WO2021215122A1 - Light control element - Google Patents

Abstract

This light control element comprises: a plurality of first electrodes having transparency and disposed in parallel; a plurality of second electrodes disposed in parallel respectively facing the plurality of first electrodes; an electrolyte disposed between the plurality of first electrodes and the plurality of second electrodes and including a metal; and a power supply for supplying a voltage to the electrolyte, wherein the power supply alternately switches the polarity of current based on the voltage applied to the electrolyte, and causes the metal to be precipitated or melted to at least one among the plurality of first electrodes and the plurality of second electrodes.

Description

Dimming element

This disclosure relates to a dimming element.

In Patent Document 1, at least one of the first electrically conductive layer and the second electrically conductive layer has a pattern conductive layer having a pattern layer made of an insulating material and a layer made of a resistant material, and the first electrically conductive layer and the second electrically conductive layer. An electrochromic device is disclosed in which the resistance value is changed according to the distance from each of the bus bars provided at the opposite ends of the second electrically conductive layer. This electrochromic device has the lowest resistance at the farthest position from each busbar.

Japan Special Table 2015-527614

The present disclosure has been devised in view of the above-mentioned conventional circumstances, and dimming that reduces display unevenness of the edge portion in the width direction of the electrode when driving an EC (electrochromic) element and realizes a high-quality display. It is an object of the present invention to provide an element.

In the present disclosure, a plurality of first electrodes having translucency and arranged in parallel, a plurality of second electrodes arranged in parallel facing each of the plurality of first electrodes, and the plurality of first electrodes. An electrolytic solution containing a metal and a power source for applying a voltage to the electrolytic solution, which are arranged between the first electrode and the plurality of second electrodes, are provided, and the power source is applied to the electrolytic solution. Provided is a dimming element that alternately switches the polarity of a current based on a voltage to deposit or dissolve the metal on one of the plurality of first electrodes and the plurality of second electrodes.

According to the present disclosure, display unevenness of the edge portion in the width direction of the electrode when driving the EC element is reduced, and high-quality display is realized.

The figure explaining the structural example of the EC element which concerns on Embodiment 1. The figure explaining the structural example of the dimming apparatus which concerns on Embodiment 1. The figure which shows the cross-sectional line of an EC element The figure explaining the structural example of the EC element which concerns on Embodiment 1. The figure explaining the structural example of the EC element in the BB cross section. Electric field distribution diagram of EC element in BB cross section The figure explaining the example of metal precipitation by the conventional current / voltage control method The figure explaining the example of metal precipitation by the current / voltage control method which concerns on Embodiment 1. The figure which shows an example of the measurement result of the voltage waveform and the current waveform applied by the EC element drive circuit which concerns on Embodiment 1. The figure which shows an example of the experimental result about the occurrence of display unevenness by the change of the supply time of a nuclear growth current and a nuclear dissolution current. The figure explaining the example of the change of the metal precipitation amount at the nuclear growth voltage: the nuclear dissolution voltage = 5: 1. The figure explaining the example of the change of the metal precipitation amount at the nuclear growth voltage: the nuclear dissolution voltage = 4: 1. The figure explaining the example of the change of the metal precipitation amount at the nuclear growth voltage: the nuclear dissolution voltage = 3.5: 1. The figure explaining the example of the change of the metal precipitation amount at the nuclear growth voltage: the nuclear dissolution voltage = 2: 1.

(Background to the contents of the first embodiment)
Conventionally, at least one of the first electrically conductive layer and the second electrically conductive layer has a pattern conductive layer having a pattern layer made of an insulating material and a layer made of a resistant material, and has a first electrically conductive layer and a second electrically conductive layer. An electrochromic device (hereinafter, referred to as an EC element) in which a resistance value is changed according to a distance from each of the bus bars provided at the opposite ends of the layers is provided. The resistance value of this EC element was minimized at the position farthest from each bus bar, and display unevenness occurring on the outer circumference of the EC element could be reduced. However, when such an EC element is driven by a passive matrix, since it has a plurality of EC display pixels (hereinafter referred to as display pixels) for a pair of electrodes, it is displayed on each edge portion of the plurality of display pixels. There was a possibility of unevenness.

Therefore, in the following embodiment 1, the electric field at the edge portion in the width direction of the electrode when the EC (electrochromic) element is passively driven in a matrix is suppressed to reduce display unevenness and realize high-quality display. An example of an EC element will be described.

Hereinafter, embodiments in which the configuration and operation of the dimming element according to the present disclosure are specifically disclosed will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
The structure of the EC (electrochromic) element 100 according to the first embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a structural example of the EC element 100 according to the first embodiment. The arrow K shown in FIG. 1 indicates the direction of the line of sight of the user (for example, the user of the EC element). Further, the metal OB1 shown in FIG. 1 is in a precipitated state, and a metal thin film is formed on the surface of the first electrode group 110.

As shown in FIG. 1, the EC element 100 includes a first electrode group 110, a first substrate 111, a first electrode connection portion 112, a second electrode group 210, a second substrate 211, and a second electrode connection. The unit 212, the electrolytic solution EL1, the spacer 300, and the EC element drive circuit 500 are included.

The first electrode group 110 is a conductive film having translucency, and is, for example, a transparent electrode such as ITO (Indium Tin Oxide). The first electrode group 110 is not limited to ITO, and may be a transparent electrode (conductive film) made of, for example, zinc oxide or tin oxide.

The first substrate 111 is formed by using an insulating material such as glass or resin. The first substrate 111 is, for example, a rectangular plate having translucency, and is provided on the first electrode group 110 so as to face the second substrate 211.

The first electrode connection portion 112 connects between the first electrode group 110 and the EC element drive circuit 500. The first electrode connecting portion 112 does not come into contact with the electrolytic solution EL1 and is connected to an exposed portion between the spacer 300 and each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N (see FIG. 2). NS.

The second electrode group 210 is a conductive film having translucency, and is, for example, a transparent electrode such as ITO (Indium Tin Oxide). The second electrode group 210 is not limited to ITO, and may be a transparent conductive film made of, for example, zinc oxide or tin oxide.

The second substrate 211 is formed by using an insulating material such as glass or resin. The second substrate 211 is, for example, a rectangular plate having translucency, and is provided on the second electrode group 210 so as to face the first substrate 111.

The second electrode connection portion 212 connects between the second electrode group 210 and the EC element drive circuit 500. The second electrode connecting portion 212 is connected to each of the plurality of second electrodes 210a, 210b, 210c, ..., 210N that are not in contact with the electrolytic solution EL1 and are exposed to the outside between the spacer 300 (see FIG. 2). It is connected to the exposed part between.

The electrolytic solution EL1 is provided in the space formed by the first electrode group 110, the second electrode group 210, and the spacer 300. The electrolytic solution EL1 is a solution containing a metal OB1 in a metal ion state and having electrical conductivity. The electrolytic solution EL1 is, for example, a solution containing silver. The metal OB1 contained in the electrolytic solution EL1 is deposited on either the first electrode group 110 or the second electrode group 210 depending on the electric field generated by the voltage applied to the first electrode group 110 and the second electrode group 210. do. The precipitated metal OB1 forms a metal thin film on the surface of either one of the first electrode group 110 and the second electrode group 210. The electrode on which the metal OB1 is deposited changes according to the polarity of the voltage applied by the EC element drive circuit 500 described later. In FIG. 1, the metal OB1 is deposited on the first electrode group 110 to form a metal thin film.

