Patent Publication Number: US-11655959-B2

Title: Optical structures for light emitting diodes (LEDs)

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/748,443, now U.S. Pat. No. 11,236,887, filed Jan. 21, 2020, which claims priority to and the benefit of U.S. Provisional Patent Application No. 62/796,933, filed Jan. 25, 2019, the disclosures of which are hereby incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     The present disclosure relates generally to light emitting diode (LED) lighting systems, and more specifically, to systems, methods, and assemblies regarding optical structures for LED lighting systems. 
     Some known light systems use LEDs as a light source. LEDs can provide instant illumination with no warm-up required. LEDs are also shock and vibration resistant. Additionally, LEDs can increase energy savings. Some applications for LED-based light systems include hazardous environments where electrical and thermal abnormalities are to be avoided to prevent explosion or other fire hazards. 
     Some known LED light system designs include a polycarbonate plate with individual bubble domes that surrounds and virtually encapsulates the LED itself. The domes can bend the light generated by the LEDs to a required or desired distribution pattern. These domes, however, are often positioned very close to the LED and may result in thermal and/or radiometric power incident on the optic plate, which is undesirable. 
     SUMMARY 
     Aspects of the present disclosure relate to a light system including: a substrate; one or more LEDs coupled to the substrate; and an optical distribution plate positioned proximate the substrate, the optical distribution plate including one or more optical structures each corresponding to the one or more LEDs, wherein the one or more optical structures include: a first surface that focuses LED light from the corresponding LED in a first orientation; and an opposite second surface that distributes LED light from the LED in a second orientation, wherein the second orientation is substantially orthogonal to the first orientation. 
     In an example, the second surface includes at least one total internal reflection (TIR) element and at least one refractive element. In another example, a centerline plane extending along the first orientation is defined on the second surface, and the at least one TIR element and the at least one refractive element are positioned symmetrically about the centerline plane. In yet another example, the at least one TIR element reflects LED light substantially away from, or across, the centerline plane, and the at least one refractive element refracts LED light substantially away from the centerline plane. In still another example, the optical distribution plate forms an Illuminating Engineering Society of North America (IESNA) type I beam pattern. In an example, the first surface includes a Fresnel element. 
     In another example, the optical distribution plate forms an Illuminating Engineering Society of North America (IESNA) type III beam pattern. In yet another example, a centerline plane extending along the second orientation is defined on the first surface, and the first surface focuses LED light towards one side of the centerline plane. In still another example, the first surface includes at least one total internal reflection (TIR) element and at least one refractive element. In an example, the first surface is disposed adjacent to and spaced away from the corresponding LED. In another example, a reflector plate is disposed between the substrate and the optical distribution plate. 
     In another aspect, the technology relates to an optical structure for a LED including: an inner surface positionable adjacent to the LED that focuses LED light emitted from the LED in a first direction; and an opposite outer surface that distributes LED light emitted from the LED in a second direction, wherein the second direction is substantially orthogonal to the first direction, and wherein the outer surface includes a plurality of total internal reflection (TIR) elements and a plurality of refractive elements. 
     In an example, a centerline plane extending along the first direction is defined on the outer surface, and a set of single TIR elements are positioned symmetrically adjacent the centerline plane and each single TIR element reflects LED light substantially away from the centerline plane. In another example, wherein a set of refractive elements are positioned symmetrically about the centerline plane and outside of the set of single TIR elements, and each refractive element of the set of refractive elements refracts LED light substantially away from the centerline plane. In yet another example, a set of double TIR elements are positioned symmetrically about the centerline plane and outside of the set of refractive elements, and each double TIR element reflects LED light substantially away from and across the centerline plane. In still another example, the set of refractive elements is a first set of refractive elements and a second set of refractive elements are positioned symmetrically about the centerline plane and outside of the set of double TIR elements, and each refractive element of the second set of refractive elements refracts LED light substantially away from the centerline plane. In an example, the inner surface includes a Fresnel element. In another example, the inner surface includes at least one TIR element and at least one refractive element, wherein a centerline plane extending along the second direction is defined on the inner surface, and the at least one TIR element is offset from the centerline plane and reflects LED light substantially towards the centerline plane. 
     In another aspect, the technology relates to a method of manufacturing an optical structure for a LED including: forming a first surface of the optical structure that focuses LED light emitted from the LED in a first orientation; and forming a second surface of the optical structure that distributes LED light emitted from the LED in a second orientation, wherein the second orientation is substantially orthogonal to the first orientation, and wherein forming the second surface includes: defining a plurality of total internal reflection (TIR) elements on the second surface; and defining a plurality of refractive elements on the second surface, wherein the plurality of TIR elements and the plurality of refractive elements are arranged symmetrically about a centerline plane extending along the first orientation defined on the outer surface. 
