CZ2000747A3 - Electrochromic mirror - Google Patents

Abstract

As a central component, the mirror has an optically active cell that it consists of two tables (1,2) arranged as a laminate, provided with an electrode on the inside, between which are the electrochromic medium (5) and which are sealed together by an adhesive bead (6) extending therethrough the circumference of the tables (1,2) so that the narrow edge strip remains free. Each edge electrode electrode is assisted by dividing thi (9a, 9b) half divided so as to form an insulated one the edge strip section (11a, 11b), each insulated the edge portion of the one sheet electrode is opposed an uninsulated edge portion of the second sheet electrode. In the interspace between these edge segments it strips the connecting wire (8a, 8b) is installed by means of an electrically conductive mass.

Description

ELECTROCHROMIC MIRROR

Technical field

The present invention relates to an electrochromic mirror with an optically active cell, consisting of two transparent panes formed in accordance with a mirror configuration, arranged as a laminate, each side facing the other with an electrically conductive electrode layer extending over the entire surface of the pan. in contact with the connection conductor, of which the plate which is facing the light inlet, is a mirror image which is spaced apart from one another by an adhesive bead running along the perimeter of the plates leaving a narrow edge strip free and between which an electrochromic medium is arranged.

BACKGROUND OF THE INVENTION

Electrochromic mirrors, also abbreviated as EC mirrors, have the property that their reflectance changes under the influence of electrical voltage. They are mainly used in the automotive industry, especially as auto-aperture rear-view mirrors.

Such auto-mirroring rearview mirrors

79300 (79300a) 9 9 9 9 9

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9 · 94 9 9 9 4 9 9 increases safety during night driving and helps prevent accidents while saving eyes.

In the dark, the driver's pupil works like a wide-open camera shutter to give the optic nerve as much light as possible. In this condition, the eye responds extremely sensitive to sudden glare. The light from the headlights of passing or following vehicles, reflected by conventional rear-view mirrors, dazzles the driver so strongly that his vision is currently severely impaired. For a fraction of a second, the driver is virtually blind due to the flashing of the light flashes and his reaction time to an obstacle visible in the road ahead increases by more than one second.

In the systematic measurement of the braking distance, this so-called Troxler effect has, for example, doubled the braking distance of the test vehicle at night conditions at 100 km / h on dry roads.

This effect affects all drivers regardless of the driver's gender, age and eye color. It is a dangerous factor when driving at night, which is only compensated by insufficient compensation by means of the existing, mechanically adjustable, screenable interior mirrors. When the interior mirror is tilted, the reflection decreases from about 90% to 4%. The low residual image of the folded-out interior mirror diminishes the dazzling effect, but makes it possible to recognize only the headlights and not the contours of the overtaking or following vehicle. In the case of mostly curved exterior mirrors, such tilt as glare protection during night driving is not possible.

79300 (79300a) 449 4 4 4 44 4 9 4 4 4 4 4 4 4 4 4 4 4 4 · W · · · · · 4 9 4 4 4 9 94 4 49 44

However, it has been proven to provide automotive equipment with automatically screenable rear-view mirrors, whose electro-optic sensors immediately detect the dazzle of glare and, by continuously reducing the reflectance of the mirror to about 10% within a few seconds, suppress it in a friendly manner. As soon as the risk of glare is over, the mirror imaging will immediately return to its default value. This automatic alternation of darkening and brightening of the rear-view mirrors is repeated again at every risk of glare, tirelessly throughout the life of the vehicle.

For more than ten years, the electrochromic behavior of certain chemicals arranged in front of the reflective surface of the EC-mirror has been used to change the reflectivity of an automatically screenable rear-view mirror. Some inorganic and organic electrochromic dyes change their absorption depth when they bring electrical potential to them through the electrodes that surround them.

These reversible absorption changes are known and systematically investigated in several inorganic transition metal oxides (eg tungsten) in thin layers of the solid side in this context liquid cells with organic dyes (eg liquid crystals or viologens) have been successfully. For functional and cost reasons, liquid cells with viologens have been established for EC-mirrors available on the market.

substances. On the other tried thin

These cells, hereinafter called optically active cells, form the heart of the EC-mirror. As a rule, they consist of two tables formed in accordance with the mirror configuration, preferably consisting of glass, i. of windscreen and rear window which are spaced apart from one another

79300 (79300a) ·

9 9 9 · ί 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 Between the two tables there is an electrochromically active medium, in particular a liquid with viologen. Each table is provided on the side facing the ECmedium with an electrically conductive electrode layer covering the entire surface of the table, provided with a ring of connections. The mirror pane itself is located on the rear pane of the glass.

