JP2574433Y2 - Transmission type electrochromic device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochromic device (hereinafter abbreviated as EC device). More specifically, the present invention relates to a transmission type EC suitable for use in a light control device such as a diaphragm for a camera lens, light control glass, and sunglasses.
It relates to a D element.

[0002]

2. Description of the Related Art As a conventional light control device, taking a diaphragm for a camera lens as an example, in addition to a device for mechanically driving a light shielding plate, a shutter device for electrically driving a liquid crystal element and a polarizing plate in combination. There is. However, these conventional light control devices have problems in terms of downsizing of the device and shortage of transmitted light when trying to transmit light.

Accordingly, the present inventors have considered using a light-transmitting electrochromic element which causes a reversible color-forming / decoloring reaction by an electrochemical reaction as a light control device such as a diaphragm for a camera lens. This EC element has a sufficiently high contrast at the time of color erasing and erasing, and the light transmittance at the time of erasing is equivalent to that of the glass used as the substrate. It focuses on something.

In a conventional light transmission type ECD, as shown in FIG. 5, an electrolyte 103 is sealed between two opposing transparent substrates 101 and 102, and transparent electrodes 104 and 105 are formed on opposing surfaces. Electrochromic materials (hereinafter, referred to as EC materials) 106 and 107 are formed thereon so as to have a uniform thickness and the same area. Note that the reference numeral 108 in the drawing denotes two substrates 101 and 102.
To seal the electrolyte 103. The light transmission type ECD is an element having a function of reversibly changing color and light transmittance (electrochromic phenomenon) by an oxidation-reduction reaction occurring at or near an electrode surface when a predetermined voltage is applied. However, EC materials have different peak wavelengths for light transmission as their composition changes,
Nothing can block light transmission uniformly in the entire visible light region. For example, in a blue EC device using a combination of tungsten oxide (WO ₃ ) and Prussian blue (PB), which are typical EC materials, light having a wavelength shorter than about 600 nm is transmitted even during coloring. There is a problem that it is impossible to block light over the entire area.

Therefore, the present inventors considered improving the light transmission characteristics in the entire visible light region by combining different kinds of EC materials that complement each other's transmission characteristics.

[0006]

However, when a light transmission type ECD is used as a light control device, each of the opposing ECDs is required.
Since it is necessary for the C material to color or decolor at the same time, the EC materials formed on both electrodes must be in an electrochemically equivalent state (equivalent charge amount). Therefore, in the structure of the conventional light transmission type ECD, when EC materials having different light absorption characteristics are combined, one of the films is insufficiently thin to block light transmission in order to form a film having an equal charge amount. In some cases, the transmittance increases. For example, Prussian blue (hereinafter, also abbreviated as PB), which is effective in shielding light in the vicinity of 600 nm to 800 nm, and iron / phenanthroline complex (hereinafter, abbreviated as PH), which is effective in shielding light in a shorter wavelength range, are used. In this case, the Prussian blue film, which has a lighter color (smaller extinction coefficient) than the phenanthroline complex, has a higher density (higher extinction coefficient) than the phenanthroline film, requires light transmission. The film thickness becomes insufficient to block light, and the light transmittance increases. That is, the transmittance around 600 nm to 800 nm, which is mainly suppressed by Prussian blue, increases. For this reason, there still remains a problem that the passage of light cannot be uniformly blocked in the entire visible light region. In other words, the conventional structure of the light transmission type ECD
Then, it is impossible to arbitrarily change the absorbance of transmitted light in the visible light region.

The present invention provides a transmission type electrochromic device capable of arbitrarily changing the absorbance of transmitted light in a visible light region,
That is, an object of the present invention is to provide a transmissive electrochromic device capable of uniformly blocking the passage of light in the entire visible light region.

[0008]

In order to achieve the above object, the present invention is to dispose a pair of transparent substrates in which a transparent electrode and two kinds of electrochromic materials having different extinction coefficients are laminated, facing each other in the light passing direction. In a transmissive electrochromic device in which an electrolyte is interposed therebetween, a pair of electrochromic materials have the same amount of charge, and opposing portions are formed with different thicknesses.

Further, in the transmission type ECD of the present invention, the film thickness of the opposing portions of the electrochromic material is formed to be relatively thicker when the absorption coefficient is smaller than when the absorption coefficient is larger.

