White light apparatus with enhanced color contrast
AssigneeGE Lighting Solutions, LLC
InventorsEmil Vergilov Radkov, Ilona Elisabeth Hausmann, Derek Allen Publicover
Life of this patent
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Abstract
A lighting apparatus for emitting white light including a semiconductor light source emitting radiation with a peak emission between from about 250 nm to about 500 nm and a first phosphor having a peak emission between about 550 and 615 nm, wherein an overall emission spectrum of the lighting apparatus has a depression between about 550 and 615 nm, whereby the red-green color contrast is increased versus a reference illuminant.
Claims32
A lighting apparatus for emitting white light having enhanced red-green color contrast and comprising:
- a semiconductor light source emitting radiation having a peak emission in the range of from about 250 to 500 nm;
- a phosphor material radiationally coupled to said light source comprising a first phosphor having a peak emission between about 550 to 615 nm, a second phosphor being a red phosphor having a peak emission in the range of from about 615 nm to 670 nm, and a third phosphor being a blue phosphor having a peak emission the range of from about 450 to 550 nm;
- a filter comprised of a layer of neodymium glass that prevents a portion of radiation emitted by the first phosphor material from being emitted by the apparatus while substantially permitting the emission of radiation from the lighting apparatus in emission wavelengths other than between 550 and 615 nm;
- and
- wherein said filter is at least one of embedded in an encapsulant surrounding said phosphor material, positioned on top of an encapsulant or shell surrounding said phosphor material, and positioned directly on a layer of said phosphor material.
A method for making a lighting apparatus for emitting white light having enhanced red-green color contrast, the method including the steps of:
- providing a light source emitting radiation having a peak emission at from about 250 to 500 nm;
- providing a phosphor material comprising:
- a first phosphor material having a peak emission between about 550 and 615 nm, a second phosphor being a red phosphor having a peak emission in the range of from about 615 nm to 670 nm, and a third phosphor being a blue phosphor having a peak emission the range of from about 450 to 550 nm;
- radiationally coupling said phosphor material to said light source, and
- forming a filter comprised of a neodymium glass layer that prevents a portion of radiation emitted by the phosphor material from being emitted by the apparatus while substantially permitting the emission of radiation from the lighting apparatus in emission wavelengths other than between 550 and 615 nm and associating said layer with said light source.
A light bulb including an optical element shaped to receive at least some light from at least one LED, wherein the optical element forms an external surface of the light bulb spaced remotely located from the at least one LED and defines an interior containing the LED and wherein the optical element filters the light to exhibit a spectral notch after being affected by the optical element, and wherein the optical element comprises
- a filtering material comprised of neodymium containing SiO2 glass which is of at least a portion of light emitted by the LED and which filters at least a portion of the transmissive light to exhibit a spectral depression.
Dependencies are inferred from the claim text.