Rearview mirror assembly for vehicle

An electro-optic mirror reflective element for a rearview mirror assembly for a vehicle, said electro-optic mirror reflective element operable to exhibit electrically variable reflectivity between a high reflectance state and a dimmed reflectance state when an electrical voltage is applied thereto, said electro-optic mirror reflective element comprising:

• a front substrate having a first surface and a second surface;
• a rear substrate having a third surface and a fourth surface;
• wherein said second surface of said front substrate and said third surface of said rear substrate oppose each other and are spaced apart by a perimeter seal, and wherein an electro-optic medium is disposed between said second surface of said front substrate and said third surface of said rear substrate and is bounded by said perimeter seal;
• wherein said electro-optic mirror reflective element comprises an electrochromic mirror reflective element, and wherein said electro-optic medium comprises an electrochromic medium;
• wherein no part of said rear substrate extends beyond said front substrate;
• a transparent electrically conductive coating established at said second surface of said front substrate;
• a specularly reflective mirror reflector established at said third surface of said rear substrate;
• wherein said specularly reflective mirror reflector comprises a stack of thin film layers;
• wherein said stack of thin film layers comprises (i) an environmentally stable electrically conductive metallic reflecting thin film layer, (ii) an environmentally vulnerable electrically conductive metallic reflecting thin film layer and (iii) a transparent electrically conductive thin film layer;
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer comprises a layer of chromium;
• wherein said environmentally vulnerable electrically conductive metallic reflecting thin film layer overcoats said layer of chromium;
• wherein said environmentally vulnerable electrically conductive metallic reflecting thin film layer comprises a layer of a metallic material selected from the group consisting of (i) aluminum and (ii) aluminum alloy;
• wherein said transparent electrically conductive thin film layer comprises a layer of aluminum doped zinc oxide;
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer is closer to said third surface of said rear substrate than is said environmentally vulnerable electrically conductive metallic reflecting thin film layer;
• wherein said environmentally vulnerable electrically conductive metallic reflecting thin film layer is closer to said third surface of said rear substrate than is said transparent electrically conductive thin film layer;
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer extends outward beyond said perimeter seal at a perimeter region of said rear substrate toward a perimeter edge of said rear substrate;
• and
• wherein said specularly reflective mirror reflector is contacted by an environmentally stable material at the perimeter region of said rear substrate.

An electro-optic mirror reflective element for a rearview mirror assembly for a vehicle, said electro-optic mirror reflective element operable to exhibit electrically variable reflectivity between a high reflectance state and a dimmed reflectance state when an electrical voltage is applied thereto, said electro-optic mirror reflective element comprising:

• a front substrate having a first surface and a second surface;
• a rear substrate having a third surface and a fourth surface;
• wherein said second surface of said front substrate and said third surface of said rear substrate oppose each other and are spaced apart by a perimeter seal, and wherein an electro-optic medium is disposed between said second surface of said front substrate and said third surface of said rear substrate and is bounded by said perimeter seal;
• wherein said electro-optic mirror reflective element comprises an electrochromic mirror reflective element, and wherein said electro-optic medium comprises an electrochromic medium;
• wherein no part of said rear substrate extends beyond said front substrate;
• a transparent electrically conductive coating established at said second surface of said front substrate;
• a specularly reflective mirror reflector established at said third surface of said rear substrate;
• wherein said specularly reflective mirror reflector comprises a stack of thin film layers;
• wherein said stack of thin film layers comprises (i) an environmentally stable electrically conductive metallic reflecting thin film layer, (ii) an environmentally vulnerable electrically conductive metallic reflecting thin film layer and (iii) a transparent electrically conductive thin film layer;
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer comprises a layer of chromium;
• wherein said environmentally vulnerable electrically conductive metallic reflecting thin film layer comprises a layer of a metallic material selected from the group consisting of (i) silver, (ii) silver alloy, (iii) aluminum and (iv) aluminum alloy;
• wherein said transparent electrically conductive thin film layer comprises a layer of aluminum doped zinc oxide;
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer is closer to said third surface of said rear substrate than is said environmentally vulnerable electrically conductive metallic reflecting thin film layer;
• wherein said environmentally vulnerable electrically conductive metallic reflecting thin film layer is closer to said third surface of said rear substrate than is said transparent electrically conductive thin film layer;
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer extends outward beyond said perimeter seal at a perimeter region of said rear substrate toward a perimeter edge of said rear substrate;
• wherein said environmentally vulnerable electrically conductive metallic reflecting thin film layer deteriorates when exposed to an environment of 85 degrees Celsius and 85 percent relative humidity;
• and
• wherein said environmentally stable electrically conductive metallic reflecting thin film layer is stable when exposed to the environment of 85 degrees Celsius and 85 percent relative humidity.