Patent Abstract:
This invention provides an optical system that collects 100% of the light emitted from the light source and effectively directs it into the desired beam pattern. This is achieved by a combination of different optical control methods including reflector and lens optics. The cost is controlled by a design that reduces the optical part count to 2 main components, which reduces manufacturing and assembling time and maintains proper alignment to the light source and system.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a PCT International Application of U.S. Patent Application No. 61/516,798 filed on 7 Apr. 2011. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to an opera house LED headlamp assembly having a reduced number of components. 
       BACKGROUND OF THE INVENTION 
       [0003]    Current LED headlamps use a projector type lens or Reflector optics or closely coupled optics. These methods suffer from one or more problems such as low optical efficiency, high cost or poor beam pattern distribution. The present invention provides a LED headlamp assembly having a reduced number of components making the assembly smaller, easier to assemble and more cost effective. 
       SUMMARY OF THE INVENTION 
       [0004]    This invention provides an optical system that collects substantially 100% of the light emitted from the light source and effectively directs it into the desired beam pattern. This is achieved by a combination of different optical control methods including reflector and lens optics. The cost is controlled by a design that reduces the optical part count to 2 main components, which reduces manufacturing and assembling time and maintains proper alignment to the light source and system. 
         [0005]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0007]      FIG. 1  is a Lamp Assembly  100  is comprised of Reflector  101  Lens  102  and LED  103 ; 
           [0008]      FIG. 2  Shows The lamp assembly  100  with the lens removed for a better view of the location of the LED  103  and light emitting surfaces  208  and identifies reflector sub segments  201 ,  202 ,  203 ,  204 , 205 ,  206  and  207 ; 
           [0009]      FIG. 3  shows a close up of LED  103  with light emitting surface  208  and identifies reflector subsegment focal points  301 - 305  as they relate to LED light emitting surface  208 ; 
           [0010]      FIG. 4  shows Lamp Assembly  100  with half of Reflector  101  removed for better view of the relative location of lens  102 , reflector  101 , and LED  103 ; 
           [0011]      FIG. 5  shows a section through lamp Assembly  100  and identifies areas  501 ,  502  and  503  illuminated by LED light emission surface  208 , and the controlled beam emission areas  504  and  505  and the relative positions of LED  103  Reflector  101  and Lens  102 ; and 
           [0012]      FIG. 6  shows a close up of Lens  102 , LED  103 , light emission area  208  and key features  601 ,  602 ,  603  and  604  of lens  102 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0013]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
         [0014]    In  FIG. 1 , lamp Assembly  100  includes a housing  99 , reflector  101 , lens  102  and LED  103 .  FIG. 2  shows the lamp assembly  100  with the lens removed for a better view of the location of the LED  103  and light emitting surfaces  208  and identifies reflector sub segments  201 ,  202 ,  203 ,  204 ,  205 ,  206  and  207 .  FIG. 3  shows a close up of LED  103  its light emitting surface  208  and identifies reflector subsegment focal points  301 ,  302 ,  303 ,  304 ,  305  as they relate to LED light emitting surface  208 .  FIG. 4  shows lamp assembly  100  with half of reflector  101  removed for better view of the relative location of lens  102 , reflector  101  and LED  103 .  FIG. 5  shows a section through lamp assembly  100  and identifies areas  501 ,  502  and  503  illuminated by LED light emission surface  208 , and the controlled beam emission areas  504  and  505  and the relative positions of LED  103 , reflector  101  and lens  102 .  FIG. 6  shows a close up of lens  102 , LED  103 , light emission area  208  and key features  601 ,  602 ,  603  and  604  of lens  102 . 
         [0015]    The present invention provides the ability to collect and control nearly 100% of the emitted light with very low levels of optical loss. This is achieved with the construction illustrated in  FIG. 1 . The lamp assembly  100  is composed of two optical components reflector  101 , lens  102  and the light source LED  103 . High optical efficiency is achieved with low losses by limiting light control to a single interaction with the reflector  101  approximately 85% reflectivity or passage through the lens  102  with only Fresnel losses at the entry and exit surfaces. Other lens interactions are loss-less total internal reflections off the sidewalls. 
