JPH07230524A - Information medium reader - Google Patents

Abstract

PURPOSE:To accurately judge the brightness of an information pattern image by irradiating plural positions of a hologram with coherent reproducing light for reproducing an information pattern from the hologram. CONSTITUTION:When a part of an embossing hologram 6 which has no blur or damage is irradiated with two beams 36a, 36b of reproducing light, a hologram image is outputted from a hologram image detector 38. When a blurred or damaged part of the hologram 6 is irradiated with one reproducing light 36a (36b) and a part having no blur. or damage is irradiated with the other reproducing light 36b (36a), one reproducing light forms a hologram image in an attenuated state corresponding to the irradiation of the blurred or damaged part but the other reproducing light can form a hologram image in the non-attenuated state because the light irradiates the part having no blur or damage. Consequently a waveform slightly attenuated due to the irradiation of the blurred or damaged part with one reproducing light 26a (36b) is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a hologram as an information medium in order to determine the authenticity of the information medium, such as various cards and certificates, for which it is necessary to prevent counterfeiting, remodeling, copying, and data tampering. The present invention relates to an information medium reading device for reading the written information pattern.

[0002]

2. Description of the Related Art Information media such as credit cards, bank cards, prepaid cards, IC cards, memory cards, identification cards, checks, passbooks, stock certificates, promissory notes, car tickets, betting tickets, boarding tickets, coupon tickets, commuter tickets, etc. There is a risk that counterfeiting, modification, copying, data tampering, etc. will occur, and in recent years, as a preventive measure, for example, Japanese Patent Laid-Open No. 11297/1991.
As disclosed in Japanese Patent Laid-Open No. 1-1999, various types utilizing hologram technology are known.

The basic structure of an information medium using this hologram technology and its reading device will be described.

First, FIG. 4 shows a configuration of a key code used to determine the authenticity of an information medium, a method of creating an information medium using the key code, and a method of reading the information medium.
-It demonstrates, referring FIG.

First, as shown in FIG. 4 (a), the information 1 to be used as the key code is, for example, a combination of numbers "132".
62 "is set, and this information is divided into information elements 2 of" 1, 3, 2, 6, 2 "as shown in FIG. Next, each of the information elements 2 shown in FIG. 4B is converted into the information element shown in FIG.
Converted to the information element basic code 3 (bar code) shown in
By combining these information element basic codes 3, FIG.
The information pattern 4 is configured as shown in FIG. An information pattern 4 including a key code such as a bar code is generated by a Fresnel hologram creating apparatus (to be described later) shown in FIG.
A hologram pattern 5 as shown in (e) is formed.
Then, the hologram pattern 5 is changed to the embossed hologram 6 by the procedure of FIG. 7 which will be described later, and as a hologram key code is transferred to the vinyl chloride card 10 of the information medium 11 as shown in FIG. In FIG. 4F, the vinyl chloride card 10 has a magnetic stripe 7,
An image hologram 8 and an embossing symbol 9 are provided.

Next, the Fresnel hologram producing apparatus will be described with reference to FIG.

In FIG. 6, first, the information pattern 4 is transferred to a transparent code original plate 12 such as a photographic film.
Further, the hologram recording material 13 is installed at a predetermined position, and the code original plate 12 is installed parallel to the hologram recording material 13 at a position separated from the hologram recording material 13 by a predetermined vertical distance a.

On the other hand, the laser beam 14a (He-Ne laser beam, wavelength λ = 632.8 nm), which is coherent light from the laser irradiation means 14, is applied to the half mirror 15.
The object light 16 and the reference light 17 are separated by, and the object light 16 is reflected by a reflection mirror 18a and made into a parallel laser beam whose diameter is enlarged by a lens 19a. The hologram recording material 13 is irradiated through the original plate 12. The reference light 17 is reflected by the reflection mirror 18b, is deflected with respect to the object light 16 by a certain deflection angle θ, and is irradiated onto the hologram recording material 13 as a parallel laser beam whose diameter is enlarged by the lens 19b. By irradiating the hologram recording material 13 with the object light 16 and the reference light 17 so as to overlap each other, the interference fringes corresponding to the information pattern 4 of the code original 12 due to the interference of light on the hologram recording material 13, that is, the hologram pattern 5 ( FIG. 4E) is recorded.

In FIG. 6, the intersection of the object beam 16 and the reference beam 17 on the hologram recording material 13 is the origin, the normal line of the recording material 13 is the Z axis, and the plane containing this Z axis and the reference beam 17 is the X axis.
The X, Y, and Z axes in FIG. 6 are set so that a plane including the Z plane and the Z axis and orthogonal to the XZ plane becomes the YZ plane. At this time, the center coordinates of the code original 12 are (xp, yp, zp)
Then, xp = yp = 0 and zp = a.

