JP2020056897A - Light control device and driving method thereof, window material, and optical filter - Google Patents

Abstract

To provide a light control device using an organic EC element capable of obtaining stable coloring/decoloring characteristics by suppressing the segregation of the organic EC element.SOLUTION: The light control device including an organic EC element includes, in addition to an organic EC element as first light control means 1, second light control means 21. A system control part 26 is configured to detect the light transmittance of the first light control means 1 and the light transmittance of the second light control means 21 with first detection means 22 and second detection means 23 respectively, and to control independently from each other using first control means 10 and second control means 25, and thereby to control the light transmittance of the entire light control device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light control device using an electrochromic element and a driving method thereof.

The electrochromic phenomenon (EC phenomenon) is a phenomenon in which the light absorption region of a material changes due to induction of a reversible electrochemical reaction that occurs when a voltage is applied, and the material is colored or decolored. An electrochromic element (EC element) is an element that performs coloring / decoloring electrochemically using the EC phenomenon, and is used as a light control device that changes light transmittance, such as a light control filter for a window or an imaging device. Application is expected. Organic EC devices that color / decolor a low molecular weight organic material in a solution state are known to have advantages such as a sufficient contrast ratio in a colored state and a high transmittance in a decolored state.
On the other hand, the organic EC element is known to have a color separation phenomenon (segregation) in a solution at the time of driving for coloring, and Patent Document 1 discloses an example of a light control device in which the viscosity of the solution is increased to suppress the progress of segregation. ing.

JP-A-9-120088

However, even in the light control device of Patent Document 1, since the segregation progresses gradually with the coloring driving time, the color separation becomes prominent after long-time driving, and the decoloring response after that is significantly reduced. Had.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a light control device using an organic EC device, which suppresses segregation of the organic EC device and provides stable color erasing / discharging characteristics.

A first aspect of the present invention is a dimmer including an organic electrochromic element and control means for controlling light transmittance of the organic electrochromic element,
The organic electrochromic element as a first light control means, the control means as a first control means,
Further, a second light control means, and a second control means for controlling the light transmittance of the second light control means independently of the first control means,
The effective optical area of the first light adjusting means and the effective optical area of the second light adjusting means are at least partially overlapped with each other.
The second of the present invention, an organic electrochromic element as a first light control means, a second light control means, a first control means for controlling the light transmittance of the first light control means, A second control means for controlling the second light control means independently of the first control means, and a control method of the light control device, wherein the first control means and the second Controlling the light transmittance of the light control device by independently controlling the light transmittance of the first light control means and the light transmittance of the second light control means by the second control means. Features.
A third aspect of the present invention is a window material including the first light control device of the present invention.
According to a fourth aspect of the present invention, there is provided an optical filter comprising the above-mentioned first light control device of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, in the light control device using an organic EC element, the segregation of an organic EC element is suppressed and a stable color erasing characteristic can be obtained.

It is a block diagram showing composition of one embodiment of a light control device of the present invention. 4 is a timing chart of an embodiment of a driving method of the light control device of the present invention. It is a schematic diagram which shows an example of the organic EC element used for this invention. It is a schematic diagram which shows the structure of the window material using the light control device of this invention. FIG. 2 is a schematic diagram illustrating a configuration of an imaging device using the light control device of the present invention.

According to the present invention, there is provided a light control device including an organic electrochromic element (organic EC element) as a first light control means, comprising a second light control means, and controlling the light transmittance of each light control means. Thus, the feature is that the segregation of the organic EC element is suppressed.
Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and may be appropriately modified based on ordinary knowledge of a person skilled in the art without departing from the spirit of the present invention. Modifications and the like are also included in the scope of the present invention.

<Light control device>
FIG. 1 is a block diagram showing the configuration of a preferred embodiment of the light control device of the present invention.
The light control device of the present invention includes a first light control means 1, a second light control means 21, a first control means 10 for controlling the light transmittance of the first light control means 1, The second control means 25 for controlling the light transmittance of the light control means 21 is provided. The first dimming means 1 and the second dimming means 21 have effective optical areas overlapping each other, and the light incident on the dimming device is divided into the first dimming means 1 and the second dimming means 21. The amount of light is adjusted by transmitting both effective optical regions. The first dimming means 1 and the second dimming means 21 may be arranged apart from each other, may be arranged closely, or may be arranged so as to share a substrate. Good. In the present invention, the “effective optical area” is an area in which the amount of light is adjusted by the dimming means 1 and 21 until the incident light exits.

  In the light control device of FIG. 1, a first detection means 22 for detecting the light transmittance of the first light control means 1 and a second detection means for detecting the light transmittance of the second light control means 21 23, and third detecting means 24 for detecting the light transmittance of the light control device. Reference numeral 26 in the figure denotes a system control unit that calculates a target light transmittance of the light control device and calculates a light transmittance of the first light control device 1 and a light transmittance of the second light control device 21. Each is controlled to control the overall light transmittance.

  In the light control device of the present invention, the first light control means 1 is an organic EC element, and the combination of the first light control means 1 and the second light control means 21 reduces the overall light transmittance. Controlled. The first control means 10 preferably has a circuit board for controlling the effective voltage by PWM (Pulse Width Modulation). Further, as the first detecting means 22, a light emitting / receiving sensor composed of an LED and a photodiode, and a Hall sensor, which are generally used as means for detecting the light transmittance of the organic EC element, are used.

