KR20100106263A

KR20100106263A - Method for controlling light transmission and reflection using particles having electical charge

Info

Publication number: KR20100106263A
Application number: KR1020100083545A
Authority: KR
Inventors: 주재현
Original assignee: 주식회사 나노브릭
Priority date: 2010-08-27
Filing date: 2010-08-27
Publication date: 2010-10-01

Abstract

Disclosed are a light transmission control method, a film, and a display device using particles having charge. The light transmission and reflection control method using the charged particles according to the present invention is characterized in that the charged particles are dispersed in the light transmitting medium, wherein the particles and the medium have at least one electrode between the upper and lower electrodes having light transmission. Located in space-By adjusting the position of the particles by applying an electric field to the particles it is characterized in that the control of the transmittance of light incident on the particles and the wavelength of the light reflected from the particles.

Description

TECHNICAL FOR CONTROLLING LIGHT TRANSMISSION AND REFLECTION USING PARTICLES HAVING ELECTICAL CHARGE}

The present invention relates to a light transmission and reflection control method using a particle having a charge. In more detail, when the microparticles having electric polarization characteristics are dispersed in an insulating medium and applied with an electric field from the outside, the particles are arranged in a constant direction by the interaction between the electrically polarized particles and thus the light transmittance The present invention relates to a light transmission and reflection control method using particles having a charge that can be adjusted and further controlled to have a uniform particle-to-particle spacing.

The light transmission control device is an optical device that functions to transmit or block light emitted from a light source or light incident from the outside.

As a conventional method of controlling light transmittance, an electrochromic method, a suspended particle device (SPD) method, a polymer disperized LC (PLDC) method, a micro-blinds method, and the like have been introduced, but according to the related art, only light transmittance is controlled. There is a limit to the application.

Thus, the present inventor can not only adjust the light transmittance at high speed at low voltage but also control the wavelength of reflected light by applying an electric field in a state in which particles having electric polarization characteristics and charges are dispersed in an insulator, It has come up with a light transmission and reflection control method that can be applied to various fields such as interior and exterior interior products such as smart windows, interior and exterior interior materials, information displays, optical elements, and optical sensors.

It is an object of the present invention to solve all the problems described above.

In addition, the present invention provides an electric field with respect to particles in which a charged particle is dispersed in a light transmitting medium, wherein the particles and medium are present in the space between the upper and lower electrodes having at least one electrode transparent. An object of the present invention is to provide a light transmission and reflection control method using particles having a charge, characterized by controlling the transmittance of light incident on the particle by adjusting the position of the particle, and controlling the wavelength of light reflected from the particle.

In order to achieve the above object, the light transmission and reflection control method using the charged particles according to the present invention, in a state in which the charged particles are dispersed in the light-transmitting medium-the particles and the medium is at least one electrode Located in the space between the upper and lower electrodes having a light transmittance, by adjusting the position of the particles by applying an electric field to the particles to control the transmittance of the light incident on the particles and the wavelength of the light reflected from the particles Characterized in that.

The particles are particles having an electric polarization characteristic, when the particles are dispersed in a medium and an electric field is not applied, the particles are randomly moved to lower the transmittance of light incident due to scattering of the particles, thereby indicating an opaque state. When the particles are dispersed in an insulator medium and an electric field is applied, scattering by the particles is reduced by rotating or moving the particles in the direction of the electric field by electric polarization, thereby increasing the transmittance of incident light and increasing a specific wavelength from the particles. Can be reflected-the particular wavelength can be controlled by adjusting the direction or intensity of the electric field.

The medium may be an insulator.

The wavelength of the light reflected from the particles can be controlled by adjusting the direction or intensity of the electric field as the visible light band.

The wavelength of the light reflected from the particles can be controlled by adjusting the direction or intensity of the electric field as an ultraviolet or infrared band.

An interval between the upper and lower electrodes may be 20 μm or less, and an intensity of a voltage applied to apply the electric field may be 10 V or less.

The refractive index difference between the particles and the medium may be 0.1 or more.

The dielectric constant of the particles may be 5 or more.

The particles may include at least one of an inorganic material and an organic material.

The medium may be in the form of a gel.

The medium in which the particles are dispersed may be encapsulated by the light transmissive medium or dispersed in the light transmissive medium.

Spacing particles larger than the particles may be dispersed in the medium, and the distance between the upper and lower electrodes may be adjusted by using a space occupied by the spacing particles.

