Patent Publication Number: US-2022231207-A1

Title: Hybrid lens for controlled light distribution

Description:
RELATED APPLICATION DATA 
     The present application is a continuation application of U.S. patent application Ser. No. 16/937,015 filed Jul. 23, 2020, which is a continuation application of U.S. patent application Ser. No. 16/587,771 filed Sep. 30, 2019, now U.S. Pat. No. 10,804,448, which is a continuation application of U.S. patent application Ser. No. 15/483,096 filed Apr. 10, 2017, now U.S. Pat. No. 10,468,566. The present application is also a continuation application of U.S. patent application Ser. No. 17/343,030 filed Jun. 9, 2021, which is a continuation application of U.S. patent application Ser. No. 16/831,369 filed Mar. 26, 2020, now U.S. Pat. No. 11,060,694, which is a continuation application of U.S. patent application Ser. No. 15/483,199 filed Apr. 10, 2017, which is now U.S. Pat. No. 10,619,823. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to lighting fixtures and, more particularly, to LED lighting fixtures for various common illumination purposes. Still more specifically, this invention relates to the field of lensing for desired LED light distribution in LED lighting fixtures. 
     BACKGROUND OF THE INVENTION 
     In recent years, the use of light-emitting diodes (LEDs) for various common lighting purposes has increased, and this trend has accelerated as advances have been made in LEDs and in LED-array bearing devices, referred to as “LED modules.” Indeed, lighting needs which have primarily been served by fixtures using high-intensity discharge (HID) lamps, alogen lamps, compact florescent light and other light sources are now increasingly beginning to be served by LEDs. Creative work continues in the field of LED development, and also in the field of effectively utilizing as much of the light emitted from LEDs as possible. 
     As is known, LED “packages,” which typically consist of an LED component (or a cluster of LEDs) on a base with or without a “primary lens,” each have a lens thereover to direct light from the LED package as intended. (Such lens is sometimes referred to as a “secondary” lens when the package with which it is used includes a primary lens.) Development efforts have been made in the field of such lenses, with the intention being to redirect some of the LED-emitted light in a manner forming illumination patterns desired for particular applications. However, such lenses have tended to fall short of the most desirable performance in that some LED-emitted light is lost or produces illuminance distributions which lack desired characteristics such as color and/or intensity uniformity. 
     Typically, some of the light from LEDs is emitted at angles that cause LED-lighting fixtures to provide less than desirable and less than fully efficient illumination patterns. Some prior lenses have been configured to prevent undesirable light from exiting the lens and others to block such light immediately upon its exiting the lens. Even though these configurations were deemed necessary to achieve desired illumination patterns and to prevent so-called lighting “trespass,” they tended to result in lost light and decreased efficiency of LED illuminators. It would be highly desirable to improve efficiency in the use of light emitted by LEDs in lighting fixtures. 
     A typical LED emits light over a wide range of angles such that light from the LED reaches a particular area of the output surface of the lens at somewhat different angles. This has made it very difficult to control direction of such light. It would be desirable to provide improved control of the direction of light exiting such lenses. 
     Trespass lighting can be evaluated by more than just the amount of light emitted in an undesired direction; also to be considered is how far from the desired direction such light is directed. It would be highly beneficial to provide a lighting apparatus which produces a desired illumination pattern with a maximum amount of light emitted toward the space intended to be illuminated, in typical commercial applications. 
     Lighting fixtures, such as sidewalk, roadway and/or parking lot fixtures, often provide high angle lighting distributions for meeting various areal lighting requirements. Lighting fixtures, for example, can provide a Type II distribution suitable for walkways, highway on-ramps and off-ramps as well as other long and narrow corridors. In other embodiments, lighting fixtures can provide a Type III distribution generally employed for roadway lighting and parking lots where a larger area of lighting is required. Alternatively, a Type V lighting distribution can be provided. Type V lighting distribution can be circular or square, having isotropic intensity over all lateral angles. 
     Achieving high angle lighting distributions with acceptable uniformity and limited glare can be difficult. High angle lighting distributions often contain severe bright spots that only exacerbate visual discomfort resulting from fixture glare. Moreover, point sources of high intensity, such as light emitting diodes (LEDs), can provide multiple bright spots over the light emitting face of a fixture. Various optics have been employed to improve luminous uniformity and glare reduction. However, such optics struggle with effectively mixing and spreading light from intense point sources over high distribution angles. 
     SUMMARY OF THE INVENTION 
     This invention is a lens with improved efficiency of distribution of light from a light emitter having an emitter axis and defining an emitter plane. Such improved efficiency of light output from the light emitter is achieved with the inventive lens which is specifically designed for refraction, reflection and useful output of light emitted in directions of the desired illumination. In certain embodiments, the inventive lens directs the great majority of light from the emitter in a preferential-side direction, including light emitted at angles which previously resulted in the loss of such light. Such efficiency of light use is provided only by configuration of the lens. 
     In certain embodiments, the lens has a faceted output region, a smooth output surface and at least one reflective surface which reflects light through total-internal-reflection (TIR) toward the faceted output region. The faceted output region is formed by pairs of transverse surfaces each surface of which redirects the received light to provide a composite illuminance pattern. The lens may further have faceted input surfaces at least partially defining a light-input cavity about the emitter axis. The faceted input region are formed by pairs of transverse surfaces each surface of which redirects the received light. The faceted input surfaces may include surface portions reflecting light through total-internal-reflection (TIR). In some embodiments, the at least one reflective surface at least partially bounds a reflection cavity offset from the light-input cavity. The faceted output surfaces may include major and minor surfaces. The minor surfaces may be formed by transverse surface portions with cross-sectional dimensions smaller than cross-sectional dimensions of transverse surface portions of the major surfaces. 
     The transverse surface portions of the faceted output surfaces may extend to substantially straight intersection regions substantially parallel to each other. The transverse surface portions may extend to substantially curved intersection regions substantially parallel to each other. 
     The inventive lens includes inner and outer surfaces. The inner surface defines an inner cavity about the emitter axis. The inner surface may have the faceted input surfaces being a plurality of transverse inner regions forming inner stepwise discontinuities redirecting light received from the emitter. The outer surface receives redirected emitter light and has the faceted output region of a plurality of transverse outer regions forming outer stepwise surface discontinuities redirecting the received light. In certain embodiments of the inventive lens at least one of the inner and outer surfaces comprising a combination of at least one smooth region and a plurality of transverse regions forming stepwise discontinuities for redirecting received light. In some of such embodiments, the outer surface includes the smooth outer region. The transverse regions forming stepwise discontinuities of the inner surface may be configured to redirect emitter light toward the smooth outer region. At least some of the transverse regions forming stepwise discontinuities may be configured for refraction of the received light. At least some of the transverse regions forming stepwise discontinuities may also be configured for total internal reflection (TIR) of the received light. 
     Certain embodiments of the lens have a secondary surface offset from the inner surface. The secondary surface may be configured for total internal reflection (TIR) of light received from the inner surface. In some embodiments, the secondary surface at least partially bounds a secondary cavity offset from the inner cavity. 
     In certain alternative embodiments, the secondary surface may be part of an exterior surface at least partially surrounding the inner cavity. In some of such alternative embodiments the secondary surface is radially offset from the inner cavity and extends from near the emitter plane away in directions along the emitter axis and sometimes away from the emitter axis. In certain examples of these embodiments of the lens with a surrounding flange, the flange may extend from such exterior secondary surface. 
     The secondary surface may have a plurality of transverse reflecting regions forming reflecting stepwise discontinuities. 
     In each of the inner, outer and reflecting stepwise discontinuities, corresponding adjacent transverse regions may extend to intersection regions which are substantially parallel to adjacent intersection regions. 
     It should be noted that the term “reflective” is used for convenience in describing the transverse regions forming stepwise discontinuities of the secondary surface. In certain examples, some of such transverse regions may be refractive such that at least a portion of the secondary surface passes light through such regions. 
     In some embodiments, the transverse reflecting regions may be substantially planar surfaces or have convex/concave cross-sections. Adjacent transverse reflecting regions may extend to an intersection region which may be a curved line or cross-sectionally concave/convex surface portion. The intersection regions may be longitudinally straight or extend along a curve. Adjacent intersection regions may be substantially parallel to each other. In addition or alternatively, adjacent intersection regions may extend in a direction away from the emitter plane. In some examples, such adjacent intersection regions may also extend away from the emitter axis. 
     A longitudinal direction of at least some of the transverse reflecting regions may be parallel to a plane of bilateral symmetry of the lens. 
     It should be appreciated that lenses according to the present invention may have symmetries other than bilateral such as a rotation symmetry, a quad-lateral or other symmetries that achieve desired illumination patter. Depending on the intended illumination pattern, the inventive lens may be shaped without symmetry and have asymmetrical surfaces. In certain embodiments, at least some of the outer stepwise discontinuities are optically aligned over the secondary surface such that light reflected by the secondary surface is received and further redirected by the outer stepwise discontinuities. 
     In at least one of the inner and outer stepwise discontinuities, corresponding adjacent transverse regions extend to intersection regions therebetween. The intersection regions of the inner stepwise discontinuities may be curved regions each adjoining a pair of the transverse inner regions adjacent to each other. The curved merger region can be convex or concave. The transverse regions of the inner and/or outer surfaces may be substantially planar surfaces or have convex/concave cross-sections. Adjacent intersection regions may be substantially parallel to each other. The intersection regions may be straight or curved lines or have convex or concave cross-sections and be longitudinally straight or extend along a curve. The intersection regions may be in planes substantially orthogonal or parallel to the emitter axis. Additionally or alternatively, longitudinal directions of the intersection regions may be substantially orthogonal or parallel to a plane of bilateral symmetry of the lens. 
     Some of the transverse outer regions may slope at different angles. In a pair of adjacent transverse outer regions, at least one of the pair refracts the received light. 
     At least some of the transverse inner regions may be configured for total internal reflection (TIR) of the light received from the emitter. In addition or alternatively, at least some of the transverse inner regions refract the light received from the emitter. 
