TWI426476B - Thermochromatic device and thermochromatic display apparatus - Google Patents

Description

Thermochromic element and thermochromic display device

The present invention relates to a thermochromic element and a thermochromic display device.

Since the thermochromic material can display different colors at different temperatures, it can be applied to a thermochromic element having a display function in a thermochromic display device. The thermochromic element in the prior thermochromic display device includes at least a color developing layer and a heating layer, and the color developing layer is disposed or spaced apart from the heating layer. Wherein, the heating layer is mainly composed of a metal plate. However, the heat capacity and thickness of the metal plate are large, and when the heating layer is operated, the temperature changes slowly, and the electrothermal conversion efficiency is low, so that the color-developing element has a slow color response and a large energy consumption during operation. In addition, the flexibility of the metal sheet is limited, making it difficult to use as a heating layer in a flexible thermochromic display device.

To overcome the shortcomings of metal sheets as heating layers for thermochromic elements, the prior art provides a thermochromic display device in which the heating layer of the thermochromic element comprises carbon ink and a polymer. Wherein the carbon ink is printed on the polymer. The material of the polymer is a dielectric film or a polyester film. Although the thermochromic element can be applied to a flexible thermochromic display device, since the carbon ink is printed on the polymer, the heat capacity of the polymer is large, so that the heat capacity of the heating layer is large, and the working time is , the temperature changes slowly, the electrothermal conversion efficiency is low, so that the thermochromic element works The color rendering response is also slower and consumes more energy.

In view of the above, it is necessary to provide a thermochromic element having a fast color development response speed and a thermochromic display device using the same.

A thermochromic element comprising an insulating substrate, a color developing element and at least one heating element for heating the color developing element, the insulating substrate having a surface, the color developing element and the heating element being disposed on the insulating substrate a surface, wherein the at least one heating element comprises at least one carbon nanotube structure, the carbon nanotube structure heating the color developing element, the color developing element comprising a reversible thermochromic material.

A thermochromic display device comprising: an insulating substrate having a surface; a plurality of row electrode leads and a plurality of column electrode leads disposed on a surface of the insulating substrate, wherein the plurality of row electrode leads and the plurality of column electrode leads are disposed to cross each other , each two adjacent row electrode leads form a grid with each two adjacent column electrode leads, and the row electrode leads are electrically insulated from the column electrode leads; and a plurality of thermochromic elements, each thermochromic The component corresponds to a grid arrangement; wherein the thermochromic element comprises a color-developing element and at least one heating element for heating the color-developing element, the at least one heating element comprises at least one carbon nanotube structure, The color developing element includes a reversible thermochromic material.

A thermochromic display device comprising: an insulating substrate having a surface; and a plurality of thermochromic elements arranged in a matrix to form an array of primitives; and a driving circuit and a plurality of An electrode lead, the driving circuit independently controlling the heating element of each thermochromic element by the plurality of electrode leads; wherein the thermochromic element comprises a color developing element and at least one is used for heating A heating element of a chromogenic element, the at least one heating element comprising at least one carbon nanotube structure, the chromogenic element comprising a reversible thermochromic material.

Compared with the prior art, the thermochromic element of the thermochromic display device adopts a carbon nanotube structure as a heating element, because the heat capacity per unit area of the carbon nanotube structure is greater than that of a metal plate or a dielectric film or a polyester film. The heat capacity per unit area is small, so the heating element composed of the carbon nanotube structure has a relatively fast thermal response speed, and can be used for rapid heating of the color developing element, so that the thermochromic display device of the present invention is painted. The prime unit has a faster response speed.

20‧‧‧Thermal color display device

202,302,402,502,602,702‧‧‧Insulation base

2020‧‧‧ surface

204‧‧‧ row electrode lead

206‧‧‧ column electrode lead

208,308,408,508,708‧‧‧ heating elements

608‧‧‧First heating element

609‧‧‧Second heating element

210,310,410,510,610,710‧‧‧first electrode

212,312,412,512,612,712‧‧‧second electrode

214‧‧‧Grid

216‧‧• dielectric insulation

218, 318, 418, 518, 618, 718‧ ‧ chromogenic components

220,320,420,520,620,720‧‧‧ thermochromic components

222‧‧‧Insulation materials

224‧‧‧Protective layer

722‧‧‧ Groove

1 is a schematic view showing the structure of a thermochromic element according to a first embodiment of the present invention.

Fig. 2 is a scanning electron micrograph of a carbon nanotube film used as a heating element in the first embodiment of the present invention.

3 is a schematic view showing the structure of a carbon nanotube segment in the carbon nanotube film of FIG. 2.

Figure 4 is a scanning electron micrograph of a non-twisted nanocarbon line used as a heating element in accordance with a first embodiment of the present invention.

Figure 5 is a scanning electron micrograph of a twisted nanocarbon line as a heating element in accordance with a first embodiment of the present invention.

Figure 6 is a schematic view showing the structure of a thermochromic element according to a second embodiment of the present invention.

Figure 7 is a schematic view showing the structure of a thermochromic element according to a third embodiment of the present invention.

Figure 8 is a schematic view showing the structure of a thermochromic element according to a fourth embodiment of the present invention.

Figure 9 is a schematic view showing the structure of a thermochromic element according to a fifth embodiment of the present invention.

Figure 10 is a schematic view showing the structure of a thermochromic element according to a sixth embodiment of the present invention.

Figure 11 is a plan view of a thermochromic display device employing the thermochromic element of the first embodiment of the present invention.

Figure 12 is a cross-sectional view taken along line XII-XII of Figure 11.

The thermochromic element of the present invention and the thermochromic display device using the thermochromic element will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , a first embodiment of the present invention provides a thermochromic element 220 including an insulating substrate 202 , a color developing element 218 , at least one heating element 208 , and a first electrode 210 and a second electrode 212 .

The insulating substrate 202 has a surface 2020. The color developing element 218 and the heating element 208 are disposed on the surface 2020 of the insulating substrate 202. The color developing element 218 is adjacent to and corresponding to the heating element 208. The corresponding arrangement means that the heating element 208 is disposed around the color developing element 218, such as above, below or around. It can be understood that the specific arrangement position of the color developing element 218 and the heating element 208 is not limited as long as the heating element 208 can be heated to the heating element 218. Preferably, the color developing element 218 and the heating element 208 are both in a layered structure, and the color developing element 218 and the heating element 208 are disposed in a laminated contact or stacked. The layered contact arrangement means that the color developing element 218 is attached to the surface of the heating element 208. For example, the color developing element 218 is disposed on the surface 2020 of the insulating substrate 202, and the heating element 208 is disposed on the surface of the color developing element 218 and is in contact with each other. The merging interval arrangement means that the color developing element 218 and the heating element 208 are arranged in parallel and spaced apart, for example, the color developing element 218 is disposed on the heating element 208 and Between the edge substrates 202, and the heating element 208 is spaced apart from the color developing element 218 by a support (not shown). The first electrode 210 is spaced apart from the second electrode 212. The first electrode 210 and the second electrode 212 are electrically connected to the heating element 208, respectively, for supplying a voltage or current to the heating element 208, and causing the heating element 208 to heat the color developing element 218.

