KR20120058726A - Security device including self-aligned icon array and method for fabricating the same - Google Patents

Abstract

PURPOSE: A security device including self-aligned icon array and method for fabricating are provided to obtain composite video as original version and have anti-counterfeiting function. CONSTITUTION: A security device including self-aligned icon arrays(131) comprise base substrate, a lens array layer, and an icon array layer. The lens array layer is formed in upper part of the base substrate. In the lens array layer, a plurality of lenses is arranged. The icon array layer is formed in lower part of the base substrate. The icon array layer includes dielectric particles. A part of dielectric particles in the icon array layer is captured on the icon focal layer. A plurality of focal points is formed in partial lens which accomplishes the lens array layer. The dielectric particles are captured at every focal point in order to accomplish the icon array.

Description

Security device including self-aligned icon array and method for fabricating the same}

The present invention relates to a security device including a self-aligned icon array and a method of manufacturing the same, and more particularly, to provide a composite image by a moire magnification effect having an icon array and a lens array provided thereon. A security device relates to a security device and a method of manufacturing the same, wherein the two arrays are accurately aligned with each other and can simplify the manufacturing process.

In order to prevent forgery of banknotes, credit cards, ID cards, product packaging and other security documents, various security technologies have been proposed and used.

Holograms are typical of such security technologies, but security thread technology, which is formed on the surface of security documents such as banknotes or embedded and embedded therein, serves as an anti-counterfeiting function, is also actively applied.

On the security hidden line, a fine icon array is formed on one side of the base substrate, which is difficult to visually identify, and on the other side, the fine lenses formed to correspond to the fine icons form an array to enlarge the moire when viewed from the side of the fine lens array. It is common to apply a security device configured to observe a composite image enlarged by a phenomenon. Figure 1 is a cross-sectional view of the structure of such a security device applied to the security hidden line.

Referring to the cross-sectional view of the security device 100 shown in FIG. 1 in more detail, the lens array layer 120 is formed on the upper surface of the base substrate 110 made of a transparent polymer material such as polyethylene terephtalate (PET). do.

An icon array layer 130 is formed on the bottom surface of the base substrate 110, and an icon array recess is formed in the icon array layer 130 and filled with ink. As a result, the icon array layer 130 is formed in the icon array layer 130. 131 is formed.

In addition, a protective layer 140 for protecting the icon array 131 and an adhesive layer 150 for adhering the security device 100 to a security document or the like may be formed below the icon array layer 130. It is not.

2 is a perspective view of a portion of the security device 200. As schematically shown in FIG. 2, the icons 220 are formed in a regular arrangement in the icon array layer 130, and the upper portions are spaced apart from each other so that the focus is formed on the icons 220. In the lens array 210 is also arranged regularly.

In this case, when each icon and the lens are aligned to have a one-to-one correspondence with each other, an enlarged composite image is observed by overlapping two array layers on the lens side. This phenomenon is referred to as moiré magnification. Since such optical phenomenon is well known, detailed description thereof will be omitted.

An example of the manufacturing method of the security device according to the prior art is shown in FIG.

First, the lens array layer 120 is formed on the base substrate 110 (S310), the lens array layer 120 is well known in the art, such as UV embossing, thermal reflow (thermal reflow). It can be formed using known methods.

Next, an icon array layer 130 is formed below the base substrate 110 (S320), and an icon array recess is formed to form an icon array at a position corresponding to the lens array already formed (S330). . Various methods may be used to form the recesses in the icon array layer 130. However, the method may be a UV embossing method for transferring an icon array formed on a previously prepared original plate to the icon array layer 130 formed of a UV curable resin. It is common to form a seth.

At this time, the size of the recess formed by the UV embossing method is the same as the size of the icon array formed on the original plate by the conventional patterning method using the exposure and etching process, dozens of the size of the pattern that can be implemented by the conventional exposure method It is difficult to form a pattern of micrometer (µm) or less. Therefore, in the case of the security hidden line icon array has a size of approximately 5㎛ ~ 30㎛.

In operation S340, the icon array 131 is formed by filling various materials such as ink, dye, metal, and magnetic material in the formed icon array recess, and the protective layer 140 and / or the adhesive layer 150 are formed thereon. (S350). Of course, step S350 is not essential, and the lens array layer 120 may proceed after the icon array layer 130 is formed.

On the other hand, if the lens array and the icon array are not aligned correctly, it is important that the two arrays are aligned correctly, since undesirable factors such as reduced magnification factor of the synthesized image or rotation of the synthesized image may occur.

