JPH0345218Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to an improvement in an anti-glare mirror that can adjust the amount of reflected light by applying a voltage.

(Background of the idea) Car rear-view mirrors are equipped with electrochromic (hereinafter abbreviated as EC) lights on the mirrors because drivers feel dazzled when the lights of cars behind them are reflected at night.
A display device is installed, and the amount of reflected light is adjusted by electrically coloring and decolorizing this EC display device (hereinafter referred to as ECD), and when night lights are reflected, the ECD
An anti-glare mirror has been proposed that reduces the amount of reflected light by coloring the ECD and increases the amount of reflected light (that is, brightens it) by decolorizing the ECD at other times, including during the day (see Utility Model Application No. 58-21120). .

ECD is basically a thin film of EC material such as WO ₃ sandwiched between a pair of electrode layers, at least one of which is transparent. When a voltage of approximately 1.4 volts is applied between these electrodes, the WO ₃ thin film turns blue. It is colored, and the coloring is maintained even when the voltage is stopped, and when the same level of reverse voltage is applied, the color disappears and returns to its original colorless and transparent state.
The decolorization is maintained even if the application of the reverse voltage is stopped.

By the way, when ECD is left in a decolored state without applying a decoloring voltage, it exhibits a photochromism phenomenon in which it naturally becomes colored when exposed to sunlight. Therefore, if you try to drive after leaving your car alone for a long time during the day, the ECD anti-glare mirror may be inadvertently tinted, making it difficult to see the rear view, which can be dangerous. I found out something.

(Purpose of the invention) Therefore, the purpose of the invention is to prevent the situation where the anti-glare mirror becomes tinted and becomes inadvertently difficult to see when driving again after leaving the car alone for a long time during the day. There is a particular thing.

(Summary of the invention) Therefore, the present invention consists of a reflective layer, an upper electrode that may or may not be used as the reflective layer, an electrochromic layer, and a transparent lower electrode, and a voltage is applied between the transparent lower electrode and the upper electrode. In an anti-glare mirror that can control the amount of reflected light by To provide an anti-glare mirror characterized by being provided with a circuit.

In the present invention, the ECD used is not particularly limited as long as it has memory properties; for example, voltage/EC layer/transparent ion conductive layer or electrolyte (electrolyte may be used) layer. / Voltage = 4-layer structure = Voltage / Reduction coloring EC layer, for example WO ₃ / Transparent ion conductive layer or electrolyte (or electrolyte) layer /
A five-layer structure consisting of an oxidative color-forming EC layer, a reversible electrolytic redox layer, and a catalyst layer/electrode is preferably used. Cations are required for the coloring and decoloring reaction of the EC layer, and it is necessary to contain H ⁺ ions and Li ⁺ ions in the EC layer and other parts. H ⁺
The ions do not have to be ions from the beginning, but only H ⁺ ions are generated when a voltage is applied. Therefore, water may be contained instead of H ⁺ ions.
Very little of this water is sufficient and often
Even moisture that naturally enters from the atmosphere can cause discoloration.

Examples of materials for the lower transparent electrode include SnO ₂ ,
In ₂ O ₃ , ITO (indium oxide mixed with about 5% tin oxide), etc. are used.

WO ₃ is generally used as the reduction color-forming EC substance.

As the transparent ion conductive layer, for example, silicon oxide, tantalum oxide, titanium oxide, aluminum oxide, niobium oxide, zirconium oxide, hafnium oxide, lanthanum oxide, magnesium fluoride, etc. are used. These thin films of materials become insulators against electrons when they contain a small amount of water during manufacturing, but
It is a good conductor for protons (H ⁺ ) and hydroxy ions (OH ^- ). An electrolyte or an electrolytic solution may be used as the ion conductive layer or in its place, such as sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid,
Used are acids such as butyric acid and oxalic acid or aqueous solutions thereof, aqueous alkali solutions such as sodium hydroxide and potassium hydroxide, and aqueous solutions of sodium chloride, potassium chloride, lithium chloride, lithium sulfate, and the like. Further, an electrolyte or an aqueous electrolyte solution gelled with a gelling agent such as PVA, CMC, agar, gelatin, etc. may also be used. Furthermore, synthetic resins containing water or having hydroxyl or carboxyl groups, such as copolymers of β-hydroxyethyl methacrylate and other vinyl monomers, copolymers of 2-acrylamide-2-methylpropanesulfone and other vinyl monomers, etc. Polymers, polyacrylic acids, hydrous polyesters, etc. can also be used.

Li ⁺ ions may be used instead of H ⁺ ions, in which case lithium salts such as LiClO ₄ and LiBF ₄ can be used in combination with methanol, ethanol, ethylene glycol, ethyl cellosolve, tetrahydrofuran, acetonitrile, pyridine, γ-butyrolactone,
dimethyl sulfoxide, dimethyl formamide,
in a solvent such as propylene carbonate or a solid lithium electrolyte such as Li ₂ WO ₄ ,
Li ₃ N, LiN, etc. are used.

