JPH03258593A - Cards and card identification methods - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a card such as a credit card or a prepaid card provided with counterfeit prevention means, and a method for identifying this card.

[Conventional technology]

In recent years, various methods have been proposed to apply counterfeit prevention measures to cards such as credit cards and prepaid cards, which are often used as payment methods in place of cash, and to identify whether or not these cards are counterfeit. .

For example, a method for preventing counterfeiting or forgery prevention by providing a card such as a magnetic card with a mark or barcode for preventing counterfeiting or identifying it that is optically readable in the visible light range, and then optically reading this to identify whether or not it is counterfeit. In order to further increase the effectiveness of the card, we have created a card in which marks and barcodes are printed using ink that absorbs infrared light in the infrared region, and the marks and barcodes are hidden on the top surface with ink that transmits infrared light, making them invisible to the naked eye. A method has been proposed in which the barcode is optically read in the infrared region to identify whether or not it is a forgery.

[Problem to be solved by the invention]

According to the latter technique mentioned above, even if it is not visible to the naked eye,
By scanning a card using an existing infrared reflective photocoupler, marks and barcodes for counterfeit prevention or identification can be easily found. Infrared absorbing materials not only can be easily reproduced using carbon-based materials, but also have the problem of being easily counterfeited because infrared-reflecting photocouplers and carbon-based materials are easily available.

In addition, when manufacturing this type of card, in order to hide marks or barcodes that can be read by infrared light with concealing ink to make them invisible, the infrared absorbing ink itself has low brightness, so it is necessary to use concealing ink. It is necessary to print with a thicker ink layer, which not only increases the number of printing steps, but also increases the thickness of the ink layer, making it easier to locate marks or barcodes. Another problem arises, such as recognition.

Furthermore, since the concealing ink itself has some infrared absorption function, it is not possible to increase the thickness of the ink layer in order to improve the contrast of optical reflection and ensure reliable detection. This contradicts the original purpose of concealment, and there is also the problem that reliable detection cannot be performed unless a material with good infrared reflection is used as the base of the mark or barcode.

The present invention was made in view of the above-mentioned problems, and its purpose is to make it possible to record complex information by changing the density of fluorescent ink, and to make it possible to manufacture cards that are the same as regular cards. It is an object of the present invention to provide a card with a new configuration that makes detection extremely difficult, requires fewer printing steps, and enables highly reliable detection.

Another object of the present invention is to change the density of the fluorescent ink so that marks, etc. can be read only after satisfying multi-step reading requirements, and from these two points, it is made difficult to read the marks. Furthermore, it is an object of the present invention to provide a novel card identification method that makes card forgery extremely difficult.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention is directed to at least one surface of a card base material by changing the concentration of a fluorescent ink containing a phosphor whose excitation light wavelength and fluorescence wavelength are both in the infrared region. at least one island-like mark is provided on or at least one side thereof, and the concentration of the fluorescent ink is varied within the mark or for each island-like mark,
Alternatively, at least one surface of the card may be coated with fluorescent ink of varying density, or a barcode may be provided with fluorescent ink of varying density on at least one of the surfaces, and the card may be capable of transmitting both of the above-mentioned wavelengths. This constitutes a card provided with a concealing layer that partially absorbs visible light.

Further, the present invention provides fluorescent ink containing a phosphor whose excitation light wavelength and fluorescence wavelength are both in the infrared vAjff range, and which is provided on the surface of a card base material with varying concentrations. A card made of a material that is capable of transmitting both of the above wavelengths and is provided with a concealing layer that partially absorbs visible light is irradiated with light having a wavelength that excites a phosphor, and receives the fluorescent wavelength. Only cards for which it has been confirmed that the amount of received light and the set value, or the received light output pattern and the reference pattern match, are identified as legitimate cards.

[Effect]

Fluorescent ink containing a phosphor whose excitation light wavelength and fluorescence wavelength are both in the infrared region may be provided on at least one surface of the card base material with varying concentrations, or the fluorescent ink may be applied to the card base material. At least one island-like mark is provided on at least one surface of the substrate, and the concentration of fluorescent ink is varied within the mark or for each mark, or fluorescent ink is provided with varying concentrations on the entire surface of at least one surface. , by changing the concentration of fluorescent ink to form a barcode shape, and making it possible to transmit both excitation and fluorescence wavelengths.
A card provided with a concealing layer that partially absorbs visible light is irradiated with excitation light from a phosphor to generate fluorescence corresponding to the concentration of fluorescent ink.

In addition, the card is irradiated with light having a wavelength that excites the fluorescent material, and the generated fluorescent light corresponding to the density of the fluorescent ink is received, and the received light output and set value, or the received light output pattern and the reference pattern. The card is determined to be a legitimate card based on the match.

〔Example〕

Embodiments of the card and card identification method of the present invention will be sequentially described below with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the card of the present invention, in which the mark setting part 3 on one side of the card base material 2 has an excitation wavelength of 800 nm and a fluorescence wavelength of 980 nm. Both are in the infrared region, and as shown in Figure 3, the reflectance is 980n when the reflectance of the white background part of the original is 100%.
Li(
Nd,, +) Yb@.