     In an example, forming the first surface includes: defining at least one TIR element on the first surface, wherein the at least one TIR element is offset from a centerline plane extending along the second orientation defined on the first surface; and defining at least one refractive element on the first surface. 
     A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the examples disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows. 
         FIG.  1    is a perspective view of an exemplary light system. 
         FIG.  2    is a partial perspective cross-sectional view of the light system shown in  FIG.  1   . 
         FIG.  3    is a schematic view of a first type of beam distribution pattern. 
         FIG.  4    is a schematic view of a second type of beam distribution pattern. 
         FIG.  5    is a top perspective view of an exemplary optical distribution plate for the light system shown in  FIGS.  1  and  2   . 
         FIG.  6    is a bottom perspective view of the optical distribution plate shown in  FIG.  5   . 
         FIG.  7    is a schematic view of an optical structure of the optical distribution plate shown in  FIGS.  5  and  6    illustrating light distribution along a y-axis. 
         FIG.  8    is a schematic view of the optical structure of the optical distribution plate shown in  FIGS.  5  and  6    illustrating light distribution along an x-axis. 
         FIGS.  9 - 12    are detailed schematic views of the optical structure shown in  FIG.  8    illustrating light distribution along the x-axis. 
         FIG.  13    is a top perspective view of another optical distribution plate for the light system shown in  FIGS.  1  and  2   . 
         FIG.  14    is a bottom perspective view of the optical distribution plate shown in  FIG.  13   . 
         FIG.  15    is a schematic view of an optical structure of the optical distribution plate shown in  FIGS.  13  and  14    illustrating light distribution along a y-axis. 
         FIG.  16    is a flowchart illustrating an exemplary method of manufacturing an optical structure. 
     
    
    
     DETAILED DESCRIPTION 
     The optical structures described herein have features that form a predetermined beam pattern from a light emitting diode (LED), which generally emit light beams in a Lambertian pattern. These optical structures can narrow the light beams along a first orientation, while widening the light beams along a substantially orthogonal second orientation. As such, the light systems that contain the optical structures can, for example, be placed near the center of a pathway and provide lighting for narrower paths or roadways and extend the light down the pathway in either direction. In another example, the light systems can be placed towards one side of the pathway and provide lighting that projects more across the pathway as well as extend the light down the pathway in either direction. Additionally, the optical structures have features that move the optic surface that faces the LED further away from the LED. This position change increases airflow around the optic surface and the LED, and reduces thermal and/or radiometric power incident on the optic surface. Thereby, increasing the performance of the light system. 
     The optical structures described herein also may be used within existing light system housings such that many of the components do not need to be modified. 
     In the below examples, the optical structures have a first surface that focuses the LED light in the first orientation and an opposite second surface that distributes the LED light in the second orientation. Sometimes this beam pattern may be referred to as a high angle batwing pattern that is often difficult to achieve with optic surfaces that are spaced away from the LED. As such, the first surface includes features that increase the spacing gap between the optic surface and the LED. In one example, the first surface may include a Fresnel element that is configured to narrow the LED light in the first orientation. In another example, the first surface may include one or more total internal reflection (TIR) elements and at least one refractive elements that are sized and shaped to narrow the LED light in the first orientation. Additionally, the second surface includes one or more total internal reflection (TIR) elements and at least one refractive elements. These elements on the second surface are configured to widen the LED light in the second orientation. 
       FIG.  1    is a perspective view of an exemplary light system  100 .  FIG.  2    is a partial perspective cross-sectional view of the light system  100 . Referring concurrently to  FIGS.  1  and  2   , the light system  100  includes a driver compartment  102  that houses a driver assembly (not shown) that can include a power supply and enable operation thereof. Coupled to the driver compartment  102  is a heat sink assembly  104  that supports an LED system  106 . In the example, the LED system  106  includes one or more LEDs  108  coupled to a substrate  110 . In some examples, the substrate  110  is an LED substrate that may include a printed circuit board (PCB) assembly that provides the necessary electrical connections to the LEDs  108  and other electrical components of the light system  100 . The substrate  110  is connected to the heat sink assembly  104  by one or more fasteners  112 . In other examples, the substrate  110  may be a heat sink substrate having the LEDs  108  and other components mounted directly thereto. 
