Electronic dimming device

Abstract

The present invention provides an electronic dimming device with which it is possible to suppress a decrease in response speed and color density during coloration driving even when coloration driving and decolorization driving are cycled. The electronic dimming device comprises: an electrochromic element that has a first electrochromic layer in which an oxidation reaction occurs, an electrolyte layer, and a second electrochromic layer in which a reduction reaction occurs, at least one of the first electrochromic layer and the second electrochromic layer producing light by means of the oxidation reaction or the reduction reaction; a voltage measurement unit that measures the open-circuit voltage of the electrochromic element; and a voltage application unit that performs coloration driving, which causes the electrochromic element to develop color by applying a voltage to said element, and refresh decolorization driving, which drives a circuit of the electrochromic element until the open-circuit voltage, which is measured by means of the voltage measurement unit, decreases to or below a prescribed value.

Description

Electronic dimming device

[0001] This invention relates to an electronic dimming device.

[0002] Patent Document 1 discloses an electrochromic element having a pair of substrates and an electrochromic medium disposed between them. When a voltage is applied to electrodes provided on the pair of substrates, the transmittance of the compound in the electrochromic medium changes. This makes it possible to adjust the amount of light passing through the electrochromic element.

[0003] Japanese Patent Publication No. 2017-167317

[0004] Such electrochromic elements may be driven to repeatedly cycle between a colored state with reduced transmittance and a decolorized state with increased transmittance. In this case, the response speed during color development may gradually decrease, potentially preventing the achievement of the target response speed.

[0005] The object of the present invention is to provide an electronic dimming device that can suppress the decrease in response speed and color density during color activation, even when color activation and deactivation are repeated.

[0006] Such objectives are achieved by the present invention as described in (1) to (14) below. (1) An electronic dimming device characterized by comprising: an electrochromic element having a first electrochromic layer in which an oxidation reaction takes place, an electrolyte layer, and a second electrochromic layer in which a reduction reaction takes place, wherein at least one of the first electrochromic layer and the second electrochromic layer emits light due to the oxidation reaction or the reduction reaction; a voltage measuring unit for measuring the open-circuit voltage of the electrochromic element; a voltage application unit for performing a color-developing drive by applying a voltage to the electrochromic element to cause color development, and a refresh decolorization drive that drives the circuit of the electrochromic element until the open-circuit voltage measured by the voltage measuring unit falls below a predetermined value.

[0007] (2) The electronic dimming device according to (1) above, wherein the voltage application unit performs a normal decolorization drive for a shorter time than the refresh decolorization drive in which the circuit of the electrochromic element is short-circuited.

[0008] (3) The electronic dimming device according to (2) above, wherein the refresh decolorization drive makes the open-circuit voltage measured thereafter lower than the open-circuit voltage measured after the normal decolorization drive.

[0009] (4) The electronic dimming device according to (2) or (3) above, wherein the voltage application unit performs the refresh decolorization drive when the open-circuit voltage measured after the normal decolorization drive becomes equal to or greater than a threshold value.

[0010] (5) The electronic dimming device according to (2) or (3) above, wherein the voltage application unit is configured to repeatedly perform the color-generating drive and the normal decolorization drive, and the voltage application unit performs the refresh decolorization drive when the number of repetitions of the color-generating drive and the normal decolorization drive exceeds a predetermined number of times.

[0011] (6) The electronic dimming device according to any one of (1) to (5) above, wherein the voltage application unit performs a reverse voltage application drive, which applies a voltage with the opposite polarity to the voltage applied in the color development drive to the electrochromic element for a time shorter than the time the circuit is driven by the refresh color development drive, before the refresh color decolorization drive.

[0012] (7) An electronic dimming device as described in any of (1) to (6) above, used as eyeglasses.

[0013] (8) An electronic dimming device comprising: an electrochromic element whose transmittance changes when a voltage is applied; and a voltage application unit that performs color driving to reduce the transmittance of the electrochromic element by applying a color pulse voltage to the electrochromic element in a first period and applying a color drive voltage to the electrochromic element in a second period after the first period, wherein the color pulse voltage is a higher voltage than the color drive voltage, and the application time of the color pulse voltage is shorter than the application time of the color drive voltage.

[0014] (9) The electronic dimming device according to claim 8, wherein the application time of the color pulse voltage is the time for injecting an amount of charge equivalent to 1% to 50% of the amount of charge required for the electrochromic element to produce the maximum color intensity.

[0015] (10) The electronic dimming device according to (8) or (9) above, wherein the color pulse voltage is 0.1V or higher than the color drive voltage, and the application time of the color pulse voltage is 0.1 seconds or more and 15 seconds or less.

[0016] (11) An electronic dimming device comprising: an electrochromic element whose transmittance changes when a voltage is applied; a voltage application unit that applies a color-generating drive voltage to the electrochromic element to reduce the transmittance of the electrochromic element, and a voltage application unit that applies a decolorization pulse voltage to the electrochromic element in a first period and performs decolorization driving by short-circuiting the circuit of the electrochromic element in a second period after the first period, wherein the decolorization pulse voltage is a voltage with the opposite polarity to the color-generating drive voltage, and the application time of the decolorization pulse voltage is shorter than the time for short-circuiting the circuit.

[0017] (12) The electronic dimming device according to (11), wherein the application time of the decolorization pulse voltage is the time for removing an amount of charge equivalent to 50% to 99% of the amount of charge removed as the maximum decolorization of the electrochromic element.

[0018] (13) The electronic dimming device according to (11) or (12) above, wherein the decolorization pulse voltage is 0.05V or more and 1.0V or less with the opposite polarity to the color-generating drive voltage, and the application time of the decolorization pulse voltage is 0.1 seconds or more and 20 seconds or less.

[0019] (14) The electronic dimming device according to (8) or (11) above, wherein the electrochromic element comprises a first electrochromic layer that develops color by an oxidation reaction, an electrolyte layer, and a second electrochromic layer that develops color by a reduction reaction.

[0020] (14) An electronic dimming device as described in (8) or (11) above, used as eyeglasses.

[0021] According to the present invention, an electronic dimming device is obtained that can suppress the decrease in response speed and color density during color activation, even when color activation and deactivation are repeated.

[0022] Figure 1 is a perspective view showing sunglasses (eyeglasses) to which the electronic dimming device according to the first embodiment is applied. Figure 2 is a perspective view of the first lens shown in Figure 1. Figure 3 is a cross-sectional view of the first lens shown in Figure 2. Figure 4 is a partially enlarged view of the EC function unit shown in Figure 3. Figure 5 is a functional block diagram of the control unit shown in Figure 1. Figure 6 is a graph showing an example of the change in voltage applied to the first electrochromic element during the color drive period, and the change in voltage measured at the first electrochromic element during the color retention period, normal decolorization period, and refresh decolorization period. Figure 7 is a graph showing the change in transmittance of the first electrochromic element during the color drive period, color retention period, and normal decolorization period shown in Figure 6. Figure 8 is a graph showing an example of the change in voltage applied to the first electrochromic element during the color drive period, and the change in voltage measured at the first electrochromic element during the color retention period, normal decolorization period, and refresh decolorization period of the electronic dimming device according to the second embodiment. Figure 9 is a graph showing an example of the voltage applied to the first electrochromic element in the electronic dimming device according to the third embodiment, as well as the change in voltage measured at the first electrochromic element during the color development retention period and the refresh decolorization period. Figure 10 is a graph showing an example of the voltage applied to the first electrochromic element during the color development drive period performed by the electronic dimming device according to the fourth embodiment, as well as the change in voltage measured at the first electrochromic element during the retention drive period and the decolorization drive period. Figure 11 is a graph showing the change in transmittance of the first electrochromic element during the color development drive period, retention drive period and decolorization drive period shown in Figure 10. Figure 12 is a graph showing an example of the voltage applied to the first electrochromic element during the color development drive period performed by the electronic dimming device according to the fifth embodiment, as well as the change in voltage measured at the first electrochromic element during the retention drive period and the decolorization drive period. Figure 13 is a graph showing the change in transmittance of the first electrochromic element during the color development drive period, retention drive period and decolorization drive period shown in Figure 12.

[0023] Hereinafter, the electronic dimming device according to the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0024] <First Embodiment> 1. Configuration of the Electronic Dimming Device According to the First Embodiment FIG. 1 is a perspective view showing sunglasses 100 (glasses) to which the electronic dimming device according to the first embodiment is applied.