However, according to the conventional manufacturing method, there is a problem that it is virtually impossible to accurately align with the lens array already formed when forming the recess by the ultraviolet embossing method, so that a certain alignment error always occurs. The same applies to the case where the lens array is formed after the icon array is formed.

In addition, since the security device having an alignment error does not appear as the designed composite image, there is a problem that can not perform the security and forgery prevention function as originally intended.

In addition, since the size of each icon of the icon array is limited to the size that can be realized by exposure and it is difficult to form a nanometer (nm) scale icon, there is a problem that forgery can be relatively easily performed.

In addition, since the process of forming the icon array layer, recess formation, ink filling, etc. to form the icon array, there is a problem that the overall process is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and its main object is to provide a method for manufacturing a security device in which a lens array and an icon array can be accurately aligned.

In addition, it is an object of the present invention to provide a security device capable of precisely aligning the lens array and the icon array to provide a composite image as designed, and to perform the security and forgery prevention function as originally intended.

In addition, it is another object to provide a security device that is more difficult to forgery, by being able to form a nanometer scale icon.

In addition, another object of the present invention is to provide a simpler manufacturing method compared to the manufacturing method of the conventional security device.

Security device including a self-aligned icon array according to the present invention for achieving the above object, the base substrate; A lens array layer formed on the base substrate and having a plurality of lenses arranged thereon; And an icon array layer formed under the base substrate and including dielectric particles, wherein at least some of the dielectric particles included in the icon array layer are positioned at a focal position of at least some lenses of the lens array layer. It is characterized by being captured to form an icon array.

Here, a plurality of focal positions are formed in at least some lenses constituting the lens array layer, and the dielectric particles may be captured at each of the plurality of focal positions to form an icon array, wherein the plurality of focal positions are the lens array layer. It may be located on the same plane parallel to or on different planes parallel to the lens array layer.

Preferably, the base substrate may include a transparent polymer material such as polyethylene terephthalate, and at least one of the lens array layer and the icon array layer may be UV curable such as acrylated urethane. It may include a resin, the dielectric particles may be colored dielectric particles.

Further, at least some of the lenses of the lens array may be spherical lenses, aspherical lenses, diffractive lenses, or green lenses, and a protective layer and / or an adhesive layer may be further formed below the icon array layer.

Meanwhile, a method of manufacturing a security device including a self-aligning icon array according to the present invention includes: forming a lens array layer having a plurality of lenses arranged on an upper portion of a base substrate; Forming an icon array layer including dielectric particles under the base substrate; Irradiating a laser beam from the lens array layer side such that at least some of the dielectric particles are captured at a focal position of at least some lenses of the lens array layer to form an icon array.

The irradiating of the laser beam may include irradiating a plurality of focal positions to at least some lenses of the lens array layer, and for this purpose, a plurality of laser beams having different incidence directions are incident to the laser beam. The beam may be irradiated, or the laser beam may be irradiated such that a plurality of laser beams having different degrees of collimation are incident.

Preferably, the icon array layer includes an ultraviolet curable resin, and after the step of irradiating the laser beam may further comprise the step of curing the icon array layer by irradiating the icon array layer with ultraviolet rays.

In addition, the forming of the lens array layer may include forming a lens array using a thermal reflow or ultraviolet embossing method, wherein at least a portion of the lens array may be a spherical lens, an aspheric lens, a diffractive lens, or a green. It may be formed by a lens.

Furthermore, the method may further include forming a protective layer and / or an adhesive layer under the icon array layer.

According to the security device according to the present invention, since the icon can be formed exactly at the focal position of each lens constituting the lens array, the lens array and the icon array are not aligned correctly in the security devices according to the conventional manufacturing method. Undesirable problems such as reduction of magnification factor or rotation of the synthesized image may be solved.

In addition, according to the security device according to the present invention, since it is possible to obtain a composite image as designed, it is possible to perform the security and forgery prevention function as originally intended.

In addition, according to the security device according to the present invention, it is possible to form an icon array including icons of the nanometer scale, it is possible to perform a more effective anti-counterfeiting function.

In addition, according to the manufacturing method of the security device according to the present invention, since the icon array recess forming process and the ink filling process can be omitted, the process can be simplified to reduce the manufacturing cost.

