Abstract: An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well, including a phosphor coating. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations.

Abstract: In one method of and apparatus for varying the luminosity of illumination, each of a plurality of light sources has an on state in which it emits light and an off state in which it does not emit light. Each of the plurality of light sources is switched cyclically between the on state and the off state in a sequence over a cycle period. The switching sequence is selected such that the number of said light sources that are on is uniform over the cycle. The luminosity of the illumination is varied by varying the proportion of each cycle for which each light source is switched on.

Abstract: A zoomable luminaire has a source of light, a primary reflector with entry and exit apertures, and at least one secondary reflector with entry and exit apertures. The source delivers light into the entry aperture of the primary reflector, and the primary reflector delivers the light at the exit aperture of the primary reflector. The luminaire has a retracted position for producing a beam of a first beam angle, where the primary reflector is nested within the secondary reflector and the secondary reflector does not substantially affect the distribution of the light. The luminaire has at least one extended position for producing a beam of a second width, where the exit aperture of the primary reflector is contiguous with the entry aperture of a secondary reflector so that the light is delivered at the exit aperture of a secondary reflector.

Abstract: A passive electro-optical tracker uses a two-band IR intensity ratio to discriminate high-speed projectiles and obtain a time-varying speed estimate from their time-varying temperature, as well as determining the trajectory back to the source of fire. In an omnidirectional system a hemispheric imager with an MWIR spectrum splitter forms two CCD images of the environment. Various methods are given to determine the azimuth and range of a projectile, both for clear atmospheric conditions and for nonhomogeneous atmospheric conditions. One approach uses the relative intensity of the image of the projectile on the pixels of a CCD camera to determine the azimuthal angle of trajectory with respect to the ground, and its range. A second uses a least squares optimization over multiple frames based on a triangle representation of the smeared image to yield a real-time trajectory estimate.

Abstract: An embodiment of a collimating downlight has front-mounted blue LED chips facing upwards, having a heat sink on the back of the LED chips exposed in ambient air. The LED chips are mounted in a collimator that sends their blue light to a remote phosphor situated near the top of the downlight can. Surrounding the remote phosphor is a downward-facing reflector that forms a beam from its stimulated emission and reflected blue light. The phosphor thickness and composition can be adjusted to give a desired color temperature.

Abstract: An optoelectrical device, which may be a luminaire or a photovoltaic concentrator, has a transparent cover plate. A target with an optoelectrical transducer that produces waste heat in operation is mounted at an inside face of the transparent cover plate. A primary mirror reflects light between being concentrated on the target and passing generally collimated through the cover plate. A heat spreader is in thermal contact with the target. The heat spreader has heat conductors that thermally connect the target with the inside surface of the cover plate. The heat conductors may be arms extending radially outwards, and may be straight, zigzag, or branching. An array of targets may be mounted on a common cover plate, and their heat spreaders may be continuous from target to target.

Abstract: An example of this light bulb has a light emitting element (which may be an LED array) mounted on a circuit board. The circuit board is mounted on one end of a heat-conducting frame. An Edison screw or other suitable connector, for attaching the light bulb electrically and mechanically to a receptacle, is mounted on the other end of the frame. A transparent phosphor-coated ball has a flat chord face optically bonded to said array. A light-permeable globular enclosure is mounted on the frame, surrounding the ball and both homogenizing the white light output of the bulb but also concealing the yellowing unlit appearance of the remote phosphor ball centrally located within it.

Abstract: A light engine has a pillar with first and second ends; a circuit board on the first end of the pillar, a light source mounted on the circuit board encircling the pillar and facing towards the second end of the pillar, and a surface extending from the second end of the pillar, that surface and the exterior of the pillar between that surface and the circuit board being coated with a reflective remote phosphor that is excited by light from the light source. The light engine may be used in a light bulb, with a frosted globe enclosing the circuit board and mounted round the outer edge of the phosphor-coated surface, and an Edison screw or other standard base connected to the second end of the pillar.

Abstract: A cylindrical light source comprises multiple LEDs mounted on either the exterior or interior surface of the cylinder, with heat-sink fins respectively on its interior or exterior. The LEDs emit radially, but their emission is redirected along the cylinder axis by individual ellipsoidal reflectors.

Abstract: The diffuse reflectivity of an LED source is utilized to recycle some of its emission, thereby enabling a luminaire to escape the étendue limit. Retroreflectors intercept the rays destined for the outer part of the luminaire aperture, which can then be truncated. The resulting smaller aperture has the same beam-width as the full original, albeit with lesser flux due to recycling losses. A reduction to half the original area is possible.

Abstract: A general method is disclosed of designing two-component dichroic short-pass filters operable for incidence angle distributions over the 0-30° range, and specific preferred embodiments are listed. The method is based on computer optimization algorithms for an N-layer design, specifically the N-dimensional conjugate-gradient minimization of a merit function based on difference from a target transmission spectrum, as well as subsequent cycles of needle synthesis for increasing N. A key feature of the method is the initial filter design, upon which the algorithm proceeds to iterate successive design candidates with smaller merit functions. This initial design, with high-index material H and low-index L, is (0.75 H, 0.5 L, 0.75 H)^m, denoting m (20-30) repetitions of a three-layer motif, giving rise to a filter with N=2 m+1.

