JP3518281B2 - Electrochromic anti-glare mirror - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention has an antiglare function,
The present invention relates to an antiglare mirror that can be used as a vehicle door mirror or the like, and more specifically to an electrochromic antiglare mirror that exhibits an antiglare function by utilizing electrochromism.

[0002]

2. Description of the Related Art Electrochromism is a phenomenon in which the color of a substance is reversibly changed by a redox reaction caused by application of a voltage. Conventionally, there is a mirror equipped with an electrochromic (hereinafter referred to as EC) element capable of causing this phenomenon, and E is provided on the front side of a light reflector that reflects light.
Generally, a C layer and a transparent glass that protects the EC layer from external mechanical stress are sequentially provided. This mirror is called an EC anti-glare mirror, and the translucency of the EC layer can be reversibly changed by coloring and erasing the EC layer by voltage application / removal operation, and an anti-glare effect can be exhibited as necessary. However, when water droplets such as raindrops adhere to the mirror surface of this EC anti-glare mirror, the incident light incident on the mirror or the reflected light reflected by the mirror is scattered by the water droplets, and the reflected image can be visually recognized clearly. I can not do it.

To address these problems, an EC anti-glare mirror has been proposed in which a heating element (heater) is provided on the back of a light reflector (JP-A-6-84437). In this EC anti-glare mirror, the water droplets adhering to the mirror surface can be evaporated and removed by the heat generated by the heating element. However, since the light reflector and the transparent glass that protects the EC antiglare layer are interposed between the heating element and the surface of the EC antiglare mirror, the heat generated from the heating element is transmitted to the surface of the mirror. Hateful. Further, if the temperature of the heat generated from the heating element is too high, the EC antiglare layer may be thermally deteriorated,
The amount of heat generated by the heating element cannot be increased. For these reasons, the EC anti-glare mirror disclosed in this publication cannot quickly evaporate water droplets attached to the surface of the mirror.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an EC anti-glare mirror capable of quickly evaporating water droplets adhering to a mirror surface.

[0005]

An EC anti-glare mirror according to claim 1, which solves the above-mentioned problems , reflects light and has an electric current.
A heat-generating light reflector that flows and generates heat, and a pair of heat-generating light reflectors
It is provided on the visible side of the reflected light and is transparent by the applied voltage.
Layer that reversibly changes, the heat generating light reflector and the EC layer
An insulating layer made of a transparent insulating material and provided between
And a transparent and thin protective layer provided on the viewing side of the reflected light with respect to the C layer .

[0006]

An EC according to claim 2 , which solves the above problems.
The anti-glare mirror is the EC anti-glare mirror according to claim 1 , wherein the protective layer comprises a titanium oxide layer made of titanium oxide and a silicon dioxide layer made of silicon dioxide. The E according to claim 3 , which solves the above problems.
The C antiglare mirror is the EC antiglare mirror according to claim 2 , wherein the surface of the protective layer is covered with a noble metal layer.

[0008]

DETAILED DESCRIPTION OF THE INVENTION First, it described embodiments of the EC antiglare mirror according to claim 1.

