Light control element and method for manufacturing the same

Abstract

To provide a light control element capable of performing light control operation at a higher speed than existing ones.SOLUTION: A light control element 1 includes: a pair of transparent electrode substrates 10 each having a transparent electrode 12 serving as a pair of electrodes arranged to face each other with a space therebetween; an electrolyte 20 filled in the space between the pair of electrodes, the electrolyte 20 including at least silver ions as metal ions of a metal salt in the composition; and a sealing material 30 for sealing the electrolyte 20 in the space between the pair of electrodes, the transparent electrode 12A on the side where the metal salt is deposited being formed as a plurality of fine electrodes FE separated from each other with gaps.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal salt deposition type electrochromic light control element and a method for manufacturing the same. [Background technology]

[0002] In recent years, a metal salt deposition electrochromic dimming element that changes light transmittance in a stepless manner has been disclosed (see Patent Document 1). This dimming element is constructed by filling the gap between an electrode pair, which consists of glass substrates with a transparent conductive film formed on them, with the transparent conductive film sides facing each other, with an electrolyte layer in which silver and copper, which serve as metal salts, are dissolved in methanol. This dimming element then reversibly repeats the deposition or reduction of the metal salt in response to changes in the electric field of the electrode pair, thereby changing the light transmittance in a stepless manner across almost the entire area of ​​the element.

[0003] Furthermore, a prototype example of a filter that uses a light control element with variable transmittance specifically for application to a television camera has been disclosed (see Non-Patent Document 1). Normally, in high-definition television systems such as 4K and 8K, if the aperture diameter (F-number) of the lens diaphragm is made smaller than a certain value, image blur occurs due to the diffraction of light, and the resolution of the captured image drops significantly. Therefore, if a light control element with variable transmittance is used as a filter for a television camera, the amount of incident light can be adjusted without relying solely on the lens diaphragm, and the brightness of the output image can be adjusted without affecting the depth of field or resolution characteristics. However, this dimming element had the problem of a long response time, taking approximately 24 seconds for the light transmittance to decrease from full transmission to 1 / 8 of the original light attenuation.

[0004] Therefore, a dimming element has been disclosed that has two electrolyte layers made of the same material and a pair of transparent electrode films made of the same material sandwiching each electrolyte layer, and by commonly driving the two electrolyte layers with a pulsed voltage, the response time is reduced to about one-fourth of the conventional time (see Non-Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6402113 [Non-patent literature]

[0006] [Non-Patent Document 1] Miyagawa et al., NHK Science & Technology Research Laboratories, Murakami Kaimeido Co., Ltd., "Prototype of Metal Salt Precipitation-Type Dimming Device," ITE Annual Convention 2016, 15B-1 [Non-patent document 2] Miyagawa et al., NHK Science & Technology Research Laboratories, Murakami Kaimeido Co., Ltd., "Improvement of Response of Metal Salt Precipitation-Type Photochromic Devices," ITE Annual Convention 2017, 23D-1 Summary of the Invention [Problem to be solved by the invention]

[0007] A conventional light-control element with two electrolyte layers can shorten the response time compared to a light-control element with a single electrolyte layer. However, to achieve the dimming operation required for broadcast cameras, it was desirable to further shorten the response time of the dimming element. The present invention has been made in view of such demands, and an object of the present invention is to provide a light control element capable of performing light control operation at a higher speed than conventional light control elements, and a method for manufacturing the same. [Means for solving the problem]

[0008] In order to solve the above problems, the light control element of the present invention is a metal salt precipitation electrochromic light control element for light control, and comprises a pair of transparent electrode substrates in which transparent electrodes forming an electrode pair are opposed to each other with a gap therebetween, an electrolyte solution filled in the gap and containing at least silver ions as metal ions of the metal salt, and a sealant that seals the electrolyte solution in the gap, and is characterized in that the transparent electrode on the side where the metal salt is precipitated is a plurality of fine electrodes with gaps between them.

[0009] In this configuration, the area where the electrical reversible reaction occurs is smaller than the area of ​​the entire device due to the gap provided in the transparent electrode on the side where the metal salt is deposited, which allows the light-control device to reduce the amount of metal salt deposited and reduced compared to when light is controlled by the entire device, thereby shortening the light-control response time.

[0010] In addition, in order to solve the above problem, the dimming element of the present invention may further comprise a translucent insulating film disposed in the gap and the microelectrode, the insulating film having a row of openings in the longitudinal direction of the microelectrode, and each opening exposing a portion of the microelectrode as a microelectrode.

[0011] In this configuration, the light-adjusting element according to the present invention can deposit and reduce metal salts using a microelectrode having an area even smaller than that of a microelectrode, thereby further shortening the response time of light-adjusting.

