KR20140020443A - A display device which can be transformed as a mirror - Google Patents

Abstract

A display device according to the present invention may comprise a display part on a substrate and an electrochromic part on the display part. The display part may comprise a transparent display such as an organic light emitting diode or an electronic paper. An electrochromic layer may be discoloured so that the electrochromic part acts as a black backplane in a display mode. To realize complete black color, the electrochromic part may comprise a first electrochromic layer and a second electrochromic layer which absorb light of wavelengths different from each other. To realize complete black color, an optical filter layer may be included between the display part and the electrochromic part. The electrochromic layer is transformed to a transparent state in a mirror mode so that a metal electrode of the electrochromic part can act as a mirror. The display device according to the present invention may be transformed to the display mode and the mirror mode.

Description

A display device which can be transformed as a mirror}

The present invention relates to a display element, and more particularly to a display element capable of mirror switching.

Recently, portable electronic devices such as mobile phones and portable information terminals include various functions to meet the needs of consumers. For example, the portable electronic device may include a mirror function. Mirror function is generally implemented by attaching a mirror to one side of the portable electronic device. This allows the user to use the mirror of the portable electronic device without having to carry a separate mirror. However, in order to attach the mirror to the portable electronic device, a separate space for attaching the mirror may be required. Therefore, there is a problem in that the volume of the electronic device increases and the constraint of design increases.

The problem to be solved of the present invention relates to a display device capable of mirror switching.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

The present invention relates to a display device capable of mirror switching. According to an embodiment, the display device may include a display unit on a substrate, a lower electrode on the display unit, an upper electrode spaced apart from and facing the lower electrode, an upper electrode including a metal material, an electrolyte layer between the lower electrode and the upper electrode, and A first electrochromic layer between the lower electrode and the electrolyte layer, and a second electrochromic layer between the electrolyte layer and the upper electrode, wherein the second electrochromic layer is light absorbed by the first electrochromic layer. It can absorb light of different wavelengths.

In some embodiments, the display unit may further include an optical filter layer between the display unit and the lower electrode, and the optical filter layer may absorb light having a wavelength different from that of the first and second electrochromic layers.

According to an embodiment, one of the first electrochromic layer and the second electrochromic layer, one includes WO ₃ , TiO ₂ , MoO ₃ , or Nb ₂ O ₅ , and the other Ni (OH) ₂ , Ir (OH) _x , or CoO ₂ .

In example embodiments, the upper electrode may include at least one of aluminum (Al), silver (Ag), gold (Au), copper (Cu), and platinum (Pt).

According to an embodiment, the lower electrode may include zinc oxide (ZnO), tin oxide (SnO ₂ ), indium tin oxide (ITO), gallium doped zinc oxide (ZnO: Al), or boron doped oxide. It may include zinc (ZnO: B), and at least one of aluminum zinc oxide (AZO) doped with aluminum.

In example embodiments, the display unit may include a liquid crystal display, an organic light emitting diode, or electronic paper.

According to an embodiment, the electrolyte layer is tantalum pentoxide (Ta ₂ O ₅ ), antimony oxide (Antimonium oxide, Sb ₂ O ₅ ), titanium oxide (Titanium oxide, TiO ₂ ), zirconium oxide (Zirconium oxide) , ZrO ₂ ), aluminum oxide (Al ₂ O ₃ ), Poly (acrylic acid), Poly (Methyl methacrylate), Poly (ethylene oxide), Poly (vinyl chloride) Propylene-based materials, and carbonate ( Carbonate) may include at least one of the materials.

According to an embodiment, a display element includes a display unit on a transparent substrate, an optical filter layer on the display unit, a transparent electrode on the optical filter layer, an electrochromic layer on the transparent electrode, an electrolyte layer on the electrochromic layer, and an ion storage on the electrolyte layer. And a metal electrode on the ion storage layer, wherein the optical filter layer may absorb light having a wavelength different from that of the electrochromic layer.

