A lighting device comprising: a first LED having a wavelength of maximum emission intensity from 620 nm to 640 nm; a second LED having a wavelength of maximum emission intensity from 500 nm to 565 nm; a third LED having a wavelength of maximum emission intensity from 430 nm to 480 nm; and a fourth LED for generating light comprising a CCT in a range from 1800K to 5000K. The first LED comprises a Phosphor-Converted LED comprising a first LED chip having a maximum emission intensity wavelength from 400 nm to 480 nm, and a narrowband red phosphor with a FWHM less than 55 nm. Light generated by the device comprises a combination of light generated by the first, second, third, and fourth LEDs and a CCT of light generated by the device is tunable by independently controlling power to the first, second, third, and fourth LEDs.

A light emitting device including a first light emitting portion that emits white light at a color temperature of 6000K or more and a second light emitting portion that emits white light at a color temperature of 3000K or less, which include light emitting diode chips and phosphors and are independently driven.

A fluorescent member includes: a wavelength converter including an incidence part on which a light of a light source is incident and an output part from which a converted light subjected to wavelength conversion as a result of excitation by an incident light is output; and a reflecting part provided in at least a portion of a surface of the wavelength converter. The wavelength converter is comprised of a material whereby a degree of scattering of the light of the light source incident via the incidence part and traveling toward the output part is smaller than in the case of a polycrystalline material.

A light emitting device includes a first light source containing a first light emitting element, and a second light source containing a second light emitting element and a second fluorescent material, the first light source emits light in a region that is demarcated in a chromaticity diagram of the CIE 1931 color coordinate system by a first straight line connecting a first point having x,y of 0.280, 0.070 in the chromaticity coordinate and a second point having x,y of 0.280, 0.500 in the chromaticity coordinate, a second straight line connecting the second point and a third point having x,y of 0.013, 0.500 in the chromaticity coordinate, a purple boundary extending from the first point toward a direction in which x decreases in the chromaticity coordinate, and a spectrum locus extending from the third point toward a direction in which y decreases in the chromaticity coordinate, in a light emission spectrum, a light emission intensity ratio I.sub.PM/I.sub.PL of a light emission intensity I.sub.PM at a wavelength of 490 nm with respect to a light emission intensity I.sub.PL at a maximum light emission peak wavelength of the first light emitting element is in a range of 0.22 or more and 0.95 or less, the second light source emits light having a color deviation duv from a blackbody radiation locus in a range of −0.02 or more and 0.02 or less measured according to JIS Z8725 with a correlated color temperature in a range of 1,500 K or more and 8,000 K or less in a chromaticity diagram of the CIE 1931 color coordinate system, and the light emitting device emits mixed color light of light emitted from the first light source and light emitted from the second light source.

The silicate of magnesium and of barium, strontium or calcium of the invention is characterized in that it is in the form of a suspension of solid crystallized particles in a liquid phase, said particles having a mean size between 0.1 μm and 1 μm. It is prepared by spray-drying a liquid mixture comprising compounds of magnesium, of silicium and of at least one first element chosen from barium, strontium and calcium, by submitting the dried mixture to a first calcination in air and to a second calcination in a reducing atmosphere and by wet milling the calcined mixture.

The invention relates to an optoelectronic component (100) having a semiconductor chip (2) for generating a primary radiation in the blue spectral range, a conversion element (4) which is arranged in the beam path of the semiconductor chip and is designed to generate a secondary radiation from the primary radiation, wherein the conversion element (4) comprises at least one first phosphor (9) and a second phosphor (10), wherein the first phosphor (9) is Sr(Sr.sub.1−xCa.sub.x)Si.sub.2Al.sub.2N.sub.6:Eu.sup.2+ and/or (Sr.sub.1−yCa.sub.y)[LiAl.sub.3N.sub.4]:Eu.sup.2+, where 0≤x≤1 and 0≤y≤1, wherein a total radiation (G) exiting from the component (100) is white mixed light.

An output of light suitable for growing plants is controlled using a white light source.

A growing system including a greenhouse and a plurality of lighting devices disposed above a plant to be grown in the greenhouse and utilizing natural light includes a plurality of white light sources, a plurality of auxiliary light sources each of which is configured to emit red light and far-red light, and an illumination controller configured to control a degree of emission of light from the white light sources or the auxiliary light sources of the plurality of lighting devices, the illumination controller configured to start or stop controlling emission of light from the white light sources or the auxiliary light sources according to sunrise or sunset.

A light source for myopia prevention article includes a light emitter to emit light having an emission spectrum continuing from a first wavelength of not less than 360 nm nor more than 400 nm to a second wavelength of more than 400 nm.

The present invention improves the performance of an analyzer and facilitates the maintenance of the analyzer. This fluorescent body is produced by firing a raw material which contains: an alumina; and at least one among Fe, Cr, Bi, Tl, Ce, Tb, Eu, and Mn, wherein the raw material contains 6.1-15.9 wt % of sodium with respect to the total amount of the raw material.

A wavelength conversion member includes: a light-transmissive member; and a wavelength conversion material located on a surface of the light-transmissive member and including: a resin, a phosphor with a median particle diameter of 10 μm or more and 30 μm or less, wherein an amount of the phosphor in the wavelength conversion material is 165 parts by mass or more and 400 parts by mass or less relative to 100 parts by mass of the resin, and a filler with a median particle diameter of 5 μm or more and 40 μm or less, wherein an amount of the filler in the wavelength conversion material is 5 parts by mass or more and 90 parts by mass or less relative to 100 parts by mass of the resin. A mixture volume ratio of the phosphor and the filler to the resin is 0.5 or more and 1.0 or less.