[0012] In order to solve the above-mentioned problems, the manufacturing method of the light control element according to the present invention is a manufacturing method of a metal salt precipitation electrochromic light control element for light control, and includes: a substrate producing step of laminating a transparent electrode on a light-transmitting substrate to produce first and second transparent electrode substrates; a microelectrode producing step of forming a plurality of gaps in the transparent electrode of the first transparent electrode substrate that expose the light-transmitting substrate, and producing a plurality of microelectrodes from the transparent electrode; an electrode pair producing step of opposing the first transparent electrode substrate on which the microelectrodes have been produced and the second transparent electrode substrate on which the transparent electrode has been laminated to produce an electrode pair spaced a predetermined distance apart; and an electrolyte filling step of filling the gap with an electrolyte containing at least silver ions as metal ions of a metal salt in its composition. The procedure included:

[0013] In this procedure, the method for manufacturing a photochromic element according to the present invention makes it possible to manufacture a photochromic element in which the area where the electrically reversible reaction takes place is smaller than the area of ​​the entire element due to the gap provided in the transparent electrode on the side where the metal salt is deposited, thereby shortening the response time of photochromic elements.

[0014] In addition, in order to solve the above problem, the manufacturing method of the dimming element according to the present invention includes a microelectrode generation step between the microelectrode generation step and the electrode pair generation step, in which an insulating film having a row of microapertures in the longitudinal direction of the microelectrodes is laminated on the microelectrodes generated in the microelectrode generation step and in the gaps between the microelectrodes, thereby generating microelectrodes in which a portion of the microelectrodes is exposed.

[0015] In this procedure, the method for manufacturing a photochromic element according to the present invention can perform deposition and reduction of metal salts using a microelectrode with an area even smaller than that of a fine electrode, thereby producing a photochromic element that can further shorten the response time of photochromic elements. [Effects of the Invention]

[0016] According to the present invention, dimming operation is performed using a metal salt precipitation electrochromic method with fine electrodes having gaps between them, which reduces the reaction area compared to conventional methods in which dimming operation is performed over the entire surface of the dimming element, thereby enabling high-speed dimming operation. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing the structure of a light control element according to a first embodiment of the present invention. [Figure 2] 1A and 1B are three-view diagrams of a transparent electrode substrate constituting a light-adjusting element according to the first embodiment of the present invention, where (a) is a front view, (b) is a cross-sectional view taken along IIb-IIb in (a), and (c) is a cross-sectional view taken along IIc-IIc in (a). [Figure 3] FIG. 2 is an explanatory diagram illustrating a partial dimming operation of the light control element according to the first embodiment of the present invention. [Figure 4] 3A and 3B are explanatory diagrams for explaining the dimming operation of the dimming element in the entire surface in one go according to the first embodiment of the present invention. [Figure 5] 3 is a flowchart showing the steps of a method for manufacturing a light control element according to the first embodiment of the present invention. [Figure 6A] FIG. 6 is an explanatory view for explaining a first procedure of the fine electrode forming step of FIG. 5. [Figure 6B] 6 is an explanatory view for explaining a second procedure of the fine electrode forming step of FIG. 5. FIG. [Figure 6C] 6 is an explanatory view for explaining a third procedure of the fine electrode forming step of FIG. 5. FIG. [Figure 6D] FIG. 6 is an explanatory view for explaining a fourth procedure of the fine electrode forming step in FIG. 5. [Figure 7] FIG. 3 is an explanatory diagram for explaining the width of the fine electrodes and the spacing between the fine electrodes when the response performance of the light control element according to the first embodiment of the present invention is measured. [Figure 8] 4 is a graph showing the relationship between response time and transmittance, which is an evaluation result of the response performance of the light control element according to the first embodiment of the present invention. [Figure 9] FIG. 4 is a cross-sectional view showing the structure of a light control element according to a second embodiment of the present invention. [Figure 10] 10A and 10B are three-view diagrams of a transparent electrode substrate constituting a light control element according to a second embodiment of the present invention, where (a) is a front view, (b) is an Xb-Xb cross-sectional view of (a), and (c) is an Xc-Xc cross-sectional view of (a). [Figure 11] 10 is a flowchart showing the steps of a method for manufacturing a light control element according to a second embodiment of the present invention. [Figure 12A] FIG. 13 is an explanatory view for explaining a first procedure of the microelectrode formation step of FIG. [Figure 12B] 13 is an explanatory view for explaining a second procedure of the microelectrode forming step of FIG. 12. FIG. [Figure 12C] 13 is an explanatory view for explaining a third procedure of the microelectrode formation step of FIG. 12. FIG. [Figure 12D] 13 is an explanatory view for explaining a fourth step of the microelectrode formation step in FIG. 12. FIG. [Figure 12E] 13 is an explanatory view for explaining a fifth step of the microelectrode formation step in FIG. 12. FIG. [Figure 13] FIG. 10 is an explanatory diagram for explaining the width and diameter of the microelectrode when measuring the response performance of the light control element according to the second embodiment of the present invention. [Figure 14] 10 is a graph showing the relationship between response time and transmittance, which is an evaluation result of the response performance of the light control element according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are intended to show the embodiments in a simplified manner, and for clarity of explanation, the scale, spacing, and positional relationships of each component may be exaggerated or some components may be omitted.

