JP6437334B2 - Digital double-sided printing method and substrate - Google Patents

Description

  The present invention relates to a digital double-sided printing method for printing on both sides of images that overlap each other on the front side and the back side of the printed material, and the printed material.

  Generally, a digital printing apparatus prints on a printing material by ejecting ink from a print head such as an inkjet. At that time, print data of various designs of the substrate can be stored in advance in the memory of the control device, and the same design can be printed accurately.

  As a digital printing apparatus that makes use of the features of digital printing, for example, as disclosed in Patent Document 1, it is a technique that can perform touch printing according to the type of fabric that is a printing object.

JP 2001-322263 A

  Printed objects such as scarves and handkerchiefs are a small variety of products that are printed in various designs. Scarves and handkerchiefs are made of thin woven silk. Silk is a luxury item. A silk screen is used to print the design. On silk screens, if you print with a relatively large amount of ink, the ink appears on the back of the fabric, so you can see the design from both sides. However, silk screen printing is expensive because it produces and prints a silk screen for each design. Not suitable for high-mix low-volume production.

On the other hand, it is difficult to print a scarf or a handkerchief with a digital printing apparatus. The reason is as follows. In other words, since the amount of ink used for ink jet printing is small, the ink does not penetrate to the back side, and even if the amount of ink that can penetrate to the back side can be secured, the ink viscosity is so low that the image quality deteriorates. It is.
If printing is performed on the front and back sides, it is possible to print on the front and back sides even with a small amount of ink. However, in the case of scarves and handkerchiefs, there are many cases in which the patterns on the front and back sides can be seen through, and if the images on the front and back sides do not completely match, the quality is lowered and the value is lowered. However, in the case of inkjet printing, it is difficult to completely match the positions of the printed images on the front and back sides.

  A problem to be solved by the present invention is a digital method for accurately printing a printed pattern (image) from the front and a printed pattern (image) from the back to a desired position when performing double-sided printing on a substrate. To provide a double-sided printing method and a substrate.

(First invention)
1st invention is equipped with the printing head which prints by moving with respect to a to-be-printed object, the printing jig which sets the to-be-printed object can be installed in a predetermined position, and the above-mentioned printing jig is turned upside down The present invention relates to a digital double-sided printing method that performs double-sided printing using a digital printing machine that can be installed at the predetermined position.
That is, a jig setting step for fixing the printed material to the printing jig in a stretched state and installing the printed material at the predetermined position;
A front side image printing step of printing a front side image and a front side position detection mark on the surface of the substrate,
A jig reversal setting step for reversing the printing jig and installing it at the predetermined position;
A back side position detection mark printing step of printing a back side position detection mark on the back surface of the substrate;
A comparison step of comparing the back side position detection mark and the front side position detection mark from either the front or back side;
A correction step of correcting the relative positions of the front side image and the back side image of the substrate based on the comparison step;
A back side image printing step of printing a back side image on the back side of the printed material at the relative position corrected in the correction step.

(Glossary)
The substrate includes a film in addition to a fabric. Here, “fabric” is a general term for textiles such as cloth and woven fabric using silk, silk, hemp, or a mixture thereof as a raw yarn.
The “mark” used for the “front side position detection mark” and the “back side position detection mark” employs a “scale” in the embodiments described later. For example, a mark imitating an insect (for example, a dragonfly) or a simple shape A mark (for example, ◇ or Δ) or a plurality of regularly arranged dots may be used.
In general, the front side position detection mark and the back side position detection mark are printed on a portion to be cut and discarded so as not to appear in the final product. However, it does not prevent the adoption of an image that makes use of the front side position detection mark and the back side position detection mark as a design of the product.
The “comparison process” includes not only automatic detection using an engineering sensor but also a case where a result of visual judgment by an operator is used.
“Correcting the relative position” in the “correction step” means that the print head is moved with respect to the printing material, the printing jig including the printing material is moved with respect to the printing head, or both are moved. In any case.
The “back side image” may be the same as the front side image, but includes a case of forming an image that is different from the front side image and that is visually recognizable when images printed on the front and back sides are combined.

