MXPA99008943A - Electrochromic rearview mirror incorporating a third surface metal reflector - Google Patents

Abstract

An EC variable reflectance mirror (110) for a vehicle includes a reflector/electrode (120) on the third surface (114a) of the mirror. This reflector/electrode forms an integral electrode in contact with the electrochromic media, and may be a single layer of a highly reflective material or may comprise a series of coatings.

Description

ELECTROCROMIC MIRROR MIRROR INCORPORATING A METAL REFLECTOR ON THE THIRD SURFACE BACKGROUND OF THE INVENTION This invention is concerned with electrochromic rear-view mirrors for motor vehicles and more particularly with improved electrochromic rear-view mirrors incorporating a third-surface reflector / electrode in contact in at least one electrochromic material in the solution phase. Up to now, several rear-view mirrors for motor vehicles have been proposed which change from the full reflectance mode (day) to the partial reflectance mode (s) (night) for purposes of protection against glare from the light emanating from the vehicle. the headlights of vehicles approaching from behind. Among such devices are those in which the transmittance is varied by thermochromic, photochromic or electro-optical elements (for example liquid crystal, dipolar, electrophoretic, electrochromic suspension, etc.) and where the characteristic of variable transmittance affects electromagnetic radiation which is at least partially in the visible spectrum (wavelengths from about 3800 Á to about 7800 Á). Variable transmittance devices have been proposed reversibly to electromagnetic radiation such as REF .: 31459 variable transmittance element in variable transmittance light filters, variable reflectance mirrors and display or indicator devices that use such light filters or mirrors to transport information. These variable transmittance light filters have included windows. Variable transmittance devices reversibly to electromagnetic radiation, where the transmittance is altered by electrochromic elements are described for example by Chang, "Electrochromic and Electrochemichromic Materials and Phenomena," in Non-emissive Electrooptic Displays, A. Kmetz and K. Von illinsen , Eds. Plenum Press, New York, NY 1976, pp. 155-196 (1976) and in various parts of Electrochromism, P.M.S. Monk, R.J. Mortimer, D.R. Rosseinsky, VCH Publishers, Inc., New York, NY (1995). Numerous electrochromic devices are known in the art. See, for example, Hands, U.S. Patent No. 3,451,741; Bredfeldt et al., U.S. Patent No. 4,090,358; Clecak et al., U.S. Patent No. 4,139,276; Kissa et al., U.S. Patent No. 3,453,038; Rogers, U.S. Patent Nos. 3,652,149, 3,774,988 and 3,873,185; and Jones et al., U.S. Patents Nos. 3,282,157, 3,282,158, 3,282,160 and 3,283,656.

In addition to these devices which are commercially available electrochromic devices and associated circuits, such as those described in U.S. Patent No. 4,902,108 entitled "Single-Compartment, Self-Erasing, Solution-Phase Electrochromic Devices Solutions for Use Therein, and Uses Thereof", issued on February 20, 1990 to HJ Byker; Canadian Patent No. 1,300,945, entitled "Automatic Rearview Mirror System for Vehicle Vehicles", issued May 19, 1992 to J. H. Bechtel et al .; U.S. Patent No. 5,128,799, entitled "Variable Reflectance Motor Vehicle Mirror", issued July 7, 1992 to H.J. Byker; U.S. Patent No. 5,202,787, entitled "Electro-Optic Device", issued April 13, 1993 to H.J. Byker et al .; U.S. Patent No. 5,204,778, entitled "Control System For Automatic Rearview Mirrors", issued April 20, 1993 to J.H. Bechtel; U.S. Patent No. 5,278,693, entitled "Tinted Solution-Phase Electrochromic Mirrors", issued on January 11, 1994 to D.A. Theiste et al .; U.S. Patent No. 5,280,380, entitled "UV-Stabilized Compositions and Methods", issued on January 18, 1994 to H.J. Byker, US Patent No. 5,282,077, entitled "Variable Reflectance Mirror", issued on January 25, 1994 to H.J. Byker; U.S. Patent No. 5,294,376, entitled "Bipyridinium Salt Solutions", issued March 15, 1994 to H.J. Byker; U.S. Patent No. 5,336,448, entitled "Electrochromic Devices with Bipyridinium Salt Solutions", issued August 9, 1994 to H.J. Byker; U.S. Patent No. 5,434,407, entitled "Automatic Rearview Mirror Incorporating Light Pipe", issued on January 18, 1995 to F.T. Bauer et al .; U.S. Patent No. 5,448,397, entitled "Outside Automatic Rearview Mirror for Automotive Vehicles", issued September 5, 1995 to W.L. Anar; and U.S. Patent No. 5,451,822, entitled "Electronic Control System", issued September 19, 1995 to J.H. Bechtel et al. Each of these patents is assigned in common with the present invention and the descriptions of each of them, in which the references contained therein are included, are hereby incorporated by reference in their entirety. Such electrochromic devices can be used in a fully integrated internal / external rear-view mirror system or as separate internal or external mirror systems. Figure 1 shows a typical electrochromic mirror device 10 having front and rear planar elements 12 and 16 respectively. A transparent conductive coating 14 is placed on the rear face of the front element 12 and another transparent conductive coating 18 is placed on the front face of the rear element 16. A reflector (20a, 20b and 20c), which commonly comprises a metal layer of silver 20a covered by a layer of protective copper metal 20b and one or more layers of protective paint 20c, is disposed on the rear face of the rear element 16. For clarity of description of such structure, the front surface of the front glass element is sometimes referred to as the first surface and the inner surface of the front glass element is sometimes referred to as the second surface. The interior surface of the rear glass element is sometimes referred to as the third surface and the rear surface of the rear glass element sometimes referred to as the fourth surface. The front and back elements are maintained in a parallel relationship and spaced apart by a seal 22, to thereby create a chamber 26. The electrochromic means 24 is contained in the space 26. The electrochromic means 24 is in direct contact with electrode layers. transparent 14 and 18 through which electromagnetic radiation passes whose intensity is reversibly modulated in the device by a variable potential contact applied to the electrode layers 14 and 18 by means of fastener contacts and an electronic circuit (not shown).

The electrochromic means 24 placed in the space 26 may include electrochromic materials of the electrodeposition type or of the solution phase type confined to the surface and combinations thereof. In a completely solution medium, the electrochemical amounts of the solvent, optional inert electrolyte, anodic materials, cathode materials and any other components that might be present in the solution are preferably such that no significant electrochemical change is present or other changes to a potential difference that oxidizes the anodic material that reduces the cathodic material other than the electrochemical oxidation of the anodic material, the electrochemical reduction of the cathodic material and the auto-deletion reaction between the oxidized form of the anodic material and the reduced form of the material cathode In most cases, when there is no electrical potential difference between the transparent conductors 14 and 18, the electrochromic means 24 in the space 26 is essentially colorless or almost colorless and the incoming light (I0) enters through the front element 12, passes through the transparent coating 14, the electrochromic containing chamber 26, the transparent coating 18, the rear element 16 and is reflected from the layer 20a and travels back to the device and outwards from the front element 12. Normally, the The magnitude of the reflected image (IR) with no difference in electrical potential is from about 45% to about 85% of the intensity of the incident light (I0). The exact value depends on many variables summarized later in the present, such as for example the residual reflection (I'R) of the front face of the front element, also as secondary reflections of the interfaces between: the front element 12 and the electrode 14 transparent front; the front transparent electrode 14 and the electrochromic means 24; the electrochromic means 24 and the second transparent electrode 18 and the second transparent electrode 18 and the rear element 16. These reflections are well known in the art and are due to the difference in the reflection rates between one material and another as the light crosses the interface between the two. If the front element and the rear element are not parallel, then the residual reflectance (I'R) or other secondary reflections will not overlap with the reflected image (IR) of the mirror surface 20a and a double image will appear (where a Observer would see what appears to be double (or triple) the number of objects actually present in the reflected image). There are minimum requirements for the magnitude of the reflected image depending on whether the electrochromic mirrors are placed on the inside or outside of the vehicle. For example, in accordance with the current requirements of most automotive manufacturers, interior mirrors should have a high end reflectivity of at least 70% and exterior mirrors should have a high end reflectivity of at least 50%. %. The electrode layers 14 and 18 are connected to electronic circuits that are effective to electrically energize the electrochromic medium, such as when a potential is applied through the transparent conductors 14 and 18, the electrochromic medium in the space 26 is darkened in such a way that the incident light (I0) is attenuated as the light passes to the reflector 20a and as it passes back after being reflected. By adjusting the potential difference between the transparent electrodes, such a device can function as a "gray scale" device, with a continuously variable transmittance over a wide range. For electrochromic systems in the solution phase, when the potential between the electrodes is eliminated or returned to zero, the device returns spontaneously to the same zero potential, equilibrium color and transmittance as the device had before the potential was applied. Other electrochromic materials are available to make electrochromic devices. For example, the electrochromic medium may include electrochromic materials that are solid metal oxides, redox active polymers and hybrid combinations of active polymers in solution phase or solid metal oxides or redox active; however, the solution phase design described above is typical of most electrochromic devices currently in progress. Even before a fourth surface electrochromic reflecting mirror was commercially available, several groups investigating electrochromic devices had discussed moving the reflector on the fourth surface to the third surface. Such a design theoretically has advantages in that it must be easier to manufacture because there are fewer parts to integrate a device, that is, the transparent electrode of the third surface is not necessary when there is a third surface reflector / electrode. Although this concept was described since 1966, no group was commercially successful due to the exact criteria demanded of a functional self-attenuating mirror that incorporates a third surface reflector. U.S. Patent No. 3,280,701 entitled "Optically Variable One-and Mirror", issued on October 25, 1966 to J.F. Donnelly et al has one of the first discussions of a third surface reflector for a system that uses a color change induced by pH to attenuate light. U.S. Patent No. 5,066,112, entitled "Perimeter Coated, Electro-Optic Mirror", issued November 19, 1991 to N.R. Lynam et al. Teaches an electro-optic mirror with a conductive coating applied to the perimeter of the front and back glass elements to hide the seal. Although a third surface reflector is discussed therein, the materials listed as useful for a third surface reflector suffer from one or more of the following deficiencies: they do not have a sufficient reflectivity to be used as a lower mirror or they are not stable when they are placed in contact with an electrochromic medium in the solution phase which contains at least one electrochromic material in the solution phase. Others have introduced the iema of a reflector / electrode arranged in the middle of solid state type devices. For example, U.S. Patent Nos. 4,762,401; 4,973,141; and 5,069,535 issued to Baucke et al. they teach an electrochromic mirror that has the following structure: a glass element; a transparent electrode (ITO); an electrochromic layer of tungsten oxide; a solid ion-conducting layer; a reflector permeable to single layer hydrogen ions; a solid ion-conducting layer; a storage layer of hydrogen ion; a catalytic layer; a metal rear layer and a support element (which represents the conventional third and fourth surfaces). The reflector is not deposited on the third surface and is not directly in contact with electrochromic materials, certainly not at least one electrochromic material in the solution phase and associated medium. Accordingly, it is desirable to provide an improved high reflectivity electrochromic rearview mirror having a third surface reflector / electrode in contact with a solution phase electrochromic medium containing at least one electrochromic material.

OBJECTS OF THE INVENTION Thus, a main object of the present invention is to provide a low , robust, improved attenuated rear view mirror incorporating a reflector / electrode of third surface of high reflectivity for motorized vehicles, which mirror is capable of operating in severe environments in wide variations of temperature, humidity, vibration, atmospheric corrosion, salt spray, electronic alterations and sand and grit and that is relatively economical and reliable for consistent manufacturing and assembly and that is durable, efficient and reliable in operation. Another object of the present invention is to provide an improved attenuated rearview mirror for motor vehicles where excellent reflectance change speed, excellent high end reflectance, good uniformity of reflectance changes through the surface area of the mirror, color are obtained. or neutral appearance in the state of high reflectance, continuously variable reflectance and good low end reflectance. Another object of the present invention is to provide an improved high conductance contact or distribution line bars for the transparent conductive electrode of the second surface by using a portion of the reflector / electrode of the third surface and a conductive seal or strip to make electrical contact with the transparent conductive electrode on the second surface.

BRIEF DESCRIPTION OF THE INVENTION The above and other objects will become apparent from the specification as a whole in which the drawings are included according to the present invention when incorporating a reflector / electrode on the inner surface (third surface). of an attenuating portion of the rear-view mirror. This reflector / electrode forms an integral electrode in contact with at least one electrochromic material in the solution phase and may consist of a single layer of a highly reflective silver alloy or may comprise a series of coatings wherein the outer coating is an alloy of highly reflective silver. When a series of coatings are used for the reflector / electrode, there must be a base coat that sticks to the glass surface and resists any adverse interaction, eg corrosive action with any constituents of the electrochromic medium, an intermediate layer (or layers) optionally it adheres well to the basecoat and resists any adverse interaction with the electrochromic medium and at least one highly reflective silver alloy which comes into direct contact with the electrochromic medium and which is chosen primarily for its proper adhesion to the peripheral seal , its high reflectance, good storage life, stable behavior as an electrode, resistance to adverse interaction with the electrochromic medium, resistance to atmospheric corrosion, resistance to contact corrosion, the ability to adhere to the layer (s) s) base or intermediate (s), if present. If a single layer of highly reflective silver alloy is used, it must also meet these operating criteria. In another embodiment of the present invention, when a very thin coating is placed on the highly reflective layer, then the highly reflective layer may be silver metal or a silver alloy. In yet another embodiment of the present invention, the reflector / electrode of the third surface includes at least one base layer that is disposed over the entire third surface of the electrochromic mirror. A highly reflective layer is disposed over the central portion of the base layers and not over the portion of the perimeter edge where the seal will be placed. Optionally, one or more intermediate layers may be disposed between the base layer and the reflective layer and may be placed over the entire third surface or may be placed over the central portion of both (if there is more than one intermediate layer). The reflector of the third surface of the present invention can further provide significant improvements to the electrical interconnection techniques used to impart a voltage or drive potential to the transparent conductor on the second surface of the electrochromic mirror. This is done by providing improved contact stability between the contacts, such as fasteners and the reflective layer and by providing unique and advantageous busbar configurations.

BRIEF DESCRIPTION OF THE DRAWINGS The material that is considered as the invention is summarized in particular and claimed in a distive manner in the final portion of the specification. The invention, together with additional objects and advantages thereof can be better understood by reference to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like components, in which: Figure 1 is a enlarged cross-sectional view of an electrochromic mirror assembly of the prior art; Figure 2 is a schematic front elevational view illustrating an indoor / outdoor electrochromic mirror system for motor vehicles wherein the interior and exterior mirrors rporate the mirror assembly of the present invention; Figure 3 is an enlarged cross-sectional view of the inner electrochromic rearview mirror rporating a third surface reflector / electrode illustrated in Figure 2, taken on line 2-2 'thereof; Figure 4 is an enlarged cross-sectional view of an electrochromic mirror rporating an alternative embodiment of a third surface reflector / electrode according to the present invention; Figure 5a is an enlarged cross-sectional view of an electrochromic mirror having an improved arrangement for applying a driving potential to the transparent conductor on the second surface of the mirror; Fig. 5b is an enlarged top view of the third surface reflector of Fig. 5a and Fig. 6 is an enlarged cross-sectional view of an electrochromic mirror utilizing a machine-cured epoxy seal to maintain the transparent elements in a separate relationship spaced.

DETAILED DESCRIPTION OF THE INVENTION Figure 2 shows a front elevation view schematically illustrating an interior mirror assembly 110 and two exterior rearview mirror assemblies Illa and 111b for the driver's side and the passenger's side respectively, all of which are adapted to be installed in a motor vehicle in a conventional manner and where the mirrors are facing the rear of the vehicle and can be visualized by the driver of the vehicle to provide a rearward view. The interior mirror assembly 110 and the exterior rearview mirror assemblies Illa and 111b may rporate electronic circuits that detect light of the type illustrated and described in Canadian Patent No. 1,300,945; U.S. Patent No. 5,204,778 or U.S. Patent No. 5,451,822 and other circuits capable of detecting glare and ambient light and providing a driving voltage to the electrochromic element. The mirror assemblies 110, Illa and 111b are essentially identical s similar numbers identify components of the interior and exterior mirrors. These components may be slightly different in configuration but work substantially in the same way and obtain substantially the same results as the components numbered in a similar manner. For example, the shape of the front glass element of the inner mirror 110 is generally longer and narrower than the outer mirrors Illa and 111b. There are also some different performance standards placed in the interior mirror 110 compared to the exterior mirrors Illa and 111b. For example, the interior mirror 110 in general when it is fully clear should have a reflectance value of about 70% to about 85% or greater while the exterior mirrors frequently have a reflectance of about 50% to about 65%. Also, in the United States of North America (as stipulated by the automobile manufacturers), the passenger side mirror 111b commonly has a spherical curvature or convex shape, while the mirror on the driver's side Illa and the interior mirror 110 must be currently flat. In Europe, the driver's side mirror Illa is commonly flat or aspherical, while the mirror 111b on the passenger side has a convex shape. In Japan both exterior mirrors have a convex shape. The following description is generally applicable to all mirror assemblies of the present invention. Figure 3 shows a cross-sectional view of the mirror assembly 110 having a front transparent element 112 having a front surface 112a and a rear surface 112b and a rear element 114 having a front surface 114a and a rear surface 114b. For clarity of description of such structure, the following designations will be used later in the present. The front surface 112a of the front glass element will be referred to as the first surface and the rear surface 112b of the front glass element as the second surface. The front surface 114a of the rear glass element will be referred to as the third surface and the rear surface 114b of the rear glass element as the fourth surface. The chamber 125 is defined by a transparent conductor layer 128 (disposed on the second surface 112b), a reflector / electrode 120 (disposed on the third surface 114a) and an internal circumferential wall 132 of the sealing element 116. The transparent front element 112 it can be any material that is transparent and has sufficient strength to function under conditions, for example, of varying temperatures and pressures commonly encountered in the automotive environment. The front element 112 can comprise any type of borosilicate glass, soda lime glass, float glass or any other material such as for example a polymer or plastic that is transparent in the visible region of the electromagnetic spectrum. The front element 112 preferably consists of a sheet of glass. The rear element must comply with the operational conditions outlined above, except that it does not need to be transparent and therefore may comprise polymers, metals, glass, ceramics and preferably consists of a sheet of glass.

The coatings of the third surface 114a are sealingly adhered to the coatings on the second surface 112b in a spaced apart and parallel relationship by a sealing element 116 disposed near the outer perimeter of the second surface 112b and the third surface 114a. The sealing element 116 may be any material that is capable of adhesively bonding the coatings on the second surface 112b to the coatings on the third surface 114a to seal the perimeter such that the electrochromic material 126 does not leak from the chamber 125. Optionally, the transparent conductive coating layer 128 and the reflector / electrode layer 120 can be separated on some portion where the sealing element is arranged (not the entire portion, otherwise the driving potential could not be applied to the components). two coatings). In such a case, the sealing element 116 should stick well to the glass. The performance requirements for a perimeter sealing element 116 used in an electrochromic device are similar to those for a perimeter seal used in a liquid crystal device (LCD) that are well known in the art. The seal must have good adhesion to glass, metals and metal oxides, must have low * permeabilities to oxygen, moisture vapor and. other harmful vapors and gases and must not interact with or poison the liquid or electrochromic crystal material that it is proposed to contain and protect. The perimetric seal can be applied by elements commonly used in the LCD industry such as screen printing or dosing. Fully airtight seals such as those made with glass alkaline flux or welding glass can be used, but the high temperatures involved in the processing (usually about 450 ° C) of this type of seal can cause numerous problems such as warping glass substrate, changes in the properties of the transparent conductive electrode and oxidation or degradation of the reflector. Due to their lower processing temperatures, thermoplastic, thermosetting or UV curing organic resin resins are preferred. Such organic resin sealing systems for LCD are described in U.S. Patent Nos. 4,297,401, 4,418,102, 4,695,490, 5,596,023 and 5,596,024. Due to its excellent adhesion to glass, low oxygen permeability and good resistance to solvents, epoxy-based organic sealant resins are preferred. These epoxy resin seals may be curable by ultraviolet light, such as described in US Patent 4,297,401 or thermally cured such as with mixtures of liquid epoxy resin with liquid polyamide resin or dicyandiamide or may be homopolymerized. The epoxy resin may contain fillers or thickeners to reduce flow and shrinkage or shrinkage such as fumed silica, silica, mica, clay, calcium carbonate, alumina, etc. and / or pigments to add color. Fillers pretreated with hydrophobic or silane surface treatments are preferred. The crosslink density of the cured resin can be controlled by the use of monofunctional, difunctional and multifunctional epoxy resin blends and curing agents. Additives such as silanes or titanates can be used to improve the hydrolytic stability of the seal and spacers such as glass beads or rods can be used to control the final seal thickness and substrate spacing. Suitable epoxy resins for use in a perimeter sealing element 116 include but are not limited to: "EPON RESIN" 813, 825, 826, 828, 830, 834, 862, 1001F, 1002F, 2012, DPS-155, 164, 1031 , 1074, 58005, 58006, 58034, 58901, 871, 872 and DPL-862 available from Shell Chemical Co., Houston, Texas; "ARALITE" GY 6010, GY 6020, CY 9579, GT 7071, XU 248, EPN 1139, EPN 1138, PY 307, ECN 1235, ECN 1273, ECN 1280, MT 01631 MY 720, MY 0500, MY 0510 and PT 810 available of Ciba Geigy, Hawthorne, NY; "D.E.R." 331, 317, 361, 383, 661, 662, 667, 732, 736, "D.E.N." 431, 438, 439 and 444 available from Dow Chemical Co., Midland, Michigan. Suitable epoxy curing agents include polyamides V-15, V-25 and V-40 from Shell Chemical Co .; "AJICURE" PN-23, PN-34 and VDH available from Ajinomoto Co., Tokyo, Japan; "CUREZOL" AMZ, 2MZ, 2E4MZ, C11Z, C17Z, 2PZ, 2IZ and 2P4MZ available from Shikoku Fine Chemicals, Tokyo, Japan; "ERISYS" DDA or DDA accelerated with U-405, 24EMI, U-41 0 and U-415 available from CVC Specialty Chemicals, Maple Shade, NJ .; "AMICURE" PACM, 352, CG, CG-325 and CG-1200 available from Air Products, Allentown, PA. Suitable fillers include sulfurized silica such as "CAB-0-SIL" L-90, LM-130, LM-5, PTG, M-5, MS-7, MS-55, TS-720, HS-5, EH -5 available from Cabot Corporation, Tuscola, IL; "AEROSIL" R972, R974, R805, R812, R812 S, R202, WS204 and US206 available from Degussa, Akron, OH. Suitable clay fillers include BUCKET, CATALPE, ASP NC, SATINTONE 5, SATINTONE SP-33, TRANSLINK 37, TRANSLINK 77, TRANSLINK 445, TRANSLINK 555 available from Engelhard Corporation, Edison, NJ. Suitable silica fillers are SILCRON G-130, G-300, G-100-T and G-100 available from SCM Chemicals, Baltimore, MD. Suitable silane coupling agents to improve the hydrolytic stability of the seal are Z-6020, Z-6030, Z-6032, Z-6040, Z-6075 and Z-6076 available from Dow Corning Corporation, Midland, MI. Appropriate precision glass microbead spacers are available in a range of sizes from Duke Scientific, Palo Alto, CA. The layer of an electrically conductive, transparent material 128 is deposited on the second surface 112b to act as an electrode. The transparent conductive material 128 can be any material that adheres well to the front element 112, which is resistant to corrosion to any materials within the electrochromic device, resistant to corrosion by the atmosphere, having minimal diffuse or specular reflectance, high transmission of light, almost neutral coloration and good electrical conductance. The transparent conductive material 128 can be tin oxide doped with fluorine, tin-doped indium oxide (ITO), ITO / metal / ITO (IMI) as described in "Transparent Conductive Multilayer-Systems for FPD Applications", by J. Stollenwerk, B. Ocker, KH Kretschmer of LEYBOLD AG, Alzenau, Germany, and the materials described in U.S. Patent No. 5,202,787, to which reference is made above, such as TEC 20 or TEC 15, available from Libbey Owens-Ford Co. of Toledo, OH. In general, the conductance of the transparent conductive material 128 will depend on its thickness and composition. The IMI generally has a higher conductivity compared to the other materials. However, IMI is more difficult and expensive to manufacture and can be useful when a high conductance is necessary. The thickness of the various layers in the IMI structure can vary but in general the thickness of the first ITO layer ranges from about 10 Á to about 200 A, the metal ranges from about 10 Á to about 200 Á and the second layer of ITO fluctuates from about 10 Á to about 200 Á. If desired, an optional layer or layers of a color suppression material 130 can be deposited between the transparent conductive material 128 and the second surface 112 to suppress reflection of any unwanted portions of the electromagnetic spectrum. In accordance with the present invention, a reflector / electrode combination 120 is disposed on the third surface 114a. The reflector / electrode 120 comprises at least one layer of a highly reflective material 121 which serves as a mirror reflectance layer and also forms an integral electrode in contact with and in stable chemical and electrochemical relationship with any constituents in an electrochromic medium. As stated above, the The conventional method of integrating electrochromic devices was to incorporate a transparent conductive material on the third surface as an electrode and place a reflector on the fourth surface. By combining the "reflector" and "electrode" and placing both on the third surface, several unexpected advantages arise that not only make the device less complex but also allow the device to function at a superior performance. The exemplary advantages of the reflector / combined electrode of the present invention will be summarized in the following. First, the reflector / combined electrode 120 on the third surface has in general a higher conductance than a conventional transparent electrode and the reflectors / electrodes previously used that allow greater design flexibility. The composition of the transparent conductive electrode on the second surface can be changed to one that has a lower conductance (since it is cheaper and easier to produce and manufacture) while maintaining coloring speeds similar to those obtainable with a fourth surface reflector, while at the same time the overall cost and time to produce the electrochromic device is substantially decreased. However, if the performance of a particular design is of relevant importance, a high conductance transparent electrode may be used on the second surface, such as for example ITO, IMI, etc. The combination of a high conductivity reflector / electrode on the third surface and a transparent high conductance electrode on the second surface will not only produce an electrochromic device with an even more global coloration but will also allow an increased rate of coloration and cleaning. In addition, in reflector mirror assemblies of fourth surface there are two transparent electrodes with relatively low conductance and in the third surface reflector mirrors used previously there is a transparent electrode and a reflector / electrode with a relatively low conductance and as such, a bar Long insertion on the front and back element to attract and expel current if necessary to ensure an appropriate color velocity. The third surface reflector / electrode of the present invention has a higher conductance and therefore a very uniform voltage or potential distribution across the conductive surface, even with a small or irregular contact area. Thus, the present invention provides greater design flexibility by allowing the electrical contact for the electrode of the third surface to be very small while still maintaining an appropriate color velocity. Secondly, a third surface reflector / electrode helps to improve the image that is visualized through the mirror. Figure 1 shows how light travels through a conventional fourth surface reflector device. In the fourth surface reflector light travels through: the first glass element; the transparent conductive electrode on the second surface; the electrochromic means; the transparent conductive electrode on the third surface and the second glass element before being reflected by the detector of the fourth surface. Both transparent conductor electrodes exhibit a highly specular transmittance but also have diffuse transmittance and reflection components, while the reflective layer used in any electrochromic mirror is chosen primarily for its specular reflectance. Component of reflectance or diffuse transmittance means a material that reflects or transmits a portion of any light that strikes it according to Lambert's law by which light rays are scattered or scattered. Component of reflectance or specular transmittance means a material that reflects or transmits the light that hits it according to the law of reflection or reflection of Snell. In practical terms, diffuse reflectors and transmitters tend to form slightly blurry images, while specular reflectors show a clear, sharp image. Accordingly, light traveling through a mirror having a device with a fourth surface reflector has two partial diffuse reflectors (on the second and third surface) that tend to blur the image and a device with a reflector / electrode The third surface of the present invention has only one diffuse reflector (on the second surface). Additionally, because the transparent electrodes act as partial diffuse transmitters and the farther away the diffuse transmitter from the more severe reflecting surface becomes blurred, a mirror with a fourth surface reflector appears significantly more blurry than a mirror with a reflector of third surface. For example, in the fourth surface reflector shown in Figure 1, the diffuse transmitter on the second surface is separated from the reflector by the electrochromic material, the second conductive electrode and the second glass element. The diffuse transmitter on the third surface is separated from the reflector by the second glass element. By incorporating a combined reflector / electrode on the third surface according to the present invention, one of the diffuse transmitters is separated and the distance between the reflector and the remaining diffuse transmitter is closer by the thickness of the rear glass element. Accordingly, the third surface metal reflector / electrode of the present invention provides an electrochromic mirror with a superior display image. Finally, a third surface metal reflector / electrode improves the ability to reduce the double image in an electrochromic mirror. As stated above, there are several interfaces where reflections can be presented. Some of these reflections can be significantly reduced with color suppression coatings or antireflective coatings; however, most significant "double-image" reflections are caused by the misalignment of the first surface and the surface that contains the reflector and the most reproducible way to minimize the impact of this reflection is to ensure that both glass elements are parallel. Currently, convex glass is frequently used for passenger-side glass and aspherical glass