[0019] [First embodiment] <Dimming element> A light control device 1 according to a first embodiment of the present invention will be described with reference to FIGS. The light control element 1 is a metal salt deposition electrochromic element for controlling light. The light-adjusting element 1 includes a pair of transparent electrode substrates 10A and 10B in which transparent electrodes 12A and 12B, which form an electrode pair, face each other with a gap therebetween, an electrolyte solution 20 filled in the gap between the electrode pair, and a sealant 30 that seals the electrolyte solution 20 in the gap between the electrodes. Furthermore, the transparent electrode 12A of the transparent electrode substrate 10A on the side where the metal salt is deposited has a plurality of fine electrodes FE formed with gaps (slits) SL therebetween, as shown in FIG. As a result, the regions of the transparent electrodes 12 (12A, 12B) are exposed to the electrolyte solution 20. Furthermore, the light-transmitting substrate 11 of the transparent electrode substrate 10A is exposed to the electrolyte solution 20 due to the gap SL provided in the transparent electrode 12A.

[0020] The light-adjusting element 1 is driven by applying a voltage to a pair of transparent electrode substrates 10 (10A, 10B) by a driving power source 2. Each of the microelectrodes FE is driven by a plurality of driving power sources 2 in parallel between the microelectrodes FE and the transparent electrode 12B.

[0021] That is, when a voltage is applied to the light-adjusting element 1 by the multiple driving power sources 2 and the microelectrodes FE of the transparent electrode 12A become the cathode (-), metal ions (here, silver ions (Ag+)) in the electrolyte 20 are precipitated as metal salts (silver) on the surface of the microelectrodes FE on the cathode (-) side, forming a precipitate layer 40. At this time, by applying a voltage of about 2.0 V to 2.5 V, coloring occurs on the surface of the microelectrodes FE. In this case, the transmittance will decrease or light will be blocked in the area where the precipitate layer 40 is formed. This allows the light control device 1 to adjust the light transmittance and emit outgoing light 200 obtained by adjusting the intensity of incident light 100.

[0022] After the deposition layer 40 is formed, the polarity of the voltage applied to the light-adjusting element 1 is reversed to reduce the metal salt in the deposition layer 40 to metal ions in the electrolyte solution 20 to improve transmittance or achieve a completely transparent state. That is, the multiple driving power sources 2 configure the microelectrodes FE of the transparent electrode 12A on the deposition side as anodes (+) and the opposing transparent electrode 12B as cathodes (-). In this case, applying a voltage of approximately 0.4 V to 0.7 V causes the microelectrodes FE to bleach. The dimming element 1 achieves reversible dimming operation by repeating this polarity reversal.

[0023] <Drive power source> The driving power supply 2 is a DC power supply that applies a voltage to the pair of transparent electrodes 12 (12A, 12B). Here, a plurality of driving power sources 2 are provided according to the number of microelectrodes FE that form the transparent electrode 12 A. One terminal of each driving power source 2 is electrically connected to the corresponding microelectrode FE, and the other terminal is electrically connected to the transparent electrode 12 B. When depositing metal salts, the driving power supply 2 applies a DC voltage of about 2.0V to 2.5V with the fine electrode FE of the transparent electrode 12A as the cathode (-) and the transparent electrode 12B as the anode (+).

[0024] When the deposited metal salt is reduced to metal ions, the driving power supply 2 applies a DC voltage of about 0.4V to 0.7V to the fine electrode FE of the transparent electrode 12A as the anode (+) and the transparent electrode 12B as the cathode (-). The driving power supply 2 can change the light transmittance of the light control element 1 by changing the voltage applied thereto in a stepwise or stepless manner. The configuration of the light control element 1 will be described in detail below.

[0025] <Transparent electrode substrate> The transparent electrode substrates 10 (10A, 10B) are transparent electrode substrates. A pair of the transparent electrode substrates 10 are arranged opposite each other and connected to the respective electrodes of the driving power source 2, thereby forming an electrode pair. The transparent electrode substrate 10 (10A, 10B) includes a light-transmitting substrate 11 and a transparent electrode 12 formed on the surface thereof.

[0026] The light-transmitting substrate 11 (11A, 11B) is a substrate that transmits light, and is, for example, a glass substrate, a resin substrate, etc. The light-transmitting substrates 11A, 11B may be made of the same type of material or different types of materials.

[0027] The transparent electrodes 12 (12A, 12B) are thin films that are both transparent and conductive. The transparent electrodes 12 are preferably made of indium tin oxide (ITO), but may be made of other transparent conductive films such as tin oxide or zinc oxide. The transparent electrodes 12A and 12B may be made of the same material or different materials. The transparent electrode 12 can be formed on the surface of the light-transmitting substrate 11 by a general sputtering film formation method.

[0028] The transparent electrode 12A on the side where the metal salt is deposited is formed as a plurality of fine electrodes FE with a plurality of gaps (slits) SL formed therein. The narrower the line width of each fine electrode FE, the smaller the reaction area for metal salt deposition, enabling high-speed dimming operation.