1 is a cross-sectional view of a security device according to the prior art.
2 is a perspective view of a security device according to the prior art;
3 is a flow chart showing a method of manufacturing a security device according to the prior art.
4 is a conceptual diagram illustrating a light trapping phenomenon using an optical forceps.
5 is a cross-sectional view of a security device according to an embodiment of the present invention.
6 is a flowchart illustrating a method of manufacturing a security device according to an embodiment of the present invention.
7 is a conceptual diagram illustrating a method of forming an icon array according to another exemplary embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

SUMMARY OF THE INVENTION The present invention aims to form an icon in a self-aligned manner at a focal position of a lens by using an optical trap phenomenon using an optical tweezer.

The light trapping phenomenon using optical forceps refers to a phenomenon in which dielectric particles having a size of several nanometers to several microns are moved by using concentrated light such as a laser. Shown.

As shown in FIG. 4, when the laser beam 410 is concentrated through the lens 420 at the focus position 440, a so-called gradient force acts in the direction of the focus position 440. This tilting force causes the surrounding dielectric particles 430 to move to the focal position. Using this phenomenon, since it is possible to move by using a laser beam without directly contacting microscopic biomolecules or dielectric particles, optical trapping using optical forceps has been actively studied in the field of biology or physics.

The present invention has applied this phenomenon to the manufacture of a security device, Figure 5 is a cross-sectional view showing a security device accurately formed icons in a self-aligned manner in the focal position of the lens according to an embodiment of the present invention.

5, the lens array layer 520 is formed on the top surface of the base substrate 510, the icon array layer 530 is formed on the bottom surface of the base substrate 510, and the icon array layer ( The dielectric particles 540 that make up the icon are included in the 530. As the base substrate 510, it is preferable to use a transparent polymer material such as polyethylene terephthalate, polyester, polypropylene, polyethylene, polyvinylidene chloride or the like to transmit light, but is not limited thereto. It is preferable to use a flexible substrate in the form of a film made of a polymer material rather than the substrate.

The lens array layer 520 formed on the upper surface of the base substrate 510 may be made of various materials depending on the formation method thereof. However, it is preferable to use an ultraviolet curable material such as acrylate urethane.

The icon array layer 530 formed on the bottom surface of the base substrate 510 is also preferably made of an ultraviolet curable material such as acrylate urethane. The dielectric particles 540 mixed with the icon array layer 530 are provided with optical forceps. It will not specifically limit, if it is a dielectric material which can light-trap by. However, in order to achieve smooth light capture, it is preferable to use the dielectric particles 540 having a size in the range of about several nanometers to 10 micrometers, and to implement the conventional patterning method in order to improve the forgery prevention function. Particular preference is given to forming at difficult nanometer scales.

In addition, the shape of the particles may be variously selected in consideration of an enlarged synthetic image such as a star shape or a tube shape. In addition, by using the colored dielectric particles 540, the same effects as in conventional ink filling can be obtained.

The dielectric particles 540 are initially distributed irregularly in the icon array layer 530, but when the laser beam 550 is irradiated through the lens, the inclined force acts toward the focal position 560. Distributing dielectric particles 540 move toward focal position 560.

Therefore, the security device according to the embodiment of the present invention manufactured in this manner is characterized in that the dielectric particles 540 constituting the icon are positioned at the correct focus position 560 of each lens as shown in FIG. Since the lens array is accurately aligned in a self-aligning manner, as well as a separate alignment process as in the prior art is not necessary, alignment errors do not occur, and forgery is more difficult when forming an icon of a nanometer scale. .

In addition, although not shown in FIG. 5, a protective layer and / or an adhesive layer may be added under the icon array layer 530. Of course, a gradient index lens (GRIN lens) can be used. In particular, when the green lens is used, since the lens array layer 520 is flattened, the range of utilization thereof may be widened.

A method of manufacturing a security device according to an embodiment of the present invention will be described in detail with reference to FIG. 6 as follows.

First, the lens array layer 520 is formed on the base substrate 510, which may be formed of a transparent polymer material such as polyethylene terephthalate (S610), and the lens array layer 520 may be UV embossed or thermally. It can be formed using a known microlens forming method such as thermal reflow, and it is particularly preferable to use an ultraviolet embossing method which is easy to mass produce. More specifically, when the ultraviolet curable resin such as acrylate urethane is applied on the base substrate 510 and irradiated with ultraviolet light while applying pressure to the negatively formed negatively formed lens shape thereon, the lens shape formed on the original is transferred. As a result, the lens array layer 520 is formed.

Next, the icon array layer 530 containing the dielectric particles 540 is applied to the lower portion of the base substrate 510 (S620), wherein the icon array layer 530 is an ultraviolet curable resin such as acrylate urethane. Preference is given to using.

