Color conversion device

Abstract

The present invention can provide a color conversion device using techniques for the direct control of reflected light and reflected color. The color conversion device according to the present invention can achieve color conversion by selectively reflecting only a wavelength of a desired color through a structural color generated by nanoscale repetition of two refractive indices n1 and n2 but not a color mixing effect of several pigments.

Description

color conversion device

[0001] The present invention relates to a color conversion device capable of color adjustment and widely applicable to mobility, electronic devices, home appliances, interior design, etc.

[0002] The design of mobility devices like automobiles demands a wide range of colors. Typically, these colors are expressed using pigments, such as paints, that absorb light of specific wavelengths to achieve a specific hue. This is achieved by appropriately mixing red, green, blue, and other primary pigments. However, these color mixing methods limit the number of colors that can be expressed, depending on the mixing ratio, and it's difficult to achieve mutual transformation between the mixed colors.

[0003] Recently, electrophoretic E-ink technology has been developed to actively change the exterior color of mobility between these expressed colors. However, electrophoretic E-ink technology also uses the principle that pigment particles move when an electric field is applied in a device that encapsulates pigment particles and then forms them into a film. In addition, the E-ink method operates in a two-time reflection-absorption method in which incident light from the outside passes through the pigment layer, is absorbed, and is reflected and absorbed again, and since the exterior color of the vehicle mainly uses the reflection mode, there is a problem that the brightness is reduced when passing through the color filter, and the color absorption range of the color-absorbing pigment ink is wide, so there is a problem that mixing occurs between colors and scattering occurs, reducing the vividness.

[0004] In addition, conventional technology requires pixel control at a resolution below the resolution of the human eye to implement various colors, but it is limited to simple color expression.

[0005] Furthermore, given the diverse color demands of mobility, applying widely used LCDs or LEDs cannot avoid surface reflection from external light, such as strong sunlight. Consequently, the readability contrast of the colors and patterns displayed on the display is significantly reduced.

[0006] The purpose of the present invention is to provide a color conversion device that can secure both a flexible form factor and visibility of external light so as to overcome the limitations of conventional color implementation methods for mobility, electronic devices, home appliances, and interiors.

[0007] As a means of solving the above problem, a color conversion device using reflected light and direct reflection color control technology can be provided. The color conversion device according to the present disclosure can be configured to selectively reflect a specific wavelength.

[0008] In the present disclosure, the color conversion device may include a nanostructure repeating structure with a length of several hundred nm corresponding to the wavelength of light reflection, as a technique for forming and controlling a reflected color.

[0009] Additionally, the structural color of nanostructures can be applied to soft structural color technology that includes them in a flexible medium.

[0010] Here, the Soft Structural Color technology can be a Nano particle - Flexible Medium, a metal - fluid overall structure or a Metasurface medium, or a helical structure of birefringent Mesogenic molecules.

[0011] Birefringent Mesogenic Molecules Can Be Chiral Liquid Crystals.

[0012] The color conversion device according to the present invention can convert colors by selectively reflecting only the wavelength of a desired color using structural color by nano-repetition of two refractive indices of n1 and n2 rather than the color mixing effect of several pigments.

[0013] In addition, the color conversion device according to the present disclosure is capable of dynamic color change to adjust vivid colors as desired.

[0014] In addition, according to the present disclosure, the design form factor and various colors of automobiles can be configured as desired by controlling a flexible color change layer without a structure of fine pixels such as a display, thereby enabling design innovation of automobiles, etc.

[0015] FIG. 1 is a conceptual diagram of a color conversion device according to one embodiment of the present disclosure.

[0016] FIG. 2 is a cross-sectional view of a color conversion device according to one embodiment of the present disclosure.

[0017] FIG. 3 is a drawing showing a cross-section of a color conversion unit in the first embodiment of the present disclosure.

[0018] FIG. 4a is a cross-sectional view of a color conversion device according to a second embodiment of the present disclosure.

[0019] Figure 4b is a drawing illustrating the concept of a structure included in a color conversion unit in the second embodiment.