In this embodiment, the number of heating elements 208 is one. The color developing element 218 and the heating element 208 are both in a layered structure. The heating element 208 is disposed on a surface 2020 of the insulating substrate 202. The color developing element 218 is disposed on the surface of the heating element 208. The first electrode 210 and the second electrode 212 are spaced apart from each other on the surface of the heating element 208 and located on both sides of the color developing element 218.

The insulating substrate 202 can be a rigid substrate or a flexible substrate. The hard substrate may be one or a plurality of ceramic substrates, glass substrates, quartz substrates, tantalum substrates, tantalum oxide substrates, diamond substrates, alumina substrates, and rigid polymer substrates. The flexible substrate may be one or a plurality of synthetic paper, fiber cloth, and flexible polymer substrate. The material of the flexible polymer substrate may be polyethylene terephthalate (PET), polyethylene (PE), polycarbonate (PC) or polyimine (PI). It is to be understood that the material of the insulating substrate 202 is not limited to the above materials, and the object of the present invention can be achieved as long as it can withstand an insulating material having a temperature of 200 ° C or higher. The size, shape and thickness of the insulating substrate 202 are not limited, and those skilled in the art can set the size of the insulating substrate 202 according to actual needs, such as according to the predetermined size of the thermochromic display device 20. In this embodiment, the insulating substrate 202 is preferably a PET substrate having a thickness of about 1 mm.

The color developing element 218 is made of a reversible thermochromic material. Reversible thermochromism Material refers to the amount of material that changes when the temperature reaches a certain range. When the temperature returns to the initial temperature, the color of the material will recover. When the color developing element 218 is heated to a specific temperature range, the color of the color developing element 218 is changed to effect display. The reversible thermochromic material has a color change temperature of less than 200 ° C. Preferably, the reversible thermochromic material has a color change temperature of greater than 40 ° C and less than 100 ° C. It can be understood that the preparation of the color developing element 218 by selecting a reversible thermochromic material having a color changing temperature of more than 40 ° C and less than 100 ° C can ensure that the thermochromic element 220 operates at room temperature on the one hand, and can reduce heat generation on the other hand. The operating voltage of the color changing element 220, thereby reducing energy consumption. The reversible thermochromic material may be an inorganic reversible thermochromic material, an organic reversible thermochromic material or a liquid crystal reversible thermochromic material.

The inorganic reversible thermochromic material comprises silver-containing iodide, silver-containing complex, silver-containing double salt, copper-containing iodide, copper-containing complex, copper-containing double salt, and mercury Iodide, mercury-containing complex, complex salt containing mercury, compound formed from cobalt salt, nickel salt and hexamethylenetetramine, vanadium oxide, vanadate, chromate and vanadium oxide, vanadic acid Any one or a mixture of salts and chromates. The inorganic reversible thermochromic material and its color change range and color change temperature are shown in Table 1.

Table 1 Inorganic reversible thermochromic materials

The organic reversible thermochromic material is usually composed of a color former (electron donor), a color developer (electron acceptor), and a solvent. Among them, the coloring agent determines the color, the coloring agent determines the color depth, and the solvent determines the color changing temperature. The coloring agent may be a triarylmethane type coloring agent, a fluoran type coloring agent, a porphyrin quinone type coloring agent, a phenothiazine type coloring agent, a spiropyran type coloring agent, a Schiff A hair coloring agent, a spiro ring type coloring agent or a bisulphonone type coloring agent. The triarylmethane type coloring agent may be crystal violet lactone, malachal green lactone or cresol red. The fluoranescent coloring agent may be FT-2, heat sensitive red or heat sensitive green or the like. The developer mainly includes an inorganic color developer and an organic color developer. Among them, the inorganic color developer may be acidic clay or activated clay, kaolin or aluminum magnesium silicate. The organic color developing agent may be a phenolic hydroxyl compound and a derivative thereof, such as bisphenol A, benzyl p-hydroxybenzoate or 4-hydroxycoumarin, etc.; a carboxyl compound and a derivative thereof, such as caproic acid, caprylic acid, and stearic acid; Acid, terephthalic acid or some Lewis acids that can provide protons. When triarylmethane is used as a color former, organic phenol is preferred. Class as a color developer. The solvent may be an alcohol such as n-dodecanol, n-tetradecanol, n-hexadecanol or n-octadecanol. In addition, some higher aliphatic ketones, esters, ethers, decylamines or carboxylic acids can be used as the solvent.

The liquid crystal is an intermediate phase between the solid state and the isotropic liquid, that is, a three-dimensional ordered spatial structure and an isotropic homogeneous molten material. The liquid crystal reversible thermochromic material refers to a crystalline substance which is caused by a change in temperature and which can only exist within a certain temperature range. The liquid crystal reversible thermochromic material may be a smectic liquid crystal, a nematic liquid crystal or a cholesteric liquid crystal. The cholesteric liquid crystal is prepared by using cholesterol as a matrix and esterification or halogen substitution.

In this embodiment, the color developing element 218 is a layer of silver mercury iodide (Ag ₂ HgI ₄ ) having a thickness of 10 μm to 500 μm. Preferably, the color developing element 218 has a thickness of 50 micrometers to 100 micrometers. The color developing element 218 may be deposited on the surface of the heating element 208 by thermal deposition or sputtering or at least between the first electrode 210 and the second electrode 212. The color developing element 218 may be spaced apart from the first electrode 210 or the second electrode 212 or may be disposed in contact with the first electrode 210 or the second electrode 212.

