JPS63135283A - Method for printing concealed image - Google Patents

Abstract

PURPOSE:To print a concealed image artificially by a four-color printing instead of a conventional five-color printing, by a method wherein, in a portion to be a concealed picture pattern, a light color among colors of the multi-color printing is substituted to be overlapped as dots of the same color and added to dots of the general picture pattern to be overlapped. CONSTITUTION:A general picture pattern is decomposed into four colors to be continuous films of Indigo A, Red A', Yellow A'', and Black A'''. On the other hand, for example, Light-indigo B to be a concealed image is prepared, and the color A of the general picture pattern and the color B are printed to a film to be overlapped as dots of the additive mixture of the colors A and B so as to be exposed to different degrees (the color A is exposed to a high degree and the color B to a low degree). Similarly, the mixtures of the color B to the colors A', A'', and A''' are respectively printed to films. Original plates G, G', G'', and G''' are made by using the added film original plates through screens S, S', S'', and S''', respectively. By using a multi-color printer with the original plates of four colors G, G', G'', and G''', a concealed image of the general picture pattern A incorporating a concealed picture pattern B can be printed.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for printing hidden images.

(Prior Art) Hidden pictures in magazine inserts, supplements, sales and advertising pamphlets, and other children's puzzles have generally been hidden in multicolor (four-color) printed pictures. You print it out and use a complementary color filter to see the hidden patterns.

Up until now, the method for printing this hidden pattern has been to print a general pattern in multiple colors (red, yellow, indigo, and ink) and then reprint the hidden pattern in a color other than the above, that is, a special color. Ta.

(Problems to be Solved by the Invention) In the above-mentioned multicolor printing in which a special color of a hidden pattern is additionally printed on the general pattern, the number of printing colors is 5, so ) It was not possible to print with just a printing press.

(Means for Solving the Problem) The present invention is an idea for avoiding 5-color printing by additionally printing a special color of a hidden pattern on the above-mentioned general pattern of 4-color printing. You can print a hidden pattern in the general pattern of printing, for example, in light blue (or half-illuminated blue), and view this with a red filter, which is a complementary color, or print it in light red (or half-illuminated red). 8M) and view it using a complementary green filter.

As a means of printing such a hidden pattern, for example, as shown in Figure 2, one of the four colors of printing, indigo, is used to print a film constituting the general pattern and a pale indigo color that becomes the hidden pattern. Filmlo and the same mesh screen (
If we consider printing on the same original plate through SL), the opening will be printed through the same screen on the original plate with the halftone dots printed with the hole, and it will be difficult to match the halftone dots between the hole and the mouth. In the original plate in which the prisoner and the depression were printed together, it cannot be said that the hidden pattern of the mouth was printed in the correct state compared to the general pattern of the prisoner.

Therefore, even if a pattern printed using such an original plate is viewed using a red filter, the expected hidden pattern opening cannot be seen.

For this reason, it is necessary to change such printing means, e.g.
As shown in the figure, when considering the hidden pattern of indigo among the films separated into four colors, we first consider the indigo film A, which is the general pattern, and the light blue film R, which is the hidden pattern.
Each item is printed onto an original plate through screens (S2) and (S3), and based on this original plate, a pattern is printed in which the prisoner and the prisoner are superimposed using ink shading. By passing the patterned film and the other three colors of general patterned film through separate screens to create separate original plates, and using these to print on a multicolor printing machine,
The result is an image with a hidden pattern opening inserted into the regular pattern.

However, with this method, it is necessary to prepare and prepare an original film in which the shading image and the image overlap in advance, which requires an extra process.

Therefore, in the printing method of the present invention, instead of using a special color as a hidden pattern, one light color in multicolor printing is replaced with a combination of halftone dots of the same color, and this is used as a halftone dot of the general pattern. By adding to the multiplication, without increasing the number of colors,
A multicolor original film is produced, and this original film is used for printing with a multicolor printing machine.

(Example) The method of the present invention will be explained below with reference to FIG.

The general pattern is divided into four colors, and it is called a continuous film indigo color, red, mu], yellow ■ko, and black color. The indigo color and the light blue l of the hidden pattern are printed on film by changing the exposure level (stronger for the dark, weaker for the old) and the addition of ten dots. In the same way, burn the red box, the yellow clay surface, and the ink box + concavity, respectively.

This added 10 figures, 圓] + 圓, 组子+口, 11ff
Holding the film original plate of l + [fl, the printing original plate (G) (prior + []), (G' ) (匡ko earth surface), (G”) (]ko+fffi), (G'”)
(I co + times) will be produced.

Next, these four-color printing plates (G), (G'),
If (G") and (G'") are printed using a multicolor printing machine, a hidden image in which a hidden picture is inserted into a general picture can be printed.

The addition of the halftone dots of the hidden pattern opening for the above general pattern prisoner is as follows:
Using a computer, doubling synthesis of a layout scanner, that is, 2 images obtained by scanning a general pattern
The pattern data for each dimensional coordinate is temporarily stored on a disk, and separately, the pattern data for each two-dimensional coordinate obtained by scanning the pattern opening is stored in another disk, and both are stored for each coordinate. It can be done easily and accurately as a method of adding at a certain predetermined ratio.

Furthermore, hidden patterns in the semi-steel parts of general patterns that were conventionally easy to see should be treated with a mosaic reproduction process, or a complementary color to the filter system should be applied so that the hidden patterns can be seen but cannot be identified. It becomes possible to reproduce a series of mosaics. Further, it is possible to use the same method as the conventional method to make the special color reproduction of the hidden pattern dotted so that it cannot be discerned with the naked eye.

(Effects of the Invention) The present invention replaces a portion that becomes a hidden pattern by multiplying one light color of multicolor printing as halftone dots of the same color, and replaces this with halftone dots of other colors of a general pattern. By adding to the multiplication of , a 4-color original plate is produced and printed with these printing original plates, so it is possible to print 5 colors by adding a special color to the hidden pattern as in the past. Unlike color printing, it prints in four colors, so it is sufficient to use only a conventional multicolor printing machine, and it is possible to print a pseudo-hidden image with four-color printing instead of the conventional five-color printing.

[Brief explanation of the drawing]

FIG. 1 is a detailed explanatory drawing of the present invention, and FIGS. 2 and 3 are explanatory drawings in the process of making the present invention. Code S, ~S3. S-5”...Screen G
-G”・・・・・・・Printing original figure 1

Claims (1)

[Claims] Instead of using a special color as a hidden pattern, the number of colors can be increased by replacing one light color in multicolor printing with a multiplication of halftone dots of that color, and adding this to the multiplication of halftone dots in a general pattern. A hidden image printing method characterized in that a multicolor original film is produced without increasing the number of hidden images, and multicolor printing is performed using this original film.