[0025] The sunglasses 100 shown in FIG. 1 include a frame 20, a first lens 31 and a second lens 32, and a control unit 40. In the following description, when the sunglasses 100 are worn on the user's head, the side of the first lens 31 and the second lens 32 on the user side is referred to as the "back", and the opposite side is referred to as the "front". Also, in the following description, the "lens" includes not only an optical element having a function of focusing or diverging light but also an optical element having a function of simply transmitting light.

[0026] 1.1. Frame The frame 20 shown in FIG. 1 has two rim portions 21, 21, a bridge portion 22, two temple portions 23, 23, and two nose pad portions 24, 24.

[0027] The frame 20 is worn on the user's head and arranges the first lens 31 and the second lens 32 near the user's eyes.

[0028] Each rim portion 21 has a ring shape. The first lens 31 is fitted inside one rim portion 21, and the second lens 32 is fitted inside the other rim portion 21.

[0029] The bridge portion 22 is rod-shaped and connects the rim portions 21 to each other. Each temple portion 23 is vine-shaped, with one end connected to each rim portion 21 and the other end being a free end.

[0030] Also, the control unit 40 is provided on the temple portion 23. The control unit 40 applies a voltage to the first lens 31 and the second lens 32 and controls their operation.

[0031] The nose pad portion 24 is provided at the edge of each rim portion 21 and is supported by the user's nose of the sunglasses 100.

[0032] The constituent materials of the frame 20 are not particularly limited, but examples include various metal materials, various resin materials, etc. Alternatively, composite materials containing these materials may also be used.

[0033] The shape of the frame 20 is not limited to the illustrated shape, as long as it can be worn on the user's head. For example, the rim portion 21 and the temple portion 23 may be omitted. Alternatively, the entire frame 20 may be omitted, and the first lens 31 and the second lens 32 may be used individually.

[0034] Furthermore, the electronic dimming device according to the present invention may be applied to eyeglasses other than sunglasses, such as prescription glasses, fashion glasses, goggles, etc. Also, the electronic dimming device according to the present invention may have one or more additional lenses similar to the first lens 31 and the second lens 32.

[0035] 1.2. First Lens and Second Lens Next, the first lens 31 and the second lens 32 will be described.

[0036] As shown in Figure 1, the first lens 31 has a first electrochromic element 1. The second lens 32 has a second electrochromic element 2, which is separate from the first electrochromic element 1. The configuration of the second lens 32 and the second electrochromic element 2 are the same as the configuration of the first lens 31 and the first electrochromic element 1, so their explanation is omitted.

[0037] Figure 2 is a perspective view of the first lens 31 shown in Figure 1. The first lens 31 shown in Figure 2 has a first electrochromic element 1 and a resin layer 35 provided on its back surface.

[0038] The first electrochromic element 1 is light-transmitting and has the function of emitting color when a voltage is applied. Furthermore, the color emission and decolorization can be reversibly switched by switching the voltage application state. The power required for the operation of the first electrochromic element 1 is supplied from the control unit 40. The control unit 40 is also responsible for switching the voltage application state.

[0039] For example, when the sunglasses 100 are used, the amount of light passing through the first lens 31 (transmittance) can be controlled by switching the color development or decolorization of the first electrochromic element 1, or by changing the color development density.

[0040] Figure 3 is a cross-sectional view of the first lens 31 shown in Figure 2. The first electrochromic element 1 shown in Figure 3 comprises a first substrate 11, a second substrate 12, a first electrode 13, a second electrode 14, an EC function section 60, a sealing section 55, a first auxiliary electrode 15, and a second auxiliary electrode 16.

[0041] 1.2.1. The first substrate 11 supports other components such as the EC function unit 60. The first substrate 11 also forms the outermost layer of the first electrochromic element 1 and protects the EC function unit 60 and the like.

[0042] The constituent material of the first substrate 11 is not particularly limited as long as it is a transparent resin material, but a material containing a thermoplastic transparent resin is preferred.

[0043] The transparent resin is not particularly limited, but examples include acrylic resins, polystyrene resins, polyethylene resins, polypropylene resins, polyester resins (polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.), polycarbonate resins, polyamide resins, cycloolefin resins, vinyl chloride resins, polyacetal resins, etc., and one or more of these can be used. Among these, the transparent resin is preferably a polycarbonate resin or a polyamide resin, and more preferably a polycarbonate resin. These have excellent transparency (light transmission) and mechanical properties, as well as excellent heat resistance and moldability. Therefore, the transparency and shape accuracy of the first substrate 11, as well as the impact resistance and heat resistance of the first substrate 11 can be improved.

[0044] Furthermore, the polycarbonate resin is preferably an aromatic polycarbonate resin. Aromatic polycarbonate resins have aromatic rings in their main chain and contribute to improving the mechanical strength of the first substrate 11.

[0045] The first substrate 11 may contain various additives as needed, such as dyes, pigments, antioxidants, fillers, plasticizers, light stabilizers, ultraviolet absorbers, heat absorbers, and flame retardants.

[0046] The thickness of the first substrate 11 is preferably 0.1 mm or more and 10.0 mm or less, and more preferably 0.3 mm or more and 5.0 mm or less. If the thickness of the first substrate 11 is within the above range, it is possible to achieve both thinness and mechanical strength of the first electrochromic element 1.

[0047] 1.2.2. The second substrate 12 is positioned opposite the first substrate 11 via the EC function unit 60 and supports the EC function unit 60 and other components. The second substrate 12 also forms the outermost layer of the first electrochromic element 1 and protects the EC function unit 60 and other components. In the following description, the space between the first substrate 11 and the second substrate 12 will also be referred to as the "inside".

[0048] The constituent material of the second substrate 12 is not particularly limited as long as it is a transparent constituent material, but a material containing a thermoplastic transparent resin is preferred. The transparent resin is the same as that used for the constituent material of the first substrate 11.

[0049] The thickness of the second substrate 12 may be the same as or different from the thickness of the first substrate 11.

[0050] The thickness of the second substrate 12 is preferably 0.1 mm or more and 10.0 mm or less, and more preferably 0.3 mm or more and 5.0 mm or less. If the thickness of the second substrate 12 is within the above range, it is possible to achieve both thinning of the first electrochromic element 1 and mechanical strength.

[0051] 1.2.3. EC Function Unit Figure 4 is a partially enlarged view of the EC function unit 60 shown in Figure 3.

[0052] The EC function unit 60 (electrochromic circuit) shown in Figure 4 comprises a first electrode 13 and a first electrochromic layer 63 sequentially stacked on the inside of a first substrate 11, a second electrode 14 and a second electrochromic layer 64 sequentially stacked on the inside of a second substrate 12, and an electrolyte layer 65 filled between the first electrochromic layer 63 and the second electrochromic layer 64.

[0053] The first electrode 13 and the second electrode 14 are electrically connected to the control unit 40. The control unit 40 controls the potentials of the first electrode 13 and the second electrode 14, and injects and extracts charge into the first electrochromic layer 63 and the second electrochromic layer 64. As a result, the EC function unit 60 can perform color development drive, holding drive, normal decolorization drive, and refresh decolorization drive.

[0054] The constituent materials of the first electrode 13 and the second electrode 14 are not particularly limited as long as they are transparent conductive materials, but for example, ITO (Indium Tin Oxide), FTO (F-dopped Tin Oxide), ATO (Antimony Tin Oxide), IZO (Indium Zinc Oxide), In ２ O ３ , SnO ２ , Sb-containing SnO ２ Examples include oxides such as Al-containing ZnO, Au, Pt, Ag, Cu, or alloys containing these, and one or more of these can be used in combination.

[0055] The thicknesses of the first electrode 13 and the second electrode 14 are set appropriately according to the required conductivity. For example, when ITO is used as the constituent material for the first electrode 13 and the second electrode 14, the thickness is preferably 50 nm to 200 nm, and more preferably 100 nm to 150 nm.

[0056] The first electrochromic layer 63 contains a material that develops color through an oxidation reaction. The material that develops color through an oxidation reaction is not particularly limited, but examples include polymers obtained by polymerizing a composition containing a radical polymerizable compound having a triarylamine, triarylamine derivatives such as triphenylamine, bisacridan compounds, Prussian blue type complexes, benzidine, nickel oxide, etc., and one or more of these can be used in combination.