The heating element 208 includes a carbon nanotube structure. The carbon nanotube structure is a self-supporting structure. The so-called "self-supporting structure" means that the carbon nanotube structure can maintain its own specific shape without being supported by a support. The self-supporting structure of the carbon nanotube structure comprises a plurality of carbon nanotubes, and the plurality of carbon nanotubes are attracted to each other by the van der Waals force, so that the carbon nanotube structure has a specific shape. The carbon nanotubes in the carbon nanotube structure include one or a plurality of single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes. The single-walled carbon nanotube has a diameter of 0.5 nm to 50 nm, the double-walled carbon nanotube has a diameter of 1.0 nm to 50 nm, and the multi-walled carbon nanotube has a diameter of 1.5. Nano ~ 50 nm. The carbon nanotube structure is a layered or linear structure. Since the carbon nanotube structure is self-supporting, a layered or linear structure can be maintained without being supported by the support. There is a large amount of gap between the carbon nanotubes in the carbon nanotube structure, so that the carbon nanotube structure has a large number of micropores. The carbon nanotube structure has a heat capacity per unit area of less than 2 x 10 ^-4 joules per square centimeter Kelvin. Preferably, the carbon nanotube structure has a heat capacity per unit area of less than or equal to 1.7 x 10 ^-6 joules per square centimeter Kelvin.

The carbon nanotube structure comprises at least one carbon nanotube membrane, at least one nanocarbon line-like structure, or a combination thereof. The carbon nanotube membrane comprises a plurality of uniformly distributed carbon nanotubes. The carbon nanotubes in the carbon nanotube film are ordered or disorderly arranged. When the carbon nanotube membrane comprises a disorderly arranged carbon nanotube, the carbon nanotubes are intertwined; when the carbon nanotube membrane comprises an ordered arrangement of carbon nanotubes, the carbon nanotubes are in one direction or plural The direction is preferred. The preferred orientation means that most of the carbon nanotubes in the carbon nanotube film have a large orientation probability in a certain direction, that is, most of the carbon nanotubes in the carbon nanotube film extend in the same direction in the same direction. When the carbon nanotube structure includes a plurality of carbon nanotubes arranged substantially in the same direction, the plurality of carbon nanotubes extend from the first electrode to the second electrode. Specifically, the carbon nanotube film may include a carbon nanotube film, a carbon nanotube film or a carbon nanotube film. The nanocarbon line-like structure includes at least one non-twisted nanocarbon line, at least one twisted nanocarbon line, or a combination thereof. When the nanocarbon line-like structure comprises a plurality of non-twisted nano carbon pipelines or twisted nanocarbon pipelines, the non-twisted nanocarbon pipeline or the twisted nanocarbon pipeline may be arranged in parallel with each other to form a bundle structure. , or twisted to each other to form a twisted wire structure .

The carbon nanotube membrane is a self-supporting structure composed of a plurality of carbon nanotubes. The plurality of carbon nanotubes are arranged in a preferred orientation along the same direction. The preferred orientation means that the majority of the carbon nanotubes in the carbon nanotube film extend substantially in the same direction. Moreover, the overall direction of extension of the majority of the carbon nanotubes is substantially parallel to the surface of the carbon nanotube film. Further, most of the carbon nanotubes in the carbon nanotube film are connected end to end by Van der Waals force. Specifically, each of the carbon nanotubes in the majority of the carbon nanotube membranes extending in the same direction and the carbon nanotubes adjacent in the extending direction are connected end to end by van der Waals force. Of course, there are a few randomly arranged carbon nanotubes in the carbon nanotube film, and these carbon nanotubes do not significantly affect the overall orientation of most of the carbon nanotubes in the carbon nanotube film. The self-supporting carbon nanotube film does not require a large-area carrier support, but can maintain a self-membrane state as long as the supporting force is provided on both sides, that is, the carbon nanotube film is placed (or fixed on) When the two supports are disposed at a certain distance apart, the carbon nanotube film located between the two supports can be suspended to maintain the self-membrane state. The self-supporting is mainly achieved by the presence of a continuous carbon nanotube in the carbon nanotube film which is continuously arranged by van der Waals force.

Specifically, most of the carbon nanotube membranes extending substantially in the same direction in the same direction are not absolutely linear, and may be appropriately bent; or may not be completely aligned in the extending direction, and may be appropriately deviated from the extending direction. Therefore, it is not possible to exclude partial contact between the carbon nanotubes juxtaposed in the majority of the carbon nanotubes extending substantially in the same direction.

Referring to FIG. 2 and FIG. 3 , specifically, the carbon nanotube film comprises a plurality of consecutive and Oriented carbon nanotube segments 143. The plurality of carbon nanotube segments 143 are connected end to end by Van der Waals force. Each of the carbon nanotube segments 143 includes a plurality of mutually parallel carbon nanotubes 145 that are tightly coupled by van der Waals forces. The carbon nanotube segments 143 have any length, thickness, uniformity, and shape. The thickness of the carbon nanotube film is 0.5 nm to 100 μm, and the width is related to the size of the carbon nanotube array for pulling out the carbon nanotube film, and the length is not limited. The carbon nanotubes 145 in the carbon nanotube film are arranged in a preferred orientation in the same direction. The carbon nanotube film has high light transmittance. The transmittance of the single-layer carbon nanotube film is over 90%. The carbon nanotube film and the preparation method thereof are described in detail in the Taiwan Patent Application No. TW200833862, filed on Feb. 12, 2008, which is hereby incorporated by reference. And its preparation method". In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the technical disclosure of the present application.

When the carbon nanotube structure comprises a stacked multi-layered carbon nanotube film, a preferred orientation of the aligned carbon nanotubes in the adjacent two layers of carbon nanotubes forms an intersection angle α, and α is greater than or equal to 0 degrees and less than or equal to 90 degrees (0° ≦ α ≦ 90 °). a gap between the plurality of carbon nanotube films or between adjacent carbon nanotubes in a carbon nanotube film, thereby forming a plurality of micropores in the carbon nanotube structure, The pores have a pore size of less than about 10 microns. In this embodiment, the carbon nanotube structure is a single-layer carbon nanotube film.

The carbon nanotube rolled film includes a uniformly distributed carbon nanotube. The carbon nanotubes are arranged in the same direction, and the carbon nanotubes can also be arranged in different directions. Preferably, the carbon nanotubes in the carbon nanotube rolled film are parallel to the carbon nanotube film s surface. The carbon nanotubes in the carbon nanotube rolled film overlap each other and are attracted to each other by the van der Waals force, so that the carbon nanotube film is very flexible and can be bent and folded. In any shape without breaking. Moreover, since the carbon nanotubes in the carbon nanotube rolled film are attracted to each other by the van der Waals force, the carbon nanotube film is a self-supporting structure, and the substrate support is not required. The carbon nanotube rolled film can be obtained by rolling an array of carbon nanotubes. The carbon nanotubes in the carbon nanotube rolled film form an angle β with the surface of the substrate forming the carbon nanotube array, wherein β is greater than or equal to 0 degrees and less than or equal to 15 degrees (0≦β≦15°). The angle β is related to the pressure applied to the array of carbon nanotubes, and the larger the pressure, the smaller the angle. The length and width of the carbon nanotube rolled film are not limited. The laminated film comprises a plurality of microporous structures uniformly and regularly distributed in a carbon nanotube rolled film, wherein the micropores have a diameter of from 1 nm to 0.5 μm. The carbon nanotube film and the preparation method thereof are described in detail in the Taiwan Patent Application No. TW200900348, filed on Jan. 29, 2009, filed on Jan. 29, 2009. Preparation". In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the technical disclosure of the present application.