Examples of the oxidative color-forming EC layer or reversible electrolytic redox layer or catalyst layer that may be used include iridium oxide or hydroxide, nickel, chromium, vanadium, ruthenium, rhodium, and the like. These materials may also be dispersed in other transparent ionic conductors or transparent electrode materials. In any case, it must be colorless and transparent when no voltage is applied, and colorless and transparent or colored when a voltage is applied.

The upper electrode may also serve as a reflective layer thereon, in which case metals such as gold, silver, aluminum, chromium, tin, zinc, nickel, ruthenium, rhodium, and stainless steel are used. If they are not used together, a transparent electrode material must be used.

As the optional reflective layer, the metals mentioned above are used.

Note that light enters from the transparent lower electrode side and is reflected by the reflective layer.

Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto.

(Embodiment) FIG. 1 is a block diagram showing the overall structure of an anti-glare mirror according to the present embodiment, particularly the electric circuit.

Here, 1 is an ECD that serves as the reflective layer and upper electrode of the mirror, 2 is a driving power source, 3 is a switch circuit for driving the ECD 1, and 4 is a light source for the following car. It is a light sensor that detects when the image is reflected in the mirror.
is a comparison circuit that compares the light detected by the optical sensor 4 with the reference light amount, determines whether it is strong enough to dazzle, and issues a coloring command if it is strong, and decolors it if not. issue an order.

On the other hand, 6 is a starting switch of the car, 7 is a detection circuit that detects when the starting switch 6 is turned on, and 8 is a refresh signal generation circuit that is activated when a signal indicating that the detection circuit 7 has detected is input. It is. These 7 and 8 constitute the refresh circuit of the present invention.

At night, when the lights of the following vehicle are reflected on this mirror, the sensor 4 detects this, and the comparison circuit 5 determines whether or not it is dazzling. If it is dazzling, the switch circuit 3 opens and the power is switched from the power supply 2 to the ECD 1. A coloring voltage is sent to the ECD 1, which colors the light and reduces the amount of reflected light, resulting in less glare.

On the other hand, when the starting switch 6 of the car is turned on, the detection circuit 7 detects this and sends a signal to the refresh signal generation circuit 8, which then generates a refresh signal, and according to that signal, the switch circuit 3 turns on the power supply. 2 to ECD 1 for a short time, for example, 0.5 to 5 seconds. Thereby, ECD1 may have been colored due to photochromism.
is decolored and refreshed, and the mirror returns to its normal state. Note that the erasing voltage for refreshing is referred to as a refresh signal here, but this refresh signal is not only a simple erasing voltage, but may also be a voltage application pattern that alternately repeats erasing and coloring. In this case, it is possible to check whether the anti-glare mirror operates normally.

FIG. 2 is an explanatory diagram schematically showing the cross-sectional structure of the ECD.

On a transparent substrate S made of glass, plastic, etc., an ITO thin film is used as the transparent lower electrode E, an iridium hydroxide thin film is used as the oxidation color-forming EC layer D, and a tantalum oxide thin film containing a trace amount of water is used as the transparent ion conductive layer C, and a reduced tantalum oxide thin film is placed on the transparent substrate S made of glass, plastic, etc. WO ₃ thin film as color-forming EC layer B;
Al thin films are sequentially laminated as the upper electrode A, which also serves as a reflective layer, and a glass plate G is further layered on top of it for protection.
is glued.

(Effects of the invention) As described above, according to the invention, an anti-glare mirror that has been inadvertently colored due to photochromism or other causes is automatically decolored in conjunction with the start of the car's engine. when trying to drive
There is no need to worry about the ECD anti-glare mirror becoming inadvertently colored and making it difficult to see the scenery behind you.

Also, in this way, each time the car is started, the ECD
is driven, eliminating the problem of performance degradation that would occur if the ECD was left unused for a long period of time.

Furthermore, if the refresh signal is set to a voltage application pattern that alternately repeats decoloring and coloring,
You can also check if the ECD is working properly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall structure, particularly the electric circuit, of an anti-glare mirror according to an embodiment of the present invention. FIG. 2 is an explanatory diagram schematically showing the cross-sectional structure of the ECD used in the example. Explanation of symbols of main parts, 1...ECD, 2...
Drive power supply, 3... Switch circuit, 4... Light sensor, 5... Comparison circuit, 6... Start switch, 7...
...Detection circuit, 8...Refresh signal generation circuit,
{G... Protective glass plate, A... Upper electrode that also serves as a reflective layer, B... Reduction color-forming EC layer, C... Transparent ion conductive layer, D... Oxidation color-forming EC layer, E...
Transparent lower electrode, S...transparent substrate}1

Claims (1)

[Claims for Utility Model Registration] Consists of a reflective layer, an upper electrode that may or may not be used as the reflective layer, an electrochromic layer, and a transparent lower electrode, and a voltage is applied between the transparent lower electrode and the upper electrode. An anti-glare mirror that can control the amount of reflected light by means of a refresh circuit that temporarily applies a decoloring voltage between the transparent lower electrode and the upper electrode of the anti-glare mirror in conjunction with the start-up of the vehicle. An anti-glare mirror characterized by: