JP3021589B2 - Information recording medium - Google Patents

Description

The present invention relates to an information recording medium having a low-melting-point metal thin film layer as a heat-sensitive recording layer, in particular, effectively preventing forgery and facilitating true / false discrimination. The present invention relates to an information recording medium which can be performed.

[Related Art] In recent years, there has been a remarkable spread of information recording media in which machine-readable information is recorded on a magnetic recording medium.
It is used in many fields such as cards, credit cards, cash cards, gift cards, prepaid cards represented by telephone cards, tickets, coupons, commuter passes, and the like.

In this type of information recording medium, a magnetic recording layer is provided on a base, and information is magnetically recorded on the magnetic recording layer. Although magnetically recorded information is visually invisible, there is a fear that the recorded information may be intentionally erased or rewritten due to the widespread use of magnetic reading machines.

Also, information is recorded on the surface of the base by means such as barcode, MICR, OCR, etc., but since the information can be read visually, there is a problem that unauthorized acts such as tampering can be easily performed. is there.

[Problems to be Solved by the Invention] As described above, in the conventional information recording medium of this type, forgery or falsification is often used for misuse, and information utilizing technology for preventing this is used. The emergence of recording media has been strongly desired.

The present invention has been made in order to solve the above-described problems, and its purpose is to make recorded information invisible, thereby making it possible to more effectively and reliably prevent forgery, tampering, and the like, An object of the present invention is to provide a highly reliable information recording information recording medium capable of easily determining whether the information is true or false.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a colored layer that absorbs infrared rays and has magnetic recording properties on a substrate made of paper, a plastic sheet, or the like. A heat-sensitive recording layer made of a low melting point metal thin film that makes infrared invisible and reflects infrared light, and a opaque layer that transmits infrared light and makes heat-recording information recorded in the heat-sensitive recording layer invisible are laminated in this order. An information recording medium is provided.

In addition, the portion of the heat-sensitive recording layer that has been melted by heating is as follows:
Provided is an information recording card comprising a low melting point metal thin film layer having a property of transmitting infrared rays but reflecting infrared rays in an unheated portion.

[Action]

According to the present invention, information such as characters and patterns is thermally applied to a thermosensitive recording layer by a thermal head or the like, and is recorded by being melted and destroyed by heating.

When irradiated with infrared rays, the portions of the characters and patterns that have been melted and destroyed by heating hardly reflect infrared rays, and the infrared rays are absorbed by the colored layer. On the other hand, unheated portions other than the pattern reflect infrared rays at a high rate. Therefore, from the large difference in the reflectance, it is possible to read the heating record information such as characters and patterns and determine the authenticity of the information recording medium. The heat-sensitive recording layer including the heat-recording information (pattern) is invisible due to the concealing layer thereon, and the portion of the pattern that has been melted and destroyed by heating and the uncolored portion are on the same plane, and the step Since it is not present, it becomes more difficult to detect its existence, and it is possible to prevent forgery, falsification, and the like.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 1 to 3 show an embodiment in which the present invention is applied to a prepaid card. FIG. 1 is a plan view of the back surface of the card, and FIG. FIG. 3 and FIG. 3 are sectional views taken along the line YY 'of FIG.

In FIGS. 1 to 3, a colored layer 2 for absorbing infrared rays is provided on the surface of a card base 1, and the colored layer (below the figure in the drawing) is made invisible thereon. 4 is provided with a thermosensitive recording layer 3 for thermally recording.
The heating record information 4 may record information such as a bar code pattern, or may simply confirm the presence of characters and patterns. On the heat-sensitive recording layer 3, a concealing layer 5 for making the heat-sensitive recording layer 3 including characters and patterns invisible is provided, and a protective layer 6 is further provided thereon.

