JPH05197848A - Information recording medium - Google Patents

Abstract

PURPOSE:To provide an information recording medium which can record not only the magnetic information but also the optical information and is effective to prevent the forgery by producing a fixed pattern with combination of the magnetic layers of different optical characteristics. CONSTITUTION:A bar code-shaped fixed pattern consisting of the magnetic layers is provided on a base 1, that is, the fixed pattern includes a magnetic recording layer 2, an optical reflecting layer 3, a magnetic bar code 4, and a concealed layer 5 which are successively laminated on each other on the base 1. It is required to combine at least two types of magnetic materials of different optical characteristics for use of the magnetic layer used for the code 4. These two different magnetic materials are substantially equal to each other in a visible area and then different from each other in an infrared area respectively. That is, a magnetic signal is read out of a bar code part by a magnetic head and at the same time, the bar code part is irradiated by the infrared rays. Then the reflected light of the bar code part is detected and therefore, the optical information of different types which are recorded on the bar code can be simultaneously read.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording medium which is provided with magnetically and optically readable code information and is effective in preventing forgery and tampering.

[0002]

2. Description of the Related Art In recent years,
A magnetic card in which a magnetic material is applied in a bar code shape on a part of the card surface and data is stored by selective magnetization is widely used. Since such a card contains confidential information as a signal, it is demanded to deal with falsification of the card. As a technique for preventing forgery / tampering of a magnetic card, for example, Japanese Patent Application Laid-Open No. 48-47723 discloses a method for a credit card having a plurality of magnetic regions having different magnetic characteristics as a unique detecting means, in addition to a magnetic track. Disclose the card. Japanese Unexamined Patent Publication No. 54-118800 discloses a forgery prevention ticket provided with a combination of a magnetic bar code and a non-magnetic bar code. In addition, JP-A-50-
No. 23931 describes a recording medium in which information such as a signal coded on a non-magnetic substrate is recorded by a paint containing a component having a light reflection amount and magnetic characteristics different from those of the substrate. Further, in JP-A-62-145585, a specific code is formed at a specific position on the magnetic recording layer with a fine magnetic material having a squareness ratio smaller than Hc of the magnetic recording layer, and then a hiding layer is provided on the entire surface. A magnetic information recording card is disclosed.

However, in the above-mentioned prior art, since the fixed code formed on the card can be easily detected by the ordinary magnetic head, it is impossible to sufficiently deal with fraud prevention. Therefore, an object of the present invention is to provide an information recording medium having a novel structure in order to eliminate the drawbacks of these conventional cards.

[0004]

As a result of earnest studies to solve the above problems, the present inventor has adopted a plurality of magnetic layers having different optical characteristics as the magnetic layer in which code information is conventionally input. As a result, we have succeeded in developing a card that can record not only magnetic information but also optical information and is sufficiently effective in preventing forgery and tampering.

That is, the present invention is characterized in that, in an information recording medium having a fixed pattern of a bar code-like magnetic layer on a substrate, the fixed pattern is formed by combining magnetic layers having different optical characteristics. An information recording medium is provided.

Further, the present invention provides an information recording medium having a fixed pattern of a bar code-like magnetic layer on a substrate,
There is also provided an information recording medium characterized by comprising a magnetic recording layer and / or an optical reflection layer on a substrate, and a fixed pattern formed by combining magnetic layers having different optical characteristics on the magnetic recording layer.

According to another aspect of the present invention, in an information recording medium having a fixed pattern of a bar code-like magnetic layer on a substrate, the magnetic recording layer is provided in one region on the substrate and the optical recording layer is provided in another region. An information recording medium comprising a fixed pattern formed by combining magnetic layers having different characteristics.

As a material for the magnetic layer for a magnetic bar code which can be used in the information recording medium of the present invention, it is necessary to use at least two kinds of magnetic materials having different optical characteristics in combination. Here, the magnetic materials having different optical characteristics mainly mean materials having different transmission, absorption or reflection spectra of light, preferably infrared rays. In particular, the combination of magnetic materials is such that the spectra of such magnetic layers are all substantially the same in the visible region, and at least two magnetic layers are different in the infrared region, because the spectrum usually absorbs light in the visible region. Is preferred. For example, a combination of γFe ₂ O ₃ having a relatively low infrared absorption rate and Fe ₃ O ₄ having a relatively high infrared absorption rate, γFe in which carbon or a material having a high infrared absorption rate is added to the binder
₂ O ₃ combined with γFe ₂ O ₃ not added,
Examples thereof include a combination of Ba ferrite in which carbon or a material having a high infrared absorptance is added to the binder and Ba ferrite in which a binder is not added, but the binder is not limited thereto, and the optical characteristics, particularly the light absorptivity are different from each other. Various combinations of magnetic layers can also be used.

