JP6507591B2 - Anti-counterfeit medium - Google Patents

Description

  The present invention relates to an anti-counterfeit medium that can be easily identified by a general-purpose imaging device such as a smartphone or a portable camera, and an identification method thereof.

  Anti-counterfeit media such as securities, cards and passes, valuable certificates such as driver's licenses, passports and insurance cards, personal certificates such as personal cards, stickers to prove goods genuinely are forged and altered to third parties It is required to always incorporate a new anti-counterfeit technology in order to avoid the problem, and there is also a need for a method of determining whether it is an authentic product or not.

  In the above forgery prevention technology, in order to enhance security, micro characters, copy check patterns, infrared absorbing ink, fluorescent light emitting ink, etc. are used. Among the above-mentioned techniques, fluorescent light-emitting ink is ink or the like which is difficult to visually recognize under ordinary visible light by the naked eye, and which can detect marks by visual inspection or a detector by irradiating ultraviolet light or infrared light is there.

  Various proposals have been made for the above-mentioned fluorescent ink in order to prevent forgery and falsification. For example, an image is formed on a substrate using an ink containing three types of phosphors that emit light of R (red), G (green), and B (blue) by being excited by ultraviolet light, and under visible light Although not visible, an image forming method has been proposed which emits RGB light when irradiated with excitation light so that a fluorescent image appears by additive color mixing. (See Patent Document 1)

JP 10-35089 A

  However, there is a problem that the tester using black light and infrared rays is not universally used, and therefore, it is necessary to have the tester in preparation for testing.

  The present invention has been made in view of the above problems, and it is possible to prevent the forgery of authenticity by using an angle sensor and an image pickup device which are included in a camera of a portable information terminal, a portable camera, etc. A medium and an identification program for identifying the medium.

As means for solving the above problems, the invention according to claim 1 is characterized in that the light excited by white light on the substrate and emitted light is at least among the values digitized by the reading of the image sensor. It provided a layer containing a phosphor which emits visible light of one or more values is above a certain value Ri Na, one value of the digitized values with the RGB is greater than the other values The anti-counterfeit medium is characterized in that a reflective layer is provided on the substrate itself or between the substrate and the layer containing a phosphor .

The invention described in Claim 2 is the medium for preventing forgery according to claim 1, characterized in that the diffractive structure is provided on the reflective layer.

  Since the present invention is configured as described above, the following effects can be obtained.

  An illumination instruction and an instruction to output an image to the imaging unit after an arbitrary time after the illumination instruction are generated by an angle sensor and an illumination unit included in a camera of the portable information terminal, a portable camera, and the like that are usually used. That is, according to this configuration, for example, an output instruction can be generated under an appropriate condition based on the measurement value of the angle sensor, and an appropriate illumination instruction is generated to output an image emitted after illumination. be able to. That is, it is possible to easily identify the presence or absence of the phosphorescence phenomenon by the irradiation of light with respect to the anti-counterfeit medium of the present invention by a general purpose image device.

It is a top view of a forgery prevention medium for describing one embodiment of the present invention. It is a sectional view of a forgery prevention medium for describing one embodiment of the present invention. It is a sectional view of a forgery prevention medium for describing one embodiment of the present invention. It is a block diagram showing an example of composition of an identification device for describing one embodiment of the present invention. It is a block diagram for demonstrating the imaging part which showed the example of a structure shown in FIG. It is a flowchart for demonstrating the operation example of the control part shown in FIG. It is explanatory drawing for demonstrating the operation example of the target object using the identification apparatus shown in FIG. 4 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail using the drawings.

  FIG. 1 is a plan view of an anti-counterfeit medium for describing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the anti-counterfeit medium for describing an embodiment of the present invention. FIG. 3 is a cross-sectional view of a forgery prevention medium for explaining an embodiment of the present invention.