In example embodiments, the display unit may include a liquid crystal display, an organic light emitting diode, or electronic paper.

According to an embodiment, the electrochromic layer may include at least one of WO ₃ , TiO ₂ , MoO _{3 ,} Nb ₂ O ₅ , Ni (OH) ₂ , Ir (OH) x, or CoO ₂ .

According to an embodiment, the electrolyte layer is tantalum pentoxide (Ta ₂ O ₅ ), antimony oxide (Antimonium oxide, Sb ₂ O ₅ ), titanium oxide (Titanium oxide, TiO ₂ ), zirconium oxide (Zirconium oxide) , ZrO ₂ ), aluminum oxide (Al ₂ O ₃ ), Poly (acrylic acid), Poly (Methyl methacrylate), Poly (ethylene oxide), Poly (vinyl chloride) Propylene-based materials, and carbonate ( Carbonate) may include at least one of the materials.

According to an embodiment, the ion storage layer may include CeO ₂ or TiO ₂ .

The display device according to the present invention may include a display unit and an electrochromic unit on a substrate. The display unit may include a transparent display such as an organic light emitting device or an electronic paper. In the display mode, the electrochromic layer may be discolored so that the electrochromic portion serves as a black backplane. The electrochromic portion may include a first electrochromic layer and a second electrochromic layer that absorb light of different wavelengths so as to realize a more complete black color. In order to realize a perfect black color, an optical filter layer may be further included between the display unit and the electrochromic unit. In the mirror mode, the electrochromic layer is converted into a transparent state so that the metal electrode can act as a mirror. Therefore, the display element can be switched between the display mode and the mirror mode.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding and assistance of the invention, reference is made to the following description, taken together with the accompanying drawings,
1 to 10 are cross-sectional views illustrating display devices according to embodiments of the present invention.

In order to fully understand the structure and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It will be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof. Those of ordinary skill in the art will understand that the concepts of the present invention may be practiced in any suitable environment.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms 'comprises' and / or 'comprising' mean that the stated element, step, operation and / or element does not imply the presence of one or more other elements, steps, operations and / Or additions.

When a film (or layer) is referred to herein as being on another film (or layer) or substrate it may be formed directly on another film (or layer) or substrate, or a third film Or layer) may be interposed.

 Although the terms first, second, third, etc. have been used in various embodiments herein to describe various regions, films (or layers), etc., it is to be understood that these regions, do. These terms are merely used to distinguish any given region or film (or layer) from another region or film (or layer). Thus, the membrane referred to as the first membrane in one embodiment may be referred to as the second membrane in another embodiment. Each embodiment described and exemplified herein also includes its complementary embodiment. Like numbers refer to like elements throughout the specification.

The terms used in the embodiments of the present invention may be construed as commonly known to those skilled in the art unless otherwise defined.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a display device according to an embodiment of the present invention.

Referring to FIG. 1, the display device 1 includes a display unit 200 and an electrochromic unit 300 on a substrate 100, and the electrochromic unit 300 is sequentially stacked on the display unit 200. The lower electrode 310, the electrochromic layer 320, the electrolyte layer 330, the ion storage layer 340, and the upper electrode 360 may be included.

The substrate 100 may be a transparent substrate. For example, the substrate 100 may be a glass substrate, a plastic substrate, an indium tin oxide (ITO) substrate, or a fluorine-doped tin oxide (FTO) substrate.

The display unit 200 may be transparent. For example, the display unit 200 may include a liquid crystal display (LCD), an organic light emitting diode (OLED), or electronic paper.

The lower electrode 310 may include a transparent conductive oxide (TCO). For example, the lower electrode 310 may be zinc oxide (ZnO), tin oxide (SnO ₂ ), indium tin oxide (ITO), gallium doped zinc oxide (ZnO: Al), or boron doped. Zinc oxide (ZnO: B), and / or aluminum doped zinc oxide (AZO: Aluminum Zinc Oxide).

