JP2002362071A - Organic el security medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a security medium for preventing forgery or alteration and improving security. SOLUTION: An organic EL security medium is the security medium having an organic EL element, and certification is performed by the light emission of the organic EL element. Electrodes and an EL layer are mounted on a base material which forms the organic EL security medium. The base material is selected from a transparent material, a translucent material, and an opaque material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a security medium used for various authentication systems.

[0002]

2. Description of the Related Art In a modern society, media such as banknotes, gift certificates, prepaid cards, and the like, which themselves have a monetary value, licenses, credit cards, membership cards, etc. Those who hold the medium and guarantee the qualification and ability are often used. Regardless of the form of these security media, it is necessary to authenticate the authenticity and validity of the media itself and the information held by the media, such as holograms, precision printing, and magnetic authentication. Are used. However, these certifications are now commonplace that can be easily created, and even now, security media is at risk of forgery and falsification, including crimes caused by counterfeiting of vouchers. . Therefore, new technology for improving security is required.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a security medium which is hard to forge or falsify and has improved security.

[0004]

The present inventor has found that by using light emission from an organic EL element, which has been actively developed in recent years, for authentication, it is possible to provide a security medium which is difficult to forge or alter. Completed.

Accordingly, the organic EL security medium of the present invention is a security medium provided with an organic EL element, wherein the authentication can be performed by the light emission of the organic EL element.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION
Testimony organic EL security medium of the present invention is characterized in that which can be authenticated by the light emission of the organic EL element provided on the medium. This security medium can be combined with any authentication means, for example precision printing, holograms or other conventional visual authentication means or electromagnetic authentication means such as magnetism. In particular, the combination of authentication by EL light emission and authentication by magnetism is preferable because it has the effect of changing the magnetism by EL light emission, and is expected to improve security and forgery prevention.

Authentication Content The content of authentication by EL emission in the organic EL security medium of the present invention is not particularly limited.
It is possible to determine whether the organic EL security medium is valid (genuine and usable) or invalid (counterfeit or used), and determine the identity. Specifically, for example, It can be to determine the registration number and account number of the holder.

Light Emission In the organic EL security medium of the present invention, the number of times of light emission can be set as desired.

In one embodiment of the present invention, the light is emitted only during the first authentication and is not emitted during the subsequent authentication. Such an organic EL security medium can be produced, for example, by using a material having low light emission stability for the light emitting layer, or by using a material which is oxidized during EL light emission and becomes an insulator for the electrode.

In another aspect of the present invention, light can be emitted only up to a plurality of preset authentications. Such an organic EL security medium is, for example, a method of providing a plurality of organic EL elements using a material having low luminescence stability in a light emitting layer, and emitting and deactivating one organic EL element at a time for each light emission. A plurality of organic EL elements using a material having light emission stability are provided, and an overcurrent is applied after light emission to destroy the element.

In still another embodiment of the present invention, the number of times of light emission may be unlimited. Such an organic EL security medium can be produced, for example, by using a material having high luminescence stability for the luminescent layer and the electrode.

In still another embodiment of the present invention, the number of times of light emission is not limited. However, by applying a current larger than the light emission current, no light emission can be performed thereafter. Such an organic EL security medium can be produced, for example, by using a material which has stability under an emission voltage but deactivates when a higher voltage is applied to the emission layer.

[0013] When using the magnetic properties to authenticate the organic EL security medium of magnetic variation present invention, as a preferred embodiment, can be assumed that the magnetic properties of the magnetic metal with the EL light emission is changed. Such an organic EL security medium can be produced, for example, by forming electrodes of an organic EL element with a specific magnetic metal. Specifically, for example, F is applied to the cathode of the organic EL element.
Using a magnetic metal such as e, Co, Ni, etc., the change or deactivation of the magnetism by EL emission oxidation can be performed.

The authentication in such an organic EL security medium may detect a change in the magnetism itself, in addition to detecting that a previously recorded magnetic record is erased.

