Abstract:
An exterior rearview mirror including a mirror mounting bracket for attachment to a vehicle, and at least one perimeter light with a light source arranged on a thermally conductive carrier (e.g. a printed circuit board) in thermally conductive connection with the mirror mounting bracket. The light source is preferably an LED.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/DE2003/003904 filed Nov. 26, 2003, which claims priority to German Patent Application No. DE 102 56 197.4 filed on Dec. 2, 2002. The disclosures of the above applications are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention concerns an exterior rearview mirror for vehicles, more particularly motor vehicles. 
     BACKGROUND OF THE INVENTION 
     Exterior rearview mirrors are known in which the mirror mounting bracket is provided with a perimeter light containing at least one lighting means. Such lighting means develop relatively intense heat which can lead to damage to the perimeter light and/or the exterior rearview mirror. 
     The object of the invention is to design an exterior rearview mirror of this type such that the heat generated by the lighting means has no adverse effects. 
     This object is attained in accordance with the invention in an exterior rearview mirror of the type of the present invention. 
     SUMMARY OF THE INVENTION 
     As a result of the inventive design, the heat generated by the lighting means is transmitted by the carrier to the mirror mounting bracket. In this way, excessive heating of the perimeter light and mirror mounting bracket is avoided. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     DESCRIPTION OF THE DRAWINGS 
     Additional features of the invention are apparent from the other claims, the description, and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is explained in detail below on the basis of several example embodiments shown in the drawings. The drawings show: 
       i.  FIG. 1  a perspective view in cross-section of a mirror mounting bracket of an inventive exterior rearview mirror with a perimeter light, 
       ii.  FIGS. 2-6  each show an additional embodiment of an inventive exterior rearview mirror in views similar to that of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a mirror mounting bracket  1  with a cover  2  and a perimeter light  3  of an exterior rearview mirror that is attached to a vehicle (not shown) by the mirror mounting bracket  1 . Fastened to the mirror mounting bracket  1  in an articulated fashion is a mirror head  100  (shown in phantom) that can be swiveled from an operating position into a non-operating position adjacent to the vehicle. An area beneath the exterior rearview mirror and adjacent to the vehicle or vehicle doors can be illuminated by means of the perimeter light  3 . 
     The mirror mounting bracket  1  has a receptacle  4  for the light  3 , preferably composed of a surrounding ridge  5 . The receptacle  4  may have a round or angular cross-section. The height of the ridge  5  varies over its extent to correspond to the varying overall height of the mirror mounting bracket  1  in the vicinity of the installation space for the perimeter light  3 . In the example embodiment, the receptacle  4  is located in the vicinity of a hole  7  that accommodates a bearing pin for swivel mounting of the mirror head. 
     The mirror mounting bracket  1  has a support  48 , which preferably is made of metal or rigid plastic. The support  48  is covered with respect to the outside by the cap-like cover  2 , which has an opening  9  for an optical window  10  of the light  3 . In advantageous fashion, the cover  2  is made of plastic. Said cover is held on the support  48  by one or more interlocking connectors  11 . The cover  2  has a curved edge section  12  and, extending approximately parallel thereto and spaced apart from it, an inner ridge  13 , the two of which define a receptacle opening  14  for a free edge  15  of the support  48 . 
     As lighting means, the perimeter light  3  has an LED  16 , which is arranged on a printed circuit board  17 , and a light housing  18  that has the optical window  10 . The printed circuit board  17  is a flat plastic plate that contains a metal core (not shown) as a thermal conductor, preferably a metal plate having a regular outer contour. In the installation position, the full surface of the metal-core circuit board rests on the flat bottom  8  of the receptacle  4 . 