In the present invention, the second dimming means 21 is preferably a dimming element that changes the light transmittance by electrical control, and may be an organic EC element like the first dimming means 1. , An inorganic EC element or a liquid crystal element. In addition, although the use is limited, the light transmittance may be controlled by a mechanical mechanism. As a mechanical mechanism, there is a mechanism that adjusts a light-blocking area, such as an “aperture” used in a camera.
The second control means 25 may be appropriately selected according to the second light control means 21. If the second dimming means 21 is an organic EC element or a liquid crystal element, it is preferable that the second dimming means 21 has a circuit board for controlling the effective voltage by PWM, like the first control means 10. In the case of a mechanical mechanism such as an aperture, a motor having a motor such as a brushless motor, a stepping motor, or an ultrasonic motor, and a circuit board for driving the motor may be used.
The second detection means 23 may be appropriately selected according to the second light control means 21. If the second light control means 21 is an organic EC element or a liquid crystal element, as in the case of the first detection means 22, a light emitting / receiving sensor including an LED and a photodiode is exemplified. In the case of a mechanical mechanism such as an aperture, a light emitting / receiving sensor that detects the number of rotations of a motor, a hall sensor, and the like are given. If the light transmittance of the second light control means 21 can be uniquely controlled on the second control means 25 side, the second detection means 23 itself may be omitted.

  The system control unit 26 obtains the light transmittance of the entire light control device, and removes the first and second light control means 1 and 21 so as to eliminate the difference between the current light transmittance and the target light transmittance. Create a control instruction for The target light transmittance may be set by a user or may be set by communication from an external device.

  When the light control device of the present invention is applied to a window material, the user may set the light transmittance according to the brightness of the external light, or may separately include an illuminance sensor for measuring the intensity of the external light, May be configured to calculate the required light transmittance based on the detected value. In addition, when the light control device of the present invention is applied to an optical filter of an imaging device such as a camera, a user may arbitrarily set the light transmittance, or based on an instruction of an exposure control mechanism of the imaging device. Light transmittance may be set.

  The detection of the light transmittance of the entire light control device is performed by the output of the third detection unit 24, but may be performed based on the result of the first detection unit 22 and the result of the second detection unit 23. Absent. In this case, the third detecting means 24 can be omitted. When the first and third detection means 22 and 24 are used, the difference may be replaced with the output of the second detection means 23. In this case, the second detection unit 23 can be omitted. Further, if the first and second control means 10 and 25 can uniquely control the light transmittance of the first and second light control means 21, the first, second, and third detection means 22 , 23 and 24 may be omitted.

  The system control unit 26 performs a step of returning the first dimming means 1 which is an organic EC element to a decolored state at a preset timing while controlling the light transmittance of the entire dimming device. Contains. After returning to the decolored state, the first dimming means 1 shifts to the colored state again. However, the first dimming device 1 is controlled so that the light transmittance of the entire dimming device is maintained at the target light transmittance. The light transmittance of the light control means 1 and the light transmittance of the second light control means 21 are controlled in cooperation. In such a control, if there is no problem even if the entire light transmittance includes a slight change as in a simple window, the light transmittance of the first and second light control means 1 and 21 changes. Any control in the transient time domain may be omitted, and control may be performed using the product of the reached light transmittance. Actually, since the fluctuation of the light transmittance of the entire light control device is not preferable, each of the light transmittances of the first and second light control means 1 and 21 is feedback-controlled so that the product is constant. Preferably, it is controlled. Further, a configuration in which only one of the first and second dimming means 1 and 21 is feedback-controlled may be used.

  The timing of returning the first light control means 1 to the decolored state may be obtained in advance from the state of segregation occurrence, or may be selected based on the output of another detection means for detecting the occurrence of segregation. Good. It may be set at a timing earlier than the occurrence of segregation. The system control unit 26 individually controls the light transmittance of the first light control means 1 and the light transmittance of the second light control means 21 based on the target light transmittance. In the step of returning the first light control means 1 to the decolored state, the light transmittance of the first light control means 1 is preferably controlled to have an arbitrary locus. Based on the difference between the target light transmittance and the light transmittance of the first light control means 1, the light transmittance required for the second light control means 21 is calculated, and the second light control means 21 is controlled. . The control order of the first light control means 1 and the second light control means 21 may be changed.

  The control of the light transmittance of the first light control means 1 is performed so that the variation range of the light transmittance is within the range of the light transmittance that can be controlled by the first light control means 1 and the target value of the light transmittance is controlled. The changing speed is controlled at a speed lower than the response of the first light control means 1. Further, since the second light control means 21 needs to follow the change in the light transmittance of the first light control means 1, the control of the first light control means 1 is controlled by the second light control means 21. It is preferable to control at a speed slower than the response.

FIG. 2 is a timing chart of an embodiment of the driving method of the light control device of the present invention, and is a diagram showing a control example of the light transmittance of each of the first light control means 1 and the second light control means 21. It is.
In this example, the light amount of the light transmitted through the first light control means 1 and the second light control means 21 is constant, that is, the light transmittance of the entire light control device is constant. The light transmittance of each of the first light control means 1 and the second light control means is independently controlled. In FIG. 2, the solid line is the light transmittance of the first light control means 1, the dashed line is the light transmittance of the second light control means 21, and the maximum light transmittance is the first light control means 1 and the second light control means. Are the light transmittances of the light control means 21 in the respective decolored states. When both the first light control means 1 and the second light control means 21 have the maximum light transmittance, the entire light control device shows the maximum light transmittance.