[0029] Furthermore, since no electrode is formed in the gap SL, no precipitate layer 40 is formed and no light control occurs. Therefore, in order to make the gap SL less noticeable, it is preferable to make the distance between the fine electrodes FE extremely narrow, and for example, the width of the gap SL is set to 30 μm or less, preferably 5 μm or less, and more preferably 1 μm or less.

[0030] As shown in FIG. 3, the microelectrodes FE are each individually connected to a transparent electrode 12B via a drive power supply 2. This allows for dimming control, such as partial dimming or gradually varying the degree of dimming, by individually controlling the applied voltage to each microelectrode FE. For example, when the dimming element 1B is used as a variable neutral density (ND) filter for a camera, the brightness of a portion of an image can be adjusted by changing the applied voltage to each microelectrode FE. To achieve such partial dimming, the transparent electrode 12B on the side where metal salts are not deposited (not involved in the deposition of metal salts) can be driven at a voltage value of 0V. Alternatively, the applied voltage to each microelectrode FE can be set to the same to achieve uniform dimming across the entire element.

[0031] The microelectrodes FE do not necessarily need to be formed individually, and may be connected at one end by a connecting portion J as shown in Fig. 4, and controlled by a single driving power source 2. In this case, controlling only one driving power source 2 allows the dimming of the entire dimming element 1 to be adjusted uniformly.

[0032] <Electrolyte> The electrolyte 20 is an electrically conductive solution in which a metal salt is dissolved. For example, the electrolyte 20 is a solution in which a silver salt such as silver nitrate (AgNO3) is dissolved in a non-aqueous solvent containing an ester solvent such as propylene carbonate and an alcohol such as methanol so as to contain silver ions. The electrolyte 20 may also contain copper ions, which have a smaller weight content than the silver ions. In this case, a copper salt such as cupric chloride (CuCl2) may be dissolved in the non-aqueous solvent. The electrolyte 20 is nearly colorless and transparent.

[0033] The non-aqueous solvent may further contain a supporting electrolyte such as lithium bromide (LiBr) to increase conductivity. The non-aqueous solvent may further contain a thickener to distribute the metal ions evenly. Examples of the thickener include polymers such as polypropylene, polyvinyl butyral, and polymethyl methacrylate.

[0034] The electrolyte solution 20 is sealed in a cavity formed by the sealing material 30 between the pair of transparent electrodes 12 (12A, 12B). When a voltage is applied, the electrolyte solution 20 deposits metal salts on the cathode (-) side transparent electrode 12A to form a deposit layer 40, and when the polarity is reversed, the deposit layer 40 is reduced to metal ions.

[0035] <Sealing material> The sealing material 30 is a sealant that seals the electrolyte solution 20 in the space between the pair of transparent electrodes 12 (12A, 12B). The material of the sealing material 30 is not particularly limited, but may be, for example, glass, resin, or the like. The sealing material 30 seals the electrolyte 20 between the pair of transparent electrodes 12 (12A, 12B) so as to maintain a gap of about 0.3 mm in thickness, thereby forming an electrolyte tank SP.

[0036] With the above-described configuration, the light-adjusting device 1 has a smaller reaction area for metal salt deposition than conventional devices due to the fine electrodes FE, and can achieve high-speed light-adjusting operation.

[0037] <Manufacturing method of light-adjusting element> Next, a method for manufacturing the light control device 1 according to the first embodiment of the present invention will be described with reference to FIG. 5 (and also with reference to FIG. 1 as appropriate). The manufacturing method of the photochromic device 1 includes a substrate forming step S1, a fine electrode forming step S2, an electrode pair forming step S3, and an electrolyte filling step S4. Note that, except for the fine electrode forming step S2, the manufacturing process is the same as that of a conventional metal salt precipitation photochromic device, so only an outline will be explained.

[0038] <Substrate generation process> The substrate producing step S1 is a step of producing a transparent electrode substrate 10. In this substrate producing step S1, a transparent electrode 12 (for example, ITO) is laminated on a light-transmitting substrate 11 (for example, a glass substrate) by a sputtering film formation method, thereby producing the transparent electrode substrate 10. Here, a transparent electrode substrate 10A (first transparent electrode substrate) and a transparent electrode substrate 10B (second transparent electrode substrate) are produced.

[0039] <Fine electrode generation process> The fine electrode forming step S2 is a step of forming fine electrodes FE from the transparent electrodes 12A on the first transparent electrode substrate 10A formed in the substrate forming step S1. This microelectrode forming step S2 will be described with reference to Figures 6A to 6D. Figures 6A to 6D show the microelectrode FE forming step in a cross section taken along IIb-IIb in Figure 2.