         [0016]      FIG. 2  identifies the seven unique reflector subsegments, including a first subsegment  201 , second subsegment  202 , third subsegment  203 , fourth subsegment  204 , fifth subsegment  205 , sixth subsegment  206  and seventh subsegment  207  required to properly control the light impinging on them from the LED  103  light emission surface  208 . LED  103  has light emission surface  208  shown close up in  FIG. 3 . Reflector first subsegment  201 , second subsegment  202 , third subsegment  203 , fourth subsegment  204 , fifth subsegment  205 , sixth subsegment  206  and seventh subsegment  207  each have unique focalpoints identified as locations  301 ,  302 ,  303 ,  304 ,  305  at light emission surface  208 . Subsegments are parabolas of revolution having their different focal points and the axis of revolution direction determined to achieve desired beam performance. With use of the identified focal point locations it is possible to keep all light rays controlled by the reflector first subsegment  201 , second subsegment  202 , third subsegment  203 , fourth subsegment  204 , fifth subsegment  205 , sixth subsegment  206  and seventh subsegment  207  under the reflector segment axis allowing the construction of the required beam cutoff gradient. 
         [0017]    Fourth reflector subsegment  204  is a cylindrical parabolic extrusion using focal point  303 . Third reflector subsegment  203  uses focal point  302 ; fifth subsegment  205  uses focal point  304 . First reflector subsegment  201  and sixth reflector subsegment  206  share focal point  305  and seventh reflector subsegments  207  and second reflector subsegment  202  share focal point  301 . 
         [0018]      FIG. 4  shows the LED  103  location, as it is inclined relative to reflector  101  and lens  102 . This inclined angle orients the light emission surface  208  so it presents the maximum surface area and therefore maximum light concentration to the most distant part of reflector  101 . This angle also eliminates light near the apex of the reflector that would be blocked by lens  102 . It further improves the mix of optical images emitted by the reflector by presenting a smaller edge on view of the light-emitting surface that counter acts the magnification effect produced by close proximity of the reflector near the apex. The inclination of the LED  103  relative to the reflector  101  presents the maximum surface area and light concentration to a most distant part  506  of the reflector  101 . A similar effect is produced in the light controlled by the lens. This rotation relative to the lens creates a mixture of thin and wide images that build an emission profiles having a bright edge near the top of the pattern and a dimmer edge near the bottom that produces a smoother beam pattern on the road. This is further illustrated in  FIG. 5 . 
         [0019]    The light emitted by light emitting surface  208  can be first area  501  second area  502 , third area  503  identified in  FIG. 5 . First area  501  illuminates reflector  101  that controls the light and forms beam  504 . Without lens  102  the light in third area  503  would illuminate the floor of the reflector  101  and bounce up in to the glare areas of the beam not contribute to the useful performance of the lamp. Similarly the light in second area  502  would escape uncontrolled out of the front of the lamp. Much of the light would contribute to glare some portion would find its way to the road however the illumination provided would be feeble. By use of lens  102  this uncontrolled light can be collected and directed into the beam pattern adding substantially to the overall performance and at the same time eliminating the unwanted glare light. The tipping of LED  103  at an angle creates a hole in the light pattern emitted from reflector  101  that allows the use of lens  102  in such a way as to avoid blocking any significant portion of light from reflector  101 . 
         [0020]    Lens  102  is constructed as a cylindrical extrusion of a condensing lens profile. The lens  102  is a cylindrical extrusion of a condensing lens profile having one or more curved edges creating long edges and flat surfaces so that light emitted from said lens  102  has a wide beam pattern. This extrusion produces a wide spread pattern. Without adjustment the pattern would be distorted into a dog bone or bow tie shape putting unwanted light above horizontal and deeper into the pattern than desired. This is corrected by curving the edges of the extrusion  601  and  602  making the lens taller and flatter relative to the straight section  603 . These changes having the effect to flatten the top and bottom of the pattern. Further some portion of the light that enters the optic will bounce off the sidewalls and then back into the lens before exiting. This reflected light would need more optical correction than needed by the lighting not bouncing off the sidewalls. Additional correction is achieved by adjusting the curvature of the side profiles  604  to provide the required correction. 
         [0021]    This innovative optical configuration collects essentially 100% of the light while effectively shaping the beam pattern. Collected light bounces only once off the reflector keeping efficiency high. Use of multiple reflector segments with different focal points allows the required control of the beam cutoff. Light that would miss the reflector or bounce in undesired directions is collected by a closely spaced lens that collects the light into a useful pattern while not interfering with the light from the reflector. The light makes one pass through this lens also keeping efficiency high. The saddle shaped lens element creates a wide spread pattern while maintaining a flat beam cutoff. 
         [0022]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the essence 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.

Technology Classification (CPC): 5