(Function)
Since the printed material expands and contracts depending on the environment such as temperature and humidity, securing the premise of maintaining high printing accuracy such as the position and size of the printed image is secured by fixing the printed material to the printing jig. .
Even if the digital printing machine can install the printing jig at a predetermined position, and the printing jig can be reversed and installed at the predetermined position, the cloth is affected by the influence of component accuracy, etc. There may be a slight positional deviation between the front side image and the back side image. In the present invention, when the front side image is printed, the front side image and the front side position detection mark are printed. On the other hand, after the jig is reversed and fixed, the back side position detection mark is printed before the back side image is printed. Therefore, the influence of component accuracy, the influence of assembly errors, and the like can be eliminated, so that the front side image and the back side image can be matched with high accuracy.
The front side position detection mark and the back side position detection mark are compared from either the front or back side. Based on the comparison, the relative positions of the front side image and the back side image of the printing material are corrected, and then the back side image is printed on the back side of the printing material. Therefore, the back side image and the front side image can be positioned with high accuracy, and printing on both sides of the substrate can be executed.
For example, a high-definition image having a high-quality image can be printed on both sides of a scarf or a handkerchief. In addition, high-definition images can be printed on both sides of thick high-quality fabrics and fabrics such as curtains, contributing to the realization of high-quality products.

(Variation 1 of the first invention)
The first invention can also provide the following variations.
That is, in the jig setting step, the printed material is sandwiched between the upper frame and the lower frame forming the printing jig, and the entire printed material is moistened, and then the outer frame and the lower frame are exposed to the outside. The upper frame and the lower frame are fixed with a fixing tool in a state where a tensile load is applied around the protruding printed material.

(Function)
When the substrate is wetted with water, the fibers stretch. Since the upper frame and the lower frame are fixed in a state where a tensile load is applied around the stretched substrate, the substrate is stretched with the printing jig. Therefore, even if printing is performed with liquid ink, it is difficult to extend further, so that a stable printed image is obtained. By adopting this step, it is possible to contribute to making the correction state of the relative position of the front side image and the back side image of the substrate more accurate.

(Variation 2 of the first invention)
The first invention can also provide the following variations.
That is, the front side position detection mark in the front side image printing step is assumed to be a scale, and printed on a straight line with a pitch P scale from the zero point of the position correction to both sides.
Further, the back side position detection mark in the back side position detection mark printing step is a scale, and the pitch (P + ΔP) is shifted from the zero point of the position correction to both sides on the same straight line as the front side image printing step. It shall be printed on the scale.
Further, in the comparison step, when the number of scales from the position of the scales that coincide with each other in the front side position detection mark and the back side position detection mark to the zero point of the position correction is α, the back side position with respect to the front side position detection mark The positional deviation amount of the detection mark is measured to be ΔP × α.

(Glossary)
“ΔP” means a minute dimension with respect to the pitch P, for example, a dimension of 0.1 of the pitch P or a dimension of 0.05.

(Function)
For example, when the front side position detection mark is printed on the X-axis in the two-dimensional direction of the X-axis and the Y-axis on the plane of the printing object and printed on the scale of the pitch P from the zero point of the position correction to both sides, The scale on one side is +1, +2, +3,..., + N, and the scale on the other side is -1, -2, -3, ..., -n.
On the other hand, when the back side position detection mark is printed on the X axis with a scale of pitch (P + ΔP) from the position correction zero point to both sides, the scale on one side from the zero point is +1, +2, +3,. .., + N, and the scale on the other side is -1, -2, -3, ..., -n.
For example, when the front side position detection mark and the back side position detection mark coincide with each other on a scale of −3, there is a positional deviation amount of ΔP × (−3). That is, the zero point of the back side position detection mark is shifted by 3 × ΔP in the + side direction on the X axis with respect to the zero point of the front side position detection mark. Therefore, the print head (11) corrects the position by 3 × ΔP in the negative direction on the X axis, so that the zero points of both the front side position detection mark and the back side position detection mark coincide. Similarly, the position is corrected on the Y axis.
As a result of the above-described position correction, for example, the back side image and the front side image, which are reverse images, are positioned with high accuracy and can be printed on both sides of the substrate.
It should be noted that the front side position detection mark and the back side position detection mark are not on the X axis and the Y axis, but on a straight line, for example, in a 45 ° oblique direction with respect to the X axis and the Y axis, and pitched from the zero point of the position correction to both sides. Printing can be performed with a P scale or a pitch (P + ΔP) scale. In this case, the positional deviation amount in the oblique 45 ° direction is converted into an X-axis positional deviation amount and a Y-axis positional deviation amount, and the position correction is performed in the same manner as described above. Alternatively, the position is corrected in an oblique 45 ° direction.