[0010]

Therefore, even if two EC materials having different extinction coefficients are formed in the state of the same charge amount, the film thickness of the opposing portions is different from each other, so that only the transmittance of one EC material is high. Never be. For example, a thin color E with a small extinction coefficient
If the film of the C material is formed thicker with a smaller film area than the darker EC material film having a larger extinction coefficient, the E material having a smaller extinction coefficient can be obtained.
The color of the C material becomes deeper, and the transmittance in the wavelength band cut off by this can be reduced. The same applies to the case where the film of the EC material having a large extinction coefficient is made thinner than the film of the EC material having a small extinction coefficient to increase the thickness of the film of the EC material having a relatively small extinction coefficient.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the transmission type ECD of the present invention. This ECD is composed of two opposing transparent substrates 1, 2
A cell structure for sealing the electrolyte 3 is formed between them, transparent electrodes 4 and 5 are formed on opposing surfaces of the transparent substrates 1 and 2, and EC materials 6 and 7 are formed thereon. Here, the transparent substrates 1 and 2 are not particularly limited, but generally, glass, a plastic plate, a plastic film, or the like having excellent light transmittance is used. In this embodiment, a glass plate was used. As the transparent electrode materials 4 and 5, a known conductive film material such as tin oxide or indium oxide is used. The electrolyte 3 may be any of solid, liquid and gel. Reference numeral 8 denotes a sealing material for bonding the first and second transparent substrates 1 and 2 to seal the electrolyte 3.

The EC materials 6 and 7 are colored or decolored simultaneously when a predetermined voltage is applied, and are decolored or colored simultaneously when a reverse voltage is applied or short-circuited. used. For example, the different EC materials 6 and 7 are preferably materials having different peak wavelengths with respect to transmittance in the visible light region, and more preferably, are complementary to each other with respect to the transmittance at the time of color development in the entire visible light region and are uniform ( Flat)
A material having a relationship to obtain transmission characteristics is selected and adopted.

In the case of this embodiment, as the EC materials 6 and 7, when a voltage is applied between the two and one of them undergoes a reduction reaction and the other undergoes an oxidation reaction, it becomes colorless and transparent at the same time and short-circuits to neutrality. Prussian blue (PB) and iron / phenanthroline complex (PH), which have a relationship of developing blue and red, respectively, when used, are used. Therefore, the transparent electrodes 4 and 5 on the first and second transparent substrates 1 and 2
When a predetermined voltage is applied or short-circuited in between, the EC materials 6 and 7 on the first and second transparent substrates 1 and 2 simultaneously emit color or become colorless and transparent to control the amount of light passing therethrough. Of course, the degree of color development also changes by controlling the applied voltage value, so that it is possible to control the amount of transmitted light. The color of Prussian blue changes from colorless and transparent to blue or from blue to colorless and transparent due to the application of a charge and a short circuit. Further, the iron-phenanthroline complex changes its color from colorless and transparent to red or from red to colorless and transparent due to application of electric charge and short circuit. These EC materials 6 and 7 are fixed on the transparent electrodes 1 and 2 by, for example, an electrolytic deposition method, a casting method by polymerizing, a polymer blending method, or the like.

The EC materials 6 and 7 are formed to have the same charge amount and have mutually different thicknesses at opposing portions. For example, the EC material 6 having a small extinction coefficient has a smaller film area and is formed thicker than the EC material 7 having a large absorption coefficient. The EC materials 6 and 7 should be formed as thin as possible so as not to impair the light transmittance at the time of decoloring, and have a minimum thickness that can block light transmission to a desired level or less during color development. is necessary.

The ECD of the present embodiment configured as described above
When the transmittance characteristics of Comparative Example 1 are described with reference to comparative products, it can be understood that the following improvements have been made. First, the two opposing E
The effect of changes in the charge amount and film thickness between the C materials on the transmittance characteristics of the ECD will be described. Here, as the EC material, a combination of Prussian blue and an iron-phenanthroline complex was used. Then, the charge amount of Prussian blue with respect to the iron-phenanthroline complex is equal to 1 ×, and the film area is reduced to 1/4 to form a thick film (hereinafter referred to as “executable product”). And the film formed so that the amount of charge on the Prussian blue side is doubled (hereinafter referred to as a comparative product). The actual product and the comparative product have the same film thickness. The transmittance characteristics of the actual product and the comparative product were as shown in FIG. Here, the graphs to graphs shown in FIG. 3 show the transmittance characteristics under the following conditions.

: In the case of ITO glass only: At the time of decolorization of the actual product: At the time of decolorization of the comparative product: At the time of color development of the comparative product: At the time of color development of the actual product As is clear from this graph, light transmission by Prussian blue The transmittance characteristics in the cutoff wavelength region of about 550 nm or more were different between the embodiment product and the comparison product.
Despite the same thickness of Prussian blue in both the actual product and the comparative product, the comparative product in which the charge amount doubled despite the same film thickness, the color disappeared due to incomplete decoloring / color-developing action and residual color due to incomplete color-developing action, and color decoloring due to insufficient color development. There is no significant difference in transmittance with time. That is, the contrast is small. On the other hand, the actual product has a complete decoloring / coloring effect, so that the contrast is at least three times higher than that of the comparative product. The transmittance is higher than that of the comparative product when the color is erased, but the transmittance is higher than that of the comparative product when the color is developed. Got lower. That is, the difference between light transmission and light shielding required for the light control device becomes clear. That is, even if the thickness of Prussian blue is simply increased, contrast cannot be obtained unless the charge amounts are equal.