     In certain embodiments, at least some of the transverse inner regions are non-planar. In some of such embodiments the transverse inner regions proximal to the emitter axis have substantially concave cross-sections in planes substantially orthogonal to the plane of bilateral symmetry of the lens. 
     Some of the transverse inner regions may longitudinally extend along an arc at least partially surrounding the emitter axis. Some or all of such transverse inner regions may have convex/concave cross-sections. Some of the adjacent transverse inner regions may extend to an intersection region that may have a concave/convex cross-section. 
     The inner surface may have a smooth inner region adjacent the inner stepwise discontinuities. 
     In certain embodiments, the transverse inner regions proximal the emitter axis have smaller cross-sectional dimensions than the transverse inner regions distal from  20  the light emitter. 
     The inner surface may have at least two sets of transverse inner regions which form a corresponding number of distinct sets of the inner stepwise discontinuities. 
     The outer surface may include a smooth outer region. In some of such embodiments which also have the inner surface with a plurality of distinct sets of the inner stepwise discontinuities, at least one of the distinct sets of the inner stepwise discontinuities redirects emitter light toward the smooth outer region. 
     Some embodiments of the inventive lens include at least two secondary surface portions each outwardly offset from the inner surface. At least one of such secondary surface portions may be configured for total internal reflection (TIR) of light received from the inner surface. 
     In certain embodiments, the secondary surface portions are separate surfaces substantially opposite each other. Additionally or alternatively, the secondary surface portions may be connected at corners. In some examples, the inventive lens may have three and more secondary surface portions. In some of such examples, the secondary surface portions are connected at corners and form polygonal shapes corresponding to the number of the secondary surface portions. In some alternative examples, at least some of the plurality of the secondary surface portions are separate from the adjacent secondary surface portions. Is some other examples, there may be a combination of the separate and connected secondary surface portions. Yet in some alternative examples, the secondary surface portions may form a substantially annular secondary surface around the inner cavity. Additionally or alternatively, such substantially annular secondary surface may be continuous or have interruptions. 
     In some of such embodiments, the outer surface comprises outer stepwise discontinuities corresponding to each of the secondary surface portions for receiving and further redirecting light received from the corresponding secondary surface portion. 
     At least one of the secondary surface portions comprises a plurality of transverse reflecting regions forming reflecting stepwise discontinuities. 
     In certain embodiments, the outer surface comprises at least two sets of transverse outer regions forming a corresponding number of distinct outer stepwise discontinuities. At least one of such distinct outer stepwise discontinuities is outward of the other for receiving light reflected or otherwise redirected by corresponding regions of the corresponding secondary surface. 
     In some of such embodiments, at least two of the distinct outer stepwise discontinuities are optically aligned over each of the secondary surface portions. 
     The sets of outer stepwise discontinuities formed by transverse outer regions may be substantially planar surfaces and may also extend to intersection regions that may be straight or curved lines or be surface portions cross-sectionally planar or convex/concave. Some or all of the intersection regions may be substantially parallel to each other. Some or all of the intersection regions may be generally in planes substantially orthogonal or parallel to the emitter axis. Such general planes of the intersection regions of the outer stepwise discontinuities may be orthogonal or parallel to a plane of bilateral symmetry of the lens. 
     The outwardmost of the sets of the outer stepwise discontinuities may be formed by transverse outer regions with smaller cross-sectional dimensions in axially-parallel planes than cross-sectional dimensions of the transverse outer regions of the other set(s) of the outer stepwise discontinuities which is/are closer to the emitter axis than the outwardmost set of the outer stepwise discontinuities. In some embodiments, the outwardmost set(s) of the outer stepwise discontinuities may be formed by a greater number of transverse outer regions. 
     In another aspect of this invention, the lens(es) according to this invention is optically coupled to an LED light source of an LED arrangement supported by an LED light fixture. In certain examples, the LED light fixture has a heat-sink structure having a mounting surface supporting the LED arrangement. The LED arrangement may include a plurality of spaced apart LED light sources and a plurality of the lenses each optically coupled with a corresponding one of the light sources. 
     In another aspect, an optic assembly described herein comprises a collimating optic directing light along a collimation axis and light redirection elements comprising facets for redirecting a portion of collimated light in one or more directions away from the collimation axis. In some embodiments, one or more of the facets intersect the collimation axis at an angle supporting redirection of the light by total internal reflection. Alternatively, facets may redirect collimated light via reflective and/or refractive surfaces. 
     In another aspect, luminaire architectures are described herein. In some embodiments, a luminaire comprises a light source and one or more optic assemblies receiving light from the light source, the optic assemblies comprising a collimating optic directing the light along a collimation axis. The optic assembly also comprises light redirection elements comprising facets for redirecting a portion of the collimated light in one or more directions away from the collimation axis. As described further herein, the optic assembly, in some embodiments, can assist in providing high angle or lateral lighting distributions from the luminaire. 
     These and other embodiments are further described in the detailed description which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an enlarged opaque perspective view from a light-output side of one embodiment the inventive lens. 
         FIG. 2  is an enlarged opaque perspective view from a light-input side of the lens of  FIG. 1 . 
         FIG. 3  is an enlarged opaque light-output plan view of the lens of  FIG. 1 . 
         FIG. 4  is an enlarged opaque light-input plan view of the lens of  FIG. 1 . 
         FIG. 5  is an enlarged opaque perspective cross-sectional view from a light-input side of the lens of  FIG. 1 , taken along a plane of bilateral symmetry of the lens. 
         FIG. 6  is an enlarged opaque perspective cross-sectional view generally from a light-output side of the lens of  FIG. 1 , taken along a plane of bilateral symmetry of the lens. 
         FIG. 7  is an enlarged opaque cross-sectional view of the lens of  FIG. 1 , shown in the plane of bilateral symmetry of the lens. 
         FIGS. 8 and 9  are enlarged opaque views of opposite lateral sides of the lens of  FIG. 1 . 
         FIG. 10  is an enlarged opaque front (preferential side) view of the lens of  FIG. 1 . 
         FIG. 11  is an enlarged opaque back (non-preferential side  5 ) view of the lens of  FIG. 1 . 
         FIG. 12  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIG. 1  primarily in the plane of bilateral symmetry of the lens. 
         FIG. 13  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIG. 1  in planes orthogonal the plane of bilateral symmetry of the lens. 
         FIGS. 14-16  are exemplary representations of simulated illuminance achieved with the lens of  FIG. 1 . 
         FIG. 17  is an exemplary representation of a simulated intensity distribution achieved with the lens of  FIG. 1 . 
         FIG. 18  is an exemplary representation of a simulated candela plot achieved with the lens of  FIG. 1 , graph  1  showing a vertical plane such as a plane including or substantially parallel to the emitter axis, graph  2  showing a horizontal cone. 
         FIG. 19  is an exemplary representation of a simulated light distribution pattern achieved on an exemplary working plane with luminaries utilizing the lens of  25   FIG. 1 . 
         FIG. 20  is an exemplary representations of simulated chromaticity showing a color uniformity achieved with the lens of  FIG. 1 . 
         FIG. 21  is another enlarged opaque cross-sectional view of the lens of  FIG. 1 , shown from an opposite side of the view in  FIG. 7 . 
         FIG. 22  is a light-output side perspective view illustrating thickness analysis of the lens of  FIG. 1 . 
         FIG. 23  is a simulated lit rendering or an illuminated near-field appearance of the lens shown in  FIG. 1 , representing areas that would appear lit or bright when viewing the lens directly to illustrate the lens spreading the light over a larger area, leading to reduced near-field glare. 
         FIG. 24  is an enlarged opaque cross-sectional lateral side view of a prior lens not utilizing stepwise discontinuities of the surfaces of the inventive lens.  FIG. 25  is a light-output side perspective view illustrating thickness analysis of the lens of  FIG. 24 , for comparison with  FIG. 23 , lightest areas represent local thickness in excess of 4 mm. 
         FIG. 26  is a simulated lit rendering or an illuminated near-field appearance of the lens shown in  FIGS. 24 and 25 , representing areas that would appear lit or bright when viewing the lens directly, to show comparison with the inventive lens illustrated in  FIG. 23 . 
         FIG. 27  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 24-26  primarily in the plane of bilateral symmetry of the lens. 
         FIG. 28  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIG. 24-27  in planes orthogonal the plane of bilateral symmetry of the lens. 
         FIG. 29  is an enlarged transparent perspective view from a light-output side of the lens of  FIG. 25 . 
         FIG. 30  is an enlarged transparent plan view of the lens of  FIG. 29 .  FIG. 31  is an enlarged opaque perspective view from a light-output side of the lens of  FIG. 29 . 
         FIG. 32  is an enlarged opaque perspective view from a light-input side of the lens of  FIG. 29 . 
         FIG. 33  is another enlarged opaque cross-sectional view of the lens of  FIGS. 25-32 , shown from an opposite side of the view in  FIG. 24 . 
         FIG. 34  is an enlarged transparent lateral side view of the lens of  FIGS. 24-33 . 
         FIGS. 35-37  are exemplary representations of simulated illuminance achieved with the lens of  FIG. 31 . 
         FIG. 38  is an exemplary representation of a simulated intensity distribution achieved with the lens of  FIG. 31 . 
         FIG. 39  is an exemplary representation of a simulated candela plot achieved with the lens of  FIG. 31 , graph  1  showing a vertical plane such as a plane including or substantially parallel to the emitter axis, graph  2  showing a horizontal cone. 
         FIG. 40  is an exemplary representation of a simulated light distribution pattern achieved on an exemplary working plane with luminaries utilizing the lens of  FIG. 31 . 
         FIG. 41  is an exemplary representations of simulated chromaticity showing a color uniformity achieved with the lens of  FIG. 31 . 
         FIG. 42  is an enlarged opaque perspective view from a light-output side of another embodiment of the inventive lens. 
         FIG. 43  is an enlarged opaque perspective view from a light-input side of the lens of  FIG. 42 . 
         FIG. 44  is an enlarged transparent perspective view from a light-output side of the lens of  FIG. 42 . 
         FIG. 45  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIG. 42  primarily in the plane of bilateral symmetry of the lens. 
         FIG. 46  is an exemplary representations of simulated illuminance achieved with the lens of  FIG. 42 . 
         FIG. 47  is an enlarged opaque perspective view from a light-output side of another embodiment the inventive lens. 
         FIG. 48  is an enlarged opaque perspective view from a light-input side of the lens of  FIG. 47 . 
         FIG. 49  is an enlarged opaque light-output plan view of the lens of  FIG. 47 . 
         FIG. 50  is an enlarged opaque light-input plan view of the lens of  30   
         FIG. 47 . FIG. 51  is an enlarged opaque perspective cross-sectional view from a light-input side of the lens of  FIG. 47 , taken along a plane of bilateral symmetry of the lens. 
         FIG. 52  is an enlarged opaque cross-sectional view of the lens of  FIG. 47 , shown in the plane of bilateral symmetry of the lens. 
         FIGS. 53 and 54  are enlarged opaque views of opposite lateral sides of the lens of  FIG. 47 . 
