C09K11/7739

Light emitting device and LED light bulb

A light emitting device includes: a first white light source which includes N pieces of first white light emitting diodes and emits a first white light; and a second white light source which includes M pieces of second white light emitting diodes and a first resistance element electrically connected in series to the second white light emitting diodes and having a first resistance value, is electrically connected in parallel to the first white light source, and emits a second white light, the light emitting device emitting a mixed white light of the first white light and the second white light. The drive voltage of the first white light source is higher than a drive voltage of the second white light source, and a color temperature of the mixed white light is higher as a total luminous flux of the mixed white light is higher.

Wavelength conversion member including phosphor

A wavelength conversion member comprises: a substrate; and a wavelength conversion layer. The wavelength conversion layer contains a first phosphor and a second phosphor. The second phosphor has a higher thermal conductivity than the first phosphor. In the wavelength conversion layer, a volume of the second phosphor is larger than a volume of the first phosphor. The wavelength conversion layer includes a first portion and a second portion. The first portion is located closer to the substrate than the second portion, and is in direct contact with the second portion. Thicknesses of the first portion and the second portion are equal to each other. A volume V11 of the first phosphor in the first portion, a volume V12 of the second phosphor in the first portion, a volume V21 of the first phosphor in the second portion, and a volume V22 of the second phosphor in the second portion satisfy V11/V12<V21/V22.

METHOD FOR MANUFACTURING LIGHT-EMITTING DEVICE
20190091355 · 2019-03-28 · ·

A light-emitting device includes a light-emitting element with a peak emission wavelength in a range of 400 nm to 410 nm and a fluorescent member that contains a first phosphor with a peak emission wavelength in a range of 440 nm to 470 nm containing a Eu-activated alkaline-earth phosphate that contains Cl in a composition, a second phosphor with a peak emission wavelength in a range of 500 nm to 530 nm containing a Eu-activated halogen-containing alkaline-earth silicate, a third phosphor with a peak emission wavelength in a range of 530 nm to 600 nm containing a Ce-activated rare-earth aluminate, and a fourth phosphor with a peak emission wavelength in a range of 600 nm to 660 nm containing a Eu-activated silicon nitride containing Al and at least one of Sr and Ca in a composition.

WHITE LIGHT SOURCE

According to one embodiment, a white light source includes a combination of a light emitting diode and phosphors. One of the phosphors is at least a cerium activated yttrium aluminum garnet-based phosphor. There is no light emission spectrum peak at which a ratio of a largest maximum value to a minimum value is greater than 1.9. The largest maximum value is largest among at least one maximum value present in a wavelength range of 400 nm to 500 nm in a light emission spectrum of white light emitted from the white light source. The minimum value is adjacent to the largest maximum value in a longer wavelength side of the light emission spectrum.

LIGHT EMITTING DEVICE
20190067531 · 2019-02-28 · ·

A light emitting device includes a light emitting element having a peak emission wavelength of 410 nm to 440 nm and a phosphor member. The phosphor member includes a first phosphor having a peak emission wavelength of 430 nm to 500 nm and containing an alkaline-earth phosphate, a second phosphor having a peak emission wavelength of 440 nm to 550 nm and containing at least one of an alkaline-earth aluminate and a silicate containing Ca, Mg, and Cl, a third phosphor having a peak emission wavelength of 500 nm to 600 nm and containing a rare-earth aluminate, a fourth phosphor having a peak emission wavelength of 610 nm to 650 nm and containing a silicon nitride containing Al and at least one of Sr and Ca, and a fifth phosphor having a peak emission wavelength of 650 nm to 670 nm and containing a fluorogermanate.

FLUORESCENT MEMBER AND LIGHT-EMITTING MODULE

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.

Blue-green light-emitting phosphor, light-emitting element, light-emitting device, and white-light-emitting device
10160905 · 2018-12-25 · ·

An object of the invention is to provide a blue-green light-emitting phosphor having excellent high-temperature property and excellent light-emitting properties such as brightness and half width. The phosphor is constituted of a plurality of alkaline earth metal elements including a barium element, phosphoric acid and a halogen element, and Eu as an activator, in which the molar ratio of the barium element to the total content of the alkaline earth metal elements is larger than 60% and smaller than 95%, and upon irradiation with a near-ultraviolet ray, the blue-green light-emitting phosphor is excited to thereby emit blue-green visible light.

OXIDE PHOSPHOR, LIGHT-EMITTING DEVICE, AND METHOD FOR PRODUCING OXIDE PHOSPHOR
20240263070 · 2024-08-08 · ·

Provided is an oxide phosphor having a light emission peak wavelength of 800 nm or greater. The oxide phosphor has a composition containing Mg, Ga, O, and Cr, and optionally containing a first element M.sup.1, a second element M.sup.2, and a third element M.sup.3. When a total molar ratio of Ga, Cr, the second element M.sup.2, and the third element M.sup.3 per mole of the composition of the oxide phosphor is 2, the molar ratio of Mg or the molar ratio of a total of Mg and the first element M.sup.1 is in a range from 0.7 to 1.3, the molar ratio of O is in a range of 3.7 to 4.3, and the molar ratio of Cr is in a range greater than 0.02 and 0.3 or less. The oxide phosphor has a light emission peak wavelength in a range of 800 nm to 1600 nm in a light emission spectrum.

Light emitting device
10141484 · 2018-11-27 · ·

A light emitting device includes a light emitting element having a peak emission wavelength of 410 nm to 440 nm and a phosphor member. The phosphor member includes a first phosphor having a peak emission wavelength of 430 nm to 500 nm and containing an alkaline-earth phosphate, a second phosphor having a peak emission wavelength of 440 nm to 550 nm and containing at least one of an alkaline-earth aluminate and a silicate containing Ca, Mg, and Cl, a third phosphor having a peak emission wavelength of 500 nm to 600 nm and containing a rare-earth aluminate, a fourth phosphor having a peak emission wavelength of 610 nm to 650 nm and containing a silicon nitride containing Al and at least one of Sr and Ca, and a fifth phosphor having a peak emission wavelength of 650 nm to 670 nm and containing a fluorogermanate.

SEMICONDUCTOR LIGHT EMITTING DEVICE, BACKLIGHT, COLOR IMAGE DISPLAY DEVICE AND PHOSPHOR TO BE USED FOR THEM

To provide a semiconductor light emitting device which is capable of accomplishing a broad color reproducibility for an entire image without losing brightness of the entire image.

A light source provided on a backlight for a color image display device has a semiconductor light emitting device comprising a solid light emitting device to emit light in a blue or deep blue region or in an ultraviolet region and phosphors, in combination. The phosphors comprise a green emitting phosphor and a red emitting phosphor. The green emitting phosphor and the red emitting phosphor are ones, of which the rate of change of the emission peak intensity at 100? C. to the emission intensity at 25? C., when the wavelength of the excitation light is 400 nm or 455 nm, is at most 40%.