Automotive signal light employing multi-focal length light pipes

Abstract

An automotive signal light is taught which employs multi-focal length light pipes to collect, collimate and direct, as needed, light emitted from one or more semiconductor light sources. Each multi-focal length light pipe includes at least one light transmission structure, each of which has a light receiving port to receive light emitted from a semiconductor light source spaced from the light receiving port by an air gap. The light transmission structure includes at least two superimposed parabolic reflecting surfaces, each having a common focal point at the light receiving port but having different focal lengths, and the superimposed parabolic reflectors operate to receive, collimate, spread and transmit the light from the semiconductor light source to a light emitting surface of the light pipe which is located adjacent to a lens of the signal light. The aesthetic arrangement of the light pipes is not particularly limited and a wide range of signal light functionalities can be provided.

What is claimed is: 
     
         1 . An automotive signal light, comprising:
 a housing;   a transparent lens connected to said housing;   at least one light source assembly mounted within said housing;   a multi-focal length light pipe disposed within said housing in proximity to said at least one light source assembly; and   at least one light transmission structure formed as part of said multi-focal length light pipe such that light produced by said at least one light source assembly transfers through said at least one light transmission structure of said multi-focal length light pipe to produce a desired beam pattern.   
     
     
         2 . The automotive signal light of  claim 1 , said at least one light source assembly further comprising a plurality of semiconductor light sources. 
     
     
         3 . The automotive signal light of  claim 2 , each of said plurality of semiconductor light sources further comprising a light emitting diode (LED). 
     
     
         4 . The automotive signal light of  claim 1 , said at least one light transmission structure further comprising at least one light receiving port for receiving light from said at least one light source assembly mounted within said housing. 
     
     
         5 . The automotive signal light of  claim 4 , wherein said at least one light receiving port is substantially conic in shape such that said at least one light receiving port substantially surrounds said at least one light source assembly to receive substantially all of the light from said at least one light source assembly. 
     
     
         6 . The automotive signal light of  claim 4 , said further comprising at least two parabolic reflector shapes formed as part of said at least one light transmission structure, each of said at least two parabolic reflector shapes having a focal point at said at least one light receiving port, and each of said at least two parabolic reflector shapes having a different focal length such that light received from said at least one light receiving port is collimated, focused, and spread to create said desired beam pattern. 
     
     
         7 . The automotive signal light of  claim 1 , wherein said at least one light transmission structure is scalloped in shape. 
     
     
         8 . The automotive signal light of  claim 1 , said housing further comprising a back panel. 
     
     
         9 . The automotive signal light of  claim 8 , further comprising:
 a heat sink which transfers heat away from said at least one light source assembly; and   a plurality of fins formed as part of said heat sink, said plurality of fins extend through said back panel of said housing for releasing heat from said heat sink.   
     
     
         10 . The automotive signal light of  claim 8 , wherein said back panel is an integral back panel formed as part of said housing. 
     
     
         11 . The automotive signal light of  claim 8 , wherein said back panel is formed by a portion of said vehicle to which said signal light is mounted. 
     
     
         12 . The automotive signal light of  claim 1 , wherein said at least one light transmission structure directs light through said multi-focal length light pipe through total internal reflection. 
     
     
         13 . The automotive signal light of  claim 1 , wherein said housing is made from one selected from the group consisting of polyvinyl chloride (PVC), polycarbonate, and combinations thereof. 
     
     
         14 . The automotive signal light of  claim 1 , wherein said multi-focal length light pipe is made of a clear, acrylic material. 
     
     
         15 . The automotive signal light of  claim 1 , further comprising:
 an emitter surface formed as part of said multi-focal length light pipe; and   said multi-focal length light pipe includes an elongate axis, wherein light emitting from said emitter surface is primarily directed parallel to said elongate axis.   
     
     
         16 . The automotive signal light of  claim 1 , wherein a first focal length of said multi-focal length light pipe provides running light functionality, a second focal length of said multi-focal length light pipe provides brake light functionality, and a third focal length of said multi-focal length light pipe provides back-up light functionality. 
     
