JPH0968729A - All-solid-state electrochromic device - Google Patents

Abstract

(57) An object of the present invention is to provide an all-solid-state ECD that can be viewed as an integral image without the display of the all-solid-state ECD appearing floating on the image formed on the screen. SOLUTION: This is an all-solid-state type formed by patterning at least a pair of electrode layers sandwiching an electrochromic layer on a substrate, and a display section by patterning the electrochromic layer, the electrode layer, or both. An all-solid-state electrochromic element, which is an electrochromic element, wherein the encapsulant for encapsulating the element surface of the element substrate and the encapsulant in the protective substrate are scattering opaque resins.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-solid-state electrochromic device used for displaying on an image-forming optical system screen.

[0002]

2. Description of the Related Art A phenomenon in which a reversible electrolytic oxidation or electrolytic reduction reaction occurs when a voltage is applied to cause reversible coloring is called electrochromism. By using an electrochromic (hereinafter sometimes abbreviated as EC) substance that causes such a phenomenon, an EC element (hereinafter,
It has been tried for about 20 years or more to make an ECD) and use this ECD for a light quantity control element (for example, a light control glass or an antiglare mirror) or a numerical display element using 7 segments. It's been done from before.

For example, an ECD (Japanese Patent Publication No. 52-46098) formed by sequentially laminating a transparent electrode film (cathode), a tungsten trioxide (WO ₃ ) thin film, an insulating thin film such as silicon dioxide, and an electrode film (anode) on a glass substrate. (See) is an all-solid-state EC
Known as D. When a voltage (coloring voltage) is applied to this all-solid-state ECD, the tungsten oxide (WO ₃ ) thin film layer is colored blue. When the leakage current is very small, this coloring state is maintained for a long time even if the application of voltage is stopped (called memory property). After that, when a reverse voltage (decoloring voltage) is applied to this ECD or the pair of electrodes is short-circuited, the blue color of the WO ₃ thin film disappears and becomes colorless.

The mechanism of this color fading and decoloring has not been clarified in detail, but it is considered that a small amount of water contained in the WO ₃ thin film and the insulating film (ion conducting layer) controls the color fading and coloring of WO ₃ . It is understood and the reaction equation for coloring is estimated as:

[0005]

[Equation 1]

Therefore, in this type of ECD, (1) the water content is consumed by the undesirable side reaction of oxygen gas generation during the coloring reaction, and (2) water is not generated by the reverse bleaching reaction. The feature is that replenishment of water from the atmosphere is required for repeated coloring. In particular, due to the latter feature (2), this type of ECD has a problem that the reproducibility of coloring is affected by atmospheric moisture.

Therefore, the same amount of water as the amount of water consumed by the coloring reaction is produced by the decoloring reaction, so that the coloring and decoloring can be repeated without replenishing the water from the outside,
Moreover, an all-solid-state ECD has been proposed in which the concentration of repeated coloring is not affected by the external environment (Japanese Patent Laid-Open No. 52-737).
49). This all-solid-state ECD is basically a transparent electrode film, an electrolytic reduction coloring thin film (EC layer such as WO
₃ ), electrolytic oxidation coloring thin film (EC layer, eg Cr
₂ O ₃ ) and a counter electrode are sequentially laminated.

According to the disclosure of the above-mentioned publication, when the voltage is released after coloring by applying a voltage, there is a phenomenon that the coloring gradually disappears due to spontaneous discharge, so that the coloring is preserved even after the voltage is released. In order to provide this all-solid-state ECD, it is necessary to provide an electronic insulating film (for example, a thin film of silicon dioxide, magnesium fluoride, etc.) between the transparent electrode and the counter electrode. .

According to Japanese Patent Publication No. 62-52845,
This insulating film is not a good conductor for electrons but a good conductor for protons or hydroxy ions, that is, it is presumed to be an ion conductive film (layer). Further, according to the disclosure of the above publication, it is most desirable that the insulating film (ion conductive layer) be present between the electrolytic reduction coloring thin film and the electrolytic oxidation thin film, and the electrolytic reduction coloring thin film and the electrolytic oxidation coloring thin film. It is said that it has been found that it is not necessary for both of them to be colored, and it is sufficient for one of them to be colored so that the change can be discriminated from the outside.

