Abstract:
An electrochromic interior reflective element for an interior rearview mirror assembly of a vehicle includes front and rear substrates and an electrochromic medium sandwiched between the front and rear substrates. The electrochromic medium is disposed in an interpane cavity established between a third surface of the rear substrate and a second surface of said the substrate, and the electrochromic medium is bounded by a perimeter seal. A conductive layer is disposed at a fourth surface of the rear substrate. A non-conductive layer covers a covered portion of the conductive layer and leaves an exposed portion of the conductive layer exposed. An electronic circuitry component is disposed at the fourth surface of the rear substrate. The electronic circuitry component is electrically connected to the exposed portion of the conductive layer.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 13/033,951, filed Feb. 24, 2011, now U.S. Pat. No. 8,179,586, which is a continuation of U.S. patent application Ser. No. 12/580,499, filed Oct. 16, 2009, now U.S. Pat. No. 7,898,719, which is a continuation of U.S. patent application Ser. No. 12/260,499, filed Oct. 29, 2008, abandoned, which is a continuation of U.S. patent application Ser. No. 10/956,749, filed Oct. 1, 2004, now U.S. Pat. No. 7,446,924, which claims the benefit of U.S. provisional application Ser. No. 60/508,086, filed Oct. 2, 2003, which are hereby incorporated herein by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to rearview mirror assemblies for vehicles and, more particularly, to rearview mirror assemblies that include one or more electronic components, such as electro-optic or electrochromic interior rearview mirror assemblies. However, aspects of the present invention may be equally suitable for use in prismatic rearview mirror assemblies and/or for exterior rearview mirror assemblies. 
     BACKGROUND OF THE INVENTION 
     It is known to attach a printed circuit board to an attachment plate adhered or otherwise affixed to a rear surface of a mirror element, such as an electro-optic reflective element assembly or a prismatic reflective element. In order to attach the printed circuit board to the attachment plate, various connectors or clips may be employed at the attachment plate and/or the circuit board. The attachment plate is typically adhered to the rear surface of the mirror element or substrate, such as via a suitable adhesive or tape or the like. The printed circuit board has a rigid printed board or substrate that is cut or formed to a desired form and has conductive traces and circuitry applied to or placed on or attached to the board. The attachment plate and printed board/substrate include multiple parts and components at the rear of the mirror element, which may be costly to manufacture and assemble. The multiple components also add to the size, weight and volume requirements for the circuit board, which thus may add to the size and weight of the mirror assembly. Also, the printed board or substrate material may add to the weight and to the cost of the mirror assembly. 
     Therefore, there is a need in the art for an interior rearview mirror assembly that overcomes the shortcomings of the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention provides an interior or exterior rearview mirror reflective element assembly that includes a conductive trace and circuitry printed on and/or applied at or to the rear surface of the mirror reflective element assembly, such as to the rear surface of the rear reflective element substrate of an electro-optic or electrochromic mirror reflective element assembly or cell. The circuitry thus may be applied to the existing hard or rigid reflective element substrate (typically glass) of the mirror reflective element assembly, such that the reflective element assembly comprises a circuitry on glass arrangement (although the reflective element substrate may comprise other materials, such as acrylic or polycarbonate or the like, without affecting the scope of the present invention), and does not require the additional printed board or substrate and attachment plate of conventional mirror assemblies. The glass substrate or reflective element substrate of the mirror reflective element assembly thus provides the hard or rigid surface for the conductive trace and electrical components and replaces the hard or rigid printed board or substrate of conventional printed circuit boards. The circuitry on glass assembly of the present invention may be applied to reflective elements or reflective element assemblies of interior mirror assemblies, such as interior rearview mirror assemblies and the like, or of exterior mirror assemblies, such as exterior rearview mirror assemblies and the like, or of other mirror assemblies of vehicles, without affecting the scope of the present invention. 
     According to an aspect of the present invention, a reflective element assembly for a mirror assembly of a vehicle includes a reflective element substrate (typically glass) having a rear surface (the surface facing generally away from the driver of the vehicle and facing generally forwardly with respect to the direction of travel of the vehicle when the mirror assembly is installed to the vehicle) and a front surface (the surface facing generally toward a driver of the vehicle and generally rearward with respect to the direction of travel of the vehicle when the mirror assembly is installed to the vehicle). The reflective element assembly includes a conductive trace or layer disposed at the rear surface of the reflective element substrate and a non-conductive layer applied to the conductive trace and covering at least some of the conductive trace and leaving at least one portion of the conductive trace exposed. The reflective element assembly includes at least one circuitry component that is applied to at least one of the portions of the conductive trace. 
     The reflective element substrate may have a reflective layer disposed at one of the front and rear surfaces for viewing by a driver of the vehicle when the mirror assembly is installed to the vehicle. The conductive trace and at least one circuitry component thus are disposed at the rear surface of the existing rigid reflective element substrate (typically glass) that includes or is associated with the reflective surface of the reflective element assembly that is viewable by the driver of the vehicle. 
     For example, a third surface electro-optic or electrochromic transflective element assembly may include a metallic reflective coating or layer and one or more non-metallic, semi-conductive layers disposed at or on a third surface or front surface of the rear or second reflective element substrate. The rear reflective element substrate of the electrochromic reflective element assembly is positioned rearward of the front reflective element substrate, with an electrochromic medium disposed between the front and rear reflective element substrates. The third surface transflective element assembly thus may provide a reflective surface for viewing by the driver of the vehicle through the front reflective element substrate of the reflective element assembly. Alternately, a fourth surface electro-optic or electrochromic reflective element assembly may have a reflective coating or layer disposed on a fourth or rear surface of the rear reflective element substrate for viewing by a driver of the vehicle through the front and rear reflective element substrates or glass substrates of the reflective element assembly or cell. Alternately, the rear surface of a prismatic element or substrate may have a reflective layer disposed thereon or applied thereto for viewing by the driver of the vehicle. 
     In any of these embodiments, the conductive trace of the present invention may be applied at the rear surface of the rear reflective element substrate (or the rear surface of the single substrate for prismatic type mirror assemblies) and rearward of the reflective layer or coating so that the conductive trace and electronic components are not viewable by the driver of the vehicle through the reflective element substrate or substrates of the reflective element assembly. In applications where the reflective layer is disposed at the rear or fourth surface of an electro-optic or electrochromic reflective element assembly or cell, an insulating layer may be applied at the rear surface and over the reflective layer or layers, whereby the conductive trace may be applied to the insulating layer. The present invention thus utilizes the existing reflective element substrate of the mirror reflective element assembly as the rigid substrate for receiving the conductive trace and electronic components and/or circuitry. 
