KR20070099838A - An optical reflecting plate, a method for preparing the same, and a reflective display device comprising the same - Google Patents

Abstract

An optical reflecting plate, a manufacturing method thereof, and a reflective screen display device including the same are provided to express various colors of reflective light and simplify processes by patterning different kinds of nano particle crystals on a substrate. An optical reflecting plate comprises a substrate(22), first and second colloid crystal patterns(24,27) which are alternatively arranged on the substrate, and a third colloid crystal pattern(28) formed on the first and second colloid crystal patterns. The first to third colloid crystal patterns output reflective light having different wavelength.

Description

Optical reflective plate, manufacturing method thereof, and reflective display device including the same {AN OPTICAL REFLECTING PLATE, A METHOD FOR PREPARING THE SAME, AND A REFLECTIVE DISPLAY DEVICE COMPRISING THE SAME}

1A is a schematic diagram showing a display mechanism of a general transmissive liquid crystal display.

1B is a schematic diagram showing a display mechanism of a typical reflective liquid crystal display device.

2 is a process chart showing the manufacturing method of the optical reflector of the present invention.

3 is a block diagram showing an example of a reflective screen display device including an optical reflector of the present invention.

Figure 4 is a photograph showing a color pixel of the optical reflector of the present invention.

Figure 5 is a process chart showing a process for producing a silicon rubber mold with a negative pattern is formed in accordance with Example 1 of the present invention.

6 is an optical micrograph (200 times) of the first colloidal crystal pattern prepared according to Example 1 of the present invention.

Figure 7 is an optical micrograph (200 times) of the first colloidal crystal pattern, and the second colloidal crystal pattern prepared according to Example 1 of the present invention.

FIG. 8 is an optical microscope photograph (200 times) of an optical reflector in which first to third colloidal crystal patterns are formed according to Example 1 of the present invention. FIG.

 9 is an optical micrograph (200 times) of the first colloidal crystal pattern prepared according to Example 2 of the present invention.

10 is an optical micrograph (200 times) of the first colloidal crystal pattern prepared according to Example 3 of the present invention.

Figure 11 a is an optical micrograph showing the color of the first colloidal crystal pattern prepared according to Example 1 of the present invention.

11 b is an optical micrograph showing the color of the first colloidal crystal pattern prepared according to Example 2 of the present invention.

11 c is an optical micrograph showing the color of the first colloidal crystal pattern prepared according to Example 3 of the present invention.

12 is a wavelength graph of reflected light measured for the first colloidal crystal pattern prepared according to Examples 1 to 3 of the present invention.

[Industrial use]

The present invention relates to an optical reflector, a manufacturing method thereof, and a reflective screen display device including the same, and more particularly, a reflective plate for a reflective screen display device that reflects light of a specific wavelength, and the reflective plate using a flexible etching method. It relates to a method of manufacturing a, and a reflective screen display device comprising the reflective plate.

[Private Technology]

In general, a liquid crystal display device applies a voltage corresponding to image information to a liquid crystal positioned between two electrodes, so that the physical state of the liquid crystal is changed to a position between horizontal and vertical and a position between horizontal and vertical according to the applied voltage. An image is implemented by performing an optical shutter function that blocks or passes light applied from a source.

The liquid crystal display device includes a transmissive liquid crystal display device in which a backlight assembly is disposed on a rear surface of the liquid crystal panel so that light from the backlight passes through the light guide plate and is applied to the liquid crystal panel. There is a reflective liquid crystal display device in which the disposed reflecting plate diffuses the light back to the liquid crystal panel.

1A is a schematic diagram showing a display mechanism of a transmissive liquid crystal display, and FIG. 1B is a schematic diagram showing a display mechanism of a reflective liquid crystal display. 1A and 1B, A represents an antiglare layer, P represents a polarizing plate, LCD represents a liquid crystal display panel, and R represents a back reflector.

Among these, the reflective liquid crystal display device has various advantages over the transmissive liquid crystal display device. As a separate device for providing light is not disposed or is additionally disposed, the reflective liquid crystal display device is configured to reflect external light, thereby reducing power consumption. There is a merit that greatly reduces, and the device is lightweight and miniaturized, and in recent years, it has been attempted to be employed in notebook PC (Personal cumputer), PDA (Personal Didital Assistant) or personal portable communication device.

