KR102141744B1 - Reflective-transmissive type film for preventing counterfeit - Google Patents

Abstract

A semi-transmissive anti-counterfeiting film is provided on a base, the base, and is formed on the diffractive optical element layer having a diffraction pattern for realizing an image for authenticity determination and along the profile of the diffraction pattern on the diffractive optical element layer. , A light transmittance control thin film that can partially reflect and transmit incident incident light. As a result, the semi-transmissive anti-counterfeiting film can reflect and transmit incident light to implement diffraction images on both sides of the film.

Description

Semi-transmissive anti-counterfeiting film{REFLECTIVE-TRANSMISSIVE TYPE FILM FOR PREVENTING COUNTERFEIT}

The present invention relates to a semi-transmissive anti-counterfeiting film. More specifically, it relates to a semi-transmissive anti-counterfeiting film capable of realizing an image for authenticity determination using a pattern for authenticity determination.

Counterfeiting of expensive items such as software, CDs, DVDs, securities, liquor, and drugs is a major social problem. Since most of the forged and produced goods have low quality, the counterfeiting acts of the company have suffered enormous damages, such as losing the trust gained through many efforts. In order to solve the counterfeit problem, companies are making efforts to prevent the distribution of counterfeit products by giving the product the technology that makes counterfeiting difficult or the technology to judge genuine and counterfeit products.

A hologram is a typical example given to the product to prevent forgery. In order to design a hologram, a hologram is designed using an interference shape between the object light and the reference light reflected from the object as object light and reference light irradiated to the object using a beam splitter.

The hologram is a medium in which an interference fringe reproducing a stereoscopic image is recorded, and is made using the principle of holography. As a result, the hologram may embody a specific image by irradiating the interference fringe at a specific angle with the reproduced light having the same frequency, wavelength, and phase as the reference light. In addition, the color or shape of the reflected light may change depending on the viewing angle.

However, since there is a limit to information that can be recorded as a hologram, there is a problem in that it is difficult to manufacture a sophisticated hologram. Furthermore, there is a limitation that the reproduced light must have the same phase, wavelength and frequency as the reference light. Such a problem has become serious as the hologram is started to be copied by a hologram copying mechanism such as a digital scanner, so that the copying is easy. In addition, the hologram pattern forming the hologram is regular as it has a certain shape.

Accordingly, a technique for recording information on a forgery-preventing film by a nanoimprinting method has been recently introduced. The nano-imprinting method is a method of forming a diffraction pattern on a forgery-preventing film using a mold having a nano-pattern, and since it can record a lot of information at a low cost, it has been widely used in recent years.

In general, the anti-counterfeiting film is irradiated in a straight direction so that the laser transmitted therein is diffracted in a constant direction. Accordingly, the anti-counterfeiting pattern is realized by the light diffracted by the diffraction pattern after the laser irradiated in the straight direction to the anti-counterfeiting film passes through the anti-counterfeiting film.

However, the transmissive anti-counterfeiting film has a problem that it is difficult to apply to products of various shapes including 3D bulk. In addition, since the transmissive anti-counterfeiting film itself needs to secure light transmittance as a whole, there is a limit to the material forming the transmissive anti-counterfeiting film.

Accordingly, one object of the present invention is to provide a semi-transmissive anti-counterfeiting film that overcomes the limitation of light transmittance of the transmissive anti-counterfeiting film.

In order to achieve the above object, a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention is provided on a base, the base, and a diffractive optical element layer having a diffraction pattern for realizing an image for authenticity determination and the It is formed along the profile of the diffraction pattern on the diffractive optical element layer, and includes a light transmittance control thin film that can partially reflect and transmit incident incident light.

In one embodiment of the present invention, the light transmittance adjustment thin film has a light transmittance within a range of 40 to 60% with respect to light having a wavelength in the visible light region, and displays an image for authenticity toward both the upper and lower parts of the base. Can be implemented,

In one embodiment of the present invention, the light transmittance control thin film may include at least one selected from a group of light reflective metals made of gold, silver, and aluminum.

In one embodiment of the present invention, at least one information pattern unit for storing information in the upper or lower portion of the base may be further provided.

Here, the light transmittance control thin film may have a thickness adjusted to have a maximum transmittance for incident light having a wavelength of 500 to 600 nm.