     According to another aspect of the present invention, a method of manufacturing a reflective element assembly for an interior rearview mirror assembly of a vehicle includes providing a reflective element substrate having a front surface and a rear surface. The reflective element substrate has a reflective layer disposed at one of the front and rear surfaces for viewing by a driver of the vehicle when the mirror assembly is installed to the vehicle. A conductive trace or layer is applied to or disposed at the rear surface of the reflective element substrate. A non-conductive layer is applied to the conductive layer to cover at least some of the conductive layer and to leave at least one portion of the conductive layer exposed. At least one circuitry component is applied to the at least one exposed portion of the conductive layer. The conductive trace or layer may comprise a conductive epoxy, such as a conductive silver epoxy or the like, and may be applied in a desired pattern onto the rear surface of the reflective element substrate. 
     The method may include providing the non-conductive material or layer or mask over portions of the conductive trace while exposing other portions or pads for receiving at least one accessory and/or circuitry component or the like, such as sensors, resistors, capacitors, display elements, and the like, thereon. Optionally, a display element, such as a light emitting diode (LED) display element, a vacuum fluorescent (VF) display element, an electroluminescent (EL) display element, a liquid crystal display (LCD) element, or a video display element or the like, may be integrally formed at the rear surface of the reflective element substrate, such that the display information is viewable through the reflective element substrate. Optionally, at least one proximity sensor or antenna may be applied to or clipped to or attached to or positioned along a portion of the rear surface of the reflective element substrate. The at least one proximity sensor or antenna may be operable to detect a presence of a person&#39;s finger at or near the mirror assembly, such as at or near one of the sensors or at or near a corresponding icon on or at the mirror casing or bezel and at which or behind which the proximity sensor is located. The circuitry or component may be operable to actuate a display menu or the like and/or actuate or toggle or control an accessory in response to such a detection. 
     The accessories or circuitry or electrical components may be applied or adhered to the exposed portions or pads of the conductive trace before the conductive trace has cured, such that the curing of the conductive trace may secure the accessories and the like to the conductive trace, or the accessories or circuitry or components may be adhered or secured to the exposed portions after curing of the conductive trace, without affecting the scope of the present invention. 
     The mirror reflective element assembly may comprise an electro-optic or electrochromic mirror reflective element assembly or cell having first and second reflective element substrates. The conductive trace may be applied to the fourth or rear surface of the second or rear reflective element substrate of the electrochromic mirror reflective element assembly. The electrochromic mirror reflective element assembly or cell may include clips or busbars extending at least partially along the upper edge of one of the reflective element substrates and the lower edge of the other of the reflective element substrates. The conductive trace may include portions that extend substantially to the upper and lower edges of the second reflective element substrate to facilitate connection to the clips or busbars. The clips or busbars may contact portions of the conductive trace applied to the rear or fourth surface of the rear or second reflective element substrate to connect the busbars to the circuitry or the like associated with or connected to the conductive trace. 
     Therefore, the interior rearview mirror assembly of the present invention provides a mirror reflective element assembly, such as an electro-optic or electrochromic mirror reflective element assembly or cell or a prismatic reflective element assembly, that includes a conductive trace and circuitry applied to or disposed at a rear surface of a reflective element substrate, such as a rear glass substrate of an electro-optic or electrochromic reflective element assembly or a single glass substrate of a prismatic reflective element assembly or the like, such that at least one electronic component and/or circuitry is integral with the reflective element substrate of the reflective element assembly. The reflective element assembly thus provides a circuitry on glass arrangement and thus utilizes the existing rigid glass reflective element substrate of the reflective element assembly as the rigid surface that receives the conductive trace and circuitry or electronic components thereon. The electronic components and/or circuitry thus are not provided on a separate rigid printed board or substrate that may be snapped onto or otherwise attached to an attachment plate adhered to or otherwise positioned at the rear surface of the reflective element. The rearview mirror reflective element assembly of the present invention thus provides a compact reflective element assembly, which may be readily manufactured, because the reflective element assembly does not include an attachment plate or the like. The mirror reflective element assembly of the present invention thus may provide a low cost, lightweight and compact reflective element assembly that provides for enhanced manufacturing and assembly processes. 
     These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an interior rearview mirror assembly in accordance with the present invention; 
         FIG. 2  is a front elevation of a rear reflective element substrate of a reflective element assembly of the mirror assembly of  FIG. 1 , viewing through the reflective element substrate to show a conductive trace applied to the rear surface of the substrate; 
         FIG. 3  is a rear elevation of the rear reflective element substrate of  FIG. 2 ; 
         FIG. 4  is an enlarged rear elevation of the rear reflective element substrate of  FIGS. 2 and 3 , with components and/or circuitry attached to the conductive trace; 
         FIG. 5  is a rear perspective view of an electrochromic mirror reflective element assembly having the rear reflective element substrate of  FIGS. 2-4 ; 
         FIG. 6  is a sectional view of the electrochromic mirror reflective element assembly of  FIG. 5 ; and 
         FIG. 7  is a rear perspective view of a portion of a reflective element assembly of the present invention, with a light pipe attached between circuitry on the reflective element substrate and a bezel portion of the mirror assembly. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings and the illustrative embodiments depicted therein, an interior rearview mirror assembly  10  includes a casing  12 , a bezel  13 , a reflective element assembly or cell  14  and a mounting arrangement  16  ( FIG. 1 ) for adjustably mounting the casing and reflective element  14  to an interior portion of a vehicle, such as to a mounting button or the like at an interior surface of a windshield of a vehicle. Mirror reflective element assembly  14  includes a conductive trace or layer or coating  18  ( FIG. 2 ) applied to or disposed on or at the rearward surface (the surface facing forward or in the direction of travel of the vehicle when the mirror assembly is installed in the vehicle) of a reflective element substrate, such as the typically glass substrate of the reflective element assembly, such as on the rear surface  20   a  ( FIGS. 3-6 ) of a second or rear substrate or glass element  20  of an electro-optic or electrochromic mirror cell (commonly referred to as the fourth surface of the electrochromic mirror cell). The reflective element substrate  20  thus may provide a substantially rigid surface for receiving the conductive trace and circuitry, and the reflective element assembly thus may comprise a circuitry on glass arrangement, whereby no separate rigid printed board or substrate or attachment plate is necessary to support the conductive trace and circuitry at the rear of the reflective element substrate of the reflective element assembly. However, the reflective element assembly and/or the mirror assembly may include other electronic elements or circuitry that may not be positioned or disposed on the glass surface, and/or that may complement the circuitry on the glass substrate, without affecting the scope of the present invention. 