Next, referring to FIG. 7, the hologram pattern 5 on the hologram recording material 13 obtained as described above is copied to the embossed hologram 6, and the information medium 1 is copied.
The procedure of transferring to No. 1 will be described.

In FIG. 7A, a photoresist 22 is brought into close contact with the hologram pattern forming side of the hologram pattern recording plate 21 in which the hologram pattern 5 is recorded on the hologram recording material 13, and from the side opposite to the hologram pattern forming side. The laser beam 23a (wavelength 488 nm) from the argon laser beam generator 23 is passed through the lens 1
The surface relief type hologram 24 as shown in FIG. 7B is formed by irradiating as parallel light having an enlarged beam diameter through 9c and performing a prescribed process.

Next, as shown in FIG. 7C, a metal vapor deposition layer 25 of Au, Ag or the like is formed on the surface relief hologram 24.
After vapor deposition to add conductivity, nickel plating 26 is applied on the vapor-deposited metal layer 25 as shown in FIG. 7 (d), and nickel plating 26 is peeled off as shown in FIG. 7 (e). To form the mold 27.

Next, when a thermoplastic resin or the like is hot-pressed using the die 27, as shown in FIG. 7F, the hologram molding layer 2 which is a duplicate of the surface relief hologram 24.
8 is obtained. A metal such as aluminum is vapor-deposited as a vapor deposition layer 29 on the hologram surface of the hologram molding layer 28,
An adhesive layer 30 is formed on the vapor deposition layer 29, and a peeling layer 31 and a base material 32 are formed on the opposite side. In this way, the embossed hologram seal 33 is obtained.

After that, as shown in FIG. 7H, the adhesive layer 30 of the embossed hologram seal 33 is transferred onto the vinyl chloride card 10 and the base material 32 is peeled off. Then, the hologram pattern corresponding to the information pattern 4 is formed. An information medium 11 having an embossed hologram 6 on which 5 is recorded is obtained.

In this case, the embossed hologram 6 has a thickness of several μm including the adhesive layer 30 and the peeling layer 31, so that the vinyl chloride card 10 can be formed on almost the same surface.

Next, an information reading device for reproducing the information pattern 4 from the embossed hologram 6 in which the hologram pattern 5 corresponding to the information pattern 4 is recorded will be described with reference to FIG.

In FIG. 8, first, the information medium insertion port 4
Insert the information medium 11 from 1 and feed rollers 43, 4
At 4, the information medium 11 is sent. When the embossed hologram 6 of this information medium 11 passes a predetermined position,
The reproduction light 36 from the reproduction illumination light generating means 34 for generating coherent light such as a semiconductor laser is generated by the lens 35.
The beam diameter is expanded by and is deflected by an angle θ ′ with respect to the vertical line of the embossed hologram 6, and the embossed hologram 6 of the information medium 11 is irradiated with the beam. Here, the angle θ ′ is an angle that satisfies tan θ ′ = (± λ / λ ′) × tan θ, where λ ′ is the wavelength of the reproduction light 36.

In FIG. 8, the irradiation position of the central axis of the reproduction light 36 on the information medium 11 is set as the origin, and the information medium 1
The normal line of 1 is the Z'axis, the plane including the Z'axis and the reproduction light 36 is the X'Z 'plane, and the plane including the Z'axis and orthogonal to the X'Z' plane is the Y'Z 'plane. Set the X ', Y', and Z'axis to. In this case, when the image forming position coordinates of the information pattern 4 which is a reproduced image is (xp ', yp', zp '), x
There is a relationship of p ′ = yp ′ = 0 and zp ′ = (± λ ′ / λ) × a. That is, the reproduced image of the information pattern 4 recorded by the embossed hologram 6 is reproduced at a distance of zp ′ on the vertical line of the embossed hologram 6 by the diffracted light 37 vertically generated from the embossed hologram 6.

Therefore, the hologram image detector 3 is located at this position.
If 8 (for example, a photodetector configured by combining a large number of photoelectric elements that convert an optical signal into an electric signal such as a photodiode) is provided, the information pattern 4 (see FIGS. 4 and 10) is detected. Then, the information pattern 4 is divided into the information element basic code 3 through the amplification / waveform shaping section 39 and the decoding section 40, the information element basic code 3 is returned to the information element 2, and the information 1 is obtained from the information element 2.

