JP2001334780A - Device for judging genuineness or spuriousness of card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for judging genuineness or spuriousness of a card by objectively and quickly judging genuineness or spuriousness of the card having the hologram on which the plural number of images based on a diffraction pattern has been formed. SOLUTION: The device is provided with a floodlighting system 22 for floodlighting a measuring light against a hologram 2 provided on the card 1 and in which an image is formed based on the plural number of diffraction patterns 6, a detecting system 23 having a line sensor 28a for detecting the plural number of reflecting lights respectively diffracted reflectingly by the diffraction pattern, and judging means 30a to 30c, 31a to 31c for judging whether the card is genuine or spurious by analyzing a photo-electric light based on each reflecting diffraction light of the line sensor 28a.

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.

Some cards 1 have a plurality of images formed by changing the direction in which the diffraction gratings constituting the diffraction pattern 3 are formed 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.

FIG. 4 shows a rectangular hologram seal 2 on which three types of images are formed based on, for example, diffraction patterns 4 ", 5" and 6 "composed of diffraction gratings having different pitches. Is one side 2 of the rectangular hologram seal 2
FIG. 5B shows an image 8 ″ based on a diffraction pattern 4 ″ formed of diffraction gratings having a pitch P1 in which diffraction gratings are arrayed in a direction orthogonal to a. FIG. 5C shows an image 9 ″ based on a diffraction pattern 5 ″ composed of diffraction gratings having the same pitch as the diffraction grating array and having a pitch P2. FIG. Diffraction pattern 6 "comprising a diffraction grating in the same direction as the arrangement forming direction and having a pitch P3.
10 ″ based on these three images 8 ″,
9 "and 10" are superposed to form the hologram seal 2 shown in FIG. 4 and 5, the arrows indicate the direction 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 formed.

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

[0007]

However, a plurality of images formed on the hologram seal 2 are visually inspected to judge the authenticity of the card because the image changes depending on the direction of the incident light beam, There is a demand for a card authenticity determination device that can objectively determine the authenticity of a card.

The present invention has been made in view of the above circumstances, and an object of the present invention is to objectively and quickly verify the authenticity of a card having a hologram in which a plurality of images based on a diffraction pattern are formed. An object of the present invention is to provide a card authenticity determination device capable of performing determination.

[0009]

According to a first aspect of the present invention, there is provided a card authenticating apparatus for projecting measurement light to a hologram provided on a card and having a plurality of images formed based on a plurality of diffraction patterns. A light projecting system that emits light, a detection system that has a line sensor that detects each of a plurality of reflected diffraction lights reflected and diffracted by the diffraction pattern, and a photoelectric output based on each of the reflected diffraction lights of the line sensor is analyzed. Determining means for determining whether the card is genuine or fake;

According to a second aspect of the present invention, in the card authenticity determining apparatus, the direction in which the plurality of reflected and diffracted light beams are formed is the same as the direction in which the line sensor extends.

According to a third aspect of the present invention, there is provided a card authenticity determining apparatus, wherein the direction in which the plurality of reflected and diffracted light beams are formed is a direction orthogonal to the direction in which the line sensor extends.

According to a fourth aspect of the present invention, there is provided a card authenticity determining apparatus, wherein the light projecting system comprises one laser light source.

According to a fifth aspect of the present invention, in the card authenticity determining apparatus, the detection system includes a Fourier transform lens interposed between the line sensor and the card.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

[0015]

First Embodiment FIG. 6 is a perspective view showing a schematic configuration of a card authenticity judging device according to a first embodiment of the present invention.

In FIG. 6, 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. 7A and 7B, a light projecting system 22 for projecting measurement light to the hologram 2 provided on the card 1 and forming an image based on a diffraction pattern is provided inside the box 20. And a detection system 23 for detecting the reflected and diffracted light reflected from the hologram 2 and a circuit block section described later.

The light projecting system 22 includes a laser light source 24. The laser light source unit 24 includes one semiconductor laser 24a and one collimating lens 24b. The collimating lens 24b is a semiconductor laser 24a
Plays a role of converting the laser light emitted from the laser beam into parallel measurement light.

The detection system 23 includes one Fourier transform lens 2
7 and one line sensor 28a. 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 28a is located at the rear focal position f ′ of the Fourier transform lens 27.
(F = f ') is set.