) Using fluorescent ink containing a fluorescent material made of PtO + □, barcodes for preventing counterfeiting or for identification are sequentially placed from the left side of the drawing with numbers 5, 6, 5, 6, 6. There is. A detailed explanation of these barcodes:
In order to increase the amount of fluorescent ink generated for barcode 5... than that for barcode 6..., the amount of fluorescent ink is increased by changing the amount of vehicle, or the amount of fluorescent ink is increased by applying two coats of the barcode. The density of the fluorescent ink in barcodes 5 and 6 is darker than that in barcodes 6 and 7 (Fig. 1). In this way, the card base material 2 is provided with barcodes 5, 6, etc. made of fluorescent ink layers of different densities.
In order to hide this fluorescent ink, as shown in Figure 4, it has spectral characteristics that allow it to transmit both the excitation wavelength of 800 nm and the fluorescence wavelength of 980 nm, as well as partially absorb visible light. A concealing layer 4 is provided using a concealing ink exhibiting such opacity that codes 5, 6, etc. cannot be visually confirmed, thereby forming a card 1 (FIG. 2).

In addition, fluorescent ink can be provided on at least one side of the card base material by changing the density of the fluorescent ink, or at least one island-like mark can be provided on one side, and fluorescent ink can be applied within this mark or for each island-like mark. It is also possible to form a barcode-like pattern by changing the density of the ink or by changing the density of the fluorescent ink.

Further, the density of the fluorescent ink can be changed digitally or analogously.

FIG. 5 shows an example of an apparatus for carrying out the card identification method of the present invention, and as shown in the spectral characteristic diagram of FIG. Alternatively, a light emitting element 7 such as a laser diode is arranged so that the angle of irradiation with respect to the card 1 is 90 degrees or more or less with respect to the surface of the card 1, and a fluorescent light with a wavelength of 98 degrees is used as shown in FIG.
A light receiving element 11 such as a photodiode or a phototransistor having a spectral sensitivity of 0 nm is arranged so as to have a light receiving angle position of 90 degrees with respect to the surface of the card 1.

In order to prevent the light-emitting element 7 and the light-receiving element 11 from optically interfering with each other, a filter is provided on the light-receiving element 11 side that cuts off the excitation wavelength of the fluorescent ink but transmits the fluorescent wavelength. Alternatively, by providing a filter on the light emitting element 7 side that allows the excitation wavelength of the fluorescent ink to pass through but cuts the fluorescent wavelength, it is possible to provide a higher degree of reliability in detection accuracy. In the embodiment, although not shown, as a filter provided on the light receiving element 11 side,
It is suitable to provide a filter made of InP (indium phosphide) having the former characteristic.

Next, the card identification method according to the above embodiment will be explained.
When the card 1 is transported in the direction of the arrow 12 by a transport device (not shown) and the card 1 is irradiated with the excitation light 9 of 800 nm emitted from the light emitting element 7, the card 1 is transported in the direction of the arrow 12. The barcodes 5.6... composed of fluorescent ink are sequentially scanned by the excitation light 9, and as a result, 980 nm fluorescent light having a peak value proportional to the concentration of the fluorescent ink is emitted from the barcodes 5.6... 10 are generated one after another, and the light receiving element 11 generates a voltage O corresponding to the reflected light from the card 1 as shown in FIG.
Three types of level voltages are detected: high-amplitude pulses P1... from barcodes 5... of high-concentration ink layers, and low-amplitude pulses P2... from barcodes 6... of low-concentration ink layers. Ru. These pulse signals are input to a discriminator (not shown), and the amplitudes are compared with the high setting value V2 and the low setting value v1.
of pulses P3... are detected, and by comparison with the high setting value V2, two pulses P4... shown in FIG. 8 are detected,
Next, the card is compared with a reference pattern consisting of the two pulse trains shown in FIGS. 7 and 8 and a pulse train formed to correspond to the two pulse trains, and a card that matches the two pulse trains is identified as a regular card.

In addition, it is also possible to identify a genuine card based on the coincidence between the amplitude values of the pulses P1 and P2 shown in FIG. 6 and the corresponding reference values VP and VL, without comparing them with the reference pattern. Of course it is possible.

In addition, Li(Ndo, q Ybo, 1)P4 explained in the above example as a fluorescent material contained in the ink
Needless to say, the present invention is not limited to the fluorescent material O10, and fluorescent materials having different spectral characteristics of excitation light wavelength and fluorescence wavelength may be used.