[0015] Configuration Example Figure 1 of the organic EL security medium is a diagram illustrating an example of an organic EL security medium of the present invention. An organic EL security medium 1 (here, for example, securities) includes therein an anode 2 which is a transparent conductive film and a cathode 3 which is a Ca electrode / Fe-based alloy.
A light emitting layer 4 sandwiched between the anode 2 and the cathode 3,
An iO ₂ barrier layer 5 is provided. The anode 2 and the cathode 3 have external contacts. And this organic EL
In a specific example of the security medium, the organic EL security medium 1 is brought into contact with the authentication device 6 at the time of authentication,
The organic EL security medium is caused to emit light by the light emitting power supply 7 in the authentication device 6, and the magnetic reading device 8 reads the magnetism of the organic EL security medium and performs authentication.

EL Element The organic EL element used for the organic EL security medium of the present invention typically has a first electrode, an EL layer formed on the first electrode, and an EL layer formed on the EL layer. It comprises at least a second electrode. Preferably, the organic EL layer may be a single layer of a light emitting layer, but furthermore, a buffer layer, a hole transport layer,
It is preferable to form a multilayer structure by appropriately combining a hole injection layer, an electron transport layer, an electron injection layer, and the like.

Light Emitting Layer In the present invention, the light emitting layer contains a material that emits fluorescent light and
There is no particular limitation as long as it emits light. It can have both a light emitting function, a hole transport function, and an electron transport function.

The organic E of the present invention, which has no limitation on the number of times of light emission,
Examples of the light emitting material used for the organic EL element provided in the L security medium include the following.

<Dye System> Cyclopentadiene derivative, tetraphenylbutadiene derivative, triphenylamine derivative, oxadiazole derivative, pyrazoloquinoline derivative, distyrylbenzene derivative, distyrylarylene derivative, silole derivative, thiophene ring compound, pyridine ring Compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifmanylamine derivatives, oxadiazole dimers, pyrazoline dimers.

<Metal complex type> Aluminum quinolinol complex,
Benzoquinolinol beryllium complex, benzoxazole zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin zinc complex, europium complex,
Al, Zn, Be, etc., or Tb, E
A metal complex having a rare earth metal such as u or Dy and having an oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure or the like as a ligand.

<Polymer system> Polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, etc., polyfluorene derivatives, polyvinylcarbazole derivatives,
A polymerized version of the above dye-based or metal complex-based luminescent material.

<Doping Material> Doping can be performed in the light emitting layer for the purpose of improving the light emission efficiency, changing the light emission wavelength, and the like. As this doping material, for example,
Examples include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squarium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazoline derivatives, decacyclene, and phenoxazone.

In the present invention, as the light emitting material used for the organic EL element provided in the organic EL security medium which emits light only once, for example, a light emitting material having a short light emitting life, such as TPD-Alq, may be mentioned. In addition, even with a normal luminescent material, by destroying the element by applying an overvoltage,
It can be used as an organic EL security medium that emits light only once.

Other EL layers (buffer layers) E that can be provided in the present invention
Examples of the L layer include a buffer layer, and the buffer layer is provided between the anode and the light-emitting layer or between the cathode and the light-emitting layer so that charge injection into the light-emitting layer is easily performed. And a layer containing an organic substance, particularly an organic conductor. For example, a conductive polymer having a function of increasing hole injection efficiency into a light-emitting layer and flattening unevenness of an electrode or the like can be used.

(Charge Transport Layer) The EL layer that can be provided in the present invention may also include a charge transport layer, and this charge transport layer includes a hole transport layer and / or an electron transport layer. These are described, for example, in Japanese Patent Application No. 9-15 / 1997.
As described in Japanese Patent No. 5284, there is no particular limitation as long as it is generally used for EL devices.

(Charge Injection Layer) The EL layer that can be provided in the present invention may also include a charge injection layer, and this charge injection layer includes a hole injection layer and / or an electron injection layer. These are described in, for example, Japanese Patent Application No. 9-155.
There is no particular limitation as long as it is generally used for EL devices, such as those described in Japanese Patent No. 284.