Here, the information pattern portion may be provided on the lower surface of the base, and may include a QR pattern layer including QR information.

Meanwhile, the light transmittance control thin film may have a thickness adjusted to have a transmittance of less than 50% for incident light having a wavelength of 500 to 600 nm.

In this case, the information pattern portion may include a hologram pattern layer provided on the light transmittance control thin film and using incident light having a wavelength of 500 to 600 nm as reproducing light. In addition, a transparent bonding layer interposed between the light transmittance control thin film and the hologram pattern layer, and a transparent bonding layer that mutually bonds the light transmittance control thin film and the hologram pattern layer may be further provided.

On the other hand, the light transmittance control thin film has a light transmittance within a range of 40 to 60% with respect to light having a wavelength in the visible light region, and the information pattern portion is a hologram pattern layer formed on the top of the base and a QR formed on the bottom of the base It may include a pattern layer.

In one embodiment of the present invention, a flattening layer provided on the light-transmitting control thin film and a bonding layer interposed between the light-transmitting control thin film and the flattening layer to bond the flattening layer and the light-transmitting control thin film to each other This may be additionally provided.

According to the semi-transmissive anti-counterfeiting film according to embodiments of the present invention, by providing a diffractive optical element that can replace the hologram, it is possible to implement a nano-sized fine pattern. Thus, a complex image can be easily implemented, and a diffraction pattern having an irregularly random shape or size can be implemented. In addition, an image having a plurality of colors can be easily implemented using light having various wavelengths and phases.

On the other hand, unlike the conventional transmissive anti-counterfeiting film, it is possible to implement a forgery determination image toward both the upper and lower surfaces of the base. Therefore, the authenticity of the object can be easily determined regardless of the degree of light transmission of the object.

Furthermore, as a separate hologram pattern layer or QR pattern layer is additionally provided, forgery determination may be performed more accurately, or additional information for tracking and managing products may be stored.

Meanwhile, as the planarization layer and the bonding layer are additionally provided, the thickness of the anti-transmissive anti-counterfeiting film can be effectively adjusted according to the change in the thickness of the bonding layer.

1 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.
FIG. 2 is a graph illustrating light transmittance according to the thickness of the light transmittance control thin film of FIG. 1.
3 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to another embodiment of the present invention.
4 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to another embodiment of the present invention.
5 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to another embodiment of the present invention.
6 is a flowchart illustrating a method of manufacturing a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.
7A is a photograph of a hologram taken as a comparative example.
7B is a photograph of a semi-transmissive anti-counterfeiting film having the diffractive optical element of the present invention.
8 is a cross-sectional view for explaining a phase difference of light passing through a diffraction pattern included in a transmissive anti-counterfeiting film.
9 is a cross-sectional view for describing a phase difference of light transmitted through a diffraction pattern included in a reflective anti-counterfeiting film.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be variously modified and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, and it should be understood that all modifications, equivalents, and substitutes included in the spirit and scope of the present invention are included. In the accompanying drawings, the size and amount of objects are enlarged or reduced than actual values for clarity of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises" or "includes" are intended to designate the existence of features, steps, functions, components, or combinations thereof described in the specification, other features or steps, functions, components Or it should be understood that the possibility of the presence or addition of those in combination is not excluded in advance.

On the other hand, unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person skilled in the art to which the present invention pertains. Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

1 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.

1, the semi-transmissive anti-counterfeiting film 100 according to an embodiment of the present invention includes a base 110, a diffractive optical element layer 130 and a light transmittance control thin film 150. In the semi-transmissive anti-counterfeiting film 100, the LED light or laser light incident from the outside is partially reflected and partially transmitted from the light transmittance control thin film 150. Thus, a specific image may be implemented toward both the upper and lower portions of the base 110. In this case, the specific image may correspond to an image for authenticity determination. For example, the specific image may include a trademark or log of the manufacturing company of the subject in need of authenticity determination.

The base 110 may be made of a polymer material. For example, the base 110 may be made of PET material. In addition, by forming a double-sided adhesive tape (not shown) on the lower surface of the base 110, it may be provided to attach the base 110 to a specific product.

A diffractive optical element layer 130 is provided on the upper surface of the base 110.