In FIG. 2A, t _A is set so that the first light control means 1 is colored so as to have a target light transmittance of the entire light control device and the second light control means 21 has a maximum light transmittance. This is the period for decoloring. Further, t _B is a period during which the second light control means 21 is colored so as to have the target light transmittance of the entire light control device, and the first light control means 1 is decolored so as to have the maximum light transmittance. is there. In FIG. 2 (a), repeats a period t _A and the period t _B alternately. Further, at the time t _C , the first light control means 1 is decolorized from the target light transmittance of the entire light control device to the maximum light transmittance, and the second light control means 21 is light-controlled from the maximum light transmittance. This is a period during which the entire device is colored to a target light transmittance. Further, at t _D , the second light control means 21 is decolorized from the target light transmittance of the entire light control device to the maximum light transmittance, and at the same time, the first light control means 1 is changed from the maximum light transmittance to the light control device. This is a period during which coloring is performed to the entire target light transmittance. Also in the periods t _C and t _D , the light transmittance of the first light control means 1 and the light of the second light control means 21 are adjusted so that the light transmittance of the entire light control device becomes a constant target light transmittance. The transmittance is feedback-controlled by the first control means 10 and the second control means 25, respectively. In FIG. 2A, the change in the light transmittance of each of the first light control means 1 and the second light control means 21 at t _C and t _D is shown by a straight line for convenience. Is adjusted so that the product of the respective light transmittances becomes constant, and thus becomes non-linear. The product of the light transmittances may be rephrased as the sum of the light absorption amounts.

  Here, a deviation from a target value in a quenching process in a general organic EC device having an EC layer in which phenazine-based material and viologen-based material are dissolved one by one in propylene carbonate will be described. The detection wavelength is set to 600 nm, the optical density of the organic EC element in the transparent (decolored) state is offset to 0, and the target optical density is adjusted so as to be interlocked with the rotation of the volume dial, and the feedback control is performed. Assuming that the maximum light transmittance is 100%, the light transmittance shift of the organic EC device with respect to the target light transmittance with respect to the dimming from 100% light transmittance to about 25% (for two steps) Was at most 2% or less.

  Therefore, in the present invention, when an organic EC element is used as the second dimming means 21, the change in the optical density of two stages (dimming from 100% light transmittance to about 25%) is obtained. The deviation of the light transmittance of the light control device from the target light transmittance is estimated to be within ± 5% at most.

  As described above, the first light control means 1, which is an organic EC element, is alternately controlled between the maximum light transmittance and the target light transmittance of the entire light control device at a constant interval, thereby providing the first light control means. The light control means 1 is periodically returned to the decolored state, so that the occurrence of segregation can be suppressed.

Further, as shown in FIG. 2B, an offset light transmittance is set between the maximum light transmittance and the target light transmittance of the entire light control device, and the first light control means 1 and the second light control means are used. The light unit 21 may control the light transmittance in an opposite phase with reference to the offset light transmittance. Incidentally, in FIG. 2 (b), the light transmittance of the second light control means 21 shown by a dashed line, in a period t _A, equal to the first light control means 1 of the light transmittance represented by a solid line . In FIG. 2B, the offset light transmittances of the first dimming means 1 and the second dimming means 21 are equalized. The control pattern can be set arbitrarily. In FIG. 2B, when the second light control means 21 is an organic EC element, the light transmittance varies between the offset light transmittance and the target light transmittance of the entire light control device. , A segregation problem occurs. Therefore, as shown in FIG. 2A, it is preferable that the first light control means 1 and the second light control means 21 include a step of alternately returning to the decolored state.

  In addition, since the organic EC material used for the organic EC element generally shows a high light transmittance when no voltage is applied, in the above description, the state where no voltage is applied is referred to as a decolored state. did. However, segregation also occurs when the organic EC material shows a colored state when no voltage is applied and shows a high light transmittance when a voltage is applied. In the present invention, even in such a case, segregation can be suppressed by alternately setting the first dimming means 1 and the second dimming means 21 to a colored state.

As described above, according to the present invention, in the light control device using the organic EC device, the second light control device 21 is used, and the organic light emitting device and the second light control device 21 are used as a whole of the light control device. By controlling the light transmittance, segregation of the organic EC element can be suppressed.
Hereinafter, the organic EC device used in the present invention will be described.

<Organic EC device>
FIG. 3 is a schematic diagram illustrating an example of the organic EC element that is the first light control unit 1. Such an organic EC element can also be used as the second light control means 21. In the present embodiment, a case will be described in which the outer shape of the organic EC element is substantially rectangular, but the shape is not limited to this.
FIG. 3A is a plan view of the organic EC element. The long side direction of the organic EC element is defined as the X axis, the short side direction is defined as the Y axis, and the depth direction of the paper is defined as the Z axis. The Z axis indicates the direction of the optical axis. FIG. 3B is a diagram in which feed terminals A1, A2, C1, and C2 are added to the end view of the section taken along line DD ′ of FIG. In this example, the Y-axis direction is the vertical direction, and the organic EC element is used upright along the Y-axis direction.