On the other hand, such a reflective liquid crystal display device can be used where there is no light by including a front light assembly. As described above, in the reflective LCD having the front light assembly, the amount of light emitted from the front light varies according to the viewing angle of the light guide plate of the front light assembly.

It is an object of the present invention to provide an optical reflector comprising a colloidal crystal pattern that emits red, green, and blue reflected light, respectively.

Another object of the present invention is to provide a method for manufacturing the optical reflector using the flexible etching method.

Still another object of the present invention is to provide a reflective screen display device including the optical reflector as a rear reflector.

The present invention, in order to achieve the above object, i) a substrate, ii) a first colloidal crystal pattern and a second colloidal crystal pattern are formed alternately arranged on the substrate; And iii) a third colloidal crystal pattern formed on the first and second colloidal crystal patterns, wherein each of the first to third colloidal crystal patterns emits reflected light having different wavelengths. .

The present invention also relates to a method of forming a colloidal crystal pattern comprising: a) forming a first colloidal crystal pattern on a substrate, b) forming a second colloidal crystal pattern between the first colloidal crystal pattern, and c) the first colloidal crystal pattern; And forming a third colloidal crystal pattern on the second colloidal crystal pattern, wherein each of the first to third colloidal crystal patterns emits reflected light having different wavelengths.

The present invention also provides a reflective screen display device including the optical reflector.

Hereinafter, the present invention will be described in more detail.

When colloidal crystals are formed using nanoparticles having a size and refractive index corresponding to a specific wavelength of visible light, only a specific wavelength is reflected among the wavelengths of visible light. Based on this principle, if the optical reflector is manufactured by adjusting the size of nanoparticles, the color of red, green, and blue (RGB) constituting the display device can be reflected up to 100% in theory, which is a highly effective reflective screen. The display element can be configured.

The optical reflector of the present invention comprises: i) a substrate, ii) a first colloidal crystal pattern and a second colloidal crystal pattern formed alternately on the substrate; And iii) a third colloidal crystal pattern formed on the first and second colloidal crystal patterns.

In this case, the first to third colloidal crystal patterns emit reflected light of different wavelengths, respectively, and it is preferable to emit reflected light of red, green, and blue irrespective of the order, and 630 ± 20nm (red) and 550 ± 20nm. (Green) and reflected light of 460 ± 20 nm (blue) are more preferable.

The wavelength of the reflected light of the colloidal crystal pattern is determined according to the refractive index and the size of the nanoparticles, and may be defined according to Equation 1 below.

[Calculation 1]

λ = 2 dn _eff

In Formula 1, λ is the wavelength of the reflected light, n _eff is the effective refractive index of the material forming the nanoparticles, d is the interlayer average distance with respect to the <111> crystal direction of the nanoparticle crystals defined by the following formula (2).

[Calculation 2]

In Formula 2, D is the average particle diameter of the nanoparticles.

The nanoparticles included in the first to third colloidal crystal patterns may each independently have an effective refractive index of 1.45 to 2.4. When the refractive index of the nanoparticles is 1.45 or more, reflected light of sufficient intensity can be obtained, and it is preferable to have an effective refractive index of 2.4 or less from the viewpoint of economy.

More preferably, the nanoparticles include any one selected from the group consisting of polystyrene, polymethylmethacrylate, zinc oxide, silica, titania, and cadmium selenide (CdSe).

The colloidal crystal patterns each include nanoparticles having a dispersion of 5% or less in size and arranged in a regular pattern. The size of the nanoparticles may be determined according to Formula 1 from the effective refractive index of the material itself and the wavelength of the reflected light to be represented.

The effective refractive index n _eff of the nanoparticles can be defined according to the following formula (3).