If a voltage is applied to the connecting conductors of both surface electrodes, for example the voltage exerted by a light sensor on the basis of the rear vehicle light, the absorption depth of the EC-medium arranged in front of the mirror table changes and thus the reflectivity of the optically active cell.

Such connections are known in the art through numerous publications.

A noticeable problem in such a typical cell is the mutually isolated mediating of contact between the connecting wires and the respective surface electrodes, since the surface electrodes coincide with only a very narrow gap of about 0.1 to 0.2 mm.

Z pat. U.S. Pat. No. 5,151,824 discloses a solution to this problem in that the front and rear glass are arranged offset from each other by a predetermined value, so that on each glass a free zone of the surface electrode is required which is necessary to make contact. Elongated contact clamps with resiliently flexible contact tabs clamping glass with free edge regions to which the connecting wire is soldered are fixed to these edge zones.

As a result of the offset of the known EC mirrors they are

79300 (79300a) »* · * * 0 0 0 0 0 0 0 0 0

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0000 «·« 0 sometimes the edge regions of the mirror are relatively large, which is undesirable. The requirements of the automotive industry focus on EC mirrors, which are virtually the same size as conventional mirrors.

This is in addition to the fact that the fastening of the resilient, respectively flexible, terminal contacting is very expensive as well as difficult, and only makes contact with the flat electrode in a relatively narrow area. This has an adverse effect on the rate at which the absorption depth of the EC medium varies.

From EP 0 434 453 (= US 5,066,112) an EC mirror of the above-mentioned type is known which has no offset of the optically active cell tables or elastic contacts in the form of clamps and in which it is applied to the surface areas of the tables including their face. electrode additional conductive contact layer to which the connecting conductor is soldered on the front side.

Such an EC-mirror is both very expensive to manufacture and, on the other hand, the contact area on the front side is very narrow for fastening the connection conductor so that it can be easily torn off and, moreover, allows only a narrow contact surface. with which the absorption depth of the EC medium varies.

SUMMARY OF THE INVENTION

The invention is based on the task of designing the above-mentioned electrochromic mirror so that reliable large-area contact can be achieved by simple means, without offsetting edges with expensive contact

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9 999 9 9 * A A A - 9 9 99 99 9999 6 terminals.

The solution according to the invention consists in that on one table in the respective electrode layer in the lower half, and on the other table in the respective electrode layer in the upper half, a slit line is formed at the height of the adhesive bead. a bonding conductor is disposed in the interstices between one insulated edge portion and the non-insulated edge portion of the counter electrode layer, and a second conductor is disposed by the electrically conductive mass, and a second conductor is deposited by the electrically conductive mass connecting wire.

The electrochromic mirror according to the invention has tables of optically active cells which cover each other. it does not exhibit any external mirror extension, does not have expensive flexible contacts and provides a reliable, stable and large-area power supply, which results in rapid darkening and brightening of the EC-mirror.

According to a further development of the invention, the slit line is preferably formed by means of a laser beam. This makes it possible to separate the respective edge section from the remainder of the flat electrode by means of a very narrow section line.

In principle, two possibilities are possible for mirroring the table facing away from the light input. According to a first embodiment of the invention, the two electrode layers consist of indium and tin oxide (ITO), and in addition a mirror layer is deposited on the back of the table facing away from the light inlet.

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According to a second embodiment of the invention, the electrode layer deposited on the front table facing the light inlet is indium tin oxide (ITO), and the electrode layer deposited on the table facing away from the light inlet is a chromium / rhodium compound.

The determined spacing between the two optically active cell sheets is simply due to the fact that the adhesive bead preferably comprises glass spheres of a diameter that corresponds to a fixed spacing between the cell sheets.

A variety of options are available to the person skilled in the art as a conductive material which is applied in the interspace between the surface electrodes and in which the connecting conductors are arranged. Preferably, the electrically conductive material is a curing conductive lacquer. This conductive lacquer not only provides a good electrical connection between the surface electrode and the connecting wire, but also gives the cell some stability.

Alternatively, the electrically conductive mass in which the lead wires are located may also be a solidifying conductive solder or the like.

Preferably, according to a further embodiment of the invention, the connecting conductor is embedded in the electrically conductive material along the entire length of the respective non-insulated edge section. This allows a good current transfer and quick darkening and lightening of the mirror.