     The light housing  18  is manufactured as a single piece with the optical window  10  of a light-transmissible plastic. The housing has a circular cross-section with a surrounding edge  19 , which edge is L-shaped in cross-section and defines an annular groove  20  for a ring seal  21 . The free end of the ridge  5  of the receptacle  4  of the support  1 ′ projects into the annular groove  20 . In this way, the housing  18  is secured against rotation in the receptacle  4  in the assembled position. The printed circuit board  17  closes the housing  18  at the end opposite the optical window  10 . 
     A central section  22  of the optical window  10  projects into the housing opening  9  such that the end face  25  of the section  22  is located in the outer side of the cover  2 . The housing section  22  completely fills the opening  9  and transitions into the remaining part of the housing through a shoulder  24 . The end face  25  is domed outward in an arc with a large radius of curvature over an adjacent lower wall  30  of the cover  2 . In the assembled position of the cover  2 , the optical window  10  projects into the opening  9  of the cover  2  so that the rim  26  of the opening is located in the shoulder  24 . The light housing  18  rests against the inside of the cover  2  adjacent to the rim  26  of the opening. The height of the light housing  18  is slightly greater than the distance between the cover  2  in the vicinity of the housing and the bottom  8  of the receptacle  4  of the support  1 ′. As a result, the light housing  18  is preloaded with respect to the printed circuit board  17  in the assembled position and with cover  2  installed, so that said circuit board rests, with preloading, against the bottom  8  of the mirror mounting bracket receptacle  4 . Since the LED  16  produces very high lumen values per watt, intense heat is developed; said heat is transmitted through the metal core in the printed circuit board  17  directly to the support  1 ′ or conducted to it. In this way, the perimeter light  3  and its housing  18  are protected from excessive heat or overheating. 
     The cover  2  is pushed over the preassembled optical window  10 . During this process, the cover  2  slides over the end face  25  of the optical window  10  with elastic expansion until the rim  26  of the opening snaps into the shoulder  24  of the optical window. In this way, the optical window  10  is braced and held against the carrier  17 . Hence additional fastening means for the optical window  10  are unnecessary. 
     Due to the preloading of the light housing  18 , the seal  21  is also elastically compressed between the ridge  5  and the housing  18 , thus reliably preventing the penetration of moisture into the housing  18 . 
     The mirror mounting bracket  71  embodiment shown in  FIG. 2  differs from the embodiment described above only in that the light housing  54  has a preferably ring-shaped cavity  27  provided between the housing walls  29 ,  29 ′ and a central midsection  28 . This midsection  28  has at its free end a recess  28 ′ into which the LED  16  projects in a form-fitting manner in the assembled light housing  54 . The optical window  50  has the central, protruding housing section  51 , which rests in the opening  9 . In contrast to the mirror mounting bracket  1  embodiment described above, the end face  52  of the central housing section  51  is designed with a convex curvature so that it lies approximately in a plane with the adjacent lower wall  30  of the cover  2 . In this mirror mounting bracket  71  embodiment as well, the light housing  54  is made of light-transmissible plastic. 
     The light housing  54  has, directly adjoining the outside shoulder  24 , another outside shoulder  43  in which is arranged a ring seal  42 . In the installation position, the ring seal  42  lies with elastic deformation between the light housing  54  and the inner side of the cover  2 , and prevents moisture and/or dirt from entering the mirror mounting bracket  71  through the opening  9 . The design of this mirror mounting bracket  71  embodiment is otherwise the same as the previous example embodiment. The metal-core of the printed circuit board  17  is again pressed firmly against the bottom  8  of the receptacle  4  of the support  48 , so the heat produced when the LED  16  is turned on is reliably conducted into the support  48 . 
     The mirror mounting bracket  81  embodiment in  FIG. 3  corresponds to the mirror mounting bracket  71  in  FIG. 2  with the sole difference that the light housing  55  is designed without the midsection  28 . Together with the LED  16 , the printed circuit board  17  with the metal core once again rests with its entire surface against the bottom  8  of the receptacle  4  of the support  48  under pressure. In the assembled position, the housing  55  in  FIG. 3  is loaded by the cover  2  in the direction of the support  48 . As a result, the ring seal  21  is elastically deformed in the annular groove  20  and the circuit board  17  is pressed against the bottom  8  of the receptacle  4 , ensuring rapid and complete heat conduction and reliable sealing of the housing  55 . 
