Abstract: A LED array spot illuminator for providing light along an optical axis comprises a substrate and at least one array of multiple LED chips without individual packaging supported by the substrate, wherein the LED chips emit light within the same or different wavelength ranges and are distributed laterally with respect to the axis over a light-emitting area. The LED chips have light emitting surfaces for emitting light in directions transverse to the area. An optical device collects and directs light emitted by the LED chips of the at least one array along the axis. An aperture passes the light emitted by the LED chips of the at least one array along the axis, wherein light collected by the optical device and passed by the aperture forms a beam of light illuminating a spot. Electric current is supplied to the multiple LED chips, causing them to emit light. Light emitted by the multiple LED chips that passed through the optical device and the aperture form a beam of light illuminating a spot.

Abstract: One embodiment provides light along an optical axis. It comprises a substrate and at least one array of multiple LED chips without individual packaging supported by the substrate. The LED chips emit light within different wavelength ranges and are distributed laterally with respect to the axis over an area, the LED chips having light emitting surfaces for emitting light in directions transverse to the area. An optical element adjacent to the light emitting surfaces of the LED chips in the at least one array collects and directs light emitted by the LED chips of the at least one array along the axis towards a target. Another embodiment is directed to a method for providing multiple wavelength light for fluorescent microscopy using the above system. Electric current is supplied to the multiple LED chips, causing them to emit light of multiple wavelengths.

Abstract: By diverting a small amount of current from a string of LED(s) powered by a LED driver at low current levels in a process of dimming the LED string, performance of the LED string light emission is improved.

Abstract: A broad-spectrum, multiple wavelength illuminator comprises a luminescent body, and a plurality of semiconductor chips spaced apart from the luminescent body emitting light within one or more wavelength ranges towards the luminescent body, causing the luminescent body to emit light of one or more wavelength ranges. An optical element adjacent to the luminescent body collects light emitted by the luminescent body. An optical device collects light collected by the optical element. An aperture located between the optical element and the optical device passes the light emitted by the luminescent body along an optical axis, wherein light collected by the optical element and the optical device and passed by the aperture forms a beam of light illuminating a target. Alternatively, instead of being spaced apart from the chips, the luminescent body may be a layer adjacent to the chips.

Abstract: The color uniformity of a light spot is measured by providing an image of the light spot by means of a camera or camera sensor with sensor elements, each of the sensor elements capturing a set of three or more color component values that together define a set of pixel values at such sensor element, wherein the image includes a plurality of sets of pixel values. The method also derives for each of the plurality of sets of pixel values at a corresponding sensor element a first ratio between a first pair of the pixel values or of values obtained therefrom in such set. Preferably a second ratio is also derived between a second pair of the pixel values or of values obtained therefrom in such set, where the second pair is different from the first pair.

Abstract: An LED array includes three or more strings of bare LEDs mounted in close proximity to each other on a substrate. The strings of LEDs emit light of one or more wavelengths of blue, indigo and/or violet light, with peak wavelengths that are less than 490 nm. Luminescent materials deposited on each of the LED chips in the array emit light of different wavelength ranges that are of longer wavelengths than and in response to light emissions from the LED chips. A control circuit applies currents to the strings of LEDs, causing the LEDs in the strings to emit light, which causes the luminescent materials to emit light. A user interface enables users to control the currents applied by the control circuit to the strings of LEDs to achieve a Correlated Color Temperature (CCT) value and hue that are desired by users, with CIE chromaticity coordinates that lie on, or near to the black body radiation curve.

Abstract: This invention relates to the thermal management, extraction of light, and cost effectiveness of Light Emitting Diode, or LED, electrical circuits. An integrated circuit LED submount is described, for the packaging of high power LEDs. The LED submount provides high thermal conductivity while preserving electrical insulation. In particular, a process is described for anodizing a high thermal conductivity aluminum alloy sheet to form a porous aluminum oxide layer and a non-porous aluminum oxide layer. This anodized aluminum alloy sheet acts as a superior electrical insulator, and also provides surface morphology and mechanical properties that are useful for the fabrication of high-density and high-power multilevel electrical circuits.

Abstract: One embodiment provides light along an optical axis. It comprises a substrate and at least one array of multiple LED chips without individual packaging supported by the substrate. The LED chips emit light within different wavelength ranges and are distributed laterally with respect to the axis over an area, the LED chips having light emitting surfaces for emitting light in directions transverse to the area. An optical element adjacent to the light emitting surfaces of the LED chips in the at least one array collects and directs light emitted by the LED chips of the at least one array along the axis towards a target. Another embodiment is directed to a method for providing multiple wavelength light for fluorescent microscopy using the above system. Electric current is supplied to the multiple LED chips, causing them to emit light of multiple wavelengths.

Abstract: One embodiment provides light along an optical axis. It comprises a substrate and at least one array of multiple LED chips without individual packaging supported by the substrate. The LED chips emit light within different wavelength ranges and are distributed laterally with respect to the axis over an area, the LED chips having light emitting surfaces for emitting light in directions transverse to the area. An optical element adjacent to the light emitting surfaces of the LED chips in the at least one array collects and directs light emitted by the LED chips of the at least one array along the axis towards a target. Another embodiment is directed to a method for providing multiple wavelength light for fluorescent microscopy using the above system. Electric current is supplied to the multiple LED chips, causing them to emit light of multiple wavelengths.

