KR102670401B1 - Method for changing color using thickness control of photonic glass nano structure - Google Patents

Abstract

The method of changing color by controlling the thickness of the optical glass nanostructure according to a preferred embodiment of the present invention changes the color by controlling the thickness of the optical glass nanostructure, thereby forming a pattern even under the same process by controlling the thickness of the nanostructure layer. and color control is possible, so it can be widely applied to various reflective material technologies.

Description

Method for changing color using thickness control of photonic glass nano structure}

The present invention relates to a method of changing color by controlling the thickness of an optical glass nanostructure, and more specifically, to a method of changing color in an optical glass nanostructure.

This study is related to the research on the development of process technology for implementing eco-mimetic structural colors (No. 2021-11-0613) conducted under the auspices of the National Institute of Ecology and funded by the Ministry of Environment in 2021.

In addition, this research is funded by the Ministry of Education and supported by the National Research Foundation of Korea in 2021, and is sponsored by Yonsei University to develop high-contrast structural color and discoloration surface implementation technology that mimics natural low-reflection and photonic crystal structures (No. 2021-11- 0524).

Reflective material technology has high value as it can secure high contrast ratio and readability like paper and ink outdoors under bright sunlight. While most existing reflective color reproduction technologies consist of a combination of dyes or pigments corresponding to subtractive color and a white reflector, natural color reproduction methods use nanostructured reflectors that reflect specific wavelengths and non-reflected light. It is composed of a combination of absorbers that absorb. Although there have been some attempts to imitate these characteristics of nature, existing technologies have been developed focusing on the photonic crystal structure that can be observed in natural butterfly and opal structures, and the photonic crystal structure is The disadvantage is that its applicability is limited because it has angle-dependent characteristics, in which the color changes depending on the angle. This problem can be solved by applying a light glass structure. Here, the optical glass structure refers to a nanostructure that has a relatively aperiodic arrangement, unlike the photonic crystal structure, and is a structure that can implement angle-independent characteristics. In order for an optical glass structure to have a photonic band gap that reflects specific light, an isotropic three-dimensional arrangement is required, and local self-uniformity must exist. In the case of an optical glass structure, it has different optical properties from a photonic crystal structure due to differences in the arrangement of the nanostructures.

In addition, in the case of a photonic crystal structure, when the thickness of the nanostructure layer is changed, the full width at half maximum of the central reflection wavelength spectrum changes and the color saturation changes, so to change the color, the size and arrangement of the nanoparticles are changed. The formation conditions of the nanostructure, such as the spacing, must be changed.

In the present invention, in the case of optical glass nanostructure, when the thickness of the nanostructure layer is changed, the central wavelength spectrum changes and the chromaticity changes as the multiscattering reflectance changes at the same time, and the thickness of the new glass nanostructure is controlled. A method of color change is presented.

The purpose of the present invention is to provide a method of changing color by controlling the thickness of the optical glass nanostructure, which changes color by controlling the thickness of the optical glass nanostructure.

Other unspecified objects of the present invention can be additionally considered within the scope that can be easily inferred from the following detailed description and its effects.

A method of changing color through thickness control of an optical glass nanostructure according to a preferred embodiment of the present invention to achieve the above object includes forming an absorption layer that absorbs light in a preset band; And forming a nanostructure layer on the absorption layer that reflects light in a preset band from incident light; wherein the nanostructure layer forming step includes adjusting the thickness of the nanostructure layer to reflect the light through the nanostructure layer. This can be done by changing the color by changing the spectrum of light.

Here, the nanostructure layer may be composed of one of amorphous nanoparticles, amorphous hollow nanoparticles, and inverse photonic glass structures.

Here, amorphous nanoparticles and amorphous hollow nanoparticles can form a nanostructure layer through a self-assembly process, and at this time, existing process technologies such as dip coating, bar coating, spray coating, drop casting, spin coating, and cast coating are used. It can be utilized.

