JPH11175689A - Recording medium and its method for use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the safety. SOLUTION: A first and a second bar codes 4, 5 consisting of thermosensitive bodies reversibly to develop a color and to become transparent by temperature, to develop a color in a temperature range lower than a certain temperature and to become transparent in a temperature range higher than the certain temperature are provided on a base material 1 of a recording medium. Bar code parts of the bar codes 4, 5 are heated at different temperature, the first and the second bar codes 4, 5 are successively made to be transparent, read by a color difference sensor, plural pieces of read data are compared with preset true data and the truth/falseness of the bar codes is judged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to
Regarding a recording medium having extremely high security and a method of using the same,
In particular, the present invention relates to a recording medium such as a magnetic card and a method for determining the authenticity thereof.

[0002]

2. Description of the Related Art Conventionally, in a magnetic card, a bar code made of magnetic ink is read by a magnetic sensor, or an IR-absorbing ink is used and detected by an infrared sensor, and collated with data registered in advance. Although a false judgment is generally performed, no remarkable effect was found in preventing forgery.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate these problems and to provide a recording medium with improved security and a method of using the same.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and at least one surface of a substrate has a plurality of types of heat which become colorless when exceeding a specific temperature range. A recording medium having a barcode made of a reversible thermosensitive material and a method for using the same.

[0005] The present invention is a recording medium provided with a bar code made of a heat-sensitive material which reversibly changes in color and colorless and transparent depending on temperature on at least one surface of a substrate.

Further, the present invention is the recording medium, wherein the bar code is composed of two or more kinds of heat-sensitive materials having different temperatures at which the coloring or the colorless and transparent becomes.

Further, the present invention provides a recording medium in which at least a part of the bar code is made colorless by heating the recording medium, read by an optical sensor, and compared with true data set in advance to determine authenticity. How to use

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a recording medium according to the present invention, under an arbitrarily set temperature condition, the color changes (colors) to an arbitrary hue in a lower temperature range, and it is colorless and transparent in a higher temperature range. The bar code is formed by using two or more kinds of reversible thermosensitive materials, and detected by an optical sensor such as a color difference sensor. Thus, an output signal having a different pattern depending on the heating temperature is obtained. These data and the true data are compared to determine the authenticity of the recording medium. Therefore, according to the recording medium of the present invention and the method of using the same, forgery becomes difficult.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the recording medium of the present invention and a method of using the same will be described below by taking a magnetic card as an example.

FIG. 1 shows the structure of a prepaid card according to the present invention. 188 μm thick as substrate 1
And a magnetic recording layer 2 using barium ferrite of Hc: 2750 Oe as a magnetic pigment is gravure coated on the entire surface of one surface of the base material 1 by a known method. The silver layer 3 mainly composed of aluminum paste was gravure coated by a known method.

Further, the color temperature range is 50 ° C.
Using a thermoreversible ink composed of an organic acid ester, a compound having a phenolic hydroxyl group and a binder so that the hue at the time of discoloration becomes black, the first bar code 4 is silk-printed, and the same. The color temperature range is 7 on the surface.
Using a thermoreversible ink composed of an organic acid ester, a compound having a phenolic hydroxyl group, and a binder so as to be 0 ° C. or lower and the hue upon discoloration to be black, silk-printing the second bar code 5, and Finally, the overcoat layer 7 was printed using an overcoat varnish with an offset printing machine.

FIG. 2 shows a method of determining the authenticity of the obtained card.
This will be described with reference to FIG. FIG. 2 shows an outline of the reading device used in the present invention. FIG. 3 shows a reading state of the magnetic card of the present invention. FIG. 4 shows a barcode output waveform according to the magnetic card of the first embodiment. FIG. 5 shows a flowchart of the authenticity determination method according to the present invention.

First, as shown in FIG. 2, the bar code portion of the obtained card 11 was read by a color difference sensor without heating by a thermal head. In addition, 70 ° C, 10
While scanning with the thermal head 13 kept at 0 ° C.,
It was read by the color difference sensor 14. As a result, FIG.
4C, different signal waveforms of three types of patterns were obtained.

At this time, as shown in FIG.
1 shows that the first and second barcodes 4 and 5 can be seen at room temperature, but when heated to 70 ° C. by the thermal head,
As shown in FIG. 3B, the first barcode 4 has become colorless. Further, when heated to 100 ° C., the second bar code 5 also became colorless.