A pair of electrodes that directly or indirectly sandwich the EC layer.
The polar layer is at least necessary to show the color of the EC layer to the outside.
One must also be transparent. Especially transparent ECD
In this case, both electrode layers must be transparent. Transparent
SnO is currently used as a good electrode material.₂, In
₂O_Three, ITO (In₂O _ThreeAnd SnO₂Mixture), ZnO
It is known that these materials have relatively high transparency.
It must be thin because it is low, and for this reason and other
For reasons ECD is a substrate (eg glass plate or plastic
Plate), for example, vapor deposition, ion plating,
Formed by vacuum thin film forming technology such as puttering
Is normal.

Depending on the application, the ECD is used by arranging a protective substrate so as to face the element substrate in order to protect the element and hermetically sealing it with, for example, an epoxy resin. By the way, a display element using an electric element is an EC
Various proposals have been made, such as those utilizing D and liquid crystal, and liquid crystal has already been put to practical use. Although the display element using the ECD has been put to practical use late, it has excellent characteristics that liquid crystal does not have, such as being able to continuously control the display transmittance over a wide range. The ECD can be roughly classified into a solution type, a gel type, an all solid type, and the like depending on the material form of each layer constituting the ECD. Among them, the all solid type ECD is an EC layer,
Each layer such as an electrolyte layer and an electrode layer is continuously formed in a thin film shape.

Therefore, the all-solid-state ECD is considered to be the most reliable type without fear of liquid leakage.

[0013]

However, when the all-solid-state ECD is arranged behind a screen for imaging optical system (hereinafter abbreviated as screen) and used as a display element on the screen, the There is a problem in that the display of the all-solid-state ECD appears to be raised with respect to the image formed on the display, and the user feels something strange.

Therefore, an object of the present invention is to provide an all-solid-state ECD in which the display of the all-solid-state ECD can be seen as an integrated image without the display of the all-solid-state ECD appearing floating with respect to the image formed on the screen. is there.

[0015]

In the present invention, firstly, "a pair of electrode layers sandwiching at least an electrochromic layer on a substrate, and a display portion is the electrochromic layer, the electrode layer, or An all-solid-state electrochromic element formed by patterning both, wherein the encapsulant for encapsulating the element surface of the element substrate and the encapsulant of the protective substrate are scattering opaque resins. An all-solid-state electrochromic device (claim 1) "is provided.

The second aspect of the present invention is that "the scattering opaque resin is an adhesive in which an inorganic substance, an organic substance, or both are dispersed, or an adhesive sheet. A solid-state electrochromic device (claim 2) is provided.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As a result of earnest research, the inventor of the present invention formed an image on a screen because a parallax is generated due to a difference between the image forming position of an image forming optical system and the display position of an all-solid-state ECD. It was found that the display of the all-solid-state ECD appears to rise to the image. That is, by bringing the image forming position (screen position) of the image forming optical system and the display position of the all-solid-state ECD close to each other (ultimately making them coincide with each other), it is possible to reduce the parallax between the two and reduce the floating phenomenon of the display. They have found the present invention and made the present invention.

The all-solid-state ECD has a structure in which the element surface is sealed by a protective substrate such as glass and a sealing resin (sealing agent) to protect the element surface. For example, when an all-solid-state ECD is used as the display element of the focusing screen (screen) of the camera, the configuration is as shown in FIG. That is, when such an all-solid-state ECD is arranged behind the screen and used as a display element on the screen, a difference in focus position occurs due to the thickness of the sealing resin and the protective substrate.

Even if the screen is not provided in front of the all-solid-state type ECD and the screen function is added to the protective substrate, the focus position is different by the thickness of the sealing resin. In the present invention, the function of the screen can be added to the all-solid-state ECD by making the sealing resin scattering and opaque. Therefore, it is not necessary to provide the screen in front of the all-solid-state ECD, and the image forming optical system The all-solid-state ECD having a small difference between the focus positions and the parallax can be provided because the difference in distance between the image formation position and the display position of the all-solid-state ECD can be made substantially zero.

A colorless and transparent resin is generally selected as the encapsulating resin, but a colored resin may be used depending on the case. An adhesive may be used as the sealing resin, and an acrylic, epoxy, silicone, polyurethane, polyester, or other adhesive may be used. As a method of making the sealing resin layer scattering and opaque, there are a method of dispersing appropriate fine particles in the resin and a method of making the resin opaque and scattering by utilizing a polymerization reaction of the resin itself.