The encapsulated medium is encapsulated in a light-transmissive medium, and the spacing particles larger than the particles are mixed with the capsule, and then the distance between the upper and lower electrodes is controlled by using the space occupied by the spacing particles. Can be.

After filling the medium in which the particles and the spacing particles are dispersed between the upper and lower electrodes, at least one of thermal energy and light energy may be applied to bond the spacing particles and the upper and lower electrodes.

The upper and lower electrodes may be flexible substrates.

According to the present invention configured as described above, by applying an electric field in a state in which particles having electrical polarization characteristics and charges are dispersed in the insulator, not only can the light transmittance be controlled at a low speed but also the wavelength of the reflected light can be controlled. Since the present invention can be applied to various fields such as indoor and outdoor interior products such as smart windows, information displays, optical elements, optical sensors, and the like, are achieved.

1 to 5 are diagrams exemplarily illustrating a configuration of controlling light transmittance and adjusting wavelength of reflected light according to an embodiment of the present invention.
6 to 7 are diagrams showing the results of performing the experiment according to an embodiment of the present invention.

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. Like reference numerals in the drawings refer to the same or similar functions throughout the several aspects.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

First, the configuration of particles and media that can be used in the present invention will be described.

Particles according to an embodiment of the present invention may be dispersed in the medium as particles having a negative charge or a positive charge. At this time, the particles may be arranged at a predetermined interval from each other due to mutual repulsive force due to the charge of the same sign. The diameter of the particles may be several nm to several hundred um, but is not necessarily limited thereto. In addition, the medium may be present in a mixture of positively charged particles and negatively charged particles.

Particles according to an embodiment of the present invention, may be configured in the form of a core-shell (core-shell) consisting of different materials, may be composed of a multi-core (multi-core) consisting of different materials It may be composed of a cluster consisting of a plurality of nanoparticles, the charge layer having a charge may be composed of a structure surrounding these particles. Particles in the present invention generally refer to the solute material dispersed in the medium, and are not limited to those listed above, but may exist in various forms such as chain form, plate form, ring form, rod form, disk form, and the like. It may also be present atypical.

More specifically, the particles according to an embodiment of the present invention may be present as metal particles, polymer particles, inorganic particles, semiconductor particles or compounds thereof. For example, the particles according to an embodiment of the present invention may be silicon (Si), titanium (Ti), carbon (C), barium (Ba), strontium (Sr), iron (Fe), nickel (Ni), cobalt (Co), lead (Pb), aluminum (Al), copper (Cu), silver (Ag), gold (Au), tungsten (W), molybdenum (Mo), zinc (Zn), zirconium (Zr), It may be made of an element such as aluminum (Al) or a compound containing them, and may be made of a polymer material such as PS (polystyrene), PE (polyethylene), PP (polypropylene), PVC (polyvinyl chloride), or PET (polyethylen terephthalate). have. In addition, the particles according to an embodiment of the present invention may be configured as a form in which a material having a charge on a particle or a cluster that does not have a charge, for example, the surface is formed by an organic compound having a hydrocarbon group Particles processed (or coated) by organic compounds having processed (or coated) particles, carboxylic acid groups, ester groups, or acyl groups, halogens (F, Cl, Br) , I, etc.) Particles whose surface is processed (coated) by complex compounds containing elements, particles whose surface is processed (coated) by coordination compounds containing amines, thiols, and phosphines For example, the particles may be charged by forming radicals on their surfaces.

In addition, in the present invention, a portion having a lower refractive index than a medium, such as a porous material or a cavity, may be understood as a particle, and a heterogeneous liquid form material which is not mixed with the medium may be understood as a particle. In addition, as the particles of the present invention, quantum dots or fluorescent materials may be used, and quantum dot characteristics or fluorescent characteristics may be mixed in addition to the photonic crystal effect.

In addition, by using a material whose refractive index changes according to an external stimulus (electric field, magnetic field, light, pressure, chemical stimulation, etc.) as a particle, it can be used in combination with the photonic crystal effect according to the change of the refractive index of the particle in addition to the photonic crystal effect due to the arrangement of the particles. .

Meanwhile, according to an embodiment of the present invention, in order to effectively exhibit photonic crystallinity by maintaining a stable colloidal state without precipitation of particles in a medium to be described later, an interfacial potential of the colloidal solution consisting of particles and a medium (electrokinetic) potential value (ie, zeta potential) may be higher than the predetermined value, and the difference in specific gravity of the particle and the medium may be equal to or less than the predetermined value. For example, the absolute value of the interfacial potential of the colloidal solution may be 10 mV or more, and the difference in specific gravity of the particles and the medium may be 5 or less.