The electrochromic layer 320 may change color in accordance with the flow of current by applying power. Thereby, the light transmittance and reflectance can be adjusted. According to an embodiment, the electrochromic layer 320 may include an inorganic coloring material. Inorganic coloring materials include cathodic coloration materials and oxidative coloration materials. Reducing discolorants are colored when the cathodic reaction occurs, and discolored when the anodic reaction occurs. Reducing discolorants are WO ₃ , TiO ₂ , MoO _{3 ,} and / or Nb ₂ O ₅ . Oxidative discoloration material may be colored during the oxidation reaction and discolored during the reduction reaction. The oxidizing material may be Ni (OH) ₂ , Ir (OH) _x , and / or CoO ₂ . According to another embodiment, the electrochromic layer 320 may include an organic coloring material. The organic coloring material may be polyaniline.

The electrolyte layer 330 may supply an oxidation / reduction material that reacts with the electrochromic material. The electrolyte layer 330 may include a solid, liquid, and / or gel electrolyte layer. The electrolyte layer 330 may include a material having high ion conductivity but low electron conductivity. The electrolyte layer 330 is tantalum pentoxide (Ta ₂ O ₅ ), antimony oxide (Antimonium oxide, Sb ₂ O ₅ ), titanium oxide (Titanium oxide, TiO ₂ ), zirconium oxide (ZrO ₂₎ ) And / or inorganic oxides such as aluminum oxide (Al ₂ O ₃ ), and may include at least one of poly (acrylic acid), Poly (Methyl methacrylate), Poly (ethylene oxide), and Poly (vinyl). At least one of a polymer material such as chloride) may be included, and may include at least one of a propylene-based material and / or a carbonate-based material. The thickness of the electrolyte layer 330 may be adjusted. Accordingly, light that is not absorbed by the electrochromic unit 300 may be minimized during the display mode operation.

The ion storage layer 340 may include CeO ₂ , and / or TiO ₂ . The ion storage layer 340 may serve to store ions (eg, hydrogen ions or lithium ions) at the time of electrochromic coloring and decolorization. The materials used in the ion storage layer do not have an absorption wavelength in the visible light in either the oxidized state or the reduced state and thus always have transparent characteristics. The upper electrode 360 may be a metal electrode. The upper electrode 360 may include at least one of aluminum (Al), silver (Ag), gold (Au), copper (Cu), and / or platinum (Pt). The upper electrode 360 may provide a mirror function.

The operating principle of the display element 1 according to the embodiment is as follows. The display element 1 may be switched between the display mode and the mirror mode.

The display mode may be operated by applying a negative voltage to the lower electrode 310 and a positive voltage to the upper electrode 360. The electrochromic layer 320 may include a reducing discoloration material such as tungsten oxide (WO ₃ ). When a voltage is applied, the electrochromic layer 320 is colored through the following formula.

≪

WO ₃ (transparent ^{color) + xe - + xM + <} ==> M x WO 3 ( dark blue)

In the above formula, M may be hydrogen (H) or lithium (Li). WO ₃ may be in a transparent state, H _x WO ₃ may be in a colored state.

When a voltage is applied, ions M ⁺ in the ion storage layer 340 may move to the electrochromic layer 320 through the electrolyte layer 330. The migrated ions may react with WO ₃ , which is a reducing color change material of the electrochromic layer 320, to generate H _x WO ₃ . The electrochromic layer 320 may be changed into a dark blue colored state. Therefore, the electrochromic unit 300 of the display device 1 may serve as a black backplane required for the operation of the display unit 200.

The mirror mode may be operated by applying a positive voltage to the lower electrode 310 and a negative voltage to the upper electrode 360. When a voltage opposite to the display mode is applied, ions M ⁺ may escape from the electrochromic layer 320 and move to the ion storage layer 340 through the electrolyte layer 330. Electrochromic layer 320 in M _x WO ₃ state can be converted to WO ₃ and M ⁺ . The electrochromic layer 320 may change to a transparent state. Therefore, the electrochromic part 300 may exhibit the characteristics of the mirror by the upper electrode 360 including a metal material.