As shown in FIG. 8, the circuit block comprises a control block 29, analysis blocks 30a to 30c, and determination blocks 31a to 31c. The control block unit 29 controls turning on / off of the laser light source unit 24.

An on / off switch S1 is connected to the control block 29. ON / OFF switch S1
Is operated, the semiconductor laser 24a is turned on.

When the semiconductor laser 24a is turned on, the incident angle θ of the parallel measurement light Q1 with respect to the hologram seal 2 is fixed 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 28a extends.

The hologram seal 2 has an image 8 ″ based on three diffraction patterns 4 ″, 5 ″ and 6 ″ shown in FIG.
9 "and 10" are formed. The parallel measurement light Q1 enters from a direction orthogonal to the direction in which each diffraction grating of the diffraction pattern 4 extends.

In the diffraction phenomenon, the incident light vector component incident from the direction perpendicular to the direction in which the diffraction grating extends contributes to the parallel measurement light incident on the diffraction grating. 7B, a plurality of reflected diffracted lights (first-order diffracted lights) 32, 32 ', 32 based on the diffraction patterns 4 ", 5", 6 ", as shown in FIG. "Is the line sensor 28a
It is formed so as to be located above.

Here, the reason why the position of each diffracted reflected light is shifted on the line sensor in the extending direction will be described below.

Now, paying attention only to the diffraction pattern 6 ", the parallel measurement light Q1 is made to enter the hologram seal 2, and the pitch P3 of the diffraction grating of the diffraction pattern 6" is ideally uniform at a constant interval. As shown by the solid line in FIG. 9, the light amount distribution R of the reflected diffracted light 32 "having a sharp peak on the line sensor 28a and having a narrow spread width W is obtained.
1 is detected. When the pitch P3 of the diffraction grating is not constant but varies, as shown by a broken line in FIG. 9, the spread width W1 of the light amount distribution R1 on the line sensor 28a is increased.
A light intensity distribution R2 of the reflected diffracted light 32 ″ having a larger spread width W is detected. The peak intensity Z of the reflected diffracted light 32 ″ is the peak intensity Z It is determined by the depth (phase depth) of the groove 41.

When a diffraction grating having a large pitch P1 different from the pitch P3 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 position of the peak intensity Z of the light quantity distribution R1 of the diffracted reflected light 32 ″ based on the pitch P3 of the diffraction grating is at the origin O (the center of the optical axis of the detection system) O, for example, △ When a diffraction grating having a small pitch P2 different from the pitch P3 of the diffraction grating is formed on the hologram seal, the peak intensity of the light amount distribution shifts to the left contrary to the above.

In the real card, 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. 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.

Note that instead of the position of the center of gravity of each reflected light beam,
Alternatively, in addition to this, the determination may be made based on the mutual distance between the positions of the centers of gravity of the respective reflected light beams.

Therefore, three images based on three diffraction patterns having different diffraction grating pitches are formed on the hologram seal 2.
However, in the case of a forged card in which only one image is formed, 3
Since two diffracted reflected lights 32, 32 ', 32 "are not obtained, that is, only one diffracted reflected light is obtained, it can be determined whether or not the card is a counterfeit card based on the number of peak intensities Z of the diffracted reflected light. become.

Therefore, as shown in FIG. 8, the diffracted and reflected lights 32, 32 ', and 3' detected by the line sensor 28a.
The photoelectric output based on 2 "is analyzed by the analysis block units 30a to 30c.
And the analysis block units 30a to 30c statistically calculate the peak intensity Z of the light quantity distribution of the diffracted reflected light 32, 32 ', 32 ", its center of gravity XG, and its spread width W (standard deviation). If the calculation is performed using the technique, it can be determined whether the card is a genuine card or a counterfeit card.

Now, in FIG. 9, the line sensor 28a
, I,..., N from the left, and the photoelectric output of each pixel is Xi, the center of gravity XG of the light quantity distribution is obtained by the following equation (1). Further, the spread width W of the light quantity distribution is obtained as the standard deviation σ by the following equation (2).

FIG. 9 shows only the diffracted reflected light 32 ". In the case of a real card, the diffracted reflected light 32 and 32 'are obtained on both sides of the diffracted reflected light 32". Becomes

[0034]

(Equation 1)

That is, each of the analysis block units 30a to 30
c 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.