[0020] FIG. 4c is a drawing showing an example of a molecular structure included in a color conversion unit in the second embodiment.

[0021] Figure 4d is a conceptual diagram illustrating the concept of controlling the wavelength of reflected light in the second embodiment.

[0022] Figure 5 is a conceptual diagram illustrating the concept of controlling the wavelength of reflected light in the second embodiment.

[0023] Figure 6a is a graph showing the change in pitch of a chiral liquid crystal depending on temperature.

[0024] Figure 6b is a graph showing the wavelength of light reflected from a chiral liquid crystal depending on temperature.

[0025] Figure 7 is an operating state diagram of the second embodiment.

[0026] Figure 8 is a graph showing a voltage pulse applied to a control unit in the second embodiment.

[0027] Figures 9a, 9b, 9c and 9d are drawings showing the wavelength of light reflected from the color conversion unit according to the control of the control unit.

[0028] FIG. 10a is a cross-sectional view of a color conversion device according to a third embodiment of the present disclosure.

[0029] Figure 10b is a diagram showing the wavelength of light reflected in black mode in the third embodiment.

[0030] FIG. 11 is a diagram illustrating the wavelength of light reflected in the white mode in a color conversion device according to the fourth embodiment of the present disclosure.

[0031] FIG. 12 is a drawing illustrating a concept of implementing different colors for each cell in a color conversion device according to the fifth embodiment of the present disclosure.

[0032] Fig. 13 is a diagram showing the state of use of a color conversion device according to the fifth embodiment of the present disclosure.

[0033] Fig. 14 is a perspective view of a color conversion device according to the sixth embodiment of the present disclosure.

[0034] FIG. 15 is a drawing showing the operating state and wavelength of reflected light of the sixth embodiment of the present disclosure.

[0035] Fig. 16 is an operating state diagram of a color conversion device according to the seventh embodiment of the present disclosure.

[0036] Hereinafter, a color conversion device according to an embodiment of the present invention will be described in detail with reference to the attached drawings. In the following description of the embodiments, the names of each component may be referred to by different names in the art. However, if they have functional similarity and identity, they can be viewed as equivalent configurations even if modified embodiments are adopted. In addition, the symbols added to each component are described for the convenience of explanation. However, the illustrated contents in the drawings in which these symbols are described do not limit each component to the scope within the drawings. Similarly, even if an embodiment with some modifications to the configuration in the drawings is adopted, they can be viewed as equivalent configurations if functional similarity and identity exist. In addition, if it is recognized as a component that should be included naturally in light of the general level of a technician in the relevant technical field, a description thereof will be omitted.

[0037] FIG. 1 is a conceptual diagram of a color conversion device according to one embodiment of the present disclosure.

[0038] Referring to FIG. 1, a color conversion device according to the present disclosure can control the color and pattern of the exterior of a mobility (1), such as an automobile, by selectively reflecting a wavelength of a specific color of ambient light. In addition, the color conversion device (10) according to the present disclosure can be applied to the interior of a mobility, such as an automobile, for example.

[0039] In this disclosure, mobility (1) may refer to various means that contribute to the convenience of human movement, such as automobiles, aircraft, ships, motorcycles, bicycles, kickboards, wheelchairs, and baby strollers.

[0040] FIG. 2 is a cross-sectional view of a color conversion device according to one embodiment of the present disclosure.

[0041] Referring to FIG. 2, a color conversion device (10)(10) according to the present disclosure may be configured to include a color conversion unit (100)(100) and a control unit (200). The color conversion unit (100) is configured so that a reflected wavelength can be selected. The control unit (200) can control the color conversion unit (100) so that a reflected wavelength from the color conversion unit (100) can be controlled.

[0042] However, although FIG. 2 illustrates the concept of the control unit (200) being provided on the lower side of the color conversion unit (100), the control unit (200) may be modified and applied in various configurations capable of controlling the wavelength of light reflected from the color conversion unit (100). As an example, the control unit (200) may be provided on the upper and lower sides of the color conversion unit (100), respectively. In addition, the control unit (200) may be provided on the side of the color control unit (200).