     The LED system  106  also includes a reflector plate  114  positioned proximate the substrate  110  and an optical distribution plate  116  covering the reflector plate  114 . The reflector plate  114  is disposed between the substrate  110  and the optical distribution plate  116  and is spaced apart from the substrate  110  with a gap  118 . The reflector plate  114  includes one or more cones  120  that extend towards the substrate  110  and correspond in location with the LEDs  108  on the substrate  110 . Each LED  108  may be at least partially disposed within one end of the cone  120  such that the emitted light is directed towards the optical distribution plate  116 . The optical distribution plate  116  is adjacent to the reflector plate  114  and opposite of the substrate  110  and is also spaced apart from the substrate  110  with a gap  122 . The optical distribution plate  116  includes one or more optical structures  124  that correspond in location with the LEDs  108  and the cones  120 . As such, each optical structure  124  covers the opposite end of the cone  120  from the LED  108  with the optical structure  124  spaced apart from the LED  108 . The reflector plate  114  and the optical distribution plate  116  are connected to the heat sink assembly  104  by one or more fasteners  126  via a nested screw boss so as to space the plates  114 ,  116  away from the substrate  110  and form an air gap  128  therebetween. 
     A cover  130  may at least partially surround the LED system  106  and enclose it within the heat sink assembly  104 . The cover  130  is transparent or translucent so as to enable light to be emitted from the light system  100 . The cover  130  may be coupled to the heat sink assembly  104  via a gasket  132  and one or more fasteners  134 . 
     In operation, the LEDs  108  emit light so that the light system  100  can illuminate a required or desired area. The light system  100  defines a longitudinal axis  136  with the LED system  106  disposed at one end of the axis  136 , and as such, the light system  100  generally directs the light towards one end  138  of the longitudinal axis  136  (e.g., in a downward direction if the light system  100  is mounted overhead). Furthermore, the optical distribution plate  116  includes one or more optical characteristics that are described further below so that the light emitted from the LEDs  108  can further be distributed in predetermined orientations and patterns for the illuminated area. That is, the light system  100  may be configured for a specific light distribution profile and to project a predetermined pattern of light onto a surface (e.g., a walkway or roadway). One classification system that is used to describe the pattern of the illuminated area by the light system  100  is established by the Illumination Engineering Society of North America (IESNA). Two types of IESNA patterns are described further below in reference to  FIGS.  3  and  4   . 
       FIG.  3    is a schematic view of a first type of beam distribution pattern  140 . The pattern  140  is characterized as an IESNA Type I beam pattern that is used when the light system  100  is placed near the center of a pathway  142  and provides lighting for narrower paths or roadways. The pattern  140  is a two-way lateral light distribution with the light being substantially directed in opposite directions. That is, the longitudinal axis  136  of the light system  100  can be generally aligned with a z-axis (in and out of the page) and the pattern  140  narrows the light along a y-axis direction  144  and widens the light along an x-axis direction  146 . In the example, the optical distribution plate  116  (shown in  FIGS.  1  and  2   ) can include one or more optical characteristics to distribute the LED light and substantially form pattern  140 . 
       FIG.  4    is a schematic view of a second type of beam distribution pattern  148 . The pattern  148  is characterized as an IESNA Type III beam pattern that is used when the light system  100  is placed towards one side of the pathway  142  and provides lighting that projects more outward in the positive y-axis direction  144  (e.g., towards the top of the page). The pattern  148  is a three-way light distribution with the light being substantially directed in opposite directions and in one substantially orthogonal direction. That is, the pattern  148  extends the light along the positive y-axis direction  144  and narrows the light along the negative y-axis direction  144 , while widening the light along the x-axis direction  146 . In the example, the optical distribution plate  116  (shown in  FIGS.  1  and  2   ) can include one or more optical characteristics to distribute the LED light and substantially form pattern  148 . It should be appreciated that the one or more optical characteristics of the optical distribution plate  116  described further below may be used to form any other type of beam distribution pattern as required or desired. 
       FIG.  5    is a top perspective view of an exemplary optical distribution plate  200  for the light system  100  (shown in  FIGS.  1  and  2   ).  FIG.  6    is a bottom perspective view of the optical distribution plate  200 . Referring concurrently to  FIGS.  5  and  6   , the optical distribution plate  200  is configured to nest on top of the reflector plate (shown in  FIG.  2   ) and is formed from transparent and/or translucent materials (e.g., polycarbonate). The optical distribution plate  200  includes one or more optical structures  202  that each corresponds to an LED light (not shown). In the example, the optical distribution plate  200  includes ( 28 ) optical structures  202  defined in a substantially hollow cylindrical plate  200 . In other examples, any other shape of the plate  200  and/or other number of optical structures  202  may be used as required or desired. In the example, the optical distribution plate  200  forms an IESNA type I beam pattern (see  FIG.  3   ). 