The metal OB1 is not limited to the silver described above. The metal OB1 may be another metal containing a noble metal such as aluminum, platinum, chromium or gold. The metal OB1 functions as a mirror (reflecting state) at the time of precipitation when it is a metal having a high reflectance to light, and functions as a light-shielding material (light-shielding state) when it is a non-reflecting metal.

Further, the EC element 100 according to the first embodiment described above assumes that the user sees the first substrate 111 from the arrow K shown in FIG. Therefore, the second electrode group 210 and the second substrate 211 may be opaque. For example, the second substrate 211 may be a silicon substrate or the like. Similarly, the second electrode group 210 may be a metal electrode such as copper.

The spacer 300 is formed by applying a resin material such as a thermosetting resin in a ring shape and curing the spacer 300. The spacer 300 is provided in an annular shape along the peripheral edges of the first electrode group 110 and the second electrode group 210 arranged so as to face each other. The spacer 300 has an exposed portion in which one end of the first electrode group 110 can be connected to the first electrode connecting portion 112 and one end of the second electrode group 210 can be connected to the second electrode connecting portion 212. It is provided except.

The EC element drive circuit 500 is a power supply unit for applying a voltage to the first electrode group 110 and the second electrode group 210. The EC element drive circuit 500 is connected to each of the first electrode connecting portion 112 and the second electrode connecting portion 212 via a lead wire, and applies a voltage to the first electrode group 110 and the second electrode group 210, respectively. The EC element drive circuit 500 controls an electrode that deposits the metal OB1 according to the polarity of the voltage applied to each of the first electrode group 110 and the second electrode group 210.

Further, the EC element drive circuit 500 controls (changes) the polarity of the current applied to each of the first electrode group 110 and the second electrode group 210 according to the applied voltage value. Specifically, the EC element drive circuit 500 applies a preset nuclear generation voltage (an example of a third voltage) for a predetermined period of time, and then applies a nuclear growth voltage (an example of a first voltage) and a nuclear dissolution voltage (an example of a first voltage). A control for switching between the second voltage (an example of the second voltage) and the second voltage is executed at each predetermined period, and the polarity of the current supplied to each of the first electrode group 110 and the second electrode group 210 is controlled (changed).

The nucleation voltage referred to here is a voltage applied to generate (precipitate) each of the crystal nuclei of the metal OB1 in the region where each of the first electrode group 110 and the second electrode group 210 intersects, and is displayed. Different voltage values are set according to the color. The nucleation voltage grows each of the crystal nuclei of the metal OB1 generated by the application of the nucleation voltage (that is, precipitates over the entire region where each of the first electrode group 110 and the second electrode group 210 intersects). Is the voltage applied for this. The nucleation voltage is set to a voltage value exceeding the nucleation voltage (for example, when the nucleation voltage is 10V, the nucleation voltage is 5V). Further, when the voltage value at which the metal OB1 starts to precipitate is used as the reference voltage, the absolute value of the difference voltage between the reference voltage and the nucleation generation voltage is the difference voltage between the reference voltage and the nuclear growth voltage. A voltage value exceeding the absolute value (for example, when the reference voltage is -1V and the nuclear generation voltage is -10V, the nuclear growth voltage is -5V) is set. The polarity of the nucleation voltage is different from the polarity of the nucleation voltage (for example, when the reference voltage is -4V and the nucleation voltage is 1V, the nucleation voltage is -2V, the reference voltage is 3V, and the nucleation voltage is When -1V, the nuclear growth voltage may be set to 2V).

The nuclear dissolution voltage is a voltage applied to dissolve the metal OB1 deposited in the region where each of the first electrode group 110 and the second electrode group 210 intersects by the nucleation voltage and the nuclear growth voltage. Further, when the karyolysis voltage is applied, the currents supplied to each of the first electrode group 110 and the second electrode group 210 are opposite to the polarities of the currents when the nuclear generation voltage and the nuclear growth voltage are applied. Has polarity.

Hereinafter, the operation method of the optical state of the EC element 100 will be described. The optical state of the EC element 100 includes a transparent state, a reflection state, and a light-shielding state.

First, the operation method when the EC element 100 switches the optical state from the transparent state to the reflective state by precipitation and dissolution of the metal OB1 will be described. In the following description, an operation method in which the operation of depositing the metal OB1 on the first electrode group 110 side is set to a reflection state or a light-shielding state will be described, but the electrode on which the metal OB1 is deposited is not limited.

The EC element drive circuit 500 applies a nucleation voltage or a nucleation voltage to the EC element 100 so that the first electrode group 110 has a low potential and the second electrode group 210 has a high potential. At this time, the direction of the electric field generated by the applied voltage of the EC element drive circuit 500 is the direction from the second electrode group 210 to the first electrode group 110.

The metal OB1 contained in the electrolytic solution EL1 is, for example, silver ion in a dissolved state. When a nucleation voltage or a nucleation voltage is applied to the EC element 100, the metal OB1 precipitates on the surface of the first electrode group 110 (electrode on the low potential side) to form a metal thin film (for example, a silver thin film). .. The deposited metal OB1 (for example, a silver thin film) has a high reflectance and functions as a mirror (reflection state) when viewed from the direction of arrow K. When the metal OB1 is formed at an extremely fast precipitation rate, it forms a metal thin film having a low density. The EC element 100 on which a metal thin film having a low density is formed functions as a light-shielding material (light-shielding state) because light is incident on the gaps between the films (that is, the gaps between the precipitated metal thin films) and strays.

The EC element drive circuit 500 is controlled by a control signal input from the EC element drive circuit control unit 400, which will be described later. The EC element drive circuit 500 switches the optical state of the EC element 100 from the transparent state to the reflection state or the light-shielding state based on the input control signal. Further, when the EC element drive circuit 500 maintains its operation in the reflected state or the light-shielded state, the nucleation voltage and the nuclear dissolution voltage are continuously applied so that the precipitation amount of the metal OB1 exceeds the dissolution amount of the metal OB1. do.

Next, an operation method when the EC element 100 switches the optical state from the reflective state to the transparent state by depositing and melting the metal OB1 will be described.

The EC element drive circuit 500 stops applying the nucleation voltage in order to dissolve the deposited metal OB1 again. As a result, the metal OB1 can be dissolved and returned to the ionic state.

When the EC element 100 is switched to the transparent state in a shorter time, the EC element drive circuit 500 is supplied with a current having the opposite polarity and applies a nuclear dissolution voltage for promoting the dissolution of the metal OB1. Specifically, the EC element drive circuit 500 applies a nuclear dissolution voltage to the EC element 100 so that the first electrode group 110 has a high potential and the second electrode group 210 has a low potential. As a result, in the EC element drive circuit 500, the metal OB1 starts to precipitate on the second electrode group 210 side, and the metal OB1 deposited on the first electrode group 110 side can be dissolved in a shorter time.

Next, a structural example of the dimmer 1000 according to the first embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating a structural example of the dimmer 1000 according to the first embodiment. The dimmer 1000 includes an EC element 100, an EC element drive circuit control unit 400, and an EC element drive circuit 500. In the EC element 100 shown in FIG. 2, the arrangement of the plurality of first electrodes 110a, 110b, 110c, ..., 110N and the plurality of second electrodes 210a, 210b, 210c, ..., 210N can be seen. For the sake of simplicity, the first electrode connecting portion 112, the second electrode connecting portion 212, the electrolytic solution EL1 and the spacer 300 are not shown.

The EC element 100 includes a first electrode group 110 composed of each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N, and a second electrode group 110 composed of each of the plurality of second electrodes 210a, 210b, 210c, ..., 210N. It is composed of an electrode group 210, an electrolytic solution EL1, and a spacer 300. In the EC element 100, the metal OB1 is deposited at each of the plurality of intersections (hereinafter, display pixels) of the first electrode group 110 and the second electrode group 210 according to the applied voltage to form a metal thin film.

