Electrochromic element

Abstract

To provide an electrochromic device that can achieve continuous transmittance gradation in which an equal transmittance line forms a substantially straight line.SOLUTION: An electrochromic element of the disclosure has a first electrode, a second electrode facing the first electrode, an electrochromic layer arranged between the first electrode and the second electrode, and a plurality of first wires electrically connected with the first electrode. The first electrode has a single section in a first area that overlaps the electrochromic layer in plan view. The plurality of first wires are electrically connected with the first electrode via a first lead-out electrode that is provided in a second area in contact with the first area in plan view. An area between the plurality of first wires and the first electrode has a lower resistance than that of an area between the adjacent first wires.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electrochromic device. [Background technology]

[0002] Electrochromic elements are known that utilize electrochromic materials whose optical absorption properties (absorption wavelength, absorbance) change due to electrochemical redox reactions. Electrochromic elements have the advantage of being able to achieve both high transmittance when bleached and low transmittance when colored, and are therefore used in displays, variable reflectance mirrors, variable transmission windows, variable neutral density (ND) filters, and other applications.

[0003] One type of ND filter is an optical filter called a half ND filter. A half ND filter is a filter that reduces the transmittance of bright areas of a subject when there is a large difference in brightness between the subject and the rest of the subject, thereby reducing the overall brightness difference. If the transmittance profile (position, density, gradation) of such a filter could be electronically controlled, the range of image expression could be expanded.

[0004] An electronic variable diaphragm is known as an optical filter configured to partially change the transmittance of the variable transmittance region of an electrochromic element. Patent Document 1 discloses a variable diaphragm having multiple electrodes divided into concentric circles. By using multiple electrodes divided into concentric circles in this way, it is possible to control a portion of the variable transmittance region of the electrochromic element to the shape of an optical diaphragm. Patent Document 2 also discloses a variable diaphragm in which wiring is arranged along a set of electrodes and a surrounding seal. This variable diaphragm uses the resistance of the electrodes to control a portion of the variable transmittance region of the electrochromic element to a continuous transmittance gradation. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 06-273806 [Patent Document 2] Special Publication No. 2002-537582 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in electrochromic elements using concentrically divided electrodes as described in Patent Document 1, the electrochromic layer in the divided areas that are not electrically conductive does not color, which can result in low transmittance in the divided areas. Also, because the transmittance of the electrochromic layer is determined for each electrode, it has been difficult to achieve a transmittance gradation that changes continuously, as required for half ND filters.

[0007] Furthermore, in the electrochromic element described in Patent Document 2, the transmittance control pattern is limited to concentric circles or similar shapes. Therefore, it has been difficult to achieve a transmittance gradation, in which equal transmittance lines are approximately straight lines, particularly in multiple directions, as required for half ND filters.

[0008] An object of the present invention is to provide an electrochromic element that can realize a continuous transmittance gradation in which equal transmittance lines form substantially straight lines. [Means for solving the problem]

[0009] According to one disclosure of the present specification, there is provided a liquid crystal display device comprising a first electrode, a second electrode facing the first electrode, an electrochromic layer disposed between the first electrode and the second electrode, and a plurality of first wirings electrically connected to the first electrode, wherein the first electrode has a single partition in a first region where the first electrode, the second electrode, and the entire electrochromic layer overlap in a plan view, and the plurality of first wirings are ElectricallyAn electrochromic element is provided in which the first wirings are independent of each other and each are electrically connected to the first electrode via a first extraction electrode provided in a second region that contacts the first region in a planar view, the first extraction electrode has a plurality of portions corresponding to the plurality of first wirings, at least a portion of the region between adjacent portions has a higher resistance than the region between the plurality of first wirings and the first electrode, an electrical path connecting one first wiring of the plurality of first wirings to the first electrode and an electrical path connecting another first wiring of the plurality of first wirings to the first electrode are independent of each other, and the region between the plurality of first wirings and the first electrode has a lower resistance than the region between adjacent first wirings. [Effects of the Invention]

[0012] According to the present invention, it is possible to realize an electrochromic element capable of forming a continuous transmittance gradation in which equal transmittance lines are substantially straight. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a plan view showing a schematic configuration of an electrochromic element according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a schematic configuration of an electrochromic element according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a plan view showing the structure of an electrode in an electrochromic element according to a first embodiment of the present invention. [Figure 4] FIG. 2 is an enlarged plan view of a connection portion between an electrode and an extraction electrode in the electrochromic element according to the first embodiment of the present invention. [Figure 5] FIG. 1 is a diagram (part 1) showing the simulation results of the electrochromic element according to the embodiment. [Figure 6] FIG. 10 is a diagram (part 2) showing the simulation results of the electrochromic element according to the embodiment. [Figure 7] FIG. 10 is a diagram (part 3) showing the simulation results of the electrochromic element according to the embodiment. [Figure 8] FIG. 10 is a diagram (part 4) showing the simulation results of the electrochromic element according to the embodiment. [Figure 9] FIG. 10 is a diagram showing a simulation result of an electrochromic element according to a comparative example. [Figure 10] FIG. 10 is a schematic diagram showing an example of the configuration of an imaging device according to a third embodiment of the present invention. [Figure 11] FIG. 10 is a diagram showing an example of the configuration of a window material according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] [First embodiment] The schematic configuration of an electrochromic element according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a plan view showing the schematic configuration of an electrochromic element according to this embodiment. FIG. 2 is a cross-sectional view showing the schematic configuration of an electrochromic element according to this embodiment. FIG. 2(a) is a cross-sectional view taken along line IIA-IIA' in FIG. 1, and FIG. 2(b) is a cross-sectional view taken along line IIB-IIB' in FIG. 1. FIG. 3 is a plan view showing the structure of electrodes in an electrochromic element according to this embodiment.

[0015] As shown in FIG. 2 , the electrochromic device 100 according to this embodiment includes a pair of electrodes 22 and 32 and an electrochromic layer 40 disposed between the electrodes 22 and 32. The electrode 22 is preferably provided on a support substrate 20, which serves as a support member for the electrode 22. Similarly, the electrode 32 is preferably provided on a support substrate 30, which serves as a support member for the electrode 32. The support substrates 20 and 30 may be disposed opposite each other, with the surface on which the electrode 22 is provided facing the surface on which the electrode 32 is provided. As shown in FIG. 1 , assuming that a rectangular region 10, a frame-shaped region 12 surrounding the region 10, and a frame-shaped region 14 surrounding the region 12 are defined in a planar view, the electrodes 22 and 32 and the electrochromic layer 40 may be disposed in the region 10. The region 10 may be defined as the region where the electrodes 22 and 32 and the electrochromic layer 40 overlap in a planar view. The region 10 is in contact with the region 12 at its periphery. Region 12 is in contact with region 14 at its outer periphery. Region 14 is spaced apart from region 10. In this specification, a plan view refers to a plan view seen from the normal direction of electrodes 22 and 32, and corresponds to the two-dimensional plan view ( FIG. 1 ) obtained by projecting each component of electrochromic element 100 onto a plane parallel to the surfaces of electrodes 22 and 32.