     In the illustrated embodiment, the reflective element assembly  14  comprises an electro-optic or electrochromic reflective element assembly or cell that includes a front reflective element substrate  22  and the rear reflective element substrate  20 . The rear reflective element substrate  20  is spaced from front reflective element substrate  22  with an electrochromic medium  21  and conductive or semi-conductive layers disposed or sandwiched therebetween, as is known in the electrochromic mirror art. The conductive trace  18  may be applied directly onto the rear surface  20   a  (or onto an insulating epoxy or other type of layer or coating applied to the rear surface, as discussed below) of the reflective element substrate  20 , and masking portions or layers of a non-conductive material  24  and circuitry components and/or accessories and the like may be applied directly to the conductive trace  18 , such that no separate printed board and attachment plate and related components are required. 
     Although shown and described as an electrochromic reflective element assembly or cell, aspects of the present invention may be equally suitable for and applicable to a prismatic reflective element substrate and assembly or other types of reflective elements and assemblies, without affecting the scope of the present invention. Also, although shown and described as an interior reflective element assembly, aspects of the present invention may be equally suitable for and applicable to exterior mirror assemblies, such as exterior electrochromic rearview mirror assemblies and exterior rearview mirror assemblies with a single reflective element and the like, without affecting the scope of the present invention. 
     The conductive trace or layer  18  may comprise a conductive epoxy, such as a conductive silver epoxy or the like, that may be screen printed in a desired pattern or trace directly onto the rear surface  20   a  of rear reflective element substrate  20  of reflective element assembly  14  (or onto an insulating layer or the like at the rear surface of the reflective element substrate). In  FIG. 2 , rear reflective element substrate  20  of reflective element assembly  14  is shown from the front side or surface  20   b , so that the conductive trace  18  is shown at the rear surface  20   a  of reflective element substrate  20  by viewing through the transparent reflective element substrate  20 . 
     If the mirror reflective element assembly or electrochromic cell  14  comprises a third surface reflective element assembly (where the front surface of the rear substrate, commonly referred to as the third surface of the reflective element assembly or cell, has a reflective and conductive metallic coating or layer or layers  39   a  ( FIG. 6 ), such as a silver or aluminum or chromium or rhodium or other metallic materials or alloys thereof, and one or more non-metallic semi-conductive layers, such as one or more layers of indium tin oxide (ITO), indium tungsten oxide (IWO), indium cerium oxide (ICO), indium oxide (IO) or the like, disposed thereon or applied thereto), the conductive layer or epoxy  18  may be applied directly to a clean glass surface at the rear surface of the rear reflective element substrate (or may be applied to an insulating layer or the like applied directly to the clean glass surface). 
     Alternately, if the mirror reflective element or electrochromic cell  14  comprises a fourth surface reflective element (where the reflective coating or layer  39   b  ( FIG. 6 ), such as a metallic layer or the like, is applied to the rear or fourth surface of the rear reflective element substrate of the cell), the protective paint layer or layers that are typically applied to the rear surface of the rear reflective element substrate may be replaced or covered with an insulating epoxy layer to provide an insulated surface at the rear of the rear reflective element substrate. The conductive trace  18  may then be applied to the insulating epoxy layer at the fourth surface of the reflective element assembly or cell. 
     The conductive epoxy layer may be applied as a conductive trace in the desired pattern onto the appropriate rear surface of the reflective element substrate. For example, the conductive epoxy may be screen printed onto the rear surface of the reflective element substrate in the desired pattern, such as shown in  FIG. 2 . Optionally, the conductive epoxy layer or coating may be applied over a substantial amount of the rear surface of the rear reflective element substrate and may function as an anti-shatter or anti-scatter element to limit or substantially preclude shattering/scattering of the glass reflective element substrate, such as in situations where the vehicle is involved in an accident or the like. 
     Optionally, the conductive trace and the mask or non-conductive layers and exposed pads or portions may be formed on the rear surface in a similar manner as it is typically formed on a conventional printed circuit board. For Example, a copper layer may be applied to the rear surface of the glass reflective element substrate and the masking or non-conductive layer may be screen printed onto the copper layer and etched away to form the desired pattern, without affecting the scope of the present invention. 
     After the conductive epoxy or trace has been screen printed or otherwise applied to the rear surface of the reflective element reflective element, the trace may be masked over with a non-conductive or masking layer  24  ( FIGS. 3-5 ) that covers the conductive trace except at portions or pads  18   a  ( FIG. 3 ) of conductive trace  18  for affixing circuitry and components thereto, as discussed below. The non-conductive layer  24  may substantially cover the conductive trace except in areas where components or wires or accessories or the like may be positioned to provide the desired function to the reflective element assembly or cell  14 . The components or wires or accessories (shown generally at  26  in  FIGS. 4 and 6 ) may be affixed to the appropriate portions or pads  18   a  that are exposed through the masking layer  24  to complete the circuitry that is integral with the mirror reflective element assembly or cell. 
     Also, after the conductive trace or epoxy layer has been screen printed or otherwise applied to the rear surface of the reflective element substrate, the conductive layer may be cured. It is envisioned that the conductive layer may be cured onto the rear surface of the reflective element substrate at the same time that the electrochromic reflective element assembly or cell is cured (such as at the same time that the epoxy seal  21   a  ( FIG. 6 ) that is disposed around the electrochromic medium and between the substrates is cured) to cure both the conductive epoxy layer and the epoxy seal of the electrochromic cell with the same curing process. The epoxy seal and the epoxy trace or layer may be cured via an air curing process or an oven curing process or the like, without affecting the scope of the present invention. 
     Optionally, the non-conductive layer and electronic components or circuitry may be applied to the conductive layer and pads or portions of the conductive layer before the conductive layer has been cured. The components may thus be temporarily affixed to the conductive pads, such as via adhesive dots or drops or the like applied (and optionally robotically applied) to the pads and/or the components, and then the reflective element assembly and epoxy seal and/or circuitry may be cured to secure the circuitry and components to the conductive trace applied to the rear surface of the mirror reflective element assembly. Such an approach provides for attachment of the components and curing of the conductive layer, and optionally of the epoxy seal of the reflective element assembly as well, in a single step, thereby substantially enhancing the manufacturing processes for manufacturing the electrochromic mirror reflective element assembly or cell. 
