JPS58118682A - Object which cannot be copied - Google Patents

Abstract

PURPOSE:To prevent leakage of secret of confidential documents through copying, by making objects in such a way that the color contrast between the ground of paper and characters and graphs written on the paper can be discriminated by naked eyes but hardly discriminated by lights for copying. CONSTITUTION:An object 9 is a sheet of vermilion color 8, on which characters 2, graphs, etc., are printed in black, and the black characters, etc., can be read by naked eyes against the vermilion color of the ground. When the object 9 is put on a PPC copying machine and a copying light 4 for forming electrostatic image is irradiated upon the object 9, the contrast between the ground color and the color of characters, etc., is very inferior and the characters 2 cannot be read. Therefore, the copy 10 of the object 9 has a black ground 11 for the whole surface by the toner. Thus the object 9 cannot be copied. In this way leakage of secrets of confidential documents through copying can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to copy-protected objects such as confidential documents whose contents must not be copied, leaked, or misappropriated.

In conventionally known copying, as shown in Figs. 1 and 2, a subject (3) representing black letters (2), figures, etc. is drawn on a white paper (1) by hand-drawing, printing, copying, etc. P
Using a PC or CPC electrostatic copying machine, Zoazo copying machine, photographic machine, etc., copy using a copying light (4) to copy black letters (6), figures, etc. onto white paper (5), etc. As shown in Figure 3, an object (7) with contrast (C1) was obtained.

The present invention is a subject that cannot be copied, and is characterized in that the color contrast between the background color and characters, figures, etc. is distinguishable with the naked eye, and the contrast is extremely poor with copying light. etc. are illegible subjects.

Figure 4 shows an embodiment of the present invention.
8) Paper with black letters (2), figures, etc. printed on it (
9), and the black characters etc. can be easily read with the naked eye against the vermillion background color.

This is then used with a PPC copying machine to form a copying light beam (4
), the contrast between the two (C2
) is extremely poor and character (2) is illegible. Therefore, it has been confirmed through repeated experiments by the present inventor that the copy (10) has a black background (11) made of black toner over the entire surface and cannot be copied.

Figure 6 also shows an embodiment of the present invention, in which the subject is a paper (14) on which letters (13) are written with light blue water-based ink on a white background (12), and the letters are colored in the background color. This can be seen with the naked eye due to the color contrast of hue and brightness, but when the copying light beam for electrostatic image formation was applied using a PPC copying machine, the copy paper (15) was completely white with no letters. The inventor's experiments have confirmed that this cannot be accepted. That is, as shown in FIG. 7, there was no contrast difference (C3) between the white background of the subject and the light blue text, and the text (13) could not be read.

According to the present invention, it is possible to prevent copying without being predicted by a third party by combining the background color of the subject and characters without making any modifications or changes to the copying machine, thereby preventing leakage of confidential documents. It is something that can be extremely effective.

The present invention is applicable to the above-mentioned vermilion sheet itself as copy paper, to the vermilion sorting itself before black characters are printed for this purpose, to electrostatically copied sheets with black characters, etc., and to the vermilion sheets on black background. , light blue paper itself on which white characters are written to prevent copying, light blue sheets with light blue characters written on a white background to prevent copying, etc., are all included in the present invention. In addition to the above-mentioned embodiments, the color contrast between the background color of the object obtained by copying and the characters and figures on it is such that the contrast cannot be recognized due to the copying light of the copying machine and the characteristics of photosensitive imaging caused by it. The present invention includes all objects in which the whole or part of the object cannot be copied.

[Brief explanation of drawings]

FIG. 1 is a side view showing a conventionally known copy, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a contrast diagram of a conventionally known copy, and FIG. 4 is a plan view of the first embodiment of the present invention. , FIG. 5 is a contrast diagram of the first embodiment of the present invention, FIG. 6 is a plan view of the second embodiment of the present invention, FIG. 7 is a contrast diagram of the second embodiment of the present invention, 8, 12
... Ground color 2, 13 ... Characters, figures, etc. 4 ... Light source for copying applicant Yoshiro Nakamatsu

Claims (1)

[Claims] A subject that cannot be copied, characterized in that the background color of characters, figures, etc. is such that the color contrast is discernible with the naked eye, and the contrast is extremely poor when exposed to copying light.