[0016] As shown in FIGS. 2 and 3 , an extraction electrode 24 electrically connected to the electrode 22 is provided around the electrode 22. As shown in FIG. 2 , a plurality of wirings 26 for supplying power to the electrode 22 via the extraction electrode 24 is provided on the extraction electrode 24. The extraction electrode 24 is divided into a plurality of portions corresponding to the plurality of wirings 26 by separation portions 28. The plurality of extraction electrodes 24 thus divided are arranged to surround the electrode 22 in a plan view. The connection portion between one extraction electrode 24 and the electrode 22 is separated from the connection portion between another extraction electrode 24 and the electrode 22. In other words, the electrical path connecting the wiring 26 arranged on one extraction electrode 24 to the electrode 22 and the electrical path connecting the wiring 26 arranged on the other extraction electrode 24 to the electrode 22 are independent from each other. The plurality of extraction electrodes 24 may be arranged extending from region 12 to region 14 so as to extend outward from region 10, for example, as shown in FIGS. 2 and 3 . 2 and 3, the wiring 26 may be disposed in the region 14. In one embodiment, the plurality of extraction electrodes 24 may be formed from the same conductive layer as the conductive layer that forms the electrode 22. In this case, the plurality of extraction electrodes 24 may be disposed on the support substrate 20, similar to the electrode 22.

[0017] Similarly, as shown in FIG. 2, an extraction electrode 34 electrically connected to the electrode 32 is provided around the electrode 32. As shown in FIG. 2, a plurality of wirings 36 for supplying power to the electrode 32 via the extraction electrode 34 are provided on the extraction electrode 34. The extraction electrode 34 is divided into a plurality of portions corresponding to the plurality of wirings 36 by separation portions 38. The plurality of extraction electrodes 34 thus divided are arranged to surround the electrode 32 in a plan view. The connection portion between one extraction electrode 34 and the electrode 32 is separated from the connection portion between another extraction electrode 34 and the electrode 32. In other words, the electrical path connecting the wiring 36 arranged on one extraction electrode 34 to the electrode 32 and the electrical path connecting the wiring 36 arranged on the other extraction electrode 34 to the electrode 32 are independent from each other. The plurality of extraction electrodes 34 may be arranged extending from region 12 to region 14 so as to extend outward from region 10, for example, as shown in FIG. 2. The wirings 36 may be arranged in region 14, for example, as shown in FIG. 2. In one embodiment, the plurality of extraction electrodes 34 can be formed from the same conductive layer as the conductive layer that forms the electrode 32. In this case, the plurality of extraction electrodes 34 can be disposed on the support substrate 30, similar to the electrode 32.

[0018] The number of lead electrodes 24 provided on each side of electrode 22 and the number of lead electrodes 34 provided on each side of electrode 32 are not limited to the examples shown in the drawings and can be increased or decreased as appropriate. The size of each of the lead electrodes 24, 34 is also not particularly limited and may all be the same, or at least some may be different. The number and size of each of the lead electrodes 24, 34 can be set as appropriate depending on the transmittance profile to be formed in the electrochromic layer 40.

[0019] In this embodiment, the electrode 22 and the extraction electrode 24, and the electrode 32 and the extraction electrode 34 have substantially the same shape, and are arranged so that the electrode 22 and the electrode 32 overlap, and the extraction electrode 24 and the extraction electrode 34 overlap, in a plan view. However, the electrode 22 and the extraction electrode 24, and the electrode 32 and the extraction electrode 34 do not necessarily have to have the same shape. Furthermore, one of the extraction electrodes 24, 34 does not necessarily have to be divided into multiple parts. For example, the extraction electrode 34 connected to the electrode 32 may be configured as a frame-shaped pattern provided in the region 12 and the region 14. In this case, the wiring 36 may be configured as a frame-shaped pattern provided over the entire region 14.

[0020] A partition wall 42 for isolating the electrochromic layer 40 from the outside may be provided around the electrochromic layer 40. In this case, the partition wall 42 may be disposed in the region 12 in plan view, for example, as shown in FIGS.

[0021] In electrochromic elements configured to change the transmittance throughout the electrochromic layer, annular metal wiring may be arranged to surround the electrode in a planar view in order to achieve a uniform in-plane transmittance. By configuring the wiring connected to the electrode in this way and suppressing the potential difference within the wiring due to the highly conductive metal properties, the potential difference within the electrode surface connected to the wiring can be kept small, resulting in a uniform in-plane transmittance.

[0022] The electrochromic element of this embodiment also uses wiring 26, 36 made of a low-resistance material in order to achieve efficient electrical connection between the external circuit and the electrodes 22, 32. However, in this embodiment, multiple extraction electrodes 24, 34 are provided extending outward from the periphery of the electrodes 22, 32, and independent wiring 26, 36 is arranged for each of these multiple extraction electrodes 24, 34. This makes it easier to generate a potential difference between the extraction electrodes 24 and between the extraction electrodes 34, and by increasing the potential difference within the plane of the electrodes 22, 32 connected to these extraction electrodes 24, 34, it becomes easier to partially change the transmittance within the electrode plane.

[0023] Next, the electrochromic device 100 according to this embodiment and each of its components will be described in more detail.

[0024] (Electrochromic element 100) An electrochromic element is an element that can electrically change the amount of light absorbed. Electrochromic elements are classified into transmission-type electrochromic elements that control the amount of light transmitted, and reflection-type electrochromic elements that control the amount of light reflected. The electrochromic element of this embodiment can be applied to either transmission-type or reflection-type forms, but transmission-type electrochromic elements are mainly used for optical filters.

[0025] Electrochromic elements include those using inorganic materials and those using organic materials, and those using organic materials include those using polymer organic materials and those using low molecular weight organic materials. Any of the electrochromic materials can be used in the electrochromic element of this embodiment. Of these, electrochromic elements using low molecular weight organic materials are particularly preferred from the viewpoints of contrast and maximum transmittance.