  The organic EC element is basically formed by bonding transparent electrodes 3 and 6 formed on transparent substrates 2 and 5 via a spacer 4 so as to face each other. The structure is such that the organic EC layer 7 exists so as to fill the formed void. The combination of the substrate 2 and the electrode 3 and the combination of the substrate 5 and the electrode 6 correspond to a transparent electrode substrate.

  The effective optical region 9 is a region through which light is transmitted, and the organic EC element adjusts the light amount (light transmittance) of light transmitted through the effective optical region 9. By applying a voltage between the electrode 3 and the electrode 6, the organic EC material of the organic EC layer 7 causes an electrochemical reaction to change the light transmittance. The light transmittance and the optical density of the organic EC element have a relationship of -LOG (light transmittance) = (optical density), and the optical density is about 0.3 each time the light transmittance becomes 1/2. Increase.

  The electrodes 3 and 6 are provided with low-resistance wires 8a to 8d having a smaller resistance value than the electrodes themselves. The low-resistance wires 8a and 8b provided on the electrode 3 and the low-resistance wires 8d and 8c provided on the electrode 6 face each other across the effective optical region 9 along the long side direction of the organic EC element. Placed in The power supply terminals A1, A2, C1, and C2 are provided on the low-resistance wires 8a, 8b, 8c, and 8d, and are connected to the first control unit 10. The driving voltage is applied to the electrode 3 and the electrode 6 from the control means 10 via the power supply terminals A1, A2, C1, C2 and the low resistance wires 8a, 8b, 8c, 8d.

The control means 10 controls the voltage applied to the electrodes 3 and 6 to adjust the amount of light transmitted through the organic EC element. The control means 10 includes, for example, an arbitrary waveform generation circuit for generating a drive voltage waveform, a relay and a switch circuit for inverting the polarity between terminals. Further, the control means 10 may include peripheral devices such as a power supply and a regulator. Further, the control means 10 may include a circuit mechanism for measuring a current or a charge generated by the electrochemical reaction. The driving circuit and the peripheral device may be directly connected to and integrated with the organic EC element, or may be indirectly connected via wiring.
Next, each part constituting the organic EC element will be described in detail.

[Substrates 2, 5]
When the organic EC element is used for a window or a light control filter, it is preferable to maintain a high light transmittance in the decolored state in order to reduce the influence on the optical system. Therefore, the substrates 2 and 5 are preferably transparent substrates that sufficiently transmit visible light, and generally, an optical glass substrate is used. In addition, even if a material such as plastic or ceramic is used, it can be used as the substrates 2 and 5 as long as it has sufficient transparency. Further, the substrates 2 and 5 are preferably made of a material that is rigid and hardly causes distortion, and more preferably has low flexibility. The thickness of the substrates 2 and 5 is generally several tens μm to several mm.

[Electrode 3, 6]
In the present invention, since the organic EC element is used in the light control device, it is preferable to maintain a high light transmittance in the decolored state in order to reduce the influence on the optical system. Therefore, it is preferable that the electrodes 3 and 6 are transparent electrodes that sufficiently transmit visible light. Further, it is more preferable that the electrodes 3 and 6 are made of a material having high conductivity as well as high light transmittance in a visible light region.

  For example, metals and metal oxides such as indium tin oxide alloy (ITO), tin oxide (NESA), indium zinc oxide (IZO), silver oxide, vanadium oxide, molybdenum oxide, gold, silver, platinum, copper, indium, and chromium Are the materials of the electrodes 3 and 6. Further, materials of the electrodes 3 and 6 include silicon-based materials such as polycrystalline silicon and amorphous silicon, and carbon materials such as carbon black, graphene, graphite, and glassy carbon. In addition, a conductive polymer (for example, polyaniline, polypyrrole, polythiophene, a complex of polyethylenedioxythiophene and polystyrenesulfonic acid (PEDOT: PSS), etc.) whose conductivity has been improved by doping or the like is also a material of the electrodes 3 and 6. .

  Since the organic EC element used in the present invention preferably has a high light transmittance in the decolored state, for example, ITO, IZO, NESA, PEDOT: PSS, graphene, etc. are particularly suitable as the material for the electrodes 3 and 6. It is. The materials of these electrodes 3 and 6 can be used in various forms such as bulk and fine particles. The materials of the electrodes 3 and 6 may be used alone or in combination.

[Organic EC layer 7]
The organic EC layer 7 is preferably formed by dissolving an electrolyte and an organic EC material such as a low molecular weight organic material in a solvent.
First, the solvent will be described. The solvent is not particularly limited as long as it can dissolve the electrolyte, but a solvent having polarity is particularly preferable. Specifically, examples of the solvent include water and organic polar solvents such as methanol, ethanol, propylene carbonate, ethylene carbonate, dimethyl sulfoxide, dimethoxyethane, acetonitrile, γ-butyrolactone, and γ-valerolactone. Further, examples of the solvent include organic polar solvents such as sulfolane, dimethylformamide, dimethoxyethane, tetrahydrofuran, acetonitrile, propionnitrile, dimethylacetamide, methylpyrrolidinone, and dioxolane.