The analysis outputs of the analysis blocks 30a to 30c are input to the determination blocks 31a to 31c. The decision block units 31a to 31c include comparators 43a to 43c.
3c, 44a to 44c, 45a to 45c, allowable value setting units 46a to 46c, 47a to 47c, 48a to 48c, and a comprehensive judgment unit 49.

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

The peak intensity Z, the center of gravity XG, and the spread width W of the light amount distribution are different for each of the diffraction patterns 4 ", 5", 6 "forming the images 8", 9 ", 10". The range is set for each line sensor.

The comparators 43a to 43c receive respective peak intensity analysis outputs from the analysis block units 30a to 30c.
The comparators 44a to 44c include the analysis block units 30a to 30
c, the output of each center-of-gravity position analysis is input to the comparators 45a to 45a.
An output of each spread width analysis is input to 45c from the analysis block unit 30c.

The comparators 43a to 43c compare whether or not there is a peak intensity analysis output within the allowable range of the peak intensity for card authenticity set by the allowable value setting units 46a to 46c. Is the tolerance setting unit 47
a to 47c to determine whether or not there is a center-of-gravity position analysis output in the center-of-gravity position allowable range.
Reference numeral 45c compares whether or not there is a spread width analysis output in the spread width allowable range for card authenticity set by the allowable value setting units 48a to 48c.

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 shown in FIG.

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

For example, on a real card 1, a hologram seal 2 on which images based on three types of diffraction patterns in which the arrangement directions of the diffraction gratings are the same and the pitches are different is formed.
Is provided, and three peaks of the diffracted light obtained by projecting the measurement light to the hologram seal 2 must be detected. However, the reflected diffracted light obtained by projecting the measurement light to the hologram seal 2 When only one peak intensity is obtained, the card can be reliably determined to be a fake.

Even if the counterfeit card is made somewhat elaborate, the peak of the light amount distribution of each of the diffracted and reflected lights 32, 32 'and 32 "obtained by projecting the measuring light onto the hologram seal 2 is shown. By judging whether the strength, the position of the center of gravity, and the spread width are within an allowable range for authenticity judgment,
The authenticity of the card can be accurately determined.

[0045]

[Embodiment 2] As described above, depending on the type of card, as shown in FIG. 3, three images are formed based on three diffraction patterns 4, 5, and 6 in which the directions of forming the diffraction gratings are different. Some have a hologram seal 2 on which 8, 9, and 10 are formed.

In this case, the diffracted reflected light 32 based on the diffraction pattern 4 is formed on the line sensor 28a as shown in FIGS. On the other hand, the diffracted reflected light 33 based on the diffraction pattern 5 is such that the incident light vector component Q1 ′ of the parallel measurement light Q1 contributes to the diffraction and the parallel measurement light Q1
Is present, the line sensor 28
a to the one side, and the diffracted reflected light 34 based on the diffraction pattern 6 is the incident light vector component Q of the parallel measurement light Q1.
1 "contributes to the diffraction and the reflection vector component of the parallel measurement light Q1 exists, and since this reflection vector component is in the opposite direction to the reflection vector component based on the diffraction pattern 5, it is diffracted at the line sensor 28a. It will be shifted to the position on the other side from the reflected light 33.

Therefore, line sensors 28b and 28c are provided at positions where the diffracted reflected lights 33 and 34 are formed in parallel with the line sensor 28a.

Then, as shown in FIG. 14, each line sensor 28a to 28c is connected to each analysis block unit 30a to 30c. Further, each of the analysis block units 30b and 30c and the line sensor 28a are formed so as to be connectable via connection switches S3 and S4. The control block unit 29 is provided with a connection changeover switch S2 in parallel with the on / off switch S1, and a circuit is formed so that when the connection changeover switch S2 is turned on, the connection switches S3 and S4 are turned on. The photoelectric output is simultaneously input to each of the analysis block units 30a to 30c.

With this configuration, when the connection changeover switch S2 is off, three images 8, 9, and 10 are formed based on three diffraction patterns 4, 5, and 6 in which the directions of forming the diffraction gratings are different. The authenticity of the card having the hologram seal 2 can be determined. That is,
The authenticity of the card can be determined in the direction in which the array forming direction of the plurality of reflected diffracted lights is orthogonal to the direction in which the line sensor extends.