A diffraction pattern is formed on the top surface of the diffractive optical element layer 130. The diffraction pattern may have various sizes and shapes. For example, the shape of the diffraction pattern may include a stripe shape, a mosaic shape, a pyramid shape, and the like. The diffraction pattern may be defined as a pattern for using diffraction characteristics for realizing a specific image through a design algorithm including a Fourier transform and a Fourier inverse transform process.

The diffraction pattern may be formed through a hot embossing process, a nano-imprinting process, or a transfer printing process.

The light transmittance control thin film 150 is formed along the profile of the diffraction pattern. Thus, the light transmittance control thin film 150 may be formed to have a uniform thickness. The light transmittance adjustment thin film 150 may reflect a part of the light incident on the outside to realize a specific image on the upper part, while transmit a part of the external light to transmit a specific image on the lower part. Therefore, the semi-transmissive anti-counterfeiting film 100 including the light transmittance adjusting thin film 150 may be used regardless of the light transmittance of the object for authenticity determination.

The light transmittance adjustment thin film 150 may include a light reflective metal material such as gold, silver, and aluminum.

The light transmittance of the light transmittance control thin film 150 may be adjusted according to its thickness. For example, the light transmittance control thin film 150 may have a thickness of 1 nm to 4 nm.

Due to the step difference in the light transmittance control thin film 150 formed in the diffraction pattern, the phase of light reflected from the surface of the light transmittance control thin film 150 is changed. As a result, a specific diffraction image can be realized by mutually interfering with the reflected light.

FIG. 2 is a graph illustrating light transmittance according to the thickness of the light transmittance control thin film of FIG. 1.

Referring to FIG. 2, when the light transmittance control thin film 150 is made of gold, light transmittance according to a wavelength for each thickness is illustrated.

When the light transmittance control thin film 150 is made of gold, the light transmittance control thin film 150 may have a thickness of 2 to 4 nm. Thus, the light transmittance control thin film in the visible light region may have a light transmittance of 40 to 60%.

In particular, in the external light of 550 nm, it is estimated that the light transmittance control thin film having a thickness of 3 nm has a light transmittance of about 50%.

According to an embodiment of the present invention, unlike the conventional transmissive anti-counterfeiting film, the semi-transmissive anti-counterfeiting film 100 may be attached to an object having various shapes including three-dimensional bulk. That is, in the case of the existing transmissive anti-counterfeiting film, by implementing the image for authenticity determination using transmitted light through which the light passes through the product, it is difficult to use the transmissive anti-counterfeiting film when the object is opaque.

On the other hand, the semi-transmissive anti-counterfeiting film 100 according to an embodiment of the present invention may have an advantage that can be used regardless of various shapes or materials of the object to which it is attached.

In one embodiment of the present invention, the anti-transmissive anti-counterfeiting film 100 further includes a flattening layer 190 and a bonding layer 170.

The planarization layer 190 is provided on the light transmission control thin film 150. The planarization layer 190 removes the step formed in the diffraction pattern to planarize the entire upper surface.

The planarization layer 190 is provided to cover the light transmittance control thin film 150. Thus, the planarization layer 190 may protect the light transmittance control thin film 150 and the diffractive optical element layer 130 from external impact. Furthermore, by covering the diffractive optical element layer 130 as a whole, the planarization layer 190 can suppress duplication of the semi-transmissive anti-counterfeiting film 100.

The planarization layer 190 may be formed of any one of light-transmitting resins made of PVC, PMMA, PET, PT, acrylic, and epoxy.

The bonding layer 170 is interposed between the planarization layer and the light transmission control thin film. The bonding layer 170 bonds the planarization layer 190 and the light transmission control thin film 150 to each other. The bonding layer 170 may be formed through a laminating process. The bonding layer 170 may be, for example, cooled to mutually bond the planarization layer 190 and the light transmission control thin film 150.

Examples of the material forming the bonding layer 170,

3 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.

Referring to FIG. 3, the semi-transmissive anti-counterfeiting film 100 according to an embodiment of the present invention includes a base 110, a diffractive optical element layer 130, a light transmittance control thin film 150 and an information pattern unit . The information pattern unit may include, for example, a hologram pattern layer 180.