Meanwhile, according to an embodiment of the present invention, when the voltage is not applied by increasing the difference between the refractive index of the particle and the medium larger than a preset value, the light blocking effect due to scattering is increased, and the particle is fixed by applying a voltage. In this case, the intensity of the reflected light can be increased. For example, when a medium having a low refractive index is used, particles having a high refractive index may be dispersed, or on the contrary, particles having a low refractive index may be dispersed in a medium having a high refractive index. The absolute value may be greater than or equal to 0.1.

In addition, by using a material whose refractive index changes according to an external stimulus (electric field, magnetic field, light, pressure, chemical stimulus, etc.) as a medium, it can be used in combination with the photonic crystal effect according to the refractive index change of the solution in addition to the photonic crystal effect by the arrangement of particles. .

In addition, as a solution of the present invention, an ionic liquid, which is an ion present in a liquid state in the operating range, may be used to effectively mix and operate a solar cell or a fuel cell.

Meanwhile, according to an exemplary embodiment of the present invention, the particles or the media included in the display device may have an electrical polarization characteristic. The particles or the media may have an external electric field due to an asymmetrical charge distribution of atoms or molecules. When applied, it may include a material that is electrically polarized by any one of electron polarization, ion polarization, interfacial polarization, and rotational polarization.

More specifically, as particles, there is no spontaneous electropolarization such as TiOx, AlOx, or SiOx, but a material in which electrical polarization occurs by an external electric field is used, or PbZrO ₃ , PbTiO ₃ , Pb (Zr, Ti) O ₃ , SrTiO ₃ BaTiO ₃ , It has ferroelectric or superparaelectric characteristics in a specific temperature range such as (Ba, Sr) TiO ₃ , CaTiO ₃ , LiNbO _3, and has a high electric polarization value compared to an external electric field due to spontaneous electric polarization. Substances can be used. In addition, since metals such as gold (Au) and silver (Ag) have very large electric polarization characteristics due to the movement of electrons according to an external electric field, metal nanoparticles can be effectively used in the application of the present invention.

In addition, polarizing media include Trichloroethylene, Carbon Tetrachloride, Di-Iso-Propyl Ether, Toluene, Methyl-t-Bytyl Ether, Xylene, Benzene, DiEthyl Ether, Dichloromethane, 1,2-Dichloroethane, Butyl Acetate, Iso-Propanol, n- Butanol, Tetrahydrofuran, n-Propanol, Chloroform, Ethyl Acetate, 2-Butanone, Dioxane, Acetone, Metanol, Ethanol, Acetonitrile, Acetic Acid, Dimethylformamide, Dimethyl Sulfoxide, Propylene carbonate, N, N-Dimethylformamide, Dimethyl Acetamide, N-Methylpyrrolodone As such, a material having a polarity index higher than 1 may be used.

By using the above-described electric polarization particles or an electric polarization medium, it may be effective to arrange the particles uniformly by mutual attraction due to the electric polarization phenomenon when an external voltage is applied.

Next, according to the present invention will be described with respect to the configuration for adjusting the transmittance of light incident on the particles and the configuration for adjusting the wavelength of the light reflected from the particles.

According to an embodiment of the present invention, when the microparticles having electric polarization characteristics and dispersed with a predetermined charge in an insulating medium and an electric field is applied from the outside, the particles are arranged in a constant direction by the interaction between the electrically polarized particles The light transmittance is adjusted, and further, the spacing between particles is uniformly controlled to adjust the wavelength of the reflected light.

That is, as shown in FIG. 1, according to an embodiment of the present invention, an electric field may be applied from the outside after dispersing fine particles having an electric polarization characteristic and charged with a constant charge in an insulating medium. Here, when the electric field is not applied, an opaque state may appear due to scattering of incident light due to the difference in refractive index between the microparticles and the medium, and when the electric field is applied, when the electric polarization is induced to the microparticles, As the electric field is arranged in the direction of the electric field, a transparent state may appear gradually.When an electric field of a certain intensity is applied, the fine particles are aligned in a certain direction, and the spacing between the particles balances the Coulomb force and the electrophoretic force due to the same charge. It can be adjusted at regular intervals to show reflected light in a specific wavelength range.

Here, the principle of the light transmittance controlled by the electric field will be described in more detail.

First, when no electric field is applied, a plurality of charged particles may be irregularly dispersed in the medium, in which case the transmittance of light to the particles is not particularly controlled. That is, the light incident on the particles may be scattered or reflected by a plurality of particles or media irregularly dispersed in the medium, or may pass through the particles and the medium as they are.