(Variation 3 of the first invention)
In the variation 2 of the first invention described above, it is more preferable that the front-side position detection mark and the back-side position detection mark are arranged close to each other so that visual comparison is possible.
For example, the left and right apple pattern is zigzag and the front position detection mark is the left half apple pattern, the back position detection mark is the right half apple pattern, and they are arranged close to each other. . Then, when there is no deviation in either the X-axis direction or the Y-axis direction, the zigzag cut ends coincide to form one apple. If the front-side position detection mark and the back-side position detection mark do not match, the position may be corrected so that the zigzag cut ends match.

(Variation 3 of the first invention)
The first invention can also provide the following variations.
That is, the front-side position detection mark and the back-side position detection mark are marks that can detect both a two-dimensional shift with respect to the X axis and the Y axis on the plane of the printed material.

(Function)
The front-side position detection mark and the back-side position detection mark simultaneously detect both two-dimensional displacements with respect to the X-axis and the Y-axis on the plane of the printed material, thereby expanding and contracting the X-axis direction and the Y-axis direction of the printed material. Can be corrected.

(Second invention)
A second invention includes a print head for printing by moving with respect to a printing material, the printing jig for setting the printing material can be installed at a predetermined position, and the printing jig is turned upside down. The present invention relates to a substrate to be used for duplex printing using a digital printing machine that can be installed at the predetermined position.
The front side image and the front side position detection mark are printed on the front surface of the substrate, and the front side of the substrate after the printing jig is inverted and installed at the predetermined position on the back surface of the substrate. This is a substrate on which a back side position detection mark is printed at a position corresponding to the position detection mark.

(Variation of the second invention)
The second invention is more preferably formed as follows.
That is, the front side position detection mark is printed on a straight line with a scale of pitch P from the zero point of position correction to both sides. The back side position detection mark is a substrate printed on the same straight line as the front side position detection mark from the zero point of position correction to both sides with the scale of the pitch (P + ΔP).

  According to the first invention, there is provided a digital double-sided printing method for accurately printing a printed pattern from the front and a printed pattern from the back to a desired position when performing double-sided printing on a substrate. did it.

  According to the second invention, printing the front side image and the front side position detection mark on the surface of the substrate, and printing the back side position detection mark on the back side of the substrate to the position aligned with the front side position detection mark, When performing double-sided printing on a substrate, it was possible to provide a substrate capable of accurately printing a printed pattern from the front and a printed pattern from the back to a desired position.

1A is a perspective view schematically showing a digital printing machine according to an embodiment of the present invention. FIG. (B) is a partial detail drawing of a printing jig. (A)-(c) is a schematic explanatory drawing which shows the process of the digital double-sided printing method of embodiment of this invention. (A), (b) is a schematic explanatory drawing which shows the process following FIG. (A), (b) is a schematic explanatory drawing which shows an example which measures the positional offset amount of a X-axis direction, (c) is a schematic explanatory drawing which shows an example of measuring the positional offset amount of a Y-axis direction. .

Embodiments of the present invention will be described below with reference to the drawings. Here, FIGS. 1 to 4 are used.
The digital double-sided printing method according to the present embodiment is a method for double-sided printing using a digital printing machine 10 as shown in FIG.

The digital printing machine 10 includes a print head 11 that prints on a substrate 50 while moving. The substrate 50 is set on the printing jig 20, and the printing jig 20 is installed at a predetermined position below the print head 11. The print head 11 is provided so as to be movable in the X-axis direction along the X-axis travel support member 12.
The print data of various designs of the substrate 50 can be stored in advance in the memory of the control device in the digital printing machine 10, and the same design can be printed accurately.

  Further, the two Y-axis travel support members 13 are arranged at positions facing each other outside a predetermined position where the printing jig 20 is set. The X-axis travel support member 12 is provided so as to be movable in the Y-axis direction along the two Y-axis travel support members 13. Therefore, the print head 11 is relatively movable in the two-dimensional direction of the X axis and the Y axis above the printing jig 20.