Here, the size of the amorphous nanoparticles and the amorphous hollow nanoparticles is designed to be half the wavelength of the desired reflected color, but as the variation in nanoparticle size increases, the angle dependence decreases, but color purity decreases.

Here, amorphous nanoparticles and amorphous hollow nanoparticles may be composed of spherical nanoparticles, triangular nanoparticles, square nanoparticles, or a combination thereof, and the shape of the nanoparticle affects the form factor and color. can change.

Here, the reverse optical glass structure may be a porous nanostructure with pores in the form of nanoparticles, an optical network, a channel-type nanostructure, or an amorphous gyroid structure.

Here, the absorption layer forming step includes forming a selective absorption layer that absorbs light in a preset band; and forming a selective reflection layer that reflects light in a preset band on the selective absorption layer. The nanostructure layer forming step may include forming the nanostructure layer on the selective reflection layer.

Here, the absorption layer forming step includes forming a selective reflection layer that reflects light in a preset band; And forming a selective absorption layer that absorbs light in a preset band on the selective reflection layer. The nanostructure layer forming step may be formed by forming the nanostructure layer on the selective absorption layer.

Here, the nanostructure layer forming step may be performed by forming the nanostructure layer on the absorption layer so that the thickness of the nanostructure layer varies in each preset pixel unit in order to adjust the color in preset pixel units.

According to the color change method by controlling the thickness of the optical glass nanostructure according to a preferred embodiment of the present invention, the color is changed by controlling the thickness of the optical glass nanostructure, thereby creating a pattern even under the same process by controlling the thickness of the nanostructure layer. Because formation and color control are possible, it can be widely applied to various reflective material technologies.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Figure 1 is a flowchart illustrating a method of changing color by controlling the thickness of an optical glass nanostructure according to a preferred embodiment of the present invention.
FIG. 2 is a diagram showing an example of a reflective display element manufactured by the color change method shown in FIG. 1.
Figure 3 is a diagram for explaining the operation of changing color through controlling the thickness of the nanostructure layer according to a preferred embodiment of the present invention.
Figure 4 is a diagram showing an example of an optical glass nanostructure according to a preferred embodiment of the present invention. Figure 4 (a) shows a case where the nanostructure layer is made of amorphous nanoparticles, and Figure 4 (b) shows a nanostructure layer. This shows a case where the structural layer is made of amorphous hollow nanoparticles, and Figure 4 (c) shows a case where the nanostructure layer is made of a reverse optical glass structure.
Figure 5 is a diagram for explaining the operation of adjusting color purity by controlling the absorption of the absorption layer according to a preferred embodiment of the present invention. Figure 5 (a) shows the case where the absorption of the absorption layer is controlled to the first absorption. , and Figure 5(b) shows a case where the absorbance of the absorption layer is controlled to a second absorbance that is different from the first absorbance.
Figure 6 is a diagram for explaining the multilayer configuration of the absorption layer according to a preferred embodiment of the present invention. Figure 6 (a) shows a case where the absorption layer is composed of a selective reflection layer and a selective absorption layer, and Figure 6 (b) shows the absorption layer. This represents a case composed of a selective absorption layer and a selective reflection layer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely intended to ensure that the disclosure of the present invention is complete, and that the present invention is not limited to the embodiments disclosed below and is provided by those skilled in the art It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings that can be commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless clearly specifically defined.

In this specification, terms such as “first” and “second” are used to distinguish one component from another component, and the scope of rights should not be limited by these terms. For example, a first component may be named a second component, and similarly, the second component may also be named a first component.

In this specification, identification codes (e.g., a, b, c, etc.) for each step are used for convenience of explanation. The identification codes do not describe the order of each step, and each step is clearly understood in the context. Unless a specific order is specified, it may occur differently from the specified order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the opposite order.

In this specification, expressions such as “have,” “may have,” “includes,” or “may include” indicate the presence of the corresponding feature (e.g., a numerical value, function, operation, or component such as a part). indicates, does not rule out the presence of additional features.