[0057] Examples of Prussian blue type complexes include Fe(III) ４[Fe(II)(CN) ６ ] ３ The materials consist of the following:

[0058] Among these, polymers obtained by polymerizing a composition containing a radical polymerizable compound having a triarylamine are particularly preferred because they can operate at a constant voltage, have excellent repeated durability, and produce high-contrast electrochromic elements.

[0059] Furthermore, a composition containing a radical polymerizable compound having a triarylamine may also contain other radical polymerizable compounds different from the radical polymerizable compound having a triarylamine, and the polymer obtained by polymerizing such a composition may be composed of crosslinked products in which these radical polymerizable compounds are crosslinked.

[0060] The thickness of the first electrochromic layer 63 is not particularly limited, but is preferably about 0.1 μm to 30 μm, and more preferably about 0.4 μm to 10 μm.

[0061] The second electrochromic layer 64 contains a material that develops color through a reduction reaction. The material that develops color through a reduction reaction is not particularly limited, but examples include inorganic electrochromic compounds, organic electrochromic compounds, conductive polymers, etc., and one or more of these can be used in combination.

[0062] Examples of inorganic electrochromic compounds include tungsten oxide, molybdenum oxide, iridium oxide, and titanium oxide, with tungsten oxide being particularly preferred. Tungsten oxide has a low reduction potential, resulting in a low decolorization potential, and furthermore, being an inorganic material, it has excellent durability.

[0063] Examples of organic electrochromic compounds include low-molecular-weight organic electrochromic compounds such as azobenzene, anthraquinone, diarylethene, dihydroprene, dipyridine, styryl, styrylspiropyran, spirooxazine, spirothiopyran, thioindigo, tetrathiafulvalene, terephthalic acid, triphenylmethane, triphenylamine, naphthopyran, viologen, pyrazoline, phenazine, phenylenediamine, phenoxazine, phenothiazine, phthalocyanine, fluorane, flugide, benzopyran, and metallocene compounds. In particular, viologen compounds or dipyridine compounds are preferred. These compounds have low color potentials and exhibit good color values.

[0064] Examples of viologen compounds include those described in Japanese Patent Publication No. 3955641 and Japanese Patent Application Publication No. 2007-171781.

[0065] Examples of dipyridine compounds include those described in Japanese Patent Publication No. 2007-171781 and Japanese Patent Publication No. 2008-116718.

[0066] Examples of conductive polymers include polypyrrole, polythiophene, polyaniline, or derivatives thereof.

[0067] Furthermore, for materials that develop color through reduction reactions, it is preferable to use materials that develop color in the same tone as the materials that develop color through oxidation reactions as described above. This improves the maximum color intensity, and as a result, improves the contrast during color development.

[0068] On the other hand, when using materials that develop color through oxidation reactions and materials that develop color through reduction reactions, which have different color tones, it becomes possible to control the color development by mixing the colors.

[0069] Also, either one of the first electrochromic layer 63 and the second electrochromic layer 64 may be set not to develop color, but when both develop color, the color density can be increased. As a result, the driving voltage applied to the EC functional unit 60 can be reduced, and the durability of the first electrochromic element 1 can be enhanced as the color development operation is repeated.

[0070] The thickness of the second electrochromic layer 64 is not particularly limited, but is preferably about 0.2 μm or more and 5.0 μm or less, and more preferably about 1.0 μm or more and 4.0 μm or less.

[0071] The electrolyte layer 65 is filled between the first electrochromic layer 63 and the second electrochromic layer 64 and contains an electrolyte having ion conductivity.

[0072] The electrolyte is not particularly limited, and examples thereof include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, acids, supporting salts of alkalis, and the like. Specifically, LiClO ４ , LiBF ４ , LiAsF ６ , LiPF ６ , LiCF ３ SO ３ , LiCF ３ COO, KCl, NaClO ３ , NaCl, NaBF ４ , NaSCN, KBF ４ , Mg(ClO ４ ) ２ , Mg(BF ４ ) ２ and the like can be mentioned, and one or a combination of two or more of these can be used.

[0073] In addition, an ionic liquid can also be used as the material of the electrolyte. Among ionic liquids, organic ionic liquids are easy to handle because they exhibit a liquid state in a wide temperature range including room temperature.

[0074] As for the molecular structure of organic ionic liquids, examples of cationic components include imidazole derivatives such as N,N-dimethylimidazole salt, N,N-methylethylimidazole salt, and N,N-methylpropylimidazole salt; pyridinium derivatives such as N,N-dimethylpyridinium salt and N,N-methylpropylpyridinium salt; and aliphatic quaternary ammonium salts such as trimethylpropylammonium salt, trimethylhexylammonium salt, and triethylhexylammonium salt. Furthermore, as for the anionic component, it is preferable to use a compound containing fluorine, considering stability in the atmosphere, for example, BF ４ － CF ３ SO ３ － , PF ４ － (CF ３ SO ２ ) ２ N － , (SO ２ F) ２ N － These are some examples.

[0075] Such electrolyte materials may be ionic liquids obtained by arbitrarily combining cationic and anionic components.

[0076] The ionic liquid may be directly dissolved in any of the photopolymerizable monomers, oligomers, or liquid crystal materials. If the solubility in these materials is poor, a solution may be obtained by dissolving the ionic liquid in a small amount of solvent, and then this solution may be mixed with any of the photopolymerizable monomers, oligomers, or liquid crystal materials to achieve dissolution.

[0077] Examples of solvents include propylene carbonate, acetonitrile, γ-butyrolactone, ethylene carbonate, sulfolane, dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, 1,2-dimethoxyethane, 1,2-ethoxymethoxyethane, polyethylene glycol, alcohols, etc., or mixed solvents containing two or more of these.

[0078] Furthermore, in addition to low-viscosity liquids, the electrolyte can take the form of gels, solids, polymer-crosslinked types, liquid crystal dispersions, etc. Of these, the electrolyte is preferably in the form of a gel or solid. This enhances the mechanical strength and reliability of the EC functional part 60.

[0079] The thickness of the electrolyte layer 65 is not particularly limited, but is preferably set to about 10 μm to 100 μm, and more preferably to about 20 μm to 80 μm.

[0080] Furthermore, an intermediate layer, such as an insulating porous layer or a protective layer, may be provided between the first electrode 13 and the second electrode 14, if necessary.

[0081] Furthermore, in this embodiment, the EC function unit 60 has a first electrochromic layer 63 and a second electrochromic layer 64, but either one of these may be omitted.

[0082] 1.2.4. Sealing portion The sealing portion 55 is positioned between the first substrate 11 and the second substrate 12, as shown in Figure 3, and defines the colored region 70. This allows the EC function portion 60 to be sealed within the colored region 70. The first electrode 13 and the second electrode 14 shown in Figure 3 extend beyond the sealing portion 55 to the outside of the colored region 70.

[0083] The constituent material of the sealing portion 55 is not particularly limited as long as it is a transparent insulating material, but for example, resin materials such as acrylic resin or epoxy resin, silicon oxide (SiO2) ２ ), silicon oxynitride (SiON), aluminum oxide (Al ２ O ３ Examples include inorganic oxides such as )

[0084] The thickness of the sealing portion 55 is adjusted according to the thickness of the EC functional portion 60, but is preferably about 20 μm to 100 μm, and more preferably about 40 μm to 80 μm.

[0085] 1.2.5. First Auxiliary Electrode The first auxiliary electrode 15 is laminated on the first electrode 13, which extends to the outside of the colored region 70. The constituent material of the first auxiliary electrode 15 is a material with higher conductivity than that of the first electrode 13. This improves the efficiency of controlling the potential of the first electrode 13.

[0086] The constituent material of the first auxiliary electrode 15 is not particularly limited as long as it has a higher conductivity than the first electrode 13, but examples include silver, aluminum, copper, chromium, molybdenum, etc., and one or more of these can be used in combination. The first auxiliary electrode 15 may be provided as needed and may be omitted.

[0087] 1.2.6. Second Auxiliary Electrode The second auxiliary electrode 16 is laminated on the second electrode 14, which extends to the outside of the colored region 70. The constituent material of the second auxiliary electrode 16 is a material with higher conductivity than that of the second electrode 14. This improves the efficiency of controlling the potential of the second electrode 14.

