Abstract:
An automotive light assembly produces numerous beam patterns meeting automotive requirements through the reduction of light scatter and collection and redirection in efficiencies. A light source projects light laterally, which is collected by a light conducting body having a hub and a plurality of fingers extending from the hub. By using a plurality of small individual fingers, large and bulky light pipes are eliminated and the light collection and redirection efficiency is improved.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to light assemblies for automotive applications, and more particularly relates to light assemblies employing light emitting diodes as light sources.  
         [0002]     Accordingly, there exists a need to provide an automotive lighting assembly capable of employing an LED light source to meet the special requirements of automotive lighting functions.  
       BACKGROUND OF THE INVENTION  
       [0003]     Light emitting diodes (LED&#39;s) are fast becoming a preferable light source for automotive lighting applications, as they consume less power but provide light output which is acceptable for such applications. In order to employ LED&#39;s and automotive applications, high levels of efficiency must be obtained in both light collection as well as light distribution. Typically, reflectors or lenses or light pipes are utilized to collect and distribute the light for the particular lighting application. Unfortunately, not all automotive applications, such as the stop function of a tail light, have been effectively produced utilizing an LED light source and such reflectors, lenses or light pipes.  
       BRIEF SUMMARY OF THE INVENTION  
       [0004]     The present invention provides an automotive light assembly which produces numerous beam patterns meeting automotive requirements through the reduction of light scatter and efficient collection and redirection of light from a light source. The light assembly is arranged along a longitudinal axis, and generally comprises a light source and a light conducting body. The light source projects light laterally relative to the longitudinal axis. The light conducting body includes a hub and a plurality of fingers extending from the hub. The hub is positioned adjacent the light source and has a laterally facing surface receiving light from the light source. Each of the plurality of fingers extends laterally and longitudinally from the hub, and include a longitudinally facing surface for emitting the light passing through the plurality of fingers. By using a plurality of small individual fingers, large and bulky light pipes may be eliminated and the light collection and redirection efficiency improved.  
         [0005]     According to more detailed aspects, each of the plurality of fingers includes a first portion connected to the hub and extending laterally from the hub, and a second portion connected to the first portion and extending longitudinally from the first portion. An angled outer surface is provided at the intersection of the first and second portions to redirect light from the lateral direction to the longitudinal direction. Alternatively, each of the plurality of fingers may follow a curved shape which redirects light from the lateral direction to the longitudinal direction. The plurality of fingers is arranged in a pattern corresponding to an automotive lighting function, and preferably are circumferentially spaced and arranged in a circular pattern. The longitudinally facing surfaces of the plurality of fingers may take many forms, including flat, curved or other shapes which include beam spreading features for creating the desired beam pattern. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:  
         [0007]      FIG. 1  is a perspective view of a light assembly constructed in accordance with the teachings of the present invention;  
         [0008]      FIG. 2  is an enlarged, partially cut-away view of the light assembly depicted in  FIG. 1 ;  
         [0009]      FIG. 3  is an enlarged, partially cut-away view of an alternate embodiment of a light assembly constructed in accordance with the teachings of the present invention;  
         [0010]      FIG. 4  is an enlarged, partially cut-away view of an alternate embodiment of a light assembly constructed in accordance with the teachings of the present invention; and  
         [0011]      FIG. 5  is an enlarged, partially cut-away view of an alternate embodiment of a light assembly constructed in accordance with the teachings of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     Turning now to the figures,  FIG. 1  depicts a perspective view of an automotive light assembly  20  constructed in accordance with the teachings of the present invention. The light assembly  20  is generally arranged along a longitudinal axis  10 , and includes a light conducting body  22  and a light source  24 .  
         [0013]     As best seen in the enlarged, partially cut-away view of  FIG. 2 , the light source  24  generally includes a light emitting diode (LED)  23  coupled with a near field lens  25  for redirecting the light laterally relative to the longitudinal axis  10 . It will be recognized by those skilled in the art that various types of LED&#39;s or other light sources may be employed, and likewise various lenses, reflectors or other devices may be used to direct the light laterally. For example, numerous LED&#39;s are constructed to emit light to the side (i.e. laterally) thus obviating the need for a redirecting lens  25 . Alternatively, a side-emitting, ring-shaped, near field lens may be built as an integral part of the hub  26  replacing the laterally facing inner surface  28 .  
