JPH0621741Y2 - Information hiding copy slip - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an information concealment type copy slip in which information such as letters and numbers written on a leaflet is not readable by anyone other than a specific person.

[Prior Art] As a means for preventing the secret leakage of secret information such as a secret code copied on a storage slip of a bank or the like, there has been proposed a technique of irradiating ultraviolet light of a specific wavelength for reading information (for example, JP 58-196160 and JP 6
0-18946).

Of these, the former technique is to provide a carbon layer containing a fluorescent substance that emits a certain short-wavelength ultraviolet light on the back surface of the upper paper,
On the surface of the lower leaf paper corresponding to the carbon layer, a random pattern printing layer of the same color as the carbon layer is provided,
In the latter technique, a carbon layer containing a fluorescent substance that emits a certain short-wavelength ultraviolet light is provided on the back surface of the upper leaf paper, and a concealment printing layer is provided on the surface of the lower leaf paper corresponding to the carbon layer, and irregular In each technology, a print layer of the same color as the carbon layer of the upper leaf paper is provided on the printing layer of the lower leaf paper surface on which information is copied, so that the secret numbers are visible to the naked eye. It is possible to read only when it is not visually recognized and is irradiated with ultraviolet light.

[Problems to be Solved by the Invention] In any of the above-mentioned conventional techniques, the surface of the lower leaf paper is dented by the writing pressure, so that rubbing the portion with a tip of a pencil or the like causes the surroundings to become dark regardless of the presence or absence of embossing. At the same time, the recessed part becomes white and the information is legible, and the writing pressure applied to the back side of the lower leaf paper projects so that the embossed pattern is destroyed even if embossed. However, the embossing has a disadvantage that it can be read from the back side of the lower leaf paper, and since the embossing requires time and labor for processing, there is a problem that the cost becomes higher and the appearance is spoiled.

The present invention has been made in view of the above problems of the prior art, and the purpose thereof is to prevent the leakage of information because the information cannot be read from both the front surface and the back surface of the lower sheet. It is intended to provide a copy slip.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention employs the following technical means, that is, 25
A carbon layer containing a fluorescent substance that emits short-wavelength ultraviolet light of about 0 nanometer is provided, and a negative pattern print made of black ink that interferes with letters and numbers is provided on the surface of the lower paper corresponding to the carbon layer. It is an information hiding type copy slip in which a layer is provided and a positive pattern hiding layer made of black ink that interferes with letters and numbers is provided on the back surface of the lower paper corresponding to the printing layer.

[Operation] When information such as a secret code is written on the front surface of the upper leaf paper, the information is copied from the carbon layer on the back surface to the negative pattern printing layer on the front surface of the lower leaf paper. Since the printed layer interferes with the personal identification number, information cannot be read with the naked eye, but since the carbon layer contains a fluorescent substance, the information transferred to the printed layer is irradiated with short wavelength ultraviolet light of about 250 nanometers. By doing so, it emits a fluorescent color tone and can therefore be read.

Although the writing pressure when writing from the upper leaf paper to the lower leaf paper extends to the back surface of the lower leaf paper, a positive pattern concealing layer that interferes with the secret code is provided on the back surface, so the information is written on the lower leaf paper. It is impossible to read with the naked eye from the back side.

[Embodiment] Next, the present invention will be described with reference to an embodiment of the drawings. Reference numeral 1 is an upper paper having a carbon layer 2 on its back surface, and the carbon layer is irradiated with ultraviolet light having a short wavelength of about 250 nanometers. It contains a fluorescent substance that emits light only when Reference numeral 3 is a lower paper for storage, and a negative pattern printing layer 4 made of black ink that interferes with the information M such as a secret code is provided on the surface corresponding to the carbon layer of the upper paper. That is, the negative pattern of the printed layer 4 may be a random combination of numbers as shown in FIG. 3 or an irregular linear pattern. Since these patterns have a blank appearance, carbon is used. The information M transferred from the layer 2 is interfered by the negative pattern and cannot be read by the naked eye.
Moreover, even if the surface of the printing layer 4 is rubbed with a pencil, the information cannot be read due to the interference of the negative pattern (when the white pattern is rubbed strongly enough to be erased with a pencil, the writing pressure is used. This is because the recessed information M also becomes black and invisible. Reference numeral 5 is a positive pattern concealing layer made of black ink provided on the back surface of the lower leaf paper 3 corresponding to the negative pattern print layer 4, and is applied symmetrically to the negative pattern of the print layer 4. That is, the information M transferred to the front surface of the lower leaf paper 3 has a protruding shape on the back surface due to the writing pressure.
It is unreadable because it is interfered by. Further, even if the back surface is rubbed with a pencil, the projected information is blackened by the pencil and interferes with the positive pattern of the concealing layer 5, so that it cannot be read.

[Effects of the Invention] The present invention has the following unique effects.

(1) Since the information copied from the carbon layer on the back surface of the upper sheet is interfered by the negative pattern printing layer, it is impossible for anyone other than a person having a short wavelength ultraviolet light irradiation device to read the information with the naked eye. It is possible to prevent the leakage of data and to read the recessed information even if the surface of the lower leaf paper is rubbed with a pencil. (2) Even if the information is projected on the back surface of the lower leaf paper by the writing pressure, it is interfered with by the positive pattern hiding layer. Information cannot be read, and even if the back side of the lower leaf paper is rubbed with a pencil, etc., the positive pattern interferes with the protruding information, so that the information cannot be read, and therefore the front and back sides of the lower leaf paper cannot be read. Since the information cannot be read with the naked eye, it is possible to make every effort to prevent the leakage of secrets.

(3) Since the negative pattern printing layer on the front surface of the lower paper is made of the black ink, it is not restricted by the color of the carbon layer on the back surface of the upper paper, and the processing is not troublesome.

(4) Since both the negative pattern printed layer and the positive pattern concealing layer are visually recognized on a uniform plane, the appearance is different from the embossed pattern.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view, FIG. 2 is a plan view of a lower sheet without the pattern of a negative pattern print layer, and FIG. 3 is a negative pattern. FIG. 4 is an enlarged plan view showing the printed layer, FIG. 4 is an enlarged plan view showing the positive pattern concealing layer, FIG. 5 is an enlarged cross-sectional view of the main part of the lower leaf paper, and FIG. FIG. 3 is a plan view of a lower leaflet similar to that of FIG. 1: Top paper, 2: Carbon layer 3: Bottom paper, 4: Negative pattern printing layer 5: Positive pattern hiding layer, M: Information

Claims (1)

[Scope of utility model registration request] 1. A carbon layer containing a fluorescent substance that emits short-wavelength ultraviolet light of about 250 nanometers is provided on the back surface of an upper leaf paper, and letters and numbers are formed on the surface of the lower leaf paper corresponding to the carbon layer. An information hiding type in which a negative pattern printing layer made of black ink that interferes is provided, and a positive pattern hiding layer made of black ink that interferes with letters and numbers is provided on the back surface of the lower sheet corresponding to the printing layer. Copy slip.