The light emitting material, hole transporting material, or electron transporting material constituting the above layers may be used alone or in combination. The mixture may be a material having the same property or materials having different properties. Further, the layer containing these materials may be a single layer or a plurality of layers.

Electrodes In the present invention, the electrodes are not limited as long as they are commonly used for EL devices. The electrode provided first on the substrate is called the first electrode, and the electrode provided after the EL layer is formed is called the second electrode. One or both of these electrodes may be patterned. These electrodes include an anode and a cathode. One of the anode and the cathode is transparent or translucent, and the anode is made of a conductive material having a large work function so that holes can be easily injected. Preferably, on the contrary, as the cathode, a conductive material having a small work function is preferable so that electrons can be easily injected. Further, a plurality of materials may be mixed. The resistance of each electrode is preferably as low as possible. In general, a metal material is used, but an organic substance or an inorganic compound may be used.

Specific preferred anode materials include, for example, ITO, indium oxide, and gold. Preferred cathode materials include, for example, magnesium alloy (MgA).
g, etc.), aluminum alloys (AlLi, AlCa, Al
Mg, etc.), metallic calcium and metals having a low work function.

In an organic EL security medium according to a preferred embodiment of the present invention, the magnetism of which changes with EL emission,
For example, a metal having a small work function, such as an alkali metal, is formed in the light emitting layer thinly as a cathode electrode, and then an alloy containing a magnetic metal such as Fe, Co, or Ni as a main element is formed into a thin film, which can be used as a cathode of an organic EL. . This way,
The magnetic signal can be read from the magnetic thin film, and the organic EL
The light emission of the element oxidizes the cathode electrode and deactivates or changes the magnetic signal.

Substrate The substrate that can be used in the present invention is a substrate that forms an organic EL security medium, on which an electrode or an EL
A layer is provided and can be made of a transparent material as desired, but may be a translucent material or an opaque material. Even if it is a translucent material or an opaque material, it is sufficient if EL emission can be confirmed by some means.

Applications When the organic EL security medium of the present invention is used for one-time use vouchers, it can be used for judging the use or non-use of vouchers, and the light emission can be used for authentication of authenticity judgment. Other uses include credit cards, employee ID cards, gift certificates, highway cards, admission tickets for amusement parks and the like, ride tickets, coupons for buses and trains, air tickets, and the like. Among them, a device that combines authentication using EL light emission and magnetism has an advantage that not only an authentication device using EL light emission and magnetism but also a widely used authentication device using magnetism can be authenticated. On the other hand, even if authentication using EL light emission alone is not used in combination with magnetic authentication, authentication with high security is possible because organic EL itself is rare at present.

[0033]

EXAMPLE 1 A transparent conductive film (ITO) was formed as an anode on a resin substrate by a sputtering method, and then a hole transport layer was formed thereon, followed by a light emitting layer. The cathode was formed by evaporation and sputtering. Finally, an overcoat layer was formed and light emission was attempted.

The materials and film forming conditions used in Example 1 are as follows.

(Resin base material) Aluminum oxide 80 was used as a barrier layer on a polyvinyl fluoride resin sheet (PVF) having a thickness of 100 μm by an electron beam (EB) method.
A substrate coated with 0 ° was used as a substrate.