[Calculation 3]

In Formula 3, f _m is the volume fraction of the medium (air) surrounding the particles, which is defined as 0.26 in the present invention, n _m is the refractive index of air 1.000293, n _p is the refractive index of the particles, in the present invention polystyrene Are defined as 1.59 to 1.6 for silica, 1.45 for silica, 1.8 to 2.0 for amorphous titania, 2.4 to 2.6 for anatase titania, 2.9 for rutile titania, and 2.0 for zinc oxide (ZnO).

The refractive index value is a positive value for obtaining an effective refractive index for the nanoparticles of the present invention, and the size of the nanoparticles suitable for a desired wavelength from the refractive index of each material may be determined from Equation 3.

For example, when silica nanoparticles are used, the effective refractive index of silica is 1.35, so the average of 290 ± 10 nm for emitting red reflected light, 255 ± 10 nm for emitting green reflected light, and 210 ± 10 nm for emitting blue reflected light It is preferable to have a particle diameter.

Preferably, the first to third colloidal crystal patterns are formed in a plurality of linear patterns repeatedly formed. The smaller the width of each pattern is, the better the width is, and preferably, the resolution is 200 μm or less. In consideration of this, the thickness is preferably 20 µm or more.

In the optical reflector of the present invention, it is preferable that the first and second colloidal crystal patterns are formed in an alternating linear arrangement. In addition, the third colloidal crystal pattern may be formed in a direction not parallel to the first and second colloidal crystal patterns, and cross or perpendicular to the first and second colloidal crystal patterns diagonally. More preferably, they are formed to intersect in the direction.

The optical reflector may be used as a back reflector of the reflective screen display device, and the reflective display device including the reflector may operate a screen without a back light, thereby saving energy, and the first through The third colloidal crystal pattern serves as a color filter, and thus the sharpness is improved even without a separate color filter.

The optical reflector of the present invention is manufactured by forming a colloidal crystal pattern on a substrate by using a soft etching method, more preferably, a) forming a first colloidal crystal pattern on the substrate, b) the first colloidal crystal Forming a second colloidal crystal pattern between the patterns, and c) forming a third colloidal crystal pattern on the first colloidal crystal pattern and the second colloidal crystal pattern, wherein the first to third colloids are formed. The crystal pattern may be manufactured according to the method of manufacturing an optical reflector that each emits reflected light of different wavelengths.

In the forming of each colloidal crystal pattern, it is preferable to use a soft etching method. Flexible etching is a technique for forming a regular pattern on a specific substrate using a flexible material having a pattern of several tens of nanometers to several tens of micrometers. In the present invention, a crystallized pattern may be formed on a substrate using MIMIC (micromolding in capillary), which is one kind of the soft etching method.

2 is a process chart showing a method of manufacturing an optical reflector using a flexible etching method.

Referring to FIG. 2, the forming of the first colloidal crystal pattern in the method of manufacturing an optical reflector of the present invention may include: i) covering the flexible mold 21 having the intaglio pattern on the substrate 22, ii) the Injecting the nanoparticle monodisperse solution 23 into the space of the intaglio pattern formed between the stretchable mold and the substrate and self-assembling to form a first colloidal crystal pattern 24, and iii) the stretchable mold 21. )).

In this case, the stretchable mold preferably includes at least one selected from the group consisting of silicone rubber, polyurethane, polymethylmethacrylate, and polystyrene, and the first colloidal crystal pattern to be formed on the substrate is engraved. It is preferable to be molded in a shape, and the intaglio pattern is preferably a linear pattern is repeated regularly.

The material of the substrate is not particularly limited, but is preferably any one selected from the group consisting of glass, silicone, polyurethane, polymethyl methacrylate, polycarbonate, and polyethylene terephthalate.

In the nanoparticle monodisperse solution used to form the first colloidal crystal pattern, nanoparticles forming the unit structure of the colloidal crystal pattern are preferably dispersed in a colloidal state in water, alcohol, or an organic solvent. Examples of the nanoparticles are the same as described above, it is preferable to use one or more selected from the group consisting of a hydrocarbon solvent such as hexane, heptane, octane, or an aromatic such as toluene.

The nanoparticle monodisperse solution preferably contains at least 5% by weight of nanoparticles, more preferably at least 7% by weight of nanoparticles in order to ensure self-assembly of the nanoparticles, and prevents crystallization during injection. In order to improve the injection characteristics, it is preferable to include 20% by weight or less of the nanoparticles.