The printing jig 20 can be installed at a predetermined position, and can be installed at the predetermined position with the front and back reversed. In the present embodiment, the printing jig 20 is composed of an upper frame 21 and a lower frame 22 that form a rectangular frame material. In other words, the upper frame 21 and the lower frame 22 sandwich the outer peripheral portion of the fabric that is the printed material 50 from the front surface and the back surface.
As shown in FIG. 1 (b), the upper frame 21 and the lower frame 22 are provided with positioning through holes 24a,..., 24a for positioning and fixing at the corners of the four corners.

  A plurality of fixing through-holes 24b,..., 24b are provided between the above-mentioned four-corner positioning through-holes 24a,. .., 24a are inserted into the through holes 24a,..., 24a for positioning at the four corners, and fixing screws 23a,. .., 24b are fixed to the plurality of fixing through holes 24b,..., 24b by inserting fixing screws 23b,.

The printing jig 20 is provided with a printing jig mounting table 14 for mounting the frame portions (the upper frame 21 and the lower frame 22). The printing jig mounting table 14 is provided with an abutting reference surface 15 for abutting the side edges of two adjacent sides of the frame portion of the printing jig 20 that are adjacent to each other. Accordingly, the side edge of the frame portion of the printing jig 20 can be placed at the predetermined position by abutting against the abutting reference surface 15.
After reversing the printing jig 20, the side edge of the frame portion of the printing jig 20 is abutted against the abutting reference surface 15, and can be installed at a predetermined position.

  Another method for installing the printing jig 20 at a predetermined position on the printing jig mounting table 14 is to project positioning pins on both ends of the positioning fastening screws 23a, ..., 23a. it can. On the other hand, a positioning reference hole portion into which positioning pins 23a,..., 23a for positioning at four corners to which the upper frame 21 and the lower frame 22 are fixed is inserted in the printing jig mounting table 14. can do.

  Therefore, by inserting the positioning pins of the positioning screws 23a,..., 23a at the four corners of the printing jig 20 into the positioning reference holes of the printing jig mounting table 14, the printing jig 20 is predetermined. Even if the printing jig 20 is inverted, it can be installed at the predetermined position.

Next, a method for duplex printing using the digital printer 10 will be described.
The digital double-sided printing method of this embodiment includes a jig setting step, a jig setting step, a front side image printing step, a jig reversal setting step, a back side position detection mark printing step, a comparison step, and a correction step. And a back side image printing step.

In the jig setting step, the fabric 51 as the substrate 50 is stretched and fixed to the printing jig 20. Then, it installs in the predetermined position of the printing jig mounting base 14. The printed material 50 includes a film in addition to the fabric 51. Here, the fabric 51 is a general term for fiber products such as cloth and woven fabric using silk, silk, hemp, or a mixture thereof as a raw yarn.
As shown in FIG. 2A, the fabric 51 is sandwiched between the upper frame 21 and the lower frame 22 of the printing jig 20 from the front surface and the back surface. As shown in FIGS. 1 (a) and 2 (b), the entire fabric 51 is moistened and then a tensile load is applied to the periphery of the fabric 51 protruding from the upper frame 21 and the lower frame 22. The upper frame 21 and the lower frame 22 are fixed with positioning fixing screws 23a,..., 23a and fixing screws 23b,.

  In the present embodiment, as shown in FIG. 2A, a tensile load is applied by hooking a plurality of weights 25,... When the fabric 51 is wetted with water, the fibers are stretched. Since the upper frame 21 and the lower frame 22 are fixed in a state where a tensile load is applied around the stretched fabric 51, the fabric 51 is stretched in the printing jig 20. When the fabric 51 is printed in a subsequent process, the fabric 51 does not stretch any more even if it is printed with liquid ink, so that a stable printed image is obtained. That is, as will be described in detail later, this contributes to making the correction state of the relative position of the front-side image 31 on the front surface of the fabric 51 and the back-side image 41 that is the reverse image of the back surface more accurate.

  The method of applying a tensile load to the fabric 51 is not limited to the weights 25,..., 25, and a tension spring can be used, or another method may be used. The timing of wetting the fabric 51 with water may be sandwiched between the upper frame 21 and the lower frame 22 after a pretreatment agent such as water is sprayed on the fabric 51 without pretreatment.