Additionally, the term '~unit' used in this specification refers to software or hardware components such as FPGA (field-programmable gate array) or ASIC, and the '~unit' performs certain roles. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuits, data structures, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'.

Hereinafter, with reference to the attached drawings, a preferred embodiment of the method for changing color through thickness control of optical glass nanostructure according to the present invention will be described in detail.

The method of changing color by controlling the thickness of the optical glass nanostructure according to the present invention can change the color by controlling the thickness of the optical glass nanostructure.

In other words, the color change method through thickness control of the optical glass nanostructure according to the present invention applies the optical glass nanostructure, and when the thickness of the nanostructure layer is changed, the central wavelength spectrum changes and the multiple scattering reflectance changes simultaneously. You can control color.

In addition, the color change method through thickness control of the optical glass nanostructure according to the present invention is differentiated from the existing Fabry-Perot interferometer-based technology and thin film-based technology that change color depending on the thickness. The invention can be expanded to include ultraviolet and infrared reflection technologies in addition to the visible light range.

In more detail, the color change method through thickness control of the optical glass nanostructure according to the present invention was designed to propose a new color change process by applying reflective materials observed in natural bird feathers, and is designed to provide color purity (color purity). Unlike existing technologies that utilize multi-layered photonic crystal nanostructures to increase saturation, this is about a material form and technology that can change color by changing the thickness of the optical glass nanostructure layer. By using optical glass nanostructures, it is possible to secure technology that can change colors from dark blue to white depending on the thickness of the internal nanostructure layer while realizing angle-independent colors.

First, a method of changing color through thickness control of an optical glass nanostructure according to a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 4.

Figure 1 is a flowchart for explaining a color change method through thickness control of an optical glass nanostructure according to a preferred embodiment of the present invention, and Figure 2 is a flow chart of a reflective display element manufactured by the color change method shown in Figure 1. It is a drawing showing an example, and FIG. 3 is a drawing to explain the operation of changing color through controlling the thickness of the nanostructure layer according to a preferred embodiment of the present invention, and FIG. 4 is a drawing showing an optical glass according to a preferred embodiment of the present invention. A drawing showing an example of a nanostructure. Figure 4 (a) shows a case where the nanostructure layer is made of amorphous nanoparticles, and Figure 4 (b) shows a case where the nanostructure layer is made of amorphous hollow nanoparticles. , Figure 4 (c) shows a case where the nanostructure layer is made of a reverse optical glass structure.

Referring to Figure 1, the color change method (hereinafter referred to as 'color change method') through thickness control of the optical glass nanostructure according to the present invention can form an absorption layer that absorbs light in a preset band (S110). .

For example, as shown in FIG. 2, an absorption layer that absorbs light can be formed.

Here, the absorption layer can increase color clarity by absorbing the remaining light transmitted to the bottom in addition to the light selectively reflected from the nanostructure layer.

Then, the color change method can form a nanostructure layer that reflects light in a preset band from incident light on the absorption layer (S120).

For example, as shown in FIG. 2, a nanostructure layer containing a plurality of nanoparticles can be formed on the absorption layer.

Here, the preset band in which the nanostructure layer reflects light may be set to a different wavelength band than the preset band in which the absorption layer absorbs light.

Here, the nanostructure layer forming step (S120) may be performed by adjusting the thickness of the nanostructure layer to change the color by changing the spectrum of light reflected through the nanostructure layer. That is, as shown in Figure 3, as the thickness of the nanostructure layer increases, the color of the structural color expressed in the nanostructure layer changes. Of course, in the present invention, in addition to the thickness of the nanostructure layer, the color can be additionally adjusted by the size of the nanoparticles, the shape of the nanoparticles, the pitch of the nanoparticles, and the uniformity of the gaps.

At this time, the nanostructure layer forming step (S120) may be performed by forming a nanostructure layer on the absorption layer so that the thickness of the nanostructure layer varies in preset pixel units in order to adjust the color in preset pixel units.