Next, the electrolyte will be described. The electrolyte is not particularly limited as long as it is a salt containing a cation or anion, which is an ion-dissociable salt, exhibits good solubility, and has an electron-donating property enough to secure coloring of the organic EC material. Examples of the electrolyte include inorganic ion salts such as various alkali metal salts and alkaline earth metal salts, and quaternary ammonium salts and cyclic quaternary ammonium salts. More _{specifically, LiClO 4, LiSCN, LiBF 4} , LiAsF 6, LiCF 3 SO 3, LiPF 6, LiI, NaI, NaSCN, NaClO 4, NaBF 4, NaAsF 6, KSCN, the KCl like Li, Na, K And the like. Further, (CH ₃ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBF ₄ , (n-C ₄ H ₉ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₄ NBr, (C ₂ H ₅ ) are used as electrolytes. ₄ NClO _4, include _{(n-C 4 H 9)} 4 NClO 4 quaternary ammonium salts and cyclic quaternary ammonium salts such as _4. As the anionic species, generally known structures such as ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and (CF ₃ SO ₂ ) ₂ N ⁻ are used. Further, an ionic liquid may be used as the electrolyte. These electrolyte materials may be used alone or in combination.

  Next, the organic EC material will be described. In general, an organic EC material takes a neutral state when no voltage is applied, and has no absorption in the visible light region. In such a decolored state, the organic EC element exhibits high light transmittance. When a voltage is applied between the electrodes 3 and 6, an electrochemical reaction occurs in the organic EC material, and the anodic organic EC material changes from a neutral state to an oxidized state (cation), and the cathodic organic EC material reduces from a neutral state to a reduced state. State (anion). The organic EC material has absorption in the visible light region in a cation or anion state and is colored, so that the organic EC element has a low light transmittance.

  In the EC device according to the present invention, the EC layer includes one or more anode organic EC materials and one or more cathode organic EC materials. Each of the anodic organic EC material and the cathodic organic EC material may be a single material, a multiple material, or one may be a single material and the other may be a multiple material. Further, any material may be used as long as it has solubility in a solvent and can express coloring and decoloring by an electrochemical reaction.

  Examples of the anodic organic EC material include thiophene derivatives, metallocene derivatives such as ferrocene, and aromatic amine derivatives such as phenazine derivatives, triphenylamine derivatives, phenothiazine derivatives, and phenoxazine derivatives. In addition, examples of the anodic organic EC material include a pyrrole derivative and a pyrazoline derivative. However, the anodic organic EC material used in the present invention is not limited to these.

  Examples of the cathodic organic EC material include a viologen compound, an anthraquinone compound, a ferrocenium salt compound, and a styrylated compound. However, the cathode organic EC material used in the present invention is not limited to these.

  In order to maintain an absorption spectrum against a temperature change, it is preferable that the organic EC material does not easily form an association. When the material forms an aggregate, the absorption of the monomer and the absorption of the aggregate are superimposed in the absorption spectrum. Since the ease with which an aggregate is formed changes with temperature, in a material that easily forms an aggregate, the change in temperature changes the ratio of monomer absorption to aggregate absorption. Therefore, in order to avoid the formation of aggregates, a method of providing a bulky substituent and suppressing the formation of aggregates due to steric hindrance is preferably used.

  The organic EC layer 7 is preferably a liquid or a gel. The organic EC layer 7 is preferably used in a solution state, but may be used in a gel or viscous state as long as the response speed is not significantly impaired. For gelation, the solution further contains a polymer and a gelling agent. Examples of the polymer (gelling agent) include polyacrylonitrile, carboxymethylcellulose, polyvinyl chloride, polyvinyl bromide, polyethylene oxide, and polypropylene oxide. Further, examples of the polymer include polyurethane, polyacrylate, polymethacrylate, polyamide, polyacrylamide, polyester, polyvinylidene fluoride, and Nafion. In addition to using the solution in a mixed state, a structure having a transparent and flexible network structure (for example, a sponge-like structure) may carry these solutions.

[Low resistance wiring 8a to 8d]
The low resistance wires 8a to 8d reduce the in-plane distribution of the voltage supplied to the electrodes 3 and 6 from the power supply terminals A1, A2, C1 and C2. When the low resistance wirings 8a to 8d are not provided, if a potential gradient is formed in the plane of the electrodes 3 and 6 at a distance from the power supply terminals A1, A2, C1 and C2, the amount of electrochemical reaction in the plane of the organic EC element becomes uneven. Will occur. As shown in FIG. 3, the power supply terminals A1, A2, C1, and C2 face each other on the long side and across the effective optical region 9 in order to minimize the potential distribution in the effective optical region 9. Preferably, it is installed at a location.

  When a potential distribution exists in the electrode surface, the amount of electrochemical reaction varies according to the potential distribution. For example, in the organic EC device shown in FIG. 3, when the low-resistance wiring is only 8a and 8c, the power supply terminals are only A1 and C1, and the power supply terminal A1 is the anode and the power supply terminal C1 is the cathode, the coloring operation is continued. The anode material is strongly colored in the vicinity of A1 and the low resistance wiring 8a. In the vicinity of the power supply terminal C1 and the low resistance wiring 8c, the cathode material is strongly colored. In order to avoid this, as shown in FIG. 3, in addition to the power supply terminals A1 and C1, power supply terminals C2 and A2 are provided at positions facing each other with the effective optical area 9 interposed therebetween. A voltage is applied from both sides with the power supply terminals A1 and A2 as anodes and the power supply terminals C1 and C2 as cathodes at the same time. Alternatively, the power supply terminals A1 and A2 are alternately anodes, and the power supply terminals C1 and C2 are alternately cathodes. It is possible to suppress the influence of the potential distribution by using a method such as applying a voltage from the substrate. The switching between the power supply terminals A1 and A2 and the switching between the power supply terminals C1 and C2 are performed by the control unit 10, and the timing of the switching is arbitrarily selected from several kHz to several mHz.