[0026] The control range of light absorptance in an electrochromic element is not particularly limited, but it is desirable that it encompasses a range that satisfies the performance of a partially variable transmittance filter. For example, an ideal control range of light absorptance is 0% to 99%, and a practical control range of light absorptance is 3% to 90%. Furthermore, it is desirable that a stepless gradation can be achieved when controlling light absorptance within these ranges.

[0027] (Electrochromic layer 40) The electrochromic layer 40 includes a material (electrochromic material) that exhibits electrochromic properties. The electrochromic layer 40 may be a solid electrochromic layer formed by depositing an electrochromic material on an electrode, or may be a solution electrochromic layer in which the electrochromic material is dissolved in a solvent.

[0028] Electrochromic materials include inorganic electrochromic materials, organic polymer electrochromic materials, and organic low-molecular-weight electrochromic materials. Examples of inorganic electrochromic materials include tungsten oxide and iridium oxide. Examples of organic high-molecular-weight electrochromic materials include polythiophene and polyaniline. Examples of organic low-molecular-weight electrochromic materials include derivatives of pyridine salts, aromatic amine compounds, and derivatives of heterocyclic compounds, which can be used in a dissolved state in a solvent.

[0029] The solvent can be appropriately selected depending on the application, taking into consideration the solubility, vapor pressure, viscosity, potential window, etc. of the solute, including the electrochromic material, but is preferably a polar solvent. Examples of the solvent include organic polar solvents such as methanol, ethanol, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, γ-butyrolactone, γ-valerolactone, sulfolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, acetonitrile, propionitrile, benzonitrile, dimethylacetamide, methylpyrrolidinone, and dioxolane, as well as water. Among these, cyclic ester compounds are preferably used in terms of boiling point and solubility.

[0030] Furthermore, the electrochromic layer 40 may further contain an electrolyte, a viscosity modifier, a UV stabilizer, etc., as necessary. The electrolyte layer containing the electrolyte may be disposed integrally with the electrochromic layer, or may be disposed so as to overlap the electrochromic layer.

[0031] A partition wall 42 is preferably used to hold the electrochromic layer 40 and the electrolyte layer between the electrodes 22 and 32 and to maintain the distance between the electrodes 22 and 32. A sealing material is preferably used as the partition wall 42. The sealing material is preferably a material that is chemically stable, impermeable to gases and liquids, and does not inhibit the oxidation-reduction reaction of the electrochromic material. Examples of the sealing material that can be used include inorganic materials such as glass frit, organic materials such as epoxy resins and acrylic resins, and metal materials.

[0032] The sealing material may function as a spacer to define and maintain the distance between the electrodes 22 and 32. In this case, the sealing material may contain a spacer material. If the sealing material does not function as a spacer, a separate spacer may be disposed to maintain the distance between the electrodes 22 and 32. Examples of spacer materials include inorganic materials such as silica beads and glass fiber, and organic materials such as polyimide, polytetrafluoroethylene, polydivinylbenzene, fluororubber, and epoxy resin.

[0033] (electrodes 22,32) The electrodes 22 and 32 have the role of controlling the coloring and fading of the electrochromic layer 40 by the voltage applied thereto. In the case of a transmissive electrochromic element 100, the electrodes 22 and 32 are made of a transparent electrode material. In the case of a reflective electrochromic element 100, at least one of the electrodes 22 and 32 is made of a transparent electrode material. Of the electrodes 22 and 32, the rear electrode on the light path may be a light-reflective electrode (e.g., a metal electrode).

[0034] The electrodes 22 and 32 are preferably made of a material that is transparent, conductive, and stable during the redox reaction of the electrochromic material. Examples of such materials include transparent conductive oxide materials such as indium tin oxide (ITO) and fluorine-doped tin oxide. The electrodes 22 and 32 may be made of these electrode materials with thin metal wires or thin metal films to reduce resistance, or may be made of transparent conductive films using other conductive materials such as carbon nanotubes. The sheet resistance of the electrodes 22 and 32 made of ITO is, for example, approximately 13.9 Ω / □.

[0035] When the electrodes 22, 32 are disposed on a substrate (e.g., support substrates 20, 30), the substrate may be made of a light-transmitting material. Here, "light-transmitting" means transmitting light and may be defined as having a light transmittance of 50% or more and 100% or less. Specifically, the substrate may be made of glass, a polymer compound, or the like, and may be provided with a coating such as an anti-reflection film as needed.

[0036] The electrodes 22 and 32 are provided in a region 10 that overlaps with the electrochromic layer 40 in a planar view. The electrodes 22 and 32 provided in the region 10 are formed from a single section. Here, a single section means that the electrodes are not separated by a high-resistance portion or the like and are formed from a single continuous conductive member. A typical example is when the region 10 has uniform conductivity throughout. As long as the electrodes are formed from a single section, they may be configured to have a desired in-plane distribution of conductivity, such as a configuration in which the conductivity changes continuously within the plane, in order to achieve the desired characteristics of the optical filter.

[0037] The reason why the electrodes 22, 32 are configured as a single partition is to obtain a continuous gradation profile of transmittance within the plane. If one region of the electrodes 22, 32 is separated from another region by a high-resistance portion or the like, an electric field cannot be applied to the electrochromic layer 40 at that portion, making it impossible to control the transmittance. As a result, the electrochromic layer 40 in the portion overlapping the separated portion in a plan view is in a discontinuous state, with a different transmittance from the surrounding electrochromic layer 40, and it is no longer possible to obtain a gradation profile in which the transmittance changes continuously within the plane.

[0038] In this regard, in the electrochromic element 100 of this embodiment, as described above, the electrodes 22, 32 are configured as a continuous single section that is not divided by high resistance portions, etc. Therefore, with the electrochromic element 100 of this embodiment, it is possible to obtain the transmittance characteristics required for a half ND filter, that is, a gradation profile in which the transmittance changes continuously within the plane.

[0039] The electrodes 22 and 32 preferably have a substantially rectangular shape in plan view. This is because many of the imaging elements of cameras that use half ND filters are rectangular, and the displays and photographic paper that display the captured images are often rectangular. Specifically, the shape of the electrodes 22 and 32 in plan view is preferably rectangular or a similar shape.