The nanoparticles contained in the monodisperse solution preferably include any one selected from the group consisting of polystyrene, polymethyl methacrylate, zinc oxide, silica, titania, and cadmium selenide (CdSe).

In particular, in the case of the polystyrene, it is preferable to use the polymerized by an emulsion-free emulsion polymerization, and in the case of the polymethyl methacrylate, it is preferable to use the polymerized by dispersion polymerization. Preferably, in the case of the silica, it is preferable to use the one prepared through the Stober-Fink-Bohn method, which is a kind of sol-gel reaction, In this case, it is preferable to use one prepared according to the method of Younan Xia described in Advanced Materials, July 2003.

However, the manufacturing method of the nanoparticles is only an example for explaining the manufacturing method of the nanoparticles, the nanoparticles of the present invention is not limited to that produced by the method, the nanoparticles described in the specification of the present invention Any product manufactured in any manner may be used as long as it meets the requirements of.

When the nanoparticle monodisperse solution is injected into the space of the intaglio pattern and water, alcohol or organic solvent is evaporated, the nanoparticles themselves are regularly arranged to form a first colloidal crystal pattern.

When the solvent of the nanoparticle monodisperse solution is an organic solvent, injection is easy without a separate surface treatment process, but when the solvent is water or alcohol, the surface of the substrate may be oxygen plasma, piranha solution or It is preferable to treat with ozone or the like. This treatment changes the nature of the substrate surface to hydrophilic, making it easier to inject colloidal solutions.

Forming the second colloidal crystal pattern in the method of manufacturing an optical reflector of the present invention comprises the steps of: i) covering the stretchable mold 25 without a pattern on the first colloidal crystal pattern 24, ii) the first colloid Injecting the nanoparticle monodisperse solution 26 between the crystal pattern, and self-assembled to form a second colloidal crystal pattern 27, and iii) removing the stretchable mold 25 Do.

The forming of the third colloidal crystal pattern may include: i) covering the stretchable mold 21 on which the intaglio pattern is formed on the first and second colloidal crystal patterns 24 and 27, and ii) the stretchable mold ( 21) and the nanoparticle monodisperse solution is injected into the space of the intaglio pattern formed between the first and second colloidal crystal patterns 24 and 27 and self-assembled to form the third colloidal crystal pattern 28. Step, and iii) removing the stretchable mold 21.

In this case, the first and second colloidal crystal patterns are preferably formed in a linear arrangement alternately. In addition, the third colloidal crystal pattern may be formed in a direction that is not parallel to the first and second colloidal crystal patterns, and cross or perpendicular to the first and second colloidal crystal patterns diagonally. More preferably, they are formed so as to cross in the direction.

In the forming of the second colloidal crystal pattern and the third colloidal crystal pattern, except that there is no pattern in the stretchable mold used to form the second colloidal crystal pattern, the remaining conditions are the forming of the first colloidal crystal pattern Is the same as However, nanoparticles used in the first to third colloidal crystal patterns may be used to emit reflected light having different wavelengths.

The forming of the first to third colloidal crystal patterns may be performed in a plurality of linear patterns, each having a width of 20 to 200 μm. The width of the colloidal crystal pattern may be adjusted using the intaglio pattern of the stretchable mold.

The forming of the first to second colloidal crystal patterns may further include applying a binder after the formation of each pattern to fix each crystal pattern, and removing the binder after all the patterns are formed.

When the nanoparticles are organic high molecules such as polystyrene and polymethyl methacrylate, it is preferable to use a hydrogel-based water-soluble polymer as the binder. The water-soluble polymer of the hydrogel system serves as a binder to become a solid below a certain temperature, and to recover the liquid phase again above a certain temperature, and after the formation of all the colloidal crystal pattern is finished, the temperature is raised and the binder is dissolved in water. Can be removed with In the present invention, a hydrogel-based water-soluble polymer having the above characteristics can be used without limitation, and preferably, agarose gel, k-carrageenan, or a mixture thereof can be used.