  As shown in FIG. 1A, the printing jig 20 fixed with the fabric 51 stretched as described above has a side edge of the frame portion of the printing jig 20 that is abutting reference surface on the printing jig mounting table 14. It can be installed at a predetermined position.

  In the front side image printing step, as shown in FIG. 2C, the print head 11 is moved in the two-dimensional direction of the X axis and the Y axis, and ink is ejected from the print head 11 to the surface of the fabric 51. The image 31 and the front side position detection mark 32 are printed. At this time, the fabric 51 in a state of being wet and stretched with water on the printing jig 20 does not stretch any more even when printed with liquid ink, that is, does not loosen. Therefore, a high-precision printed image that maintains stable positional accuracy. It becomes. The front side position detection mark 32 is printed at a position deviated from the front side image 31, that is, at a position that is not a product.

  The front-side position detection mark 32 is printed on a straight line with a scale of pitch P from the zero point of position correction to both sides. As an example, as shown in FIGS. 4A and 4B, the X-axis front side position detection mark 32x is printed. Further, as shown in FIG. 4C, the Y-axis front side position detection mark 32y is printed.

  4A, 4B, and 4C show the back side position detection mark 42, but the back side position detection mark 42 is not printed in this step. In addition, although the color of the front side position detection mark 32 is black in this Embodiment, it should just be a conspicuous color and is not specifically limited.

  In the jig reversal setting step, after the printing jig 20 printed on the surface of the fabric 51 in the front side image printing step is reversed, as shown in FIG. To install. That is, the printing jig 20 is installed at a predetermined position by abutting the side edge of the frame portion of the printing jig 20 against the abutting reference surface 15 of the printing jig mounting table 14. At this time, the back surface of the fabric 51 in the printing jig 20 is placed at a predetermined position so as to be in a mirror-symmetrical position with the front image 31.

  In the back side position detection mark printing step, as shown in FIG. 3A, the print head 11 is moved in the two-dimensional direction of the X axis and the Y axis, and ink is ejected from the print head 11 to invert the above-described reversed printing process. A back side position detection mark 42 is printed on the back surface of the fabric 51 in the tool 20 at a position corresponding to the front side position detection mark 32.

  It is assumed that the back side position detection mark 42 is printed on the same straight line as the front side image printing process from the zero point of position correction to both sides with a pitch (P + ΔP) scale. As an example, as shown in FIGS. 4A and 4B, the X-axis back side position detection mark 42x is shifted from the X-axis front side position detection mark 32x by a constant pitch in the Y-axis direction. Next to each other. Here, ΔP means a minute dimension with respect to the pitch P, for example, a dimension of 0.1 of the pitch P or a dimension of 0.05.

  As shown in FIG. 4C, the Y-axis back side position detection mark 42y is shifted from the Y-axis front side position detection mark 32y by a fixed pitch in the X-axis direction and printed adjacently. The color of the back side position detection mark 42 is red in this embodiment. A conspicuous color is preferable, but not particularly limited. However, in order to distinguish from the front side position detection mark 32 described above, it is desirable that the color is different from that of the front side position detection mark 32.

  In the comparison step, the comparison is made from either the back side position detection mark 42, the front side position detection mark 32, or the front or back side. At this time, for example, the positional deviation amount in the X-axis direction and the positional deviation amount in the Y-axis direction between the back side position detection mark 42 and the front side position detection mark 32 are measured. For example, when the number of graduations from the position of the scales that coincide with each other in the front side position detection mark 32 and the back side position detection mark 42 to the zero point of position correction is α, the back side position detection mark 42 with respect to the front side position detection mark 32. Is measured to be ΔP × α.

  As shown in FIGS. 4A and 4B, the X-axis front-side position detection mark 32x is printed on the X-axis, for example, with a scale of pitch P from the zero point of position correction to both sides. The scale on one side from the zero point is +1, +2, +3,..., + N, and the scale on the other side is −1, −2, −3,. On the other hand, when the back side position detection mark 42x on the X axis is printed with a scale of pitch (P + ΔP) from the zero point of position correction to both sides on the X axis, the scale on one side from the zero point is +1, +2 , +3,..., + N, and the scale on the other side is -1, -2, -3, ..., -n.

