229 results about "Spectral power distribution" patented technology

The present invention provides a system and method for generating light using light-emitting elements and detecting the intensity and spectral power distribution of light using the same light-emitting elements as spectrally sensitive photodetectors. The light-emitting elements function in two modes, an ON mode and an OFF mode, wherein in the ON mode the light-emitting elements are activated and emit light of a particular frequency or range of frequencies. When in the OFF mode, the light-emitting elements are deactivated, wherein they do not emit light but serve to detect photons incident upon them thus generating an electrical signal representative of the intensity and spectral power distribution of the incident photons. The detected signal from the deactivated light-emitting elements can be used to provide photonic feedback to a lighting system, and thereby may be used to control the brightness and color balance of the lighting system. In addition, the light-emitting elements may be arranged such that no spectrally selective filters or optics are necessary to block or focus light onto the light-emitting elements when in the detection or OFF mode.

A white-light electro-luminescent lamp having an adjustable spectral power distribution, including a first light-emitting element which emits light within each of three wavelength bands, 1) between 440 and 520 nm, 2) between 520 and 600 nm, and 3) between 600 and 680 nm. A second light-emitting element emits light within each of three wavelength bands, 1) between 440 and 520 nm, 2) between 520 and 600 nm, and 3) between 600 and 680 nm. A controller modulates the integrated spectral power of the light produced by the first and the second light-emitting elements such that the spectral power distribution of the light formed by combining the light produced by the modulated first and second light-emitting elements is substantially equal to a CIE standard daylight spectral power distribution for correlated color temperatures between 4000K-9500K.

A light-emitting diode (LED)-based solid-state device comprises a color mixing mechanism to dynamically change the correlated color temperature (CCT) of a white light. With different lumen proportions for white phosphor-coated LEDs and integrated red and green LEDs, the light mixtures can be located in any one of eight CCT quadrangles. In practice, CCTs of a white-light can be tuned in a continuous manner. Because all the possible light mixtures on the chromaticity diagram correspond to a line segment that overlays the Planckian locus within the eight CCT tolerance quadrangles, the effect of LED intensity fluctuations that may put the mixture out of white light region is reduced. Also, because the two additional LEDs that mix with the white phosphor-coated LEDs contribute to the overall spectral power distribution (SPD) that substantially matches the SPD of standard illuminants, a CRI of 80 can be reached.

Solid state lighting devices and illumination methods involve use of multiple solid state emitters of different colored outputs (optionally including at least one white or near-white emitter). Operation of the solid state emitters is controlled with at least one circuit element to emphasize and / or deemphasize perception of at least one color of a target surface based upon a reflectance spectral distribution of the target surface. At least one emitter may have an associated passive or active filter; the filterable emitter and / or active filter may be operated to deemphasize perception of at least one color of a target surface. Activation and / or alteration of emphasis or deemphasis of perception of color of a target surface may be selected by a user or automatically controlled.

A tunable LED lamp for producing biologically-adjusted light having a housing, a power circuit, a driver circuit disposed within the housing and electrically coupled with the power circuit, and a plurality of LED dies electrically coupled to and driven by the driver circuit. The driver circuit may drive the plurality of LED dies to emit a phase-shift light having a first spectral power distribution, a general illuminating light having a second spectral power distribution, and a pre-sleep light having a third spectral power distribution. The phase-shift light may be configured to affect a first biological effect in an observer, and the pre-sleep light may be configured to affect a second biological effect in an observer. The LED lamp may include an intermediate base to couple the lamp to an Edison screw base. The LED lamp may be configured to operate responsive to a three-way switch.

The present application is directed to a method for the regulation of the development of ocular refractive errors, comprising: controlling at least one light source using a processor, the at least one light source emitting an electromagnetic radiation variable with respect to one or more of a direction, an illuminance, a retinal area, an amplitude, a wavelength, and a spectral output; and regulating the at least one light source and producing a spectral power distribution at a plane of an eye.

A projector projects pixels to form an image in accordance with image data. The projector includes a modulator which modulates light from a light source and outputs projected pixels in a plurality of color spectral bands. The projector has a light source with a non-uniform spectral power distribution with spectral energy within each of the plurality of color spectral bands. A first notch filter removes spectral energy from a first spectral range within a first color spectral band to improve gamut.