The reading operation by the above information medium reading device will be described with reference to FIGS. 9 and 10. 9 shows that the embossed hologram 6 of the information medium 11 is irradiated with the reproduction light 36 as shown in FIG.
3 is an enlarged view showing a state in which a reproduced image is formed at the position of the hologram image detector 38 by the diffracted light 37 from FIG.
In FIG. 9, the information medium 11 is H1, ...
.., Hn, Hn + 1 by moving 45 so that the embossed hologram 6 is H1, ..., Hn, Hn +
When it is moved as shown in FIG. 1, R is diffracted on the hologram image detector 38 by the diffracted light 37 reflected from the embossed hologram 6.
, ..., Rn, Rn + 1, the information pattern 4 composed of a bar code that moves 46 is imaged and detected, and passes through the amplification / waveform shaping unit 39 and the decoding unit 40.
Is divided into the information basic element code 3, the information element basic code 3 is returned to the information element 2, and the information 1 is obtained from the information element 2.

FIG. 10 shows the output waveform. The horizontal axis shows the detection position of the reproduced image of the information pattern 4, and the vertical axis shows the output of the hologram image detector 38.

[0022]

However, in the above-mentioned conventional example, when the surface state of the embossed hologram 6 on the surface of the information medium 11 is contaminated, scratched or the like, and the surface state is optically varied, as shown in FIG. Attenuation of the diffracted light 37 due to stains and scratches occurs, so that the output of the reproduced image of the information pattern 4 changes significantly as described below.

FIG. 11 shows a case where the surface of the embossed hologram 6 on the information medium 11 has stains or scratches 50.
12 is a diagram similar to that of FIG. 12, and FIG. 12 shows the information pattern 4 in that case.
The output waveform of the reproduced image of is shown. In FIG. 12, the horizontal axis shows the detection position of the reproduced image of the information pattern 4, and the vertical axis shows the output of the hologram image detector 38. As shown in FIG. 12, when stains or scratches 50 are present on the surface of the embossed hologram 6 on the information medium 11, the output level is lowered at the locations where the stains or scratches 50 are present, and information is output at the threshold level L. There is a problem in that it is impossible to determine the presence or absence of an image such as a barcode that forms the pattern 4, and it becomes impossible to determine the information pattern.

In view of the above-mentioned conventional problems, the present invention provides an information medium reading device capable of accurately discriminating the information pattern of the embossed hologram even if the surface of the embossed hologram on the information medium has dirt or scratches. Is intended.

[0025]

An information medium reading device of the present invention is an information medium reading device having an embossed hologram obtained by embossing a hologram pattern in which an arbitrary information pattern is recorded, on the surface thereof. A reproducing illumination light generating means for irradiating a plurality of positions of the hologram with coherent reproducing light for reproducing the information pattern, and a hologram reproduced image formed by forming diffracted light from the hologram generated by the reproducing light irradiation. And a hologram image detector for detecting an information pattern.

Preferably, the information pattern is a bar code.

[0027]

According to the present invention, by irradiating a plurality of positions on the hologram with coherent reproduction light for reproducing the information pattern from the hologram, stains, scratches, etc. are present on the surface of the hologram on the information medium surface. Therefore, even if the output level of the information pattern due to one reproduction light decreases, the output level of the information pattern due to the other reproduction light maintains a normal level, so the threshold level for determining the brightness of the information pattern image is set. The value can be set to an appropriate value necessary for reliable detection, and the brightness of the information pattern image can be determined accordingly.

Further, when the information pattern is a bar code, the above action becomes remarkable.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An information media reading apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

The information medium used in this embodiment is
Since it is the same as the information medium 11 using the hologram technique described in the conventional example, description thereof will be omitted. Since the basic configuration of the information medium reading device is also the same as that described with reference to FIG. 8, the description of common components will be cited, and only different components will be described.

In FIG. 1, in the conventional example of FIG. 8, one reproduction light 36 is applied to the embossed hologram 6 on the surface of the information medium 11, but in the present embodiment, two reproduction lights 36 are emitted.
The embossed hologram 6 is irradiated with a and 36b.

FIG. 2 shows the operation in the case where the embossed hologram 6 on the surface of the information medium 11 is used with dirt and scratches 50 present. In FIG. 2, the reproduction light 36a, 36 having the wavelength λ ′ emitted from the two reproduction irradiation light generating means 34 is used.
Even if one reproduction light in b irradiates the stain or scratch 50, the other reproduction light irradiates a portion having no stain or scratch 50. It should be noted that the hologram means that if the reproduction light of the same wavelength is irradiated at the same angle, no matter which position of the embossed hologram 6 is irradiated with the reproduction light, each of the information patterns has a predetermined positional relationship with respect to the embossed hologram 6. It has the characteristic of forming the entire image, and therefore even if the two reproduction beams 36a and 36b irradiate different positions, the same hologram image is formed at the same position.

