JP2002055216A - Optical change element and reading device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optically variable device having a complicated form which is hardly forged or falsified, and to provide a device for reading the above variable device. SOLUTION: The optically variable device 2 has a polymer layer 4 having minute recesses and projections which diffract light and a conductor layer 3 on the surface having the recesses and projections of the polymer layer, and has at least two layers each consisting of the above polymer layer 4 and conductor layer 3, with at least a part of the polymer layer 4 and the conductor layer 3 constituting a resonant circuit. By sticking the optically variable device 2 to a valuable printed matter 1 and by changing illumination or viewing angles, the variable device 2 vary its colors and patterns, and this phenomenon can be used to determine forgery or falsification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optically variable element for giving valuable printed matter such as banknotes, passports, securities, cards, stamps and the like an effect of suppressing counterfeiting and alteration, and a reading device therefor. It is.

[0002]

2. Description of the Related Art Banknotes, passports, securities, cards,
Due to their properties, valuable printed materials such as stamps are required to be hard to forge or falsify. It is known to attach an optically variable element such as a hologram to a valuable printed matter as one of the preventive measures. At the same time, since these valuable printed materials need to be subjected to authenticity determination and other mechanical processing, as a method of mechanical reading, the attached optically variable element is irradiated with a thin light beam such as a laser beam, and the intensity of the diffracted light is irradiated. For the hologram, a method for reading a reproduced image has been devised.

[0003]

The optically variable element has such a characteristic that its color and pattern appear to change when the angle of observation under illumination is changed. This characteristic is exhibited because the optically variable element has a structure that diffracts or interferes with light due to minute unevenness or the like. Due to its structure, it is difficult to forge the optical change element itself,
In addition, it is considered to be an effective counterfeit prevention measure against color copying, counterfeiting using a personal computer and a printer, etc. due to the property of diffracting or interfering light. However, in recent years, materials similar to optically variable elements have been used for decoration, packaging, toys, etc., and using these materials, genuine optical In some cases, a forgery is made that is indistinguishable from a variable element, and merely attaching an optical variable element to a valuable printed matter is no longer a significant preventive measure against counterfeiting or falsification.

[0004] Due to its characteristics, optically variable elements are often provided with suitability for mechanical processing by optical reading. In this case, however, irregularities on the surface of a substrate to which the optically variable element is attached are reduced. There is a high possibility that an error will occur at the time of reading due to bending or wrinkling.

By the way, in order to prevent shoplifting of goods, etc., an example is used in which a tag composed of a resonance circuit element in which a capacitor and a coil are combined is attached to a product and the tag is detected by radio waves of a specific frequency. There is. However, these tags do not have decorative properties due to their properties, and it is hard to imagine using them as they are to prevent forgery and falsification of valuable printed matter.

The present invention has been made in view of such a situation, and has the characteristics of a conventional optically variable element such that a color or a pattern appears to change when an observation angle is changed.
Another object of the present invention is to provide an optically variable element having a complicated shape that is extremely difficult to forge and falsify, and further having a function of causing a resonance phenomenon with respect to a radio wave of a specific frequency.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a polymer layer having minute unevenness for diffracting light, and a conductor on the uneven surface of the polymer layer. An optical variable element having at least two layers comprising a polymer layer and a conductor layer, wherein at least a part of the polymer layer and the conductor layer constitute a resonance circuit. An optical change element characterized by the following.

[0008] Further, a polymer layer having minute unevenness for diffracting light, and a conductor layer on the uneven surface of the polymer layer, and at least two layers composed of the polymer layer and the conductor layer are provided. An optical change element, in which a capacitor having capacitance is formed by two conductive layers and a polymer layer therebetween, and a coil is formed by a pattern of one or two conductive layers to form a resonance circuit. Is an optically variable element.

Further, since the optical change element of the present invention exhibits changes in optical color and design, it is difficult to realize that the polymer layer and the upper and lower conductive layers constitute a resonance circuit. It is characterized by the following.

[0010] The optical variable element of the present invention is characterized in that it is possible to determine the authenticity by reading the emission of a radio wave of a specific frequency due to resonance.

Further, the optical change element according to the present invention is characterized in that the optical change element is attached to a security or a passport booklet for authenticity determination or machine reading.