[0040] As shown in FIG. 6A, in the fine electrode forming step S2, a resist 60 is applied to the entire transparent electrode 12A side of the transparent electrode substrate 10A. 6B, in the microelectrode generating step S2, a mask 50 processed to fit the shape of the microelectrode is placed in close contact with the resist 60 and exposed to light. Here, a light-opaque metal such as chromium is used as the mask 50, which is processed to fit the shape of the microelectrode and brought into close contact with the resist 60, and exposed to ultraviolet light 300. After exposure, the mask 50 is peeled off.

[0041] 6C, in the fine electrode generating step S2, the resist 60 irradiated with the ultraviolet rays 300 is peeled off with a developer to form an opening, and the transparent electrode 12A in the opening is removed by etching. Note that in this example, a positive resist is used as the resist 60, and the exposed portion irradiated with the ultraviolet rays 300 is peeled off with a developer. Thereafter, as shown in FIG. 6D, in the fine electrode forming step S2, the resist 60 (FIG. 6C) is removed using a remover, thereby forming the transparent electrode 12A as the fine electrode FE. Returning to FIG. 5, the method for manufacturing the light control element 1 will be described further.

[0042] <Electrode pair generation process> The electrode pair forming step S3 is a step of forming an electrode pair by opposing the first and second transparent electrode substrates 10A and 10B and spaced apart by a predetermined distance. In this electrode pair forming step S3, the transparent electrode substrates 10A, 10B are arranged with a gap (e.g., 0.3 mm) between them so that the transparent electrodes 12A, 12B face each other, using the sealant 30 as a spacer. The sealant 30 is arranged so as to surround all four sides of the gap. The transparent electrodes 12A, 12B and the sealant 30 may be bonded with an adhesive or the like, leaving a small opening (not shown) for filling with the electrolyte solution 20 in the electrolyte solution filling step S4 described below.

[0043] <Electrolyte filling process> The electrolyte filling step S4 is a step of filling the space formed by the sealing material 30 of the electrode pair generated in the electrode pair generation step S3 with an electrolyte 20 containing at least silver ions as the metal ions of the metal salt. In the electrolyte filling step S4, for example, a fine syringe needle is used to fill the electrolyte 20 through the small opening left in the electrode pair generating step S3. The opening is then sealed with an adhesive or the like. This forms the electrolyte tank SP. By applying a voltage to the transparent electrodes 12A and 12B of the light control device 1 produced by the above steps, the light control device 1 can improve the responsiveness of the light control operation due to the fine electrodes FE.

[0044] <Response performance test results> Next, with reference to FIGS. 7 and 8 (and also with reference to FIG. 1 as needed), the results of an experiment on the response performance in the dimming operation of the dimming element 1 depending on the line width of the fine electrode FE will be described. In this example, in the light-controlling element 1 shown in FIG. 1, a transparent electrode 12A (material: crystalline ITO, film thickness: 150 nm, film resistance: 9.1 Ω / cm ) is formed on the surface of a light-transmitting substrate 11A (thickness: 0.7 mm, size: 50 mm × 34 mm). 2 ) was formed with the line width W (μm) of the fine electrodes FE and the gap width L (μm) between the fine electrodes FE as shown in FIG. A transparent electrode 12B (material: crystalline ITO, film thickness: 150 nm, film resistance: 9.1 Ω / cm) was formed on the entire surface of the opposing light-transmitting substrate 11B (thickness: 0.7 mm, size: 50 mm × 34 mm). 2 ) was formed.

[0045] Here, the transmittance over time was measured for four cases: when the gap width L was 30 μm and the line width W was 5 μm, 50 μm, and 500 μm, and when the transparent electrode 12A was formed on the entire surface of the light-transmitting substrate 11A without providing the micro-electrodes FE. Note that the transmittance of incident light 100 with a central wavelength of visible light (550 nm) passing through the light-adjusting element 1 when it was not operating (not colored) was set to 100%.

[0046] The measurement results are shown in Figure 8. The horizontal axis of the graph in Figure 8 represents the response time (seconds), and the vertical axis represents the transmittance (%). W1 represents the case where the line width W was 5 μm, W2 represents the case where the line width W was 50 μm, W3 represents the case where the line width W was 500 μm, and WA represents the case where the transparent electrode 12A was formed over the entire surface of the translucent substrate 11A. As shown in Figure 8, the response time until the transmittance fell to 20% or less was significantly shorter when the fine electrodes FE were provided (W1, W2, W3) than when the fine electrodes FE were not provided (WA). For example, the response time was approximately 9 seconds for WA, compared to approximately 0.9 seconds for W1, approximately 2.0 seconds for W2, and approximately 2.8 seconds for W3. Furthermore, when a fine electrode FE is provided, the response time becomes shorter as the line width becomes narrower. That is, here, the response time is shortest when the line width W is 5 μm (W1). The above measurement results demonstrate that the metal salt deposition electrochromic light control element 1 achieves high-speed light control operation by using a fine electrode FE as the transparent electrode 12A on which the metal salt is deposited.