  As shown in FIG. 4A, when the X-axis front side position detection mark 32x and the X-axis back side position detection mark 42x coincide with a scale of 0 (zero point), α is 0 (zero). Therefore, ΔP × α of the positional deviation amount on the X axis is ΔP × (0) = 0 (zero).

  As another example, as shown in FIG. 4B, when the X-axis front side position detection mark 32x and the X-axis back side position detection mark 42x coincide on the scale of −5, α is −5 (α = −5), ΔP × α of the positional deviation amount on the X-axis becomes ΔP × (−5).

Also on the Y axis, the amount of positional deviation is measured in the same manner as on the X axis. As an example, as shown in FIG. 4C, the front-side position detection mark 32y on the Y-axis is printed on the Y-axis on the scale of pitch P from the zero point of position correction to both sides, for example. The scale on one side from the point is +1, +2, +3,..., + N, and the scale on the other side is −1, −2, −3,.
On the other hand, when the Y-axis back side position detection mark 42y is printed on the Y axis with a scale of pitch (P + ΔP) from the position correction zero point to both sides, the scale on one side from the zero point is +1, +2 , +3,..., + N, and the scale on the other side is -1, -2, -3, ..., -n.

  As in the case of FIG. 4C, when the Y-axis front side position detection mark 32y and the Y-axis back side position detection mark 42y coincide with a scale of 0 (zero point), α is 0 (zero). Therefore, ΔP × α of the positional deviation amount on the Y axis is ΔP × (0) = 0 (zero). If the front-side position detection mark 32y on the Y-axis and the back-side position detection mark 42y on the Y-axis coincide with each other on the +3 scale, α is +3 (α = + 3), and thus the displacement amount ΔP on the Y-axis. × α is ΔP × (3).

Note that the comparison process includes not only automatic detection using an engineering sensor but also the case of using a result of visual judgment by an operator. In the case of automatic detection by a sensor, the back side position detection mark 42 and the front side position detection mark 32 are imaged from either the front or back surface by an imaging means such as a CCD camera. The image processing apparatus measures the above-described positional deviation amount in the X-axis direction and the positional deviation amount in the Y-axis direction with an image processing apparatus.
On the other hand, when the operator visually observes, the positional displacement amount in the X-axis direction and the positional displacement amount in the Y-axis direction are measured from either the front or back surface of the back-side position detection mark 42 and the front-side position detection mark 32 as described above.

  In the correction step, the relative position of the front side image and the back side image of the substrate 50 is corrected based on the comparison step. For example, the relative position of the print head 11 is corrected based on the positional deviation amount in the X-axis direction and the positional deviation amount in the Y-axis direction. In the correction process, “correcting the relative position” means that when the position of the print head 11 is moved and corrected with respect to the fabric 51, the printing jig 20 including the fabric 51 is moved with respect to the print head 11. In this case, both cases of correction by moving both sides are included.

Further, at least one image position of the front and back image data can be corrected by a RIP (Raster Image Processor). The data of the positional deviation amount in the X-axis direction and the positional deviation amount in the Y-axis direction measured in the comparison process is rasterized to dot information, corrected, and transferred to the control device. A command is sent from the control device to correct the position of the print head 11.
Note that the above correction can be performed by an operator by manually inputting correction data to the control device. Alternatively, it can be automatically corrected (reset). For example, correction data measured by automatic detection by an engineering sensor based on the comparison process is transmitted to the control device. A command is sent from the control device to correct (reset) the position of the print head 11.

  In the case of FIG. 4A described above, the displacement amount ΔP × α on the X-axis is ΔP × (0) = 0 (zero), so the print head 11 corrects the position on the X-axis. It will not be necessary.

  In the case of FIG. 4B described above, ΔP × α of the positional deviation amount on the X axis is ΔP × (−5). Therefore, the zero point of the back side position detection mark 42 is shifted by 5 × ΔP in the + side direction on the X axis with respect to the zero point of the front side position detection mark 32. The print head 11 corrects the position by 5 × ΔP in the − side direction on the X axis, so that the zero points of both the front side position detection mark 32 and the back side position detection mark 42 coincide.

  In the case of FIG. 4C described above, the positional deviation amount ΔP × α on the Y axis is ΔP × (0) = 0 (zero), so the print head 11 corrects the position on the Y axis. It will not be necessary.

