JPS60230657A - Manufacture of original film for forming print prevented from improper copying - Google Patents

Abstract

PURPOSE:To obtain an original film stated in the titled by overlaying a densely lined negative film and a specified negative film of different kind on an unexposed film, exposing them, then, overlaying dotted negative film, and a positive film of different kind, and exposing them. CONSTITUTION:The negative film 2 having a large number of fine lines densely formed, and the negative film 3 of different kind having a pattern dazzling naked eyes are successively overlaid on the unexposed film to form a film group of three-layers structure, and it is subjected to the first exposure from above. Then, the film 2 is replaced by the dotted negative film 5, and the film 3 is replaced by the positive film 6 of different kind to form another film group of three layers structure, and it is subjected to the second exposure from above to obtain the intended original film. When the prints formed by using this original film is copied in a copying machine, the contents recorded on the surface of the obtained copy cannot be easily deciphered.

Description

[Detailed Description of the Invention] (Industrial Application Field) In order to prevent misuse such as forgery and falsification caused by copying, this invention creates printed matter that, when applied to a copying machine, reveals a pattern that dazzles the naked eye on its surface. The present invention relates to a method for producing a film original plate suitable for.

(Prior Art) With the advent of high-precision copying machines, various documents are copied in a state similar to that of the original Japanese ship, leading to unauthorized use through forgery or alteration. As a result, various printed materials suitable for preventing copying have been proposed. There is. For example, Tokuko Sho 55-4540
0 and Japanese Patent Publication No. 58-47708, when a latent image that is difficult to discern with the naked eye is printed on the surface of the paper with halftone dots indicating "invalid", "copy", etc., and when copies are made. A good example is a printed matter in which the latent image is clearly recognized so that it is obvious that it is a copy. The halftone dots of the latent image and the background part are difficult to distinguish before copying due to the difference in the size of the halftone dots. This method takes advantage of the functional limitation of not accurately reproducing color and gradation to create a difference in brightness between the latent image and the background. Therefore, after copying, it can be recognized at a glance that it is a copy, which is effective in preventing misuse, but since the copied characters and symbols are also clearly reproduced, it is extremely easy to know what is written on the surface of the paper. Of course, there is a risk that such printed matter may occur due to the configuration of the plate before manufacture.

(Problem to be solved by the invention) This invention provides a method for manufacturing a film original plate with a special plate configuration in order to produce printed matter in which the written information on the surface of the paper cannot be easily read after copying. .

(Another means to solve the problem) In other words, in this invention, different types of negative films with patterns that dazzle the naked eye are superposed on the top surface of a parallel line negative film superimposed on the top surface of an unexposed film to form a three-layer film group. After forming a first exposure to the film group from above, the line negative film is replaced with a halftone negative film, and the different types of negative films are replaced with different types of positive film to form a film group, and the film group is It is hoped that the above-mentioned drawbacks of the prior art will be overcome by applying a second exposure upwardly. In the film group having the above structure, the same purpose can be achieved by using different types of negative films before the first exposure as different types of positive films, and different types of positive films before the second exposure as different types of negative films, and further, a film group with a three-layer structure. By superimposing the negative film for the cam 7 large on the top surface of the cam 7, it is expected to have the feature that the dazzling pattern on the printed matter before copying is completely invisible to the naked eye.

(Example 1) To explain the drawings below, 1 is an unexposed film on the bottom surface, 2 is a 60-line negative film of about 10%, which is superimposed on the upper surface of the unexposed film 1, and 3 is a waveform that dazzles the naked eye. - A different type of negative film is formed with a pattern such as a spiral shape in accordance with the direction of the lines, and is superposed on the upper surface of the line negative film 2. A light source 4 provided above the group of films having a three-layer structure provides a first exposure (FIG. 1). By this first exposure, the pattern of the different types of negative film 3 is exposed as parallel lines on the unexposed film 1 on the bottom surface. Next, the 150-line, 10% halftone dot negative film 5 is replaced with the straight-line negative film 2, and the different type of positive film 6, which has formed the same pattern that dazzles the naked eye as the different type of negative film 3, is replaced with the different type of negative film 3. Give a second exposure. Then, the halftone dots of the replaced halftone negative film 5 were exposed to the unexposed film 1 in a portion outside the pattern of the different type of positive film 6, and as a result, halftone dots and a pattern that dazzled the naked eye were shown by parallel lines on the printing plate. A film master is obtained.