is sometimes used to mirror the driver's side to increase the field of vision and reduce potential blind spots. However, it is difficult to bend or bend in a reproducible manner successive glass elements having identical radii of curvature. Accordingly, when an electrochromic mirror is integrated the front glass element and the rear glass element may not be perfectly parallel (they do not have identical radii of curvature) and therefore the double image problems controlled otherwise become much more pronounced . By incorporating a combined reflector electrode on the third surface of the device according to the invention, the light does not have to travel through the rear glass element before being reflected and any double image that is presented of the elements that are out of parallelism will be significantly reduced. It is desirable in the construction of external rear view mirrors to incorporate thinner glass in order to reduce the overall weight of the mirrors, in such a way that the mechanisms used to manipulate the orientation of the mirror are not overloaded. Decreasing the weight of the device also improves the dynamic stability of the mirror assembly when exposed to vibrations. Until now, no electrochromic mirror incorporating an electrochromic medium in the solution phase and two thin glass elements have been commercially available because thin glass has the disadvantage of being flexible and is prone to warping or ruptures, especially when exposed to extreme environments. This problem is substantially improved by using an improved electrochromic device incorporating two thin glass elements having an improved gel material. This improved device is described in the commonly assigned US patent application entitled "AN ELECTROCHROMIC MIRROR ITH TWO THIN GLASS ELEMENTS AND A GELLED ELECTROCHROMIC MÉDIUM", filed on April 2, 1997. All the description, in which references are included contained therein of this U.S. patent application is incorporated herein by reference. The addition of the reflector / combined electrode on the third surface of the device also helps to eliminate any residual double image formation resulting from the two glass elements that are out of parallelism. The most important factors for obtaining a reliable electrochromic mirror having a reflector / electrode of third surface 120 are: that the reflector / electrode has a sufficient reflectance and that the mirror incorporating the reducer / electrode has an appropriate operational life. With respect to reflectance, the automobile manufacturer requires a highly reflective mirror for the interior mirror that has a minimum reflectivity of at least 70%, while the reflectivity requirements for the exterior mirrors are less severe and in general must be at least 50% To produce an electrochromic mirror with 70% reflectance the reflector must have a higher reflectance because having the electrochromic medium in contact with the reflector will reduce the reflectance of that interface compared to having the reflector in air, because the medium has a higher reflection index compared to air. Also, the glass, the transparent electrode and the electrochromic medium, even in their clear state, are slightly absorbent of light. Normally, if a global reflectance of 70% is desired, the reflector should have a reflectance of approximately 80%. Accordingly, a high reflectance in the context of the present invention means a reflector whose reflectance in air is at least 80%. With respect to the operational life, the layer or layers comprising the reflector / electrode 120 must have a proper adhesion strength to the peripheral seal, the outer layer must have good storage life between the time it is coated and the time when the When the mirror is mounted, the layer or layers must be resistant to atmospheric corrosion and to electrical contact corrosion and must be glued to the glass surface or to other layers arranged under them, for example the base layer or intermediate layer (122). or 123 respectively). The overall resistance of the sheet for the reflector / electrode 120 can range from about 0.01 ohms / square to about 20 ohms / square and preferably ranges from about 0.2 / to about 6 ohms / square. As will be discussed in more detail later in this, improved dielectric interconnections can be employed which use a portion of the third surface reflector / electrode as a high conductance contact or a busbar for the transparent conductive electrode of the second surface, when the reflector / electrode conductance of the third surface is less than about 2 ohms / square. With reference to Figure 3 for an embodiment of the present invention, a reflector / electrode is provided which is made from a single layer of a highly reflective silver alloy 121 which is in contact with at least one electrochromic material in the solution phase. . The silver alloy layer covers the entire third surface 114a of the second element 114, provided that a section of the reflector / electrode can be removed for an indicator (or screen) device and a glare detector according to the request of US patent entitled "AN INFORMATION DISPLAY REA ON ELECTROCHROMIC MIRRORS HAVING A THIRD SURFACE REFLECTOR" and filed on April 2, 1997. This application is hereby incorporated by reference in its entirety. Highly reflective silver alloy means a homogeneous or inhomogeneous mixture of silver and one or more metals or an unsaturated, saturated or supersaturated solid solution of silver or one or more metals. The thickness of the highly reflective layer 121 ranges from about 50 Á to about 2000 Á and more preferably from about 200 Á to about 1000 Á. If the highly reflective layer 121 is disposed directly to the glass surface, it is preferable that the glass surface be treated by plasma discharge to improve adhesion. Table 1 shows the relevant properties of a variety of different metals that have been proposed as third surface reflectors as compared to the appropriate materials for the reflector / electrode 120 of the present invention. The only materials in Table 1 that have suitable reflectance properties for use as a third surface reflector / electrode in contact with at least one electrochromic material in solution phase for an indoor electrochromic mirror for a motor vehicle are aluminum, silver and Silver alloys. Aluminum works very poorly when placed in contact with materials in the solution phase in the electrochromic medium because the aluminum reacts with or is corroded by these materials. Reacted aluminum or corroded aluminum is non-reflective and non-conductive and will normally dissolve, flake or delaminate from the glass surface. Silver is more stable than aluminum but can fail when deposited on the entire third surface because it does not have a long storage life and is not resistant to electrical contact corrosion when exposed to environmental extremes found in the environment. motorized vehicles. These environmental extremes include temperatures ranging from about -40 ° C to about 85 ° C and humidities ranging from about 0% to about 100%. In addition, the mirrors must survive at these temperatures and humidity by times of color cycles of up to 100,000 cycles. The other materials of the prior art (silver / copper, chromium, stainless steel, rhodium, platinum, palladium, Inconel®, copper or titanium) suffer from one or a variety of deficiencies such as: very poor color neutrality (silver / copper) and copper); poor reflectance (chrome, stainless steel, rhodium, platinum, palladium, Inconel® and titanium) or poor cleaning capacity (chrome). When silver is bonded with certain materials to produce a third surface reflector / electrode, the deficiencies associated with silver metal and aluminum metal can be overcome. Suitable materials for the reflective layer are silver / palladium alloys, silver / gold, silver / platinum, silver / rhodium, silver / titanium, etc. The amount of the solute material, for example palladium, gold, etc. may vary. As can be seen from table 1, the silver alloys surprisingly retain the high reflectance and low silver sheet strength properties, while simultaneously improving their contact stability, shelf life and also increase their potential stability space when they are used as electrodes in propylene carbonate containing 0.2 molar tetraethylammonium tetrafluoroborate. The presently preferred materials for the highly reflective layer 121 are Ag / Au, Ag / Pt and Ag / Pd. More commonly, the reflector / electrode 120 has, in addition to the layer of a highly reflective alloy 121, an optional base layer of a conductive metal or alloy 122 deposited directly on the third surface 114a. There may also be an optional intermediate layer of a conductive metal or alloy 123 disposed between the layer of the highly reflective material 121 and the base coat 122. If the reflector / electrode 120 includes more than one layer there should be no galvanic corrosion between the two metals or alloys. If the optional base layer 122 is deposited between the highly reflective layer 121 and the glass element 114, it must be environmentally robust, for example sticking well to the third (glass) surface 114a and the highly reflective layer 121 and maintaining this bond when the seal 116 is glued to the reflective layer. The base layer 122 should have a thickness from about 50 A to about 2000 A and more preferably from about 100 A to about 1000 A. Suitable materials for the base layer 122 are chrome, stainless steel, titanium and chromium / molybdenum alloys / nickel, molybdenum and nickel-based alloys (commonly referred to as Inconel®, available from Castle Metals, Chicago, IL). The main constituents of Inconel® with nickel can fluctuate from approximately 52% to 76% (Inconel® 617 and 600 respectively), iron that can fluctuate from 1.5% to 18.5% (Inconel® 617 and Inconel® 718 respectively) and chromium that it can fluctuate from 15% to 23% (Inconel® 600 and Inconel® 601 respectively). In the present examples Inconel® 617 was used which has 52% nickel, 1.5% iron, 22% chromium and "other" typical constituents including 12.5% cobalt, 9.0% molybdenum and 1.2% aluminum. In some instances it is desirable to provide an optional intermediate layer 123 between the highly reflective layer 121 and the base layer 122 in the event that the material of the layer 121 does not adhere well to the material of the layer 122 or that there are any adverse interactions between the materials, for example galvanic corrosion. If used, the intermediate layer 123 should exhibit robustness or environmental resistance, for example sticking well to the base layer 122 and the highly reflective layer 121 and maintain this bond when the seal element 116 is bonded to the highly reflective layer 121. The thickness of the intermediate layer 123 ranges from about 50 Á to about 2000 Á and more preferably from about 100 Á to about 1000 Á. Suitable materials for the optional intermediate layer 123 are molybdenum, rhodium, stainless steel, titanium, copper, nickel and platinum. Reference is made to Examples 1 and 2 to show how the insertion of an intermediate layer of rhodium between a base layer of chromium and a reflecting layer of silver or silver alloy increases the time to failure in accelerated acetic acid aspersion by copper (CASS) by a factor of 10. Example 4 shows how the insertion of an intermediate layer of molybdenum between a base layer of chromium and a silver alloy having an instantaneous coating of molybdenum increases the time to failure in CASS by a factor of 12. Finally, it is sometimes desirable to provide an optional instantaneous coating 124 on the highly reflective layer 121 such that it is contacted (and not the highly reflective layer 121) with the electrochromic medium. This instantaneous coating layer 124 must have a stable behavior as an electrode, it must have a good storage life, it must stick well to the highly reflective layer 121 and maintain this bond when the sealing element 116 is glued to it. It should be thin enough that it does not completely block the reflectivity of the highly reflective layer 121. According to another embodiment of the present invention, when a very thin instantaneous coating 124 is placed on the highly reflective layer, then the highly reflective layer 121 can consist of a silver metal or a silver alloy because the instantaneous coating layer protects the highly reflective layer while still allowing the highly reflective layer 121 to contribute to the reflectivity of the mirror. In such cases a thin layer (from about 25 A and about 300 A) of rhodium, platinum or molybdenum is deposited on the highly reflective layer 121. It is preferable, but not essential, that the reflector / third surface electrode 121 be maintained as the cathode in the circuits because this eliminates the possibility of anodic dissolution or anodic corrosion that could occur if the reflector / electrode were used as the anode. Although as can be seen in the table, if certain silver alloys with the used positive potential limit of stability are sufficiently extended, for example 1.2 volts, in such a way that the silver alloy reflector / electrode could be used safely as the anode in contact with at least one electrochromic material in the solution phase.