In addition, when the binder is used for inorganic particles such as zinc oxide, silica, titania, cadmium selenide (CdSe), and the like, an ultraviolet curable binder or a water-soluble polymer of the hydrogel system may be used, and the third colloid may be used. It is preferable to further include a step of removing the binder by baking at a high temperature after the formation of the crystal pattern. The firing temperature is not particularly limited, it is possible to select a suitable temperature to remove all the binder, it is preferable to bake at a temperature of 300 to 500 ℃.

The reflective screen display device including the optical reflector of the present invention is not particularly limited, but is preferably a projection screen display device or a reflective liquid crystal display device.

3 is a configuration diagram showing an example of a reflective screen display device including the optical reflector 31 of the present invention. As shown in FIG. 3, the reflective display device of the present invention includes the optical reflecting plate as the back reflecting plate 31 of the liquid crystal display device 32 without backlight and color filter.

4 is a view showing color pixels formed on the optical reflector of the present invention.

Hereinafter, preferred embodiments of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

EXAMPLE

Example 1

(Production of the stretchable mold with the intaglio pattern formed)

The manufacturing process of the silicone rubber mold is summarized in FIG.

After the photoresist solution 52 was applied onto the silicon wafer 51, a mask 53 was covered and UV was irradiated to form a pattern 54 having a width of 50 mu m.

A polydimethylsiloxane (PDMS) monomer and a crosslinking agent (PDMS 184A, B-Dow corning) 55 were coated on the formed photoresist pattern, cured in an oven at 70 degrees Celsius, and then removed. A silicon rubber mold 56 having a negative pattern was formed.

(Formation of the First Colloidal Crystal Pattern)

The silicon rubber mold having the engraved pattern was attached to the silicon wafer to form a capillary pattern between the silicon rubber mold and the substrate.

The aqueous solution of nanoparticle dispersion containing 10% by weight of polystyrene nanoparticles having an average particle diameter of 210 nm and a dispersion degree of 1% using water as a solvent was injected into the capillary, and dried to form a first colloidal crystal pattern. The rubber mold was removed.

An optical micrograph (200 times) of the prepared first colloidal crystal pattern is shown in FIG. 6.

 (Formation of Second Colloidal Crystal Pattern)

An agarose gel was applied to the first colloidal crystal pattern at a temperature of 40 ° C. or higher, and the temperature was lowered to 30 ° C. or lower to fix the first colloidal crystal pattern.

A silicon rubber mold without a pattern was attached on the first colloidal crystal pattern to form a capillary tube between the first colloidal crystal pattern.

A nanoparticle dispersion solution containing 25% by weight of silica nanoparticles having an average particle diameter of 250 nm and a dispersion degree of 1% using ethanol as a solvent was injected into the capillary, and dried to form a second colloidal crystal pattern between the first colloidal crystal patterns. After forming, the silicone rubber mold was removed.

The optical micrograph (200 times) of the prepared first colloidal crystal pattern and the second colloidal crystal pattern is shown in FIG. 7.

(Formation of the third colloidal crystal pattern)

An agarose gel was applied to the second colloidal crystal pattern at a temperature of 40 ° C. or higher, and lowered to 30 ° C. or lower to fix the second colloidal crystal pattern between the first colloidal crystal patterns.

The silicon rubber mold used for the first colloidal crystal pattern was attached to the first and second colloidal crystal patterns in the vertical direction to form capillaries.

The aqueous solution of nanoparticle dispersion containing 30% by weight of silica nanoparticles having an average particle diameter of 300 nm and a dispersion degree of 1% using water as a solvent was injected into the capillary, and dried to form a third colloidal crystal pattern. The rubber mold was removed to prepare an optical reflector.

After the formation of the third colloidal crystal pattern, the agarose gel was removed with water at 40 ° C. or higher.

An optical micrograph (200 times) of the optical reflector plate on which the first to third colloidal crystal patterns are formed is shown in FIG. 8.