       FIG. 4  shows a mirror mounting bracket  91  embodiment corresponding to that in  FIG. 3 , wherein a light housing  57  has a reflector as an insert reflector  31 . It rests against the inner wall of the housing  57  and is provided with an opening  32  through which the LED  16  projects. The reflector  31  has a reflective surface  33 , which reflects the light emitted by the LED  16  to an optical window  58 . The reflector  31  can have various designs depending on the desired lighting effect, for example it can take the shape of a paraboloid. The free edge of the reflector  31  is supported on an inner shoulder  34  of the housing  58 , which shoulder is also present in the housings  18 ,  54  in  FIGS. 2 and 3 . The inner shoulder  34  is recessed inward with respect to the outer shoulder  24 . The reflector  31  also rests on the printed circuit board  17 . The reflector  31  is preferably made of heat-resistant plastic. The design of the perimeter light  59  is otherwise the same as in the perimeter light  61  embodiment shown in  FIG. 3 . 
     The reflector  31  can also be designed as a heat-dissipating element. In this case, it is made of metallic material and is designed such that it incorporates the shape of the light housing  57 . The annular groove  20  is then located on the outside of the reflector  31 . A lens is then set into the free end of such a reflector. In such a design, not only is the heat generated by the LED  16  conducted into the support  48  through the carrier  17 , it is also conducted through the reflector  31  into the ridge  5 . 
     Here, too, the heat generated by the LED  16  is rapidly and completely conducted into the support  48  through the printed circuit board  17  of the perimeter light  3 . 
       FIG. 5  shows a mirror mounting bracket  92  embodiment in which the light housing  63  largely corresponds to that shown in  FIG. 3 . However, an end face  65  of a central section  66  of the optical window has a concave curvature as in the mirror mounting bracket  1  embodiment in  FIG. 1 . The inner side of the optical window  66  is provided with an optical structure  38  which can be used to achieve a directed guidance of the light emitted by the LED  16 . Located a distance behind the optical window  66  is an optical element  39 , which is designed as a Fresnel lens, for example. A lens  40  is accommodated in the housing  63  between the optical element  39  and the LED  16 . The optical elements  38  through  40  can, of course, also be built into the housing in a different arrangement. Different combinations of these optical elements can also be employed to achieve directed guidance of the light. 
     The optical elements  67 ,  39  and  4  are provided in the mirror mounting bracket  96  embodiment in  FIG. 6  as in the previous example mirror mounting bracket  91  embodiment. In addition, a face  68  of the optical window  69  is provided with an optical structure  41 . 
     In place of the light housings, described in the embodiments shown in  FIGS. 1-6 , an optical waveguide or a combination of an optical waveguide and light housing can also be used. The installation depth of the LEDs can likewise be varied with appropriate adjustment of the mirror mounting bracket in order to change the illuminated area. 
     Finally, the position of the perimeter light on the mirror mounting brackets described in  FIGS. 1-6  on the mirror mounting bracket support  48  can also be changed as desired depending on which area next to the vehicle and on the ground is to be illuminated. 
     Of course, additional LEDs, for example arranged next to one another in rows, can also be used in place of the one LED  16  to increase the light intensity. 
     In all the embodiments described, there may be built into the exterior rearview mirror, in particular into the mirror head, lighting means as auxiliary turn signals, transmitters and/or receivers for garage door openers and/or for navigation systems, sensors as part of the control system for an EC or LCD glass, antennas for automotive radios, compasses and the like, loudspeakers and the like. Additional components, such as transmitters and/or receivers for garage door openers or for navigation systems, may also be built into the mirror mounting bracket. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.