         FIG. 55  is an enlarged opaque front (preferential side) view of the lens of  FIG. 47 . 
         FIG. 56  is an enlarged opaque back (non-preferential side  5 ) view of the lens of  FIG. 47 . 
         FIG. 57  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved primarily in the plane of bilateral symmetry of the lens with a lens having some characteristics of input and output surfaces of the lens of  15   FIG. 47 . 
         FIG. 58  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved in planes orthogonal the plane of bilateral symmetry of the lens with the lens of  FIG. 57 . 
         FIGS. 59-61  are exemplary representations of simulated illuminance achieved with the lens of  FIG. 47 . 
         FIG. 62  is an exemplary representation of a simulated intensity distribution achieved with the lens of  FIG. 47 . 
         FIG. 63  is an exemplary representation of a simulated candela plot achieved with the lens of  FIG. 47 , graph  1  showing a vertical plane such as a plane including or substantially parallel to the emitter axis, graph  2  showing a horizontal cone. 
         FIG. 64  is an exemplary representation of a simulated light distribution pattern achieved on an exemplary working plane with luminaries utilizing the lens of  FIG. 47 . 
         FIG. 65  is an exemplary representations of simulated chromaticity showing a color uniformity achieved with the lens of  FIG. 47 . 
         FIG. 66  is an enlarged opaque perspective view from a light-output side of yet another embodiment the inventive lens. 
         FIG. 67  is an enlarged opaque perspective view from a light-input side of the lens of  FIG. 66 . 
         FIG. 68  is an enlarged opaque light-output plan view of the lens of  FIG. 66 . 
         FIG. 69  is an enlarged opaque light-input plan view of the lens of  FIG. 66 . 
         FIG. 70  is an enlarged opaque perspective cross-sectional view from a light-input side of the lens of  FIG. 66 , taken along a plane of bilateral symmetry of the lens. 
         FIG. 71  is an enlarged opaque perspective cross-sectional view from a light-output side of the lens of  FIG. 66 , taken along a plane of bilateral symmetry of the lens. 
         FIG. 72  is an enlarged opaque cross-sectional view of the lens of  FIG. 66 , shown in the plane of bilateral symmetry of the lens. 
         FIGS. 73 and 74  are enlarged opaque views of opposite sides along the plane of bilateral symmetry of the lens of  FIG. 66 . 
         FIGS. 75 and 76  are enlarged opaque views of opposite sides substantially orthogonal to the plane of bilateral symmetry of the lens of  FIG. 66 . 
         FIG. 77  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with one example of a lens similar to that of  FIG. 66  and having substantially planar transverse inner regions. 
         FIG. 78  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved in planes orthogonal the plane of bilateral symmetry with the lens of  FIG. 77 . 
         FIG. 79  is an exemplary representation of simulated illuminance achieved with the lens having the type of inner-surface configuration of the lens shown in  FIGS. 77 and 78 . 
         FIG. 80  is an exemplary representations of simulated chromaticity showing a color uniformity achieved with the lens of  FIGS. 77 and 78 . 
         FIG. 81  is an enlarged opaque cross-sectional view of the lens of  FIGS. 77 and 78 , shown in the plane substantially orthogonal to the plane of bilateral symmetry of the lens. 
         FIG. 82  is an enlarged opaque cross-sectional view of the lens of  FIG. 66 , shown substantially orthogonal to the plane of bilateral symmetry of the lens. 
         FIG. 83  is an enlarged axially-adjacent fragment of the opaque cross-sectional view of  FIG. 82 , showing axially-adjacent transverse inner regions having substantially concave cross-sections. 
         FIG. 84  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIG. 66  in planes substantially parallel to the plane of bilateral symmetry of the lens. 
         FIG. 85  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes orthogonal to the plane of bilateral symmetry. 
         FIG. 86  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes substantially orthogonal the plane of bilateral symmetry, showing light output at major outer stepwise discontinuities of the outer surface. 
         FIG. 87  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes substantially parallel the plane of bilateral symmetry, showing light output at major outer stepwise discontinuities of the outer surface. 
         FIG. 88  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes substantially orthogonal the plane of bilateral symmetry, showing light output at minor outer stepwise discontinuities outward of the major outer stepwise discontinuities of the outer surface. 
         FIG. 89  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes substantially parallel the plane of bilateral symmetry, showing light output at minor outer stepwise discontinuities outward of the major outer stepwise discontinuities of the outer surface. 
         FIG. 90  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes substantially parallel the plane of bilateral symmetry, showing light output at smooth outer region  35 D of outer surface  30 D. 
         FIG. 91  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with the lens of  FIGS. 66 and 82  in planes substantially orthogonal the plane of bilateral symmetry, showing light output at smooth outer region  35 D of outer surface  30 D. 
         FIGS. 92-94  are exemplary representations of simulated illuminance achieved with the lens of  FIGS. 66 and 82 . 
         FIG. 95  is an exemplary representation of a simulated intensity distribution achieved with the lens of  FIGS. 66 and 82 . 
         FIG. 96  is an exemplary representation of a simulated candela plot achieved with the lens of  FIGS. 66 and 82 , graph  1  showing a vertical plane such as a plane including or substantially parallel to the emitter axis, graph  2  showing a horizontal cone. 
         FIG. 97  is an exemplary representation of a simulated light distribution pattern achieved on an exemplary working plane with luminaries utilizing the lens of  FIGS. 66 and 82 . 
         FIG. 98  is an exemplary representations of simulated chromaticity showing a color uniformity achieved with the lens of  FIGS. 66 and 82 . 
         FIG. 99  is an enlarged simplified representation with ray-fan simulation showing light distribution achieved with another exemplary embodiment of a lens according to the present invention in planes substantially parallel the plane of bilateral symmetry of such lens. 
         FIG. 100  is an exemplary representation of a simulated illuminance achieved with the lens of  FIG. 99 . 
         FIG. 101  is an exemplary representation of simulated chromaticity showing a color uniformity achieved with the lens of  FIG. 99 . 
         FIG. 102  is a perspective view from a light-output side of an example of a light fixture utilizing a pair of LED-array modules each having a plurality of lenses of the type shown in  FIG. 1 . 
         FIG. 103  is a fragment of  FIG. 102  showing an LED arrangement at a greater scale. 
         FIG. 104  is a fragment of the LED arrangement of  FIG. 103  at a greater scale. 
         FIG. 105  is a fragmentary perspective view showing a plurality of inventive lenses each optically coupled with a corresponding one of LED light sources supported on a circuit board. 
         FIG. 106  is a perspective view from a light-output side of an exemplary LED-array module. 
         FIG. 107  is a plan view from a light-output side of an example of a light fixture utilizing the LED-array module of the type shown in  FIG. 106 . 
         FIG. 108  is a fragmentary perspective view from a light-output side of the light fixture of  FIG. 107 . 
         FIG. 109  is a greatly enlarged example of stepwise surface discontinuities with sharp intersection regions. 
         FIG. 110  is a greatly enlarged example of stepwise surface discontinuities with concave (“fillets”) and convex (“rounding”) intersection regions. 
         FIG. 111  is a much enlarged fragment of  FIG. 110 . 
         FIG. 112  is an enlarged perspective view of one example of an LED package and including an array of eight LEDs on a submount and an asymmetric primary lens overmolded over the LED array. 
         FIG. 113  is an enlarged perspective view of another example of an LED package and including an array of forty-eight LEDs on a submount and an asymmetric primary lens overmolded over the LED array. 
         FIG. 114  is an enlarged perspective of yet another example of an LED package which has a single LED on a submount with a hemispheric primary lens overmolded over the LED. 
         FIG. 115  is an enlarged side view of the LED package of  FIG. 114 . 
         FIG. 116  is an enlarged top view of the LED package of  FIG. 114 . 
         FIG. 117  is an enlarged top view of another exemplary LED package including an array of four LEDs on a submount and a hemispheric primary lens overmolded over the LED array such that the axis of the primary lens is offset from the axis of the LED array. 
         FIG. 118  illustrates a collimating optic of an assembly according to some embodiments. 
         FIG. 119  is a ray diagram illustrating collimation by the optic of  FIG. 118  according to some embodiments. 
         FIG. 120  is a ray diagram illustrating operation of a collimating optic according to some embodiments. 
         FIG. 121  is a ray diagram illustrating operation of a collimating optic according to some embodiments. 
         FIG. 122  is a perspective view of a light redirection element according to some embodiments. 
         FIG. 123  is a perspective view of a light redirection element according to some embodiments. 
         FIG. 124  is a perspective view of a light redirection element according to some embodiments. 
         FIG. 125( a )  illustrates light distribution provided by the redirection element of  FIG. 122 . 
         FIG. 125( b )  illustrates light distribution provided by the redirection element of  FIG. 123 . 
         FIG. 125( c )  illustrates light distribution provided by the redirection element of  FIG. 124 . 
         FIG. 125( d )  illustrates light distribution of the array illustrated in  FIG. 126 . 
         FIG. 126  illustrates an array of light redirection elements according to some embodiments. 
         FIG. 127  illustrates an array of light redirection elements according to some embodiments. 
         FIG. 128  is a ray diagram of an optic assembly according to some embodiments. 
         FIG. 129  illustrates the lighting distribution provided the optic assembly of  FIGS. 128 and 13 . 
         FIG. 130  is a ray diagram of the optic assembly illustrated in  FIG. 128 . 
         FIG. 131  illustrates color uniformity of the lighting distribution provided by the optic of  FIGS. 128 and 130 . 
         FIGS. 132( a ) and 132( b )  are ray diagrams of an optic assembly according to some embodiments. 
         FIG. 133  illustrates lighting distribution of the optic assembly of  FIGS. 132( a ) and 132( b ) . 
         FIG. 134  illustrates color uniformity of the lighting distribution provided by the optic assembly of  FIGS. 132( a ) and 132( b ) . 
         FIGS. 135( a ) and 135( b )  are ray diagrams of an optic assembly according to some embodiments. 
         FIG. 136  illustrates lighting distribution of the optic assembly of  FIGS. 135( a ) and 135( b ) . 
         FIG. 137  illustrates color uniformity of the lighting distribution provided by the optic assembly of  FIGS. 135( a ) and 135( b ) . 
         FIG. 138  illustrates a Fresnel optic tilted relative to a vertical axis according to some embodiments. 
         FIG. 139  illustrates a light redirection optic according to some embodiments. 
         FIG. 140  is a ray diagram illustrating light redirection by total internal reflection facets and refractive surfaces of the optic illustrated in  FIG. 139 . 
         FIG. 141  is a perspective view of the optic having the cross-section illustrated in  FIG. 139 . 
         FIG. 142  is a perspective view of redirection optic employing total internal reflection facets in the form of annular segments according to some embodiments. 
         FIG. 143  is a ray diagram of the optic of  FIG. 142  illustrating redirection of light away from the vertical axis of the optic by total internal reflection facets and refractive surfaces according to some embodiments. 
         FIGS. 144( a ) and 144( b )  illustrate LED panels comprising array of LED modules coupled to the base of a heatsink of a luminaire according to some embodiments. 
         FIGS. 144( c ) and 144( d )  illustrate a monolithic optic comprising an array of optic assemblies according to some embodiments. 
