Abstract:
The optics system is a lamp assembly which produces the desired beam pattern by using a reflector, a lens, a retainer lens, and an LED as a light source. The lamp assembly has three main components (the reflector, the lens, and the retainer lens) that maintain proper alignment between the light source and the reflector, the lens, and the retainer lens. The optical system collects substantially 100% of the light from the light source while effectively shaping the beam pattern using both cylindrical and revolved reflector elements. The lens has a saddle-shape which is used with the surface of a revolution to eliminate any “dogbone” light pattern shape. The use of a reflective element forms the foreground of the beam pattern.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 61/399,968 filed on Jul. 20, 2010. This application also claims priority to the PCT application PCT/US2011/001279 filed on 19 Jul. 2011. The disclosure of the above application is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to an optical system which collects substantially all of the light emitted from a light source to produce a desired beam pattern. 
     BACKGROUND OF THE INVENTION 
     Current headlamps which incorporate the use of a light emitting diode (LED) use a projector type lens, reflector optics, or closely coupled optics. These types of headlamps suffer from low optical efficiency, high cost, or poor beam pattern distribution. 
     Accordingly, there exists a need for a headlamp having an LED light source which also includes an optical system that is able to collect substantially all of the light produced by the LED light source, and produce a desired beam pattern efficiently. 
     SUMMARY OF THE INVENTION 
     The optical system of the present invention solves the drawbacks of previous designs by using an optical system that collects substantially 100% of the light emitted from the light source and effectively directs it to produce the desired beam pattern. This is achieved by a complex combination of different optical control methods including reflector and lens optics. More specifically, the optics system is a lamp assembly which produces the desired beam pattern by using a reflector, a lens, a retainer lens, and an LED as a light source. The cost of producing the lamp assembly according to the present invention is controlled by a design that reduces the optical part count to three main components that maintain proper alignment between the light source and the reflector, the lens, and the retainer lens. 
     The innovative optical system of the present invention collects substantially 100% of the light from the light source while effectively shaping the beam pattern using both cylindrical and revolved reflector elements. The combination of a saddle-shaped lens element and the surface of a revolution eliminates any “dogbone” light pattern shape, and the use of a reflective element forms the foreground of the beam pattern. The present invention has the combination of a prism and culminating lens with a culminating and flat reflective reflector. Another feature of the present invention is the integration of retaining features in a retainer lens and the reflector. 
     In one embodiment, the lamp assembly of the present invention has a light source in the form of a light emitting diode, a reflector operable for producing a desired beam pattern with light emitted from the light emitting diode, and at least one cylindrical extrusion sidewall formed as part of the reflector which is operable for forming a central portion of the desired beam pattern. 
     The present invention also includes a vertical culminating reflector segment formed as part of the reflector, and is operable for controlling a vertical edge profile of the wide angle spread light portion and the hotspot portion of the desired beam pattern. The lamp assembly also includes two lenses, a lens mounted to the reflector operable for forming a foreground portion of the desired beam pattern, and a retainer lens connected to and supporting a portion of the reflector operable for directing a portion of the light emitted from the light emitting diode toward the vertical culminating reflector segment. The retainer lens, the light emitting diode, and the reflector mounted to a printed circuit board (PCB). 
     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 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a first perspective view of a hybrid optic LED headlamp, according to the present invention; 
         FIG. 2  is a second perspective view of a hybrid optic LED headlamp with half of the reflector removed, according to the present invention; 
         FIG. 3  is a third perspective view of a hybrid optic LED headlamp with the lens and retainer lens removed, according to the present invention; 
         FIG. 4  is a sectional side view of the hybrid optic LED headlamp taken along lines  4 - 4  of  FIG. 1 , according to the present invention; 
         FIG. 5  is a sectional bottom view of a lens and a heat sink used for a hybrid optic LED headlamp taken along lines  5 - 5  of  FIG. 1 , according to the present invention; 
         FIG. 6  is a sectional bottom view of a retainer lens, an LED, and a heat sink used for a hybrid optic LED headlamp taken along lines  6 - 6  of  FIG. 1 , according to the present invention; 
         FIG. 7  is a perspective view of a lens used for a hybrid optic LED headlamp, according to the present invention; 
         FIG. 8  is a perspective view of a retainer lens used for a hybrid optic LED headlamp, according to the present invention; 
         FIG. 9  is a perspective view of a reflector used for a hybrid optic LED headlamp, according to the present invention; 
         FIG. 10  is a perspective view of a hybrid optic LED headlamp used as part of an array of a headlamp for an automobile, according to the present invention; and 
         FIG. 11  is a perspective view of an alternate embodiment of a hybrid optic LED headlamp, according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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. 