[0043] FIG. 3 is a drawing showing a cross-section of a color conversion unit (100) in the first embodiment of the present disclosure.

[0044] Referring to FIG. 3, the color conversion unit (100) according to the first embodiment of the present disclosure may include a double refractive nano repeater. The first structure (110) and the second structure (120) may have refractive indices of 1 to 3. The first refractive index (n1) of the first structure (110) may be greater than the second refractive index (n2) of the second structure (120).

[0045] Here, the first structure (110) and the second structure (120) can be alternately and repeatedly laminated, in which case Bragg reflection conditions can be formed. The period (P) at which the first structure (110) and the second structure (120) are repeatedly laminated can be 10 nm to 2000 nm. In this embodiment, the wavelength of the reflected light is determined depending on the selection of the first refractive index and the second refractive index and the selection of the period.

[0046] FIG. 4a is a cross-sectional view of a color conversion device (10) according to a second embodiment of the present disclosure.

[0047] Referring to FIG. 4a, a color conversion device (10) according to the second embodiment of the present disclosure may include a color conversion unit (100), a control unit (210, 220), a protective film (300), and a substrate (400).

[0048] The control unit (210, 220) can be provided on the upper and lower surfaces with the color conversion unit (100) in between.

[0049] The substrate (400) serves as a base for supporting the color conversion device (10). The lower surface of the substrate (400) may be provided so as to be attached to an external structure.

[0050] The substrate (400) and the protective film (300) can be applied with various and widely used configurations.

[0051] Figure 4b is a drawing illustrating the concept of a structure included in a color conversion unit in the second embodiment.

[0052] Referring to FIG. 4b, in the second embodiment, the color conversion unit may include a structure (1000) having two refractive indices. The structure may have a first refractive index (n1) and a second refractive index (n2) that are repeated. This structure may include a helical rotation structure.

[0053] In this embodiment, the structure may be a chiral liquid crystal having a helical structure. The chiral liquid crystal may form a color conversion unit (100) using a single substance or an elastomer.

[0054] FIG. 4c is a drawing showing an example of a molecular structure included in a color conversion unit in the second embodiment.

[0055] The chiral liquid crystal constituting the color conversion unit can be formed of a material including a molecular structure capable of forming a UV-curable chain. For example, the color conversion unit can include a monoacrylate or diacrylate molecular material having one or two UV-curable acrylate reactive groups. In this case, the molecular material has a bonding structure "R" composed of all various birefringences, and the molecule of R can include any one of all other reactive bonding structures, including a phenyl group, a heagonal group, a methyl group, an ester group, and an ether group.

[0056] Figure 4d is a conceptual diagram illustrating the concept of controlling the wavelength of reflected light in the second embodiment.

[0057] Referring to FIG. 4d, by adjusting the pitch (P) at which the first refractive index (n1) and the second refractive index (n2) are repeated in the color conversion unit (100), the wavelength of light reflected by the structure can be changed. For example, by adjusting the spiral twist length of the structure (1000) within tens to hundreds of nm representing the color of light, light within visible light can be selectively reflected. Chiral liquid crystals tend to reflect light with a shorter wavelength as the pitch length becomes shorter, and tend to reflect light with a longer wavelength as the pitch length becomes longer.

[0058] Figure 5 is a conceptual diagram showing the concept of the structure's sebum changing depending on temperature in the second embodiment.

[0059] Referring to FIG. 5, the pitch of the structure included in the color conversion unit (100) in the second embodiment may change depending on temperature changes. For example, when the temperature increases, the pitch of the helical structure (1000) may shorten. Conversely, when the temperature of the structure decreases, the pitch of the helical structure may lengthen.

[0060] Figure 6a is a graph showing the change in pitch of a chiral liquid crystal depending on temperature.

[0061] When the temperature of a chiral liquid crystal changes, a phase transition phenomenon occurs, changing to a smectic rotational phase or a nematic phase.