         FIG. 145  is a perspective view of a roadway luminaire according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1-23 and 42-97  illustrate embodiments of lens  10  according to the present invention. Lens  10  has an improved efficiency of distribution of light from a light emitter  12  having an emitter axis  14  and defining an emitter plane  15 . In embodiments shown in  FIGS. 1-23 and 42-65 , lenses  10 A,  10 B,  10 C and  10 D direct the great majority of light from emitter  12  in a preferential-side direction  4 , including light emitted at angles which previously resulted in the loss of such light. 
     Lens  10  includes an inner surface  20  and an outer surface  30 . Inner surface  20  extends from emitter plane  15  defines an inner cavity  21  about emitter axis  14 . Inner surface  20  has a plurality of transverse inner regions  22  forming inner stepwise discontinuities  23  redirecting light received from emitter  12 . 
     Outer surface  30  receives redirected emitter light and has a plurality of transverse outer regions  32  forming outer stepwise discontinuities  33  redirecting the received light. In illustrated embodiments, lens  10  has a secondary surface  40  offset from inner surface  20 . As best seen in  FIGS. 12, 45, 73, 80, 83 and 85 , secondary surface  40  is configured for total internal reflection (TIR) of light received from the inner surface  20 . 
     In some of the illustrated embodiments of lens  10 , secondary surface  40  at least partially bounds a secondary cavity  41  offset from inner cavity  21 .  FIGS. 5-7  illustrate secondary cavity  41 A being further bound by a rear surface  45  of a rear wall  450  with a flange  46  extending outwardly therefrom for securing lens  10 A with respect to light emitter  12 . 
     In lens  10 C illustrated in  FIGS. 47-58 , secondary surface  40 C has a plurality of transverse reflecting regions  42  forming reflecting stepwise discontinuities  43 . The primary purpose of such TIR features is to re-direct high-angle light from the light source  12  to a more vertical direction (e.g., closer to parallel to the optic axis  14  or source surface-normal). This ‘upward’ light may be re-directed or spread into a lateral direction (e.g., parallel to the roadway) by adding facets to the adjacent surface such as outer stepwise discontinuities  33  above the TIR reflector, or by adding facets to the TIR surface itself (reflecting stepwise discontinuities  43 ), or any combination thereof “Faceted,” “step-like” or “Fresnel-like” surfaces, as used herein, refer to surface regions formed by a plurality of planar or curved surface portions each extending along a plane or a curve, respectively, which intersects with a plane or a curve of an adjacent planar or curved surface portion. Some of the adjacent planes or curves intersect with unequal slopes. As described further in this section, certain embodiments include curved merger regions between adjacent planar or curved surface portions. Such curved merger regions serve to smooth intersections between adjacent surface portions. 
       FIGS. 48 and 50  show lens  10 C having a third stepwise discontinuity  233 C rearwardly bounding inner cavity  21 C and extending from emitter-adjacent surface  27 C away from emitter plane  15  toward transverse inner regions  222 C. 
       FIGS. 3, 4, 42, 49, 50, 68 and 69  show that in inner stepwise discontinuities  23 , in outer stepwise discontinuities  33  and in reflecting stepwise discontinuities  43  pairs of adjacent transverse regions extend to corresponding inner intersection regions  24 , outer intersection regions  34  and reflective intersection regions  44  which are substantially parallel to adjacent intersection regions  24 ,  34 ,  44 . In illustrated lens embodiment  10 C, transverse reflecting regions  42 C have convex/concave cross-sections best seen in  FIGS. 51 and 52 .  FIGS. 48, 50 and 51  show adjacent transverse reflecting regions  42 C extending to an intersection region  44 C which is a curved line. Adjacent intersection regions  44 C are shown substantially parallel to each other and extend in a direction away from emitter plane  15  and away from emitter axis  14 , as also seen in  FIGS. 51 and 52 .  FIG. 50  further shows a longitudinal direction of transverse reflecting regions  42 C being parallel to a plane  16  of bilateral symmetry of lens  10 C. 
     In illustrated lens embodiments  10 A and  10 D, each of outer stepwise discontinuities  33 A,  33 D is optically aligned over corresponding secondary surface  40 A,  40 D such that light reflected by secondary surface  40 A,  40 D is received and further redirected by outer stepwise discontinuities  33 A,  33 D. 
       FIGS. 3-4, 49-50, and 68-69  show intersection regions  24  of inner stepwise discontinuities  23  as curved regions each adjoining a pair of transverse inner regions  22  adjacent to each other.  FIGS. 2, 4 and 5 and 48, 50 and 51  show intersection regions  24 A,  24 C curved about emitter axis  14  in planes substantially orthogonal to emitter axis  14  and plane  16  of bilateral symmetry of lens  10 A,  10 C and substantially parallel emitter plane  15 .  FIGS. 2, 4 and 48 and 50  illustrate transverse inner regions  223 A,  223 C longitudinally arcing partially around emitter axis  14 . 
       FIGS. 67, 68 and 70-72  show intersection regions  24 D curved in planes substantially transverse emitter plane  15  and substantially parallel plane  16  of bilateral symmetry of lens  10 . 
     The addition of faceted surfaces such as inner stepwise discontinuities may introduce sharp angles that can result in non-uniformities such as visible lines or striations in brightness and/or color in the resulting illuminance patterns seen in  FIGS. 79 and 80 . These non-uniformities can be compared to more smoothly varying analogue surfaces in conventional lenses, an example of which is illustrated in  FIGS. 24-37 . 
     In order to reduce such non-uniformities, a slight curvature may be added to the facet surfaces to spread out the light.  FIGS. 82 and 83  show substantially concave transverse inner regions  224 D proximal emitter axis  14 . 
     Other approaches for ‘smoothing out’ intensity or color artifacts may include adding slight ripples to various surfaces, or adding slight roughness. Additionally, in order to reduce the impact of light incident on the surface from opposite edges of the source and to reduce visual artifacts, it is helpful to reduce the size and to modify the geometry of the transverse regions directly above light emitter  12  such as an LED component. 
       FIGS. 77-85  illustrate a comparison of an example of linear sharp intersections between transverse regions ( FIG. 81 ) in a lens  10 D′ and lens  10 D with facets providing improved illuminance and color uniformity ( FIGS. 82 and 83 ) which have a slight curvature to the facets, rounded facet corners, and reduced size of the facets directly over light emitter  12 . 
     Intersection regions  24 ,  34 ,  44  may be concave merger regions  71  or convex merger regions  72 . In addition or alternatively, intersection regions  24 ,  34 ,  44  may be longitudinally straight or extend along a curve. 
     The addition of cross-sectional curvature, such as concave merger regions  71  may also be referred to as “fillets.” And convex merger regions  72  may be described as a ‘rounding’ of the sharp facet edges. The “fillets” and “rounding” of the sharp facet edges, as seen in  FIGS. 109-111 , may facilitate reducing far-field illuminance artifacts. In addition, such fillets and rounding of the sharp edges facilitates standard manufacturing processes such as injection molding due to machining constraints and the desire to minimize stress-concentration features. Intentionally increasing the radius of such fillets above what is required for manufacturing can allow further ‘smoothing’ of illuminance patterns. 
       FIGS. 12, 13, 78 and 85  show transverse inner regions  22  refracting the light received from emitter  12 . 
       FIGS. 48 and 50-52  illustrate inner surface  20 C which has a smooth inner region  25 C adjacent inner stepwise discontinuities  23 C. 
       FIGS. 2, 4-7 and 48 and 50-52  show lens embodiments  10 A and  10 C with inner surface  20 A,  20 C having two sets of transverse inner regions  221 A,  222 A and  221 C,  222 C which form a corresponding number of distinct sets of the inner stepwise discontinuities  231 A,  232 A and  231 C,  232 C, respectively. 
       FIGS. 78 and 85  illustrate pairs of adjacent transverse outer regions  32 D with one transverse outer region  321 D of the pair refracts the received light and the other transverse outer region  322 D of the pair reflects the received light through TIR. 
       FIGS. 1, 3, 5-9, 47, 49, 51-54, 66, 68 and 70-74  show outer surface  30 A,  30 C,  30 D including a smooth outer region  35 A,  35 C,  35 D.  FIG. 12  shows that, in lens  10 A, distinct set  231 A of inner stepwise discontinuities  23 A redirects emitter light toward smooth outer region  35 A. 
     The use of input coupling facets (transverse inner regions  22 ) combined with an output free-form surface (smooth outer region  35 ) facilitates direction of the light into a desired illuminance pattern.  FIGS. 90 and 91  show the simulated rayfan illustrating the combined effect of the input facets and output free-form surface to spread the light. Both the input facets (transverse inner regions  22 D) and the output free-form surface (smooth outer region  35 D) utilize primarily refraction to re-direct the light into the desired pattern. Alternately or additionally, some or all of the input facets may utilize TIR to re-direct light. The free-form surface (smooth outer region  35 ) could also comprise a geometric surface such as an ellipse, a cylinder, etc. depending on the desired output illuminance profile. 
       FIGS. 67, 69, 70-74 and 77  illustrate lens  10 D which includes two secondary surface portions  40 D which are separate surfaces substantially opposite each other and each outwardly offset from inner surface  20 D.  FIG. 77  best illustrates secondary surface portions  40 D being configured for total internal reflection (TIR) of light received from inner surface  20 D. 
     The use of opposing TIR reflectors (secondary surfaces  40 ) is beneficial in achieving a narrow light distribution, as in the case of a Type II roadway optic. This feature has distinct advantages over typical optics for this application that utilize a single TIR reflector (secondary surface  40 ) in combination with a free-form surface (smooth outer region  35 ) in that the opposing TIR reflectors  40 D serve to effectively limit the light to the desired narrow band, with little light ‘overflow’ or loss. An example of this feature in lens  10 D (shown in  FIGS. 66-74 ) can be compared to the single-sided TIR feature  40 A of lens  10 A (shown in  FIGS. 1-9 ). Some embodiments of this inventive feature may have three or more TIR reflectors arranged in a triangular, square, rectangular, hexagonal or other arrangement. Such arrangements would be useful for creating symmetric or asymmetric distributions where it is important to limit the ‘overflow’ of light beyond specific boundaries such as roadway curbs or to reduce glare due to high-angle light. Correspondingly, a single TIR surface elongated into a circular, elliptical, semicircular, semi-elliptical, parabolic, etc. profile may be desired to create more rounded illuminance distributions. Certain exemplary embodiments may use four linear or curved TIR surfaces arranged in a square pattern (connected at the corners or separate at the corners), or a circular TIR ring to create a Type V symmetric illuminance distribution for roadways or area lighting. 
       FIGS. 66-74  show outer surface  30 D including outer stepwise discontinuities  33 D corresponding to each of secondary surface portions  40 D for receiving and further redirecting light received from the corresponding secondary surface portion, as illustrated in  FIGS. 77, 84, 87 and 89 . 
       FIGS. 66, 68 and 71-74  show outer surface  30 D having two sets of transverse outer regions  323  and  324  forming a corresponding number of distinct outer stepwise discontinuities  331  and  332 . Outer stepwise discontinuity  331  is outward of outer stepwise discontinuity  332 . Each of outer stepwise discontinuities  331  and  332  are optically aligned over each of secondary surface portions  40 D for receiving light reflected or otherwise redirected by corresponding regions of corresponding secondary surface  40 D, as shown in  FIGS. 77, 84, 87 and 89 . 
       FIGS. 84-89  illustrate how the present invention utilizes sets  323  and  324  of facets positioned directly above a TIR reflector formed by secondary surface  40 D which serve to expand light laterally along the roadway parallel to the curb. In this arrangement, the TIR reflector re-directs the light ‘upward’ towards the facets as shown in  FIGS. 86-89 . Each facet has two sides (also referred to as transverse outer regions  32 D) sloped at different angles for spreading the light laterally along the roadway. 
     In traditional Fresnel facets, one side of the facet is usually intended to not interact strongly with the light (typically oriented nearly parallel to the incident rays so as to minimize light loss in unintended directions). Due to fabrication limitations such as the need to avoid ‘undercuts’, this ‘invisible’ facet generally interacts with some light rays and has a negative impact on performance. 
