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: 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 cassegrain-type concentrator section that provides for a full-tracking solar collector with one moving part and with a high efficiency of coupling of collected solar irradiation to a stationary duct. In some cases, the disclosed concentrating daylight collectors can be used more conventionally, such as for directing sunlight onto a photovoltaic cell for generation of electrical power, or an absorbing surface for extraction of thermal energy.

Abstract: The present disclosure describes light delivery and distribution components of a light duct that can be used as a luminaire, such as a bollard-style luminaire that can be useful for the illumination of pedestrian crosswalks. The bollard luminaire includes a design that generally confines light to illuminate the cross-walk and the pedestrian in the crosswalk, such that light that could produce glare for the pedestrian and/or a driver approaching the crosswalk is minimized The delivery and distribution system (i.e., light duct and light duct extractor) can function effectively with any light source that is capable of delivering light which is substantially collimated about the longitudinal axis of the light duct, and which is also preferably substantially uniform over the inlet of the light duct.

Abstract: The present disclosure provides a novel construction for an illuminated light splitter in a mirror-lined light duct. In particular, the present disclosure addresses the ability to split partially collimated light travelling through a light duct into two different light ducts using light diverters, while extracting a portion of the light from each of the light ducts and also from the common intersection region. In some cases, the visual appearance of the illumination in the intersection region can appear non-uniform due to the presence of the light diverters, and the present disclosure provides an illuminated light duct splitter (100, 200, 300) configuration that homogenizes the output from the illuminated duct within the intersection region (117, 217, 317).

Abstract: The present disclosure describes light delivery and distribution components of a ducted lighting system having a cross-section that includes at least one curved portion and a remote light source. The delivery and distribution system (i.e., light duct and light duct extractor) can function effectively with any light source (480) that is capable of delivering light which is substantially collimated about the longitudinal axis (405) of the light duct (410), and which is also preferably substantially uniform over the inlet of the light duct. A turning film (450) comprising parallel ridged microstructures intercepts and redirects light rays exiting the light output region. The light duct (410) is hollow and comprises a light transmissive region (430) which may vary in size along the longitudinal axis (405).

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: The present disclosure describes light delivery and distribution components of a ducted lighting system having a cross-section that includes planar duct portions, and a light source. The delivery and distribution system (that is, light duct and light duct extractor) can function effectively with any light source that is capable of delivering light which is substantially collimated about the longitudinal axis of the light duct, and which is also preferably substantially uniform over the inlet of the light duct.

Abstract: The present disclosure describes light delivery and distribution components of a ducted lighting system having a cross-section that includes at least one curved portion and a light source. The delivery and distribution system (that is, light duct and light duct extractor) can function effectively with any light source that is capable of delivering light which is substantially collimated about the longitudinal axis of the light duct, and which is also preferably substantially uniform over the inlet of the light duct.

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: 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: Illumination devices whose function are to inject light into backlights, particularly into backlights that incorporate a recycling cavity formed by a front (50) and back (52) reflector, are described. In some embodiments, the device includes a light source (59) disposed proximate the back reflector, and first (42) and second (44) reflecting structures. The first reflecting structure includes an inner reflective surface (41b) at least a portion of which is inclined to form a wedge with the back reflector. The wedge partially collimates and directs light from the light source generally away from the recycling cavity. The second reflecting structure receives light exiting the wedge and redirects such light into an injection beam directed into the recycling cavity.

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 cassegrain-type concentrator section that provides for a full-tracking solar collector with one moving part and with a high efficiency of coupling of collected solar irradiation to a stationary duct. In some cases, the disclosed concentrating daylight collectors can be used more conventionally, such as for directing sunlight onto a photo-voltaic cell for generation of electrical power, or an absorbing surface for extraction of thermal energy.

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: The disclosure generally relates to efficient hollow light duct bends (200) that are capable of retaining a higher on axis transmission for partially collimated light propagating within a light duct (220, 230). In particular, the described hollow light duct bends (200) include input and output plates (214, 216) that have low reflectivity for near nonnal incident light, and high reflectivity for near grazing incident light.

Abstract: A backlight (120) that includes a front reflector (130) and a back reflector (160) that form a hollow light recycling cavity (162) having an output surface (164) is disclosed. The front reflector includes at least four directional recycling films (132). The backlight also includes a semi-specular diffuser disposed between the front reflector and the back reflector, and one or more light sources (166) disposed to emit light into the light recycling cavity.

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 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: 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.