base 17a Linear motion motor (stator), 17b Direct Motor (movable element)
18 Linear Motion Motor 20 UV Light 21 Supply Reel 22, 25 Dancer Roller 23, 24 Guide Roller 26 Collection Reel 27 Upper Roller 30 Detection Device 31 Camera Unit 32 Light Source 33 Lens 34 Camera 35 Image Processing Device 40 Control Device 41 CPU
42 main scanning control unit 43 sub-scanning control unit 44 print control unit 45 θ stage drive control unit 47 supply reel drive control unit 48 recovery reel drive control unit 100 printing apparatus

Claims (8)

A table that supports the back surface of a part of the printing section of the print object extending in a strip shape;
A print head equipped with an inkjet head that discharges UV curable ink that is cured by being irradiated with ultraviolet rays; and
A UV light source that generates ultraviolet light;
A first moving mechanism for moving the table in the longitudinal direction of the print object;
A second moving mechanism for moving the print head and the UV light source in the width direction of the print object while keeping the print head at a predetermined distance from the surface of the table;
The printing head, the first moving mechanism, and the second moving mechanism are controlled, and the printing head prints an image on a printing section of the printing object supported by the table, A control device for irradiating the printing object with ultraviolet rays generated from a UV light source and curing the UV curable ink;
The table has a plurality of suction holes for sucking the print object, and the distance between the suction holes is the amount by which the print object is lifted from the table by the irradiation of ultraviolet rays generated from the UV light source. A printing apparatus having a length that is smaller than a gap between the surface of the previous printing object and the print head. The table has the plurality of suction holes in the width direction of the print object around the end of the print object supported by the table at a shorter interval than the central part of the print object. The printing apparatus according to claim 1. The table includes the plurality of suction holes in the longitudinal direction of the print object, inside the print section of the print object supported by the table and outside the print section of the print object. The printing apparatus according to claim 1, wherein: 4. The diameter of each suction hole of the table is such that the amount of deformation of the print object due to suction becomes a predetermined value or less according to the suction pressure. 5. The printing apparatus according to one item. The back surface of a part of the printing section of the print object extending in a band shape is supported by a table having a plurality of suction holes,
The first moving mechanism moves the table in the longitudinal direction of the print object,
The second moving mechanism generates the print head and ultraviolet rays while keeping a print head mounted with an inkjet head that discharges UV curable ink that is cured by being irradiated with ultraviolet rays at a predetermined distance from the surface of the table. Moving the UV light source in the width direction of the print object,
The printing head irradiates the printing object with ultraviolet rays generated from the UV light source while curing the UV curable ink while printing an image on a printing section of the printing object supported by the table. And
The distance between the suction holes of the table is determined by the gap between the surface of the print object before the lift and the print head when the print object is lifted from the table by the irradiation of ultraviolet rays generated from the UV light source. A printing method comprising printing an image on a print section of the print object supported by the table while adsorbing the print object by the plurality of suction holes as a length that decreases. In the width direction of the printing object, the plurality of suction holes are provided around the edge of the printing object supported by the table at intervals shorter than the center part of the printing object. The printing method according to claim 5. In the longitudinal direction of the print object, the plurality of suction holes are respectively provided inside the print section of the print object supported by the table and outside the print section of the print object. The printing method according to claim 5 or 6. 8. The diameter of each suction hole of the table is set to a size such that the amount of deformation of the print object due to suction becomes a predetermined value or less according to the suction pressure. The printing method according to item.

Images