     The circuitry and components, such as resistors, capacitors, jumpers, and clips and the like, and accessories, such as sensors, display elements, such as light emitting diodes (LEDs), liquid crystal display elements (LCDs), vacuum fluorescent (VF) display elements, electroluminescent (EL) display elements or video display elements or other types of display elements or displays, sensors or antennae and the like, may be applied to and secured to the appropriate exposed pads or portions of the conductive trace, such as after the trace has been masked or covered by the non-conductive layer or material. Some of the electronic components or circuitry may also be screened or applied to the conductive trace. For example, it is envisioned that carbon ink resistors may be printed onto the conductive trace with another printing pass or screening pass. The carbon ink resistors may be applied utilizing lasers to tighten the tolerances to a desired level. This approach may reduce the need for separate resistors that would otherwise have to be applied during a later step. However, other known or conventional type resistors may be attached to the appropriate pads or portions, without affecting the scope of the present invention. In situations where circuitry paths need to cross over one another (in such situations, the other side of a printed circuit board is used to make such a cross over in a conventional printed circuit board), a zero ohm jumper or resistor may be attached to spaced apart pads or portions of the conductive trace to bridge or span the gap between the pads or portions and effectively cross over a portion of a conductive trace positioned between the spaced apart pads or portions. 
     Although described above as being applied directly to the rear surface of the reflective element substrate and being cured thereon, it is envisioned that the conductive trace may be applied to a substantially non-stick surface and cured thereon and then peeled from the surface and applied to the rear surface of the reflective element substrate as a pre-cured flexible conductive trace. This may be preferred in some applications to minimize the waste of conductive traces in situations where some of the reflective element assemblies may be discarded or scrapped due to defects in the reflective element assemblies. The conductive trace may then be applied to a reflective element substrate of a reflective element assembly or cell after the epoxy seal has been cured and after the reflective element assembly or cell has met the quality requirements. The conductive trace may be a flexible element that may be readily applied to or adhered to the reflective element substrate surface. 
     It is further envisioned that the conductive trace may be initially applied to the separate surface, and the non-conductive layer or masking and the circuitry and electronic components and accessories may be applied to the conductive trace, such as in the manner as described above. The pre-cured flexible circuit sheet may then be peeled from the surface and applied to or rolled onto the rear surface of the reflective element substrate. The busbars and other accessories or components may be connected to the appropriate exposed pads or portions of the conductive trace on the flexible circuit sheet either while the flexible circuit sheet is at the separate surface or at another surface, or after the sheet has been applied to the rear surface of the reflective element substrate. The flexible circuit sheet may be adhered to or bonded to or otherwise secured to the rear surface of the reflective element substrate via any suitable means, without affecting the scope of the present invention. 
     As discussed above, the rearview mirror reflective element assembly of the present invention may comprise an electro-optic or electrochromic reflective element assembly or cell, such as an electrochromic mirror reflective element assembly utilizing principles disclosed in commonly assigned U.S. Pat. Nos. 6,690,268; 5,140,455; 5,151,816; 6,178,034; 6,154,306; 6,002,544; 5,567,360; 5,525,264; 5,610,756; 5,406,414; 5,253,109; 5,076,673; 5,073,012; 5,117,346; 5,724,187; 5,668,663; 5,910,854; 5,142,407; and/or 4,712,879, which are hereby incorporated herein by reference, and/or as disclosed in the following publications: N. R. Lynam, “Electrochromic Automotive Day/Night Mirrors”, SAE Technical Paper Series 870636 (1987); N. R. Lynam, “Smart Windows for Automobiles”, SAE Technical Paper Series 900419 (1990); N. R. Lynam and A. Agrawal, “Automotive Applications of Chromogenic Materials”, Large Area Chromogenics: Materials and Devices for Transmittance Control, C. M. Lampert and C. G. Granquist, EDS., Optical Engineering Press, Wash. (1990), which are hereby incorporated by reference herein. 
     As shown in  FIGS. 4 and 5 , mirror reflective element assembly or cell  14  may include front reflective element substrate  22  and rear reflective element substrate  20  with electrochromic medium  21  sandwiched therebetween. The front reflective element substrate  22  has a front surface  22   a  (the first surface of the electrochromic cell) and a rear surface  22   b  (the second surface of the electrochromic cell), which may include one or more transparent semi-conductive layers (such as an ITO layer or the like, or such as disclosed in PCT Application No. PCT/US03/29776, filed Sep. 19, 2003 and published Apr. 1, 2004 as International Publication No. WO 2004/026633, which is hereby incorporated herein by reference) thereon. The rear reflective element substrate  20  may include one or more transparent semi-conductive layers (such as an ITO layer or the like), and/or a metallic conductive layer (such as a layer of silver, aluminum, chromium or the like or an alloy thereof), on its front surface  20   b  (the third surface of the electrochromic cell), and may include multiple layers such as disclosed in PCT Application No. PCT/US03/29776, filed Sep. 19, 2003 and published Apr. 1, 2004 as International Publication No. WO 2004/026633, which is hereby incorporated herein by reference. The reflective element assembly  14  thus may comprise a third surface transflective element assembly or cell, whereby the reflective layer or surface is disposed at the third surface of the cell or at the front surface of the rear reflective element substrate for viewing by a driver of the vehicle. 
     Electrochromic reflective element assembly or cell  14  may include a front busbar or clip  30  that may engage or clip onto an edge portion (such as an upper edge portion  22   c ) of front reflective element substrate  22  to provide electrical power or current to the semiconductive layer or layers on the rear surface  22   b  of front reflective element substrate  22 . The cell  14  may also include a rear busbar or clip  32  that may engage or clip onto an edge portion (such as a lower edge portion  20   c ) of rear substrate  20  to provide electrical power or current to the semiconductive or conductive layer or layers on the front surface  20   b  of rear substrate  20 . The front clip  30  may include an extension  30   a  that extends rearward over the rear substrate  20  and that engages a busbar pad  18   b  at an upper portion of the conductive trace  18 , while the rear clip  32  may engage a busbar pad  18   c  at a lower portion of the conductive trace  18 , such that electrical power or current may be applied to front clip  30  and to rear clip  32  to darken or color the electrochromic medium  21  as desired. 
