Abstract: A device used in laser display systems for despeckling includes a liquid crystal cell disposed in sandwiched relation between an input and a grounded electrode. A glass cover overlies each electrode. In a first embodiment, the cell may include vertically or randomly oriented liquid crystal molecules and the liquid crystal cell is larger than a laser beam in size for random phase modulation or retardation. Light loss due to diffraction and scattering are substantially eliminated in the absence of pixel structures. In another embodiment, the input electrode is divided into two separate parts. Vertically aligned liquid crystal molecules rotate and follow field fringes created by applying a first voltage to the input electrodes. Additional embodiments include a device that has two wedge-shaped liquid crystal layers, a device that includes plural field-induced gradient index prisms, a device including a tilted mirror, and composite devices.

Abstract: A device used in laser display systems for despeckling includes a liquid crystal cell disposed in sandwiched relation between an input and a grounded electrode. A glass cover overlies each electrode. In a first embodiment, the cell may include vertically or randomly oriented liquid crystal molecules and the liquid crystal cell is larger than a laser beam in size for random phase modulation or retardation. Light loss due to diffraction and scattering are substantially eliminated in the absence of pixel structures. In another embodiment, the input electrode is divided into two separate parts. Vertically aligned liquid crystal molecules rotate and follow field fringes created by applying a first voltage to the input electrodes. Additional embodiments include a device that has two wedge-shaped liquid crystal layers, a device that includes plural field-induced gradient index prisms, a device including a tilted mirror, and composite devices.

Abstract: A high efficiency thermal management system for solid state lighting devices includes an LED heat sink housing formed by a flat bottom wall and a sidewall mounted about its periphery that extends radially outwardly so that the heat sink housing has a frusto-conical shape. Heat-dissipating pin-shaped fins of differing lengths depend from the exterior of the angled wall and from the bottom of the flat bottom wall. The radially inward side of the angled wall has a highly light-reflective surface for collimating light. The base of the device provides a housing for driver electronics. The heat sink housing, the pin-shaped fins, and the base are collectively contoured so that the system has the overall size and shape of a type A light bulb.

Abstract: A solid state lighting device includes a first group of semiconductor light emitting devices that produces a yellowish white light, a second group of semiconductor light emitting devices that includes at least one light emitting device that produces a reddish orange light, and a third group of semiconductor light emitting devices that includes at least one wavelength down-converted white light device. A combination of the second and third groups produces a sub-mixture of reddish warm white light. A combination of the first, second and third groups produces a mixture of warm white light with a correlated color temperature between 2700k to 3500K and a color rendering index higher than 85.

Abstract: A lighting apparatus includes at least one LED and a chromaticity tuning cavity adapted to capture light from the LED. The chromaticity tuning cavity is defined by a light translucent window and a plurality of backscattering light recycling surfaces. The light translucent window is adapted to backscatter at least a portion of the LED light. A preselected chromaticity tuning member is positioned within the chromaticity tuning cavity. It is selected from a group of chromaticity tuning members adapted to tune the chromaticity of various lighting apparatuses within one quadrangle on a chromaticity diagram. At least a portion of the LED light, having been backscattered and tuned by the preselected tuning member, passes through the light translucent window as warm white extraction light.

Abstract: A projector has a transmissive spatial light modulator backlit by a collimated illuminator that includes a light source that outputs red, green, blue (RGB) light, and a combiner disposed in light-receiving relation to the light source for mixing or combining the RGB light. The combiner has cavity features associated therewith for outputting collimated light, where such light preferably has a divergent cone angle less than plus or minus fifteen degrees (+/?15°).

Abstract: A backlighting apparatus for a flat panel LCD display includes an elongate light guide having a front wall through which travels polarized light in a direction toward the LCD display. An RGB LED set is positioned adjacent a first end wall of the light guide so that light enters the light guide from the first end wall. A retardation and reflection film covers respective external surfaces of the bottom wall and a second end wall. Microlenses are formed in the front wall along its extent and each microlens is filled with a birefringent material. Light emitted by the LED set travels through a collimated light coupling module and exits the light guide through the birefringent microlenses in polarized form toward the LCD display. The viewing angles and angular light distributions of the LCD display in vertical and horizontal directions are optimized for enhancing the brightness without involving DBEF and BEF.

Abstract: An image presentation device (100) incorporates an optical combiner (130) that utilizes a multi-state optical switch (131, 137) for use with a plurality of colored light sources (122, 124,126). The switch (131,137) includes an electronically switchable holographic optical element HOE (131) having a first and a second mode of operation. Light from first and second light sources (124, 126) passes through HOE (131) in a diffracted manner in at least one of the first and second modes of operation. Light from a third light source (122) is reflected by a reflector (137) in a third mode of operation. The combiner (130) operates to combine light from the various light sources (122, 124, 126) into a common light path.