(Aluminum oxide film formation conditions) Evaporation source: Aluminum Additive gas: Oxygen 10 sccm FB output: 40 kV Film formation pressure: 2.1 × 10 ⁻⁴ Pa (ITO film formation conditions) Gas flow rate: Ar / O ₂ 100 / 3 sccm Film forming pressure: 0.5 Pa Film forming power: 2.5 kW Film thickness: 1500 Å, (Hole transport layer film forming conditions) Material: PEDOT (manufactured by Bayer) Coating method: spin coating method Film thickness: 80 nm Heat drying: 150 ° C. (light emitting layer film forming condition) Light emitting material: polyvinyl carbazole (PVK) Coating method: spin coating method Film thickness: 80 nm (cathode interface electrode film forming condition) Material: Ca (99.5%) Film forming method: EB vapor deposition thickness: 20 nm film formation pressure: 1 × ¹⁰ -4 Pa or less (cathode deposition conditions) material: Fe (99.9%) film-forming method: EB vapor deposition film thickness: 150 nm Film formation pressure: × ¹⁰ -4 Pa or less (overcoat layer) Material: SiO ₂ film thickness: 50 nm film formation method: RF sputtering film formation _{pressure: 0.5Pa Ar / O 2: 100/2} sccm deposition power: 1.5 kW Note that no film was formed at the electrode outlet by performing mask film formation.

When the magnetic signal was measured before EL emission,
It was readable enough. Thereafter, when a current of 6 mA was applied between the ITO and the cathode, light emission was observed from the translucent resin surface. When the voltage was further applied and the applied current was set to 20 mA, the light was extinguished. Here, when the magnetic characteristics were evaluated again, it was found that the magnetic characteristics were so deteriorated that reading was impossible.

Example 2 After a transparent conductive film was formed as an anode on a paper base material by a sputtering method, a hole transport layer was formed by coating, and then a light emitting layer was formed by coating. A cathode formed by vapor deposition (interface electrode), sputtering (magnetic film), or the like was used, and finally an overcoat layer was formed. The layer configuration was paper substrate / peeling PET (paper overcoat) / ITO / hole transport layer / light emitting layer / cathode (metal layer) / barrier layer (element overcoat).

The materials and conditions used in Example 2 were the same as in Example 1 except for the following. The base material used was a material obtained by transferring release PET to fine wood paper, and the release PET thickness was 12 μm. Further, a heat sealing material having a thickness of 3 μm before pressing was used. Drying condition is 100
C. for 1 minute.

When the magnetic signal was measured before EL emission,
It was readable enough. Thereafter, when a current of 6 mA was applied between the ITO and the cathode, light emission was observed from the translucent paper surface. When the voltage was further applied and the applied current was set to 20 mA, the light was extinguished. Here, when the magnetic characteristics were evaluated again, it was found that the magnetic characteristics were so deteriorated that reading was impossible.

[0041]

According to the present invention, it is possible to provide a security medium with improved security which is difficult to forge or falsify various cards and securities.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of an organic EL security medium of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 organic EL security medium 2 transparent conductive film (anode) 3 cathode 4 light emitting layer 5 SiO ₂ barrier layer 6 authentication device 7 organic EL element light emitting power supply 8 magnetic reader

Claims (10)

[Claims] 1. A security medium provided with an organic EL element, wherein authentication can be performed by light emission of the organic EL element. 2. The device according to claim 1, wherein the organic EL element emits light only during the first authentication, and does not emit light during the subsequent authentication.
The organic EL security medium according to claim 1. 3. The organic EL security medium according to claim 1, wherein the organic EL element emits light only up to a plurality of preset authentications. 4. The organic EL device according to claim 1, wherein said organic EL element has no limitation on the number of times of light emission for authentication.
L security medium. 5. The organic EL security medium according to claim 3, wherein a current larger than the light emission current is supplied so that no light is emitted thereafter. 6. The organic EL security medium according to claim 1, wherein the EL element is a combination of a magnetic metal and an electrode, and the magnetic properties of the magnetic metal change with EL light emission. 7. The organic EL security medium according to claim 1, wherein the substrate of the organic EL security medium is made of an opaque material. 8. The organic EL security medium according to claim 1, wherein the substrate of the organic EL security medium is made of a transparent or translucent material. 9. The organic EL security medium according to claim 1, wherein the authentication determines whether the organic EL security medium is valid or invalid. 10. The organic EL security medium according to claim 1, wherein the authentication determines the identity of the organic EL security medium.