Abstract: An LED-powered replacement for the conventional incandescent screw-in light bulb comprises a phosphor coated sphere emitting white light into the same spherical pattern as a frosted incandescent bulb. In one embodiment inside the hollow sphere there is a dielectric cone emitting blue light, which causes the phosphor coating to glow. The blue light comes into the cone from a dielectric totally internally reflecting concentrator (DTIRC), which receives light from a conical reflector surrounding an LED array. The array has blue chips for energizing the phosphor and red chips for supplementing the phosphor light, enabling separate electronic control of the color temperature as well as the overall luminosity of the LED Lamp. Both blue and red chips are controlled by a quantum dimmer.

Abstract: A passive electro-optical tracker uses a two-band IR intensity ratio to discriminate high-speed projectiles and obtain a speed estimate from their temperature, as well as determining the trajectory back to the source of fire. In an omnidirectional system a hemispheric imager with an MWIR spectrum splitter forms two CCD images of the environment. Three methods are given to determine the azimuth and range of a projectile, one for clear atmospheric conditions and two for nonhomogeneous atmospheric conditions. The first approach uses the relative intensity of the image of the projectile on the pixels of a CCD camera to determine the azimuthal angle of trajectory with respect to the ground, and its range. The second calculates this angle using a different algorithm. The third uses a least squares optimization over multiple frames based on a triangle representation of the smeared image to yield a real-time trajectory estimate.

Abstract: Some photovoltaic cells have a front face accepting incoming incident light and opaque gridlines overlying part of the front face, electrically bonded to the face, with upper reflective facets oblique to the plane of the front face and producing outgoing reflected light. An optical interface parallel to and in front of the front face transmits incoming light to the front face and to the gridlines and reflects back towards the front face by total internal reflection at least some of the outgoing reflected light. Some photovoltaic devices have a triple junction photovoltaic cell, a single junction photovoltaic cell, and a reflective surface arranged to distribute incoming light between the cells. The surface may be a frequency-selective mirror that apportions light so when the cells are in series the power produced, and preferably the photocurrent, is greater than if all the light fell on the triple junction cell alone.

Abstract: The present embodiments provide systems, backlights, films, apparatuses and methods of generating back lighting. Some embodiments provide backlights that include a cavity with at least one interior light source and diffusely reflecting wall of high reflectivity, a top surface with multiple intermittently spaced holes allowing exit of light generated by the light sources, and external collimators extending from each of the holes such that the external collimators spatially expand and angularly narrow the light exiting the holes.

Abstract: The present embodiments provide methods and systems for use in providing enhanced illumination. Some embodiments include at least two light sources and one or more smoothly rotating wheels, where the one or more wheels comprises at least one mirror sector, the circumferential portion of the mirror sector is the inverse of the number of said sources, a first source of the sources is so disposed that the mirror sector reflects light from the first source into a common output path, where the first source pulsing such that a duty cycle of the first source corresponds to a time the mirror sector reflects light from the first source into the common output path.

Abstract: A heat sink for an LED downlight utilizes tilted fins forming helical air passages that can enhance thermal performance by 30% over conventional fins. To overcome the thermal challenge of installation within the stagnant hot air of insulated ceiling cans, a heat sink has an integral electrostatic air pump on its exterior, to move hot air downwards and drain the stagnant air from the can by establishing a chimney-like circulation up through the heat sink and back down around the outside of the heat sink. The air mover can be powered by a compact high-voltage, low-current power supply similar to those of neon signs. An embodiment of the heat sink is also revealed that is suitable for cooling an LED replacement for standard screw-in or equivalent light bulbs. This device can perform well in variety of orientations (horizontal, vertical, etc.) and fixtures.

Abstract: An optical device for coupling the luminous output of a light-emitting diode (LED) to a predominantly spherical pattern comprises a transfer section that receives the LED's light within it and an ejector positioned adjacent the transfer section to receive light from the transfer section and spread the light generally spherically. A base of the transfer section is optically aligned and/or coupled to the LED so that the LED's light enters the transfer section. The transfer section can comprises a compound elliptic concentrator operating via total internal reflection. The ejector section can have a variety of shapes, and can have diffusive features on its surface as well. The transfer section can in some implementations be polygonal, V-grooved, faceted and other configurations.

Abstract: An optical manifold for efficiently combining a plurality of blue LED outputs to illuminate a phosphor for a single, substantially homogeneous output, in a small, cost-effective package. Embodiments are disclosed that use a single or multiple LEDs and a remote phosphor, and an intermediate wavelength-selective filter arranged so that backscattered photoluminescence is recycled to boost the luminance and flux of the output aperture. A further aperture mask is used to boost phosphor luminance with only modest loss of luminosity. Alternative non-recycling embodiments provide blue and yellow light in collimated beams, either separately or combined into white.

Abstract: A zoomable luminaire has a source of light, a primary reflector with entry and exit apertures, and at least one secondary reflector with entry and exit apertures. The source delivers light into the entry aperture of the primary reflector, and the primary reflector delivers the light at the exit aperture of the primary reflector. The luminaire has a retracted position for producing a beam of a first beam angle, where the primary reflector is nested within the secondary reflector and the secondary reflector does not substantially affect the distribution of the light. The luminaire has at least one extended position for producing a beam of a second width, where the exit aperture of the primary reflector is contiguous with the entry aperture of a secondary reflector so that the light is delivered at the exit aperture of a secondary reflector.