The display device including the oxidative color change material may drive the display mode and the mirror mode by applying a voltage in a direction opposite to the display device including the reduction color change material.

2 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Referring to FIG. 1, overlapping contents are omitted for simplicity of description.

Referring to FIG. 2, the display device 2 includes a display unit 200 on the substrate 100, an optical filter layer 400 on the display unit 200, and an electrochromic unit 300 on the optical filter layer 400. can do. The electrochromic unit 300 includes a lower electrode 310, an electrochromic layer 320, an electrolyte layer 330, an ion storage layer 340, and an upper electrode 360 that are sequentially stacked on the display unit 200. It may include.

The optical filter layer 400 may implement a more complete black backplane in the display mode operation. The optical filter layer 400 may absorb light having a wavelength that the electrochromic layer 320 does not absorb. For example, when the electrochromic layer 320 includes tungsten oxide (WO ₃ ), the optical filter layer 400 may selectively absorb dark blue light that is not absorbed by tungsten oxide. The thickness of the optical filter layer 400 may be adjusted.

3 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Referring to FIG. 1, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 3, the display device 3 includes a display unit 200 and an electrochromic unit 300 on the substrate 100, and the electrochromic unit 300 includes a lower electrode (eg, a display unit 200) on the display unit 200. 310, a first electrochromic layer 320, an electrolyte layer 330, a second electrochromic layer 350, and an upper electrode 360 may be included.

According to an embodiment, the first electrochromic layer 320 may include a reducing color change material. For example, the first electrochromic layer 320 may include WO ₃ , TiO ₂ , MoO _{3 ,} and / or Nb ₂ O ₅ . According to another embodiment, the first electrochromic layer 320 may include an oxidative color change material. For example, the first electrochromic layer 320 may include at least one of Ni (OH) ₂ , Ir (OH) _x , and / or CoO ₂ .

The second electrochromic layer 350 may be provided on the electrolyte layer 330. When the first electrochromic layer 320 includes a reducing color change material, the second electrochromic layer 350 may be an oxidative color change material (eg, Ni (OH) ₂ , Ir (OH) _x , and / or CoO _2). ) May be included. When the first electrochromic layer 320 includes an oxidative color change material, the second electrochromic layer 350 may be a reducing color change material (eg, WO ₃ , TiO ₂ , MoO _{3 ,} and / or Nb ₂ O ₅ ). It may include.

If a negative voltage is applied to the lower electrode 310 and a positive voltage is applied to the upper electrode 360 of the display device 3 according to the exemplary embodiment, the display mode may be activated. Ions may migrate from the second electrochromic layer 350 including the oxidizing material to the first electrochromic layer 320 including the reducing material. Both the first electrochromic layer 320 and the second electrochromic layer 350 may be colored. The second electrochromic layer 350 may absorb light having a wavelength different from that of the light absorbed by the first electrochromic layer 320. For example, the second electrochromic layer 350 may include a color change material having a complementary color relationship with the color change material of the first electrochromic layer 320. The lower electrode 310, the first electrochromic layer 320, the electrolyte layer 330, the second electrochromic layer 350 and / or the upper electrode 360 absorb the maximum light from the electrochromic part 300. The thickness can be adjusted so that The thickness of the lower electrode 310, the first electrochromic layer 320, the electrolyte layer 330, the second electrochromic layer 350, and / or the upper electrode 360 may be the first electrochromic layer 320 and the first electrode. 2 may be adjusted to absorb light having a wavelength that is not absorbed by the electrochromic layer 350 through interference. Therefore, the display 200 may display a completely black color.

