JP2001301370A - Card genuiness judging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a card genuineness judging device which is capable of objectively judging the genuineness of a card with a hologram in which an image based on a diffraction pattern is formed, with high degree of certainty and rapidity. SOLUTION: This card genuineness judging device has a first detection system 7A which projects a laser measuring light to the hologram 2, showing a hologram image formed based on a diffraction pattern, which is incorporated in the card 1 and detects the reflective diffraction light reflected from the hologram 2 in order to judge whether the card 1 is genuine or false and a second detection system 7B which irradiates the hologram 2 with a laser irradiation light and detects the hologram image formed in the hologram 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a device for determining the authenticity of a card having a hologram on which an image based on a diffraction pattern is formed.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
Hologram sticker 2 on a card 1 such as a credit card
Is known. On the hologram seal 2, an image 4 'based on the diffraction pattern 3 is formed. The hologram seal 2 is used to determine the authenticity of the card 1.

The card 1 has a plurality of images formed on the hologram 2 by changing the arrangement direction of the diffraction gratings constituting the diffraction pattern 3 in order to prevent forgery.

FIG. 2 shows, for example, three diffraction patterns 4, 5,.
6A and 6B show a rectangular hologram seal 2 on which three types of images are formed, and FIG. 3A shows a diffraction pattern 4 in which diffraction gratings are arranged and formed in a direction orthogonal to one side 2 a of the rectangular hologram seal 2. FIG. 3 shows an image 8 based on
FIG. 3B shows an image 9 based on the diffraction pattern 5 in which the diffraction gratings are arranged in a direction obliquely 45 degrees to the right with respect to the arrangement direction of the diffraction gratings in the diffraction pattern 4, and FIG. FIG. 2 shows an image 10 based on a diffraction pattern 6 in which diffraction gratings are arranged diagonally at 45 degrees to the left with respect to the arrangement direction of the gratings. The seal 2 is formed,
The appearance of the images 8, 9, and 10 changes depending on the state of the incident light beam on the hologram seal 2. In FIG. 3, the arrows indicate the directions in which the diffraction gratings are formed, and the direction in which each diffraction grating extends is orthogonal to the direction in which the diffraction gratings are arranged.

Conventionally, the authenticity of the card 1 has been determined by visually checking the image formed on the hologram seal 2.

[0006]

However, when the image formed on the hologram seal 2 is visually inspected to judge the authenticity of the card, the image changes depending on the direction of the incident light beam or the card is damaged. It is difficult
There is a demand for a card authentication device that can objectively and highly accurately and quickly determine the authenticity of a card.

The present invention has been made in view of the above circumstances, and has as its object to objectively and highly accurately verify the authenticity of a card having a hologram on which an image based on a diffraction pattern is formed. An object of the present invention is to provide a card authenticity determination device that can quickly determine a card.

[0008]

According to a first aspect of the present invention, there is provided a card authenticating apparatus for determining whether a card is genuine or fake, wherein the hologram image is provided on the card and based on a diffraction pattern. A first detection system for projecting a laser measurement light beam onto the hologram on which the hologram is formed and detecting a reflected diffraction light reflected from the hologram, and irradiating the hologram with laser irradiation light to form the hologram; And a second detection system for detecting the hologram image thus obtained.

According to a second aspect of the present invention, there is provided a card authenticity determining apparatus, wherein the first detection system includes a line sensor for receiving the reflected light, and a Fourier transform lens interposed between the line sensor and the card. It is characterized by the following.

According to a third aspect of the present invention, there is provided a card authentication apparatus, wherein the second detection system includes a line sensor for receiving the hologram image.

According to a fourth aspect of the present invention, there is provided the card authenticity determining apparatus, wherein the first detection system and the second detection system are provided in a box side by side, and the card is carried into the box. The hologram image is detected by the second detection system during the transport of the card, and the reflected diffracted light is detected at the transport stop position of the card.

[0012]

FIG. 4 is a perspective view showing a schematic structure of an example of a card authenticity judging device according to the present invention.

In FIG. 4, reference numeral 20 denotes a box of a card authenticity judging device. The box 20 is provided with an entrance 21 for the card 1. As shown in FIGS. 5A and 5B, the first detection system 7A
And a second detection system 7B.

The first detection system 7A is a light projecting system 2 that is provided on the card 1 and projects laser measurement light onto the hologram 2 on which a hologram image based on a diffraction pattern is formed.
2 and a detection system 23 for detecting the reflected diffracted light reflected from the hologram 2.