[0047] [Second embodiment] <Dimming element> A light control device 1B according to a second embodiment of the present invention will be described with reference to FIGS. The light control element 1B is a metal salt deposition electrochromic element that controls light, similar to the light control element 1 (FIG. 1). The dimming element 1B is configured such that a transparent insulating film 13 is laminated on a plurality of microelectrodes FE, which are the transparent electrodes 12A of the dimming element 1, and on the gaps SL between the microelectrodes FE, and a row of minute openings is provided in the insulating film 13 in the longitudinal direction of each microelectrode FE.

[0048] The light-adjusting element 1B includes a pair of transparent electrode substrates 10C, 10B in which transparent electrodes 12A, 12B forming an electrode pair face each other with a gap therebetween, an electrolyte solution 20 filled in the gap between the electrode pair, and a sealant 30 that seals the electrolyte solution 20 in the gap between the electrodes. As shown in Fig. 10, the transparent electrode 12A of the transparent electrode substrate 10C on the metal salt deposition side is formed with a plurality of fine electrodes FE with gaps (slits) SL therebetween, similar to the light-adjusting element 1 (Fig. 1).

[0049] In the light-adjusting element 1B, a transparent insulating film 13 is laminated between a plurality of fine electrodes FE, which are the transparent electrode 12A on the side where the metal salt is deposited, and the gap SL. Furthermore, in the dimming element 1B, by providing an array of micro-apertures in the insulating film 13 with the micro-apertures aligned at a predetermined interval (e.g., 5 μm) in the longitudinal direction of the micro-electrode FE, the apertures become exposed to the electrolyte 20 as the micro-electrodes ME. The size and shape of the microelectrode ME may be, for example, a circle with a diameter of 1000 μm or less, a polygon with a diagonal dimension of 1000 μm or less, etc. When the microelectrode ME is circular or polygonal, it is sufficient that the light control element 1B is exposed, and it does not have to be a perfect circle or a regular polygon.

[0050] The size of the microelectrodes ME and the spacing between them may be set to values ​​designed according to the application. For example, if the light control element 1B is used as a variable ND filter for a camera, the size and spacing may be set to correspond to the pixel size and pixel pitch of the imaging element. This allows the light control element 1B to achieve light control on a pixel-by-pixel basis.

[0051] The light-adjusting element 1B is driven by applying a voltage to a pair of transparent electrode substrates 10 (10A, 10B) by a driving power supply 2. The microelectrodes ME formed on the microelectrodes FE are driven by a plurality of driving power supplies 2 in parallel between each microelectrode FE and the transparent electrode 12B.

[0052] That is, when a voltage is applied to the light-adjusting element 1B by the multiple driving power sources 2 and the microelectrode ME of the transparent electrode 12A becomes the cathode (-), the metal ions (here, silver ions (Ag+)) in the electrolyte 20 are precipitated as metal salts (silver) on the surface of the microelectrode ME on the cathode (-) side, forming a precipitate layer 40. At this time, by applying a voltage of about 2.0 V to 2.5 V, a coloring action occurs on the surface of the microelectrode ME. In this case, in the region where the precipitate layer 40 is formed, the transmittance decreases or light is blocked to an extreme extent. This allows the light control device 1B to adjust the light transmittance and emit outgoing light 200 obtained by adjusting the intensity of incident light 100.

[0053] After the deposition layer 40 is formed, the polarity of the voltage applied to the light-adjusting device 1B is reversed to reduce the metal salt in the deposition layer 40 to metal ions in the electrolyte solution 20 to improve transmittance or achieve a completely transparent state. That is, the multiple driving power sources 2 configure the microelectrode ME of the transparent electrode 12A on the deposition side as an anode (+) and the opposing transparent electrode 12B as a cathode (-). In this case, applying a voltage of approximately 0.4 V to 0.7 V causes the microelectrode ME to bleach. The light control device 1B achieves reversible light control by repeating this polarity reversal. The configuration of the light control device 1B other than the insulating film 13 is the same as that of the light control device 1 described in FIG. 1, and therefore the same reference numerals are used and the description thereof will be omitted.

[0054] <Insulating film> The insulating film 13 transmits light and blocks current. The insulating film 13 has a volume resistivity of 10 8 It is preferable to use a material with a resistivity of Ω·cm or higher. The insulating film 13 may be made of, for example, aluminum oxide, silicon oxide, gallium oxide, cerium oxide, silicon nitride, carbon nitride, silicon carbide, or the like. The insulating film 13 may be formed by a semiconductor process, such as a CVD (Chemical Vapor Deposition) method or an ALD (Atomic Layer Deposition) method.

[0055] The insulating film 13 may be made of, for example, glass, a resin material (Teflon (registered trademark), film, stencil mask, plastic, etc.), a light-transmitting tape (Kapton (registered trademark) tape), a light-transmitting paper (cellulose nanofiber), etc. However, in order to achieve high precision and miniaturization, it is preferable to stack the insulating film 13 by a semiconductor process. Furthermore, since the density of the film is important in the present invention, the ALD method, which realizes high-density film formation, is more preferable.