(Effect) When printing is performed on paper 7 using the film original plate manufactured in this way, a surface with a mixed pattern of 150 lines and 10 square halftone dots and a pattern of 60 lines and 10% parallel lines is created. A printed matter A having the following properties is obtained. When this printed material is run through a copying machine, the dark areas such as halftone dots are not reproduced and appear whitish due to the limits of the resolution of the copying machine, whereas the pattern areas consisting of parallel lines are reproduced and appear black. At this time, since letters and symbols are written on the surface of the printed matter in advance, these letters and symbols can be reproduced by copying, but patterns such as waveforms and spiral shapes that dazzle the naked eye clearly appear on the surface of the printed matter. Characters, symbols, etc. appear distorted and faded due to the interference of the pattern, and are not easily readable.

(Example 2) Even if the different types of negative film 3 before the first exposure in Example 1 were changed to the different types of positive film 6, and the different types of positive film 6 before the second exposure were changed to the different types of negative film 3, the object of the invention was achieved and the same effect could be obtained. I can demonstrate it. In other words, in this case, the pattern that dazzles the naked eye is composed of halftone dots and appears whitish, while other parts are composed of lines and appear black (see Fig. 8).

(Example 3) Further, on the top surface of the three-layered film group of Examples 1 and 2, a negative film 8 for cam fujiji, on which a cam flash pattern 9 with a ripple-like complicated pattern is formed, is prepolymerized. In this case, the same object as the invention of the above-mentioned embodiment is achieved, and in this case, the pattern that dazzles the naked eye in the printed matter is completely invisible due to the camouflage pattern 8.

(Effect of the invention) “Invalidity” in conventional abuse prevention printed matter
Techniques such as "copying" in which a latent image appears after copying are characterized by simply making a latent image appear, but when the film master produced in the present invention is used, patterns that dazzle the naked eye can be clearly revealed. Not only can it be visually recognized as a copy when it is taken out, but it also has the effect of killing two birds with one stone by making use of the weak point of the naked eye to prevent the letters and symbols on the paper from being easily deciphered, thus preventing the contents of the document from being leaked. It is something that can be demonstrated.

[Brief explanation of the drawing]

Figure 1 is a schematic side view during the first exposure to produce a film master, Figure 2 is a side view during the second exposure, Figure 3 is a plan view of a parallel line negative film, and Figure 4 is a schematic side view of a different type of negative film. Plan view,
FIG. 5 is a plan view of a halftone negative film, FIG. 6 is a plan view of a different type of positive film, FIG. 7 is a plan view of a printed matter obtained by the original film, and FIG. 8 is a plan view of a printed matter obtained by the second embodiment. FIG. 9 is a plan view of the camouflage pattern. 1 is an unexposed film, 2 is a line negative film, 3 is a different name negative film, 5 is a halftone negative film, 6 is a different type of positive film, and 8 is a negative film for camouflage. Patent applicant Hosokawa Letterpress Co., Ltd. Agent Patent attorney Yukihiko Kaneko

Claims (1)

[Claims] 1. On the upper surface of the parallel line negative film 2 superposed on the upper surface of the unexposed film 1, a different type of negative film 3 with a pattern that dazzles the naked eye is superposed to form a film group with a three-layer structure, After applying a first exposure to the film group from above, the line negative film 2 is replaced with a halftone negative film 5, and the different type of negative film 3 is replaced with a different type of positive film 6 to form a film group, and the film group is A method for producing a film original plate for producing abuse-proof printed matter by copying in which a second exposure is applied from above. 2. The method for producing a film original plate according to claim 1, wherein the different type of negative film 3 before the second exposure is used as the different type of positive film 6, and the different type of positive film 6 before the second exposure is used as the different type of negative film 3. 3. Claims 1 and 2 in which the negative film 8 for Camfujiji is polymerized on the top surface of the film group having a three-layer structure.
2. Method for producing a film master plate as described in Section 1.