〔Effect of the invention〕

As described above, according to the present invention, fluorescent ink containing a phosphor whose excitation light wavelength and fluorescence wavelength are both in the infrared region is applied to at least one of the card base materials by changing its concentration. or a small (one island-like) mark is provided on at least one side of the card base material, and the density is different within this mark or for each mark, or on at least one side of the card base material. Fluorescent ink with different densities is applied to the entire surface of the card, or barcode-like marks with different densities of fluorescent ink are provided on the entire surface, and the card base material is made to be able to transmit the above-mentioned frequency wavelengths, and to transmit visible light. The card is equipped with a concealing layer that absorbs a portion of the phosphor, and is excited by the excitation light of the phosphor to generate fluorescence corresponding to the concentration of the fluorescent ink, making it possible to store complex information on the card. In addition to making it possible to record data, it is also possible to recognize that the card is equipped with phosphors with different concentrations, recognize that this phosphor is excited by the excitation light of the phosphor, and create a complex process corresponding to the concentration. Cards cannot be manufactured2 without the recognition of receiving fluorescent output having a waveform, which not only makes it extremely difficult to counterfeit genuine cards, but also makes it difficult to use fluorescent ink. The fluorescent material that forms is difficult to reproduce and obtain compared to carbon-based materials, making counterfeiting of cards even more difficult.Also, unlike infrared absorbing ink, some fluorescent materials have a high brightness. Because of this, it is possible to thin the concealment printing to make it invisible to the naked eye, which reduces the number of printing steps and reduces manufacturing costs.Furthermore,
Since it is possible to detect without being affected by the substrate, it is possible to not only increase the detection sensitivity, but also
Marks etc. can also be provided on the magnetic layer of the card, making it possible to provide marks etc. at arbitrary positions without being subject to space constraints.

Further, according to the present invention, fluorescent ink containing a phosphor whose excitation light wavelength and fluorescence wavelength are both in the infrared region is provided on the surface of a card base material with varying concentrations, and the card base material A card having a concealing layer that allows the above-mentioned wavelengths to pass through and partially absorbs visible light is irradiated with light having a wavelength that excites the phosphor, receives a fluorescent output corresponding to the concentration, and then The system is configured so that only cards for which the amount of light received and the set value, or the received light output pattern and the reference pattern match, are identified as genuine cards, so the cards are equipped with phosphors with different densities. The card cannot be read unless all of the following requirements are met: the phosphor is excited by excitation light of the wavelength it has, and the phosphor receives complex fluorescence output corresponding to the concentration. An identification method can be provided. Moreover, unless these points are solved and the product is manufactured, it is not possible to read out the marks etc. of genuine cards. Therefore, it is possible to further ensure the prevention of counterfeiting of genuine cards. This makes it possible to further improve safety. Also,
Since it uses optics in the infrared region, signal detection can be performed with a high degree of reliability regardless of the dirt on the card surface.

[Brief explanation of drawings]

FIG. 1 is a top view of an embodiment of the card of the present invention;
Figure 2 is a sectional view taken from section line A-A in Figure 1;
The figure is a spectral characteristic diagram showing the reflectance of the fluorescent ink applied to the embodiment of the present invention, FIG. 4 is a spectral characteristic diagram of the card concealing ink applied to the embodiment of the present invention, and FIG. FIG. 6 is a diagram of the pulse waveform detected by the light receiving element of the device implementing the method of the present invention. FIG. Figure 8 is a diagram of the detected pulse waveform, Figure 8 is a diagram of the pulse waveform detected by comparing the above pulse with a high setting value, Figure 9 is a spectroscopic diagram showing the relative radiation intensity of the light emitting element of the apparatus implementing the method of the present invention. FIG. 10 is a spectral characteristic diagram showing the radiation sensitivity of the light-receiving element of the apparatus implementing the method of the present invention. 1. Card, 2. Card base material, 4. Hiding layer, 5.
・Barcode formed with highly concentrated fluorescent ink,
6. Barcode formed from fluorescent ink with lower density than barcode 5, 7. Light emitting element that emits excitation light, 11. Light receiving element that receives fluorescence wavelength 5, 9. Excitation light, 10... Fluorescence, 6 Figure 1 Applicant

Claims (5)

[Claims] (1) Fluorescent ink containing a fluorescent substance whose excitation light wavelength and fluorescence wavelength are both in the infrared region is provided on at least one surface of a card base material with varying concentrations, and the card base material A card characterized in that a masking layer is provided on the surface of the card that allows both wavelengths to pass therethrough and absorbs a portion of visible light. (2) The fluorescent ink is provided as at least one island mark on at least one surface of the card base material, and the concentration of the fluorescent ink is adjusted within the island mark or for each island mark. Claims characterized in that (
1) The card listed. (3) The card according to claim 1, characterized in that the fluorescent ink is provided on the entire surface of at least one side of the card base material by varying the concentration of the fluorescent ink. (4) The card according to claim (1), wherein the fluorescent ink is provided in the form of a barcode on at least one surface of the card base material by varying the concentration of the fluorescent ink. (5) Fluorescent ink containing a phosphor whose excitation light wavelength and fluorescence wavelength are both in the infrared region is provided on the surface of the card base material with varying concentrations, and both of the above wavelengths are applied to the card base material. A card provided with a concealing layer that is transparent and partially absorbs visible light is irradiated with light having a wavelength that excites the phosphor, receives the wavelength of fluorescence from the phosphor, and emits the phosphor. A card identification method that compares the amount of light received at a wavelength and a set value, or the received light output pattern and a reference pattern, and identifies only cards for which a match is confirmed as genuine cards.