Table 1 Metal Reflectance of light Reflectance in Stability §1 Potential limit White potential limit in air negative contact device of positive space of stability space of potential stability (V) potential (V) Al > 92 N / A very poor N / AN / A Cr 65 N / A deficient N / AN / A Stainless steel 60 N / A good N / AN / A Rh 75 N / A very good N / AN / A Pt 72 N / A very good N / AN / A Inconel 55 N / AN / AN / AN / A Ag 97 84 fair -2.29 0.86 Ag2.7Pd 93 81 good -2.26 0.87 AglOPd 80 68 good -2.05 0.97 Ag6Pt 92 80 good -1.66 * 0.91 Ag6Au 96 84 good -2.25 0.98 Agl5Au 94 82 good -2.3 1.2 * This number is supposed to be due to the fact that the test was carried out on propylene carbonate containing some water.

The various reflector / electrode layers 120 can be deposited by a variety of deposition methods, such as RF and DC sputtering, electron beam evaporation, chemical vapor deposition, electrodeposition, etc., which are known to those skilled in the art. in the technique. Preferred alloys are preferably deposited by sputtering (RF or DC) a target of the desired alloy or by sputtering targets separate from the individual metals that make up the desired alloy, such that mixing metals during the Deposition process and the desired alloy occur when the mixed metals are deposited and solidified on the surface of the substrate. In another embodiment, the reflector / electrode 120 shown in Figure 4 has at least 2 layers (121 and 122) wherein at least one layer of a base material 122 covers the entire portion of the third surface 114a (except for sections separate for a screen device and a glare detector according to the North American patent application entitled "AN INFORMATION DISPLAY AREA ON ELECTROCHROMIC MIRRORS HAVING TO THIRD SURFACE REFLECTOR") and at least one layer of a highly reflective material 121 covers the section internal of the third surface 114a but does not cover the peripheral edge portion 127 where the sealing element 116 is disposed. The peripheral portion 127 may be created by masking that portion of the layer 122 during deposition of the highly reflective material layer 121 or the layer of highly reflective material can be deposited on the entire third surface and subsequently removed or partially removed. in the peripheral portion. The masking of the layer 122 can be carried out by the use of a physical mask or by other well-known techniques such as photolithography and the like. Alternatively, the layer 122 may be partially separated in the peripheral portion by a variety of techniques such as for example etching (laser, chemical or otherwise), mechanical scraping, sand spraying or the like. Engraving or laser attack is the currently preferred method due to its accuracy, speed and control. The partial removal is preferably carried out by laser etching in a configuration where enough metal is separated or removed to allow the sealing element 116 to stick directly to the third surface 114a while leaving enough metal in this area of such that the conductance in this area is not significantly reduced. For example, the metal can be separated into a dot pattern or other geometric shape as taught for removal of metal to display information in the US patent application referenced above. In addition, an optional intermediate layer of a conductive material 123 may be placed over the entire area of the third surface 114a and exposed between the highly reflective layer 121 and the base layer 122 or may be placed only below the area covered by the layer 121, that is, not on the peripheral edge portion 127. If this optional intermediate layer is used, it can cover all • the area of the third surface 114a or it can be masked or separated from the peripheral edge portion as discussed above. An optional instantaneous coating layer 124 can be coated on the highly reflective layer 121. The highly reflective layer 121, the optional intermediate layer 123 and the base layer 122 have properties similar to those described above, except that the layer of highly reflective material 121 it does not need to stick well to the epoxy seal since it is separated at the peripheral portion where the seal element 116 is placed. Because the interaction with the epoxy seal is eliminated, the silver metal itself, in addition to the alloys of Silver described above, will function as the highly reflective layer.