The second detection system 7B has a laser light source section 7C for irradiating the hologram 2 with laser irradiation light and a line sensor 7D. The laser light source unit 7C includes a semiconductor laser 7E and a collimating lens 7 that converts the laser irradiation light emitted from the semiconductor laser 7E into a parallel light beam.
F is provided. The line sensor 7D is provided near the entrance 21 of the box 20, as shown in FIG.

The light projecting system 22 here comprises three laser light source sections 24-26. Each laser light source 2
4 to 26 are composed of semiconductor lasers 24a to 26a and collimating lenses 24b to 26b. The collimating lenses 24b to 26b serve to convert the laser light emitted from the semiconductor lasers 24a to 26a into parallel measurement light.

The detection system 23 includes a Fourier transform lens 27 and a line sensor 28. The card 1 is drawn into the box 20 and set at the front focal position f of the Fourier transform lens 27. The line sensor 28 is set at the rear focal position f ′ (f = f ′) of the Fourier transform lens 26. The line sensor 28 is arranged in the box 20 in parallel with the line sensor 7D as shown in FIG.

The circuit block shown in FIG. 6 is provided inside the box 20. The circuit block includes a control block 29, an analysis block 30, and a determination block 3.
1, an image processing unit 7G and a card type determination unit 7H. The control block unit 29 includes the laser light source units 24-2.
6 has a function of performing control of turning on / off light and setting control of an allowable value for authenticity determination of an allowable value setting device described later.

The changeover switch S0 is connected to the control block 29. The changeover switch section S0 here has changeover switches S1, S2, S3. When the changeover switch S1 is turned on, the semiconductor laser 24a is turned on. When the changeover switch S2 is turned on, the semiconductor laser 25a is turned on. When the changeover switch S3 is turned on, the semiconductor laser 26a is turned on.

The changeover switches S1, S2, S3 are turned on / off depending on the type of the card. Box 20
Is inserted into the hologram seal 2 from the laser light source unit 7C, the first-order diffracted light is detected by the line sensor 7D disposed right above, and as shown in FIG. During the transportation of the card 1, a tomographic image in a direction orthogonal to the transport direction is detected by the line sensor 7D, and the detection output is input to the image processing unit 7G, and the image processing unit 7G is based on the tomographic image of the line sensor 7D. The hologram image 7I formed on the hologram seal 2 is constructed. The image output of the image processing unit 7G is input to the card type determination unit 7H. Card type determination unit 7
H determines which type of the card 1 inserted in the box 20 is a commercially available type, and based on the determination result, which semiconductor laser 24a to 2
4c is turned on.

When the semiconductor laser 24a is turned on, the parallel measurement light Q1 is incident on the hologram seal 2 at a constant incident angle θ as shown in FIG.
As shown in (b), the light enters the hologram seal 2 from an incident direction at an angle φ = 0 with respect to the direction in which the line sensor 28 extends. When the semiconductor laser 25a is turned on, the parallel measurement light Q2 is incident at an angle φ = φ1 with respect to the direction in which the line sensor 28 extends as shown in FIG. The light enters the hologram seal 2 from the direction. When the semiconductor laser 26a is turned on, the parallel measurement light Q3 is incident on the hologram seal 2 at a constant incident angle θ, as shown in FIG.
As shown in FIG. 2B, the hologram seal 2 is formed from the incident direction at an angle φ = −φ1 with respect to the direction in which the line sensor 28 extends.
Incident on Its changeover switches S1, S2, S3
Accordingly, the incident direction of the parallel measurement light to the hologram seal 2 is changed.

Here, it is assumed that images 8, 9, and 10 based on three diffraction patterns 4, 5, and 6 are formed on the hologram seal 2. The parallel measurement light Q1 enters from a direction perpendicular to the direction in which each diffraction grating of the diffraction pattern 4 extends, the parallel measurement light Q2 enters from a direction perpendicular to the direction in which each diffraction grating of the diffraction pattern 5 extends, It is assumed that the parallel measurement light Q3 is incident from a direction orthogonal to the direction in which the diffraction grating of the diffraction pattern 6 extends.