The reading of the optical variable element according to the present invention is a reading apparatus which determines whether the optical variable element is authentic by reading the transmission of a specific frequency radio wave by resonance, and transmits a radio wave of a frequency at which the optical variable element resonates by the CPU. Control the timing of transmission, transmit a radio wave from the transmission antenna via the transmission amplifier, receive the radio wave via the reception antenna, input to the reception control unit via the reception amplifier, and based on the signal from the timing control unit, An optical change that forms a resonance circuit that causes the polymer layer and the upper and lower conductive layers to resonate with the radio wave of the specific frequency when output and input to the CPU via the A / D converter. A reading device for an optically variable element, characterized in that the presence / absence of an element is determined to determine whether the element is true or false.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an optical variable element and a reader therefor according to the present invention will be described with reference to the drawings based on embodiments. The polymer layer of the present invention is a resin capable of embossing a diffraction grating pattern such as a hologram by heat and pressure.
According to the present invention, colors and figures appear to change optically. The thickness of this polymer layer is preferably about several μm to several tens μm.

The conductor layer of the present invention is provided on the uneven surface of the polymer layer, and has both the purpose of promoting the change of the optical color and the figure of the present invention and the purpose of forming a resonance circuit. The materials used for this are aluminum, copper, silver,
It is a transparent conductor such as a metal such as gold, or indium tin oxide which is a transparent electrode material.

In order for the optical variable element of the present invention to form a resonance circuit with the polymer layer and the upper and lower conductive layers, a part of the conductive layer needs to form a coil pattern. The width is preferably about 0.1 mm to 5 mm. In addition, it is preferable that the distance between the coils is approximately the same.

Further, one end of the coil pattern of the conductor layer is electrically connected to another conductor layer, and the other end has a shape having a certain area. The other conductor layer having the area of is formed facing the same position with the polymer layer interposed therebetween to form a capacitor. The area of this capacitor is 10m
It is preferably about m ^{2 to} 2500 mm ² .

Further, the pattern of the conductor layer is such that a part of the resonance circuit or the other part has a complicated shape such as a color pattern, so that it is difficult to realize that the pattern is a resonance circuit. It is possible to further enhance the effect of suppressing forgery and falsification. The present invention will be described in more detail below, including its reader.

(Embodiment) A description will be given below of the present invention with reference to the drawings. The present invention is not limited to the present embodiment, and the frequency of a radio wave used for authenticity determination or machine reading of the present invention can be arbitrarily set depending on the shape of the conductive layer and the thickness of the polymer layer.

FIG. 1 is a view for explaining an embodiment of the present invention. FIG. 1 (a) shows a state in which an optical change element 2 of the present invention is stuck on a valuable printed matter 1. FIG. Here, the optically variable element 2 exhibits various color and pattern changes by changing the illumination and viewing angle, such as a hologram, and is used at first glance to prevent forgery and falsification by color copying and the like. It has an appearance similar to that shown.

FIG. 1B shows an optical change element 2 of the present invention.
FIG. 2 is a diagram for explaining the configuration of FIG. 1, and is a diagram showing a cross section taken along aa ′ of FIG. In this embodiment, the conductor layer 3 is made of aluminum, and the polymer layer 4 is made of polyurethane having a thickness of about 7 μm. 1 (b), a capacitor is formed by the upper and lower conductive layers 3 and the polymer layer 4 between them, and in b ′, the upper and lower conductive layers 3 form a coil-like pattern. ing. Here, the lower conductive layer is shaped so as to fill the gap between the upper conductive layers, and the coil-shaped pattern can be recognized at a glance at the precious printed matter to which the optical variable element of the present invention is attached. It has become difficult. As the adhesive layer 5, a hot-melt resin was used so that the optical change element of the present invention could be stuck to a valuable printed matter by thermocompression bonding. However, the adhesive layer 5 is not particularly limited as long as it is a material capable of sticking the optical change element to a valuable printed matter.

The formation of the coil pattern and the like of the conductor layer 3 was performed by vapor deposition with a mask in close contact with the polymer layer 4, and the other polymer layer and a layer having a conductor layer were bonded together.

The radius of the coil pattern of one conductive layer 3 constituting the optical variable element of the present invention is about 10 mm, the number of turns is 5, the pitch is about 2 mm, and the area of one end of the coil pattern is about 11 mm. ² and the other conductor layer 3 having the same area as the conductor layer 3 and pasting it at the same position in a shape sandwiching the polymer layer 4, the authenticity or machine reading can be performed by radio waves of a frequency of about 30 MHz. It was possible.