Examples of the substrate used in the information recording medium of the present invention include plastics such as PET and PVC, paper, metal, alloy plate and the like, but the present invention is not particularly limited thereto and the object of the present invention can be achieved. Any material that can be used can be used.

In the information recording medium of the present invention, a magnetic recording layer can be provided between the substrate and the bar code magnetic layer. Such a magnetic recording layer can be used as an information source other than a bar code, for example, γFe ₂ O ₃ , BaO.
6Fe ₂ O ₃ , SrO.6Fe ₂ O ₃ , Fe-Co, F
A magnetic thin film such as e-Ni-Co can be used.
Further, such a magnetic recording layer may be provided in one area on the substrate and the barcode magnetic layer may be provided in another area.

Further, an optical reflection layer may be formed between the substrate and the bar code magnetic layer in combination with the magnetic recording layer or alone. The optical reflection layer is a layer for reflecting and detecting infrared rays that have passed through the barcode magnetic layer. For example, a pigment (white pigment) having a high infrared reflectance is dispersed in a binder, or Sn, Al, Zn or the like is used. It can be formed by providing a metal or alloy thin film on the substrate. However, the magnetic recording layer is a magnetic material having a high infrared reflectance, such as Fe, Fe-Cr, and Fe-C.
In the case of a magnetic thin film such as o, the optical reflective layer is unnecessary because it itself functions as a reflective layer.

In the present invention, an ordinary synthetic resin for magnetic recording media such as vinyl chloride / vinyl acetate copolymer, urethane resin, polyester resin, and cellulose resin can be used as a binder.

In the information recording medium of the present invention, in order to prevent the magnetic bar code information from being detected by the naked eye, the bar code portion is opaque to visible light and transparent to infrared light. Concealment with a material is preferred.
Such a hiding layer can be formed by coating or printing by adding various dyes having such optical properties to form a paint or an ink.

The information recording medium produced by the above means has a signal magnetically recorded and a signal optically recorded on one bar code at the same time, so that it can be read magnetically or optically. Different code information can be taken out depending on whether it is read. Thus, for example, the magnetic signal can be used as a dummy and the optical signal can be used as a true signal to provide a tamper proof card.

FIG. 1 and FIG. 2 show a specific example of the information recording medium of the present invention having a magnetic recording layer and an optical reflection layer. FIG. 1 is a plan view of a card type magnetic recording medium. In the figure, a set of magnetic bar codes 4 is provided on the lower side, and a bar code area A is provided.
Areas B and B are areas having different absorptances with respect to infrared rays having a specific wavelength. FIG. 2 is a cross-sectional view of the arrow portion of the magnetic recording medium of FIG. 1, in which the magnetic recording layer 2 is formed on the PET base 1.
An optical reflection layer 3, a magnetic bar code 4, and a masking layer 5 are sequentially provided. Each layer of such an information recording medium can be manufactured by a coating method, a printing method or the like used in the art.

The present invention also provides a method for reading the above information recording medium. That is, there is provided a method of irradiating the bar code portion of the above-described information recording medium of the present invention with infrared rays and detecting reflected light to read the information recorded in the bar code. Further, the present invention is
The magnetic signal is read by the magnetic head from the bar code portion of the information recording medium of the present invention, the bar code portion is irradiated with infrared rays, and the optical reflected light from the bar code is detected to detect the optical signal recorded on the bar code. It also provides a way to read information simultaneously.

As the infrared irradiating means, for example, a light emitting diode, an optical fiber, a semiconductor laser or the like can be used, and an infrared wavelength of 800 to 1000 nm is suitable. An infrared sensor or the like can be used to detect the reflected light. FIG. 4 shows a conceptual diagram of one embodiment of the method of the present invention for simultaneously reading magnetic and optical signals from a bar code. A specific example of the magnetic signal read by the magnetic head from the bar code in this manner is shown in FIG. This shows the case where the magnetic characteristics of each area of the barcode are substantially the same and the magnetic signals are all the same, that is, the case where the magnetic signal is used as the dummy signal. Further, FIG. 3B shows an optical signal read from the barcode by the infrared sensor. The on / off of the signal indicates a signal corresponding to the optical characteristics of the regions A and B shown in FIG. 1, that is, the difference in reflectance of infrared rays. Examples of the present invention will be shown below, but they are merely specific examples of the present invention and do not limit the present invention at all.