Each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N and each of the plurality of second electrodes 210a, 210b, 210c, ..., 210N are arranged orthogonally to each other. The plurality of first electrodes 110a, 110b, 110c, ..., 110N, and the plurality of second electrodes 210a, 210b, 210c, ..., 210N are not limited to the above-mentioned orthogonal arrangements, and are not limited to the above-mentioned orthogonal arrangements, for example, 120 °. They may be arranged at an angle. In other words, the shape of the metal OB1 deposited on each of the plurality of display pixels is not limited to a square shape, and may be a quadrangle such as a rhombus.

The EC element drive circuit control unit 400 includes a processor (not shown) and a memory (not shown). The processor is configured by using, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array).

The processor (not shown) of the EC element drive circuit control unit 400 performs various processes and controls in cooperation with the memory. Specifically, the processor refers to the program and data stored in the memory and executes the program to realize the function of the EC element drive circuit control unit 400. For example, the processor transmits a control signal for controlling the timing of changing the voltage applied to each of the first electrode group 110 and the second electrode group 210 included in the EC element 100 by the EC element drive circuit 500, the applied voltage value, and the like. Output to the EC element drive circuit 500. The processor periodically changes the polarity of the current supplied to each of the first electrode group 110 and the second electrode group 210 included in the EC element 100 by executing the control of switching the applied voltage value. The processor executes control to change the polarity of the current a plurality of times to further suppress the concentration of the electric field on each edge portion of the region where each of the first electrode group 110 and each of the second electrode group 210 intersects. While depositing the metal OB1.

The memory (not shown) of the EC element drive circuit control unit 400 operates, for example, a RAM (Random Access Memory) as a work memory used when processing the EC element drive circuit control unit 400 and the operation of the EC element drive circuit control unit 400. It has a ROM (Read Only Memory) for storing the specified program and data. Data or information generated or acquired by the processor is temporarily stored in the RAM. A program that defines the operation of the EC element drive circuit control unit 400 (for example, the method of driving the EC element 100 executed by the EC element drive circuit 500 according to the first embodiment) is written in the ROM.

The EC element drive circuit 500 is connected to each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N via the first electrode connection unit 112 based on the control signal output from the EC element drive circuit control unit 400. A voltage is applied, and a voltage is applied to each of the plurality of second electrodes 210a, 210b, 210c, ..., 210N via the second electrode connecting portion 212.

FIG. 3 is a diagram showing a cross-sectional line of the EC element 100. The cross-sectional view used in the description of each of the drawings shown below is a cross-sectional view taken along the line BB shown in FIG.

The BB cross-sectional line is a cross-sectional view of the EC element 100 with the longitudinal direction as the cut end at the center position in the width direction of the first electrode 110a. The BB cross section shown by the BB cross section is equal to the cross-sectional view of the center position in the width direction of each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N constituting the first electrode group 110.

The width direction described above is the direction in which the plurality of first electrodes 110a, 110b, 110c, ..., 110N are arranged in parallel, or the plurality of second electrodes 210a, 210b, 210c, ..., 210N are arranged in parallel. Yes, it is the lateral direction of each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N and the plurality of second electrodes 210a, 210b, 210c, ..., 210N formed in a rectangular shape.

Further, the X direction shown in FIG. 3 indicates the longitudinal direction in the first electrode group 110 of the EC element 100 or the width direction in the second electrode group 210. The Y direction shown in FIG. 3 indicates the width direction of the first electrode group 110 of the EC element 100 or the longitudinal direction of the second electrode group 210.

Next, a structural example of the EC element 100 will be described with reference to FIGS. 4 and 5. FIG. 4 is a three-dimensional perspective view of the EC element 100, and FIG. 5 is a cross-sectional view of the EC element 100 in the BB cross section.

FIG. 4 is a diagram illustrating a structural example of the EC element 100 according to the first embodiment. FIG. 5 is a diagram illustrating a structural example of the EC element 100 in the BB cross section. The Z direction shown in FIG. 4 indicates a direction in which the first electrode group 110 and the second electrode group 210 face each other. In FIG. 4, a part of the three-dimensional perspective view of the EC element 100 will be used for easy explanation.

Each of the plurality of first electrodes 110a, 110b, 110c, ..., 110N constituting the first electrode group 110 has a predetermined gap and is arranged in parallel in the Y direction. The first electrode group 110 includes an exposed portion at an end portion in the −X direction. In the first electrode group 110, the first electrode connecting portion 112 is connected to the exposed portion, and a voltage is applied by the EC element drive circuit 500. In addition, in FIG. 4 and FIG. 5, the first electrode connection portion 112 is omitted.

The first substrate 111 is integrally provided on the surface of the first electrode group 110 in the direction opposite to the surface facing the second electrode group 210 (hereinafter, Z direction) so as to cover the first electrode group 110.

Each of the plurality of second electrodes 210a, 210b, 210c, ..., 210N constituting the second electrode group 210 has a predetermined gap and is arranged in parallel in the X direction facing the first electrode group 110. .. The second electrode group 210 includes an exposed portion at an end portion in the Y direction. In the second electrode group 210, the second electrode connecting portion 212 is connected to the exposed portion, and a voltage is applied by the EC element drive circuit 500. In addition, in FIG. 4 and FIG. 5, the second electrode connection portion 212 is omitted.

The second substrate 211 is integrally provided on the surface of the second electrode group 210 in the direction opposite to the direction facing the first electrode group 110 (hereinafter, -Z direction) so as to cover the second electrode group 210.

The spacer 300 is of the first electrode group 110 and the second electrode group 210, except for the exposed portion provided at one end of the first electrode group 110 and the exposed portion provided at one end of the second electrode group 210. It is provided in an annular shape along the peripheral edge. Note that the spacer 300 is omitted in FIG.

The electrolytic solution EL1 is provided in the space formed by the first electrode group 110, the second electrode group 210, and the spacer 300.

FIG. 6 is an electric field distribution diagram EM of the EC element 100 in the BB cross section. FIG. 6 is a diagram showing the electric field strength between the first substrate 111 and the second substrate 211 in the BB cross section when a voltage capable of depositing the metal OB1 is applied. The number of the plurality of second electrodes shown in FIG. 6 is 3, but it goes without saying that the number is not limited to this.

In the electric field distribution diagram EM shown in FIG. 6, each of the points R1, R2, R3, R4, R5, R6, R7, and R8 indicates a portion where the electric field is concentrated.

Each of the points R1 and R2 shows an electric field concentrated at both ends in the longitudinal direction of the first electrode group 110. Each of the points R3 and R4 is installed at both ends of the plurality of second electrodes 210a, ..., 210N, and both ends in the width direction of the electrodes having no adjacent electrodes (for example, the second electrodes 210a, 210N). Shows the electric field concentrated in the part. Each of the points R5, R6, R7, and R8 shows an electric field concentrated between the end and the void of each of the plurality of second electrodes 210a, ..., 210N. Further, since the electric fields of points R5, R6, R7, and R8 have small gaps between the installation of the plurality of second electrodes 210a, ..., 210N, they are compared with the electric fields of points R3 and R4. , The range where the electric field is concentrated is small.

In the portion where the electric field strength is high shown at each of the above-mentioned points R1 to R8, the metal OB1 is deposited beyond the region where the first electrode group 110 and the second electrode group 210 intersect, or the metal OB1 is partially formed in the region. Display unevenness occurs due to concentrated precipitation. Further, since the electric field is likely to be concentrated in the portion where the electric field strength is high shown at each of the points R1 to R8, the time until the metal OB1 is deposited or melted is short. Further, since each of these points R1 to R8 has a strong electric field strength and more metal OB1 is deposited, many metal OB1s are deposited when the EC element 100 is switched to the transparent state even when the application of the voltage is stopped. It takes time.