[0040] (Extraction electrodes 24, 34) The extraction electrode 24 serves as a voltage supply path when a voltage is supplied from the wiring 26 to the electrode 22. In this embodiment, a plurality of extraction electrodes 24 are arranged so as to surround the electrode 22 in a plan view. Adjacent extraction electrodes 24 are separated from each other by a separation portion 28. Each of the plurality of extraction electrodes 24 is provided with a wiring 26 for supplying power to the electrode 22 via the extraction electrode 24.

[0041] Fig. 4 is an enlarged view of the connection portion between electrode 22 and extraction electrode 24. As shown in Fig. 4, the multiple extraction electrodes 24 are preferably spaced apart via spacing portions 28 so as to be aligned along direction D2 intersecting direction D1 from wiring 26 toward electrode 22. By arranging the multiple extraction electrodes 24 in this manner, the voltage applied to the multiple wirings 26 can be transmitted to electrode 22 without reducing its independence.

[0042] If an annular extraction electrode 24 and wiring 26 were arranged to surround the electrode 22, the potential difference inside the wiring 26, which is made of a low-resistance material, would be small, making it difficult to form a desired potential distribution within the surface of the electrode 22. In this regard, in this embodiment, the extraction electrode 24 and wiring 26 are divided into multiple regions, making it possible to apply multiple types of voltage to the electrode 22 from these multiple wirings 26 via the multiple extraction electrodes 24. Therefore, a desired potential distribution can be formed within the surface of the electrode 22, and the transmittance distribution within the region 10 can be controlled.

[0043] It is preferable that the extraction electrodes 24 are provided on at least one side of the electrode 22 and the opposite side. This is because a transmittance gradation that changes in a direction perpendicular to one side of the electrode 22 and the opposite side is often used in half ND filters, and such an arrangement of the connection parts is preferable for forming this transmittance gradation. Note that a preferable transmittance gradation in a half ND filter is one in which the line connecting the equal transmittance points within the filter (equal transmittance line) is approximately linear. It is preferable that this approximately linear equal transmittance line is approximately perpendicular to one side of the electrode 22.

[0044] Furthermore, it is desirable to arrange the multiple extraction electrodes 24 so as to surround the electrode 22. By arranging the multiple extraction electrodes 24 in this manner, it is possible to form a desired potential distribution throughout the entire region of the electrode 22 that overlaps with the region 10. For example, consider a case where extraction electrodes 24 are arranged on the upper and lower edges of the electrode 22 in a planar view, but extraction electrodes 24 are not arranged on the left and right edges of the electrode 22 in a planar view. In this case, it is possible to form a potential gradient in the vertical direction of the electrode 22, but it is difficult to form a potential gradient in the horizontal direction of the electrode 22. In contrast, by providing extraction electrodes 24 on all of the upper, lower, left, and right edges of the electrode 22 so as to surround the periphery of the electrode 22, as in the present embodiment, it is possible to generate a potential gradient in all directions within the surface of the electrode 22.

[0045] Furthermore, it is preferable that multiple extraction electrodes 24 be provided on one side of the electrode 22. This is because it is advantageous for forming a potential gradient on that side of the electrode 22. If the extraction electrodes 24 and wiring 26 were continuous along that side of the electrode 22, it would be difficult to form a potential gradient along that side of the electrode 22 due to the low resistance of the wiring 26. By providing multiple extraction electrodes 24 on that side of the electrode 22, it becomes easier to form a potential gradient on that side of the electrode 22. Note that it is not necessary to apply a voltage to the multiple wirings 26 lined up along that side. Dividing the extraction electrodes 24 and wiring 26 into multiple parts along that side also serves to prevent the potential from becoming uniform along that side of the electrode 22 through the wiring 26. Providing multiple extraction electrodes 24 on one side of the electrode 22 is also preferable because it allows for a high degree of freedom in controlling the density of the half ND filter.

[0046] Furthermore, it is preferable that a plurality of extraction electrodes 24 are provided on each side of the electrode 22, and that a voltage can be independently supplied to the electrode 22 via these plurality of extraction electrodes 24. It is preferable that three or more extraction electrodes 24 are provided on each side of the electrode 22, and it is even more preferable that five or more extraction electrodes 24 are provided. By providing three or more connectors on one side of the electrode 22, it becomes possible to control the equal transmittance lines in the filter with a high degree of freedom. Furthermore, by providing three or more connectors on each side of the electrode 22, it is possible to form, for example, a transmittance gradation in which the substantially linear equal transmittance lines are inclined with respect to the sides of the electrodes 22 and 32, or a transmittance gradation in which the equal transmittance lines are curved.

[0047] The separated portion 28 is preferably a region having a higher resistance than the electrode 22, and more preferably an insulating region. For example, the sheet resistance of the separated portion 28 is preferably 100 Ω / □ or more, and more preferably 1000 Ω / □ or more. The method for forming the separated portion 28 is not particularly limited. For example, the separated portion 28 may be formed by patterning the conductive layer constituting the extraction electrode 24 and the conductive layer constituting the wiring 26 using laser processing or photolithography. Alternatively, the separated portion 28 may be selectively formed in the desired region by using a lift-off method or the like.

[0048] In this embodiment, the separation portions 28 are provided so that the extraction electrode 24 is divided into a plurality of portions corresponding to the plurality of wirings 26 in the regions 12 and 14, but the configuration of the extraction electrode 24 is not limited to this. The separation portions 28 have the role of forming a potential gradient in accordance with the potential difference of the applied voltages in the portions of the electrode 22 corresponding to the wirings 26 when different voltages are supplied from these wirings 26. The configuration of the extraction electrode 24 can be changed as appropriate as long as it can fulfill this role.

[0049] For example, the extraction electrode 24 may be configured so that the region between the wiring 26 and the electrode 22 has a lower resistance than the region between the wirings 26. In this case, it is desirable that the region between the wiring 26 and the electrode 22 has a resistance that is at least one order of magnitude lower than the region between adjacent wirings 26. Alternatively, the extraction electrode 24 may be configured so that the resistance value between each of the wirings 26 and the electrode 22 is smaller than the resistance value between the wirings 26.

[0050] For this purpose, the region between the wirings 26 is preferably a separation portion 28 where the extraction electrode 24 has been removed, a high-resistance region where the extraction electrode 24 has been thinned, or a region that is a combination of these. It is preferable that the separation portion 28 or the high-resistance region where the extraction electrode 24 has been thinned be provided in the region 12 as well, but if the above purpose can be achieved without the separation portion 28 or the high-resistance region, it is not necessarily necessary to provide them in the region 12.