[0018]

【Example】

Example 1 A magnetic recording layer in which barium ferrite (Hc3000Oe) was dispersed was applied to a surface of a PET base having a thickness of 250 μm in a thickness of 10 to 15 μm, and a part of the surface of the magnetic recording layer was applied. A light reflection layer formed of a coating film in which a 2 μm white pigment was dispersed in a binder to reflect infrared rays was formed by a screen printing method. Next, γFe ₂ O ₃ (Hc 300 having respective reflection spectra as shown in FIG. 7)
Oe, Br 1000 Gauss) and γFe ₂ O ₃ containing carbon
(Hc 300 Oe, Br 1000 Gauss) was used to prepare a printing ink for a magnetic bar code, and a bar code was formed on the light reflection layer by a printing method. Further, a dark gray-colored infrared transparent ink was formed by a screen printing method as a concealing layer that does not transmit light in the visible light region and transmits light in the infrared region. Thus, the magnetic recording medium of the present invention having the structure shown in FIG. 2 was obtained. When the magnetic signal and the optical signal were read from this medium by the method shown in FIG. 4, the information shown in FIG. 3 was obtained.

Example 2 As shown in FIG. 5, a PET base 1 having a thickness of 250 μm
A magnetic recording layer 6 in which barium ferrite (Hc3000Oe) was dispersed was formed in a stripe shape on a part of the surface of the. As shown in the figure, γFe ₂ O ₃ (Hc 300 Oe, Br 1000 is formed on the surface of the PET base and below the magnetic recording layer.
GaFe) and carbon containing γFe ₂ O ₃ (Hc 300O
e, Br1000 gauss), and two types of magnetic bar code printing inks prepared respectively were used to form the bar code 4. Then, the concealing layer 5 was further formed thereon in the same manner as in Example 1. FIG. 6 is a sectional view including the bar code portion of the magnetic recording medium of the present invention shown in FIG. 5 thus obtained.

Example 3 A magnetic recording layer and a light reflection layer were formed by the same means as in Example 1. Next, two kinds of barcode inks similar to those in Example 1 were prepared, and the inks were screen-printed with the inks to remove the hairs so that the gap between the magnetic barcodes was substantially zero. Then, a concealing layer similar to that in Example 1 was formed thereon. The bar code portion formed in this manner generates a code signal for infrared light, but magnetically acts as a magnetic recording layer in one stripe state (that is, no code signal is generated).

[0021]

INDUSTRIAL APPLICABILITY Since the information recording medium of the present invention can write information that can only be read out optically on the magnetic layer, it can be utilized as a key code for encryption and is extremely effective as a card for counterfeiting. Can be used. Moreover, since a plurality of types of code information can be simultaneously input to one set of barcode, the recording density is increased. Further, since the recording medium of the present invention has a lower material cost and a simple manufacturing process as compared with the conventional infrared barcode type recording medium, a recording medium suitable for mass production can be manufactured.

[Brief description of drawings]

FIG. 1 is a plan view of an information recording medium that is a specific example of the present invention.

2 is a cross-sectional view of the information recording medium of FIG.

3 is a signal waveform read from the bar code of the information recording medium shown in FIG. 1, (A) is a magnetically read signal, and (B) is an optically read signal. It is a signal.

FIG. 4 is a conceptual diagram showing a method of reading a signal recorded on the information recording medium of the present invention.

FIG. 5 is a plan view of an information recording medium that is another specific example of the present invention.

6 is a cross-sectional view of the information recording medium of FIG.

FIG. 7 is a reflection spectrum of γFe ₂ O ₃ containing carbon and γFe ₂ O ₃ used as an ink for a magnetic barcode in Example 1.

[Explanation of symbols]

 1 PET Base 2 Magnetic Recording Layer 3 Optical Reflection Layer 4 Magnetic Bar Code 5 Concealment Layer

Claims (7)

[Claims] 1. An information recording medium having a fixed pattern of a bar code-like magnetic layer on a substrate, wherein the fixed pattern is formed by combining magnetic layers having different optical characteristics. 2. An information recording medium having a fixed pattern of a magnetic layer in the form of a bar code on a substrate, wherein a magnetic recording layer and / or an optical reflection layer are provided on the substrate, and a magnetic layer having different optical characteristics is provided thereon. An information recording medium comprising a fixed pattern formed in combination. 3. An information recording medium having a bar code-shaped fixed pattern of a magnetic layer on a substrate, wherein a magnetic recording layer is provided in one region on the substrate and magnetic layers having different optical characteristics are combined in the other region. An information recording medium having a fixed pattern formed by the method. 4. The optical characteristics of the magnetic layer constituting the fixed pattern are substantially the same in the visible region,
4. The information recording medium according to claim 1, wherein at least two magnetic layers differ in the infrared region. 5. The information recording medium according to any one of claims 1 to 4, wherein the bar code portion is covered with a protective layer that is opaque in the visible region and transparent in the infrared region. 6. A method for reading information recorded in a bar code of a magnetic layer by irradiating a bar code portion of the information recording medium according to claim 1 with infrared rays and detecting reflected light. .. 7. A magnetic signal is read by a magnetic head from the bar code portion of the information recording medium according to claim 1, and the bar code portion is irradiated with infrared rays.
A method of simultaneously reading the optical information recorded in a barcode by detecting the reflected light from the barcode.