     In the inventive lens, with the described inventive facet orientation also shown in  FIGS. 66, 71, 85, 86 and 88 , both sides (transverse outer regions  32 D) of each facet redirect light onto the roadway and thus may be optically active with minimal loss. The use of two separate sets of facets at different positions with respect to emitter axis  14 , as further shown in  FIGS. 66, 68, 71 and 86-89 , may ensure that the maximum local thickness of lens  10 D above TIR reflector  40 D does not exceed the thickness desired for a single-shot molding as mentioned above. 
     Individual facets (transverse regions  32 D) may have a linear profile, or a curved profile to improve illuminance uniformity and color mixing. Additionally or alternatively, the facets may comprise a linear or ‘straight’ extruded element—transverse outer regions  323 , or they may comprise a ‘swept’ element where the path of extrusion is curved (as is the case for the input facets—transverse inner regions  22 D, seen in  FIGS. 70-72 ) or segmented (e.g., each segment having an differing angular path) to provide additional light control or mixing. 
       FIGS. 86-89  illustrate simulated ray paths showing lateral light spreading with minimal loss by a set of major facets (stepwise discontinuity  331 ) and minor facets (outwardmost outer stepwise discontinuity  332 ) positioned above the TIR reflector secondary surface  40 D) and oriented such that the ridges (intersecting regions  34 D) are perpendicular to the ‘curb’ of the roadway. 
       FIGS. 66, 68, 71, 86 and 88 , show sets  331  and  332  of outer stepwise discontinuities  33 D as substantially planar surfaces which extend to straight intersection regions  34 D parallel to each other and extending in planes substantially parallel to plane  16  of bilateral symmetry of lens  10 D. 
     As best seen in  FIGS. 66 and 68 , outwardmost set  331  of outer stepwise discontinuities  331 D is shown to be formed by transverse outer regions  323  which in axially-parallel planes orthogonal to plane  16  has cross-sectional dimensions smaller than cross-sectional dimensions of transverse outer regions  323  of set  324  of the outer stepwise discontinuities  332 D which is closer to emitter axis  12  than outwardmost set  331  of the outer stepwise discontinuities  331 D. Outwardmost set  331  of outer stepwise discontinuities  331 D is also shown to be formed by a greater number of transverse outer regions  324 . 
     In summary, the present invention utilizes a “hybrid” combination to faceted Fresnel-like surfaces, surfaces configured for total-internal-reflection (TIR), and smooth surfaces (e.g., parabolic, elliptical, free-form, etc.) to create complex illuminance distributions such as those required for streetlight illumination. The term “smooth,” as used herein with respect to lens surfaces, means having an even and regular surface or consistency free from facets, discontinuities and perceptible projections, lumps or indentations. Smooth surface can be, e.g., parabolic, elliptical, cylindrical, free-form etc. 
     Potential advantages of the present invention include a low profile, more compact lens geometry for applications with space constraints. 
       FIGS. 42-45  show lens  10 B which can viewed in comparison of the Fresnel-like surfaces in some aspects of the inventive lens with more traditional geometric surfaces (such as parabolas) of lens  10 P shown in  FIGS. 24-28 . Lens  10 B has been ‘collapsed’ down to more 2-dimensional structures which occupy less volume.  FIGS. 27, 28 and 45  present a simplified representation with ray-fan simulations showing similar light distributions achieved with a conventional geometric lens  10 P and a thinner, low profile “collapsed” Hybrid lens  10 B. Another advantage of the present invention is simplified, reduced cost fabrication. The incorporation of Fresnel-like surfaces can enable lenses with a maximum local thickness of less than 4 mm, and preferably less than 3 mm. This allows for simplified, less costly ‘single-shot’ molding processes compared to lenses with thicker regions that are subject to slumping and shrinkage, thus requiring multiple molding steps or ‘shots’ to build up the structure to the final desired dimensions while maintaining surface fidelity and tolerance. This is particularly beneficial in cases where larger LED components (→3 mm) are used, as overall lens dimensions typically scale with source size. 
       FIGS. 21, 22, 24 and 25  illustrate a comparison between a conventional geometric streetlight lens  10 P (shown in  FIGS. 24-37 ) and the inventive lens  10 A incorporating the invention, with associated thickness analysis seen in  FIGS. 22 and 25  with the lightest regions being higher thickness. White regions in  FIG. 25  represent local thickness in excess of 4 mm. 
     Another advantage of the present invention is an improved optical performance. The incorporation of additional, simplified control surfaces (e.g., ‘collapsing’ a parabolic surface into a series of linear facets-transverse regions forming stepwise discontinuities) facilitates simplifying of the lens-design process by allowing optimization of each sequential and separate lens surface. This leads to improved lens designs with better optical efficiency and more control over illuminance distributions resulting in improved performance in the final application. Still another advantage of the present invention is an improved color uniformity. Many LED light sources/components do not have uniform color emission over all angles. For example, many LED components emit significantly ‘yellower’ light at high angles. This can cause undesirable color artifacts (e.g. yellowish streaks or striations visible on illuminated surfaces such as roadways). The combination of faceted surfaces with smooth surfaces facilitates improved control and mixing of light emitted at various angles (with corresponding color variances). 
     Yet another advantage of the present invention is a near-field glare reduction. Faceted Fresnel-like surfaces of the stepwise discontinuities facilitate the effect of ‘spreading out’ light emitted from a small source such as an LED component so as to make it appear that the light is coming from a larger area, leading to reduced near-field glare. 
       FIGS. 23 and 26  illustrate simulated renderings of inventive lens  10 A (shown in  FIG. 23 ) and prior lens  10 P (shown in  FIG. 26 ) comparing the ‘lit’ or illuminated near-field appearance of prior lens  10 P and inventive hybrid lens  10 A described earlier in this disclosure. The lighter regions represent areas that would appear lit or bright when viewing the lens directly. The inventive hybrid lens  10 A spreads the light over a larger area, leading to reduced near-field glare. 
     In certain instances of the present invention, the faceted surface may be a unique addition of one or more facets to an existing smooth surface with the intent of, for example, directing light to a specific direction, improving illuminance uniformity, or mixing light rays emitted by the LED source at different angles to reduce color artifacts due to inherent color-angle-non-uniformity of some sources. Each individual facet (also referred herein as a surface of one of a plurality of transverse regions) may serve to re-direct light using primarily TIR or refraction. In some cases, the facet may be designed to intentionally utilize both TIR and refraction, depending on the angle of incidence of the incoming light rays. 
       FIG. 77  illustrates an example of an addition of a single facet of outer surface  30 D formed by two transverse outer regions  325  extending at smooth outer region  35 D substantially orthogonally to plane  16  of bilateral symmetry of lens  10 D.  FIG. 77  also shows that optical coupling of lens  10 D is such that one of two TIR surfaces  40 D is disposed closer to emitter axis the opposite TIR surface  40 . The single facet  325  is proximal to that TIR surface  40  which is farther from emitter axis  14 . 
       FIGS. 102-108  show examples of LED light fixtures  100 A and  100 B, each of which has a heat-sink structure  110  having a mounting surface  111  supporting an LED arrangement  120 .  FIGS. 105 and 106  best illustrate an exemplary LED arrangement  120  having an LED-array module  121  which has a plurality of lenses  10  each optically coupled to an LED light source  12  supported on a circuit board  11 . In the illustrated embodiments, LED arrangement  120  also has a frame member  17  securing lenses  10  according to the present invention with respect to circuit board  11  and the corresponding light emitters  12 . 
       FIGS. 102-104  show an exemplary light fixture  100 A utilizing two LED-array modules  121 A supported on heat sink  110 A.  FIGS. 107 and 108  show an exemplary light fixture  100 B utilizing one LED-array module  121 B supported on heat sink  110 A. Heat sink  110  is shown extending from a housing portion  130  which forms a closed chamber  131 . Fixture  100  is shown to have venting apertures  140  permitting air and water flow through the fixture for convection cooling of heat-dissipating regions of heat-sink  110  which conducts heat away from mounting surface  111  receiving heat from circuit board  11  during operation of LED arrangement  120 . 
       FIGS. 112-117  the show light emitter in the form of an LED package  230  which has a primary lens  240  over the at least one LED  220 . In such embodiments, the inventive lens is a secondary lens placed over primary lens  240 . The light emitter may be of the type illustrated in  FIGS. 114-116  which show LED package  230 D with single LED  220  on a submount  260  and hemispheric primary lens  240 D coaxially overmolded on submount  260  over LED  220 . 
       FIGS. 112 and 113  illustrate exemplary LED packages  230 A and  230 B each including an array of LEDs  220  on an LED-populated area  250  which has an aspect ratio greater than 1, and primary lens  240  being overmolded on a submount  260  over LED-populated area  250 . It is seen in  FIG. 113  that the array may include LEDs  220  emitting different-wavelength light of different colors such as including red LEDs along with light green or other colors to achieve natural white light. Light emitters of the type as LED packages  230 A and  230 B are described in detail in application Ser. No. 13/441,558, filed on Apr. 6, 2012, and in application Ser. No. 13/441,620, filed on Apr. 6, 2012. The contents of both applications are incorporated herein by reference in their entirety. 
       FIGS. 112, 113 and 117  illustrate versions of the LED light emitter configured to refract LED-emitted light in a forward direction (i.e., toward preferential side P). In each LED package  230 A,  230 B and  230 C, each LED array defines an emitter axis.  FIGS. 112 and 113  illustrate primary lens  240 A configured to refract LED-emitted light forward.  FIG. 117  shows hemispheric primary lens  240 C having a centerline  240  offset from the emitter axis  14 . It should be understood that for higher efficiency, the LED emitter may have a primary lens having both its centerline offset from the emitter axis and also being shaped for refraction of LED-emitted light toward preferential side P. In  FIGS. 112 and 113 , primary lens  240 A is shown as asymmetric. 
     Lenses described herein can assist in providing Type II, Type III or Type V lighting distributions from luminaires. Accordingly, luminaires comprising lenses according to the present invention can be used in a variety of outdoor lighting applications including, but not limited to, sidewalk lighting as well as roadway and parking lot lighting. Luminaires comprising lenses according to the present invention described herein can also be employed in several indoor lighting applications. For example, luminaire can provide illumination to narrow spaces, such as aisles, hallways and/or corners of a building or house. Indoor applications also include wall washing. An asymmetric lighting distribution provided by a luminaire can illuminate surfaces of one or more walls. In some embodiments, for example, multiple walls illuminated by the luminaire intersect to form a corner. In other embodiments, multiple walls face one another such as in a hallway or corridor. In some embodiments, light fixtures are mounted on the ceiling or recessed into the ceiling for wall illumination. Alternatively, the light fixtures can be mounted on the floor or recessed into the floor for wall illumination according to methods described herein. As described herein, high angle or lateral lighting distributions can be provided by luminaires comprising lenses described herein. The lighting distributions can be asymmetric or symmetric in nature. In some embodiments, lighting distributions provided by luminaires comprising optic assemblies have peak intensity at angles greater than 30 degrees relative to nadir. Peak intensity of a lighting distribution provided by light fixtures described herein can also have one or more values selected from Table I. 
     