7 to 14 show a current / voltage control method capable of reducing the electric field strength shown at each of the points R1 to R8 and suppressing the concentration and precipitation of the metal OB1 in a part of the region. It will be explained with reference to.

<Conventional current / voltage control method>
First, a method of controlling current and voltage in a conventional EC element will be described with reference to FIG. 7. FIG. 7 is a diagram illustrating an example of precipitation of metal OB1 by a conventional current control method.

In the conventional EC element drive circuit, a nucleation voltage for forming a crystal nucleus of the metal OB1 is applied over GP0 for a predetermined period, and either the first electrode group 110 or the second electrode group 210 included in the EC element 100 is applied. Crab metal OB1 is deposited. The EC element drive circuit applies a nucleation voltage over GP0 for a predetermined period of time, and then grows the formed crystal nuclei (that is, a metal over a region where the first electrode group 110 and the second electrode group 210 intersect. Continue to apply the nucleation voltage for depositing OB1). The voltage value of the nucleation voltage is smaller than the voltage value of the nucleation voltage.

In the EC element drive circuit in the conventional voltage control method shown in FIG. 7, a nucleation voltage is applied from time 0 (zero) to time S1 (that is, GP0 for a predetermined period), and a nucleation voltage is applied from time S1. do. As a result, the current waveform CW0 of the current supplied to the EC element 100 increases in current value during a predetermined period GP0 when the nucleation voltage is applied by the EC element drive circuit, and the current value changes from the nucleation voltage to the nucleation voltage. It has a peak at the switching timing (time S1). Further, when the nuclear growth voltage is applied, the current supplied to the EC element 100 drops in value corresponding to the nuclear growth voltage smaller than the nucleation voltage. After the current value drops to the value corresponding to the nucleation voltage, this current value is maintained thereafter.

The precipitation graph PW0 shows the amount of metal OB1 deposited in the region where the first electrode group 110 and the second electrode group 210 intersect. As shown in the precipitation graph PW0, the amount of metal OB1 deposited increases with the passage of time. Note that FIG. 7 shows an example of a precipitation graph PW0 in which the amount of precipitation increases in proportion to the passage of time for the sake of simplicity, but the actual amount of precipitation has the maximum amount of precipitation that can be deposited in the region as an asymptote. It increases to draw a quadratic curve.

The state of precipitation of the metal OB1 in the region where the first electrode 110a and the second electrode 210N intersect each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect will be described. The region CC1 at time S1 indicates the state immediately after the crystal nuclei are generated. In the region CC2 at time S2, the application of the nucleation voltage is started, and the amount of metal OB1 deposited increases as compared with the region CC1. In the region CC3 at time S3, the amount of metal OB1 deposited is further increased as compared with the region CC2. In the region CC4 at time S4, the amount of metal OB1 deposited increases as compared with the region CC3, and the electric field strength of the edge portion CC41 (the upper side and the right side of the paper surface of the rectangular region CC4) becomes higher, causing display unevenness.

<Method of controlling current / voltage according to the first embodiment>
Next, with reference to FIG. 8, a current / voltage control method executed by the EC element drive circuit 500 according to the first embodiment will be described. FIG. 8 is a diagram illustrating an example of precipitation of metal OB1 by the current / voltage control method according to the first embodiment.

First, a voltage control method by the EC element drive circuit 500 according to the first embodiment will be described. In the EC element drive circuit 500 according to the first embodiment, a nucleation voltage is applied over GP1 for a predetermined period, and the metal OB1 is applied to either the first electrode group 110 or the second electrode group 210 included in the EC element 100. Precipitate.

The EC element drive circuit 500 applies a nucleation voltage over a predetermined period of GP1 and then applies a nuclear growth voltage having a voltage value smaller than the nucleation voltage over a predetermined period of PP1.

The EC element drive circuit 500 applies a nuclear growth voltage over a predetermined period of PP1 and then applies a nuclear dissolution voltage over a predetermined period of MP1, in a region where the first electrode group 110 and the second electrode group 210 intersect. The metal OB1 precipitated over the entire surface is dissolved. The voltage value of the nuclear dissolution voltage is a voltage value that reverses the polarity of the current flowing through the EC element 100 as compared with the voltage value of the nuclear growth voltage. The EC element drive circuit 500 applies a nuclear dissolution voltage over a predetermined period of MP1, then switches the voltage value to a predetermined nuclear growth voltage, and applies the voltage over a predetermined period of PP1.

After applying the nucleation voltage once, the EC element drive circuit 500 alternately (that is, periodically) executes the application of the nucleation voltage over the predetermined period PP1 and the application of the nuclear dissolution voltage over the predetermined period MP1. do. That is, the EC element drive circuit 500 repeatedly executes the control of applying the nuclear growth voltage over the predetermined period PP1 and then applying the nuclear dissolution voltage over the predetermined period MP1 as one cycle. The period of the cycle TP1 is the sum of the predetermined period PP1 and the predetermined period MP1.

In the EC element drive circuit 500 in the voltage control method according to the first embodiment shown in FIG. 8, a nuclear generation voltage is applied from time 0 (zero) to time t11, and nuclear growth occurs from time t11 to time t12. A voltage is applied and a nuclear dissolution voltage is applied from time t12 to time t13. The EC element drive circuit 500 reapplies the nuclear growth voltage from time t13 to time t14, reapplies the nuclear dissolution voltage from time t14 to time t15, and reapplies the nuclear growth voltage from time t15 to time t16. Is reapplied (that is, the control of alternately switching and applying the nuclear growth voltage and the nuclear dissolution voltage) is executed. The control of the EC element drive circuit 500 in the subsequent time is omitted.

The EC element drive circuit 500 according to the first embodiment controls the voltage values applied to the first electrode group 110 and the second electrode group 210, and supplies currents having different polarities based on the applied voltage values. .. The current waveform CW1 is a graph showing the time change of the current value flowing through the EC element 100 according to the first embodiment. The polarity of the supplied current changes in the current supplied to the first electrode group 110 and the second electrode group 210 based on the applied nuclear growth voltage or karyolysis voltage. Hereinafter, the time change of the current value supplied to the first electrode group 110 and the second electrode group 210 according to the first embodiment will be described.

First, the current supplied to the first electrode group 110 and the second electrode group 210 is applied to the first electrode group 110 and the second electrode group 210 when the application of the nuclear generation voltage by the EC element drive circuit 500 is started. The current value peaks (nuclear generation current I10) at the timing (time t10) when the voltage value to be adjusted reaches the set nuclear generation voltage.

Next, when the application of the nuclear growth voltage by the EC element drive circuit 500 is started at time t11, the current is further reduced, and the voltage values applied to the first electrode group 110 and the second electrode group 210 are set. The nuclear growth current I11 is reached at the timing (time t11) when the nuclear growth voltage is reached. When the application of the nuclear dissolution voltage by the EC element drive circuit 500 was started at time t13, the polarities of the currents were reversed, and the voltage values applied to the first electrode group 110 and the second electrode group 210 were set. The nuclear dissolution current I12 is reached at the timing (time t14) when the nuclear dissolution voltage is reached.