[0088] The constituent material of the second auxiliary electrode 16 is not particularly limited as long as it has a higher conductivity than the second electrode 14, but examples include silver, aluminum, copper, chromium, molybdenum, etc., and one or more of these can be used in combination. The second auxiliary electrode 16 may be provided as needed and may be omitted.

[0089] 1.3. Control Unit The control unit 40 is located in the temple portion 23 and controls the operation of the first electrochromic element 1 and the second electrochromic element 2. Since the control unit 40 performs similar control on both the first electrochromic element 1 and the second electrochromic element 2, the control of the first electrochromic element 1 will be described below as a representative example.

[0090] Figure 5 is a functional block diagram of the control unit 40 shown in Figure 1. The control unit 40 controls the operation of the first electrochromic element 1 so as to select and execute a first operation, which is a normal coloring operation that causes the first electrochromic element 1 to develop color and then decolorize (see Figure 6), and a second operation, which differs from the first operation only in the operation during decolorization (see Figure 6). The control unit 40 basically repeats the first operation, but performs the second operation when triggered by conditions described later.

[0091] As will be explained in detail later, as shown in Figure 6, the period during which a voltage is applied to the first electrochromic element 1 to change the color intensity is called the "color drive period." When the color drive period ends, the voltage is stopped, and the electrochromic circuit (circuit) of the first electrochromic element 1 is opened. In the following explanation, opening the electrochromic circuit may be referred to as "opening the element," and short-circuiting the electrochromic circuit may be referred to as "short-circuiting the element."

[0092] After the color development drive period ends, the color intensity is maintained by the memory effect of the first electrochromic element 1. This period is called the "color development retention period." Subsequently, if necessary, the color development state is resolved and the color is deactivated by short-circuiting the first electrochromic element 1. The period during which the color is deactivated is called the "normal de-colorization period."

[0093] Furthermore, in the second operation, after the color development drive period and color development retention period have passed in the same manner as in the first operation, the first electrochromic element 1 is short-circuited (driven) to perform a refresh decolorization drive. The period during which this refresh decolorization drive is performed is called the "refresh decolorization period".

[0094] The control unit 40 shown in Figure 5 has a voltage measurement unit 42, a voltage determination unit 44, and a voltage application unit 46 as functional units.

[0095] The voltage measuring unit 42 measures the open-circuit voltage of the first electrochromic element 1 during the first and second operations. These open-circuit voltages are the voltages between the first electrode 13 and the second electrode 14 (open-circuit voltages) measured when the first electrochromic element 1 is open.

[0096] The voltage determination unit 44 determines the color-generating drive voltage and the application time applied to the first electrochromic element 1 during the first and second operations.

[0097] The function of the voltage determination unit 44 is realized by hardware, for example, a CPU, memory, and an interface. Such hardware may include, for example, a microcontroller. The CPU is a Central Processing Unit. Examples of memory include any non-volatile memory element (ROM), any volatile memory element (RAM), or a removable external memory element. Examples of interfaces include a digital input / output port such as USB (Universal Serial Bus). The function of the voltage determination unit 44 is realized by the CPU executing a program that has been pre-loaded into memory. Alternatively, instead of, or in conjunction with, the method in which the CPU executes a program to realize the above function may be used, in which hardware such as an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit) realizes the above function.

[0098] In the first and second operations, the voltage application unit 46 applies the color development drive voltage determined by the voltage determination unit 44 to the first electrochromic element 1 for a predetermined time.

[0099] The first operation is to perform color development drive, hold drive, and normal color decolorization drive in that order. Hereafter, the period during which color development drive is performed will be called the "color development drive period," the period during which hold drive is performed will be called the "color development hold period," and the period during which normal color decolorization drive is performed will be called the "normal color decolorization period."

[0100] The second operation is to perform the same color development drive, the same holding drive, and the refresh decolorization drive as described above, in that order. Hereafter, the period during which the refresh decolorization drive is performed will be referred to as the "refresh decolorization period".

[0101] The conditions for color development and holding in the second operation may differ from those for color development and holding in the first operation.

[0102] The refresh decolorization drive short-circuits the circuit of the first electrochromic element 1 until the open-circuit voltage measured by the voltage measurement unit 42 drops below a predetermined value. This condition will be described in detail later. Although the refresh decolorization drive is described as short-circuiting the circuit of the first electrochromic element 1, the present invention is not limited to this, and a configuration in which a reverse voltage is applied to the circuit of the first electrochromic element 1 is also possible.

[0103] The voltage application unit 46 includes, for example, a DC power supply, a voltage converter, and a switch. The DC power supply is a power source that generates a predetermined DC voltage and is composed of, for example, a primary battery, a secondary battery, or an external power supply. The voltage converter converts the DC voltage generated by the DC power supply to a target value. The voltage converter may also have a function to generate a pulse width modulated voltage from the DC voltage and to change its duty cycle to bring the effective voltage closer to the target value. The switch switches the color development drive period, color development retention period, etc., in response to user operation.

[0104] 2. Operation of the Electronic Light-Dimening Device 2.1. First Operation Next, the operation of the sunglasses 100 will be described. In the following explanation, the operation of the first electrochromic element 1 will be described as representative.

[0105] As mentioned above, in the first operation, the color development drive, the holding drive, and the normal color decolorization drive are executed in this order, for example.

[0106] Figure 6 is a graph showing an example of the change in voltage V applied to the first electrochromic element 1 during the color development drive period T1, and the voltage V measured at the first electrochromic element 1 during the color development retention period T2, the normal decolorization period T3, and the refresh decolorization period T4. In Figure 6, the horizontal axis represents time, and the vertical axis represents voltage.

[0107] Figure 7 is a graph showing the change in transmittance of the first electrochromic element 1 during the color development drive period T1, color development retention period T2, normal decolorization period T3, and refresh decolorization period T4 shown in Figure 6. In Figure 7, the horizontal axis represents time, and the vertical axis represents transmittance.

[0108] During the color development drive period T1 shown in Figure 6, a voltage V is applied to the first electrochromic element 1. This injects charge into the first electrochromic element 1, increasing the color intensity. As a result, as shown in Figure 7, a color development drive occurs during the color development drive period T1 in which the transmittance gradually decreases.

[0109] In the example shown in Figure 6, the first electrochromic element 1 is opened after the color development drive period T1 ends. This initiates the color development retention period T2.

[0110] In the example shown in Figure 7, immediately after the start of the color retention period T2, the transmittance (transmittance TR) at the end of the color drive period T1 is maintained due to the memory effect. This allows for color retention driving that maintains transmittance without consuming power.

[0111] In the example shown in Figure 6, the first electrochromic element 1 is short-circuited after the color retention period T2 ends. This initiates the normal decolorization period T3. During the normal decolorization period T3, the voltage application is stopped, causing the color density to decrease, and a normal decolorization drive occurs in which the transmittance increases, as shown in Figure 7.

[0112] The color-generating drive, color-retention drive, and normal color-decolorizing drive described above constitute the basic operation of the sunglasses 100.

[0113] The period during which normal decolorization is performed, i.e., the normal decolorization period T3, is shorter in duration than the refresh decolorization period T4 described later. This reduces the time required for normal decolorization, resulting in greater convenience.

[0114] 2.2. Second Operation When the sunglasses 100 as an electronic dimming device are used repeatedly, that is, when the first operation is repeated, the transmittance of the first electrochromic element 1 may not decrease sufficiently during the color drive period T1 and the color retention period T2. In this case, the density of the first electrochromic element 1 when it is colored may become locally or overall low, which may reduce the functionality and design of the sunglasses 100. In particular, there is concern about a decrease in the response speed during color drive.

[0115] One possible cause of this malfunction is a decrease in charge mobility due to the use of the sunglasses 100. When charge mobility decreases, the injection and extraction of charge into and out of the first electrochromic layer 63 is inhibited, and it is thought that the rate of increase in color density during color development decreases.

[0116] Therefore, in the second operation, as mentioned above, after performing the color development drive and the holding drive, a refresh color decolorization drive is performed.

[0117] During the refresh decolorization period shown in Figure 6, the first electrochromic element 1 is kept short-circuited until the open-circuit voltage measured by the voltage measurement unit 42 drops to below a predetermined value. This allows the charge injected into the first electrochromic layer 63 to be sufficiently removed, preventing or suppressing the above-mentioned problems. As a result, an unintended decrease in color density during color development (an unintended increase in luminous transmittance during color development) can be suppressed, as can a decrease in response speed during color development. Consequently, the repeated resistance of the color development operation of the sunglasses 100 (ensuring sufficient response speed during color development) can be improved.