       
         
           
               
             
               
                 TABLE I 
               
               
                   
               
               
                 Peak Intensity of Lateral Lighting 
               
               
                 Distribution Relative to Nadir 
               
               
                   
               
             
            
               
                 &gt;40 
               
               
                 &gt;50 
               
               
                 &gt;60 
               
               
                 &gt;70 
               
               
                 &gt;80 
               
               
                 30-85 
               
               
                 40-85 
               
               
                 50-70 
               
               
                 50-85 
               
               
                 60-85 
               
               
                   
               
            
           
         
       
     
     Luminaires can also comprise light redirection optics in addition to or in place of optic assemblies. Luminaires, for example, can comprise light redirection optics comprising total internal reflection facets of Fresnel architecture as well as refractive surfaces, including those illustrated in the figures. Light redirection optics can also have any design to provide lighting distributions similar to or the same as lenses described herein. 
     LED light sources may comprise packaged LED chip(s) or unpackaged LED chip(s). LED elements or modules can use LEDs of the same or different types and/or configurations. The LEDs, for example, can be monochromatic or any desired color combination. The LEDs can comprise single or multiple phosphor-converted white and/or color LEDs, and/or bare LED chip(s) mounted separately or together on a single substrate or package that comprises, for example, at least one phosphor-coated LED chip either alone or in combination with at least one color LED chip, such as a green LED, a yellow LED, a red LED, etc. The LED module can comprise phosphor-converted white or color LED chips and/or bare LED chips of the same or different colors mounted directly on a printed circuit board (e.g., chip on board) and/or packaged phosphor-converted white or color LEDs mounted on the printed circuit board, such as a metal core printed circuit board or FR4 board. In some embodiments, the LEDs can be mounted directly to a heat sink or another type of board or substrate. Depending on the embodiment, LED arrangements or lighting arrangements using remote phosphor technology can be employed as would be understood by one of ordinary skill in the art, and examples of remote phosphor technology are described in U.S. Pat. No. 7,614,759, assigned to the assignee of the present invention and hereby incorporated by reference. 
     In those cases where a soft white illumination with improved color rendering is to be produced, each LED element or module or a plurality of such elements or modules may include one or more blue shifted yellow LEDs and one or more red or red/orange LEDs as described in U.S. Pat. No. 7,213,940, assigned to the assignee of the present invention and hereby incorporated by reference. The LEDs may be disposed in different configurations and/or layouts along one or more edges of the waveguide body, as desired. Different color temperatures and appearances could be produced using other LED combinations of single and/or multiple LED chips packaged into discrete packages and/or directly mounted to a printed circuit board as a chip-on board arrangement. 
     In one embodiment, the light sources can comprise any LED, for example, an XP-Q LED incorporating TrueWhite® LED technology or as disclosed in U.S. patent application Ser. No. 13/649,067, filed Oct. 10, 2012, entitled “LED Package with Multiple Element Light Source and Encapsulant Having Planar Surfaces” by Lowes et al., (Cree Docket No. P1912US1-7), the disclosure of which is hereby incorporated by reference herein, as developed and manufactured by Cree, Inc., the assignee of the present application. In another embodiment, the light sources can comprise XQ-E LEDs developed by Cree, Inc. 
     Any of the embodiments disclosed herein incorporating LED light sources may include power or driver circuitry having a buck regulator, a boost regulator, a buck-boost regulator, a fly-back converter, a SEPIC power supply or the like and/or multiple stage power converter employing the like, and may comprise a driver circuit as disclosed in U.S. patent application Ser. No. 14/291,829, filed May 30, 2014, entitled “High Efficiency Driver Circuit with Fast Response” by Hu et al. (Cree docket no. P2276US1, attorney docket no. 034643-000618) or U.S. patent application Ser. No. 14/292,001, filed May 30, 2014, entitled “SEPIC Driver Circuit with Low Input Current Ripple” by Hu et al. (Cree docket no. P2291US1, attorney docket no. 034643-000616) incorporated by reference herein. The circuit may further be used with light control circuitry that controls color temperature of any of the embodiments disclosed herein, such as disclosed in U.S. patent application Ser. No. 14/292,286, filed May 30, 2014, entitled “Lighting Fixture Providing Variable CCT” by Pope et al. (Cree docket no. P2301US1) incorporated by reference herein. 
     I. Optic Assemblies 
     In one aspect, optic assemblies are provided comprising a collimating optic directing light along a collimation axis and light redirection elements comprising facets for redirecting a portion of the light in one or more directions away from the collimation axis. As described further herein, collimating light from a light source prior to redirection of the collimated light with redirection elements can enhance uniformity of various lighting distributions, thereby reducing glare and bright spots. 
     Turning now to specific components, the optic assembly comprises a collimating optic operable for collimating light received from the light source along a collimation axis. Any collimating optic not inconsistent with the objectives of the present invention can be employed. In some embodiments, a collimating optic comprises a plurality of refractive facets for collimating light along a collimation axis. Refractive facets of the collimation optic can have any desired angular arrangement relative to the collimation axis. In some embodiments, facets of the collimation optic have a Fresnel architecture and/or arrangement. Facets having concentric arrangement of Fresnel architecture can have any slope angle, draft angle and/or facet spacing. Facet spacing can be periodic or aperioidic. In some embodiments, facets have equal slope angle across the concentric annular sections. In other embodiments, slope angle varies across concentric annular sections. Facet slope angle, for example, can increase or decrease in a radial direction extending from the center of the optic to the optic perimeter. Facet slope angle of each concentric annular section can be selected to provide desired collimation performance. Facet slope angles can generally range from 10 degrees to 80 degrees, in some embodiments. Moreover, facet height can be constant between concentric annular sections of a collimating optic employing Fresnel architecture. In other embodiments, facet height can increase or decrease in a radial direction extending from the center of the optic to the optic perimeter. 
       FIG. 118  illustrates one non-limiting embodiment of a collimating optic of an assembly described herein. As illustrated in  FIG. 118 , the collimating optic  10  comprises Fresnel architecture of facets  11  having a concentric annular arrangement. Slope angle and facet height varies between the concentric annular sections.  FIG. 119  is a ray diagram illustrating collimation by the optic of  FIG. 118 . Light entering the optic  10  from the light source  23  is refracted and collimated along a collimation axis  21 . In the embodiment of  FIG. 119 , the collimation axis  21  is parallel or substantially parallel to the vertical axis  22  of the optic  10 .  FIGS. 120 and 121  also illustrate light collimation by optics  30 ,  40  comprising facets having a concentric annular arrangement. Similar to  FIG. 2 , collimation axes  31 ,  41  of  FIGS. 120 and 121  are parallel to the vertical axes  32 ,  42 . In some embodiments, the collimated beam of light is symmetrical or substantially symmetrical about the vertical axis of the collimating element. Alternatively, the beam of collimated light may be asymmetrical about the vertical axis. Collimating optics employing Fresnel architecture can be formed of any light transmissive material of suitable refractive index. In some embodiments, the collimating optic is formed of glass or radiation transmissive polymeric material. Suitable radiation transmissive polymeric materials include acrylics or polycarbonates. 
     As described herein, the optic assembly further comprises light redirection elements comprising facets for redirecting at least a portion of the light exiting the collimation optic in one or more directions away from the collimation axis. Facets of the light redirection elements can have any geometry and design for providing desired lighting distributions via redirection of the collimated light away from the collimation axis. In some embodiments, for example, facets redirect light from the collimation axis at one or more angles greater than 50 degrees. In some embodiments, the light redirection elements are arranged in an array. When in array format, the facets can have uniform spacing or non-uniform spacing. Moreover, one or more of the facets intersect the collimation axis at an angle supporting redirection of the light by total internal reflection. For intersection angles not supporting total internal reflection, facets can comprise reflective surface coatings and/or redirect light away from the collimation axis by refraction. In some embodiments, an array comprises any combination of redirection elements comprising facets redirecting light by total internal reflection, specular or diffuse reflection and/or refraction. Light redirection mechanism of an individual redirection element may be selected according to several considerations including, but not limited to, position of the element in the array, facet angle of the element relative to the collimation axis, design of neighboring redirection elements and desired lighting distribution provided by the optic. In some embodiments, for example, an array can comprise elements redirecting light from the collimation axis by total internal reflection at angles of 50-65 degrees. For redirection of light at angles exceeding 65 degrees, the array can comprise light redirection elements comprising facets with reflective coatings and/or refractive surfaces 
       FIG. 122  illustrates a perspective view of a light redirection element according to some embodiments. The light redirection element  50  comprises a facet  51  having radial curvature (r c ). In the embodiment of  FIG. 5 , radial curvature (r c ) of the facet  51  extends 90 degrees. The facet  51  also has constant height (h) over the radial curvature (r c ). As illustrated in  FIG. 122 , radial curvature (r c ) in conjunction with height (h) forms a curved interior surface  51 ′ of the facet  51 .  FIG. 123  illustrates a perspective view of a light redirection element according to another embodiment. The light redirection element  60  also comprises a facet  61  having radial curvature (r c ) extending 90 degrees. However, unlike the redirection element of  FIG. 5 , height (h) of the redirection element of  FIG. 6  varies over the radial curvature (r c ). In some embodiments, height of the radial curvature (r c ) is set according to several polynomial functions forming segments of the facet  61 .  FIG. 124  also illustrates a light redirection element  70  comprising a facet  71  wherein facet height (h) varies over radial curvature (r c ). Facet height can be varied to alter lighting distributions produced by the redirection elements.  FIG. 125( a )  illustrates the lighting distribution provided by the light redirection element  50  of  FIG. 122 . As illustrated in  FIG. 125( a ) , the light redirection element  50  provides a narrow light distribution surrounding the optical axis (o a ) of the element. This is in contrast to the lighting distribution provided by the redirection element  60  of  FIG. 6 . As illustrated in  FIG. 125( b ) , the light redirection element  60  provides an output wherein the light is redistributed at high angles relative to the optical axis (o a ) of the element. Light output of the redirection element  70  of  FIG. 124  also redistributes the light at high angles relative to the optical axis (o a ) of the element, as illustrated in  FIG. 125( c ) . 
     Specific output of a light redirection elements can be varied according to facet radial curvature and facet height. A light redirection element can have any desired radial curvature, such as curvature extending a full 360 degrees or any subset of 360 degrees. In some embodiments, a light redirection element has radial curvature less than 90 degrees or greater than 90 degrees. Radial curvature of a light redirection element, in some embodiment, has a value of radial curvature selected from Table II. 
     