     Referring to the Figures generally, and with specific reference to  FIG. 1 , a lamp assembly according to the present invention is shown generally at  10 . The lamp assembly  10  includes a reflector  12 , a lens  14 , a retainer lens  16 , an LED  18 , a printed circuit board (PCB)  20 , a heatsink  22 , and a plurality of fasteners  24 . Referring now to  FIG. 2 , a perspective view of the lamp assembly  10  is shown with a section of the reflector  12  removed for a better view of the interior of the assembly  10 . One of the fasteners  24  in the interior of the reflector  12  is visible, as well as one of a plurality of apertures  26  present in the PCB  20 . Some of the apertures  26  are used for providing proper alignment, others are used for receiving one of the fasteners  24 , the function of which will be described later. 
     Referring now to  FIG. 3 , the interior of reflector  12  is shown having the lens  14  and the retainer lens  16  removed, allowing the light emitting area, shown generally at  28 , of LED  18  to be seen more clearly. The assembly  10  includes a foreground illumination reflector  30 , which collects at least some light emitted from the light emitting area  28  and directs it forward out of the reflector  12  such that the light reflected by the foreground illumination reflector  30  passes through the lens  14 . A cylindrical extrusion sidewall  32  is also part of the reflector  12 ; the cylindrical extrusion sidewall  32  is adjacent to and extends away from the foreground illumination reflector  30 . The cylindrical extrusion sidewall  32  reflects the light emitted from the LED  18 , and concentrates the light to form the central portion of the beam pattern. At least one revolution  34  is formed with the cylindrical extrusion sidewall  32 . In this embodiment, there are two revolutions  34  which reflect light to form the hotspot portion of the beam pattern and maintains a flat angular presentation of the light source image, thereby keeping the hotspot tight vertically. The reflector  12  also includes side wall reflector segments  36 ; the side wall reflector segments  36  are connected to the cylindrical extrusion sidewall  32  and the revolution  34 . The side wall reflector segments  36  are substantially flat, and function to reflect light from the LED  18  to produce wide angle spread light. 
     Connected and adjacent to the side wall reflector segments  36  is a vertical culminating reflector segment  38 , and the vertical culminating reflector segment  38  is operable with the retainer lens  16  (shown in  FIGS. 1 and 2 ) to control the vertical edge profile of the wide angle spread light and a portion of the hotspot light reflected from surface of revolution  34 . 
     Referring now to  FIG. 4 , the control of how all the light emitted from the LED  18  by the assembly  10  is shown. The light emitting area  28  of the assembly  10  has several zones through which the light from the LED  18  is directed. Some of the light emitted from the LED  18  passes through a bottom zone, generally shown at  40 , and is intercepted by the retainer lens  16 . The retainer lens  16  has two distinct areas, a prism area  42 , which simply bends the light while maintaining a general dispersion angle, and a focusing section  44  that generally culminates the light. All of the light that passes through the prism area  42  and the focusing section  44  is redirected forward and aligned horizontally by a first reflector segment  46  formed as part of the vertical culminating reflector segment  38 , and the reflector segment  46  then focuses the dispersive light from prism area  42 . A second reflector segment  48  is also formed as part of the vertical culminating reflector segment  38 , and the reflector segment  48  redirects the already culminated light from the focusing section  44 . The light emitting area  28  of the assembly  10  also has a forward zone, generally shown at  50 , and the light emitted that passes through the forward zone  50  is intercepted and culminated by lens  14 . The light emitted that passes through a top zone, generally shown at  52 , is intercepted by the foreground illumination reflector  30 , and is directed towards the lens  14  that culminates the light into a portion of the foreground of the beam pattern. 
     With reference to  FIG. 5 , a bottom view through the center of the lens  14  is shown illustrating how all of the light is controlled as the light from the LED  18  is emitted outwardly toward the lens  14 . Again, the light emitting area  28  has several zones in which the light from the LED  18  passes through. Light emitted from the LED  18  in a center zone  54  passes through the lens  14  and contributes to the medium spread portion of the beam pattern. Light emitted from LED  18  in a left zone  56  and a right zone  58  is culminated horizontally, the light then passes through the lens  14  contributing to the hotspot portion of the beam pattern. 
       FIG. 6  is a sectional bottom view through the retainer lens  16  and reflector  12  illustrating how all of the light is controlled as the light from the LED  18  is emitted outwardly from the reflector  12  in the area not covered by the lens  14 . Light emitted from the LED  18  into a center section  60  of the light emitting area  28  passes through the retainer lens  16  and then either reflects off the side wall reflector segment  36 , or reflects directly off the vertical culminating reflector segment  38 . The light reflected by these segments  36 , 38  makes up the widest spread portion of the beam pattern. There are also areas the light passes through to form part of the hotspot portion of the beam pattern. Light passing through the right area  62  and left area  64  is reflected off the surface of the revolution  34  and then through retainer lens  16  and reflects off the vertical culminating reflector segment  38 . This portion of the light contributes to the near hotspot area of the beam pattern. 
       FIG. 7  is an enlarged perspective view of the lens  14 . Molded into the lens  14  is a retention snap feature, shown generally at  66 . Instead of having a cylindrical shape, the lens  14  has a saddle shape achieved by the use of a saddle surface, shown generally at  68 , that corrects the dogbone beam pattern shape in the wide spread light portion of the beam pattern that would occur if the lens  14  were of a simple cylindrical shape. 
