WO2016071845A1

WO2016071845A1 - Asymmetric lens and linear lighting apparatus

Info

Publication number: WO2016071845A1
Application number: PCT/IB2015/058511
Authority: WO
Inventors: Luc Guy Louis Lacroix
Original assignee: Philips Lighting Holding B.V.
Priority date: 2014-11-06
Filing date: 2015-11-04
Publication date: 2016-05-12

Abstract

Linear lighting control apparatus and asymmetrical, curvilinear lenses (100) for use thereon are described herein. In some embodiments, an asymmetrical, curvilinear lens (100) may define an LED recess (114) with a multi-surface ceiling (116) spanning two side walls (118a, 18b). The multi-surface ceiling may include discrete first and second inner surfaces (122, 124). In some embodiments, the first inner surface may be shaped differently than the second inner surface, and may consequently refract differently. For example, in some embodiments, a contour of the first inner surface may track a contour of a top surface (102) of the lens, so that optical power is not added by the first inner surface. A contour of the second inner surface, by contrast, may not track a contour of the top surface of the lens, such that optical power may be added.

Description

ASYMMETRIC LENS AND LINEAR LIGHTING APPARATUS

Technical Field

[0001] The present invention is directed generally to lighting control. More particularly, various inventive methods and apparatus disclosed herein relate to clusters of light sources and asymmetric lenses, and methods of using clusters of light sources and asymmetric lenses to provide more uniform illumination in the near field.

Background

[0002] Digital lighting technologies, i.e., illumination based on semiconductor light sources, such as light-emitting diodes (LEDs), offer a viable alternative to traditional fluorescent, HID, and incandescent lamps. Functional advantages and benefits of LEDs include high energy conversion and optical efficiency, durability, lower operating costs, and many others. Recent advances in LED technology have provided efficient and robust full-spectrum lighting sources that enable a variety of lighting effects in many applications. Some of the fixtures embodying these sources feature a lighting module, including one or more LEDs capable of producing different colors, e.g., red, green, and blue, as well as a processor for independently controlling the output of the LEDs in order to generate a variety of colors and color-changing lighting effects, for example, as discussed in detail in U .S. Patent Nos. 6,016,038 and 6,211,626, incorporated herein by reference.

[0003] With indirect lighting applications such as "cove lighting" or "wall washing," linear lighting fixtures may be connected end-to-end and concealed within various architectural features, such as coves, soffits, and so forth. These linear lighting fixtures often include LEDs of different colors evenly distributed in a linear pattern. When these fixtures are illuminated close to a surface such as a wall, the lighting effects they create on the surface may be uneven in color and/or intensity. While existing diffusive lenses may help smooth the emitted beams of light, they also may reduce light quality and/or intensity. Thus, there is a need in the art to provide more uniform light in the near field from linear light fixtures used in indirect lighting applications. Summary

[0004] The present disclosure is directed to inventive methods and apparatus for lighting control that include use of asymmetric, curvilinear lenses to direct light from one side of a linear lighting apparatus differently, particularly at near-field range, than light from another side. For example, suppose a linear lighting apparatus such as LED tape or rope is used in a cove lighting application, e.g., near a surface such as a wall or ceiling. One or more asymmetric, cu rvilinear lenses may be provided to refract light from one or more underlying linear clusters of differently-colored LEDs so that when the light hits the nearby surface, it appears relatively uniform, as opposed to the individual colors being visible.

[0005] In one aspect, an asymmetrical, curvilinear lens may define a top surface and an LED recess with a multi-surface ceiling spanning two side walls that define planes parallel to a longitudinal axis of the lens. The multi-surface ceiling may include discrete first and second inner surfaces. A contour of the first inner surface may track a contour of the top surface along both the longitudinal axis and a transverse axis that is perpendicular to the longitudinal axis and passes through the two side walls. A contour of the second inner surface may track the contour of the top surface along the longitudinal axis and deviate from the contour of the top surface along the transverse axis. In various embodiments, a contour of the multi-surface ceiling along the longitudinal axis may be concave. In various embodiments, a transition between the first and second inner surfaces may be abrupt.