  The forgery prevention medium 3 of the present invention is a forgery prevention medium such as a document for preventing forgery, and a layer 302 containing at least a phosphor is provided on a substrate 301. It is desirable to have a reflective layer 303 between the substrate 301 and the layer 302 containing phosphor. Furthermore, it is desirable that the reflective layer 303 be provided with a diffractive structure.

  The base material 301 is selected according to each use. For example, when this anti-counterfeit medium is provided in part of a ticket, for example, high-quality paper is selected, but when used for a label, high-quality paper or coated paper which has been tacked is used. Furthermore, from the viewpoint of preventing replacement, use is made of a film obtained by solution film formation from a film having both brittleness, for example, a highly crystalline plastic material such as cellulose acetate, low density polyethylene, polystyrene and polyphenylene sulfide. . Thus, the substrate is not particularly limited.

The layer 302 containing the phosphor can be formed by mixing the phosphor and the ink medium of the printing method according to the application, and printing by a known printing method. The printing method may be any known printing method such as screen printing, offset printing, gravure printing, flexographic printing, inkjet printing, etc., and the printing method is not limited thereto. In order to be excited by white light such as a white LED, the phosphor needs to have at least an excitation wavelength in the range of 400 nm to 700 nm of visible light. In addition, at least a phosphorescence wavelength is in the range of 400 nm to 700 nm in order to detect by RGB using an easy imaging device such as CMOS. If it exists in this range, even if it has an excitation wavelength or a phosphorescence wavelength also in an ultraviolet-ray and a near-infrared area | region, it is called white light in this specification. Rather than the phosphorescence color of the phosphor, the background color of the phosphor itself is a color close to white or desirable, but it may be the same color as the phosphorescence color or a different color. The phosphor is not particularly limited as long as it has the above conditions, and examples thereof include the light emitter of the SrSc ₂ O ₄ : Eu compound described in Patent Publication 2009-161576.

  A phosphor is a substance that emits energy by light when it absorbs energy, and is a substance that absorbs and emits light (ultraviolet and visible light) energy in this light emission phenomenon. Light has energy represented by E = hν (E: energy, h: Planck's constant, ν: frequency). When light strikes a substance, the energy possessed by the light may be absorbed by the substance, and due to the absorption of energy, a substance that has been in a stable energy state (ground state) temporarily becomes a high energy state (excitation state) Become. The substance then releases energy and tries to return to a stable ground state. At this time, the phenomenon of emitting the difference energy as light instead of heat is called light emission. Many materials emit a portion of the absorbed energy as heat energy, which produces light of a longer wavelength than the absorbed light, but some produce light of a shorter wavelength.

  Although light emission due to light stimulation includes fluorescence and phosphorescence, etc., it may be called fluorescence as a large bundle, and in the present invention, phosphorescence and fluorescence are distinguished and described as phosphorescence. In fluorescence, part of the absorbed energy is released as heat and the remaining energy is released as light. On the other hand, heat is emitted similarly in the case of phosphorescence. At this time, phosphorescence is a phenomenon in which intersystem crossing occurs and the light can not return to the ground state immediately and continues to emit light slowly. In most cases, fluorescence emits nanosecond-order phosphorescence in micro to millisecond order. When a substance absorbs ultraviolet light and visible light, an electronic transition occurs. This electron has a spin direction, and it is determined that two electrons exist in opposite directions, that is, Pauli's exclusion principle. In normal excitation, the direction of spin remains reversed, but in the case of phosphorescence, an intersystem crossing occurs, the spin becomes the same direction, and as it is, it can not return to the ground state, and it takes time to return to the ground state It is a thing.

  In the anti-counterfeit medium according to the present invention and its identification program, in order to be able to be detected by an easy device, it is necessary to identify even without installing a filter that prevents excitation light from entering the imaging unit. Therefore, since it is preferable that the time for emitting light after excitation is long, it is necessary that the phosphor emits light in the micro to millisecond order.