     The extension  30   a  of front clip or busbar  30  may be a separate extension attached to the clip or busbar, or may be integral with the clip or busbar, without affecting the scope of the present invention. The conductive trace  18  and exposed portions or pads  18   b ,  18   c  may extend to the upper and lower edges of the reflective element substrate and may act as a conductive rail along the edges so the clips  30 ,  32  may contact the conductive trace directly, with no wiring being necessary to connect the clips or busbars to the circuitry. The present invention thus may avoid the need to solder leads onto the busbars as is typically required with conventional busbars, such that the electrochromic mirror reflective element assembly of the present invention may provide for enhanced manufacturing processing. Optionally, an ASIC (application specific integrated circuit) die with external capacitors and clips may be applied at or near the upper and lower edges of the rear reflective element substrate for connection to the electrochromic clips or busbars  30 ,  32 . Optionally, and as shown in  FIG. 4 , the extension  30   a  may comprise a wire or lead that is soldered or otherwise conductively connected or secured to the busbar pad  18   b  to connect an end or portion of the clip or busbar  30  to the busbar pad  18   b , without affecting the scope of the present invention. The clips or busbars and substrates and coatings may be configured and may function similar to known busbars and substrates and coatings, or may be of the types described in PCT Application No. PCT/US03/35381, filed Nov. 5, 2003 and published on May 21, 2004 as International Publication No. WO 2004/042457, which is hereby incorporated herein by reference. 
     The conductive trace  18  and electronic components and/or circuitry  26  may comprise or mount or attach one or more accessories, such as lights, a microphone, user actuatable controls or inputs, sensors, such as photo sensors or the like, or any other type of accessory suitable for such an application, as discussed below. For example, and as shown in  FIGS. 4-6 , one or more light sensors or photo diodes  34 ,  36  may be attached or mounted to appropriate exposed pads or portions  18   d  ( FIG. 3 ) of conductive trace  18 , and may be operable to sense light at the mirror assembly. More particularly, light sensor  34  may be a forwardly facing (with respect to the direction of travel of the vehicle) sensor operable to detect the ambient light at the mirror assembly (such as via detecting light through an opening in the mirror casing or the like that receives light from forward of the mirror assembly and in the direction of travel of the vehicle), while light sensor  36  may be operable to detect glare at the mirror reflective element (such as by detecting light from rearward of the mirror assembly and from rearward of the vehicle). In order for light sensor  36  to detect the glare light rearward of the mirror assembly, it is envisioned that a window or transparent portion or area may be formed in the reflective layer or coating of the reflective element substrates to allow the sensor to view or receive light from rearwardly of the mirror assembly. Alternately, the light sensor may receive light that passes through the electro-optic reflective element assembly or cell, such as in display on demand or transflective cells and the like, without affecting the scope of the present invention. 
     Optionally, and with reference to  FIG. 7 , a light pipe  37  may be implemented to direct light though the bezel or casing of the mirror assembly and to bend the light, such as approximately 90 degrees or approximately 180 degrees (depending on the mounting orientation of the sensor) to direct or deliver the light to the sensor  36  at the circuitry on the back of the rear or second reflective element substrate, without affecting the scope of the present invention. In the illustrated embodiment of  FIG. 7 , the light pipe  37  functions to bend the light about 180 degrees to direct light from rearward of the mirror assembly (such as light at the bezel portion  13 ′ of the mirror assembly  10 ′) to the forward facing light sensor or photo sensor  36  at the conductive trace and circuitry  26  at the rear or fourth surface of the reflective element assembly. Optionally, the light pipe may extend between the circuitry and the back of an electrochromic reflective element assembly or cell where the light will be sensed/gathered/received from light passing through the cell, without affecting the scope of the present invention. Such an application may be suitable for use in applications with a transflective or display on demand type of cell. The sensors thus may face in generally the same direction on the circuitry, but may utilize light gathering means, such as one or more light pipes or the like, to gather and/or receive light from different directions, and may utilize aspects of the sensors described in U.S. patent application Ser. No. 10/229,573, filed Aug. 28, 2002, published Mar. 6, 2003 as U.S. Publication No. 2003-0043589, now U.S. Pat. No. 7,008,090, which is hereby incorporated herein by reference. 
     Although shown and described as comprising an electrochromic reflective element assembly, the present invention is equally applicable to prismatic reflective element assemblies and the like. For example, a conductive trace may be applied to a rear surface of a prismatic or wedge-shaped reflective element substrate, and electronic components and/or circuitry may be applied to the conductive trace, such as in a similar manner as described above, without affecting the scope of the present invention. The prismatic mirror assembly may comprise any type of prismatic mirror assembly, such as prismatic mirror assembly utilizing aspects described in U.S. Pat. Nos. 6,318,870; 5,327,288; 4,948,242; 4,826,289; 4,436,371; and 4,435,042; and PCT Application No. PCT/US04/015424, filed May 18, 2004 and published on Dec. 2, 2004, as International Publication No. WO 2004/103772; and U.S. patent application Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S. Pat. No. 7,249,860, which are hereby incorporated herein by reference. Optionally, the prismatic reflective element may comprise a conventional prismatic reflective element or prism or may comprise a prismatic reflective element of the types described in PCT Application No. PCT/US03/29776, filed Sep. 19, 2003 and published Apr. 1, 2004 as International Publication No. WO 2004/026633; U.S. patent application Ser. No. 10/709,434, filed May 5, 2004, now U.S. Pat. No. 7,420,756; and U.S. provisional application Ser. No. 60/525,952, filed Nov. 26, 2003 by Lynam for MIRROR REFLECTIVE ELEMENT FOR A VEHICLE, which are all hereby incorporated herein by reference, without affecting the scope of the present invention. A variety of mirror accessories and constructions are known in the art, such as those disclosed in U.S. Pat. Nos. 5,555,136; 5,582,383; 5,680,263; 6,227,675; 6,229,319; and 6,315,421 (the entire disclosures of which are hereby incorporated by reference herein), that can utilize aspects of the present invention. 
     Optionally, the mirror reflective element assembly or cell  14  and electronic components and/or circuitry applied to the rear surface of the rear reflective element substrate may include display elements, such as for a display on demand type of display, such as of the types disclosed in commonly assigned U.S. Pat. Nos. 6,690,268; 5,668,663 and 5,724,187, and/or in U.S. patent application Ser. No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381, and/or in PCT Application No. PCT/US03/29776, filed Sep. 9, 2003 and published Apr. 1, 2004 as International Publication No. WO 2004/026633; and/or PCT Application No. PCT/US03/40611, filed Dec. 19, 2003 and published on Jul. 15, 2004 as International Publication No. WO 2004/058540, which are all hereby incorporated herein by reference. 
