JPH0455877B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a non-recopyable paper that allows a manuscript to be copied but cannot itself be copied as a manuscript to another paper.

[Prior Art] With the remarkable development of copying machines, it has become easier to create documents that are confused with the real thing, and alteration, forgery, and leakage of document contents have become social problems. Copy-prevention paper and copy-prevention paper that darken and make recorded characters difficult to read have been developed.

One example is the technology disclosed in Japanese Patent Application Laid-open No. 158674/1983, which determines the color depending on whether the substrate is transparent, semi-transparent or opaque, and is suitable for transmission copying and reflection copying. Regardless of which copying machine is used, the paper after copying is intended to turn black and make the recorded characters unreadable.

[Problems to be Solved by the Invention] The above-mentioned conventional technology has the complexity of applying different colors depending on the transparency and type of the substrate.
There was a problem in that the recorded characters were reproduced to some extent on the copy because it was a simple selection or combination of colors.

The present invention was developed in view of these problems, and when re-copied, the surface becomes noticeably dark.
Further, the purpose is to prevent recorded characters from becoming illegible due to interference with the printed pattern.

[Means for Solving the Problems] In order to achieve the above object, the present invention takes the following technical means, namely, a pattern that interferes with recorded characters formed on the surface of a translucent base paper. The printed surface uses a sepia tone ink that is easily reproduced in copies, and the reflection density value of the sepia tone ink measured by a color densitometer is yellow.
1.98, magenta 1.87, and cyan 1.42, and is characterized by transmission density values of yellow 1.34, magenta 1.27, and cyan 0.71.

[Function] Characters recorded with black ink or toner on the surface of paper having the above density values can be read well with the naked eye, and are even easier to read when the paper is viewed diagonally.

Since the sepia tone ink itself is dark in color, when the paper is copied as a document, the surface becomes dark, making it difficult to read the recorded characters, and the pattern printed surface interferes with the recorded characters, making it difficult to distinguish between the characters and the printed surface. The recorded characters become completely illegible.

[Example] A pattern printed surface that is easily reproduced by copying is provided on the surface of a semi-transparent smooth base paper using sepia tone ink. With sepia tone ink, the reflection density value measured in solid printing is yellow.
1.98, magenta 1.87, and cyan 1.42, and the transmission density values are yellow 1.34, magenta 1.27, and cyan.
It is 0.71. The above density values were measured using a commercially available Macbeth color densitometer model RD918-SB (narrow band, no changing filter); yellow is blue light, magenta is green light;
Cyan is a value measured through red light.

The pattern printing surface is composed of, for example, a combination of vertical and horizontal lines with wavy lines or a continuous polygonal pattern that interferes with the lines of the recorded characters.

The paper printed with the sepia tone ink is
It is relatively easy to distinguish the recorded characters from black, but when the other side is copied, the color develops black.When this is measured using the color densitometer mentioned above, the above density value makes it possible to visually recognize the recorded characters and to make copies. We were able to confirm that the best effect was that the entire image was darkened and unreadable.

Therefore, when this paper is used as a copy paper, the recorded characters of the original are clearly copied, and when this paper after copying is used as a manuscript and copied onto regular copy paper, the copy paper becomes black and the pattern printed surface is It interfered with the recorded characters, making them completely impossible to read.

In the present invention, specific numerical values are shown for the concentration in the above-mentioned Examples, etc., but the present invention also includes numerical values around the above-mentioned concentration values within a range that achieves the objects and effects of the present invention.

[Effect of the invention] When the paper of the present invention is used as copy paper,
Since the recorded characters of the original are transferred to the surface of the paper in black, the recorded characters copied in black can be clearly read by transmitted light regardless of the surface on which the pattern is printed.

On the other hand, if you copy this paper with recorded characters copied onto other copy paper as a manuscript,
The copy paper is colored black, and the pattern printed surface interferes with the recorded characters even if the density of the copying machine is adjusted, making it impossible to read the characters.

Therefore, once the transcription traces and original manuscript are disposed of on this paper, the recorded characters cannot be copied again, so forgery and alteration due to copying can be prevented, and this is effective in maintaining confidentiality.

Claims (1)

[Claims] 1 A pattern-printed surface that interferes with the recorded characters is provided on the surface of a semi-transparent base paper, and the pattern-printed surface is made of a sepia-toned ink that is easily reproduced in copies, and that the sepia-toned ink is The reflection density value measured by the color densitometer is 1.98 for yellow and magenta.
1.87, cyan 1.42, and non-recopyable paper characterized by transmission density values of yellow 1.34, magenta 1.27, and cyan 0.71.