Example 2

A nanoparticle dispersion aqueous solution containing 10 wt% of polystyrene nanoparticles having an average particle diameter of 210 nm and a dispersion degree of 1% using water as a solvent for formation of the first colloidal crystal pattern,

In the formation of the second colloidal crystal pattern, using a nanoparticle dispersion solution containing 25% by weight of silica nanoparticles having an average particle diameter of 250 nm and a dispersion degree of 1% using ethanol as a solvent,

Optical formation was carried out in the same manner as in Example 1, except that an aqueous dispersion of nanoparticles containing 30 wt% of silica nanoparticles having an average particle diameter of 300 nm and a dispersion degree of 1% using water as a solvent to form the third colloidal crystal pattern was used. The reflector was produced.

However, agarose gel used as a binder was removed by calcining at 500 ℃.

9 is an optical micrograph (200 times) of the prepared second colloidal crystal pattern.

Example 3

A nanoparticle dispersion aqueous solution containing 30% by weight of silica nanoparticles having an average particle diameter of 300 nm and a dispersion degree of 1% using water as a solvent to form the first colloidal crystal pattern,

A nanoparticle dispersion aqueous solution containing 10% by weight of polystyrene nanoparticles having an average particle diameter of 210 nm and a dispersion degree of 1% using water as a solvent for the formation of the second colloidal crystal pattern,

Optical formation was carried out in the same manner as in Example 2, except that a nanoparticle dispersion solution containing 25% by weight of silica nanoparticles having an average particle diameter of 250 nm and a dispersion degree of 1% using ethanol as a solvent to form the third colloidal crystal pattern was used. The reflector was produced.

10 is an optical micrograph (200 times) of the prepared first colloidal crystal pattern.

Comparative Example 1

An aluminum plate used as an optical reflector of a conventional reflective display device was used as Comparative Example 1.

11A, 11B, and 11C are optical micrographs showing blue, green, and red colors of the first to third colloidal crystal patterns prepared according to Example 2, and FIG. 12 is prepared according to Example 2. It is a graph measuring the wavelength of the reflected light with respect to the first to third colloidal crystal pattern.

The optical reflecting plate of the present invention may exhibit reflected light of various colors, and has an advantage of making the color of the reflective screen display device more clear. In addition, the manufacturing method of the optical reflector of the present invention simplifies the process by patterning different types of nanoparticle crystals on the substrate, the reflective screen display device comprising the optical reflector of the present invention is a backlight (backlight) Since it does not require energy savings, it is possible to achieve clear picture quality even under sunlight.

Claims (16)

Board; First and second colloidal crystal patterns arranged alternately on the substrate; And A third colloidal crystal pattern formed on the first and second colloidal crystal patterns It includes, wherein the first to third colloidal crystal pattern is to reflect light of different wavelengths, respectively. The method of claim 1, The first to third colloidal crystal patterns are reflected light for optical 630 ± 20nm (red), 550 ± 20nm (green), and 460 ± 20nm (blue), respectively, irrespective of the order. The method of claim 1, Each of the first to third colloidal crystal patterns includes nanoparticles having a particle diameter of less than 5% and arranged in a regular pattern. The effective refractive index of the nanoparticles is 1.45 to 2.4 and have an average particle diameter satisfying the reflected light wavelength range of 630 ± 20 nm (red), 550 ± 20 nm (green), and 460 ± 20 nm (blue), respectively, from the following formula 1 Optic Reflector: [Calculation 1] λ = 2 dn _eff Where? Is the wavelength of the reflected light, d is the average distance between layers in the <111> crystal direction of the nanoparticle crystal defined by Formula 2 below, and n _eff is the effective refractive index of the nanoparticles defined according to Formula 3 below; [Calculation 2]

In Formula 2, D is the average particle diameter of the nanoparticles, [Calculation 3]