Here, the card base 1 is made of paper or a plastic sheet. The coloring layer 2 is made of carbon powder,
A desired resin, such as an infrared absorber, or a dispersion obtained by dispersing in an ink vehicle, a gravure method, formed by a roll coating method, or the like, and, if necessary, γ-Fe ₂ , Co ₃ , A magnetic recording layer may be formed by adding a magnetic powder such as Co-coated γ-Fe ₂ O ₃ , Fe ₃ O ₄ , Ba ferrite, and Fe. For the heat-sensitive recording layer 3, low melting point metals such as Sn, Bi, In, Cd, and Pb or alloys thereof are used in consideration of toxicity and the like. The concealing layer 5 is a gray ink that mixes a process ink (yellow, magenta, cyan) having a spectral reflectance characteristic as shown in FIG. 4, for example, as shown in FIG. Is formed by offset or screen printing.

The protective layer 6 is made of resin such as acrylic resin, vinyl chloride resin, polyester resin, nitrocellulose, toluene,
A material dissolved in a solvent such as xylene is formed by a gravure method, a roll coating method, or the like.

Heat recording information such as a pattern such as a barcode or a mark, or a character, is recorded on the heat-sensitive recording layer 3 of the prepaid card having the above-described structure by a thermal head. The pattern portion (recorded portion) is melted and destroyed by heating, and a lower colored layer appears. However, since the colored layer is concealed by the concealing layer 5, its presence cannot be detected from outside.

Next, a method of reading this pattern is performed by irradiating the card with infrared rays. In other words, the characters that have been melted and destroyed by heating, the pattern part, and the uncolored part are:
In the infrared region having a spectral reflectance as shown in FIG. 5 and a wavelength of 700 nm or more, the pattern portion hardly reflects infrared light, but the undestructed portion shows high reflectance.

Therefore, from the large difference in the reflectivity, it is possible to read characters and patterns and determine whether the card is authentic or not, and recognize data such as the amount of money.

As a specific method, the character and the pattern are scanned by an infrared sensor, an output signal corresponding to the character and the pattern is obtained, and whether the output signal is a predetermined one is checked to determine whether the output signal is a predetermined one. It is possible to determine the authenticity by discriminating or visually observing these characters and patterns using an IR scope.

[Effects of the Invention] As described above, according to the present invention, a colored layer is provided on a substrate made of paper, a plastic sheet, or the like, and a heat-sensitive recording layer for recording characters and patterns is provided thereon, and further a The structure is provided with a concealment layer that makes the pattern and the character invisible by heating and melted and destroyed by heat recording means such as a thermal head and a thermal printing plate for heat-sensitive recording. Is impossible to detect, and forgery and falsification can be prevented more reliably. Also, characters recorded on the thermosensitive recording layer,
A pattern such as a bar code can be arbitrarily recorded by any heating recording means. Therefore, when the method of the present invention is compared with other methods, for example, a method of printing and fixing a pattern on a substrate with an ink containing an infrared absorbing agent instead of the heat-sensitive recording layer of the present invention, the former printing method is used. The method is to make sure that the patterns are of the same type,
Although it is limited to several types at most, the latter one using the heat-sensitive recording layer of the present invention is very flexible because the required characters and patterns can be freely recorded by heating recording means such as a thermal head. It becomes possible.

[Brief description of the drawings]

1 to 3 are views showing an embodiment in which the present invention is applied to a prepaid card. FIG. 1 is a plan view of the back side of the card, and FIG. 2 is Χ-Χ ′ in FIG. Sectional view, third
FIG. 4 is a cross-sectional view taken along the line YY ′ of FIG. 1; FIG. 4 is a curve diagram showing spectral reflectance characteristics of a process ink used for forming a concealing layer;
FIG. 5 is a curve diagram showing the spectral reflectance characteristics of the heat-fusible destructive printing portion and the non-destructive printing portion of the thermosensitive recording layer. DESCRIPTION OF SYMBOLS 1 ... Card base | substrate 2 ... Coloring layer 3 ... Thermal recording layer 4 ... Heat recording information 5 ... Hiding layer 6 ... Protective layer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B42D 15/10 501 B41M 5/26

Claims (1)

(57) [Claims] 1. A colored layer having a magnetic recording property that absorbs infrared rays, a heat-sensitive recording layer made of a low melting point metal thin film that makes the colored layers invisible and reflects infrared rays, on a substrate made of paper, a plastic sheet, or the like. An information recording medium, characterized in that a concealing layer which transmits infrared rays and makes invisible heating recording information recorded in the thermosensitive recording layer is laminated in this order.