[Driving method of organic EC element]
The colored state of the organic EC element is maintained by PWM driving in which a voltage pulse is applied between the power supply terminals A1 and A2 and the power supply terminals C1 and C2. In PWM driving, the effective voltage is controlled by setting one or both of a time width (duty ratio) for applying a voltage occupying a pulse period and a peak value of the voltage. Thereby, the amount of electrochemical reaction of the organic EC element can be adjusted, and the light transmittance thereof can be arbitrarily controlled. If the duty ratio is gradually increased with the driving voltage kept constant, the coloring amount of the organic EC element increases and the transmittance decreases. Conversely, if the duty ratio is gradually lowered, the coloring amount will follow and decrease, and the transmittance will increase.

  During the period in which no voltage is applied in the pulse cycle, the electrical contact between the drive power supply and the power supply terminal is cut off, or the current is cut off by inserting a high-resistance element, so that coloring due to the electrochemical reaction is not reduced or caused. . Specifically, conduction / non-conduction is performed by a switching element such as a relay or a transistor.

  The pulse cycle can be arbitrarily selected, but if the cycle is slow, an increase or decrease in the light transmittance of the organic EC element is visually recognized, resulting in flickering. Therefore, a pulse period of 10 Hz or more, preferably 100 Hz or more is preferable.

  When the driving voltage is constant, the light transmittance of the organic EC element depends on the duty ratio. If the relationship between the light transmittance, the driving voltage, and the duty ratio is acquired in advance, the light transmittance can be controlled without a sensor. When performing more precise control of the light transmittance, a light receiving element, which is a sensor for directly detecting the amount of transmitted light, is arranged near the effective optical area 9 of the organic EC element, and based on information on the light receiving element, the light receiving element of the organic EC element is Control light transmittance. The light receiving element may be an existing one such as a photodiode made of Si or Ge. Further, it can be used as a light emitting / receiving sensor in combination with a light emitting element such as an LED. In this case, the light emitting element and the light receiving element are respectively arranged on the front and back surfaces of the organic EC element.

When the organic EC element quickly reaches the target colored state, the drive voltage is applied with the duty ratio set to 100%. In addition, acceleration driving in which the driving voltage is applied several hundred mV higher than the voltage during normal driving during coloring can be appropriately selected.
In order to make the organic EC element quickly reach the decolored state, a method of short-circuiting between the anode and cathode terminals or short-circuiting after applying a drive voltage of the opposite polarity once is used.
The responsivity of coloring and decoloring of the organic EC element depends on the diffusion of the material in the solution and depends on the change width of the light transmittance, but is several hundred milliseconds to several seconds in a normal temperature environment, and several seconds to several seconds in a low temperature environment. May require 10 seconds.

  The light transmittance of the organic EC element can be feedback-controlled based on the information value of the light emitting / receiving sensor. When it is desired to control the change of the light transmittance along an arbitrary trajectory, the change range of the target value of the light transmittance is set within the range of the light transmittance that can be controlled by the organic EC element, and the change of the target value of the light transmittance The speed is controlled at a speed lower than the response of the organic EC element. In such a control, the light transmittance of the organic EC element can be smoothly controlled without any disturbance in an arbitrary trajectory in both directions of coloring and decoloring experimentally.

When an organic EC device is used upright along the vertical direction (Y-axis direction), vertical segregation caused by the influence of gravity is due to the difference in the tendency of solvation of cations and anions with nonaqueous solvents. It is considered. The cation has a large solvation with the non-aqueous solvent and is strongly associated with the solvent molecule, so that the specific gravity of the solvent around the cation is larger than that of the solvent alone. Conversely, in order to reduce the solvation of the anion, the specific gravity of the solvent around the anion is made smaller than the specific gravity of the solvent alone. Due to such a difference in specific gravity, cations are unevenly distributed in the vertical direction and anions are unevenly distributed in the vertical direction, and segregation occurs.
It has been confirmed that when segregation occurs, when the organic EC element is to be in a decolorized state, the decolorization responsiveness of the color-separated portion is significantly deteriorated. Experimentally, it took several minutes for the organic EC device in which segregation had occurred to be completely erased.

  On the other hand, even if the organic EC element has undergone segregation, if the color is completely erased over time, the segregation is canceled at that time. It has been experimentally confirmed that after the elimination of the segregation, the characteristics before the occurrence of the segregation are restored in the subsequent coloring and decoloring operations. For this reason, when coloring the organic EC element for a long time, it is desirable to interpose a step of temporarily returning to the decolored state even in the colored state.

  The segregation due to gravity occurs so as to gradually accumulate. For example, in an organic EC device made of a solution, the effect becomes significant in a state where coloring is maintained after several tens of minutes to several hours. However, since the segregation occurs gradually, there is a case where even if there is no influence at the time of coloring, it remains undisturbed at the time of erasing. In order to avoid the influence of the remaining disappearance, it is preferable to interpose a step of returning to the decolored state at an earlier timing of several minutes to several tens minutes after coloring.