When the application of the nuclear growth voltage by the EC element drive circuit 500 is restarted at time t15, the current reaches the set nuclear growth voltage with the voltage values applied to the first electrode group 110 and the second electrode group 210. At the timing (time t16), the nuclear growth current I11 is reached again. When the application of the nuclear dissolution voltage by the EC element drive circuit 500 is started at time t17, the polarity of the current is reversed, and the timing at which the voltage value applied to the EC element 100 reaches the set nuclear dissolution voltage ( At time t18), the nuclear dissolution current I12 is reached.

When the application of the nuclear growth voltage by the EC element drive circuit 500 is restarted at time t19, the current reaches the set nuclear growth voltage with the voltage values applied to the first electrode group 110 and the second electrode group 210. At the timing (time t20), the nuclear growth current I11 is reached again. As for the current, the application of the nuclear dissolution voltage by the EC element drive circuit 500 is started at time t21.

The amount of metal OB1 deposited in the region where the first electrode group 110 and the second electrode group 210 intersect increases with the passage of time from the time of nucleation as shown in the precipitation graph PW1. In FIG. 8, for the sake of simplicity, the precipitation graph PW1 in which the precipitation amount is linearly changed will be used for explanation.

The state of precipitation of the metal OB1 in the region where the first electrode 110a and the second electrode 210N intersect each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect will be described. The region C1 at time t10 is a state immediately after the crystal nuclei are generated at the timing when the nucleation current I10 flows (that is, the timing when the voltage value applied by the EC element drive circuit 500 reaches the set nucleation voltage). Is shown. In the region C2 at time t13, since the nucleation current smaller than the nucleation current is continuously supplied to the first electrode group 110 and the second electrode group 210 by the EC element drive circuit 500, the metal OB1 is larger than the region C2. The amount of precipitation increases.

On the other hand, in the region C3 at time t15, the nuclear dissolution current having a polarity opposite to that of the nuclear growth current is continuously supplied to the first electrode group 110 and the second electrode group 210 by the EC element drive circuit 500 from time t13. , The precipitation amount of the metal OB1 is smaller than the precipitation amount of the region C2 at time t13.

In the region C4 at the time t17, the nuclear growth current having a polarity opposite to that of the nuclear dissolution current is continuously supplied to the first electrode group 110 and the second electrode group 210 by the EC element drive circuit 500 from the time t15. The amount of metal OB1 deposited is higher than that of C3.

Further, in the region C5 at time t19, the nuclear dissolution current having a polarity opposite to that of the nuclear growth current is continuously supplied to the first electrode group 110 and the second electrode group 210 by the EC element drive circuit 500 from time t17. , The precipitation amount of the metal OB1 is smaller than the precipitation amount of the region C4 at time t17.

In the region C6 at the time t21, the nuclear growth current having a polarity opposite to that of the nuclear dissolution current is continuously supplied to the first electrode group 110 and the second electrode group 210 by the EC element drive circuit 500 from the time t19. The amount of metal OB1 deposited is higher than that of C5.

The metal OB1 is dissolved in the respective voltage values of the nuclear generation voltage and the nuclear dissolution voltage applied by the EC element drive circuit 500 according to the first embodiment and the respective current values of the nuclear generation current and the nuclear dissolution current. The respective voltage values of the nuclear generation voltage and the nuclear dissolution voltage are set in consideration of the resistance value based on the component of the medium to be used, the loss based on the path length of the electric circuit in the EC element 100, and the like.

Further, each of the nuclear generation current and the nuclear dissolution current supplied by the EC element drive circuit 500 according to the first embodiment will be described with an example in which the polarity of the nuclear generation voltage and the polarity of the nuclear dissolution voltage are the same. , The polarity of the current may be changed by applying a voltage in which the polarity of the nuclear generation voltage and the polarity of the nuclear dissolution voltage are changed.

As described above, the EC element drive circuit 500 according to the first embodiment alternately switches the voltage value between the nuclear growth voltage and the nuclear dissolution voltage and supplies the voltage value to the first electrode group 110 and the second electrode group 210. Change the polarity of the current. As a result, the EC element 100 can suppress the concentration of the electric field strength on the edge portion and the like, and can suppress the occurrence of display unevenness due to the electric field concentration.

Further, the metal OB1 is more likely to be precipitated or dissolved as the electric field strength is stronger. Therefore, the EC element 100 according to the first embodiment alternately and repeatedly switches between the nuclear growth voltage and the nuclear dissolution voltage even when the electric field strength is concentrated in a partial region such as an edge portion. The metal OB1 gradually precipitates while repeating precipitation and dissolution. Therefore, the EC element 100 can uniformly deposit the metal OB1 over the entire region where the first electrode group 110 and the second electrode group 210 intersect.

Next, with reference to FIG. 9, the voltage waveform VW2 of the voltage applied to the first electrode group 110 and the second electrode group 210 and the current waveform CW2 of the current by the EC element drive circuit 500 according to the first embodiment will be described. do. FIG. 9 is a diagram showing an example of measurement results of the voltage waveform VW2 and the current waveform CW2 applied by the EC element drive circuit 500 according to the first embodiment.

When the polarity of the current is changed in a predetermined cycle as shown in FIG. 8, the EC element drive circuit 500 changes the voltage value of the voltage applied to the first electrode group 110 and the second electrode group 210 in a predetermined cycle. Take control. In the example shown in FIG. 9, the EC element drive circuit 500 applies a nuclear generation voltage of about 2 V for an application time of 0.04 s (that is, a period GP2 = 0.04 s), and then applies an application time of 0.1 s (that is, a period GP2 = 0.04 s). That is, the nuclear growth voltage is 1.8 V over the period PP2 = 0.1 s), and the nuclear growth voltage is 0.2 V over the application time of 0.025 s (that is, the period MP2 = 0.025 s). TP2 = 0.125 s is alternately switched and applied. The voltage waveform VW2 shows the time change of the voltage applied by the EC element drive circuit 500.

When the above voltage is applied by the EC element drive circuit 500, the polarity of the current supplied to the first electrode group 110 and the second electrode group 210 is the voltage applied as shown in the current waveform CW2. It changes alternately as the value changes. Specifically, the polarity of the current alternates so that it becomes a positive electrode during the period PP2 where the nuclear growth voltage is applied and becomes a negative electrode during the period MP2 where the karyolysis voltage is applied.

As a result, the amount of metal OB1 deposited in the region where the first electrode group 110 and the second electrode group 210 intersect is the period during which the nuclear growth voltage is applied (that is, as shown in the precipitation graph PW1 shown in FIG. 8). The metal OB1 is precipitated during the period (the period during which the nuclear growth current is supplied), and the precipitated metal OB1 is dissolved during the period during which the nuclear dissolution voltage is applied (that is, the period during which the nuclear dissolution current is supplied). Further, by executing the voltage control for alternately switching the polarity of the current in this way, the EC element drive circuit 500 causes the electric field in the edge portion of the region where the first electrode group 110 and the second electrode group 210 intersect. Concentration can be suppressed more. That is, the EC element drive circuit 500 according to the first embodiment can further suppress the electric field at the edge portion of the electrode to reduce display unevenness and realize high-quality display. Further, in the EC element 100, even when the electric field strength is concentrated in a partial region such as an edge portion, the metal OB1 is deposited and dissolved by alternately and repeatedly switching between the nuclear growth voltage and the nuclear dissolution voltage. Gradually precipitates while repeating. Therefore, the EC element 100 can uniformly deposit the metal OB1 over the entire region where the first electrode group 110 and the second electrode group 210 intersect.

