Abstract: The disclosure generally relates to highly efficient light duct light extractors that are capable of extracting a portion of the light propagating within a light duct with nearly 100 percent efficiency. In particular, the described light extractors are configured in a “Tee” shape with a reflective diverter element.

Abstract: The disclosure generally relates to concentrating daylight collectors, and in particular to concentrating daylight collectors useful for interior lighting of a building. The concentrating daylight collectors generally include a plurality of moveable reflective vanes and a Cassegrain-type concentrator section.

Abstract: A backlight that includes a front reflector and a back reflector that form a hollow light recycling cavity including an output surface is disclosed. The backlight further includes one or more light sources disposed to emit light into the light recycling cavity. The front reflector includes an on-axis average reflectivity of at least 90% for visible light polarized in a first plane, and an on-axis average reflectivity of at least 25% but less than 90% for visible light polarized in a second plane perpendicular to the first plane.

Abstract: A recycling cavity such as used in a backlight or similar extended area source includes a front and back reflector, the front reflector being partially transmissive to provide an output illumination area. The recycling cavity also includes a component that provides the cavity with a balance of specular and diffuse characteristics so as to balance cavity efficiency and brightness uniformity over the output area. The component can be characterized by a transport ratio of greater than 15% for a 15 degree incidence angle, and less than 95% for a 45 degree incidence angle.

Abstract: The disclosure generally relates to highly efficient light duct light splitters that are capable of splitting the light propagating within a light duct into two different ducts, with nearly 100 percent efficiency. In particular, the described light splitters are configured in a “Tee” shape with a reflective splitter element.

Abstract: A front and back reflector are arranged to form a hollow light recycling cavity having an output region, and one or more light sources (e.g. LEDs) are disposed to emit light into the cavity. In one aspect, the back reflector has a design characterized by a first and second parameter. The first design parameter is a ratio of the collective emitting area of the light sources Aemit to the area of the output region Aout, and Aemit/Aout is preferably from 0.0001 to 0.1. The second design parameter is SEP/H, where H is the depth of the recycling cavity, and SEP is an average plan view source separation associated with the light sources. Other aspects of the disclosed extended area light sources are also described.

Abstract: A hollow light-recycling backlight has a “semi-specular” component providing a balance of specularly and diffusely reflected light improving the uniformity of the light output. The component may be arranged on the reflectors (1021), (1014) or inside the cavity (1016). This balance is achieved by designing the component's “transport ratio” defined by (F?B)/(F+B), (F and B are the amounts of incident light scattered forwards and backwards respectively by the component in the plane of the cavity) to lie in a certain range. Furthermore, the product of the front and back reflector “hemispherical” reflectivities should also lie in a given range. Alternatively, the “cavity transport value”, a measure of how well the cavity can spread injected light from the injection point to distant points in the cavity should lie in a further range and the “hemispherical” reflectivity of the back reflector should be >0.7.

Abstract: Suspended optical film assemblies including a frame, an optical film, and an elastomeric film are disclosed. The elastomeric films include a first attachment region, a second attachment region, and a free region between the first and second attachment regions. The first attachment region is affixed to the frame; the second attachment region is affixed to the optical film, so that the free region is in tension and supports the optical film within the frame. The tension in the elastomeric film free region can help maintain flatness and reduce distortion in the optical film during environmental changes that influence dimensional changes in the frame, optical film, and elastomeric film.

Abstract: An edge-lit backlight comprises a front and back reflector forming a hollow light recycling cavity having a cavity depth H and an output region of area Aout, and one or more light sources disposed proximate a periphery of the backlight to emit light into the light recycling cavity. The light sources have an average plan view source separation of SEP collectively having an active emitting area Aemit, wherein a first parameter equals Aemit/Aout and a second parameter equals SEP/H. The first parameter is in a range from 0.0001 to 0.1, and by the second parameter is in a range from 3 to 10. The front reflector has a hemispherical reflectivity for unpolarized visible light of Rfhemi, and the back reflector has a hemispherical reflectivity for unpolarized visible light of Rbhemi, and Rfhemi*Rbhemi is at least 0.70.

