Provided is a light emitting device that is bright in both scotopic vision and photopic vision, and has reduced glare for humans.

The light emitting device includes a light emitting element having a dominant wavelength in a range of 430 nm or more and 500 nm or less, and a fluorescent material that is excited by light emitted from the light emitting element and has a light emission peak wavelength in a range of 507 nm or more and 660 nm or less, wherein the light emitting device emits light having a dominant wavelength in a range of 490 nm or more and 500 nm or less, wherein the light emitting device has an S/P ratio, which is the ratio of a luminous flux in photopic vision to a luminous flux in scotopic vision, being 6.5 or less, and wherein the light emitting device has a light emission intensity in the light emission peak wavelength of the light emitting element that is greater than that in the light emission peak wavelength of the fluorescent material.

An object is to provide a new type of near-infrared ray-emitting phosphor which exhibits excellent emission intensity. A near-infrared ray-emitting phosphor is represented by a general formula, (Y, Lu, Gd).sub.3-x-y (Ga,Al,Sc).sub.5O.sub.12:(Cr.sub.x,(Yb,Nd).sub.y) (0.05<x<0.3, 0≤y<0.3).

A wavelength conversion module includes a base, a wavelength conversion member consisting of a phosphor, and a bonding member including a metal part that bonds the base and the wavelength conversion member. A thickness of the wavelength conversion member is less than 100 μm.

The invention provides a light generating device (1000), wherein: (I) the light generating device (1000) comprises: (a) a first light source (110) configured to generate first light source light (111) having a first light source light spectral power distribution, wherein the first light source (110) comprises a first laser light source (10) configured to generate first laser light source light (11); (b) a first luminescent material (210) configured to convert at least part of the first light source light (111) into first luminescent material light (211) having a first luminescent material spectral power distribution having an emission at one or more wavelengths selected from the wavelength range of 590-780 nm, wherein the first luminescent material (210) is configured in an optical resonator (230); (II) the first light source (110) and the first luminescent material (210) are configured to generate first luminescent material laser light (1211) having a first luminescent material laser light spectral power distribution comprising at least part of the first luminescent material light (211); (III) the first light source light spectral power distribution and the first luminescent material laser light spectral power distribution mutually differ; and (IV) the light generating device (1000) is configured to generate in one or more operational modes white device light (1001) comprising the first luminescent material laser light (1211).

The invention provides a light generating device (1000) comprising a light source (10) and a luminescent element (20), wherein:—the light source (10) is configured to generate the first radiation (11); wherein the light source (10) comprises a laser light source;—the luminescent element (20) comprises (i) a plurality of element bodies (200) and (ii) a thermally conductive support (400); wherein the plurality of element bodies (200) comprises a plurality of first bodies (210) and a plurality of second bodies (220);—the plurality of first bodies (210) comprise a luminescent material (50), wherein the luminescent material (50) is configured to convert at least part of first radiation (11), selected from one or more of UV radiation and visible radiation, into luminescent material light (51); wherein the first bodies have a first thermal conductivity K1; wherein the first bodies (210) are configured in a light receiving relationship with the light source (10);—the plurality of second bodies (220), different from the first bodies (210) are light transmissive for one or more wavelengths of the first radiation (11) and the luminescent material light (51); wherein the second bodies (220) have a second thermal conductivity K2, wherein K2≥0.2*K1;—the plurality of first bodies (210) and the plurality of second bodies (220) are configured in a 2D arrangement (205), wherein for a plurality of second bodies (220) applies that they are configured adjacent to different first bodies (210); and—the plurality of first bodies (210) and second bodies (220) are configured in thermal contact with the thermally conductive support (400).

Disclosed is a blue to white light conversion device, comprising: a light conversion subassembly comprising at least one light conversion layer, sandwiched between two light transmitting members, wherein the light conversion layer comprises a light conversion material comprising phosphors and/or quantum dots; at least one light diffusing subassembly neighboring the light conversion subassembly; and a top frame and a bottom frame surrounding the light diffusing subassembly and light conversion subassembly, respectively.

A wavelength converter 100 includes: a first phosphor 1 composed of an inorganic phosphor activated by Ce.sup.3+; and a second phosphor 2 composed of an inorganic phosphor activated by Ce.sup.3+ and different from the first phosphor. At least one of the first phosphor and the second phosphor is particulate. The first phosphor and the second phosphor are bonded to each other by at least one of a chemical reaction in a contact portion between the compound that constitutes the first phosphor and a compound that constitutes the second phosphor and of adhesion between the compound that constitutes the first phosphor and the compound that constitutes the second phosphor.

The invention provides an assembly (2000) comprising a luminescent body (200), a thermally conductive element (400), and a coating layer (500), wherein: the luminescent body (200) comprises a luminescent material (210), wherein the luminescent body (200) comprises a ceramic luminescent body, and wherein the luminescent body (200) comprises an external surface (220); the thermally conductive element (400) comprises metal material (410); at least 25% of the external surface (220) is in thermal contact with the thermally conductive element (400); and—the coating layer (500) is configured between the luminescent body (200) and the thermally conductive element (400).

A light emitting assembly comprising at least one of each of a solid state device and a thermal radiation source, couplable with a power supply constructed and arranged to power the solid state device and the thermal radiation source, to emit from the solid state device a first, relatively shorter wavelength radiation, and to emit from the thermal radiation source non-visible infrared radiation, and a down-converting luminophoric medium arranged in receiving relationship to said first, relatively shorter wavelength radiation, and the infrared radiation, and which in exposure to said first, relatively shorter wavelength radiation, and infrared radiation, is excited to responsively emit second, relatively longer wavelength radiation. In a specific embodiment, monochromatic blue light output from a light-emitting diode is down-converted to white light by packaging the diode and the thermal radiation device with fluorescent or phosphorescent organic and/or inorganic fluorescers and phosphors in an enclosure.

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.