Referring again to Figure 3, the chamber 127 defined by the transparent conductor 128 (disposed on the rear surface 112b of the front element), the reflector / electrode 120 (disposed on the front surface 114a of the rear element) and a circumferential wall internal 132 of the sealing element 116 contains an electrochromic means 126. The electrochromic means 126 is capable of attenuating the light that travels through it and has at least one electrochromic material in the solution phase in intimate contact with the reflector / electrode 120. and at least one additional electroactive material which may be a solution phase, combined on the surface or one which is coated on a surface. However, the presently preferred means are solution-phase redox electrochromic materials such as those described in the aforementioned US Pat. Nos. 4,902,108; 5,128,799, 5,278,693; 5,280,380; 5,282,077; 5,294,376; 5,336,448. The US patent application filed on the same date entitled "AN IMPROVED ELECTROCHROMIC MÉDIUM CAPABLE OF PRODUCING A PRE-SELECTED COLOR" describes electrochromic media that are perceived as gray throughout their normal range of operation. The entire description of this application is incorporated herein by reference. If an electrochromic medium is used in the solution phase, it can be inserted into the chamber 125 through a sealable fill orifice 142 by means of well-known techniques such as vacuum filling and the like. A resistive heating element 138 disposed on the fourth glass surface 114b may optionally be an ITO layer, tin oxide doped with fluorine or may consist of other heating layers or structures well known in the art. Electrically conductive spring fasteners 134a and 134b are placed on the coated glass sheets (112 and 114) to make electrical contact with the exposed areas of the transparent conductive coating 118 (fastener 134b) and the reflector / electrode 120 of the third surface (fastener 134a). Suitable electrical conductors (not shown) can be welded or otherwise connected to the spring clips (134a and 134b) in such a way that a desired voltage can be applied to the device of an appropriate power source. An electrical circuit 150, such as those taught in the Canadian patent referenced above No. 1,300,945 and U.S. Patent Nos. 5,204,778; 5,434,407 and 5,451,822 is connected to and allows the control of the potential to be applied through the reflector / electrode 120 and the transparent electrode 128 in such a way that the electrochromic means 126 will be obscured and thereby attenuate various amounts of light traveling through it. and thus varies the reflectance of the mirror containing the electrochromic means 126. As stated above, the low resistance of the reflector / electrode 120 allows for greater design flexibility by allowing the electrical contact for the reflector / electrode of the third surface to be small while maintaining an appropriate color velocity. This flexibility extends to improve interconnection techniques to the transparent conductive material layer 128 on the second surface 112b. Referring now to Figures 5a and 5b there is shown an improved mechanism for applying a drive potential to the layer of transparent conductive material 128. The electrical connection between the power supply and the layer of transparent conductive material 128 is made by connecting the main distribution bars (or fasteners 119a) to the reflector / electrode area 120a such that the driving potential travels through the area of the reflector / electrode 120a and the conductive particles 116b in the sealing element 116b before reaching the driver transparent 128. The reflector / electrode should not be present in the area 120c in such a way that there is no opportunity for current flow from the reflector / electrode area 120a to 120b. This configuration is advantageous since it allows connection to the transparent conductive material 128 almost around the entire circumference and therefore improves the rate of attenuation and clarification of the electrochromic means 126. In such configuration, the sealing element 116 comprises a typical sealant material, for example epoxy 116a with conductive particles 116b contained therein. The conductive particles can be adhesives such as plastic coated with gold, silver, copper, etc. with a diameter ranging from about 5 microns to about 8 microns in which case there must be a sufficient number of particles to ensure sufficient conductivity between the reflector / electrode area 120a and the transparent conductive material 128. Alternatively, the conductive particles may be Large enough to act as separators, such as for example glass or plastic beads coated with gold, silver, copper, etc. The reflector / electrode 120 is separated into two different reflector / electrode areas (120a and 120b, separated by an area 120c devoid of reflector / electrodes). There are many methods for separating reflector / electrode 120 from area 120c such as chemical etching, laser ablation, physical scraping, etc. Deposition in area 120c can also be avoided by the use of a mask during the deposition of the reflector / electrode. The sealing element 116 with particles 116b contacts the area 120z in such a way that there is a conductive path between the reflector / electrode area 120a and the transparent conductive material layer 128. Thus, the electrical connection to the reflector area / electrode 120b which imparts a potential to the electrochromic means is connected by means of fasteners 119b to the electronic circuits in the area of the reflector / electrode 120d (figure 5b). No conductive particle 116b can be placed in this reflector / electrode area 120b due to the possibility of an electrical short between the reflector / electrode area 120b and the area of transparent conductive material 128. If such an electrical short were to occur the electrochromic device would not it would work properly. Additionally, no conductive seal 116b should be present in the 120d area. A variety of methods can be used to ensure that no conductive particle 116b enters this reflector / electrode area 120b, such as for example disposition of a non-conductive material to the reflector / electrode area 120c devoid of conductive material. A double doser could be used to deposit the seal 116 with conductive particles 116b over the area of the reflector / electrode 120a and simultaneously deposit the non-conductive material to the area of the reflector / electrode 120c. Another method would be to cure a nonconductive seal in the area 120c and then arrange a conductive material 116c to the edge space to electrically interconnect the reflector / electrode area 120a with the transparent conductive layer 128. A general method to ensure that no conductive particle arrives The area of the reflector / electrode 120b is to ensure that the seal 116 has appropriate flow characteristics, such that the conductive portion 116b tends to remain behind as the sealant is ejected during assembly and only the non-conductive portion of the flow 116 to area 120b. In an alternative embodiment, the spacer element 116 need not contain conductive particles and a conductive element or material 116c may be placed on or at the outer edge of the element 116 to interconnect the transparent conductive material 128 to the area of the reflector / electrode 120a. Still another embodiment of an improved electrical interconnection technique is illustrated in Figure 6 wherein a first portion of the sealant element 116 is applied directly on the third surface 114a and cured before the application of the reflector / electrode 120. Then the reflector / electrode 120 is deposited on the third surface 114a on the first portion of the sealing element 116, a portion of the cured seal element 116 is machined to leave the portion 116i as shown with a predetermined thickness (which will vary depending on the desired cell spacing between the second surface 112b and the third surface 114a). The cell spacing ranges from about 20 microns to about 400 microns and preferably ranges from about 90 microns to about 230 microns. By curing the first portion of the sealing and machining element to a predetermined thickness (116i) the need for the glass beads to ensure a constant cell spacing is eliminated. Glass beads are useful for providing cellular spacing, however, they provide stress points where they are contacted with the reflector / electrode 120 and the transparent conductor 128. By removing the glass beads these stress points are also eliminated. During the maging, the reflector / electrode 120 which is coated on the first portion of the sealing element 116 is removed to leave an area devoid of reflector / electrode 120. Then a second portion of the sealing element 116ii is deposited on the machined area of the electrode. the first portion of the sealing element 116i or the coatings on the second surface 12b in the area corresponding to 116i and the sealing element 116ii is cured after assembly in a conventional manner. Finally, an external conductive sealing element 117 may optionally be deposited on the outer peripheral portion of the sealing element 116 to make electrical contact between the outer edge of the reflector / electrode 120 and the outer peripheral edge of the transparent conductive material layer 128. This configuration is advantageous since it allows connection to the transparent conductive material 128 almost all around the circumference and therefore improves the rate of attenuation and clarification of the electrochromic means 126. With reference again to Figure 2, the rear-view mirrors that implement The present invention preferably includes a molding 144 extending around the entire periphery of each individual assembly 110, Illa and / or 111b. The molding 144 hides and protects the spring clips 134a and 134b of Fig. 3 (or 116a and 116b of Fig. 5a, 116i, 116ii and 117 of Fig. 6) and the peripheral edge portions of the sealing element and the sealing elements. front and rear glass (112 and 114 respectively). A wide variety of molding designs are well known in the art, such as for example the molding taught and claimed in U.S. Patent No. 5,448,397 referred to above. There is also a wide variety of boxes well known in the art for attaching the mirror assembly 110 to the interior front windshield of an automobile or for attaching the mirror assemblies Illa and 111b to the exterior of an automobile. A bracket or bracket of the preferred assembly is described in U.S. Patent No. 5,337,948 referred to above. The electrical circuit preferably incorporates a room light detector (not shown) and a glare light detector 160, the glare detector is positioned either behind the mirror glass and is viewed through a section of the mirror with the reflector material completely or partially removed or the glare detector can be positioned outside the reflecting surfaces, for example in the molding 144. Additionally, an area or areas of the reflector and electrode, such as 146 can be removed completely. or partially for example in a configuration of points or lines to allow a fluorescent vacuum screen, such as a compass, watch or other indicia to be displayed to the driver of the vehicle. The US patent application filed on the same date as the present one, referred to above entitled "AN INFORMATION DISPLAY AREA ON ELECTROCHROMIC MIRRORS HAVING TO THIRD SURFACE REFLECTOR" shows a currently preferred line configuration. The present invention is also applicable to a mirror which uses only a video chip light detector to measure glare and ambient light and which is also capable of determining the direction of glare. An automatic mirror inside the vehicle, constructed in accordance with this invention can also control one or both exterior mirrors as dependents in an automatic mirror system. The following examples propose not to limit the scope of the present invention but to illustrate its application and use: EXAMPLE 1 Electrochromic mirror devices incorporating a high reflectivity third surface reflector / electrode were prepared by sequentially depositing approximately 700 Á of chromium and approximately 500 Á of silver on the surface of sheets of 2.3 mm thickness of float glass of soda lime plane cut to a shape of automotive mirror element. A second set of reflectors / electrodes of high reflectivity third surface were also prepared by sequentially depositing 700 Á of chromium and about 500 Á of a silver alloy containing 3% by weight of palladium on the shapes of the glass element. The deposition was carried out by passing the shapes of the glass element past the separated metal targets in a magnetron sputtering system with a base pressure of 3 X 10 ~ 6 torricellis and an argon pressure of 3 X 10 ~ 3 torricellis. The automotive glass mirror shapes of chrome / silver alloy and chrome / silver 3% palladium were used as the back plane elements of an electrochromic mirror device. The front element consisted of a sheet of glass covered with TEC 15 transparent conductor of LOF cut similar in shape and size to the rear glass element. The front and back elements were glued together by a perimetric epoxy seal with the flat conductive surfaces facing each other and parallel to each other with a displacement. The spacing between the electrodes was approximately 137 microns. The devices were filled under vacuum through a filling hole left in the perimeter seal with an electrochromic solution composed of: 5,10-dihydro-510-dimethylphenacin 0.028 molar. Di (tetrafluoroborate) of 1,1 '-di- (3-phenyl- (n-propane)) -4, 0.034 molar bipyridinium. 2- (2'-Hydroxy-5'-methylphenyl) -benzotriazole 0.030 molar in a 3% by weight solution of Elvacite ™ 2051 polymethylmethacrylate resin dissolved in propylene carbonate. The filling hole was covered with a curing adhesive by ultraviolet radiation which was cured by exposure to ultraviolet light. The devices were subjected to accelerated durability testing until the integrity of the device seal is broken or the lamination of the reflector / electrode layers or the transparent electrode layers were substantially degraded or dilapidated at which time the device is said to fail . The first test carried out consisted of a steam autoclave test in which the devices were sealed in a container containing water and subjected to a temperature of 120 ° C at a pressure of 1.05 Kg / cm2 (15 pounds per square inch) (psi)). The second test carried out was copper accelerated acetic acid aspersion with copper (CASS) as described in the ASTM B 368-85 standard. When electrochromic devices were observed after one day of testing, all devices failed to withstand CASS tests and all devices failed to withstand steam autoclave tests.