[0051] The above description of the extraction electrode 24 also applies to the extraction electrode 34 for the electrode 32 .

[0052] (Wiring 26, 36) The electrochromic element 100 has wiring 26, 36 for efficiently applying a driving voltage from an external circuit to the electrodes 22, 32. The material of the wiring 26, 36 is not particularly limited as long as it has high conductivity per unit volume, but metal materials, particularly silver, copper, and aluminum, are preferred. The sheet resistance of the wiring 26, 36 made of silver wiring is, for example, approximately 15.8 mΩ / □. The method for forming the wiring 26, 36 can be selected depending on the characteristics of the wiring 26, 36, the electrodes 22, 32, and the support substrates 20, 30. For example, techniques such as printing using a metal paste, sputtering, and plating can be applied. By combining these methods with techniques such as patterning and polishing, the wiring 26, 36 can be formed in the desired shape in the desired area.

[0053] Next, a method for driving the electrochromic element 100 according to this embodiment will be described. The method for driving the electrochromic element 100 is not particularly limited, but an example is a method for controlling the transmittance of the electrochromic element 100 by pulse width modulation. For example, the peak value of the pulse voltage waveform applied between the electrode 22 and the electrode 32 is not changed, but the proportion of the application period of the applied voltage in one cycle of the pulse voltage waveform is changed to control the effective voltage to the electrochromic layer 40 and thereby the transmittance.

[0054] As a means for realizing a continuous transmittance gradation, the electrochromic element 100 of this embodiment includes voltage supply means (lead-out electrodes 24, 34, wiring 26, 36) for forming a potential gradient within the plane of the electrodes 22, 32. That is, a potential gradient is formed within the plane of the electrodes 22, 32 by applying multiple types of voltages to the electrodes 22, 32 from an external circuit via the wiring 26, 36 and lead-out electrodes 24, 34.

[0055] The transmittance of the electrochromic layer 40 varies depending on the effective potential difference (effective voltage) between the electrode 22 and the electrode 32. Therefore, the voltage supplied to the electrochromic element 100 is set appropriately depending on the transmittance profile desired to be formed in the electrochromic layer 40. Specifically, the voltage supplied to the electrodes 22 and 32 from the wirings 26 and 36 via the lead-out electrodes 24 and 34 is set so that the effective voltage between the electrode 22 and the electrode 32 at each portion of the electrochromic layer 40 is a value necessary to achieve the desired transmittance profile. By appropriately setting the respective voltages supplied to the electrodes 22 and 32 via the multiple wirings 26 and 36 and the multiple lead-out electrodes 24 and 34, various transmittance profiles can be formed in the electrochromic layer 40.

[0056] The transmittance profile may have a gradation, for example, where the highest transmittance portion is at or near the maximum transmittance of the electrochromic element, and the lowest transmittance portion is less than half the transmittance of the highest transmittance portion. Partial ND filters, such as half ND filters, are often used to reduce the amount of light in bright areas within the angle of view and suppress the difference in light intensity between dark areas. Therefore, filters with a higher transmittance corresponding to these dark areas are preferred because they allow for more effective use of incident light. When using the electrochromic element 100 in this manner, it is preferable to employ the following potential control method.

[0057] First, a voltage is applied to the portions of electrode 22 and electrode 32 corresponding to the portions where the electrochromic layer 40 should be controlled to have the highest transmittance, so that the electrochromic layer 40 will be in a highly transmittant state. Also, a voltage is applied to the portions of electrode 22 and electrode 32 corresponding to the portions where the electrochromic layer 40 should be controlled to have the lowest transmittance, so that the electrochromic layer 40 will be in a desired transmittance state. Then, the potential difference between the wirings 26 and 36 corresponding to the portions of electrodes 22 and 32, respectively, is controlled so that these voltage applications are possible.

[0058] Another preferred use is to reduce the amount of light in bright areas within the field of view while reducing the overall amount of light, which is particularly effective when shooting video, where ND filters are frequently used.

[0059] As described above, the electrochromic element 100 of this embodiment achieves a continuous transmittance gradation. To achieve this, it includes a voltage supply means capable of forming a potential gradient within the planes of the electrodes 22 and 32. That is, each of the electrodes 22 and 32 is formed from a single continuous conductive electrode to achieve a transmittance profile with a continuous transmittance gradation. The electrodes 22 and 32 are provided with multiple connection portions for connecting the wirings 26 and 36, and these connection portions are spaced apart to facilitate the generation of a potential difference between these connection portions. This increases the potential difference within the planes of the electrodes 22 and 32, thereby making it easier to partially change the transmittance within the planes of the electrodes 22 and 32.

[0060] Therefore, according to the electrochromic element 100 of this embodiment, it is possible to realize a transmittance gradation in which the transmittance changes continuously, and it is also possible to realize a transmittance gradation in multiple directions in which the equal transmittance lines are approximately straight lines.

[0061] By using such an electrochromic element 100 as an optical filter, the transmittance profile (position, density, gradation, etc.) can be electronically controlled with a high degree of freedom using this single filter. Furthermore, by applying this filter to an imaging device or the like, the range of image expression can be expanded and the quality of the resulting image can be improved. Furthermore, because a single filter can achieve a variety of transmittance profiles, it is also effective in reducing the number of components and saving space.

[0062] The electrochromic element 100 of this embodiment can be applied to optical filters such as variable half ND filters. Furthermore, an optical filter using the electrochromic element 100 of this embodiment can be used in an imaging device, a lens unit, or a component attached to these. For example, an optical filter using the electrochromic element 100 of this embodiment can be applied to cameras, digital cameras, video cameras, and digital video cameras. Furthermore, an optical filter using the electrochromic element 100 of this embodiment can also be applied to products with built-in imaging devices, such as mobile phones, smartphones, PCs, and tablets. [Example]

[0063] (1) Fabrication of EC device (a) Fabrication of EC element body according to the embodiment A silver wiring with a sheet resistance of 15.8 mΩ / □ and a width of 2.2 mm was formed on a glass substrate (size: 37.4 mm × 50.6 mm) provided with an ITO film with a sheet resistance of 22.5 Ω / □. A mask was used to cover the areas corresponding to region 10 (size: 28.6 mm × 41.8 mm), region 12 (width: 2.2 mm), and spacer 28, preventing silver from being deposited in these areas. The area where the silver wiring was to be formed corresponds to region 14.