[0006] In another aspect, a linear lighting apparatus may include: a linear base defining a longitudinal axis; a plurality of linear clusters of differently-colored LEDs disposed along the linear base, each linear cluster aligned with the longitudinal axis of the linear base; and a plurality of asymmetrical lenses disposed along the linear base over the plurality of linear clusters. Each asymmetrical lens includes an LED recess with a multi-surface ceiling spanning at least two side walls that define planes parallel to the longitudinal axis, the multi-surface ceiling including discrete first and second inner surfaces, the first inner surface shaped to more widely disperse light emitted by an underlying linear cluster of the plurality of linear clusters than the second inner surface. [0007] In various embodiments, a contour of the first inner surface along a transverse axis that is perpendicular to the longitudinal axis and passes through the two side walls may be substantially flat. In various embodiments, a contour of the first inner surface along the longitudinal axis may be curved. In various embodiments, light emitted through each asymmetrical lens on a first side of the longitudinal axis is more uniform at the given distance from an underlying linear cluster than light emitted through the asymmetrical lens on a second side of the longitudinal axis at the given distance.

[0008] In various embodiments, a contour of the first inner surface along the longitudinal axis of each asymmetrical lens may be concave. In various versions, the multi-surface ceiling may further span two additional side walls that define planes perpendicular to the longitudinal axis. In various embodiments, a contour of the second inner surface of each asymmetrical lens along the transverse axis may be convex, and a contour of the second inner surface along the longitudinal axis may be concave. In various versions, in each asymmetrical lens, at least a portion of the second inner surface may be closer to an underlying linear cluster than the first inner surface.

[0009] In yet another aspect, an LED-based light source may include: a linear cluster of differently-colored LEDs aligned to define a first axis; and an asymmetrical, curvilinear lens defining an LED recess that contains the linear cluster of differently-colored LEDs, the LED recess including first and second inner surfaces that face the linear cluster from an opposite side of the LED recess. A contour of the first inner surface may be concave along the first axis and substantially flat along a second axis that is perpendicular to the first axis, and a contour of the second inner surface may be concave along the first axis and convex along the second axis. In various embodiments, light emitted by the cluster of differently-colored LEDs is dispersed more widely by the first inner surface than by the second.

[0010] As used herein for purposes of the present disclosure, the term "LED" should be understood to include any electroluminescent diode or other type of carrier injection/junction- based system that is capable of generating radiation in response to an electric signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures that emit light in response to current, light emitting polymers, organic light emitting diodes (OLEDs), electroluminescent strips, and the like. In particular, the term LED refers to light emitting diodes of all types (including semi-conductor and organic light emitting diodes) that may be configured to generate radiation in one or more of the infrared spectrum, ultraviolet spectrum, and various portions of the visible spectrum (generally including radiation wavelengths from approximately 400 nanometers to approximately 700 nanometers). Some examples of LEDs include, but are not limited to, various types of infrared LEDs, ultraviolet LEDs, red LEDs, blue LEDs, green LEDs, yellow LEDs, amber LEDs, orange LEDs, and white LEDs (discussed further below). It also should be appreciated that LEDs may be configured and/or controlled to generate radiation having various bandwidths (e.g., full widths at half maximum, or FWHM) for a given spectrum (e.g., narrow bandwidth, broad bandwidth), and a variety of dominant wavelengths within a given general color categorization.

[0011] For example, one implementation of an LED configured to generate essentially white light (e.g., a white LED) may include a number of dies which respectively emit different spectra of electroluminescence that, in combination, mix to form essentially white light. In another implementation, a white light LED may be associated with a phosphor material that converts electroluminescence having a first spectrum to a different second spectrum. In one example of this implementation, electroluminescence having a relatively short wavelength and narrow bandwidth spectrum "pumps" the phosphor material, which in turn radiates longer wavelength radiation having a somewhat broader spectrum.