[0056] With the above-described configuration, the light-adjusting device 1B can achieve light-adjusting operation at a higher speed than the light-adjusting device 1 because the reaction area for metal salt deposition is further reduced by the microelectrodes ME.

[0057] <Manufacturing method of light-adjusting element> Next, a method for manufacturing the light control device 1B according to the second embodiment of the present invention will be described with reference to FIG. 11 (and also with reference to FIG. 9 as needed). The manufacturing method of the light-adjustable device 1B includes a substrate creating step S1, a microelectrode creating step S2, a microelectrode creating step S2B, an electrode pair creating step S3, and an electrolyte filling step S4. Note that the manufacturing process of the light-adjustable device 1B is the same as that of the light-adjustable device 1 described in FIG. 5 except for the microelectrode creating step S2B, and therefore the description thereof will be omitted. After the substrate producing step S1 and the microelectrode producing step S2, the microelectrode producing step S2B is carried out.

[0058] The microelectrode generation process S2B is a process of generating a microelectrode ME by stacking an insulating film 13 having a row of microapertures in the longitudinal direction of the microelectrode FE on the microelectrode FE generated in the microelectrode generation process S2 and the gap SL between the microelectrodes FE.

[0059] This microelectrode producing step S2B will be described with reference to Figures 12A to 12E, which show the microelectrode ME producing step in the Xc-Xc cross section of Figure 10. As shown in FIG. 12A, in the microelectrode forming step S2B, a resist 60 is applied to the entire transparent electrode 12A side of the transparent electrode substrate 10A on which the microelectrodes FE have been formed in the microelectrode forming step S2. 12B, in the microelectrode generation step S2B, a mask 50 processed to fit the shape of the microelectrode is placed in close contact with the resist 60 and exposed to light. Here, a metal that does not transmit light, such as chromium, is used as the mask 50, which is processed to fit the shape of the microelectrode and brought into close contact with the resist 60, and exposed to ultraviolet light 300. After exposure, the mask 50 is peeled off.

[0060] 12C, in the microelectrode generating step S2B, the resist 60 irradiated with the ultraviolet light 300 is stripped off with a developer. Note that in this example, a positive resist is used as the resist 60, and the exposed portion irradiated with the ultraviolet light 300 is stripped off with a developer. Then, as shown in FIG. 12D, in the microelectrode forming step S2B, an insulating film 13 made of aluminum oxide or the like is formed on the entire surface of the transparent electrode 12 including the resist 60 by a CVD method, an ALD method or the like. Thereafter, as shown in FIG. 12E, in the microelectrode forming step S2B, the resist 60 (FIG. 12D) is removed using a remover to form the openings on the microelectrodes FE as the microelectrodes ME.

[0061] Thereafter, the electrode pair generating step S3 and the electrolyte filling step S4 are performed, whereby the light-adjusting device 1B can be manufactured. By applying a voltage to the transparent electrodes 12A and 12B of the light control device 1B produced by the above steps, the light control device 1B can improve the responsiveness of the light control operation due to the microelectrodes ME.

[0062] <Response performance test results> Next, with reference to FIGS. 13 and 14 (and also with reference to FIG. 9 as needed), the results of an experiment on the response performance in the dimming operation of the dimming device 1B depending on the size of the microelectrode ME will be described. In this example, in the light-adjusting element 1B of FIG. 9, a transparent electrode 12A (material: crystalline ITO, film thickness: 150 nm, film resistance: 9.1 Ω / cm ) is formed on the surface of a light-transmitting substrate 11A (thickness: 0.7 mm, size: 50 mm × 34 mm). 2 ) was formed with the line width W (μm) of the fine electrodes FE and the gap width L (μm) between the fine electrodes FE as shown in FIG. In addition, an insulating film 13 was formed by laminating aluminum oxide having a row of circular openings with a diameter D (μm) in the longitudinal direction of the microelectrode FE to a film thickness of 20 nm. A transparent electrode 12B (material: crystalline ITO, film thickness: 150 nm, film resistance: 9.1 Ω / cm) was formed on the entire surface of the opposing light-transmitting substrate 11B (thickness: 0.7 mm, size: 50 mm × 34 mm). 2 ) was formed.

[0063] Here, the transmittance over time was measured for three cases: when the gap width L was 0.5 mm, the line width W was 600 μm, and the diameter D of the microelectrode ME was 50 μm and 500 μm, and when the transparent electrode 12A was formed on the entire surface of the translucent substrate 11A without the microelectrodes FE and microelectrodes ME. Note that here, the transmittance measured was set to 100% when incident light 100 with a central wavelength of visible light (550 nm) was transmitted through the dimming element 1B when it was not operating (not colored) when one microelectrode of the corresponding size was operated.