Next, with reference to FIG. 10, the ratio of the application time to the nuclear growth voltage and the nuclear dissolution voltage applied by the EC element drive circuit 500 according to the first embodiment will be described. FIG. 10 is a diagram showing an example of experimental results regarding the occurrence of display unevenness due to changes in the supply times of the nuclear growth current and the nuclear dissolution current. FIG. 10 shows the results of an experiment on the presence or absence of display unevenness when the supply time of the nuclear growth current was set to 100 ms and the supply time of the nuclear dissolution current was changed.

When the supply time of the nuclear growth current is set to 100 ms and the supply time of the nuclear dissolution current is set to 0 (zero) ms, the first electrode group 110 and the second electrode group 210 intersect each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect. The electric field is concentrated on the edge portions of the plurality of regions where the electrode group 110 and the second electrode group 210 intersect, and the metal OB1 is excessive on the edge portions and the like as in the conventional current / voltage control method shown in FIG. Since it is deposited on the surface, display unevenness occurs.

The presence or absence of display unevenness when the supply time of the nuclear growth current is set to 100 ms and the supply time of the nuclear dissolution current is set to 5 ms (that is, the ratio of the supply time is the nuclear growth current: the nuclear dissolution current = 20: 1) will be described. In each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect, the electric field is concentrated on the edge portions of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect. , Metal OB1 is excessively deposited on the edge portion and the like, and display unevenness occurs.

The presence or absence of display unevenness when the supply time of the nuclear growth current is set to 100 ms and the supply time of the nuclear dissolution current is set to 10 ms (that is, the ratio of the supply time is set to nuclear growth current: nuclear dissolution current = 10: 1) will be described. In each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect, the electric field is concentrated on the edge portions of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect. , A large amount of metal OB1 is deposited on the edge portion and the like, and slight display unevenness occurs.

Explain the presence or absence of display unevenness when the supply time of the nuclear growth current is set to 100 ms and the supply time of the nuclear dissolution current is set to 25 ms (that is, the ratio of the supply time is set to nuclear growth current: nuclear dissolution current = 4: 1). In each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect, the electric field is concentrated on the edge portions of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect. It disappears and display unevenness does not occur.

The presence or absence of display unevenness when the supply time of the nuclear growth current is set to 100 ms and the supply time of the nuclear dissolution current is set to 50 ms (that is, the ratio of the supply time is set to nuclear growth current: nuclear dissolution current = 2: 1) will be described. In each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect, the electric field is concentrated on the edge portions of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect. It disappears and display unevenness does not occur. On the other hand, the difference between the dissolution amount of the metal OB1 that dissolves with the supply time of the nuclear dissolution current and the reprecipitation amount of the metal OB1 that reprecipitates with the supply time of the re-supplied nuclear growth current becomes large. In each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect, flicker such that the display blinks occurs.

The presence or absence of display unevenness when the supply time of the nuclear growth current is set to 100 ms and the supply time of the nuclear dissolution current is set to 100 ms (that is, the ratio of the supply time is set to nuclear growth current: nuclear dissolution current = 1: 1) will be described. In each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect, the dissolution amount of the metal OB1 that dissolves with the supply time of the nuclear dissolution current and the supply time of the nuclear growth current to be supplied again As a result, the amount of reprecipitation of the metal OB1 reprecipitated becomes substantially the same, and it becomes difficult to maintain the deposited metal OB1.

With reference to FIG. 11, the voltage waveform VW3 when the application time of the nuclear growth voltage and the nuclear dissolution voltage corresponding to the ratio of the supply time of the nuclear growth current: the supply time of the nuclear dissolution current = 5: 1 is set, and the first The change in the amount of metal OB1 deposited in each of the plurality of regions where the one electrode group 110 and the second electrode group 210 intersect will be described. FIG. 11 is a diagram illustrating an example of a change in the amount of metal precipitation at a nuclear growth voltage: a nuclear dissolution voltage = 5: 1. Note that FIG. 11 shows the voltage waveform VW3 of the nucleation voltage and the nuclear dissolution voltage after the application of the nucleation voltage, and the description will be omitted before and during the application of the nucleation voltage.

The voltage waveform VW3 shows the time change of the voltage applied by the EC element drive circuit 500. The EC element drive circuit 500 shown in FIG. 11 repeatedly executes control of applying the nuclear growth voltage V31 over a predetermined period PP3 and then applying the nuclear dissolution voltage V32 over a predetermined period MP3. The length of the cycle TP3 is the sum of the predetermined period PP3 and the predetermined period MP3, and the predetermined period PP3: the predetermined period MP3 = 5: 1.

The precipitation graph PW3 precipitates in each of the regions where the first electrode group 110 and the second electrode group 210 intersect when the nuclear growth voltage V31 and the nuclear dissolution voltage V32 are applied at a ratio of application time of 5: 1. The change in the precipitation amount of the metal OB1 is shown. The amount of the metal OB1 deposited increases while the nuclear growth voltage V31 is applied (that is, PP3 for a predetermined period), and the precipitation amount of the metal OB1 increases while the nuclear dissolution voltage V32 is applied (that is, MP3 for a predetermined period). The amount of precipitation decreases. The amount of metal OB1 deposited increases each time the control including the application control of the nuclear growth voltage and the application control of the nuclear dissolution voltage (that is, the period TP3) is repeated.

As described above, when the ratio of the application time of the nuclear growth voltage V31 and the nuclear dissolution voltage V32 is set to 5: 1, the EC element 100 repeats the precipitation and dissolution of the metal OB1 to form an edge portion or the like. It is possible to further suppress the concentration of the electric field strength on the surface and suppress the occurrence of display unevenness. Further, in the EC element 100, even when the electric field strength is concentrated in a partial region such as an edge portion, the metal OB1 is deposited and dissolved by alternately and repeatedly switching between the nuclear growth voltage and the nuclear dissolution voltage. Gradually precipitates while repeating. Therefore, the EC element 100 can uniformly deposit the metal OB1 over the entire region where the first electrode group 110 and the second electrode group 210 intersect.

With reference to FIG. 12, the voltage waveform VW4 when the application time of the nuclear growth voltage and the nuclear dissolution voltage corresponding to the supply time ratio of nuclear growth current: nuclear dissolution current = 4: 1 is set, and the first electrode group. A change in the amount of metal OB1 deposited in each of the plurality of regions where 110 and the second electrode group 210 intersect will be described. FIG. 12 is a diagram illustrating an example of a change in the amount of metal precipitation at a nuclear growth voltage: a nuclear dissolution voltage = 4: 1. Note that FIG. 12 shows the voltage waveform VW4 of the nucleation voltage and the nuclear dissolution voltage after the application of the nucleation voltage, and the description will be omitted before and during the application of the nucleation voltage.

The voltage waveform VW4 indicates the time change of the voltage applied by the EC element drive circuit 500. The EC element drive circuit 500 shown in FIG. 12 repeatedly executes control of applying the nuclear growth voltage V41 over a predetermined period PP4 and then applying the nuclear dissolution voltage V42 over a predetermined period MP4. The length of the cycle TP4 is the sum of the predetermined period PP4 and the predetermined period MP4, and the predetermined period PP4: the predetermined period MP4 = 4: 1.

The precipitation graph PW4 precipitates in each of the regions where the first electrode group 110 and the second electrode group 210 intersect when the nuclear growth voltage V41 and the nuclear dissolution voltage V42 are applied at a ratio of the application time of 4: 1. The change in the precipitation amount of the metal OB1 is shown. The amount of the metal OB1 deposited increases while the nuclear growth voltage V41 is applied (that is, PP4 for a predetermined period), and the precipitation amount of the metal OB1 increases while the nuclear dissolution voltage V42 is applied (that is, MP4 for a predetermined period). The amount of precipitation decreases. The amount of metal OB1 deposited increases each time the control including the application control of the nuclear growth voltage and the application control of the nuclear dissolution voltage (that is, the period TP4) is repeated.