In the case of a method of dispersing appropriate fine particles to make the sealing resin layer scattering and opaque, fine particles that scatter white are generally preferable for forming a screen, but in some cases, a color other than white scattering may be used. I don't care. The types of fine particles to be dispersed are generally inorganic materials such as silicon oxide,
Examples thereof include aluminum oxide, titanium oxide, zirconium oxide, tantalum oxide, tungsten oxide, magnesium oxide, vanadium oxide, molybdenum oxide and the like. Also,
Examples of organic substances include CR39, polythiourethane, polycarbonate, polymethylmethacrylate, polystyrene, mixed polymers and copolymers thereof.

The type of fine particles to be dispersed depends on the sealing resin used. In order to be used as a screen, the difference in refractive index between the sealing resin and the fine particles needs to be 0.01 or more, preferably 0.05 or more. Also,
The particle size of the fine particles to be dispersed is 1 to 500 μm, preferably 10 to 30 μm.

If it is smaller than 1 μm, a sufficiently scattered and opaque state cannot be obtained and it cannot be used as a screen. On the other hand, if it is larger than 500 μm, the image becomes rough and a high-quality image cannot be obtained. The sealing thickness is 1 to 100 μm, preferably 1 to 10 μm. If it is thinner than 1 μm, the sealing strength becomes weak, and if it is thicker than 100 μm, an image cannot be clearly formed.

In order to be used as a screen, a combination of a sealing resin, fine particles dispersed in the sealing resin, and a sealing thickness is important, and the light transmittance is 50 to 95%, preferably 70 to 90. The dispersion mixing ratio is adjusted so as to be%. If it is made too opaque, it becomes dark and the image becomes difficult to see. Further, if the scattering and opacity are not sufficient, the contrast of the image cannot be obtained, which makes it difficult to see.

As described above, the kind of fine particles to be dispersed,
The particle size is not limited to one type, and a combination of two or more types may be used. Further, the shape of the fine particles is not always spherical. The laminated structure of the all-solid-state ECD in the present invention is not particularly limited, but for example, a four-layer structure such as an electrode layer / EC layer / ion conducting layer / electrode layer, in this case, an EC layer and an ion layer. The conductive layer may be either upside or downside.

Further, a reversible electrolytic oxidation layer or a catalyst layer may be arranged between the EC layer and an ion conducting layer (which also serves as an oxidation coloring EC layer in some cases) between the EC layer and the electrode layer / reduction coloring. Examples include a five-layer structure such as a type EC layer / ion conduction layer / reversible electrolytic oxidation layer / electrode layer. Tungsten trioxide, molybdenum trioxide, etc. are generally used for the reduction coloring type EC layer.

The ion conducting layer includes, for example, silicon oxide,
Tantalum oxide, titanium oxide, aluminum oxide, niobium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, magnesium fluoride, etc. are used. The ion conducting layer, which is an insulator for electrons, has protons (H ⁺ )
And it is a good conductor for hydroxy ion (OH ⁻ ). Cations are required for the coloring reaction of the EC layer, and H
It is necessary to add ⁺ or Li ⁺ to the EC layer or the like.

H ⁺ and Li ⁺ do not have to be ions from the beginning and H ⁺ may be generated when a voltage is applied. Therefore, water may be contained instead of H ⁺ . This water is very small and sufficient, and often discolors even with water that naturally enters from the atmosphere. For the reversible electrolytic oxidation layer, for example, iridium oxide or hydroxide, nickel, chromium, vanadium, ruthenium, rhodium, etc. are used. These substances may be dispersed in the ion conducting layer or the transparent electrode layer, or vice versa.

The pattern corresponding to the display portion can be formed by patterning an electrode layer, a reduction coloring type EC layer, a reversible electrolytic oxidation layer or two or more layers thereof by lift-off, etching, printing or the like.

[0030]

The present invention will be specifically described below with reference to Examples and the drawings. The present invention is not limited to this. [Embodiment 1] FIG. 1 shows an all-solid-state EC produced in this embodiment.
It is a vertical sectional view of D.

Thickness 0.2 μ carried on glass substrate 1
An electrode gap 3 was formed on the transparent electrode (ITO) 2 of m by a known wet process. Ion plating method (oxygen gas pressure 1
˜5 × 10 ⁻⁴ Torr, RF output 0 to 600 W, vapor deposition rate 0.1 to 2 × 10 ⁻⁴ μm / sec), and a thickness of about 0.1.
μm Ir—Sn oxide mixture (Ir atomic mixing ratio 5-7
0%) of the display pattern 4 was formed in the lift-off process.