[0062] The change in pitch of the helical structure of a chiral liquid crystal depending on temperature can be determined according to the relationship of the Keating Theory below.

[0063]

[0064] Referring to Figure 6a, chiral liquid crystals have high viscosity in the smectic phase and low viscosity in the nematic phase. As the temperature increases, the chiral liquid crystal transitions to the nematic phase, lowering its viscosity and increasing its rotational force per unit length. Therefore, as the temperature increases, the pitch length of the chiral liquid crystal shortens.

[0065] Conversely, as the temperature decreases, the chiral liquid crystal undergoes a phase transition from the nematic phase to the smectic phase, and the pitch of the helical structure becomes longer.

[0066] Ultimately, chiral liquid crystals are formed by temperature changes, which satisfy the De Vires condition Δλ= Δn. Continuous adjustment of p (Δλ: wavelength range of the selectively reflected expression color, Δn: difference in refractive index (n1-n2), p: rotational pitch repetition length) is possible.

[0067] Figure 6b is a graph showing the wavelength of light reflected from a chiral liquid crystal depending on temperature.

[0068] Referring to FIG. 6b, in this embodiment, the wavelength of reflected light can be selectively controlled by changing the temperature of the chiral liquid crystal included in the color conversion unit (100).

[0069] Figure 7 is an operating state diagram of the second embodiment.

[0070] Referring to Fig. 7, in the present embodiment, the control unit (200) can control the temperature of the color conversion unit (100) by Joule heating. As an example, the control unit (200) can include electrodes (210, 220') provided on the upper and lower surfaces of the color conversion unit (100). The electrode provided on the upper surface of the color conversion unit (100) can be configured as a transparent electrode (210). Accordingly, light from the outside can be transmitted into the color conversion unit (100). The transparent electrode (210) can be configured to have a light transmittance of 80% or more and less than 100%.

[0071] In this embodiment, the substrate may be composed of a black substrate (400') that does not transmit light.

[0072] When voltage is applied to the electrodes (210, 220'), the color conversion unit (100) is heated to determine a desired temperature, and depending on the temperature of the color conversion unit (100), the wavelength of the reflected light is determined, so that a specific color can appear when viewed from the outside. In addition, light of a wavelength that is not reflected can be absorbed by the black substrate.

[0073] Figure 8 is a graph showing a voltage pulse applied to a control unit (200) in the second embodiment.

[0074] Referring to FIG. 8, the control unit (200) can control at least one element for controlling the Joule heat, such as voltage, voltage pulse period, duty cycle, voltage application time, and RMS value, to control the temperature when heating the color conversion unit (100) as Joule heat.

[0075] As an example, the relationship between the time (t1) during which the voltage constituting the voltage pulse is applied and the time (t2) during which the voltage is not applied may be t1 > t2, t1 < t2, or t1=t2.

[0076] As an example, by applying a voltage pulse to the control unit (200) to heat the coil, the temperature can be raised higher by increasing the duty cycle as shown in the upper part of Fig. 8. In contrast, in the lower part of Fig. 8, the temperature rise can be somewhat alleviated by lowering the duty cycle (t3 > t2).

[0077] Figures 9a, 9b, 9c and 9d are drawings showing the wavelength of light reflected from the color conversion unit (100) according to the control of the control unit (200).

[0078] The control unit (200) can control the voltage applied to the color conversion unit (100) from 0.1 V to 1000 V, the On / Off Duty rate from 100:0 to 0:100, and the frequency from 0.1 Hz to 10 kHz. At this time, the application time can be from 10 μs to 60 s.

[0079] Referring to Fig. 9a, this varies depending on the voltage applied to the color conversion unit (100), and as the voltage increases, the shift in the reflected wavelength range may increase.

[0080] Referring to Fig. 9b, the shift of the reflected wavelength can be increased depending on the Dute rate under the same conditions as Fig. 9a.

[0081] Referring to Fig. 9c, the shift in the wavelength band reflected from the color conversion unit can increase depending on the frequency of the voltage applied to the control unit.

