JPH0445903Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention is based on the invention that, even if the density of the copying machine is adjusted to either the dark or light range, the latent image that indicates that it is a copy will remain on the paper after copying. This invention relates to a full-range functional type copy counterfeit prevention paper that has a function that appears at the location.

[Prior Art] The surface of anti-counterfeiting paper consists of a background printed with minute dots and lines and a latent image.The latent image is normally not visible on the surface of the paper, but the presence of the latent image becomes visible when the paper is run through a copying machine. However, with the rapid development of copying machines, the range of adjustment of shading was greatly expanded.
It has become possible to erase latent images from the visual field while characters and symbols recorded on the surface of paper remain intact. In other words, as the density adjustment of the copying machine is made weaker, the reproducibility of the background and the latent image becomes weaker, resulting in a problem in which both are hardly reproduced. Therefore, in order to solve this problem, Jitsukaiaki
There is a technique disclosed in the publication No. 61-122868. In this technology, by providing a gradation printing layer on the top or bottom of the latent image printing layer consisting of the background and latent image, either the background or the latent image is reproduced even if the copying machine density is reduced, resulting in the latent image being reproduced. It is hoped that the presence of the statue will be visible.

[Problem to be solved by the invention] The above-mentioned conventional technology is effective as a countermeasure when the copying machine density is reduced, but when the copying machine density is increased and reproduced, both the background and the latent image are black. The latent image appears in a dark color, making it difficult to distinguish between the two, resulting in the problem that the presence of the latent image is difficult to decipher.

[Means for Solving the Problems] This idea was made in view of the conventional problems, namely, a background composed of microscopic particles and a plurality of latent images composed of microscopic particles are applied to the surface. , paper on which the latent image is normally not visible but is visible when copied, distinguishing it from the background, and the background occupies one-third of the surface and the latent image is a light color printed with ink having a density of about 0.50. The background and the latent image that occupy two-thirds of the surface are composed of a dark-colored surface printed with ink having a density of about 1.50. Overprint or underprint a gradation printing layer on one half of the area,
The present invention aims to provide copy forgery prevention paper that solves the above-mentioned problems.

[Example] On the surface of a vertically long sheet of paper 1, a latent image 3 with the word "copy" written in multiple rows is applied from the top to the bottom along with a background 2, and the background 2 is a 150-line 10% halftone fine dot image. The latent image 3 is composed of 50 lines and 10% parallel line fine particles. The upper background 2 and latent image 3, which occupy one-third of the surface, are the light colored surface A printed with corner ink having a density of 0.50, and the middle and lower background 2, which occupy two-thirds of the surface. and latent image 3
is a dark-colored surface B printed with corner ink having a density of 1.50, and the entire surface is a single-color shading printing layer 4. The light-colored surface A and the dark-colored surface B are formed by the so-called rainbow printing method, and the light-colored surface A is formed using ink that has been made light in color using a medium in advance. The boundary between the light colored surface A and the dark colored surface B is not clearly defined. In addition, 150 lines 20% to 100
% halftone gradation plate 6 is used to overprint the gradation printing layer 5 with a filler ink having a density of 0.50, so that the dark side B is darker at the bottom than at the top.

The background 2, which is made up of 150 lines and 10% halftone dots, and the latent image 3, which is made up of 50 lines and 10% parallel lines, are difficult to see with the naked eye and it is difficult to distinguish between them. Although they are not easily readable, when used in a copying machine adjusted to normal density, the halftone dots are not reproduced and appear as a white background, while the parallel line fines are reproduced and appear black. The black latent image 3' of the copy paper 1' contrasts with the white background 2', making it clear that the two are distinct and that it is a copy (FIG. 4). However, the latent image in the upper light-colored area is not reproduced.

When the density of the copying machine is adjusted to the maximum density, the background 2 and the latent image 3 are reproduced on the upper and lower parts of the dark side B of the dark and light printing layer, making it black, making it difficult to distinguish between the background and the latent image, but the density is around 0.50. Since the background 2 consisting of halftone dots on the light-colored surface A having . . . is not reproduced, the latent image 2 clearly appears. That is, as shown in FIG. 5, a black latent image 3' is recognized in the white background 2' in the upper third of the copy paper 1'.

Contrary to the above, if the copying machine is adjusted to the lowest density, the background 2 and the latent image 3 on the upper half of the light-colored side A and the dark-colored side B of the light and dark printed layer 4 will not be reproduced, respectively, and the two will not be distinguishable. Since the lower half of the dark color surface B is overprinted with a gradation printing layer 5, the latent image 3 in this area is reproduced and distinguished from the background 2. In other words, as shown in Figure 6, copy paper 1'
A latent image 3' appears and is clearly recognized in the lower one-third of the area.

In the above embodiment, the gradation printing layer 5 is overprinted on the upper surface of the gradation printing layer 4, but the same effect can be obtained even if the gradation printing layer 5 is underprinted on the lower surface of the gradation printing layer 4. If the purpose can be achieved and the shapes of the microscopic particles of the background 2 and the latent image 3 are reversed from those in the above embodiment, the background will be reproduced and the latent image will not be reproduced, but this also falls within the scope of free implementation of this proposal. Of course.

[Effect of the invention] In this invention, the background 2 and the latent image 3, which occupy one-third of the paper 1, are light colored surfaces A with an ink density of about 0.50, and the two-thirds part has an ink density of 1.05. Since the latent image 3 is divided into two dark-colored surfaces B, the latent image 3 appears in a visible state on any part of the paper corresponding to the normal density and high density of the copying machine, and the latent image 3 appears on a half of the dark-colored surface B. Since the gradation printing layer 5 is provided in the gradation printing layer 5, when the density of the copying machine is adjusted to a low value, a latent image clearly appears in the corresponding area, and therefore, the entire adjustment range of the copying machine of normal density, high density, and body density is achieved. This has the effect that a latent image always appears over a period of time.

[Brief explanation of the drawing]

Figure 1 is a plan view of the proposed paper, Figure 2 is a cross-sectional view taken along the line E-A of Figure 1, Figure 3 is a partially enlarged plan view of Figure 1, and Figures 4 to 6 are copies of the present invention. Fig. 4 shows normal concentration, Fig. 5 shows high concentration, and Fig. 6 shows the state of
The figures are plan views of each low-density version, and FIG. 7 is a plan view of a gradation plate. 1... paper, 2... background, 3... latent image, 4...
Shade printing layer, 5...Gradation printing layer, A...
...Light colored side, B...Dark colored side.

Claims (1)

[Scope of utility model registration request] A sheet of paper on which a plurality of latent images composed of microscopic particles are applied to the surface along with a background composed of microscopic particles, and the latent images are normally not visible but are visible when copied, distinguishing them from the background, A light-colored surface printed with ink in which the background and latent image occupying one-third of the surface have a density of approximately 0.50, and the background and latent image occupying two-thirds of the surface are printed with ink having a density of approximately 1.50. This full-area functional copy counterfeiting paper is composed of a dark and light printed layer printed in one color, which is a printed dark color side, and a gradation printing layer is overprinted on one-half of the dark color side of the light and shade printed layer.