The mirror mode may be operated by applying a positive voltage to the lower electrode 310 and a negative voltage to the upper electrode 360. Ions may migrate from the first electrochromic layer 320 including a reducing color change material to the second electrochromic layer 350 including an oxidative color change material. The first electrochromic layer 320 and the second electrochromic layer 350 may be discolored to indicate a transparent state. The display element 3 may act as a mirror by the upper electrode 360 including a metal material.

When the first electrochromic layer 320 includes an oxidizing color change material and the second electrochromic layer 350 includes a reducing color change material, voltages in opposite directions are applied to change the display mode and the mirror mode of the display element 3. It can work.

4 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Referring to FIG. 3, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 4, the display element 4 may include a display unit 200, an optical filter layer 400, and an electrochromic unit 300, which are sequentially provided on the substrate 100. The display unit 200 and the electrochromic unit 300 may be the same as or similar to those described with reference to FIG. 3.

An optical filter layer 400 may be provided between the display unit 200 and the electrochromic unit to absorb light having a wavelength that is not absorbed by the first electrochromic layer 320 and / or the second electrochromic layer 350. have. The optical filter layer 400 may implement a more complete black backplane in the display mode operation.

5 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. 1 and 2, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 5, the display element 5 includes a display unit 200 including an organic light emitting element, an electrochromic unit 300, and an optical filter layer 400 between the display unit 200 and the electrochromic unit 300. ) May be included. The display unit 200 may include a first electrode 201, an organic light emitting layer 203, and / or a second electrode 205 sequentially stacked on the substrate 100. The electrochromic unit 300 may include a lower electrode 310, an electrochromic layer 320, an electrolyte layer 330, an ion storage layer 340, and an upper electrode 360.

The substrate 100 can transmit light. The substrate 100 may be a glass substrate, a plastic substrate, an ITO substrate, or an FTO substrate.

The first electrode 201 may be an anode electrode. The first electrode 201 may receive a voltage from the outside to supply holes to the organic light emitting layer 203. The first electrode 201 may transmit light. The first electrode 201 may include a transparent conductive oxide (TCO). For example, the first electrode 201 may be zinc oxide (ZnO), tin oxide (SnO ₂ ), indium tin oxide (ITO), gallium doped zinc oxide (ZnO: Al), or boron doped. Zinc oxide (ZnO: B), and / or aluminum doped zinc oxide (AZO: Aluminum Zinc Oxide).

The organic light emitting layer 203 may generate light through recombination of holes supplied from the first electrode 201 and electrons supplied from the second electrode 205. The organic light emitting layer 203 may have a single layer structure or a multilayer structure including an auxiliary layer. The organic light emitting layer 203 may further include an auxiliary layer for increasing luminous efficiency. The auxiliary layer may include at least one of a hole injecting layer, a hole transfer layer, an electron transfer layer, and / or an electron injecting layer.

The organic light emitting layer 203 may include at least one of organic light emitting materials. For example, the organic light emitting layer 203 may be a polyfluorene derivative, a (poly) paraphenylenevinylene derivative, a polyphenylene derivative, or a polyvinylcarbazole derivative. , Polythiophene derivatives, anthracene derivatives, butadiene derivatives, tetratracene derivatives, distyrylarylene derivatives, benzazole derivatives and / or carbazole It may include at least one of). According to an embodiment, the organic light emitting layer 203 may further include a dopant in the organic light emitting material. Dopants are xanthene, perylene, coumarin, rhodamine, rubrene, dicyanomethylenepyran, thiopyran, (thia) pyryl At least any of (thia) pyrilium, periflanthene derivatives, indenoperylene derivatives, carbostyryl, nile red, and / or quinacridone Can contain one

The second electrode 205 may be a cathode. The second electrode 205 may be supplied with a voltage from the outside to supply electrons to the organic light emitting layer 203. The second electrode 205 may be a transparent electrode. The second electrode 205 may include the same or similar material as the first electrode 201.