The hologram pattern layer 180 is provided on the light transmittance control thin film 150. The hologram pattern layer 180 uses reflected light from which some of the incident light incident to the outside is reflected from the light transmittance control thin film 150. Thus, the semi-transmissive anti-counterfeiting film 100 may implement a hologram on its top.

Meanwhile, the transmitted light through which some of the incident light incident to the outside passes through the light transmittance control thin film 150 is a diffraction pattern formed on the diffraction optical element layer 130 and the light transmittance control thin film 150 and the diffraction optical element A specific image may be implemented by a difference in refractive index between the layers 130. Accordingly, the anti-transmissive anti-counterfeiting film 100 may determine whether the counterfeit is forged using the specific image.

As a result, the reflective transmissive anti-counterfeiting film 100 may implement a hologram on its upper part and simultaneously implement a specific image on its lower part.

Here, the light transmittance adjustment thin film 150 may have a thickness adjusted to have a transmittance of less than 50% for incident light having a wavelength of 500 to 600 nm. Accordingly, as the light transmittance control thin film 150 has a relatively high light reflectivity with respect to the incident light, light required for the implementation of the hologram may reach the hologram pattern layer 180 in a larger amount.

4 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.

4, the semi-transmissive anti-counterfeiting film 100 according to an embodiment of the present invention includes a base 110, a diffractive optical element layer 130, a light transmittance adjustment thin film 150 and an information pattern unit . The information pattern unit may include, for example, a QR pattern layer 120.

The QR pattern layer 120 is located under the base 110. The QR pattern layer 120 uses transmitted light through which the light transmittance control thin film 150 is transmitted through a part of incident light incident to the outside. As a result, the semi-transmissive anti-counterfeiting film 100 enables the information stored in the QR pattern layer 120 located under the bonding layer 170 to be recognized. That is, by scanning the QR pattern layer 120, a QR scanner (not shown) may facilitate tracking and management of an object using the information, for example, a production lot.

As a result, the anti-counterfeiting anti-counterfeiting film 100 may implement a specific image on its lower portion and read QR information formed on its lower portion.

Here, the light transmittance control thin film 150 may have a thickness adjusted to have a maximum transmittance for incident light having a wavelength of 500 to 600 nm. Accordingly, as the light transmittance control thin film 150 has a relatively high light transmittance with respect to the incident light, it is possible to reach the QR pattern layer 120 in a larger amount. Therefore, the QR scanner can effectively recognize the information stored in the QR pattern layer 120.

5 is a cross-sectional view illustrating a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.

5, the semi-transmissive anti-counterfeiting film 100 according to an embodiment of the present invention includes a base 110, a diffractive optical element layer 130, a light transmittance control thin film 150 and an information pattern unit . The information pattern unit may include, for example, a hologram pattern layer 180 and a QR pattern layer 120.

The hologram pattern layer 180 is provided on the light transmittance control thin film 150. The hologram pattern layer 180 uses reflected light from which some of the incident light incident to the outside is reflected from the light transmittance control thin film 150. Thus, the semi-transmissive anti-counterfeiting film 100 may implement a hologram on its top.

Meanwhile, the QR pattern layer 120 is positioned under the base 110. The QR pattern layer 120 uses transmitted light through which the light transmittance control thin film 150 is transmitted through a part of incident light incident to the outside. Thus, the semi-transmissive anti-counterfeiting film 100 is configured to recognize information stored in the QR pattern layer 120 located under the base 110. That is, by scanning the QR pattern layer 120, the QR scanner may facilitate tracking and management of the object using the information, for example, a production lot.

6 is a flowchart illustrating a method of manufacturing a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention.

1 and 6, in the method of manufacturing a semi-transmissive anti-counterfeiting film according to an embodiment of the present invention, first, the diffractive optical element layer 130 is formed on one surface of the base 110 (S110) ). The diffractive optical element layer 130 having the diffraction pattern may be formed through a hot embossing process, a nano-imprinting process, or a transfer printing process.

Subsequently, along with the profile of the diffraction pattern, a light transmittance control thin film 150 for reflecting and transmitting light incident on the outside is formed (S130 ). The light transmittance control thin film 150 may be formed through an atomic layer deposition process, a sputtering process, or an ion beam process.

The light transmittance adjustment thin film 150 may be formed using a light reflective metal material such as gold, silver, and aluminum. The light transmittance control thin film 150 may be formed to have a thickness of 1 nm to 4 nm.