Therefore, when the embossed hologram 6 is irradiated with the two reproduction beams 36a and 36b on a portion where there is no stain or scratch 50, the hologram image formed without attenuation due to stain or scratch is a hologram image. The detector 38 outputs and outputs at the same regular level over the entire length of the formed hologram image as shown by the solid line. Therefore, when the embossed hologram 6 has no stain or scratch 50, the information pattern 4 can be discriminated by the threshold level L shown in FIG.

On the other hand, the embossed hologram 6 has dirt and scratches 5.
One reproduction light 36a or 36b irradiates a portion where 0 is present, and another reproduction light 3 is applied to a portion where there is no stain or scratch 50.
When 6b or 36a irradiates, one reproduction light forms a hologram image in a state of being attenuated by the amount of irradiation of a portion having a stain or a scratch 50, but another reproduction light does not stain. Since the holographic image is formed in a state where there is no attenuation because it irradiates the portion where there is no scratch 50, the total of these is a little as much as one reproduction light irradiates the portion where there is dirt or the scratch 50. Output the attenuated waveform shown by the broken line. Therefore, in this case, the information pattern 4 can be discriminated by the threshold level L without causing much attenuation as in the case of the conventional example shown in FIG.

It is conceivable to increase the irradiation area of one reproduction light so that even if there is a stain or a scratch 50, the other area can be irradiated, but in reality, the reproduction light 36 of the hologram is used. Since uniform light is required, it is practically difficult to obtain the reproduction light 36 having a large area at low cost, which is not practical.

As described above, by using the information medium reading apparatus of this embodiment, the information pattern 4 can be accurately discriminated even when the embossed hologram 6 on the surface of the information medium 11 has a stain or a scratch 50.

In particular, when the information pattern 4 is a bar code, the presence or absence of the bar code and the thickness can be detected in a good condition, and the effect is remarkable.

In the above embodiment, the two reproduction irradiation light generating means 34 emit the reproduction lights 36a and 36b, respectively. However, the reproduction irradiation light generating means 34 is one, and the beam splitter or the like is used. It is also possible to irradiate reproduction light into a plurality of branches. In the above embodiment, the information medium 11 is moved and the hologram image detector 38 is fixedly arranged. However, the information medium 11 is installed at a predetermined position and the hologram image detector 38 is set to the embossed hologram 6.
You may make it move parallel to.

[0039]

According to the information medium reading apparatus of the present invention, as is apparent from the above description, the coherent reproduction light for reproducing the information pattern from the hologram is applied to a plurality of positions of the hologram. , Even if the output level of the information pattern by one reproduction light decreases due to the presence of dirt or scratches on the surface of the hologram on the information media surface, the output level of the information pattern by the other reproduction light is normal. In order to maintain the level, the threshold level for determining the lightness / darkness of the information pattern image can be set to a reasonable value necessary for reliable detection, and thus the lightness / darkness of the information pattern image can be determined. Exert the effect of being able to.

Further, when the information pattern is a bar code, the above effect is more remarkably exhibited.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of an information media reading device of the present invention.

FIG. 2 is an operation explanatory diagram of the embodiment.

FIG. 3 is an output waveform diagram of the hologram image detector of the same embodiment.

FIG. 4 is an explanatory diagram of a procedure for creating an information medium.

FIG. 5 is an explanatory diagram of a contrasting relationship between information elements and information element basic codes.

FIG. 6 is a configuration diagram of a hologram pattern creation device.

FIG. 7 is an explanatory diagram of a procedure for creating an embossed hologram.

FIG. 8 is a configuration diagram of a conventional information medium reading device.

FIG. 9 is an operation explanatory diagram of a conventional example.

FIG. 10 is an output waveform diagram of a conventional hologram image detector.

FIG. 11 is an explanatory diagram of an operation when the surface of the embossed hologram has stains or scratches.

FIG. 12 is an output waveform diagram of the hologram image detector when the surface of the embossed hologram has stains or scratches.

[Explanation of symbols]

 1 information 4 information pattern 5 hologram pattern 6 embossed hologram 11 information medium 34 reproduction illumination light generating means 36a reproduction light 36b reproduction light 37 diffracted light 38 hologram image detector 50 dirt and scratches

Claims (2)

[Claims] 1. A device for reading an information medium having an embossed hologram, which is formed by embossing a hologram pattern recording an arbitrary information pattern, on a surface thereof.
Reproducing illumination light generating means for irradiating a plurality of positions of the hologram with coherent reproducing light for reproducing the information pattern from the hologram, and a hologram formed by imaging diffracted light from the hologram generated by the irradiation of the reproducing light. An information media reading device comprising: a hologram image detector that detects an information pattern from a reproduced image. 2. The information medium reading device according to claim 1, wherein the information pattern is a bar code.