[0012] It should also be understood that the term LED does not limit the physical and/or electrical package type of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies that are configured to respectively emit different spectra of radiation (e.g., that may or may not be individually controllable). Also, an LED may be associated with a phosphor that is considered as an integral part of the LED (e.g., some types of white LEDs). In general, the term LED may refer to packaged LEDs, non-packaged LEDs, surface mount LEDs, chip-on-board LEDs, T-package mount LEDs, radial package LEDs, power package LEDs, LEDs including some type of encasement and/or optical element (e.g., a diffusing lens), etc. [0013] The term "light source" should be understood to refer to any one or more of a variety of radiation sources, including, but not limited to, LED-based sources (including one or more LEDs as defined above), incandescent sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high-intensity discharge sources (e.g., sodium vapor, mercury vapor, and metal halide lamps), lasers, other types of electroluminescent sources, pyro-luminescent sources (e.g., flames), candle-luminescent sources (e.g., gas mantles, carbon arc radiation sources), photo-luminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvano-luminescent sources, crystallo- luminescent sources, kine-luminescent sources, thermo-luminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and luminescent polymers.

[0014] A given light source may be configured to generate electromagnetic radiation within the visible spectrum, outside the visible spectrum, or a combination of both. Hence, the terms "light" and "radiation" are used interchangeably herein. Additionally, a light source may include as an integral component one or more filters (e.g., color filters), lenses, or other optical components. Also, it should be understood that light sources may be configured for a variety of applications, including, but not limited to, indication, display, and/or illumination. An

"illumination source" is a light source that is particularly configured to generate radiation having a sufficient intensity to effectively illuminate an interior or exterior space. In this context, "sufficient intensity" refers to sufficient radiant power in the visible spectrum generated in the space or environment (the unit "lumens" often is employed to represent the total light output from a light source in all directions, in terms of radiant power or "luminous flux") to provide ambient illumination (i.e., light that may be perceived indirectly and that may be, for example, reflected off of one or more of a variety of intervening surfaces before being perceived in whole or in part).

[0015] The term "spectrum" should be understood to refer to any one or more frequencies (or wavelengths) of radiation produced by one or more light sources. Accordingly, the term "spectrum" refers to frequencies (or wavelengths) not only in the visible range, but also frequencies (or wavelengths) in the infrared, ultraviolet, and other areas of the overall electromagnetic spectrum. Also, a given spectrum may have a relatively narrow bandwidth (e.g., a FWH M having essentially few frequency or wavelength components) or a relatively wide ba ndwidth (severa l frequency or wavelength components having various relative strengths). It shou ld a lso be a ppreciated that a given spectru m may be the resu lt of a mixing of two or more other spectra (e.g., mixing radiation respectively emitted from multiple light sources).

[0016] For pu rposes of this disclosu re, the term "color" is used interchangeably with the term "spectru m." However, the term "color" generally is used to refer primarily to a property of radiation that is perceivable by a n observer (although this usage is not intended to li mit the scope of this term). Accordingly, the terms "different colors" i mplicitly refer to multiple spectra having different wavelength components and/or bandwidths. It a lso should be appreciated that the term "color" may be used in connection with both white a nd non-wh ite light.

[0017] The term "color temperature" generally is used herein in con nection with white light, although this usage is not intended to limit the scope of this term. Color temperature essentia lly refers to a pa rticula r color content or shade (e.g., reddish, bluish) of white light. The color temperature of a given radiation sample conventiona lly is characterized according to the temperature i n degrees Kelvin (K) of a black body radiator that radiates essentia lly the same spectrum as the radiation sample in q uestion. Black body radiator color temperatures generally fall within a range of approxi mately 700 degrees K (typically considered the first visible to the hu man eye) to over 10,000 degrees K; white light generally is perceived at color temperatures above 1500-2000 degrees K.

[0018] Lower color temperatures generally indicate white light having a more significa nt red component or a "warmer feel," while higher color temperatures genera lly indicate white light having a more significant blue component or a "cooler feel." By way of example, fire has a color temperature of approximately 1,800 degrees K, a conventiona l incandescent bul b has a color temperature of approximately 2848 degrees K, early morning daylight has a color temperature of approximately 3,000 degrees K, a nd overcast midday skies have a color temperature of approximately 10,000 degrees K. A color image viewed u nder white light having a color temperatu re of approximately 3,000 degree K has a relatively reddish tone, whereas the same color image viewed under white light having a color temperature of approximately 10,000 degrees K has a relatively bluish tone.