[0118] The "predetermined value" mentioned above is the open-circuit voltage value at which the charge can be considered to have been released to a sufficient extent to adequately suppress the occurrence of the above-mentioned malfunction, and can be determined experimentally in advance, for example.

[0119] Furthermore, it is preferable that the voltage application unit 46 performs the refresh decolorization drive such that the open-circuit voltage VR measured after the refresh decolorization drive is lower than the open-circuit voltage VN measured after the normal decolorization drive. This allows the charge injected into the first electrochromic layer 63 to be removed more effectively, thereby more effectively improving the resistance to repeated color development operations.

[0120] The ratio VR / VN, which is the ratio of the open-circuit voltage VR to the open-circuit voltage VN, is not particularly limited, but is preferably 0.05 or more and 0.95 or less, more preferably 0.1 or more and 0.9 or less, and even more preferably 0.2 or more and 0.8 or less.

[0121] This increases the probability that charges that could not be sufficiently extracted by normal decolorization drive can be extracted by refresh decolorization drive, thus more reliably achieving the above effects.

[0122] If the ratio VR / VN is too large, the effect of performing refresh decolorization drive tends to be diminished. On the other hand, if the ratio VR / VN is too small, the amount of charge remaining in the first electrochromic layer 63 after normal decolorization drive tends to increase, and the response speed gradually decreases.

[0123] The open-circuit voltage VN referred to here is the threshold value at which a refresh decolorization drive is required. When this value is exceeded, a refresh decolorization drive is performed. The specific value of the open-circuit voltage VN is not particularly limited, but it is approximately 1.2 times to 5.0 times the open-circuit voltage measured after normal decolorization of the first electrochromic element 1 in an unused state.

[0124] The refresh decolorization period T4 for performing the refresh decolorization drive is preferably longer than the normal decolorization period T3. This allows the charge injected into the first electrochromic layer 63 to be removed more effectively, thereby more effectively improving the resistance to repeated color development operations.

[0125] The ratio T4 / T3, which is the ratio of the normal decolorization period T3 to the refresh decolorization period T4, is not particularly limited, but is preferably between 1.1 and 2160, and more preferably between 1.5 and 450. This allows the above effects to be more reliably achieved.

[0126] If the ratio T4 / T3 is too large, the refresh decolorization period T4 will become relatively long, and it will tend to take a long time before the next first operation is possible. In this case, convenience may decrease. Also, if the ratio T4 / T3 is too large, the normal decolorization period T3 will become relatively short, and it will tend to result in insufficient decolorization after the first operation. In this case, the frequency of refresh decolorization drives will increase, which may result in decreased convenience.

[0127] Furthermore, if the ratio T4 / T3 is too small, the refresh decolorization period T4 may become relatively short, potentially resulting in insufficient effectiveness of the present invention.

[0128] Note that the ratio T4 / T3 does not have to be within the above numerical range. In other words, if the open-circuit voltage drops below a predetermined value during the refresh decolorization drive, the normal decolorization period T3 and the refresh decolorization period T4 may be the same length, and the refresh decolorization period T4 may be shorter than the normal decolorization period T3.

[0129] The normal decolorization period T3 is not particularly limited, but is preferably 20 seconds or more and 100 seconds or less, and more preferably 40 seconds or more and 80 seconds or less.

[0130] The refresh decolorization period T4 is not particularly limited, but is preferably 110 seconds or more and 12 hours or less, and more preferably 120 seconds or more and 5 hours or less.

[0131] Furthermore, a combination in which the ratio VR / VN is 0.2 or more and 0.8 or less, and the ratio T4 / T3 is 1.5 or more and 450 or less, is particularly preferred. This allows the above effects to be exhibited even more reliably and significantly through a synergistic effect.

[0132] 2.3. Timing for the second operation (timing for refresh decolorization drive) In this embodiment, each time the first operation is completed, the circuit is opened and the voltage measuring unit 42 measures the open-circuit voltage. That is, after the first operation, a measurement period T5 is provided in which the voltage measuring unit 42 measures the open-circuit voltage. If the measured value is less than the threshold, the first operation is performed next time, and the second operation is performed when the measured value becomes equal to or greater than the threshold.

[0133] The threshold value is a value at which it can be determined that if the charge injected into the first electrochromic layer 63 after the decolorization drive has not been sufficiently removed, and the second operation is performed in that state, it will lead to an undesirable increase in the luminous transmittance during color development. This threshold value can be determined experimentally in advance, for example.

[0134] In this way, by performing the second action only when necessary, the frequency of performing the second action can be reduced, thereby improving convenience.

[0135] Furthermore, a measurement period T5 may be provided again after the refresh decolorization drive. In this case, it is possible to confirm whether or not the refresh decolorization drive was performed properly.

[0136] Furthermore, the timing of the refresh decolorization drive is not limited to the above. For example, it may be performed immediately after the color development drive, or immediately after the normal decolorization drive.

[0137] 3. Effects of the First Embodiment The sunglasses 100 to which the electronic dimming device according to the first embodiment is applied comprises a first electrochromic element 1 and a second electrochromic element 2, which are electrochromic elements having a first electrochromic layer 63 and an electrolyte layer 65 to which an oxidation reaction takes place, and at least one of the first electrochromic layer 63 and the second electrochromic layer 64 emits light due to an oxidation or reduction reaction; a voltage measuring unit 42 that measures the open-circuit voltages of the first electrochromic element 1 and the second electrochromic element 2, respectively; a voltage application unit 46 that performs a color-developing drive by applying a voltage to the first electrochromic element 1 and the second electrochromic element 2 to cause color development, and a refresh decolorization drive that drives (short-circuits in this embodiment) the circuits of the first electrochromic element 1 and the second electrochromic element 2, respectively, until the open-circuit voltage measured by the voltage measuring unit 42 drops to a predetermined value or less. By performing this refresh decolorization drive, it is possible to suppress an unintended decrease in color density (an unintended increase in luminous transmittance during color development) when the first electrochromic element 1 and the second electrochromic element 2 are driven to develop color. Therefore, even when the color development drive and decolorization drive are repeated, the decrease in color density during the color development drive can be suppressed. In other words, the resistance of repeated color development operations of the sunglasses 100 can be improved.

[0138] In this embodiment, the case in which both the first electrochromic layer 63 and the second electrochromic layer 64 emit light has been described, but the present invention is not limited to this, and a configuration in which only one of the first electrochromic layer 63 or the second electrochromic layer 64 emits light is also possible.

[0139] Furthermore, the voltage application unit 46 performs a normal decolorization drive, which involves a shorter short-circuiting time for the circuits of the electrochromic elements, the first electrochromic element 1 and the second electrochromic element 2, than the refresh decolorization drive. This reduces the time required for the normal decolorization drive, resulting in superior convenience.

[0140] The refresh decolorization drive lowers the open-circuit voltage measured afterward compared to the open-circuit voltage measured after normal decolorization drive. This more reliably suppresses the unintended decrease in color density (unintended increase in luminous transmittance during color development) when the first electrochromic element 1 and the second electrochromic element 2 are driven to develop color. Therefore, the repeated resistance of the color development operation of the sunglasses 100 can be more effectively improved.

[0141] The voltage application unit 46 performs a refresh decolorization drive when the open-circuit voltage measured after the normal decolorization drive exceeds a threshold value. In this way, by performing the second operation as needed, the frequency of performing the second operation can be reduced, thereby improving convenience.

[0142] Furthermore, the sunglasses 100 to which the electronic dimming device according to the first embodiment is applied can be used as eyeglasses. With such a configuration, eyeglasses with high resistance to repeated use can be realized.

[0143] <Second Embodiment> 4. In the electronic dimming device according to the second embodiment, the timing diagram 8 for performing the second operation is a graph showing an example of the voltage applied to the first electrochromic element during the color drive period T1 of the electronic dimming device according to the second embodiment, as well as the change in the voltage measured by the first electrochromic element during the color retention period, the normal decolorization period, and the refresh decolorization period.

[0144] The following explanation will focus on the differences from the first embodiment, and similar matters will be omitted.

[0145] In this embodiment, the control unit 40 counts the number of times the first operation has been performed, and when the number of times the first operation has been performed reaches a predetermined number, it performs a refresh decolorization operation. That is, when the number of repetitions of the color development drive and the normal decolorization drive exceeds a predetermined number, it performs a refresh decolorization drive.