In operation S630, the array of icons is formed by irradiating the laser beam 550 on the lens array side to capture the dielectric particles 540 at the focal position 560. In this case, since the focal position 560 is to be formed in the icon array layer 530, the thickness of the base substrate 510 should be determined in consideration of the focal length of the lens.

Irradiation of the laser beam 550 may proceed sequentially for each lens, but it may be preferable in terms of production efficiency that the laser beam 550 irradiated at one time is irradiated to an area including a plurality of lenses. In addition, a plurality of laser beams 550 may be used instead of a single laser beam 550, and the wavelength, intensity, irradiation time, etc. of the laser beam 550 may include optical characteristics of the lens array, types of dielectric particles 540, and the like. It will be apparent to those skilled in the art that the size, the properties of the icon array layer 530, etc. can be appropriately adjusted.

Once the dielectric particles 540 are accurately captured at the focal position 560 in step S630, the icon array layer 530 is cured. If the UV curable resin is used, the icon array layer 530 is simply irradiated with ultraviolet rays. It can be cured.

In addition, although not shown in FIG. 6, the method may further include adding a protective layer and / or an adhesive layer under the icon array layer 530.

In the above-described preferred embodiment of the present invention, the case where the laser beam 550 is incident perpendicularly to the lens array layer 520 has been described as an example, but is not necessarily limited thereto. In particular, when the laser beam 550 is incident perpendicularly to the lens array layer 520, since only a single focal point is formed in one lens, a method for configuring one icon with one dielectric particle 540 is provided. Although it is appropriate, there are limited methods for forming various types of icons such as letters, symbols, and numbers.

Therefore, in another embodiment of the present invention, a plurality of focal points are formed under one lens by adjusting the method of irradiating the laser beam 550 so that the plurality of dielectric particles 540 may be gathered to form one icon. 7 is a conceptual diagram illustrating a method of forming an icon array according to another exemplary embodiment of the present invention, in which a plurality of focal points are formed under one lens by adjusting an irradiation method of a laser beam 550, and dielectric particles are captured at each focal point. Demonstrate techniques to help

Referring to FIG. 7A, a first dielectric particle (1) is formed at a first focal position 761 formed by a first laser beam 751 incident perpendicularly to the lens array layer 721 as a first optical forceps. 741 is captured. On the other hand, when the second laser beam 752 is incident at a predetermined angle from the axis perpendicular to the lens array layer 721, that is, in a different incident direction from the first laser beam 751, the second laser beam 752 ) Acts as a second optical forceps to form a second focus position 762 at a position spaced apart from the first focus position 761, whereby the second dielectric particles 742 are captured at the second focus position. .

According to this principle, since a plurality of optical trap sites can be formed under one lens by irradiating a plurality of laser beams in different preset incidence directions, they are included in the icon array layer 731. The plurality of dielectric particles may be used to form icons of various shapes such as numbers, letters, and symbols.

The embodiment of FIG. 7A illustrates a case in which the lens is made of a spherical lens as an example. In this case, as shown in the drawing, the second focus position 762 is perpendicular to the first focus position 761. Formed on top, this also provides the effect of providing a wider viewing angle. However, the dielectric particles constituting the icon array may be located on the same plane in the vertical direction, that is, on the same plane parallel to the lens array layer, which may be used using an aspherical lens as shown in FIG. This can be achieved by using a diverging laser beam as shown in Fig. 7 (c).

Referring to Figure 7 (b) in detail, the lens array layer 723 according to this embodiment is composed of an aspherical lens. Accordingly, the second laser beam 754 is incident in a direction different from the first laser beam 754 incident to the lens array layer 723 at a predetermined inclination angle with the axis perpendicular to the lens array layer 723. It is possible to adjust the second focal position 764 formed by) to be coplanar with the first focal position 763 formed by the first laser beam 753 in the vertical direction.

FIG. 7C illustrates an embodiment in which the second focusing position 766 and the first focusing position 765 are formed on the same plane in the vertical direction while using a spherical lens. Compared to the case where the beam incident on the lens is accurately collimated so that it is parallel to the incident optical axis, the focusing position is formed further downward when a diverging beam is used as the incident beam, and the converging beam is formed by the incident beam. In the case of using a converging beam, the focal position is further formed. The embodiment of FIG. 7C uses the diverging beam as the second laser beam by using this principle.

That is, even when the same spherical lens is used, when the divergent beam is used as the second laser beam 756 incident on the lens array layer 725 to have a predetermined tilt angle with the vertical axis, the second focal point in FIG. The second focus position 766 is formed downward in the vertical direction relative to the position 762, so that the first focus position 765 and the second focus position 766 are located on the same plane in the vertical direction. It becomes possible.