Next, when an electric field is applied, the plurality of particles having charge in the medium can be aligned in a direction parallel to the electric field, thereby allowing the transmittance of light incident on the particles to be controlled. More specifically, when an electric field is applied to the particles according to an embodiment of the present invention, each of the plurality of particles may rotate or move due to the charges of the plurality of particles. Further, according to one embodiment of the present invention, when an electric field is applied, each of the plurality of particles that are polarized so that the plurality of particles can be electropolarized by the electric field and the direction of the polarization is the same as the direction of the electric field is rotated Can be moved. Electrical attraction or repulsive force is generated between the plurality of rotated or moved particles, such that the plurality of particles may be regularly aligned in a direction parallel to the direction of the electric field. Here, when the alignment direction of the particles is parallel to the direction of the incident light, the transmittance of the incident light may be relatively high since the incident light is relatively reflected or scattered by the particles. On the contrary, in the case where the alignment direction of the particles is not parallel to the direction of the incident light and has a predetermined angle, since the incident light is reflected or scattered by the particles 310 and 410, the transmittance of the incident light is relatively high. Can be lowered. Although the particles have been described with respect to particles that are charged with charge and have electrical polarization characteristics, when controlling only the transmittance, the particles are not charged with charge, but they exhibit only electrical polarization characteristics by using a material having a dielectric constant higher than a predetermined dielectric constant. The effect may appear.

In addition, the principle of adjusting the wavelength of the reflected light by the electric field will be described in more detail as follows.

According to an embodiment of the present invention, when an electric field is applied to a particle and a medium in a state in which a plurality of particles having a charge of the same sign are dispersed in the medium, the electric field strength and the intensity of the electric field may be applied to the plurality of particles due to the charge of the particle. An electric force proportional to the amount of charge is applied, and thus, the plurality of particles are electrophoresis and move in a predetermined direction, thereby narrowing the distance between the particles. As the applied voltage increases, the spacing between the particles decreases, so that the electrical repulsive force generated between the plurality of particles having the same charge as each other increases, so that the spacing between the particles does not continue to narrow. The electrophoretic force and the repulsive force due to the same charge between the particles achieve a certain balance, and as a result, the particles dispersed in the medium are arranged at regular distances according to the voltage and reflect light of a specific wavelength (photonic crystal color). Done.

In addition, in the above configuration, when the particles or the medium becomes electropolarized, in addition to the electrophoretic force and the interparticle repulsive force described above, mutual attraction between the electric polarizations may be applied according to an external voltage to help regular particle arrangement. have. In the present invention, the above-described forces are described with respect to the particles dispersed in the solution, but not limited to the forces described in the above examples, gravity due to the mass of the particles, buoyancy due to the specific gravity difference between the particles and the medium, and between the particles and the solution It should be understood that particles are arranged with a certain rule due to various force balances such as frictional force.

When voltage is applied, the particle array may be a one-dimensional photonic crystal with a certain rule only in one axis, a two-dimensional photonic crystal with a certain rule in two axes (area), or a three-dimensional photonic crystal having a regular rule in three axes (space). . For example, the particles may be regularly arranged only in the direction in which the voltage is applied, the particles may be regularly arranged in the vertical direction in which the voltage is applied, or may be regularly arranged in both the vertical and horizontal directions of the applied voltage. .

On the other hand, the particle array in the present invention may have a long range ordering, may have a short range ordering, in particular, by forming a quasi-crystal that is partly disorderly mixed It is also possible to improve the viewing angle dependency. Decision making is an ordered but non-periodic structure that can be seen as an intermediate state between crystal and glass, and has a rather complex Bragg diffraction. Such a decision may be implemented by mixing particles of different sizes, or may form a decision by controlling the particle size distribution (PSD) of particles distributed in a solution. More specifically, it is possible to implement a decision to set the dispersion degree (PSD) of the particles constituting the present invention to be 0.001 to 0.01 to 50 nm or less, which is a variation of reflected light of all wavelengths up to a viewing angle of 50 degrees.

On the other hand, with reference to Figures 1 to 2 will be described with respect to the configuration for adjusting the light transmittance and the wavelength of the reflected light according to an embodiment of the present invention.