[0082] Referring to Fig. 9d, different voltages are applied to the color conversion unit, and the wavelength of the reflected light may change depending on the application time.

[0083] FIG. 10a is a cross-sectional view of a color conversion device (10) according to a third embodiment of the present disclosure, and FIG. 10b is a drawing showing the wavelength of light reflected in black mode in the third embodiment.

[0084] Referring to FIG. 10a, a color conversion device (10) according to a third embodiment of the present disclosure may include a control unit (200) that includes a transparent electrode (210) and a black electrode (221).

[0085] The transparent electrode (210) may be provided at a shallow position from the outside, and the black electrode (221) may be provided at a deep position. The transparent electrode (210) may be composed of at least one of indium tin oxide, silver nano wire, and poly-polystyrene sulfonate (PEDOT:PSS).

[0086] The black electrode (221) may be composed of a conductive carbon material. For example, it may be composed of a known conductive material such as Carbon, CNT, Graphite, etc.

[0087] However, in this embodiment, as in the embodiment described above, a substrate (401) may be included, and in this case, since light is blocked by a black electrode (221), the material of the substrate (401) may be selected in various ways.

[0088] Referring to FIG. 10b, the control unit (200) can adjust the wavelength of light reflected from the color control unit (200) to the near-infrared region (wavelength > 780 nm). The pitch of the chiral liquid crystals within the color control unit (200) becomes considerably long, thereby reflecting light in the near-infrared region. Light in the near-infrared region is reflected from the color conversion unit (100), and visible light passes through the color conversion unit (100) and is absorbed by the black electrode. As a result, the reflected near-infrared light is not recognized by the human eye, and the color of the black electrode can be recognized.

[0089] Of course, in this embodiment as well, the control unit (200) can control the pitch of the chiral liquid crystal by controlling the temperature of the color conversion unit (100), as in the embodiments described above, and can selectively reflect wavelengths in a certain range within the visible light range.

[0090] FIG. 11 is a drawing showing the wavelength of light reflected in the white mode in the color conversion device (10) according to the fourth embodiment of the present disclosure.

[0091] Referring to Fig. 11, in the fourth embodiment, the color conversion unit (100) can be controlled to a state in which chiral liquid crystals are randomly arranged under specific voltage conditions. The control unit (200) can apply a weak voltage to the color conversion unit (100) to configure the chiral liquid crystal molecules into a focal conic state. When the chiral liquid crystal molecules are in the focal conic state, light irradiated from the outside to the color conversion unit (100) is strongly scattered and can pass through the transparent electrode (210) and the protective film (300). The color conversion device (10) can implement white by the reflected light. At this time, the light is reflected and scattered by the incident tube in the color conversion unit (100), so that a high-quality white color like milk can be implemented.

[0092] FIG. 12 is a drawing illustrating a concept of implementing different colors for each cell in a color conversion device (10) according to the fifth embodiment of the present disclosure.

[0093] Referring to FIG. 12, a color conversion device (10) according to the fifth embodiment of the present disclosure can have cells distinguished by gap spacers (500) so that colors can be adjusted for each region. At this time, each control unit (200) is configured to independently adjust the voltage applied to each color conversion unit (100).

[0094] As an example, the control unit (200) can operate in white mode by applying a weak voltage to the first cell (11) and inducing strong scattering under a constant temperature (T1).

[0095] The control unit (200) can apply a strong voltage to the second cell (12) to raise the chiral liquid crystal of the color conversion unit (100) above the isotropic transition temperature (T2). The isotropic transition temperature may be the temperature at which the chiral liquid crystal loses its liquid crystal state. At this time, the black electrode absorbs light, so that isotropic black can be implemented in the color conversion unit (100).

[0096] The control unit (200) can lower the voltage to a predetermined temperature (T3) after heating the third cell to a temperature higher than the isotropic temperature. At this time, the control unit (200) can control the temperature of the color conversion unit (100) of the third cell (13) to a predetermined temperature so as to enable selective reflection within visible light.