As described above, when the ratio of the application time of the nuclear growth voltage V41 and the nuclear dissolution voltage V42 is set to 4: 1, the EC element 100 repeats the precipitation and dissolution of the metal OB1 to form an edge portion or the like. It is possible to further suppress the concentration of the electric field strength on the surface and suppress the occurrence of display unevenness. Further, even when the electric field strength is concentrated in a partial region such as an edge portion, the EC element 100 is in a region where the electric field strength is concentrated by alternately switching between the nuclear growth voltage and the nuclear dissolution voltage. By repeating excessive precipitation and excessive dissolution of the metal OB1, the metal OB1 can be uniformly deposited over each of the plurality of regions where the first electrode group 110 and the second electrode group 210 intersect.

With reference to FIG. 13, the voltage waveform VW5 when the application time of the nuclear growth voltage and the nuclear dissolution voltage corresponding to the supply time ratio of nuclear growth current: nuclear dissolution current = 3.5: 1 is set, and the first The change in the amount of metal OB1 deposited in each of the plurality of regions where the electrode group 110 and the second electrode group 210 intersect will be described. FIG. 13 is a diagram illustrating an example of a change in the amount of metal precipitation at a nuclear growth voltage: a nuclear dissolution voltage = 3.5: 1. Note that FIG. 13 shows the voltage waveform VW5 of the nucleation voltage and the nuclear dissolution voltage after the application of the nucleation voltage, and the description will be omitted before and during the application of the nucleation voltage.

The voltage waveform VW5 indicates the time change of the voltage applied by the EC element drive circuit 500. The EC element drive circuit 500 shown in FIG. 13 repeatedly executes control of applying the nuclear growth voltage V51 over a predetermined period PP5 and then applying the nuclear dissolution voltage V52 over a predetermined period MP5. The length of the cycle TP5 is the sum of the predetermined period PP5 and the predetermined period MP5, and the predetermined period PP5: the predetermined period MP5 = 3.5: 1.

The precipitation graph PW5 is shown in each of the regions where the first electrode group 110 and the second electrode group 210 intersect when the nuclear growth voltage V51 and the nuclear dissolution voltage V52 are applied at a ratio of application time of 3.5: 1. The change in the precipitation amount of the deposited metal OB1 is shown. The amount of the metal OB1 deposited increases while the nuclear growth voltage V51 is applied (that is, PP5 for a predetermined period), and the precipitation amount of the metal OB1 increases while the nuclear dissolution voltage V52 is applied (that is, MP5 for a predetermined period). The amount of precipitation decreases. The amount of metal OB1 deposited increases each time the control including the application control of the nuclear growth voltage and the application control of the nuclear dissolution voltage (that is, the period TP5) is repeated.

As described above, when the ratio of the application time of the nuclear growth voltage V51 and the nuclear dissolution voltage V52 is set to 3.5: 1, the EC element 100 repeats the precipitation and dissolution of the metal OB1 to form an edge. It is possible to further suppress the concentration of the electric field strength on the portion and the like, and suppress the occurrence of display unevenness. Further, in the EC element 100, even when the electric field strength is concentrated in a partial region such as an edge portion, the metal OB1 is deposited and dissolved by alternately and repeatedly switching between the nuclear growth voltage and the nuclear dissolution voltage. Gradually precipitates while repeating. Therefore, the EC element 100 can uniformly deposit the metal OB1 over the entire region where the first electrode group 110 and the second electrode group 210 intersect.

With reference to FIG. 14, the voltage waveform VW6 when the application time of the nuclear growth voltage and the nuclear dissolution voltage corresponding to the supply time ratio of nuclear growth current: nuclear dissolution current = 2: 1 is set, and the first electrode group. A change in the amount of metal OB1 deposited in each of the plurality of regions where 110 and the second electrode group 210 intersect will be described. FIG. 14 is a diagram illustrating an example of a change in the amount of metal precipitation at a nuclear growth voltage: a nuclear dissolution voltage = 2: 1. Note that FIG. 14 shows the voltage waveform VW6 of the nucleation voltage and the nuclear dissolution voltage after the application of the nucleation voltage, and the description will be omitted before and during the application of the nucleation voltage.

The voltage waveform VW6 indicates the time change of the voltage applied by the EC element drive circuit 500. The EC element drive circuit 500 shown in FIG. 14 repeatedly executes control of applying the nuclear growth voltage V61 over a predetermined period of PP6 and then applying the nuclear dissolution voltage V62 over a predetermined period of MP6. The length of the cycle TP6 is the sum of the predetermined period PP6 and the predetermined period MP6, and the predetermined period PP6: the predetermined period MP6 = 2: 1.

The precipitation graph PW6 precipitates in each of the regions where the first electrode group 110 and the second electrode group 210 intersect when the nuclear growth voltage V61 and the nuclear dissolution voltage V62 are applied at a ratio of the application time of 2: 1. The change in the precipitation amount of the metal OB1 is shown. The amount of the metal OB1 deposited increases while the nuclear growth voltage V61 is applied (that is, PP6 for a predetermined period), and the precipitation amount of the metal OB1 increases while the nuclear dissolution voltage V62 is applied (that is, MP6 for a predetermined period). The amount of precipitation decreases. The amount of metal OB1 deposited increases each time the control including the application control of the nuclear growth voltage and the application control of the nuclear dissolution voltage (that is, the period TP6) is repeated.

As described above, when the ratio of the application time of the nuclear growth voltage V61 and the nuclear dissolution voltage V62 is set to 2: 1, the EC element 100 repeats the precipitation and dissolution of the metal OB1 to form an edge portion or the like. It is possible to further suppress the concentration of the electric field strength on the surface and suppress the occurrence of display unevenness. Further, in the EC element 100, even when the electric field strength is concentrated in a partial region such as an edge portion, the metal OB1 is deposited and dissolved by alternately and repeatedly switching between the nuclear growth voltage and the nuclear dissolution voltage. Gradually precipitates while repeating. Therefore, the EC element 100 can uniformly deposit the metal OB1 over the entire region where the first electrode group 110 and the second electrode group 210 intersect.

As described above, the EC element 100 according to the first embodiment has translucency and has a plurality of first electrodes 110a, ..., 110N arranged in parallel and a plurality of first electrodes 110a, ..., 110N, respectively. A plurality of second electrodes 210a, ..., 210N arranged in parallel facing each other, a plurality of first electrodes 110a, ..., 110N and a plurality of second electrodes 210a, ..., 210N. The electrolytic solution EL1 containing the metal OB1 and the EC element drive circuit 500 for applying a voltage to the electrolytic solution EL1 are provided. The EC element drive circuit 500 alternately switches the polarity of the current based on the voltage applied to the electrolytic solution EL1, and one of a plurality of first electrodes 110a, ..., 110N and a plurality of second electrodes 210a, ..., 210N. Metal OB1 is precipitated or dissolved on one side.

As a result, in the EC element 100 according to the first embodiment, the EC element drive circuit 500 can further suppress the electric field concentration on the edge portion of the region where the first electrode group 110 and the second electrode group 210 intersect. , The metal OB1 can be gradually precipitated to form a metal thin film having a more uniform thickness in the region. Therefore, the EC element 100 can further reduce display unevenness and realize a high-quality display. Further, in the EC element 100, even when the electric field strength is concentrated in a partial region such as an edge portion, the metal OB1 is deposited and dissolved by alternately and repeatedly switching between the nuclear growth voltage and the nuclear dissolution voltage. Gradually precipitates while repeating. Therefore, the EC element 100 can uniformly deposit the metal OB1 over the entire region where the first electrode group 110 and the second electrode group 210 intersect.