The length, width and thickness of the carbon nanotube film are not limited and can be selected according to actual needs. The carbon nanotube flocculation film provided by the embodiment of the invention has a length of 1 to 10 cm, a width of 1 to 10 cm, and a thickness of 1 to 2 mm. The carbon nanotube flocculation membrane comprises intertwined carbon nanotubes having a length greater than 10 microns. The carbon nanotubes are attracted and entangled by van der Waals forces to form a network structure. The carbon nanotubes in the carbon nanotube flocculation membrane are uniformly distributed and arranged irregularly, so that the carbon nanotube flocculation membrane is isotropic, and the carbon nanotubes in the carbon nanotube flocculation membrane are isotactic. between A large number of micropores are formed, and the pore diameter of the micropores is from 1 nm to 0.5 μm. The carbon nanotube film and the preparation method thereof are described in detail in the Taiwan Patent Application No. TW200844041 filed on Nov. 16, 2008, the entire disclosure of which is incorporated herein by reference. Preparation". In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the technical disclosure of the present application.

Referring to FIG. 4, the non-twisted nanocarbon pipeline includes a plurality of carbon nanotubes arranged along the length of the non-twisted nanocarbon pipeline. Specifically, the non-twisted nanocarbon pipeline includes a plurality of carbon nanotube segments, and the plurality of carbon nanotube segments are connected end to end by Van der Waals force, and each of the carbon nanotube segments includes a plurality of parallel and pass through each other Deval's tightly integrated carbon nanotubes. The carbon nanotube segments have any length, thickness, uniformity, and shape. The non-twisted nano carbon line is not limited in length and has a diameter of 0.5 nm to 100 μm. The non-twisted nano carbon pipeline is obtained by treating the carbon nanotube film with an organic solvent. Specifically, the organic solvent is used to impregnate the entire surface of the carbon nanotube film, and under the action of the surface tension generated by the volatilization of the volatile organic solvent, a plurality of nano carbons parallel to each other in the carbon nanotube film are drawn. The tube is tightly bonded by van der Waals force, thereby shrinking the carbon nanotube film into a non-twisted nano carbon line. The organic solvent is a volatile organic solvent such as ethanol, methanol, acetone, dichloroethane or chloroform, and ethanol is used in this embodiment. The non-twisted nanocarbon line treated by the organic solvent has a smaller specific surface area and a lower viscosity than the carbon nanotube film which is not treated with the organic solvent.

The twisted nanocarbon pipeline is obtained by twisting both ends of the carbon nanotube film in the opposite direction by a mechanical force. Referring to FIG. 5, the twisted nanocarbon pipeline includes a plurality of carbon nanotubes arranged in an axial spiral around the twisted nanocarbon pipeline. specifically, The twisted nanocarbon pipeline includes a plurality of carbon nanotube segments, the plurality of carbon nanotube segments are connected end to end by Van der Waals force, and each of the carbon nanotube segments includes a plurality of parallel and through Van der Waals force Tightly bonded carbon nanotubes. The carbon nanotube segments have any length, thickness, uniformity, and shape. The twisted nanocarbon line is not limited in length and has a diameter of 0.5 nm to 100 μm. Further, the twisted nanocarbon line can be treated with a volatile organic solvent. Under the action of the surface tension generated by the volatilization of the volatile organic solvent, the adjacent carbon nanotubes in the treated twisted nanocarbon pipeline are tightly bonded by the van der Waals force, so that the specific surface area of the twisted nanocarbon pipeline Decrease, increase in density and strength.

For details of the nano carbon pipeline and the preparation method thereof, please refer to the Taiwan Patent Publication No. I303239, which was filed on November 5, 2002, which was filed on November 5, 2008. The method, and the Taiwan Patent Application No. TW200724486, which was filed on Dec. 1, 2005, which is hereby incorporated by reference in its entirety in its entirety in In order to save space, only the above is cited, but all the technical disclosures of the above application are also considered as part of the technical disclosure of the present application.

Since the carbon nanotube structure has a large specific surface area and itself has good adhesion, the heating element 208 composed of a carbon nanotube structure can be directly disposed on the surface 2020 of the insulating substrate 202. In addition, the heating element 208 can also be fixed to the surface 2020 of the insulating substrate 202 by a bonding agent (not shown). The heating element 208 may be directly fixed to the surface of the first electrode 210 and the second electrode 212, or may be fixed to the surfaces of the first electrode 210 and the second electrode 212 by a conductive adhesive (not shown). In this embodiment, the preferred conductive adhesive is silver paste.

Since the heating element 208 is directly disposed on the surface 2020 of the insulating substrate 202, the The heat element 208 may also be a carbon nanotube layer formed by a method such as screen printing, and the carbon nanotube layer includes a plurality of carbon nanotubes disorderly distributed.

The heating element 208 can also include a carbon nanotube composite structure. The carbon nanotube composite structure includes a carbon nanotube structure and a filler material dispersed in the carbon nanotube structure. The filler material is filled in the micropores in the carbon nanotube structure or on the surface of the carbon nanotube structure. The filler material includes one or more of a metal, a resin, a ceramic, a glass, and a fiber. Alternatively, the carbon nanotube composite structure may include a matrix and a carbon nanotube structure composited in the matrix. The material of the substrate includes one or more of a metal, a resin, a ceramic, a glass, and a fiber. The substrate completely encapsulates the carbon nanotube structure, and the matrix material is at least partially infiltrated into the carbon nanotube structure.