As shown in FIG. 1, according to an embodiment of the present invention, an electric field may be applied from the outside after dispersing fine particles having an electric polarization characteristic and charged with a constant charge in an insulating medium. Here, when the electric field is not applied, an opaque state may appear due to scattering of incident light due to the difference in refractive index between the fine particles and the medium.In the case of applying the electric field, the particles are gradually arranged in the direction of the electric field and the light transmittance gradually increases. Can be increased. In the case where a larger electric field is applied, the particles are arranged at a constant distance by the inter-particle coulomb repulsive force with charges, and as a result, the reflected light by the photonic crystal may appear.

Alternatively, as shown in FIG. 2, according to an embodiment of the present invention, an electric field may be applied from the outside after dispersing the fine particles having an electric polarization characteristic and charged with a constant charge in an insulating medium. Here, when the electric field is not applied, the incident light may be scattered due to the difference in refractive index between the microparticles and the medium, and when the electric field is applied, an opaque state may appear. Coulomb repulsive force and electrophoretic force due to external voltage are balanced to show reflected light in a specific wavelength range.In the case of applying an electric field with a predetermined intensity or more, the reflected light wavelength is transmitted to the ultraviolet region while all visible light region is transmitted. A transparent state may appear.

On the other hand, according to another embodiment of the present invention, the electric field can be applied from the outside after dispersing the fine particles charged with a constant charge in a medium having an electric polarization characteristics. Here, the microparticles are indirectly arranged in a predetermined direction by the electric polarization characteristic of the medium, and thus the light transmittance is controlled. Furthermore, the spacing between the particles is uniformly controlled to adjust the wavelength of the reflected light.

3 is a diagram showing a configuration of a film that can control the transmission and reflection of light according to an embodiment of the present invention by way of example. Referring to FIG. 3, the medium in which the microparticles are dispersed may be encapsulated or partitioned in a light transmissive medium, and the medium in which the microparticles are dispersed may be dispersed in the light transmissive medium in the form of droplets to produce a film.

In addition, although not shown, by adding a polymer having a network structure to the medium in which the fine particles are dispersed, it may also be produced in the form of a film by limiting the movement of the fine particles and the medium, or dispersed in a medium having a constant viscosity into a film It can also be manufactured in the form of formation.

In addition, as shown in Figure 4, it can be produced in the form of a film by dispersing the particles (spacer particles) larger than the microparticles in the medium in which the microparticles are dispersed, and by adjusting the spacing between the upper and lower electrodes with the spacer particles. The spacer particles in contact with the upper and lower electrodes may be fixed to the upper and lower electrodes by thermal energy or light energy, and thus the upper and lower electrodes may be manufactured in a film form at regular intervals. Alternatively, the medium in which the microparticles are dispersed is encapsulated using a light-transmitting material, mixed with the capsule and a large particle (spacer particle) having a predetermined size (upper and lower electrode gap), and then filled between the upper and lower electrodes, and the upper and lower electrode gaps are separated by a spacer. The solution controlled by the particles, the light transmittance and the reflectance is adjusted by sealing the capsule (Seal) can easily produce a film form. In particular, when ITO glass is used as the upper and lower electrodes, the unit cost is high, and thus the unit cost can be remarkably reduced when the transparent electrode is coated with a flexible film type substrate by the method described in FIG. 4.

According to one embodiment of the present invention, the spacer particles may be configured using organic particles such as polystyrene, and may be configured using inorganic particles such as silicon oxide. In addition, the liquid in which the particles are dispersed may be applied to the front surface using equipment such as ODF (One Drop Filling) or filled between the upper and lower electrodes by using an air pressure difference, or printed by a method such as gravure offset.

5 is a view showing a configuration that can more effectively control the light transmittance of the present invention by locally applying the electric field to a portion of the upper or lower electrode according to an embodiment of the present invention to adjust the microparticles locally.

That is, the present invention may adjust the light transmittance according to the degree of alignment in the electric field direction, as shown in FIG. 5, the light transmittance may be adjusted by moving the particles to a portion of the electrode.

On the other hand, the light transmittance and reflected light wavelength control device according to the present invention can be used in combination with a solar cell, fuel cell, information display, etc. to increase its utility, in particular, the medium in which the fine particles are dispersed encapsulated in a light transmitting medium In addition, by dispersing in a light-transmissive medium to form a film, its application range can be expanded.

6 is a view showing the results of performing the experiment according to an embodiment of the present invention. For reference, in the experiment of FIG. 6, the inorganic fine particles were dispersed between the glass substrates coated with the ITO electrode, and the transparency was observed by applying an electric field from the outside.