The heat-generating light reflector reflects light and allows a current to flow.
It is not particularly limited as long as it is heated and generates heat.
Yes. For example, aluminum on a substrate with a smooth surface
And metals such as silver, chrome and titanium, or nickel
Skin made of chrome alloy or nickel-titanium alloy
What formed the film layer can be used. In this example
Is placed with the surface with the coating layer facing toward the visible side of the reflected light.
Let The coating layer on the substrate reflects light and the current
It is washed away and heats up. The substrate used in this example is a metal
Limited as long as it has excellent mechanical strength such as glass and glass
It is not something that will be done. This heating light reflector is installed outside
An electric current can be passed from the power source to generate heat. E
The C layer is not particularly limited as long as the translucency changes reversibly with an applied voltage, and a known EC layer can be used. For example, the C layer is oxidized between a pair of transparent electrode layers. An EC layer having a multilayer structure in which a color forming layer, a solid electrolyte layer and a reducing color forming layer are sequentially arranged can be used. In this example, the transparent electrode layer is ITO (Indium.
Tin oxide) or tin dioxide (SnO ₂ ). The oxidative coloring layer can be composed of iridium oxide (IrO _x ) or nickel oxide (NiO). On the other hand, the reduction coloring layer can be made of tungsten oxide (WO ₃ ), molybdenum oxide (MoO ₃ ), vanadium oxide (V _X O _Y ), or the like. It should be noted that "coloring" includes transparency. The solid electrolyte layer is a solid state layer having an electrolytic component such as a water component, and is composed of, for example, ditantalum pentoxide (Ta ₂ O ₅ ), silicon oxide (SiO ₂ ), chromium oxide (Cr ₂ O ₃ ) and the like as a matrix. it can. The EC anti-glare layer may be arranged in any direction, i.e., the viewing side of the reflected light or the opposite direction.

The thickness of each layer constituting the EC layer can be appropriately selected according to each material. Further, in order to form these layers, known thin film forming means such as an electron beam evaporation method, a heating evaporation method, a sputtering method and an ion plating method can be used. The order of forming the EC layers is not particularly limited.

The coloration and decoloration of the EC layer can be carried out by applying a voltage between the pair of transparent electrode layers so that the oxidative coloring layer and the reducing coloring layer are colored. The voltage adding / removing operation can be performed by providing a power source that can arbitrarily control the voltage outside the mirror .

[0012]

The insulating layer is not particularly limited as long as it is made of a transparent insulating material. For example, Al ₂ O ₃ ,
SiC, SiN, Ta ₂ O ₅ , SiO ₂ , ZrO ₂ and Y ₂
A material such as O ₃ can be used. The thickness of this layer can be appropriately selected according to the insulating property and thermal conductivity. The protective layer is a transparent and thin layer.
Is a layer that protects the E C layer and the insulating layer from mechanical stress from the outside, moisture from the outside air, and the like. The material of this layer is not particularly limited, and may be a hard material such as silicon dioxide or a soft material having a cushioning property.

In particular, when the protective layer is made of a material having excellent hydrophilicity such as silicon dioxide, when a water drop adheres to the mirror surface, the water drop spreads. As a result, the contact area of the water droplet with respect to the mirror surface increases, and the heat generated from the heating element is easily transferred to the water droplet. Further, the maximum total amount of water droplets that can be attached to the mirror surface is reduced by forming the water film. Therefore, the water droplets adhering to the mirror surface can be quickly evaporated, the amount of water droplets adhering to the mirror surface can be reduced, and the efficiency of removing the water droplets adhering to the mirror surface becomes high.

As described above , the E C layer, the insulating layer and the protective layer can be respectively formed, but it is preferable that the respective layers are in contact with each other with good adhesion. This allows
Not only is the mechanical strength of the mirror increased, but the heat generated by the heat generating light reflector is easily transferred to the surface of the mirror. As described above , the EC anti-glare mirror in which the E C layer, the insulating layer and the protective layer are in close contact with each other using a well-known thin film forming means such as an electron beam evaporation method, a heat evaporation method, a sputtering method and an ion plating method. To form the respective layers. The order of forming the E C layer, the insulating layer, and the protective layer is not particularly limited.

[0016] In the EC anti-glare mirror according to claim 1, originating
The heat generated by the thermal light reflector is transmitted to the mirror surface without passing through the light reflector. Further, since the protective layer is thin, heat is easily transferred from the back surface to the front surface, and the temperature of the front surface can be quickly raised. For these reasons, the EC anti-glare mirror according to claim 1 can evaporate water droplets attached to the mirror surface more quickly than the conventional EC anti-glare mirror.

By the way, depending on the type of the EC layer, the response time of coloration / decoloration may be delayed in cold weather. When such an EC layer is used, the EC layer can be warmed to a temperature at which it operates properly by utilizing the heat generated by the heat- reflecting body .