Abstract: A compact high-brightness LED aquarium light fixture is described for use in illuminating aquarium tanks artificial light. (18) The LED aquarium light uses a densely-packed array of high-brightness light emitting diodes (LEDs) that are not individually packaged, where the array behaves similarly to a point source of light. The LED chips are distributed laterally over an area, where the LED chips have light emitting surfaces for emitting light in directions transverse to said area, wherein the dimensions of the area do not exceed 25 mm. Adjacent chips of the array are preferably separated by less than about 0.2 mm. The extended point source LED array, with its lens and associated reflector, result in a concentrated light source that attractively illuminates the contents of the aquarium, and creates a desirable shimmering effect within the aquarium. A clamp-on, flexible gooseneck mounting arrangement allows for use with aquarium tanks of various sizes.

Abstract: The LED grow light fixture uses a densely-packed array of high-brightness LEDs that are not individually packaged where the array behaves similarly to a point source of light. The extended point source LED array, with its lens and associated reflector, result in a concentrated, partially-collimated light source, such that the intensity of the light does not diminish rapidly as distance from the light source increases. The LED array contains a plurality of LED strings that may be separately controlled, thereby allowing the spectral content of the LED grow light to be varied, to facilitate desired plant growth at various stages of plant life. The light emitted at each of the multiple different wavelengths from the array is evenly distributed, when the objects being illuminated by the array are at a distance of less than about 6 feet or even less than 1 foot from the array.

Abstract: A LED array spot illuminator for providing light along an optical axis comprises a substrate and at least one array of multiple LED chips without individual packaging supported by the substrate, wherein the LED chips emit light within the same or different wavelength ranges and are distributed laterally with respect to the axis over a light-emitting area. The LED chips have light emitting surfaces for emitting light in directions transverse to the area. An optical device collects and directs light emitted by the LED chips of the at least one array along the axis. An aperture passes the light emitted by the LED chips of the at least one array along the axis, wherein light collected by the optical device and passed by the aperture forms a beam of light illuminating a spot. Electric current is supplied to the multiple LED chips, causing them to emit light. Light emitted by the multiple LED chips that passed through the optical device and the aperture form a beam of light illuminating a spot.

Abstract: A compact high-brightness LED grow light fixture is described for use in growing plants under artificial light, or as a supplement to natural sunlight. The LED grow light uses a densely-packed array of high-brightness light emitting diodes (LEDs) that are not individually packaged where the array behaves similarly to a point source of light. The LED chips are distributed laterally over an area, where the LED chips have light emitting surfaces for emitting light in directions transverse to said area, wherein the dimensions of the area do not exceed 25 mm. Adjacent chips of the array are preferably separated by less than about 0.2 mm. The extended point source LED array, with its lens and associated reflector, result in a concentrated, partially-collimated light source, such that the intensity of the light does not diminish rapidly as distance from the light source increases. Thus, foliage that is lower down on the plant will receive almost as much light energy as does foliage on the top of the plant.

Abstract: This invention relates to the thermal management, extraction of light, and cost effectiveness of Light Emitting Diode, or LED, electrical circuits. An integrated circuit LED submount is described, for the packaging of high power LEDs. The LED submount provides high thermal conductivity while preserving electrical insulation. In particular, a process is described for anodizing a high thermal conductivity aluminum alloy sheet to form a porous aluminum oxide layer and a non-porous aluminum oxide layer. This anodized aluminum alloy sheet acts as a superior electrical insulator, and also provides surface morphology and mechanical properties that are useful for the fabrication of high-density and high-power multilevel electrical circuits.

Abstract: In one embodiment of the invention, a bonding material is used to bond a substitute substrate to the LED, wherein the bonding material does not including gold or tin. The bonding material preferably includes gallium (Ga), such as a combination of Ga and Al or Cu. This bonding material has high thermal conductivity, high strength, high temperature stability and is low cost. In another embodiment of the invention, the substitute substrate is first thinned before it is bonded to the LED structure, so that the substitute substrate is flexible and conforms to the shape of the LED structure. In yet another embodiment of the invention, an apparatus is used for bonding a substitute substrate to a LED which includes a plurality of semiconductor epitaxial layers, said semiconductor epitaxial layers having been grown on the growth substrate so that said semiconductor epitaxial layers are curved in shape.

Abstract: At least one diffraction element is used to diffract light of multiple wavelengths into different wavelength components. Instead of moving the diffraction element as in certain prior filters, light from the at least one element is reflected back towards the at least one element so that light is diffracted at least twice by the at least one element. The reflection is such that at least one selected wavelength component of said wavelength components will pass from an input port to an output port or to another device.

Abstract: In one embodiment of an epitaxial LED device, a buffer layer (e.g. dielectric layer) between the current spreading layer and the substitute substrate includes a plurality of vias and has a refractive index that is below that of the current spreading layer. A reflective metal layer between the buffer layer and the substitute substrate is connected to the current spreading layer through the vias in the buffer layer. The buffer layer separates the current spreading layer from the reflective metal layer. In yet another embodiment, stress management is provided by causing or preserving stress, such as compressive stress, in the LED so that stress in the LED is reduced when it experiences thermal cycles.