[0097] The control unit (200) performs cooling to a predetermined temperature (T4) by releasing the voltage after heating the fourth cell (14) to a temperature higher than the isotropic temperature, similar to the second cell (12). At this time, the cooling may be natural cooling or forced cooling. The wavelength of the light reflected by the fourth cell (14) under specific temperature conditions may be a wavelength in the infrared range. In this case, since infrared rays invisible to the human eye are reflected, the human eye may perceive it as black, the color of the black electrode (black mode).

[0098] Meanwhile, although not described in detail, each cell can operate in black, white, and color modes, so that the wavelengths it reflects can be selectively determined individually. Meanwhile, each cell can be determined in a fine size, and each cell can clearly express colors even without a combination of RGB. Furthermore, the color conversion device according to the present disclosure can adjust the visible color by controlling the temperature differently for each area. In the embodiment of the present disclosure, the method of adjusting the color for each area can be equally applied even if the color conversion device is configured to have a large area.

[0099] Fig. 13 is a diagram showing the state of use of a color conversion device according to the fifth embodiment of the present disclosure.

[0100] Referring to FIG. 13, a color conversion device (10) according to a fifth embodiment of the present disclosure can be flexibly configured. The fifth embodiment of the present disclosure can include a control unit and a color conversion unit on a flexible film substrate. The flexible film substrate can be composed of a polymer material such as a stretchable polydimethylsiloxane (PDMS).

[0101] Additionally, transparent electrodes and black electrodes can be flexibly provided.

[0102] In this embodiment, since the color conversion device is flexibly configured, it can be placed along the exterior of a vehicle, for example, a car. In particular, it can be placed along the edge or curved surface of the vehicle. In addition, although not illustrated, the color conversion device according to the present disclosure can be installed to conform to the shape of the interior of the vehicle. Furthermore, the color conversion device according to the present disclosure can be widely applied without limitation to the target application. For example, it can be applied to mobility such as cars, motorcycles, bicycles, kickboards, ships, airplanes, and drones. It can also be externally installed on objects directly exposed to the external environment, such as outdoor signboards, signboards, and buildings. It can also be externally or internally installed in buildings. It can also be applied to objects such as home appliances, electronic devices, smartphones, laptops, PCs, and smart pads.

[0103] Fig. 14 is a perspective view of a color conversion device (10) according to the sixth embodiment of the present disclosure.

[0104] Referring to FIG. 14, a color conversion device (10) according to the sixth embodiment of the present disclosure may be configured to include a color conversion unit (100) and a control unit that can extend the color conversion unit (100) at a side of the color conversion unit.

[0105] In this embodiment, the color conversion unit may be provided with a chiral liquid crystal along the thickness direction. At this time, the control unit may be configured to extend the color conversion unit (100) in a direction orthogonal to the direction of the chiral liquid crystal. Hinges may be provided on both sides centered around the color conversion unit (100). The control unit may include a driving unit (not shown) configured to transmit force to each hinge unit (230).

[0106] FIG. 15 is a drawing showing the operating state and wavelength of reflected light of the sixth embodiment of the present disclosure.

[0107] Referring to FIG. 15, in the sixth embodiment of the present disclosure, when the color conversion unit (100) is pulled from both sides and stretched, the reflected wavelength may vary depending on the length of the stretching. The control unit may finely adjust the wavelength of the reflected light by finely adjusting the stretching length of the color conversion unit (100) via the hinge unit (230).

[0108] For example, when the color conversion unit is stretched laterally, the pitch of the chiral liquid crystal becomes shorter. At this time, the longer the stretching length, the shorter the pitch of the chiral liquid crystal. Consequently, when the color conversion unit (100) is stretched less (top of FIG. 15), light with a long wavelength is mainly reflected. Conversely, when the color conversion unit (100) is stretched greatly (bottom of FIG. 15), light with a short wavelength is mainly reflected. Therefore, the control unit determines the stretching length according to the color to be displayed by the color conversion unit (100) and adjusts the position of the hinge unit (230). In addition, the control unit (200) can adjust the stretching length so as to change from one color to another.