  In addition, in order to facilitate identification of this phosphorescence, it is preferable to provide a reflective layer 303 in the lower layer. The reflective layer 303 needs to reflect light. For example, at least one of Ti, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, Si, Ge, Or the compound of these elements is mention | raise | lifted. As a method of providing the reflective layer 303, for example, a physical vapor deposition method such as a vacuum vapor deposition method or a sputtering method can be suitably used. Moreover, you may print the ink which has a titanium oxide etc. as a main component by the known printing method.

  As in the diffractive structure layer 304, it is desirable to provide a diffractive structure by an embossed portion such as a hologram, which is formed by embossing a minute unevenness according to the diffraction grating. It is desirable to use a diffractive structure to amplify the emitted light to the imaging unit, but it is possible to view the holographic image visually and to observe the image or color depending on the position and angle to be observed It may be The diffractive structure layer 304 may be provided on or below the reflective layer 303.

  In order to emboss the micropattern on the diffractive structure layer 304, the phosphor-containing layer 302, the reflective layer 303, and the diffractive structure layer 304 are provided by the transfer method by providing the adhesive layer 305 as necessary. In this case, a release layer or a protective layer may be provided, and the phosphor-containing layer 302 may function as a release layer or a protective layer. In addition, if necessary, an adhesive layer or a base material may be added to form a sticker.

  FIG. 4 is a block diagram showing an example of the configuration of the identification device 1 for explaining an embodiment of the present invention. The identification program of the present invention is a program for moving the identification device 1. For example, the identification device 1 includes an imaging unit 11, a control unit 12, an angle sensor 13, a display unit 14, and an illumination unit 15. The imaging unit 11 sequentially displays images until the imaging condition is reached, and the display unit 14 indicates that output is possible when the imaging condition is met.

  FIG. 5 is a block diagram for describing a configuration example of the imaging unit shown in FIG. The imaging unit 11 includes an imaging device 23 and an exposure control unit 24. The exposure control unit 24 includes a shutter speed control unit 25 and an aperture value control unit 26. The imaging unit 11 includes an angle sensor 13 ing. It is desirable to provide an illumination unit 15 in the imaging unit 11 as necessary. In addition, the control unit 12 is provided with a storage unit 21 and an operation unit 22.

  FIG. 6 is a flowchart for explaining an operation example of the control unit shown in FIG. 4, and FIG. 7 is for explaining an operation example of an object using the identification device shown in FIG. 4 of the present invention. FIG.

  In the present application, the condition for imaging means a setting condition representing a method of imaging such as an imaging condition. For example, it is information representing a specification at the time of imaging such as a shutter speed at the time of shooting, an aperture value, and a sensitivity (ISO sensitivity) of the imaging device. In addition, the identifier 2 moves so that the value of the angle sensor 13 attached to the imaging unit 11 falls within a predetermined range.

  The value of the angle sensor 13 needs to be such that the angle between the normal to the identification device 1 and the anti-counterfeit medium 3 is not 90 ° in order to prevent the light from the illumination unit 15 from entering too much. The light emitted by the phosphor-containing layer 302 is considerably weaker than the light of the illumination portion. Therefore, although it is necessary for the light of the illumination unit 15 to emit light, it is necessary to keep the light from entering the imaging device 23 as much as possible, and the angle is limited as one condition for that. Assuming that an angle formed by the normal line of the imaging device and the anti-counterfeit medium is θ, it is preferable that the angle of the imaging condition be 20 ° ≦ θ ≦ 80 °. Further, by designing the emboss of the diffraction grating of the diffractive structure layer 304, a suitable value can be appropriately set, and the designated range of the angle may be narrowed.

  Further, the imaging condition may include the presence or absence of illumination by the illumination unit 15 and the difference in the intensity of the illumination as necessary. Although it is preferable to use predetermined values as the setting values of these imaging conditions, setting may be instructed as appropriate. It is desirable that the illumination unit 15 be integrated with the imaging unit 11. The color and the image may be changed by changing the angle of the illumination unit 15 though it may not be integrated, but it is necessary to set the angle of the illumination unit 15 in consideration of this.