According to the exemplary embodiments of the present invention described with reference to FIG. 7, various icons composed of a plurality of dielectric particles may be formed under each lens constituting the lens array, as well as horizontal and horizontal shapes of the respective dielectric particles. It is possible to exert various optical effects by freely adjusting the vertical position.

In this case, as a method of irradiating a plurality of laser beams, it is also possible to irradiate one laser beam sequentially while changing the incident angle, and also to inject a plurality of laser beams having various incident angles and / or collimation degrees at one time. It will be apparent to one skilled in the art that it is also possible.

Technical ideas described in the embodiments of the present invention as described above may be implemented independently, or may be implemented in combination with each other. In addition, the present invention has been described through the embodiments described in the drawings and the detailed description of the invention, which is merely exemplary, and those skilled in the art to which the present invention pertains have various modifications and equivalent other embodiments. It is possible. Accordingly, the technical scope of the present invention should be determined by the appended claims.

100, 200: Security device
110, 510, 711, 713, 715: base substrate
120, 520, 721, 723, 725: lens array layer
130, 530, 731, 733, 735: icon array layer
131: icon array 140: protective layer
150: adhesive layer 210: lens array
220: icon
410, 550: laser beam 420: lens
430, 540, 741 to 746: dielectric particles 440 and 560: focus position
751, 753, 755: first laser beam 752, 754, 756: second laser beam
761, 763, 765: first focus position 762, 764, 766: second focus position

Claims (19)

Base substrate;
A lens array layer formed on the base substrate and having a plurality of lenses arranged thereon; And
An icon array layer formed under the base substrate and including dielectric particles,
And at least some of the dielectric particles included in the icon array layer are captured at a focal position of at least some lenses of the lens array layer to form an icon array.
The method of claim 1,
A plurality of focal positions are formed in at least some lenses constituting the lens array layer,
And the dielectric particles are captured at each of the plurality of focal positions to form an icon array.
The method of claim 2,
And the plurality of focal positions are on the same plane in a vertical direction.
The method of claim 2,
And the plurality of focal positions are on different planes in a vertical direction.
5. The method according to any one of claims 1 to 4,
And the base substrate comprises a transparent polymeric material.
5. The method according to any one of claims 1 to 4,
And at least one of the lens array layer and the icon array layer comprises an ultraviolet curable resin.
5. The method according to any one of claims 1 to 4,
And at least some of the lenses in the lens array are spherical lenses, aspherical lenses, diffractive lenses, or green lenses.
5. The method according to any one of claims 1 to 4,
And at least one of a protective layer and an adhesive layer under the icon array layer.
5. The method according to any one of claims 1 to 4,
And the dielectric particles are colored particles.
Forming a lens array layer having a plurality of lenses arranged on the base substrate;
Forming an icon array layer including dielectric particles under the base substrate;
Irradiating a laser beam from the lens array layer side such that at least some of the dielectric particles are captured at a focal position of at least some lenses of the lens array layer to form an icon array;
Method of manufacturing a security device comprising a self-aligned icon array comprising a.
The method of claim 10,
Irradiating the laser beam,
And arranging a plurality of focal positions in at least some of the lenses forming the lens array layer.
The method of claim 11,
Irradiating the laser beam,
A method of manufacturing a security device including an array of self-aligning icons, characterized by irradiating a laser beam such that a plurality of laser beams having different incidence directions are incident.
The method of claim 11,
Irradiating the laser beam,
A method of manufacturing a security device including an array of self-aligned icons, characterized by irradiating a laser beam such that a plurality of laser beams having different collimation degrees are incident.
14. The method according to any one of claims 10 to 13,
And hardening the icon array layer after the step of irradiating the laser beam.
The method of claim 14,
The icon array layer includes an ultraviolet curable resin,
Hardening the icon array layer comprises irradiating ultraviolet rays to the icon array layer.
14. The method according to any one of claims 10 to 13,
Forming the lens array layer comprises forming a lens array using a thermal reflow or ultraviolet embossing method.
14. The method according to any one of claims 10 to 13,
The forming of the lens array layer includes forming a lens array such that at least some of the lenses of the lens array are spherical lenses, aspherical lenses, diffractive lenses, or green lenses. Method of manufacturing a security device.
14. The method according to any one of claims 10 to 13,
And forming at least one of a protective layer and an adhesive layer under the icon array layer.
14. The method according to any one of claims 10 to 13,
The dielectric particle is a method of manufacturing a security device comprising a self-aligning icon array, characterized in that the colored particles.

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