  In the present invention, the occurrence of segregation can be suppressed by using the organic EC element in combination with the second light control means 21 and returning the organic EC element to the decolored state at predetermined intervals. In addition, during the period of returning the organic EC element to the decolored state, it is possible to maintain the light transmittance required by the second dimming means 21, so that sufficient time is required for decoloring the organic EC element. Is possible.

  Hereinafter, a window material using the light control device of the present invention and an example in which the light control device of the present invention is used for an optical filter will be described.

<Window materials>
A window member using the light control device of the present invention will be described with reference to FIG. FIG. 4A is a perspective view of the present embodiment, and FIG. 4B is an end view of a cross section EE ′ in FIG. 4A.
The window material is a dimming window for adjusting the amount of transmission of incident light, and has the dimming device of the present invention. In this example, the light control device of the present invention and a transparent plate 32 sandwiching each of the first light control means 1 and the second light control means 21 of the light control device are integrally surrounded by the whole. And a frame 31 to be mounted. As the first dimming means 1 and the second dimming means 21, the organic EC element shown in FIG. 3 is used. In FIG. 4, the low resistance wirings 8a to 8d and the power supply terminals A1, Illustration of A2, C1, and C2 is omitted. Further, the first control means and the second control means (not shown) may be integrated in the frame 31, and are arranged outside the frame 31 and the first light control means 1 and the second light control means It may be connected to the light control means 21. As the second light control means 21, an inorganic EC element and a liquid crystal element are suitably used in addition to the organic EC element.

The transparent plate 32 is not particularly limited as long as it has a high light transmittance, and is preferably a glass material in consideration of use as a window. In the present example, the first light control means 1 and the second light control means 21 and the transparent plate 32 are formed of different components, but the present invention is not limited to this. For example, a substrate of an organic EC element (FIG. 2, 6) may be used as the transparent plate 32.
The frame 31 may be made of any material, but may be any frame that covers at least a part of the first and second dimming means 1 and 21 and has an integrated form.

  INDUSTRIAL APPLICABILITY The window material of the present invention can be applied to, for example, an application for adjusting the amount of daylight sunlight entering a room. Since the present invention can be applied to adjustment of the amount of heat as well as the amount of light of the sun, it can be used for controlling the brightness and temperature of a room. Further, the shutter can be applied to an application for blocking a view from the outside to the room. Such a window material can be applied to a window of a vehicle such as an automobile, a train, an airplane, and a ship, a filter of a display surface of a clock or a mobile phone, in addition to a glass window for a building.

<Optical filter>
The light control device of the present invention can be applied as an optical filter. The optical filter may be used in an imaging device such as a camera, and when used in an imaging device, it may be provided in the imaging device body or in a lens unit. Hereinafter, a case will be described in which a neutral density (ND) filter is configured as the optical filter. When the light control device of the present invention is used for an optical filter, an organic EC element, an inorganic EC element, or a liquid crystal element is preferably used as the second light control means 21.

  The neutral density filter requires uniform light absorption in the visible light region. In order to realize a neutral density filter using an organic EC material, it is preferable to mix a plurality of materials having different absorption wavelength ranges in the visible light range to make the absorption intensity in the visible light range flat. Since the absorption spectrum when organic EC materials are mixed is expressed as the sum of the absorption spectra of each material, uniform light absorption can be achieved by selecting multiple materials with appropriate wavelength ranges and adjusting their concentrations. Is possible.

  In a low molecular organic EC material, the wavelength range that can be generally covered by one material is 100 nm to 200 nm. In order to cover the entire visible light range of 380 nm to 750 nm, it is preferable to use at least three or more organic EC materials. For example, three or more anode organic EC materials, three or more cathode organic EC materials, or two or more anode organic EC materials and two or more cathode organic EC materials are used as organic EC materials. Is preferred.

Generally, a neutral density filter sets the light amount to 1/2 ⁿ (n is an integer). At 1/2, the light transmittance goes from 100% to 50%, and at 1/4, the light transmittance goes from 100% to 25%. In addition, when the light transmittance is reduced to 吸 光, the change in the absorbance is 0.3 due to the relationship of −LOG (transmittance) = (absorbance), and is 0.6 in １ ／. In order to perform the dimming from 1/2 to 1/64, it is sufficient that the amount of change in absorbance can be controlled from 0 to 1.8 in 0.3 steps.

<Lens unit and imaging device>
The configuration of the optical filter of the present invention, that is, the configuration of the lens unit and the imaging device using the light control device of the present invention will be described with reference to FIG. FIG. 5A illustrates an imaging device 43 having a lens unit 42 using the optical filter 41 of the present invention, and FIG. 5B illustrates a configuration of the imaging device 43 having the optical filter 41 of the present invention. FIG. As shown in FIG. 5, the lens unit 42 is detachably connected to the imaging device 43 via a mount member (not shown). In FIG. 5, F is the optical axis.

  The lens unit 42 is a unit having a plurality of lenses or lens groups. For example, the lens unit 42 shown in FIG. 5A is a rear focus type zoom lens that performs focusing behind the stop. The first lens group 44 having a positive refractive power, the second lens group 45 having a negative refractive power, the third lens group 46 having a positive refractive power, and the positive refraction are arranged in this order from the subject side (left side as viewed in the drawing). The fourth lens group 47 has four lens groups. Zooming is performed by changing the distance between the second lens group 45 and the third lens group 46, and focusing is performed by moving a part of the fourth lens group 47.