Next, the read data is digitally converted to obtain the waveforms shown in FIGS. 4 (e) to 4 (g). After performing the arithmetic processing, the data is collated with the data pattern set in advance by the comparison device. Is made. If the card is used normally at the time of the transaction, it matches the data pattern set in advance, so it is treated as the same data and is transacted as a true card.

On the other hand, in the case of a card having an abnormality such as falsification of bar code data at the time of a transaction, for example, when the bar code is falsified with black ink which does not change reversibly, FIGS. 4D and 4H Is generated, and the transaction is stopped as a fake card.

(Embodiment 2) FIG. 6 shows a configuration of an ID card according to the present invention. Hard vinyl chloride is used as the base material 1, and Hc: 650 Oe is entirely formed on one surface of the base material 1.
The magnetic recording layer 21 using Co-γFe ₂ O ₃ as a magnetic pigment was silk-printed by a known method, and the overcoat layer 7 was silk-printed thereon. On the other side, use a thermoreversible ink composed of organic acid esters, a compound having a phenolic hydroxyl group, and a binder so that the color development temperature range is 50 ° C. or less and the hue upon discoloration becomes black. , First
Is printed on the same surface, and is composed of organic acid esters, a compound having a phenolic hydroxyl group, and a binder such that the color development temperature range is 70 ° C. or less and the hue upon discoloration is black. Using thermoreversible ink,
The second barcode 5 was silk-printed, and the third barcode 6 was printed with an ink in which a black coloring pigment was dispersed in an acrylic binder. Finally, the overcoat layer 7 was silk-printed to protect the barcode surface.

As shown in FIG. 5, the bar code portion of the card obtained in this manner is firstly used in the same manner as in the first embodiment.
Reading was performed by a color difference sensor without heating by a thermal head. Next, while scanning with a thermal head kept at 70 ° C., reading was performed with a color difference sensor. In addition, 100 ° C
While scanning with a thermal head kept warm, the color difference sensor read. The read data is subjected to digital conversion, arithmetic processing and collation with a data pattern set in advance by a data comparison device. If the card is used normally at the time of the transaction, it matches the data pattern set in advance, so it is treated as the same data and is transacted as a true card. In the case of a card with abnormalities such as falsification of barcode data at the time of transaction,
For example, if the barcode is tampered with black ink that does not change reversibly, a different signal is generated and the transaction is stopped as a fake card.

[0019]

According to the present invention, a recording medium with improved security and a method of using the same can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a magnetic card according to a first embodiment.

FIG. 2 is an explanatory view schematically showing a reading device used in the present invention.

FIG. 3 is a plan view showing a reading state of the magnetic card of the present invention. FIG. 3A is a plan view showing a normal state. FIG.
(B) is a top view which shows the state at the time of heating at 70 degreeC. FIG.
(C) is a top view which shows the state at the time of heating to 100 degreeC.

FIG. 4 is a view showing an output waveform of a bar code according to the magnetic card of the first embodiment. FIG. 4A is a diagram showing a read waveform before heating. FIG. 4B is a diagram showing a read waveform after heating to 70 ° C. FIG. 4C is a diagram showing a read waveform after heating to 100 ° C. FIG. 4D is a diagram showing a read waveform at the time of a transaction (after heating to 100 ° C.) in the case of an abnormal card. FIG. 4E is a diagram showing a digital conversion waveform before heating. FIG. 4F is a diagram showing a digital conversion waveform after heating to 70 ° C. FIG. 4G is a diagram showing a digital conversion waveform after heating to 100 ° C. FIG. 4H is a diagram showing a digital conversion waveform at the time of a transaction (after heating to 100 ° C.) in the case of an abnormal card.

FIG. 5 is a flowchart of a true / false judgment method according to the present invention.

FIG. 6 is a diagram illustrating a configuration of a magnetic card according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 1 base material 2, 21 magnetic recording layer 3 silver layer 4 first barcode 5 second barcode 6 third barcode 7 overcoat layer 11 card 13 thermal head 14 color difference sensor 15 card transport direction 16 facing roller 17 Conveying belt 18 Conveying roller

Claims (3)

[Claims] 1. A recording medium comprising a barcode made of a heat-sensitive material which changes color and reversibly into colorless and transparent depending on temperature on at least one surface of a substrate. 2. The recording medium according to claim 1, wherein the bar code is made of two or more kinds of heat-sensitive materials having different temperatures at which the color or colorless and transparent becomes. 3. The method according to claim 1, wherein the recording medium is heated, at least a part of the bar code is rendered colorless, read by an optical sensor, and compared with preset true data to determine whether the bar code is true or false. Item 10. A method for using the recording medium according to Item 1 or 2.