6 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. 4 and 5, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 6, the display element 6 includes an optical filter layer 400 between a display unit 200 including an organic light emitting element, an electrochromic unit 300, and a display unit 200 and an electrochromic unit 300. It may include. The display unit 200 may include a first electrode 201, an organic light emitting layer 203, and a second electrode 205 that are sequentially stacked on the substrate 100. The electrochromic unit 300 may include a lower electrode 310, a first electrochromic layer 320, an electrolyte layer 330, a second electrochromic layer 350, and an upper electrode 360.

According to an embodiment, the electrochromic layer 320 may include a reducing color change material. For example, the electrochromic layer 320 may include WO ₃ , TiO ₂ , MoO _{3 ,} and / or Nb ₂ O ₅ . According to another embodiment, the first electrochromic layer 320 may include an oxidative color change material. For example, the first electrochromic layer 320 may include Ni (OH) ₂ , Ir (OH) _x , and / or CoO ₂ .

When the first electrochromic layer 320 includes a reducing color change material, the second electrochromic layer 350 may include an oxidative color change material (eg, Ni (OH) ₂ , Ir (OH) _x , and CoO ₂ ). Can be. When the first electrochromic layer 320 includes an oxidative color change material, the second electrochromic layer 350 may include a reducing color change material. The first electrochromic layer 320 may absorb light having a wavelength different from that of the light absorbed by the second electrochromic layer 350. For example, the second electrochromic layer 350 may include a color change material having a complementary color relationship with the color change material of the first electrochromic layer 320. Thus, the second electrochromic layer 350 may allow the electrochromic portion 300 to serve as a more complete black backplane.

The optical filter layer 400 may absorb light having a wavelength that the first electrochromic layer 320 and the second electrochromic layer 350 do not absorb.

7 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Hereinafter, referring to FIG. 1, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 7, the display element 7 may include a display unit 200 including an electrophoretic electronic paper, an electrochromic unit 300, and an optical filter layer between the display unit 200 and the electrochromic unit 300. 400. The display unit 200 may include a first electrode 211 on the substrate 100, a second electrode 217 facing and spaced apart from the first electrode 211, and a first electrode 211 and a second electrode 217. ) May include a microcapsule 213 and a binder 215. The electrochromic unit 300 may include a lower electrode 310, an electrochromic layer 320, an electrolyte layer 330, an ion storage layer 340, and an upper electrode 360.

The first electrode 211 may include a transparent conductive oxide (TCO). For example, the first electrode 211 may be zinc oxide (ZnO), tin oxide (SnO ₂ ), indium tin oxide (ITO), gallium doped zinc oxide (ZnO: Al), or boron doped. Zinc oxide (ZnO: B), and / or aluminum doped zinc oxide (AZO: Aluminum Zinc Oxide).

The second electrode 217 may be provided to face the first electrode 211 while being spaced apart from each other. The second electrode 217 may include the same or similar material as the first electrode 211.

The microcapsule 213 may be provided between the first electrode 211 and the second electrode 217. The microcapsule 213 may include a dielectric fluid 213a, first particles 213b, and second particles 213c. The dielectric fluid 213a may be filled in the gap between the first fine particles 213b and the second fine particles 213c in the capsule. The first fine particles 213b represent a first color and may be charged with a positive charge. The second fine particles 213c may exhibit a second color different from the first color and may be charged with a negative charge. The binder 215 may fill the voids between the microcapsules 213. When a positive voltage is applied to the first electrode 211, the negatively charged second fine particles 213c may move to the first electrode 211. Therefore, the display unit 200 including the electronic paper may display the second color. When a negative voltage is applied to the first electrode 211, the first particles 213b may move to the first electrode 211 to display a first color. Therefore, the display 200 may display a text or an image.

8 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Hereinafter, referring to FIG. 7, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 8, the display element 8 may include a display unit 200 and an electrochromic unit 300. The display unit 200 may be the same as or similar to that described with reference to FIG. 7. The electrochromic unit 300 may include a lower electrode 310, a first electrochromic layer 320, an electrolyte layer 330, a second electrochromic layer 350, and an upper electrode 360.