       
         
           
               
             
               
                 TABLE II 
               
               
                   
               
               
                 Light Redirection Element Radial 
               
               
                 Curvature (r c )—degrees 
               
               
                   
               
             
            
               
                  90-270 
               
               
                  45-270 
               
               
                  45-180 
               
               
                  90-180 
               
               
                 180-360 
               
               
                 30-90 
               
               
                   
               
            
           
         
       
     
     A light redirection element can also comprise any height in combination with radial curvature to produce the desired light output. Height can be constant over the entire radial curvature or can vary over the radial curvature. In some embodiments, facet height can have a single peak or multiple peaks and valleys. In some embodiments, facet height over the radial curvature can vary according to multiple polynomial segments, such as in a spline curve. A spline curve defining facet height over the radial curvature can be set by any desired number of control points. Depending on specific facet height parameters, suitable polynomials defining the spline curve can be quadratic and/or cubic. Under these design parameters, a light redirection element can be design with any height variation over the radial curvature. 
     As described herein, the light redirection elements can be arranged in array format.  FIG. 126  illustrates an array of light redirection elements according to some embodiments. Light redirection elements of the two-dimensional array can be selected independently of one another to provide the desired lighting distribution from redirecting the collimated light. Alternatively, the light redirection elements are selected with reference to one another to provide the desired lighting distribution. For example, light redirection elements can be selected from the designs illustrated in  FIGS. 122-124 . As shown in  FIGS. 125( a )-( c ) , the redirection elements provide differing light outputs. Two or more redirection elements of differing structure can be arranged in an array in one or several ways to tailor output of the redirected collimated light.  FIG. 125( d )  illustrates light redirection output of the array detailed in  FIG. 126 . It can be seen that light output of the array is a summation of the individual outputs of redirection elements  91  selected from  FIGS. 122-124 . 
     Specific arrangement of light redirection elements in an array be selected according to several considerations including, but not limited to, light output of the redirection elements, design and structure of the redirection elements, properties of the collimated light received by the redirection elements and structure and/or properties of the collimating optic upstream of the array in the optical path. In some embodiments, for example, light redirection elements are arranged to provide periodic or uniform spacing between facets of the elements. In other embodiments, light redirection elements are arranged to provide aperiodic or varying spacing between facets of the elements. Additionally, light redirection elements can be arranged to align facets of the elements with facets of the collimating optic. In other embodiments, light redirection elements can be arranged to offset facets of the elements from facets of the collimating optic. 
       FIG. 127  illustrates an array of light redirection elements according to some embodiments. As illustrated in  FIG. 127 , the light redirection elements  101  of the optic are arranged to provide uniform or substantially uniform facet  102  spacing. Facet height (h) decreases from the array center to the array periphery. While decreasing in height (h) over the array  100 , the individual facets  102  exhibit the same or similar variances in height (h) over the facet radial curvature (r c ). In some embodiments, a single spline curve can have repeated across the radial curvature of the facets  102 . In other embodiments, spline curves vary across facets  102  of the array  100 . 
     As described herein, light redirection elements can receive collimated light directly from the collimating optic. In some embodiments, light redirection elements can reside on a downstream surface of the collimating optic. The collimating optic may comprise a planar or curved downstream surface on which light redirection elements reside. For example, light redirection elements described herein can be reside on the planar side of a Fresnel collimating optic, in some embodiments. Light redirection elements can be formed of the same material as the collimating optic to inhibit or preclude disruption of the collimated beam by different indices or refraction between the light redirection elements and collimating optic. In some embodiments, for example, the collimating optic and light redirection elements are formed as a single monolithic construction. When provided as a single monolithic construction, the collimating optic and light redirection elements can have thickness less than 4 mm. In some embodiments, thickness of the collimating optic and light redirection elements is 1 mm to 3 mm. Low thickness of the collimating optic and light redirection elements can facilitate placement over LED modules of luminaires. 
     In other embodiments, light redirection elements and the collimating optic may have differing indices of refraction. Differing indices of refraction can be employed to refract the collimated light at higher angles prior to redirection by the redirection elements. In this way, higher angles of light distribution may be achieved. In some embodiments, for example, the collimating optic and light redirection elements are formed independently and subsequently coupled by adhesive or other means. In other embodiments, light redirection elements do not reside on one or more surfaces of the collimating optic. Light redirection elements, for example, can part of an independent optic downstream of the collimating optic. When provided as a separate optic, indices of refraction can be further manipulated to achieve high angle or lateral lighting distributions as the collimated light will pass through a medium, such as air, prior to reaching the redirection elements. 
       FIG. 128  is a ray diagram of an optic assembly comprising a collimation optic in conjunction with light redirection elements according to some embodiments. As illustrated in  FIG. 128 , the collimation optic  111  of the assembly  110  comprises Fresnel architecture. The collimation optic  111  collimates light received from a light source  115 , such as one or more LEDs, and passes the collimated light along an axis  113  to the light redirection elements  112 . Facets  114  of the light redirection elements  112  redirect the light in directions away from the collimation axis  113 .  FIG. 129  illustrates the lighting distribution provided the optic assembly of  FIG. 11 . As illustrated in  FIG. 129 , collimated light is redirected at angles greater than 50 degrees.  FIG. 130  is another ray diagram of the collimating optic  111  and light redirection elements  112  illustrated in  FIG. 128 . Collimating light from a light source  115 , such as a plurality of LEDs, prior to redistribution by the light redirection elements can improve color mixing and light uniformity. In such embodiments, hot spots or bright spots can be mitigated, leading to lighting solutions with less discomfort and glare.  FIG. 131  illustrates color uniformity of the lighting distribution provided by the optic assembly  110  of  FIGS. 128 and 130 . 
       FIGS. 132( a ) and 132( b )  are ray diagrams of another optic assembly comprising a collimation optic and associated light redirection elements. The optic assembly  150  also provides a high angle distribution of light exceeding 50 degrees, as provided in  FIG. 133 . Color uniformity of the lighting distribution is provided in  FIG. 134 .  FIGS. 135( a ) and 135( b )  are ray diagrams of another optic assembly comprising a collimation optic and associated light redirection elements. The optic assembly  180  provides a high angle distribution of light exceeding 50 degrees with good color uniformity as illustrated in  FIGS. 19 and 20  respectively. 
     In another aspect, a collimating optic having a Fresnel architecture described herein can be angled relative to the light source to provide collimation along an axis intersecting with the optic vertical axis. Facets of the Fresnel optic, for example, can be arranged relative to the vertical axis at angle(s) supporting total internal reflection along facet surfaces. Total internal reflection of light received by the facets can redirect the light along a collimation axis intersecting the vertical axis of the optic.  FIG. 138  is a ray diagram of a Fresnel optic angled relative to the light source according to some embodiments. As illustrated in  FIG. 138 , the Fresnel optic  210  is angled relative to the light source  211  such that facets  213  of the optic redirect the light via total internal reflection. A portion of the light is steered along a collimation axis  215  intersecting the vertical axis  216  at the desired angle. The Fresnel optic  210  can also refract light in one or more directions to provide the desired lighting distribution, such as a high angle distribution. In some embodiments, the Fresnel optic can comprise one or more surfaces having a reflective coating for redirecting light into the desired distribution. Reflective coatings can be employed in any combination with total internal reflection surfaces and/or refractive surfaces to provide the desired lighting distribution. 
     In another aspect, optics are described herein which do not collimate light for redirection into the desired lighting distribution. In some embodiments, a light redirection optic comprises facets supporting total internal reflection in conjunction with refractive optics to provide desired lighting distributions.  FIG. 139  illustrates a cross-sectional view of a light redirection optic comprising total internal reflection facets and refractive elements according to some embodiments. As provided in  FIG. 139 , the redirection optic  220  comprises facets  221  having orientation relative to the vertical axis  222  of the optic  220  at angle(s) supporting total internal reflection. Specific angles supporting total internal reflection are dependent upon the refractive index of the material forming the redirection optic. The redirection optic also includes refractive elements or surfaces in addition to the facets supporting total internal reflection. The refractive elements  223  can have any structure or geometry to provide the desired lighting distribution. In the embodiment of  FIG. 139 , the optic  220  comprises refractive surfaces  223  adjacent to the facets  221 .  FIG. 140  is a ray diagram illustrating total internal reflection by the facets  221  to direct light away from a vertical axis  222  of the redirection optic  220 . Refractive surfaces  223  also direct light away from the vertical axis  222 . In some embodiments, high angle lighting distributions, such as those illustrated in  FIGS. 129, 133 and 136 , are provided by the redirection optic.  FIG. 141  is a perspective view of the optic having the cross-section illustrated in  FIG. 139 . The facets  221  can be annular segments  226  defining a cavity  225  of the optic  220 . The cavity can be aligned with or surround a light source  227  as illustrated in  FIG. 140 . 
       FIG. 142  is a perspective view of another redirection optic  250  employing total internal reflection facets  251  in the form of annular segments  256 . The annular segments  256  also form a cavity  255  for covering or receiving a light source  257  as illustrated in  FIG. 143 . The redirection optic  250  also comprises refractive surfaces  253  for directing light away from the vertical axis  258  of the redirection element  250  in conjunction with the total internal reflection facets  251 .  FIG. 143  is a ray diagram of the optic of  FIG. 142  illustrating redirection of light away from the vertical axis  258  of the optic  250  by total internal reflection facets  251  and refractive surfaces  253 . 
     II. Luminaires 
     In another aspect, luminaire architectures are described herein. In some embodiments, a luminaire comprises a light source and one or more optic assemblies receiving light from the light source, the optic assemblies comprising a collimating optic directing the light along a collimation axis and light redirection elements. The light redirection elements comprise facets for redirecting a portion of the light in one or more directions away from the collimation axis. As described further herein, the optic assembly, in some embodiments, can assist in providing high angle or lateral lighting distributions from the luminaire. 
     Luminaires described herein, can comprise individual modules including one or more light sources. In some embodiments, for example, a luminaire comprises individual modules comprising one or more LEDs.  FIGS. 144( a ) and 144( b )  illustrate LED panels comprising array of LED modules  60 ,  61  coupled to the base  52  of a heatsink  51  of a luminaire according to some embodiments. In the embodiment illustrated in  FIGS. 144( a ) and 144( b ) , two LED panels are arranged around the central aperture  53  of the heatsink base  52 . LED panels can be fabricated to match any shape of the heatsink base. For example, in some embodiments, the heatsink base can be circular or elliptical, wherein the LED panels are provided arcuate shapes for coupling to the base. Pins  62  can be used to secure the LED panels and associated modules  60 ,  61  in place for rough alignment followed by electrical connection of the panels to wires  59 ′ of the wire harness  57 . Thermal paste or glue can be used to improve the adhesion and/or thermal coupling to the heatsink  51 . Optic assemblies having any construction and/or properties described in Section I herein can be positioned over each of the LED modules  60 ,  61   a  to provide the desired lighting distribution from the luminaire. In some embodiments, optic assemblies of the same design and/or construction are provided over the LED modules  60 ,  61 . Alternatively, optic assemblies described herein of differing construction can be applied over the LED modules  60 ,  61 . For example, specific design of the optic assemblies can vary according to position of the LED module in the array. In the embodiment of  FIGS. 144( a )-( b ) , optic assemblies of LED modules  60 ,  61  at the perimeter of the panels may differ from optic assemblies of LED modules  60 ,  61  residing at interior positions of the panels. 
     In some embodiments, optic assemblies are provided in an individual or independent format for positioning over LED modules. For example, a single optic assembly can be independently positioned over a single LED module. Depending on desired lighting distribution from the luminaire, single optic assemblies can be provided for each of the LED modules in an array or any subset of LED modules in an array. Referring once again to  FIGS. 144( a )-( b ) , individual optic assemblies can be independently arranged over all the LED modules,  60 ,  61  or a subset of the LED modules  60 ,  61 . When arranged over a subset of LED modules, the optic assemblies described herein can work in conjunction with optical element and/or assemblies of differing design and architecture to provide desired lighting distributions from the luminaire. Alternatively, optic assemblies described herein can be part of a single or monolithic optic covering modules of an LED array. A monolithic optic can employ an array of optic assemblies having placement corresponding to LED modules of an array. In some embodiments, each of the optic assemblies of the monolithic optic can have construction and/or properties described in Section I herein. In other embodiments, a monolithic optic can comprise an array of optic assemblies having construction and/or properties described in Section I herein in combination with optics of differing construction to provide desired lighting distributions from the luminaire. In some embodiments, a single monolithic optic can cover the entire LED array or portion(s) of the LED array. In other embodiments, multiple monolithic optics can be employed to cover the entire LED array. Monolithic optics covering an LED array can have the same construction or differing constructions depending on desired lighting distribution from the luminaire. For example, monolithic optic(s) comprising an array of optic assemblies described herein can be combined with monolithic optic(s) comprising optic assemblies or elements of differing construction. In further embodiments, a monolithic optic can be combined with individual or single optic assemblies or elements to cover LED modules of an array. A monolithic optic comprising an array of optic assemblies described herein can cover one or more portions of an LED array wherein remaining LED modules are covered by individual optics or elements. In other embodiments, individual optic assemblies described herein cover a portion of LED modules in an array with the remainder of the modules being covered by a monolithic optic comprising optical elements of differing construction and properties. 
       FIG. 144( c )  illustrates a monolithic optic comprising an array of optic assemblies according to some embodiments. Optic assemblies  68  of the array can have any construction described herein. In some embodiments, the optic assemblies  68  have the same construction and properties. In other embodiments, construction and properties of the optic assemblies  68  can vary across the array according to desired lighting distributions from the luminaire. As described above, all the optic assemblies  68  of the array can have construction and properties of Section I. In other embodiments, any subset of the optic assemblies  68  can have construction and properties of Section I. The optic  67  also includes a central aperture  69  commensurate with the central aperture  53  of the LED heatsink. The underlying LED array  63  can have guide features  65  permitting proper alignment of the optic  67 . The guide features  65  can have any desired location on the LED array  63 . In the embodiment of  FIG. 144( d ) , the guide features  65  are located along the rim of the LED array  63  bordering the central aperture  53 . The optic  67  is rotated to engage the guide features and placed in proper alignment as illustrated in  FIG. 144( d ) . In some embodiments, the guide features  65  can have design to lock the optic  67  in place. 
     The luminaire of  FIGS. 144( a )-( b )  and  FIGS. 27( c )-( d )  can be a high bay light fixture or low bay light fixture in some embodiments. The luminaire of  FIGS. 27( a )-( d )  can be a fixture described in U.S. patent application Ser. No. 15/181,065, filed on Jun. 13, 2016 (Cree Docket No. P2532US2) and/or U.S. patent application Ser. No. 15/018,606 (Cree Docket P2532US1), each of which is incorporated herein by reference in its entirety. 
     In some embodiments, roadway luminaires or fixtures comprise LED modules in which optic assemblies can be incorporated.  FIG. 145  is a perspective view of a roadway luminaire according to some embodiments. The light emitting face  281  of the roadway luminaire  280  comprises two arrays  282 ,  283  of LED modules  284 . Optic assemblies  285  having any construction and/or properties described in Section I herein can be positioned over each of the LED modules  284  to provide the desired lighting distribution from the luminaire. In some embodiments, optic assemblies  285  of the same design and/or construction are provided over the LED modules  284 . Alternatively, optic assemblies  285  described herein of differing construction can be applied over the LED modules  284 . For example, specific design of the optic assemblies  285  can vary according to position of the LED module  284  in the array  282 ,  283 . Additionally, the optic assemblies can be provided in individual format or part of an array in a monolithic optic construction described above. 
     Optic assemblies described herein can assist in providing Type II, Type III or Type V lighting distributions from luminaires. Accordingly, luminaires comprising the optic assemblies can be used in a variety of outdoor lighting applications including, but not limited to, sidewalk lighting as well as roadway and parking lot lighting. Luminaires comprising optic assemblies described herein can also be employed in several indoor lighting applications. For example, luminaire can provide illumination to narrow spaces, such as aisles, hallways and/or corners of a building or house. Indoor applications also include wall washing. An asymmetric lighting distribution provided by a luminaire can illuminate surfaces of one or more walls. In some embodiments, for example, multiple walls illuminated by the luminaire intersect to form a corner. In other embodiments, multiple walls face one another such as in a hallway or corridor. In some embodiments, light fixtures are mounted on the ceiling or recessed into the ceiling for wall illumination. Alternatively, the light fixtures can be mounted on the floor or recessed into the floor for wall illumination according to methods described herein. 
     As described herein, high angle or lateral lighting distributions can be provided by luminaires comprising optic assemblies described herein. The lighting distributions can be asymmetric or symmetric in nature. In some embodiments, lighting distributions provided by luminaires comprising optic assemblies have peak intensity at angles greater than 30 degrees relative to nadir. Peak intensity of a lighting distribution provided by light fixtures described herein can also have one or more values selected from Table III. 
     