[0018]

An embodiment of the EC anti-glare mirror according to claim 2 will be described below. The EC anti-glare mirror is the same as the EC anti-glare mirror according to claim 1, except that the protective layer includes a titanium oxide layer made of titanium oxide and a silicon dioxide layer made of silicon dioxide. It has the form of. In this EC anti-glare mirror, the silicon dioxide layer is preferably arranged so as to be a mirror surface. The protective layer may have a structure of two or more layers, and in addition to the titanium oxide layer and the silicon dioxide layer, the protective layer may be provided with a silicon dioxide layer, a titanium oxide layer, and a silicon dioxide layer. Further, the titanium oxide layer and the silicon dioxide layer are preferably in close contact with each other. This not only increases the mechanical strength of the mirror, but also facilitates the transfer of heat generated by the heat generating light reflector to the surface of the mirror.

In the EC anti-glare mirror according to the second aspect , since the silicon dioxide layer excellent in hydrophilicity is exposed, the reason is that water droplets attached to the mirror surface are easily evaporated and the mirror surface is as described above. It is possible to reduce the amount of water drops attached to the. By the way, if an organic substance such as hydrocarbon drifting in the air adheres to the surface of the silicon dioxide layer, its hydrophilicity is deteriorated. However, in this protective layer, the organic substances attached to the surface of the mirror by the titanium oxide layer can be decomposed and removed into water, carbon dioxide, etc. by a photocatalytic action. Therefore, even if an organic substance such as hydrocarbon floating in the air adheres to the surface of the silicon dioxide layer to reduce its hydrophilicity, the original hydrophilicity can be restored by shining light on the mirror surface. .

An embodiment of the EC antiglare mirror according to claim 3 will be described below. This EC anti-glare mirror has the same form as the EC anti-glare mirror described in claim 2 , except that the surface of the protective layer is coated with a noble metal. As the noble metal, platinum or palladium can be used. In the EC anti-glare mirror according to the third aspect , the photocatalytic ability of the titanium oxide layer can be further improved by the noble metal coating the surface of the protective layer. As a result, even if an organic substance such as hydrocarbon drifting in the air adheres to the mirror surface, it can be decomposed into water, carbon dioxide, etc. by a photocatalytic action faster than the EC anti-glare mirror according to claim 2. . Therefore, when the organic substances such as hydrocarbons floating in the air adhere to the surface of the silicon dioxide layer and the hydrophilicity of the mirror surface is lowered, the hydrophilicity is recovered more quickly.

In any of the EC antiglare mirrors according to claims 1 to 3 , the translucency of the EC layer is reversibly changed by changing the color of the EC layer by a voltage application / removal operation, and the antiglare layer is adjusted as necessary. The action can be expressed. Further, any EC anti-glare mirror may constitute all of the mirrors to be used, or may constitute a part of all.

[0023]

EXAMPLES The present invention will be specifically described below with reference to examples. Reference Example 1 An EC anti-glare mirror 100 of this reference example has a light reflector 110 that reflects light, as schematically shown in the cross section in FIG.
The first layer 120 is provided on the visible side of the reflected light of the light reflector 110 and has an EC layer whose translucency changes reversibly by an applied voltage, and is provided on the visible side of the reflected light with respect to the first layer 120. The second, which consists of a transparent heating layer that generates heat when an electric current is applied
The layer 130, the insulating layer 140 made of a transparent insulator provided between the first layer 120 and the second layer 130, and the second layer 13
An EC anti-glare mirror including a transparent and thin protective layer 150 provided on the viewing side of reflected light with respect to 0.