     With such a display, it is not only desirable to adjust the display brightness according to ambient lighting conditions, but it is also desirable to adjust the display brightness such that a sufficient contrast ratio is maintained against the variable background brightness of the reflected scene. Also, it may be desirable to compensate for changes in transmission of the electrochromic device to control rearward glare sources, so that the display brightness appears to be maintained at a generally constant level. The display and/or transmissivity of the electro-optic device may be adjusted to provide the desired function or viewability, such as by utilizing aspects of the systems described in U.S. patent application Ser. No. 10/427,026, filed Apr. 30, 2003, now U.S. Pat. No. 6,918,674, which is hereby incorporated herein by reference. Optionally, the circuitry  26  may include a light emitting diode (LED) array module or the like bonded or placed on or at or connected to the appropriate portions or pads of the conductive trace applied to the rear surface of the rear reflective element substrate and operable to emit light or display information through the mirror cell for viewing through the reflective element substrate or substrates by the driver or occupant of the vehicle. Other types of display elements may be implemented without affecting the scope of the present invention. 
     Optionally, and as shown in  FIG. 6 , the electrochromic mirror cell  14  may incorporate an integrated display element, such as a liquid crystal display (LCD) element  38 , on or at the rear surface  20   a  of rear reflective element substrate  20 . Typically, a liquid crystal display element may include two sheets of spaced apart glass sheets with an appropriate conductive pattern printed on one of the surfaces of one of the sheets. The present invention may incorporate such a display on the rear surface of the rear reflective element substrate by applying a clear conductive pattern  38   a  (such as an ITO or the like) on the rear surface of the rear reflective element substrate, and such as at a window formed in the silvering or reflective layer of the mirror reflective element assembly or cell. The conductive pattern may be connected directly to the conductive trace applied to the rear surface of the reflective element substrate. An outer LCD glass sheet  40  may be provided with a continuous conductive coating (such as an ITO or the like) on its rear surface  40   a  and may be placed at the conductive pattern  38   a  and spaced therefrom, such as via glass spacer beads or the like. The glass sheet  40  may include a jumper lead to connect to an appropriate trace or pad at the rear surface  20   a  of rear substrate  20 , or a connecting bump or pad may be formed in the trace to span the gap between the glass sheet  40  and the rear surface of the rear reflective element substrate and to connect the conductive trace to the continuous conductive coating on the glass sheet  40 , without affecting the scope of the present invention. The mirror reflective element assembly or cell of the present invention thus may integrate an LCD display onto the reflective element or glass substrate of the reflective element assembly by using the reflective element or glass substrate of the mirror cell as the front glass sheet of the LCD display element. 
     Optionally, the printed circuit board of the mirror assembly of the present invention may include a display element along or partially along an edge of the board and may include one or more user-actuatable controls or buttons near or adjacent to the display element. The display element may be any type of display element, such as a vacuum fluorescent (YF) display element, a light emitting diode (LED) display element, an electroluminescent (EL) display element, a liquid crystal display (LCD) element, a video screen display element or the like, and may be operable to display various information (as discrete characters, icons or the like, or in a multi-pixel manner) to the driver of the vehicle, such as passenger side inflatable restraint (PSIR) information, tire pressure status, and/or the like. The buttons may be for actuating or controlling various accessories or controls or components associated with the vehicle, such as for a compass calibration setting or zone setting, a telematics actuation, a garage door opener, an electronic toll control (such as disclosed in U.S. Pat. No. 6,690,268, which is hereby incorporated herein by reference), and/or the like, or may be for switching the display between various functions or modes, without affecting the scope of the present invention. 
     Optionally, and as can be seen with reference to  FIG. 1 , electrochromic mirror reflective element assembly or cell  14  may include or may be associated with one or more switchable accessories, which may be toggled via actuation of one or more switches or buttons or inputs  42  at the front of the mirror assembly  10 , such as along the bezel  13  of the mirror assembly  10 . The user inputs or buttons may be for actuating or controlling various accessories or controls or components associated with the vehicle, such as for a compass calibration setting or zone setting, a telematics actuation, a garage door opener, an electronic toll control (such as disclosed in U.S. Pat. No. 6,690,268, which is hereby incorporated herein by reference), and/or the like, or may be for switching the display between various functions or modes, without affecting the scope of the present invention. Optionally, the user inputs may comprise touch sensors or proximity sensing inputs or the like, such as sensors of the types described in U.S. Pat. Nos. 6,001,486; 6,310,611; 6,320,282; 6,627,918; and 5,594,222; and/or U.S. Pat. Publication No. 2002/0044065, published Apr. 18, 2002, now U.S. Pat. No. 7,224,324; and/or U.S. patent application Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S. Pat. No. 7,249,860; and/or PCT Application No. PCT/US03/40611, filed Dec. 19, 2003 and published on Jul. 15, 2004 as International Publication No. WO 2004/058540, which are hereby incorporated herein by reference, or may comprise inputs molded within the bezel of the mirror assembly, such as described in U.S. provisional applications Ser. No. 60/535,559, filed Jan. 9, 2004 by Lindahl for MIRROR ASSEMBLY; and/or Ser. No. 60/553,517, filed Mar. 16, 2004 by Lindahl et al. for MIRROR ASSEMBLY, which are hereby incorporated herein by reference, or may comprise membrane type switches, such as described in U.S. provisional application Ser. No. 60/575,904, filed Jun. 1, 2004 by Uken for MIRROR ASSEMBLY FOR VEHICLE, which is hereby incorporated herein by reference; and/or the like, without affecting the scope of the present invention. 
     It is envisioned that the inputs  42  may be formed in the bezel  13  and that the circuitry applied to or disposed at the rear surface of the rear reflective element substrate may include one or more proximity sensors or sensing elements or antennae  44  ( FIGS. 5 and 6 ) positioned along a lower edge of the rear surface of the rear reflective element substrate and generally corresponding with a respective one of the inputs  42 . For example, the antenna or antennae or sensing elements may be adhered or clipped or otherwise secured to appropriate exposed pads or portions of the conductive trace  18  to position the antenna or antennae at the desired or appropriate location at the rear of the reflective element substrate. The antenna or antennae or sensing elements  44  may detect the presence of a person&#39;s finger at or near the respective input or inputs  42  and may actuate or control a display element or the like or may actuate or control or trigger the circuitry to switch or toggle the device associated with the input  42  in response to such a detection. 