[0019] The term "lighting fixture" is used herein to refer to an implementation or

arrangement of one or more lighting units in a particular form factor, assembly, or package. The term "lighting unit" is used herein to refer to an apparatus including one or more light sources of same or different types. A given lighting unit may have any one of a variety of mounting arrangements for the light source(s), enclosure/housing arrangements and shapes, and/or electrical and mechanical connection configurations. Additionally, a given lighting unit optionally may be associated with (e.g., include, be coupled to and/or packaged together with) various other components (e.g., control circuitry) relating to the operation of the light source(s). An "LED-based lighting unit" refers to a lighting unit that includes one or more LED-based light sources as discussed above, alone or in combination with other non LED-based light sources. A "multi-channel" lighting unit refers to an LED-based or non LED-based lighting unit that includes at least two light sources configured to respectively generate different spectrums of radiation, wherein each different source spectrum may be referred to as a "channel" of the multi-channel lighting unit.

[0020] The term "lighting effect" as used herein may refer to the visible phenomenon that is created when emitted light is reflected off a surface such as a wall, floor or ceiling. Lighting effects may take various forms, depending on a variety of factors about the light source, the luminaire, etc. For instance, a spotlight may cast a relatively discrete and clearly delineated circle or similar shape onto a surface. By contrast, a more diffusive light source or luminaire may cause light to be more diffusely cast against the surface, creating a "murkier" lighting effect.

[0021] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

Brief Description of the Drawings

[0022] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

[0023] Fig. 1 is a perspective view of an example asymmetric, curvilinear lens, in accordance with various embodiments.

[0024] Fig. 2 is a view of a cross section of the asymmetric, curvilinear lens of Fig. 1, in accordance with various embodiments.

[0025] Figs. 3 are front, side and bottom views, respectively, of the asymmetrical curvilinear lens of Figs. 1 and 2, in accordance with various embodiments.

[0026] Fig. 4 is a view of a cross section of the asymmetric, curvilinear lens of Fig. 1, which also depicts how light may be refracted by the lens, in accordance with various embodiments.

[0027] Fig. 5 is a side view of a plurality of asymmetric lenses disposed along a base to form a linear lighting apparatus, in accordance with various embodiments.

[0028] Fig. 6 is a chart showing example lighting results that may be attained using lighting apparatus described herein, in accordance with various embodiments.

Detailed Description

[0029] With indirect lighting applications such as "cove lighting" or "wall washing," linear lighting fixtures may be connected end-to-end and concealed within various architectural features, such as coves, soffits, and so forth. These linear lighting fixtures often include LEDs of different colors evenly distributed along the fixture in a linear pattern. When these fixtures are illuminated close to a surface such as a wall, the lighting effects they create on the surface may be uneven in color and/or intensity. While existing diffusive lenses may help smooth the emitted beams of light, they also may reduce light quality and/or intensity. Thus, there is a need in the art to provide more uniform light from linear light fixtures used in indirect lighting applications. More generally, Applicants have recognized and appreciated that it would be beneficial to provide an asymmetrical lens that creates a relatively uniform lighting effect on a nearby surface on at least one side.

[0030] Referring to Figs. 1-4, in one embodiment, an asymmetric, curvilinear lens 100 may receive light from an underlying light source such as a cluster of LEDs (not depicted in Figs. 1-4). Curvilinear lens 100 may define a longitudinal axis 112 and a transverse axis 113 that is perpendicular to longitudinal axis 112. Lens 100 may include a top surface 102 that spans two side surfaces 104a and 104b. Top surface 102 may, in various embodiments, be curved along longitudinal axis 112 of asymmetrical, curvilinear lens. For example, in Figs. 1-4, top surface 102 is convex along longitudinal axis 112. I n some embodiments, top surface 102 may also span (e.g., perpendicularly to side surfaces 104a-b) structure such as flanges 106a and 106b, which may be used, e.g., for mounting lens 100 to a base (not depicted in Fig. 1, see Fig. 5), though this is not required. Also depicted in Fig. 1 is a midpoint line 110 on side surface 104a midway between first flange 106a and second flange 106b along a longitudinal axis 112 of lens 100. While various surfaces and features are described with relative adjectives such as "top," "side," and so forth, these terms are only meant to describe spatial relationships of the features relative to each other when viewed from the viewing angle of Figs. 1-4— these are not meant to be understood as "absolute." For example, features like "top" surface 102 may, depending on the nature of the installation environment, actually face down, to one side, or in any other direction when installed.