When a carbon nanotube film is used as the heating element 208, the carbon nanotube film can be directly laid on the surface 2020 of the insulating substrate 202 or the surface of the layered color developing element 218; when a single nanocarbon line structure is used as the heating element At 208, the single nanocarbon line-like structure may be folded or wound into a layered structure and then laid on the surface 2020 of the insulating substrate 202 or the surface of the layered color developing element 218, or the single nanocarbon line structure may be The coil is disposed around the one-piece color developing element 218; when a plurality of nano carbon line-like structures are used as the heating element 208, the plurality of nano carbon line-like structures may be arranged in parallel, cross-arranged or woven into a layer structure. It is then laid on the surface 2020 of the insulating substrate 202 or the surface of the layered color developing element 218.

Since the heating element 208 of the embodiment is mainly composed of a carbon nanotube, the carbon nanotube has a high electrothermal conversion efficiency and a relatively high heat radiation efficiency, so the heating element 208 has high electrothermal conversion efficiency and heat radiation efficiency. Due to the heat of the carbon nanotube structure The heating element 208 composed of the carbon nanotube structure has a relatively fast thermal response speed and can be used for rapid heating of the color developing element 218. For example, a single layer of carbon nanotube film can be heated to about 2000K in 1 millisecond. This property allows the thermochromic element 220 prepared in the embodiment of the present invention to have a faster response speed. Since the carbon nanotube has strong chemical stability, the electric resistance of the heating element 208 using the carbon nanotube structure is stabilized, thereby improving the stability of the thermochromic element 220. In addition, since the carbon nanotube has a small size, the use of the carbon nanotube structure as the heating element 208 can reduce the size of the thermochromic element 220, thereby improving the display device using the thermochromic element 220. Resolution.

The first electrode 210 and the second electrode 212 are not limited in position, and may be directly disposed on the surface 2020 of the insulating substrate 202, or disposed on the surface of the heating element 208, or disposed on the surface of the color developing element 218, or disposed on a support. Body (not shown). The first electrode 210 and the second electrode 212 are made of a conductive material, and the shapes of the first electrode 210 and the second electrode 212 are not limited, and may be a conductive film, a metal piece or a metal lead. Preferably, the first electrode 210 and the second electrode 212 are each a conductive film. The conductive film has a thickness of from 0.5 nm to 500 μm. The material of the conductive film may be a metal, an alloy, indium tin oxide (ITO), antimony tin oxide (ATO), a conductive paste or a conductive polymer. The metal or alloy material may be an alloy of aluminum, copper, tungsten, molybdenum, gold, titanium, silver, rhodium, palladium, iridium or any combination of the foregoing. In this embodiment, the material of the first electrode 210 and the second electrode 212 is a conductive paste, which is printed on the insulating substrate 202 by screen printing. The composition of the conductive paste includes metal powder, low melting point glass powder, and a binder. Among them, the metal powder is preferably silver powder, and the binder is preferably terpineol or ethyl cellulose. The weight ratio of the metal powder in the conductive paste It is 50%~90%, the weight ratio of low-melting glass powder is 2%~10%, and the weight ratio of binder is 8%~40%.

When the thermochromic element 220 is in use, when a voltage is applied between the first electrode 210 and the second electrode 212, the heating element 208 begins to heat up and heat the color developing element 218. When the color developing element 218 is heated to a color changing temperature, the color developing element 218 displays a color or undergoes a color change. For example, the color developing element 218 prepared by Ag ₂ HgI _{4 is taken} as an example, and when heated to 42 ° C, the color developing element 218 changes from yellow to red. When the voltage is kept constant, the temperature of the color developing element 218 remains unchanged, thereby displaying a fixed color. It will be appreciated that by controlling the magnitude of the voltage applied between the first electrode 210 and the second electrode 212, the heating temperature of the heating element 208 can also be varied, thereby changing the color displayed by the color developing element 218. Since the color developing element 218 is made of a reversible thermochromic material, the color developing element 218 returns to its original color when heating is stopped.

The thermochromic element 220 provided by the first embodiment of the present invention is prepared by first laying a single-layer carbon nanotube film on the surface 2020 of the insulating substrate 202; secondly, printing the nano carbon through the screen. The surface of the tube is formed with a first electrode 210 and a second electrode 212 which are disposed at intervals; then, a layer of silver mercury iodide is deposited as a color developing element 218 between the first electrode 210 and the second electrode 212.

Referring to FIG. 6 , a second embodiment of the present invention provides a thermochromic element 320 including an insulating substrate 302 , a color developing element 318 , a heating element 308 , and a first electrode 310 and a second electrode 312 . The thermochromic element 320 is substantially identical in structure to the thermochromic element 220 provided by the first embodiment of the present invention, except that the color developing element 318 is disposed between the insulating substrate 302 and the heating element 308. Specifically, the color developing element 318 is disposed on the surface of the insulating substrate 302. The first electrode 310 and one The second electrodes 312 are respectively disposed on the surfaces of the insulating substrates 302 on both sides of the color developing element 318. The heating element 308 is disposed on the surface of the color developing element 318 to adhere to the color developing element 318 and covers the first electrode 310 and the second electrode 312. In this embodiment, since the heating element 308 covers the color developing element 318, the heating element 308 should have a good transparency, and a transparent carbon nanotube structure can be selected as a transparent carbon nanotube structure. Preferably, The heating element 308 is a single layer of carbon nanotube film. The method for preparing the thermochromic element 320 according to the second embodiment of the present invention is as follows: first, a first electrode 310 and a second electrode 312 are formed on the surface of the insulating substrate 302 by screen printing; and then, at the first electrode A layer of silver mercury iodide is deposited between the 310 and the second electrode 312 as the color developing element 318, and the color developing element 318 has the same thickness as the first electrode 310 and the second electrode 312; finally, a single layer of carbon nanotubes is used. A pull film is laid on the first electrode 310 and the second electrode 312 and covers the color developing element 318.