In addition, the nanostructure layer according to the present invention includes amorphous nanoparticles as shown in (a) of Figure 4, amorphous hollow nanoparticles as shown in (b) of Figure 4, and (c) of Figure 4. It can be made of one of the reverse optical glass structures as described above.

At this time, the method of changing color by controlling the thickness of the optical glass nanostructure according to the present invention can be implemented by following a bottom-up process through the self-assembly process of nanoparticles. For example, a reflective nanostructure can be produced through a self-assembly process of nanoparticles such as SiO ₂ or polystyrene with a size of approximately 150 nm to 400 nm that can reflect in the visible light range. In addition, the reflective nanostructure produced through the self-assembly process is not only in the form of simple packed nanoparticles, but also hollow nanoparticles or nanoparticles through the atomic layer deposition (ALD) process and the coating process of heterogeneous materials. It can be implemented with a reverse optical glass structure, etc. In the case of hollow nanoparticles or reverse optical glass structures, if a material with a relatively high refractive index is deposited compared to the basic nanoparticle, it can have higher saturation and reflectance at more long wavelengths.

Accordingly, the method of changing color by controlling the thickness of the optical glass nanostructure according to the present invention can change the color from black to dark blue to white by increasing the thickness of the internal nanostructure layer.

Next, the operation of controlling the absorption degree of the absorption layer according to a preferred embodiment of the present invention will be described with reference to FIG. 5.

Figure 5 is a diagram for explaining the operation of adjusting color purity by controlling the absorption of the absorption layer according to a preferred embodiment of the present invention. Figure 5 (a) shows the case where the absorption of the absorption layer is controlled to the first absorption. , and Figure 5(b) shows a case where the absorbance of the absorption layer is controlled to a second absorbance that is different from the first absorbance.

The method of changing color by controlling the thickness of the optical glass nanostructure according to the present invention can control color not only according to the thickness of the nanostructure layer but also according to the absorbency of the absorption layer. Even if it has the same nanostructure layer, if the absorbance layer has a high absorbance in the visible light range, a vivid structural color is expressed. However, if the absorbance layer has a low absorbance in the visible light range, a structural color with low saturation appears, so basically, it is clear even in low light. Although it is advantageous to increase the absorption of the absorption layer to display color, it is also possible to change the absorption of the absorption layer to suit the application case.

That is, in order to control color, the present invention can primarily change the spectrum of reflected light by adjusting the thickness of the nanostructure layer, and depending on the absorption of the absorption layer, other than the light primarily reflected from the nanostructure layer Since the degree to which the remaining light is reflected changes, color purity can be controlled by controlling the absorption degree of the absorption layer, as shown in FIG. 5.

Next, the multilayer structure of the absorption layer according to a preferred embodiment of the present invention will be described with reference to FIG. 6.

Figure 6 is a diagram for explaining the multilayer configuration of the absorption layer according to a preferred embodiment of the present invention. Figure 6 (a) shows a case where the absorption layer is composed of a selective reflection layer and a selective absorption layer, and Figure 6 (b) shows the absorption layer. This represents a case composed of a selective absorption layer and a selective reflection layer.

Each of the nanostructure layer that reflects light and the absorption layer that absorbs light according to the present invention may be made of a multi-layer structure.

For example, the absorption layer shown in FIG. 2 may be replaced with a selective reflection layer and a selective absorption layer as shown in (a) of FIG. 6, and may be replaced with a selective absorption layer and a selective reflection layer as shown in (b) of FIG. 6. You can. That is, the present invention may be composed of one reflective layer (nanostructure layer) and one absorption layer, or may be composed of a multilayer structure such as a plurality of reflection layers (including a nanostructure layer) and a plurality of absorption layers. Figure 6 shows an example of a multilayer structure according to the present invention.