     The optical distribution plate  200  defines an x-axis  204  and a y-axis  206 , with a z-axis  208  being orthogonal thereto. A bottom surface  210  (shown in  FIG.  6   ) of each of the optical structures  202  is positioned adjacent to the LED and is sized and shaped to receive the LED light. The bottom surface  210  focuses the light in a first orientation that is substantially parallel to the y-axis  206 . A top surface  212  (shown in  FIG.  5   ) of each of the optical structures  202  is sized and shaped to emit the LED light and distribute the light in a second orientation that is substantially parallel to the x-axis  204 . The first orientation aligned with the y-axis  206  being substantially orthogonal to the second orientation aligned with the x-axis  204 . As such, both the bottom and top surfaces  210 ,  212  work in conjunction to form the IESNA type I beam pattern (e.g., narrowing the light along the y-axis  206  and widening the light along the x-axis  204 ). To perform this function, the bottom surface  210  includes a Fresnel element and the top surface  212  includes one or more total internal reflection (TIR) elements and one or more refractive elements, with the Fresnel element extending in a direction that is substantially orthogonal to the TIR/refractive elements. The structure of the optical structures  202  is described further below in  FIGS.  7 - 12   . 
     As used herein, TIR is a type of optical surface that reflects the light beam so that the light beam substantially changes direction. These TIR surfaces reflect the light beam in such a way that the angle at which the beams approach the surface approximately equals the angle at which the beams reflect off the surface. In contrast, refraction is a type of optical surface that changes the direction of the light beam as the beams pass through the surface. Thus, refraction may be also considered as bending the path of the beams, while the beams substantially maintain the same general direction. 
       FIG.  7    is a schematic view of the optical structure  202  of the optical distribution plate  200  (shown in  FIGS.  5  and  6   ) illustrating light distribution along the y-axis  206 . With continued reference to  FIGS.  5  and  6    and as described above, an LED  214  may be coupled to a PCB substrate  216  such that light  218  is emitted in the z-axis  208  direction. The reflector plate is not illustrated for clarity in  FIG.  7   , but may be disposed between the optical distribution plate  200  and the PCB substrate  216 . The optical structure  202  is positioned over the LED  214  such that the light  218  (schematically illustrated as light beams) is channeled therethrough. The bottom surface  210  is adjacent to, but offset from, the LED  214  and forms an air gap  220  between the LED  214  and the optical structure  202  and reduces thermal and/or radiometric power incident on the material forming the optical distribution plate  200 . 
     The bottom surface  210  includes a Fresnel element that enables the optical structure  202  to capture the light  218  emitted by the LED  214  and focus (e.g., narrow) the emitted LED light  218  in a direction along the y-axis  206 . The Fresnel element enables the optical structure  202  to have a large optical aperture that the light  218  travels through and a short focal length with a thinner lens structure than compared to a conventional design (e.g., a spherical convex lens). As such, the optic surface of the bottom surface  210  forms a larger air gap  220  for increased airflow and reduces incident power when compared to the conventional design in the light system. In the example, the Fresnel element is a non-imaging linear Fresnel lens that focuses the light  218  into a narrow elongate band in the y-axis  206  direction. The Fresnel element, includes one or more segments  222 ,  224 ,  226 , that extend substantially along the x-axis  204  direction (shown in  FIG.  6   ). This orientation of the segments  222 ,  224 ,  226  facilitates focusing the light  218  in the substantially orthogonal y-axis  206  direction. The segments  222 ,  224 ,  226  are also all refractive elements that generally change the direction of the light beams  218  as they pass through the bottom surface  210  of the optical structure  202 . 
     With reference to  FIG.  6   , a first centerline plane  228  extends substantially parallel to the y-axis  206  direction and divides the bottom surface  210  in half. Each segment  222 ,  224 ,  226  may be curved relative to the first centerline plane  228  such that when looking down in the z-axis  208  direction the segments are substantially C-shaped along the x-axis  204  direction. Additionally, in the example, the orientation of each segment  222 ,  224 ,  226  (e.g., the direction of the curve relative to the first centerline plane  228 ) may be rotated approximately 180° in the optical structures  202  that are on either side of the y-axis  206 . This different orientation of the optical structures  202  facilitates evening out the light pattern in the y-axis  206  direction. In another example, each quadrant of optical structures  202  may have a different segment  222 ,  224 ,  226  orientations. In other examples, each optical structure  202  may have different segment orientations, or each optical structure  202  may have the same segment orientation. 