Referring to FIG. 7 , a third embodiment of the present invention provides a thermochromic element 420 including an insulating substrate 402 , a color developing element 418 , a heating element 408 , and a first electrode 410 and a second electrode 412 . The thermochromic element 420 is substantially identical in construction to the thermochromic element 320 provided by the second embodiment of the present invention, with the difference that the heating element 408 is spaced from the color developing element 418. Specifically, the color developing element 418 is disposed on the surface of the insulating substrate 402. The first electrode 410 and the second electrode 412 are respectively disposed on the surface of the insulating substrate 402 on both sides of the color developing element 418, and the height of the first electrode 410 and the second electrode 412 is higher than the thickness of the color developing element 418. The two ends of the heating element 408 are respectively disposed on the first electrode 410 and the second electrode 412, so that the heating element 408 is spaced apart from the color developing element 418 by the first electrode 410 and a second electrode 412. . It can be understood that the heating element 408 can be spaced apart from the color developing element 418 by two supports (not shown). Preferably, the heating element 408 should have a smaller heat capacity per unit area, preferably less than 2 x 10 ^-4 joules per square centimeter of Kelvin. In this embodiment, the heating element 408 is a single-layer carbon nanotube film with a heat capacity per unit area of 1.7×10 ^-6 joules per square centimeter Kelvin. Since the heating element 408 is spaced apart from the color developing element 418, heat exchange between the heating element 408 and the color developing element 418 is primarily performed by means of thermal radiation. Moreover, since the heating element 408 has a smaller heat capacity per unit area, the heating element 408 can reach a predetermined temperature in a shorter time. Therefore, the heating element 408 that reaches the predetermined temperature can provide a short and strong thermal pulse to the color developing element 418, thereby increasing the response speed of the thermochromic element 420. The method for preparing the thermochromic element 420 provided by the third embodiment of the present invention is substantially the same as the method for preparing the thermochromic element 320 provided by the second embodiment of the present invention, except that the thickness of the color developing element 418 is smaller than the first method. The thickness of the electrode 410 and the second electrode 412. Since the single-layer carbon nanotube film is self-supporting, the single-layer carbon nanotube film is spaced apart from the color developing element 418.

Referring to FIG. 8 , a fourth embodiment of the present invention provides a thermochromic element 520 including an insulating substrate 502 , a color developing element 518 , a heating element 508 , and a first electrode 510 and a second electrode 512 . The thermochromic element 520 has substantially the same structure as the thermochromic element 220 provided by the first embodiment of the present invention, except that the heating element 508 is disposed not only between the color developing element 518 and the insulating substrate 502 but also further extends to the display. The side of the color element 518. Specifically, the heating element 508 is disposed on the surface of the insulating substrate 502. The color developing element 518 is disposed on the surface of the heating element 508. The first electrode 510 and the second electrode 512 are respectively disposed on the surface of the insulating substrate 502 and located at Both sides of the color developing element 518. The heating element 508 further extends from the side of the color-developing element 518 opposite the first electrode 510 or the second electrode 512 to the surface of the first electrode 510 and the second electrode 512, thereby partially encapsulating the color-developing element 518. It can be understood that the heating element 508 can also be disposed on the upper surface of the color developing element 518 and further extend to the side of the color developing element 518 opposite to the first electrode 510 or the second electrode 512, thereby partially covering the color developing element 518. . In this embodiment, preferably, the heating element 508 is a single layer carbon nanotube film. Since the heating element 508 and the color developing element 518 have a large contact area, the heating efficiency of the heating element 508 to the color developing element 518 can be improved, thereby increasing the sensitivity of the thermochromic element 520. The method for preparing the thermochromic element 520 according to the fourth embodiment of the present invention is as follows: first, a first electrode 510 and a second electrode 512 are formed on the surface of the insulating substrate 502 by screen printing; and then a single layer is formed. A carbon nanotube film is laid on the first electrode 510 and the second electrode 512, and a pressure is applied to the carbon nanotube film to be adsorbed on the opposite side wall of the first electrode 510 and the second electrode 512. On the insulating substrate 502 between the first electrode 510 and the second electrode 512; a layer of silver mercury iodide is deposited as a color developing element 518 between the first electrode 510 and the second electrode 512.

Referring to FIG. 9, a fifth embodiment of the present invention provides a thermochromic element 620 including an insulating substrate 602, a color developing element 618, a first heating element 608, a second heating element 609, and a first electrode. 610 and a second electrode 612. The thermochromic element 620 is substantially identical in structure to the thermochromic element 220 provided by the first embodiment of the present invention, except that the thermochromic element 620 further includes a second heating element 609 disposed on the surface of the color developing element 618. Specifically, the first heating element 608 is disposed on a surface of the insulating substrate 602. The color developing element 618 is disposed on the first plus Thermal element 608 surface. The first electrode 610 and the second electrode 612 are respectively disposed on the surface of the first heating element 608 and on both sides of the color developing element 618. The second heating element 609 is disposed on the surface of the color developing element 618 and covers the first electrode 610 and the second electrode 612. In this embodiment, the first heating element 608 and the second heating element 609 are both single-layer carbon nanotube film. The sensitivity of the thermochromic element 620 can be further improved by heating the color developing element 618 simultaneously with the second heating element 608 and the second heating element 609. The method for preparing the thermochromic element 620 according to the fifth embodiment of the present invention is as follows: first, a first single-layer carbon nanotube film is laid on the surface of the insulating substrate 602; secondly, the nano carbon is printed on the surface through the screen. A first electrode 610 and a second electrode 612 are formed on the surface of the tube; and a layer of silver mercury iodide is deposited as a color developing element 618 between the first electrode 610 and the second electrode 612, and the color developing element 618 The thickness of the first electrode 610 and the second electrode 612 are the same; finally, a second single-layer carbon nanotube film is laid on the first electrode 610 and the second electrode 612 and the color developing element 618 is covered.

Referring to FIG. 10, a sixth embodiment of the present invention provides a thermochromic element 720 including an insulating substrate 702, a color developing element 718, a heating element 708, and a first electrode 710 and a second electrode 712. The thermochromic element 720 is substantially identical in structure to the thermochromic element 220 provided by the first embodiment of the present invention, except that the surface of the insulating substrate 702 has a recess 722, and the color developing element 718 is disposed in the recess. Inside the slot 722. Specifically, the color developing element 718 is disposed in the groove 722 and has a thickness equal to the depth of the groove 722. The heating element 708 is disposed on the surface of the color developing element 718 to cover the recess 722 and extend to the surface of the insulating substrate 702 outside the recess 722. The first electrode 710 and the second electrode 712 are disposed on the insulating substrate outside the recess 722 The surface of the heating element 708 on 702. The size, depth and shape of the groove 722 are not limited. Preferably, the color developing element 718 has the same thickness as the groove 722. In this embodiment, the heating element 708 is a single layer carbon nanotube film. Since the color developing element 718 is disposed in the recess 722, the original shape can still be maintained when the color developing element 718 is heated. The method for preparing the thermochromic element 720 according to the sixth embodiment of the present invention is as follows: first, a recess 722 is formed on the surface of the insulating substrate 702; secondly, a layer of silver-mercury iodide is deposited in the recess 722 as a color developing. Element 718; then, a single layer of carbon nanotube film is laid on the groove 722 and the color developing element 718 is covered; finally, the screen is printed on the surface of the carbon nanotube film to form a space. The first electrode 710 and the second electrode 712 are located on the insulating substrate 702 outside the recess 722.