Next, the effect of the film thickness on the equal charge amount will be described in comparison with a conventional product. Here, the conventional product is
It refers to a material in which opposite EC materials are formed in the same film area with the same charge amount. FIG. 4 shows a conventional type E having an equal charge amount and an equal film area.
As is clear from the comparison between the spectral characteristics b of the colored CD and the spectral characteristics c of the colored product, the colored product was approximately 55%.
The cutoff characteristic in the wavelength region of 0 nm or more is improved, and the entire region is flat in the visible light region. This is because the two EC materials have the same amount of charge, so that both the decoloring and color-forming effects occur completely, but the actual product has a larger thickness of Prussian blue, so the transmittance, especially the color-forming transmittance, is reduced. Or lower it. Incidentally, a indicates the time of decoloring between the actual product and the conventional product.

The transmissive electrochromic device configured as described above can be used, for example, as a diaphragm for a camera lens, light control glass, a lens for spectacles, and the like. For example, when the present invention is applied to a diaphragm for a camera lens, the ECD elements are formed concentrically in a ring shape independently of each other, and each ECD element is formed.
What is necessary is just to be able to control the coloring and erasing of the elements individually. At this time, if the coloring and decoloring of the ring-shaped ECD element are controlled based on the measured values of the light quantity measuring device, the automatic aperture device can be easily realized.

FIG. 2 shows another embodiment. This embodiment uses E
The film area of the C material / Prussian blue 6 and the film area of the EC material / phenanthroline 7 were almost equal. In order to form a thick film of Prussian blue 6 and a thin film of phenanthroline 7 at the portion opposite thereto, the excess amount of phenanthroline is solved by forming the film thickness of the peripheral portion 7a of phenanthroline 7 to be large. doing. In this case, the thin phenanthroline 7 portion facing the Prussian blue 6 and the peripheral portion 7a need not be formed as a continuous film as long as they are on the same transparent electrode and the same voltage is applied simultaneously.

The above-described embodiment is an exemplification of a preferred embodiment of the present invention, but the present invention is not limited to this. Various modifications can be made without departing from the scope of the present invention. For example, in this embodiment, as the EC material, Prussian blue and an iron-phenanthroline complex are used as an example, but the present invention is not particularly limited to this, and any EC material that can uniformly block light in the visible region can be used. Other EC materials can also be used. In this embodiment, the color is mainly erased by applying a voltage, and the color is developed by a short circuit.
Although the C material is used, the reverse case or a combination of EC materials that develop color by applying a voltage and decolor by applying a reverse voltage or vice versa may be used. In addition, the EC material may have a relationship in which two or more films are divided as long as they have a common electrolyte and the same voltage is applied at the same time.

The application of the present invention is suitable for an aperture of a camera lens. However, the present invention is not limited to the lens aperture, and can be applied to light control glass, sunglasses, and the like.

[0023]

As is clear from the above description, in the transmission type electrochromic device of the present invention, a pair of electrochromic materials have the same charge amount, and the opposing portions have different film thicknesses. Since two EC materials having different extinction coefficients are formed in the state of equal charge amount because the film is formed, the film thickness of the opposing portions is different from each other. Is not increased, and the uniform transmittance at the time of color development and the contrast between color development and color erasure can be enhanced in the entire visible light region. Especially,
If a thin EC material film with a small extinction coefficient is formed thicker with a smaller film area than a darker EC material film with a larger extinction coefficient, the color of the EC material with a smaller extinction coefficient becomes darker, which is cut off. The transmittance of the wavelength band to be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a transmission type electrochromic device of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment of the transmission type electrochromic device of the present invention.

FIG. 3 is a view showing an example of a transmission electrochromic device in which opposing E
It is a spectral transmission spectrum diagram which shows the influence which the change of the electric charge amount and film thickness between C materials has.

FIG. 4 is a spectral characteristic diagram showing a comparison between the transmission type electrochromic device of the present example and a conventional type.

FIG. 5 is a longitudinal sectional view of a conventional transmission type electrochromic device.

[Explanation of symbols]

 1, 2 Transparent substrate 3 Electrolyte 4, 5 Transparent electrode 6, 7 EC material

Claims (2)

(57) [Scope of request for utility model registration] 1. A transmission type electrochromic device comprising a transparent electrode and a pair of transparent substrates, each of which is formed by laminating two kinds of electrochromic materials having different extinction coefficients, facing each other in a light passing direction and an electrolyte disposed therebetween. A transmission type electrochromic element, wherein the pair of electrochromic materials have the same amount of electric charge as each other, and opposing portions are formed with different film thicknesses. 2. The transmission type electro-optical device according to claim 1, wherein the film thickness of the opposing portions of the electrochromic material is formed relatively thicker with a smaller absorption coefficient than with a larger one. Chromic element.