The diffraction phenomenon is caused by the incident light vector component incident perpendicular to the direction in which the diffraction grating extends out of the parallel measurement light incident on the diffraction grating. Therefore, for example, the parallel measurement light Q1 is incident on the incident direction φ = 0 degree. From the direction of hologram seal 2
8, the diffracted reflected light (first-order diffracted light) 32 based on the diffraction pattern 4 is reflected by the line sensor 2 as shown in FIG.
8 is formed. On the other hand, the diffracted reflected light 33 based on the diffraction pattern 5 is the parallel measurement light Q1.
Since the incident light vector component Q1 'contributes to the diffraction and the reflected vector component of the parallel measurement light Q1 exists, it is formed at a position shifted to one side from the line sensor 28. Also,
The diffraction reflected light 34 based on the diffraction pattern 6 is a parallel measurement light.
Since the incident light vector component Q1 ″ of Q1 contributes to the diffraction and there is a reflection vector component of the parallel measurement light Q1 and this reflection vector component is opposite to the reflection vector component based on the diffraction pattern 5, the line It is formed at a position shifted from the sensor 28 to the side opposite to the diffracted reflected light 33.

For example, as shown in FIG. 9, when the parallel measurement light Q2 is incident on the hologram seal 2 from the incident direction φ = φ1, the diffracted reflected light 33 based on the diffraction pattern 5 is projected onto the line sensor 28. It is formed to be located. Further, for example, the parallel measurement light Q3 is incident in the incident direction φ = −φ.
1 is incident on the hologram seal 2 from the direction of FIG.
0, the diffraction reflected light 3 based on the diffraction pattern 6
4 is formed on the line sensor 28.

Now, focusing on the diffraction pattern 4 alone, let it be assumed that the parallel measurement light Q1 is incident on the hologram seal 2 and that the pitches P1 of the diffraction gratings of the diffraction pattern 4 are ideally arranged at regular intervals. As shown by the solid line in FIG. 11, a light amount distribution R1 of the reflected diffraction light 32 having a sharp peak and a narrow spread width W on the line sensor 28 is detected. In the case where the pitch P1 of the diffraction grating is not constant but varies, as shown by the broken line in FIG. 11, the reflected diffracted light having a larger width W than the width W of the light amount distribution R1 on the line sensor 28. 32 light amount distributions R2 are detected. The peak intensity Z of the reflected diffraction light 32 is determined by the depth (phase depth) of the groove 41 of the diffraction grating formed on the hologram seal 2 as shown in FIG.

When a diffraction grating having a large pitch P2 different from the pitch P1 of the diffraction grating is formed on the hologram seal 2, the position of the peak intensity Z of the light amount distribution R1 of the diffracted reflected light 32 is shown in FIG. As described above, assuming that the peak intensity Z of the light amount distribution R1 of the diffracted reflected light 32 based on the diffraction grating pitch P1 is located at the origin (the optical axis center of the detection system 23) O, the peak intensity Z is shifted from the origin O. .

In a real card, since the pitch of the diffraction grating formed on the hologram seal 2 and the depth of the groove of the diffraction grating are strictly controlled, the peak intensity Z of the light intensity distribution of the reflected diffraction light and the light intensity distribution thereof Is considered to be within a predetermined range.

On the other hand, in the counterfeit card, the pitch of the diffraction grating is significantly different from the pitch of the diffraction grating of the real card, or the pitch is almost the same but the pitch varies widely, or the pitch of the diffraction grating is large. The depth of the groove 41 is greatly different from the depth of the groove of the diffraction grating of the real card. These appear as optical characteristics such as the peak intensity of the light intensity distribution of the reflected diffracted light, the position of the center of gravity of the light intensity distribution, and the spread of the light intensity distribution. By analyzing these optical characteristics, a genuine card or a forged card is analyzed. Can be determined.

Also, depending on the type of the card, as described in the section of the prior art, three images based on three diffraction patterns having different directions must be formed on the hologram seal 2; In the case of a counterfeit card in which only three images are formed, three diffracted reflected lights 32, 33, and 34 are not obtained, and only one diffracted reflected light is obtained. Z
, It can be determined whether or not the card is a counterfeit card.

Therefore, first, the type of the card is determined based on the shape of the detected hologram image and the like, and the semiconductor laser most suitable for determining the authenticity of the card is turned on. As shown in FIG. The photoelectric output based on the diffracted and reflected lights 32, 33, and 34 detected by the sensor 28 is input to the analysis block unit 30, and the analysis block unit 3
By calculating the peak intensity Z of the light intensity distribution of the diffracted reflected light 32, 33, 34, its center of gravity position XG, and its spread width W (standard deviation) using a statistical method, a genuine card or a forged card can be used. It will be possible to determine whether there is.

In FIG. 6, when the pixel numbers of the line sensor 28 are 1, 2,... I,..., N in order from the left, and the photoelectric output of each pixel is Xi, the light quantity is expressed by the following equation (1). The position of the center of gravity XG of the distribution is obtained. Further, the spread width W of the light amount distribution is obtained as a standard deviation by the following equation (2).