According to an embodiment, the electrochromic layer 320 may include a reducing color change material. For example, the electrochromic layer 320 may include WO ₃ , TiO ₂ , MoO _{3 ,} and / or Nb ₂ O ₅ . According to another embodiment, the first electrochromic layer 320 may include an oxidative color change material. For example, the first electrochromic layer 320 may include at least one of Ni (OH) ₂ , Ir (OH) _x , and / or CoO ₂ .

When the first electrochromic layer 320 includes a reducing color change material, the second electrochromic layer 350 may include an oxide color change material. When the first electrochromic layer 320 includes an oxidative color change material, the second electrochromic layer 350 may include a reducing color change material. The second electrochromic layer 350 may absorb light having a wavelength different from that of the light absorbed by the first electrochromic layer 320. Thus, the second electrochromic layer 350 may allow the electrochromic portion 300 to provide a more complete black backplane.

The optical filter layer 400 may be further included between the display unit 200 and the electrochromic unit 300. The optical filter layer 400 may absorb light having a wavelength that is not absorbed by the first electrochromic layer 320 and / or the second electrochromic layer 350.

9 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 9, the display element 9 may include a display unit 200 including dry electronic paper, an electrochromic unit 300, and an optical filter layer 400. The display unit 200 includes a first electrode 220 on the substrate 100, a second electrode 229, a first electrode 220, and a second electrode 229 spaced apart from and facing the first electrode 220. The partition wall 223 forming the cells 221 isolated from each other, and the positively charged particles 225 and the auxiliary charged particles 227 filled in the cells 221 between the first electrode 220 and the second electrode 229. ) May be included. The electrochromic part 300 and the light filter layer 400 may be the same as or similar to those described with reference to FIG. 2.

The first electrode 220 may be a transparent electrode such as ITO.

The second electrode 229 may be provided to face the first electrode 220 while being spaced apart from each other. The second electrode 229 may be a transparent electrode such as ITO.

The partition wall 223 may be provided between the first electrode 220 and the second electrode 229. The partition wall 223 may separate the space between the first electrode 220 and the second electrode 229. One or more cells 221 may be provided that are isolated from each other by the partition wall 223.

The positively charged particles 225 and the auxiliary charged particles 227 are provided in the space between the first electrode 220 and the second electrode 229. The positive charging particle 225 may be black, and the auxiliary charging particle 227 may be white. The positively charged particles 225 may be charged with positive charges, and the secondary charged particles 227 may be charged with negative charges. Voltage may be applied to the first electrode 220 and the second electrode 229. The positive charged particles 225 and the auxiliary charged particles 227 may move toward the first electrode 220 and / or the second electrode 229 to implement the color of the display unit 200 according to the characteristics of the applied voltage.

10 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Hereinafter, referring to FIG. 9, overlapping contents will be omitted for simplicity of description.

Referring to FIG. 10, the display element 10 may include a display unit 200, an electrochromic unit 300, and an optical filter layer 400 between the display unit 200 and the electrochromic unit 300. . The display unit 200 may be the same as or similar to that described with reference to FIG. 9. The electrochromic unit 300 may include a lower electrode 310, a first electrochromic layer 320, an electrolyte, a second electrochromic layer 350, and an upper electrode 360.

The first electrochromic layer 320 may be provided on the lower electrode 310. According to an embodiment, the electrochromic layer 320 may include a reducing color change material. For example, the electrochromic layer 320 may include WO ₃ , TiO ₂ , MoO _{3 ,} and / or Nb ₂ O ₅ . According to another embodiment, the first electrochromic layer 320 may include an oxidative color change material. For example, the first electrochromic layer 320 may include Ni (OH) ₂ , Ir (OH) _x , and / or CoO ₂ .