For reliable environmental protection, the fronts of the cell sheets are preferably sealed with an insulating curing compound.

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The material of the cell sheets may be glass, preferably float glass, but also plastic.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will be apparent from the exemplary embodiments illustrated in the drawings, in which:

Fig. 1 is an exploded view of an arrangement of an optically active EC-mirror cell according to the invention; and Fig. 2 is a greatly enlarged sectional view of an assembled optically active cell with a connection conductor connection.

DETAILED DESCRIPTION OF THE INVENTION

Giant. 1 is an exploded view of the arrangement of an optically active cell according to the invention as the basis of the EC mirror of the invention in conjunction with the cross-sectional view of FIG. 2, taken along the finished optically active cell along the imaginary section line; cells.

The optically active mirror cell consists of two transparent panes formed in accordance with the mirror configuration, here the exterior mirror of a passenger car, which, in an exemplary embodiment, consists of glass, preferably float glass, namely a windscreen 1 arranged in the light entrance direction and a rear glass 2.

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In principle, it is also possible to create tables from transparent plastic.

The windshield 1 is provided on the side facing away from the light inlet with an electrically conductive surface electrode 3, which extends over the entire surface of the windshield] Similarly, the rear glass 2 is provided on the light-facing side with electrically conductive surface electrodes 4, the entire area of the rear window 2.

In the present embodiment, the electrically conductive surface electrode 3 comprises a layer of ITO (Indium-Tin-Oxide, Indium-Tin Oxide), which is transparent, whereas the surface electrode 4 is a chrome / rhodium layer, which represents a reflecting surface.

It is also possible for the surface electrode 4 to also consist of an ITO layer, whereupon a separate mirror layer is applied to the rear side of the rear window 2.

Between the two tables 1 resp. 2 with respective surface electrodes 3 and 3 respectively. 4, the electrochromic medium 5 is present, preferably in the form of an electrochromic solution of the kind previously described. To this end, the two tables 1, 2 are glued to each other on the sides on which the surface electrodes 3, 4 are located, forming a closed cell which can be filled with liquid. The respective bonding material, which must consist of an electrically insulating adhesive, in order to prevent internal short-circuiting of the two electrodes, forms the adhesive bead 6, as is particularly apparent from FIG. 2. This adhesive bead 6 is located on the side facing the EC medium

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The electrode 3 is provided with a caterpillar 6 on the side facing ECmedia 5.

The adhesive comprises small glass spheres which determine the spacing of both cell walls, which is generally 0.1 to 0.2 mm.

By means of an adhesive bead 6, an electrically conductive edge strip 7a is formed on the surface electrode 3 associated with the windshield and an electrically conductive edge section 7b on the surface electrode 4 associated with the rear window 2. The connecting conductor 8a is connected by means of the edge section 7a and the connecting conductor 8b by means of the edge section 7b. In order to make a large surface contact with the contact strips 7a and 7, respectively. 7b, as shown in FIG. 2, by filling in the space between the tables 1 and 2, respectively. 2 with their surface electrodes 3, respectively. 4 by means of a conductive lacquer, solder or other conductive paste 10, in which the connecting wire 8a, 8b is always arranged, the insulating electrodes 3, 4 overlapping each other must be provided. This insulation is realized by dividing grooves 9a and 9b, respectively. 9b, which are each formed on the second surface electrode, of the spatially opposed adhesive bead 6 such that, as can be seen from FIG. 2, the insulating adhesive bead 6 always overlaps the groove 9a and 9b respectively. 9b, so that only the outer region 11a, 11b of the opposing surface electrodes is covered between the glasses due to the filling of the edge regions of the electrode surfaces, but not the inside part of the surface electrodes.

The formation of the slit lines 9a, 9b is preferably carried out by means of a laser, preferably by means of a neodymium YAG laser. As can be seen from FIG. 1, the laser-formed slit line 9a extends on the transparent electrode 3 at the lower edge to somewhat below the center. Isolates the edge strip 11a on which it is attached

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9 9 9 9 9 is in electrical contact with the opposite reflective electrode 6. In this reflective electrode 4, a laser-cut slit 7b extends at the upper edge on both sides to slightly below the center. It insulates the edge strip, 11b, on which the electrical contact is located on the opposite transparent electrode 3. In this way, the surface electrodes 3, 4 can be provided with two electrically insulated connection conductors 8a, 8b, which are internally mechanically stable due to the conductive medium. contact with the respective surface electrodes.