  Note that the imaging unit 11 may fix or change the focal length at telephoto or wide angle. In this case, the focal length can be changed by the aperture value control unit 26 of the exposure control unit 24 in accordance with an instruction from the control unit 12 or the like, for example. In addition, the aperture control unit 26 may be provided with an auto focus function for automatically focusing on an object, or may be provided with a manual focus function.

  The illumination unit 15 is a device that illuminates the forgery prevention medium 3 which is an imaging target of the imaging unit 11. The illumination unit 15 performs predetermined illumination on the forgery prevention medium 3 immediately before the imaging unit 11 captures an image in response to the instruction output by the control unit 12. The illumination unit 15 is preferably a light emitting device that emits strong visible light in a short time toward an imaging target called flash, strobe, etc., so that light can be taken after an arbitrary time after the light of the illumination unit 15 is turned off. Set The arbitrary time is preferably between 50 microseconds and 5 milliseconds for the imaging device 23 to read phosphorescence. The predetermined illumination performed on the imaging target object by the illumination unit 15 in accordance with the instruction means illumination in which the amount of light emission is made different depending on the presence or absence of the instruction. That is, the illumination unit 15 emits a strong light for a short time to the object to be imaged or strengthens the intensity of the illumination in accordance with the instruction. The control unit 12 may detect the brightness from the image acquired by the imaging unit 11, or may attach an illuminance sensor to the imaging unit 11, and change the indication of the illumination intensity by the numerical value of the brightness. It is good.

  It is desirable that the identification device 1 integrally include the imaging unit 11, the control unit 12, the angle sensor 13, the display unit 14, and the illumination unit 15. However, the identification device 1 can be configured as a separate device for each element. As an example integrally provided, it is desirable to use a part or all of a camera of a portable information terminal, a portable camera, etc. as the identification device 1, but the imaging unit 11 and the angle sensor 13 which are a part of the identification device 1 The illumination unit 15 can also be configured.

  An operation example of the identification program of the present invention will be described with reference to FIG. For example, when the identifier 2 performs a predetermined instruction operation, the program starts (step 31). The identifier 2 follows the instruction while looking at the display unit 14, and as shown in FIG. 7, the normal of the identification device 1 and the layer 302 containing the phosphor of the anti-counterfeit medium 3 are included in the imaged area. The identification device 1 is held so that the angle formed by the forgery prevention medium 3 is an arbitrary angle 302 (step 32). At this time, it is desirable that the angle θ formed by the normal to the identification device 1 and the anti-counterfeit medium 3 not be 90 ° so that the reflected light of the illumination does not enter, and preferably 20 ° ≦ θ ≦ 80 °. It may be another angle.

  The identification device 1 acquires an image (step 33), verifies that the brightness is appropriate (step 34), and if it is out of the specified range, adjusts the brightness (step 35), and acquires the image (step 35) Return to 33). If the brightness is suitable, it is verified whether the focus is suitable (step 36), and if it is out of the prescribed range, the focus is adjusted (step 37), and the process returns to image acquisition (step 33). Here, other imaging conditions of images may be defined, and conditions may be added.

  If the focus is in a suitable range, the value of the angle sensor 13 is obtained. Whether the angle sensor 13 has a suitable value is verified (step 39). If the value is out of the specified range, it is not suitable, and the display unit 14 displays it so that the identifier 2 can be seen (step 40). The identifier 2 looks at the display unit 14 and corrects the angle of the identification device 1 according to the instruction (step 41). It is desirable that step 32 to step 39 which is adjustment of operation and adjustment of the imaging unit or step 33 to step 36 which is adjustment of image are sequentially repeated operation and sequentially displayed on the display unit 14.