The light reflector 110 is a flat glass substrate 112.
With an aluminum coating 114 formed on a smooth surface
is there. The aluminum film 114 is formed by the sputtering method.
Was deposited. The first layer (EC layer) 120 is a pair of IT
IrO between the transparent electrode layers made of O _XOxidation of
Color layer, Ta₂O_FiveSolid electrolyte layer composed of WO and WO₃Than
The reduction coloring layer was formed in this order. These transparent phones
Each layer of electrode layer, oxidation coloring layer, solid electrolyte layer and reduction coloring layer
Are sequentially formed using a well-known electron beam evaporation system.
I made it. The pair of transparent electrode layers can be applied in any direction
An external power supply (not shown) that can be switched to
Has been done. This external power supply applies voltage to the transparent electrode layer.
The removal operation can be performed arbitrarily, and the oxidation coloring layer and reduction
Coloring of the EC layer can be performed by coloring the color layer.

The second layer (heating layer) 130 is made of ITO. Suitably the thickness of this layer is between 20 and 50 nm. It is appropriate that the sheet resistance is 30 to 100 Ω / cm ² , and the heat output is 40 to 120 mW / c.
m ² is suitable. An external power supply (not shown) capable of passing a current along the layer expansion direction is also connected to this layer. This external power source has a second layer 130 of 40 m.
An electric current that generates heat with a heating value of W / cm ² or more can be passed.

The insulating layer 140 is made of Al ₂ O ₃ . Suitably the thickness of this layer is between 20 and 30 nm. The protective layer 150 is made of SiO ₂ . The thickness of this layer is 10-20
nm is suitable. In the EC anti-glare mirror 100 of the present reference example, first, the light reflector 110 is prepared, and the first surface is provided on the surface opposite to the surface on which the aluminum film 114 is provided.
Layer 120, insulating layer 140, second layer 130, protective layer 150
Were sequentially formed by a sputtering method.

In the EC anti-glare mirror of this reference example, water droplets adhering to the mirror surface can be quickly evaporated and, in addition, ITO
The maximum total amount of water droplets that can adhere to the mirror surface can be reduced by 50% compared to the EC anti-glare mirror that is exposed. Reference Example 2 An EC anti-glare mirror 200 of this reference example has a light reflector 210 that reflects light, as schematically shown in its cross section in FIG.
A first layer 220, which is provided on the visible side of the reflected light of the light reflector 210 and has an EC layer whose translucency changes reversibly according to an applied voltage, and the first layer 220 is provided on the visible side of the reflected light. The second, which consists of a transparent heating layer that generates heat when an electric current is applied
The layer 230, the insulating layer 240 made of a transparent insulator provided between the first layer 220 and the second layer 230, and the second layer 23.
0, a transparent and thin protective layer 250 provided on the visible side of reflected light, and the protective layer 250 is a titanium oxide layer 252 made of titanium oxide, and the reflected light is visually recognized with respect to the titanium oxide layer 252. An EC anti-glare mirror including a silicon dioxide layer 254 provided on the side and made of silicon dioxide.

The light reflector 210 is formed by forming an aluminum film 214 on a smooth surface of a glass substrate 212, and the aluminum film 214 is arranged so as to face the visible side of reflected light. The aluminum film 214 was formed by a sputtering method. First layer 220 and insulating layer 240
Is the same as that of the EC anti-glare mirror of Reference Example 1.

The second layer (heat generating layer) 230 is made of ITO. Suitably the thickness of this layer is between 40 and 60 nm. It is appropriate that the sheet resistance is 20 to 30 Ω / cm ² , and the heat output is 40 to 120 mW / cm 2.
² is appropriate. The titanium oxide layer 252 is 100
The silicon dioxide layer 254 has a thickness of
It has a layer thickness of 2 nm. Both layers were formed by the vapor deposition method.