  The lens unit 42 has, for example, an aperture stop 48 between the second lens group 45 and the third lens group 46, and an optical filter between the third lens group 46 and the fourth lens group 47. 41. The light passing through the lens unit 42 is arranged so as to pass through each of the lens groups 42 to 47, the aperture stop 48, and the optical filter 41, and the light amount can be adjusted using the aperture stop 48 and the optical filter 41. .

  The configuration inside the lens unit 42 can be changed as appropriate. For example, the optical filter 41 can be disposed before (subject side) or behind (the imaging device 43 side) the aperture stop 48, and may be disposed before the first lens group 44, and the fourth lens group You may arrange after 47. If the optical filter 41 is arranged at a position where light converges, there is an advantage that the area of the optical filter 41 can be reduced. In addition, the form of the lens unit 42 can be appropriately selected. In addition to the rear focus type, the lens unit 42 may be an inner focus type that performs focusing before the stop, or may be another type. In addition to the zoom lens, a special lens such as a fisheye lens or a macro lens can be appropriately selected.

  The glass block 49 included in the imaging device 43 is a glass block such as a low-pass filter, a face plate, and a color filter. The light receiving element 50 is a sensor unit that receives light that has passed through the lens unit 42, and an imaging element such as a CCD or a CMOS can be used. Further, an optical sensor such as a photodiode may be used, and a sensor that acquires and outputs information on light intensity or wavelength can be used as appropriate.

  As shown in FIG. 5A, when the optical filter is incorporated in the lens unit 42, some components such as the control means (10, 25) may be arranged in the lens unit 42. It may be arranged outside the unit 42. When it is arranged outside the lens unit 42, it is connected to the optical filter 41 inside the lens unit 42 through a wiring and is driven and controlled.

  As shown in FIG. 5B, the imaging device 43 itself may have the optical filter 41. The optical filter 41 may be arranged at an appropriate place inside the imaging device 43, and the light receiving element 50 may be arranged to receive the light passing through the optical filter 41. In FIG. 5B, for example, the optical filter 41 is disposed immediately before the light receiving element 50. When the imaging device 43 itself includes the optical filter 41, the lens unit 42 to be connected does not need to have the optical filter 41. Therefore, the dimmable imaging device 43 using the existing lens unit is configured. Becomes possible.

  Further, in application to an imaging device such as a camera, the second light control means 21 may be a mechanical mechanism such as a diaphragm. In this case, the positions of the first light control means 1 and the second light control means 21 may be appropriately selected according to the imaging device or the optical system of the lens. In addition, an aperture conventionally provided on the lens side may be regarded as the second light control unit 21. Further, in the image pickup apparatus, a configuration in which the sensitivity of the image pickup element is controlled as the second light control means 21 is also conceivable.

  Such an imaging device is applicable to a product having a combination of light quantity adjustment and a light receiving element. For example, it can be used for a camera, a digital camera, a video camera, a digital video camera, and can also be applied to a product having a built-in imaging device such as a mobile phone, a smartphone, a PC, and a tablet.

  By using the optical filter (that is, the light control device) of the present invention as a light control member, the light transmittance can be appropriately changed by one filter, and there are advantages such as reduction in the number of members and space saving.

  1: first light control means, 10: first control means, 21: second light control means, 22, 23, 24: detection means, 25: second control means

Claims (12)

An organic electrochromic element, and a control unit for controlling light transmittance of the organic electrochromic element, a light control device including:
The organic electrochromic element as a first light control means, the control means as a first control means,
Further, a second light control means, and a second control means for controlling the light transmittance of the second light control means independently of the first control means,
A light control device, wherein an effective optical area of the first light control means and an effective optical area of the second light control means are at least partially overlapped with each other.   The light control device according to claim 1, further comprising a detection unit that detects a light transmittance of the first light control unit.   The light control device according to claim 1, further comprising a detection unit configured to detect a light transmittance of the second light control unit.   The light control device according to any one of claims 1 to 3, further comprising a detection unit configured to detect a light transmittance of the light control device.   The light control device according to any one of claims 1 to 4, wherein the second light control means is an electrochromic element.   The dimming device according to any one of claims 1 to 4, wherein the second dimming unit is a liquid crystal element.   An organic electrochromic element as a first light control means, a second light control means, a first control means for controlling the light transmittance of the first light control means, and the first control means A second control means for independently controlling the second light control means, and an effective optical area of the first light control means and an effective optical area of the second light control means A method of controlling dimming devices overlapping each other, wherein the first control means and the second control means, the light transmittance of the first dimming means and the second dimming means A method for driving a light control device, wherein the light transmittance of the light control device is controlled by independently controlling the light transmittance.   The light transmittance of the light control device is controlled by feedback-controlling at least one of the light transmittance of the first light control device and the light transmittance of the second light control device. A driving method of the light control device according to claim 7.   The light transmittance of the entire light control device is constant, and at least one of the light transmittance of the first light control device and the light transmittance of the second light control device is controlled. The method for driving a light control device according to claim 7.   A period in which one of the first light control means and the second light control means is in a colored state, the other is in a decolored state, and one is in a decolored state, and a period is in which the other is in a colored state. The method of driving a light control device according to claim 9, wherein the method is repeated alternately.   A window material comprising the light control device according to claim 1.   An optical filter comprising the light control device according to any one of claims 1 to 7.

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