The present invention further provides a thermochromic display device to which the thermochromic elements of the first to sixth embodiments described above are applied. The thermochromic display device includes a plurality of thermochromic elements arranged in a matrix to form a pixel array; and a driving circuit and a plurality of electrode leads, the driving circuit respectively controlling each heat through the plurality of electrode leads The heating elements of the color-changing elements operate independently. Specifically, embodiments of the present invention share a plurality of thermochromic elements with an insulating substrate, and independently control each thermochromic element to operate by an addressing circuit formed by row and column electrodes to achieve a display effect. Hereinafter, the thermochromic display device of the present invention will be further described in detail by taking a thermochromic display device to which the thermochromic element 220 of the first embodiment of the present invention is applied as an example.

Referring to FIG. 11 and FIG. 12, an embodiment of the present invention provides a thermochromic display device 20 including an insulating substrate 202, a plurality of row electrode leads 204, and a plurality of column electrodes. Lead 206 and a plurality of thermochromic elements 220. The plurality of row electrode leads 204 and the plurality of column electrode leads 206 are respectively disposed on the insulating substrate 202 at intervals in parallel, and the row electrode leads 204 and the column electrode leads 206 are disposed to form a network structure. Each two adjacent row electrode leads 204 and two adjacent column electrode leads 206 form a grid 214, and each grid 214 positions a pixel unit, that is, a thermochromic layer is disposed in each grid 214. Element 220.

The size, shape and thickness of the insulating substrate 202 are not limited, and those skilled in the art can set the size of the insulating substrate 202 according to actual needs, such as according to the predetermined size of the thermochromic display device 20. In this embodiment, the insulating substrate 202 is preferably a PET substrate having a thickness of about 1 mm and a side length of 48 mm. Since the plurality of thermochromic elements 220 in this embodiment share an insulating substrate 202, each of the thermochromic elements 220 does not require a special insulating substrate.

A plurality of row electrode leads 204 and a plurality of column electrode leads 206 intersect each other with a dielectric insulating layer 216 that ensures electrical insulation between the row electrode leads 204 and the column electrode leads 206 to prevent short circuits. The plurality of row electrode leads 204 or the column electrode leads 206 may be disposed at equal intervals or may be disposed at unequal intervals. Preferably, a plurality of row electrode leads 204 or column electrode leads 206 are equally spaced apart. The row electrode lead 204 and the column electrode lead 206 are a conductive material or an insulating material coated with a conductive material layer. The conductive material may be a conductive paste, a metal thin film, a nano carbon line, or indium tin oxide (ITO). In this embodiment, the plurality of row electrode leads 204 and the plurality of column electrode leads 206 are preferably planar conductors printed by using a conductive paste, and the row spacing of the plurality of row electrode leads 204 is 50 micrometers to 5 centimeters. The columnar pitch of the plurality of column electrode leads 206 is 50 micrometers to 2 centimeters. The line The pole lead 204 and the column electrode lead 206 have a width of 30 micrometers to 100 micrometers and a thickness of 10 micrometers to 50 micrometers. In this embodiment, the intersection angle of the row electrode lead 204 and the column electrode lead 206 may be 10 degrees to 90 degrees, preferably 90 degrees. In this embodiment, the row electrode lead 204 and the column electrode lead 206 can be prepared by printing a conductive paste on the insulating substrate 202 by a screen printing method. The composition of the conductive paste includes metal powder, low melting point glass powder, and a binder. Among them, the metal powder is preferably silver powder, and the binder is preferably terpineol or ethyl cellulose. In the conductive paste, the weight ratio of the metal powder is 50% to 90%, the weight ratio of the low-melting glass powder is 2% to 10%, and the weight ratio of the binder is 8% to 40%.

The material of the first electrode 210 and the second electrode 212 may be the same as or different from the material of the row electrode lead 204 and the column electrode lead 206. The first electrode 210 can be an extension of the row electrode lead 204, and the second electrode 212 can be an extension of the column electrode lead 206. The first electrode 210 and the row electrode lead 204 may be integrally formed, and the second electrode 212 and the column electrode lead 206 may also be integrally formed. In this embodiment, the first electrode 210 and the second electrode 212 are both planar conductors, and the size thereof is determined by the size of the grid 214. The first electrode 210 is directly electrically connected to the row electrode lead 204, and the second electrode 212 is directly electrically connected to the column electrode lead 206. The first electrode 210 and the second electrode 212 have a length of 20 micrometers to 1.5 centimeters, a width of 30 micrometers to 1 centimeter, and a thickness of 10 micrometers to 50 micrometers. Preferably, the second electrode 212 and the first electrode 210 have a length of 100 micrometers to 700 micrometers, a width of 50 micrometers to 500 micrometers, and a thickness of 20 micrometers to 100 micrometers. In this embodiment, the material of the first electrode 210 and the second electrode 212 is a conductive paste, which is printed on the insulating substrate 202 by screen printing.

In the present embodiment, 16 x 16 thermochromic elements 220 were prepared on an insulating substrate 202 having a side length of 48 mm. The heating element 208 in each thermochromic element 220 is a The carbon nanotubes are drawn, and each of the carbon nanotubes has a length of 300 microns and a width of 100 microns. The carbon nanotubes in the carbon nanotube film are connected end to end and extend from the first electrode 210 to the second electrode 212. Both ends of the carbon nanotube film are disposed between the first electrode 210 and the insulating substrate 202 and between the second electrode 212 and the insulating substrate 202. The carbon nanotube film is fixed to the insulating substrate 202 by its own adhesiveness.

Further, the thermochromic display device 20 may include a heat insulating material 222 disposed around each of the thermochromic elements 220. Specifically, the heat insulating material 222 may be disposed at all positions between the thermochromic element 220 and the row electrode lead 204 or the column electrode lead 206 in each of the grids 214 such that between adjacent thermochromic elements 220 Thermal isolation is achieved to reduce interference between the thermochromic elements 220. The heat insulating material 222 is aluminum oxide or an organic material. The organic material may be polyethylene terephthalate, polyethylene, polycarbonate or polyimine. In the embodiment, the heat insulating material 222 is preferably polyethylene terephthalate, and the thickness thereof is the same as the thickness of the row electrode lead 204 and the column electrode lead 206 and the first electrode 210 and the second electrode 212. The heat insulating material 222 can be prepared by a method such as physical vapor deposition or chemical vapor deposition. The physical vapor deposition method includes sputtering or evaporation, and the like.