In the EC anti-glare mirror of this reference example, water droplets adhering to the mirror surface can be quickly evaporated, and at the same time, organic substances such as hydrocarbons floating in the air are EC of Example 1.
The maximum total amount of water droplets that can adhere to the mirror surface can be reduced by 40 to 50% compared to the case where the water drops adhere to the surface of the antiglare mirror. Reference Example 3 An EC anti-glare mirror 300 of this reference example has a light reflector 310 that reflects light, as schematically shown in the cross section in FIG.
The first layer 320, which is provided on the visible side of the reflected light of the light reflector 310 and includes an EC layer whose translucency changes reversibly according to the applied voltage, and the first layer 320 is provided on the visible side of the reflected light. The second, which consists of a transparent heating layer that generates heat when an electric current is applied
The layer 330, the insulating layer 340 made of a transparent insulator provided between the first layer 320 and the second layer 330, and the second layer 33.
0, a transparent and thin protective layer 350 provided on the visible side of reflected light, and the protective layer 350 includes a titanium oxide layer 352 made of titanium oxide and a silicon dioxide layer 354 made of silicon dioxide, Moreover, the surface of the protective layer 350 is covered with the noble metal layer 360.

Light reflector 310, first layer 320, second layer 3
30, the insulating layer 340 and the protective layer 350 are E of Reference Example 2 .
C It is the same as that of the anti-glare mirror. Noble metal layer 360
Is Pt. This layer was formed by vapor deposition. The thickness of the noble metal layer 360 is suitably 0.1 nm or less. (Embodiment 1 ) The EC anti-glare mirror 400 of the present embodiment has a heat generating light reflector 410 that reflects light and generates heat when an electric current is passed, as shown in the cross section of FIG. An EC layer 420, which is provided on the viewing side of the reflected light with respect to the reflector 410 and whose translucency changes reversibly by an applied voltage, and the heat generation light reflector 41.
0 and the EC layer 420, and an insulating layer 430 made of a transparent insulator, and a transparent thin protective layer 440 provided on the visible side of the EC layer 420 for reflected light.
C is an anti-glare mirror.

The heat-generating light reflector 410 is composed of a glass substrate 412.
An alloy film 414 of nickel and chromium was formed on the smooth surface of No. 3, and the alloy film 414 was arranged toward the visible side of the reflected light. The layer thickness of the alloy film 414 is 50 to
A suitable value is 100 nm, and the sheet resistance is 2
It is suitable to be in the range of 0 to 30 Ω / cm ² . EC layer 42
0 and the insulating layer 430 are the same as those of the EC anti-glare mirror of Reference Example 1, respectively.

The protective layer 440 is composed of a titanium oxide layer 442 made of titanium oxide and a silicon dioxide layer 444 made of silicon dioxide and provided on the visible side of the titanium oxide layer 442 for reflected light. Note that when a photocatalytic action occurs in the titanium oxide layer 442, free electrons are generated in that layer. An insulating layer 446 made of SiO ₂ is provided between the titanium oxide layer 442 and the EC layer 420 so that the free electrons do not affect the EC layer 420.

The EC anti-glare mirror 400 of this embodiment is
A heat generating light reflector 410 is prepared, and an insulating layer 430 and an EC layer 42 are formed on the surface of the alloy film 414 of nickel and chromium.
0, the insulating layer 446, the titanium oxide layer 442, and the silicon dioxide layer 444 were sequentially formed by a vapor deposition method. (Embodiment 2 ) An EC anti-glare mirror 500 of this embodiment is a door mirror mounted on the right side of a vehicle as schematically shown in Fig. 5, and is a portion surrounded by a square line (A portion). Reference Example 1
3 to 3 and the first embodiment, the EC anti-glare mirror is formed in the same layer form. Point B is the center of curvature of the mirror. In portions other than the A portion, a light reflector that reflects light, an EC layer, and transparent glass that protects the EC layer from external mechanical stress are sequentially provided on the visible side of the reflected light of the light reflector. Consists of

In many cases, the driver of the vehicle visually confirms the reflected image reflected on the A section from behind. Therefore, the antiglare effect is most required in the A part. In the door mirror of the present embodiment, when water droplets such as raindrops adhere to the mirror surface, A
It is possible to quickly evaporate the water droplets attached to the part. Therefore, the reflection image displayed on the A portion can always be clearly recognized, and the rearward confirmation can be surely performed.