     The C-shaped curve of the segments  222 ,  224 ,  226  enable increased manufacturing efficiencies and use of diamond turned tooling. As such, the radius of the C-shaped curve may be at least partially based on the method of tooling. In yet another example, one or more of the segments  222 ,  224 ,  226  may extend linearly along the x-axis  204  direction. In still another example, one or more of the segments  222 ,  224 ,  226  may be substantially V-shaped along the x-axis  204  direction. For example, each segment  222 ,  224 ,  226  may be angled a relative to the first centerline plane  228  and the angle α may be between 80° and 89°. In some examples, the C-shaped segments may be offset from the first centerline plane  228 . In further examples, the Fresnel element may be a non-imaging spot Fresnel lens with ring-shaped segments. 
     Referring back to  FIG.  7   , a second centerline plane  230  extends substantially parallel to the x-axis  204  direction (e.g., in and out of the page) and also divides the bottom surface  210  in half. The segments  222 ,  224 ,  226  are positioned symmetrically about the second centerline plane  230  with the first segment  222  centered on the centerline plane  230  and extending to both the left and right side of it. The second segment  224  is positioned on the outside of the first segment  222  with one part on the left side and the other part on the right side of the second centerline plane  230 . The third segment  226  is positioned on the outside of the second segment  224  with one part of the left side and the other part on the right side of the second centerline plane  230 . The first segment  222  is substantially convex in shape and the second and third segments  224 ,  226  are substantially linear and disposed at an angle β relative to the y-axis  206  direction. The second segment  224  may have a greater angle than the third segment  226 . In the example, the second segment  224  may be disposed at the angle β between about 15° and 35°. In an aspect, the angle β of the second segment  224  may be about 24°. In the example, the third segment  226  may be disposed at the angle β between about 1° and 14°. In an aspect, the angle β of the third segment  226  may be about 5°. In other example, a number of segments greater than, or less than, three may be used as required or desired. In another example, some or all of the segments may be curved rather than linear, or linear rather than curved. In still other examples, the segments may be offset from the second centerline plane  230  and/or the left side segment parts different than the right side segment parts as required or desired. 
       FIG.  8    is a schematic view of the optical structure  202  of the optical distribution plate  200  (shown in  FIGS.  5  and  6   ) illustrating light distribution along the x-axis  204 . With continued reference to  FIGS.  5  and  6   , a number of components are described above in  FIGS.  5 - 7   , and as such, are not necessarily described further. The top surface  212  includes at least one TIR element  232  and at least one refractive element  234  that in combination distributes (e.g., widens) the emitted LED light  218  in a direction along the x-axis  204 . In the example, the TIR elements  232  and the refractive elements  234  extend substantially along the y-axis  206  direction (shown in  FIG.  5   ). This orientation of the elements  232 ,  234  facilitates throwing the light  218  in the substantially orthogonal x-axis  204  direction and away from the LED  214  further than a typical Lambertian distribution. 
     With reference to  FIG.  5   , the second centerline plane  230  extends substantially parallel to the x-axis  204  direction and divides the top surface  212  in half. The TIR element  232  and the refractive element  234  may be curved relative to the second centerline plane  230  such that when looking down in the z-axis direction the elements are substantially C-shaped along the y-axis  206  direction. Additionally, in the example, the orientation of each element  232 ,  234  (e.g., the curve relative to the second centerline plane  230 ) may be rotated approximately 180° in the optical structures  202  that are on either side of the y-axis  206 . This different orientation of the optical structures  202  facilitates evening out the light pattern in the x-axis  204  direction. In another example, each quadrant of optical structures  202  may have a different element  232 ,  234  orientations. In other examples, each optical structure  202  may have different element orientations, or each optical structure  202  may have the same element orientation. 
     As described above the C-shaped curve of the elements  232 ,  234  enable increased manufacturing efficiencies and use of diamond turned tooling. In yet another example, one or more of the elements  232 ,  234  may extend linearly along the y-axis  206  direction. In still another example, one or more of the elements  232 ,  234  may be substantially V-shaped along the y-axis  206  direction. For example, each element  232 ,  234  may be angled y relative to the second centerline plane  230  and the angle γ may be between 80° and 89°. In some examples, the C-shaped elements may be offset from the second centerline plane  230 . 