In Formula 3, f _m is the volume fraction of the medium surrounding the particles, n _m is the refractive index of the medium, n _p is the refractive index of the particle. The method of claim 1, Each of the first to third colloidal crystal patterns may include nanoparticles including any one selected from the group consisting of polystyrene, polymethylmethacrylate, zinc oxide, silica, titania, and cadmium selenide (CdSe). Reflective plate for optics. The method of claim 1, The first to third colloidal crystal pattern is a reflector for optics is formed a plurality of linear patterns each having a width of 20 to 200 ㎛. The method of claim 1, The first and second colloidal crystal patterns are formed in an alternating linear arrangement, and the third colloidal crystal pattern crosses the first and second colloidal crystal patterns diagonally or in a vertical direction. Optical reflector to be formed. a) forming a first colloidal crystal pattern on the substrate; b) forming a second colloidal crystal pattern between the first colloidal crystal patterns; And c) forming a third colloidal crystal pattern on the first colloidal crystal pattern and the second colloidal crystal pattern It includes, The first to third colloidal crystal pattern is a method for manufacturing an optical reflector for each of the reflected light of different wavelengths. The method of claim 7, wherein Forming the first colloidal crystal pattern is i) covering the substrate with the stretchable mold on which the intaglio pattern is formed; ii) injecting nanoparticle monodisperse solution into the space of the intaglio pattern formed between the stretchable mold and the substrate and self-assemble to form a first colloidal crystal pattern; And iii) removing the stretchable mold Method for producing a reflector for optics comprising a. The method of claim 7, wherein Forming the second colloidal crystal pattern is i) covering the patternless stretchable mold over the first colloidal crystal pattern; ii) injecting a nanoparticle monodisperse solution between the first colloidal crystal patterns and self-assembling to form a second colloidal crystal pattern; And iii) removing the stretchable mold To include, wherein the nanoparticles of the nanoparticle monodisperse solution is a method for producing an optical reflector that can emit reflected light of a different wavelength than the nanoparticles used in the first colloidal crystal pattern. The method of claim 7, wherein Forming the third colloidal crystal pattern is i) covering the first and second colloidal crystal patterns on the flexible mold having the intaglio pattern formed thereon; ii) injecting nanoparticle monodisperse solution into the space of the intaglio pattern formed between the stretchable mold and the first and second colloidal crystal patterns, and self-assemble to form a third colloidal crystal pattern; And iii) removing the stretchable mold To include, wherein the nanoparticle monodispersion solution of the nanoparticles in the size of the nanoparticles used in the first and second colloidal crystal pattern can produce a reflection light of a wavelength different from that of the optical reflector. The method of claim 7, wherein The steps of forming the first to third colloidal crystal patterns are each independently i) the dispersion degree of the particle diameter is within 5%, ii) the effective refractive index is 1.45 to 2.4, iii) 630 ± 20nm (Equation 1) Method for producing an optical reflector using nanoparticles having an average particle diameter satisfying the wavelength range of red, 550 ± 20nm (green), and 460 ± 20nm (blue). [Calculation 1] λ = 2 dn _eff In the above formula, λ is the wavelength of the reflected light, d is the average distance between layers in the <111> crystal direction of the nanoparticle crystal defined by the following formula 2, n _eff is the effective refractive index of the nanoparticles defined according to the following formula (3); [Calculation 2]

In Formula 2, D is the average particle diameter of the nanoparticles, [Calculation 3]

In Formula 3, f _m is the volume fraction of the medium surrounding the particles, n _m is the refractive index of the medium, n _p is the refractive index of the particle. The method of claim 7, wherein The forming of the first to third colloidal crystal patterns may each independently include any one selected from the group consisting of polystyrene, polymethylmethacrylate, zinc oxide, silica, titania, and cadmium selenide (CdSe). Method for producing an optical reflector comprising nanoparticles. The method of claim 7, wherein Wherein the first to third colloidal crystal pattern forming step is to form a plurality of linear patterns each having a width of 20 to 200 ㎛ the optical reflector. The method of claim 7, wherein The manufacturing method of the optical reflecting plate further comprises the step of fixing each crystal pattern using a binder after the formation of the first and second colloidal crystal pattern. The method of claim 7, wherein The first and second colloidal crystal patterns are alternately arranged in a linear form, and the third colloidal crystal pattern is formed to intersect the first and second colloidal crystal patterns diagonally or in a vertical direction. Method for producing an optical reflector to be. A reflective screen display device comprising the optical reflector according to any one of claims 1 to 6.

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