[0031] In various embodiments, lens 100 may be a total internal reflection ("TIR") lens, and/or may include one or more features shaped so that light emitted through a first region of lens 100 is dispersed more uniformly at a given distance from lens 100 than light emitted through a second region of lens 100 at the given distance from lens 100. Light emitted th rough the first region may be cast onto a surface that lies near lens 100, such as a surface within or adjacent a cove or soffit, so that the resulting lighting effect on the surface appears relatively uniform. Light emitted through the second region, by contrast, may be more generally cast into space, e.g., to illuminate surfaces and/or objects that are further from lens 100 than the given distance.

[0032] Fig. 2 depicts lens 100 in cross section from midpoint 110. Lens 100 may define a recess 114 for one or more light sources (not depicted in Fig. 2), such as a cluster of LEDs. Recess 114 may include a ceiling 116 spanning two side walls 118a and 118b. In the embodiment depicted in Fig. 2, side walls 118a and 118b are tilted slightly towards each other; however, this is not meant to be limiting. In other embodiments, side walls 118a and 118b may be parallel to each other, or even tilted away from each other. Multi -surface ceiling 116 may include a first inner surface 122 and a second inner surface 124. Both may face one or more light sources (e.g., a cluster of LED clusters described below) contained within recess 114. In various embodiments, first inner surface 122 may be shaped differently than second inner surface 124. In various embodiments, texturing of various forms may be applied to some or all of multi-surface ceiling 116, such as to first inner surface 122 and/or second inner surface 124.

[0033] Figs. 3A-C are side, front and bottom views, respectively, of lens 100. In Fig. 3A, it can be seen that lens 100 has a profile that is wider at a top than at a bottom. However, this is not required, and other embodiments of lens 100 may have different profiles. In some embodiments, there may be texturing applied top surface 102, though this is not required.

[0034] In Fig. 3B, the convex profile of lens 100 from the side is visible between first flange 106a and second flange 106b. Also visible in dashed lines is recess 114, as well as ceiling 116, which is concave in a direction parallel to longitudinal axis 112 in Fig. 3B. I n this example, recess 114 also includes additional side walls 118c and 118d that define planes perpendicular to longitudinal axis 112, and that span multi-surface ceiling 116 near flanges 106a and 106b, though this is not required. I n Fig. 3B, additional side walls 118c and 118d are substantially flat (though texturing may be applied), though this is not required. In some embodiments (not depicted in Fig. 3B), side walls 118c and 118d may be tilted so that portions of side walls 118c and 118d farthest from multi-surface ceiling 116 are farther from, or closer to, flanges 106a and 106b than portions closer to multi-surface ceiling 116. Also visible on ceiling 116 are first inner surface 122 and second inner surface 124, both concave in a direction parallel to longitudinal axis 112. Multi-surface ceiling 116 of recess 114, including first inner surface 122 and second inner surface 124, are also visible in Fig. 3C.

[0035] Fig. 4 is another cross section view of lens 100, similar to Fig. 2, except that it is from a point on longitudinal axis 112. I n Fig. 4, the black arrows represent how light emitted by a light source (schematically represented at 125) contained in recess 114 may be emitted through lens 100 in various regions. As shown, first inner surface 122 may be shaped to more widely disperse light emitted by underlying light source 125 than second inner surface 124. This effect may be accomplished in various ways. In some embodiments, the contour of first inner surface 122 in one or more directions parallel to one or more axes may track a contour of top surface 102 in one or more directions parallel to the same one or more axes. By contrast, the contour of second inner surface 124 in one or more directions parallel to one or more axes, particularly transverse axis 113, may be independent from, and may even deviate from, a contour of top surface 102 in a direction parallel to transverse axis 113. As a result, first inner surface 122 may allow a simple refraction of light without introducing optical power, whereas second inner surface 124 may introduce optical power.

