JPH0215385B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and a printing plate for printing a seamless band pattern around a three-dimensional object, and the present invention relates to a method and a printing plate for printing a seamless band pattern around a three-dimensional object, and the method and printing plate for printing a seamless strip pattern around a three-dimensional object. An object of the present invention is to provide a method and a printing plate for printing a seamless band-like pattern on a curved surface without increasing the density or causing linear non-printing areas between the printing start area and the printing end area. That is.

Conventionally, methods such as silk screen printing, flexo printing, and offset printing are widely known as methods for printing strip patterns on the surface of three-dimensional objects.

However, since the inked portion of the printing plate used in these printing methods is made with dimensions that match the circumference of a standard printing medium, variations in the circumference of the printing medium may cause seams to form. This caused a problem in that the product value of the printing material was significantly reduced. In other words, if the circumference of the printing medium is longer than the inked part, the printing start part and the printing end part will not match and there will be a part with no ink, or if the circumference of the printing medium is longer than the inked part. If it is shorter than , the print start portion and print end portion overlap, resulting in a portion where the ink density is doubled.

As a result of intensive research to solve this problem, the inventor of the present invention actively made the inking parts overlap on the surface of the three-dimensional object, and made a plate in such a way that the overlapping parts overlap to achieve the necessary color density. The inventors have discovered that the above-mentioned problems can be solved by printing using a printed printing plate, and have completed the present invention.

That is, in the present invention, when printing a strip pattern around a three-dimensional object, the strip pattern is made longer than the circumference of the three-dimensional object so that it overlaps around the three-dimensional object, and one side of the overlapping portion on both sides is printed. It is also necessary for seams around three-dimensional objects, which are characterized by printing using a printing plate made so that the color density gradually increases from the edge and on the other side, the color density gradually decreases toward the edge. A method for printing a band-like pattern with a high color density, and a printing plate capable of expressing the band-like pattern, which is made longer than the circumference of the three-dimensional object so that the band pattern overlaps around the three-dimensional object, and overlaps on both sides. Colors that are also necessary for the seams around three-dimensional objects, which are characterized in that the color density on one side of the part is made so that the color density gradually increases from the end, and on the other side, the color density gradually decreases toward the end. This is a printing plate that prints a striped pattern with density.

This will be explained below with reference to the drawings.

Figure 1 shows the color density (Y axis) and printing direction (X
This is a graph showing the relationship with the cylindrical object (axis), where X ₁ is the circumferential length of the cylindrical object, and y ₁ is the required color density of the pattern. The present invention, as shown in FIG.
The circumferential length of the cylinder: x ₁ is extended to a length of x ₂ so that the pattern partially or completely overlaps on the surface of the cylinder. At this time, the pattern between x ₁ and x ₂ must be accurately extended by a composer or the like so that it becomes the same pattern as the pattern between 0 and x ₃ . Next, as shown in FIG. 3, the color density is adjusted between 0 and x ₃ so that the required color density y ₁ is obtained by overlapping both ends x ₁ to x ₂ and 0 to x ₃ of the inked portion. gradually increases the color density from 0 to y ₁ as it moves from 0 to x ₃ , and gradually decreases the color density from y ₁ to ₀ as it moves from x ₁ to x ₂ between x ₁ and x 2 . Gradual increase/decrease in color density can be achieved by successively using blur masks with different color densities or by performing multi-stage exposure using masks with successively different sizes.

The printing plate of the present invention can reduce the color density by performing the plate-making process, but even if it is a conventional gravure plate in which changes in color density are expressed by changes in plate depth, the area changes. It may be a halftone gravure plate, a screen printing plate, a flexographic plate, an offset plate, etc. For example, a cross-sectional view of a conventional gravure plate in the printing direction is as shown in FIG. 4, and a relationship between the size of halftone dots and the printing direction of a halftone plate is as shown in FIG.

The above-mentioned steps of the present invention can be added as appropriate in any step of the plate-making process, and the order thereof is not specified.

Since the present invention is configured as described above, when the color density is expressed in terms of the thickness of the ink layer, as shown in FIG. becomes constant. Therefore, the required color density can be obtained in just the right amount at the joints of the three-dimensional object, and a seamless belt-like pattern can be expressed around the three-dimensional object.

As explained above, the present invention uses a printing plate that is longer than the circumference of the curved surface so that the pattern overlaps on the surface of the curved surface, and that is made so that the overlapping portion has the necessary color density. Since printing is performed on a curved surface, there is no possibility that the printing start part and the printing end part will not match, resulting in non-printing areas or areas where the ink density is doubled, resulting in beautiful seamless printing. is a possible method.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between color density and printing length in a conventional method. FIG. 2 is a diagram showing the relationship between color density and print length in an intermediate step of the present invention. FIG. 3 is a diagram showing the relationship between color density and printing length according to the present invention. FIG. 4 shows a cross-sectional view of the conventional gravure plate of the present invention. FIG. 5 is a diagram showing the relationship between the size of halftone dots and the printing direction in the printing plate of the present invention. FIG. 6 is a diagram showing a printed matter obtained by the present invention. In the figure, the X axis is the printing length, the Y axis is the color density, Ox ₁ is the circumference of the cylinder, x ₁ x ₂ is the overlapping area, Ox ₃ is the overlapping area, Oy ₁ is the required color density, and 1 is the plate material. , 2 is a gravure cell, 3 is a halftone dot, 4 is a printing medium, and 5 is an ink layer.

Claims (1)

[Claims] 1. When printing a strip pattern around a three-dimensional object,
The strip pattern is made longer than the circumference of the three-dimensional object so that it overlaps around the three-dimensional object, and in the overlapping area on both sides, the color density gradually increases from the edge on one side, and the color density increases from the edge on the other side. A method for printing a band-like pattern that achieves the required color density even at the seams around the periphery of a three-dimensional object, characterized by printing using a printing plate that is made so that the color density gradually decreases toward the end of the object. 2. In a printing plate capable of expressing a band-like pattern, the plate is made longer than the circumference of the three-dimensional object so that the band-like pattern overlaps around the three-dimensional object, and the color density gradually increases on one side in the overlapping area on both sides. A printing plate that prints a band-like pattern that has the required color density even at the seams around the three-dimensional object, characterized in that the plate is made so that the color density on the other side gradually decreases toward the edge.