Further, the thermochromic display device 20 may further include a protective layer 224 disposed on the insulating substrate 202 to cover the row electrode leads 204, the column electrode leads 206, and each of the thermochromic elements 220. The protective layer 224 is a transparent and insulating protective layer, and the material thereof may be an organic polymer, cerium oxide or aluminum oxide. The organic polymer may be polyethylene terephthalate, polyethylene, polycarbonate or polyimine. The thickness of the protective layer 224 is not limited, and may be selected according to actual conditions. Choose. In this embodiment, the protective layer 224 is made of polyethylene terephthalate and has a thickness of 0.5 mm to 2 mm. The protective layer may be formed on the insulating substrate 202 by a coating or deposition method. The protective layer serves to prevent the thermochromic display device 20 from making electrical contact with the outside during use, while also preventing the carbon nanotube structure in the heating element 208 from adsorbing foreign matter.

The thermochromic display device 20 further includes a driving circuit (not shown) for selectively applying current to the row electrode lead 204 and the column electrode lead 206 through the driving circuit to make the row electrode When the thermochromic element 220 electrically connected to the lead 204 and the column electrode lead 206 is operated, the display effect of the thermochromic display device 20 can be achieved.

The thermochromic element 220 of the thermochromic display device 20 uses a carbon nanotube as the heating element 208. Since the heat capacity of the carbon nanotube structure is small, the heating element 208 composed of the carbon nanotube structure With a faster thermal response speed, it can be used to rapidly heat the color developing element 218, so that the pixel unit of the thermochromic display device 20 of the present invention has a faster response speed. The thermochromic display device 20 controls the operation of each thermochromic element 220 by the row electrode lead 204 and the column electrode lead 206, respectively, and dynamic display can be realized. The thermochromic display device 20 can be applied to fields such as billboards, newspapers, books, and the like.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

220‧‧‧Thermal color change element

202‧‧‧Insulation base

2020‧‧‧ surface

208‧‧‧ heating element

210‧‧‧First electrode

212‧‧‧second electrode

218‧‧‧Color components

Claims (20)

A thermochromic element comprising: an insulating substrate, a color developing element and at least one heating element for heating the color developing element, the insulating substrate having a surface, the color developing element and the heating element being disposed on the insulating The surface of the substrate is modified in that the at least one heating element comprises at least one carbon nanotube structure, the carbon nanotube structure heating the color developing element, the color developing element comprising a reversible thermochromic material . The thermochromic element according to claim 1, wherein the color developing element and the at least one heating element are each a layered structure, and the color developing element and the at least one heating element are disposed in a laminated contact. The thermochromic element according to claim 2, wherein the thermochromic element comprises two heating elements respectively disposed on opposite surfaces of the color developing element. The thermochromic element according to claim 1, wherein the color developing element and the at least one heating element are each a layered structure, and the color developing element is spaced from the at least one heating element by a support. Settings. The thermochromic element according to claim 1, wherein the surface of the insulating substrate has a groove, and the color developing element is disposed on a surface of the insulating substrate in the groove. The thermochromic element according to claim 1, wherein the thermochromic element further comprises a first electrode and a second electrode, and the first electrode and the second electrode are spaced apart from the at least one The heating elements are electrically connected. The thermochromic element according to claim 1, wherein the reversible thermochromic material has a color change temperature of less than 200 °C. The thermochromic element according to claim 1, wherein the reversible thermochromic material is an inorganic reversible thermochromic material, and the inorganic reversible thermochromic material comprises silver-containing iodide, including Silver complex, silver-containing double salt, copper-containing iodide, copper-containing complex, copper-containing double salt, mercury-containing iodide, mercury-containing complex, mercury-containing double salt, a compound formed from a cobalt salt, a nickel salt and hexamethylenetetramine, a vanadium oxide, a vanadate, a chromate, and a mixture of any one or more of vanadium oxide, vanadate, and chromate. The thermochromic element according to claim 1, wherein the reversible thermochromic material is an organic reversible thermochromic material, and the organic reversible thermochromic material comprises a coloring agent and a color developing agent. And solvent. The thermochromic element according to claim 1, wherein the reversible thermochromic material is a liquid crystal reversible thermochromic material, and the liquid crystal reversible thermochromic material is a smectic liquid crystal or a nematic type. Liquid crystal or cholesteric liquid crystal. The thermochromic element according to claim 1, wherein the carbon nanotube structure comprises at least one carbon nanotube film. The thermochromic element according to claim 11, wherein the carbon nanotube film has a heat capacity per unit area of 2 × 10 ^-4 Joules per square centimeter Kelvin. The thermochromic element according to claim 11, wherein the carbon nanotube film is a self-supporting structure composed of a plurality of carbon nanotubes, and the plurality of carbon nanotubes are preferentially oriented in the same direction. Orientation. The thermochromic element according to claim 13, wherein a plurality of carbon nanotubes in the carbon nanotube film are connected end to end by van der Waals force. The thermochromic element according to claim 1, wherein the carbon nanotube structure comprises at least one nano carbon line, and the nano carbon line comprises a plurality of carbon nanotubes along the nano carbon The length of the pipeline is arranged in parallel or spirally along the length of the nanocarbon pipeline. A thermochromic display device comprising: an insulating substrate having a surface; a plurality of row electrode leads and a plurality of column electrode leads disposed on a surface of the insulating substrate, wherein the plurality of row electrode leads and the plurality of column electrode leads cross each other , each two adjacent row electrode leads form a grid with each two adjacent column electrode leads, and the row electrode leads are electrically insulated from the column electrode leads; and a plurality of items are in items 1 to 15 of the patent application scope In any of the thermochromic elements of any of the above, each thermochromic element corresponds to a grid arrangement. The thermochromic display device of claim 16, wherein the thermochromic display device further comprises a photochromic display device disposed between each of the thermochromic elements and the row electrode lead or the column electrode lead. Thermal insulation material. The thermochromic display device according to claim 17, wherein the heat insulating material is aluminum oxide or an organic material. The thermochromic display device of claim 16, wherein the thermochromic display device further comprises a plurality of row electrode leads, a plurality of column electrode leads, and a plurality of thermochromic elements. A transparent protective layer on the surface. A thermochromic display device comprising: an insulating substrate having a surface; and a plurality of thermochromic elements according to any one of claims 1 to 15, wherein the plurality of thermochromic elements are in a row Arranged to form a pixel array; And a driving circuit and a plurality of electrode leads, the driving circuit independently controlling the heating elements of each of the thermochromic elements to operate independently through the plurality of electrode leads.