[0109] Figure 16 is an operating state diagram of a color conversion device (10) according to the seventh embodiment of the present disclosure.

[0110] Referring to FIG. 16, a color conversion device (10) according to a seventh embodiment of the present disclosure may include a Hybridge nanoparticle body in which a plurality of nanoparticles (110') having a high refractive index (n1) are regularly dispersed and arranged within a flexible medium (120') having a low refractive index (n2). The flexible medium (120') may be composed of a stretchable polymer material. The nanoparticles (110') may be composed of a material having a high refractive index, such as polystyrene or TiO2.

[0111] By extending the color conversion unit by the control unit, the number of times the light incident on the color conversion unit passes through the nanoparticles (110') can be changed. As described above, when a medium having two refractions is repeatedly provided, light of a specific wavelength is reflected, and by controlling the pitch at which the nanomaterials (110') are repeated, the wavelength of the reflected light can be controlled.

[0112] As described above, the color conversion device according to the present disclosure enables design innovation of automobiles, etc., by configuring the design form factor and various colors as desired by controlling the flexible color change layer without a structure of fine pixels such as a display.

Claims

1. A color conversion unit configured to change the wavelength of light reflected from at least a portion; and A color conversion device including a control unit configured to control the wavelength of the reflected light.

2. In paragraph 1, A color conversion device further comprising an attachment portion configured to be attachable to the mobility, the attachment portion being provided in a direction opposite to the direction in which external light is incident.

3. In paragraph 1, A color conversion device in which the color conversion unit is configured and arranged to have a predetermined size, and the control unit is configured to control each of the color conversion units.

4. In paragraph 1, The above color conversion part, A color conversion device comprising a color conversion structure having a first refractive index and a second refractive index that are different from each other.

5. In paragraph 4, A color conversion device in which the first refractive index and the second refractive index are within a range of 1 to 3.

6. In paragraph 1, A color conversion device wherein the wavelength of the reflected light is 380 nm to 780 nm.

7. In paragraph 1, The above control unit is a color conversion device configured to control the wavelength of the reflected light to 400 nm or less or 700 nm or more so that the color conversion unit can appear black.

8. In paragraph 7, The above color conversion structure is a color conversion device that is a part of a chiral liquid crystal composed of a birefringent material that is rotated in a spiral manner.

9. In paragraph 8, The above control unit is a color conversion device configured to control the temperature of the color conversion layer.

10. In paragraph 11, The above color conversion layer is a color conversion device in which the wavelength of the reflected light becomes shorter as the temperature increases.

11. In paragraph 10, The above control unit, A color conversion device comprising electrodes provided on both sides of the color conversion layer.

12. In paragraph 11, A color conversion device in which the above control unit is configured to heat the color conversion layer by means of Joule heating.

13. In paragraph 12, A color conversion device in which the control unit is configured to control at least one of the voltage applied to the color conversion layer, the voltage pulse period, the duty cycle, and the voltage application time.

14. In paragraph 13, The above control unit, The above voltage is 0.1 V to 1000 V, The above duty cycle is 100:0 to 0:100, The voltage pulse cycle is 0.1 Hz to 10 KHz, A color conversion device having an above-mentioned authorization time of 10 μs to 1 min.

15. In paragraph 11, The above control unit, A color conversion device that adjusts the wavelength of light reflected from the chiral liquid crystal to 780 nm or more when the chiral liquid crystal implements black.

16. In paragraph 14, A color conversion device in which the shallow electrode is composed of a transparent electrode.

17. In paragraph 16, The above transparent electrode is a color conversion device having a light transmittance of 80% or more and less than 100%.

18. In paragraph 17, A color conversion device in which the transparent electrode comprises at least one of indium tin oxide, silver nano wire, and poly-polystyrene sulfonate (PEDOT:PSS).

19. In paragraph 18, The above transparent electrode is a color conversion device that is flexibly configured.

20. In paragraph 19, The above control unit, It includes a black electrode facing the transparent electrode centered on the color conversion part, The above black electrode is a color conversion device that is flexibly configured.

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