[0036] In Fig. 4, for instance, a contour of first inner surface 122 in a direction parallel to transverse axis 113, approximately from longitudinal axis 112 to side wall 18b, may be substantially "flat" or "neutral" (e.g., defined by a neutral first spline). Put another way, no matter where a cross section is taken from lens 100 in a direction parallel to longitudinal axis 112 between flanges 106a and 106b, inner surface 122 will appear "flat." This "flatness" or "neutrality" tracks the substantially flat/neutral contour of the profile of top surface 102 in a direction parallel to transverse axis 113. Likewise, a contour of first inner surface 122 in a direction parallel to longitudinal axis 112 is curved, or "active" (e.g., defined by an active second spline that is orthogonal to the neutral first spline), which tracks the curved contour of top surface 102 in a direction parallel to longitudinal axis 112. I n this instance, first inner su rface 122 is concave in a direction parallel to longitudinal axis 112 while top surface 102 is convex in a direction parallel to longitudinal axis 112. [0037] In contrast to first inner surface 122, a contour of second inner surface 124 in a direction parallel to transverse axis 113 may be curved (e.g., defined by an active spline and/or hyperbolic), and may deviate from the contour of top surface 102 in a direction parallel to transverse axis 113 (which may be defined by a neutral spline, e.g., "flat"). In Fig.4, for instance, a contour of second inner surface 124 in a direction parallel to transverse axis 113 from longitudinal axis 112 to side wall 118a is convex, whereas a contour of top surface 102 in a direction parallel to transverse axis 113 is relatively flat or "neutral." In various embodiments, a hyperbolic equation selected to define a curvature of second inner surface 124 may be selected to satisfy a particular (e.g., best) collimating fit for the particular source of light employed (e.g., cluster of LEDs, single LED, etc.).

[0038] Light passing from light source 125 through side walls 118a and 118b may be reflected by curved reflective surfaces 126a and 126b straight upwards as shown. Likewise, light passing from light source 125 through second inner surface 124 may be directed straight upwards as shown. By contrast, light redirected by first inner surface 122 may be dispersed more widely than light dispersed by second inner surface 124. This may cause light emitted through lens 100 by way of first inner surface 122 to be more uniform at a given distance from light source 125 than light emitted through lens 100 by way the second inner surface 124 at the given distance from light source 125. In this particular example, light emitted through lens 100 on a first side of longitudinal axis 112 (e.g., on the left in Fig.4) may be more uniform at a given distance from an underlying light source than light emitted through lens 100 on a second side of longitudinal axis 112 (e.g., on the right in Fig.4) at the given distance.

[0039] Shaping lens 100 as depicted in Figs.1-4 may facilitate placement of lens 100 relatively close to a surface on the left-hand side, such as a wall associated with a cove or soffit. Light emitted through lens 100 by way of first inner surface 122 may create a relatively uniform lighting effect on the surface nearby on the left, even if light source 125 includes a cluster of differently-colored LEDs. By contrast, if there were a nearby surface on the right, light emitted from the same differently-colored LED-based light source through lens 100 by way of second inner surface 124 may create a lighting effect that is less uniform. [0040] In some embodiments, at least a portion of second inner surface 124 is closer to an underlying light source 125 than first inner surface 122, though this is not required. I n some embodiments, longitudinal axis 112 may separate the first and second inner surfaces 122, 124 from each other. In some embodiments, such as that in Fig. 4, a transition between first inner surface 122 and second inner surface 124 may be relatively abrupt, such that a vertical wall 128 is formed between them.

[0041] Fig. 5 depicts an example linear lighting apparatus 560 that may be employed, for instance, along a surface of a cove or soffit. Linear lighting apparatus 560 may include a linear base 562 defining a longitudinal axis 512. Base 562 may have various cross sectional shapes, such as flat, rectangular, elliptical, circular, and so forth. Base 562 may be relatively flexible in some embodiments, relatively stiff in others, and may be constructed with various materials, such as plastic or rubber. In some embodiments, base 562 may include means for attaching base 562 to a surface, such as adhesive, pin and loop fasteners, magnets, and so forth, though that is not required.

[0042] A plurality of linear clusters 564a-d of differently-colored LEDs may be disposed along linear base 562, e.g., within recesses 116a-d of asymmetric lenses lOOa-d disposed along base 562. It can be seen that in this embodiment, recesses 116a-d have ceilings that are curvilinear, in this case concave, in a direction parallel to longitudinal axis 512, though this is not required. In various embodiments, each linear cluster 564 may be aligned with longitudinal axis 512 of linear base 562. Individual LEDs of first cluster 564a are labeled 566B (blue), 566R (red), 566G (green), and 566Am (amber). Though not similarly labeled, the other clusters 564b-d may have similar arrangements of differently-colored LEDs. Different orders of colored LEDs may be employed in other embodiments, intra-cluster and/or across multiple linear clusters 564.