When the connection changeover switch S2 is on, the direction in which the diffraction gratings forming each diffraction pattern are formed (the direction in which the plurality of reflected diffracted lights are formed) is the same as the direction in which the line sensor 28a extends. In addition, authenticity of cards having different diffraction grating pitches can be determined.

[0051]

The card authentication device according to the present invention is constructed as described above, so that the authenticity of a card having a hologram in which a plurality of images based on a diffraction pattern are formed can be objectively and quickly determined. It has the effect that it can be done.

[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 diagram showing a rectangular hologram seal on which three types of images are formed based on diffraction patterns formed by diffraction gratings having different pitches.

5A and 5B are explanatory diagrams of the hologram seal shown in FIG. 4. FIG. 5A shows a diffraction pattern in which diffraction gratings are arranged and formed in a direction orthogonal to one side 2a of a rectangular hologram seal 2 and have a predetermined pitch. Shows an image based on
(B) shows an image based on a diffraction pattern composed of diffraction gratings in the same direction as the diffraction grating arrangement forming direction shown in (a) and at a pitch different from the predetermined pitch, and (c) shows images based on (a),
The image based on the diffraction pattern which consists of the diffraction grating of the same direction as the arrangement | sequence formation direction of the diffraction grating shown to (b), and the pitch different from the pitch shown to (a), (b) is shown.

FIG. 6 is a perspective view showing a schematic configuration of a card authenticity determination device according to the present invention.

FIG. 7 is an explanatory diagram showing a schematic configuration of an optical system of the card authentication device according to the first embodiment of the present invention;
(A) is the front view, (b) is the top view.

FIG. 8 is a circuit block diagram of the card authenticity determination device according to the first embodiment of the present invention.

FIG. 9 is an explanatory diagram of a light amount distribution based on reflected diffraction light when parallel measurement light is incident from a direction orthogonal to a direction in which each diffraction grating forming a diffraction pattern extends.

FIG. 10 is an explanatory diagram showing the depth of grooves of the diffraction grating of the diffraction pattern shown in FIG.

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

FIG. 12 is an explanatory diagram illustrating a schematic configuration of an optical system of a card authenticity determination device according to a second embodiment of the present invention;
(A) is the front view, (b) is the top view.

FIG. 13 is an enlarged explanatory view for explaining reflected and diffracted light formed by the parallel measurement light incident on the hologram seal shown in FIG. 2, in which parallel measurement light extends in each diffraction grating forming a diffraction pattern; 3 shows reflected diffracted light when the light enters from a direction orthogonal to FIG.

FIG. 14 is a circuit block diagram of a device for determining the authenticity of a card according to Embodiment 2 of the present invention.

[Explanation of symbols]

 Reference Signs List 1 Card 2 Hologram seal (hologram) 22 Projection system 23 Detection system 28a Line sensor 30a-30c Analysis block unit (judgment unit) 31a-31c Judgment block unit (judgment unit) Q1 Parallel measurement light (measurement light)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06K 19/06 G11B 7/0065 5D090 G11B 7/0065 G06K 19/00 DF Term (Reference) 2C005 HA02 HA26 HB09 JB08 LB17 LB60 2K008 AA13 CC01 FF07 HH06 HH28 5B035 AA13 BB03 BB05 5B058 CA33 KA31 KA32 5B072 AA01 AA02 CC02 CC35 DD01 LL12 LL18 MM09 5D090 AA03 BB16 CC04 CC18 DD03 DD05 KK09 FF09

Claims (5)

[Claims] 1. A light projection system for projecting measurement light to a hologram provided on a card and having a plurality of images formed based on a plurality of diffraction patterns, and a plurality of light reflected and diffracted by the diffraction patterns. A detection system having a line sensor for detecting each reflected diffracted light, and a judging means for analyzing a photoelectric output based on each reflected diffracted light of the line sensor to determine whether the card is genuine or fake. A card authenticity determination device, characterized in that a card is provided. 2. The card authentication apparatus according to claim 1, wherein the direction in which the plurality of reflected and diffracted light beams are arranged is the same as the direction in which the line sensor extends. 3. The device according to claim 1, wherein the direction in which the plurality of reflected and diffracted light beams are formed is a direction orthogonal to a direction in which the line sensor extends. 4. The card authentication apparatus according to claim 1, wherein said light projecting system comprises one laser light source. 5. The card authentication device according to claim 1, wherein the detection system has a Fourier transform lens interposed between the line sensor and the card.