  As described in the above comparison process, if ΔP × α of the positional deviation amount on the Y-axis becomes ΔP × (3), the zero point of the back side position detection mark 42 is the front side position detection mark. A shift of 3 × ΔP is generated in the negative direction on the Y axis with respect to the zero point of 32. The print head 11 corrects the position by 3 × ΔP in the + direction on the Y axis, so that the zero points of both the front side position detection mark 32 and the back side position detection mark 42 coincide.

In the back side image printing step, the print head 11 is moved in the two-dimensional direction of the X axis and the Y axis at the relative position corrected in the above correction step. Ink is ejected from the print head 11 to print on the back surface of the fabric 51 a back side image 41 that is a reverse image overlapping the front side image 31. Here, “the back side image 41 that is the reverse image overlapping the front side image 31” means that not only the print position of the image but also the size of the image overlap.
Further, the back side image 41 includes both a case where it is a reverse image overlapping the front side image 31 and a case where it is an image different from the front side image 31. That is, it is not always necessary to overlap, and the front image 31 and the back image 41 can be seen through, so that both images can be combined into a single pattern.

  In the printing by each process as described above, the back side image 41 and the front side image 31 are positioned with high accuracy, and high-definition images can be printed on both surfaces of the fabric 51. For example, even if the fabric 51 is a silk scarf or a handkerchief or the like, high-definition images that are positioned with high accuracy on the front side and the back side by the digital double-sided printing method according to this embodiment are applied to both sides of the fabric 51. Can be printed.

  Silk products are required to be printed in small quantities with various designs in the case of expensive products. That is, it becomes a product with a small variety of products. However, if the digital double-sided printing method according to the present embodiment is adopted, it is possible to print accurately and efficiently, and to produce a low-priced and high-quality product, thereby reducing the manufacturing price and improving the profit margin. Contribute to.

  For thick products such as carpets and curtain fabrics, the printed image on the front side does not appear to the back side. However, even for a thick substrate, if the digital double-sided printing method of the present embodiment is employed, high-definition images that are positioned with high accuracy on the front side and the back side can be printed on both sides. Since efficient production is possible, even a high-quality product can contribute to a reduction in manufacturing price. After the printing of the printing material 50 is finished, the color is fixed during printing, and the product is completed through a washing process.

  The front-side position detection mark 32 and the back-side position detection mark 42 described above are not on the X axis and the Y axis, but on both sides from the zero point of the position correction, for example, on a straight line in the direction of 45 ° obliquely with respect to the X axis and the Y axis. Printing can be performed on the scale of the pitch P or on the scale of the pitch (P + ΔP).

  In this case, the positional deviation amount in the oblique 45 ° direction is converted into an X-axis positional deviation amount and a Y-axis positional deviation amount, and the position correction is performed in the same manner as described above. Alternatively, the position is corrected in an oblique 45 ° direction. The method of measuring the amount of misalignment varies depending on the specifications required for the final product, restrictions at the manufacturing site, etc., but it is possible to adopt a measuring means such as visual inspection by the manufacturer, scale measuring instrument, CCD camera, etc. .

  The “mark” used for the “front side position detection mark” and the “back side position detection mark” employs “scale” in the above-described embodiment. For example, a mark imitating an insect (for example, a dragonfly), simple A mark made of a shape (for example, ◇, Δ, or ●) may be used.

The substrate 50 according to the embodiment of the present invention will be described.
The substrate 50 of the present embodiment is manufactured by the above-described digital double-sided printing method using the above-described digital printer 10. That is, the front side image 31 and the front side position detection mark 32 are printed on the surface of the substrate 50.
Further, on the back surface of the substrate 50, the back side position detection mark 42 is printed at a position corresponding to the front side position detection mark 32 after the printing jig 20 is reversed and installed at the predetermined position. Is.

  As the substrate 50, the front side position detection marks 32 are printed on a straight line with a scale of pitch P from the zero point of position correction to both sides. On the other hand, the back side position detection mark 42 can be printed on the same straight line as the front side position detection mark 32 from the zero point of the position correction to both sides with the scale of the pitch (P + ΔP).

