A system for emitting device for emitting emitted light, including (a) a first light emitter comprising a first LED and having only blue phosphor; (b) a second light emitter comprising a second LED and having only green phosphor; (c) a third light emitter comprising a third LED and having only red phosphor; wherein said first, second and third LEDs are blue LEDs, wherein said first and third LEDs having a peak wavelength of about 450 nm to about 455 nm; and (d) a control circuit configured to independently control said first, second and third light emitters to vary said emitted light, said emitted light falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature (CCT) between 2500K and 5500K, with each LED string being driven with a separately controllable drive current in order to tune the generated light output.

The present disclosure provides methods for generating tunable white light. The methods include using a plurality of LED strings to generate light with color points that fall within white, red, and cyan color ranges, with each LED string being driven with a separately controllable drive current in order to tune the generated light output.

An aircraft reading light with a color-tunable reading light output includes: a white light source for emitting white light; a colored light source for emitting colored light; and an optical element, which is arranged for directing colored light that is emitted by the colored light source onto the white light source for being diffusely reflected at the white light source. The colored light source is controllable independently from the white light source.

There is presented an illumination device (244) comprising a plurality of light sources (103) emitting light along an optical axis (247); a light collector (241) adapted to collect light from the light sources, wherein the plurality of light sources (103) comprises: A first group (404) of light sources comprising a plurality of light sources, which can be driven to emit white light, a second group (405) of light sources comprising a plurality of light sources which can be driven, such as can only be driven, to emit non-white light (such as green light), wherein the plurality of light sources can be driven so that a total D.sub.uv value of light emitted from the illumination device is closer to zero than each of a first D.sub.uv value of light emitted from the illumination device originating from the first group (404) of light sources and a second D.sub.uv value of light emitted form the illumination device originating from the second group (405) of light sources, and a luminous efficacy of the second group (405) of light sources is higher than a luminous efficacy of the first group (404) of light sources.

The present disclosure provides systems for generating tunable white light. The systems include a plurality of LED strings that generate light with color points that fall within red, blue, green, and cyan color ranges, with each LED string being driven with a separately controllable drive current in order to tune the generated light output. Methods of generating white light by combining light generated by red, blue, green, and cyan color channels. Methods of generating white light points at substantially the same 1931 CIE chromaticity diagram color coordinates having different EML.

A dual LED light fixture is comprised by a lower LED light source housing and an upper LED light source housing. A lower LED light source is mounted in the lower light source housing to generate downlight. An upper LED light source is mounted in the upper LED light source housing and remote from an outer circumferential light transmitting outer side area of the upper light source housing and from which is emitted side light illumination. An LED power supply and light control circuit mounted in the LED light fixture and adapted for connection to a power source. The LED light power supply and control circuit has a dimming circuit and a lower and upper driver current supply circuit. A switch is operative to connect driver current to the upper LED light source when actuated to an on position and to disconnect driver current to the upper LED light source when in a normal off position. The switch is operative for engagement to its on position when desirable to provide drive current to the upper light source and illumination from both the lower and upper LED light sources of the LED light fixture. Various embodiments of the LED light fixture is described.

A light supplying device includes a box and a light emitting device. The box is provided with a cavity and configured to be fully closed or semi-closed, and the light emitting device is arranged in the box and configured to provide ultraviolet light and/or visible light. The device supplies light to a light receiving device such as luminous sporting goods to excite the fluorescent agent on the surface to produce fluorescence effect and shows luminous effect at night or in the dark. In such a way, the light receiving device such as the luminous sporting goods may receive the light anytime and anywhere, without sunlight irradiation, thereby improving the user's experience. Moreover, the device is convenient and portable, and has simple structure and high efficiency.

A light emitting device configured to tunably emit light with a total color temperature (CT.sub.tot), comprising: a carrier comprising a first major surface and an opposite second major surface, a first light source, arranged on said first major surface, and arranged to emit light with a first color temperature (CT.sub.1) tunably adjustable within a first range from a first low to a first high color temperature, a second light source, arranged on said second major surface, and arranged to emit light with a second color temperature (CT.sub.2) tunably adjustable within a second range from a second high to second low temperature, a controller configured to individually control the first and second light sources so to tunably adjust CT.sub.1 and CT.sub.2 from a first state to a second state according to a preselected scheme, by increasing CT.sub.1 and decreasing CT.sub.2 between said first and second states, such that CT.sub.tot remains unvaried.

Some examples herein include systems and methods of creating standards of gemstones of various classifications, which may display certain characteristics of the various classifications when excited by ultraviolet radiation and fluoresce in response. In some examples, a set of standards are created using fluorescent material, filters, and a radiation source to compare against a sample gemstone. In some examples, specific Light Emitting Diodes are selected to illuminate the gemstone samples under analysis.

An underwater directional light is provided. The directional light includes a lamp assembly, a tube assembly, and a printed circuit board assembly. The lamp assembly includes a housing and a lamp having a plurality of lighting elements. The tube assembly is coupled to the lamp and has a hollow interior. The printed circuit board assembly is mechanically coupled to the tube assembly and electrically coupled to the lamp.