[0032]

(Equation 1)

That is, the analysis block unit 30 has a function of performing a calculation based on the above equations (1) and (2) and temporarily storing the calculation result, and a function of temporarily storing the peak intensity Z. Have.

The analysis output of the analysis block unit 30 is input to the determination block unit 31. The judgment block unit 31
Are comparators 43, 44, 45, tolerance setting units 46, 4
7, 48, and a general determination unit 49.

The allowable value setting unit 46 has a peak intensity of the light quantity distribution.
The allowable range of Z is set, the allowable value setting unit 47 sets the allowable range of the center of gravity of the light amount distribution, and the allowable value setting unit 48 sets the allowable range of the spread width of the light amount distribution.

Even if it is a real card, images 8, 9, 1
Since the peak intensity Z, the barycentric position XG, and the spread width W of the light amount distribution may differ for each of the diffraction patterns 4, 5, and 6 forming 0, the tolerance set in each of the tolerance setting units 46, 47, and 48. It is desirable to change the range in accordance with the on / off of the changeover switches S1, S2, S3.

The comparator 43 receives the peak intensity analysis output from the analysis block 30, the comparator 44 receives the centroid position analysis output from the analysis block 30, and
5 is input with a spread width analysis output from the analysis block unit 30.

The comparator 43 compares whether or not the peak intensity analysis output is within the allowable range of the peak intensity for the card authenticity set by the allowable value setting unit 46.
Numeral 4 compares whether or not there is a center-of-gravity position analysis output within the center-of-gravity position allowable range set by the allowable value setting unit 47. The comparator 45 sets the spread width for card authenticity determination set by the allowable value setting unit 48. It is compared whether or not there is a spread width analysis output in the allowable range.

The results of these comparisons are input to the overall judgment section 49, and the overall judgment section 49 judges whether the card is a genuine card or a counterfeit card based on these comparison results. The determination result is displayed on the display unit 50.

According to the embodiment of the present invention, whether the card is a genuine card or a counterfeit card can be determined by the method described below.

For example, when the hologram image is determined by the second detection system 7B, it is determined that a hologram image based on three types of diffraction patterns must be formed on the hologram seal 2 in the real card 1. Indicates that the direction of incidence of the measurement light on the hologram seal 2 is 3
The direction of the measurement light is sequentially changed and the measurement light is projected. The authenticity of the card 1 is determined based on whether three peak intensities of the diffraction light obtained by the measurement are detected.

That is, the changeover switches S1, S2, S3
Are automatically switched in order, and the semiconductor laser 24a
26a are sequentially turned on, and the incident direction of the measurement light to the hologram seal 2 is automatically changed sequentially. Then
For each incident direction of the measurement directions with respect to the hologram seal 2, it is determined whether or not the peak intensity Z of the light quantity distribution, its center of gravity XG, and its spread width W are within an allowable range.

Some counterfeit cards have only an image based on one diffraction pattern formed thereon. In such a counterfeit card, the direction of incidence of the measurement light on the hologram seal 2 is changed to three directions and then projected. Since only one peak intensity of the reflected diffraction light obtained by light emission is obtained, the card can be reliably determined to be a fake.

Even if the counterfeit card is made somewhat elaborate, the incident direction of the measuring light on the hologram seal 2 is changed in order, and the amount of diffracted reflected light is changed for each incident direction of the measuring light on the hologram seal 2. Since the authenticity of the card can be determined based on whether or not the peak intensity of the distribution, its center of gravity position, and its spread width are within the allowable range for authenticity determination, the accuracy of the authenticity determination of the card can be increased.

Also, for example, as a result of determining the hologram image by the second detection system 7B, for example, the genuine card 1
If it is determined that the hologram image is a hologram image based on one type of diffraction pattern, a semiconductor laser suitable for determining the authenticity of the card 1 is selected, and measurement light is projected on the hologram seal 2; By determining whether or not the peak intensity Z of the light quantity distribution of the diffracted reflected light, the center of gravity position XG, and the spread width W are within an allowable range, it can be determined whether or not the card is a counterfeit card.

[0046]

As described above, the authenticity determination apparatus for a card according to the present invention is constructed as described above, so that the authenticity of a card having a hologram on which an image based on a diffraction pattern is formed can be objectively, accurately, and quickly. This has the effect of making it possible to make a

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a card having a hologram seal.