[0064] Next, a laser processing machine was used to remove the ITO film in the area corresponding to the separated portion 28, thereby forming the separated portion 28. At this time, the sheet resistance of the separated portion was 10 8 The electrical resistance was about Ω / □. In this way, a first electrode substrate was formed, on which electrodes 22 and lead electrodes 24 made of ITO films and wiring 26 made of silver wiring were provided. The number of lead electrodes 24 and wiring 26 provided on each side of the electrode 22 was 21 on the long sides and 15 on the short sides.

[0065] Furthermore, separately from the first electrode substrate, a second electrode substrate was formed using the same method as for the first electrode substrate, on which an electrode 32 and an extraction electrode 34 made of an ITO film and a wiring 36 made of silver wiring were provided.

[0066] Next, lead wires were connected to the wires 26 and 36 provided on the first electrode substrate and the second electrode substrate, respectively.

[0067] Next, a UV-curable sealant mixed with 30 μmφ spacer beads was applied to the portions of the first electrode substrate and the second electrode substrate corresponding to the region 12, and the first electrode substrate and the second electrode substrate were overlapped so that the ITO surface of the first electrode substrate faced each other. Thereafter, the sealant was cured by irradiation with UV light, and the partition wall 42 was formed.

[0068] (b) Fabrication of an EC element body according to a comparative example An EC element body according to a comparative example was fabricated using the same method as that for fabricating the EC element body according to the example. The EC element body according to the comparative example was the same as the EC element body according to the example, except that the ITO film and the silver wiring did not have the separation portion 28.

[0069] That is, when forming the silver wiring, a mask was used that covered the areas corresponding to the areas 10 and 12 but did not cover the area corresponding to the separated portion 28, and a ring-shaped silver wiring was formed in the area corresponding to the area 14. In addition, the ITO film was not processed using a laser processing machine, and a ring-shaped extraction electrode was formed in the areas corresponding to the areas 12 and 14.

[0070] (c) Injection of electrolyte solution An electrochromic compound (EC compound) and PMMA (polymethyl methacrylate resin) were dissolved in propylene carbonate to prepare an electrolyte solution (EC solution). The following EC compounds (1) to (6) were used as the EC compounds.

[0071] [ka] The concentrations (unit: mmol / L) of the EC compounds (1) to (6) in the dimmed state at this time are shown in Table 1. The concentration of PMMA was set to 25 g / L.

[0072] [Table 1]

[0073] Next, the electrolyte solution prepared in this manner was injected into the gap that would become the electrochromic layer through an injection port (not shown) provided in the partition wall 42 of the EC element body according to the example and the EC element body according to the comparative example, and sealed with a UV-curable sealant.

[0074] In the electrochromic element thus manufactured, the electrochromic layer 40 and the electrolyte layer are integrated, and the electrochromic layer 40 is in contact with the electrodes 22 and 32 .

[0075] (2) Evaluation of EC elements A transmittance simulation of the electrochromic elements according to the examples and comparative examples was carried out using parameters extracted from an electrochromic element having a unit area of ​​1 cm x 1 cm, which was fabricated using the same substrate, wiring material, and EC solution as in the examples and comparative examples described above. In the transmittance simulation, the sheet resistance of the electrodes 22, 32 and the extraction electrodes 24, 34 was set to 22.5 Ω / □ (uniform over the entire area), the sheet resistance of the wiring 26, 36 was set to 15.8 mΩ / □, and the sheet resistance of the separation portion 28 was set to 10 8 The resistance was set to Ω / □. The voltage applied between the wiring 26 and the wiring 36 at the power supply position was 0.65 V, the wiring 26 and the wiring 36 at the non-power supply position were in an open state, and the distance between the electrodes 22 and 32 was 30 μm. The EC solution was as described above.

[0076] 5 to 8 show the results of a transmittance simulation performed on an electrochromic element according to an embodiment. In each figure, (a) is a schematic diagram showing the power supply position to the electrochromic element, (b) is a transmission image (plan view) of region 10 when a voltage is applied, and (c) is an isotransmittance line profile of region 10 when a voltage is applied. The blackened areas in the schematic diagram (a) are the power supply positions to wiring 26 and 36. That is, FIG. 5 shows the case where power is supplied from the upper side of electrodes 22 and 32, and FIG. 6 shows the case where power is supplied from the lower side of electrodes 22 and 32. FIG. 7 shows the case where power is supplied from the left side of electrodes 22 and 32, and FIG. 8 shows the case where power is supplied from the right side of electrodes 22 and 32. (c) of The numerical values ​​shown in the isotransmittance line profiles are transmittances.

[0077] 5 to 8, it can be seen that the electrochromic element according to the embodiment can form a continuous transmittance gradation in multiple directions. Furthermore, the electrochromic element according to the embodiment can form a transmittance gradation in which the transmittance changes continuously in the direction perpendicular to one side of the electrodes 22 and 32, and the equal transmittance lines become linear.

[0078] Figure 9 shows the results of a transmittance simulation performed on an electrochromic element according to a comparative example. Figure 9(a) is a schematic diagram showing the power supply position to the electrochromic element, Figure 9(b) is a transmission image (plan view) of region 10 when a voltage is applied, and Figure 9(c) is an isotransmittance line profile of region 10 when a voltage is applied. The blackened areas in the schematic diagram of Figure 9(a) are the power supply positions to wiring 26 and 36.

[0079] The simulation results shown in Figure 9 confirm that the electrochromic element according to the comparative example has a transmittance profile in which the transmittance near the center is slightly high but the transmittance is low overall. This transmittance profile does not change significantly even when the power supply position is changed. In other words, even if the position of the relatively high transmittance region is slightly away from the power supply position, the transmittance near the center remains slightly high and the transmittance is low overall.

[0080] As described above, the electrochromic element according to the comparative example can form a transmittance profile in which the transmittance changes continuously, but it is difficult to form a continuous transmittance gradation in multiple directions.Furthermore, the electrochromic element according to the comparative example has difficulty in forming a transmittance gradation in which the transmittance changes continuously in a direction perpendicular to one side of the electrodes 22 and 32, or a transmittance gradation in which the equal transmittance lines are linear.

[0081] [Second embodiment] A lens unit according to a second embodiment of the present invention will be described. The lens unit according to this embodiment may include an imaging optical system having multiple lenses and an optical filter. The electrochromic element according to the first embodiment may be used as the optical filter. The optical filter may include a drive circuit for driving the electrochromic element. The optical filter may be provided either between multiple lenses of the imaging optical system or outside the lens. The optical filter is preferably disposed on the optical axis of the lens.