If the optically active cell is filled with EC solution 5, its light transmittance can be varied by connecting an electrical potential between the surface electrodes 3, 4. To this end, the two surface electrodes are electrically insulated from each other and connected by connecting wires 8a, 8b to a direct current source.

In order to avoid an internal short circuit, the conductive lacquer 10 is interrupted by means of an insulating material at the transitions from the insulated edge strips to the non-insulated edge sections.

As can be seen from FIG. 2, the edge between the two glued sheets 1, 2 is provided with a seal 12 which closes the inside of the optically active cell hermetically to the environment.

The thickness of the sheets 1, 2 is in the range of 1 to 2 mm, while the electrode layers generally have a thickness of the order of 1000 angstroem. The width of the edge strips 7a, 7b and 11a, 11b is of the order of 0.8 mm.

The transparent surface electrode can also be formed as a zinc or oxide layer instead of the ITL layer

79300 (79300a) zinc.

Placing the optically active cell in the corresponding mirror handle can be realized by known constructions, such as in the aforementioned US 5 151 824,

Claims (10)

An electrochromic mirror with an optically active cell, consisting of two transparent panes (1, 2) formed in accordance with a mirror configuration, arranged as a laminate, each having an electrically conductive electrode layer (3, 4) extending on the side facing the other the entire surface of the plate, which is always in contact with the connecting conductor (8a, 8b), of which the plate (2) that faces the light inlet is mirror-like, which are closely connected to each other by an adhesive bead (6) extending along the circumference of the plates (1, 2) and leaving a narrow edge strip free and between which an electrochromic medium is disposed, characterized in that on one table (1) there is a lower half in the respective electrode layer (3), and in the second table (2), a separating groove (9a, 9) is formed in the respective electrode layer (4) in the upper half, each at the height of the adhesive bead (6) b), overlapped by this bead, defining in the respective electrode layer (3, 4) an insulated edge section (11a, 11b), wherein in the interstice between one insulated edge section (11a) and the non-insulated edge section (7b) of the opposite electrode layer (4) one connecting conductor (8b) is arranged by means of an electrically conductive mass (10), and is placed electrically between the second insulated edge section (11b) and the non-insulated edge section (7a) of the opposite electrode layer (3) 16 79300 0 0 0 0 0 • 0 0000 0 « 0 « 000 00 00 · 9 <0 0 0 0 0 0 0 0 0 0 0 00 00000 0 0 0 0 0 0 0 0 00 0000 00 00 conductive mass (10) second connecting wire (8a). 2. A mirror as claimed in that the slit lines of the laser beam. of claim 1, characterized by (9a, 9b) are formed by means of a Mirror according to claim 1 or characterized in that the two electrode layers (3, indium and tin (ITO)) are additionally applied to (2) facing away from the light inlet. 2; 4) consist of the oxide back of the table mirror layer. A mirror according to claim 1 or 2, characterized in that the electrode layer (3) deposited on the front light-input face plate (1) consists of indium tin oxide (ITO), and the electrode layer (4) deposited. in the table (2) facing away from the light entrance, it consists of a chromium / rhodium compound. Mirror according to one of Claims 1 to 4, characterized in that the adhesive bead (6) comprises glass spheres of a diameter which corresponds to a predetermined distance between the cell plates (1, 2). Mirror according to one of Claims 1 to 5, characterized in that the electrically conductive mass (10) in which the supply conductors (8a, 8b) are arranged is a hardening conductive lacquer. Mirror according to one of Claims 1 to 5, characterized in that the electrically conductive mass (10) in which the conductors (8a, 8b) are arranged is a solidifying conductive solder. 16 79300 (79300a) 44 ·· 4 * ·· 444 «4 4 4 4» 444 • 44 4 4 4 4 4 4 4,444 44 4 4 4 4 4 * 4 4 4 4 4 4444 4444 44 «4444 44 44 Mirror according to one of Claims 1 to 7, characterized in that the connecting conductors (8a, 8b) are embedded in the electrically conductive material (10) over the entire length of the respective non-insulated edge section (7a, 7b). Mirror according to one of Claims 1 to 8, characterized in that the faces of the optically active cell plates (1, 2) are sealed with an insulating curing compound (12). Mirror according to claim 1 or 9, characterized in that the optically active cell tables (1, 2) consist of float glass.