[0146] The predetermined number of cycles is a value at which it can be determined that the charge injected into the first electrochromic layer 63 after the decolorization drive is insufficiently removed, and that performing the first operation again would result in an undesirable increase in luminous transmittance during color development. This value can be determined experimentally in advance, for example.

[0147] In this way, by performing the second operation as needed, the frequency of performing the second operation can be reduced, thereby improving convenience. Furthermore, in this embodiment, since only a simple control of counting the number of repetitions is required, the control operation of the control unit 40 can be simplified.

[0148] When the predetermined number of operations is n, n is preferably between 1 and 100, and more preferably between 5 and 50. This makes it possible to suppress an undesirable decrease in color density during color development (an undesirable increase in luminous transmittance during color development) while reducing the frequency of performing the second operation.

[0149] Furthermore, the first and second embodiments may be combined. That is, the determination of whether the number of repetitions of color-generating drive and normal decolorization drive has reached a predetermined number, and the determination of whether the open-circuit voltage measured after the normal decolorization drive has exceeded a threshold value may be performed in parallel. In this case, the configuration may be such that the second operation is performed if the determination result in either of the two judgments indicates that the second operation is necessary, or the configuration may be such that the second operation is performed if the determination result in both of the two judgments indicates that the second operation is necessary.

[0150] 5. Effects of the Second Embodiment In the second embodiment, the voltage application unit 46 is configured to repeatedly perform color development drive and normal decolorization drive, and the voltage application unit 46 performs refresh decolorization drive when the number of repetitions of color development drive and normal decolorization drive exceeds a predetermined number. This allows the second operation to be performed as needed, reducing the frequency of the second operation and improving convenience. Furthermore, the control operation can be simplified.

[0151] <Third Embodiment> 6. The second operation diagram 9 of the electronic dimming device according to the third embodiment is a graph showing an example of the voltage applied to the first electrochromic element in the electronic dimming device according to the third embodiment, as well as the change in voltage measured at the first electrochromic element during the color retention period and the refresh decolorization period.

[0152] The following explanation will focus on the differences from the first embodiment, and similar matters will be omitted.

[0153] In this embodiment, a reverse voltage application drive is performed in the second operation. Specifically, the second operation includes a color development drive, a color development retention drive, a reverse voltage application drive, and a refresh decolorization drive. The color development drive, color development retention drive, reverse voltage application drive, and refresh decolorization drive are performed in this order. That is, the voltage application unit 46 performs the reverse voltage application drive before the refresh decolorization drive.

[0154] In reverse voltage application drive, a voltage with the opposite polarity to the voltage applied in color development drive is applied to the first electrochromic element 1 and the second electrochromic element 2. Furthermore, the time during which the voltage is applied in reverse voltage application drive (reverse voltage application period T6) is shorter than the time during which the circuit is short-circuited in refresh decolorization drive (refresh decolorization period T4).

[0155] By performing this reverse voltage application drive, the voltage application unit 46 can quickly extract the charge injected into the first electrochromic layer 63, thereby shortening the refresh decolorization period T4. Consequently, the repeated resistance of the color development operation of the sunglasses 100 can be improved.

[0156] The ratio T6 / T4 of the reverse voltage application period T6 to the refresh decolorization period T4 is not particularly limited, but is preferably 0.9 or less, and more preferably 0.1 or less. This allows the above effects to be more reliably achieved.

[0157] The reverse voltage application period T6 is not particularly limited, but is preferably 0.1 seconds or more and 20 seconds or less, and more preferably 0.2 seconds or more and 10 seconds or less. This allows the above effects to be more reliably achieved.

[0158] 7. Effects of the Third Embodiment In the third embodiment, the voltage application unit 46 applies a reverse voltage drive to the first electrochromic element 1 and the second electrochromic element 2 for a shorter time than the time it takes to drive the circuit (short-circuit in this embodiment) with the refresh decolorization drive, before the refresh decolorization drive. This shortens the refresh decolorization period T4. Therefore, the resistance to repeated color development of the sunglasses 100 can be improved.

[0159] <Fourth Embodiment> 8. Operation of the Electronic Dimming Device in the Fourth Embodiment The operation of the sunglasses 100 to which the electronic dimming device according to the fourth embodiment is applied will be described below. In the following description, the operation of the first electrochromic element 1 will be described as representative.

[0160] In sunglasses 100, the color-generating drive, the holding drive, and the color-deactivating drive are executed in this order, for example.

[0161] Figure 10 is a graph showing an example of the voltage applied to the first electrochromic element 1 during the color development drive period T1, and the change in voltage measured at the first electrochromic element 1 during the holding drive period T20 and the decolorization drive period T30. In Figure 10, the horizontal axis represents time, and the vertical axis represents voltage.

[0162] Figure 11 is a graph showing the change in transmittance of the first electrochromic element 1 during the color development drive period T1, the holding drive period T20, and the decolorization drive period T30 shown in Figure 10. In Figure 11, the horizontal axis represents time, and the vertical axis represents transmittance.

[0163] During the color development drive period T1 shown in Figure 10, a voltage is applied to the first electrochromic element 1. This injects charge into the first electrochromic element 1, increasing the color intensity. As a result, as shown in Figure 11, a color development drive occurs during the color development drive period T1 in which the transmittance TR gradually decreases.

[0164] In the example shown in Figure 11, the first electrochromic element 1 is released after the color development drive period T1 ends. This initiates the transition to the holding drive period T20.

[0165] In the example shown in Figure 11, immediately after the start of the hold-drive period T20, the transmittance TR from immediately after the end of the color development drive period T1 is retained due to the memory effect. As a result, a hold-drive is performed that retains the transmittance TR without consuming power.

[0166] In the example shown in Figure 11, the first electrochromic element 1 is short-circuited after the holding drive period T20 ends. This initiates the decolorization drive period T30. During the decolorization drive period T30, the color density decreases, and as shown in Figure 11, a decolorization drive is performed in which the transmittance TR increases.

[0167] Here, the color development drive period T1 is divided into a first period TA and a second period TB. That is, the voltage application unit 46 applies a color development pulse voltage VA to the first electrochromic element 1 during the first period TA. Next, the voltage application unit 46 applies a color development drive voltage VB to the first electrochromic element 1 during the second period TB. That is, the voltage application unit 46 applies a color development pulse voltage VA to the first electrochromic element 1 prior to applying the color development drive voltage VB. The color development pulse voltage VA is a higher voltage than the color development drive voltage VB.

[0168] In the initial stage of color development, simply applying a low voltage as in the conventional method tends to result in a relatively long delay in the decrease in transmittance (increase in color density) (see dashed line in Figure 11). By applying a relatively high color development pulse voltage VA to the first electrochromic element 1 for a short time during this initial stage, the decrease in transmittance TR (increase in color density) can be achieved rapidly. As a result, the responsiveness of the transmittance change is excellent. Furthermore, because the response speed is increased by applying the color development pulse voltage VA to the first electrochromic element 1, the color development drive period T1 can be shortened, resulting in superior convenience.

[0169] Next, in the second period TB after the decrease in transmittance (increase in color density) has been promoted to some extent, by applying a normal color drive voltage VB, which is lower than the color pulse voltage VA, to the first electrochromic element 1, the burden on the first electrochromic element 1 can be reduced and the deterioration of the first electrochromic element 1 can be suppressed, compared to a configuration in which the color pulse voltage VA is constantly applied.

[0170] Thus, according to the present invention, it is possible to increase the rate of change in color density while suppressing the degradation of the first electrochromic element 1.

[0171] The ratio VA / VB between the color pulse voltage VA and the color drive voltage VB is not particularly limited, but is preferably 1.05 to 3.9, and more preferably 1.12 to 2.45. This makes it possible to achieve a high level of both suppression of degradation of the first electrochromic element 1 and improvement of the rate of change in color density.

[0172] The difference between the color pulse voltage VA and the color drive voltage VB is preferably 0.1V to 2.0V, and more preferably 0.2V to 1.0V. This makes it possible to achieve a high level of both suppression of degradation of the first electrochromic element 1 and improvement of the rate of change in color density.

[0173] The color pulse voltage VA is not particularly limited, but is preferably 1.1V to 3.9V, and more preferably 1.3V to 2.7V. This makes it possible to more effectively improve the responsiveness of the transmittance change and shorten the color drive period T1. Furthermore, it is possible to suppress the degradation of the first electrochromic element 1.

[0174] The color development drive voltage VB is not particularly limited, but is preferably 1.0V to 1.9V, and more preferably 1.1V to 1.7V. This makes it possible to more reliably suppress the degradation of the first electrochromic element 1.

[0175] The color drive voltage VB can be determined by the measurement method defined in (1) or (2) below.

[0176] (1) The midpoint of the voltage values ​​at the peaks of oxidation and reduction reactions observed when cyclic voltammetry (CV) measurement is performed at a low speed (sweep speed of 2 mV / s). (2) The voltage value at which the visible transmittance decreases by 20% or more when voltage is applied for 10 seconds.

[0177] The application time of the color pulse voltage, i.e., the first period TA, is preferably 0.1 seconds or more and 15 seconds or less, and more preferably 0.2 seconds or more and 10 seconds or less. This makes it possible to more effectively improve the responsiveness of the transmittance change and shorten the color drive period T1.

[0178] Furthermore, the application time of the color-developing pulse voltage VA, i.e., the first period TA, is preferably the time for injecting an amount of charge equivalent to 1% to 50% of the amount of charge required for the first electrochromic element 1 to develop its maximum color intensity, more preferably 2% to 45%, and even more preferably 3% to 40%. This makes it possible to more effectively improve responsiveness and shorten the color-developing drive period T1. In addition, it is possible to suppress the degradation of the first electrochromic element 1.

[0179] The maximum density is defined as the density at which the luminous transmittance value is lowest when the color is produced within the controllable range of the electronic dimming device.

[0180] 9. Effects of the Fourth Embodiment The sunglasses 100 to which the electronic dimming device is applied include a first electrochromic element 1 and a second electrochromic element 2, which are electrochromic elements whose transmittance changes when a voltage is applied, and a voltage application unit 46 that performs color driving to reduce the transmittance of the first electrochromic element 1 and the second electrochromic element 2 by applying a color pulse voltage VA to the first electrochromic element 1 and the second electrochromic element 2 during a first period TA, and applying a color drive voltage VB to the first electrochromic element 1 and the second electrochromic element 2 during a second period TB after the first period TA. The color pulse voltage VA is a higher voltage than the color drive voltage VB, and the application time of the color pulse voltage VA (first period TA) is shorter than the application time of the color drive voltage VB (second period TB).

[0181] According to the present invention, it is possible to increase the rate of change in color density while suppressing the degradation of the first electrochromic element 1 and the second electrochromic element 2.

[0182] The number of times the color-developing pulse voltage VA is applied is not particularly limited and may be two or more times. In other words, the color-developing pulse voltage VA may be applied in multiple steps. In the case of a configuration in which the color-developing pulse voltage VA is applied in multiple steps, the voltage for each step may be the same or different. Furthermore, the color-developing pulse voltage VA may be applied multiple times in a continuous manner over time, in which case the value of the color-developing pulse voltage VA may change continuously.

[0183] The application time of the color-developing pulse voltage VA (first period TA) is preferably the time for injecting an amount of charge equivalent to 1% to 50% of the amount of charge required for the development of the maximum color intensity of the first electrochromic element 1 and the second electrochromic element 2. This makes it possible to more effectively improve the responsiveness of the transmittance change of the first electrochromic element 1 and the second electrochromic element 2 and shorten the time required for color development driving.

[0184] The color-developing pulse voltage VA is preferably 0.1V or higher than the color-developing drive voltage VB, and the application time of the color-developing pulse voltage VA (first period TA) is preferably 0.1 seconds or more and 15 seconds or less. This further effectively improves the responsiveness of the transmittance change of the first electrochromic element 1 and the second electrochromic element 2 and shortens the time required for color development drive.

[0185] Furthermore, the first electrochromic element 1 and the second electrochromic element 2, which are electrochromic elements, each have a first electrochromic layer 63 that develops color through an oxidation reaction, an electrolyte layer 65, and a second electrochromic layer 64 that develops color through a reduction reaction. With this configuration, an electronic dimming device can be obtained that can increase the rate of change in color intensity while suppressing degradation by applying a color pulse voltage VA and a color drive voltage VB.

[0186] Furthermore, the electronic dimming device in this embodiment is used as eyeglasses. With this configuration, eyeglasses with high durability for repeated switching between color and decolorization can be realized.

[0187] <Fifth Embodiment> 10. The operation diagram 12 of the electronic dimming device according to the fifth embodiment is a graph showing an example of the change in voltage applied to the first electrochromic element 1 during the color development drive period T1 performed by the electronic dimming device according to the fifth embodiment, and the change in voltage measured at the first electrochromic element 1 during the holding drive period T20 and the decolorization drive period T30. Figure 13 is a graph showing the change in transmittance of the first electrochromic element 1 during the color development drive period T1, the holding drive period T20 and the decolorization drive period T30 shown in Figure 12.

[0188] The following explanation will focus on the differences from the fourth embodiment, and similar matters will be omitted from the explanation.

[0189] As shown in Figure 12, the decolorization drive period T30 is divided into a first period TC and a second period TD. Specifically, the voltage application unit 46 applies a decolorization pulse voltage VC to the first electrochromic element 1 during the first period TC. Then, during the second period TD, the voltage application unit 46 short-circuits the circuit of the first electrochromic element 1. This reduces the color density, and as shown in Figure 13, a decolorization drive is performed that increases the transmittance TR.

[0190] The decolorization pulse voltage VC is a voltage with the opposite polarity to the coloring voltage (coloring pulse voltage VA and coloring drive voltage VB) described in the first embodiment. Furthermore, the application time of the decolorization pulse voltage VC (first period TC) is shorter than the time (second period TD) for short-circuiting the circuit of the first electrochromic element 1.

[0191] In the decolorization drive period T30, if the configuration is such that only the circuit of the first electrochromic element 1 is short-circuited, it takes a relatively long time for the transmittance to increase, as shown by the dashed line in Figure 13. In contrast, in this embodiment, prior to short-circuiting the circuit of the first electrochromic element 1, that is, prior to the second period TD, a decolorization pulse voltage VC is applied for a short time during the first period TC.

[0192] In the initial first period TC, which is the initial stage where it tends to take time for the transmittance to increase (the color density to decrease), applying the decolorization pulse voltage VC to the first electrochromic element 1 allows for a rapid increase in transmittance TR (a decrease in color density). As a result, the responsiveness of the transmittance change is excellent. Furthermore, by applying the decolorization pulse voltage VC to the first electrochromic element 1, the decolorization drive period T30 can be shortened, resulting in superior convenience.

[0193] Next, in the second period TD, after a certain degree of increase in transmittance (decrease in color density), by short-circuiting the circuit of the first electrochromic element 1, the burden on the first electrochromic element 1 can be reduced and the deterioration of the first electrochromic element 1 can be suppressed, compared to a configuration in which the decolorization pulse voltage VC is constantly applied.

[0194] Thus, according to the present invention, it is possible to increase the rate of change in color density while suppressing the degradation of the first electrochromic element 1.

[0195] The decolorization pulse voltage VC is not particularly limited as long as it is a voltage with the opposite polarity to the color development voltage (color development pulse voltage VA and color development drive voltage VB), but it is preferably 0.05V to 1.0V, and more preferably 0.1V to 0.9V. This makes it possible to more reliably increase the rate of change in color development density.

[0196] The ratio VC / VB between the decolorization pulse voltage VC and the color development drive voltage VB described in the first embodiment is not particularly limited, but is preferably 0.02 or more and 1.0 or less, and more preferably 0.05 or more and 0.82 or less. This makes it possible to achieve a high level of both suppression of degradation of the first electrochromic element 1 and improvement of the rate of change of color development density.

[0197] The application time of the decolorization pulse voltage VC, i.e., the first period TC, is preferably the time for removing 50% to 99% of the charge amount removed during the maximum decolorization of the first electrochromic element 1, more preferably 60% to 98%, and even more preferably 70% to 97%. This makes it possible to more effectively improve responsiveness and shorten the decolorization drive period T30.

[0198] The application time of the decolorization pulse voltage VC (first period TC) is preferably 0.1 seconds or more and 20 seconds or less, and more preferably 0.2 seconds or more and 10 seconds or less. This makes it possible to achieve a high level of both suppression of degradation of the first electrochromic element 1 and improvement of the rate of change in color density.