[0064] The measurement results are shown in Figure 14. The horizontal axis of the graph in Figure 14 represents the response time (seconds), and the vertical axis represents the transmittance (%). D1 represents the case where the diameter D is 50 μm, D2 represents the case where the diameter D is 500 μm, and DA represents the case where the transparent electrode 12A is formed over the entire surface of the translucent substrate 11A. For reference, Figure 14 also shows the case where the line width of the microelectrode FE shown in Figure 8 is 5 μm (W1). As shown in Figure 14, the response time until the transmittance falls below 20% is significantly shorter when the microelectrode ME is provided (D1, D2) than when the microelectrode ME is not provided (DA). For example, it takes approximately 9 seconds for DA, compared to approximately 0.4 seconds for D1 and approximately 0.9 seconds for D2. Furthermore, when comparing D1 and D2, which use a microelectrode ME, D1, which has a shorter diameter, has a shorter response time until the transmittance drops below 20%. Furthermore, when a microelectrode ME with a diameter of 50 μm is used (D1), the response time until the transmittance drops below 20% is shorter than when a microelectrode FE with a line width of 5 μm is used (W1). For example, the response time for W1 is approximately 0.9 seconds, while for D1 it is approximately 0.4 seconds.

[0065] In addition, when a microelectrode ME with a diameter of 50 μm was used (D1), unstable operation was observed after a transmittance of 20% was achieved. This was because, after this measurement, a burr had appeared on the circular edge of the microelectrode ME part of the insulating film 13, and it became clear that abnormal deposition had occurred at this burr part due to electric field concentration.

[0066] The above measurement results demonstrate that the metal salt deposition electrochromic dimming element 1B can achieve even faster dimming operation by using a microelectrode ME as the transparent electrode 12A on which the metal salt is deposited. The light control elements 1 and 1B according to the first and second embodiments of the present invention described above can significantly reduce the response time of the light control operation compared to conventional methods. Furthermore, the light control elements 1 and 1B can perform partial variable control of the transmittance. [Explanation of symbols]

[0067] 1,1B dimming element 2. Drive power supply 10 Transparent electrode substrate 11 Translucent substrate 12 Transparent electrode 13 Insulating film 20 Electrolyte 30 Encapsulating material FE Microelectrode ME microelectrode SL Gap 50 Mask 60 Resist 100 incident light 200 emitted light 300 UV rays

Claims

1. A metal salt deposition electrochromic dimming element for dimming, a pair of transparent electrode substrates in which transparent electrodes forming an electrode pair are opposed to each other with a gap therebetween; an electrolyte solution filled in the gap and containing at least silver ions as metal ions of a metal salt; a sealant that seals the electrolyte in the gap, A light-adjusting element, wherein the transparent electrode on the side where the metal salt is deposited is a plurality of fine electrodes with gaps therebetween.

2. a transparent insulating film is further disposed in the gap and the fine electrode; 2. The light control element according to claim 1, wherein the insulating film has a row of openings in the longitudinal direction of the microelectrodes, and a part of the microelectrodes is exposed as a microelectrode in each opening.

3. The light control element according to claim 1 , wherein the minute electrodes are voltage-controlled by individual driving power sources.

4. 4. The light-adjusting element according to claim 3, wherein the transparent electrode on the side where the metal salt is not deposited is voltage-controlled with a voltage value of 0V.

5. 2. The light-adjusting element according to claim 1, wherein the width of the gap is 30 [mu]m or less.

6. 3. The light-adjusting element according to claim 2, wherein the array of openings is formed by circular openings each having a diameter of 1000 μm or less or polygonal openings each having a diagonal dimension of 1000 μm or less, the circular openings being arranged at predetermined intervals.

7. The insulating film has a volume resistivity of 10 ８ 3. The light-adjusting element according to claim 2, wherein the resistivity is Ω·cm or more.

8. 3. The light control element according to claim 2, wherein the insulating film is made of aluminum oxide, silicon oxide, gallium oxide, cerium oxide, silicon nitride, carbon nitride, or silicon carbide.

9. A method for manufacturing a metal salt deposition electrochromic dimming element for dimming, comprising: a substrate producing step of laminating transparent electrodes on a light-transmitting substrate to produce first and second transparent electrode substrates; a microelectrode forming step of forming a plurality of gaps in the transparent electrode of the first transparent electrode substrate, exposing the light-transmitting substrate, and forming a plurality of microelectrodes from the transparent electrode; an electrode pair generating step of generating an electrode pair by opposing the first transparent electrode substrate on which the fine electrodes are generated and the second transparent electrode substrate on which the transparent electrodes are laminated, the electrode pair being spaced apart by a predetermined interval; an electrolyte filling step of filling the gap with an electrolyte containing at least silver ions as metal ions of a metal salt; A method for manufacturing a light control element, comprising:

10. Between the fine electrode generation step and the electrode pair generation step, 10. The method for manufacturing a photochromic element according to claim 9, further comprising a microelectrode generation step of stacking an insulating film having a row of microapertures in the longitudinal direction of the microelectrodes on the microelectrodes generated in the microelectrode generation step and in the gaps between the microelectrodes, thereby generating microelectrodes in which a portion of the microelectrodes is exposed.

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