FIG. 2 is an explanatory diagram illustrating an example of a diffraction pattern formed on a hologram seal.

3A and 3B are explanatory diagrams for explaining the details of the diffraction pattern shown in FIG. 2; FIG. 3A shows a diffraction pattern in which an arrangement direction of a diffraction grating is formed in a direction orthogonal to one side of a hologram seal; (B) shows a diffraction pattern in which the arrangement direction of the diffraction grating is formed at an angle of 45 degrees to the right with respect to the arrangement direction of the diffraction pattern shown in (a), and (c) shows the arrangement of the diffraction pattern shown in (a). A diffraction pattern in which the arrangement direction of the diffraction grating is formed at an angle of 45 degrees to the left with respect to the direction is shown.

FIG. 4 is a perspective view showing a schematic configuration of a card authenticity determination device according to the present invention.

FIGS. 5A and 5B are explanatory views showing a schematic configuration of an optical system of a card authenticity determination device according to the present invention, wherein FIG. 5A is a front view and FIG.

FIG. 6 is a circuit block diagram of a card authenticity determination device according to the present invention.

7 is a diagram showing an example of a hologram image constructed by the image processing unit shown in FIG.

FIG. 8 is an explanatory diagram for explaining reflected diffracted light formed by the parallel measurement light Q1 incident on the hologram seal shown in FIG. 2, wherein the parallel measurement light Q1 is a diffraction grating of each diffraction grating constituting the diffraction pattern 4; The figure shows the reflected diffracted light when entering from a direction perpendicular to the extending direction.

FIG. 9 is an explanatory diagram for explaining reflected diffraction light formed by the parallel measurement light Q2 incident on the hologram seal shown in FIG. 2, wherein the parallel measurement light Q2 is a diffraction pattern 5;
Shows the reflected diffracted light when incident from a direction orthogonal to the direction in which each diffraction grating constituting

FIG. 10 is an explanatory diagram for explaining reflected and diffracted light formed by the parallel measurement light Q3 incident on the hologram seal shown in FIG. 2, wherein the parallel measurement light Q3 of each diffraction grating forming the diffraction pattern 6 is used. Shows reflected and diffracted light when incident from a direction perpendicular to the direction in which it extends

FIG. 11 is an explanatory diagram of a light amount distribution based on reflected diffraction light when the parallel measurement light Q1 is incident from a direction orthogonal to a direction in which each diffraction grating forming the diffraction pattern 4 extends.

FIG. 12 is an explanatory diagram showing the depth of a groove of the diffraction grating of the diffraction pattern shown in FIG.

FIG. 13 is an explanatory diagram of a light amount distribution based on reflected diffraction light when the parallel measurement light Q1 is incident from a direction orthogonal to a direction in which each diffraction grating constituting the diffraction pattern 4 extends.
11 shows a light quantity distribution based on the reflected diffraction light of a diffraction grating having a pitch larger than the pitch of the diffraction grating of the diffraction pattern 4 shown in FIG.

[Explanation of symbols]

 1 Card 2 Hologram seal (hologram) 7A First detection system 7B Second detection system Q1, Q2, Q3 Parallel measurement light (measurement light) S1, S2, S3 switch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G07D 7/12 G07D 7/12 F term (Reference) 2C005 HA02 HB09 JB08 JB09 LB15 LB17 LB60 2K008 AA13 CC01 CC03 EE04 FF07 FF11 FF21 HH03 HH06 HH28 3E041 AA10 BA11 BB03 5B072 AA01 AA02 BB00 CC02 CC35 DD02 DD21 DD23 GG07 JJ01 LL07 LL12 LL19

Claims (4)

[Claims] 1. A method for judging whether a card is genuine or fake, by projecting a laser measurement beam onto a hologram provided on the card and having a hologram image formed based on a diffraction pattern, and A first detection system that detects reflected diffraction light reflected from the hologram; and a second detection system that irradiates the hologram with laser irradiation light and detects a hologram image formed on the hologram. Card authenticity determination device. 2. The apparatus according to claim 1, wherein the first detection system includes a line sensor for receiving the reflected diffracted light, and a Fourier transform lens interposed between the line sensor and the card. Card authenticity determination device. 3. The apparatus according to claim 1, wherein the second detection system has a line sensor for receiving the hologram image. 4. The first detection system and the second detection system are provided side by side in a box, the card is carried into the box, and the card is conveyed by the second detection system while the card is being conveyed. 4. The card authenticity determination apparatus according to claim 3, wherein a hologram image is detected, and the reflected diffracted light is detected at a transfer stop position of the card.