[0043] While four linear clusters 564 are depicted in Fig. 5, that is not meant to be limiting. More or less linear clusters 564 may be included along bases 562 of various lengths. I n some embodiments, for instance, each linear lighting apparatus 560 may include five linear clusters 564. Moreover, linear clusters 564a-d may be spaced closer to each other or further away from each other than in Fig. 5. Base 562 may come in various forms, and may include wiring and/or other conductive and/or communicative paths that may be used to provide power and/or commands to linear clusters 564a-d. I n some embodiments, base 562 may be electrically coupled with one or more power sources, such as a battery, AC mains, a solar- powered power source, and so forth. In some embodiments, multiple linear lighting apparatus 560 may be connected in series, so that lighting can be extended along any given distance.

[0044] Linear clusters 564 may come in various sizes, and may include more or less LEDs than are depicted in Fig. 5. In some embodiments, each linear cluster 564 may span a distance along axis 512 of less than 10 mm, such as about 8 mm. In some embodiments, each LED 566 may be spaced from one or more adjacent LEDs 566 in the same linear cluster 564 by approximately 2.1 mm center-to-center, and/or approximately .5 mm edge-to-edge, though other distributions are possible.

[0045] As described above, asymmetrical, curvilinear lenses lOOa-d may be shaped so that light emitted from one side of longitudinal axis 512 is more uniform in the near field (e.g., closer to each lens 100) than light emitted from the other side. On the other side of longitudinal axis 512, light emitted from each lens may be less uniform in the near field, but may be stronger in the far field (e.g., farther away from lens 100). Thus, linear lighting apparatus 560 may be placed along and near a surface, such as a wall, so that first inner surface 122 is closer to the surface than second inner surface 124. That way, light cast onto the nearby wall may be relatively uniform, while light cast away from the wall may be less uniform near linear lighting apparatus 560 but stronger throughout an environment in which linear lighting apparatus 560 is installed.

[0046] Fig. 6 depicts an example chart 600 depicting light results that may be achieved using a lens such as lens 100 in conjunction with a linear cluster of LEDs aligned along longitudinal axis 112 or 512, in accordance with various embodiments. The vertical axis in the center represents luminous intensity (in candelas). The horizontal axis represents an angle about a particular axis. The curved entitled "Y section" represents luminous intensity observed about longitudinal axis 112 or 512. The curved entitled "X-section" represents luminous intensity observed about an axis that is perpendicular to longitudinal axis 112 or 512. [0047] It can be seen to the right of the vertical axis that an anomaly 650 exists in the "X section" curve that is different than the same part of the "X section" curve on the left of the vertical axis. This anomaly represents the more uniform lighting provided near field on the side of longitudinal axis 112 that includes first inner surface 122, and may be referred to as "forward bias," in that it may be considered a more subtle variation of "forward throw" lighting (aka "Type IV" light distribution as defined by the Illuminating Engineering Society of North America, or "IESNA"). On the other side of the vertical axis, the light is less uniform at the same distance, indicating less forward bias. Forward bias may be subtle, and may not break symmetry of a light beam, e.g., like "forward throw" might. Instead, forward bias allows light emitted th rough lens 100 to gradually transition in intensity and colors from the near field to the far field.

[0048] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure. [0049] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

[0050] The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

[0051] The phrase "and/or," as used herein in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and/or" should be construed in the same fashion, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and/or B", when used in conjunction with open-ended language such as "comprising" can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0052] As used herein in the specification and in the claims, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in the claims, shall have its ordinary meaning as used in the field of patent law. [0053] As used herein in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently "at least one of A and/or B") can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0054] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0055] In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of" and "consisting essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMS What is claimed is:

1. A linear lighting apparatus (560), comprising:

a linear base (562) defining a longitudinal axis (112, 512);

a plurality of linear clusters (564) of differently-colored LEDs (566) disposed along the linear base, each linear cluster aligned with the longitudinal axis of the linear base; and

a plurality of asymmetrical lenses (100) disposed along the linear base over the plurality of linear clusters;

wherein each asymmetrical lens includes an LED recess (114) with a multi-surface ceiling (116) spanning at least two side walls (118a, 118b) that define planes parallel to the

longitudinal axis, the multi-surface ceiling including discrete first and second inner surfaces (122, 124), the first inner surface shaped to more widely disperse light emitted by an underlying linear cluster of the plurality of linear clusters than the second inner surface.