With such a structure of the door mirror, the manufacturing cost of the door mirror can be reduced.

[0037]

When the EC anti-glare mirror according to claim 1 is used for a vehicle door mirror, the following effects can be obtained. When the driver drives the vehicle in the rain, raindrops attached to the door mirror can be quickly evaporated, so that the rearward confirmation by the door mirror can be reliably performed, and the vehicle can be driven more safely.

Further, in the case where the mirror surface has a high hydrophilicity, even if the mirror surface is fogged, a water film is immediately formed and spread to form a water film, so that light scattering due to water droplets can be prevented and an anti-fog effect can be obtained. . Furthermore, since the heat generated by the heat generating light reflector can be efficiently used to evaporate the water droplets attached to the mirror surface,
It is possible to save the power used for heat generation of the heat generating light reflector .

Further , the light reflector and the heat generating layer are separately provided.
Compared with the EC anti-glare mirror (the EC anti-glare mirror shown in the reference example) , the number of constituent layers can be further reduced, so that the mirror can be made thinner and lighter. Moreover, since the number of steps for forming the layer can be reduced by one, the manufacturing cost can be reduced.

When the EC anti-glare mirror according to claim 2 is used for a vehicle door mirror, the following effect is obtained in addition to the effect obtained with the EC anti-glare mirror according to claim 1 . With this EC anti-glare mirror, even if the hydrophilicity of the mirror surface decreases due to the adhesion of organic substances such as hydrocarbons floating in the air to the surface of the silicon dioxide layer, the original hydrophilicity can be restored by applying light to the mirror surface. Since it can be recovered, raindrops adhering to the door mirror can be quickly evaporated and the anti-fog effect can be permanently obtained.

When the EC anti-glare mirror according to claim 3 is used for a vehicle door mirror, the following effect is obtained in addition to the effect obtained with the EC anti-glare mirror according to claim 2 . In this EC anti-glare mirror, it is possible to recover hydrophilicity when an organic substance such as hydrocarbon floating in the air adheres to the surface of the silicon dioxide layer to reduce the hydrophilicity of the mirror surface.
Since it is even faster than the EC anti-glare mirror described in 2 , the raindrops adhering to the door mirror can be quickly evaporated and the anti-fog effect can be more quickly obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view schematically showing a cross section of an EC antiglare mirror of Reference Example 1.

FIG. 2 is a schematic sectional view schematically showing a section of an EC antiglare mirror of Reference Example 2.

FIG. 3 is a schematic sectional view schematically showing a section of an EC antiglare mirror of Reference Example 3.

FIG. 4 is a schematic sectional view schematically showing a section of the EC anti-glare mirror of Example 1 .

FIG. 5 is a diagram schematically showing the front of the EC anti-glare mirror of Example 2 .

[Explanation of symbols]

100: EC anti-glare mirror 110: Light reflector 112:
Glass substrate 114: Aluminum film 120: First
Layer 130: Second layer 140: Insulating layer 150: Protective layer
410: Heat generating light reflector 420: EC layer 430: Absolute
Edge layer 440: protective layer

Claims (3)

(57) [Claims] 1. A heat-generating light reflector that reflects light and generates heat when an electric current is applied, and a heat-transmitting light reflector provided on the visible side of the reflected light and having a reversible translucency by an applied voltage. An electrochromic layer that changes to, an insulating layer that is provided between the exothermic light reflector and the electrochromic layer and that is made of a transparent insulator, and that is provided on the visible side of the reflected light with respect to the electrochromic layer, An electrochromic antiglare mirror comprising: a transparent and thin protective layer. 2. The electrochromic antiglare mirror according to claim 1, wherein the protective layer comprises a titanium oxide layer made of titanium oxide and a silicon dioxide layer made of silicon dioxide. 3. The electrochromic antiglare mirror according to claim 2 , wherein the surface of the protective layer is coated with a noble metal layer.