[0199] The time for short-circuiting the circuit of the first electrochromic element 1 (second period TD) is preferably 40 seconds or more and 100 seconds or less, and more preferably 60 seconds or more and 80 seconds or less. This makes it possible to more effectively suppress the degradation of the first electrochromic element 1.

[0200] 11. The fifth embodiment provides an electronic dimming device to which sunglasses 100 are applied. The sunglasses 100 are equipped with a first electrochromic element 1 and a second electrochromic element 2, which are electrochromic elements whose transmittance changes when a voltage is applied. The fifth embodiment provides a voltage application unit 46 which applies a color-developing voltage (color-developing drive voltage VB) to the first electrochromic element 1 and the second electrochromic element 2 to reduce their transmittance, and applies a decolorization pulse voltage VC to the first electrochromic element 1 and the second electrochromic element 2 during a first period TC, and performs decolorization driving by short-circuiting the circuits of the first electrochromic element 1 and the second electrochromic element 2 during a second period TD after the first period TC. The decolorization pulse voltage VC is a voltage with the opposite polarity to the color-developing voltage (color-developing drive voltage VB), and the application time of the decolorization pulse voltage VC (first period TC) is shorter than the time for short-circuiting the circuits (second period TD).

[0201] According to the present invention, it is possible to increase the rate of change in color density while suppressing the degradation of the first electrochromic element 1 and the second electrochromic element 2.

[0202] The number of times the decolorization pulse voltage VC is applied is not particularly limited and may be two or more times. In other words, the decolorization pulse voltage VC may be applied in multiple steps. In the case of a configuration in which the decolorization pulse voltage VC is applied in multiple steps, the voltage for each step may be the same or different. Furthermore, the decolorization pulse voltage VC may be applied multiple times in a continuous manner over time, in which case the value of the decolorization pulse voltage VC may change continuously.

[0203] Furthermore, the decolorization pulse voltage VC is preferably 0.05V to 1.0V with the opposite polarity to the color development drive voltage VB, and the application time of the decolorization pulse voltage VC (first period TC) is preferably 0.1 seconds to 20 seconds. This makes it possible to achieve a high level of both suppression of degradation of the first electrochromic element 1 and improvement of the rate of change in color development density.

[0204] The application time of the decolorization pulse voltage VC, i.e., the first period TC, is preferably the time for removing an amount of charge equivalent to 50% to 99% of the amount of charge removed during the maximum decolorization of the first electrochromic element 1. This makes it possible to more effectively improve responsiveness and shorten the decolorization drive period T30.

[0205] Furthermore, the first embodiment and the third embodiment may be combined, the second embodiment and the third embodiment may be combined, or the first embodiment, the second embodiment and the third embodiment may be combined. In addition, the first to fifth embodiments may be combined arbitrarily.

[0206] Although the electronic dimming device of the present invention has been described above, the present invention is not limited to the embodiments described above.

[0207] For example, in the electronic dimming device of the present invention, each part of each embodiment may be replaced with any component having a similar function, or any component may be added to each embodiment.

[0208] According to the present invention, it is possible to provide a heat dissipation sheet that has excellent heat dissipation properties and is miniaturized, particularly in the thickness direction. Therefore, the present invention has industrial applicability.

[0209] 1 First electrochromic element 2 Second electrochromic element 11 First substrate 12 Second substrate 13 First electrode 14 Second electrode 15 First auxiliary electrode 16 Second auxiliary electrode 20 Frame 21 Rim part 22 Bridge part 23 Temple part 24 Nose pad part 31 First lens 32 Second lens 35 Resin layer 40 Control unit 42 Voltage measurement unit 44 Voltage determination unit 46 Voltage application unit 55 Sealing unit 60 EC function unit 63 First electrochromic layer 64 Second electrochromic layer 65 Electrolyte layer 70 Colored area 100 Sunglasses T1 Color development drive period T2 Color development retention period T20 Retention drive period T3 Normal decolorization period T30 Decolorization drive period T4 Refresh decolorization period T5 Measurement period T6 Reverse voltage application period TA Period 1 TB Period 2 TC Period 1 TD Period 2 TR Transmittance V Voltage VA Color pulse voltage VB Color drive voltage VC Decolorization pulse voltage VN Open circuit voltage VR Open circuit voltage

Claims

1. An electronic dimming device comprising: an electrochromic element having a first electrochromic layer where an oxidation reaction takes place, an electrolyte layer, and a second electrochromic layer where a reduction reaction takes place, wherein at least one of the first electrochromic layer and the second electrochromic layer emits light due to the oxidation reaction or the reduction reaction; a voltage measuring unit for measuring the open-circuit voltage of the electrochromic element; a voltage application unit for performing a color-developing drive by applying a voltage to the electrochromic element to cause color development, and a refresh-decolorization drive that drives the circuit of the electrochromic element until the open-circuit voltage measured by the voltage measuring unit falls below a predetermined value.

2. The electronic dimming device according to claim 1, wherein the voltage application unit performs a normal decolorization drive for a shorter time than the refresh decolorization drive in which the circuit of the electrochromic element is short-circuited.

3. The electronic dimming device according to claim 2, wherein the refresh decolorization drive makes the open-circuit voltage measured thereafter lower than the open-circuit voltage measured after the normal decolorization drive.

4. The electronic dimming device according to claim 2 or 3, wherein the voltage application unit performs the refresh decolorization drive when the open-circuit voltage measured after the normal decolorization drive becomes equal to or greater than a threshold value.

5. The electronic dimming device according to claim 2 or 3, wherein the voltage application unit is configured to repeatedly perform the color-generating drive and the normal decolorization drive, and the voltage application unit performs the refresh decolorization drive when the number of repetitions of the color-generating drive and the normal decolorization drive exceeds a predetermined number of times.

6. The electronic dimming device according to any one of claims 1 to 3, wherein the voltage application unit performs a reverse voltage application drive, which applies a voltage with the opposite polarity to the voltage applied in the color development drive to the electrochromic element for a shorter time than the time the circuit is driven by the refresh color development drive, before the refresh color decolorization drive.

7. An electronic dimming device according to any one of claims 1 to 3, used as eyeglasses.

8. An electronic dimming device comprising: an electrochromic element whose transmittance changes when a voltage is applied; and a voltage application unit that performs color driving to reduce the transmittance of the electrochromic element by applying a color pulse voltage to the electrochromic element during a first period and applying a color drive voltage to the electrochromic element during a second period after the first period, wherein the color pulse voltage is a higher voltage than the color drive voltage, and the application time of the color pulse voltage is shorter than the application time of the color drive voltage.

9. The electronic dimming device according to claim 8, wherein the application time of the color-developing pulse voltage is the time for injecting an amount of charge equivalent to 1% to 50% of the amount of charge required for the electrochromic element to develop the maximum color intensity.

10. The electronic dimming device according to claim 8 or 9, wherein the color pulse voltage is 0.1 V or higher than the color drive voltage, and the application time of the color pulse voltage is 0.1 seconds or more and 15 seconds or less.

11. An electronic dimming device comprising: an electrochromic element whose transmittance changes when a voltage is applied; a voltage application unit that applies a color-generating drive voltage to the electrochromic element to reduce the transmittance of the electrochromic element, and a voltage application unit that applies a decolorization pulse voltage to the electrochromic element during a first period and performs decolorization driving by short-circuiting the circuit of the electrochromic element during a second period after the first period, wherein the decolorization pulse voltage is a voltage with the opposite polarity to the color-generating drive voltage, and the application time of the decolorization pulse voltage is shorter than the time for short-circuiting the circuit.

12. The electronic dimming device according to claim 11, wherein the application time of the decolorization pulse voltage is the time for removing an amount of charge equivalent to 50% to 99% of the amount of charge removed as the maximum decolorization of the electrochromic element.

13. The electronic dimming device according to claim 11 or 12, wherein the decolorization pulse voltage is 0.05V or more and 1.0V or less with the opposite polarity to the color-generating drive voltage, and the application time of the decolorization pulse voltage is 0.1 seconds or more and 20 seconds or less.

14. The electronic dimming device according to claim 8 or 11, wherein the electrochromic element comprises a first electrochromic layer that develops color by an oxidation reaction, an electrolyte layer, and a second electrochromic layer that develops color by a reduction reaction.

15. An electronic dimming device according to claim 8 or 11, used as eyeglasses.

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