     Referring back to  FIG.  8   , the first centerline plane  228  extends along the y-axis  206  (e.g., in and out of the page) and divides the top surface  212  in half. The elements  232 ,  234  are positioned symmetrically about the first centerline plane  228  and the light  218  may be directed substantially away from, or across, the centerline plane  228  as required or desired to achieve the beam pattern. In other examples, the elements  232 ,  234  may be offset from the second centerline plane  228  and/or may be different on the left side than the right side of the centerline plane  228 . The orientation and the layout of the TIR elements  232  and refractive elements  234  are described further below in reference to  FIGS.  9 - 12   . 
       FIGS.  9 - 12    are detailed schematic views of the optical structure  202  shown in  FIG.  8    illustrating light distribution along the x-axis  204 . A number of components are described above in  FIGS.  5 - 8   , and as such, are not necessarily described further. It should be appreciated that  FIGS.  9 - 12    illustrate the light beams  218  only on the right side of the first centerline plane  228  for clarity. The light beams  218  on the left side of the centerline plane  228  will be mirrored as illustrated in  FIG.  8   . Furthermore, while a plurality of TIR elements  232  and a plurality of refractive elements  234  are described below, it should be appreciated that any other number and/or layout of elements  232 ,  234  may be used so as to enable the beam distribution profile as required or desired (e.g., widening the beam  218  along the x-axis  204  direction). 
     Referring first to  FIG.  9   , the plurality of TIR elements  232  may include a set of single TIR elements  236  that are positioned symmetrically about the first centerline plane  228  and directly adjacent to one another. The TIR element  236  includes an oblique linear TIR surface  238  that reflects the light  218  substantially away from the centerline plane  228 . In examples, the TIR surface  238  may be disposed at an angle relative to a horizontal axis. The angles of TIR surface depend on the index of refraction of the material of the optical structure  202 , and as such, this angle is based at least partially on the incident light ray and the material index of refraction so that TIR occurs. The TIR element  236  also includes a refractive surface  240  so that the reflected light  218  from the TIR surface  238  can exit the optical structure  202 . The refractive surface  240  may be linear or curved as required or desired. 
       FIG.  10    illustrates a first set of refractive elements  242  that are positioned symmetrically about the first centerline plane  228  and outside of the set of single TIR elements  236 . The refractive element  242  includes a curved refractive surface  244  that refracts the light  218  substantially away from the centerline plane  228 . In other examples, the refractive surface  244  may be linear as required or desired. 
       FIG.  11    illustrates a set of double TIR elements  246  that are positioned symmetrically about the first centerline plane  228  and outside of the first set of refractive elements  242 . The TIR element  246  includes two oblique linear TIR surfaces  248 ,  250 . The TIR surface  248  reflects the light  218  substantially away from the centerline plane  228  and the TIR surface  250  reflects the light  218  substantially across the centerline plane  228 . In the example, TIR surface  248  is disposed at a different angle relative to a horizontal axis than the TIR surface  250 . In other examples, these angles may be approximately equal. In examples, the TIR surfaces  248 ,  250  may be disposed at an angle between relative to a horizontal axis. The angles of TIR surface depend on the index of refraction of the material of the optical structure  202 , and as such, this angle is based at least partially on the incident light ray and the material index of refraction so that TIR occurs. In other examples, one or more of the double TIR elements  246  may be at an angle that is approximately equal to the single TIR elements  236  (shown in  FIG.  9   ). 
       FIG.  12    illustrates a second set of refractive elements  252  that are positioned symmetrically about the first centerline plane  228  and outside of the set of double TIR elements  246 . The refractive element  252  includes a curved refractive surface  254  that refracts the light  218  substantially away from the centerline plane  228 . In other examples, the refractive surface  244  may be linear as required or desired. 
       FIG.  13    is a top perspective view of another optical distribution plate  300  for the light system  100  (shown in  FIGS.  1  and  2   ).  FIG.  14    is a bottom perspective view of the optical distribution plate  300 . Referring concurrently to  FIGS.  13  and  14   , the optical distribution plate  300  is configured to nest on top of the reflector plate (shown in  FIG.  2   ) and is formed from transparent and/or translucent materials (e.g., polycarbonate). The optical distribution plate  300  includes one or more optical structures  302  that each corresponds to an LED light (not shown). In the example, the optical distribution plate  300  includes ( 28 ) optical structures  302  defined in a substantially hollow cylindrical plate  300 . In other examples, any other shape of the plate  300  and/or other number of optical structures  302  may be used as required or desired. In the example, the optical distribution plate  300  forms an IESNA type III beam pattern (see  FIG.  4   ). 