Meanwhile, an information pattern layer such as the QR pattern layer 120 is formed on the other surface of the base 110. Alternatively, an information pattern layer such as a holographic spam pattern layer 180 (see FIG. 5) is formed on a separate base.

Thereafter, the information pattern layer is bonded onto the light transmittance control thin film 150. Accordingly, a semi-transmissive anti-counterfeiting film 100 including the information pattern layer and the light transmittance control thin film 150 is manufactured.

7A is a photograph of a hologram taken as a comparative example. 7B is a photograph of a semi-transmissive anti-counterfeiting film having the diffractive optical element of the present invention.

7A and 7B, the hologram has a structure in which an interference fringe is formed with a periodicity repeatedly, whereas a transflective anti-counterfeiting film having the diffractive optical element of the present invention has a structure in which an irregular pattern is formed in multiple layers. can confirm.

8 is a cross-sectional view for explaining a phase difference of light passing through a diffraction pattern included in a transmissive anti-counterfeiting film.

Referring to FIG. 8, when a height difference (h) between diffraction patterns exists and the diffraction pattern has n _p (=1+p),

The phase difference (φ ₁ -φ ₂ ) at different positions is as shown in Equation 1 below.

Here, k ₀ (=2π/λ), p is a difference value greater than 1, which is the refractive index of air, and h is the height difference of the diffraction pattern.

By using the phase difference, an image for authenticity determination can be implemented from a diffraction pattern.

9 is a cross-sectional view for describing a phase difference of light transmitted through a diffraction pattern included in a reflective anti-counterfeiting film.

Referring to FIG. 9, when a height difference (h) between diffraction patterns exists and the diffraction pattern has n _p (=1+p),

The phase difference (φ ₁ -φ ₂ ) at different positions is as shown in Equation 1 below.

Here, k ₀ (=2π/λ), p is a difference value greater than 1, which is the refractive index of air, and h is the height difference of the diffraction pattern.

By using the phase difference, an image for authenticity determination can be implemented from a diffraction pattern.

The present invention has been illustrated and described with reference to preferred embodiments, as described above, but is not limited to the above embodiments and is varied by those skilled in the art to which the present invention pertains without departing from the spirit of the present invention. Modifications and modifications are possible. Such modifications and variations should be considered within the scope of the invention and appended claims.

100: semi-transmissive anti-counterfeiting film 110: base
130: diffractive optical element layer 150: light transmittance control thin film
170: bonding layer 190: planarization layer

Claims (11)

Base;
A diffractive optical element layer provided on the base and having a diffraction pattern for realizing an image for authenticity determination;
A light transmittance control thin film formed along the profile of the diffraction pattern on the diffractive optical element layer and partially reflecting and transmitting incident incident light; And
It includes at least one information pattern unit for storing information in the upper or lower portion of the base,
The information pattern portion is provided on the lower surface of the base, and includes a QR pattern layer including QR information and a hologram pattern layer provided on the light transmittance control thin film and using incident light having a wavelength of 500 to 600 nm as reproducing light. Semi-transmissive anti-counterfeiting film. The method of claim 1, wherein the light transmittance control thin film has a light transmittance within a range of 40 to 60% with respect to light having a wavelength in the visible light region, and can implement an image for authenticity determination toward both the upper and lower parts of the base. Semi-transmissive anti-counterfeiting film, characterized in that. The anti-transmissive anti-counterfeiting film according to claim 1, wherein the light transmittance control thin film comprises at least one selected from a group of light reflective metals formed by gold, silver, and aluminum. delete The anti-transmissive anti-counterfeiting film according to claim 1, wherein the light transmittance adjusting thin film has a thickness adjusted to have a maximum transmittance with respect to incident light having a wavelength of 500 to 600 nm. delete The anti-transmissive anti-counterfeiting film according to claim 1, wherein the light transmittance control thin film has a thickness adjusted to have a transmittance of less than 50% for incident light having a wavelength of 500 to 600 nm. delete The anti-transmissive anti-counterfeiting method according to claim 1, further comprising a transparent bonding layer interposed between the light transmission control thin film and the hologram pattern layer, and further bonding the light transmission control thin film and the hologram pattern layer to each other. film. delete delete

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