That is, the absorption layer forming step (S110) includes forming a selective absorption layer that absorbs light in a preset band and forming a selective reflection layer that reflects light in a preset band on the selective absorption layer, forming the absorption layer as shown in FIG. 6. As shown in (a), it can be formed in a multi-layer configuration. In this case, the nanostructure layer forming step (S120) may consist of forming the nanostructure layer on the selective reflection layer.

In addition, the absorption layer forming step (S110) includes forming a selective reflection layer that reflects light in a preset band and forming a selective absorption layer that absorbs light in a preset band on the selective reflection layer, forming the absorption layer as shown in FIG. 6. As shown in (b), it can be formed in a multi-layer configuration. In this case, the nanostructure layer forming step (S120) may consist of forming a nanostructure layer on the selective absorption layer.

For example, if the absorption layer does not have a wide absorption in the visible light range and absorbs a specific wavelength band more selectively, it is possible to control the light that cannot be controlled by the reflector to produce more colorful colors. This can be implemented through a multi-layer configuration of a selective absorption layer that selectively absorbs light in a specific wavelength band and a selective reflection layer that selectively reflects light in a specific wavelength band. For example, magenta color can be expressed by reflecting blue and red through a dual configuration of a selective reflection layer without a selective absorption layer. When a selective absorption layer is used, red is absorbed through the selective absorption layer, and blue and green are reflected, resulting in a cyan color. In this way, the combination of a selective absorption layer and a selective reflection layer is a configuration method that can compensate for the disadvantage that it is physically difficult to produce angle-independent red color through optical glass nanostructures.

Even though all the components constituting the embodiments of the present invention described above are described as being combined or operated in combination, the present invention is not necessarily limited to these embodiments. That is, as long as it is within the scope of the purpose of the present invention, all of the components may be operated by selectively combining one or more of them. In addition, although all of the components may be implemented as a single independent hardware, a program module in which some or all of the components are selectively combined to perform some or all of the combined functions in one or more pieces of hardware. It may also be implemented as a computer program with . In addition, such a computer program can be stored in a computer readable media such as USB memory, CD disk, flash memory, etc. and read and executed by a computer, thereby implementing embodiments of the present invention. Recording media for computer programs may include magnetic recording media, optical recording media, and the like.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications, changes, and substitutions can be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the attached drawings are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments and the attached drawings. . The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

Claims (5)

Forming an absorption layer that absorbs light in a preset band; and
Forming a nanostructure layer on the absorption layer that reflects light in a preset band from incident light;
Includes,
The nanostructure layer forming step is,
The color is changed by changing the spectrum of light reflected through the nanostructure layer by changing the multiple scattering reflectance by adjusting the thickness of the nanostructure layer above the absorption layer,
The nanostructure layer is made of amorphous nanoparticles or an amorphous hollow nanoparticle structure,
The amorphous nanoparticle or amorphous hollow nanoparticle structure is formed through a self-assembly process of nanoparticles,
Color change method by controlling the thickness of optical glass nanostructures. delete In paragraph 1:
The absorption layer forming step is,
Forming a selective absorption layer that absorbs light in a preset band; and
forming a selective reflection layer that reflects light in a preset band on the selective absorption layer;
Includes,
The nanostructure layer forming step is,
Consisting of forming the nanostructure layer on the selective reflection layer,
Color change method by controlling the thickness of optical glass nanostructures. In paragraph 1:
The absorption layer forming step is,
Forming a selective reflective layer that reflects light in a preset band; and
forming a selective absorption layer that absorbs light in a preset band on the selective reflection layer;
Includes,
The nanostructure layer forming step is,
Consisting of forming the nanostructure layer on the selective absorption layer,
Color change method by controlling the thickness of optical glass nanostructures. In paragraph 1:
The nanostructure layer forming step is,
In order to adjust the color in preset pixel units, the nanostructure layer is formed on the absorption layer so that the thickness of the nanostructure layer varies in preset pixel units,
Color change method by controlling the thickness of optical glass nanostructures.

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