EXAMPLE 2 In a manner other than as specifically mentioned, the devices in this example were constructed in accordance with the conditions and teachings in Example 1. A multilayer combination of reflector / electrodes was prepared by sequentially depositing approximately 700A of chromium, approximately 100 A rhodium and approximately 500 A of silver on the surface of the shapes of glass elements. A second set of multilayer reflector / electrode combinations were also prepared by sequentially depositing approximately 700 Á of chromium, approximately 100 Á of rhodium and approximately 500 Á of a silver alloy containing 3% by weight of palladium on the surface of the forms of glass element. The electrochromic devices were constructed and tested according to example 1. The device incorporating the sequential multilayer combination of reflector / chrome electrode, rhodium and silver endured the steam autoclave test twice as long and the CASS tests ten times more than the device of example 1 before failures occurred. The device incorporating the sequential multilayer combination of reflector / electrode of chrome, rhodium and 3% palladium silver alloy withstands steam autoclaving tests three times more and CASS tests ten times more than the devices in example 1 before the flaws showed up.

EXAMPLE 3 In a manner different from that specifically mentioned, the devices in this example were constructed in accordance with the conditions and teachings in Example 1. Multi-layer reflector / electrode combinations were prepared by sequentially depositing about 700 μA of chromium, approximately 500 A of molybdenum and approximately 500 A of a silver alloy containing 3% by weight of palladium on the surface of the shapes of the glass element. The electrochromic devices were conceived and tested according to example 1. The device incorporating the sequential multilayer combined electrode / reflector of chrome, molybdenum and 3% palladium silver alloy withstood the CASS tests ten times more than the devices in Example 1 before the failures were presented.

EXAMPLE 4 Differently from what is specifically mentioned, the devices in this example were constructed in accordance with the conditions and teachings in Example 1. Multi-layer combinations of reflector / electrode were prepared by sequentially depositing about 700 μA of chromium, approximately 500A of a silver alloy containing 3% by weight of palladium and about 100A of molybdenum on the surface of the shapes of the glass element. A second multilayer reflector / electrode combination assembly was also prepared by sequentially depositing about 700 A of chromium, about 500 A of molybdenum, about 500 A of a silver alloy containing 3 wt.% Of palladium and about 100 A of molybdenum on the surface of the shapes of the glass element. The electrochromic devices were constructed and tested according to example 1. The device incorporates the sequential multilayer reflector / electrode combination of chromium, molybdenum, 3% palladium silver, molybdenum supported the autoclave tests with 25% more steam and CASS tests twelve times more than the reflector / electrode device in sequential multilayer combination of chromium, silver 3% palladium, molybdenum before failure occurred. Also, the device incorporating the reflector / electrode in combination in sequential multilayer of chromium, molybdenum, silver 3% palladium, molybdenum supported the CASS tests three times more than the device constructed in example 3. Finally, the device in combination reflector / electrode in multilayer sequential chrome, silver 3% palladium, molybdenum supported twice CASS tests and twenty times more autoclave tests with steam than the device in combination reflector / electrode in sequential chrome multilayer, 3% palladium silver of example 1.

EXAMPLE 5 In a manner other than as specifically mentioned, the devices in this example were constructed in accordance with the conditions and teachings in Example 1. A multilayer reflector / electrode combination is prepared by sequentially depositing about 700 μA of chromium, approximately 100 Á of rhodium and approximately 500 Á of silver on the surface of the forms of glass element. A second multi-layer reflector / electrode combination assembly is also prepared by sequentially depositing around 700 Á of chromium, approximately 100 Á of rhodium and approximately 500 Á of a silver alloy containing 3% by weight of palladium on the surface of the forms of glass element. A third multi-layer reflector / electrode assembly is also prepared by sequentially depositing about 700 Á of chromium, about 100 A of rhodium and about 500 Á of a silver alloy containing 6% by weight of platinum on the surface of the shapes of the glass element. A fourth multi-layer reflector / electrode assembly is also prepared by sequentially depositing about 700 Á of chromium, about 100 Á of rhodium and about 500 Á of a silver alloy containing 6% by weight of gold on the surface of the shapes of the glass element. A fifth multi-layer combination reflector / electrode assembly is also prepared by sequentially depositing about 700 chromium A, approximately 100 Á of rhodium and approximately 500 Á of a silver alloy containing 15% by weight of gold on the surface of the shapes of the glass element. The electrochromic devices were constructed in accordance with Example 1. Conductive fasteners were connected to the offset portions of the front and rear elements of the devices. A power source was connected to the fasteners and 1.2 volts are applied to the devices continuously for approximately 250 hours at a temperature of approximately 20 degrees Celsius, the connection is arranged in such a way that the reflector / electrode consists of the cathode. The device incorporating the reflector / electrode in sequential multi-layer combination of chromium, rhodium and silver exhibits a yellowing effect in the electrochromic medium. This phenomenon of yellowing was not evident in any of the silver alloy devices. While the invention has been described in detail herein in accordance with certain preferred embodiments thereof, many modifications and changes thereto can be made by those skilled in the art without deviating from the spirit of the invention. Thus, it is not intended to be limited only by the scope of the appended claims and in no way by the details and instrumentations describing the embodiments shown herein. It is noted that, in relation to this date, the best method known by the applicant to carry out the aforementioned invention is conventional for the manufacture of the objects to which they refer.