     The optical distribution plate  300  defines an x-axis  304  and a y-axis  306 , with a z-axis  308  being orthogonal thereto. A bottom surface  310  (shown in  FIG.  14   ) of each of the optical structures  302  is positioned adjacent to the LED and is sized and shaped to receive the LED light. The bottom surface  310  focuses the light in a first orientation that is substantially parallel to the y-axis  306 . A top surface  312  (shown in  FIG.  13   ) of each of the optical structures  302  is sized and shaped to emit the LED light and distribute the light in a second orientation that is substantially parallel to the x-axis  308 . The first orientation aligned with the y-axis  306  being substantially orthogonal to the second orientation aligned with the x-axis  304 . As such, both the bottom and top surfaces  310 ,  312  work in conjunction to form the IESNA type III beam pattern (e.g., focusing the light in one direction along the y-axis  306  and widening the light along the x-axis  304 ). To perform this function, the bottom surface  310  includes one or more total internal reflection (TIR) elements and one or more refractive elements and the top surface  312  also includes one or more TIR elements and one or more refractive elements, with the bottom surface elements extending in a direction that is substantially orthogonal to the top surface elements. 
     In the example, the top surface  312  of the optical structures  302  have TIR elements and refractive elements that are similar to the top surface structure described above in  FIGS.  5  and  8 - 12   , and as such, the structure of the top surface  312  is not described further herein. However, the bottom surface  310  is different than the example described above, and thus, is described further below in  FIG.  15   . 
       FIG.  15    is a schematic view of the optical structure  302  of the optical distribution plate  300  (shown in  FIGS.  13  and  14   ) illustrating light distribution along the y-axis  306 . With continued reference to  FIGS.  13  and  14    and as described above, an LED  314  may be coupled to a PCB substrate (not shown) such that light  318  is emitted in the z-axis  308  direction. The reflector plate is not illustrated for clarity in  FIG.  15   , but may be disposed between the optical distribution plate  300  and the PCB substrate. The optical structure  302  is positioned over the LED  314  such that the light  318  (schematically illustrated as light beams) is channeled therethrough. The bottom surface  310  is adjacent to, but offset from, the LED  314  and forms an air gap  320  between the LED  314  and the optical structure  302  and reduces thermal and/or radiometric power incident on the material forming the optical distribution plate  300 . 
     The bottom surface  310  includes at least one TIR element  322  and at least one refractive element  324  that enables the optical structure  302  to capture the light  318  emitted by the LED  314  and focus (e.g., narrow) the emitted LED light  318  in a direction along the y-axis  306 . A first centerline plane  326  extends substantially parallel to the x-axis  304  direction (e.g., in and out of the page) and also divides the bottom surface  310  in half. The TIR element  322  and the refractive elements  324  are positioned asymmetrically about the first centerline plane  326  with the TIR element  322  offset  328  from the centerline plane  326 . The TIR element  322  also extends a greater distance toward the LED  314  than the refractive elements  324  which are in a stepped configuration relative to the TIR element  322 . This stepped configuration enables the optic surface of the bottom surface  310  to form a larger air gap  320  for increased airflow and reduces incident power when compared to the conventional designs (e.g., a spherical convex lens) in the light system. In the example, the bottom surface  310  of the optical structure  302  focuses the light  318  in a y-axis  206  direction that is away from the TIR element  322  (e.g., focuses the light  318  towards one side of the centerline plane  326 ). The TIR element  322  and the refractive elements  324  extend substantially along the x-axis  304  direction (shown in  FIG.  14   ). This orientation of the elements  322 ,  324  facilitates focusing the light  318  in the substantially orthogonal y-axis  306  direction. 
     With reference to  FIG.  14   , a second centerline plane  330  extends substantially parallel to the y-axis  306  direction and divides the bottom surface  310  in half. Each element  322 ,  324  may be curved relative to the second centerline plane  330  such that when looking down in the z-axis  308  direction the segments are substantially C-shaped along the x-axis  304  direction. Additionally, in the example, the orientation of each element  322 ,  324  (e.g., the direction of the curve relative to the second centerline plane  330 ) is the same for each optical structure  302  (e.g., in a direction towards the top of the page along the y-axis  306 ). This orientation of the optical structures  302  facilitates directing the light pattern towards one side of the y-axis  306 . In another example, the optical structures  302  may have different element  322 ,  324  orientations. In yet another example, one or more of the elements  322 ,  324  may extend linearly along the x-axis  304  direction. In still another example, one or more of the elements  322 ,  324  may be angled along the x-axis  304  direction such that a V-shape is formed. In some examples, the curved elements may be offset from the second centerline plane  330 . 