  When the angle sensor 13 is a suitable value and the imaging condition is satisfied, the control unit 12 of the identification device 1 enables imaging of the imaging unit 11 (shutter release) and instructs the display unit 14 to perform imaging. Is displayed (step 42). When the identifier 2 who looks at the display unit 14 turns on the shutter (step 43) and turns on the illumination unit 15 for a fixed time (step 44), the imaging unit 11 issues an imaging instruction after an arbitrary time has elapsed (step 45) . The image obtained by the imaging unit 11 is recorded in the storage unit 21 of the control unit 12 as RGB light emission luminance (Step 46).

  When the imaging condition is satisfied, the control unit 12 causes the display unit 14 to display an imaging instruction, the discriminator 2 releases the shutter, and the control unit 12 causes the imaging unit 11 to capture an image according to the judgment of the discriminator 2 However, the control unit 12 may directly determine that the shutter is to be released and cause the imaging unit 11 to capture an image.

  The image recorded in the storage unit 21 may be displayed on the display unit 14, but the identification range of the image (output signal) is set in advance, and it is within the identification range by the calculation unit 22 of the control unit 12 The determination is made (step 47). The setting of the identification range is performed in advance in consideration of variations in light emission of the phosphor-containing layer 302 of the anti-counterfeit medium 3. If it is within the range, it is desirable to display “OK” on the display unit 14, and if it is out of the range, it is desirable to display “NG” on the display unit 14.

  Next, the present invention will be more specifically described by way of examples.

  An ink SSN S A 611 white (made by Toyo Ink Co., Ltd.) containing titanium oxide as a reflective layer is printed on high-quality paper by screen printing, and a phosphor that emits red light by exciting with blue described below is printed thereon The ink composition of the layer to be contained was printed by screen printing to obtain an anti-counterfeit medium.

[Ink composition of layer containing phosphor]
SrSc ₂ O ₄ : Eu 10 parts by weight SS NSA Medium (made by Toyo Ink) 90 parts by weight

  The portable information terminal containing the identification program of the present invention is held over the anti-counterfeit medium obtained in Example 1, and according to the instruction, the flash is lit with the angle θ between the normal of the identification device and the identification medium being about 60 °. After that, I got an image. Since the values of RGB are displayed on the display unit, the value of R is a large value, and the value is within the setting range, the determination of OK is displayed on the display unit.

  Instead of the anti-counterfeit medium of Example 2, the phosphor was not changed to a printed material, and the other images were obtained under the same conditions. Since the values of RGB were displayed on the display unit and all the values of RGB were small and out of the setting range, the determination of NG was displayed on the display unit.

  The phenomenon of phosphorescence can be identified by the RGB values output in Example 1, and it can be easily identified that the target anti-counterfeit medium is an authentic product. However, in Example 3, it could be easily identified that it is a non-authentic print that does not show phosphorescence in the image of the print.

1 · · · Identification device 2 · · · · · · identification person 3 · · · · anti-counterfeit medium 11 · · · imaging unit 12 · control unit 13 · · · angle sensor 14 · · · display unit Lighting unit 21 ... storage unit 22 ... operation unit 23 ... imaging device 24 ... exposure control unit 25 ... shutter speed control unit 26 ... aperture value control unit 27 ... illumination intensity control Unit 28: illumination time control unit S31 to S47: number of steps in the flowchart 301: base material 302: layer containing phosphor 303: reflective layer 304: diffractive structure layer 305 ..Adhesive layer

Claims (2)

A phosphor which emits visible light which is excited by white light and whose emitted light is at least one or more of the values digitized by RGB by the reading of the image sensor is above a certain value on a substrate Ri Na and a layer containing is provided, one value of the digitized values with the RGB is a value greater than the other values, it contains the the base material itself, or the substrate and the phosphor A reflective layer is provided between the layers . The anti-counterfeit medium according to claim 1 , wherein the reflective layer is provided with a diffractive structure.

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