     As shown in  FIG. 5 , the sensing elements  44  may be disposed along the lower or bottom edge of the rear reflective element substrate and may monitor a respective zone around the lower edge of the reflective element substrate or glass substrate. The sensing element or elements may provide a three dimensional cylinder of detection that extends along the bottom edge of the reflective element substrate and that encompasses the respective icon or input  42  at the bezel. As also shown in  FIG. 5 , the sensing element may comprise multiple separate sensing elements or antennae or antenna segments that may monitor separate zones corresponding to the respective inputs  42  at the bezel. The inputs  42  at the bezel thus may comprise a screen printed icon or character or the like at the bezel, and may not comprise any movable buttons or inputs or the like. As the user&#39;s finger approaches the desired input  42  (or spot or icon on the bezel), the corresponding antenna segment may detect the presence of the finger prior to contact as the finger enters the zone or cylinder of detection for that antenna segment. The electronic components and/or circuitry associated with that particular antenna may then toggle the device or accessory associated with the input, such as between an on/off status, a temperature or compass selection (such as for a temperature/compass display), a degrees F./degrees C. selection (such as for a temperature display), and/or the like. 
     Optionally, the controls may be operable to activate/deactivate/toggle/control an accessory in response to a detection of a user&#39;s finger or the like approaching the input or button region or sensing element at the mirror assembly. Because such inputs may be individual or separate proximity sensors or antennae positioned within the mirror assembly and not readily viewable or discernable by the driver or occupant of the vehicle, the mirror assembly may include a display or indicator that indicates the function of each input. Preferably, the mirror assembly may include a control or circuitry that selectively or occasionally activates a display to temporarily display the feature or function or accessory associated with the particular input or input region of the mirror assembly, such as in response to the user&#39;s finger or the like approaching the input area or the like. For example, it is further envisioned that when a user&#39;s finger is first detected as it approaches the input region (such as when the user&#39;s finger or the like is within a first threshold distance from one of the sensors, such as within about ¼ or ½ of an inch or thereabouts), the control or circuitry may activate a display (such as a display on demand type of display or transflective display that is viewable through the reflective element of the mirror assembly, such as described in U.S. Pat. Nos. 6,690,268; 5,668,663 and/or 5,724,187, and/or in U.S. patent application Ser. No. 10/054,633, filed Jan. 22, 2002, now U.S. Pat. No. 7,195,381, and/or Ser. No. 10/933,842, filed Sep. 3, 2004, now U.S. Pat. No. 7,249,860; and/or PCT Application No. PCT/US03/29776, filed Sep. 9, 2003 and published Apr. 1, 2004 as International Publication No. WO 2004/026633; and/or PCT Application No. PCT/US03/40611, filed Dec. 19, 2003 and published on Jul. 15, 2004 as International Publication No. WO 2004/058540, which are all hereby incorporated herein by reference) that indicates the accessory or feature or function associated with at least some or all of the inputs along the bezel or other region of the mirror assembly. The display may list or indicate the features (such as via text or icons or other indicia) at areas of the reflective element that are near to or generally adjacent to the respective inputs or input regions. 
     When the user then moves his or her finger to touch or contact the desired or appropriate input (or may move the finger closer to the input region or sensor, such as within a second threshold distance from the sensor that is smaller than the first threshold distance), such as at the bezel or the like, the detection of the contact (or of a closer proximity of the finger) may cause the control to activate/deactivate or toggle/adjust or control the accessory or feature or function associated with that input or input region. As the user&#39;s finger is moved closer to or contacts the selected input region, the displays for the other inputs may deactivate so that only the display for the selected input remains viewable by the user. Optionally, the detection of the closer proximity (such as within the second threshold distance or touching) may cause other menus or the like to appear at the mirror assembly, whereby the user may toggle or scroll through the menus to accomplish the desired task or activate/deactivate/adjust the desired or appropriate accessory or function or feature. The user thus may activate/deactivate/toggle/adjust/control the accessory or function or feature associated with the selected input or may scroll through a menu shown in the display at the reflective element. 
     Optionally, it is envisioned that the control or circuitry may initially activate a display element or display device associated with one of the inputs or buttons or sensor regions, such that as the user&#39;s finger approaches a particular input or button or sensor region (such as when the user&#39;s finger is within a threshold distance of the input, such as within approximately ¼ or ½ inches or thereabouts of the input or input region), the control or circuitry may activate the respective display that indicates the accessory or feature or function associated with that particular input or input region or sensor. The user thus may move their finger along the front of the mirror assembly (and over and along the separate/distinct sensors or input regions) and view the display or information for the accessory or feature or function associated with each region or input. When the user&#39;s finger is located at the desired function, the user may then contact the input region (or may move the finger closer to the input region or sensor), whereby the detection of the contact (or of a closer proximity of the finger) may cause the control to activate/deactivate or toggle/adjust or control the accessory or feature or function associated with that input or input region, or may cause other menus or the like to appear at the minor assembly, such as described above. 
     The present invention thus provides for the circuitry and electronic components to be kept substantially or entirely at the rear of the mirror reflective element assembly or cell, yet provides for front switching of an accessory or the like. The present invention provides for such front switching in response to a touch or approach of a designated area at the bezel (or elsewhere around the mirror assembly), without any buttons and associated wires or leads being needed at the bezel area. Also, because the proximity sensors or antennae or antenna segments are positioned at the rear of the reflective element or cell, no soldering or otherwise connecting of leads or wires to the buttons at the front of the mirror assembly is required. The present invention thus provides for such functions with a bezel that provides a reduced cost and complexity of the bezel and the casing of the mirror assembly. 
     The electronic components or circuitry and/or accessories may receive power from the vehicle power source, whereby the vehicle may include wiring to the mirror assembly, such as two wires for power and ground to the mirror assembly. Optionally, the vehicle may incorporate a telematics system, such as an ONSTAR® system or the like, which may have circuitry in the instrument panel of the vehicle. The telematics circuitry may include wires connected to the buttons or inputs at the mirror assembly that provide a toggling function to the telematics system in response to actuation of the respective telematics inputs. It is envisioned that the same wiring to the mirror assembly may also be selectably usable to provide for signal transmission from the telematics system to the mirror assembly, such as for a global positioning system (GPS) function or the like. 