Claims (36)

1. Claims Having described the invention as above, the content of the following claims is claimed as property: 1. An electrochromic mirror of variable reflectance for automotive vehicles, characterized in that it comprises front and rear spacing elements, each having front and rear surfaces, the surface After the front element has a layer of transparent conductive material disposed thereon, the front surface of the rear element has a reflector / electrode including at least one layer of highly reflective silver alloy, wherein the front and rear spaced elements are united in a sealable manner together in spaced apart relationship to include a chamber, wherein the chamber contains at least one electrochromic material in solution phase in contact with the reflector / electrode and wherein the reflector / electrode is effective to reflect light through d the means and the front element when the light reaches the reflector / electrode after passing through the front element and the at least one electrochromic material. The mirror according to claim 1, characterized in that the silver alloy is a combination of silver and an element selected from the group consisting essentially of gold, platinum, rhodium and palladium. The mirror according to claim 1, characterized in that the reflector / electrode comprises a plurality of layers. 4. The mirror in accordance with the claim 3, characterized in that the reflector / electrode further includes a base layer disposed below the highly reflective alloy. 5. The mirror in accordance with the claim 4, characterized in that the base layer comprises a material selected from the group consisting essentially of: chromium; chrome-molybdenum-nickel alloys; nickel-iron-chromium alloys; stainless steel and titanium. 6. The mirror in accordance with the claim 5, characterized in that the reflector / electrode further includes at least one intermediate layer disposed between the highly reflective alloy and the base layer, wherein the intermediate layer comprises a material selected from the group consisting essentially of: molybdenum; rhodium; stainless steel and titanium. 7. The mirror in accordance with the claim 6, characterized in that the reflector / electrode further includes at least one instantaneous deposited overlay deposited on the highly reflective layer, wherein the instantaneously deposited overlayer comprises a material selected from the group consisting essentially of: rhodium, molybdenum and platinum. The mirror according to claim 1, characterized in that the layer of transparent conductive material has a sheet resistance ranging from about 0.1 ohms per square to about 40 ohms per square. The mirror according to claim 12, characterized in that the sheet resistance of the multilayer transparent conductor ranges from about 0.5 ohms per square to about 15 ohms per square. 10. An electrochromic mirror of variable reflectance for automotive vehicles, characterized in that it comprises front and rear spaced elements, each having front and rear surfaces, the rear surface of the element. The front panel has a layer of transparent conductive material disposed thereon, the front surface of the rear element has a reflector / electrode including at least one layer of highly reflective material and an instantaneous coating layer wherein the front and rear spaced elements are sealingly joined together in a spaced apart relation to define a chamber, wherein the chamber contains at least one electrochromic material in solution phase in contact with the instantaneous deposition layer and wherein the reflector / electrode is effective to reflect light through the medium and the front element when the light reaches the reflector / electrode after passing through the front element and in at least one electrochromic material. 11. The mirror in accordance with the claim 10, characterized in that the highly reflective material is a material selected from the group consisting of silver and silver alloys, wherein the silver alloy is a combination of silver and an element selected from the group consisting essentially of gold, platinum, rhodium and palladium. The mirror according to claim 11, characterized in that the reflector / electrode further includes a base layer disposed below the highly reflective alloy. The mirror according to claim 12, characterized in that the base layer comprises a material selected from the group consisting essentially of: chromium; chrome-molybdenum-nickel alloys; nickel-iron-chromium alloys; stainless steel and titanium. 14. The mirror in accordance with the claim 11, characterized in that the reflector / electrode further includes at least one intermediate layer disposed between the highly reflective alloy and the base layer, wherein the intermediate layer comprises a material selected from the group consisting essentially of: molybdenum; rhodium; stainless steel and titanium. 15. The mirror in accordance with the claim 10, characterized in that the instantaneously deposited overlayer comprises a material selected from the group consisting essentially of: rhodium, molybdenum and platinum. 16. An electrochromic mirror of variable reflectance for automotive vehicles, characterized in that it comprises spaced front and rear elements, each having front and rear surfaces, the rear surface of the front element has a layer of transparent conductive material disposed thereon, the front surface of the rear element has a reflector / electrode comprising a base layer covering the entire portion of the front surface of the rear element and at least one additional layer covering an internal portion of the front surface of the rear element, the at least one The additional layer includes a layer of highly reflective material, wherein the spaced apart front and back elements are jointly joined together in a spaced apart relationship to define a chamber, wherein the chamber contains at least one electrochromic material in the solution phase in contact with the reflector / electrode and wherein the reflector / electrode is effective to reflect light through the medium and the front element when the light reaches the reflector / electrode after passing through the front element and into at least one electrochromic material. The mirror according to claim 16, characterized in that the highly reflective material is a material selected from the group consisting of silver and silver alloys, wherein the silver alloy is a combination of silver and an element selected from the group that consists essentially of gold, platinum, rhodium and palladium. The mirror according to claim 16, characterized in that the base layer comprises a material selected from the group consisting essentially of: chromium; chrome-molybdenum-nickel alloys; nickel-iron-chromium alloys; stainless steel and titanium. The mirror according to claim 16, characterized in that the reflector / electrode further includes at least one intermediate layer disposed between the highly reflective alloy and the base layer, wherein the intermediate layer comprises a material selected from the group consisting essentially of of: molybdenum; rhodium; stainless steel; titanium and alloys and combinations thereof. 20. The mirror according to claim 19, characterized in that the intermediate layer covers the entire surface of the front surface of the rear element. The mirror according to claim 19, characterized in that the intermediate layer covers the internal portion of the front surface of the rear element. 22. The mirror according to claim 16, characterized in that the reflector / electrode further includes at least one instantaneous deposition overlay disposed on the highly reflective layer, wherein the instantaneously deposited overlayer comprises a material selected from the group consisting essentially of: rhodium, molybdenum and platinum. The mirror according to claim 16, characterized in that the layer of transparent conductive material has a sheet resistance ranging from about 0.1 ohms per square to about 40 ohms per square. The mirror according to claim 16, characterized in that the sheet resistance of the multilayer transparent conductor ranges from about 0.5 ohms per square to about 15 ohms per square. 25. The mirror according to any of claims 1, 20 and 16, characterized in that the reflector / electrode is removed in a peripheral portion. 26. The mirror according to claim 25, characterized in that the reflector / electrode is removed by a technique selected from the group consisting of etching, mechanical scraping and sand spraying. 27. An electrochromic mirror of variable reflectance for automotive vehicles, characterized in that it comprises spaced front and rear elements, each having front and rear surfaces, the rear surface of the front element has a layer of transparent conductive material disposed thereon, the front surface of the rear element has at least one layer of a reflector / electrode comprising a highly reflective material covering an internal portion of the front surface of the rear element and extending to a small area of an edge thereof, a conductive material arranged on a peripheral portion of the front surface of the rear element separated from the reflector / electrode by an area devoid of reflector / electrode and conductive material, the front and rear spaced elements are joined together in spaced apart relation to define a chamber by means of a sealing element disposed on the conductive material, wherein the mirror further includes means for providing electrical interconnection between the conductive material and the transparent conductive material, wherein the chamber contains at least one electrochromic material in the solution phase in contact with the reflector / electrode and wherein the reflector / electrode is effective to reflect light through the medium and the front element when the light reaches the reflector / electrode after passing through the front element and into at least one electrochromic material. 28. The mirror in accordance with the claim 27, characterized in that the interconnection means comprise conductive particles arranged in the sealing element. 29. The mirror in accordance with the claim 28, characterized in that the conductive particles consist of silver. 30. The mirror according to claim 28, characterized in that the conductive particles are beads coated with a conductive material. The mirror according to claim 30, characterized in that the conductive beads are coated with one of: gold, silver and copper and used as separators. 32. The mirror according to claim 28, characterized in that the interconnection means comprise a conductive interconnecting material disposed on the outer edge of the sealing element. 33. The mirror in accordance with the claim 27, characterized in that a non-conductive material is disposed on the portion of the front surface of the rear element devoid of the conductive material. 34. An electrochromic mirror of variable reflectance for automotive vehicles, characterized in that it comprises front and rear spaced elements, each having front and rear surfaces, the rear surface of the front element has a layer of transparent conductive material disposed thereon, the front surface of the rear element has a first cured portion of a peripheral sealing element covered by a reflector / electrode comprising a highly reflective material, wherein the first cured portion of the sealing element is removed to a predetermined thickness such that the reflector / electrode is separated into an inner portion covering an inner portion of the front surface of the rear element and extending to a small area of one edge thereof and an outer portion separated from the inner portion by the first cured portion of a sealing element , where the external portion of The reflector / electrode is not in electrical contact with the inner portion, the spaced front and rear elements are glued together, in a spaced apart relationship to define a chamber, by a second portion of the sealing element disposed on the first cured portion of the sealing element, wherein the mirror further includes means for providing interconnection between the external portion of the reflector / electrode and the transparent conductive material, wherein the chamber contains at least one electrochromic material in the solution phase in contact with the reflector / electrode and wherein the reflector / electrode is effective to reflect light through the medium and the front element when the light reaches the reflector / electrode after passing through the front element and in at least one electrochromic material. 35. The mirror in accordance with the claim 34, characterized in that the interconnection means comprise a conductive interconnecting material disposed on the outer edge of the sealing element. 36. The mirror in accordance with the claim 35, characterized in that the conductive interconnecting material comprises a material selected from a conductive epoxy and a conductive paint.