     Referring now to  FIG. 8 , details of the retainer lens  16  are shown. The retainer lens  16  has an alignment nub  70  which locates the retainer lens  16  relative to the LED  18 . The alignment nub  70  locates in one of the apertures  26  in the PCB  20  shown in  FIG. 2 . The lens  16  also has one or more attachment legs  72 ; each attachment leg  72  has an aperture  88  to receive one of the fasteners  24 . The lens  16  also has a relief area  74 , which allows for flexing of a snap feature  76  during assembly. 
       FIG. 9  shows further details of the reflector  12  with the lens  14  and retainer lens  16  removed. The reflector  12  has alignment nubs  78  formed as part of a reflector standoff feature  80 . The alignment nubs  78  locate the reflector  12  relative to the LED  18  by locating in apertures  26  in the PCB  20  shown in  FIG. 2 . The cylindrical extrusion sidewalls  32  are mounted on the reflector standoff feature  80 . The reflector standoff feature  80  properly positions the reflector  12  to the proper height above the LED  18 . The reflector  12  has a snap feature  82  which engages the snap feature  76  on the retainer lens  16  when assembled. There is an aperture  84  which allows for attachment with one of the fasteners  24 . Another aperture  86  provides a mating snap feature for the snap feature  66  on the lens  14 . Use of a high reflective coating like silver further improves efficiency over the use of aluminum. 
     Referring again to the Figures generally, during assembly the retainer lens  16  is assembled to the PCB  20 . One of the fasteners  24  extends through a corresponding aperture  88 , through one of the apertures  26  in the PCB  20 , and into an aperture (not shown) formed as part of the heat sink  22 , securing the retainer lens  16  to the PCB  20  and heat sink  22 . In this embodiment, there are two of the fasteners  24  which extend through the corresponding apertures  88  formed as part of each of the attachment legs  72 . Each alignment nub  70  is disposed in a corresponding aperture  26  when the retainer lens  16  is connected to the PCB  20 , providing proper alignment of the retainer lens  16  relative to the PCB  20 . The reflector  12  is then attached to the retainer lens  16  using the snap feature  76  and the snap feature  82 . More specifically, the snap feature  76  includes an angled portion  90  which deflects and snaps into place in a recess  92  formed as part of the snap feature  82 . When the retainer lens  16  and the reflector  12  are in place, an arcuate surface  94  of the retainer lens  16  is in contact with a corresponding arcuate surface  96  formed as part of each of the side wall reflector segments  36 . 
     Once the retainer lens  16  is in place and the reflector  12  is connected to the retainer lens  16 , another one of the fasteners  24  is inserted through the aperture  84  formed as part of the reflector standoff feature  80 , and then extends into one of the apertures  26  of the PCB  20  and into an aperture  102  formed as part of the heat sink  22 , best shown in  FIGS. 2-4 . The alignment nubs  78  on the bottom of the reflector standoff feature  80  are received into a corresponding aperture  26  of the PCB  20 , providing the correct positioning of the reflector  12  relative to the LED  18 . 
     The lens  14  is then attached to the reflector  12  through the use of the retention snap features  66  being received into the corresponding apertures  86 . More specifically, there is a snap feature  66  on each side of the lens  14 , and each snap feature  66  has an angled portion  98  which deflects corresponding arcuate wall portions  100  formed as part of the side wall reflector segments  30  as the lens  14  is moved past the wall portions  100 . Once the lens  14  has moved enough, the angled portions  98  are in alignment with the apertures  86 , allowing the angled portions  98  to move into the apertures  86  as the wall portions  100  are no longer deflected. The arcuate wall portions  100  have substantially the same curvature as the lens  14 , best seen in  FIG. 1 . 
     Once assembled, the lamp assembly  10  provides high efficiency by collecting substantially 100% of the light produced by the LED  18 , and shaping the beam pattern using the lenses  14 , 16 , the reflector  30 , and the various sidewalls  32 , revolution  34 , and segments  36 , 38 . Furthermore, the lamp assembly  10  is easily assembled to the PCB  20  and heat sink  22 . 
       FIG. 10  shows an application of the lamp assembly  10  according to the present invention, which includes an array, shown generally at  104  used for functioning as a headlamp for an automobile. There are two lamp assemblies  10  on one end of the array, and a plurality of lighting devices  106  which also make up part of the array  104 . The lamp assemblies  10  are used to produce a beam pattern having a hot sport portion, and medium spread portion. 
     Referring to  FIG. 11 , an alternate embodiment of the lamp assembly  10  is shown, with like numbers referring to like elements. However, in this embodiment, the lamp assembly  10  is disposed within a casing  108  having several flanges  110  which include apertures  112 . Several of the fasteners  24  may be extended through the apertures  112  to connected the casing  108  to a corresponding mount on a vehicle, allowing the lamp assembly  10  to be located as desired. 
     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.