On the above substrate, an ion plating method (oxygen gas pressure 1 to 6 × 10 ^-4 Torr, RF output 0 to 6) was used.
A transparent film 5 of tantalum pentoxide having a thickness of about 0.7 μm was formed at a deposition rate of 00 W and a vapor deposition rate of 0.1 to 4 × 10 ⁻⁴ μm / sec. Then, a vacuum deposition method (oxygen gas pressure 1 to 5 × 1
0 ^-4 Torr, deposition rate 0.1 to 2 × 10 ^-4 μm / sec)
As a result, a transparent film 6 of tungsten trioxide having a thickness of about 0.6 μm was formed.

Further, the thickness of the above substrate was measured by an ion plating method (oxygen gas pressure 1 to 4 × 10 ⁻⁴ Torr, RF output 0 to 600 W, vapor deposition rate 1 to 8 × 10 ⁻⁴ μm / sec). An ITO transparent electrode 7 having a thickness of about 0.2 μm was formed. Aluminum oxide (refractive index 1.75, particle size 20 μm)
Using an epoxy adhesive (refractive index 1.54) 8 in which is dispersed (weight ratio 10%), a protective glass 9 having an adhesive thickness of 10 μm
Then, it was sealed and adhered to prepare an all-solid-state ECD.

The prepared all-solid-state ECD is placed at the image-forming position of the image-forming optical system to project an image, and at the same time, the all-solid-state ECD is formed.
No difference in focus between the image and the all-solid-state ECD display was observed. [Comparative Example 1] FIG. 2 is an all-solid-state EC prepared in this Comparative Example.
It is a vertical sectional view of D.

Thin films were laminated in the same manner as in Examples 1 to 3. Then, an epoxy adhesive (refractive index 1.54) 10 was used to hermetically adhere the cover glass 9 with an adhesive thickness of 10 μm to produce an all-solid-state ECD. The all-solid-state ECD produced is combined with a screen, placed at the image-forming position of the image-forming optical system, and an image is projected on the screen.
Image display position and all-solid-state ECD
The difference in focus from the display position of was observed.

[Comparative Example 2] FIG. 3 is a vertical sectional view of an all-solid-state ECD prepared in this Comparative Example. Of Example 1
The thin films were laminated in the same manner as in. Next, a screen (diameter of surface irregularities: 20 μm, depth of irregularities: 3 μm) 12 produced by injection molding using an epoxy adhesive (refractive index 1.54) 11
Was sealed and adhered with an adhesive thickness of 10 μm to prepare an all-solid-state ECD.

The produced ECD was placed at the image forming position of the image forming optical system, an image was projected, and at the same time, display was carried out by the all-solid-state ECD. Focusing between the image forming position and the display position of the all-solid-state ECD Difference was observed.

[0038]

As described above, according to the present invention, all-solid-state E
By mixing fine particles (scatterers) in the CD sealing resin to form a screen, the image displayed on the screen and the display position of the all-solid-state ECD can be displayed without a difference in focus. It is possible, and the display of the all-solid-state ECD does not appear to be raised with respect to the image formed on the screen, and no discomfort is felt.

Since the display function and the screen function can be integrated by adding the screen function to the all-solid-state ECD, the number of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a vertical cross section of an all-solid-state ECD shown in Example 1.

FIG. 2 is a conceptual diagram showing a vertical cross section of the all-solid-state ECD shown in Comparative Example 1.

FIG. 3 is a conceptual diagram showing an all-solid-state vertical cross section of ECD shown in Comparative Example 2.

FIG. 4 is a layout diagram when a conventional all-solid-state ECD is used as a display element of a focusing screen of a camera.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... ITO transparent electrode 3 ... Electrode gap 4 ... Display pattern sealing resin with Ir / Sn mixed oxide 5 ... Tantalum pentoxide 6 ... Tungsten trioxide 7・ ・ ・ ITO transparent electrode 8 ・ ・ ・ Aluminum oxide dispersed epoxy adhesive 9 ・ ・ ・ Protective glass 10 ・ ・ ・ Epoxy adhesive 11 ・ ・ ・ Screen by injection molding

Claims (2)

[Claims] 1. An all-solid-state formed by patterning at least a pair of electrode layers sandwiching an electrochromic layer on a substrate, and a display section of the electrochromic layer, the electrode layer, or both. All-solid-state electrochromic device, wherein the encapsulant for encapsulating the element surface of the element substrate and the encapsulant of the protective substrate are resins that are scattering and opaque. 2. The all-solid-state electrochromic device according to claim 1, wherein the scattering opaque resin is an adhesive in which an inorganic substance, an organic substance, or both are dispersed, or an adhesive sheet.