     
         17 . An automotive signal light, comprising:
 a housing;   a transparent lens connected to said housing;   a plurality of semiconductor light source assemblies mounted within said housing;   a multi-focal length light pipe disposed within said housing;   a plurality of light transmission structures formed as part of said multi-focal length light pipe, each of said plurality of light transmission structures having one focal length, and each of said plurality of light transmission structures receives light from one of said plurality of semiconductor light source assemblies; and   an emitter surface formed as part of said multi-focal length light pipe such that light is received by said plurality of light transmission structures and is directed out of said emitter surface, and each of said plurality of light transmission structures produces a desired beam pattern,   
     
     
         18 . The automotive signal light of  claim 17 , each of said plurality of light transmission structures further comprising:
 at least one light receiving port for receiving light from one of said plurality of semiconductor light sources; and   at least two parabolic reflector shapes having a different focal length, and each of said at least two parabolic reflector shapes having a focal point located in proximity to said at least one light receiving port such that light received from said at least one light receiving port is collimated, focused, and spread by said light transmission structure to create said desired beam pattern emitted from said emitter surface.   
     
     
         19 . The automotive signal light of  claim 18 , wherein said at least one light receiving port is substantially conic in shape such that said at least one light receiving port substantially surrounds a respective one of said plurality of semiconductor light source assemblies to receive substantially all of the light from said respective one of said plurality of light sources assemblies. 
     
     
         20 . The automotive signal light of  claim 17 , further comprising:
 a heat sink which removes heat from said plurality of light source assemblies; and   a plurality of fins formed as part of said heat sink, said plurality of fins extending out of said housing for releasing heat from said heat sink.   
     
     
         21 . The automotive signal light of  claim 20 , said housing further comprising an integral back panel, wherein said plurality of fins formed as part of said heat sink extend out of said back panel. 
     
     
         22 . The automotive signal light of  claim 20 , said housing further comprising a back panel formed by a portion of said vehicle to which said signal light is mounted, wherein said plurality of fins formed as part of said heat sink extend out of said back panel. 
     
     
         23 . The automotive signal light of  claim 17 , wherein each of said plurality of light transmission structures directs light through said multi-focal length light pipe through total internal reflection. 
     
     
         24 . The automotive signal light of  claim 17 , wherein said housing is made from one selected from the group consisting of polyvinyl chloride (PVC), polycarbonate, and combinations thereof. 
     
     
         25 . The automotive signal light of  claim 17 , wherein said multi-focal length light pipe is made of a clear, acrylic material. 
     
     
         26 . The automotive signal light of  claim 17 , said multi-focal length light pipe further comprising an elongate axis, wherein light emitting from said emitter surface is primarily directed parallel to said elongate axis. 
     
     
         27 . The automotive signal light of  claim 17 , wherein a first focal length of said multi-focal length light pipe provides running light functionality, a second focal length of said multi-focal length light pipe provides brake light functionality, and a third focal length of said multi-focal length light pipe provides back-up light functionality. 
     
     
         28 . The automotive signal light of  claim 17 , wherein said at least one light transmission structure is scalloped in shape 
     
     
         29 . The automotive signal light of  claim 17 , wherein each of said plurality of semi-conductor light source assemblies is a light emitting diode (LED). 
     
     
         30 . An automotive signal light comprising:
 a substantially weather proof volume defined by at least a housing and a lens;   at least one semiconductor light source and heat sink assembly located within the volume; and   at least one multi-focal length light pipe located within the volume having at least one light transmission structure with a light receiving port positioned adjacent a respective semiconductor light source to receive light emitted by said one semiconductor light source, the light transmission structure including at least two superimposed parabolic reflecting structures each having a common focal point at the light receiving port and each having a focal length differing from the focal length of the other such that the light transmitting structure receives, collimates, directs and spreads and transmits the light received at the light receiving port to a light emitting surface of the light pipe adjacent the lens to from a desired output light pattern.   
     
     
         31 . An automotive signal light in accordance with  claim 30 , comprising at least two multi-focal length light pipes located within the volume. 
     
     
         32 . An automotive signal light in accordance with  claim 31 , wherein each multi-focal length light pipe provides a different signal function. 
     
     
         33 . An automotive signal light in accordance with  claim 30 , wherein the signal light includes at least two semiconductor light sources and the multi-focal length light pipe includes a corresponding number of light transmission structures.