     Optionally, the power and ground connection may only be provided to the mounting bracket, which may provide an electrical contact to the mirror circuitry via an electrical contact or wiper action at the ball and socket connection of the mounting arm or mounting arrangement of the mirror assembly. For example, the signals may be provided via a mounting arrangement utilizing aspects of the mounting arrangements described in U.S. patent application Ser. No. 10/032,401, filed Dec. 20, 2001, now U.S. Pat. Publication No. US2002/0088916A1, published Jul. 11, 2002, now U.S. Pat. No. 6,877,709; and/or PCT Application No. PCT/US2004/015424, filed May 18, 2004 and published on Dec. 2, 2004, as International Publication No. WO 2004/103772, and/or U.S. provisional application Ser. No. 60/609,642, filed Sep. 14, 2004 by Kamer for MOUNTING ASSEMBLY FOR MIRROR AND METHOD OF MAKING SAME, which are hereby incorporated herein by reference, or may utilize electrical connection principles of the type described in International Publication No. WO 2003/095269 A3, published Nov. 20, 2003 for REARVIEW MIRROR ASSEMBLIES, which is hereby incorporated herein by reference. The signals to control the accessories or circuitry of the mirror assembly may optionally be provided through an infrared link between the mounting bracket and the circuitry in the mirror, such as described in U.S. patent application Ser. No. 10/456,599, filed Jun. 6, 2003, now U.S. Pat. No. 7,004,593, which is hereby incorporated herein by reference. 
     Optionally, the conductive trace and electronic components or circuitry at the reflective element substrate of the mirror assembly may provide or include or be associated with other accessories, such as a rain sensor (such as the type disclosed in commonly assigned U.S. Pat. Nos. 6,320,176; 6,353,392 and 6,313,454, which are hereby incorporated herein by reference), an image sensor (such as a video camera, such as a CMOS imaging array sensor, a CCD sensor or the like, such as the types disclosed in commonly assigned, U.S. Pat. Nos. 5,550,677; 6,097,023 and 5,796,094, which are hereby incorporated herein by reference), a temperature sensor (such as a contact temperature sensor for measuring the temperature at or of the windshield), an antenna, a compass (such as the types disclosed in U.S. patent application Ser. No. 10/456,599, filed Jun. 6, 2003, now U.S. Pat. No. 7,004,593, which is hereby incorporated herein by reference) or any other sensor or accessory or device. For example, the mirror assembly may include a forward facing video image sensor or system, which may include an intelligent rain sensor (such as the type disclosed in commonly assigned U.S. Pat. Nos. 6,320,176; 6,353,392 and 6,313,454, which are hereby incorporated herein by reference), an image or vision system (including an imaging sensor, such as a video camera, such as a CMOS imaging array sensor, a CCD sensor or the like, such as the types disclosed in commonly assigned, U.S. Pat. Nos. 5,550,677; 6,097,023 and 5,796,094, and U.S. patent application Ser. No. 10/422,378, filed Apr. 24, 2003, now U.S. Pat. No. 6,946,978, which are hereby incorporated herein by reference), an intelligent headlamp controller (such as the type disclosed in U.S. Pat. No. 5,796,094 and/or in U.S. patent application Ser. No. 10/355,454, filed Jan. 31, 2003, now U.S. Pat. No. 6,824,281, which are hereby incorporated herein by reference), an intelligent lane departure warning system, such as the type disclosed in U.S. patent application Ser. No. 10/427,051, filed Apr. 30, 2003, now U.S. Pat. No. 7,038,577, which is hereby incorporated herein by reference, and/or the like. Optionally, the mirror assembly of the present invention may include one or more displays, such as a text display, an iconistic display, a display on demand type display (such as may be implemented with a transflective reflective element, such as described in U.S. Pat. Nos. 6,690,268; 5,668,663 and 5,724,187, which are hereby incorporated by reference herein), a video or touch screen interface display, or the like, and/or one or more sensors or other accessories, such as a biometric imager, such as for fingerprint authentication or the like, an infrared sensor, such as a zonal temperature sensor, such as suitable for an auto climate control, a forward facing image sensor, such as described above, a rearward facing image sensor (such as for biometric imaging (such as for face recognition, iris recognition or the like), seat height or position detection, drowsiness detection, safety/restraints, object detection and position, emergency response image capture system, intrusion detection or the like), and/or an electronic field sensor (such as the type disclosed in commonly assigned U.S. Pat. No. 6,768,420, which is hereby incorporated herein by reference) and/or the like. The display and/or accessories may be associated with a communication system, a speaker, a telematics module (which may include a GPS module, a wireless communication module, an human/machine interface (HMI), a display, such as an LED display, a dot matrix display, an alpha numeric display, a video display or the like, and/or a microphone, which may be operable for speech or voice recognition, noise reduction or noise cancellation), a humidity sensor, a remote keyless entry sensor, a tire pressure monitoring system (TPMS) (such as the types described in U.S. Pat. Nos. 6,731,205; 6,294,989; 6,124,647; 6,445,287; and/or 6,472,979, and/or U.S. provisional application Ser. No. 60/611,796, filed Sep. 21, 2004 by O&#39;Brien for TIRE PRESSURE ALERT SYSTEM, which are hereby incorporated herein by reference), an electronic toll collection sensor, an intelligent headlamp control, user interface controls (such as buttons, switches or the like for controlling various accessories of the vehicle, such as a sunroof, a communication system, lamps, security systems, displays or the like) or any other accessories, sensors, lights, indicators, displays or the like which may be suitable for mounting or positioning at or within the rearview mirror assembly. 
     The accessories or components of the rearview mirror assembly may be connected to the vehicle electronic or communication systems and may be connected via various protocols or nodes, such as Bluetooth, SCP, UBP, J1850, CAN J2284, Fire Wire 1394, MOST, LIN and/or the like, depending on the particular application of the rearview mirror assembly of the present invention. The rearview mirror assembly may be electronically integrated with the vehicle electrical and/or control systems. For example, the rearview mirror assembly may connect to a sunroof control, rain sensor control, mass motion sensor, roof lighting control, microphone/cell phone control, climate control, and/or the like. 
     Therefore, the rearview mirror assembly and mirror reflective element assembly of the present invention provides a mirror reflective element assembly that includes the conductive trace and electronic components or circuitry applied directly to or integrated with the rear surface of the reflective element substrate of the mirror reflective element assembly or cell. The present invention thus provides a circuitry on glass arrangement and thus obviates the need for a separate rigid board or substrate for receiving circuitry thereon, and also obviates the need for an attachment plate and associated connectors for attaching such a printed circuit board to the rear of the reflective element assembly or cell. The present invention thus provides a compact and lightweight mirror reflective element assembly that provides enhanced assembly processing and minimizes electrical wiring and connections that may have to be made to connect the circuitry to various components or accessories associated with the mirror reflective element assembly. 
     Changes and modifications in the specifically described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law.