         [0014]     The light conducting body  22  generally comprises a hub  26  and a plurality of fingers  30 . The hub  26  is positioned adjacent the light source  24  and has a laterally facing surface  28  receiving light from the light source  24 . Stated another way, the hub  26  includes a central passageway which defines the laterally facing surface  28  and receives at least a portion of the light from light source  24 . The hub  26  has been depicted as annular, and specifically circular in shape, although it will be recognized by those skilled in the art that the light source  24  could emit light over a limited range that is less than 360 degrees, and thus the hub  26  could similarly span less than 360 degrees and be semi-annular.  
         [0015]     The plurality of fingers  30  are connected to the hub  26  and extend laterally and longitudinally from the hub  26 . Each of the fingers  30  includes a longitudinally facing surface  32  for emitting light passing through the fingers  30 . As such, the laterally directed light from the source  24  is collected by the hub  26  and its laterally facing surface  28 , and is then transmitted and redirected by the plurality of fingers  30  longitudinally to the longitudinally facing surface  32 .  
         [0016]     As shown in  FIG. 2 , each finger  30  generally includes a first portion  34  which extends laterally and directs light therealong through the principle of total internal reflection. That is, the outer surface  36  of the first portion  34  reflects a majority of the light passing therethrough, the light laterally away from the light source  24 . A bend  38  of each finger  30  includes an outer angled surface  40  which redirects the light from the first portion  34  to a second portion  44 . A curved inner surface  42  is positioned on the opposite side of the angled outer surface  40  for reflection of incident light. The curved inner surface  42  may also be deleted, causing surface  36  and  46  to meet at a sharp corner. The second portion  44  of the finger  30  extends longitudinally, and similar to the first portion  34  includes an outer surface  46  which directs light there along to the longitudinally facing surface  32  where light exits. As shown in  FIG. 2 , the longitudinally facing surface  32  is generally flat. In sum, it can be seen that light is projected laterally from the light source  24  through the hub  26  and into one of the first portions  34  of the fingers  30 , and is then redirected by angled outer surface  40  through second portion  44  and exits via the longitudinally facing surface  32 .  
         [0017]     In this manner, a typically large reflector or light pipe can be replaced by the light conducting body  22  of the present invention, which contains significantly less material. As such, less light is scattered, and more light is efficiently collected and redirected in the desired direction. Furthermore, the plurality of fingers  30  may be arranged and constructed to provide a desired beam pattern. For example, the fingers  30  and their longitudinally facing surfaces  32  have been shown in a circumferentially spaced and circular pattern, corresponding to the stop function for a tail light. While this particular function and shape has been shown, it will be recognized by those skilled in the art that numerous other shapes and automotive functions may be readily employed through the lighting assembly  20  constructed in accordance with the teachings of the present invention.  
         [0018]     It will also be recognized by those skilled in the art that various other functional effects may be obtained through the construction of the light conducting body  22 . For example, the longitudinally facing surfaces  132  may take a curved shape, as shown in  FIG. 3 . Likewise, the longitudinally facing surfaces  232  may include beam spreading optics such as the pillows  233  depicted in  FIG. 4 . It will be recognized that various other beams spreading optics may be formed in the longitudinally facing surface  232 , such as flutes, prisms, grooves, series of undulations, or other surface disturbances or surface shapes. It will also be recognized that the use of laterally extending first portion  34  and longitudinally extending second portion  44 , interconnected by bend  38  may be replaced with a curved finger  330 , as is shown in  FIG. 5 . The finger  330  may follow a parabolic shape or alternatively may follow a numerically generated curvature which is designed to redirect substantially all of the light from the lateral direction to the longitudinal direction and out of the longitudinally facing surface  332 .  
         [0019]     The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.