[0082] By configuring a lens unit having an optical filter using the electrochromic element according to the first embodiment, it is possible to modulate light incident on the lens unit in accordance with various transmittance profiles.

[0083] [Third embodiment] An imaging device according to a third embodiment of the present invention will be described with reference to Fig. 10. Fig. 10 is a schematic diagram showing an example of the configuration of the imaging device according to this embodiment.

[0084] The imaging device according to this embodiment may be configured to include an optical filter and a light-receiving element that receives light that has passed through the optical filter. Specific examples of imaging devices include cameras, video cameras, and mobile phones with cameras. The imaging device may be configured such that a main body having a light-receiving element and a lens unit having a lens can be separated. If the imaging device is configured such that the main body and the lens unit can be separated, the present invention also includes a configuration in which an optical filter separate from the imaging device is used during imaging. In such cases, the optical filter may be located outside the lens unit, between the lens unit and the light-receiving element, or between multiple lenses (if the lens unit has multiple lenses).

[0085] Fig. 10(a) is a schematic diagram of an example of an imaging device in which an optical filter is disposed in a lens unit, and Fig. 10(b) is a schematic diagram of an example of an imaging device in which an optical filter is disposed in the imaging device.

[0086] The imaging device 200 includes a lens unit 202 and an imaging unit 203. The lens unit 202 includes an imaging optical system having a plurality of lenses or a lens group, and an optical filter 201. The optical filter 201 is the optical filter of the present embodiment described above.

[0087] 10(a) shows a rear-focusing zoom lens that performs focusing behind the aperture as the lens unit 202. The lens unit 202 has four lens groups, in order from the subject side: a first lens group 204 with positive refractive power, a second lens group 205 with negative refractive power, a third lens group 206 with positive refractive power, and a fourth lens group 207 with positive refractive power. Magnification is changed by changing the distance between the second lens group 205 and the third lens group 206, and focusing is performed by moving some of the lens groups in the fourth lens group 207.

[0088] The lens unit 202 has, for example, an aperture stop 208 between the second lens group 205 and the third lens group 206, and an optical filter 201 between the third lens group 206 and the fourth lens group 207. The lens unit is arranged so that light passing through the first to fourth lens groups 204 to 207, the aperture stop 208, and the optical filter 201, and the amount of light can be adjusted using the aperture stop 208 and the optical filter 201.

[0089] The lens unit 202 is detachably connected to the imaging unit 203 via a mount member (not shown).

[0090] In this embodiment, the optical filter 201 is disposed between the third lens group 206 and the fourth lens group 207 in the lens unit 202, but the imaging device 200 is not limited to this configuration. For example, the optical filter 201 may be disposed either in front of (on the subject side) or behind (on the imaging unit 203 side) the aperture stop 208, or may be disposed in front of, behind, or between any of the first to fourth lens groups 204 to 207. Note that disposing the optical filter 201 at a position where light converges has the advantage of making it possible to reduce the area of ​​the optical filter 201.

[0091] The configuration of the lens unit 202 is not limited to the above configuration and can be selected as appropriate. For example, in addition to a rear focus type, it may be an inner focus type in which focusing is performed in front of the aperture, or any other type. Furthermore, special lenses such as a fisheye lens or a macro lens can be selected as appropriate in addition to a zoom lens.

[0092] The imaging unit 203 has a glass block 209 and a light receiving element 210. The glass block 209 is a glass block that includes a low-pass filter, a face plate, a color filter, or the like. The light receiving element 210 is a sensor unit that receives light that has passed through the lens unit, and an imaging element such as a CCD or CMOS can be used. An optical sensor such as a photodiode can also be used, and any device that acquires and outputs information on the intensity or wavelength of light can be used as appropriate.

[0093] 10(a), when the optical filter 201 is incorporated into the lens unit 202, the driving device may be disposed inside or outside the lens unit 202. When disposed outside the lens unit 202, the electrochromic element in the lens unit 202 is connected to the driving device through wiring to control driving.

[0094] Furthermore, in the configuration of the imaging device 200 described above, the optical filter 201 is disposed inside the lens unit 202. However, the present invention is not limited to this configuration, and it is sufficient that the optical filter 201 is disposed at an appropriate location inside the imaging device 200, and the light receiving element 210 is disposed so as to receive light that has passed through the optical filter 201.

[0095] For example, as shown in Fig. 10(b), the imaging unit 203 may have an optical filter 201. Fig. 10(b) is a diagram for explaining the configuration of another example of the imaging device of this embodiment, and is a schematic diagram of the configuration of an imaging device having the optical filter 201 in the imaging unit 203. In Fig. 10(b), for example, the optical filter 201 is arranged immediately before the light receiving element 210. When the imaging device itself has the optical filter 201 built in, the connected lens unit 202 itself does not need to have the optical filter 201, and therefore it is possible to configure a dimmable imaging device using an existing lens unit 202.

[0096] The imaging device 200 of this embodiment can be applied to products that combine light intensity adjustment and a light receiving element, such as cameras, digital cameras, video cameras, and digital video cameras, as well as to products with built-in imaging devices, such as mobile phones, smartphones, PCs, and tablets.

[0097] According to the imaging device 200 of this embodiment, by using the optical filter 201 as a dimming component, it is possible to appropriately change the amount of dimming using a single filter, which has the advantages of reducing the number of components and saving space.

[0098] [Fourth embodiment] A window material according to a fourth embodiment of the present invention will be described with reference to FIG. The window material according to this embodiment includes an electrochromic element and an active element connected to the electrochromic element. The active element constitutes a drive circuit that drives the electrochromic element and adjusts the amount of light passing through the electrochromic element. Examples of the active element include a transistor. The transistor may have an oxide semiconductor such as InGaZnO in its active region. The window material according to this embodiment may also be called a variable transmittance window.

[0099] Fig. 11(a) is an overview diagram showing a light-control window as a window material using an electrochromic element, and Fig. 11(b) is a schematic diagram showing the X-X' cross section of Fig. 11(a). The light-control window 300 of this embodiment is composed of an electrochromic element 100 (optical filter), transparent plates 313 that sandwich it, and a frame 312 that surrounds and integrates the entire element. The electrochromic element 100 has a driving device (not shown), which may be integrated within the frame 312, or may be located outside the frame 312 and connected to the electrochromic element 100 via wiring.