FIG. 2 shows an example of the configuration of a reading device for an optically variable element according to the present invention. The CPU 6 controls the timing of transmitting a radio wave having a frequency at which the optical change element of the present invention resonates, and transmits a radio wave from the transmission antenna 9 via the transmission amplifier 8.

The reception is performed by the receiving antenna 10,
The signal is input to the reception control unit 12 via the reception amplifier 11,
A received signal component is output based on a signal from the timing control unit 7. The signal is sent to the CPU via the A / D converter 13.
6 to determine whether the optical change element 2 of the present invention exists or not. It is also possible to take a method of notifying the operator of the determination result with a speaker or a light emitting element connected to the CPU.

[0025]

According to the optical change element and the reading device of the present invention, the color change to iridescent under the illumination of the optical change element attached for the purpose of suppressing forgery by color copy or the like at present. It is possible to provide an optically variable element having such characteristics as to be able to perform true / false discrimination or machine reading by radio waves of a specific frequency.

Further, the present invention is less susceptible to irregularities and wrinkles on the surface of the base material to which the optically variable element is attached, as compared with the conventional optical mechanical reading method of the optically variable element. It is possible to reduce the possibility of occurrence of an error.

Further, in the present invention, since the conductor layer has a complicated pattern shape, it is very difficult to forge and falsify as compared with the conventional optically variable element, and at the same time, the impression of color change under illumination is apparent. Is strong, and it is difficult to realize that a resonance circuit is configured, which is effective in preventing forgery and falsification.

[Brief description of the drawings]

FIG. 1A is a view of an embodiment to which an optical change element of the present invention is attached. (B) is a figure which shows the cross section of aa 'of (a).

FIG. 2 is a configuration diagram of a reading device for an optically variable element according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 valuable printed matter 2 optical change element 3 conductive layer 4 polymer layer 5 adhesive layer 6 CPU 7 timing control section 8 transmission amplifier 9 transmission antenna 10 reception antenna 11 reception amplifier 12 reception control section 13 A / D conversion section

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06K 19/07 G09F 3/00 M G09F 3/00 G06K 19/00 HF term (Reference) 2C005 HA02 HB02 HB10 JA18 JA19 JB08 JB09 KA70 LB19 2H049 AA07 AA12 AA25 AA34 AA55 CA05 CA22 CA28 2K008 AA13 EE04 GG05 5B035 AA15 BA05 BB03 BB11 BC00 CA23

Claims (6)

[Claims] 1. A polymer layer having minute unevenness for diffracting light, and a conductor layer on an uneven surface of the polymer layer,
An optical variable element having at least two layers composed of the polymer layer and the conductor layer, wherein at least a part of the polymer layer and the conductor layer constitute a resonance circuit. Target change element. 2. A polymer layer having minute unevenness for diffracting light, and a conductor layer on an uneven surface of the polymer layer,
An optical variable element having at least two layers composed of the polymer layer and the conductor layer, wherein a capacitor having a capacitance is formed by the two conductor layers and the polymer layer therebetween, and one or more layers are formed. An optical change element, wherein a resonance circuit is formed by forming a coil by a pattern of two conductive layers. 3. Since the optically variable element exhibits changes in optical color and design, it is difficult to realize that a resonance circuit is formed by the polymer layer and the upper and lower conductive layers. The optical change element according to claim 1 or 2, wherein 4. The optically variable element according to claim 1, wherein the optically variable element can determine whether the optically variable element is authentic or not by reading a transmission of a specific frequency wave by resonance. . 5. For authenticity determination or machine reading,
The optical change element according to any one of claims 1 to 4, which is attached to a security or a passport booklet. 6. A reading device for determining authenticity by reading transmission of a radio wave of a specific frequency due to resonance, wherein a CPU controls timing of transmitting a radio wave of a frequency at which an optically variable element resonates, and controls a transmission amplifier. A radio wave is transmitted from the transmitting antenna via the receiving antenna, received by the receiving antenna, input to the receiving control unit via the receiving amplifier, and outputs the received signal component based on the signal from the timing control unit,
Existence of an optical change element that forms a resonance circuit that, when input to the CPU via an A / D conversion unit, causes the polymer layer and the upper and lower conductive layers to resonate with the radio wave of the specific frequency. A reading device for an optically variable element, which determines the presence or absence of an image and determines whether it is true or false.