Referring to FIG. 6, when an external voltage is not applied, it is opaque due to scattering of particles in the medium. However, as the external voltage is applied, the transparency gradually increases. As described above, the light transmittance may be dependent on the intensity of the electric field applied, the concentration of the particles, and the dielectric constant (electropolarization) of the particles.

7 is a view showing the results of performing the experiment according to an embodiment of the present invention. For reference, in the experiment of FIG. 7, the inorganic fine particles charged by the charge were dispersed between the glass substrates coated with the ITO electrode, and the transparency and the reflected light were observed by applying an electric field from the outside.

Referring to FIG. 7, when no external voltage is applied, opaque due to scattering of particles in a medium, photonic crystal reflected light having a shorter wavelength appears due to a regular arrangement of particles as an external voltage is applied, and a higher voltage is applied. In the case of application, it is understood that the reflected light becomes transparent because the reflected light moves to the ultraviolet region beyond the visible region. As described above, the light transmittance and the reflected light wavelength may be dependent on the intensity of the applied electric field, the concentration of the particles, and the dielectric constant (electropolarization) of the particles.

In the above invention, when the particles have magnetic properties, the same effect can be obtained with the above-described magnetic field other than the electric field, and the magnetic field and the electric field can be applied simultaneously.

As described above, the present invention has been described by specific embodiments such as specific components and the like. For those skilled in the art to which the present invention pertains, various modifications and variations are possible.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents or equivalents of the claims as well as the claims to be described later will belong to the scope of the present invention. .

Claims

With charged particles dispersed in a light transmissive medium, wherein the particles and the medium are located in the space between the upper and lower electrodes having at least one electrode transmissive, and applying the electric field to the particles The light transmission and reflection control method using a particle having a charge, characterized in that for controlling the transmittance of the light incident on the particle by adjusting the position of the light and the wavelength of the light reflected from the particle.

The method of claim 1,
The particles are particles having an electrical polarization property,
When the particles are dispersed in a medium and an electric field is not applied, the particles are randomly moved to lower the transmittance of light incident on the particles, thereby indicating an opaque state.
When the particles are dispersed in an insulator medium and an electric field is applied, the particles are rotated or moved in accordance with the direction of the electric field by electric polarization, thereby increasing the transmittance of light incident on the particles and reflecting light of a specific wavelength from the particles. The specific wavelength can be controlled by adjusting the direction or intensity of the electric field.

The method of claim 2,
And the medium is an insulator.

The method of claim 1,
The wavelength of light reflected from the particles can be controlled by adjusting the direction or intensity of the electric field as a visible light band, the light transmission and reflection control method using a particle having a charge.

The method of claim 1,
The wavelength of light reflected from the particles can be controlled by adjusting the direction or intensity of the electric field in the ultraviolet or infrared band, light transmission and reflection control method using the particles having a charge.

The method of claim 1,
The distance between the upper and lower electrodes is 20um or less, and the intensity of the voltage applied to apply the electric field is 10V or less, characterized in that the light transmission and reflection control method using a particle having a charge.

The method of claim 1,
And a refractive index difference between the particles and the medium is 0.1 or more.

The method of claim 1,
The light transmittance and reflection control method using a particle having a charge, characterized in that the dielectric constant of the particle is 5 or more.

The method of claim 1,
The particle is light transmission and reflection control method using a particle having a charge, characterized in that it comprises at least one of inorganic and organic.

The method of claim 1,
The medium is a gel (gel), characterized in that the light transmission and reflection control method using a particle having a charge.

The method of claim 1,
And the medium in which the particles are dispersed is encapsulated by the light transmissive medium or dispersed in the light transmissive medium.

The method of claim 1,
Spacing particles larger in size than the particles are dispersed in the medium, and the distance between the upper and lower electrodes is controlled by using the space occupied by the spacing particles to control light transmission and reflection using the charged particles. Way.

The method of claim 1,
The encapsulated medium is encapsulated in a light-transmissive medium, and the spacing particles larger than the particles are mixed together with the capsule, and then the distance between the upper and lower electrodes is controlled by using the space occupied by the spacing particles. Light transmission and reflection control method using a particle having a charge, characterized in that.

The method according to claim 12 or 13,
And filling the medium in which the particles and the spacing particles are dispersed between the upper and lower electrodes, and then applying at least one of thermal energy and light energy to couple the spacing particles and the upper and lower electrodes. Light transmission and reflection control method using the particles having a.

The method of claim 1,
The upper and lower electrodes are a flexible (flexible) substrate, characterized in that the light transmission and reflection control method using a particle having a charge.