[0100] The transparent plate 313 is not particularly limited as long as it is made of a material with high light transmittance, and is preferably made of glass considering its use as a window. The material of the frame 312 is not limited, but any material that covers at least a portion of the electrochromic element 100 and has an integrated form may be considered to be a frame. In Figure 11, the electrochromic element 100 is a component independent of the transparent plate 313, but for example, the support substrates 20 and 30 of the electrochromic element 100 may also be considered to be the transparent plate 313.

[0101] The dimming window 300 can be used to adjust the amount of sunlight entering a room during the day, for example. Since it can be used to adjust not only the amount of sunlight but also the amount of heat, it can be used to control the brightness and temperature inside a room. It can also be used as a shutter to block views from outside into the room. In addition to glass windows for buildings, such dimming windows can also be used as windows for vehicles such as cars, trains, airplanes, and ships.

[0102] [Modified embodiment] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, an example in which part of the configuration of any one of the embodiments is added to another embodiment, or an example in which part of the configuration of another embodiment is substituted therefor, is also an embodiment of the present invention.

[0103] Furthermore, in the above embodiment, examples have been shown in which the electrochromic element according to the present invention is applied to an optical filter, a lens unit, an imaging device, and a window material, but application examples of the electrochromic element according to the present invention are not limited to these.

[0104] For example, an electrochromic mirror can be formed by providing a reflective member on one of the light paths of the electrochromic element. The electrochromic mirror may be provided in an automobile as an anti-glare mirror. The electrochromic mirror can be constructed by having an electrochromic element and a reflective member inside or outside the electrochromic element. Having a reflective member inside means that the electrode of the electrochromic element is reflective. Having a reflective member outside means that a reflective member is provided in contact with the transparent electrode of the electrochromic element or via another transparent member.

[0105] It should be noted that the above-described embodiments are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be carried out in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0106] 10,12,14…area 20, 30...Support substrate 22,32...electrode 24, 34...Extraction electrodes 26,36...Wiring 28,38…Separation part 40...Electrochromic layer 42...Bulkhead 100...Electrochromic element 200...imaging device 300...window

Claims

1. A first electrode; a second electrode facing the first electrode; an electrochromic layer disposed between the first electrode and the second electrode; a plurality of first wirings electrically connected to the first electrodes; the first electrode has a single section in a first region where the first electrode, the second electrode, and the entire electrochromic layer overlap in a plan view; the plurality of first wirings are electrically independent from one another, and each is electrically connected to the first electrode via a first extraction electrode provided in a second region that contacts the first region in a plan view; the first extraction electrode has a plurality of portions corresponding to the plurality of first wirings, and at least a part of a region between adjacent portions has a higher resistance than a region between the plurality of first wirings and the first electrode; an electrical path connecting one of the plurality of first wirings to the first electrode and an electrical path connecting another of the plurality of first wirings to the first electrode are independent of each other; A region between the plurality of first wirings and the first electrode has a lower resistance than a region between adjacent first wirings. An electrochromic element characterized by:

2. A region between the plurality of first wirings and the first electrode has a resistance that is at least one order of magnitude lower than a region between adjacent first wirings.

2. The electrochromic device according to claim 1.

3. The resistance value between each of the plurality of first wirings and the first electrode is smaller than the resistance value between adjacent first wirings.

3. The electrochromic device according to claim 1 or 2.

4. The plurality of portions of the first extraction electrode are spaced apart from one another.

4. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

5. The plurality of portions are arranged in a direction intersecting a direction from each of the plurality of first wirings toward the first electrode in a plan view.

5. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

6. the second region is a frame-shaped region surrounding the first region, The plurality of first wirings are arranged in a frame-shaped third region surrounding the second region.

6. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

7. the first extraction electrode extends to the third region, The plurality of first wirings are provided on the first extraction electrode extending into the third region.

7. The electrochromic device according to claim 6.

8. Voltages supplied to at least two of the first wirings are controlled independently of each other.

8. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

9. The semiconductor device further includes an electrolyte layer provided between the first electrode and the second electrode.

9. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

10. the first electrode has a quadrangular shape in a plan view, The plurality of first wirings are provided in a portion corresponding to one side of the rectangle.

10. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

11. the first electrode has a quadrangular shape in a plan view, The plurality of first wirings are provided in a portion corresponding to one side of the rectangle and a side opposite to the one side.

10. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

12. the first electrode has a quadrangular shape in a plan view, The plurality of first wirings are provided in portions corresponding to the respective sides of the quadrangle.

10. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

13. The first electrode and the first extraction electrode are formed from the same conductive layer.

13. The electrochromic device according to claim 1, wherein the first and second electrodes are electrically connected to each other.

14. further comprising a plurality of second wirings electrically connected to the second electrodes; the second electrode has a single section in the first region; the plurality of second wirings are electrically connected to the second electrode via a second extraction electrode provided in the second region; A region between the plurality of second wirings and the second electrode has a lower resistance than a region between adjacent second wirings.

14. The electrochromic device according to claim 1, wherein the electrochromic element is a polyimide.

15. The plurality of first wirings do not have paths that electrically connect each other except for a path via the first electrode.

15. The electrochromic device according to claim 1, wherein the electrochromic element is a polyimide.

16. The device further includes a voltage supply means for supplying a voltage supplied from the plurality of first wirings to the first electrode so as to form a potential gradient within the plane of the first electrode.

16. The electrochromic device according to claim 1, wherein the electrochromic element is a polyimide.

17. the first electrode has a quadrangular shape in a plan view, The voltage supply means is configured to form a transmittance gradation in the electrochromic layer along a direction perpendicular to one side of the rectangle.

17. The electrochromic device according to claim 16.

18. the first electrode has a quadrangular shape in a plan view, The voltage supply means is configured to form a transmittance gradation in the electrochromic layer such that a line connecting equal transmittance points is linear.

18. The electrochromic device according to claim 16 or 17.

19. An electrochromic device according to any one of claims 1 to 18; a driving circuit for driving the electrochromic element; An optical filter comprising:

20. The optical filter is a half ND filter.

20. The optical filter of claim 19.

21. an optical filter according to claim 19 or 20; an imaging optical system having a plurality of lenses; A lens unit comprising:

22. an optical filter according to claim 19 or 20; an image sensor that receives light that has passed through the optical filter; An imaging device comprising:

23. An electrochromic device according to any one of claims 1 to 18; a drive circuit for driving the electrochromic element; A window material comprising:

Images