Abstract: A backlight that includes a front reflector and a back reflector that form a hollow light recycling cavity including an output surface is disclosed. The backlight further includes one or more light sources disposed to emit light into the light recycling cavity. The front reflector includes an on-axis average reflectivity of at least 90% for visible light polarized in a first plane, and an on-axis average reflectivity of at least 25% but less than 90% for visible light polarized in a second plane perpendicular to the first plane.

Abstract: The disclosure generally relates to concentrating daylight collectors, and in particular to concentrating daylight collectors useful for interior lighting of a building. The concentrating daylight collectors generally include a plurality of moveable reflective vanes and a Cassegrain-type concentrator section.

Abstract: A light directing composite film includes a planar top major surface, a planar bottom major surface, a plurality of lenticular lens elements disposed between the top major surface and the bottom major surface, and a plurality of light reflection regions and light transmission regions disposed between the plurality of lenticular lens and the planar bottom major surface.

Abstract: A light directing substrate includes a back major surface and a front major surface opposing the back surface. The back major surface includes light reflection regions and light transmission regions. The front surface includes a plurality of lenticular lens elements. A graphic image disposed on or in the light directing substrate.

Abstract: Generally, the present disclosure provides a light duct bend used in a mirror-lined light duct system. In one aspect, the light duct bend includes an input region having a first propagation direction, an output region having a second propagation direction disposed at a bend angle to the first propagation direction, and a transition region connecting the input region to the output region. The transition region includes a plurality of vanes that subdivide the duct into channels, which can reduce the loss and/or disruption of collimation about one or more bends in the light duct system.

Abstract: Generally, the present disclosure provides a light duct bend used in a mirror-lined light duct system. In one aspect, the light duct bend includes an input region having a first propagation direction, an output region having a second propagation direction disposed at a bend angle to the first propagation direction, and a transition region connecting the input region to the output region. The transition region includes a plurality of vanes that subdivide the duct into channels, which can reduce the loss and/or disruption of collimation about one or more bends in the light duct system.

Abstract: The present disclosure relates to illumination or lighting assemblies and systems that provide illumination using LEDs. In one aspect, the present disclosure provides a lighting assembly, comprising: multiple light emitting diodes that emit light; an optical system that directs the light emitted by the light emitting diodes, the optical system positioned adjacent to light emitting diodes; and a cooling fin including a two-phase cooling system, the cooling fin positioned adjacent to the light emitting diodes such that the two-phase cooling system removes heat from the light emitting diodes. In another aspect, the present disclosure provides a lighting system including multiple lighting assemblies.

Abstract: The disclosure generally relates to switchable light extractors and in particular to switchable light extractors useful for extracting light from light ducts used for interior lighting of a building. The disclosure also relates to lighting systems that include the light extractors, and methods of extracting light from a lighting system. The switchable light extractors generally include a first and a second reflective film, each having a plurality of voids that can aligned to extract light from a light duct.

Abstract: A lighting system has one or more light guides capable of guiding light, each comprising a core and two optically smooth faces. A cavity adjacent to two of the optically smooth faces has an opening and a reflective-transmissive surface opposite the opening. A cover having a light source is proximate to and occludes the opening. A major portion of any light emitted from the light source is reflected by the reflective-transmissive surface of the cavity and is injected into the light guides, and a minor portion of any light emitted by the light source is transmitted through the reflective-transmissive surfaces of the cavity and emitted from the lighting system. A light injection coupler is also disclosed that has an optically transmissive housing and suitable for use to couple ends of at least one light guide thereby making a lighting system.

Abstract: A decollimator for a daylighting system includes a conical section having a circular end, a square end, and a conical shape tapering inwardly from the circular end to the square end. A mixing zone section is attached to the square end of the conical section and has a square cross sectional shape of a substantially constant cross sectional dimension. The decollimator also includes either a window with a converging Fresnel lens on the circular end of the conical section, a window with a diverging Fresnel lens on an end of the mixing zone section opposite the conical section, or both. When the conical section receives collimated light, the conical section, the mixing zone section, and the Fresnel lens together decollimate the light and provide the decollimated light out of the mixing zone section.

Abstract: Illumination devices having a partially transmissive front reflector, a back reflector, and a cavity between them are disclosed. At least one light injector including a baffle and a light source is disposed in the cavity. The light injector is capable of injecting partially collimated light into the cavity. The output area of the illumination device can be increased by disposing light injectors progressively within the cavity, without sacrificing uniformity of the light emitted through the output area.