The second electrochromic layer 350 may be provided on the electrolyte layer 330. When the first electrochromic layer 320 includes a reducing color change material, the second electrochromic layer 350 may include an oxide color change material. When the first electrochromic layer 320 includes an oxidative color change material, the second electrochromic layer 350 may include a reducing color change material. The second electrochromic layer 350 may absorb light having a wavelength different from that of the light absorbed by the first electrochromic layer 320.

The display device according to the present invention can be switched between the display mode and the mirror mode.

Claims (12)

A display unit on the substrate;
A lower electrode on the display unit;
An upper electrode spaced apart from and facing the lower electrode and including a metal material;
An electrolyte layer between the lower electrode and the upper electrode;
A first electrochromic layer between the lower electrode and the electrolyte layer; And
Including a second electrochromic layer between the electrolyte layer and the upper electrode,
And the second electrochromic layer absorbs light having a wavelength different from that of the light absorbed by the first electrochromic layer.
The method of claim 1,
Further comprising an optical filter layer between the display unit and the lower electrode,
And the optical filter layer absorbs light having a wavelength different from that of the first electrochromic layer and the second electrochromic layer.
The method of claim 1,
Among the first electrochromic layer and the second electrochromic layer, one includes WO ₃ , TiO ₂ , MoO _{3 ,} or Nb ₂ O ₅ , the other is Ni (OH) ₂ , Ir (OH) _x Or CoO ₂ .
The method of claim 1, wherein
The upper electrode includes at least one of aluminum (Al), silver (Ag), gold (Au), copper (Cu), and platinum (Pt).
The method of claim 1,
The lower electrode includes zinc oxide (ZnO), tin oxide (SnO ₂ ), indium tin oxide (ITO), gallium-doped zinc oxide (ZnO: Al), and boron-doped zinc oxide (ZnO: B And aluminum zinc-doped zinc oxide (AZO).
The method of claim 1,
The electrolyte layer is tantalum oxide (Tantalum pentoxide, Ta ₂ O ₅ ), antimony oxide (Antimonium oxide, Sb ₂ O ₅ ), titanium oxide (Titanium oxide, TiO ₂ ), zirconium oxide (ZrO ₂ ), Among aluminum oxide, Al ₂ O ₃ , Poly (acrylic acid), Poly (Methyl methacrylate), Poly (ethylene oxide), Poly (vinyl chloride) Propylene-based material, and Carbonate-based material Display device comprising at least one.
The method of claim 1, wherein
The display unit includes a liquid crystal display device, an organic light emitting device or electronic paper.
A display unit on the transparent substrate;
An optical filter layer on the display unit;
A transparent electrode on the optical filter layer;
An electrochromic layer on the transparent electrode;
An electrolyte layer on the electrochromic layer;
An ion storage layer on the electrolyte layer; And
A metal electrode on the ion storage layer,
The optical filter layer absorbs light of a wavelength different from that of the electrochromic layer.
The method of claim 8, wherein
The display unit includes a liquid crystal display device, an organic light emitting device or electronic paper.
The method of claim 8,
The electrochromic layer includes at least one of WO ₃ , TiO ₂ , MoO _{3 ,} Nb ₂ O ₅ , Ni (OH) ₂ , Ir (OH) x, and CoO ₂ .
The method of claim 8,
The electrolyte layer is tantalum oxide (Tantalum pentoxide, Ta ₂ O ₅ ), antimony oxide (Antimonium oxide, Sb ₂ O ₅ ), titanium oxide (Titanium oxide, TiO ₂ ), zirconium oxide (ZrO ₂ ), Among aluminum oxide, Al ₂ O ₃ , Poly (acrylic acid), Poly (Methyl methacrylate), Poly (ethylene oxide), Poly (vinyl chloride) Propylene-based material, and Carbonate-based material Display device comprising at least one.
The method of claim 8,
The ion storage layer includes a CeO ₂ or TiO ₂ display device.

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