     Referring back to  FIG.  15   , the TIR element  322  is offset  328  from the first centerline plane  326 . The TIR element  322  includes an oblique linear TIR surface  332  that forms an outside surface of the bottom surface  310 . The TIR surface  332  reflects the light  318  substantially towards the centerline plane  326 . In examples, the TIR surface  332  may be disposed at an angle between relative to a horizontal axis. The angles of TIR surface depend on the index of refraction of the material of the optical structure  302 , and as such, this angle is based at least partially on the incident light ray and the material index of refraction so that TIR occurs. The TIR element  322  also includes a refractive surface  334  so that the light  318  from LED  314  can enter into the optical structure  302  and reach the TIR surface  332 . The refractive surface  334  may be linear (as illustrated) or curved as required or desired. The TIR element  322  is sized and shaped so as to fit within the reflector cone of the reflector plate (shown in  FIG.  2   ). 
     The refractive elements  324  are adjacent to the TIR element  322  and include one or more refractive surfaces  336 . In the example, one refractive surface  336  is disposed at the first centerline plane  326  and one refractive surface  336  is offset from the first centerline plane  326 . In other examples, any other number of refractive elements  324  may be used. The refractive surfaces  336  refract the light  318  to the side of the y-axis  306  that the TIR surface  332  reflects the light  318  towards. In examples, the refractive surfaces  336  may be disposed at an angle relative to a horizontal axis so as to refract the light  318  towards one side of the y-axis  306 . Each refractive surface  336  may be disposed at approximately equal angles or may be disposed at different angles as required or desired. The refractive surfaces  336  may be linear (as illustrated) or curved as required or desired. 
       FIG.  16    is a flowchart illustrating an exemplary method  400  of manufacturing an optical structure. In the example, the method  400  includes forming a first surface of the optical structure that focuses LED light from the LED in a first orientation (operation  402 ). Additionally, a second opposite surface of the optical structure is formed (operation  404 ). The second surface distributes LED light from the LED in a second orientation, and the second orientation is substantially orthogonal to the first orientation. Forming the second surface (operation  404 ) may further include defining a plurality of total internal reflection (TIR) elements on the second surface (operation  406 ) and defining a plurality of refractive elements on the second surface (operation  408 ). The plurality of TIR elements and the plurality of refractive elements being arranged symmetrically about a centerline plane extending along the first orientation defined on the outer surface. 
     In some examples, the method  400  may further include forming the first surface (operation  402 ) by defining at least one TIR element on the first surface (operation  410 ). The at least one TIR element being offset from a centerline plane extending along the second orientation defined on the first surface. Additionally, at least one refractive element is defined on the first surface (operation  412 ). In some examples, the optical structures may be formed by a molding process with diamond cut tooling. In other examples, the optical structures may be formed by an additive manufacturing process (e.g., 3D printed) or any other manufacturing process now known or developed in the future. In still other examples, one or more of the surfaces of the optical structures may be formed by an extrusion process. 
     In the examples disclosed herein, the optical structures form the desired or required beam pattern while moving the optic surface that faces the LED further away from the LED. For example, on the inner surface of the optical structure a Fresnel element may be used or one or more total internal reflection (TIR) elements and at least one refractive elements may be used. This gap between the optical structure and the LED increases airflow around the optic surface and the LED, and reduces thermal and/or radiometric power incident on the optic surface. Thereby, increasing the performance of the light system. The optical structures described herein can also be used within existing light system housings. The inner surface also is used to narrow the LED in a first orientation. Additionally, on the outer surface of the optical structure one or more total internal reflection (TIR) elements and at least one refractive elements are used to widen the LED light in a second orientation. As such, the optical structures enable a high angle batwing pattern to be formed. 
     This disclosure describes some examples of the present technology with reference to the accompanying drawings, in which only some of the possible examples were shown. Other aspects can, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein. Rather, these examples were provided so that this disclosure was thorough and complete and fully conveyed the scope of the possible examples to those skilled in the art. Any number of the features of the different examples described herein may be combined into one single example and alternate examples having fewer than or more than all of the features herein described are possible. It is to be understood that terminology employed herein is used for the purpose of describing particular examples only and is not intended to be limiting. It must be noted that, as used in this specification, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. 
     Although specific examples were described herein, the scope of the technology is not limited to those specific examples. One skilled in the art will recognize other examples or improvements that are within the scope of the present technology. Therefore, the specific structure, acts, or media are disclosed only as illustrative examples. Examples according to the technology may also combine elements or components of those that are disclosed in general but not expressly exemplified in combination, unless otherwise stated herein. The scope of the technology is defined by the following claims and any equivalents therein.