As described above, the EC element drive circuit 500 in the EC element 100 according to the first embodiment has a nuclear generation voltage or a nuclear growth voltage (an example of a first voltage) for precipitating the metal OB1 and a nuclear dissolution voltage for melting the metal OB1 (an example of the first voltage). An example of the second voltage) is switched and applied. As a result, the EC element 100 according to the first embodiment has an edge portion in the region where the first electrode group 110 and the second electrode group 210 intersect during the period in which the nuclear dissolution voltage (that is, the nuclear dissolution current) is applied. The electric field value concentrated on can be reduced. That is, the EC element drive circuit 500 according to the first embodiment can further suppress the electric field concentration on the edge portion of the electrode, reduce the display unevenness, and realize a high-quality display.

As described above, the EC element drive circuit 500 according to the first embodiment applies the nucleation voltage (an example of the third voltage) that exceeds the nucleation voltage first, and then applies the nucleation voltage and the karyolysis voltage. As a result, in the EC element 100 according to the first embodiment, after each of the crystal nuclei of the metal OB1 is first generated (precipitated) in the region where each of the first electrode group 110 and the second electrode group 210 intersects, the EC element 100 is first generated (precipitated). By alternately applying a nuclear growth voltage that grows (precipitates) the crystal nuclei of the metal OB1 and a nuclear dissolution voltage that dissolves the metal OB1 that has grown when the nuclear growth voltage is applied, the precipitation amount of the metal OB1 becomes more uniform. The voltage control can be easily performed.

As described above, in the EC element drive circuit 500 according to the first embodiment, the absolute value of the difference from the reference voltage at which the metal OB1 starts to precipitate is the reference voltage (for example, 3V) and the nuclear growth voltage (for example, 2V). A nuclear production voltage (eg, -1V) that exceeds the absolute value of the difference is first applied, and then a nuclear growth voltage and a nuclear dissolution voltage are applied. As a result, in the EC element 100 according to the first embodiment, after each of the crystal nuclei of the metal OB1 is first generated (precipitated) in the region where each of the first electrode group 110 and the second electrode group 210 intersects, the EC element 100 is first generated (precipitated). By alternately applying a nuclear growth voltage that grows (precipitates) the crystal nuclei of the metal OB1 and a nuclear dissolution voltage that dissolves the metal OB1 that has grown when the nuclear growth voltage is applied, the precipitation amount of the metal OB1 becomes more uniform. The voltage control can be easily performed.

As described above, the EC element drive circuit 500 according to the first embodiment periodically alternately switches and applies the nuclear growth voltage and the nuclear dissolution voltage. As a result, the EC element 100 according to the first embodiment further suppresses the concentration of the electric field on the edge portion of the electrode, and gradually applies the metal OB1 to the region where the first electrode group 110 and the second electrode group 210 intersect. It can be precipitated to form a metal thin film having a more uniform thickness in the region. Therefore, the EC element 100 can further reduce display unevenness and realize a high-quality display.

As described above, the EC element drive circuit 500 according to the first embodiment alternately switches so that the ratio of the application time of the nuclear growth voltage and the application time of the nuclear dissolution voltage is 2: 1. As a result, the EC element 100 according to the first embodiment further suppresses the concentration of the electric field on the edge portion of the electrode and reduces display unevenness, and the precipitation time of the metal OB1 exceeds the dissolution time of the metal OB1. The metal OB1 can be gradually deposited in the region where the first electrode group 110 and the second electrode group 210 intersect to form a metal thin film having a more uniform thickness in the region. Therefore, the EC element 100 can further reduce display unevenness and realize a high-quality display.

As described above, the EC element drive circuit 500 according to the first embodiment alternately switches so that the ratio of the application time of the nuclear growth voltage and the application time of the nuclear dissolution voltage is 3.5: 1. As a result, the EC element 100 according to the first embodiment further suppresses the concentration of the electric field on the edge portion of the electrode to reduce display unevenness, and the precipitation time of the metal OB1 exceeds the dissolution time of the metal OB1. The metal OB1 can be gradually deposited in the region where the 1-electrode group 110 and the 2nd electrode group 210 intersect to form a metal thin film having a more uniform thickness in the region. Therefore, the EC element 100 can further reduce display unevenness and realize a high-quality display.

As described above, the EC element drive circuit 500 according to the first embodiment alternately switches so that the application time of the nuclear dissolution voltage is 1/10 or more of the application time of the nuclear growth voltage. As a result, the EC element 100 according to the first embodiment further suppresses the concentration of the electric field on the edge portion of the electrode and reduces display unevenness, and the precipitation time of the metal OB1 exceeds the dissolution time of the metal OB1. The metal OB1 can be gradually deposited in the region where the first electrode group 110 and the second electrode group 210 intersect to form a metal thin film having a more uniform thickness in the region. Therefore, the EC element 100 can further reduce display unevenness and realize a high-quality display.

Although various embodiments have been described above with reference to the attached drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modifications, modifications, substitutions, additions, deletions, and equality within the scope of the claims. It is understood that it belongs to the technical scope of the present disclosure. Further, each component in the various embodiments described above may be arbitrarily combined as long as the gist of the invention is not deviated.

Note that this application is based on a Japanese patent application filed on April 24, 2020 (Japanese Patent Application No. 2020-07775), the contents of which are incorporated herein by reference.

The present disclosure is useful as a dimming element that reduces display unevenness of an edge portion in the width direction of an electrode when driving an EC (electrochromic) element and realizes a high-quality display.

100 EC element 110 1st electrode group 111 1st substrate 210 2nd electrode group 211 2nd substrate 500 EC element drive circuit EL1 Electrolyte I11 Nuclear growth current I12 Karyolysis current OB1 Metal V31, V41, V51, V61 Nuclear growth voltage V32 , V42, V52, V62 Karyolysis voltage

Claims (8)

1. With a plurality of first electrodes that are translucent and are arranged in parallel,
   A plurality of second electrodes arranged in parallel facing each of the plurality of first electrodes,
   An electrolytic solution containing a metal, which is arranged between the plurality of first electrodes and the plurality of second electrodes.
   A power source for applying a voltage to the electrolytic solution is provided.
   The power source alternately switches the polarity of the current based on the voltage applied to the electrolytic solution to deposit or dissolve the metal on one of the plurality of first electrodes and the plurality of second electrodes.
   Dimming element.
2. The power supply is applied by switching between a first voltage for precipitating the metal and a second voltage for melting the metal.
   The dimming element according to claim 1.
3. The power supply first applies a third voltage exceeding the first voltage, and then applies the first voltage and the second voltage.
   The dimming element according to claim 2.
4. The power supply first applies a third voltage in which the absolute value of the difference from the reference voltage at which the metal starts to precipitate exceeds the absolute value of the difference between the reference voltage and the first voltage, and then the first application. Apply the voltage of 1, the second voltage,
   The dimming element according to claim 2.
5. The power supply applies the first voltage and the second voltage by alternately switching periodically.
   The dimming element according to claim 2.
6. The power supply is alternately switched so that the ratio of the application time of the first voltage to the application time of the second voltage is 2: 1.
   The dimming element according to claim 2.
7. The power supply is alternately switched so that the ratio of the application time of the first voltage to the application time of the second voltage is 3.5: 1.
   The dimming element according to claim 2.
8. The power supply is alternately switched so that the application time of the second voltage is 1/10 or more of the application time of the first voltage.
   The dimming element according to claim 2.

Images