       
         
           
               
             
               
                 TABLE III 
               
               
                   
               
               
                 Peak Intensity of Lateral Lighting 
               
               
                 Distribution Relative to Nadir 
               
               
                   
               
             
            
               
                 ≥40 
               
               
                 ≥50 
               
               
                 ≥60 
               
               
                 ≥70 
               
               
                 ≥80 
               
               
                 30-85 
               
               
                 40-85 
               
               
                 50-70 
               
               
                 50-85 
               
               
                 60-85 
               
               
                   
               
            
           
         
       
     
     Luminaires can also comprise light redirection optics in addition to or in place of optic assemblies. Luminaires, for example, can comprise light redirection optics comprising total internal reflection facets of Fresnel architecture as well as refractive surfaces, including those illustrated in  FIGS. 139-142 . Light redirection optics can be coupled to LED modules in a manner similar to that for optic assemblies described herein. Light redirection optics can also have any design to provide lighting distributions similar to or the same as optic assemblies described herein. 
     LED light sources may comprise packaged LED chip(s) or unpackaged LED chip(s). LED elements or modules can use LEDs of the same or different types and/or configurations. The LEDs, for example, can be monochromatic or any desired color combination. The LEDs can comprise single or multiple phosphor-converted white and/or color LEDs, and/or bare LED chip(s) mounted separately or together on a single substrate or package that comprises, for example, at least one phosphor-coated LED chip either alone or in combination with at least one color LED chip, such as a green LED, a yellow LED, a red LED, etc. The LED module can comprise phosphor-converted white or color LED chips and/or bare LED chips of the same or different colors mounted directly on a printed circuit board (e.g., chip on board) and/or packaged phosphor-converted white or color LEDs mounted on the printed circuit board, such as a metal core printed circuit board or FR4 board. In some embodiments, the LEDs can be mounted directly to a heat sink or another type of board or substrate. Depending on the embodiment, LED arrangements or lighting arrangements using remote phosphor technology can be employed as would be understood by one of ordinary skill in the art, and examples of remote phosphor technology are described in U.S. Pat. No. 7,614,759, assigned to the assignee of the present invention and hereby incorporated by reference. In those cases where a soft white illumination with improved color rendering is to be produced, each LED element or module or a plurality of such elements or modules may include one or more blue shifted yellow LEDs and one or more red or red/orange LEDs as described in U.S. Pat. No. 7,213,940, assigned to the assignee of the present invention and hereby incorporated by reference. The LEDs may be disposed in different configurations and/or layouts along one or more edges of the waveguide body, as desired. Different color temperatures and appearances could be produced using other LED combinations of single and/or multiple LED chips packaged into discrete packages and/or directly mounted to a printed circuit board as a chip-on board arrangement. In one embodiment, the light sources can comprise any LED, for example, an XP-Q LED incorporating TrueWhite® LED technology or as disclosed in U.S. patent application Ser. No. 13/649,067, filed Oct. 10, 2012, entitled “LED Package with Multiple Element Light Source and Encapsulant Having Planar Surfaces” by Lowes et al., (Cree Docket No. P1912US1-7), the disclosure of which is hereby incorporated by reference herein, as developed and manufactured by Cree, Inc., the assignee of the present application. In another embodiment, the light sources can comprise XQ-E LEDs developed by Cree, Inc. 
     Any of the embodiments disclosed herein incorporating LED light sources may include power or driver circuitry having a buck regulator, a boost regulator, a buck-boost regulator, a fly-back converter, a SEPIC power supply or the like and/or multiple stage power converter employing the like, and may comprise a driver circuit as disclosed in U.S. patent application Ser. No. 14/291,829, filed May 30, 2014, entitled “High Efficiency Driver Circuit with Fast Response” by Hu et al. (Cree docket no. P2276US1, attorney docket no. 034643-000618) or U.S. patent application Ser. No. 14/292,001, filed May 30, 2014, entitled “SEPIC Driver Circuit with Low Input Current Ripple” by Hu et al. (Cree docket no. P2291US1, attorney docket no. 034643-000616) incorporated by reference herein. The circuit may further be used with light control circuitry that controls color temperature of any of the embodiments disclosed herein, such as disclosed in U.S. patent application Ser. No. 14/292,286, filed May 30, 2014, entitled “Lighting Fixture Providing Variable CCT” by Pope et al. (Cree docket no. P2301US1) incorporated by reference herein. 
     Various embodiments of the invention have been described in fulfillment of the various objects of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the invention. 
     While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.