2. The linear lighting apparatus of claim 1, wherein a contour of the first inner surface along a transverse axis (113) that is perpendicular to the longitudinal axis and passes through the two side walls is substantially flat, and a contour of the first inner surface along the longitudinal axis is curved.

3. The linear lighting apparatus of claim 2, wherein light emitted through each asymmetrical lens on a first side of the longitudinal axis is more uniform at the given distance from an underlying linear cluster than light emitted through the asymmetrical lens on a second side of the longitudinal axis at the given distance.

4. The linear lighting apparatus of claim 2, wherein a contour of the first inner surface along the longitudinal axis of each asymmetrical lens is concave.

5. The linear lighting apparatus of claim 4, wherein the multi-surface ceiling further spans two additional side walls (118c, 118d) that define planes perpendicular to the

longitudinal axis.

6. The linear lighting apparatus of claim 4, wherein a contour of the second inner surface of each asymmetrical lens along the transverse axis is convex, and a contour of the second inner surface along the longitudinal axis is concave.

7. The linear lighting apparatus of claim 6, wherein in each asymmetrical lens, at least a portion of the second inner surface is closer to an underlying linear cluster than the first inner surface.

8. The linear lighting apparatus of claim 6, wherein a transition between the first and second inner surfaces in each asymmetrical lens is abrupt.

9. The linear lighting apparatus of claim 1, wherein a profile of each asymmetrical lens viewed from a point along the longitudinal axis is wider at a top than at a bottom.

10. The linear lighting apparatus of claim 9, wherein a contour of the top (102) of the profile is flat.

11. An LED-based light source, comprising:

a linear cluster (564) of differently-colored LEDs (566) aligned to define a first axis (112, 512); and

an asymmetrical, curvilinear lens (100) defining an LED recess (114) that contains the linear cluster of differently-colored LEDs, the LED recess including first and second inner surfaces (122, 124) that face the linear cluster from an opposite side of the LED recess, a contour of the first inner surface being concave along the first axis and substantially flat along a second axis that is perpendicular to the first axis, and a contour of the second inner surface being concave along the first axis and convex along the second axis;

wherein light emitted by the cluster of differently-colored LEDs is dispersed more widely by the first inner surface than by the second.

12. The LED-based light source of claim 11, wherein one or both of the first and second inner surfaces spans two side walls (118a, 118b) along the first axis.

13. The LED-based light source of claim 12, wherein one or both of the first and second inner surfaces spans two additional side walls (118c, 118d) along the second axis.

14. The LED-based light source of claim 11, wherein the asymmetrical lens is shaped so that light emitted through the asymmetrical lens on a first side of the first axis is more uniform at a given distance from the linear cluster than light emitted through the asymmetrical lens on a second side of the first axis at the given distance.

15. The LED-based light source of claim 11, wherein at least a portion of the second inner surface is closer to the linear cluster than the first inner surface.

16. The LED-based light source of claim 15, wherein a transition between the first and second inner surfaces is abrupt.

17. The LED-based light source of claim 11, wherein a profile of the asymmetrical lens viewed from a point along the first axis is wider at a top than at a bottom.

18. An asymmetrical, curvilinear lens (100) defining a top surface (102) and an LED recess (114) with a multi-surface ceiling (116) spanning two side walls (118a, 118b) that define planes parallel to a longitudinal axis (112) of the lens, the multi-surface ceiling including discrete first and second inner surfaces (122, 124); wherein a contour of the first inner surface track a contour of the top surface along both the longitudinal axis and a transverse axis (113) that is perpendicular to the longitudinal axis and passes through the two side walls; and

a contour of the second inner surface tracks the contour of the top surface along the longitudinal axis and deviates from the contour of the top surface along the transverse axis.

19. The asymmetrical, curvilinear lens of claim 18, wherein a contour of the multi- surface ceiling along the longitudinal axis is concave.

20. The asymmetrical, curvilinear lens of claim 18, wherein a transition between the first and second inner surfaces is abrupt.