  As described above, the substrate 50 of the present embodiment prints the front side image 31 and the front side position detection mark 32 on the surface of the fabric 51, and backs the back side of the fabric 51 to the position that matches the front side position detection mark 32. By printing the position detection mark 42, when performing double-sided printing on the fabric 51, the front side image 31 that is the printed pattern from the front and the back side image 41 that is the printed pattern from the back are executed at the desired positions. It was possible.

  The present invention can be used in a wide range of fields such as printing and dyeing, sales and manufacturing in the textile and clothing fields, sales and manufacturing of thick fabric products such as carpets, and sales and manufacturing of printed materials in printing. Have

DESCRIPTION OF SYMBOLS 10; Digital printing machine 11; Print head 12; X-axis traveling support member 13; Y-axis traveling support member 14; Printing jig mounting base 15; Butting reference surface 20; Printing jig 21; Upper frame 22; 23; fixing tool 23a; positioning screw 23b; fixing screw 24a; positioning through hole 24b; fixing through hole 25; weight 31; front image 32; front position detection mark 32x; Front-side position detection mark 32y; Y-axis front-side position detection mark 41; Back-side image 42; Back-side position detection mark 42x; X-axis back-side position detection mark 42y; Y-axis back-side position detection mark 50; Substrate 51;

Claims (6)

A digital double-sided printing method for performing double-sided printing using a digital printing machine that includes a print head for printing by moving relative to the substrate, and a printing jig for setting the substrate to be printed can be installed at a predetermined position. There,
A jig setting step for setting a substrate to be printed on the printing jig;
A front side image printing step of printing a front side image and a front side position detection mark on the surface of the substrate,
A jig reversal setting step for reversing the printing jig and setting it at the predetermined position,
A back side position detection mark printing step of printing a back side position detection mark on the back surface of the substrate;
A comparison step of comparing the back side position detection mark and the front side position detection mark from either one of the front and back surfaces and measuring the amount of positional deviation of both marks in the X axis direction and the Y axis direction on the plane; ,
A correction step of correcting the relative position of the front image and the back image of the printed matter on the basis of a more measured position shift amount of the the comparison step,
A back side image printing step of printing a back side image on the back side of the substrate at the relative position corrected in the correction step;
A digital double-sided printing method.   In the jig setting step, the printed material is sandwiched between the upper frame and the lower frame forming the printing jig and the whole printed material is moistened, and then protrudes outside the upper frame and the lower frame. The digital double-sided printing method according to claim 1, wherein the upper frame and the lower frame are fixed with a fixture while a tensile load is applied to the periphery of the substrate. The front side position detection mark in the front side image printing step is a scale, and is printed with a scale of pitch P from the zero point of position correction on both sides on a straight line,
The back side position detection mark in the back side position detection mark printing step is a scale, and on the same straight line as the front side image printing step, the pitch (P + ΔP) from the zero point of the position correction to both sides Printed on a scale,
In the comparison step, when the number of graduations from the position of the graduation that coincides with each other in the front side position detection mark and the back side position detection mark to the position correction zero point is α, the back side position detection mark of the front side position detection mark The digital double-sided printing method according to claim 1, wherein the positional deviation amount is measured as ΔP × α.   The digital double-sided printing method according to claim 3, wherein the front side position detection mark and the back side position detection mark are arranged close to each other so that a visual comparison is possible. A printing head for printing by moving with respect to the substrate to be printed is provided, a printing jig for setting the substrate to be printed can be installed at a predetermined position, and the printing jig is turned upside down to the predetermined position. A substrate to be used for duplex printing using a digital printing machine that can be installed,
The front side image and the front side position detection mark are printed on the surface of the substrate,
On the back side of the substrate, the printing jig is reversed and installed at the predetermined position, and then the position corresponding to the front side position detection mark is set to either the front side position detection mark or the front and back side. The back side for measuring the positional deviation amount of both marks in the X-axis direction and the Y-axis direction on the plane as compared with the surface, and correcting the relative position of the front side image and the back side image based on the positional deviation amount A substrate to be printed with position detection marks. The front side position detection mark is printed on a straight line with a scale of pitch P from the zero point of position correction on both sides, and the back side position detection mark is zero on the same straight line as the front side position detection mark. The substrate to be printed according to claim 5 , printed from a point to both sides with a scale of the pitch (P + ΔP).